Apply k4412 kernel from HardKernel for ODROID-X.

66 files changed, 15836 insertions, 273 deletions

diff --git a/fs/Kconfig b/fs/Kconfig
index 19891aab9c6..88701cc00e0 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -192,6 +192,10 @@ source "fs/hfsplus/Kconfig"
 source "fs/befs/Kconfig"
 source "fs/bfs/Kconfig"
 source "fs/efs/Kconfig"
+
+# Patched by YAFFS
+source "fs/yaffs2/Kconfig"
+
 source "fs/jffs2/Kconfig"
 # UBIFS File system configuration
 source "fs/ubifs/Kconfig"
diff --git a/fs/Makefile b/fs/Makefile
index fb68c2b8cf8..2999b4d4b26 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -124,3 +124,6 @@ obj-$(CONFIG_GFS2_FS)           += gfs2/
 obj-$(CONFIG_EXOFS_FS)          += exofs/
 obj-$(CONFIG_CEPH_FS)           += ceph/
 obj-$(CONFIG_PSTORE)            += pstore/
+
+# Patched by YAFFS
+obj-$(CONFIG_YAFFS_FS)          += yaffs2/
diff --git a/fs/aio.c b/fs/aio.c
index 278ed7dc71b..99bb74461b0 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1618,7 +1618,6 @@ long do_io_submit(aio_context_t ctx_id, long nr,
         struct kioctx *ctx;
         long ret = 0;
         int i;
-        struct blk_plug plug;
 
         if (unlikely(nr < 0))
                 return -EINVAL;
@@ -1635,8 +1634,6 @@ long do_io_submit(aio_context_t ctx_id, long nr,
                 return -EINVAL;
         }
 
-        blk_start_plug(&plug);
-
         /*
          * AKPM: should this return a partial result if some of the IOs were
          * successfully submitted?
@@ -1659,7 +1656,6 @@ long do_io_submit(aio_context_t ctx_id, long nr,
                 if (ret)
                         break;
         }
-        blk_finish_plug(&plug);
 
         put_ioctx(ctx);
         return i ? i : ret;
diff --git a/fs/block_dev.c b/fs/block_dev.c
index a580028e2fb..8d78633c00b 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -44,24 +44,28 @@ inline struct block_device *I_BDEV(struct inode *inode)
 {
         return &BDEV_I(inode)->bdev;
 }
-
 EXPORT_SYMBOL(I_BDEV);
 
 /*
- * move the inode from it's current bdi to the a new bdi. if the inode is dirty
- * we need to move it onto the dirty list of @dst so that the inode is always
- * on the right list.
+ * Move the inode from its current bdi to a new bdi. If the inode is dirty we
+ * need to move it onto the dirty list of @dst so that the inode is always on
+ * the right list.
  */
 static void bdev_inode_switch_bdi(struct inode *inode,
                         struct backing_dev_info *dst)
 {
-        spin_lock(&inode_wb_list_lock);
+        struct backing_dev_info *old = inode->i_data.backing_dev_info;
+
+        if (unlikely(dst == old))               /* deadlock avoidance */
+                return;
+        bdi_lock_two(&old->wb, &dst->wb);
         spin_lock(&inode->i_lock);
         inode->i_data.backing_dev_info = dst;
         if (inode->i_state & I_DIRTY)
                 list_move(&inode->i_wb_list, &dst->wb.b_dirty);
         spin_unlock(&inode->i_lock);
-        spin_unlock(&inode_wb_list_lock);
+        spin_unlock(&old->wb.list_lock);
+        spin_unlock(&dst->wb.list_lock);
 }
 
 sector_t blkdev_max_block(struct block_device *bdev)
@@ -1429,11 +1433,6 @@ static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
                 WARN_ON_ONCE(bdev->bd_holders);
                 sync_blockdev(bdev);
                 kill_bdev(bdev);
-                /* ->release can cause the old bdi to disappear,
-                 * so must switch it out first
-                 */
-                bdev_inode_switch_bdi(bdev->bd_inode,
-                                        &default_backing_dev_info);
         }
         if (bdev->bd_contains == bdev) {
                 if (disk->fops->release)
@@ -1445,6 +1444,8 @@ static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
                 disk_put_part(bdev->bd_part);
                 bdev->bd_part = NULL;
                 bdev->bd_disk = NULL;
+                bdev_inode_switch_bdi(bdev->bd_inode,
+                                        &default_backing_dev_info);
                 if (bdev != bdev->bd_contains)
                         victim = bdev->bd_contains;
                 bdev->bd_contains = NULL;
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 7e20a65d2d4..f88d5363114 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3329,7 +3329,8 @@ static int shrink_delalloc(struct btrfs_trans_handle *trans,
                 smp_mb();
                 nr_pages = min_t(unsigned long, nr_pages,
                        root->fs_info->delalloc_bytes >> PAGE_CACHE_SHIFT);
-                writeback_inodes_sb_nr_if_idle(root->fs_info->sb, nr_pages);
+                writeback_inodes_sb_nr_if_idle(root->fs_info->sb, nr_pages,
+                                                WB_REASON_FS_FREE_SPACE);
 
                 spin_lock(&space_info->lock);
                 if (reserved > space_info->bytes_reserved)
diff --git a/fs/buffer.c b/fs/buffer.c
index d42162672c7..d7586936b25 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -285,7 +285,7 @@ static void free_more_memory(void)
         struct zone *zone;
         int nid;
 
-        wakeup_flusher_threads(1024);
+        wakeup_flusher_threads(1024, WB_REASON_FREE_MORE_MEM);
         yield();
 
         for_each_online_node(nid) {
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 18fee6daecd..00a5acdd654 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2687,8 +2687,12 @@ static int ext4_writepage(struct page *page,
                  * We don't want to do block allocation, so redirty
                  * the page and return.  We may reach here when we do
                  * a journal commit via journal_submit_inode_data_buffers.
-                 * We can also reach here via shrink_page_list
+                 * We can also reach here via shrink_page_list but it
+                 * should never be for direct reclaim so warn if that
+                 * happens
                  */
+                WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD)) ==
+                                                                PF_MEMALLOC);
                 goto redirty_page;
         }
         if (commit_write)
@@ -3117,7 +3121,7 @@ static int ext4_nonda_switch(struct super_block *sb)
          * start pushing delalloc when 1/2 of free blocks are dirty.
          */
         if (free_blocks < 2 * dirty_blocks)
-                writeback_inodes_sb_if_idle(sb);
+                writeback_inodes_sb_if_idle(sb, WB_REASON_FS_FREE_SPACE);
 
         return 0;
 }
diff --git a/fs/fat/dir.c b/fs/fat/dir.c
index 4ad64732cbc..dc563788fa8 100644
--- a/fs/fat/dir.c
+++ b/fs/fat/dir.c
@@ -754,6 +754,13 @@ static int fat_ioctl_readdir(struct inode *inode, struct file *filp,
         return ret;
 }
 
+static int fat_ioctl_volume_id(struct inode *dir)
+{
+        struct super_block *sb = dir->i_sb;
+        struct msdos_sb_info *sbi = MSDOS_SB(sb);
+        return sbi->vol_id;
+}
+
 static long fat_dir_ioctl(struct file *filp, unsigned int cmd,
                           unsigned long arg)
 {
@@ -770,6 +777,8 @@ static long fat_dir_ioctl(struct file *filp, unsigned int cmd,
                 short_only = 0;
                 both = 1;
                 break;
+        case VFAT_IOCTL_GET_VOLUME_ID:
+                return fat_ioctl_volume_id(inode);
         default:
                 return fat_generic_ioctl(filp, cmd, arg);
         }
diff --git a/fs/fat/fat.h b/fs/fat/fat.h
index 8276cc282de..74fe5d3ed01 100644
--- a/fs/fat/fat.h
+++ b/fs/fat/fat.h
@@ -78,6 +78,7 @@ struct msdos_sb_info {
         const void *dir_ops;                 /* Opaque; default directory operations */
         int dir_per_block;           /* dir entries per block */
         int dir_per_block_bits;      /* log2(dir_per_block) */
+        unsigned long vol_id;        /* volume ID */
 
         int fatent_shift;
         struct fatent_operations *fatent_ops;
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index cb8d8391ac0..9836839e0eb 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -1245,6 +1245,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
         struct inode *root_inode = NULL, *fat_inode = NULL;
         struct buffer_head *bh;
         struct fat_boot_sector *b;
+        struct fat_boot_bsx *bsx;
         struct msdos_sb_info *sbi;
         u16 logical_sector_size;
         u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
@@ -1390,6 +1391,8 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
                         goto out_fail;
                 }
 
+                bsx = (struct fat_boot_bsx *)(bh->b_data + FAT32_BSX_OFFSET);
+
                 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
                 if (!IS_FSINFO(fsinfo)) {
                         fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: "
@@ -1405,8 +1408,14 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
                 }
 
                 brelse(fsinfo_bh);
+        } else {
+                bsx = (struct fat_boot_bsx *)(bh->b_data + FAT16_BSX_OFFSET);
         }
 
+        /* interpret volume ID as a little endian 32 bit integer */
+        sbi->vol_id = (((u32)bsx->vol_id[0]) | ((u32)bsx->vol_id[1] << 8) |
+                ((u32)bsx->vol_id[2] << 16) | ((u32)bsx->vol_id[3] << 24));
+
         sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
         sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
 
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index fe190a8b0bc..1d9ebbbd343 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -35,16 +35,29 @@
 struct wb_writeback_work {
         long nr_pages;
         struct super_block *sb;
+        unsigned long *older_than_this;
         enum writeback_sync_modes sync_mode;
         unsigned int tagged_writepages:1;
         unsigned int for_kupdate:1;
         unsigned int range_cyclic:1;
         unsigned int for_background:1;
+        enum wb_reason reason;          /* why was writeback initiated? */
 
         struct list_head list;          /* pending work list */
         struct completion *done;        /* set if the caller waits */
 };
 
+const char *wb_reason_name[] = {
+        [WB_REASON_BACKGROUND]          = "background",
+        [WB_REASON_TRY_TO_FREE_PAGES]   = "try_to_free_pages",
+        [WB_REASON_SYNC]                = "sync",
+        [WB_REASON_PERIODIC]            = "periodic",
+        [WB_REASON_LAPTOP_TIMER]        = "laptop_timer",
+        [WB_REASON_FREE_MORE_MEM]       = "free_more_memory",
+        [WB_REASON_FS_FREE_SPACE]       = "fs_free_space",
+        [WB_REASON_FORKER_THREAD]       = "forker_thread"
+};
+
 /*
  * Include the creation of the trace points after defining the
  * wb_writeback_work structure so that the definition remains local to this
@@ -114,7 +127,7 @@ static void bdi_queue_work(struct backing_dev_info *bdi,
 
 static void
 __bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,
-                      bool range_cyclic)
+                      bool range_cyclic, enum wb_reason reason)
 {
         struct wb_writeback_work *work;
 
@@ -134,6 +147,7 @@ __bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,
         work->sync_mode = WB_SYNC_NONE;
         work->nr_pages  = nr_pages;
         work->range_cyclic = range_cyclic;
+        work->reason    = reason;
 
         bdi_queue_work(bdi, work);
 }
@@ -149,9 +163,10 @@ __bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,
  *   completion. Caller need not hold sb s_umount semaphore.
  *
  */
-void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages)
+void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,
+                        enum wb_reason reason)
 {
-        __bdi_start_writeback(bdi, nr_pages, true);
+        __bdi_start_writeback(bdi, nr_pages, true, reason);
 }
 
 /**
@@ -181,12 +196,13 @@ void bdi_start_background_writeback(struct backing_dev_info *bdi)
  */
 void inode_wb_list_del(struct inode *inode)
 {
-        spin_lock(&inode_wb_list_lock);
+        struct backing_dev_info *bdi = inode_to_bdi(inode);
+
+        spin_lock(&bdi->wb.list_lock);
         list_del_init(&inode->i_wb_list);
-        spin_unlock(&inode_wb_list_lock);
+        spin_unlock(&bdi->wb.list_lock);
 }
 
-
 /*
  * Redirty an inode: set its when-it-was dirtied timestamp and move it to the
  * furthest end of its superblock's dirty-inode list.
@@ -196,11 +212,9 @@ void inode_wb_list_del(struct inode *inode)
  * the case then the inode must have been redirtied while it was being written
  * out and we don't reset its dirtied_when.
  */
-static void redirty_tail(struct inode *inode)
+static void redirty_tail(struct inode *inode, struct bdi_writeback *wb)
 {
-        struct bdi_writeback *wb = &inode_to_bdi(inode)->wb;
-
-        assert_spin_locked(&inode_wb_list_lock);
+        assert_spin_locked(&wb->list_lock);
         if (!list_empty(&wb->b_dirty)) {
                 struct inode *tail;
 
@@ -214,11 +228,9 @@ static void redirty_tail(struct inode *inode)
 /*
  * requeue inode for re-scanning after bdi->b_io list is exhausted.
  */
-static void requeue_io(struct inode *inode)
+static void requeue_io(struct inode *inode, struct bdi_writeback *wb)
 {
-        struct bdi_writeback *wb = &inode_to_bdi(inode)->wb;
-
-        assert_spin_locked(&inode_wb_list_lock);
+        assert_spin_locked(&wb->list_lock);
         list_move(&inode->i_wb_list, &wb->b_more_io);
 }
 
@@ -226,7 +238,7 @@ static void inode_sync_complete(struct inode *inode)
 {
         /*
          * Prevent speculative execution through
-         * spin_unlock(&inode_wb_list_lock);
+         * spin_unlock(&wb->list_lock);
          */
 
         smp_mb();
@@ -251,15 +263,16 @@ static bool inode_dirtied_after(struct inode *inode, unsigned long t)
 /*
  * Move expired dirty inodes from @delaying_queue to @dispatch_queue.
  */
-static void move_expired_inodes(struct list_head *delaying_queue,
+static int move_expired_inodes(struct list_head *delaying_queue,
                                struct list_head *dispatch_queue,
-                                unsigned long *older_than_this)
+                               unsigned long *older_than_this)
 {
         LIST_HEAD(tmp);
         struct list_head *pos, *node;
         struct super_block *sb = NULL;
         struct inode *inode;
         int do_sb_sort = 0;
+        int moved = 0;
 
         while (!list_empty(delaying_queue)) {
                 inode = wb_inode(delaying_queue->prev);
@@ -270,12 +283,13 @@ static void move_expired_inodes(struct list_head *delaying_queue,
                         do_sb_sort = 1;
                 sb = inode->i_sb;
                 list_move(&inode->i_wb_list, &tmp);
+                moved++;
         }
 
         /* just one sb in list, splice to dispatch_queue and we're done */
         if (!do_sb_sort) {
                 list_splice(&tmp, dispatch_queue);
-                return;
+                goto out;
         }
 
         /* Move inodes from one superblock together */
@@ -287,6 +301,8 @@ static void move_expired_inodes(struct list_head *delaying_queue,
                                 list_move(&inode->i_wb_list, dispatch_queue);
                 }
         }
+out:
+        return moved;
 }
 
 /*
@@ -302,9 +318,11 @@ static void move_expired_inodes(struct list_head *delaying_queue,
  */
 static void queue_io(struct bdi_writeback *wb, unsigned long *older_than_this)
 {
-        assert_spin_locked(&inode_wb_list_lock);
+        int moved;
+        assert_spin_locked(&wb->list_lock);
         list_splice_init(&wb->b_more_io, &wb->b_io);
-        move_expired_inodes(&wb->b_dirty, &wb->b_io, older_than_this);
+        moved = move_expired_inodes(&wb->b_dirty, &wb->b_io, older_than_this);
+        trace_writeback_queue_io(wb, older_than_this, moved);
 }
 
 static int write_inode(struct inode *inode, struct writeback_control *wbc)
@@ -317,7 +335,8 @@ static int write_inode(struct inode *inode, struct writeback_control *wbc)
 /*
  * Wait for writeback on an inode to complete.
  */
-static void inode_wait_for_writeback(struct inode *inode)
+static void inode_wait_for_writeback(struct inode *inode,
+                                     struct bdi_writeback *wb)
 {
         DEFINE_WAIT_BIT(wq, &inode->i_state, __I_SYNC);
         wait_queue_head_t *wqh;
@@ -325,15 +344,15 @@ static void inode_wait_for_writeback(struct inode *inode)
         wqh = bit_waitqueue(&inode->i_state, __I_SYNC);
         while (inode->i_state & I_SYNC) {
                 spin_unlock(&inode->i_lock);
-                spin_unlock(&inode_wb_list_lock);
+                spin_unlock(&wb->list_lock);
                 __wait_on_bit(wqh, &wq, inode_wait, TASK_UNINTERRUPTIBLE);
-                spin_lock(&inode_wb_list_lock);
+                spin_lock(&wb->list_lock);
                 spin_lock(&inode->i_lock);
         }
 }
 
 /*
- * Write out an inode's dirty pages.  Called under inode_wb_list_lock and
+ * Write out an inode's dirty pages.  Called under wb->list_lock and
  * inode->i_lock.  Either the caller has an active reference on the inode or
  * the inode has I_WILL_FREE set.
  *
@@ -344,13 +363,15 @@ static void inode_wait_for_writeback(struct inode *inode)
  * livelocks, etc.
  */
 static int
-writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
+writeback_single_inode(struct inode *inode, struct bdi_writeback *wb,
+                       struct writeback_control *wbc)
 {
         struct address_space *mapping = inode->i_mapping;
+        long nr_to_write = wbc->nr_to_write;
         unsigned dirty;
         int ret;
 
-        assert_spin_locked(&inode_wb_list_lock);
+        assert_spin_locked(&wb->list_lock);
         assert_spin_locked(&inode->i_lock);
 
         if (!atomic_read(&inode->i_count))
@@ -368,14 +389,16 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
                  * completed a full scan of b_io.
                  */
                 if (wbc->sync_mode != WB_SYNC_ALL) {
-                        requeue_io(inode);
+                        requeue_io(inode, wb);
+                        trace_writeback_single_inode_requeue(inode, wbc,
+                                                             nr_to_write);
                         return 0;
                 }
 
                 /*
                  * It's a data-integrity sync.  We must wait.
                  */
-                inode_wait_for_writeback(inode);
+                inode_wait_for_writeback(inode, wb);
         }
 
         BUG_ON(inode->i_state & I_SYNC);
@@ -384,7 +407,7 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
         inode->i_state |= I_SYNC;
         inode->i_state &= ~I_DIRTY_PAGES;
         spin_unlock(&inode->i_lock);
-        spin_unlock(&inode_wb_list_lock);
+        spin_unlock(&wb->list_lock);
 
         ret = do_writepages(mapping, wbc);
 
@@ -415,7 +438,7 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
                         ret = err;
         }
 
-        spin_lock(&inode_wb_list_lock);
+        spin_lock(&wb->list_lock);
         spin_lock(&inode->i_lock);
         inode->i_state &= ~I_SYNC;
         if (!(inode->i_state & I_FREEING)) {
@@ -438,7 +461,7 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
                                 /*
                                  * slice used up: queue for next turn
                                  */
-                                requeue_io(inode);
+                                requeue_io(inode, wb);
                         } else {
                                 /*
                                  * Writeback blocked by something other than
@@ -447,7 +470,7 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
                                  * retrying writeback of the dirty page/inode
                                  * that cannot be performed immediately.
                                  */
-                                redirty_tail(inode);
+                                redirty_tail(inode, wb);
                         }
                 } else if (inode->i_state & I_DIRTY) {
                         /*
@@ -456,7 +479,7 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
                          * submission or metadata updates after data IO
                          * completion.
                          */
-                        redirty_tail(inode);
+                        redirty_tail(inode, wb);
                 } else {
                         /*
                          * The inode is clean.  At this point we either have
@@ -467,33 +490,39 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
                 }
         }
         inode_sync_complete(inode);
+        trace_writeback_single_inode(inode, wbc, nr_to_write);
         return ret;
 }
 
-/*
- * For background writeback the caller does not have the sb pinned
- * before calling writeback. So make sure that we do pin it, so it doesn't
- * go away while we are writing inodes from it.
- */
-static bool pin_sb_for_writeback(struct super_block *sb)
+static long writeback_chunk_size(struct backing_dev_info *bdi,
+                                 struct wb_writeback_work *work)
 {
-        spin_lock(&sb_lock);
-        if (list_empty(&sb->s_instances)) {
-                spin_unlock(&sb_lock);
-                return false;
-        }
-
-        sb->s_count++;
-        spin_unlock(&sb_lock);
+        long pages;
 
-        if (down_read_trylock(&sb->s_umount)) {
-                if (sb->s_root)
-                        return true;
-                up_read(&sb->s_umount);
+        /*
+         * WB_SYNC_ALL mode does livelock avoidance by syncing dirty
+         * inodes/pages in one big loop. Setting wbc.nr_to_write=LONG_MAX
+         * here avoids calling into writeback_inodes_wb() more than once.
+         *
+         * The intended call sequence for WB_SYNC_ALL writeback is:
+         *
+         *      wb_writeback()
+         *          writeback_sb_inodes()       <== called only once
+         *              write_cache_pages()     <== called once for each inode
+         *                   (quickly) tag currently dirty pages
+         *                   (maybe slowly) sync all tagged pages
+         */
+        if (work->sync_mode == WB_SYNC_ALL || work->tagged_writepages)
+                pages = LONG_MAX;
+        else {
+                pages = min(bdi->avg_write_bandwidth / 2,
+                            global_dirty_limit / DIRTY_SCOPE);
+                pages = min(pages, work->nr_pages);
+                pages = round_down(pages + MIN_WRITEBACK_PAGES,
+                                   MIN_WRITEBACK_PAGES);
         }
 
-        put_super(sb);
-        return false;
+        return pages;
 }
 
 /*
@@ -503,24 +532,36 @@ static bool pin_sb_for_writeback(struct super_block *sb)
  * inodes. Otherwise write only ones which go sequentially
  * in reverse order.
  *
- * Return 1, if the caller writeback routine should be
- * interrupted. Otherwise return 0.
+ * Return the number of pages and/or inodes written.
  */
-static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb,
-                struct writeback_control *wbc, bool only_this_sb)
+static long writeback_sb_inodes(struct super_block *sb,
+                                struct bdi_writeback *wb,
+                                struct wb_writeback_work *work)
 {
+        struct writeback_control wbc = {
+                .sync_mode              = work->sync_mode,
+                .tagged_writepages      = work->tagged_writepages,
+                .for_kupdate            = work->for_kupdate,
+                .for_background         = work->for_background,
+                .range_cyclic           = work->range_cyclic,
+                .range_start            = 0,
+                .range_end              = LLONG_MAX,
+        };
+        unsigned long start_time = jiffies;
+        long write_chunk;
+        long wrote = 0;  /* count both pages and inodes */
+
         while (!list_empty(&wb->b_io)) {
-                long pages_skipped;
                 struct inode *inode = wb_inode(wb->b_io.prev);
 
                 if (inode->i_sb != sb) {
-                        if (only_this_sb) {
+                        if (work->sb) {
                                 /*
                                  * We only want to write back data for this
                                  * superblock, move all inodes not belonging
                                  * to it back onto the dirty list.
                                  */
-                                redirty_tail(inode);
+                                redirty_tail(inode, wb);
                                 continue;
                         }
 
@@ -529,7 +570,7 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb,
                          * Bounce back to the caller to unpin this and
                          * pin the next superblock.
                          */
-                        return 0;
+                        break;
                 }
 
                 /*
@@ -540,104 +581,124 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb,
                 spin_lock(&inode->i_lock);
                 if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) {
                         spin_unlock(&inode->i_lock);
-                        requeue_io(inode);
+                        redirty_tail(inode, wb);
                         continue;
                 }
-
-                /*
-                 * Was this inode dirtied after sync_sb_inodes was called?
-                 * This keeps sync from extra jobs and livelock.
-                 */
-                if (inode_dirtied_after(inode, wbc->wb_start)) {
-                        spin_unlock(&inode->i_lock);
-                        return 1;
-                }
-
                 __iget(inode);
+                write_chunk = writeback_chunk_size(wb->bdi, work);
+                wbc.nr_to_write = write_chunk;
+                wbc.pages_skipped = 0;
+
+                writeback_single_inode(inode, wb, &wbc);
 
-                pages_skipped = wbc->pages_skipped;
-                writeback_single_inode(inode, wbc);
-                if (wbc->pages_skipped != pages_skipped) {
+                work->nr_pages -= write_chunk - wbc.nr_to_write;
+                wrote += write_chunk - wbc.nr_to_write;
+                if (!(inode->i_state & I_DIRTY))
+                        wrote++;
+                if (wbc.pages_skipped) {
                         /*
                          * writeback is not making progress due to locked
                          * buffers.  Skip this inode for now.
                          */
-                        redirty_tail(inode);
+                        redirty_tail(inode, wb);
                 }
                 spin_unlock(&inode->i_lock);
-                spin_unlock(&inode_wb_list_lock);
+                spin_unlock(&wb->list_lock);
                 iput(inode);
                 cond_resched();
-                spin_lock(&inode_wb_list_lock);
-                if (wbc->nr_to_write <= 0) {
-                        wbc->more_io = 1;
-                        return 1;
+                spin_lock(&wb->list_lock);
+                /*
+                 * bail out to wb_writeback() often enough to check
+                 * background threshold and other termination conditions.
+                 */
+                if (wrote) {
+                        if (time_is_before_jiffies(start_time + HZ / 10UL))
+                                break;
+                        if (work->nr_pages <= 0)
+                                break;
                 }
-                if (!list_empty(&wb->b_more_io))
-                        wbc->more_io = 1;
         }
-        /* b_io is empty */
-        return 1;
+        return wrote;
 }
 
-void writeback_inodes_wb(struct bdi_writeback *wb,
-                struct writeback_control *wbc)
+static long __writeback_inodes_wb(struct bdi_writeback *wb,
+                                  struct wb_writeback_work *work)
 {
-        int ret = 0;
-
-        if (!wbc->wb_start)
-                wbc->wb_start = jiffies; /* livelock avoidance */
-        spin_lock(&inode_wb_list_lock);
-        if (!wbc->for_kupdate || list_empty(&wb->b_io))
-                queue_io(wb, wbc->older_than_this);
+        unsigned long start_time = jiffies;
+        long wrote = 0;
 
         while (!list_empty(&wb->b_io)) {
                 struct inode *inode = wb_inode(wb->b_io.prev);
                 struct super_block *sb = inode->i_sb;
 
-                if (!pin_sb_for_writeback(sb)) {
-                        requeue_io(inode);
+                if (!grab_super_passive(sb)) {
+                        /*
+                         * grab_super_passive() may fail consistently due to
+                         * s_umount being grabbed by someone else. Don't use
+                         * requeue_io() to avoid busy retrying the inode/sb.
+                         */
+                        redirty_tail(inode, wb);
                         continue;
                 }
-                ret = writeback_sb_inodes(sb, wb, wbc, false);
+                wrote += writeback_sb_inodes(sb, wb, work);
                 drop_super(sb);
 
-                if (ret)
-                        break;
+                /* refer to the same tests at the end of writeback_sb_inodes */
+                if (wrote) {
+                        if (time_is_before_jiffies(start_time + HZ / 10UL))
+                                break;
+                        if (work->nr_pages <= 0)
+                                break;
+                }
         }
-        spin_unlock(&inode_wb_list_lock);
         /* Leave any unwritten inodes on b_io */
+        return wrote;
 }
 
-static void __writeback_inodes_sb(struct super_block *sb,
-                struct bdi_writeback *wb, struct writeback_control *wbc)
+long writeback_inodes_wb(struct bdi_writeback *wb, long nr_pages,
+                                enum wb_reason reason)
 {
-        WARN_ON(!rwsem_is_locked(&sb->s_umount));
+        struct wb_writeback_work work = {
+                .nr_pages       = nr_pages,
+                .sync_mode      = WB_SYNC_NONE,
+                .range_cyclic   = 1,
+                .reason         = reason,
+        };
 
-        spin_lock(&inode_wb_list_lock);
-        if (!wbc->for_kupdate || list_empty(&wb->b_io))
-                queue_io(wb, wbc->older_than_this);
-        writeback_sb_inodes(sb, wb, wbc, true);
-        spin_unlock(&inode_wb_list_lock);
-}
+        spin_lock(&wb->list_lock);
+        if (list_empty(&wb->b_io))
+                queue_io(wb, NULL);
+        __writeback_inodes_wb(wb, &work);
+        spin_unlock(&wb->list_lock);
 
-/*
- * The maximum number of pages to writeout in a single bdi flush/kupdate
- * operation.  We do this so we don't hold I_SYNC against an inode for
- * enormous amounts of time, which would block a userspace task which has
- * been forced to throttle against that inode.  Also, the code reevaluates
- * the dirty each time it has written this many pages.
- */
-#define MAX_WRITEBACK_PAGES     1024
+        return nr_pages - work.nr_pages;
+}
 
-static inline bool over_bground_thresh(void)
+static bool over_bground_thresh(struct backing_dev_info *bdi)
 {
         unsigned long background_thresh, dirty_thresh;
 
         global_dirty_limits(&background_thresh, &dirty_thresh);
 
-        return (global_page_state(NR_FILE_DIRTY) +
-                global_page_state(NR_UNSTABLE_NFS) > background_thresh);
+        if (global_page_state(NR_FILE_DIRTY) +
+            global_page_state(NR_UNSTABLE_NFS) > background_thresh)
+                return true;
+
+        if (bdi_stat(bdi, BDI_RECLAIMABLE) >
+                                bdi_dirty_limit(bdi, background_thresh))
+                return true;
+
+        return false;
+}
+
+/*
+ * Called under wb->list_lock. If there are multiple wb per bdi,
+ * only the flusher working on the first wb should do it.
+ */
+static void wb_update_bandwidth(struct bdi_writeback *wb,
+                                unsigned long start_time)
+{
+        __bdi_update_bandwidth(wb->bdi, 0, 0, 0, 0, 0, start_time);
 }
 
 /*
@@ -658,46 +719,16 @@ static inline bool over_bground_thresh(void)
 static long wb_writeback(struct bdi_writeback *wb,
                          struct wb_writeback_work *work)
 {
-        struct writeback_control wbc = {
-                .sync_mode              = work->sync_mode,
-                .tagged_writepages      = work->tagged_writepages,
-                .older_than_this        = NULL,
-                .for_kupdate            = work->for_kupdate,
-                .for_background         = work->for_background,
-                .range_cyclic           = work->range_cyclic,
-        };
+        unsigned long wb_start = jiffies;
+        long nr_pages = work->nr_pages;
         unsigned long oldest_jif;
-        long wrote = 0;
-        long write_chunk = MAX_WRITEBACK_PAGES;
         struct inode *inode;
+        long progress;
 
-        if (wbc.for_kupdate) {
-                wbc.older_than_this = &oldest_jif;
-                oldest_jif = jiffies -
-                                msecs_to_jiffies(dirty_expire_interval * 10);
-        }
-        if (!wbc.range_cyclic) {
-                wbc.range_start = 0;
-                wbc.range_end = LLONG_MAX;
-        }
-
-        /*
-         * WB_SYNC_ALL mode does livelock avoidance by syncing dirty
-         * inodes/pages in one big loop. Setting wbc.nr_to_write=LONG_MAX
-         * here avoids calling into writeback_inodes_wb() more than once.
-         *
-         * The intended call sequence for WB_SYNC_ALL writeback is:
-         *
-         *      wb_writeback()
-         *          __writeback_inodes_sb()     <== called only once
-         *              write_cache_pages()     <== called once for each inode
-         *                   (quickly) tag currently dirty pages
-         *                   (maybe slowly) sync all tagged pages
-         */
-        if (wbc.sync_mode == WB_SYNC_ALL || wbc.tagged_writepages)
-                write_chunk = LONG_MAX;
+        oldest_jif = jiffies;
+        work->older_than_this = &oldest_jif;
 
-        wbc.wb_start = jiffies; /* livelock avoidance */
+        spin_lock(&wb->list_lock);
         for (;;) {
                 /*
                  * Stop writeback when nr_pages has been consumed
@@ -719,55 +750,57 @@ static long wb_writeback(struct bdi_writeback *wb,
                  * For background writeout, stop when we are below the
                  * background dirty threshold
                  */
-                if (work->for_background && !over_bground_thresh())
+                if (work->for_background && !over_bground_thresh(wb->bdi))
                         break;
 
-                wbc.more_io = 0;
-                wbc.nr_to_write = write_chunk;
-                wbc.pages_skipped = 0;
+                if (work->for_kupdate) {
+                        oldest_jif = jiffies -
+                                msecs_to_jiffies(dirty_expire_interval * 10);
+                        work->older_than_this = &oldest_jif;
+                }
 
-                trace_wbc_writeback_start(&wbc, wb->bdi);
+                trace_writeback_start(wb->bdi, work);
+                if (list_empty(&wb->b_io))
+                        queue_io(wb, work->older_than_this);
                 if (work->sb)
-                        __writeback_inodes_sb(work->sb, wb, &wbc);
+                        progress = writeback_sb_inodes(work->sb, wb, work);
                 else
-                        writeback_inodes_wb(wb, &wbc);
-                trace_wbc_writeback_written(&wbc, wb->bdi);
+                        progress = __writeback_inodes_wb(wb, work);
+                trace_writeback_written(wb->bdi, work);
 
-                work->nr_pages -= write_chunk - wbc.nr_to_write;
-                wrote += write_chunk - wbc.nr_to_write;
+                wb_update_bandwidth(wb, wb_start);
 
                 /*
-                 * If we consumed everything, see if we have more
+                 * Did we write something? Try for more
+                 *
+                 * Dirty inodes are moved to b_io for writeback in batches.
+                 * The completion of the current batch does not necessarily
+                 * mean the overall work is done. So we keep looping as long
+                 * as made some progress on cleaning pages or inodes.
                  */
-                if (wbc.nr_to_write <= 0)
+                if (progress)
                         continue;
                 /*
-                 * Didn't write everything and we don't have more IO, bail
+                 * No more inodes for IO, bail
                  */
-                if (!wbc.more_io)
+                if (list_empty(&wb->b_more_io))
                         break;
                 /*
-                 * Did we write something? Try for more
-                 */
-                if (wbc.nr_to_write < write_chunk)
-                        continue;
-                /*
                  * Nothing written. Wait for some inode to
                  * become available for writeback. Otherwise
                  * we'll just busyloop.
                  */
-                spin_lock(&inode_wb_list_lock);
                 if (!list_empty(&wb->b_more_io))  {
+                        trace_writeback_wait(wb->bdi, work);
                         inode = wb_inode(wb->b_more_io.prev);
-                        trace_wbc_writeback_wait(&wbc, wb->bdi);
                         spin_lock(&inode->i_lock);
-                        inode_wait_for_writeback(inode);
+                        inode_wait_for_writeback(inode, wb);
                         spin_unlock(&inode->i_lock);
                 }
-                spin_unlock(&inode_wb_list_lock);
         }
+        spin_unlock(&wb->list_lock);
 
-        return wrote;
+        return nr_pages - work->nr_pages;
 }
 
 /*
@@ -801,13 +834,14 @@ static unsigned long get_nr_dirty_pages(void)
 
 static long wb_check_background_flush(struct bdi_writeback *wb)
 {
-        if (over_bground_thresh()) {
+        if (over_bground_thresh(wb->bdi)) {
 
                 struct wb_writeback_work work = {
                         .nr_pages       = LONG_MAX,
                         .sync_mode      = WB_SYNC_NONE,
                         .for_background = 1,
                         .range_cyclic   = 1,
+                        .reason         = WB_REASON_BACKGROUND,
                 };
 
                 return wb_writeback(wb, &work);
@@ -841,6 +875,7 @@ static long wb_check_old_data_flush(struct bdi_writeback *wb)
                         .sync_mode      = WB_SYNC_NONE,
                         .for_kupdate    = 1,
                         .range_cyclic   = 1,
+                        .reason         = WB_REASON_PERIODIC,
                 };
 
                 return wb_writeback(wb, &work);
@@ -959,7 +994,7 @@ int bdi_writeback_thread(void *data)
  * Start writeback of `nr_pages' pages.  If `nr_pages' is zero, write back
  * the whole world.
  */
-void wakeup_flusher_threads(long nr_pages)
+void wakeup_flusher_threads(long nr_pages, enum wb_reason reason)
 {
         struct backing_dev_info *bdi;
 
@@ -972,7 +1007,7 @@ void wakeup_flusher_threads(long nr_pages)
         list_for_each_entry_rcu(bdi, &bdi_list, bdi_list) {
                 if (!bdi_has_dirty_io(bdi))
                         continue;
-                __bdi_start_writeback(bdi, nr_pages, false);
+                __bdi_start_writeback(bdi, nr_pages, false, reason);
         }
         rcu_read_unlock();
 }
@@ -1098,10 +1133,10 @@ void __mark_inode_dirty(struct inode *inode, int flags)
                         }
 
                         spin_unlock(&inode->i_lock);
-                        spin_lock(&inode_wb_list_lock);
+                        spin_lock(&bdi->wb.list_lock);
                         inode->dirtied_when = jiffies;
                         list_move(&inode->i_wb_list, &bdi->wb.b_dirty);
-                        spin_unlock(&inode_wb_list_lock);
+                        spin_unlock(&bdi->wb.list_lock);
 
                         if (wakeup_bdi)
                                 bdi_wakeup_thread_delayed(bdi);
@@ -1193,7 +1228,9 @@ static void wait_sb_inodes(struct super_block *sb)
  * on how many (if any) will be written, and this function does not wait
  * for IO completion of submitted IO.
  */
-void writeback_inodes_sb_nr(struct super_block *sb, unsigned long nr)
+void writeback_inodes_sb_nr(struct super_block *sb,
+                            unsigned long nr,
+                            enum wb_reason reason)
 {
         DECLARE_COMPLETION_ONSTACK(done);
         struct wb_writeback_work work = {
@@ -1202,6 +1239,7 @@ void writeback_inodes_sb_nr(struct super_block *sb, unsigned long nr)
                 .tagged_writepages      = 1,
                 .done                   = &done,
                 .nr_pages               = nr,
+                .reason                 = reason,
         };
 
         WARN_ON(!rwsem_is_locked(&sb->s_umount));
@@ -1218,9 +1256,9 @@ EXPORT_SYMBOL(writeback_inodes_sb_nr);
  * on how many (if any) will be written, and this function does not wait
  * for IO completion of submitted IO.
  */
-void writeback_inodes_sb(struct super_block *sb)
+void writeback_inodes_sb(struct super_block *sb, enum wb_reason reason)
 {
-        return writeback_inodes_sb_nr(sb, get_nr_dirty_pages());
+        return writeback_inodes_sb_nr(sb, get_nr_dirty_pages(), reason);
 }
 EXPORT_SYMBOL(writeback_inodes_sb);
 
@@ -1231,11 +1269,11 @@ EXPORT_SYMBOL(writeback_inodes_sb);
  * Invoke writeback_inodes_sb if no writeback is currently underway.
  * Returns 1 if writeback was started, 0 if not.
  */
-int writeback_inodes_sb_if_idle(struct super_block *sb)
+int writeback_inodes_sb_if_idle(struct super_block *sb, enum wb_reason reason)
 {
         if (!writeback_in_progress(sb->s_bdi)) {
                 down_read(&sb->s_umount);
-                writeback_inodes_sb(sb);
+                writeback_inodes_sb(sb, reason);
                 up_read(&sb->s_umount);
                 return 1;
         } else
@@ -1252,11 +1290,12 @@ EXPORT_SYMBOL(writeback_inodes_sb_if_idle);
  * Returns 1 if writeback was started, 0 if not.
  */
 int writeback_inodes_sb_nr_if_idle(struct super_block *sb,
-                                   unsigned long nr)
+                                   unsigned long nr,
+                                   enum wb_reason reason)
 {
         if (!writeback_in_progress(sb->s_bdi)) {
                 down_read(&sb->s_umount);
-                writeback_inodes_sb_nr(sb, nr);
+                writeback_inodes_sb_nr(sb, nr, reason);
                 up_read(&sb->s_umount);
                 return 1;
         } else
@@ -1280,6 +1319,7 @@ void sync_inodes_sb(struct super_block *sb)
                 .nr_pages       = LONG_MAX,
                 .range_cyclic   = 0,
                 .done           = &done,
+                .reason         = WB_REASON_SYNC,
         };
 
         WARN_ON(!rwsem_is_locked(&sb->s_umount));
@@ -1303,6 +1343,7 @@ EXPORT_SYMBOL(sync_inodes_sb);
  */
 int write_inode_now(struct inode *inode, int sync)
 {
+        struct bdi_writeback *wb = &inode_to_bdi(inode)->wb;
         int ret;
         struct writeback_control wbc = {
                 .nr_to_write = LONG_MAX,
@@ -1315,11 +1356,11 @@ int write_inode_now(struct inode *inode, int sync)
                 wbc.nr_to_write = 0;
 
         might_sleep();
-        spin_lock(&inode_wb_list_lock);
+        spin_lock(&wb->list_lock);
         spin_lock(&inode->i_lock);
-        ret = writeback_single_inode(inode, &wbc);
+        ret = writeback_single_inode(inode, wb, &wbc);
         spin_unlock(&inode->i_lock);
-        spin_unlock(&inode_wb_list_lock);
+        spin_unlock(&wb->list_lock);
         if (sync)
                 inode_sync_wait(inode);
         return ret;
@@ -1339,13 +1380,14 @@ EXPORT_SYMBOL(write_inode_now);
  */
 int sync_inode(struct inode *inode, struct writeback_control *wbc)
 {
+        struct bdi_writeback *wb = &inode_to_bdi(inode)->wb;
         int ret;
 
-        spin_lock(&inode_wb_list_lock);
+        spin_lock(&wb->list_lock);
         spin_lock(&inode->i_lock);
-        ret = writeback_single_inode(inode, wbc);
+        ret = writeback_single_inode(inode, wb, wbc);
         spin_unlock(&inode->i_lock);
-        spin_unlock(&inode_wb_list_lock);
+        spin_unlock(&wb->list_lock);
         return ret;
 }
 EXPORT_SYMBOL(sync_inode);
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 2aaf3eaaf13..c858b5c8320 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -19,6 +19,7 @@
 #include <linux/pipe_fs_i.h>
 #include <linux/swap.h>
 #include <linux/splice.h>
+#include <linux/freezer.h>
 
 MODULE_ALIAS_MISCDEV(FUSE_MINOR);
 MODULE_ALIAS("devname:fuse");
@@ -387,7 +388,10 @@ __acquires(fc->lock)
          * Wait it out.
          */
         spin_unlock(&fc->lock);
-        wait_event(req->waitq, req->state == FUSE_REQ_FINISHED);
+
+        while (req->state != FUSE_REQ_FINISHED)
+                wait_event_freezable(req->waitq,
+                                     req->state == FUSE_REQ_FINISHED);
         spin_lock(&fc->lock);
 
         if (!req->aborted)
diff --git a/fs/inode.c b/fs/inode.c
index 43566d17d1b..09f334bf27d 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -37,7 +37,7 @@
  *   inode_lru, inode->i_lru
  * inode_sb_list_lock protects:
  *   sb->s_inodes, inode->i_sb_list
- * inode_wb_list_lock protects:
+ * bdi->wb.list_lock protects:
  *   bdi->wb.b_{dirty,io,more_io}, inode->i_wb_list
  * inode_hash_lock protects:
  *   inode_hashtable, inode->i_hash
@@ -48,7 +48,7 @@
  *   inode->i_lock
  *     inode_lru_lock
  *
- * inode_wb_list_lock
+ * bdi->wb.list_lock
  *   inode->i_lock
  *
  * inode_hash_lock
@@ -68,7 +68,6 @@ static LIST_HEAD(inode_lru);
 static DEFINE_SPINLOCK(inode_lru_lock);
 
 __cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_sb_list_lock);
-__cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_wb_list_lock);
 
 /*
  * iprune_sem provides exclusion between the icache shrinking and the
diff --git a/fs/internal.h b/fs/internal.h
index b29c46e4e32..c905f59dbbe 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -97,6 +97,7 @@ extern struct file *get_empty_filp(void);
  * super.c
  */
 extern int do_remount_sb(struct super_block *, int, void *, int);
+extern bool grab_super_passive(struct super_block *sb);
 extern void __put_super(struct super_block *sb);
 extern void put_super(struct super_block *sb);
 extern struct dentry *mount_fs(struct file_system_type *,
@@ -135,3 +136,5 @@ extern void inode_wb_list_del(struct inode *inode);
 extern int get_nr_dirty_inodes(void);
 extern void evict_inodes(struct super_block *);
 extern int invalidate_inodes(struct super_block *, bool);
+
+extern struct dentry *__d_alloc(struct super_block *, const struct qstr *);
diff --git a/fs/ioprio.c b/fs/ioprio.c
index 7da2a06508e..95a6c2b04e0 100644
--- a/fs/ioprio.c
+++ b/fs/ioprio.c
@@ -30,7 +30,7 @@
 
 int set_task_ioprio(struct task_struct *task, int ioprio)
 {
-        int err;
+        int err, i;
         struct io_context *ioc;
         const struct cred *cred = current_cred(), *tcred;
 
@@ -60,12 +60,17 @@ int set_task_ioprio(struct task_struct *task, int ioprio)
                         err = -ENOMEM;
                         break;
                 }
+                /* let other ioc users see the new values */
+                smp_wmb();
                 task->io_context = ioc;
         } while (1);
 
         if (!err) {
                 ioc->ioprio = ioprio;
-                ioc->ioprio_changed = 1;
+                /* make sure schedulers see the new ioprio value */
+                wmb();
+                for (i = 0; i < IOC_IOPRIO_CHANGED_BITS; i++)
+                        set_bit(i, ioc->ioprio_changed);
         }
 
         task_unlock(task);
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 58bb9994b94..d5ef7e933b7 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1571,8 +1571,7 @@ int nfs_write_inode(struct inode *inode, struct writeback_control *wbc)
                 int status;
                 bool sync = true;
 
-                if (wbc->sync_mode == WB_SYNC_NONE || wbc->nonblocking ||
-                    wbc->for_background)
+                if (wbc->sync_mode == WB_SYNC_NONE || wbc->for_background)
                         sync = false;
 
                 status = pnfs_layoutcommit_inode(inode, sync);
diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index 96d13c81eae..811960a5ef6 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -366,10 +366,21 @@ static void part_release(struct device *dev)
         kfree(p);
 }
 
+static int part_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+        struct hd_struct *part = dev_to_part(dev);
+
+        add_uevent_var(env, "PARTN=%u", part->partno);
+        if (part->info && part->info->volname[0])
+                add_uevent_var(env, "PARTNAME=%s", part->info->volname);
+        return 0;
+}
+
 struct device_type part_type = {
         .name           = "partition",
         .groups         = part_attr_groups,
         .release        = part_release,
+        .uevent         = part_uevent,
 };
 
 static void delete_partition_rcu_cb(struct rcu_head *head)
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 22794e8ab99..600faf5ba2f 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -133,6 +133,12 @@ struct pid_entry {
                 NULL, &proc_single_file_operations,     \
                 { .proc_show = show } )
 
+/* ANDROID is for special files in /proc. */
+#define ANDROID(NAME, MODE, OTYPE)                      \
+        NOD(NAME, (S_IFREG|(MODE)),                     \
+                &proc_##OTYPE##_inode_operations,       \
+                &proc_##OTYPE##_operations, {})
+
 /*
  * Count the number of hardlinks for the pid_entry table, excluding the .
  * and .. links.
@@ -205,7 +211,8 @@ static struct mm_struct *mm_access(struct task_struct *task, unsigned int mode)
 
         mm = get_task_mm(task);
         if (mm && mm != current->mm &&
-                        !ptrace_may_access(task, mode)) {
+                        !ptrace_may_access(task, PTRACE_MODE_READ) &&
+                        !capable(CAP_SYS_RESOURCE)) {
                 mmput(mm);
                 mm = ERR_PTR(-EACCES);
         }
@@ -789,13 +796,13 @@ static int mem_open(struct inode* inode, struct file* file)
         return 0;
 }
 
-static ssize_t mem_rw(struct file *file, char __user *buf,
-                        size_t count, loff_t *ppos, int write)
+static ssize_t mem_read(struct file * file, char __user * buf,
+                        size_t count, loff_t *ppos)
 {
-        struct mm_struct *mm = file->private_data;
-        unsigned long addr = *ppos;
-        ssize_t copied;
+        int ret;
         char *page;
+        unsigned long src = *ppos;
+        struct mm_struct *mm = file->private_data;
 
         if (!mm)
                 return 0;
@@ -804,54 +811,80 @@ static ssize_t mem_rw(struct file *file, char __user *buf,
         if (!page)
                 return -ENOMEM;
 
-        copied = 0;
-        if (!atomic_inc_not_zero(&mm->mm_users))
-                goto free;
-
+        ret = 0;
+ 
         while (count > 0) {
-                int this_len = min_t(int, count, PAGE_SIZE);
-
-                if (write && copy_from_user(page, buf, this_len)) {
-                        copied = -EFAULT;
-                        break;
-                }
+                int this_len, retval;
 
-                this_len = access_remote_vm(mm, addr, page, this_len, write);
-                if (!this_len) {
-                        if (!copied)
-                                copied = -EIO;
+                this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
+                retval = access_remote_vm(mm, src, page, this_len, 0);
+                if (!retval) {
+                        if (!ret)
+                                ret = -EIO;
                         break;
                 }
 
-                if (!write && copy_to_user(buf, page, this_len)) {
-                        copied = -EFAULT;
+                if (copy_to_user(buf, page, retval)) {
+                        ret = -EFAULT;
                         break;
                 }
-
-                buf += this_len;
-                addr += this_len;
-                copied += this_len;
-                count -= this_len;
+ 
+                ret += retval;
+                src += retval;
+                buf += retval;
+                count -= retval;
         }
-        *ppos = addr;
+        *ppos = src;
 
-        mmput(mm);
-free:
         free_page((unsigned long) page);
-        return copied;
+        return ret;
 }
 
-static ssize_t mem_read(struct file *file, char __user *buf,
-                        size_t count, loff_t *ppos)
-{
-        return mem_rw(file, buf, count, ppos, 0);
-}
+#define mem_write NULL
 
-static ssize_t mem_write(struct file *file, const char __user *buf,
+#ifndef mem_write
+/* This is a security hazard */
+static ssize_t mem_write(struct file * file, const char __user *buf,
                          size_t count, loff_t *ppos)
 {
-        return mem_rw(file, (char __user*)buf, count, ppos, 1);
+        int copied;
+        char *page;
+        unsigned long dst = *ppos;
+        struct mm_struct *mm = file->private_data;
+
+        if (!mm)
+                return 0;
+
+        page = (char *)__get_free_page(GFP_TEMPORARY);
+        if (!page)
+                return -ENOMEM;
+
+        copied = 0;
+        while (count > 0) {
+                int this_len, retval;
+
+                this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
+                if (copy_from_user(page, buf, this_len)) {
+                        copied = -EFAULT;
+                        break;
+                }
+                retval = access_remote_vm(mm, dst, page, this_len, 1);
+                if (!retval) {
+                        if (!copied)
+                                copied = -EIO;
+                        break;
+                }
+                copied += retval;
+                buf += retval;
+                dst += retval;
+                count -= retval;                        
+        }
+        *ppos = dst;
+
+        free_page((unsigned long) page);
+        return copied;
 }
+#endif
 
 loff_t mem_lseek(struct file *file, loff_t offset, int orig)
 {
@@ -1060,6 +1093,39 @@ out:
         return err < 0 ? err : count;
 }
 
+static int oom_adjust_permission(struct inode *inode, int mask,
+                                 unsigned int flags)
+{
+        uid_t uid;
+        struct task_struct *p;
+
+        if (flags & IPERM_FLAG_RCU)
+                return -ECHILD;
+
+        p = get_proc_task(inode);
+        if(p) {
+                uid = task_uid(p);
+                put_task_struct(p);
+        }
+
+        /*
+         * System Server (uid == 1000) is granted access to oom_adj of all 
+         * android applications (uid > 10000) as and services (uid >= 1000)
+         */
+        if (p && (current_fsuid() == 1000) && (uid >= 1000)) {
+                if (inode->i_mode >> 6 & mask) {
+                        return 0;
+                }
+        }
+
+        /* Fall back to default. */
+        return generic_permission(inode, mask, flags, NULL);
+}
+
+static const struct inode_operations proc_oom_adjust_inode_operations = {
+        .permission     = oom_adjust_permission,
+};
+
 static const struct file_operations proc_oom_adjust_operations = {
         .read           = oom_adjust_read,
         .write          = oom_adjust_write,
@@ -2766,7 +2832,7 @@ static const struct pid_entry tgid_base_stuff[] = {
         REG("cgroup",  S_IRUGO, proc_cgroup_operations),
 #endif
         INF("oom_score",  S_IRUGO, proc_oom_score),
-        REG("oom_adj",    S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
+        ANDROID("oom_adj",S_IRUGO|S_IWUSR, oom_adjust),
         REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
 #ifdef CONFIG_AUDITSYSCALL
         REG("loginuid",   S_IWUSR|S_IRUGO, proc_loginuid_operations),
diff --git a/fs/quota/quota.c b/fs/quota/quota.c
index 10b6be3ca28..4bae57fc603 100644
--- a/fs/quota/quota.c
+++ b/fs/quota/quota.c
@@ -286,7 +286,7 @@ static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
                 /* caller already holds s_umount */
                 if (sb->s_flags & MS_RDONLY)
                         return -EROFS;
-                writeback_inodes_sb(sb);
+                writeback_inodes_sb(sb, WB_REASON_SYNC);
                 return 0;
         default:
                 return -EINVAL;
diff --git a/fs/splice.c b/fs/splice.c
index 9d890085f9b..6d0dfb89c75 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -133,7 +133,7 @@ error:
         return err;
 }
 
-static const struct pipe_buf_operations page_cache_pipe_buf_ops = {
+const struct pipe_buf_operations page_cache_pipe_buf_ops = {
         .can_merge = 0,
         .map = generic_pipe_buf_map,
         .unmap = generic_pipe_buf_unmap,
@@ -265,7 +265,7 @@ ssize_t splice_to_pipe(struct pipe_inode_info *pipe,
         return ret;
 }
 
-static void spd_release_page(struct splice_pipe_desc *spd, unsigned int i)
+void spd_release_page(struct splice_pipe_desc *spd, unsigned int i)
 {
         page_cache_release(spd->pages[i]);
 }
diff --git a/fs/super.c b/fs/super.c
index caf4dfa28ee..e2cf58cad6a 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -241,17 +241,48 @@ static int grab_super(struct super_block *s) __releases(sb_lock)
 }
 
 /*
+ *      grab_super_passive - acquire a passive reference
+ *      @s: reference we are trying to grab
+ *
+ *      Tries to acquire a passive reference. This is used in places where we
+ *      cannot take an active reference but we need to ensure that the
+ *      superblock does not go away while we are working on it. It returns
+ *      false if a reference was not gained, and returns true with the s_umount
+ *      lock held in read mode if a reference is gained. On successful return,
+ *      the caller must drop the s_umount lock and the passive reference when
+ *      done.
+ */
+bool grab_super_passive(struct super_block *sb)
+{
+        spin_lock(&sb_lock);
+        if (list_empty(&sb->s_instances)) {
+                spin_unlock(&sb_lock);
+                return false;
+        }
+
+        sb->s_count++;
+        spin_unlock(&sb_lock);
+
+        if (down_read_trylock(&sb->s_umount)) {
+                if (sb->s_root)
+                        return true;
+                up_read(&sb->s_umount);
+        }
+
+        put_super(sb);
+        return false;
+}
+
+/*
  * Superblock locking.  We really ought to get rid of these two.
  */
 void lock_super(struct super_block * sb)
 {
-        get_fs_excl();
         mutex_lock(&sb->s_lock);
 }
 
 void unlock_super(struct super_block * sb)
 {
-        put_fs_excl();
         mutex_unlock(&sb->s_lock);
 }
 
@@ -822,7 +853,7 @@ struct dentry *mount_bdev(struct file_system_type *fs_type,
         } else {
                 char b[BDEVNAME_SIZE];
 
-                s->s_flags = flags | MS_NOSEC;
+                s->s_flags = flags;
                 s->s_mode = mode;
                 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
                 sb_set_blocksize(s, block_size(bdev));
diff --git a/fs/sync.c b/fs/sync.c
index c38ec163da6..2385e128a35 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -18,6 +18,9 @@
 #include <linux/backing-dev.h>
 #include "internal.h"
 
+bool fsync_enabled = true;
+module_param(fsync_enabled, bool, 0755);
+
 #define VALID_FLAGS (SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE| \
                         SYNC_FILE_RANGE_WAIT_AFTER)
 
@@ -43,7 +46,7 @@ static int __sync_filesystem(struct super_block *sb, int wait)
         if (wait)
                 sync_inodes_sb(sb);
         else
-                writeback_inodes_sb(sb);
+                writeback_inodes_sb(sb, WB_REASON_SYNC);
 
         if (sb->s_op->sync_fs)
                 sb->s_op->sync_fs(sb, wait);
@@ -98,7 +101,7 @@ static void sync_filesystems(int wait)
  */
 SYSCALL_DEFINE0(sync)
 {
-        wakeup_flusher_threads(0);
+        wakeup_flusher_threads(0, WB_REASON_SYNC);
         sync_filesystems(0);
         sync_filesystems(1);
         if (unlikely(laptop_mode))
@@ -139,6 +142,9 @@ SYSCALL_DEFINE1(syncfs, int, fd)
         int ret;
         int fput_needed;
 
+        if (!fsync_enabled)
+                return 0;
+
         file = fget_light(fd, &fput_needed);
         if (!file)
                 return -EBADF;
@@ -168,6 +174,9 @@ int vfs_fsync_range(struct file *file, loff_t start, loff_t end, int datasync)
         struct address_space *mapping = file->f_mapping;
         int err, ret;
 
+        if (!fsync_enabled)
+                return 0;
+
         if (!file->f_op || !file->f_op->fsync) {
                 ret = -EINVAL;
                 goto out;
@@ -200,6 +209,9 @@ EXPORT_SYMBOL(vfs_fsync_range);
  */
 int vfs_fsync(struct file *file, int datasync)
 {
+        if (!fsync_enabled)
+                return 0;
+                
         return vfs_fsync_range(file, 0, LLONG_MAX, datasync);
 }
 EXPORT_SYMBOL(vfs_fsync);
@@ -209,6 +221,9 @@ static int do_fsync(unsigned int fd, int datasync)
         struct file *file;
         int ret = -EBADF;
 
+        if (!fsync_enabled)
+                return 0;
+
         file = fget(fd);
         if (file) {
                 ret = vfs_fsync(file, datasync);
@@ -219,11 +234,17 @@ static int do_fsync(unsigned int fd, int datasync)
 
 SYSCALL_DEFINE1(fsync, unsigned int, fd)
 {
+        if (!fsync_enabled)
+                return 0;
+                
         return do_fsync(fd, 0);
 }
 
 SYSCALL_DEFINE1(fdatasync, unsigned int, fd)
 {
+        if (!fsync_enabled)
+                return 0;
+                
         return do_fsync(fd, 1);
 }
 
@@ -237,6 +258,9 @@ SYSCALL_DEFINE1(fdatasync, unsigned int, fd)
  */
 int generic_write_sync(struct file *file, loff_t pos, loff_t count)
 {
+        if (!fsync_enabled)
+                return 0;
+                
         if (!(file->f_flags & O_DSYNC) && !IS_SYNC(file->f_mapping->host))
                 return 0;
         return vfs_fsync_range(file, pos, pos + count - 1,
@@ -301,6 +325,9 @@ SYSCALL_DEFINE(sync_file_range)(int fd, loff_t offset, loff_t nbytes,
         int fput_needed;
         umode_t i_mode;
 
+        if (!fsync_enabled)
+                return 0;
+
         ret = -EINVAL;
         if (flags & ~VALID_FLAGS)
                 goto out;
diff --git a/fs/ubifs/budget.c b/fs/ubifs/budget.c
index 315de66e52b..bc4f94b2870 100644
--- a/fs/ubifs/budget.c
+++ b/fs/ubifs/budget.c
@@ -63,7 +63,7 @@
 static void shrink_liability(struct ubifs_info *c, int nr_to_write)
 {
         down_read(&c->vfs_sb->s_umount);
-        writeback_inodes_sb(c->vfs_sb);
+        writeback_inodes_sb(c->vfs_sb, WB_REASON_FS_FREE_SPACE);
         up_read(&c->vfs_sb->s_umount);
 }
 
diff --git a/fs/yaffs2/Kconfig b/fs/yaffs2/Kconfig
new file mode 100644
index 00000000000..63541405999
--- /dev/null
+++ b/fs/yaffs2/Kconfig
@@ -0,0 +1,161 @@
+#
+# YAFFS file system configurations
+#
+
+config YAFFS_FS
+        tristate "YAFFS2 file system support"
+        default n
+        depends on MTD_BLOCK
+        select YAFFS_YAFFS1
+        select YAFFS_YAFFS2
+        help
+          YAFFS2, or Yet Another Flash Filing System, is a filing system
+          optimised for NAND Flash chips.
+
+          To compile the YAFFS2 file system support as a module, choose M
+          here: the module will be called yaffs2.
+
+          If unsure, say N.
+
+          Further information on YAFFS2 is available at
+          <http://www.aleph1.co.uk/yaffs/>.
+
+config YAFFS_YAFFS1
+        bool "512 byte / page devices"
+        depends on YAFFS_FS
+        default y
+        help
+          Enable YAFFS1 support -- yaffs for 512 byte / page devices
+
+          Not needed for 2K-page devices.
+
+          If unsure, say Y.
+
+config YAFFS_9BYTE_TAGS
+        bool "Use older-style on-NAND data format with pageStatus byte"
+        depends on YAFFS_YAFFS1
+        default n
+        help
+
+          Older-style on-NAND data format has a "pageStatus" byte to record
+          chunk/page state.  This byte is zero when the page is discarded.
+          Choose this option if you have existing on-NAND data using this
+          format that you need to continue to support.  New data written
+          also uses the older-style format.  Note: Use of this option
+          generally requires that MTD's oob layout be adjusted to use the
+          older-style format.  See notes on tags formats and MTD versions
+          in yaffs_mtdif1.c.
+
+          If unsure, say N.
+
+config YAFFS_DOES_ECC
+        bool "Lets Yaffs do its own ECC"
+        depends on YAFFS_FS && YAFFS_YAFFS1 && !YAFFS_9BYTE_TAGS
+        default n
+        help
+          This enables Yaffs to use its own ECC functions instead of using
+          the ones from the generic MTD-NAND driver.
+
+          If unsure, say N.
+
+config YAFFS_ECC_WRONG_ORDER
+        bool "Use the same ecc byte order as Steven Hill's nand_ecc.c"
+        depends on YAFFS_FS && YAFFS_DOES_ECC && !YAFFS_9BYTE_TAGS
+        default n
+        help
+          This makes yaffs_ecc.c use the same ecc byte order as Steven
+          Hill's nand_ecc.c. If not set, then you get the same ecc byte
+          order as SmartMedia.
+
+          If unsure, say N.
+
+config YAFFS_YAFFS2
+        bool "2048 byte (or larger) / page devices"
+        depends on YAFFS_FS
+        default y
+        help
+          Enable YAFFS2 support -- yaffs for >= 2K bytes per page devices
+
+          If unsure, say Y.
+
+config YAFFS_AUTO_YAFFS2
+        bool "Autoselect yaffs2 format"
+        depends on YAFFS_YAFFS2
+        default y
+        help
+          Without this, you need to explicitely use yaffs2 as the file
+          system type. With this, you can say "yaffs" and yaffs or yaffs2
+          will be used depending on the device page size (yaffs on
+          512-byte page devices, yaffs2 on 2K page devices).
+
+          If unsure, say Y.
+
+config YAFFS_DISABLE_TAGS_ECC
+        bool "Disable YAFFS from doing ECC on tags by default"
+        depends on YAFFS_FS && YAFFS_YAFFS2
+        default n
+        help
+          This defaults Yaffs to using its own ECC calculations on tags instead of
+          just relying on the MTD.
+          This behavior can also be overridden with tags_ecc_on and
+          tags_ecc_off mount options.
+
+          If unsure, say N.
+
+config YAFFS_ALWAYS_CHECK_CHUNK_ERASED
+        bool "Force chunk erase check"
+        depends on YAFFS_FS
+        default n
+        help
+          Normally YAFFS only checks chunks before writing until an erased
+          chunk is found. This helps to detect any partially written
+          chunks that might have happened due to power loss.
+
+          Enabling this forces on the test that chunks are erased in flash
+          before writing to them. This takes more time but is potentially
+          a bit more secure.
+
+          Suggest setting Y during development and ironing out driver
+          issues etc. Suggest setting to N if you want faster writing.
+
+          If unsure, say Y.
+
+config YAFFS_EMPTY_LOST_AND_FOUND
+        bool "Empty lost and found on boot"
+        depends on YAFFS_FS
+        default n
+        help
+          If this is enabled then the contents of lost and found is
+          automatically dumped at mount.
+
+          If unsure, say N.
+
+config YAFFS_DISABLE_BLOCK_REFRESHING
+        bool "Disable yaffs2 block refreshing"
+        depends on YAFFS_FS
+        default n
+        help
+         If this is set, then block refreshing is disabled.
+         Block refreshing infrequently refreshes the oldest block in
+         a yaffs2 file system. This mechanism helps to refresh flash to
+         mitigate against data loss. This is particularly useful for MLC.
+
+          If unsure, say N.
+
+config YAFFS_DISABLE_BACKGROUND
+        bool "Disable yaffs2 background processing"
+        depends on YAFFS_FS
+        default n
+        help
+         If this is set, then background processing is disabled.
+         Background processing makes many foreground activities faster.
+
+         If unsure, say N.
+
+config YAFFS_XATTR
+        bool "Enable yaffs2 xattr support"
+        depends on YAFFS_FS
+        default y
+        help
+         If this is set then yaffs2 will provide xattr support.
+         If unsure, say Y.
diff --git a/fs/yaffs2/Makefile b/fs/yaffs2/Makefile
new file mode 100644
index 00000000000..e63a28aa3ed
--- /dev/null
+++ b/fs/yaffs2/Makefile
@@ -0,0 +1,17 @@
+#
+# Makefile for the linux YAFFS filesystem routines.
+#
+
+obj-$(CONFIG_YAFFS_FS) += yaffs.o
+
+yaffs-y := yaffs_ecc.o yaffs_vfs.o yaffs_guts.o yaffs_checkptrw.o
+yaffs-y += yaffs_packedtags1.o yaffs_packedtags2.o yaffs_nand.o
+yaffs-y += yaffs_tagscompat.o yaffs_tagsvalidity.o
+yaffs-y += yaffs_mtdif.o yaffs_mtdif1.o yaffs_mtdif2.o
+yaffs-y += yaffs_nameval.o yaffs_attribs.o
+yaffs-y += yaffs_allocator.o
+yaffs-y += yaffs_yaffs1.o
+yaffs-y += yaffs_yaffs2.o
+yaffs-y += yaffs_bitmap.o
+yaffs-y += yaffs_verify.o
+
diff --git a/fs/yaffs2/yaffs_allocator.c b/fs/yaffs2/yaffs_allocator.c
new file mode 100644
index 00000000000..f9cd5becd8f
--- /dev/null
+++ b/fs/yaffs2/yaffs_allocator.c
@@ -0,0 +1,396 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_allocator.h"
+#include "yaffs_guts.h"
+#include "yaffs_trace.h"
+#include "yportenv.h"
+
+#ifdef CONFIG_YAFFS_KMALLOC_ALLOCATOR
+
+void yaffs_deinit_raw_tnodes_and_objs(struct yaffs_dev *dev)
+{
+        dev = dev;
+}
+
+void yaffs_init_raw_tnodes_and_objs(struct yaffs_dev *dev)
+{
+        dev = dev;
+}
+
+struct yaffs_tnode *yaffs_alloc_raw_tnode(struct yaffs_dev *dev)
+{
+        return (struct yaffs_tnode *)kmalloc(dev->tnode_size, GFP_NOFS);
+}
+
+void yaffs_free_raw_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
+{
+        dev = dev;
+        kfree(tn);
+}
+
+void yaffs_init_raw_objs(struct yaffs_dev *dev)
+{
+        dev = dev;
+}
+
+void yaffs_deinit_raw_objs(struct yaffs_dev *dev)
+{
+        dev = dev;
+}
+
+struct yaffs_obj *yaffs_alloc_raw_obj(struct yaffs_dev *dev)
+{
+        dev = dev;
+        return (struct yaffs_obj *)kmalloc(sizeof(struct yaffs_obj));
+}
+
+void yaffs_free_raw_obj(struct yaffs_dev *dev, struct yaffs_obj *obj)
+{
+
+        dev = dev;
+        kfree(obj);
+}
+
+#else
+
+struct yaffs_tnode_list {
+        struct yaffs_tnode_list *next;
+        struct yaffs_tnode *tnodes;
+};
+
+struct yaffs_obj_list {
+        struct yaffs_obj_list *next;
+        struct yaffs_obj *objects;
+};
+
+struct yaffs_allocator {
+        int n_tnodes_created;
+        struct yaffs_tnode *free_tnodes;
+        int n_free_tnodes;
+        struct yaffs_tnode_list *alloc_tnode_list;
+
+        int n_obj_created;
+        struct yaffs_obj *free_objs;
+        int n_free_objects;
+
+        struct yaffs_obj_list *allocated_obj_list;
+};
+
+static void yaffs_deinit_raw_tnodes(struct yaffs_dev *dev)
+{
+
+        struct yaffs_allocator *allocator =
+            (struct yaffs_allocator *)dev->allocator;
+
+        struct yaffs_tnode_list *tmp;
+
+        if (!allocator) {
+                YBUG();
+                return;
+        }
+
+        while (allocator->alloc_tnode_list) {
+                tmp = allocator->alloc_tnode_list->next;
+
+                kfree(allocator->alloc_tnode_list->tnodes);
+                kfree(allocator->alloc_tnode_list);
+                allocator->alloc_tnode_list = tmp;
+
+        }
+
+        allocator->free_tnodes = NULL;
+        allocator->n_free_tnodes = 0;
+        allocator->n_tnodes_created = 0;
+}
+
+static void yaffs_init_raw_tnodes(struct yaffs_dev *dev)
+{
+        struct yaffs_allocator *allocator = dev->allocator;
+
+        if (allocator) {
+                allocator->alloc_tnode_list = NULL;
+                allocator->free_tnodes = NULL;
+                allocator->n_free_tnodes = 0;
+                allocator->n_tnodes_created = 0;
+        } else {
+                YBUG();
+        }
+}
+
+static int yaffs_create_tnodes(struct yaffs_dev *dev, int n_tnodes)
+{
+        struct yaffs_allocator *allocator =
+            (struct yaffs_allocator *)dev->allocator;
+        int i;
+        struct yaffs_tnode *new_tnodes;
+        u8 *mem;
+        struct yaffs_tnode *curr;
+        struct yaffs_tnode *next;
+        struct yaffs_tnode_list *tnl;
+
+        if (!allocator) {
+                YBUG();
+                return YAFFS_FAIL;
+        }
+
+        if (n_tnodes < 1)
+                return YAFFS_OK;
+
+        /* make these things */
+
+        new_tnodes = kmalloc(n_tnodes * dev->tnode_size, GFP_NOFS);
+        mem = (u8 *) new_tnodes;
+
+        if (!new_tnodes) {
+                yaffs_trace(YAFFS_TRACE_ERROR,
+                        "yaffs: Could not allocate Tnodes");
+                return YAFFS_FAIL;
+        }
+
+        /* New hookup for wide tnodes */
+        for (i = 0; i < n_tnodes - 1; i++) {
+                curr = (struct yaffs_tnode *)&mem[i * dev->tnode_size];
+                next = (struct yaffs_tnode *)&mem[(i + 1) * dev->tnode_size];
+                curr->internal[0] = next;
+        }
+
+        curr = (struct yaffs_tnode *)&mem[(n_tnodes - 1) * dev->tnode_size];
+        curr->internal[0] = allocator->free_tnodes;
+        allocator->free_tnodes = (struct yaffs_tnode *)mem;
+
+        allocator->n_free_tnodes += n_tnodes;
+        allocator->n_tnodes_created += n_tnodes;
+
+        /* Now add this bunch of tnodes to a list for freeing up.
+         * NB If we can't add this to the management list it isn't fatal
+         * but it just means we can't free this bunch of tnodes later.
+         */
+
+        tnl = kmalloc(sizeof(struct yaffs_tnode_list), GFP_NOFS);
+        if (!tnl) {
+                yaffs_trace(YAFFS_TRACE_ERROR,
+                        "Could not add tnodes to management list");
+                return YAFFS_FAIL;
+        } else {
+                tnl->tnodes = new_tnodes;
+                tnl->next = allocator->alloc_tnode_list;
+                allocator->alloc_tnode_list = tnl;
+        }
+
+        yaffs_trace(YAFFS_TRACE_ALLOCATE,"Tnodes added");
+
+        return YAFFS_OK;
+}
+
+struct yaffs_tnode *yaffs_alloc_raw_tnode(struct yaffs_dev *dev)
+{
+        struct yaffs_allocator *allocator =
+            (struct yaffs_allocator *)dev->allocator;
+        struct yaffs_tnode *tn = NULL;
+
+        if (!allocator) {
+                YBUG();
+                return NULL;
+        }
+
+        /* If there are none left make more */
+        if (!allocator->free_tnodes)
+                yaffs_create_tnodes(dev, YAFFS_ALLOCATION_NTNODES);
+
+        if (allocator->free_tnodes) {
+                tn = allocator->free_tnodes;
+                allocator->free_tnodes = allocator->free_tnodes->internal[0];
+                allocator->n_free_tnodes--;
+        }
+
+        return tn;
+}
+
+/* FreeTnode frees up a tnode and puts it back on the free list */
+void yaffs_free_raw_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
+{
+        struct yaffs_allocator *allocator = dev->allocator;
+
+        if (!allocator) {
+                YBUG();
+                return;
+        }
+
+        if (tn) {
+                tn->internal[0] = allocator->free_tnodes;
+                allocator->free_tnodes = tn;
+                allocator->n_free_tnodes++;
+        }
+        dev->checkpoint_blocks_required = 0;    /* force recalculation */
+}
+
+static void yaffs_init_raw_objs(struct yaffs_dev *dev)
+{
+        struct yaffs_allocator *allocator = dev->allocator;
+
+        if (allocator) {
+                allocator->allocated_obj_list = NULL;
+                allocator->free_objs = NULL;
+                allocator->n_free_objects = 0;
+        } else {
+                YBUG();
+        }
+}
+
+static void yaffs_deinit_raw_objs(struct yaffs_dev *dev)
+{
+        struct yaffs_allocator *allocator = dev->allocator;
+        struct yaffs_obj_list *tmp;
+
+        if (!allocator) {
+                YBUG();
+                return;
+        }
+
+        while (allocator->allocated_obj_list) {
+                tmp = allocator->allocated_obj_list->next;
+                kfree(allocator->allocated_obj_list->objects);
+                kfree(allocator->allocated_obj_list);
+
+                allocator->allocated_obj_list = tmp;
+        }
+
+        allocator->free_objs = NULL;
+        allocator->n_free_objects = 0;
+        allocator->n_obj_created = 0;
+}
+
+static int yaffs_create_free_objs(struct yaffs_dev *dev, int n_obj)
+{
+        struct yaffs_allocator *allocator = dev->allocator;
+
+        int i;
+        struct yaffs_obj *new_objs;
+        struct yaffs_obj_list *list;
+
+        if (!allocator) {
+                YBUG();
+                return YAFFS_FAIL;
+        }
+
+        if (n_obj < 1)
+                return YAFFS_OK;
+
+        /* make these things */
+        new_objs = kmalloc(n_obj * sizeof(struct yaffs_obj), GFP_NOFS);
+        list = kmalloc(sizeof(struct yaffs_obj_list), GFP_NOFS);
+
+        if (!new_objs || !list) {
+                if (new_objs) {
+                        kfree(new_objs);
+                        new_objs = NULL;
+                }
+                if (list) {
+                        kfree(list);
+                        list = NULL;
+                }
+                yaffs_trace(YAFFS_TRACE_ALLOCATE,
+                        "Could not allocate more objects");
+                return YAFFS_FAIL;
+        }
+
+        /* Hook them into the free list */
+        for (i = 0; i < n_obj - 1; i++) {
+                new_objs[i].siblings.next =
+                    (struct list_head *)(&new_objs[i + 1]);
+        }
+
+        new_objs[n_obj - 1].siblings.next = (void *)allocator->free_objs;
+        allocator->free_objs = new_objs;
+        allocator->n_free_objects += n_obj;
+        allocator->n_obj_created += n_obj;
+
+        /* Now add this bunch of Objects to a list for freeing up. */
+
+        list->objects = new_objs;
+        list->next = allocator->allocated_obj_list;
+        allocator->allocated_obj_list = list;
+
+        return YAFFS_OK;
+}
+
+struct yaffs_obj *yaffs_alloc_raw_obj(struct yaffs_dev *dev)
+{
+        struct yaffs_obj *obj = NULL;
+        struct yaffs_allocator *allocator = dev->allocator;
+
+        if (!allocator) {
+                YBUG();
+                return obj;
+        }
+
+        /* If there are none left make more */
+        if (!allocator->free_objs)
+                yaffs_create_free_objs(dev, YAFFS_ALLOCATION_NOBJECTS);
+
+        if (allocator->free_objs) {
+                obj = allocator->free_objs;
+                allocator->free_objs =
+                    (struct yaffs_obj *)(allocator->free_objs->siblings.next);
+                allocator->n_free_objects--;
+        }
+
+        return obj;
+}
+
+void yaffs_free_raw_obj(struct yaffs_dev *dev, struct yaffs_obj *obj)
+{
+
+        struct yaffs_allocator *allocator = dev->allocator;
+
+        if (!allocator)
+                YBUG();
+        else {
+                /* Link into the free list. */
+                obj->siblings.next = (struct list_head *)(allocator->free_objs);
+                allocator->free_objs = obj;
+                allocator->n_free_objects++;
+        }
+}
+
+void yaffs_deinit_raw_tnodes_and_objs(struct yaffs_dev *dev)
+{
+        if (dev->allocator) {
+                yaffs_deinit_raw_tnodes(dev);
+                yaffs_deinit_raw_objs(dev);
+
+                kfree(dev->allocator);
+                dev->allocator = NULL;
+        } else {
+                YBUG();
+        }
+}
+
+void yaffs_init_raw_tnodes_and_objs(struct yaffs_dev *dev)
+{
+        struct yaffs_allocator *allocator;
+
+        if (!dev->allocator) {
+                allocator = kmalloc(sizeof(struct yaffs_allocator), GFP_NOFS);
+                if (allocator) {
+                        dev->allocator = allocator;
+                        yaffs_init_raw_tnodes(dev);
+                        yaffs_init_raw_objs(dev);
+                }
+        } else {
+                YBUG();
+        }
+}
+
+#endif
diff --git a/fs/yaffs2/yaffs_allocator.h b/fs/yaffs2/yaffs_allocator.h
new file mode 100644
index 00000000000..4d5f2aec89f
--- /dev/null
+++ b/fs/yaffs2/yaffs_allocator.h
@@ -0,0 +1,30 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_ALLOCATOR_H__
+#define __YAFFS_ALLOCATOR_H__
+
+#include "yaffs_guts.h"
+
+void yaffs_init_raw_tnodes_and_objs(struct yaffs_dev *dev);
+void yaffs_deinit_raw_tnodes_and_objs(struct yaffs_dev *dev);
+
+struct yaffs_tnode *yaffs_alloc_raw_tnode(struct yaffs_dev *dev);
+void yaffs_free_raw_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn);
+
+struct yaffs_obj *yaffs_alloc_raw_obj(struct yaffs_dev *dev);
+void yaffs_free_raw_obj(struct yaffs_dev *dev, struct yaffs_obj *obj);
+
+#endif
diff --git a/fs/yaffs2/yaffs_attribs.c b/fs/yaffs2/yaffs_attribs.c
new file mode 100644
index 00000000000..9b47d376310
--- /dev/null
+++ b/fs/yaffs2/yaffs_attribs.c
@@ -0,0 +1,124 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_guts.h"
+#include "yaffs_attribs.h"
+
+void yaffs_load_attribs(struct yaffs_obj *obj, struct yaffs_obj_hdr *oh)
+{
+        obj->yst_uid = oh->yst_uid;
+        obj->yst_gid = oh->yst_gid;
+        obj->yst_atime = oh->yst_atime;
+        obj->yst_mtime = oh->yst_mtime;
+        obj->yst_ctime = oh->yst_ctime;
+        obj->yst_rdev = oh->yst_rdev;
+}
+
+void yaffs_load_attribs_oh(struct yaffs_obj_hdr *oh, struct yaffs_obj *obj)
+{
+        oh->yst_uid = obj->yst_uid;
+        oh->yst_gid = obj->yst_gid;
+        oh->yst_atime = obj->yst_atime;
+        oh->yst_mtime = obj->yst_mtime;
+        oh->yst_ctime = obj->yst_ctime;
+        oh->yst_rdev = obj->yst_rdev;
+
+}
+
+void yaffs_load_current_time(struct yaffs_obj *obj, int do_a, int do_c)
+{
+        obj->yst_mtime = Y_CURRENT_TIME;
+        if (do_a)
+                obj->yst_atime = obj->yst_mtime;
+        if (do_c)
+                obj->yst_ctime = obj->yst_mtime;
+}
+
+void yaffs_attribs_init(struct yaffs_obj *obj, u32 gid, u32 uid, u32 rdev)
+{
+        yaffs_load_current_time(obj, 1, 1);
+        obj->yst_rdev = rdev;
+        obj->yst_uid = uid;
+        obj->yst_gid = gid;
+}
+
+loff_t yaffs_get_file_size(struct yaffs_obj *obj)
+{
+        YCHAR *alias = NULL;
+        obj = yaffs_get_equivalent_obj(obj);
+
+        switch (obj->variant_type) {
+        case YAFFS_OBJECT_TYPE_FILE:
+                return obj->variant.file_variant.file_size;
+        case YAFFS_OBJECT_TYPE_SYMLINK:
+                alias = obj->variant.symlink_variant.alias;
+                if (!alias)
+                        return 0;
+                return strnlen(alias, YAFFS_MAX_ALIAS_LENGTH);
+        default:
+                return 0;
+        }
+}
+
+int yaffs_set_attribs(struct yaffs_obj *obj, struct iattr *attr)
+{
+        unsigned int valid = attr->ia_valid;
+
+        if (valid & ATTR_MODE)
+                obj->yst_mode = attr->ia_mode;
+        if (valid & ATTR_UID)
+                obj->yst_uid = attr->ia_uid;
+        if (valid & ATTR_GID)
+                obj->yst_gid = attr->ia_gid;
+
+        if (valid & ATTR_ATIME)
+                obj->yst_atime = Y_TIME_CONVERT(attr->ia_atime);
+        if (valid & ATTR_CTIME)
+                obj->yst_ctime = Y_TIME_CONVERT(attr->ia_ctime);
+        if (valid & ATTR_MTIME)
+                obj->yst_mtime = Y_TIME_CONVERT(attr->ia_mtime);
+
+        if (valid & ATTR_SIZE)
+                yaffs_resize_file(obj, attr->ia_size);
+
+        yaffs_update_oh(obj, NULL, 1, 0, 0, NULL);
+
+        return YAFFS_OK;
+
+}
+
+int yaffs_get_attribs(struct yaffs_obj *obj, struct iattr *attr)
+{
+        unsigned int valid = 0;
+
+        attr->ia_mode = obj->yst_mode;
+        valid |= ATTR_MODE;
+        attr->ia_uid = obj->yst_uid;
+        valid |= ATTR_UID;
+        attr->ia_gid = obj->yst_gid;
+        valid |= ATTR_GID;
+
+        Y_TIME_CONVERT(attr->ia_atime) = obj->yst_atime;
+        valid |= ATTR_ATIME;
+        Y_TIME_CONVERT(attr->ia_ctime) = obj->yst_ctime;
+        valid |= ATTR_CTIME;
+        Y_TIME_CONVERT(attr->ia_mtime) = obj->yst_mtime;
+        valid |= ATTR_MTIME;
+
+        attr->ia_size = yaffs_get_file_size(obj);
+        valid |= ATTR_SIZE;
+
+        attr->ia_valid = valid;
+
+        return YAFFS_OK;
+}
diff --git a/fs/yaffs2/yaffs_attribs.h b/fs/yaffs2/yaffs_attribs.h
new file mode 100644
index 00000000000..33d541d6944
--- /dev/null
+++ b/fs/yaffs2/yaffs_attribs.h
@@ -0,0 +1,28 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_ATTRIBS_H__
+#define __YAFFS_ATTRIBS_H__
+
+#include "yaffs_guts.h"
+
+void yaffs_load_attribs(struct yaffs_obj *obj, struct yaffs_obj_hdr *oh);
+void yaffs_load_attribs_oh(struct yaffs_obj_hdr *oh, struct yaffs_obj *obj);
+void yaffs_attribs_init(struct yaffs_obj *obj, u32 gid, u32 uid, u32 rdev);
+void yaffs_load_current_time(struct yaffs_obj *obj, int do_a, int do_c);
+int yaffs_set_attribs(struct yaffs_obj *obj, struct iattr *attr);
+int yaffs_get_attribs(struct yaffs_obj *obj, struct iattr *attr);
+
+#endif
diff --git a/fs/yaffs2/yaffs_bitmap.c b/fs/yaffs2/yaffs_bitmap.c
new file mode 100644
index 00000000000..7df42cd0066
--- /dev/null
+++ b/fs/yaffs2/yaffs_bitmap.c
@@ -0,0 +1,98 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_bitmap.h"
+#include "yaffs_trace.h"
+/*
+ * Chunk bitmap manipulations
+ */
+
+static inline u8 *yaffs_block_bits(struct yaffs_dev *dev, int blk)
+{
+        if (blk < dev->internal_start_block || blk > dev->internal_end_block) {
+                yaffs_trace(YAFFS_TRACE_ERROR,
+                        "BlockBits block %d is not valid",
+                        blk);
+                YBUG();
+        }
+        return dev->chunk_bits +
+            (dev->chunk_bit_stride * (blk - dev->internal_start_block));
+}
+
+void yaffs_verify_chunk_bit_id(struct yaffs_dev *dev, int blk, int chunk)
+{
+        if (blk < dev->internal_start_block || blk > dev->internal_end_block ||
+            chunk < 0 || chunk >= dev->param.chunks_per_block) {
+                yaffs_trace(YAFFS_TRACE_ERROR,
+                        "Chunk Id (%d:%d) invalid",
+                        blk, chunk);
+                YBUG();
+        }
+}
+
+void yaffs_clear_chunk_bits(struct yaffs_dev *dev, int blk)
+{
+        u8 *blk_bits = yaffs_block_bits(dev, blk);
+
+        memset(blk_bits, 0, dev->chunk_bit_stride);
+}
+
+void yaffs_clear_chunk_bit(struct yaffs_dev *dev, int blk, int chunk)
+{
+        u8 *blk_bits = yaffs_block_bits(dev, blk);
+
+        yaffs_verify_chunk_bit_id(dev, blk, chunk);
+
+        blk_bits[chunk / 8] &= ~(1 << (chunk & 7));
+}
+
+void yaffs_set_chunk_bit(struct yaffs_dev *dev, int blk, int chunk)
+{
+        u8 *blk_bits = yaffs_block_bits(dev, blk);
+
+        yaffs_verify_chunk_bit_id(dev, blk, chunk);
+
+        blk_bits[chunk / 8] |= (1 << (chunk & 7));
+}
+
+int yaffs_check_chunk_bit(struct yaffs_dev *dev, int blk, int chunk)
+{
+        u8 *blk_bits = yaffs_block_bits(dev, blk);
+        yaffs_verify_chunk_bit_id(dev, blk, chunk);
+
+        return (blk_bits[chunk / 8] & (1 << (chunk & 7))) ? 1 : 0;
+}
+
+int yaffs_still_some_chunks(struct yaffs_dev *dev, int blk)
+{
+        u8 *blk_bits = yaffs_block_bits(dev, blk);
+        int i;
+        for (i = 0; i < dev->chunk_bit_stride; i++) {
+                if (*blk_bits)
+                        return 1;
+                blk_bits++;
+        }
+        return 0;
+}
+
+int yaffs_count_chunk_bits(struct yaffs_dev *dev, int blk)
+{
+        u8 *blk_bits = yaffs_block_bits(dev, blk);
+        int i;
+        int n = 0;
+
+        for (i = 0; i < dev->chunk_bit_stride; i++, blk_bits++)
+                n += hweight8(*blk_bits);
+
+        return n;
+}
diff --git a/fs/yaffs2/yaffs_bitmap.h b/fs/yaffs2/yaffs_bitmap.h
new file mode 100644
index 00000000000..cf9ea58da0d
--- /dev/null
+++ b/fs/yaffs2/yaffs_bitmap.h
@@ -0,0 +1,33 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+/*
+ * Chunk bitmap manipulations
+ */
+
+#ifndef __YAFFS_BITMAP_H__
+#define __YAFFS_BITMAP_H__
+
+#include "yaffs_guts.h"
+
+void yaffs_verify_chunk_bit_id(struct yaffs_dev *dev, int blk, int chunk);
+void yaffs_clear_chunk_bits(struct yaffs_dev *dev, int blk);
+void yaffs_clear_chunk_bit(struct yaffs_dev *dev, int blk, int chunk);
+void yaffs_set_chunk_bit(struct yaffs_dev *dev, int blk, int chunk);
+int yaffs_check_chunk_bit(struct yaffs_dev *dev, int blk, int chunk);
+int yaffs_still_some_chunks(struct yaffs_dev *dev, int blk);
+int yaffs_count_chunk_bits(struct yaffs_dev *dev, int blk);
+
+#endif
diff --git a/fs/yaffs2/yaffs_checkptrw.c b/fs/yaffs2/yaffs_checkptrw.c
new file mode 100644
index 00000000000..4e40f437e65
--- /dev/null
+++ b/fs/yaffs2/yaffs_checkptrw.c
@@ -0,0 +1,415 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_checkptrw.h"
+#include "yaffs_getblockinfo.h"
+
+static int yaffs2_checkpt_space_ok(struct yaffs_dev *dev)
+{
+        int blocks_avail = dev->n_erased_blocks - dev->param.n_reserved_blocks;
+
+        yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                "checkpt blocks_avail = %d", blocks_avail);
+
+        return (blocks_avail <= 0) ? 0 : 1;
+}
+
+static int yaffs_checkpt_erase(struct yaffs_dev *dev)
+{
+        int i;
+
+        if (!dev->param.erase_fn)
+                return 0;
+        yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                "checking blocks %d to %d",
+                dev->internal_start_block, dev->internal_end_block);
+
+        for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
+                struct yaffs_block_info *bi = yaffs_get_block_info(dev, i);
+                if (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT) {
+                        yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                        "erasing checkpt block %d", i);
+
+                        dev->n_erasures++;
+
+                        if (dev->param.
+                            erase_fn(dev,
+                                     i - dev->block_offset /* realign */ )) {
+                                bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
+                                dev->n_erased_blocks++;
+                                dev->n_free_chunks +=
+                                    dev->param.chunks_per_block;
+                        } else {
+                                dev->param.bad_block_fn(dev, i);
+                                bi->block_state = YAFFS_BLOCK_STATE_DEAD;
+                        }
+                }
+        }
+
+        dev->blocks_in_checkpt = 0;
+
+        return 1;
+}
+
+static void yaffs2_checkpt_find_erased_block(struct yaffs_dev *dev)
+{
+        int i;
+        int blocks_avail = dev->n_erased_blocks - dev->param.n_reserved_blocks;
+        yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                "allocating checkpt block: erased %d reserved %d avail %d next %d ",
+                dev->n_erased_blocks, dev->param.n_reserved_blocks,
+                blocks_avail, dev->checkpt_next_block);
+
+        if (dev->checkpt_next_block >= 0 &&
+            dev->checkpt_next_block <= dev->internal_end_block &&
+            blocks_avail > 0) {
+
+                for (i = dev->checkpt_next_block; i <= dev->internal_end_block;
+                     i++) {
+                        struct yaffs_block_info *bi =
+                            yaffs_get_block_info(dev, i);
+                        if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
+                                dev->checkpt_next_block = i + 1;
+                                dev->checkpt_cur_block = i;
+                                yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                                        "allocating checkpt block %d", i);
+                                return;
+                        }
+                }
+        }
+        yaffs_trace(YAFFS_TRACE_CHECKPOINT, "out of checkpt blocks");
+
+        dev->checkpt_next_block = -1;
+        dev->checkpt_cur_block = -1;
+}
+
+static void yaffs2_checkpt_find_block(struct yaffs_dev *dev)
+{
+        int i;
+        struct yaffs_ext_tags tags;
+
+        yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                "find next checkpt block: start:  blocks %d next %d",
+                dev->blocks_in_checkpt, dev->checkpt_next_block);
+
+        if (dev->blocks_in_checkpt < dev->checkpt_max_blocks)
+                for (i = dev->checkpt_next_block; i <= dev->internal_end_block;
+                     i++) {
+                        int chunk = i * dev->param.chunks_per_block;
+                        int realigned_chunk = chunk - dev->chunk_offset;
+
+                        dev->param.read_chunk_tags_fn(dev, realigned_chunk,
+                                                      NULL, &tags);
+                        yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                                "find next checkpt block: search: block %d oid %d seq %d eccr %d",
+                                i, tags.obj_id, tags.seq_number,
+                                tags.ecc_result);
+
+                        if (tags.seq_number == YAFFS_SEQUENCE_CHECKPOINT_DATA) {
+                                /* Right kind of block */
+                                dev->checkpt_next_block = tags.obj_id;
+                                dev->checkpt_cur_block = i;
+                                dev->checkpt_block_list[dev->
+                                                        blocks_in_checkpt] = i;
+                                dev->blocks_in_checkpt++;
+                                yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                                        "found checkpt block %d", i);
+                                return;
+                        }
+                }
+
+        yaffs_trace(YAFFS_TRACE_CHECKPOINT, "found no more checkpt blocks");
+
+        dev->checkpt_next_block = -1;
+        dev->checkpt_cur_block = -1;
+}
+
+int yaffs2_checkpt_open(struct yaffs_dev *dev, int writing)
+{
+
+        dev->checkpt_open_write = writing;
+
+        /* Got the functions we need? */
+        if (!dev->param.write_chunk_tags_fn ||
+            !dev->param.read_chunk_tags_fn ||
+            !dev->param.erase_fn || !dev->param.bad_block_fn)
+                return 0;
+
+        if (writing && !yaffs2_checkpt_space_ok(dev))
+                return 0;
+
+        if (!dev->checkpt_buffer)
+                dev->checkpt_buffer =
+                    kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
+        if (!dev->checkpt_buffer)
+                return 0;
+
+        dev->checkpt_page_seq = 0;
+        dev->checkpt_byte_count = 0;
+        dev->checkpt_sum = 0;
+        dev->checkpt_xor = 0;
+        dev->checkpt_cur_block = -1;
+        dev->checkpt_cur_chunk = -1;
+        dev->checkpt_next_block = dev->internal_start_block;
+
+        /* Erase all the blocks in the checkpoint area */
+        if (writing) {
+                memset(dev->checkpt_buffer, 0, dev->data_bytes_per_chunk);
+                dev->checkpt_byte_offs = 0;
+                return yaffs_checkpt_erase(dev);
+        } else {
+                int i;
+                /* Set to a value that will kick off a read */
+                dev->checkpt_byte_offs = dev->data_bytes_per_chunk;
+                /* A checkpoint block list of 1 checkpoint block per 16 block is (hopefully)
+                 * going to be way more than we need */
+                dev->blocks_in_checkpt = 0;
+                dev->checkpt_max_blocks =
+                    (dev->internal_end_block - dev->internal_start_block) / 16 +
+                    2;
+                dev->checkpt_block_list =
+                    kmalloc(sizeof(int) * dev->checkpt_max_blocks, GFP_NOFS);
+                if (!dev->checkpt_block_list)
+                        return 0;
+
+                for (i = 0; i < dev->checkpt_max_blocks; i++)
+                        dev->checkpt_block_list[i] = -1;
+        }
+
+        return 1;
+}
+
+int yaffs2_get_checkpt_sum(struct yaffs_dev *dev, u32 * sum)
+{
+        u32 composite_sum;
+        composite_sum = (dev->checkpt_sum << 8) | (dev->checkpt_xor & 0xFF);
+        *sum = composite_sum;
+        return 1;
+}
+
+static int yaffs2_checkpt_flush_buffer(struct yaffs_dev *dev)
+{
+        int chunk;
+        int realigned_chunk;
+
+        struct yaffs_ext_tags tags;
+
+        if (dev->checkpt_cur_block < 0) {
+                yaffs2_checkpt_find_erased_block(dev);
+                dev->checkpt_cur_chunk = 0;
+        }
+
+        if (dev->checkpt_cur_block < 0)
+                return 0;
+
+        tags.is_deleted = 0;
+        tags.obj_id = dev->checkpt_next_block;  /* Hint to next place to look */
+        tags.chunk_id = dev->checkpt_page_seq + 1;
+        tags.seq_number = YAFFS_SEQUENCE_CHECKPOINT_DATA;
+        tags.n_bytes = dev->data_bytes_per_chunk;
+        if (dev->checkpt_cur_chunk == 0) {
+                /* First chunk we write for the block? Set block state to
+                   checkpoint */
+                struct yaffs_block_info *bi =
+                    yaffs_get_block_info(dev, dev->checkpt_cur_block);
+                bi->block_state = YAFFS_BLOCK_STATE_CHECKPOINT;
+                dev->blocks_in_checkpt++;
+        }
+
+        chunk =
+            dev->checkpt_cur_block * dev->param.chunks_per_block +
+            dev->checkpt_cur_chunk;
+
+        yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                "checkpoint wite buffer nand %d(%d:%d) objid %d chId %d",
+                chunk, dev->checkpt_cur_block, dev->checkpt_cur_chunk,
+                tags.obj_id, tags.chunk_id);
+
+        realigned_chunk = chunk - dev->chunk_offset;
+
+        dev->n_page_writes++;
+
+        dev->param.write_chunk_tags_fn(dev, realigned_chunk,
+                                       dev->checkpt_buffer, &tags);
+        dev->checkpt_byte_offs = 0;
+        dev->checkpt_page_seq++;
+        dev->checkpt_cur_chunk++;
+        if (dev->checkpt_cur_chunk >= dev->param.chunks_per_block) {
+                dev->checkpt_cur_chunk = 0;
+                dev->checkpt_cur_block = -1;
+        }
+        memset(dev->checkpt_buffer, 0, dev->data_bytes_per_chunk);
+
+        return 1;
+}
+
+int yaffs2_checkpt_wr(struct yaffs_dev *dev, const void *data, int n_bytes)
+{
+        int i = 0;
+        int ok = 1;
+
+        u8 *data_bytes = (u8 *) data;
+
+        if (!dev->checkpt_buffer)
+                return 0;
+
+        if (!dev->checkpt_open_write)
+                return -1;
+
+        while (i < n_bytes && ok) {
+                dev->checkpt_buffer[dev->checkpt_byte_offs] = *data_bytes;
+                dev->checkpt_sum += *data_bytes;
+                dev->checkpt_xor ^= *data_bytes;
+
+                dev->checkpt_byte_offs++;
+                i++;
+                data_bytes++;
+                dev->checkpt_byte_count++;
+
+                if (dev->checkpt_byte_offs < 0 ||
+                    dev->checkpt_byte_offs >= dev->data_bytes_per_chunk)
+                        ok = yaffs2_checkpt_flush_buffer(dev);
+        }
+
+        return i;
+}
+
+int yaffs2_checkpt_rd(struct yaffs_dev *dev, void *data, int n_bytes)
+{
+        int i = 0;
+        int ok = 1;
+        struct yaffs_ext_tags tags;
+
+        int chunk;
+        int realigned_chunk;
+
+        u8 *data_bytes = (u8 *) data;
+
+        if (!dev->checkpt_buffer)
+                return 0;
+
+        if (dev->checkpt_open_write)
+                return -1;
+
+        while (i < n_bytes && ok) {
+
+                if (dev->checkpt_byte_offs < 0 ||
+                    dev->checkpt_byte_offs >= dev->data_bytes_per_chunk) {
+
+                        if (dev->checkpt_cur_block < 0) {
+                                yaffs2_checkpt_find_block(dev);
+                                dev->checkpt_cur_chunk = 0;
+                        }
+
+                        if (dev->checkpt_cur_block < 0)
+                                ok = 0;
+                        else {
+                                chunk = dev->checkpt_cur_block *
+                                    dev->param.chunks_per_block +
+                                    dev->checkpt_cur_chunk;
+
+                                realigned_chunk = chunk - dev->chunk_offset;
+
+                                dev->n_page_reads++;
+
+                                /* read in the next chunk */
+                                dev->param.read_chunk_tags_fn(dev,
+                                                              realigned_chunk,
+                                                              dev->
+                                                              checkpt_buffer,
+                                                              &tags);
+
+                                if (tags.chunk_id != (dev->checkpt_page_seq + 1)
+                                    || tags.ecc_result > YAFFS_ECC_RESULT_FIXED
+                                    || tags.seq_number !=
+                                    YAFFS_SEQUENCE_CHECKPOINT_DATA)
+                                        ok = 0;
+
+                                dev->checkpt_byte_offs = 0;
+                                dev->checkpt_page_seq++;
+                                dev->checkpt_cur_chunk++;
+
+                                if (dev->checkpt_cur_chunk >=
+                                    dev->param.chunks_per_block)
+                                        dev->checkpt_cur_block = -1;
+                        }
+                }
+
+                if (ok) {
+                        *data_bytes =
+                            dev->checkpt_buffer[dev->checkpt_byte_offs];
+                        dev->checkpt_sum += *data_bytes;
+                        dev->checkpt_xor ^= *data_bytes;
+                        dev->checkpt_byte_offs++;
+                        i++;
+                        data_bytes++;
+                        dev->checkpt_byte_count++;
+                }
+        }
+
+        return i;
+}
+
+int yaffs_checkpt_close(struct yaffs_dev *dev)
+{
+
+        if (dev->checkpt_open_write) {
+                if (dev->checkpt_byte_offs != 0)
+                        yaffs2_checkpt_flush_buffer(dev);
+        } else if (dev->checkpt_block_list) {
+                int i;
+                for (i = 0;
+                     i < dev->blocks_in_checkpt
+                     && dev->checkpt_block_list[i] >= 0; i++) {
+                        int blk = dev->checkpt_block_list[i];
+                        struct yaffs_block_info *bi = NULL;
+                        if (dev->internal_start_block <= blk
+                            && blk <= dev->internal_end_block)
+                                bi = yaffs_get_block_info(dev, blk);
+                        if (bi && bi->block_state == YAFFS_BLOCK_STATE_EMPTY)
+                                bi->block_state = YAFFS_BLOCK_STATE_CHECKPOINT;
+                        else {
+                                /* Todo this looks odd... */
+                        }
+                }
+                kfree(dev->checkpt_block_list);
+                dev->checkpt_block_list = NULL;
+        }
+
+        dev->n_free_chunks -=
+            dev->blocks_in_checkpt * dev->param.chunks_per_block;
+        dev->n_erased_blocks -= dev->blocks_in_checkpt;
+
+        yaffs_trace(YAFFS_TRACE_CHECKPOINT,"checkpoint byte count %d",
+                dev->checkpt_byte_count);
+
+        if (dev->checkpt_buffer) {
+                /* free the buffer */
+                kfree(dev->checkpt_buffer);
+                dev->checkpt_buffer = NULL;
+                return 1;
+        } else {
+                return 0;
+        }
+}
+
+int yaffs2_checkpt_invalidate_stream(struct yaffs_dev *dev)
+{
+        /* Erase the checkpoint data */
+
+        yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                "checkpoint invalidate of %d blocks",
+                dev->blocks_in_checkpt);
+
+        return yaffs_checkpt_erase(dev);
+}
diff --git a/fs/yaffs2/yaffs_checkptrw.h b/fs/yaffs2/yaffs_checkptrw.h
new file mode 100644
index 00000000000..361c6067717
--- /dev/null
+++ b/fs/yaffs2/yaffs_checkptrw.h
@@ -0,0 +1,33 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_CHECKPTRW_H__
+#define __YAFFS_CHECKPTRW_H__
+
+#include "yaffs_guts.h"
+
+int yaffs2_checkpt_open(struct yaffs_dev *dev, int writing);
+
+int yaffs2_checkpt_wr(struct yaffs_dev *dev, const void *data, int n_bytes);
+
+int yaffs2_checkpt_rd(struct yaffs_dev *dev, void *data, int n_bytes);
+
+int yaffs2_get_checkpt_sum(struct yaffs_dev *dev, u32 * sum);
+
+int yaffs_checkpt_close(struct yaffs_dev *dev);
+
+int yaffs2_checkpt_invalidate_stream(struct yaffs_dev *dev);
+
+#endif
diff --git a/fs/yaffs2/yaffs_ecc.c b/fs/yaffs2/yaffs_ecc.c
new file mode 100644
index 00000000000..e95a8069a8c
--- /dev/null
+++ b/fs/yaffs2/yaffs_ecc.c
@@ -0,0 +1,298 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ * This code implements the ECC algorithm used in SmartMedia.
+ *
+ * The ECC comprises 22 bits of parity information and is stuffed into 3 bytes.
+ * The two unused bit are set to 1.
+ * The ECC can correct single bit errors in a 256-byte page of data. Thus, two such ECC
+ * blocks are used on a 512-byte NAND page.
+ *
+ */
+
+/* Table generated by gen-ecc.c
+ * Using a table means we do not have to calculate p1..p4 and p1'..p4'
+ * for each byte of data. These are instead provided in a table in bits7..2.
+ * Bit 0 of each entry indicates whether the entry has an odd or even parity, and therefore
+ * this bytes influence on the line parity.
+ */
+
+#include "yportenv.h"
+
+#include "yaffs_ecc.h"
+
+static const unsigned char column_parity_table[] = {
+        0x00, 0x55, 0x59, 0x0c, 0x65, 0x30, 0x3c, 0x69,
+        0x69, 0x3c, 0x30, 0x65, 0x0c, 0x59, 0x55, 0x00,
+        0x95, 0xc0, 0xcc, 0x99, 0xf0, 0xa5, 0xa9, 0xfc,
+        0xfc, 0xa9, 0xa5, 0xf0, 0x99, 0xcc, 0xc0, 0x95,
+        0x99, 0xcc, 0xc0, 0x95, 0xfc, 0xa9, 0xa5, 0xf0,
+        0xf0, 0xa5, 0xa9, 0xfc, 0x95, 0xc0, 0xcc, 0x99,
+        0x0c, 0x59, 0x55, 0x00, 0x69, 0x3c, 0x30, 0x65,
+        0x65, 0x30, 0x3c, 0x69, 0x00, 0x55, 0x59, 0x0c,
+        0xa5, 0xf0, 0xfc, 0xa9, 0xc0, 0x95, 0x99, 0xcc,
+        0xcc, 0x99, 0x95, 0xc0, 0xa9, 0xfc, 0xf0, 0xa5,
+        0x30, 0x65, 0x69, 0x3c, 0x55, 0x00, 0x0c, 0x59,
+        0x59, 0x0c, 0x00, 0x55, 0x3c, 0x69, 0x65, 0x30,
+        0x3c, 0x69, 0x65, 0x30, 0x59, 0x0c, 0x00, 0x55,
+        0x55, 0x00, 0x0c, 0x59, 0x30, 0x65, 0x69, 0x3c,
+        0xa9, 0xfc, 0xf0, 0xa5, 0xcc, 0x99, 0x95, 0xc0,
+        0xc0, 0x95, 0x99, 0xcc, 0xa5, 0xf0, 0xfc, 0xa9,
+        0xa9, 0xfc, 0xf0, 0xa5, 0xcc, 0x99, 0x95, 0xc0,
+        0xc0, 0x95, 0x99, 0xcc, 0xa5, 0xf0, 0xfc, 0xa9,
+        0x3c, 0x69, 0x65, 0x30, 0x59, 0x0c, 0x00, 0x55,
+        0x55, 0x00, 0x0c, 0x59, 0x30, 0x65, 0x69, 0x3c,
+        0x30, 0x65, 0x69, 0x3c, 0x55, 0x00, 0x0c, 0x59,
+        0x59, 0x0c, 0x00, 0x55, 0x3c, 0x69, 0x65, 0x30,
+        0xa5, 0xf0, 0xfc, 0xa9, 0xc0, 0x95, 0x99, 0xcc,
+        0xcc, 0x99, 0x95, 0xc0, 0xa9, 0xfc, 0xf0, 0xa5,
+        0x0c, 0x59, 0x55, 0x00, 0x69, 0x3c, 0x30, 0x65,
+        0x65, 0x30, 0x3c, 0x69, 0x00, 0x55, 0x59, 0x0c,
+        0x99, 0xcc, 0xc0, 0x95, 0xfc, 0xa9, 0xa5, 0xf0,
+        0xf0, 0xa5, 0xa9, 0xfc, 0x95, 0xc0, 0xcc, 0x99,
+        0x95, 0xc0, 0xcc, 0x99, 0xf0, 0xa5, 0xa9, 0xfc,
+        0xfc, 0xa9, 0xa5, 0xf0, 0x99, 0xcc, 0xc0, 0x95,
+        0x00, 0x55, 0x59, 0x0c, 0x65, 0x30, 0x3c, 0x69,
+        0x69, 0x3c, 0x30, 0x65, 0x0c, 0x59, 0x55, 0x00,
+};
+
+
+/* Calculate the ECC for a 256-byte block of data */
+void yaffs_ecc_cacl(const unsigned char *data, unsigned char *ecc)
+{
+        unsigned int i;
+
+        unsigned char col_parity = 0;
+        unsigned char line_parity = 0;
+        unsigned char line_parity_prime = 0;
+        unsigned char t;
+        unsigned char b;
+
+        for (i = 0; i < 256; i++) {
+                b = column_parity_table[*data++];
+                col_parity ^= b;
+
+                if (b & 0x01) { /* odd number of bits in the byte */
+                        line_parity ^= i;
+                        line_parity_prime ^= ~i;
+                }
+        }
+
+        ecc[2] = (~col_parity) | 0x03;
+
+        t = 0;
+        if (line_parity & 0x80)
+                t |= 0x80;
+        if (line_parity_prime & 0x80)
+                t |= 0x40;
+        if (line_parity & 0x40)
+                t |= 0x20;
+        if (line_parity_prime & 0x40)
+                t |= 0x10;
+        if (line_parity & 0x20)
+                t |= 0x08;
+        if (line_parity_prime & 0x20)
+                t |= 0x04;
+        if (line_parity & 0x10)
+                t |= 0x02;
+        if (line_parity_prime & 0x10)
+                t |= 0x01;
+        ecc[1] = ~t;
+
+        t = 0;
+        if (line_parity & 0x08)
+                t |= 0x80;
+        if (line_parity_prime & 0x08)
+                t |= 0x40;
+        if (line_parity & 0x04)
+                t |= 0x20;
+        if (line_parity_prime & 0x04)
+                t |= 0x10;
+        if (line_parity & 0x02)
+                t |= 0x08;
+        if (line_parity_prime & 0x02)
+                t |= 0x04;
+        if (line_parity & 0x01)
+                t |= 0x02;
+        if (line_parity_prime & 0x01)
+                t |= 0x01;
+        ecc[0] = ~t;
+
+#ifdef CONFIG_YAFFS_ECC_WRONG_ORDER
+        /* Swap the bytes into the wrong order */
+        t = ecc[0];
+        ecc[0] = ecc[1];
+        ecc[1] = t;
+#endif
+}
+
+/* Correct the ECC on a 256 byte block of data */
+
+int yaffs_ecc_correct(unsigned char *data, unsigned char *read_ecc,
+                      const unsigned char *test_ecc)
+{
+        unsigned char d0, d1, d2;       /* deltas */
+
+        d0 = read_ecc[0] ^ test_ecc[0];
+        d1 = read_ecc[1] ^ test_ecc[1];
+        d2 = read_ecc[2] ^ test_ecc[2];
+
+        if ((d0 | d1 | d2) == 0)
+                return 0;       /* no error */
+
+        if (((d0 ^ (d0 >> 1)) & 0x55) == 0x55 &&
+            ((d1 ^ (d1 >> 1)) & 0x55) == 0x55 &&
+            ((d2 ^ (d2 >> 1)) & 0x54) == 0x54) {
+                /* Single bit (recoverable) error in data */
+
+                unsigned byte;
+                unsigned bit;
+
+#ifdef CONFIG_YAFFS_ECC_WRONG_ORDER
+                /* swap the bytes to correct for the wrong order */
+                unsigned char t;
+
+                t = d0;
+                d0 = d1;
+                d1 = t;
+#endif
+
+                bit = byte = 0;
+
+                if (d1 & 0x80)
+                        byte |= 0x80;
+                if (d1 & 0x20)
+                        byte |= 0x40;
+                if (d1 & 0x08)
+                        byte |= 0x20;
+                if (d1 & 0x02)
+                        byte |= 0x10;
+                if (d0 & 0x80)
+                        byte |= 0x08;
+                if (d0 & 0x20)
+                        byte |= 0x04;
+                if (d0 & 0x08)
+                        byte |= 0x02;
+                if (d0 & 0x02)
+                        byte |= 0x01;
+
+                if (d2 & 0x80)
+                        bit |= 0x04;
+                if (d2 & 0x20)
+                        bit |= 0x02;
+                if (d2 & 0x08)
+                        bit |= 0x01;
+
+                data[byte] ^= (1 << bit);
+
+                return 1;       /* Corrected the error */
+        }
+
+        if ((hweight8(d0) + hweight8(d1) + hweight8(d2)) == 1) {
+                /* Reccoverable error in ecc */
+
+                read_ecc[0] = test_ecc[0];
+                read_ecc[1] = test_ecc[1];
+                read_ecc[2] = test_ecc[2];
+
+                return 1;       /* Corrected the error */
+        }
+
+        /* Unrecoverable error */
+
+        return -1;
+
+}
+
+/*
+ * ECCxxxOther does ECC calcs on arbitrary n bytes of data
+ */
+void yaffs_ecc_calc_other(const unsigned char *data, unsigned n_bytes,
+                          struct yaffs_ecc_other *ecc_other)
+{
+        unsigned int i;
+
+        unsigned char col_parity = 0;
+        unsigned line_parity = 0;
+        unsigned line_parity_prime = 0;
+        unsigned char b;
+
+        for (i = 0; i < n_bytes; i++) {
+                b = column_parity_table[*data++];
+                col_parity ^= b;
+
+                if (b & 0x01) {
+                        /* odd number of bits in the byte */
+                        line_parity ^= i;
+                        line_parity_prime ^= ~i;
+                }
+
+        }
+
+        ecc_other->col_parity = (col_parity >> 2) & 0x3f;
+        ecc_other->line_parity = line_parity;
+        ecc_other->line_parity_prime = line_parity_prime;
+}
+
+int yaffs_ecc_correct_other(unsigned char *data, unsigned n_bytes,
+                            struct yaffs_ecc_other *read_ecc,
+                            const struct yaffs_ecc_other *test_ecc)
+{
+        unsigned char delta_col;        /* column parity delta */
+        unsigned delta_line;    /* line parity delta */
+        unsigned delta_line_prime;      /* line parity delta */
+        unsigned bit;
+
+        delta_col = read_ecc->col_parity ^ test_ecc->col_parity;
+        delta_line = read_ecc->line_parity ^ test_ecc->line_parity;
+        delta_line_prime =
+            read_ecc->line_parity_prime ^ test_ecc->line_parity_prime;
+
+        if ((delta_col | delta_line | delta_line_prime) == 0)
+                return 0;       /* no error */
+
+        if (delta_line == ~delta_line_prime &&
+            (((delta_col ^ (delta_col >> 1)) & 0x15) == 0x15)) {
+                /* Single bit (recoverable) error in data */
+
+                bit = 0;
+
+                if (delta_col & 0x20)
+                        bit |= 0x04;
+                if (delta_col & 0x08)
+                        bit |= 0x02;
+                if (delta_col & 0x02)
+                        bit |= 0x01;
+
+                if (delta_line >= n_bytes)
+                        return -1;
+
+                data[delta_line] ^= (1 << bit);
+
+                return 1;       /* corrected */
+        }
+
+        if ((hweight32(delta_line) +
+             hweight32(delta_line_prime) +
+             hweight8(delta_col)) == 1) {
+                /* Reccoverable error in ecc */
+
+                *read_ecc = *test_ecc;
+                return 1;       /* corrected */
+        }
+
+        /* Unrecoverable error */
+
+        return -1;
+}
diff --git a/fs/yaffs2/yaffs_ecc.h b/fs/yaffs2/yaffs_ecc.h
new file mode 100644
index 00000000000..b0c461d699e
--- /dev/null
+++ b/fs/yaffs2/yaffs_ecc.h
@@ -0,0 +1,44 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+/*
+ * This code implements the ECC algorithm used in SmartMedia.
+ *
+ * The ECC comprises 22 bits of parity information and is stuffed into 3 bytes.
+ * The two unused bit are set to 1.
+ * The ECC can correct single bit errors in a 256-byte page of data. Thus, two such ECC
+ * blocks are used on a 512-byte NAND page.
+ *
+ */
+
+#ifndef __YAFFS_ECC_H__
+#define __YAFFS_ECC_H__
+
+struct yaffs_ecc_other {
+        unsigned char col_parity;
+        unsigned line_parity;
+        unsigned line_parity_prime;
+};
+
+void yaffs_ecc_cacl(const unsigned char *data, unsigned char *ecc);
+int yaffs_ecc_correct(unsigned char *data, unsigned char *read_ecc,
+                      const unsigned char *test_ecc);
+
+void yaffs_ecc_calc_other(const unsigned char *data, unsigned n_bytes,
+                          struct yaffs_ecc_other *ecc);
+int yaffs_ecc_correct_other(unsigned char *data, unsigned n_bytes,
+                            struct yaffs_ecc_other *read_ecc,
+                            const struct yaffs_ecc_other *test_ecc);
+#endif
diff --git a/fs/yaffs2/yaffs_getblockinfo.h b/fs/yaffs2/yaffs_getblockinfo.h
new file mode 100644
index 00000000000..d87acbde997
--- /dev/null
+++ b/fs/yaffs2/yaffs_getblockinfo.h
@@ -0,0 +1,35 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_GETBLOCKINFO_H__
+#define __YAFFS_GETBLOCKINFO_H__
+
+#include "yaffs_guts.h"
+#include "yaffs_trace.h"
+
+/* Function to manipulate block info */
+static inline struct yaffs_block_info *yaffs_get_block_info(struct yaffs_dev
+                                                              *dev, int blk)
+{
+        if (blk < dev->internal_start_block || blk > dev->internal_end_block) {
+                yaffs_trace(YAFFS_TRACE_ERROR,
+                        "**>> yaffs: get_block_info block %d is not valid",
+                        blk);
+                YBUG();
+        }
+        return &dev->block_info[blk - dev->internal_start_block];
+}
+
+#endif
diff --git a/fs/yaffs2/yaffs_guts.c b/fs/yaffs2/yaffs_guts.c
new file mode 100644
index 00000000000..f4ae9deed72
--- /dev/null
+++ b/fs/yaffs2/yaffs_guts.c
@@ -0,0 +1,5164 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yportenv.h"
+#include "yaffs_trace.h"
+
+#include "yaffs_guts.h"
+#include "yaffs_tagsvalidity.h"
+#include "yaffs_getblockinfo.h"
+
+#include "yaffs_tagscompat.h"
+
+#include "yaffs_nand.h"
+
+#include "yaffs_yaffs1.h"
+#include "yaffs_yaffs2.h"
+#include "yaffs_bitmap.h"
+#include "yaffs_verify.h"
+
+#include "yaffs_nand.h"
+#include "yaffs_packedtags2.h"
+
+#include "yaffs_nameval.h"
+#include "yaffs_allocator.h"
+
+#include "yaffs_attribs.h"
+
+/* Note YAFFS_GC_GOOD_ENOUGH must be <= YAFFS_GC_PASSIVE_THRESHOLD */
+#define YAFFS_GC_GOOD_ENOUGH 2
+#define YAFFS_GC_PASSIVE_THRESHOLD 4
+
+#include "yaffs_ecc.h"
+
+/* Forward declarations */
+
+static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
+                             const u8 * buffer, int n_bytes, int use_reserve);
+
+
+
+/* Function to calculate chunk and offset */
+
+static void yaffs_addr_to_chunk(struct yaffs_dev *dev, loff_t addr,
+                                int *chunk_out, u32 * offset_out)
+{
+        int chunk;
+        u32 offset;
+
+        chunk = (u32) (addr >> dev->chunk_shift);
+
+        if (dev->chunk_div == 1) {
+                /* easy power of 2 case */
+                offset = (u32) (addr & dev->chunk_mask);
+        } else {
+                /* Non power-of-2 case */
+
+                loff_t chunk_base;
+
+                chunk /= dev->chunk_div;
+
+                chunk_base = ((loff_t) chunk) * dev->data_bytes_per_chunk;
+                offset = (u32) (addr - chunk_base);
+        }
+
+        *chunk_out = chunk;
+        *offset_out = offset;
+}
+
+/* Function to return the number of shifts for a power of 2 greater than or
+ * equal to the given number
+ * Note we don't try to cater for all possible numbers and this does not have to
+ * be hellishly efficient.
+ */
+
+static u32 calc_shifts_ceiling(u32 x)
+{
+        int extra_bits;
+        int shifts;
+
+        shifts = extra_bits = 0;
+
+        while (x > 1) {
+                if (x & 1)
+                        extra_bits++;
+                x >>= 1;
+                shifts++;
+        }
+
+        if (extra_bits)
+                shifts++;
+
+        return shifts;
+}
+
+/* Function to return the number of shifts to get a 1 in bit 0
+ */
+
+static u32 calc_shifts(u32 x)
+{
+        u32 shifts;
+
+        shifts = 0;
+
+        if (!x)
+                return 0;
+
+        while (!(x & 1)) {
+                x >>= 1;
+                shifts++;
+        }
+
+        return shifts;
+}
+
+/*
+ * Temporary buffer manipulations.
+ */
+
+static int yaffs_init_tmp_buffers(struct yaffs_dev *dev)
+{
+        int i;
+        u8 *buf = (u8 *) 1;
+
+        memset(dev->temp_buffer, 0, sizeof(dev->temp_buffer));
+
+        for (i = 0; buf && i < YAFFS_N_TEMP_BUFFERS; i++) {
+                dev->temp_buffer[i].line = 0;   /* not in use */
+                dev->temp_buffer[i].buffer = buf =
+                    kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
+        }
+
+        return buf ? YAFFS_OK : YAFFS_FAIL;
+}
+
+u8 *yaffs_get_temp_buffer(struct yaffs_dev * dev, int line_no)
+{
+        int i, j;
+
+        dev->temp_in_use++;
+        if (dev->temp_in_use > dev->max_temp)
+                dev->max_temp = dev->temp_in_use;
+
+        for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
+                if (dev->temp_buffer[i].line == 0) {
+                        dev->temp_buffer[i].line = line_no;
+                        if ((i + 1) > dev->max_temp) {
+                                dev->max_temp = i + 1;
+                                for (j = 0; j <= i; j++)
+                                        dev->temp_buffer[j].max_line =
+                                            dev->temp_buffer[j].line;
+                        }
+
+                        return dev->temp_buffer[i].buffer;
+                }
+        }
+
+        yaffs_trace(YAFFS_TRACE_BUFFERS,
+                "Out of temp buffers at line %d, other held by lines:",
+                line_no);
+        for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
+                yaffs_trace(YAFFS_TRACE_BUFFERS," %d", dev->temp_buffer[i].line);
+
+        /*
+         * If we got here then we have to allocate an unmanaged one
+         * This is not good.
+         */
+
+        dev->unmanaged_buffer_allocs++;
+        return kmalloc(dev->data_bytes_per_chunk, GFP_NOFS);
+
+}
+
+void yaffs_release_temp_buffer(struct yaffs_dev *dev, u8 * buffer, int line_no)
+{
+        int i;
+
+        dev->temp_in_use--;
+
+        for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
+                if (dev->temp_buffer[i].buffer == buffer) {
+                        dev->temp_buffer[i].line = 0;
+                        return;
+                }
+        }
+
+        if (buffer) {
+                /* assume it is an unmanaged one. */
+                yaffs_trace(YAFFS_TRACE_BUFFERS,
+                  "Releasing unmanaged temp buffer in line %d",
+                   line_no);
+                kfree(buffer);
+                dev->unmanaged_buffer_deallocs++;
+        }
+
+}
+
+/*
+ * Determine if we have a managed buffer.
+ */
+int yaffs_is_managed_tmp_buffer(struct yaffs_dev *dev, const u8 * buffer)
+{
+        int i;
+
+        for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
+                if (dev->temp_buffer[i].buffer == buffer)
+                        return 1;
+        }
+
+        for (i = 0; i < dev->param.n_caches; i++) {
+                if (dev->cache[i].data == buffer)
+                        return 1;
+        }
+
+        if (buffer == dev->checkpt_buffer)
+                return 1;
+
+        yaffs_trace(YAFFS_TRACE_ALWAYS,
+          "yaffs: unmaged buffer detected.");
+        return 0;
+}
+
+/*
+ * Functions for robustisizing TODO
+ *
+ */
+
+static void yaffs_handle_chunk_wr_ok(struct yaffs_dev *dev, int nand_chunk,
+                                     const u8 * data,
+                                     const struct yaffs_ext_tags *tags)
+{
+        dev = dev;
+        nand_chunk = nand_chunk;
+        data = data;
+        tags = tags;
+}
+
+static void yaffs_handle_chunk_update(struct yaffs_dev *dev, int nand_chunk,
+                                      const struct yaffs_ext_tags *tags)
+{
+        dev = dev;
+        nand_chunk = nand_chunk;
+        tags = tags;
+}
+
+void yaffs_handle_chunk_error(struct yaffs_dev *dev,
+                              struct yaffs_block_info *bi)
+{
+        if (!bi->gc_prioritise) {
+                bi->gc_prioritise = 1;
+                dev->has_pending_prioritised_gc = 1;
+                bi->chunk_error_strikes++;
+
+                if (bi->chunk_error_strikes > 3) {
+                        bi->needs_retiring = 1; /* Too many stikes, so retire this */
+                        yaffs_trace(YAFFS_TRACE_ALWAYS, "yaffs: Block struck out");
+
+                }
+        }
+}
+
+static void yaffs_handle_chunk_wr_error(struct yaffs_dev *dev, int nand_chunk,
+                                        int erased_ok)
+{
+        int flash_block = nand_chunk / dev->param.chunks_per_block;
+        struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
+
+        yaffs_handle_chunk_error(dev, bi);
+
+        if (erased_ok) {
+                /* Was an actual write failure, so mark the block for retirement  */
+                bi->needs_retiring = 1;
+                yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
+                  "**>> Block %d needs retiring", flash_block);
+        }
+
+        /* Delete the chunk */
+        yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
+        yaffs_skip_rest_of_block(dev);
+}
+
+/*
+ * Verification code
+ */
+
+/*
+ *  Simple hash function. Needs to have a reasonable spread
+ */
+
+static inline int yaffs_hash_fn(int n)
+{
+        n = abs(n);
+        return n % YAFFS_NOBJECT_BUCKETS;
+}
+
+/*
+ * Access functions to useful fake objects.
+ * Note that root might have a presence in NAND if permissions are set.
+ */
+
+struct yaffs_obj *yaffs_root(struct yaffs_dev *dev)
+{
+        return dev->root_dir;
+}
+
+struct yaffs_obj *yaffs_lost_n_found(struct yaffs_dev *dev)
+{
+        return dev->lost_n_found;
+}
+
+/*
+ *  Erased NAND checking functions
+ */
+
+int yaffs_check_ff(u8 * buffer, int n_bytes)
+{
+        /* Horrible, slow implementation */
+        while (n_bytes--) {
+                if (*buffer != 0xFF)
+                        return 0;
+                buffer++;
+        }
+        return 1;
+}
+
+static int yaffs_check_chunk_erased(struct yaffs_dev *dev, int nand_chunk)
+{
+        int retval = YAFFS_OK;
+        u8 *data = yaffs_get_temp_buffer(dev, __LINE__);
+        struct yaffs_ext_tags tags;
+        int result;
+
+        result = yaffs_rd_chunk_tags_nand(dev, nand_chunk, data, &tags);
+
+        if (tags.ecc_result > YAFFS_ECC_RESULT_NO_ERROR)
+                retval = YAFFS_FAIL;
+
+        if (!yaffs_check_ff(data, dev->data_bytes_per_chunk) ||
+                tags.chunk_used) {
+                yaffs_trace(YAFFS_TRACE_NANDACCESS, "Chunk %d not erased", nand_chunk);
+                retval = YAFFS_FAIL;
+        }
+
+        yaffs_release_temp_buffer(dev, data, __LINE__);
+
+        return retval;
+
+}
+
+static int yaffs_verify_chunk_written(struct yaffs_dev *dev,
+                                      int nand_chunk,
+                                      const u8 * data,
+                                      struct yaffs_ext_tags *tags)
+{
+        int retval = YAFFS_OK;
+        struct yaffs_ext_tags temp_tags;
+        u8 *buffer = yaffs_get_temp_buffer(dev, __LINE__);
+        int result;
+
+        result = yaffs_rd_chunk_tags_nand(dev, nand_chunk, buffer, &temp_tags);
+        if (memcmp(buffer, data, dev->data_bytes_per_chunk) ||
+            temp_tags.obj_id != tags->obj_id ||
+            temp_tags.chunk_id != tags->chunk_id ||
+            temp_tags.n_bytes != tags->n_bytes)
+                retval = YAFFS_FAIL;
+
+        yaffs_release_temp_buffer(dev, buffer, __LINE__);
+
+        return retval;
+}
+
+
+int yaffs_check_alloc_available(struct yaffs_dev *dev, int n_chunks)
+{
+        int reserved_chunks;
+        int reserved_blocks = dev->param.n_reserved_blocks;
+        int checkpt_blocks;
+
+        checkpt_blocks = yaffs_calc_checkpt_blocks_required(dev);
+
+        reserved_chunks =
+            ((reserved_blocks + checkpt_blocks) * dev->param.chunks_per_block);
+
+        return (dev->n_free_chunks > (reserved_chunks + n_chunks));
+}
+
+static int yaffs_find_alloc_block(struct yaffs_dev *dev)
+{
+        int i;
+
+        struct yaffs_block_info *bi;
+
+        if (dev->n_erased_blocks < 1) {
+                /* Hoosterman we've got a problem.
+                 * Can't get space to gc
+                 */
+                yaffs_trace(YAFFS_TRACE_ERROR,
+                  "yaffs tragedy: no more erased blocks" );
+
+                return -1;
+        }
+
+        /* Find an empty block. */
+
+        for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
+                dev->alloc_block_finder++;
+                if (dev->alloc_block_finder < dev->internal_start_block
+                    || dev->alloc_block_finder > dev->internal_end_block) {
+                        dev->alloc_block_finder = dev->internal_start_block;
+                }
+
+                bi = yaffs_get_block_info(dev, dev->alloc_block_finder);
+
+                if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
+                        bi->block_state = YAFFS_BLOCK_STATE_ALLOCATING;
+                        dev->seq_number++;
+                        bi->seq_number = dev->seq_number;
+                        dev->n_erased_blocks--;
+                        yaffs_trace(YAFFS_TRACE_ALLOCATE,
+                          "Allocated block %d, seq  %d, %d left" ,
+                           dev->alloc_block_finder, dev->seq_number,
+                           dev->n_erased_blocks);
+                        return dev->alloc_block_finder;
+                }
+        }
+
+        yaffs_trace(YAFFS_TRACE_ALWAYS,
+                "yaffs tragedy: no more erased blocks, but there should have been %d",
+                dev->n_erased_blocks);
+
+        return -1;
+}
+
+static int yaffs_alloc_chunk(struct yaffs_dev *dev, int use_reserver,
+                             struct yaffs_block_info **block_ptr)
+{
+        int ret_val;
+        struct yaffs_block_info *bi;
+
+        if (dev->alloc_block < 0) {
+                /* Get next block to allocate off */
+                dev->alloc_block = yaffs_find_alloc_block(dev);
+                dev->alloc_page = 0;
+        }
+
+        if (!use_reserver && !yaffs_check_alloc_available(dev, 1)) {
+                /* Not enough space to allocate unless we're allowed to use the reserve. */
+                return -1;
+        }
+
+        if (dev->n_erased_blocks < dev->param.n_reserved_blocks
+            && dev->alloc_page == 0)
+                yaffs_trace(YAFFS_TRACE_ALLOCATE, "Allocating reserve");
+
+        /* Next page please.... */
+        if (dev->alloc_block >= 0) {
+                bi = yaffs_get_block_info(dev, dev->alloc_block);
+
+                ret_val = (dev->alloc_block * dev->param.chunks_per_block) +
+                    dev->alloc_page;
+                bi->pages_in_use++;
+                yaffs_set_chunk_bit(dev, dev->alloc_block, dev->alloc_page);
+
+                dev->alloc_page++;
+
+                dev->n_free_chunks--;
+
+                /* If the block is full set the state to full */
+                if (dev->alloc_page >= dev->param.chunks_per_block) {
+                        bi->block_state = YAFFS_BLOCK_STATE_FULL;
+                        dev->alloc_block = -1;
+                }
+
+                if (block_ptr)
+                        *block_ptr = bi;
+
+                return ret_val;
+        }
+
+        yaffs_trace(YAFFS_TRACE_ERROR, "!!!!!!!!! Allocator out !!!!!!!!!!!!!!!!!" );
+
+        return -1;
+}
+
+static int yaffs_get_erased_chunks(struct yaffs_dev *dev)
+{
+        int n;
+
+        n = dev->n_erased_blocks * dev->param.chunks_per_block;
+
+        if (dev->alloc_block > 0)
+                n += (dev->param.chunks_per_block - dev->alloc_page);
+
+        return n;
+
+}
+
+/*
+ * yaffs_skip_rest_of_block() skips over the rest of the allocation block
+ * if we don't want to write to it.
+ */
+void yaffs_skip_rest_of_block(struct yaffs_dev *dev)
+{
+        if (dev->alloc_block > 0) {
+                struct yaffs_block_info *bi =
+                    yaffs_get_block_info(dev, dev->alloc_block);
+                if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING) {
+                        bi->block_state = YAFFS_BLOCK_STATE_FULL;
+                        dev->alloc_block = -1;
+                }
+        }
+}
+
+static int yaffs_write_new_chunk(struct yaffs_dev *dev,
+                                 const u8 * data,
+                                 struct yaffs_ext_tags *tags, int use_reserver)
+{
+        int attempts = 0;
+        int write_ok = 0;
+        int chunk;
+
+        yaffs2_checkpt_invalidate(dev);
+
+        do {
+                struct yaffs_block_info *bi = 0;
+                int erased_ok = 0;
+
+                chunk = yaffs_alloc_chunk(dev, use_reserver, &bi);
+                if (chunk < 0) {
+                        /* no space */
+                        break;
+                }
+
+                /* First check this chunk is erased, if it needs
+                 * checking.  The checking policy (unless forced
+                 * always on) is as follows:
+                 *
+                 * Check the first page we try to write in a block.
+                 * If the check passes then we don't need to check any
+                 * more.        If the check fails, we check again...
+                 * If the block has been erased, we don't need to check.
+                 *
+                 * However, if the block has been prioritised for gc,
+                 * then we think there might be something odd about
+                 * this block and stop using it.
+                 *
+                 * Rationale: We should only ever see chunks that have
+                 * not been erased if there was a partially written
+                 * chunk due to power loss.  This checking policy should
+                 * catch that case with very few checks and thus save a
+                 * lot of checks that are most likely not needed.
+                 *
+                 * Mods to the above
+                 * If an erase check fails or the write fails we skip the 
+                 * rest of the block.
+                 */
+
+                /* let's give it a try */
+                attempts++;
+
+                if (dev->param.always_check_erased)
+                        bi->skip_erased_check = 0;
+
+                if (!bi->skip_erased_check) {
+                        erased_ok = yaffs_check_chunk_erased(dev, chunk);
+                        if (erased_ok != YAFFS_OK) {
+                                yaffs_trace(YAFFS_TRACE_ERROR,
+                                  "**>> yaffs chunk %d was not erased",
+                                  chunk);
+
+                                /* If not erased, delete this one,
+                                 * skip rest of block and
+                                 * try another chunk */
+                                yaffs_chunk_del(dev, chunk, 1, __LINE__);
+                                yaffs_skip_rest_of_block(dev);
+                                continue;
+                        }
+                }
+
+                write_ok = yaffs_wr_chunk_tags_nand(dev, chunk, data, tags);
+
+                if (!bi->skip_erased_check)
+                        write_ok =
+                            yaffs_verify_chunk_written(dev, chunk, data, tags);
+
+                if (write_ok != YAFFS_OK) {
+                        /* Clean up aborted write, skip to next block and
+                         * try another chunk */
+                        yaffs_handle_chunk_wr_error(dev, chunk, erased_ok);
+                        continue;
+                }
+
+                bi->skip_erased_check = 1;
+
+                /* Copy the data into the robustification buffer */
+                yaffs_handle_chunk_wr_ok(dev, chunk, data, tags);
+
+        } while (write_ok != YAFFS_OK &&
+                 (yaffs_wr_attempts <= 0 || attempts <= yaffs_wr_attempts));
+
+        if (!write_ok)
+                chunk = -1;
+
+        if (attempts > 1) {
+                yaffs_trace(YAFFS_TRACE_ERROR,
+                        "**>> yaffs write required %d attempts",
+                        attempts);
+                dev->n_retired_writes += (attempts - 1);
+        }
+
+        return chunk;
+}
+
+/*
+ * Block retiring for handling a broken block.
+ */
+
+static void yaffs_retire_block(struct yaffs_dev *dev, int flash_block)
+{
+        struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
+
+        yaffs2_checkpt_invalidate(dev);
+
+        yaffs2_clear_oldest_dirty_seq(dev, bi);
+
+        if (yaffs_mark_bad(dev, flash_block) != YAFFS_OK) {
+                if (yaffs_erase_block(dev, flash_block) != YAFFS_OK) {
+                        yaffs_trace(YAFFS_TRACE_ALWAYS,
+                                "yaffs: Failed to mark bad and erase block %d",
+                                flash_block);
+                } else {
+                        struct yaffs_ext_tags tags;
+                        int chunk_id =
+                            flash_block * dev->param.chunks_per_block;
+
+                        u8 *buffer = yaffs_get_temp_buffer(dev, __LINE__);
+
+                        memset(buffer, 0xff, dev->data_bytes_per_chunk);
+                        yaffs_init_tags(&tags);
+                        tags.seq_number = YAFFS_SEQUENCE_BAD_BLOCK;
+                        if (dev->param.write_chunk_tags_fn(dev, chunk_id -
+                                                           dev->chunk_offset,
+                                                           buffer,
+                                                           &tags) != YAFFS_OK)
+                                yaffs_trace(YAFFS_TRACE_ALWAYS,
+                                        "yaffs: Failed to write bad block marker to block %d",
+                                        flash_block);
+
+                        yaffs_release_temp_buffer(dev, buffer, __LINE__);
+                }
+        }
+
+        bi->block_state = YAFFS_BLOCK_STATE_DEAD;
+        bi->gc_prioritise = 0;
+        bi->needs_retiring = 0;
+
+        dev->n_retired_blocks++;
+}
+
+/*---------------- Name handling functions ------------*/
+
+static u16 yaffs_calc_name_sum(const YCHAR * name)
+{
+        u16 sum = 0;
+        u16 i = 1;
+
+        const YUCHAR *bname = (const YUCHAR *)name;
+        if (bname) {
+                while ((*bname) && (i < (YAFFS_MAX_NAME_LENGTH / 2))) {
+
+                        /* 0x1f mask is case insensitive */
+                        sum += ((*bname) & 0x1f) * i;
+                        i++;
+                        bname++;
+                }
+        }
+        return sum;
+}
+
+void yaffs_set_obj_name(struct yaffs_obj *obj, const YCHAR * name)
+{
+#ifndef CONFIG_YAFFS_NO_SHORT_NAMES
+        memset(obj->short_name, 0, sizeof(obj->short_name));
+        if (name && 
+                strnlen(name, YAFFS_SHORT_NAME_LENGTH + 1) <=
+            YAFFS_SHORT_NAME_LENGTH)
+                strcpy(obj->short_name, name);
+        else
+                obj->short_name[0] = _Y('\0');
+#endif
+        obj->sum = yaffs_calc_name_sum(name);
+}
+
+void yaffs_set_obj_name_from_oh(struct yaffs_obj *obj,
+                                const struct yaffs_obj_hdr *oh)
+{
+#ifdef CONFIG_YAFFS_AUTO_UNICODE
+        YCHAR tmp_name[YAFFS_MAX_NAME_LENGTH + 1];
+        memset(tmp_name, 0, sizeof(tmp_name));
+        yaffs_load_name_from_oh(obj->my_dev, tmp_name, oh->name,
+                                YAFFS_MAX_NAME_LENGTH + 1);
+        yaffs_set_obj_name(obj, tmp_name);
+#else
+        yaffs_set_obj_name(obj, oh->name);
+#endif
+}
+
+/*-------------------- TNODES -------------------
+
+ * List of spare tnodes
+ * The list is hooked together using the first pointer
+ * in the tnode.
+ */
+
+struct yaffs_tnode *yaffs_get_tnode(struct yaffs_dev *dev)
+{
+        struct yaffs_tnode *tn = yaffs_alloc_raw_tnode(dev);
+        if (tn) {
+                memset(tn, 0, dev->tnode_size);
+                dev->n_tnodes++;
+        }
+
+        dev->checkpoint_blocks_required = 0;    /* force recalculation */
+
+        return tn;
+}
+
+/* FreeTnode frees up a tnode and puts it back on the free list */
+static void yaffs_free_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
+{
+        yaffs_free_raw_tnode(dev, tn);
+        dev->n_tnodes--;
+        dev->checkpoint_blocks_required = 0;    /* force recalculation */
+}
+
+static void yaffs_deinit_tnodes_and_objs(struct yaffs_dev *dev)
+{
+        yaffs_deinit_raw_tnodes_and_objs(dev);
+        dev->n_obj = 0;
+        dev->n_tnodes = 0;
+}
+
+void yaffs_load_tnode_0(struct yaffs_dev *dev, struct yaffs_tnode *tn,
+                        unsigned pos, unsigned val)
+{
+        u32 *map = (u32 *) tn;
+        u32 bit_in_map;
+        u32 bit_in_word;
+        u32 word_in_map;
+        u32 mask;
+
+        pos &= YAFFS_TNODES_LEVEL0_MASK;
+        val >>= dev->chunk_grp_bits;
+
+        bit_in_map = pos * dev->tnode_width;
+        word_in_map = bit_in_map / 32;
+        bit_in_word = bit_in_map & (32 - 1);
+
+        mask = dev->tnode_mask << bit_in_word;
+
+        map[word_in_map] &= ~mask;
+        map[word_in_map] |= (mask & (val << bit_in_word));
+
+        if (dev->tnode_width > (32 - bit_in_word)) {
+                bit_in_word = (32 - bit_in_word);
+                word_in_map++;;
+                mask =
+                    dev->tnode_mask >> ( /*dev->tnode_width - */ bit_in_word);
+                map[word_in_map] &= ~mask;
+                map[word_in_map] |= (mask & (val >> bit_in_word));
+        }
+}
+
+u32 yaffs_get_group_base(struct yaffs_dev *dev, struct yaffs_tnode *tn,
+                         unsigned pos)
+{
+        u32 *map = (u32 *) tn;
+        u32 bit_in_map;
+        u32 bit_in_word;
+        u32 word_in_map;
+        u32 val;
+
+        pos &= YAFFS_TNODES_LEVEL0_MASK;
+
+        bit_in_map = pos * dev->tnode_width;
+        word_in_map = bit_in_map / 32;
+        bit_in_word = bit_in_map & (32 - 1);
+
+        val = map[word_in_map] >> bit_in_word;
+
+        if (dev->tnode_width > (32 - bit_in_word)) {
+                bit_in_word = (32 - bit_in_word);
+                word_in_map++;;
+                val |= (map[word_in_map] << bit_in_word);
+        }
+
+        val &= dev->tnode_mask;
+        val <<= dev->chunk_grp_bits;
+
+        return val;
+}
+
+/* ------------------- End of individual tnode manipulation -----------------*/
+
+/* ---------Functions to manipulate the look-up tree (made up of tnodes) ------
+ * The look up tree is represented by the top tnode and the number of top_level
+ * in the tree. 0 means only the level 0 tnode is in the tree.
+ */
+
+/* FindLevel0Tnode finds the level 0 tnode, if one exists. */
+struct yaffs_tnode *yaffs_find_tnode_0(struct yaffs_dev *dev,
+                                       struct yaffs_file_var *file_struct,
+                                       u32 chunk_id)
+{
+        struct yaffs_tnode *tn = file_struct->top;
+        u32 i;
+        int required_depth;
+        int level = file_struct->top_level;
+
+        dev = dev;
+
+        /* Check sane level and chunk Id */
+        if (level < 0 || level > YAFFS_TNODES_MAX_LEVEL)
+                return NULL;
+
+        if (chunk_id > YAFFS_MAX_CHUNK_ID)
+                return NULL;
+
+        /* First check we're tall enough (ie enough top_level) */
+
+        i = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
+        required_depth = 0;
+        while (i) {
+                i >>= YAFFS_TNODES_INTERNAL_BITS;
+                required_depth++;
+        }
+
+        if (required_depth > file_struct->top_level)
+                return NULL;    /* Not tall enough, so we can't find it */
+
+        /* Traverse down to level 0 */
+        while (level > 0 && tn) {
+                tn = tn->internal[(chunk_id >>
+                                   (YAFFS_TNODES_LEVEL0_BITS +
+                                    (level - 1) *
+                                    YAFFS_TNODES_INTERNAL_BITS)) &
+                                  YAFFS_TNODES_INTERNAL_MASK];
+                level--;
+        }
+
+        return tn;
+}
+
+/* AddOrFindLevel0Tnode finds the level 0 tnode if it exists, otherwise first expands the tree.
+ * This happens in two steps:
+ *  1. If the tree isn't tall enough, then make it taller.
+ *  2. Scan down the tree towards the level 0 tnode adding tnodes if required.
+ *
+ * Used when modifying the tree.
+ *
+ *  If the tn argument is NULL, then a fresh tnode will be added otherwise the specified tn will
+ *  be plugged into the ttree.
+ */
+
+struct yaffs_tnode *yaffs_add_find_tnode_0(struct yaffs_dev *dev,
+                                           struct yaffs_file_var *file_struct,
+                                           u32 chunk_id,
+                                           struct yaffs_tnode *passed_tn)
+{
+        int required_depth;
+        int i;
+        int l;
+        struct yaffs_tnode *tn;
+
+        u32 x;
+
+        /* Check sane level and page Id */
+        if (file_struct->top_level < 0
+            || file_struct->top_level > YAFFS_TNODES_MAX_LEVEL)
+                return NULL;
+
+        if (chunk_id > YAFFS_MAX_CHUNK_ID)
+                return NULL;
+
+        /* First check we're tall enough (ie enough top_level) */
+
+        x = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
+        required_depth = 0;
+        while (x) {
+                x >>= YAFFS_TNODES_INTERNAL_BITS;
+                required_depth++;
+        }
+
+        if (required_depth > file_struct->top_level) {
+                /* Not tall enough, gotta make the tree taller */
+                for (i = file_struct->top_level; i < required_depth; i++) {
+
+                        tn = yaffs_get_tnode(dev);
+
+                        if (tn) {
+                                tn->internal[0] = file_struct->top;
+                                file_struct->top = tn;
+                                file_struct->top_level++;
+                        } else {
+                                yaffs_trace(YAFFS_TRACE_ERROR, "yaffs: no more tnodes");
+                                return NULL;
+                        }
+                }
+        }
+
+        /* Traverse down to level 0, adding anything we need */
+
+        l = file_struct->top_level;
+        tn = file_struct->top;
+
+        if (l > 0) {
+                while (l > 0 && tn) {
+                        x = (chunk_id >>
+                             (YAFFS_TNODES_LEVEL0_BITS +
+                              (l - 1) * YAFFS_TNODES_INTERNAL_BITS)) &
+                            YAFFS_TNODES_INTERNAL_MASK;
+
+                        if ((l > 1) && !tn->internal[x]) {
+                                /* Add missing non-level-zero tnode */
+                                tn->internal[x] = yaffs_get_tnode(dev);
+                                if (!tn->internal[x])
+                                        return NULL;
+                        } else if (l == 1) {
+                                /* Looking from level 1 at level 0 */
+                                if (passed_tn) {
+                                        /* If we already have one, then release it. */
+                                        if (tn->internal[x])
+                                                yaffs_free_tnode(dev,
+                                                                 tn->
+                                                                 internal[x]);
+                                        tn->internal[x] = passed_tn;
+
+                                } else if (!tn->internal[x]) {
+                                        /* Don't have one, none passed in */
+                                        tn->internal[x] = yaffs_get_tnode(dev);
+                                        if (!tn->internal[x])
+                                                return NULL;
+                                }
+                        }
+
+                        tn = tn->internal[x];
+                        l--;
+                }
+        } else {
+                /* top is level 0 */
+                if (passed_tn) {
+                        memcpy(tn, passed_tn,
+                               (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8);
+                        yaffs_free_tnode(dev, passed_tn);
+                }
+        }
+
+        return tn;
+}
+
+static int yaffs_tags_match(const struct yaffs_ext_tags *tags, int obj_id,
+                            int chunk_obj)
+{
+        return (tags->chunk_id == chunk_obj &&
+                tags->obj_id == obj_id && !tags->is_deleted) ? 1 : 0;
+
+}
+
+static int yaffs_find_chunk_in_group(struct yaffs_dev *dev, int the_chunk,
+                                     struct yaffs_ext_tags *tags, int obj_id,
+                                     int inode_chunk)
+{
+        int j;
+
+        for (j = 0; the_chunk && j < dev->chunk_grp_size; j++) {
+                if (yaffs_check_chunk_bit
+                    (dev, the_chunk / dev->param.chunks_per_block,
+                     the_chunk % dev->param.chunks_per_block)) {
+
+                        if (dev->chunk_grp_size == 1)
+                                return the_chunk;
+                        else {
+                                yaffs_rd_chunk_tags_nand(dev, the_chunk, NULL,
+                                                         tags);
+                                if (yaffs_tags_match(tags, obj_id, inode_chunk)) {
+                                        /* found it; */
+                                        return the_chunk;
+                                }
+                        }
+                }
+                the_chunk++;
+        }
+        return -1;
+}
+
+static int yaffs_find_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
+                                    struct yaffs_ext_tags *tags)
+{
+        /*Get the Tnode, then get the level 0 offset chunk offset */
+        struct yaffs_tnode *tn;
+        int the_chunk = -1;
+        struct yaffs_ext_tags local_tags;
+        int ret_val = -1;
+
+        struct yaffs_dev *dev = in->my_dev;
+
+        if (!tags) {
+                /* Passed a NULL, so use our own tags space */
+                tags = &local_tags;
+        }
+
+        tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
+
+        if (tn) {
+                the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
+
+                ret_val =
+                    yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
+                                              inode_chunk);
+        }
+        return ret_val;
+}
+
+static int yaffs_find_del_file_chunk(struct yaffs_obj *in, int inode_chunk,
+                                     struct yaffs_ext_tags *tags)
+{
+        /* Get the Tnode, then get the level 0 offset chunk offset */
+        struct yaffs_tnode *tn;
+        int the_chunk = -1;
+        struct yaffs_ext_tags local_tags;
+
+        struct yaffs_dev *dev = in->my_dev;
+        int ret_val = -1;
+
+        if (!tags) {
+                /* Passed a NULL, so use our own tags space */
+                tags = &local_tags;
+        }
+
+        tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
+
+        if (tn) {
+
+                the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
+
+                ret_val =
+                    yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
+                                              inode_chunk);
+
+                /* Delete the entry in the filestructure (if found) */
+                if (ret_val != -1)
+                        yaffs_load_tnode_0(dev, tn, inode_chunk, 0);
+        }
+
+        return ret_val;
+}
+
+int yaffs_put_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
+                            int nand_chunk, int in_scan)
+{
+        /* NB in_scan is zero unless scanning.
+         * For forward scanning, in_scan is > 0;
+         * for backward scanning in_scan is < 0
+         *
+         * nand_chunk = 0 is a dummy insert to make sure the tnodes are there.
+         */
+
+        struct yaffs_tnode *tn;
+        struct yaffs_dev *dev = in->my_dev;
+        int existing_cunk;
+        struct yaffs_ext_tags existing_tags;
+        struct yaffs_ext_tags new_tags;
+        unsigned existing_serial, new_serial;
+
+        if (in->variant_type != YAFFS_OBJECT_TYPE_FILE) {
+                /* Just ignore an attempt at putting a chunk into a non-file during scanning
+                 * If it is not during Scanning then something went wrong!
+                 */
+                if (!in_scan) {
+                        yaffs_trace(YAFFS_TRACE_ERROR,
+                                "yaffs tragedy:attempt to put data chunk into a non-file"
+                                );
+                        YBUG();
+                }
+
+                yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
+                return YAFFS_OK;
+        }
+
+        tn = yaffs_add_find_tnode_0(dev,
+                                    &in->variant.file_variant,
+                                    inode_chunk, NULL);
+        if (!tn)
+                return YAFFS_FAIL;
+
+        if (!nand_chunk)
+                /* Dummy insert, bail now */
+                return YAFFS_OK;
+
+        existing_cunk = yaffs_get_group_base(dev, tn, inode_chunk);
+
+        if (in_scan != 0) {
+                /* If we're scanning then we need to test for duplicates
+                 * NB This does not need to be efficient since it should only ever
+                 * happen when the power fails during a write, then only one
+                 * chunk should ever be affected.
+                 *
+                 * Correction for YAFFS2: This could happen quite a lot and we need to think about efficiency! TODO
+                 * Update: For backward scanning we don't need to re-read tags so this is quite cheap.
+                 */
+
+                if (existing_cunk > 0) {
+                        /* NB Right now existing chunk will not be real chunk_id if the chunk group size > 1
+                         *    thus we have to do a FindChunkInFile to get the real chunk id.
+                         *
+                         * We have a duplicate now we need to decide which one to use:
+                         *
+                         * Backwards scanning YAFFS2: The old one is what we use, dump the new one.
+                         * Forward scanning YAFFS2: The new one is what we use, dump the old one.
+                         * YAFFS1: Get both sets of tags and compare serial numbers.
+                         */
+
+                        if (in_scan > 0) {
+                                /* Only do this for forward scanning */
+                                yaffs_rd_chunk_tags_nand(dev,
+                                                         nand_chunk,
+                                                         NULL, &new_tags);
+
+                                /* Do a proper find */
+                                existing_cunk =
+                                    yaffs_find_chunk_in_file(in, inode_chunk,
+                                                             &existing_tags);
+                        }
+
+                        if (existing_cunk <= 0) {
+                                /*Hoosterman - how did this happen? */
+
+                                yaffs_trace(YAFFS_TRACE_ERROR,
+                                        "yaffs tragedy: existing chunk < 0 in scan"
+                                        );
+
+                        }
+
+                        /* NB The deleted flags should be false, otherwise the chunks will
+                         * not be loaded during a scan
+                         */
+
+                        if (in_scan > 0) {
+                                new_serial = new_tags.serial_number;
+                                existing_serial = existing_tags.serial_number;
+                        }
+
+                        if ((in_scan > 0) &&
+                            (existing_cunk <= 0 ||
+                             ((existing_serial + 1) & 3) == new_serial)) {
+                                /* Forward scanning.
+                                 * Use new
+                                 * Delete the old one and drop through to update the tnode
+                                 */
+                                yaffs_chunk_del(dev, existing_cunk, 1,
+                                                __LINE__);
+                        } else {
+                                /* Backward scanning or we want to use the existing one
+                                 * Use existing.
+                                 * Delete the new one and return early so that the tnode isn't changed
+                                 */
+                                yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
+                                return YAFFS_OK;
+                        }
+                }
+
+        }
+
+        if (existing_cunk == 0)
+                in->n_data_chunks++;
+
+        yaffs_load_tnode_0(dev, tn, inode_chunk, nand_chunk);
+
+        return YAFFS_OK;
+}
+
+static void yaffs_soft_del_chunk(struct yaffs_dev *dev, int chunk)
+{
+        struct yaffs_block_info *the_block;
+        unsigned block_no;
+
+        yaffs_trace(YAFFS_TRACE_DELETION, "soft delete chunk %d", chunk);
+
+        block_no = chunk / dev->param.chunks_per_block;
+        the_block = yaffs_get_block_info(dev, block_no);
+        if (the_block) {
+                the_block->soft_del_pages++;
+                dev->n_free_chunks++;
+                yaffs2_update_oldest_dirty_seq(dev, block_no, the_block);
+        }
+}
+
+/* SoftDeleteWorker scans backwards through the tnode tree and soft deletes all the chunks in the file.
+ * All soft deleting does is increment the block's softdelete count and pulls the chunk out
+ * of the tnode.
+ * Thus, essentially this is the same as DeleteWorker except that the chunks are soft deleted.
+ */
+
+static int yaffs_soft_del_worker(struct yaffs_obj *in, struct yaffs_tnode *tn,
+                                 u32 level, int chunk_offset)
+{
+        int i;
+        int the_chunk;
+        int all_done = 1;
+        struct yaffs_dev *dev = in->my_dev;
+
+        if (tn) {
+                if (level > 0) {
+
+                        for (i = YAFFS_NTNODES_INTERNAL - 1; all_done && i >= 0;
+                             i--) {
+                                if (tn->internal[i]) {
+                                        all_done =
+                                            yaffs_soft_del_worker(in,
+                                                                  tn->internal
+                                                                  [i],
+                                                                  level - 1,
+                                                                  (chunk_offset
+                                                                   <<
+                                                                   YAFFS_TNODES_INTERNAL_BITS)
+                                                                  + i);
+                                        if (all_done) {
+                                                yaffs_free_tnode(dev,
+                                                                 tn->internal
+                                                                 [i]);
+                                                tn->internal[i] = NULL;
+                                        } else {
+                                                /* Hoosterman... how could this happen? */
+                                        }
+                                }
+                        }
+                        return (all_done) ? 1 : 0;
+                } else if (level == 0) {
+
+                        for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0; i--) {
+                                the_chunk = yaffs_get_group_base(dev, tn, i);
+                                if (the_chunk) {
+                                        /* Note this does not find the real chunk, only the chunk group.
+                                         * We make an assumption that a chunk group is not larger than
+                                         * a block.
+                                         */
+                                        yaffs_soft_del_chunk(dev, the_chunk);
+                                        yaffs_load_tnode_0(dev, tn, i, 0);
+                                }
+
+                        }
+                        return 1;
+
+                }
+
+        }
+
+        return 1;
+
+}
+
+static void yaffs_remove_obj_from_dir(struct yaffs_obj *obj)
+{
+        struct yaffs_dev *dev = obj->my_dev;
+        struct yaffs_obj *parent;
+
+        yaffs_verify_obj_in_dir(obj);
+        parent = obj->parent;
+
+        yaffs_verify_dir(parent);
+
+        if (dev && dev->param.remove_obj_fn)
+                dev->param.remove_obj_fn(obj);
+
+        list_del_init(&obj->siblings);
+        obj->parent = NULL;
+
+        yaffs_verify_dir(parent);
+}
+
+void yaffs_add_obj_to_dir(struct yaffs_obj *directory, struct yaffs_obj *obj)
+{
+        if (!directory) {
+                yaffs_trace(YAFFS_TRACE_ALWAYS,
+                        "tragedy: Trying to add an object to a null pointer directory"
+                        );
+                YBUG();
+                return;
+        }
+        if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+                yaffs_trace(YAFFS_TRACE_ALWAYS,
+                        "tragedy: Trying to add an object to a non-directory"
+                        );
+                YBUG();
+        }
+
+        if (obj->siblings.prev == NULL) {
+                /* Not initialised */
+                YBUG();
+        }
+
+        yaffs_verify_dir(directory);
+
+        yaffs_remove_obj_from_dir(obj);
+
+        /* Now add it */
+        list_add(&obj->siblings, &directory->variant.dir_variant.children);
+        obj->parent = directory;
+
+        if (directory == obj->my_dev->unlinked_dir
+            || directory == obj->my_dev->del_dir) {
+                obj->unlinked = 1;
+                obj->my_dev->n_unlinked_files++;
+                obj->rename_allowed = 0;
+        }
+
+        yaffs_verify_dir(directory);
+        yaffs_verify_obj_in_dir(obj);
+}
+
+static int yaffs_change_obj_name(struct yaffs_obj *obj,
+                                 struct yaffs_obj *new_dir,
+                                 const YCHAR * new_name, int force, int shadows)
+{
+        int unlink_op;
+        int del_op;
+
+        struct yaffs_obj *existing_target;
+
+        if (new_dir == NULL)
+                new_dir = obj->parent;  /* use the old directory */
+
+        if (new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+                yaffs_trace(YAFFS_TRACE_ALWAYS,
+                        "tragedy: yaffs_change_obj_name: new_dir is not a directory"
+                        );
+                YBUG();
+        }
+
+        /* TODO: Do we need this different handling for YAFFS2 and YAFFS1?? */
+        if (obj->my_dev->param.is_yaffs2)
+                unlink_op = (new_dir == obj->my_dev->unlinked_dir);
+        else
+                unlink_op = (new_dir == obj->my_dev->unlinked_dir
+                             && obj->variant_type == YAFFS_OBJECT_TYPE_FILE);
+
+        del_op = (new_dir == obj->my_dev->del_dir);
+
+        existing_target = yaffs_find_by_name(new_dir, new_name);
+
+        /* If the object is a file going into the unlinked directory,
+         *   then it is OK to just stuff it in since duplicate names are allowed.
+         *   else only proceed if the new name does not exist and if we're putting
+         *   it into a directory.
+         */
+        if ((unlink_op ||
+             del_op ||
+             force ||
+             (shadows > 0) ||
+             !existing_target) &&
+            new_dir->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY) {
+                yaffs_set_obj_name(obj, new_name);
+                obj->dirty = 1;
+
+                yaffs_add_obj_to_dir(new_dir, obj);
+
+                if (unlink_op)
+                        obj->unlinked = 1;
+
+                /* If it is a deletion then we mark it as a shrink for gc purposes. */
+                if (yaffs_update_oh(obj, new_name, 0, del_op, shadows, NULL) >=
+                    0)
+                        return YAFFS_OK;
+        }
+
+        return YAFFS_FAIL;
+}
+
+/*------------------------ Short Operations Cache ----------------------------------------
+ *   In many situations where there is no high level buffering  a lot of
+ *   reads might be short sequential reads, and a lot of writes may be short
+ *   sequential writes. eg. scanning/writing a jpeg file.
+ *   In these cases, a short read/write cache can provide a huge perfomance
+ *   benefit with dumb-as-a-rock code.
+ *   In Linux, the page cache provides read buffering and the short op cache 
+ *   provides write buffering.
+ *
+ *   There are a limited number (~10) of cache chunks per device so that we don't
+ *   need a very intelligent search.
+ */
+
+static int yaffs_obj_cache_dirty(struct yaffs_obj *obj)
+{
+        struct yaffs_dev *dev = obj->my_dev;
+        int i;
+        struct yaffs_cache *cache;
+        int n_caches = obj->my_dev->param.n_caches;
+
+        for (i = 0; i < n_caches; i++) {
+                cache = &dev->cache[i];
+                if (cache->object == obj && cache->dirty)
+                        return 1;
+        }
+
+        return 0;
+}
+
+static void yaffs_flush_file_cache(struct yaffs_obj *obj)
+{
+        struct yaffs_dev *dev = obj->my_dev;
+        int lowest = -99;       /* Stop compiler whining. */
+        int i;
+        struct yaffs_cache *cache;
+        int chunk_written = 0;
+        int n_caches = obj->my_dev->param.n_caches;
+
+        if (n_caches > 0) {
+                do {
+                        cache = NULL;
+
+                        /* Find the dirty cache for this object with the lowest chunk id. */
+                        for (i = 0; i < n_caches; i++) {
+                                if (dev->cache[i].object == obj &&
+                                    dev->cache[i].dirty) {
+                                        if (!cache
+                                            || dev->cache[i].chunk_id <
+                                            lowest) {
+                                                cache = &dev->cache[i];
+                                                lowest = cache->chunk_id;
+                                        }
+                                }
+                        }
+
+                        if (cache && !cache->locked) {
+                                /* Write it out and free it up */
+
+                                chunk_written =
+                                    yaffs_wr_data_obj(cache->object,
+                                                      cache->chunk_id,
+                                                      cache->data,
+                                                      cache->n_bytes, 1);
+                                cache->dirty = 0;
+                                cache->object = NULL;
+                        }
+
+                } while (cache && chunk_written > 0);
+
+                if (cache)
+                        /* Hoosterman, disk full while writing cache out. */
+                        yaffs_trace(YAFFS_TRACE_ERROR,
+                                "yaffs tragedy: no space during cache write");
+
+        }
+
+}
+
+/*yaffs_flush_whole_cache(dev)
+ *
+ *
+ */
+
+void yaffs_flush_whole_cache(struct yaffs_dev *dev)
+{
+        struct yaffs_obj *obj;
+        int n_caches = dev->param.n_caches;
+        int i;
+
+        /* Find a dirty object in the cache and flush it...
+         * until there are no further dirty objects.
+         */
+        do {
+                obj = NULL;
+                for (i = 0; i < n_caches && !obj; i++) {
+                        if (dev->cache[i].object && dev->cache[i].dirty)
+                                obj = dev->cache[i].object;
+
+                }
+                if (obj)
+                        yaffs_flush_file_cache(obj);
+
+        } while (obj);
+
+}
+
+/* Grab us a cache chunk for use.
+ * First look for an empty one.
+ * Then look for the least recently used non-dirty one.
+ * Then look for the least recently used dirty one...., flush and look again.
+ */
+static struct yaffs_cache *yaffs_grab_chunk_worker(struct yaffs_dev *dev)
+{
+        int i;
+
+        if (dev->param.n_caches > 0) {
+                for (i = 0; i < dev->param.n_caches; i++) {
+                        if (!dev->cache[i].object)
+                                return &dev->cache[i];
+                }
+        }
+
+        return NULL;
+}
+
+static struct yaffs_cache *yaffs_grab_chunk_cache(struct yaffs_dev *dev)
+{
+        struct yaffs_cache *cache;
+        struct yaffs_obj *the_obj;
+        int usage;
+        int i;
+        int pushout;
+
+        if (dev->param.n_caches > 0) {
+                /* Try find a non-dirty one... */
+
+                cache = yaffs_grab_chunk_worker(dev);
+
+                if (!cache) {
+                        /* They were all dirty, find the last recently used object and flush
+                         * its cache, then  find again.
+                         * NB what's here is not very accurate, we actually flush the object
+                         * the last recently used page.
+                         */
+
+                        /* With locking we can't assume we can use entry zero */
+
+                        the_obj = NULL;
+                        usage = -1;
+                        cache = NULL;
+                        pushout = -1;
+
+                        for (i = 0; i < dev->param.n_caches; i++) {
+                                if (dev->cache[i].object &&
+                                    !dev->cache[i].locked &&
+                                    (dev->cache[i].last_use < usage
+                                     || !cache)) {
+                                        usage = dev->cache[i].last_use;
+                                        the_obj = dev->cache[i].object;
+                                        cache = &dev->cache[i];
+                                        pushout = i;
+                                }
+                        }
+
+                        if (!cache || cache->dirty) {
+                                /* Flush and try again */
+                                yaffs_flush_file_cache(the_obj);
+                                cache = yaffs_grab_chunk_worker(dev);
+                        }
+
+                }
+                return cache;
+        } else {
+                return NULL;
+        }
+}
+
+/* Find a cached chunk */
+static struct yaffs_cache *yaffs_find_chunk_cache(const struct yaffs_obj *obj,
+                                                  int chunk_id)
+{
+        struct yaffs_dev *dev = obj->my_dev;
+        int i;
+        if (dev->param.n_caches > 0) {
+                for (i = 0; i < dev->param.n_caches; i++) {
+                        if (dev->cache[i].object == obj &&
+                            dev->cache[i].chunk_id == chunk_id) {
+                                dev->cache_hits++;
+
+                                return &dev->cache[i];
+                        }
+                }
+        }
+        return NULL;
+}
+
+/* Mark the chunk for the least recently used algorithym */
+static void yaffs_use_cache(struct yaffs_dev *dev, struct yaffs_cache *cache,
+                            int is_write)
+{
+
+        if (dev->param.n_caches > 0) {
+                if (dev->cache_last_use < 0 || dev->cache_last_use > 100000000) {
+                        /* Reset the cache usages */
+                        int i;
+                        for (i = 1; i < dev->param.n_caches; i++)
+                                dev->cache[i].last_use = 0;
+
+                        dev->cache_last_use = 0;
+                }
+
+                dev->cache_last_use++;
+
+                cache->last_use = dev->cache_last_use;
+
+                if (is_write)
+                        cache->dirty = 1;
+        }
+}
+
+/* Invalidate a single cache page.
+ * Do this when a whole page gets written,
+ * ie the short cache for this page is no longer valid.
+ */
+static void yaffs_invalidate_chunk_cache(struct yaffs_obj *object, int chunk_id)
+{
+        if (object->my_dev->param.n_caches > 0) {
+                struct yaffs_cache *cache =
+                    yaffs_find_chunk_cache(object, chunk_id);
+
+                if (cache)
+                        cache->object = NULL;
+        }
+}
+
+/* Invalidate all the cache pages associated with this object
+ * Do this whenever ther file is deleted or resized.
+ */
+static void yaffs_invalidate_whole_cache(struct yaffs_obj *in)
+{
+        int i;
+        struct yaffs_dev *dev = in->my_dev;
+
+        if (dev->param.n_caches > 0) {
+                /* Invalidate it. */
+                for (i = 0; i < dev->param.n_caches; i++) {
+                        if (dev->cache[i].object == in)
+                                dev->cache[i].object = NULL;
+                }
+        }
+}
+
+static void yaffs_unhash_obj(struct yaffs_obj *obj)
+{
+        int bucket;
+        struct yaffs_dev *dev = obj->my_dev;
+
+        /* If it is still linked into the bucket list, free from the list */
+        if (!list_empty(&obj->hash_link)) {
+                list_del_init(&obj->hash_link);
+                bucket = yaffs_hash_fn(obj->obj_id);
+                dev->obj_bucket[bucket].count--;
+        }
+}
+
+/*  FreeObject frees up a Object and puts it back on the free list */
+static void yaffs_free_obj(struct yaffs_obj *obj)
+{
+        struct yaffs_dev *dev = obj->my_dev;
+
+        yaffs_trace(YAFFS_TRACE_OS, "FreeObject %p inode %p",
+                obj, obj->my_inode);
+
+        if (!obj)
+                YBUG();
+        if (obj->parent)
+                YBUG();
+        if (!list_empty(&obj->siblings))
+                YBUG();
+
+        if (obj->my_inode) {
+                /* We're still hooked up to a cached inode.
+                 * Don't delete now, but mark for later deletion
+                 */
+                obj->defered_free = 1;
+                return;
+        }
+
+        yaffs_unhash_obj(obj);
+
+        yaffs_free_raw_obj(dev, obj);
+        dev->n_obj--;
+        dev->checkpoint_blocks_required = 0;    /* force recalculation */
+}
+
+void yaffs_handle_defered_free(struct yaffs_obj *obj)
+{
+        if (obj->defered_free)
+                yaffs_free_obj(obj);
+}
+
+static int yaffs_generic_obj_del(struct yaffs_obj *in)
+{
+
+        /* First off, invalidate the file's data in the cache, without flushing. */
+        yaffs_invalidate_whole_cache(in);
+
+        if (in->my_dev->param.is_yaffs2 && (in->parent != in->my_dev->del_dir)) {
+                /* Move to the unlinked directory so we have a record that it was deleted. */
+                yaffs_change_obj_name(in, in->my_dev->del_dir, _Y("deleted"), 0,
+                                      0);
+
+        }
+
+        yaffs_remove_obj_from_dir(in);
+        yaffs_chunk_del(in->my_dev, in->hdr_chunk, 1, __LINE__);
+        in->hdr_chunk = 0;
+
+        yaffs_free_obj(in);
+        return YAFFS_OK;
+
+}
+
+static void yaffs_soft_del_file(struct yaffs_obj *obj)
+{
+        if (obj->deleted &&
+            obj->variant_type == YAFFS_OBJECT_TYPE_FILE && !obj->soft_del) {
+                if (obj->n_data_chunks <= 0) {
+                        /* Empty file with no duplicate object headers,
+                         * just delete it immediately */
+                        yaffs_free_tnode(obj->my_dev,
+                                         obj->variant.file_variant.top);
+                        obj->variant.file_variant.top = NULL;
+                        yaffs_trace(YAFFS_TRACE_TRACING,
+                                "yaffs: Deleting empty file %d",
+                                obj->obj_id);
+                        yaffs_generic_obj_del(obj);
+                } else {
+                        yaffs_soft_del_worker(obj,
+                                              obj->variant.file_variant.top,
+                                              obj->variant.
+                                              file_variant.top_level, 0);
+                        obj->soft_del = 1;
+                }
+        }
+}
+
+/* Pruning removes any part of the file structure tree that is beyond the
+ * bounds of the file (ie that does not point to chunks).
+ *
+ * A file should only get pruned when its size is reduced.
+ *
+ * Before pruning, the chunks must be pulled from the tree and the
+ * level 0 tnode entries must be zeroed out.
+ * Could also use this for file deletion, but that's probably better handled
+ * by a special case.
+ *
+ * This function is recursive. For levels > 0 the function is called again on
+ * any sub-tree. For level == 0 we just check if the sub-tree has data.
+ * If there is no data in a subtree then it is pruned.
+ */
+
+static struct yaffs_tnode *yaffs_prune_worker(struct yaffs_dev *dev,
+                                              struct yaffs_tnode *tn, u32 level,
+                                              int del0)
+{
+        int i;
+        int has_data;
+
+        if (tn) {
+                has_data = 0;
+
+                if (level > 0) {
+                        for (i = 0; i < YAFFS_NTNODES_INTERNAL; i++) {
+                                if (tn->internal[i]) {
+                                        tn->internal[i] =
+                                            yaffs_prune_worker(dev,
+                                                               tn->internal[i],
+                                                               level - 1,
+                                                               (i ==
+                                                                0) ? del0 : 1);
+                                }
+
+                                if (tn->internal[i])
+                                        has_data++;
+                        }
+                } else {
+                        int tnode_size_u32 = dev->tnode_size / sizeof(u32);
+                        u32 *map = (u32 *) tn;
+
+                        for (i = 0; !has_data && i < tnode_size_u32; i++) {
+                                if (map[i])
+                                        has_data++;
+                        }
+                }
+
+                if (has_data == 0 && del0) {
+                        /* Free and return NULL */
+
+                        yaffs_free_tnode(dev, tn);
+                        tn = NULL;
+                }
+
+        }
+
+        return tn;
+
+}
+
+static int yaffs_prune_tree(struct yaffs_dev *dev,
+                            struct yaffs_file_var *file_struct)
+{
+        int i;
+        int has_data;
+        int done = 0;
+        struct yaffs_tnode *tn;
+
+        if (file_struct->top_level > 0) {
+                file_struct->top =
+                    yaffs_prune_worker(dev, file_struct->top,
+                                       file_struct->top_level, 0);
+
+                /* Now we have a tree with all the non-zero branches NULL but the height
+                 * is the same as it was.
+                 * Let's see if we can trim internal tnodes to shorten the tree.
+                 * We can do this if only the 0th element in the tnode is in use
+                 * (ie all the non-zero are NULL)
+                 */
+
+                while (file_struct->top_level && !done) {
+                        tn = file_struct->top;
+
+                        has_data = 0;
+                        for (i = 1; i < YAFFS_NTNODES_INTERNAL; i++) {
+                                if (tn->internal[i])
+                                        has_data++;
+                        }
+
+                        if (!has_data) {
+                                file_struct->top = tn->internal[0];
+                                file_struct->top_level--;
+                                yaffs_free_tnode(dev, tn);
+                        } else {
+                                done = 1;
+                        }
+                }
+        }
+
+        return YAFFS_OK;
+}
+
+/*-------------------- End of File Structure functions.-------------------*/
+
+/* AllocateEmptyObject gets us a clean Object. Tries to make allocate more if we run out */
+static struct yaffs_obj *yaffs_alloc_empty_obj(struct yaffs_dev *dev)
+{
+        struct yaffs_obj *obj = yaffs_alloc_raw_obj(dev);
+
+        if (obj) {
+                dev->n_obj++;
+
+                /* Now sweeten it up... */
+
+                memset(obj, 0, sizeof(struct yaffs_obj));
+                obj->being_created = 1;
+
+                obj->my_dev = dev;
+                obj->hdr_chunk = 0;
+                obj->variant_type = YAFFS_OBJECT_TYPE_UNKNOWN;
+                INIT_LIST_HEAD(&(obj->hard_links));
+                INIT_LIST_HEAD(&(obj->hash_link));
+                INIT_LIST_HEAD(&obj->siblings);
+
+                /* Now make the directory sane */
+                if (dev->root_dir) {
+                        obj->parent = dev->root_dir;
+                        list_add(&(obj->siblings),
+                                 &dev->root_dir->variant.dir_variant.children);
+                }
+
+                /* Add it to the lost and found directory.
+                 * NB Can't put root or lost-n-found in lost-n-found so
+                 * check if lost-n-found exists first
+                 */
+                if (dev->lost_n_found)
+                        yaffs_add_obj_to_dir(dev->lost_n_found, obj);
+
+                obj->being_created = 0;
+        }
+
+        dev->checkpoint_blocks_required = 0;    /* force recalculation */
+
+        return obj;
+}
+
+static int yaffs_find_nice_bucket(struct yaffs_dev *dev)
+{
+        int i;
+        int l = 999;
+        int lowest = 999999;
+
+        /* Search for the shortest list or one that
+         * isn't too long.
+         */
+
+        for (i = 0; i < 10 && lowest > 4; i++) {
+                dev->bucket_finder++;
+                dev->bucket_finder %= YAFFS_NOBJECT_BUCKETS;
+                if (dev->obj_bucket[dev->bucket_finder].count < lowest) {
+                        lowest = dev->obj_bucket[dev->bucket_finder].count;
+                        l = dev->bucket_finder;
+                }
+
+        }
+
+        return l;
+}
+
+static int yaffs_new_obj_id(struct yaffs_dev *dev)
+{
+        int bucket = yaffs_find_nice_bucket(dev);
+
+        /* Now find an object value that has not already been taken
+         * by scanning the list.
+         */
+
+        int found = 0;
+        struct list_head *i;
+
+        u32 n = (u32) bucket;
+
+        /* yaffs_check_obj_hash_sane();  */
+
+        while (!found) {
+                found = 1;
+                n += YAFFS_NOBJECT_BUCKETS;
+                if (1 || dev->obj_bucket[bucket].count > 0) {
+                        list_for_each(i, &dev->obj_bucket[bucket].list) {
+                                /* If there is already one in the list */
+                                if (i && list_entry(i, struct yaffs_obj,
+                                                    hash_link)->obj_id == n) {
+                                        found = 0;
+                                }
+                        }
+                }
+        }
+
+        return n;
+}
+
+static void yaffs_hash_obj(struct yaffs_obj *in)
+{
+        int bucket = yaffs_hash_fn(in->obj_id);
+        struct yaffs_dev *dev = in->my_dev;
+
+        list_add(&in->hash_link, &dev->obj_bucket[bucket].list);
+        dev->obj_bucket[bucket].count++;
+}
+
+struct yaffs_obj *yaffs_find_by_number(struct yaffs_dev *dev, u32 number)
+{
+        int bucket = yaffs_hash_fn(number);
+        struct list_head *i;
+        struct yaffs_obj *in;
+
+        list_for_each(i, &dev->obj_bucket[bucket].list) {
+                /* Look if it is in the list */
+                if (i) {
+                        in = list_entry(i, struct yaffs_obj, hash_link);
+                        if (in->obj_id == number) {
+
+                                /* Don't tell the VFS about this one if it is defered free */
+                                if (in->defered_free)
+                                        return NULL;
+
+                                return in;
+                        }
+                }
+        }
+
+        return NULL;
+}
+
+struct yaffs_obj *yaffs_new_obj(struct yaffs_dev *dev, int number,
+                                enum yaffs_obj_type type)
+{
+        struct yaffs_obj *the_obj = NULL;
+        struct yaffs_tnode *tn = NULL;
+
+        if (number < 0)
+                number = yaffs_new_obj_id(dev);
+
+        if (type == YAFFS_OBJECT_TYPE_FILE) {
+                tn = yaffs_get_tnode(dev);
+                if (!tn)
+                        return NULL;
+        }
+
+        the_obj = yaffs_alloc_empty_obj(dev);
+        if (!the_obj) {
+                if (tn)
+                        yaffs_free_tnode(dev, tn);
+                return NULL;
+        }
+
+        if (the_obj) {
+                the_obj->fake = 0;
+                the_obj->rename_allowed = 1;
+                the_obj->unlink_allowed = 1;
+                the_obj->obj_id = number;
+                yaffs_hash_obj(the_obj);
+                the_obj->variant_type = type;
+                yaffs_load_current_time(the_obj, 1, 1);
+
+                switch (type) {
+                case YAFFS_OBJECT_TYPE_FILE:
+                        the_obj->variant.file_variant.file_size = 0;
+                        the_obj->variant.file_variant.scanned_size = 0;
+                        the_obj->variant.file_variant.shrink_size = ~0; /* max */
+                        the_obj->variant.file_variant.top_level = 0;
+                        the_obj->variant.file_variant.top = tn;
+                        break;
+                case YAFFS_OBJECT_TYPE_DIRECTORY:
+                        INIT_LIST_HEAD(&the_obj->variant.dir_variant.children);
+                        INIT_LIST_HEAD(&the_obj->variant.dir_variant.dirty);
+                        break;
+                case YAFFS_OBJECT_TYPE_SYMLINK:
+                case YAFFS_OBJECT_TYPE_HARDLINK:
+                case YAFFS_OBJECT_TYPE_SPECIAL:
+                        /* No action required */
+                        break;
+                case YAFFS_OBJECT_TYPE_UNKNOWN:
+                        /* todo this should not happen */
+                        break;
+                }
+        }
+
+        return the_obj;
+}
+
+static struct yaffs_obj *yaffs_create_fake_dir(struct yaffs_dev *dev,
+                                               int number, u32 mode)
+{
+
+        struct yaffs_obj *obj =
+            yaffs_new_obj(dev, number, YAFFS_OBJECT_TYPE_DIRECTORY);
+        if (obj) {
+                obj->fake = 1;  /* it is fake so it might have no NAND presence... */
+                obj->rename_allowed = 0;        /* ... and we're not allowed to rename it... */
+                obj->unlink_allowed = 0;        /* ... or unlink it */
+                obj->deleted = 0;
+                obj->unlinked = 0;
+                obj->yst_mode = mode;
+                obj->my_dev = dev;
+                obj->hdr_chunk = 0;     /* Not a valid chunk. */
+        }
+
+        return obj;
+
+}
+
+
+static void yaffs_init_tnodes_and_objs(struct yaffs_dev *dev)
+{
+        int i;
+
+        dev->n_obj = 0;
+        dev->n_tnodes = 0;
+
+        yaffs_init_raw_tnodes_and_objs(dev);
+
+        for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
+                INIT_LIST_HEAD(&dev->obj_bucket[i].list);
+                dev->obj_bucket[i].count = 0;
+        }
+}
+
+struct yaffs_obj *yaffs_find_or_create_by_number(struct yaffs_dev *dev,
+                                                 int number,
+                                                 enum yaffs_obj_type type)
+{
+        struct yaffs_obj *the_obj = NULL;
+
+        if (number > 0)
+                the_obj = yaffs_find_by_number(dev, number);
+
+        if (!the_obj)
+                the_obj = yaffs_new_obj(dev, number, type);
+
+        return the_obj;
+
+}
+
+YCHAR *yaffs_clone_str(const YCHAR * str)
+{
+        YCHAR *new_str = NULL;
+        int len;
+
+        if (!str)
+                str = _Y("");
+
+        len = strnlen(str, YAFFS_MAX_ALIAS_LENGTH);
+        new_str = kmalloc((len + 1) * sizeof(YCHAR), GFP_NOFS);
+        if (new_str) {
+                strncpy(new_str, str, len);
+                new_str[len] = 0;
+        }
+        return new_str;
+
+}
+/*
+ *yaffs_update_parent() handles fixing a directories mtime and ctime when a new
+ * link (ie. name) is created or deleted in the directory.
+ *
+ * ie.
+ *   create dir/a : update dir's mtime/ctime
+ *   rm dir/a:   update dir's mtime/ctime
+ *   modify dir/a: don't update dir's mtimme/ctime
+ *
+ * This can be handled immediately or defered. Defering helps reduce the number
+ * of updates when many files in a directory are changed within a brief period.
+ *
+ * If the directory updating is defered then yaffs_update_dirty_dirs must be
+ * called periodically.
+ */
+
+static void yaffs_update_parent(struct yaffs_obj *obj)
+{
+        struct yaffs_dev *dev;
+        if (!obj)
+                return;
+        dev = obj->my_dev;
+        obj->dirty = 1;
+        yaffs_load_current_time(obj, 0, 1);
+        if (dev->param.defered_dir_update) {
+                struct list_head *link = &obj->variant.dir_variant.dirty;
+
+                if (list_empty(link)) {
+                        list_add(link, &dev->dirty_dirs);
+                        yaffs_trace(YAFFS_TRACE_BACKGROUND,
+                          "Added object %d to dirty directories",
+                           obj->obj_id);
+                }
+
+        } else {
+                yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
+        }
+}
+
+void yaffs_update_dirty_dirs(struct yaffs_dev *dev)
+{
+        struct list_head *link;
+        struct yaffs_obj *obj;
+        struct yaffs_dir_var *d_s;
+        union yaffs_obj_var *o_v;
+
+        yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update dirty directories");
+
+        while (!list_empty(&dev->dirty_dirs)) {
+                link = dev->dirty_dirs.next;
+                list_del_init(link);
+
+                d_s = list_entry(link, struct yaffs_dir_var, dirty);
+                o_v = list_entry(d_s, union yaffs_obj_var, dir_variant);
+                obj = list_entry(o_v, struct yaffs_obj, variant);
+
+                yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update directory %d",
+                        obj->obj_id);
+
+                if (obj->dirty)
+                        yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
+        }
+}
+
+/*
+ * Mknod (create) a new object.
+ * equiv_obj only has meaning for a hard link;
+ * alias_str only has meaning for a symlink.
+ * rdev only has meaning for devices (a subset of special objects)
+ */
+
+static struct yaffs_obj *yaffs_create_obj(enum yaffs_obj_type type,
+                                          struct yaffs_obj *parent,
+                                          const YCHAR * name,
+                                          u32 mode,
+                                          u32 uid,
+                                          u32 gid,
+                                          struct yaffs_obj *equiv_obj,
+                                          const YCHAR * alias_str, u32 rdev)
+{
+        struct yaffs_obj *in;
+        YCHAR *str = NULL;
+
+        struct yaffs_dev *dev = parent->my_dev;
+
+        /* Check if the entry exists. If it does then fail the call since we don't want a dup. */
+        if (yaffs_find_by_name(parent, name))
+                return NULL;
+
+        if (type == YAFFS_OBJECT_TYPE_SYMLINK) {
+                str = yaffs_clone_str(alias_str);
+                if (!str)
+                        return NULL;
+        }
+
+        in = yaffs_new_obj(dev, -1, type);
+
+        if (!in) {
+                if (str)
+                        kfree(str);
+                return NULL;
+        }
+
+        if (in) {
+                in->hdr_chunk = 0;
+                in->valid = 1;
+                in->variant_type = type;
+
+                in->yst_mode = mode;
+
+                yaffs_attribs_init(in, gid, uid, rdev);
+
+                in->n_data_chunks = 0;
+
+                yaffs_set_obj_name(in, name);
+                in->dirty = 1;
+
+                yaffs_add_obj_to_dir(parent, in);
+
+                in->my_dev = parent->my_dev;
+
+                switch (type) {
+                case YAFFS_OBJECT_TYPE_SYMLINK:
+                        in->variant.symlink_variant.alias = str;
+                        break;
+                case YAFFS_OBJECT_TYPE_HARDLINK:
+                        in->variant.hardlink_variant.equiv_obj = equiv_obj;
+                        in->variant.hardlink_variant.equiv_id =
+                            equiv_obj->obj_id;
+                        list_add(&in->hard_links, &equiv_obj->hard_links);
+                        break;
+                case YAFFS_OBJECT_TYPE_FILE:
+                case YAFFS_OBJECT_TYPE_DIRECTORY:
+                case YAFFS_OBJECT_TYPE_SPECIAL:
+                case YAFFS_OBJECT_TYPE_UNKNOWN:
+                        /* do nothing */
+                        break;
+                }
+
+                if (yaffs_update_oh(in, name, 0, 0, 0, NULL) < 0) {
+                        /* Could not create the object header, fail the creation */
+                        yaffs_del_obj(in);
+                        in = NULL;
+                }
+
+                yaffs_update_parent(parent);
+        }
+
+        return in;
+}
+
+struct yaffs_obj *yaffs_create_file(struct yaffs_obj *parent,
+                                    const YCHAR * name, u32 mode, u32 uid,
+                                    u32 gid)
+{
+        return yaffs_create_obj(YAFFS_OBJECT_TYPE_FILE, parent, name, mode,
+                                uid, gid, NULL, NULL, 0);
+}
+
+struct yaffs_obj *yaffs_create_dir(struct yaffs_obj *parent, const YCHAR * name,
+                                   u32 mode, u32 uid, u32 gid)
+{
+        return yaffs_create_obj(YAFFS_OBJECT_TYPE_DIRECTORY, parent, name,
+                                mode, uid, gid, NULL, NULL, 0);
+}
+
+struct yaffs_obj *yaffs_create_special(struct yaffs_obj *parent,
+                                       const YCHAR * name, u32 mode, u32 uid,
+                                       u32 gid, u32 rdev)
+{
+        return yaffs_create_obj(YAFFS_OBJECT_TYPE_SPECIAL, parent, name, mode,
+                                uid, gid, NULL, NULL, rdev);
+}
+
+struct yaffs_obj *yaffs_create_symlink(struct yaffs_obj *parent,
+                                       const YCHAR * name, u32 mode, u32 uid,
+                                       u32 gid, const YCHAR * alias)
+{
+        return yaffs_create_obj(YAFFS_OBJECT_TYPE_SYMLINK, parent, name, mode,
+                                uid, gid, NULL, alias, 0);
+}
+
+/* yaffs_link_obj returns the object id of the equivalent object.*/
+struct yaffs_obj *yaffs_link_obj(struct yaffs_obj *parent, const YCHAR * name,
+                                 struct yaffs_obj *equiv_obj)
+{
+        /* Get the real object in case we were fed a hard link as an equivalent object */
+        equiv_obj = yaffs_get_equivalent_obj(equiv_obj);
+
+        if (yaffs_create_obj
+            (YAFFS_OBJECT_TYPE_HARDLINK, parent, name, 0, 0, 0,
+             equiv_obj, NULL, 0)) {
+                return equiv_obj;
+        } else {
+                return NULL;
+        }
+
+}
+
+
+
+/*------------------------- Block Management and Page Allocation ----------------*/
+
+static int yaffs_init_blocks(struct yaffs_dev *dev)
+{
+        int n_blocks = dev->internal_end_block - dev->internal_start_block + 1;
+
+        dev->block_info = NULL;
+        dev->chunk_bits = NULL;
+
+        dev->alloc_block = -1;  /* force it to get a new one */
+
+        /* If the first allocation strategy fails, thry the alternate one */
+        dev->block_info =
+                kmalloc(n_blocks * sizeof(struct yaffs_block_info), GFP_NOFS);
+        if (!dev->block_info) {
+                dev->block_info =
+                    vmalloc(n_blocks * sizeof(struct yaffs_block_info));
+                dev->block_info_alt = 1;
+        } else {
+                dev->block_info_alt = 0;
+        }
+
+        if (dev->block_info) {
+                /* Set up dynamic blockinfo stuff. Round up bytes. */
+                dev->chunk_bit_stride = (dev->param.chunks_per_block + 7) / 8;
+                dev->chunk_bits =
+                        kmalloc(dev->chunk_bit_stride * n_blocks, GFP_NOFS);
+                if (!dev->chunk_bits) {
+                        dev->chunk_bits =
+                            vmalloc(dev->chunk_bit_stride * n_blocks);
+                        dev->chunk_bits_alt = 1;
+                } else {
+                        dev->chunk_bits_alt = 0;
+                }
+        }
+
+        if (dev->block_info && dev->chunk_bits) {
+                memset(dev->block_info, 0,
+                       n_blocks * sizeof(struct yaffs_block_info));
+                memset(dev->chunk_bits, 0, dev->chunk_bit_stride * n_blocks);
+                return YAFFS_OK;
+        }
+
+        return YAFFS_FAIL;
+}
+
+static void yaffs_deinit_blocks(struct yaffs_dev *dev)
+{
+        if (dev->block_info_alt && dev->block_info)
+                vfree(dev->block_info);
+        else if (dev->block_info)
+                kfree(dev->block_info);
+
+        dev->block_info_alt = 0;
+
+        dev->block_info = NULL;
+
+        if (dev->chunk_bits_alt && dev->chunk_bits)
+                vfree(dev->chunk_bits);
+        else if (dev->chunk_bits)
+                kfree(dev->chunk_bits);
+        dev->chunk_bits_alt = 0;
+        dev->chunk_bits = NULL;
+}
+
+void yaffs_block_became_dirty(struct yaffs_dev *dev, int block_no)
+{
+        struct yaffs_block_info *bi = yaffs_get_block_info(dev, block_no);
+
+        int erased_ok = 0;
+
+        /* If the block is still healthy erase it and mark as clean.
+         * If the block has had a data failure, then retire it.
+         */
+
+        yaffs_trace(YAFFS_TRACE_GC | YAFFS_TRACE_ERASE,
+                "yaffs_block_became_dirty block %d state %d %s",
+                block_no, bi->block_state,
+                (bi->needs_retiring) ? "needs retiring" : "");
+
+        yaffs2_clear_oldest_dirty_seq(dev, bi);
+
+        bi->block_state = YAFFS_BLOCK_STATE_DIRTY;
+
+        /* If this is the block being garbage collected then stop gc'ing this block */
+        if (block_no == dev->gc_block)
+                dev->gc_block = 0;
+
+        /* If this block is currently the best candidate for gc then drop as a candidate */
+        if (block_no == dev->gc_dirtiest) {
+                dev->gc_dirtiest = 0;
+                dev->gc_pages_in_use = 0;
+        }
+
+        if (!bi->needs_retiring) {
+                yaffs2_checkpt_invalidate(dev);
+                erased_ok = yaffs_erase_block(dev, block_no);
+                if (!erased_ok) {
+                        dev->n_erase_failures++;
+                        yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
+                          "**>> Erasure failed %d", block_no);
+                }
+        }
+
+        if (erased_ok &&
+            ((yaffs_trace_mask & YAFFS_TRACE_ERASE)
+             || !yaffs_skip_verification(dev))) {
+                int i;
+                for (i = 0; i < dev->param.chunks_per_block; i++) {
+                        if (!yaffs_check_chunk_erased
+                            (dev, block_no * dev->param.chunks_per_block + i)) {
+                                yaffs_trace(YAFFS_TRACE_ERROR,
+                                        ">>Block %d erasure supposedly OK, but chunk %d not erased",
+                                        block_no, i);
+                        }
+                }
+        }
+
+        if (erased_ok) {
+                /* Clean it up... */
+                bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
+                bi->seq_number = 0;
+                dev->n_erased_blocks++;
+                bi->pages_in_use = 0;
+                bi->soft_del_pages = 0;
+                bi->has_shrink_hdr = 0;
+                bi->skip_erased_check = 1;      /* Clean, so no need to check */
+                bi->gc_prioritise = 0;
+                yaffs_clear_chunk_bits(dev, block_no);
+
+                yaffs_trace(YAFFS_TRACE_ERASE,
+                        "Erased block %d", block_no);
+        } else {
+                /* We lost a block of free space */
+                dev->n_free_chunks -= dev->param.chunks_per_block;
+                yaffs_retire_block(dev, block_no);
+                yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
+                        "**>> Block %d retired", block_no);
+        }
+}
+
+
+
+static int yaffs_gc_block(struct yaffs_dev *dev, int block, int whole_block)
+{
+        int old_chunk;
+        int new_chunk;
+        int mark_flash;
+        int ret_val = YAFFS_OK;
+        int i;
+        int is_checkpt_block;
+        int matching_chunk;
+        int max_copies;
+
+        int chunks_before = yaffs_get_erased_chunks(dev);
+        int chunks_after;
+
+        struct yaffs_ext_tags tags;
+
+        struct yaffs_block_info *bi = yaffs_get_block_info(dev, block);
+
+        struct yaffs_obj *object;
+
+        is_checkpt_block = (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT);
+
+        yaffs_trace(YAFFS_TRACE_TRACING,
+                "Collecting block %d, in use %d, shrink %d, whole_block %d",
+                block, bi->pages_in_use, bi->has_shrink_hdr,
+                whole_block);
+
+        /*yaffs_verify_free_chunks(dev); */
+
+        if (bi->block_state == YAFFS_BLOCK_STATE_FULL)
+                bi->block_state = YAFFS_BLOCK_STATE_COLLECTING;
+
+        bi->has_shrink_hdr = 0; /* clear the flag so that the block can erase */
+
+        dev->gc_disable = 1;
+
+        if (is_checkpt_block || !yaffs_still_some_chunks(dev, block)) {
+                yaffs_trace(YAFFS_TRACE_TRACING,
+                        "Collecting block %d that has no chunks in use",
+                        block);
+                yaffs_block_became_dirty(dev, block);
+        } else {
+
+                u8 *buffer = yaffs_get_temp_buffer(dev, __LINE__);
+
+                yaffs_verify_blk(dev, bi, block);
+
+                max_copies = (whole_block) ? dev->param.chunks_per_block : 5;
+                old_chunk = block * dev->param.chunks_per_block + dev->gc_chunk;
+
+                for ( /* init already done */ ;
+                     ret_val == YAFFS_OK &&
+                     dev->gc_chunk < dev->param.chunks_per_block &&
+                     (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) &&
+                     max_copies > 0; dev->gc_chunk++, old_chunk++) {
+                        if (yaffs_check_chunk_bit(dev, block, dev->gc_chunk)) {
+
+                                /* This page is in use and might need to be copied off */
+
+                                max_copies--;
+
+                                mark_flash = 1;
+
+                                yaffs_init_tags(&tags);
+
+                                yaffs_rd_chunk_tags_nand(dev, old_chunk,
+                                                         buffer, &tags);
+
+                                object = yaffs_find_by_number(dev, tags.obj_id);
+
+                                yaffs_trace(YAFFS_TRACE_GC_DETAIL,
+                                        "Collecting chunk in block %d, %d %d %d ",
+                                        dev->gc_chunk, tags.obj_id,
+                                        tags.chunk_id, tags.n_bytes);
+
+                                if (object && !yaffs_skip_verification(dev)) {
+                                        if (tags.chunk_id == 0)
+                                                matching_chunk =
+                                                    object->hdr_chunk;
+                                        else if (object->soft_del)
+                                                matching_chunk = old_chunk;     /* Defeat the test */
+                                        else
+                                                matching_chunk =
+                                                    yaffs_find_chunk_in_file
+                                                    (object, tags.chunk_id,
+                                                     NULL);
+
+                                        if (old_chunk != matching_chunk)
+                                                yaffs_trace(YAFFS_TRACE_ERROR,
+                                                        "gc: page in gc mismatch: %d %d %d %d",
+                                                        old_chunk,
+                                                        matching_chunk,
+                                                        tags.obj_id,
+                                                        tags.chunk_id);
+
+                                }
+
+                                if (!object) {
+                                        yaffs_trace(YAFFS_TRACE_ERROR,
+                                                "page %d in gc has no object: %d %d %d ",
+                                                old_chunk,
+                                                tags.obj_id, tags.chunk_id,
+                                                tags.n_bytes);
+                                }
+
+                                if (object &&
+                                    object->deleted &&
+                                    object->soft_del && tags.chunk_id != 0) {
+                                        /* Data chunk in a soft deleted file, throw it away
+                                         * It's a soft deleted data chunk,
+                                         * No need to copy this, just forget about it and
+                                         * fix up the object.
+                                         */
+
+                                        /* Free chunks already includes softdeleted chunks.
+                                         * How ever this chunk is going to soon be really deleted
+                                         * which will increment free chunks.
+                                         * We have to decrement free chunks so this works out properly.
+                                         */
+                                        dev->n_free_chunks--;
+                                        bi->soft_del_pages--;
+
+                                        object->n_data_chunks--;
+
+                                        if (object->n_data_chunks <= 0) {
+                                                /* remeber to clean up the object */
+                                                dev->gc_cleanup_list[dev->
+                                                                     n_clean_ups]
+                                                    = tags.obj_id;
+                                                dev->n_clean_ups++;
+                                        }
+                                        mark_flash = 0;
+                                } else if (0) {
+                                        /* Todo object && object->deleted && object->n_data_chunks == 0 */
+                                        /* Deleted object header with no data chunks.
+                                         * Can be discarded and the file deleted.
+                                         */
+                                        object->hdr_chunk = 0;
+                                        yaffs_free_tnode(object->my_dev,
+                                                         object->
+                                                         variant.file_variant.
+                                                         top);
+                                        object->variant.file_variant.top = NULL;
+                                        yaffs_generic_obj_del(object);
+
+                                } else if (object) {
+                                        /* It's either a data chunk in a live file or
+                                         * an ObjectHeader, so we're interested in it.
+                                         * NB Need to keep the ObjectHeaders of deleted files
+                                         * until the whole file has been deleted off
+                                         */
+                                        tags.serial_number++;
+
+                                        dev->n_gc_copies++;
+
+                                        if (tags.chunk_id == 0) {
+                                                /* It is an object Id,
+                                                 * We need to nuke the shrinkheader flags first
+                                                 * Also need to clean up shadowing.
+                                                 * We no longer want the shrink_header flag since its work is done
+                                                 * and if it is left in place it will mess up scanning.
+                                                 */
+
+                                                struct yaffs_obj_hdr *oh;
+                                                oh = (struct yaffs_obj_hdr *)
+                                                    buffer;
+
+                                                oh->is_shrink = 0;
+                                                tags.extra_is_shrink = 0;
+
+                                                oh->shadows_obj = 0;
+                                                oh->inband_shadowed_obj_id = 0;
+                                                tags.extra_shadows = 0;
+
+                                                /* Update file size */
+                                                if (object->variant_type ==
+                                                    YAFFS_OBJECT_TYPE_FILE) {
+                                                        oh->file_size =
+                                                            object->variant.
+                                                            file_variant.
+                                                            file_size;
+                                                        tags.extra_length =
+                                                            oh->file_size;
+                                                }
+
+                                                yaffs_verify_oh(object, oh,
+                                                                &tags, 1);
+                                                new_chunk =
+                                                    yaffs_write_new_chunk(dev,
+                                                                          (u8 *)
+                                                                          oh,
+                                                                          &tags,
+                                                                          1);
+                                        } else {
+                                                new_chunk =
+                                                    yaffs_write_new_chunk(dev,
+                                                                          buffer,
+                                                                          &tags,
+                                                                          1);
+                                        }
+
+                                        if (new_chunk < 0) {
+                                                ret_val = YAFFS_FAIL;
+                                        } else {
+
+                                                /* Ok, now fix up the Tnodes etc. */
+
+                                                if (tags.chunk_id == 0) {
+                                                        /* It's a header */
+                                                        object->hdr_chunk =
+                                                            new_chunk;
+                                                        object->serial =
+                                                            tags.serial_number;
+                                                } else {
+                                                        /* It's a data chunk */
+                                                        int ok;
+                                                        ok = yaffs_put_chunk_in_file(object, tags.chunk_id, new_chunk, 0);
+                                                }
+                                        }
+                                }
+
+                                if (ret_val == YAFFS_OK)
+                                        yaffs_chunk_del(dev, old_chunk,
+                                                        mark_flash, __LINE__);
+
+                        }
+                }
+
+                yaffs_release_temp_buffer(dev, buffer, __LINE__);
+
+        }
+
+        yaffs_verify_collected_blk(dev, bi, block);
+
+        if (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
+                /*
+                 * The gc did not complete. Set block state back to FULL
+                 * because checkpointing does not restore gc.
+                 */
+                bi->block_state = YAFFS_BLOCK_STATE_FULL;
+        } else {
+                /* The gc completed. */
+                /* Do any required cleanups */
+                for (i = 0; i < dev->n_clean_ups; i++) {
+                        /* Time to delete the file too */
+                        object =
+                            yaffs_find_by_number(dev, dev->gc_cleanup_list[i]);
+                        if (object) {
+                                yaffs_free_tnode(dev,
+                                                 object->variant.
+                                                 file_variant.top);
+                                object->variant.file_variant.top = NULL;
+                                yaffs_trace(YAFFS_TRACE_GC,
+                                        "yaffs: About to finally delete object %d",
+                                        object->obj_id);
+                                yaffs_generic_obj_del(object);
+                                object->my_dev->n_deleted_files--;
+                        }
+
+                }
+
+                chunks_after = yaffs_get_erased_chunks(dev);
+                if (chunks_before >= chunks_after)
+                        yaffs_trace(YAFFS_TRACE_GC,
+                                "gc did not increase free chunks before %d after %d",
+                                chunks_before, chunks_after);
+                dev->gc_block = 0;
+                dev->gc_chunk = 0;
+                dev->n_clean_ups = 0;
+        }
+
+        dev->gc_disable = 0;
+
+        return ret_val;
+}
+
+/*
+ * FindBlockForgarbageCollection is used to select the dirtiest block (or close enough)
+ * for garbage collection.
+ */
+
+static unsigned yaffs_find_gc_block(struct yaffs_dev *dev,
+                                    int aggressive, int background)
+{
+        int i;
+        int iterations;
+        unsigned selected = 0;
+        int prioritised = 0;
+        int prioritised_exist = 0;
+        struct yaffs_block_info *bi;
+        int threshold;
+
+        /* First let's see if we need to grab a prioritised block */
+        if (dev->has_pending_prioritised_gc && !aggressive) {
+                dev->gc_dirtiest = 0;
+                bi = dev->block_info;
+                for (i = dev->internal_start_block;
+                     i <= dev->internal_end_block && !selected; i++) {
+
+                        if (bi->gc_prioritise) {
+                                prioritised_exist = 1;
+                                if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
+                                    yaffs_block_ok_for_gc(dev, bi)) {
+                                        selected = i;
+                                        prioritised = 1;
+                                }
+                        }
+                        bi++;
+                }
+
+                /*
+                 * If there is a prioritised block and none was selected then
+                 * this happened because there is at least one old dirty block gumming
+                 * up the works. Let's gc the oldest dirty block.
+                 */
+
+                if (prioritised_exist &&
+                    !selected && dev->oldest_dirty_block > 0)
+                        selected = dev->oldest_dirty_block;
+
+                if (!prioritised_exist) /* None found, so we can clear this */
+                        dev->has_pending_prioritised_gc = 0;
+        }
+
+        /* If we're doing aggressive GC then we are happy to take a less-dirty block, and
+         * search harder.
+         * else (we're doing a leasurely gc), then we only bother to do this if the
+         * block has only a few pages in use.
+         */
+
+        if (!selected) {
+                int pages_used;
+                int n_blocks =
+                    dev->internal_end_block - dev->internal_start_block + 1;
+                if (aggressive) {
+                        threshold = dev->param.chunks_per_block;
+                        iterations = n_blocks;
+                } else {
+                        int max_threshold;
+
+                        if (background)
+                                max_threshold = dev->param.chunks_per_block / 2;
+                        else
+                                max_threshold = dev->param.chunks_per_block / 8;
+
+                        if (max_threshold < YAFFS_GC_PASSIVE_THRESHOLD)
+                                max_threshold = YAFFS_GC_PASSIVE_THRESHOLD;
+
+                        threshold = background ? (dev->gc_not_done + 2) * 2 : 0;
+                        if (threshold < YAFFS_GC_PASSIVE_THRESHOLD)
+                                threshold = YAFFS_GC_PASSIVE_THRESHOLD;
+                        if (threshold > max_threshold)
+                                threshold = max_threshold;
+
+                        iterations = n_blocks / 16 + 1;
+                        if (iterations > 100)
+                                iterations = 100;
+                }
+
+                for (i = 0;
+                     i < iterations &&
+                     (dev->gc_dirtiest < 1 ||
+                      dev->gc_pages_in_use > YAFFS_GC_GOOD_ENOUGH); i++) {
+                        dev->gc_block_finder++;
+                        if (dev->gc_block_finder < dev->internal_start_block ||
+                            dev->gc_block_finder > dev->internal_end_block)
+                                dev->gc_block_finder =
+                                    dev->internal_start_block;
+
+                        bi = yaffs_get_block_info(dev, dev->gc_block_finder);
+
+                        pages_used = bi->pages_in_use - bi->soft_del_pages;
+
+                        if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
+                            pages_used < dev->param.chunks_per_block &&
+                            (dev->gc_dirtiest < 1
+                             || pages_used < dev->gc_pages_in_use)
+                            && yaffs_block_ok_for_gc(dev, bi)) {
+                                dev->gc_dirtiest = dev->gc_block_finder;
+                                dev->gc_pages_in_use = pages_used;
+                        }
+                }
+
+                if (dev->gc_dirtiest > 0 && dev->gc_pages_in_use <= threshold)
+                        selected = dev->gc_dirtiest;
+        }
+
+        /*
+         * If nothing has been selected for a while, try selecting the oldest dirty
+         * because that's gumming up the works.
+         */
+
+        if (!selected && dev->param.is_yaffs2 &&
+            dev->gc_not_done >= (background ? 10 : 20)) {
+                yaffs2_find_oldest_dirty_seq(dev);
+                if (dev->oldest_dirty_block > 0) {
+                        selected = dev->oldest_dirty_block;
+                        dev->gc_dirtiest = selected;
+                        dev->oldest_dirty_gc_count++;
+                        bi = yaffs_get_block_info(dev, selected);
+                        dev->gc_pages_in_use =
+                            bi->pages_in_use - bi->soft_del_pages;
+                } else {
+                        dev->gc_not_done = 0;
+                }
+        }
+
+        if (selected) {
+                yaffs_trace(YAFFS_TRACE_GC,
+                        "GC Selected block %d with %d free, prioritised:%d",
+                        selected,
+                        dev->param.chunks_per_block - dev->gc_pages_in_use,
+                        prioritised);
+
+                dev->n_gc_blocks++;
+                if (background)
+                        dev->bg_gcs++;
+
+                dev->gc_dirtiest = 0;
+                dev->gc_pages_in_use = 0;
+                dev->gc_not_done = 0;
+                if (dev->refresh_skip > 0)
+                        dev->refresh_skip--;
+        } else {
+                dev->gc_not_done++;
+                yaffs_trace(YAFFS_TRACE_GC,
+                        "GC none: finder %d skip %d threshold %d dirtiest %d using %d oldest %d%s",
+                        dev->gc_block_finder, dev->gc_not_done, threshold,
+                        dev->gc_dirtiest, dev->gc_pages_in_use,
+                        dev->oldest_dirty_block, background ? " bg" : "");
+        }
+
+        return selected;
+}
+
+/* New garbage collector
+ * If we're very low on erased blocks then we do aggressive garbage collection
+ * otherwise we do "leasurely" garbage collection.
+ * Aggressive gc looks further (whole array) and will accept less dirty blocks.
+ * Passive gc only inspects smaller areas and will only accept more dirty blocks.
+ *
+ * The idea is to help clear out space in a more spread-out manner.
+ * Dunno if it really does anything useful.
+ */
+static int yaffs_check_gc(struct yaffs_dev *dev, int background)
+{
+        int aggressive = 0;
+        int gc_ok = YAFFS_OK;
+        int max_tries = 0;
+        int min_erased;
+        int erased_chunks;
+        int checkpt_block_adjust;
+
+        if (dev->param.gc_control && (dev->param.gc_control(dev) & 1) == 0)
+                return YAFFS_OK;
+
+        if (dev->gc_disable) {
+                /* Bail out so we don't get recursive gc */
+                return YAFFS_OK;
+        }
+
+        /* This loop should pass the first time.
+         * We'll only see looping here if the collection does not increase space.
+         */
+
+        do {
+                max_tries++;
+
+                checkpt_block_adjust = yaffs_calc_checkpt_blocks_required(dev);
+
+                min_erased =
+                    dev->param.n_reserved_blocks + checkpt_block_adjust + 1;
+                erased_chunks =
+                    dev->n_erased_blocks * dev->param.chunks_per_block;
+
+                /* If we need a block soon then do aggressive gc. */
+                if (dev->n_erased_blocks < min_erased)
+                        aggressive = 1;
+                else {
+                        if (!background
+                            && erased_chunks > (dev->n_free_chunks / 4))
+                                break;
+
+                        if (dev->gc_skip > 20)
+                                dev->gc_skip = 20;
+                        if (erased_chunks < dev->n_free_chunks / 2 ||
+                            dev->gc_skip < 1 || background)
+                                aggressive = 0;
+                        else {
+                                dev->gc_skip--;
+                                break;
+                        }
+                }
+
+                dev->gc_skip = 5;
+
+                /* If we don't already have a block being gc'd then see if we should start another */
+
+                if (dev->gc_block < 1 && !aggressive) {
+                        dev->gc_block = yaffs2_find_refresh_block(dev);
+                        dev->gc_chunk = 0;
+                        dev->n_clean_ups = 0;
+                }
+                if (dev->gc_block < 1) {
+                        dev->gc_block =
+                            yaffs_find_gc_block(dev, aggressive, background);
+                        dev->gc_chunk = 0;
+                        dev->n_clean_ups = 0;
+                }
+
+                if (dev->gc_block > 0) {
+                        dev->all_gcs++;
+                        if (!aggressive)
+                                dev->passive_gc_count++;
+
+                        yaffs_trace(YAFFS_TRACE_GC,
+                                "yaffs: GC n_erased_blocks %d aggressive %d",
+                                dev->n_erased_blocks, aggressive);
+
+                        gc_ok = yaffs_gc_block(dev, dev->gc_block, aggressive);
+                }
+
+                if (dev->n_erased_blocks < (dev->param.n_reserved_blocks)
+                    && dev->gc_block > 0) {
+                        yaffs_trace(YAFFS_TRACE_GC,
+                                "yaffs: GC !!!no reclaim!!! n_erased_blocks %d after try %d block %d",
+                                dev->n_erased_blocks, max_tries,
+                                dev->gc_block);
+                }
+        } while ((dev->n_erased_blocks < dev->param.n_reserved_blocks) &&
+                 (dev->gc_block > 0) && (max_tries < 2));
+
+        return aggressive ? gc_ok : YAFFS_OK;
+}
+
+/*
+ * yaffs_bg_gc()
+ * Garbage collects. Intended to be called from a background thread.
+ * Returns non-zero if at least half the free chunks are erased.
+ */
+int yaffs_bg_gc(struct yaffs_dev *dev, unsigned urgency)
+{
+        int erased_chunks = dev->n_erased_blocks * dev->param.chunks_per_block;
+
+        yaffs_trace(YAFFS_TRACE_BACKGROUND, "Background gc %u", urgency);
+
+        yaffs_check_gc(dev, 1);
+        return erased_chunks > dev->n_free_chunks / 2;
+}
+
+/*-------------------- Data file manipulation -----------------*/
+
+static int yaffs_rd_data_obj(struct yaffs_obj *in, int inode_chunk, u8 * buffer)
+{
+        int nand_chunk = yaffs_find_chunk_in_file(in, inode_chunk, NULL);
+
+        if (nand_chunk >= 0)
+                return yaffs_rd_chunk_tags_nand(in->my_dev, nand_chunk,
+                                                buffer, NULL);
+        else {
+                yaffs_trace(YAFFS_TRACE_NANDACCESS,
+                        "Chunk %d not found zero instead",
+                        nand_chunk);
+                /* get sane (zero) data if you read a hole */
+                memset(buffer, 0, in->my_dev->data_bytes_per_chunk);
+                return 0;
+        }
+
+}
+
+void yaffs_chunk_del(struct yaffs_dev *dev, int chunk_id, int mark_flash,
+                     int lyn)
+{
+        int block;
+        int page;
+        struct yaffs_ext_tags tags;
+        struct yaffs_block_info *bi;
+
+        if (chunk_id <= 0)
+                return;
+
+        dev->n_deletions++;
+        block = chunk_id / dev->param.chunks_per_block;
+        page = chunk_id % dev->param.chunks_per_block;
+
+        if (!yaffs_check_chunk_bit(dev, block, page))
+                yaffs_trace(YAFFS_TRACE_VERIFY,
+                        "Deleting invalid chunk %d", chunk_id);
+
+        bi = yaffs_get_block_info(dev, block);
+
+        yaffs2_update_oldest_dirty_seq(dev, block, bi);
+
+        yaffs_trace(YAFFS_TRACE_DELETION,
+                "line %d delete of chunk %d",
+                lyn, chunk_id);
+
+        if (!dev->param.is_yaffs2 && mark_flash &&
+            bi->block_state != YAFFS_BLOCK_STATE_COLLECTING) {
+
+                yaffs_init_tags(&tags);
+
+                tags.is_deleted = 1;
+
+                yaffs_wr_chunk_tags_nand(dev, chunk_id, NULL, &tags);
+                yaffs_handle_chunk_update(dev, chunk_id, &tags);
+        } else {
+                dev->n_unmarked_deletions++;
+        }
+
+        /* Pull out of the management area.
+         * If the whole block became dirty, this will kick off an erasure.
+         */
+        if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING ||
+            bi->block_state == YAFFS_BLOCK_STATE_FULL ||
+            bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCANNING ||
+            bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
+                dev->n_free_chunks++;
+
+                yaffs_clear_chunk_bit(dev, block, page);
+
+                bi->pages_in_use--;
+
+                if (bi->pages_in_use == 0 &&
+                    !bi->has_shrink_hdr &&
+                    bi->block_state != YAFFS_BLOCK_STATE_ALLOCATING &&
+                    bi->block_state != YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
+                        yaffs_block_became_dirty(dev, block);
+                }
+
+        }
+
+}
+
+static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
+                             const u8 * buffer, int n_bytes, int use_reserve)
+{
+        /* Find old chunk Need to do this to get serial number
+         * Write new one and patch into tree.
+         * Invalidate old tags.
+         */
+
+        int prev_chunk_id;
+        struct yaffs_ext_tags prev_tags;
+
+        int new_chunk_id;
+        struct yaffs_ext_tags new_tags;
+
+        struct yaffs_dev *dev = in->my_dev;
+
+        yaffs_check_gc(dev, 0);
+
+        /* Get the previous chunk at this location in the file if it exists.
+         * If it does not exist then put a zero into the tree. This creates
+         * the tnode now, rather than later when it is harder to clean up.
+         */
+        prev_chunk_id = yaffs_find_chunk_in_file(in, inode_chunk, &prev_tags);
+        if (prev_chunk_id < 1 &&
+            !yaffs_put_chunk_in_file(in, inode_chunk, 0, 0))
+                return 0;
+
+        /* Set up new tags */
+        yaffs_init_tags(&new_tags);
+
+        new_tags.chunk_id = inode_chunk;
+        new_tags.obj_id = in->obj_id;
+        new_tags.serial_number =
+            (prev_chunk_id > 0) ? prev_tags.serial_number + 1 : 1;
+        new_tags.n_bytes = n_bytes;
+
+        if (n_bytes < 1 || n_bytes > dev->param.total_bytes_per_chunk) {
+                yaffs_trace(YAFFS_TRACE_ERROR,
+                  "Writing %d bytes to chunk!!!!!!!!!",
+                   n_bytes);
+                YBUG();
+        }
+
+        new_chunk_id =
+            yaffs_write_new_chunk(dev, buffer, &new_tags, use_reserve);
+
+        if (new_chunk_id > 0) {
+                yaffs_put_chunk_in_file(in, inode_chunk, new_chunk_id, 0);
+
+                if (prev_chunk_id > 0)
+                        yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
+
+                yaffs_verify_file_sane(in);
+        }
+        return new_chunk_id;
+
+}
+
+
+
+static int yaffs_do_xattrib_mod(struct yaffs_obj *obj, int set,
+                                const YCHAR * name, const void *value, int size,
+                                int flags)
+{
+        struct yaffs_xattr_mod xmod;
+
+        int result;
+
+        xmod.set = set;
+        xmod.name = name;
+        xmod.data = value;
+        xmod.size = size;
+        xmod.flags = flags;
+        xmod.result = -ENOSPC;
+
+        result = yaffs_update_oh(obj, NULL, 0, 0, 0, &xmod);
+
+        if (result > 0)
+                return xmod.result;
+        else
+                return -ENOSPC;
+}
+
+static int yaffs_apply_xattrib_mod(struct yaffs_obj *obj, char *buffer,
+                                   struct yaffs_xattr_mod *xmod)
+{
+        int retval = 0;
+        int x_offs = sizeof(struct yaffs_obj_hdr);
+        struct yaffs_dev *dev = obj->my_dev;
+        int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
+
+        char *x_buffer = buffer + x_offs;
+
+        if (xmod->set)
+                retval =
+                    nval_set(x_buffer, x_size, xmod->name, xmod->data,
+                             xmod->size, xmod->flags);
+        else
+                retval = nval_del(x_buffer, x_size, xmod->name);
+
+        obj->has_xattr = nval_hasvalues(x_buffer, x_size);
+        obj->xattr_known = 1;
+
+        xmod->result = retval;
+
+        return retval;
+}
+
+static int yaffs_do_xattrib_fetch(struct yaffs_obj *obj, const YCHAR * name,
+                                  void *value, int size)
+{
+        char *buffer = NULL;
+        int result;
+        struct yaffs_ext_tags tags;
+        struct yaffs_dev *dev = obj->my_dev;
+        int x_offs = sizeof(struct yaffs_obj_hdr);
+        int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
+
+        char *x_buffer;
+
+        int retval = 0;
+
+        if (obj->hdr_chunk < 1)
+                return -ENODATA;
+
+        /* If we know that the object has no xattribs then don't do all the
+         * reading and parsing.
+         */
+        if (obj->xattr_known && !obj->has_xattr) {
+                if (name)
+                        return -ENODATA;
+                else
+                        return 0;
+        }
+
+        buffer = (char *)yaffs_get_temp_buffer(dev, __LINE__);
+        if (!buffer)
+                return -ENOMEM;
+
+        result =
+            yaffs_rd_chunk_tags_nand(dev, obj->hdr_chunk, (u8 *) buffer, &tags);
+
+        if (result != YAFFS_OK)
+                retval = -ENOENT;
+        else {
+                x_buffer = buffer + x_offs;
+
+                if (!obj->xattr_known) {
+                        obj->has_xattr = nval_hasvalues(x_buffer, x_size);
+                        obj->xattr_known = 1;
+                }
+
+                if (name)
+                        retval = nval_get(x_buffer, x_size, name, value, size);
+                else
+                        retval = nval_list(x_buffer, x_size, value, size);
+        }
+        yaffs_release_temp_buffer(dev, (u8 *) buffer, __LINE__);
+        return retval;
+}
+
+int yaffs_set_xattrib(struct yaffs_obj *obj, const YCHAR * name,
+                      const void *value, int size, int flags)
+{
+        return yaffs_do_xattrib_mod(obj, 1, name, value, size, flags);
+}
+
+int yaffs_remove_xattrib(struct yaffs_obj *obj, const YCHAR * name)
+{
+        return yaffs_do_xattrib_mod(obj, 0, name, NULL, 0, 0);
+}
+
+int yaffs_get_xattrib(struct yaffs_obj *obj, const YCHAR * name, void *value,
+                      int size)
+{
+        return yaffs_do_xattrib_fetch(obj, name, value, size);
+}
+
+int yaffs_list_xattrib(struct yaffs_obj *obj, char *buffer, int size)
+{
+        return yaffs_do_xattrib_fetch(obj, NULL, buffer, size);
+}
+
+static void yaffs_check_obj_details_loaded(struct yaffs_obj *in)
+{
+        u8 *chunk_data;
+        struct yaffs_obj_hdr *oh;
+        struct yaffs_dev *dev;
+        struct yaffs_ext_tags tags;
+        int result;
+        int alloc_failed = 0;
+
+        if (!in)
+                return;
+
+        dev = in->my_dev;
+
+        if (in->lazy_loaded && in->hdr_chunk > 0) {
+                in->lazy_loaded = 0;
+                chunk_data = yaffs_get_temp_buffer(dev, __LINE__);
+
+                result =
+                    yaffs_rd_chunk_tags_nand(dev, in->hdr_chunk, chunk_data,
+                                             &tags);
+                oh = (struct yaffs_obj_hdr *)chunk_data;
+
+                in->yst_mode = oh->yst_mode;
+                yaffs_load_attribs(in, oh);
+                yaffs_set_obj_name_from_oh(in, oh);
+
+                if (in->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
+                        in->variant.symlink_variant.alias =
+                            yaffs_clone_str(oh->alias);
+                        if (!in->variant.symlink_variant.alias)
+                                alloc_failed = 1;       /* Not returned to caller */
+                }
+
+                yaffs_release_temp_buffer(dev, chunk_data, __LINE__);
+        }
+}
+
+static void yaffs_load_name_from_oh(struct yaffs_dev *dev, YCHAR * name,
+                                    const YCHAR * oh_name, int buff_size)
+{
+#ifdef CONFIG_YAFFS_AUTO_UNICODE
+        if (dev->param.auto_unicode) {
+                if (*oh_name) {
+                        /* It is an ASCII name, do an ASCII to
+                         * unicode conversion */
+                        const char *ascii_oh_name = (const char *)oh_name;
+                        int n = buff_size - 1;
+                        while (n > 0 && *ascii_oh_name) {
+                                *name = *ascii_oh_name;
+                                name++;
+                                ascii_oh_name++;
+                                n--;
+                        }
+                } else {
+                        strncpy(name, oh_name + 1, buff_size - 1);
+                }
+        } else {
+#else
+        {
+#endif
+                strncpy(name, oh_name, buff_size - 1);
+        }
+}
+
+static void yaffs_load_oh_from_name(struct yaffs_dev *dev, YCHAR * oh_name,
+                                    const YCHAR * name)
+{
+#ifdef CONFIG_YAFFS_AUTO_UNICODE
+
+        int is_ascii;
+        YCHAR *w;
+
+        if (dev->param.auto_unicode) {
+
+                is_ascii = 1;
+                w = name;
+
+                /* Figure out if the name will fit in ascii character set */
+                while (is_ascii && *w) {
+                        if ((*w) & 0xff00)
+                                is_ascii = 0;
+                        w++;
+                }
+
+                if (is_ascii) {
+                        /* It is an ASCII name, so do a unicode to ascii conversion */
+                        char *ascii_oh_name = (char *)oh_name;
+                        int n = YAFFS_MAX_NAME_LENGTH - 1;
+                        while (n > 0 && *name) {
+                                *ascii_oh_name = *name;
+                                name++;
+                                ascii_oh_name++;
+                                n--;
+                        }
+                } else {
+                        /* It is a unicode name, so save starting at the second YCHAR */
+                        *oh_name = 0;
+                        strncpy(oh_name + 1, name,
+                                      YAFFS_MAX_NAME_LENGTH - 2);
+                }
+        } else {
+#else
+        {
+#endif
+                strncpy(oh_name, name, YAFFS_MAX_NAME_LENGTH - 1);
+        }
+
+}
+
+/* UpdateObjectHeader updates the header on NAND for an object.
+ * If name is not NULL, then that new name is used.
+ */
+int yaffs_update_oh(struct yaffs_obj *in, const YCHAR * name, int force,
+                    int is_shrink, int shadows, struct yaffs_xattr_mod *xmod)
+{
+
+        struct yaffs_block_info *bi;
+
+        struct yaffs_dev *dev = in->my_dev;
+
+        int prev_chunk_id;
+        int ret_val = 0;
+        int result = 0;
+
+        int new_chunk_id;
+        struct yaffs_ext_tags new_tags;
+        struct yaffs_ext_tags old_tags;
+        const YCHAR *alias = NULL;
+
+        u8 *buffer = NULL;
+        YCHAR old_name[YAFFS_MAX_NAME_LENGTH + 1];
+
+        struct yaffs_obj_hdr *oh = NULL;
+
+        strcpy(old_name, _Y("silly old name"));
+
+        if (!in->fake || in == dev->root_dir ||
+            force || xmod) {
+
+                yaffs_check_gc(dev, 0);
+                yaffs_check_obj_details_loaded(in);
+
+                buffer = yaffs_get_temp_buffer(in->my_dev, __LINE__);
+                oh = (struct yaffs_obj_hdr *)buffer;
+
+                prev_chunk_id = in->hdr_chunk;
+
+                if (prev_chunk_id > 0) {
+                        result = yaffs_rd_chunk_tags_nand(dev, prev_chunk_id,
+                                                          buffer, &old_tags);
+
+                        yaffs_verify_oh(in, oh, &old_tags, 0);
+
+                        memcpy(old_name, oh->name, sizeof(oh->name));
+                        memset(buffer, 0xFF, sizeof(struct yaffs_obj_hdr));
+                } else {
+                        memset(buffer, 0xFF, dev->data_bytes_per_chunk);
+                }
+
+                oh->type = in->variant_type;
+                oh->yst_mode = in->yst_mode;
+                oh->shadows_obj = oh->inband_shadowed_obj_id = shadows;
+
+                yaffs_load_attribs_oh(oh, in);
+
+                if (in->parent)
+                        oh->parent_obj_id = in->parent->obj_id;
+                else
+                        oh->parent_obj_id = 0;
+
+                if (name && *name) {
+                        memset(oh->name, 0, sizeof(oh->name));
+                        yaffs_load_oh_from_name(dev, oh->name, name);
+                } else if (prev_chunk_id > 0) {
+                        memcpy(oh->name, old_name, sizeof(oh->name));
+                } else {
+                        memset(oh->name, 0, sizeof(oh->name));
+                }
+
+                oh->is_shrink = is_shrink;
+
+                switch (in->variant_type) {
+                case YAFFS_OBJECT_TYPE_UNKNOWN:
+                        /* Should not happen */
+                        break;
+                case YAFFS_OBJECT_TYPE_FILE:
+                        oh->file_size =
+                            (oh->parent_obj_id == YAFFS_OBJECTID_DELETED
+                             || oh->parent_obj_id ==
+                             YAFFS_OBJECTID_UNLINKED) ? 0 : in->
+                            variant.file_variant.file_size;
+                        break;
+                case YAFFS_OBJECT_TYPE_HARDLINK:
+                        oh->equiv_id = in->variant.hardlink_variant.equiv_id;
+                        break;
+                case YAFFS_OBJECT_TYPE_SPECIAL:
+                        /* Do nothing */
+                        break;
+                case YAFFS_OBJECT_TYPE_DIRECTORY:
+                        /* Do nothing */
+                        break;
+                case YAFFS_OBJECT_TYPE_SYMLINK:
+                        alias = in->variant.symlink_variant.alias;
+                        if (!alias)
+                                alias = _Y("no alias");
+                        strncpy(oh->alias, alias, YAFFS_MAX_ALIAS_LENGTH);
+                        oh->alias[YAFFS_MAX_ALIAS_LENGTH] = 0;
+                        break;
+                }
+
+                /* process any xattrib modifications */
+                if (xmod)
+                        yaffs_apply_xattrib_mod(in, (char *)buffer, xmod);
+
+                /* Tags */
+                yaffs_init_tags(&new_tags);
+                in->serial++;
+                new_tags.chunk_id = 0;
+                new_tags.obj_id = in->obj_id;
+                new_tags.serial_number = in->serial;
+
+                /* Add extra info for file header */
+
+                new_tags.extra_available = 1;
+                new_tags.extra_parent_id = oh->parent_obj_id;
+                new_tags.extra_length = oh->file_size;
+                new_tags.extra_is_shrink = oh->is_shrink;
+                new_tags.extra_equiv_id = oh->equiv_id;
+                new_tags.extra_shadows = (oh->shadows_obj > 0) ? 1 : 0;
+                new_tags.extra_obj_type = in->variant_type;
+
+                yaffs_verify_oh(in, oh, &new_tags, 1);
+
+                /* Create new chunk in NAND */
+                new_chunk_id =
+                    yaffs_write_new_chunk(dev, buffer, &new_tags,
+                                          (prev_chunk_id > 0) ? 1 : 0);
+
+                if (new_chunk_id >= 0) {
+
+                        in->hdr_chunk = new_chunk_id;
+
+                        if (prev_chunk_id > 0) {
+                                yaffs_chunk_del(dev, prev_chunk_id, 1,
+                                                __LINE__);
+                        }
+
+                        if (!yaffs_obj_cache_dirty(in))
+                                in->dirty = 0;
+
+                        /* If this was a shrink, then mark the block that the chunk lives on */
+                        if (is_shrink) {
+                                bi = yaffs_get_block_info(in->my_dev,
+                                                          new_chunk_id /
+                                                          in->my_dev->param.
+                                                          chunks_per_block);
+                                bi->has_shrink_hdr = 1;
+                        }
+
+                }
+
+                ret_val = new_chunk_id;
+
+        }
+
+        if (buffer)
+                yaffs_release_temp_buffer(dev, buffer, __LINE__);
+
+        return ret_val;
+}
+
+/*--------------------- File read/write ------------------------
+ * Read and write have very similar structures.
+ * In general the read/write has three parts to it
+ * An incomplete chunk to start with (if the read/write is not chunk-aligned)
+ * Some complete chunks
+ * An incomplete chunk to end off with
+ *
+ * Curve-balls: the first chunk might also be the last chunk.
+ */
+
+int yaffs_file_rd(struct yaffs_obj *in, u8 * buffer, loff_t offset, int n_bytes)
+{
+
+        int chunk;
+        u32 start;
+        int n_copy;
+        int n = n_bytes;
+        int n_done = 0;
+        struct yaffs_cache *cache;
+
+        struct yaffs_dev *dev;
+
+        dev = in->my_dev;
+
+        while (n > 0) {
+                /* chunk = offset / dev->data_bytes_per_chunk + 1; */
+                /* start = offset % dev->data_bytes_per_chunk; */
+                yaffs_addr_to_chunk(dev, offset, &chunk, &start);
+                chunk++;
+
+                /* OK now check for the curveball where the start and end are in
+                 * the same chunk.
+                 */
+                if ((start + n) < dev->data_bytes_per_chunk)
+                        n_copy = n;
+                else
+                        n_copy = dev->data_bytes_per_chunk - start;
+
+                cache = yaffs_find_chunk_cache(in, chunk);
+
+                /* If the chunk is already in the cache or it is less than a whole chunk
+                 * or we're using inband tags then use the cache (if there is caching)
+                 * else bypass the cache.
+                 */
+                if (cache || n_copy != dev->data_bytes_per_chunk
+                    || dev->param.inband_tags) {
+                        if (dev->param.n_caches > 0) {
+
+                                /* If we can't find the data in the cache, then load it up. */
+
+                                if (!cache) {
+                                        cache =
+                                            yaffs_grab_chunk_cache(in->my_dev);
+                                        cache->object = in;
+                                        cache->chunk_id = chunk;
+                                        cache->dirty = 0;
+                                        cache->locked = 0;
+                                        yaffs_rd_data_obj(in, chunk,
+                                                          cache->data);
+                                        cache->n_bytes = 0;
+                                }
+
+                                yaffs_use_cache(dev, cache, 0);
+
+                                cache->locked = 1;
+
+                                memcpy(buffer, &cache->data[start], n_copy);
+
+                                cache->locked = 0;
+                        } else {
+                                /* Read into the local buffer then copy.. */
+
+                                u8 *local_buffer =
+                                    yaffs_get_temp_buffer(dev, __LINE__);
+                                yaffs_rd_data_obj(in, chunk, local_buffer);
+
+                                memcpy(buffer, &local_buffer[start], n_copy);
+
+                                yaffs_release_temp_buffer(dev, local_buffer,
+                                                          __LINE__);
+                        }
+
+                } else {
+
+                        /* A full chunk. Read directly into the supplied buffer. */
+                        yaffs_rd_data_obj(in, chunk, buffer);
+
+                }
+
+                n -= n_copy;
+                offset += n_copy;
+                buffer += n_copy;
+                n_done += n_copy;
+
+        }
+
+        return n_done;
+}
+
+int yaffs_do_file_wr(struct yaffs_obj *in, const u8 * buffer, loff_t offset,
+                     int n_bytes, int write_trhrough)
+{
+
+        int chunk;
+        u32 start;
+        int n_copy;
+        int n = n_bytes;
+        int n_done = 0;
+        int n_writeback;
+        int start_write = offset;
+        int chunk_written = 0;
+        u32 n_bytes_read;
+        u32 chunk_start;
+
+        struct yaffs_dev *dev;
+
+        dev = in->my_dev;
+
+        while (n > 0 && chunk_written >= 0) {
+                yaffs_addr_to_chunk(dev, offset, &chunk, &start);
+
+                if (chunk * dev->data_bytes_per_chunk + start != offset ||
+                    start >= dev->data_bytes_per_chunk) {
+                        yaffs_trace(YAFFS_TRACE_ERROR,
+                                "AddrToChunk of offset %d gives chunk %d start %d",
+                                (int)offset, chunk, start);
+                }
+                chunk++;        /* File pos to chunk in file offset */
+
+                /* OK now check for the curveball where the start and end are in
+                 * the same chunk.
+                 */
+
+                if ((start + n) < dev->data_bytes_per_chunk) {
+                        n_copy = n;
+
+                        /* Now folks, to calculate how many bytes to write back....
+                         * If we're overwriting and not writing to then end of file then
+                         * we need to write back as much as was there before.
+                         */
+
+                        chunk_start = ((chunk - 1) * dev->data_bytes_per_chunk);
+
+                        if (chunk_start > in->variant.file_variant.file_size)
+                                n_bytes_read = 0;       /* Past end of file */
+                        else
+                                n_bytes_read =
+                                    in->variant.file_variant.file_size -
+                                    chunk_start;
+
+                        if (n_bytes_read > dev->data_bytes_per_chunk)
+                                n_bytes_read = dev->data_bytes_per_chunk;
+
+                        n_writeback =
+                            (n_bytes_read >
+                             (start + n)) ? n_bytes_read : (start + n);
+
+                        if (n_writeback < 0
+                            || n_writeback > dev->data_bytes_per_chunk)
+                                YBUG();
+
+                } else {
+                        n_copy = dev->data_bytes_per_chunk - start;
+                        n_writeback = dev->data_bytes_per_chunk;
+                }
+
+                if (n_copy != dev->data_bytes_per_chunk
+                    || dev->param.inband_tags) {
+                        /* An incomplete start or end chunk (or maybe both start and end chunk),
+                         * or we're using inband tags, so we want to use the cache buffers.
+                         */
+                        if (dev->param.n_caches > 0) {
+                                struct yaffs_cache *cache;
+                                /* If we can't find the data in the cache, then load the cache */
+                                cache = yaffs_find_chunk_cache(in, chunk);
+
+                                if (!cache
+                                    && yaffs_check_alloc_available(dev, 1)) {
+                                        cache = yaffs_grab_chunk_cache(dev);
+                                        cache->object = in;
+                                        cache->chunk_id = chunk;
+                                        cache->dirty = 0;
+                                        cache->locked = 0;
+                                        yaffs_rd_data_obj(in, chunk,
+                                                          cache->data);
+                                } else if (cache &&
+                                           !cache->dirty &&
+                                           !yaffs_check_alloc_available(dev,
+                                                                        1)) {
+                                        /* Drop the cache if it was a read cache item and
+                                         * no space check has been made for it.
+                                         */
+                                        cache = NULL;
+                                }
+
+                                if (cache) {
+                                        yaffs_use_cache(dev, cache, 1);
+                                        cache->locked = 1;
+
+                                        memcpy(&cache->data[start], buffer,
+                                               n_copy);
+
+                                        cache->locked = 0;
+                                        cache->n_bytes = n_writeback;
+
+                                        if (write_trhrough) {
+                                                chunk_written =
+                                                    yaffs_wr_data_obj
+                                                    (cache->object,
+                                                     cache->chunk_id,
+                                                     cache->data,
+                                                     cache->n_bytes, 1);
+                                                cache->dirty = 0;
+                                        }
+
+                                } else {
+                                        chunk_written = -1;     /* fail the write */
+                                }
+                        } else {
+                                /* An incomplete start or end chunk (or maybe both start and end chunk)
+                                 * Read into the local buffer then copy, then copy over and write back.
+                                 */
+
+                                u8 *local_buffer =
+                                    yaffs_get_temp_buffer(dev, __LINE__);
+
+                                yaffs_rd_data_obj(in, chunk, local_buffer);
+
+                                memcpy(&local_buffer[start], buffer, n_copy);
+
+                                chunk_written =
+                                    yaffs_wr_data_obj(in, chunk,
+                                                      local_buffer,
+                                                      n_writeback, 0);
+
+                                yaffs_release_temp_buffer(dev, local_buffer,
+                                                          __LINE__);
+
+                        }
+
+                } else {
+                        /* A full chunk. Write directly from the supplied buffer. */
+
+                        chunk_written =
+                            yaffs_wr_data_obj(in, chunk, buffer,
+                                              dev->data_bytes_per_chunk, 0);
+
+                        /* Since we've overwritten the cached data, we better invalidate it. */
+                        yaffs_invalidate_chunk_cache(in, chunk);
+                }
+
+                if (chunk_written >= 0) {
+                        n -= n_copy;
+                        offset += n_copy;
+                        buffer += n_copy;
+                        n_done += n_copy;
+                }
+
+        }
+
+        /* Update file object */
+
+        if ((start_write + n_done) > in->variant.file_variant.file_size)
+                in->variant.file_variant.file_size = (start_write + n_done);
+
+        in->dirty = 1;
+
+        return n_done;
+}
+
+int yaffs_wr_file(struct yaffs_obj *in, const u8 * buffer, loff_t offset,
+                  int n_bytes, int write_trhrough)
+{
+        yaffs2_handle_hole(in, offset);
+        return yaffs_do_file_wr(in, buffer, offset, n_bytes, write_trhrough);
+}
+
+/* ---------------------- File resizing stuff ------------------ */
+
+static void yaffs_prune_chunks(struct yaffs_obj *in, int new_size)
+{
+
+        struct yaffs_dev *dev = in->my_dev;
+        int old_size = in->variant.file_variant.file_size;
+
+        int last_del = 1 + (old_size - 1) / dev->data_bytes_per_chunk;
+
+        int start_del = 1 + (new_size + dev->data_bytes_per_chunk - 1) /
+            dev->data_bytes_per_chunk;
+        int i;
+        int chunk_id;
+
+        /* Delete backwards so that we don't end up with holes if
+         * power is lost part-way through the operation.
+         */
+        for (i = last_del; i >= start_del; i--) {
+                /* NB this could be optimised somewhat,
+                 * eg. could retrieve the tags and write them without
+                 * using yaffs_chunk_del
+                 */
+
+                chunk_id = yaffs_find_del_file_chunk(in, i, NULL);
+                if (chunk_id > 0) {
+                        if (chunk_id <
+                            (dev->internal_start_block *
+                             dev->param.chunks_per_block)
+                            || chunk_id >=
+                            ((dev->internal_end_block +
+                              1) * dev->param.chunks_per_block)) {
+                                yaffs_trace(YAFFS_TRACE_ALWAYS,
+                                        "Found daft chunk_id %d for %d",
+                                        chunk_id, i);
+                        } else {
+                                in->n_data_chunks--;
+                                yaffs_chunk_del(dev, chunk_id, 1, __LINE__);
+                        }
+                }
+        }
+
+}
+
+void yaffs_resize_file_down(struct yaffs_obj *obj, loff_t new_size)
+{
+        int new_full;
+        u32 new_partial;
+        struct yaffs_dev *dev = obj->my_dev;
+
+        yaffs_addr_to_chunk(dev, new_size, &new_full, &new_partial);
+
+        yaffs_prune_chunks(obj, new_size);
+
+        if (new_partial != 0) {
+                int last_chunk = 1 + new_full;
+                u8 *local_buffer = yaffs_get_temp_buffer(dev, __LINE__);
+
+                /* Rewrite the last chunk with its new size and zero pad */
+                yaffs_rd_data_obj(obj, last_chunk, local_buffer);
+                memset(local_buffer + new_partial, 0,
+                       dev->data_bytes_per_chunk - new_partial);
+
+                yaffs_wr_data_obj(obj, last_chunk, local_buffer,
+                                  new_partial, 1);
+
+                yaffs_release_temp_buffer(dev, local_buffer, __LINE__);
+        }
+
+        obj->variant.file_variant.file_size = new_size;
+
+        yaffs_prune_tree(dev, &obj->variant.file_variant);
+}
+
+int yaffs_resize_file(struct yaffs_obj *in, loff_t new_size)
+{
+        struct yaffs_dev *dev = in->my_dev;
+        int old_size = in->variant.file_variant.file_size;
+
+        yaffs_flush_file_cache(in);
+        yaffs_invalidate_whole_cache(in);
+
+        yaffs_check_gc(dev, 0);
+
+        if (in->variant_type != YAFFS_OBJECT_TYPE_FILE)
+                return YAFFS_FAIL;
+
+        if (new_size == old_size)
+                return YAFFS_OK;
+
+        if (new_size > old_size) {
+                yaffs2_handle_hole(in, new_size);
+                in->variant.file_variant.file_size = new_size;
+        } else {
+                /* new_size < old_size */
+                yaffs_resize_file_down(in, new_size);
+        }
+
+        /* Write a new object header to reflect the resize.
+         * show we've shrunk the file, if need be
+         * Do this only if the file is not in the deleted directories
+         * and is not shadowed.
+         */
+        if (in->parent &&
+            !in->is_shadowed &&
+            in->parent->obj_id != YAFFS_OBJECTID_UNLINKED &&
+            in->parent->obj_id != YAFFS_OBJECTID_DELETED)
+                yaffs_update_oh(in, NULL, 0, 0, 0, NULL);
+
+        return YAFFS_OK;
+}
+
+int yaffs_flush_file(struct yaffs_obj *in, int update_time, int data_sync)
+{
+        int ret_val;
+        if (in->dirty) {
+                yaffs_flush_file_cache(in);
+                if (data_sync)  /* Only sync data */
+                        ret_val = YAFFS_OK;
+                else {
+                        if (update_time)
+                                yaffs_load_current_time(in, 0, 0);
+
+                        ret_val = (yaffs_update_oh(in, NULL, 0, 0, 0, NULL) >=
+                                   0) ? YAFFS_OK : YAFFS_FAIL;
+                }
+        } else {
+                ret_val = YAFFS_OK;
+        }
+
+        return ret_val;
+
+}
+
+
+/* yaffs_del_file deletes the whole file data
+ * and the inode associated with the file.
+ * It does not delete the links associated with the file.
+ */
+static int yaffs_unlink_file_if_needed(struct yaffs_obj *in)
+{
+
+        int ret_val;
+        int del_now = 0;
+        struct yaffs_dev *dev = in->my_dev;
+
+        if (!in->my_inode)
+                del_now = 1;
+
+        if (del_now) {
+                ret_val =
+                    yaffs_change_obj_name(in, in->my_dev->del_dir,
+                                          _Y("deleted"), 0, 0);
+                yaffs_trace(YAFFS_TRACE_TRACING,
+                        "yaffs: immediate deletion of file %d",
+                        in->obj_id);
+                in->deleted = 1;
+                in->my_dev->n_deleted_files++;
+                if (dev->param.disable_soft_del || dev->param.is_yaffs2)
+                        yaffs_resize_file(in, 0);
+                yaffs_soft_del_file(in);
+        } else {
+                ret_val =
+                    yaffs_change_obj_name(in, in->my_dev->unlinked_dir,
+                                          _Y("unlinked"), 0, 0);
+        }
+
+        return ret_val;
+}
+
+int yaffs_del_file(struct yaffs_obj *in)
+{
+        int ret_val = YAFFS_OK;
+        int deleted;            /* Need to cache value on stack if in is freed */
+        struct yaffs_dev *dev = in->my_dev;
+
+        if (dev->param.disable_soft_del || dev->param.is_yaffs2)
+                yaffs_resize_file(in, 0);
+
+        if (in->n_data_chunks > 0) {
+                /* Use soft deletion if there is data in the file.
+                 * That won't be the case if it has been resized to zero.
+                 */
+                if (!in->unlinked)
+                        ret_val = yaffs_unlink_file_if_needed(in);
+
+                deleted = in->deleted;
+
+                if (ret_val == YAFFS_OK && in->unlinked && !in->deleted) {
+                        in->deleted = 1;
+                        deleted = 1;
+                        in->my_dev->n_deleted_files++;
+                        yaffs_soft_del_file(in);
+                }
+                return deleted ? YAFFS_OK : YAFFS_FAIL;
+        } else {
+                /* The file has no data chunks so we toss it immediately */
+                yaffs_free_tnode(in->my_dev, in->variant.file_variant.top);
+                in->variant.file_variant.top = NULL;
+                yaffs_generic_obj_del(in);
+
+                return YAFFS_OK;
+        }
+}
+
+int yaffs_is_non_empty_dir(struct yaffs_obj *obj)
+{
+        return (obj &&
+                obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY) &&
+                !(list_empty(&obj->variant.dir_variant.children));
+}
+
+static int yaffs_del_dir(struct yaffs_obj *obj)
+{
+        /* First check that the directory is empty. */
+        if (yaffs_is_non_empty_dir(obj))
+                return YAFFS_FAIL;
+
+        return yaffs_generic_obj_del(obj);
+}
+
+static int yaffs_del_symlink(struct yaffs_obj *in)
+{
+        if (in->variant.symlink_variant.alias)
+                kfree(in->variant.symlink_variant.alias);
+        in->variant.symlink_variant.alias = NULL;
+
+        return yaffs_generic_obj_del(in);
+}
+
+static int yaffs_del_link(struct yaffs_obj *in)
+{
+        /* remove this hardlink from the list assocaited with the equivalent
+         * object
+         */
+        list_del_init(&in->hard_links);
+        return yaffs_generic_obj_del(in);
+}
+
+int yaffs_del_obj(struct yaffs_obj *obj)
+{
+        int ret_val = -1;
+        switch (obj->variant_type) {
+        case YAFFS_OBJECT_TYPE_FILE:
+                ret_val = yaffs_del_file(obj);
+                break;
+        case YAFFS_OBJECT_TYPE_DIRECTORY:
+                if (!list_empty(&obj->variant.dir_variant.dirty)) {
+                        yaffs_trace(YAFFS_TRACE_BACKGROUND,
+                                "Remove object %d from dirty directories",
+                                obj->obj_id);
+                        list_del_init(&obj->variant.dir_variant.dirty);
+                }
+                return yaffs_del_dir(obj);
+                break;
+        case YAFFS_OBJECT_TYPE_SYMLINK:
+                ret_val = yaffs_del_symlink(obj);
+                break;
+        case YAFFS_OBJECT_TYPE_HARDLINK:
+                ret_val = yaffs_del_link(obj);
+                break;
+        case YAFFS_OBJECT_TYPE_SPECIAL:
+                ret_val = yaffs_generic_obj_del(obj);
+                break;
+        case YAFFS_OBJECT_TYPE_UNKNOWN:
+                ret_val = 0;
+                break;          /* should not happen. */
+        }
+
+        return ret_val;
+}
+
+static int yaffs_unlink_worker(struct yaffs_obj *obj)
+{
+
+        int del_now = 0;
+
+        if (!obj->my_inode)
+                del_now = 1;
+
+        if (obj)
+                yaffs_update_parent(obj->parent);
+
+        if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
+                return yaffs_del_link(obj);
+        } else if (!list_empty(&obj->hard_links)) {
+                /* Curve ball: We're unlinking an object that has a hardlink.
+                 *
+                 * This problem arises because we are not strictly following
+                 * The Linux link/inode model.
+                 *
+                 * We can't really delete the object.
+                 * Instead, we do the following:
+                 * - Select a hardlink.
+                 * - Unhook it from the hard links
+                 * - Move it from its parent directory (so that the rename can work)
+                 * - Rename the object to the hardlink's name.
+                 * - Delete the hardlink
+                 */
+
+                struct yaffs_obj *hl;
+                struct yaffs_obj *parent;
+                int ret_val;
+                YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];
+
+                hl = list_entry(obj->hard_links.next, struct yaffs_obj,
+                                hard_links);
+
+                yaffs_get_obj_name(hl, name, YAFFS_MAX_NAME_LENGTH + 1);
+                parent = hl->parent;
+
+                list_del_init(&hl->hard_links);
+
+                yaffs_add_obj_to_dir(obj->my_dev->unlinked_dir, hl);
+
+                ret_val = yaffs_change_obj_name(obj, parent, name, 0, 0);
+
+                if (ret_val == YAFFS_OK)
+                        ret_val = yaffs_generic_obj_del(hl);
+
+                return ret_val;
+
+        } else if (del_now) {
+                switch (obj->variant_type) {
+                case YAFFS_OBJECT_TYPE_FILE:
+                        return yaffs_del_file(obj);
+                        break;
+                case YAFFS_OBJECT_TYPE_DIRECTORY:
+                        list_del_init(&obj->variant.dir_variant.dirty);
+                        return yaffs_del_dir(obj);
+                        break;
+                case YAFFS_OBJECT_TYPE_SYMLINK:
+                        return yaffs_del_symlink(obj);
+                        break;
+                case YAFFS_OBJECT_TYPE_SPECIAL:
+                        return yaffs_generic_obj_del(obj);
+                        break;
+                case YAFFS_OBJECT_TYPE_HARDLINK:
+                case YAFFS_OBJECT_TYPE_UNKNOWN:
+                default:
+                        return YAFFS_FAIL;
+                }
+        } else if (yaffs_is_non_empty_dir(obj)) {
+                return YAFFS_FAIL;
+        } else {
+                return yaffs_change_obj_name(obj, obj->my_dev->unlinked_dir,
+                                             _Y("unlinked"), 0, 0);
+        }
+}
+
+static int yaffs_unlink_obj(struct yaffs_obj *obj)
+{
+
+        if (obj && obj->unlink_allowed)
+                return yaffs_unlink_worker(obj);
+
+        return YAFFS_FAIL;
+
+}
+
+int yaffs_unlinker(struct yaffs_obj *dir, const YCHAR * name)
+{
+        struct yaffs_obj *obj;
+
+        obj = yaffs_find_by_name(dir, name);
+        return yaffs_unlink_obj(obj);
+}
+
+/* Note:
+ * If old_name is NULL then we take old_dir as the object to be renamed.
+ */
+int yaffs_rename_obj(struct yaffs_obj *old_dir, const YCHAR * old_name,
+                     struct yaffs_obj *new_dir, const YCHAR * new_name)
+{
+        struct yaffs_obj *obj = NULL;
+        struct yaffs_obj *existing_target = NULL;
+        int force = 0;
+        int result;
+        struct yaffs_dev *dev;
+
+        if (!old_dir || old_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
+                YBUG();
+        if (!new_dir || new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
+                YBUG();
+
+        dev = old_dir->my_dev;
+
+#ifdef CONFIG_YAFFS_CASE_INSENSITIVE
+        /* Special case for case insemsitive systems.
+         * While look-up is case insensitive, the name isn't.
+         * Therefore we might want to change x.txt to X.txt
+         */
+        if (old_dir == new_dir && 
+                old_name && new_name && 
+                strcmp(old_name, new_name) == 0)
+                force = 1;
+#endif
+
+        if (strnlen(new_name, YAFFS_MAX_NAME_LENGTH + 1) >
+            YAFFS_MAX_NAME_LENGTH)
+                /* ENAMETOOLONG */
+                return YAFFS_FAIL;
+
+        if(old_name)
+                obj = yaffs_find_by_name(old_dir, old_name);
+        else{
+                obj = old_dir;
+                old_dir = obj->parent;
+        }
+
+
+        if (obj && obj->rename_allowed) {
+
+                /* Now do the handling for an existing target, if there is one */
+
+                existing_target = yaffs_find_by_name(new_dir, new_name);
+                if (yaffs_is_non_empty_dir(existing_target)){
+                        return YAFFS_FAIL;      /* ENOTEMPTY */
+                } else if (existing_target && existing_target != obj) {
+                        /* Nuke the target first, using shadowing,
+                         * but only if it isn't the same object.
+                         *
+                         * Note we must disable gc otherwise it can mess up the shadowing.
+                         *
+                         */
+                        dev->gc_disable = 1;
+                        yaffs_change_obj_name(obj, new_dir, new_name, force,
+                                              existing_target->obj_id);
+                        existing_target->is_shadowed = 1;
+                        yaffs_unlink_obj(existing_target);
+                        dev->gc_disable = 0;
+                }
+
+                result = yaffs_change_obj_name(obj, new_dir, new_name, 1, 0);
+
+                yaffs_update_parent(old_dir);
+                if (new_dir != old_dir)
+                        yaffs_update_parent(new_dir);
+
+                return result;
+        }
+        return YAFFS_FAIL;
+}
+
+/*----------------------- Initialisation Scanning ---------------------- */
+
+void yaffs_handle_shadowed_obj(struct yaffs_dev *dev, int obj_id,
+                               int backward_scanning)
+{
+        struct yaffs_obj *obj;
+
+        if (!backward_scanning) {
+                /* Handle YAFFS1 forward scanning case
+                 * For YAFFS1 we always do the deletion
+                 */
+
+        } else {
+                /* Handle YAFFS2 case (backward scanning)
+                 * If the shadowed object exists then ignore.
+                 */
+                obj = yaffs_find_by_number(dev, obj_id);
+                if (obj)
+                        return;
+        }
+
+        /* Let's create it (if it does not exist) assuming it is a file so that it can do shrinking etc.
+         * We put it in unlinked dir to be cleaned up after the scanning
+         */
+        obj =
+            yaffs_find_or_create_by_number(dev, obj_id, YAFFS_OBJECT_TYPE_FILE);
+        if (!obj)
+                return;
+        obj->is_shadowed = 1;
+        yaffs_add_obj_to_dir(dev->unlinked_dir, obj);
+        obj->variant.file_variant.shrink_size = 0;
+        obj->valid = 1;         /* So that we don't read any other info for this file */
+
+}
+
+void yaffs_link_fixup(struct yaffs_dev *dev, struct yaffs_obj *hard_list)
+{
+        struct yaffs_obj *hl;
+        struct yaffs_obj *in;
+
+        while (hard_list) {
+                hl = hard_list;
+                hard_list = (struct yaffs_obj *)(hard_list->hard_links.next);
+
+                in = yaffs_find_by_number(dev,
+                                          hl->variant.
+                                          hardlink_variant.equiv_id);
+
+                if (in) {
+                        /* Add the hardlink pointers */
+                        hl->variant.hardlink_variant.equiv_obj = in;
+                        list_add(&hl->hard_links, &in->hard_links);
+                } else {
+                        /* Todo Need to report/handle this better.
+                         * Got a problem... hardlink to a non-existant object
+                         */
+                        hl->variant.hardlink_variant.equiv_obj = NULL;
+                        INIT_LIST_HEAD(&hl->hard_links);
+
+                }
+        }
+}
+
+static void yaffs_strip_deleted_objs(struct yaffs_dev *dev)
+{
+        /*
+         *  Sort out state of unlinked and deleted objects after scanning.
+         */
+        struct list_head *i;
+        struct list_head *n;
+        struct yaffs_obj *l;
+
+        if (dev->read_only)
+                return;
+
+        /* Soft delete all the unlinked files */
+        list_for_each_safe(i, n,
+                           &dev->unlinked_dir->variant.dir_variant.children) {
+                if (i) {
+                        l = list_entry(i, struct yaffs_obj, siblings);
+                        yaffs_del_obj(l);
+                }
+        }
+
+        list_for_each_safe(i, n, &dev->del_dir->variant.dir_variant.children) {
+                if (i) {
+                        l = list_entry(i, struct yaffs_obj, siblings);
+                        yaffs_del_obj(l);
+                }
+        }
+
+}
+
+/*
+ * This code iterates through all the objects making sure that they are rooted.
+ * Any unrooted objects are re-rooted in lost+found.
+ * An object needs to be in one of:
+ * - Directly under deleted, unlinked
+ * - Directly or indirectly under root.
+ *
+ * Note:
+ *  This code assumes that we don't ever change the current relationships between
+ *  directories:
+ *   root_dir->parent == unlinked_dir->parent == del_dir->parent == NULL
+ *   lost-n-found->parent == root_dir
+ *
+ * This fixes the problem where directories might have inadvertently been deleted
+ * leaving the object "hanging" without being rooted in the directory tree.
+ */
+
+static int yaffs_has_null_parent(struct yaffs_dev *dev, struct yaffs_obj *obj)
+{
+        return (obj == dev->del_dir ||
+                obj == dev->unlinked_dir || obj == dev->root_dir);
+}
+
+static void yaffs_fix_hanging_objs(struct yaffs_dev *dev)
+{
+        struct yaffs_obj *obj;
+        struct yaffs_obj *parent;
+        int i;
+        struct list_head *lh;
+        struct list_head *n;
+        int depth_limit;
+        int hanging;
+
+        if (dev->read_only)
+                return;
+
+        /* Iterate through the objects in each hash entry,
+         * looking at each object.
+         * Make sure it is rooted.
+         */
+
+        for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
+                list_for_each_safe(lh, n, &dev->obj_bucket[i].list) {
+                        if (lh) {
+                                obj =
+                                    list_entry(lh, struct yaffs_obj, hash_link);
+                                parent = obj->parent;
+
+                                if (yaffs_has_null_parent(dev, obj)) {
+                                        /* These directories are not hanging */
+                                        hanging = 0;
+                                } else if (!parent
+                                           || parent->variant_type !=
+                                           YAFFS_OBJECT_TYPE_DIRECTORY) {
+                                        hanging = 1;
+                                } else if (yaffs_has_null_parent(dev, parent)) {
+                                        hanging = 0;
+                                } else {
+                                        /*
+                                         * Need to follow the parent chain to see if it is hanging.
+                                         */
+                                        hanging = 0;
+                                        depth_limit = 100;
+
+                                        while (parent != dev->root_dir &&
+                                               parent->parent &&
+                                               parent->parent->variant_type ==
+                                               YAFFS_OBJECT_TYPE_DIRECTORY
+                                               && depth_limit > 0) {
+                                                parent = parent->parent;
+                                                depth_limit--;
+                                        }
+                                        if (parent != dev->root_dir)
+                                                hanging = 1;
+                                }
+                                if (hanging) {
+                                        yaffs_trace(YAFFS_TRACE_SCAN,
+                                                "Hanging object %d moved to lost and found",
+                                                obj->obj_id);
+                                        yaffs_add_obj_to_dir(dev->lost_n_found,
+                                                             obj);
+                                }
+                        }
+                }
+        }
+}
+
+/*
+ * Delete directory contents for cleaning up lost and found.
+ */
+static void yaffs_del_dir_contents(struct yaffs_obj *dir)
+{
+        struct yaffs_obj *obj;
+        struct list_head *lh;
+        struct list_head *n;
+
+        if (dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
+                YBUG();
+
+        list_for_each_safe(lh, n, &dir->variant.dir_variant.children) {
+                if (lh) {
+                        obj = list_entry(lh, struct yaffs_obj, siblings);
+                        if (obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY)
+                                yaffs_del_dir_contents(obj);
+
+                        yaffs_trace(YAFFS_TRACE_SCAN,
+                                "Deleting lost_found object %d",
+                                obj->obj_id);
+
+                        /* Need to use UnlinkObject since Delete would not handle
+                         * hardlinked objects correctly.
+                         */
+                        yaffs_unlink_obj(obj);
+                }
+        }
+
+}
+
+static void yaffs_empty_l_n_f(struct yaffs_dev *dev)
+{
+        yaffs_del_dir_contents(dev->lost_n_found);
+}
+
+
+struct yaffs_obj *yaffs_find_by_name(struct yaffs_obj *directory,
+                                     const YCHAR * name)
+{
+        int sum;
+
+        struct list_head *i;
+        YCHAR buffer[YAFFS_MAX_NAME_LENGTH + 1];
+
+        struct yaffs_obj *l;
+
+        if (!name)
+                return NULL;
+
+        if (!directory) {
+                yaffs_trace(YAFFS_TRACE_ALWAYS,
+                        "tragedy: yaffs_find_by_name: null pointer directory"
+                        );
+                YBUG();
+                return NULL;
+        }
+        if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+                yaffs_trace(YAFFS_TRACE_ALWAYS,
+                        "tragedy: yaffs_find_by_name: non-directory"
+                        );
+                YBUG();
+        }
+
+        sum = yaffs_calc_name_sum(name);
+
+        list_for_each(i, &directory->variant.dir_variant.children) {
+                if (i) {
+                        l = list_entry(i, struct yaffs_obj, siblings);
+
+                        if (l->parent != directory)
+                                YBUG();
+
+                        yaffs_check_obj_details_loaded(l);
+
+                        /* Special case for lost-n-found */
+                        if (l->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
+                                if (!strcmp(name, YAFFS_LOSTNFOUND_NAME))
+                                        return l;
+                        } else if (l->sum == sum
+                                   || l->hdr_chunk <= 0) {
+                                /* LostnFound chunk called Objxxx
+                                 * Do a real check
+                                 */
+                                yaffs_get_obj_name(l, buffer,
+                                                   YAFFS_MAX_NAME_LENGTH + 1);
+                                if (strncmp
+                                    (name, buffer, YAFFS_MAX_NAME_LENGTH) == 0)
+                                        return l;
+                        }
+                }
+        }
+
+        return NULL;
+}
+
+/* GetEquivalentObject dereferences any hard links to get to the
+ * actual object.
+ */
+
+struct yaffs_obj *yaffs_get_equivalent_obj(struct yaffs_obj *obj)
+{
+        if (obj && obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
+                /* We want the object id of the equivalent object, not this one */
+                obj = obj->variant.hardlink_variant.equiv_obj;
+                yaffs_check_obj_details_loaded(obj);
+        }
+        return obj;
+}
+
+/*
+ *  A note or two on object names.
+ *  * If the object name is missing, we then make one up in the form objnnn
+ *
+ *  * ASCII names are stored in the object header's name field from byte zero
+ *  * Unicode names are historically stored starting from byte zero.
+ *
+ * Then there are automatic Unicode names...
+ * The purpose of these is to save names in a way that can be read as
+ * ASCII or Unicode names as appropriate, thus allowing a Unicode and ASCII
+ * system to share files.
+ *
+ * These automatic unicode are stored slightly differently...
+ *  - If the name can fit in the ASCII character space then they are saved as 
+ *    ascii names as per above.
+ *  - If the name needs Unicode then the name is saved in Unicode
+ *    starting at oh->name[1].
+
+ */
+static void yaffs_fix_null_name(struct yaffs_obj *obj, YCHAR * name,
+                                int buffer_size)
+{
+        /* Create an object name if we could not find one. */
+        if (strnlen(name, YAFFS_MAX_NAME_LENGTH) == 0) {
+                YCHAR local_name[20];
+                YCHAR num_string[20];
+                YCHAR *x = &num_string[19];
+                unsigned v = obj->obj_id;
+                num_string[19] = 0;
+                while (v > 0) {
+                        x--;
+                        *x = '0' + (v % 10);
+                        v /= 10;
+                }
+                /* make up a name */
+                strcpy(local_name, YAFFS_LOSTNFOUND_PREFIX);
+                strcat(local_name, x);
+                strncpy(name, local_name, buffer_size - 1);
+        }
+}
+
+int yaffs_get_obj_name(struct yaffs_obj *obj, YCHAR * name, int buffer_size)
+{
+        memset(name, 0, buffer_size * sizeof(YCHAR));
+
+        yaffs_check_obj_details_loaded(obj);
+
+        if (obj->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
+                strncpy(name, YAFFS_LOSTNFOUND_NAME, buffer_size - 1);
+        }
+#ifndef CONFIG_YAFFS_NO_SHORT_NAMES
+        else if (obj->short_name[0]) {
+                strcpy(name, obj->short_name);
+        }
+#endif
+        else if (obj->hdr_chunk > 0) {
+                int result;
+                u8 *buffer = yaffs_get_temp_buffer(obj->my_dev, __LINE__);
+
+                struct yaffs_obj_hdr *oh = (struct yaffs_obj_hdr *)buffer;
+
+                memset(buffer, 0, obj->my_dev->data_bytes_per_chunk);
+
+                if (obj->hdr_chunk > 0) {
+                        result = yaffs_rd_chunk_tags_nand(obj->my_dev,
+                                                          obj->hdr_chunk,
+                                                          buffer, NULL);
+                }
+                yaffs_load_name_from_oh(obj->my_dev, name, oh->name,
+                                        buffer_size);
+
+                yaffs_release_temp_buffer(obj->my_dev, buffer, __LINE__);
+        }
+
+        yaffs_fix_null_name(obj, name, buffer_size);
+
+        return strnlen(name, YAFFS_MAX_NAME_LENGTH);
+}
+
+int yaffs_get_obj_length(struct yaffs_obj *obj)
+{
+        /* Dereference any hard linking */
+        obj = yaffs_get_equivalent_obj(obj);
+
+        if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
+                return obj->variant.file_variant.file_size;
+        if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
+                if (!obj->variant.symlink_variant.alias)
+                        return 0;
+                return strnlen(obj->variant.symlink_variant.alias,
+                                     YAFFS_MAX_ALIAS_LENGTH);
+        } else {
+                /* Only a directory should drop through to here */
+                return obj->my_dev->data_bytes_per_chunk;
+        }
+}
+
+int yaffs_get_obj_link_count(struct yaffs_obj *obj)
+{
+        int count = 0;
+        struct list_head *i;
+
+        if (!obj->unlinked)
+                count++;        /* the object itself */
+
+        list_for_each(i, &obj->hard_links)
+            count++;            /* add the hard links; */
+
+        return count;
+}
+
+int yaffs_get_obj_inode(struct yaffs_obj *obj)
+{
+        obj = yaffs_get_equivalent_obj(obj);
+
+        return obj->obj_id;
+}
+
+unsigned yaffs_get_obj_type(struct yaffs_obj *obj)
+{
+        obj = yaffs_get_equivalent_obj(obj);
+
+        switch (obj->variant_type) {
+        case YAFFS_OBJECT_TYPE_FILE:
+                return DT_REG;
+                break;
+        case YAFFS_OBJECT_TYPE_DIRECTORY:
+                return DT_DIR;
+                break;
+        case YAFFS_OBJECT_TYPE_SYMLINK:
+                return DT_LNK;
+                break;
+        case YAFFS_OBJECT_TYPE_HARDLINK:
+                return DT_REG;
+                break;
+        case YAFFS_OBJECT_TYPE_SPECIAL:
+                if (S_ISFIFO(obj->yst_mode))
+                        return DT_FIFO;
+                if (S_ISCHR(obj->yst_mode))
+                        return DT_CHR;
+                if (S_ISBLK(obj->yst_mode))
+                        return DT_BLK;
+                if (S_ISSOCK(obj->yst_mode))
+                        return DT_SOCK;
+        default:
+                return DT_REG;
+                break;
+        }
+}
+
+YCHAR *yaffs_get_symlink_alias(struct yaffs_obj *obj)
+{
+        obj = yaffs_get_equivalent_obj(obj);
+        if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK)
+                return yaffs_clone_str(obj->variant.symlink_variant.alias);
+        else
+                return yaffs_clone_str(_Y(""));
+}
+
+/*--------------------------- Initialisation code -------------------------- */
+
+static int yaffs_check_dev_fns(const struct yaffs_dev *dev)
+{
+
+        /* Common functions, gotta have */
+        if (!dev->param.erase_fn || !dev->param.initialise_flash_fn)
+                return 0;
+
+#ifdef CONFIG_YAFFS_YAFFS2
+
+        /* Can use the "with tags" style interface for yaffs1 or yaffs2 */
+        if (dev->param.write_chunk_tags_fn &&
+            dev->param.read_chunk_tags_fn &&
+            !dev->param.write_chunk_fn &&
+            !dev->param.read_chunk_fn &&
+            dev->param.bad_block_fn && dev->param.query_block_fn)
+                return 1;
+#endif
+
+        /* Can use the "spare" style interface for yaffs1 */
+        if (!dev->param.is_yaffs2 &&
+            !dev->param.write_chunk_tags_fn &&
+            !dev->param.read_chunk_tags_fn &&
+            dev->param.write_chunk_fn &&
+            dev->param.read_chunk_fn &&
+            !dev->param.bad_block_fn && !dev->param.query_block_fn)
+                return 1;
+
+        return 0;               /* bad */
+}
+
+static int yaffs_create_initial_dir(struct yaffs_dev *dev)
+{
+        /* Initialise the unlinked, deleted, root and lost and found directories */
+
+        dev->lost_n_found = dev->root_dir = NULL;
+        dev->unlinked_dir = dev->del_dir = NULL;
+
+        dev->unlinked_dir =
+            yaffs_create_fake_dir(dev, YAFFS_OBJECTID_UNLINKED, S_IFDIR);
+
+        dev->del_dir =
+            yaffs_create_fake_dir(dev, YAFFS_OBJECTID_DELETED, S_IFDIR);
+
+        dev->root_dir =
+            yaffs_create_fake_dir(dev, YAFFS_OBJECTID_ROOT,
+                                  YAFFS_ROOT_MODE | S_IFDIR);
+        dev->lost_n_found =
+            yaffs_create_fake_dir(dev, YAFFS_OBJECTID_LOSTNFOUND,
+                                  YAFFS_LOSTNFOUND_MODE | S_IFDIR);
+
+        if (dev->lost_n_found && dev->root_dir && dev->unlinked_dir
+            && dev->del_dir) {
+                yaffs_add_obj_to_dir(dev->root_dir, dev->lost_n_found);
+                return YAFFS_OK;
+        }
+
+        return YAFFS_FAIL;
+}
+
+int yaffs_guts_initialise(struct yaffs_dev *dev)
+{
+        int init_failed = 0;
+        unsigned x;
+        int bits;
+
+        yaffs_trace(YAFFS_TRACE_TRACING, "yaffs: yaffs_guts_initialise()" );
+
+        /* Check stuff that must be set */
+
+        if (!dev) {
+                yaffs_trace(YAFFS_TRACE_ALWAYS,
+                        "yaffs: Need a device"
+                        );
+                return YAFFS_FAIL;
+        }
+
+        dev->internal_start_block = dev->param.start_block;
+        dev->internal_end_block = dev->param.end_block;
+        dev->block_offset = 0;
+        dev->chunk_offset = 0;
+        dev->n_free_chunks = 0;
+
+        dev->gc_block = 0;
+
+        if (dev->param.start_block == 0) {
+                dev->internal_start_block = dev->param.start_block + 1;
+                dev->internal_end_block = dev->param.end_block + 1;
+                dev->block_offset = 1;
+                dev->chunk_offset = dev->param.chunks_per_block;
+        }
+
+        /* Check geometry parameters. */
+
+        if ((!dev->param.inband_tags && dev->param.is_yaffs2 &&
+                dev->param.total_bytes_per_chunk < 1024) ||
+                (!dev->param.is_yaffs2 &&
+                        dev->param.total_bytes_per_chunk < 512) ||
+                (dev->param.inband_tags && !dev->param.is_yaffs2) ||
+                 dev->param.chunks_per_block < 2 ||
+                 dev->param.n_reserved_blocks < 2 ||
+                dev->internal_start_block <= 0 || 
+                dev->internal_end_block <= 0 || 
+                dev->internal_end_block <= 
+                (dev->internal_start_block + dev->param.n_reserved_blocks + 2)
+                ) {
+                /* otherwise it is too small */
+                yaffs_trace(YAFFS_TRACE_ALWAYS,
+                        "NAND geometry problems: chunk size %d, type is yaffs%s, inband_tags %d ",
+                        dev->param.total_bytes_per_chunk,
+                        dev->param.is_yaffs2 ? "2" : "",
+                        dev->param.inband_tags);
+                return YAFFS_FAIL;
+        }
+
+        if (yaffs_init_nand(dev) != YAFFS_OK) {
+                yaffs_trace(YAFFS_TRACE_ALWAYS, "InitialiseNAND failed");
+                return YAFFS_FAIL;
+        }
+
+        /* Sort out space for inband tags, if required */
+        if (dev->param.inband_tags)
+                dev->data_bytes_per_chunk =
+                    dev->param.total_bytes_per_chunk -
+                    sizeof(struct yaffs_packed_tags2_tags_only);
+        else
+                dev->data_bytes_per_chunk = dev->param.total_bytes_per_chunk;
+
+        /* Got the right mix of functions? */
+        if (!yaffs_check_dev_fns(dev)) {
+                /* Function missing */
+                yaffs_trace(YAFFS_TRACE_ALWAYS,
+                        "device function(s) missing or wrong");
+
+                return YAFFS_FAIL;
+        }
+
+        if (dev->is_mounted) {
+                yaffs_trace(YAFFS_TRACE_ALWAYS, "device already mounted");
+                return YAFFS_FAIL;
+        }
+
+        /* Finished with most checks. One or two more checks happen later on too. */
+
+        dev->is_mounted = 1;
+
+        /* OK now calculate a few things for the device */
+
+        /*
+         *  Calculate all the chunk size manipulation numbers:
+         */
+        x = dev->data_bytes_per_chunk;
+        /* We always use dev->chunk_shift and dev->chunk_div */
+        dev->chunk_shift = calc_shifts(x);
+        x >>= dev->chunk_shift;
+        dev->chunk_div = x;
+        /* We only use chunk mask if chunk_div is 1 */
+        dev->chunk_mask = (1 << dev->chunk_shift) - 1;
+
+        /*
+         * Calculate chunk_grp_bits.
+         * We need to find the next power of 2 > than internal_end_block
+         */
+
+        x = dev->param.chunks_per_block * (dev->internal_end_block + 1);
+
+        bits = calc_shifts_ceiling(x);
+
+        /* Set up tnode width if wide tnodes are enabled. */
+        if (!dev->param.wide_tnodes_disabled) {
+                /* bits must be even so that we end up with 32-bit words */
+                if (bits & 1)
+                        bits++;
+                if (bits < 16)
+                        dev->tnode_width = 16;
+                else
+                        dev->tnode_width = bits;
+        } else {
+                dev->tnode_width = 16;
+        }
+
+        dev->tnode_mask = (1 << dev->tnode_width) - 1;
+
+        /* Level0 Tnodes are 16 bits or wider (if wide tnodes are enabled),
+         * so if the bitwidth of the
+         * chunk range we're using is greater than 16 we need
+         * to figure out chunk shift and chunk_grp_size
+         */
+
+        if (bits <= dev->tnode_width)
+                dev->chunk_grp_bits = 0;
+        else
+                dev->chunk_grp_bits = bits - dev->tnode_width;
+
+        dev->tnode_size = (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8;
+        if (dev->tnode_size < sizeof(struct yaffs_tnode))
+                dev->tnode_size = sizeof(struct yaffs_tnode);
+
+        dev->chunk_grp_size = 1 << dev->chunk_grp_bits;
+
+        if (dev->param.chunks_per_block < dev->chunk_grp_size) {
+                /* We have a problem because the soft delete won't work if
+                 * the chunk group size > chunks per block.
+                 * This can be remedied by using larger "virtual blocks".
+                 */
+                yaffs_trace(YAFFS_TRACE_ALWAYS, "chunk group too large");
+
+                return YAFFS_FAIL;
+        }
+
+        /* OK, we've finished verifying the device, lets continue with initialisation */
+
+        /* More device initialisation */
+        dev->all_gcs = 0;
+        dev->passive_gc_count = 0;
+        dev->oldest_dirty_gc_count = 0;
+        dev->bg_gcs = 0;
+        dev->gc_block_finder = 0;
+        dev->buffered_block = -1;
+        dev->doing_buffered_block_rewrite = 0;
+        dev->n_deleted_files = 0;
+        dev->n_bg_deletions = 0;
+        dev->n_unlinked_files = 0;
+        dev->n_ecc_fixed = 0;
+        dev->n_ecc_unfixed = 0;
+        dev->n_tags_ecc_fixed = 0;
+        dev->n_tags_ecc_unfixed = 0;
+        dev->n_erase_failures = 0;
+        dev->n_erased_blocks = 0;
+        dev->gc_disable = 0;
+        dev->has_pending_prioritised_gc = 1;    /* Assume the worst for now, will get fixed on first GC */
+        INIT_LIST_HEAD(&dev->dirty_dirs);
+        dev->oldest_dirty_seq = 0;
+        dev->oldest_dirty_block = 0;
+
+        /* Initialise temporary buffers and caches. */
+        if (!yaffs_init_tmp_buffers(dev))
+                init_failed = 1;
+
+        dev->cache = NULL;
+        dev->gc_cleanup_list = NULL;
+
+        if (!init_failed && dev->param.n_caches > 0) {
+                int i;
+                void *buf;
+                int cache_bytes =
+                    dev->param.n_caches * sizeof(struct yaffs_cache);
+
+                if (dev->param.n_caches > YAFFS_MAX_SHORT_OP_CACHES)
+                        dev->param.n_caches = YAFFS_MAX_SHORT_OP_CACHES;
+
+                dev->cache = kmalloc(cache_bytes, GFP_NOFS);
+
+                buf = (u8 *) dev->cache;
+
+                if (dev->cache)
+                        memset(dev->cache, 0, cache_bytes);
+
+                for (i = 0; i < dev->param.n_caches && buf; i++) {
+                        dev->cache[i].object = NULL;
+                        dev->cache[i].last_use = 0;
+                        dev->cache[i].dirty = 0;
+                        dev->cache[i].data = buf =
+                            kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
+                }
+                if (!buf)
+                        init_failed = 1;
+
+                dev->cache_last_use = 0;
+        }
+
+        dev->cache_hits = 0;
+
+        if (!init_failed) {
+                dev->gc_cleanup_list =
+                    kmalloc(dev->param.chunks_per_block * sizeof(u32),
+                                        GFP_NOFS);
+                if (!dev->gc_cleanup_list)
+                        init_failed = 1;
+        }
+
+        if (dev->param.is_yaffs2)
+                dev->param.use_header_file_size = 1;
+
+        if (!init_failed && !yaffs_init_blocks(dev))
+                init_failed = 1;
+
+        yaffs_init_tnodes_and_objs(dev);
+
+        if (!init_failed && !yaffs_create_initial_dir(dev))
+                init_failed = 1;
+
+        if (!init_failed) {
+                /* Now scan the flash. */
+                if (dev->param.is_yaffs2) {
+                        if (yaffs2_checkpt_restore(dev)) {
+                                yaffs_check_obj_details_loaded(dev->root_dir);
+                                yaffs_trace(YAFFS_TRACE_CHECKPOINT | YAFFS_TRACE_MOUNT,
+                                        "yaffs: restored from checkpoint"
+                                        );
+                        } else {
+
+                                /* Clean up the mess caused by an aborted checkpoint load
+                                 * and scan backwards.
+                                 */
+                                yaffs_deinit_blocks(dev);
+
+                                yaffs_deinit_tnodes_and_objs(dev);
+
+                                dev->n_erased_blocks = 0;
+                                dev->n_free_chunks = 0;
+                                dev->alloc_block = -1;
+                                dev->alloc_page = -1;
+                                dev->n_deleted_files = 0;
+                                dev->n_unlinked_files = 0;
+                                dev->n_bg_deletions = 0;
+
+                                if (!init_failed && !yaffs_init_blocks(dev))
+                                        init_failed = 1;
+
+                                yaffs_init_tnodes_and_objs(dev);
+
+                                if (!init_failed
+                                    && !yaffs_create_initial_dir(dev))
+                                        init_failed = 1;
+
+                                if (!init_failed && !yaffs2_scan_backwards(dev))
+                                        init_failed = 1;
+                        }
+                } else if (!yaffs1_scan(dev)) {
+                        init_failed = 1;
+                }
+
+                yaffs_strip_deleted_objs(dev);
+                yaffs_fix_hanging_objs(dev);
+                if (dev->param.empty_lost_n_found)
+                        yaffs_empty_l_n_f(dev);
+        }
+
+        if (init_failed) {
+                /* Clean up the mess */
+                yaffs_trace(YAFFS_TRACE_TRACING,
+                  "yaffs: yaffs_guts_initialise() aborted.");
+
+                yaffs_deinitialise(dev);
+                return YAFFS_FAIL;
+        }
+
+        /* Zero out stats */
+        dev->n_page_reads = 0;
+        dev->n_page_writes = 0;
+        dev->n_erasures = 0;
+        dev->n_gc_copies = 0;
+        dev->n_retired_writes = 0;
+
+        dev->n_retired_blocks = 0;
+
+        yaffs_verify_free_chunks(dev);
+        yaffs_verify_blocks(dev);
+
+        /* Clean up any aborted checkpoint data */
+        if (!dev->is_checkpointed && dev->blocks_in_checkpt > 0)
+                yaffs2_checkpt_invalidate(dev);
+
+        yaffs_trace(YAFFS_TRACE_TRACING,
+          "yaffs: yaffs_guts_initialise() done.");
+        return YAFFS_OK;
+
+}
+
+void yaffs_deinitialise(struct yaffs_dev *dev)
+{
+        if (dev->is_mounted) {
+                int i;
+
+                yaffs_deinit_blocks(dev);
+                yaffs_deinit_tnodes_and_objs(dev);
+                if (dev->param.n_caches > 0 && dev->cache) {
+
+                        for (i = 0; i < dev->param.n_caches; i++) {
+                                if (dev->cache[i].data)
+                                        kfree(dev->cache[i].data);
+                                dev->cache[i].data = NULL;
+                        }
+
+                        kfree(dev->cache);
+                        dev->cache = NULL;
+                }
+
+                kfree(dev->gc_cleanup_list);
+
+                for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
+                        kfree(dev->temp_buffer[i].buffer);
+
+                dev->is_mounted = 0;
+
+                if (dev->param.deinitialise_flash_fn)
+                        dev->param.deinitialise_flash_fn(dev);
+        }
+}
+
+int yaffs_count_free_chunks(struct yaffs_dev *dev)
+{
+        int n_free = 0;
+        int b;
+
+        struct yaffs_block_info *blk;
+
+        blk = dev->block_info;
+        for (b = dev->internal_start_block; b <= dev->internal_end_block; b++) {
+                switch (blk->block_state) {
+                case YAFFS_BLOCK_STATE_EMPTY:
+                case YAFFS_BLOCK_STATE_ALLOCATING:
+                case YAFFS_BLOCK_STATE_COLLECTING:
+                case YAFFS_BLOCK_STATE_FULL:
+                        n_free +=
+                            (dev->param.chunks_per_block - blk->pages_in_use +
+                             blk->soft_del_pages);
+                        break;
+                default:
+                        break;
+                }
+                blk++;
+        }
+
+        return n_free;
+}
+
+int yaffs_get_n_free_chunks(struct yaffs_dev *dev)
+{
+        /* This is what we report to the outside world */
+
+        int n_free;
+        int n_dirty_caches;
+        int blocks_for_checkpt;
+        int i;
+
+        n_free = dev->n_free_chunks;
+        n_free += dev->n_deleted_files;
+
+        /* Now count the number of dirty chunks in the cache and subtract those */
+
+        for (n_dirty_caches = 0, i = 0; i < dev->param.n_caches; i++) {
+                if (dev->cache[i].dirty)
+                        n_dirty_caches++;
+        }
+
+        n_free -= n_dirty_caches;
+
+        n_free -=
+            ((dev->param.n_reserved_blocks + 1) * dev->param.chunks_per_block);
+
+        /* Now we figure out how much to reserve for the checkpoint and report that... */
+        blocks_for_checkpt = yaffs_calc_checkpt_blocks_required(dev);
+
+        n_free -= (blocks_for_checkpt * dev->param.chunks_per_block);
+
+        if (n_free < 0)
+                n_free = 0;
+
+        return n_free;
+
+}
diff --git a/fs/yaffs2/yaffs_guts.h b/fs/yaffs2/yaffs_guts.h
new file mode 100644
index 00000000000..307eba28676
--- /dev/null
+++ b/fs/yaffs2/yaffs_guts.h
@@ -0,0 +1,915 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_GUTS_H__
+#define __YAFFS_GUTS_H__
+
+#include "yportenv.h"
+
+#define YAFFS_OK        1
+#define YAFFS_FAIL  0
+
+/* Give us a  Y=0x59,
+ * Give us an A=0x41,
+ * Give us an FF=0xFF
+ * Give us an S=0x53
+ * And what have we got...
+ */
+#define YAFFS_MAGIC                     0x5941FF53
+
+#define YAFFS_NTNODES_LEVEL0            16
+#define YAFFS_TNODES_LEVEL0_BITS        4
+#define YAFFS_TNODES_LEVEL0_MASK        0xf
+
+#define YAFFS_NTNODES_INTERNAL          (YAFFS_NTNODES_LEVEL0 / 2)
+#define YAFFS_TNODES_INTERNAL_BITS      (YAFFS_TNODES_LEVEL0_BITS - 1)
+#define YAFFS_TNODES_INTERNAL_MASK      0x7
+#define YAFFS_TNODES_MAX_LEVEL          6
+
+#ifndef CONFIG_YAFFS_NO_YAFFS1
+#define YAFFS_BYTES_PER_SPARE           16
+#define YAFFS_BYTES_PER_CHUNK           512
+#define YAFFS_CHUNK_SIZE_SHIFT          9
+#define YAFFS_CHUNKS_PER_BLOCK          32
+#define YAFFS_BYTES_PER_BLOCK           (YAFFS_CHUNKS_PER_BLOCK*YAFFS_BYTES_PER_CHUNK)
+#endif
+
+#define YAFFS_MIN_YAFFS2_CHUNK_SIZE     1024
+#define YAFFS_MIN_YAFFS2_SPARE_SIZE     32
+
+#define YAFFS_MAX_CHUNK_ID              0x000FFFFF
+
+#define YAFFS_ALLOCATION_NOBJECTS       100
+#define YAFFS_ALLOCATION_NTNODES        100
+#define YAFFS_ALLOCATION_NLINKS         100
+
+#define YAFFS_NOBJECT_BUCKETS           256
+
+#define YAFFS_OBJECT_SPACE              0x40000
+#define YAFFS_MAX_OBJECT_ID             (YAFFS_OBJECT_SPACE -1)
+
+#define YAFFS_CHECKPOINT_VERSION        4
+
+#ifdef CONFIG_YAFFS_UNICODE
+#define YAFFS_MAX_NAME_LENGTH           127
+#define YAFFS_MAX_ALIAS_LENGTH          79
+#else
+#define YAFFS_MAX_NAME_LENGTH           255
+#define YAFFS_MAX_ALIAS_LENGTH          159
+#endif
+
+#define YAFFS_SHORT_NAME_LENGTH         15
+
+/* Some special object ids for pseudo objects */
+#define YAFFS_OBJECTID_ROOT             1
+#define YAFFS_OBJECTID_LOSTNFOUND       2
+#define YAFFS_OBJECTID_UNLINKED         3
+#define YAFFS_OBJECTID_DELETED          4
+
+/* Pseudo object ids for checkpointing */
+#define YAFFS_OBJECTID_SB_HEADER        0x10
+#define YAFFS_OBJECTID_CHECKPOINT_DATA  0x20
+#define YAFFS_SEQUENCE_CHECKPOINT_DATA  0x21
+
+#define YAFFS_MAX_SHORT_OP_CACHES       20
+
+#define YAFFS_N_TEMP_BUFFERS            6
+
+/* We limit the number attempts at sucessfully saving a chunk of data.
+ * Small-page devices have 32 pages per block; large-page devices have 64.
+ * Default to something in the order of 5 to 10 blocks worth of chunks.
+ */
+#define YAFFS_WR_ATTEMPTS               (5*64)
+
+/* Sequence numbers are used in YAFFS2 to determine block allocation order.
+ * The range is limited slightly to help distinguish bad numbers from good.
+ * This also allows us to perhaps in the future use special numbers for
+ * special purposes.
+ * EFFFFF00 allows the allocation of 8 blocks per second (~1Mbytes) for 15 years,
+ * and is a larger number than the lifetime of a 2GB device.
+ */
+#define YAFFS_LOWEST_SEQUENCE_NUMBER    0x00001000
+#define YAFFS_HIGHEST_SEQUENCE_NUMBER   0xEFFFFF00
+
+/* Special sequence number for bad block that failed to be marked bad */
+#define YAFFS_SEQUENCE_BAD_BLOCK        0xFFFF0000
+
+/* ChunkCache is used for short read/write operations.*/
+struct yaffs_cache {
+        struct yaffs_obj *object;
+        int chunk_id;
+        int last_use;
+        int dirty;
+        int n_bytes;            /* Only valid if the cache is dirty */
+        int locked;             /* Can't push out or flush while locked. */
+        u8 *data;
+};
+
+/* Tags structures in RAM
+ * NB This uses bitfield. Bitfields should not straddle a u32 boundary otherwise
+ * the structure size will get blown out.
+ */
+
+#ifndef CONFIG_YAFFS_NO_YAFFS1
+struct yaffs_tags {
+        unsigned chunk_id:20;
+        unsigned serial_number:2;
+        unsigned n_bytes_lsb:10;
+        unsigned obj_id:18;
+        unsigned ecc:12;
+        unsigned n_bytes_msb:2;
+};
+
+union yaffs_tags_union {
+        struct yaffs_tags as_tags;
+        u8 as_bytes[8];
+};
+
+#endif
+
+/* Stuff used for extended tags in YAFFS2 */
+
+enum yaffs_ecc_result {
+        YAFFS_ECC_RESULT_UNKNOWN,
+        YAFFS_ECC_RESULT_NO_ERROR,
+        YAFFS_ECC_RESULT_FIXED,
+        YAFFS_ECC_RESULT_UNFIXED
+};
+
+enum yaffs_obj_type {
+        YAFFS_OBJECT_TYPE_UNKNOWN,
+        YAFFS_OBJECT_TYPE_FILE,
+        YAFFS_OBJECT_TYPE_SYMLINK,
+        YAFFS_OBJECT_TYPE_DIRECTORY,
+        YAFFS_OBJECT_TYPE_HARDLINK,
+        YAFFS_OBJECT_TYPE_SPECIAL
+};
+
+#define YAFFS_OBJECT_TYPE_MAX YAFFS_OBJECT_TYPE_SPECIAL
+
+struct yaffs_ext_tags {
+
+        unsigned validity0;
+        unsigned chunk_used;    /*  Status of the chunk: used or unused */
+        unsigned obj_id;        /* If 0 then this is not part of an object (unused) */
+        unsigned chunk_id;      /* If 0 then this is a header, else a data chunk */
+        unsigned n_bytes;       /* Only valid for data chunks */
+
+        /* The following stuff only has meaning when we read */
+        enum yaffs_ecc_result ecc_result;
+        unsigned block_bad;
+
+        /* YAFFS 1 stuff */
+        unsigned is_deleted;    /* The chunk is marked deleted */
+        unsigned serial_number; /* Yaffs1 2-bit serial number */
+
+        /* YAFFS2 stuff */
+        unsigned seq_number;    /* The sequence number of this block */
+
+        /* Extra info if this is an object header (YAFFS2 only) */
+
+        unsigned extra_available;       /* There is extra info available if this is not zero */
+        unsigned extra_parent_id;       /* The parent object */
+        unsigned extra_is_shrink;       /* Is it a shrink header? */
+        unsigned extra_shadows; /* Does this shadow another object? */
+
+        enum yaffs_obj_type extra_obj_type;     /* What object type? */
+
+        unsigned extra_length;  /* Length if it is a file */
+        unsigned extra_equiv_id;        /* Equivalent object Id if it is a hard link */
+
+        unsigned validity1;
+
+};
+
+/* Spare structure for YAFFS1 */
+struct yaffs_spare {
+        u8 tb0;
+        u8 tb1;
+        u8 tb2;
+        u8 tb3;
+        u8 page_status;         /* set to 0 to delete the chunk */
+        u8 block_status;
+        u8 tb4;
+        u8 tb5;
+        u8 ecc1[3];
+        u8 tb6;
+        u8 tb7;
+        u8 ecc2[3];
+};
+
+/*Special structure for passing through to mtd */
+struct yaffs_nand_spare {
+        struct yaffs_spare spare;
+        int eccres1;
+        int eccres2;
+};
+
+/* Block data in RAM */
+
+enum yaffs_block_state {
+        YAFFS_BLOCK_STATE_UNKNOWN = 0,
+
+        YAFFS_BLOCK_STATE_SCANNING,
+        /* Being scanned */
+
+        YAFFS_BLOCK_STATE_NEEDS_SCANNING,
+        /* The block might have something on it (ie it is allocating or full, perhaps empty)
+         * but it needs to be scanned to determine its true state.
+         * This state is only valid during scanning.
+         * NB We tolerate empty because the pre-scanner might be incapable of deciding
+         * However, if this state is returned on a YAFFS2 device, then we expect a sequence number
+         */
+
+        YAFFS_BLOCK_STATE_EMPTY,
+        /* This block is empty */
+
+        YAFFS_BLOCK_STATE_ALLOCATING,
+        /* This block is partially allocated.
+         * At least one page holds valid data.
+         * This is the one currently being used for page
+         * allocation. Should never be more than one of these.
+         * If a block is only partially allocated at mount it is treated as full.
+         */
+
+        YAFFS_BLOCK_STATE_FULL,
+        /* All the pages in this block have been allocated.
+         * If a block was only partially allocated when mounted we treat
+         * it as fully allocated.
+         */
+
+        YAFFS_BLOCK_STATE_DIRTY,
+        /* The block was full and now all chunks have been deleted.
+         * Erase me, reuse me.
+         */
+
+        YAFFS_BLOCK_STATE_CHECKPOINT,
+        /* This block is assigned to holding checkpoint data. */
+
+        YAFFS_BLOCK_STATE_COLLECTING,
+        /* This block is being garbage collected */
+
+        YAFFS_BLOCK_STATE_DEAD
+            /* This block has failed and is not in use */
+};
+
+#define YAFFS_NUMBER_OF_BLOCK_STATES (YAFFS_BLOCK_STATE_DEAD + 1)
+
+struct yaffs_block_info {
+
+        int soft_del_pages:10;  /* number of soft deleted pages */
+        int pages_in_use:10;    /* number of pages in use */
+        unsigned block_state:4; /* One of the above block states. NB use unsigned because enum is sometimes an int */
+        u32 needs_retiring:1;   /* Data has failed on this block, need to get valid data off */
+        /* and retire the block. */
+        u32 skip_erased_check:1;        /* If this is set we can skip the erased check on this block */
+        u32 gc_prioritise:1;    /* An ECC check or blank check has failed on this block.
+                                   It should be prioritised for GC */
+        u32 chunk_error_strikes:3;      /* How many times we've had ecc etc failures on this block and tried to reuse it */
+
+#ifdef CONFIG_YAFFS_YAFFS2
+        u32 has_shrink_hdr:1;   /* This block has at least one shrink object header */
+        u32 seq_number;         /* block sequence number for yaffs2 */
+#endif
+
+};
+
+/* -------------------------- Object structure -------------------------------*/
+/* This is the object structure as stored on NAND */
+
+struct yaffs_obj_hdr {
+        enum yaffs_obj_type type;
+
+        /* Apply to everything  */
+        int parent_obj_id;
+        u16 sum_no_longer_used; /* checksum of name. No longer used */
+        YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];
+
+        /* The following apply to directories, files, symlinks - not hard links */
+        u32 yst_mode;           /* protection */
+
+        u32 yst_uid;
+        u32 yst_gid;
+        u32 yst_atime;
+        u32 yst_mtime;
+        u32 yst_ctime;
+
+        /* File size  applies to files only */
+        int file_size;
+
+        /* Equivalent object id applies to hard links only. */
+        int equiv_id;
+
+        /* Alias is for symlinks only. */
+        YCHAR alias[YAFFS_MAX_ALIAS_LENGTH + 1];
+
+        u32 yst_rdev;           /* device stuff for block and char devices (major/min) */
+
+        u32 win_ctime[2];
+        u32 win_atime[2];
+        u32 win_mtime[2];
+
+        u32 inband_shadowed_obj_id;
+        u32 inband_is_shrink;
+
+        u32 reserved[2];
+        int shadows_obj;        /* This object header shadows the specified object if > 0 */
+
+        /* is_shrink applies to object headers written when we shrink the file (ie resize) */
+        u32 is_shrink;
+
+};
+
+/*--------------------------- Tnode -------------------------- */
+
+struct yaffs_tnode {
+        struct yaffs_tnode *internal[YAFFS_NTNODES_INTERNAL];
+};
+
+/*------------------------  Object -----------------------------*/
+/* An object can be one of:
+ * - a directory (no data, has children links
+ * - a regular file (data.... not prunes :->).
+ * - a symlink [symbolic link] (the alias).
+ * - a hard link
+ */
+
+struct yaffs_file_var {
+        u32 file_size;
+        u32 scanned_size;
+        u32 shrink_size;
+        int top_level;
+        struct yaffs_tnode *top;
+};
+
+struct yaffs_dir_var {
+        struct list_head children;      /* list of child links */
+        struct list_head dirty; /* Entry for list of dirty directories */
+};
+
+struct yaffs_symlink_var {
+        YCHAR *alias;
+};
+
+struct yaffs_hardlink_var {
+        struct yaffs_obj *equiv_obj;
+        u32 equiv_id;
+};
+
+union yaffs_obj_var {
+        struct yaffs_file_var file_variant;
+        struct yaffs_dir_var dir_variant;
+        struct yaffs_symlink_var symlink_variant;
+        struct yaffs_hardlink_var hardlink_variant;
+};
+
+struct yaffs_obj {
+        u8 deleted:1;           /* This should only apply to unlinked files. */
+        u8 soft_del:1;          /* it has also been soft deleted */
+        u8 unlinked:1;          /* An unlinked file. The file should be in the unlinked directory. */
+        u8 fake:1;              /* A fake object has no presence on NAND. */
+        u8 rename_allowed:1;    /* Some objects are not allowed to be renamed. */
+        u8 unlink_allowed:1;
+        u8 dirty:1;             /* the object needs to be written to flash */
+        u8 valid:1;             /* When the file system is being loaded up, this
+                                 * object might be created before the data
+                                 * is available (ie. file data records appear before the header).
+                                 */
+        u8 lazy_loaded:1;       /* This object has been lazy loaded and is missing some detail */
+
+        u8 defered_free:1;      /* For Linux kernel. Object is removed from NAND, but is
+                                 * still in the inode cache. Free of object is defered.
+                                 * until the inode is released.
+                                 */
+        u8 being_created:1;     /* This object is still being created so skip some checks. */
+        u8 is_shadowed:1;       /* This object is shadowed on the way to being renamed. */
+
+        u8 xattr_known:1;       /* We know if this has object has xattribs or not. */
+        u8 has_xattr:1;         /* This object has xattribs. Valid if xattr_known. */
+
+        u8 serial;              /* serial number of chunk in NAND. Cached here */
+        u16 sum;                /* sum of the name to speed searching */
+
+        struct yaffs_dev *my_dev;       /* The device I'm on */
+
+        struct list_head hash_link;     /* list of objects in this hash bucket */
+
+        struct list_head hard_links;    /* all the equivalent hard linked objects */
+
+        /* directory structure stuff */
+        /* also used for linking up the free list */
+        struct yaffs_obj *parent;
+        struct list_head siblings;
+
+        /* Where's my object header in NAND? */
+        int hdr_chunk;
+
+        int n_data_chunks;      /* Number of data chunks attached to the file. */
+
+        u32 obj_id;             /* the object id value */
+
+        u32 yst_mode;
+
+#ifndef CONFIG_YAFFS_NO_SHORT_NAMES
+        YCHAR short_name[YAFFS_SHORT_NAME_LENGTH + 1];
+#endif
+
+#ifdef CONFIG_YAFFS_WINCE
+        u32 win_ctime[2];
+        u32 win_mtime[2];
+        u32 win_atime[2];
+#else
+        u32 yst_uid;
+        u32 yst_gid;
+        u32 yst_atime;
+        u32 yst_mtime;
+        u32 yst_ctime;
+#endif
+
+        u32 yst_rdev;
+
+        void *my_inode;
+
+        enum yaffs_obj_type variant_type;
+
+        union yaffs_obj_var variant;
+
+};
+
+struct yaffs_obj_bucket {
+        struct list_head list;
+        int count;
+};
+
+/* yaffs_checkpt_obj holds the definition of an object as dumped
+ * by checkpointing.
+ */
+
+struct yaffs_checkpt_obj {
+        int struct_type;
+        u32 obj_id;
+        u32 parent_id;
+        int hdr_chunk;
+        enum yaffs_obj_type variant_type:3;
+        u8 deleted:1;
+        u8 soft_del:1;
+        u8 unlinked:1;
+        u8 fake:1;
+        u8 rename_allowed:1;
+        u8 unlink_allowed:1;
+        u8 serial;
+        int n_data_chunks;
+        u32 size_or_equiv_obj;
+};
+
+/*--------------------- Temporary buffers ----------------
+ *
+ * These are chunk-sized working buffers. Each device has a few
+ */
+
+struct yaffs_buffer {
+        u8 *buffer;
+        int line;               /* track from whence this buffer was allocated */
+        int max_line;
+};
+
+/*----------------- Device ---------------------------------*/
+
+struct yaffs_param {
+        const YCHAR *name;
+
+        /*
+         * Entry parameters set up way early. Yaffs sets up the rest.
+         * The structure should be zeroed out before use so that unused
+         * and defualt values are zero.
+         */
+
+        int inband_tags;        /* Use unband tags */
+        u32 total_bytes_per_chunk;      /* Should be >= 512, does not need to be a power of 2 */
+        int chunks_per_block;   /* does not need to be a power of 2 */
+        int spare_bytes_per_chunk;      /* spare area size */
+        int start_block;        /* Start block we're allowed to use */
+        int end_block;          /* End block we're allowed to use */
+        int n_reserved_blocks;  /* We want this tuneable so that we can reduce */
+        /* reserved blocks on NOR and RAM. */
+
+        int n_caches;           /* If <= 0, then short op caching is disabled, else
+                                 * the number of short op caches (don't use too many).
+                                 * 10 to 20 is a good bet.
+                                 */
+        int use_nand_ecc;       /* Flag to decide whether or not to use NANDECC on data (yaffs1) */
+        int no_tags_ecc;        /* Flag to decide whether or not to do ECC on packed tags (yaffs2) */
+
+        int is_yaffs2;          /* Use yaffs2 mode on this device */
+
+        int empty_lost_n_found; /* Auto-empty lost+found directory on mount */
+
+        int refresh_period;     /* How often we should check to do a block refresh */
+
+        /* Checkpoint control. Can be set before or after initialisation */
+        u8 skip_checkpt_rd;
+        u8 skip_checkpt_wr;
+
+        int enable_xattr;       /* Enable xattribs */
+
+        /* NAND access functions (Must be set before calling YAFFS) */
+
+        int (*write_chunk_fn) (struct yaffs_dev * dev,
+                               int nand_chunk, const u8 * data,
+                               const struct yaffs_spare * spare);
+        int (*read_chunk_fn) (struct yaffs_dev * dev,
+                              int nand_chunk, u8 * data,
+                              struct yaffs_spare * spare);
+        int (*erase_fn) (struct yaffs_dev * dev, int flash_block);
+        int (*initialise_flash_fn) (struct yaffs_dev * dev);
+        int (*deinitialise_flash_fn) (struct yaffs_dev * dev);
+
+#ifdef CONFIG_YAFFS_YAFFS2
+        int (*write_chunk_tags_fn) (struct yaffs_dev * dev,
+                                    int nand_chunk, const u8 * data,
+                                    const struct yaffs_ext_tags * tags);
+        int (*read_chunk_tags_fn) (struct yaffs_dev * dev,
+                                   int nand_chunk, u8 * data,
+                                   struct yaffs_ext_tags * tags);
+        int (*bad_block_fn) (struct yaffs_dev * dev, int block_no);
+        int (*query_block_fn) (struct yaffs_dev * dev, int block_no,
+                               enum yaffs_block_state * state,
+                               u32 * seq_number);
+#endif
+
+        /* The remove_obj_fn function must be supplied by OS flavours that
+         * need it.
+         * yaffs direct uses it to implement the faster readdir.
+         * Linux uses it to protect the directory during unlocking.
+         */
+        void (*remove_obj_fn) (struct yaffs_obj * obj);
+
+        /* Callback to mark the superblock dirty */
+        void (*sb_dirty_fn) (struct yaffs_dev * dev);
+
+        /*  Callback to control garbage collection. */
+        unsigned (*gc_control) (struct yaffs_dev * dev);
+
+        /* Debug control flags. Don't use unless you know what you're doing */
+        int use_header_file_size;       /* Flag to determine if we should use file sizes from the header */
+        int disable_lazy_load;  /* Disable lazy loading on this device */
+        int wide_tnodes_disabled;       /* Set to disable wide tnodes */
+        int disable_soft_del;   /* yaffs 1 only: Set to disable the use of softdeletion. */
+
+        int defered_dir_update; /* Set to defer directory updates */
+
+#ifdef CONFIG_YAFFS_AUTO_UNICODE
+        int auto_unicode;
+#endif
+        int always_check_erased;        /* Force chunk erased check always on */
+};
+
+struct yaffs_dev {
+        struct yaffs_param param;
+
+        /* Context storage. Holds extra OS specific data for this device */
+
+        void *os_context;
+        void *driver_context;
+
+        struct list_head dev_list;
+
+        /* Runtime parameters. Set up by YAFFS. */
+        int data_bytes_per_chunk;
+
+        /* Non-wide tnode stuff */
+        u16 chunk_grp_bits;     /* Number of bits that need to be resolved if
+                                 * the tnodes are not wide enough.
+                                 */
+        u16 chunk_grp_size;     /* == 2^^chunk_grp_bits */
+
+        /* Stuff to support wide tnodes */
+        u32 tnode_width;
+        u32 tnode_mask;
+        u32 tnode_size;
+
+        /* Stuff for figuring out file offset to chunk conversions */
+        u32 chunk_shift;        /* Shift value */
+        u32 chunk_div;          /* Divisor after shifting: 1 for power-of-2 sizes */
+        u32 chunk_mask;         /* Mask to use for power-of-2 case */
+
+        int is_mounted;
+        int read_only;
+        int is_checkpointed;
+
+        /* Stuff to support block offsetting to support start block zero */
+        int internal_start_block;
+        int internal_end_block;
+        int block_offset;
+        int chunk_offset;
+
+        /* Runtime checkpointing stuff */
+        int checkpt_page_seq;   /* running sequence number of checkpoint pages */
+        int checkpt_byte_count;
+        int checkpt_byte_offs;
+        u8 *checkpt_buffer;
+        int checkpt_open_write;
+        int blocks_in_checkpt;
+        int checkpt_cur_chunk;
+        int checkpt_cur_block;
+        int checkpt_next_block;
+        int *checkpt_block_list;
+        int checkpt_max_blocks;
+        u32 checkpt_sum;
+        u32 checkpt_xor;
+
+        int checkpoint_blocks_required; /* Number of blocks needed to store current checkpoint set */
+
+        /* Block Info */
+        struct yaffs_block_info *block_info;
+        u8 *chunk_bits;         /* bitmap of chunks in use */
+        unsigned block_info_alt:1;      /* was allocated using alternative strategy */
+        unsigned chunk_bits_alt:1;      /* was allocated using alternative strategy */
+        int chunk_bit_stride;   /* Number of bytes of chunk_bits per block.
+                                 * Must be consistent with chunks_per_block.
+                                 */
+
+        int n_erased_blocks;
+        int alloc_block;        /* Current block being allocated off */
+        u32 alloc_page;
+        int alloc_block_finder; /* Used to search for next allocation block */
+
+        /* Object and Tnode memory management */
+        void *allocator;
+        int n_obj;
+        int n_tnodes;
+
+        int n_hardlinks;
+
+        struct yaffs_obj_bucket obj_bucket[YAFFS_NOBJECT_BUCKETS];
+        u32 bucket_finder;
+
+        int n_free_chunks;
+
+        /* Garbage collection control */
+        u32 *gc_cleanup_list;   /* objects to delete at the end of a GC. */
+        u32 n_clean_ups;
+
+        unsigned has_pending_prioritised_gc;    /* We think this device might have pending prioritised gcs */
+        unsigned gc_disable;
+        unsigned gc_block_finder;
+        unsigned gc_dirtiest;
+        unsigned gc_pages_in_use;
+        unsigned gc_not_done;
+        unsigned gc_block;
+        unsigned gc_chunk;
+        unsigned gc_skip;
+
+        /* Special directories */
+        struct yaffs_obj *root_dir;
+        struct yaffs_obj *lost_n_found;
+
+        /* Buffer areas for storing data to recover from write failures TODO
+         *      u8            buffered_data[YAFFS_CHUNKS_PER_BLOCK][YAFFS_BYTES_PER_CHUNK];
+         *      struct yaffs_spare buffered_spare[YAFFS_CHUNKS_PER_BLOCK];
+         */
+
+        int buffered_block;     /* Which block is buffered here? */
+        int doing_buffered_block_rewrite;
+
+        struct yaffs_cache *cache;
+        int cache_last_use;
+
+        /* Stuff for background deletion and unlinked files. */
+        struct yaffs_obj *unlinked_dir; /* Directory where unlinked and deleted files live. */
+        struct yaffs_obj *del_dir;      /* Directory where deleted objects are sent to disappear. */
+        struct yaffs_obj *unlinked_deletion;    /* Current file being background deleted. */
+        int n_deleted_files;    /* Count of files awaiting deletion; */
+        int n_unlinked_files;   /* Count of unlinked files. */
+        int n_bg_deletions;     /* Count of background deletions. */
+
+        /* Temporary buffer management */
+        struct yaffs_buffer temp_buffer[YAFFS_N_TEMP_BUFFERS];
+        int max_temp;
+        int temp_in_use;
+        int unmanaged_buffer_allocs;
+        int unmanaged_buffer_deallocs;
+
+        /* yaffs2 runtime stuff */
+        unsigned seq_number;    /* Sequence number of currently allocating block */
+        unsigned oldest_dirty_seq;
+        unsigned oldest_dirty_block;
+
+        /* Block refreshing */
+        int refresh_skip;       /* A skip down counter. Refresh happens when this gets to zero. */
+
+        /* Dirty directory handling */
+        struct list_head dirty_dirs;    /* List of dirty directories */
+
+        /* Statistcs */
+        u32 n_page_writes;
+        u32 n_page_reads;
+        u32 n_erasures;
+        u32 n_erase_failures;
+        u32 n_gc_copies;
+        u32 all_gcs;
+        u32 passive_gc_count;
+        u32 oldest_dirty_gc_count;
+        u32 n_gc_blocks;
+        u32 bg_gcs;
+        u32 n_retired_writes;
+        u32 n_retired_blocks;
+        u32 n_ecc_fixed;
+        u32 n_ecc_unfixed;
+        u32 n_tags_ecc_fixed;
+        u32 n_tags_ecc_unfixed;
+        u32 n_deletions;
+        u32 n_unmarked_deletions;
+        u32 refresh_count;
+        u32 cache_hits;
+
+};
+
+/* The CheckpointDevice structure holds the device information that changes at runtime and
+ * must be preserved over unmount/mount cycles.
+ */
+struct yaffs_checkpt_dev {
+        int struct_type;
+        int n_erased_blocks;
+        int alloc_block;        /* Current block being allocated off */
+        u32 alloc_page;
+        int n_free_chunks;
+
+        int n_deleted_files;    /* Count of files awaiting deletion; */
+        int n_unlinked_files;   /* Count of unlinked files. */
+        int n_bg_deletions;     /* Count of background deletions. */
+
+        /* yaffs2 runtime stuff */
+        unsigned seq_number;    /* Sequence number of currently allocating block */
+
+};
+
+struct yaffs_checkpt_validity {
+        int struct_type;
+        u32 magic;
+        u32 version;
+        u32 head;
+};
+
+struct yaffs_shadow_fixer {
+        int obj_id;
+        int shadowed_id;
+        struct yaffs_shadow_fixer *next;
+};
+
+/* Structure for doing xattr modifications */
+struct yaffs_xattr_mod {
+        int set;                /* If 0 then this is a deletion */
+        const YCHAR *name;
+        const void *data;
+        int size;
+        int flags;
+        int result;
+};
+
+/*----------------------- YAFFS Functions -----------------------*/
+
+int yaffs_guts_initialise(struct yaffs_dev *dev);
+void yaffs_deinitialise(struct yaffs_dev *dev);
+
+int yaffs_get_n_free_chunks(struct yaffs_dev *dev);
+
+int yaffs_rename_obj(struct yaffs_obj *old_dir, const YCHAR * old_name,
+                     struct yaffs_obj *new_dir, const YCHAR * new_name);
+
+int yaffs_unlinker(struct yaffs_obj *dir, const YCHAR * name);
+int yaffs_del_obj(struct yaffs_obj *obj);
+
+int yaffs_get_obj_name(struct yaffs_obj *obj, YCHAR * name, int buffer_size);
+int yaffs_get_obj_length(struct yaffs_obj *obj);
+int yaffs_get_obj_inode(struct yaffs_obj *obj);
+unsigned yaffs_get_obj_type(struct yaffs_obj *obj);
+int yaffs_get_obj_link_count(struct yaffs_obj *obj);
+
+/* File operations */
+int yaffs_file_rd(struct yaffs_obj *obj, u8 * buffer, loff_t offset,
+                  int n_bytes);
+int yaffs_wr_file(struct yaffs_obj *obj, const u8 * buffer, loff_t offset,
+                  int n_bytes, int write_trhrough);
+int yaffs_resize_file(struct yaffs_obj *obj, loff_t new_size);
+
+struct yaffs_obj *yaffs_create_file(struct yaffs_obj *parent,
+                                    const YCHAR * name, u32 mode, u32 uid,
+                                    u32 gid);
+
+int yaffs_flush_file(struct yaffs_obj *obj, int update_time, int data_sync);
+
+/* Flushing and checkpointing */
+void yaffs_flush_whole_cache(struct yaffs_dev *dev);
+
+int yaffs_checkpoint_save(struct yaffs_dev *dev);
+int yaffs_checkpoint_restore(struct yaffs_dev *dev);
+
+/* Directory operations */
+struct yaffs_obj *yaffs_create_dir(struct yaffs_obj *parent, const YCHAR * name,
+                                   u32 mode, u32 uid, u32 gid);
+struct yaffs_obj *yaffs_find_by_name(struct yaffs_obj *the_dir,
+                                     const YCHAR * name);
+struct yaffs_obj *yaffs_find_by_number(struct yaffs_dev *dev, u32 number);
+
+/* Link operations */
+struct yaffs_obj *yaffs_link_obj(struct yaffs_obj *parent, const YCHAR * name,
+                                 struct yaffs_obj *equiv_obj);
+
+struct yaffs_obj *yaffs_get_equivalent_obj(struct yaffs_obj *obj);
+
+/* Symlink operations */
+struct yaffs_obj *yaffs_create_symlink(struct yaffs_obj *parent,
+                                       const YCHAR * name, u32 mode, u32 uid,
+                                       u32 gid, const YCHAR * alias);
+YCHAR *yaffs_get_symlink_alias(struct yaffs_obj *obj);
+
+/* Special inodes (fifos, sockets and devices) */
+struct yaffs_obj *yaffs_create_special(struct yaffs_obj *parent,
+                                       const YCHAR * name, u32 mode, u32 uid,
+                                       u32 gid, u32 rdev);
+
+int yaffs_set_xattrib(struct yaffs_obj *obj, const YCHAR * name,
+                      const void *value, int size, int flags);
+int yaffs_get_xattrib(struct yaffs_obj *obj, const YCHAR * name, void *value,
+                      int size);
+int yaffs_list_xattrib(struct yaffs_obj *obj, char *buffer, int size);
+int yaffs_remove_xattrib(struct yaffs_obj *obj, const YCHAR * name);
+
+/* Special directories */
+struct yaffs_obj *yaffs_root(struct yaffs_dev *dev);
+struct yaffs_obj *yaffs_lost_n_found(struct yaffs_dev *dev);
+
+void yaffs_handle_defered_free(struct yaffs_obj *obj);
+
+void yaffs_update_dirty_dirs(struct yaffs_dev *dev);
+
+int yaffs_bg_gc(struct yaffs_dev *dev, unsigned urgency);
+
+/* Debug dump  */
+int yaffs_dump_obj(struct yaffs_obj *obj);
+
+void yaffs_guts_test(struct yaffs_dev *dev);
+
+/* A few useful functions to be used within the core files*/
+void yaffs_chunk_del(struct yaffs_dev *dev, int chunk_id, int mark_flash,
+                     int lyn);
+int yaffs_check_ff(u8 * buffer, int n_bytes);
+void yaffs_handle_chunk_error(struct yaffs_dev *dev,
+                              struct yaffs_block_info *bi);
+
+u8 *yaffs_get_temp_buffer(struct yaffs_dev *dev, int line_no);
+void yaffs_release_temp_buffer(struct yaffs_dev *dev, u8 * buffer, int line_no);
+
+struct yaffs_obj *yaffs_find_or_create_by_number(struct yaffs_dev *dev,
+                                                 int number,
+                                                 enum yaffs_obj_type type);
+int yaffs_put_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
+                            int nand_chunk, int in_scan);
+void yaffs_set_obj_name(struct yaffs_obj *obj, const YCHAR * name);
+void yaffs_set_obj_name_from_oh(struct yaffs_obj *obj,
+                                const struct yaffs_obj_hdr *oh);
+void yaffs_add_obj_to_dir(struct yaffs_obj *directory, struct yaffs_obj *obj);
+YCHAR *yaffs_clone_str(const YCHAR * str);
+void yaffs_link_fixup(struct yaffs_dev *dev, struct yaffs_obj *hard_list);
+void yaffs_block_became_dirty(struct yaffs_dev *dev, int block_no);
+int yaffs_update_oh(struct yaffs_obj *in, const YCHAR * name,
+                    int force, int is_shrink, int shadows,
+                    struct yaffs_xattr_mod *xop);
+void yaffs_handle_shadowed_obj(struct yaffs_dev *dev, int obj_id,
+                               int backward_scanning);
+int yaffs_check_alloc_available(struct yaffs_dev *dev, int n_chunks);
+struct yaffs_tnode *yaffs_get_tnode(struct yaffs_dev *dev);
+struct yaffs_tnode *yaffs_add_find_tnode_0(struct yaffs_dev *dev,
+                                           struct yaffs_file_var *file_struct,
+                                           u32 chunk_id,
+                                           struct yaffs_tnode *passed_tn);
+
+int yaffs_do_file_wr(struct yaffs_obj *in, const u8 * buffer, loff_t offset,
+                     int n_bytes, int write_trhrough);
+void yaffs_resize_file_down(struct yaffs_obj *obj, loff_t new_size);
+void yaffs_skip_rest_of_block(struct yaffs_dev *dev);
+
+int yaffs_count_free_chunks(struct yaffs_dev *dev);
+
+struct yaffs_tnode *yaffs_find_tnode_0(struct yaffs_dev *dev,
+                                       struct yaffs_file_var *file_struct,
+                                       u32 chunk_id);
+
+u32 yaffs_get_group_base(struct yaffs_dev *dev, struct yaffs_tnode *tn,
+                         unsigned pos);
+
+int yaffs_is_non_empty_dir(struct yaffs_obj *obj);
+#endif
diff --git a/fs/yaffs2/yaffs_linux.h b/fs/yaffs2/yaffs_linux.h
new file mode 100644
index 00000000000..3b508cbc4e8
--- /dev/null
+++ b/fs/yaffs2/yaffs_linux.h
@@ -0,0 +1,41 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_LINUX_H__
+#define __YAFFS_LINUX_H__
+
+#include "yportenv.h"
+
+struct yaffs_linux_context {
+        struct list_head context_list;  /* List of these we have mounted */
+        struct yaffs_dev *dev;
+        struct super_block *super;
+        struct task_struct *bg_thread;  /* Background thread for this device */
+        int bg_running;
+        struct mutex gross_lock;        /* Gross locking mutex*/
+        u8 *spare_buffer;       /* For mtdif2 use. Don't know the size of the buffer
+                                 * at compile time so we have to allocate it.
+                                 */
+        struct list_head search_contexts;
+        void (*put_super_fn) (struct super_block * sb);
+
+        struct task_struct *readdir_process;
+        unsigned mount_id;
+};
+
+#define yaffs_dev_to_lc(dev) ((struct yaffs_linux_context *)((dev)->os_context))
+#define yaffs_dev_to_mtd(dev) ((struct mtd_info *)((dev)->driver_context))
+
+#endif
diff --git a/fs/yaffs2/yaffs_mtdif.c b/fs/yaffs2/yaffs_mtdif.c
new file mode 100644
index 00000000000..7cf53b3d91b
--- /dev/null
+++ b/fs/yaffs2/yaffs_mtdif.c
@@ -0,0 +1,54 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yportenv.h"
+
+#include "yaffs_mtdif.h"
+
+#include "linux/mtd/mtd.h"
+#include "linux/types.h"
+#include "linux/time.h"
+#include "linux/mtd/nand.h"
+
+#include "yaffs_linux.h"
+
+int nandmtd_erase_block(struct yaffs_dev *dev, int block_no)
+{
+        struct mtd_info *mtd = yaffs_dev_to_mtd(dev);
+        u32 addr =
+            ((loff_t) block_no) * dev->param.total_bytes_per_chunk
+            * dev->param.chunks_per_block;
+        struct erase_info ei;
+
+        int retval = 0;
+
+        ei.mtd = mtd;
+        ei.addr = addr;
+        ei.len = dev->param.total_bytes_per_chunk * dev->param.chunks_per_block;
+        ei.time = 1000;
+        ei.retries = 2;
+        ei.callback = NULL;
+        ei.priv = (u_long) dev;
+
+        retval = mtd->erase(mtd, &ei);
+
+        if (retval == 0)
+                return YAFFS_OK;
+        else
+                return YAFFS_FAIL;
+}
+
+int nandmtd_initialise(struct yaffs_dev *dev)
+{
+        return YAFFS_OK;
+}
diff --git a/fs/yaffs2/yaffs_mtdif.h b/fs/yaffs2/yaffs_mtdif.h
new file mode 100644
index 00000000000..666507417fe
--- /dev/null
+++ b/fs/yaffs2/yaffs_mtdif.h
@@ -0,0 +1,23 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_MTDIF_H__
+#define __YAFFS_MTDIF_H__
+
+#include "yaffs_guts.h"
+
+int nandmtd_erase_block(struct yaffs_dev *dev, int block_no);
+int nandmtd_initialise(struct yaffs_dev *dev);
+#endif
diff --git a/fs/yaffs2/yaffs_mtdif1.c b/fs/yaffs2/yaffs_mtdif1.c
new file mode 100644
index 00000000000..51083695eb3
--- /dev/null
+++ b/fs/yaffs2/yaffs_mtdif1.c
@@ -0,0 +1,330 @@
+/*
+ * YAFFS: Yet another FFS. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ * This module provides the interface between yaffs_nand.c and the
+ * MTD API.  This version is used when the MTD interface supports the
+ * 'mtd_oob_ops' style calls to read_oob and write_oob, circa 2.6.17,
+ * and we have small-page NAND device.
+ *
+ * These functions are invoked via function pointers in yaffs_nand.c.
+ * This replaces functionality provided by functions in yaffs_mtdif.c
+ * and the yaffs_tags compatability functions in yaffs_tagscompat.c that are
+ * called in yaffs_mtdif.c when the function pointers are NULL.
+ * We assume the MTD layer is performing ECC (use_nand_ecc is true).
+ */
+
+#include "yportenv.h"
+#include "yaffs_trace.h"
+#include "yaffs_guts.h"
+#include "yaffs_packedtags1.h"
+#include "yaffs_tagscompat.h"   /* for yaffs_calc_tags_ecc */
+#include "yaffs_linux.h"
+
+#include "linux/kernel.h"
+#include "linux/version.h"
+#include "linux/types.h"
+#include "linux/mtd/mtd.h"
+
+#ifndef CONFIG_YAFFS_9BYTE_TAGS
+# define YTAG1_SIZE 8
+#else
+# define YTAG1_SIZE 9
+#endif
+
+/* Write a chunk (page) of data to NAND.
+ *
+ * Caller always provides ExtendedTags data which are converted to a more
+ * compact (packed) form for storage in NAND.  A mini-ECC runs over the
+ * contents of the tags meta-data; used to valid the tags when read.
+ *
+ *  - Pack ExtendedTags to packed_tags1 form
+ *  - Compute mini-ECC for packed_tags1
+ *  - Write data and packed tags to NAND.
+ *
+ * Note: Due to the use of the packed_tags1 meta-data which does not include
+ * a full sequence number (as found in the larger packed_tags2 form) it is
+ * necessary for Yaffs to re-write a chunk/page (just once) to mark it as
+ * discarded and dirty.  This is not ideal: newer NAND parts are supposed
+ * to be written just once.  When Yaffs performs this operation, this
+ * function is called with a NULL data pointer -- calling MTD write_oob
+ * without data is valid usage (2.6.17).
+ *
+ * Any underlying MTD error results in YAFFS_FAIL.
+ * Returns YAFFS_OK or YAFFS_FAIL.
+ */
+int nandmtd1_write_chunk_tags(struct yaffs_dev *dev,
+                              int nand_chunk, const u8 * data,
+                              const struct yaffs_ext_tags *etags)
+{
+        struct mtd_info *mtd = yaffs_dev_to_mtd(dev);
+        int chunk_bytes = dev->data_bytes_per_chunk;
+        loff_t addr = ((loff_t) nand_chunk) * chunk_bytes;
+        struct mtd_oob_ops ops;
+        struct yaffs_packed_tags1 pt1;
+        int retval;
+
+        /* we assume that packed_tags1 and struct yaffs_tags are compatible */
+        compile_time_assertion(sizeof(struct yaffs_packed_tags1) == 12);
+        compile_time_assertion(sizeof(struct yaffs_tags) == 8);
+
+        yaffs_pack_tags1(&pt1, etags);
+        yaffs_calc_tags_ecc((struct yaffs_tags *)&pt1);
+
+        /* When deleting a chunk, the upper layer provides only skeletal
+         * etags, one with is_deleted set.  However, we need to update the
+         * tags, not erase them completely.  So we use the NAND write property
+         * that only zeroed-bits stick and set tag bytes to all-ones and
+         * zero just the (not) deleted bit.
+         */
+#ifndef CONFIG_YAFFS_9BYTE_TAGS
+        if (etags->is_deleted) {
+                memset(&pt1, 0xff, 8);
+                /* clear delete status bit to indicate deleted */
+                pt1.deleted = 0;
+        }
+#else
+        ((u8 *) & pt1)[8] = 0xff;
+        if (etags->is_deleted) {
+                memset(&pt1, 0xff, 8);
+                /* zero page_status byte to indicate deleted */
+                ((u8 *) & pt1)[8] = 0;
+        }
+#endif
+
+        memset(&ops, 0, sizeof(ops));
+        ops.mode = MTD_OOB_AUTO;
+        ops.len = (data) ? chunk_bytes : 0;
+        ops.ooblen = YTAG1_SIZE;
+        ops.datbuf = (u8 *) data;
+        ops.oobbuf = (u8 *) & pt1;
+
+        retval = mtd->write_oob(mtd, addr, &ops);
+        if (retval) {
+                yaffs_trace(YAFFS_TRACE_MTD,
+                        "write_oob failed, chunk %d, mtd error %d",
+                        nand_chunk, retval);
+        }
+        return retval ? YAFFS_FAIL : YAFFS_OK;
+}
+
+/* Return with empty ExtendedTags but add ecc_result.
+ */
+static int rettags(struct yaffs_ext_tags *etags, int ecc_result, int retval)
+{
+        if (etags) {
+                memset(etags, 0, sizeof(*etags));
+                etags->ecc_result = ecc_result;
+        }
+        return retval;
+}
+
+/* Read a chunk (page) from NAND.
+ *
+ * Caller expects ExtendedTags data to be usable even on error; that is,
+ * all members except ecc_result and block_bad are zeroed.
+ *
+ *  - Check ECC results for data (if applicable)
+ *  - Check for blank/erased block (return empty ExtendedTags if blank)
+ *  - Check the packed_tags1 mini-ECC (correct if necessary/possible)
+ *  - Convert packed_tags1 to ExtendedTags
+ *  - Update ecc_result and block_bad members to refect state.
+ *
+ * Returns YAFFS_OK or YAFFS_FAIL.
+ */
+int nandmtd1_read_chunk_tags(struct yaffs_dev *dev,
+                             int nand_chunk, u8 * data,
+                             struct yaffs_ext_tags *etags)
+{
+        struct mtd_info *mtd = yaffs_dev_to_mtd(dev);
+        int chunk_bytes = dev->data_bytes_per_chunk;
+        loff_t addr = ((loff_t) nand_chunk) * chunk_bytes;
+        int eccres = YAFFS_ECC_RESULT_NO_ERROR;
+        struct mtd_oob_ops ops;
+        struct yaffs_packed_tags1 pt1;
+        int retval;
+        int deleted;
+
+        memset(&ops, 0, sizeof(ops));
+        ops.mode = MTD_OOB_AUTO;
+        ops.len = (data) ? chunk_bytes : 0;
+        ops.ooblen = YTAG1_SIZE;
+        ops.datbuf = data;
+        ops.oobbuf = (u8 *) & pt1;
+
+        /* Read page and oob using MTD.
+         * Check status and determine ECC result.
+         */
+        retval = mtd->read_oob(mtd, addr, &ops);
+        if (retval) {
+                yaffs_trace(YAFFS_TRACE_MTD,
+                        "read_oob failed, chunk %d, mtd error %d",
+                        nand_chunk, retval);
+        }
+
+        switch (retval) {
+        case 0:
+                /* no error */
+                break;
+
+        case -EUCLEAN:
+                /* MTD's ECC fixed the data */
+                eccres = YAFFS_ECC_RESULT_FIXED;
+                dev->n_ecc_fixed++;
+                break;
+
+        case -EBADMSG:
+                /* MTD's ECC could not fix the data */
+                dev->n_ecc_unfixed++;
+                /* fall into... */
+        default:
+                rettags(etags, YAFFS_ECC_RESULT_UNFIXED, 0);
+                etags->block_bad = (mtd->block_isbad) (mtd, addr);
+                return YAFFS_FAIL;
+        }
+
+        /* Check for a blank/erased chunk.
+         */
+        if (yaffs_check_ff((u8 *) & pt1, 8)) {
+                /* when blank, upper layers want ecc_result to be <= NO_ERROR */
+                return rettags(etags, YAFFS_ECC_RESULT_NO_ERROR, YAFFS_OK);
+        }
+#ifndef CONFIG_YAFFS_9BYTE_TAGS
+        /* Read deleted status (bit) then return it to it's non-deleted
+         * state before performing tags mini-ECC check. pt1.deleted is
+         * inverted.
+         */
+        deleted = !pt1.deleted;
+        pt1.deleted = 1;
+#else
+        deleted = (yaffs_count_bits(((u8 *) & pt1)[8]) < 7);
+#endif
+
+        /* Check the packed tags mini-ECC and correct if necessary/possible.
+         */
+        retval = yaffs_check_tags_ecc((struct yaffs_tags *)&pt1);
+        switch (retval) {
+        case 0:
+                /* no tags error, use MTD result */
+                break;
+        case 1:
+                /* recovered tags-ECC error */
+                dev->n_tags_ecc_fixed++;
+                if (eccres == YAFFS_ECC_RESULT_NO_ERROR)
+                        eccres = YAFFS_ECC_RESULT_FIXED;
+                break;
+        default:
+                /* unrecovered tags-ECC error */
+                dev->n_tags_ecc_unfixed++;
+                return rettags(etags, YAFFS_ECC_RESULT_UNFIXED, YAFFS_FAIL);
+        }
+
+        /* Unpack the tags to extended form and set ECC result.
+         * [set should_be_ff just to keep yaffs_unpack_tags1 happy]
+         */
+        pt1.should_be_ff = 0xFFFFFFFF;
+        yaffs_unpack_tags1(etags, &pt1);
+        etags->ecc_result = eccres;
+
+        /* Set deleted state */
+        etags->is_deleted = deleted;
+        return YAFFS_OK;
+}
+
+/* Mark a block bad.
+ *
+ * This is a persistant state.
+ * Use of this function should be rare.
+ *
+ * Returns YAFFS_OK or YAFFS_FAIL.
+ */
+int nandmtd1_mark_block_bad(struct yaffs_dev *dev, int block_no)
+{
+        struct mtd_info *mtd = yaffs_dev_to_mtd(dev);
+        int blocksize = dev->param.chunks_per_block * dev->data_bytes_per_chunk;
+        int retval;
+
+        yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
+                "marking block %d bad", block_no);
+
+        retval = mtd->block_markbad(mtd, (loff_t) blocksize * block_no);
+        return (retval) ? YAFFS_FAIL : YAFFS_OK;
+}
+
+/* Check any MTD prerequists.
+ *
+ * Returns YAFFS_OK or YAFFS_FAIL.
+ */
+static int nandmtd1_test_prerequists(struct mtd_info *mtd)
+{
+        /* 2.6.18 has mtd->ecclayout->oobavail */
+        /* 2.6.21 has mtd->ecclayout->oobavail and mtd->oobavail */
+        int oobavail = mtd->ecclayout->oobavail;
+
+        if (oobavail < YTAG1_SIZE) {
+                yaffs_trace(YAFFS_TRACE_ERROR,
+                        "mtd device has only %d bytes for tags, need %d",
+                        oobavail, YTAG1_SIZE);
+                return YAFFS_FAIL;
+        }
+        return YAFFS_OK;
+}
+
+/* Query for the current state of a specific block.
+ *
+ * Examine the tags of the first chunk of the block and return the state:
+ *  - YAFFS_BLOCK_STATE_DEAD, the block is marked bad
+ *  - YAFFS_BLOCK_STATE_NEEDS_SCANNING, the block is in use
+ *  - YAFFS_BLOCK_STATE_EMPTY, the block is clean
+ *
+ * Always returns YAFFS_OK.
+ */
+int nandmtd1_query_block(struct yaffs_dev *dev, int block_no,
+                         enum yaffs_block_state *state_ptr, u32 * seq_ptr)
+{
+        struct mtd_info *mtd = yaffs_dev_to_mtd(dev);
+        int chunk_num = block_no * dev->param.chunks_per_block;
+        loff_t addr = (loff_t) chunk_num * dev->data_bytes_per_chunk;
+        struct yaffs_ext_tags etags;
+        int state = YAFFS_BLOCK_STATE_DEAD;
+        int seqnum = 0;
+        int retval;
+
+        /* We don't yet have a good place to test for MTD config prerequists.
+         * Do it here as we are called during the initial scan.
+         */
+        if (nandmtd1_test_prerequists(mtd) != YAFFS_OK)
+                return YAFFS_FAIL;
+
+        retval = nandmtd1_read_chunk_tags(dev, chunk_num, NULL, &etags);
+        etags.block_bad = (mtd->block_isbad) (mtd, addr);
+        if (etags.block_bad) {
+                yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
+                        "block %d is marked bad", block_no);
+                state = YAFFS_BLOCK_STATE_DEAD;
+        } else if (etags.ecc_result != YAFFS_ECC_RESULT_NO_ERROR) {
+                /* bad tags, need to look more closely */
+                state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
+        } else if (etags.chunk_used) {
+                state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
+                seqnum = etags.seq_number;
+        } else {
+                state = YAFFS_BLOCK_STATE_EMPTY;
+        }
+
+        *state_ptr = state;
+        *seq_ptr = seqnum;
+
+        /* query always succeeds */
+        return YAFFS_OK;
+}
diff --git a/fs/yaffs2/yaffs_mtdif1.h b/fs/yaffs2/yaffs_mtdif1.h
new file mode 100644
index 00000000000..07ce4524f0f
--- /dev/null
+++ b/fs/yaffs2/yaffs_mtdif1.h
@@ -0,0 +1,29 @@
+/*
+ * YAFFS: Yet another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_MTDIF1_H__
+#define __YAFFS_MTDIF1_H__
+
+int nandmtd1_write_chunk_tags(struct yaffs_dev *dev, int nand_chunk,
+                              const u8 * data,
+                              const struct yaffs_ext_tags *tags);
+
+int nandmtd1_read_chunk_tags(struct yaffs_dev *dev, int nand_chunk,
+                             u8 * data, struct yaffs_ext_tags *tags);
+
+int nandmtd1_mark_block_bad(struct yaffs_dev *dev, int block_no);
+
+int nandmtd1_query_block(struct yaffs_dev *dev, int block_no,
+                         enum yaffs_block_state *state, u32 * seq_number);
+
+#endif
diff --git a/fs/yaffs2/yaffs_mtdif2.c b/fs/yaffs2/yaffs_mtdif2.c
new file mode 100644
index 00000000000..d1643df2c38
--- /dev/null
+++ b/fs/yaffs2/yaffs_mtdif2.c
@@ -0,0 +1,225 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/* mtd interface for YAFFS2 */
+
+#include "yportenv.h"
+#include "yaffs_trace.h"
+
+#include "yaffs_mtdif2.h"
+
+#include "linux/mtd/mtd.h"
+#include "linux/types.h"
+#include "linux/time.h"
+
+#include "yaffs_packedtags2.h"
+
+#include "yaffs_linux.h"
+
+/* NB For use with inband tags....
+ * We assume that the data buffer is of size total_bytes_per_chunk so that we can also
+ * use it to load the tags.
+ */
+int nandmtd2_write_chunk_tags(struct yaffs_dev *dev, int nand_chunk,
+                              const u8 * data,
+                              const struct yaffs_ext_tags *tags)
+{
+        struct mtd_info *mtd = yaffs_dev_to_mtd(dev);
+        struct mtd_oob_ops ops;
+        int retval = 0;
+
+        loff_t addr;
+
+        struct yaffs_packed_tags2 pt;
+
+        int packed_tags_size =
+            dev->param.no_tags_ecc ? sizeof(pt.t) : sizeof(pt);
+        void *packed_tags_ptr =
+            dev->param.no_tags_ecc ? (void *)&pt.t : (void *)&pt;
+
+        yaffs_trace(YAFFS_TRACE_MTD,
+                "nandmtd2_write_chunk_tags chunk %d data %p tags %p",
+                nand_chunk, data, tags);
+
+        addr = ((loff_t) nand_chunk) * dev->param.total_bytes_per_chunk;
+
+        /* For yaffs2 writing there must be both data and tags.
+         * If we're using inband tags, then the tags are stuffed into
+         * the end of the data buffer.
+         */
+        if (!data || !tags)
+                BUG();
+        else if (dev->param.inband_tags) {
+                struct yaffs_packed_tags2_tags_only *pt2tp;
+                pt2tp =
+                    (struct yaffs_packed_tags2_tags_only *)(data +
+                                                            dev->
+                                                            data_bytes_per_chunk);
+                yaffs_pack_tags2_tags_only(pt2tp, tags);
+        } else {
+                yaffs_pack_tags2(&pt, tags, !dev->param.no_tags_ecc);
+        }
+
+        ops.mode = MTD_OOB_AUTO;
+        ops.ooblen = (dev->param.inband_tags) ? 0 : packed_tags_size;
+        ops.len = dev->param.total_bytes_per_chunk;
+        ops.ooboffs = 0;
+        ops.datbuf = (u8 *) data;
+        ops.oobbuf = (dev->param.inband_tags) ? NULL : packed_tags_ptr;
+        retval = mtd->write_oob(mtd, addr, &ops);
+
+        if (retval == 0)
+                return YAFFS_OK;
+        else
+                return YAFFS_FAIL;
+}
+
+int nandmtd2_read_chunk_tags(struct yaffs_dev *dev, int nand_chunk,
+                             u8 * data, struct yaffs_ext_tags *tags)
+{
+        struct mtd_info *mtd = yaffs_dev_to_mtd(dev);
+        struct mtd_oob_ops ops;
+
+        size_t dummy;
+        int retval = 0;
+        int local_data = 0;
+
+        loff_t addr = ((loff_t) nand_chunk) * dev->param.total_bytes_per_chunk;
+
+        struct yaffs_packed_tags2 pt;
+
+        int packed_tags_size =
+            dev->param.no_tags_ecc ? sizeof(pt.t) : sizeof(pt);
+        void *packed_tags_ptr =
+            dev->param.no_tags_ecc ? (void *)&pt.t : (void *)&pt;
+
+        yaffs_trace(YAFFS_TRACE_MTD,
+                "nandmtd2_read_chunk_tags chunk %d data %p tags %p",
+                nand_chunk, data, tags);
+
+        if (dev->param.inband_tags) {
+
+                if (!data) {
+                        local_data = 1;
+                        data = yaffs_get_temp_buffer(dev, __LINE__);
+                }
+
+        }
+
+        if (dev->param.inband_tags || (data && !tags))
+                retval = mtd->read(mtd, addr, dev->param.total_bytes_per_chunk,
+                                   &dummy, data);
+        else if (tags) {
+                ops.mode = MTD_OOB_AUTO;
+                ops.ooblen = packed_tags_size;
+                ops.len = data ? dev->data_bytes_per_chunk : packed_tags_size;
+                ops.ooboffs = 0;
+                ops.datbuf = data;
+                ops.oobbuf = yaffs_dev_to_lc(dev)->spare_buffer;
+                retval = mtd->read_oob(mtd, addr, &ops);
+        }
+
+        if (dev->param.inband_tags) {
+                if (tags) {
+                        struct yaffs_packed_tags2_tags_only *pt2tp;
+                        pt2tp =
+                            (struct yaffs_packed_tags2_tags_only *)&data[dev->
+                                                                         data_bytes_per_chunk];
+                        yaffs_unpack_tags2_tags_only(tags, pt2tp);
+                }
+        } else {
+                if (tags) {
+                        memcpy(packed_tags_ptr,
+                               yaffs_dev_to_lc(dev)->spare_buffer,
+                               packed_tags_size);
+                        yaffs_unpack_tags2(tags, &pt, !dev->param.no_tags_ecc);
+                }
+        }
+
+        if (local_data)
+                yaffs_release_temp_buffer(dev, data, __LINE__);
+
+        if (tags && retval == -EBADMSG
+            && tags->ecc_result == YAFFS_ECC_RESULT_NO_ERROR) {
+                tags->ecc_result = YAFFS_ECC_RESULT_UNFIXED;
+                dev->n_ecc_unfixed++;
+        }
+        if (tags && retval == -EUCLEAN
+            && tags->ecc_result == YAFFS_ECC_RESULT_NO_ERROR) {
+                tags->ecc_result = YAFFS_ECC_RESULT_FIXED;
+                dev->n_ecc_fixed++;
+        }
+        if (retval == 0)
+                return YAFFS_OK;
+        else
+                return YAFFS_FAIL;
+}
+
+int nandmtd2_mark_block_bad(struct yaffs_dev *dev, int block_no)
+{
+        struct mtd_info *mtd = yaffs_dev_to_mtd(dev);
+        int retval;
+        yaffs_trace(YAFFS_TRACE_MTD,
+                "nandmtd2_mark_block_bad %d", block_no);
+
+        retval =
+            mtd->block_markbad(mtd,
+                               block_no * dev->param.chunks_per_block *
+                               dev->param.total_bytes_per_chunk);
+
+        if (retval == 0)
+                return YAFFS_OK;
+        else
+                return YAFFS_FAIL;
+
+}
+
+int nandmtd2_query_block(struct yaffs_dev *dev, int block_no,
+                         enum yaffs_block_state *state, u32 * seq_number)
+{
+        struct mtd_info *mtd = yaffs_dev_to_mtd(dev);
+        int retval;
+
+        yaffs_trace(YAFFS_TRACE_MTD, "nandmtd2_query_block %d", block_no);
+        retval =
+            mtd->block_isbad(mtd,
+                             block_no * dev->param.chunks_per_block *
+                             dev->param.total_bytes_per_chunk);
+
+        if (retval) {
+                yaffs_trace(YAFFS_TRACE_MTD, "block is bad");
+
+                *state = YAFFS_BLOCK_STATE_DEAD;
+                *seq_number = 0;
+        } else {
+                struct yaffs_ext_tags t;
+                nandmtd2_read_chunk_tags(dev, block_no *
+                                         dev->param.chunks_per_block, NULL, &t);
+
+                if (t.chunk_used) {
+                        *seq_number = t.seq_number;
+                        *state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
+                } else {
+                        *seq_number = 0;
+                        *state = YAFFS_BLOCK_STATE_EMPTY;
+                }
+        }
+        yaffs_trace(YAFFS_TRACE_MTD,
+                "block is bad seq %d state %d", *seq_number, *state);
+
+        if (retval == 0)
+                return YAFFS_OK;
+        else
+                return YAFFS_FAIL;
+}
+
diff --git a/fs/yaffs2/yaffs_mtdif2.h b/fs/yaffs2/yaffs_mtdif2.h
new file mode 100644
index 00000000000..d82112610d0
--- /dev/null
+++ b/fs/yaffs2/yaffs_mtdif2.h
@@ -0,0 +1,29 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_MTDIF2_H__
+#define __YAFFS_MTDIF2_H__
+
+#include "yaffs_guts.h"
+int nandmtd2_write_chunk_tags(struct yaffs_dev *dev, int nand_chunk,
+                              const u8 * data,
+                              const struct yaffs_ext_tags *tags);
+int nandmtd2_read_chunk_tags(struct yaffs_dev *dev, int nand_chunk,
+                             u8 * data, struct yaffs_ext_tags *tags);
+int nandmtd2_mark_block_bad(struct yaffs_dev *dev, int block_no);
+int nandmtd2_query_block(struct yaffs_dev *dev, int block_no,
+                         enum yaffs_block_state *state, u32 * seq_number);
+
+#endif
diff --git a/fs/yaffs2/yaffs_nameval.c b/fs/yaffs2/yaffs_nameval.c
new file mode 100644
index 00000000000..daa36f989d3
--- /dev/null
+++ b/fs/yaffs2/yaffs_nameval.c
@@ -0,0 +1,201 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ * This simple implementation of a name-value store assumes a small number of values and fits
+ * into a small finite buffer.
+ *
+ * Each attribute is stored as a record:
+ *  sizeof(int) bytes   record size.
+ *  strnlen+1 bytes name null terminated.
+ *  nbytes    value.
+ *  ----------
+ *  total size  stored in record size 
+ *
+ * This code has not been tested with unicode yet.
+ */
+
+#include "yaffs_nameval.h"
+
+#include "yportenv.h"
+
+static int nval_find(const char *xb, int xb_size, const YCHAR * name,
+                     int *exist_size)
+{
+        int pos = 0;
+        int size;
+
+        memcpy(&size, xb, sizeof(int));
+        while (size > 0 && (size < xb_size) && (pos + size < xb_size)) {
+                if (strncmp
+                    ((YCHAR *) (xb + pos + sizeof(int)), name, size) == 0) {
+                        if (exist_size)
+                                *exist_size = size;
+                        return pos;
+                }
+                pos += size;
+                if (pos < xb_size - sizeof(int))
+                        memcpy(&size, xb + pos, sizeof(int));
+                else
+                        size = 0;
+        }
+        if (exist_size)
+                *exist_size = 0;
+        return -1;
+}
+
+static int nval_used(const char *xb, int xb_size)
+{
+        int pos = 0;
+        int size;
+
+        memcpy(&size, xb + pos, sizeof(int));
+        while (size > 0 && (size < xb_size) && (pos + size < xb_size)) {
+                pos += size;
+                if (pos < xb_size - sizeof(int))
+                        memcpy(&size, xb + pos, sizeof(int));
+                else
+                        size = 0;
+        }
+        return pos;
+}
+
+int nval_del(char *xb, int xb_size, const YCHAR * name)
+{
+        int pos = nval_find(xb, xb_size, name, NULL);
+        int size;
+
+        if (pos >= 0 && pos < xb_size) {
+                /* Find size, shift rest over this record, then zero out the rest of buffer */
+                memcpy(&size, xb + pos, sizeof(int));
+                memcpy(xb + pos, xb + pos + size, xb_size - (pos + size));
+                memset(xb + (xb_size - size), 0, size);
+                return 0;
+        } else {
+                return -ENODATA;
+        }
+}
+
+int nval_set(char *xb, int xb_size, const YCHAR * name, const char *buf,
+             int bsize, int flags)
+{
+        int pos;
+        int namelen = strnlen(name, xb_size);
+        int reclen;
+        int size_exist = 0;
+        int space;
+        int start;
+
+        pos = nval_find(xb, xb_size, name, &size_exist);
+
+        if (flags & XATTR_CREATE && pos >= 0)
+                return -EEXIST;
+        if (flags & XATTR_REPLACE && pos < 0)
+                return -ENODATA;
+
+        start = nval_used(xb, xb_size);
+        space = xb_size - start + size_exist;
+
+        reclen = (sizeof(int) + namelen + 1 + bsize);
+
+        if (reclen > space)
+                return -ENOSPC;
+
+        if (pos >= 0) {
+                nval_del(xb, xb_size, name);
+                start = nval_used(xb, xb_size);
+        }
+
+        pos = start;
+
+        memcpy(xb + pos, &reclen, sizeof(int));
+        pos += sizeof(int);
+        strncpy((YCHAR *) (xb + pos), name, reclen);
+        pos += (namelen + 1);
+        memcpy(xb + pos, buf, bsize);
+        return 0;
+}
+
+int nval_get(const char *xb, int xb_size, const YCHAR * name, char *buf,
+             int bsize)
+{
+        int pos = nval_find(xb, xb_size, name, NULL);
+        int size;
+
+        if (pos >= 0 && pos < xb_size) {
+
+                memcpy(&size, xb + pos, sizeof(int));
+                pos += sizeof(int);     /* advance past record length */
+                size -= sizeof(int);
+
+                /* Advance over name string */
+                while (xb[pos] && size > 0 && pos < xb_size) {
+                        pos++;
+                        size--;
+                }
+                /*Advance over NUL */
+                pos++;
+                size--;
+
+                if (size <= bsize) {
+                        memcpy(buf, xb + pos, size);
+                        return size;
+                }
+
+        }
+        if (pos >= 0)
+                return -ERANGE;
+        else
+                return -ENODATA;
+}
+
+int nval_list(const char *xb, int xb_size, char *buf, int bsize)
+{
+        int pos = 0;
+        int size;
+        int name_len;
+        int ncopied = 0;
+        int filled = 0;
+
+        memcpy(&size, xb + pos, sizeof(int));
+        while (size > sizeof(int) && size <= xb_size && (pos + size) < xb_size
+               && !filled) {
+                pos += sizeof(int);
+                size -= sizeof(int);
+                name_len = strnlen((YCHAR *) (xb + pos), size);
+                if (ncopied + name_len + 1 < bsize) {
+                        memcpy(buf, xb + pos, name_len * sizeof(YCHAR));
+                        buf += name_len;
+                        *buf = '\0';
+                        buf++;
+                        if (sizeof(YCHAR) > 1) {
+                                *buf = '\0';
+                                buf++;
+                        }
+                        ncopied += (name_len + 1);
+                } else {
+                        filled = 1;
+                }
+                pos += size;
+                if (pos < xb_size - sizeof(int))
+                        memcpy(&size, xb + pos, sizeof(int));
+                else
+                        size = 0;
+        }
+        return ncopied;
+}
+
+int nval_hasvalues(const char *xb, int xb_size)
+{
+        return nval_used(xb, xb_size) > 0;
+}
diff --git a/fs/yaffs2/yaffs_nameval.h b/fs/yaffs2/yaffs_nameval.h
new file mode 100644
index 00000000000..2bb02b62762
--- /dev/null
+++ b/fs/yaffs2/yaffs_nameval.h
@@ -0,0 +1,28 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __NAMEVAL_H__
+#define __NAMEVAL_H__
+
+#include "yportenv.h"
+
+int nval_del(char *xb, int xb_size, const YCHAR * name);
+int nval_set(char *xb, int xb_size, const YCHAR * name, const char *buf,
+             int bsize, int flags);
+int nval_get(const char *xb, int xb_size, const YCHAR * name, char *buf,
+             int bsize);
+int nval_list(const char *xb, int xb_size, char *buf, int bsize);
+int nval_hasvalues(const char *xb, int xb_size);
+#endif
diff --git a/fs/yaffs2/yaffs_nand.c b/fs/yaffs2/yaffs_nand.c
new file mode 100644
index 00000000000..e816cabf43f
--- /dev/null
+++ b/fs/yaffs2/yaffs_nand.c
@@ -0,0 +1,127 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_nand.h"
+#include "yaffs_tagscompat.h"
+#include "yaffs_tagsvalidity.h"
+
+#include "yaffs_getblockinfo.h"
+
+int yaffs_rd_chunk_tags_nand(struct yaffs_dev *dev, int nand_chunk,
+                             u8 * buffer, struct yaffs_ext_tags *tags)
+{
+        int result;
+        struct yaffs_ext_tags local_tags;
+
+        int realigned_chunk = nand_chunk - dev->chunk_offset;
+
+        dev->n_page_reads++;
+
+        /* If there are no tags provided, use local tags to get prioritised gc working */
+        if (!tags)
+                tags = &local_tags;
+
+        if (dev->param.read_chunk_tags_fn)
+                result =
+                    dev->param.read_chunk_tags_fn(dev, realigned_chunk, buffer,
+                                                  tags);
+        else
+                result = yaffs_tags_compat_rd(dev,
+                                              realigned_chunk, buffer, tags);
+        if (tags && tags->ecc_result > YAFFS_ECC_RESULT_NO_ERROR) {
+
+                struct yaffs_block_info *bi;
+                bi = yaffs_get_block_info(dev,
+                                          nand_chunk /
+                                          dev->param.chunks_per_block);
+                yaffs_handle_chunk_error(dev, bi);
+        }
+
+        return result;
+}
+
+int yaffs_wr_chunk_tags_nand(struct yaffs_dev *dev,
+                             int nand_chunk,
+                             const u8 * buffer, struct yaffs_ext_tags *tags)
+{
+
+        dev->n_page_writes++;
+
+        nand_chunk -= dev->chunk_offset;
+
+        if (tags) {
+                tags->seq_number = dev->seq_number;
+                tags->chunk_used = 1;
+                if (!yaffs_validate_tags(tags)) {
+                        yaffs_trace(YAFFS_TRACE_ERROR, "Writing uninitialised tags");
+                        YBUG();
+                }
+                yaffs_trace(YAFFS_TRACE_WRITE,
+                        "Writing chunk %d tags %d %d",
+                        nand_chunk, tags->obj_id, tags->chunk_id);
+        } else {
+                yaffs_trace(YAFFS_TRACE_ERROR, "Writing with no tags");
+                YBUG();
+        }
+
+        if (dev->param.write_chunk_tags_fn)
+                return dev->param.write_chunk_tags_fn(dev, nand_chunk, buffer,
+                                                      tags);
+        else
+                return yaffs_tags_compat_wr(dev, nand_chunk, buffer, tags);
+}
+
+int yaffs_mark_bad(struct yaffs_dev *dev, int block_no)
+{
+        block_no -= dev->block_offset;
+
+        if (dev->param.bad_block_fn)
+                return dev->param.bad_block_fn(dev, block_no);
+        else
+                return yaffs_tags_compat_mark_bad(dev, block_no);
+}
+
+int yaffs_query_init_block_state(struct yaffs_dev *dev,
+                                 int block_no,
+                                 enum yaffs_block_state *state,
+                                 u32 * seq_number)
+{
+        block_no -= dev->block_offset;
+
+        if (dev->param.query_block_fn)
+                return dev->param.query_block_fn(dev, block_no, state,
+                                                 seq_number);
+        else
+                return yaffs_tags_compat_query_block(dev, block_no,
+                                                     state, seq_number);
+}
+
+int yaffs_erase_block(struct yaffs_dev *dev, int flash_block)
+{
+        int result;
+
+        flash_block -= dev->block_offset;
+
+        dev->n_erasures++;
+
+        result = dev->param.erase_fn(dev, flash_block);
+
+        return result;
+}
+
+int yaffs_init_nand(struct yaffs_dev *dev)
+{
+        if (dev->param.initialise_flash_fn)
+                return dev->param.initialise_flash_fn(dev);
+        return YAFFS_OK;
+}
diff --git a/fs/yaffs2/yaffs_nand.h b/fs/yaffs2/yaffs_nand.h
new file mode 100644
index 00000000000..543f1987124
--- /dev/null
+++ b/fs/yaffs2/yaffs_nand.h
@@ -0,0 +1,38 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_NAND_H__
+#define __YAFFS_NAND_H__
+#include "yaffs_guts.h"
+
+int yaffs_rd_chunk_tags_nand(struct yaffs_dev *dev, int nand_chunk,
+                             u8 * buffer, struct yaffs_ext_tags *tags);
+
+int yaffs_wr_chunk_tags_nand(struct yaffs_dev *dev,
+                             int nand_chunk,
+                             const u8 * buffer, struct yaffs_ext_tags *tags);
+
+int yaffs_mark_bad(struct yaffs_dev *dev, int block_no);
+
+int yaffs_query_init_block_state(struct yaffs_dev *dev,
+                                 int block_no,
+                                 enum yaffs_block_state *state,
+                                 unsigned *seq_number);
+
+int yaffs_erase_block(struct yaffs_dev *dev, int flash_block);
+
+int yaffs_init_nand(struct yaffs_dev *dev);
+
+#endif
diff --git a/fs/yaffs2/yaffs_packedtags1.c b/fs/yaffs2/yaffs_packedtags1.c
new file mode 100644
index 00000000000..a77f0954fc1
--- /dev/null
+++ b/fs/yaffs2/yaffs_packedtags1.c
@@ -0,0 +1,53 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_packedtags1.h"
+#include "yportenv.h"
+
+void yaffs_pack_tags1(struct yaffs_packed_tags1 *pt,
+                      const struct yaffs_ext_tags *t)
+{
+        pt->chunk_id = t->chunk_id;
+        pt->serial_number = t->serial_number;
+        pt->n_bytes = t->n_bytes;
+        pt->obj_id = t->obj_id;
+        pt->ecc = 0;
+        pt->deleted = (t->is_deleted) ? 0 : 1;
+        pt->unused_stuff = 0;
+        pt->should_be_ff = 0xFFFFFFFF;
+
+}
+
+void yaffs_unpack_tags1(struct yaffs_ext_tags *t,
+                        const struct yaffs_packed_tags1 *pt)
+{
+        static const u8 all_ff[] =
+            { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+                0xff
+        };
+
+        if (memcmp(all_ff, pt, sizeof(struct yaffs_packed_tags1))) {
+                t->block_bad = 0;
+                if (pt->should_be_ff != 0xFFFFFFFF)
+                        t->block_bad = 1;
+                t->chunk_used = 1;
+                t->obj_id = pt->obj_id;
+                t->chunk_id = pt->chunk_id;
+                t->n_bytes = pt->n_bytes;
+                t->ecc_result = YAFFS_ECC_RESULT_NO_ERROR;
+                t->is_deleted = (pt->deleted) ? 0 : 1;
+                t->serial_number = pt->serial_number;
+        } else {
+                memset(t, 0, sizeof(struct yaffs_ext_tags));
+        }
+}
diff --git a/fs/yaffs2/yaffs_packedtags1.h b/fs/yaffs2/yaffs_packedtags1.h
new file mode 100644
index 00000000000..d6861ff505e
--- /dev/null
+++ b/fs/yaffs2/yaffs_packedtags1.h
@@ -0,0 +1,39 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+/* This is used to pack YAFFS1 tags, not YAFFS2 tags. */
+
+#ifndef __YAFFS_PACKEDTAGS1_H__
+#define __YAFFS_PACKEDTAGS1_H__
+
+#include "yaffs_guts.h"
+
+struct yaffs_packed_tags1 {
+        unsigned chunk_id:20;
+        unsigned serial_number:2;
+        unsigned n_bytes:10;
+        unsigned obj_id:18;
+        unsigned ecc:12;
+        unsigned deleted:1;
+        unsigned unused_stuff:1;
+        unsigned should_be_ff;
+
+};
+
+void yaffs_pack_tags1(struct yaffs_packed_tags1 *pt,
+                      const struct yaffs_ext_tags *t);
+void yaffs_unpack_tags1(struct yaffs_ext_tags *t,
+                        const struct yaffs_packed_tags1 *pt);
+#endif
diff --git a/fs/yaffs2/yaffs_packedtags2.c b/fs/yaffs2/yaffs_packedtags2.c
new file mode 100644
index 00000000000..8e7fea3d286
--- /dev/null
+++ b/fs/yaffs2/yaffs_packedtags2.c
@@ -0,0 +1,196 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_packedtags2.h"
+#include "yportenv.h"
+#include "yaffs_trace.h"
+#include "yaffs_tagsvalidity.h"
+
+/* This code packs a set of extended tags into a binary structure for
+ * NAND storage
+ */
+
+/* Some of the information is "extra" struff which can be packed in to
+ * speed scanning
+ * This is defined by having the EXTRA_HEADER_INFO_FLAG set.
+ */
+
+/* Extra flags applied to chunk_id */
+
+#define EXTRA_HEADER_INFO_FLAG  0x80000000
+#define EXTRA_SHRINK_FLAG       0x40000000
+#define EXTRA_SHADOWS_FLAG      0x20000000
+#define EXTRA_SPARE_FLAGS       0x10000000
+
+#define ALL_EXTRA_FLAGS         0xF0000000
+
+/* Also, the top 4 bits of the object Id are set to the object type. */
+#define EXTRA_OBJECT_TYPE_SHIFT (28)
+#define EXTRA_OBJECT_TYPE_MASK  ((0x0F) << EXTRA_OBJECT_TYPE_SHIFT)
+
+static void yaffs_dump_packed_tags2_tags_only(const struct
+                                              yaffs_packed_tags2_tags_only *ptt)
+{
+        yaffs_trace(YAFFS_TRACE_MTD,
+                "packed tags obj %d chunk %d byte %d seq %d",
+                ptt->obj_id, ptt->chunk_id, ptt->n_bytes, ptt->seq_number);
+}
+
+static void yaffs_dump_packed_tags2(const struct yaffs_packed_tags2 *pt)
+{
+        yaffs_dump_packed_tags2_tags_only(&pt->t);
+}
+
+static void yaffs_dump_tags2(const struct yaffs_ext_tags *t)
+{
+        yaffs_trace(YAFFS_TRACE_MTD,
+                "ext.tags eccres %d blkbad %d chused %d obj %d chunk%d byte %d del %d ser %d seq %d",
+                t->ecc_result, t->block_bad, t->chunk_used, t->obj_id,
+                t->chunk_id, t->n_bytes, t->is_deleted, t->serial_number,
+                t->seq_number);
+
+}
+
+void yaffs_pack_tags2_tags_only(struct yaffs_packed_tags2_tags_only *ptt,
+                                const struct yaffs_ext_tags *t)
+{
+        ptt->chunk_id = t->chunk_id;
+        ptt->seq_number = t->seq_number;
+        ptt->n_bytes = t->n_bytes;
+        ptt->obj_id = t->obj_id;
+
+        if (t->chunk_id == 0 && t->extra_available) {
+                /* Store the extra header info instead */
+                /* We save the parent object in the chunk_id */
+                ptt->chunk_id = EXTRA_HEADER_INFO_FLAG | t->extra_parent_id;
+                if (t->extra_is_shrink)
+                        ptt->chunk_id |= EXTRA_SHRINK_FLAG;
+                if (t->extra_shadows)
+                        ptt->chunk_id |= EXTRA_SHADOWS_FLAG;
+
+                ptt->obj_id &= ~EXTRA_OBJECT_TYPE_MASK;
+                ptt->obj_id |= (t->extra_obj_type << EXTRA_OBJECT_TYPE_SHIFT);
+
+                if (t->extra_obj_type == YAFFS_OBJECT_TYPE_HARDLINK)
+                        ptt->n_bytes = t->extra_equiv_id;
+                else if (t->extra_obj_type == YAFFS_OBJECT_TYPE_FILE)
+                        ptt->n_bytes = t->extra_length;
+                else
+                        ptt->n_bytes = 0;
+        }
+
+        yaffs_dump_packed_tags2_tags_only(ptt);
+        yaffs_dump_tags2(t);
+}
+
+void yaffs_pack_tags2(struct yaffs_packed_tags2 *pt,
+                      const struct yaffs_ext_tags *t, int tags_ecc)
+{
+        yaffs_pack_tags2_tags_only(&pt->t, t);
+
+        if (tags_ecc)
+                yaffs_ecc_calc_other((unsigned char *)&pt->t,
+                                     sizeof(struct
+                                            yaffs_packed_tags2_tags_only),
+                                     &pt->ecc);
+}
+
+void yaffs_unpack_tags2_tags_only(struct yaffs_ext_tags *t,
+                                  struct yaffs_packed_tags2_tags_only *ptt)
+{
+
+        memset(t, 0, sizeof(struct yaffs_ext_tags));
+
+        yaffs_init_tags(t);
+
+        if (ptt->seq_number != 0xFFFFFFFF) {
+                t->block_bad = 0;
+                t->chunk_used = 1;
+                t->obj_id = ptt->obj_id;
+                t->chunk_id = ptt->chunk_id;
+                t->n_bytes = ptt->n_bytes;
+                t->is_deleted = 0;
+                t->serial_number = 0;
+                t->seq_number = ptt->seq_number;
+
+                /* Do extra header info stuff */
+
+                if (ptt->chunk_id & EXTRA_HEADER_INFO_FLAG) {
+                        t->chunk_id = 0;
+                        t->n_bytes = 0;
+
+                        t->extra_available = 1;
+                        t->extra_parent_id =
+                            ptt->chunk_id & (~(ALL_EXTRA_FLAGS));
+                        t->extra_is_shrink =
+                            (ptt->chunk_id & EXTRA_SHRINK_FLAG) ? 1 : 0;
+                        t->extra_shadows =
+                            (ptt->chunk_id & EXTRA_SHADOWS_FLAG) ? 1 : 0;
+                        t->extra_obj_type =
+                            ptt->obj_id >> EXTRA_OBJECT_TYPE_SHIFT;
+                        t->obj_id &= ~EXTRA_OBJECT_TYPE_MASK;
+
+                        if (t->extra_obj_type == YAFFS_OBJECT_TYPE_HARDLINK)
+                                t->extra_equiv_id = ptt->n_bytes;
+                        else
+                                t->extra_length = ptt->n_bytes;
+                }
+        }
+
+        yaffs_dump_packed_tags2_tags_only(ptt);
+        yaffs_dump_tags2(t);
+
+}
+
+void yaffs_unpack_tags2(struct yaffs_ext_tags *t, struct yaffs_packed_tags2 *pt,
+                        int tags_ecc)
+{
+
+        enum yaffs_ecc_result ecc_result = YAFFS_ECC_RESULT_NO_ERROR;
+
+        if (pt->t.seq_number != 0xFFFFFFFF && tags_ecc) {
+                /* Chunk is in use and we need to do ECC */
+
+                struct yaffs_ecc_other ecc;
+                int result;
+                yaffs_ecc_calc_other((unsigned char *)&pt->t,
+                                     sizeof(struct
+                                            yaffs_packed_tags2_tags_only),
+                                     &ecc);
+                result =
+                    yaffs_ecc_correct_other((unsigned char *)&pt->t,
+                                            sizeof(struct
+                                                   yaffs_packed_tags2_tags_only),
+                                            &pt->ecc, &ecc);
+                switch (result) {
+                case 0:
+                        ecc_result = YAFFS_ECC_RESULT_NO_ERROR;
+                        break;
+                case 1:
+                        ecc_result = YAFFS_ECC_RESULT_FIXED;
+                        break;
+                case -1:
+                        ecc_result = YAFFS_ECC_RESULT_UNFIXED;
+                        break;
+                default:
+                        ecc_result = YAFFS_ECC_RESULT_UNKNOWN;
+                }
+        }
+
+        yaffs_unpack_tags2_tags_only(t, &pt->t);
+
+        t->ecc_result = ecc_result;
+
+        yaffs_dump_packed_tags2(pt);
+        yaffs_dump_tags2(t);
+}
diff --git a/fs/yaffs2/yaffs_packedtags2.h b/fs/yaffs2/yaffs_packedtags2.h
new file mode 100644
index 00000000000..f3296697bc0
--- /dev/null
+++ b/fs/yaffs2/yaffs_packedtags2.h
@@ -0,0 +1,47 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+/* This is used to pack YAFFS2 tags, not YAFFS1tags. */
+
+#ifndef __YAFFS_PACKEDTAGS2_H__
+#define __YAFFS_PACKEDTAGS2_H__
+
+#include "yaffs_guts.h"
+#include "yaffs_ecc.h"
+
+struct yaffs_packed_tags2_tags_only {
+        unsigned seq_number;
+        unsigned obj_id;
+        unsigned chunk_id;
+        unsigned n_bytes;
+};
+
+struct yaffs_packed_tags2 {
+        struct yaffs_packed_tags2_tags_only t;
+        struct yaffs_ecc_other ecc;
+};
+
+/* Full packed tags with ECC, used for oob tags */
+void yaffs_pack_tags2(struct yaffs_packed_tags2 *pt,
+                      const struct yaffs_ext_tags *t, int tags_ecc);
+void yaffs_unpack_tags2(struct yaffs_ext_tags *t, struct yaffs_packed_tags2 *pt,
+                        int tags_ecc);
+
+/* Only the tags part (no ECC for use with inband tags */
+void yaffs_pack_tags2_tags_only(struct yaffs_packed_tags2_tags_only *pt,
+                                const struct yaffs_ext_tags *t);
+void yaffs_unpack_tags2_tags_only(struct yaffs_ext_tags *t,
+                                  struct yaffs_packed_tags2_tags_only *pt);
+#endif
diff --git a/fs/yaffs2/yaffs_tagscompat.c b/fs/yaffs2/yaffs_tagscompat.c
new file mode 100644
index 00000000000..7578075d9ac
--- /dev/null
+++ b/fs/yaffs2/yaffs_tagscompat.c
@@ -0,0 +1,422 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_guts.h"
+#include "yaffs_tagscompat.h"
+#include "yaffs_ecc.h"
+#include "yaffs_getblockinfo.h"
+#include "yaffs_trace.h"
+
+static void yaffs_handle_rd_data_error(struct yaffs_dev *dev, int nand_chunk);
+
+
+/********** Tags ECC calculations  *********/
+
+void yaffs_calc_ecc(const u8 * data, struct yaffs_spare *spare)
+{
+        yaffs_ecc_cacl(data, spare->ecc1);
+        yaffs_ecc_cacl(&data[256], spare->ecc2);
+}
+
+void yaffs_calc_tags_ecc(struct yaffs_tags *tags)
+{
+        /* Calculate an ecc */
+
+        unsigned char *b = ((union yaffs_tags_union *)tags)->as_bytes;
+        unsigned i, j;
+        unsigned ecc = 0;
+        unsigned bit = 0;
+
+        tags->ecc = 0;
+
+        for (i = 0; i < 8; i++) {
+                for (j = 1; j & 0xff; j <<= 1) {
+                        bit++;
+                        if (b[i] & j)
+                                ecc ^= bit;
+                }
+        }
+
+        tags->ecc = ecc;
+
+}
+
+int yaffs_check_tags_ecc(struct yaffs_tags *tags)
+{
+        unsigned ecc = tags->ecc;
+
+        yaffs_calc_tags_ecc(tags);
+
+        ecc ^= tags->ecc;
+
+        if (ecc && ecc <= 64) {
+                /* TODO: Handle the failure better. Retire? */
+                unsigned char *b = ((union yaffs_tags_union *)tags)->as_bytes;
+
+                ecc--;
+
+                b[ecc / 8] ^= (1 << (ecc & 7));
+
+                /* Now recvalc the ecc */
+                yaffs_calc_tags_ecc(tags);
+
+                return 1;       /* recovered error */
+        } else if (ecc) {
+                /* Wierd ecc failure value */
+                /* TODO Need to do somethiong here */
+                return -1;      /* unrecovered error */
+        }
+
+        return 0;
+}
+
+/********** Tags **********/
+
+static void yaffs_load_tags_to_spare(struct yaffs_spare *spare_ptr,
+                                     struct yaffs_tags *tags_ptr)
+{
+        union yaffs_tags_union *tu = (union yaffs_tags_union *)tags_ptr;
+
+        yaffs_calc_tags_ecc(tags_ptr);
+
+        spare_ptr->tb0 = tu->as_bytes[0];
+        spare_ptr->tb1 = tu->as_bytes[1];
+        spare_ptr->tb2 = tu->as_bytes[2];
+        spare_ptr->tb3 = tu->as_bytes[3];
+        spare_ptr->tb4 = tu->as_bytes[4];
+        spare_ptr->tb5 = tu->as_bytes[5];
+        spare_ptr->tb6 = tu->as_bytes[6];
+        spare_ptr->tb7 = tu->as_bytes[7];
+}
+
+static void yaffs_get_tags_from_spare(struct yaffs_dev *dev,
+                                      struct yaffs_spare *spare_ptr,
+                                      struct yaffs_tags *tags_ptr)
+{
+        union yaffs_tags_union *tu = (union yaffs_tags_union *)tags_ptr;
+        int result;
+
+        tu->as_bytes[0] = spare_ptr->tb0;
+        tu->as_bytes[1] = spare_ptr->tb1;
+        tu->as_bytes[2] = spare_ptr->tb2;
+        tu->as_bytes[3] = spare_ptr->tb3;
+        tu->as_bytes[4] = spare_ptr->tb4;
+        tu->as_bytes[5] = spare_ptr->tb5;
+        tu->as_bytes[6] = spare_ptr->tb6;
+        tu->as_bytes[7] = spare_ptr->tb7;
+
+        result = yaffs_check_tags_ecc(tags_ptr);
+        if (result > 0)
+                dev->n_tags_ecc_fixed++;
+        else if (result < 0)
+                dev->n_tags_ecc_unfixed++;
+}
+
+static void yaffs_spare_init(struct yaffs_spare *spare)
+{
+        memset(spare, 0xFF, sizeof(struct yaffs_spare));
+}
+
+static int yaffs_wr_nand(struct yaffs_dev *dev,
+                         int nand_chunk, const u8 * data,
+                         struct yaffs_spare *spare)
+{
+        if (nand_chunk < dev->param.start_block * dev->param.chunks_per_block) {
+                yaffs_trace(YAFFS_TRACE_ERROR,
+                        "**>> yaffs chunk %d is not valid",
+                        nand_chunk);
+                return YAFFS_FAIL;
+        }
+
+        return dev->param.write_chunk_fn(dev, nand_chunk, data, spare);
+}
+
+static int yaffs_rd_chunk_nand(struct yaffs_dev *dev,
+                               int nand_chunk,
+                               u8 * data,
+                               struct yaffs_spare *spare,
+                               enum yaffs_ecc_result *ecc_result,
+                               int correct_errors)
+{
+        int ret_val;
+        struct yaffs_spare local_spare;
+
+        if (!spare && data) {
+                /* If we don't have a real spare, then we use a local one. */
+                /* Need this for the calculation of the ecc */
+                spare = &local_spare;
+        }
+
+        if (!dev->param.use_nand_ecc) {
+                ret_val =
+                    dev->param.read_chunk_fn(dev, nand_chunk, data, spare);
+                if (data && correct_errors) {
+                        /* Do ECC correction */
+                        /* Todo handle any errors */
+                        int ecc_result1, ecc_result2;
+                        u8 calc_ecc[3];
+
+                        yaffs_ecc_cacl(data, calc_ecc);
+                        ecc_result1 =
+                            yaffs_ecc_correct(data, spare->ecc1, calc_ecc);
+                        yaffs_ecc_cacl(&data[256], calc_ecc);
+                        ecc_result2 =
+                            yaffs_ecc_correct(&data[256], spare->ecc2,
+                                              calc_ecc);
+
+                        if (ecc_result1 > 0) {
+                                yaffs_trace(YAFFS_TRACE_ERROR,
+                                        "**>>yaffs ecc error fix performed on chunk %d:0",
+                                        nand_chunk);
+                                dev->n_ecc_fixed++;
+                        } else if (ecc_result1 < 0) {
+                                yaffs_trace(YAFFS_TRACE_ERROR,
+                                        "**>>yaffs ecc error unfixed on chunk %d:0",
+                                        nand_chunk);
+                                dev->n_ecc_unfixed++;
+                        }
+
+                        if (ecc_result2 > 0) {
+                                yaffs_trace(YAFFS_TRACE_ERROR,
+                                        "**>>yaffs ecc error fix performed on chunk %d:1",
+                                        nand_chunk);
+                                dev->n_ecc_fixed++;
+                        } else if (ecc_result2 < 0) {
+                                yaffs_trace(YAFFS_TRACE_ERROR,
+                                        "**>>yaffs ecc error unfixed on chunk %d:1",
+                                        nand_chunk);
+                                dev->n_ecc_unfixed++;
+                        }
+
+                        if (ecc_result1 || ecc_result2) {
+                                /* We had a data problem on this page */
+                                yaffs_handle_rd_data_error(dev, nand_chunk);
+                        }
+
+                        if (ecc_result1 < 0 || ecc_result2 < 0)
+                                *ecc_result = YAFFS_ECC_RESULT_UNFIXED;
+                        else if (ecc_result1 > 0 || ecc_result2 > 0)
+                                *ecc_result = YAFFS_ECC_RESULT_FIXED;
+                        else
+                                *ecc_result = YAFFS_ECC_RESULT_NO_ERROR;
+                }
+        } else {
+                /* Must allocate enough memory for spare+2*sizeof(int) */
+                /* for ecc results from device. */
+                struct yaffs_nand_spare nspare;
+
+                memset(&nspare, 0, sizeof(nspare));
+
+                ret_val = dev->param.read_chunk_fn(dev, nand_chunk, data,
+                                                   (struct yaffs_spare *)
+                                                   &nspare);
+                memcpy(spare, &nspare, sizeof(struct yaffs_spare));
+                if (data && correct_errors) {
+                        if (nspare.eccres1 > 0) {
+                                yaffs_trace(YAFFS_TRACE_ERROR,
+                                        "**>>mtd ecc error fix performed on chunk %d:0",
+                                        nand_chunk);
+                        } else if (nspare.eccres1 < 0) {
+                                yaffs_trace(YAFFS_TRACE_ERROR,
+                                        "**>>mtd ecc error unfixed on chunk %d:0",
+                                        nand_chunk);
+                        }
+
+                        if (nspare.eccres2 > 0) {
+                                yaffs_trace(YAFFS_TRACE_ERROR,
+                                        "**>>mtd ecc error fix performed on chunk %d:1",
+                                        nand_chunk);
+                        } else if (nspare.eccres2 < 0) {
+                                yaffs_trace(YAFFS_TRACE_ERROR,
+                                        "**>>mtd ecc error unfixed on chunk %d:1",
+                                        nand_chunk);
+                        }
+
+                        if (nspare.eccres1 || nspare.eccres2) {
+                                /* We had a data problem on this page */
+                                yaffs_handle_rd_data_error(dev, nand_chunk);
+                        }
+
+                        if (nspare.eccres1 < 0 || nspare.eccres2 < 0)
+                                *ecc_result = YAFFS_ECC_RESULT_UNFIXED;
+                        else if (nspare.eccres1 > 0 || nspare.eccres2 > 0)
+                                *ecc_result = YAFFS_ECC_RESULT_FIXED;
+                        else
+                                *ecc_result = YAFFS_ECC_RESULT_NO_ERROR;
+
+                }
+        }
+        return ret_val;
+}
+
+/*
+ * Functions for robustisizing
+ */
+
+static void yaffs_handle_rd_data_error(struct yaffs_dev *dev, int nand_chunk)
+{
+        int flash_block = nand_chunk / dev->param.chunks_per_block;
+
+        /* Mark the block for retirement */
+        yaffs_get_block_info(dev,
+                             flash_block + dev->block_offset)->needs_retiring =
+            1;
+        yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
+                "**>>Block %d marked for retirement",
+                flash_block);
+
+        /* TODO:
+         * Just do a garbage collection on the affected block
+         * then retire the block
+         * NB recursion
+         */
+}
+
+int yaffs_tags_compat_wr(struct yaffs_dev *dev,
+                         int nand_chunk,
+                         const u8 * data, const struct yaffs_ext_tags *ext_tags)
+{
+        struct yaffs_spare spare;
+        struct yaffs_tags tags;
+
+        yaffs_spare_init(&spare);
+
+        if (ext_tags->is_deleted)
+                spare.page_status = 0;
+        else {
+                tags.obj_id = ext_tags->obj_id;
+                tags.chunk_id = ext_tags->chunk_id;
+
+                tags.n_bytes_lsb = ext_tags->n_bytes & 0x3ff;
+
+                if (dev->data_bytes_per_chunk >= 1024)
+                        tags.n_bytes_msb = (ext_tags->n_bytes >> 10) & 3;
+                else
+                        tags.n_bytes_msb = 3;
+
+                tags.serial_number = ext_tags->serial_number;
+
+                if (!dev->param.use_nand_ecc && data)
+                        yaffs_calc_ecc(data, &spare);
+
+                yaffs_load_tags_to_spare(&spare, &tags);
+
+        }
+
+        return yaffs_wr_nand(dev, nand_chunk, data, &spare);
+}
+
+int yaffs_tags_compat_rd(struct yaffs_dev *dev,
+                         int nand_chunk,
+                         u8 * data, struct yaffs_ext_tags *ext_tags)
+{
+
+        struct yaffs_spare spare;
+        struct yaffs_tags tags;
+        enum yaffs_ecc_result ecc_result = YAFFS_ECC_RESULT_UNKNOWN;
+
+        static struct yaffs_spare spare_ff;
+        static int init;
+
+        if (!init) {
+                memset(&spare_ff, 0xFF, sizeof(spare_ff));
+                init = 1;
+        }
+
+        if (yaffs_rd_chunk_nand(dev, nand_chunk, data, &spare, &ecc_result, 1)) {
+                /* ext_tags may be NULL */
+                if (ext_tags) {
+
+                        int deleted =
+                            (hweight8(spare.page_status) < 7) ? 1 : 0;
+
+                        ext_tags->is_deleted = deleted;
+                        ext_tags->ecc_result = ecc_result;
+                        ext_tags->block_bad = 0;        /* We're reading it */
+                        /* therefore it is not a bad block */
+                        ext_tags->chunk_used =
+                            (memcmp(&spare_ff, &spare, sizeof(spare_ff)) !=
+                             0) ? 1 : 0;
+
+                        if (ext_tags->chunk_used) {
+                                yaffs_get_tags_from_spare(dev, &spare, &tags);
+
+                                ext_tags->obj_id = tags.obj_id;
+                                ext_tags->chunk_id = tags.chunk_id;
+                                ext_tags->n_bytes = tags.n_bytes_lsb;
+
+                                if (dev->data_bytes_per_chunk >= 1024)
+                                        ext_tags->n_bytes |=
+                                            (((unsigned)tags.
+                                              n_bytes_msb) << 10);
+
+                                ext_tags->serial_number = tags.serial_number;
+                        }
+                }
+
+                return YAFFS_OK;
+        } else {
+                return YAFFS_FAIL;
+        }
+}
+
+int yaffs_tags_compat_mark_bad(struct yaffs_dev *dev, int flash_block)
+{
+
+        struct yaffs_spare spare;
+
+        memset(&spare, 0xff, sizeof(struct yaffs_spare));
+
+        spare.block_status = 'Y';
+
+        yaffs_wr_nand(dev, flash_block * dev->param.chunks_per_block, NULL,
+                      &spare);
+        yaffs_wr_nand(dev, flash_block * dev->param.chunks_per_block + 1,
+                      NULL, &spare);
+
+        return YAFFS_OK;
+
+}
+
+int yaffs_tags_compat_query_block(struct yaffs_dev *dev,
+                                  int block_no,
+                                  enum yaffs_block_state *state,
+                                  u32 * seq_number)
+{
+
+        struct yaffs_spare spare0, spare1;
+        static struct yaffs_spare spare_ff;
+        static int init;
+        enum yaffs_ecc_result dummy;
+
+        if (!init) {
+                memset(&spare_ff, 0xFF, sizeof(spare_ff));
+                init = 1;
+        }
+
+        *seq_number = 0;
+
+        yaffs_rd_chunk_nand(dev, block_no * dev->param.chunks_per_block, NULL,
+                            &spare0, &dummy, 1);
+        yaffs_rd_chunk_nand(dev, block_no * dev->param.chunks_per_block + 1,
+                            NULL, &spare1, &dummy, 1);
+
+        if (hweight8(spare0.block_status & spare1.block_status) < 7)
+                *state = YAFFS_BLOCK_STATE_DEAD;
+        else if (memcmp(&spare_ff, &spare0, sizeof(spare_ff)) == 0)
+                *state = YAFFS_BLOCK_STATE_EMPTY;
+        else
+                *state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
+
+        return YAFFS_OK;
+}
diff --git a/fs/yaffs2/yaffs_tagscompat.h b/fs/yaffs2/yaffs_tagscompat.h
new file mode 100644
index 00000000000..8cd35dcd3ca
--- /dev/null
+++ b/fs/yaffs2/yaffs_tagscompat.h
@@ -0,0 +1,36 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_TAGSCOMPAT_H__
+#define __YAFFS_TAGSCOMPAT_H__
+
+#include "yaffs_guts.h"
+int yaffs_tags_compat_wr(struct yaffs_dev *dev,
+                         int nand_chunk,
+                         const u8 * data, const struct yaffs_ext_tags *tags);
+int yaffs_tags_compat_rd(struct yaffs_dev *dev,
+                         int nand_chunk,
+                         u8 * data, struct yaffs_ext_tags *tags);
+int yaffs_tags_compat_mark_bad(struct yaffs_dev *dev, int block_no);
+int yaffs_tags_compat_query_block(struct yaffs_dev *dev,
+                                  int block_no,
+                                  enum yaffs_block_state *state,
+                                  u32 * seq_number);
+
+void yaffs_calc_tags_ecc(struct yaffs_tags *tags);
+int yaffs_check_tags_ecc(struct yaffs_tags *tags);
+int yaffs_count_bits(u8 byte);
+
+#endif
diff --git a/fs/yaffs2/yaffs_tagsvalidity.c b/fs/yaffs2/yaffs_tagsvalidity.c
new file mode 100644
index 00000000000..4358d79d4be
--- /dev/null
+++ b/fs/yaffs2/yaffs_tagsvalidity.c
@@ -0,0 +1,27 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_tagsvalidity.h"
+
+void yaffs_init_tags(struct yaffs_ext_tags *tags)
+{
+        memset(tags, 0, sizeof(struct yaffs_ext_tags));
+        tags->validity0 = 0xAAAAAAAA;
+        tags->validity1 = 0x55555555;
+}
+
+int yaffs_validate_tags(struct yaffs_ext_tags *tags)
+{
+        return (tags->validity0 == 0xAAAAAAAA && tags->validity1 == 0x55555555);
+
+}
diff --git a/fs/yaffs2/yaffs_tagsvalidity.h b/fs/yaffs2/yaffs_tagsvalidity.h
new file mode 100644
index 00000000000..36a021fc8fa
--- /dev/null
+++ b/fs/yaffs2/yaffs_tagsvalidity.h
@@ -0,0 +1,23 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_TAGS_VALIDITY_H__
+#define __YAFFS_TAGS_VALIDITY_H__
+
+#include "yaffs_guts.h"
+
+void yaffs_init_tags(struct yaffs_ext_tags *tags);
+int yaffs_validate_tags(struct yaffs_ext_tags *tags);
+#endif
diff --git a/fs/yaffs2/yaffs_trace.h b/fs/yaffs2/yaffs_trace.h
new file mode 100644
index 00000000000..6273dbf9f63
--- /dev/null
+++ b/fs/yaffs2/yaffs_trace.h
@@ -0,0 +1,57 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YTRACE_H__
+#define __YTRACE_H__
+
+extern unsigned int yaffs_trace_mask;
+extern unsigned int yaffs_wr_attempts;
+
+/*
+ * Tracing flags.
+ * The flags masked in YAFFS_TRACE_ALWAYS are always traced.
+ */
+
+#define YAFFS_TRACE_OS                  0x00000002
+#define YAFFS_TRACE_ALLOCATE            0x00000004
+#define YAFFS_TRACE_SCAN                0x00000008
+#define YAFFS_TRACE_BAD_BLOCKS          0x00000010
+#define YAFFS_TRACE_ERASE               0x00000020
+#define YAFFS_TRACE_GC                  0x00000040
+#define YAFFS_TRACE_WRITE               0x00000080
+#define YAFFS_TRACE_TRACING             0x00000100
+#define YAFFS_TRACE_DELETION            0x00000200
+#define YAFFS_TRACE_BUFFERS             0x00000400
+#define YAFFS_TRACE_NANDACCESS          0x00000800
+#define YAFFS_TRACE_GC_DETAIL           0x00001000
+#define YAFFS_TRACE_SCAN_DEBUG          0x00002000
+#define YAFFS_TRACE_MTD                 0x00004000
+#define YAFFS_TRACE_CHECKPOINT          0x00008000
+
+#define YAFFS_TRACE_VERIFY              0x00010000
+#define YAFFS_TRACE_VERIFY_NAND         0x00020000
+#define YAFFS_TRACE_VERIFY_FULL         0x00040000
+#define YAFFS_TRACE_VERIFY_ALL          0x000F0000
+
+#define YAFFS_TRACE_SYNC                0x00100000
+#define YAFFS_TRACE_BACKGROUND          0x00200000
+#define YAFFS_TRACE_LOCK                0x00400000
+#define YAFFS_TRACE_MOUNT               0x00800000
+
+#define YAFFS_TRACE_ERROR               0x40000000
+#define YAFFS_TRACE_BUG                 0x80000000
+#define YAFFS_TRACE_ALWAYS              0xF0000000
+
+#endif
diff --git a/fs/yaffs2/yaffs_verify.c b/fs/yaffs2/yaffs_verify.c
new file mode 100644
index 00000000000..738c7f69a5e
--- /dev/null
+++ b/fs/yaffs2/yaffs_verify.c
@@ -0,0 +1,535 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_verify.h"
+#include "yaffs_trace.h"
+#include "yaffs_bitmap.h"
+#include "yaffs_getblockinfo.h"
+#include "yaffs_nand.h"
+
+int yaffs_skip_verification(struct yaffs_dev *dev)
+{
+        dev = dev;
+        return !(yaffs_trace_mask &
+                 (YAFFS_TRACE_VERIFY | YAFFS_TRACE_VERIFY_FULL));
+}
+
+static int yaffs_skip_full_verification(struct yaffs_dev *dev)
+{
+        dev = dev;
+        return !(yaffs_trace_mask & (YAFFS_TRACE_VERIFY_FULL));
+}
+
+static int yaffs_skip_nand_verification(struct yaffs_dev *dev)
+{
+        dev = dev;
+        return !(yaffs_trace_mask & (YAFFS_TRACE_VERIFY_NAND));
+}
+
+static const char *block_state_name[] = {
+        "Unknown",
+        "Needs scanning",
+        "Scanning",
+        "Empty",
+        "Allocating",
+        "Full",
+        "Dirty",
+        "Checkpoint",
+        "Collecting",
+        "Dead"
+};
+
+void yaffs_verify_blk(struct yaffs_dev *dev, struct yaffs_block_info *bi, int n)
+{
+        int actually_used;
+        int in_use;
+
+        if (yaffs_skip_verification(dev))
+                return;
+
+        /* Report illegal runtime states */
+        if (bi->block_state >= YAFFS_NUMBER_OF_BLOCK_STATES)
+                yaffs_trace(YAFFS_TRACE_VERIFY,
+                        "Block %d has undefined state %d",
+                        n, bi->block_state);
+
+        switch (bi->block_state) {
+        case YAFFS_BLOCK_STATE_UNKNOWN:
+        case YAFFS_BLOCK_STATE_SCANNING:
+        case YAFFS_BLOCK_STATE_NEEDS_SCANNING:
+                yaffs_trace(YAFFS_TRACE_VERIFY,
+                        "Block %d has bad run-state %s",
+                        n, block_state_name[bi->block_state]);
+        }
+
+        /* Check pages in use and soft deletions are legal */
+
+        actually_used = bi->pages_in_use - bi->soft_del_pages;
+
+        if (bi->pages_in_use < 0
+            || bi->pages_in_use > dev->param.chunks_per_block
+            || bi->soft_del_pages < 0
+            || bi->soft_del_pages > dev->param.chunks_per_block
+            || actually_used < 0 || actually_used > dev->param.chunks_per_block)
+                yaffs_trace(YAFFS_TRACE_VERIFY,
+                        "Block %d has illegal values pages_in_used %d soft_del_pages %d",
+                        n, bi->pages_in_use, bi->soft_del_pages);
+
+        /* Check chunk bitmap legal */
+        in_use = yaffs_count_chunk_bits(dev, n);
+        if (in_use != bi->pages_in_use)
+                yaffs_trace(YAFFS_TRACE_VERIFY,
+                        "Block %d has inconsistent values pages_in_use %d counted chunk bits %d",
+                        n, bi->pages_in_use, in_use);
+
+}
+
+void yaffs_verify_collected_blk(struct yaffs_dev *dev,
+                                struct yaffs_block_info *bi, int n)
+{
+        yaffs_verify_blk(dev, bi, n);
+
+        /* After collection the block should be in the erased state */
+
+        if (bi->block_state != YAFFS_BLOCK_STATE_COLLECTING &&
+            bi->block_state != YAFFS_BLOCK_STATE_EMPTY) {
+                yaffs_trace(YAFFS_TRACE_ERROR,
+                        "Block %d is in state %d after gc, should be erased",
+                        n, bi->block_state);
+        }
+}
+
+void yaffs_verify_blocks(struct yaffs_dev *dev)
+{
+        int i;
+        int state_count[YAFFS_NUMBER_OF_BLOCK_STATES];
+        int illegal_states = 0;
+
+        if (yaffs_skip_verification(dev))
+                return;
+
+        memset(state_count, 0, sizeof(state_count));
+
+        for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
+                struct yaffs_block_info *bi = yaffs_get_block_info(dev, i);
+                yaffs_verify_blk(dev, bi, i);
+
+                if (bi->block_state < YAFFS_NUMBER_OF_BLOCK_STATES)
+                        state_count[bi->block_state]++;
+                else
+                        illegal_states++;
+        }
+
+        yaffs_trace(YAFFS_TRACE_VERIFY, "Block summary");
+
+        yaffs_trace(YAFFS_TRACE_VERIFY,
+                "%d blocks have illegal states",
+                illegal_states);
+        if (state_count[YAFFS_BLOCK_STATE_ALLOCATING] > 1)
+                yaffs_trace(YAFFS_TRACE_VERIFY,
+                        "Too many allocating blocks");
+
+        for (i = 0; i < YAFFS_NUMBER_OF_BLOCK_STATES; i++)
+                yaffs_trace(YAFFS_TRACE_VERIFY,
+                        "%s %d blocks",
+                        block_state_name[i], state_count[i]);
+
+        if (dev->blocks_in_checkpt != state_count[YAFFS_BLOCK_STATE_CHECKPOINT])
+                yaffs_trace(YAFFS_TRACE_VERIFY,
+                        "Checkpoint block count wrong dev %d count %d",
+                        dev->blocks_in_checkpt,
+                        state_count[YAFFS_BLOCK_STATE_CHECKPOINT]);
+
+        if (dev->n_erased_blocks != state_count[YAFFS_BLOCK_STATE_EMPTY])
+                yaffs_trace(YAFFS_TRACE_VERIFY,
+                        "Erased block count wrong dev %d count %d",
+                        dev->n_erased_blocks,
+                        state_count[YAFFS_BLOCK_STATE_EMPTY]);
+
+        if (state_count[YAFFS_BLOCK_STATE_COLLECTING] > 1)
+                yaffs_trace(YAFFS_TRACE_VERIFY,
+                        "Too many collecting blocks %d (max is 1)",
+                        state_count[YAFFS_BLOCK_STATE_COLLECTING]);
+}
+
+/*
+ * Verify the object header. oh must be valid, but obj and tags may be NULL in which
+ * case those tests will not be performed.
+ */
+void yaffs_verify_oh(struct yaffs_obj *obj, struct yaffs_obj_hdr *oh,
+                     struct yaffs_ext_tags *tags, int parent_check)
+{
+        if (obj && yaffs_skip_verification(obj->my_dev))
+                return;
+
+        if (!(tags && obj && oh)) {
+                yaffs_trace(YAFFS_TRACE_VERIFY,
+                        "Verifying object header tags %p obj %p oh %p",
+                        tags, obj, oh);
+                return;
+        }
+
+        if (oh->type <= YAFFS_OBJECT_TYPE_UNKNOWN ||
+            oh->type > YAFFS_OBJECT_TYPE_MAX)
+                yaffs_trace(YAFFS_TRACE_VERIFY,
+                        "Obj %d header type is illegal value 0x%x",
+                        tags->obj_id, oh->type);
+
+        if (tags->obj_id != obj->obj_id)
+                yaffs_trace(YAFFS_TRACE_VERIFY,
+                        "Obj %d header mismatch obj_id %d",
+                        tags->obj_id, obj->obj_id);
+
+        /*
+         * Check that the object's parent ids match if parent_check requested.
+         *
+         * Tests do not apply to the root object.
+         */
+
+        if (parent_check && tags->obj_id > 1 && !obj->parent)
+                yaffs_trace(YAFFS_TRACE_VERIFY,
+                        "Obj %d header mismatch parent_id %d obj->parent is NULL",
+                        tags->obj_id, oh->parent_obj_id);
+
+        if (parent_check && obj->parent &&
+            oh->parent_obj_id != obj->parent->obj_id &&
+            (oh->parent_obj_id != YAFFS_OBJECTID_UNLINKED ||
+             obj->parent->obj_id != YAFFS_OBJECTID_DELETED))
+                yaffs_trace(YAFFS_TRACE_VERIFY,
+                        "Obj %d header mismatch parent_id %d parent_obj_id %d",
+                        tags->obj_id, oh->parent_obj_id,
+                        obj->parent->obj_id);
+
+        if (tags->obj_id > 1 && oh->name[0] == 0)       /* Null name */
+                yaffs_trace(YAFFS_TRACE_VERIFY,
+                        "Obj %d header name is NULL",
+                        obj->obj_id);
+
+        if (tags->obj_id > 1 && ((u8) (oh->name[0])) == 0xff)   /* Trashed name */
+                yaffs_trace(YAFFS_TRACE_VERIFY,
+                        "Obj %d header name is 0xFF",
+                        obj->obj_id);
+}
+
+void yaffs_verify_file(struct yaffs_obj *obj)
+{
+        int required_depth;
+        int actual_depth;
+        u32 last_chunk;
+        u32 x;
+        u32 i;
+        struct yaffs_dev *dev;
+        struct yaffs_ext_tags tags;
+        struct yaffs_tnode *tn;
+        u32 obj_id;
+
+        if (!obj)
+                return;
+
+        if (yaffs_skip_verification(obj->my_dev))
+                return;
+
+        dev = obj->my_dev;
+        obj_id = obj->obj_id;
+
+        /* Check file size is consistent with tnode depth */
+        last_chunk =
+            obj->variant.file_variant.file_size / dev->data_bytes_per_chunk + 1;
+        x = last_chunk >> YAFFS_TNODES_LEVEL0_BITS;
+        required_depth = 0;
+        while (x > 0) {
+                x >>= YAFFS_TNODES_INTERNAL_BITS;
+                required_depth++;
+        }
+
+        actual_depth = obj->variant.file_variant.top_level;
+
+        /* Check that the chunks in the tnode tree are all correct.
+         * We do this by scanning through the tnode tree and
+         * checking the tags for every chunk match.
+         */
+
+        if (yaffs_skip_nand_verification(dev))
+                return;
+
+        for (i = 1; i <= last_chunk; i++) {
+                tn = yaffs_find_tnode_0(dev, &obj->variant.file_variant, i);
+
+                if (tn) {
+                        u32 the_chunk = yaffs_get_group_base(dev, tn, i);
+                        if (the_chunk > 0) {
+                                yaffs_rd_chunk_tags_nand(dev, the_chunk, NULL,
+                                                         &tags);
+                                if (tags.obj_id != obj_id || tags.chunk_id != i)
+                                yaffs_trace(YAFFS_TRACE_VERIFY,
+                                        "Object %d chunk_id %d NAND mismatch chunk %d tags (%d:%d)",
+                                         obj_id, i, the_chunk,
+                                         tags.obj_id, tags.chunk_id);
+                        }
+                }
+        }
+}
+
+void yaffs_verify_link(struct yaffs_obj *obj)
+{
+        if (obj && yaffs_skip_verification(obj->my_dev))
+                return;
+
+        /* Verify sane equivalent object */
+}
+
+void yaffs_verify_symlink(struct yaffs_obj *obj)
+{
+        if (obj && yaffs_skip_verification(obj->my_dev))
+                return;
+
+        /* Verify symlink string */
+}
+
+void yaffs_verify_special(struct yaffs_obj *obj)
+{
+        if (obj && yaffs_skip_verification(obj->my_dev))
+                return;
+}
+
+void yaffs_verify_obj(struct yaffs_obj *obj)
+{
+        struct yaffs_dev *dev;
+
+        u32 chunk_min;
+        u32 chunk_max;
+
+        u32 chunk_id_ok;
+        u32 chunk_in_range;
+        u32 chunk_wrongly_deleted;
+        u32 chunk_valid;
+
+        if (!obj)
+                return;
+
+        if (obj->being_created)
+                return;
+
+        dev = obj->my_dev;
+
+        if (yaffs_skip_verification(dev))
+                return;
+
+        /* Check sane object header chunk */
+
+        chunk_min = dev->internal_start_block * dev->param.chunks_per_block;
+        chunk_max =
+            (dev->internal_end_block + 1) * dev->param.chunks_per_block - 1;
+
+        chunk_in_range = (((unsigned)(obj->hdr_chunk)) >= chunk_min &&
+                          ((unsigned)(obj->hdr_chunk)) <= chunk_max);
+        chunk_id_ok = chunk_in_range || (obj->hdr_chunk == 0);
+        chunk_valid = chunk_in_range &&
+            yaffs_check_chunk_bit(dev,
+                                  obj->hdr_chunk / dev->param.chunks_per_block,
+                                  obj->hdr_chunk % dev->param.chunks_per_block);
+        chunk_wrongly_deleted = chunk_in_range && !chunk_valid;
+
+        if (!obj->fake && (!chunk_id_ok || chunk_wrongly_deleted))
+                yaffs_trace(YAFFS_TRACE_VERIFY,
+                        "Obj %d has chunk_id %d %s %s",
+                        obj->obj_id, obj->hdr_chunk,
+                        chunk_id_ok ? "" : ",out of range",
+                        chunk_wrongly_deleted ? ",marked as deleted" : "");
+
+        if (chunk_valid && !yaffs_skip_nand_verification(dev)) {
+                struct yaffs_ext_tags tags;
+                struct yaffs_obj_hdr *oh;
+                u8 *buffer = yaffs_get_temp_buffer(dev, __LINE__);
+
+                oh = (struct yaffs_obj_hdr *)buffer;
+
+                yaffs_rd_chunk_tags_nand(dev, obj->hdr_chunk, buffer, &tags);
+
+                yaffs_verify_oh(obj, oh, &tags, 1);
+
+                yaffs_release_temp_buffer(dev, buffer, __LINE__);
+        }
+
+        /* Verify it has a parent */
+        if (obj && !obj->fake && (!obj->parent || obj->parent->my_dev != dev)) {
+                yaffs_trace(YAFFS_TRACE_VERIFY,
+                        "Obj %d has parent pointer %p which does not look like an object",
+                        obj->obj_id, obj->parent);
+        }
+
+        /* Verify parent is a directory */
+        if (obj->parent
+            && obj->parent->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+                yaffs_trace(YAFFS_TRACE_VERIFY,
+                        "Obj %d's parent is not a directory (type %d)",
+                        obj->obj_id, obj->parent->variant_type);
+        }
+
+        switch (obj->variant_type) {
+        case YAFFS_OBJECT_TYPE_FILE:
+                yaffs_verify_file(obj);
+                break;
+        case YAFFS_OBJECT_TYPE_SYMLINK:
+                yaffs_verify_symlink(obj);
+                break;
+        case YAFFS_OBJECT_TYPE_DIRECTORY:
+                yaffs_verify_dir(obj);
+                break;
+        case YAFFS_OBJECT_TYPE_HARDLINK:
+                yaffs_verify_link(obj);
+                break;
+        case YAFFS_OBJECT_TYPE_SPECIAL:
+                yaffs_verify_special(obj);
+                break;
+        case YAFFS_OBJECT_TYPE_UNKNOWN:
+        default:
+                yaffs_trace(YAFFS_TRACE_VERIFY,
+                        "Obj %d has illegaltype %d",
+                   obj->obj_id, obj->variant_type);
+                break;
+        }
+}
+
+void yaffs_verify_objects(struct yaffs_dev *dev)
+{
+        struct yaffs_obj *obj;
+        int i;
+        struct list_head *lh;
+
+        if (yaffs_skip_verification(dev))
+                return;
+
+        /* Iterate through the objects in each hash entry */
+
+        for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
+                list_for_each(lh, &dev->obj_bucket[i].list) {
+                        if (lh) {
+                                obj =
+                                    list_entry(lh, struct yaffs_obj, hash_link);
+                                yaffs_verify_obj(obj);
+                        }
+                }
+        }
+}
+
+void yaffs_verify_obj_in_dir(struct yaffs_obj *obj)
+{
+        struct list_head *lh;
+        struct yaffs_obj *list_obj;
+
+        int count = 0;
+
+        if (!obj) {
+                yaffs_trace(YAFFS_TRACE_ALWAYS, "No object to verify");
+                YBUG();
+                return;
+        }
+
+        if (yaffs_skip_verification(obj->my_dev))
+                return;
+
+        if (!obj->parent) {
+                yaffs_trace(YAFFS_TRACE_ALWAYS, "Object does not have parent" );
+                YBUG();
+                return;
+        }
+
+        if (obj->parent->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+                yaffs_trace(YAFFS_TRACE_ALWAYS, "Parent is not directory");
+                YBUG();
+        }
+
+        /* Iterate through the objects in each hash entry */
+
+        list_for_each(lh, &obj->parent->variant.dir_variant.children) {
+                if (lh) {
+                        list_obj = list_entry(lh, struct yaffs_obj, siblings);
+                        yaffs_verify_obj(list_obj);
+                        if (obj == list_obj)
+                                count++;
+                }
+        }
+
+        if (count != 1) {
+                yaffs_trace(YAFFS_TRACE_ALWAYS,
+                        "Object in directory %d times",
+                        count);
+                YBUG();
+        }
+}
+
+void yaffs_verify_dir(struct yaffs_obj *directory)
+{
+        struct list_head *lh;
+        struct yaffs_obj *list_obj;
+
+        if (!directory) {
+                YBUG();
+                return;
+        }
+
+        if (yaffs_skip_full_verification(directory->my_dev))
+                return;
+
+        if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+                yaffs_trace(YAFFS_TRACE_ALWAYS,
+                        "Directory has wrong type: %d",
+                        directory->variant_type);
+                YBUG();
+        }
+
+        /* Iterate through the objects in each hash entry */
+
+        list_for_each(lh, &directory->variant.dir_variant.children) {
+                if (lh) {
+                        list_obj = list_entry(lh, struct yaffs_obj, siblings);
+                        if (list_obj->parent != directory) {
+                                yaffs_trace(YAFFS_TRACE_ALWAYS,
+                                        "Object in directory list has wrong parent %p",
+                                        list_obj->parent);
+                                YBUG();
+                        }
+                        yaffs_verify_obj_in_dir(list_obj);
+                }
+        }
+}
+
+static int yaffs_free_verification_failures;
+
+void yaffs_verify_free_chunks(struct yaffs_dev *dev)
+{
+        int counted;
+        int difference;
+
+        if (yaffs_skip_verification(dev))
+                return;
+
+        counted = yaffs_count_free_chunks(dev);
+
+        difference = dev->n_free_chunks - counted;
+
+        if (difference) {
+                yaffs_trace(YAFFS_TRACE_ALWAYS,
+                        "Freechunks verification failure %d %d %d",
+                        dev->n_free_chunks, counted, difference);
+                yaffs_free_verification_failures++;
+        }
+}
+
+int yaffs_verify_file_sane(struct yaffs_obj *in)
+{
+        in = in;
+        return YAFFS_OK;
+}
+
diff --git a/fs/yaffs2/yaffs_verify.h b/fs/yaffs2/yaffs_verify.h
new file mode 100644
index 00000000000..cc6f8899930
--- /dev/null
+++ b/fs/yaffs2/yaffs_verify.h
@@ -0,0 +1,43 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_VERIFY_H__
+#define __YAFFS_VERIFY_H__
+
+#include "yaffs_guts.h"
+
+void yaffs_verify_blk(struct yaffs_dev *dev, struct yaffs_block_info *bi,
+                      int n);
+void yaffs_verify_collected_blk(struct yaffs_dev *dev,
+                                struct yaffs_block_info *bi, int n);
+void yaffs_verify_blocks(struct yaffs_dev *dev);
+
+void yaffs_verify_oh(struct yaffs_obj *obj, struct yaffs_obj_hdr *oh,
+                     struct yaffs_ext_tags *tags, int parent_check);
+void yaffs_verify_file(struct yaffs_obj *obj);
+void yaffs_verify_link(struct yaffs_obj *obj);
+void yaffs_verify_symlink(struct yaffs_obj *obj);
+void yaffs_verify_special(struct yaffs_obj *obj);
+void yaffs_verify_obj(struct yaffs_obj *obj);
+void yaffs_verify_objects(struct yaffs_dev *dev);
+void yaffs_verify_obj_in_dir(struct yaffs_obj *obj);
+void yaffs_verify_dir(struct yaffs_obj *directory);
+void yaffs_verify_free_chunks(struct yaffs_dev *dev);
+
+int yaffs_verify_file_sane(struct yaffs_obj *obj);
+
+int yaffs_skip_verification(struct yaffs_dev *dev);
+
+#endif
diff --git a/fs/yaffs2/yaffs_vfs.c b/fs/yaffs2/yaffs_vfs.c
new file mode 100644
index 00000000000..d5b87531400
--- /dev/null
+++ b/fs/yaffs2/yaffs_vfs.c
@@ -0,0 +1,2792 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ * Acknowledgements:
+ * Luc van OostenRyck for numerous patches.
+ * Nick Bane for numerous patches.
+ * Nick Bane for 2.5/2.6 integration.
+ * Andras Toth for mknod rdev issue.
+ * Michael Fischer for finding the problem with inode inconsistency.
+ * Some code bodily lifted from JFFS
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ *
+ * This is the file system front-end to YAFFS that hooks it up to
+ * the VFS.
+ *
+ * Special notes:
+ * >> 2.4: sb->u.generic_sbp points to the struct yaffs_dev associated with
+ *         this superblock
+ * >> 2.6: sb->s_fs_info  points to the struct yaffs_dev associated with this
+ *         superblock
+ * >> inode->u.generic_ip points to the associated struct yaffs_obj.
+ */
+
+/*
+ * NB There are two variants of Linux VFS glue code. This variant supports
+ * a single version and should not include any multi-version code.
+ */
+#include <linux/version.h>
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/proc_fs.h>
+#include <linux/smp_lock.h>
+#include <linux/pagemap.h>
+#include <linux/mtd/mtd.h>
+#include <linux/interrupt.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <linux/namei.h>
+#include <linux/exportfs.h>
+#include <linux/kthread.h>
+#include <linux/delay.h>
+#include <linux/freezer.h>
+
+#include <asm/div64.h>
+
+#include <linux/statfs.h>
+
+#define UnlockPage(p) unlock_page(p)
+#define Page_Uptodate(page)     test_bit(PG_uptodate, &(page)->flags)
+
+#define yaffs_devname(sb, buf)  bdevname(sb->s_bdev, buf)
+
+#define YPROC_ROOT  NULL
+
+#define Y_INIT_TIMER(a) init_timer_on_stack(a)
+
+#define WRITE_SIZE_STR "writesize"
+#define WRITE_SIZE(mtd) ((mtd)->writesize)
+
+static uint32_t YCALCBLOCKS(uint64_t partition_size, uint32_t block_size)
+{
+        uint64_t result = partition_size;
+        do_div(result, block_size);
+        return (uint32_t) result;
+}
+
+#include <linux/uaccess.h>
+#include <linux/mtd/mtd.h>
+
+#include "yportenv.h"
+#include "yaffs_trace.h"
+#include "yaffs_guts.h"
+#include "yaffs_attribs.h"
+
+#include "yaffs_linux.h"
+
+#include "yaffs_mtdif.h"
+#include "yaffs_mtdif1.h"
+#include "yaffs_mtdif2.h"
+
+unsigned int yaffs_trace_mask = YAFFS_TRACE_BAD_BLOCKS | YAFFS_TRACE_ALWAYS;
+unsigned int yaffs_wr_attempts = YAFFS_WR_ATTEMPTS;
+unsigned int yaffs_auto_checkpoint = 1;
+unsigned int yaffs_gc_control = 1;
+unsigned int yaffs_bg_enable = 1;
+
+/* Module Parameters */
+module_param(yaffs_trace_mask, uint, 0644);
+module_param(yaffs_wr_attempts, uint, 0644);
+module_param(yaffs_auto_checkpoint, uint, 0644);
+module_param(yaffs_gc_control, uint, 0644);
+module_param(yaffs_bg_enable, uint, 0644);
+
+
+#define yaffs_inode_to_obj_lv(iptr) ((iptr)->i_private)
+#define yaffs_inode_to_obj(iptr) ((struct yaffs_obj *)(yaffs_inode_to_obj_lv(iptr)))
+#define yaffs_dentry_to_obj(dptr) yaffs_inode_to_obj((dptr)->d_inode)
+#define yaffs_super_to_dev(sb)  ((struct yaffs_dev *)sb->s_fs_info)
+
+#define update_dir_time(dir) do {\
+                        (dir)->i_ctime = (dir)->i_mtime = CURRENT_TIME; \
+                } while(0)
+
+
+static unsigned yaffs_gc_control_callback(struct yaffs_dev *dev)
+{
+        return yaffs_gc_control;
+}
+
+static void yaffs_gross_lock(struct yaffs_dev *dev)
+{
+        yaffs_trace(YAFFS_TRACE_LOCK, "yaffs locking %p", current);
+        mutex_lock(&(yaffs_dev_to_lc(dev)->gross_lock));
+        yaffs_trace(YAFFS_TRACE_LOCK, "yaffs locked %p", current);
+}
+
+static void yaffs_gross_unlock(struct yaffs_dev *dev)
+{
+        yaffs_trace(YAFFS_TRACE_LOCK, "yaffs unlocking %p", current);
+        mutex_unlock(&(yaffs_dev_to_lc(dev)->gross_lock));
+}
+
+static void yaffs_fill_inode_from_obj(struct inode *inode,
+                                      struct yaffs_obj *obj);
+
+static struct inode *yaffs_iget(struct super_block *sb, unsigned long ino)
+{
+        struct inode *inode;
+        struct yaffs_obj *obj;
+        struct yaffs_dev *dev = yaffs_super_to_dev(sb);
+
+        yaffs_trace(YAFFS_TRACE_OS, "yaffs_iget for %lu", ino);
+
+        inode = iget_locked(sb, ino);
+        if (!inode)
+                return ERR_PTR(-ENOMEM);
+        if (!(inode->i_state & I_NEW))
+                return inode;
+
+        /* NB This is called as a side effect of other functions, but
+         * we had to release the lock to prevent deadlocks, so
+         * need to lock again.
+         */
+
+        yaffs_gross_lock(dev);
+
+        obj = yaffs_find_by_number(dev, inode->i_ino);
+
+        yaffs_fill_inode_from_obj(inode, obj);
+
+        yaffs_gross_unlock(dev);
+
+        unlock_new_inode(inode);
+        return inode;
+}
+
+struct inode *yaffs_get_inode(struct super_block *sb, int mode, int dev,
+                              struct yaffs_obj *obj)
+{
+        struct inode *inode;
+
+        if (!sb) {
+                yaffs_trace(YAFFS_TRACE_OS,
+                        "yaffs_get_inode for NULL super_block!!");
+                return NULL;
+
+        }
+
+        if (!obj) {
+                yaffs_trace(YAFFS_TRACE_OS,
+                        "yaffs_get_inode for NULL object!!");
+                return NULL;
+
+        }
+
+        yaffs_trace(YAFFS_TRACE_OS,
+                "yaffs_get_inode for object %d",
+                obj->obj_id);
+
+        inode = yaffs_iget(sb, obj->obj_id);
+        if (IS_ERR(inode))
+                return NULL;
+
+        /* NB Side effect: iget calls back to yaffs_read_inode(). */
+        /* iget also increments the inode's i_count */
+        /* NB You can't be holding gross_lock or deadlock will happen! */
+
+        return inode;
+}
+
+static int yaffs_mknod(struct inode *dir, struct dentry *dentry, int mode,
+                       dev_t rdev)
+{
+        struct inode *inode;
+
+        struct yaffs_obj *obj = NULL;
+        struct yaffs_dev *dev;
+
+        struct yaffs_obj *parent = yaffs_inode_to_obj(dir);
+
+        int error = -ENOSPC;
+        uid_t uid = current->cred->fsuid;
+        gid_t gid =
+            (dir->i_mode & S_ISGID) ? dir->i_gid : current->cred->fsgid;
+
+        if ((dir->i_mode & S_ISGID) && S_ISDIR(mode))
+                mode |= S_ISGID;
+
+        if (parent) {
+                yaffs_trace(YAFFS_TRACE_OS,
+                        "yaffs_mknod: parent object %d type %d",
+                        parent->obj_id, parent->variant_type);
+        } else {
+                yaffs_trace(YAFFS_TRACE_OS,
+                        "yaffs_mknod: could not get parent object");
+                return -EPERM;
+        }
+
+        yaffs_trace(YAFFS_TRACE_OS,
+                "yaffs_mknod: making oject for %s, mode %x dev %x",
+                dentry->d_name.name, mode, rdev);
+
+        dev = parent->my_dev;
+
+        yaffs_gross_lock(dev);
+
+        switch (mode & S_IFMT) {
+        default:
+                /* Special (socket, fifo, device...) */
+                yaffs_trace(YAFFS_TRACE_OS, "yaffs_mknod: making special");
+                obj =
+                    yaffs_create_special(parent, dentry->d_name.name, mode, uid,
+                                         gid, old_encode_dev(rdev));
+                break;
+        case S_IFREG:           /* file          */
+                yaffs_trace(YAFFS_TRACE_OS, "yaffs_mknod: making file");
+                obj = yaffs_create_file(parent, dentry->d_name.name, mode, uid,
+                                        gid);
+                break;
+        case S_IFDIR:           /* directory */
+                yaffs_trace(YAFFS_TRACE_OS, "yaffs_mknod: making directory");
+                obj = yaffs_create_dir(parent, dentry->d_name.name, mode,
+                                       uid, gid);
+                break;
+        case S_IFLNK:           /* symlink */
+                yaffs_trace(YAFFS_TRACE_OS, "yaffs_mknod: making symlink");
+                obj = NULL;     /* Do we ever get here? */
+                break;
+        }
+
+        /* Can not call yaffs_get_inode() with gross lock held */
+        yaffs_gross_unlock(dev);
+
+        if (obj) {
+                inode = yaffs_get_inode(dir->i_sb, mode, rdev, obj);
+                d_instantiate(dentry, inode);
+                update_dir_time(dir);
+                yaffs_trace(YAFFS_TRACE_OS,
+                        "yaffs_mknod created object %d count = %d",
+                        obj->obj_id, atomic_read(&inode->i_count));
+                error = 0;
+                yaffs_fill_inode_from_obj(dir, parent);
+        } else {
+                yaffs_trace(YAFFS_TRACE_OS, "yaffs_mknod failed making object");
+                error = -ENOMEM;
+        }
+
+        return error;
+}
+
+static int yaffs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+        return yaffs_mknod(dir, dentry, mode | S_IFDIR, 0);
+}
+
+static int yaffs_create(struct inode *dir, struct dentry *dentry, int mode,
+                        struct nameidata *n)
+{
+        return yaffs_mknod(dir, dentry, mode | S_IFREG, 0);
+}
+
+static int yaffs_link(struct dentry *old_dentry, struct inode *dir,
+                      struct dentry *dentry)
+{
+        struct inode *inode = old_dentry->d_inode;
+        struct yaffs_obj *obj = NULL;
+        struct yaffs_obj *link = NULL;
+        struct yaffs_dev *dev;
+
+        yaffs_trace(YAFFS_TRACE_OS, "yaffs_link");
+
+        obj = yaffs_inode_to_obj(inode);
+        dev = obj->my_dev;
+
+        yaffs_gross_lock(dev);
+
+        if (!S_ISDIR(inode->i_mode))    /* Don't link directories */
+                link =
+                    yaffs_link_obj(yaffs_inode_to_obj(dir), dentry->d_name.name,
+                                   obj);
+
+        if (link) {
+                old_dentry->d_inode->i_nlink = yaffs_get_obj_link_count(obj);
+                d_instantiate(dentry, old_dentry->d_inode);
+                atomic_inc(&old_dentry->d_inode->i_count);
+                yaffs_trace(YAFFS_TRACE_OS,
+                        "yaffs_link link count %d i_count %d",
+                        old_dentry->d_inode->i_nlink,
+                        atomic_read(&old_dentry->d_inode->i_count));
+        }
+
+        yaffs_gross_unlock(dev);
+
+        if (link) {
+                update_dir_time(dir);
+                return 0;
+        }
+
+        return -EPERM;
+}
+
+static int yaffs_symlink(struct inode *dir, struct dentry *dentry,
+                         const char *symname)
+{
+        struct yaffs_obj *obj;
+        struct yaffs_dev *dev;
+        uid_t uid = current->cred->fsuid;
+        gid_t gid =
+            (dir->i_mode & S_ISGID) ? dir->i_gid : current->cred->fsgid;
+
+        yaffs_trace(YAFFS_TRACE_OS, "yaffs_symlink");
+
+        dev = yaffs_inode_to_obj(dir)->my_dev;
+        yaffs_gross_lock(dev);
+        obj = yaffs_create_symlink(yaffs_inode_to_obj(dir), dentry->d_name.name,
+                                   S_IFLNK | S_IRWXUGO, uid, gid, symname);
+        yaffs_gross_unlock(dev);
+
+        if (obj) {
+                struct inode *inode;
+
+                inode = yaffs_get_inode(dir->i_sb, obj->yst_mode, 0, obj);
+                d_instantiate(dentry, inode);
+                update_dir_time(dir);
+                yaffs_trace(YAFFS_TRACE_OS, "symlink created OK");
+                return 0;
+        } else {
+                yaffs_trace(YAFFS_TRACE_OS, "symlink not created");
+        }
+
+        return -ENOMEM;
+}
+
+static struct dentry *yaffs_lookup(struct inode *dir, struct dentry *dentry,
+                                   struct nameidata *n)
+{
+        struct yaffs_obj *obj;
+        struct inode *inode = NULL;
+
+        struct yaffs_dev *dev = yaffs_inode_to_obj(dir)->my_dev;
+
+        if (current != yaffs_dev_to_lc(dev)->readdir_process)
+                yaffs_gross_lock(dev);
+
+        yaffs_trace(YAFFS_TRACE_OS,
+                "yaffs_lookup for %d:%s",
+                yaffs_inode_to_obj(dir)->obj_id, dentry->d_name.name);
+
+        obj = yaffs_find_by_name(yaffs_inode_to_obj(dir), dentry->d_name.name);
+
+        obj = yaffs_get_equivalent_obj(obj);    /* in case it was a hardlink */
+
+        /* Can't hold gross lock when calling yaffs_get_inode() */
+        if (current != yaffs_dev_to_lc(dev)->readdir_process)
+                yaffs_gross_unlock(dev);
+
+        if (obj) {
+                yaffs_trace(YAFFS_TRACE_OS,
+                        "yaffs_lookup found %d", obj->obj_id);
+
+                inode = yaffs_get_inode(dir->i_sb, obj->yst_mode, 0, obj);
+
+                if (inode) {
+                        yaffs_trace(YAFFS_TRACE_OS, "yaffs_loookup dentry");
+                        d_add(dentry, inode);
+                        /* return dentry; */
+                        return NULL;
+                }
+
+        } else {
+                yaffs_trace(YAFFS_TRACE_OS, "yaffs_lookup not found");
+
+        }
+
+        d_add(dentry, inode);
+
+        return NULL;
+}
+
+static int yaffs_unlink(struct inode *dir, struct dentry *dentry)
+{
+        int ret_val;
+
+        struct yaffs_dev *dev;
+        struct yaffs_obj *obj;
+
+        yaffs_trace(YAFFS_TRACE_OS,
+                "yaffs_unlink %d:%s",
+                (int)(dir->i_ino), dentry->d_name.name);
+        obj = yaffs_inode_to_obj(dir);
+        dev = obj->my_dev;
+
+        yaffs_gross_lock(dev);
+
+        ret_val = yaffs_unlinker(obj, dentry->d_name.name);
+
+        if (ret_val == YAFFS_OK) {
+                dentry->d_inode->i_nlink--;
+                dir->i_version++;
+                yaffs_gross_unlock(dev);
+                mark_inode_dirty(dentry->d_inode);
+                update_dir_time(dir);
+                return 0;
+        }
+        yaffs_gross_unlock(dev);
+        return -ENOTEMPTY;
+}
+
+static int yaffs_sync_object(struct file *file, int datasync)
+{
+
+        struct yaffs_obj *obj;
+        struct yaffs_dev *dev;
+        struct dentry *dentry = file->f_path.dentry;
+
+        obj = yaffs_dentry_to_obj(dentry);
+
+        dev = obj->my_dev;
+
+        yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC, "yaffs_sync_object");
+        yaffs_gross_lock(dev);
+        yaffs_flush_file(obj, 1, datasync);
+        yaffs_gross_unlock(dev);
+        return 0;
+}
+/*
+ * The VFS layer already does all the dentry stuff for rename.
+ *
+ * NB: POSIX says you can rename an object over an old object of the same name
+ */
+static int yaffs_rename(struct inode *old_dir, struct dentry *old_dentry,
+                        struct inode *new_dir, struct dentry *new_dentry)
+{
+        struct yaffs_dev *dev;
+        int ret_val = YAFFS_FAIL;
+        struct yaffs_obj *target;
+
+        yaffs_trace(YAFFS_TRACE_OS, "yaffs_rename");
+        dev = yaffs_inode_to_obj(old_dir)->my_dev;
+
+        yaffs_gross_lock(dev);
+
+        /* Check if the target is an existing directory that is not empty. */
+        target = yaffs_find_by_name(yaffs_inode_to_obj(new_dir),
+                                    new_dentry->d_name.name);
+
+        if (target && target->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY &&
+            !list_empty(&target->variant.dir_variant.children)) {
+
+                yaffs_trace(YAFFS_TRACE_OS, "target is non-empty dir");
+
+                ret_val = YAFFS_FAIL;
+        } else {
+                /* Now does unlinking internally using shadowing mechanism */
+                yaffs_trace(YAFFS_TRACE_OS, "calling yaffs_rename_obj");
+
+                ret_val = yaffs_rename_obj(yaffs_inode_to_obj(old_dir),
+                                           old_dentry->d_name.name,
+                                           yaffs_inode_to_obj(new_dir),
+                                           new_dentry->d_name.name);
+        }
+        yaffs_gross_unlock(dev);
+
+        if (ret_val == YAFFS_OK) {
+                if (target) {
+                        new_dentry->d_inode->i_nlink--;
+                        mark_inode_dirty(new_dentry->d_inode);
+                }
+
+                update_dir_time(old_dir);
+                if (old_dir != new_dir)
+                        update_dir_time(new_dir);
+                return 0;
+        } else {
+                return -ENOTEMPTY;
+        }
+}
+
+static int yaffs_setattr(struct dentry *dentry, struct iattr *attr)
+{
+        struct inode *inode = dentry->d_inode;
+        int error = 0;
+        struct yaffs_dev *dev;
+
+        yaffs_trace(YAFFS_TRACE_OS,
+                "yaffs_setattr of object %d",
+                yaffs_inode_to_obj(inode)->obj_id);
+
+        /* Fail if a requested resize >= 2GB */
+        if (attr->ia_valid & ATTR_SIZE && (attr->ia_size >> 31))
+                error = -EINVAL;
+
+        if (error == 0)
+                error = inode_change_ok(inode, attr);
+        if (error == 0) {
+                int result;
+                if (!error) {
+                        setattr_copy(inode, attr);
+                        yaffs_trace(YAFFS_TRACE_OS, "inode_setattr called");
+                        if (attr->ia_valid & ATTR_SIZE) {
+                                truncate_setsize(inode, attr->ia_size);
+                                inode->i_blocks = (inode->i_size + 511) >> 9;
+                        }
+                }
+                dev = yaffs_inode_to_obj(inode)->my_dev;
+                if (attr->ia_valid & ATTR_SIZE) {
+                        yaffs_trace(YAFFS_TRACE_OS, "resize to %d(%x)",
+                                           (int)(attr->ia_size),
+                                           (int)(attr->ia_size));
+                }
+                yaffs_gross_lock(dev);
+                result = yaffs_set_attribs(yaffs_inode_to_obj(inode), attr);
+                if (result == YAFFS_OK) {
+                        error = 0;
+                } else {
+                        error = -EPERM;
+                }
+                yaffs_gross_unlock(dev);
+
+        }
+
+        yaffs_trace(YAFFS_TRACE_OS, "yaffs_setattr done returning %d", error);
+
+        return error;
+}
+
+#ifdef CONFIG_YAFFS_XATTR
+static int yaffs_setxattr(struct dentry *dentry, const char *name,
+                   const void *value, size_t size, int flags)
+{
+        struct inode *inode = dentry->d_inode;
+        int error = 0;
+        struct yaffs_dev *dev;
+        struct yaffs_obj *obj = yaffs_inode_to_obj(inode);
+
+        yaffs_trace(YAFFS_TRACE_OS, "yaffs_setxattr of object %d", obj->obj_id);
+
+        if (error == 0) {
+                int result;
+                dev = obj->my_dev;
+                yaffs_gross_lock(dev);
+                result = yaffs_set_xattrib(obj, name, value, size, flags);
+                if (result == YAFFS_OK)
+                        error = 0;
+                else if (result < 0)
+                        error = result;
+                yaffs_gross_unlock(dev);
+
+        }
+        yaffs_trace(YAFFS_TRACE_OS, "yaffs_setxattr done returning %d", error);
+
+        return error;
+}
+
+static ssize_t yaffs_getxattr(struct dentry * dentry, const char *name, void *buff,
+                       size_t size)
+{
+        struct inode *inode = dentry->d_inode;
+        int error = 0;
+        struct yaffs_dev *dev;
+        struct yaffs_obj *obj = yaffs_inode_to_obj(inode);
+
+        yaffs_trace(YAFFS_TRACE_OS,
+                "yaffs_getxattr \"%s\" from object %d",
+                name, obj->obj_id);
+
+        if (error == 0) {
+                dev = obj->my_dev;
+                yaffs_gross_lock(dev);
+                error = yaffs_get_xattrib(obj, name, buff, size);
+                yaffs_gross_unlock(dev);
+
+        }
+        yaffs_trace(YAFFS_TRACE_OS, "yaffs_getxattr done returning %d", error);
+
+        return error;
+}
+
+static int yaffs_removexattr(struct dentry *dentry, const char *name)
+{
+        struct inode *inode = dentry->d_inode;
+        int error = 0;
+        struct yaffs_dev *dev;
+        struct yaffs_obj *obj = yaffs_inode_to_obj(inode);
+
+        yaffs_trace(YAFFS_TRACE_OS,
+                "yaffs_removexattr of object %d", obj->obj_id);
+
+        if (error == 0) {
+                int result;
+                dev = obj->my_dev;
+                yaffs_gross_lock(dev);
+                result = yaffs_remove_xattrib(obj, name);
+                if (result == YAFFS_OK)
+                        error = 0;
+                else if (result < 0)
+                        error = result;
+                yaffs_gross_unlock(dev);
+
+        }
+        yaffs_trace(YAFFS_TRACE_OS,
+                "yaffs_removexattr done returning %d", error);
+
+        return error;
+}
+
+static ssize_t yaffs_listxattr(struct dentry * dentry, char *buff, size_t size)
+{
+        struct inode *inode = dentry->d_inode;
+        int error = 0;
+        struct yaffs_dev *dev;
+        struct yaffs_obj *obj = yaffs_inode_to_obj(inode);
+
+        yaffs_trace(YAFFS_TRACE_OS,
+                "yaffs_listxattr of object %d", obj->obj_id);
+
+        if (error == 0) {
+                dev = obj->my_dev;
+                yaffs_gross_lock(dev);
+                error = yaffs_list_xattrib(obj, buff, size);
+                yaffs_gross_unlock(dev);
+
+        }
+        yaffs_trace(YAFFS_TRACE_OS,
+                "yaffs_listxattr done returning %d", error);
+
+        return error;
+}
+
+#endif
+
+static const struct inode_operations yaffs_dir_inode_operations = {
+        .create = yaffs_create,
+        .lookup = yaffs_lookup,
+        .link = yaffs_link,
+        .unlink = yaffs_unlink,
+        .symlink = yaffs_symlink,
+        .mkdir = yaffs_mkdir,
+        .rmdir = yaffs_unlink,
+        .mknod = yaffs_mknod,
+        .rename = yaffs_rename,
+        .setattr = yaffs_setattr,
+#ifdef CONFIG_YAFFS_XATTR
+        .setxattr = yaffs_setxattr,
+        .getxattr = yaffs_getxattr,
+        .listxattr = yaffs_listxattr,
+        .removexattr = yaffs_removexattr,
+#endif
+};
+/*-----------------------------------------------------------------*/
+/* Directory search context allows us to unlock access to yaffs during
+ * filldir without causing problems with the directory being modified.
+ * This is similar to the tried and tested mechanism used in yaffs direct.
+ *
+ * A search context iterates along a doubly linked list of siblings in the
+ * directory. If the iterating object is deleted then this would corrupt
+ * the list iteration, likely causing a crash. The search context avoids
+ * this by using the remove_obj_fn to move the search context to the
+ * next object before the object is deleted.
+ *
+ * Many readdirs (and thus seach conexts) may be alive simulateously so
+ * each struct yaffs_dev has a list of these.
+ *
+ * A seach context lives for the duration of a readdir.
+ *
+ * All these functions must be called while yaffs is locked.
+ */
+
+struct yaffs_search_context {
+        struct yaffs_dev *dev;
+        struct yaffs_obj *dir_obj;
+        struct yaffs_obj *next_return;
+        struct list_head others;
+};
+
+/*
+ * yaffs_new_search() creates a new search context, initialises it and
+ * adds it to the device's search context list.
+ *
+ * Called at start of readdir.
+ */
+static struct yaffs_search_context *yaffs_new_search(struct yaffs_obj *dir)
+{
+        struct yaffs_dev *dev = dir->my_dev;
+        struct yaffs_search_context *sc =
+            kmalloc(sizeof(struct yaffs_search_context), GFP_NOFS);
+        if (sc) {
+                sc->dir_obj = dir;
+                sc->dev = dev;
+                if (list_empty(&sc->dir_obj->variant.dir_variant.children))
+                        sc->next_return = NULL;
+                else
+                        sc->next_return =
+                            list_entry(dir->variant.dir_variant.children.next,
+                                       struct yaffs_obj, siblings);
+                INIT_LIST_HEAD(&sc->others);
+                list_add(&sc->others, &(yaffs_dev_to_lc(dev)->search_contexts));
+        }
+        return sc;
+}
+
+/*
+ * yaffs_search_end() disposes of a search context and cleans up.
+ */
+static void yaffs_search_end(struct yaffs_search_context *sc)
+{
+        if (sc) {
+                list_del(&sc->others);
+                kfree(sc);
+        }
+}
+
+/*
+ * yaffs_search_advance() moves a search context to the next object.
+ * Called when the search iterates or when an object removal causes
+ * the search context to be moved to the next object.
+ */
+static void yaffs_search_advance(struct yaffs_search_context *sc)
+{
+        if (!sc)
+                return;
+
+        if (sc->next_return == NULL ||
+            list_empty(&sc->dir_obj->variant.dir_variant.children))
+                sc->next_return = NULL;
+        else {
+                struct list_head *next = sc->next_return->siblings.next;
+
+                if (next == &sc->dir_obj->variant.dir_variant.children)
+                        sc->next_return = NULL; /* end of list */
+                else
+                        sc->next_return =
+                            list_entry(next, struct yaffs_obj, siblings);
+        }
+}
+
+/*
+ * yaffs_remove_obj_callback() is called when an object is unlinked.
+ * We check open search contexts and advance any which are currently
+ * on the object being iterated.
+ */
+static void yaffs_remove_obj_callback(struct yaffs_obj *obj)
+{
+
+        struct list_head *i;
+        struct yaffs_search_context *sc;
+        struct list_head *search_contexts =
+            &(yaffs_dev_to_lc(obj->my_dev)->search_contexts);
+
+        /* Iterate through the directory search contexts.
+         * If any are currently on the object being removed, then advance
+         * the search context to the next object to prevent a hanging pointer.
+         */
+        list_for_each(i, search_contexts) {
+                if (i) {
+                        sc = list_entry(i, struct yaffs_search_context, others);
+                        if (sc->next_return == obj)
+                                yaffs_search_advance(sc);
+                }
+        }
+
+}
+
+static int yaffs_readdir(struct file *f, void *dirent, filldir_t filldir)
+{
+        struct yaffs_obj *obj;
+        struct yaffs_dev *dev;
+        struct yaffs_search_context *sc;
+        struct inode *inode = f->f_dentry->d_inode;
+        unsigned long offset, curoffs;
+        struct yaffs_obj *l;
+        int ret_val = 0;
+
+        char name[YAFFS_MAX_NAME_LENGTH + 1];
+
+        obj = yaffs_dentry_to_obj(f->f_dentry);
+        dev = obj->my_dev;
+
+        yaffs_gross_lock(dev);
+
+        yaffs_dev_to_lc(dev)->readdir_process = current;
+
+        offset = f->f_pos;
+
+        sc = yaffs_new_search(obj);
+        if (!sc) {
+                ret_val = -ENOMEM;
+                goto out;
+        }
+
+        yaffs_trace(YAFFS_TRACE_OS,
+                "yaffs_readdir: starting at %d", (int)offset);
+
+        if (offset == 0) {
+                yaffs_trace(YAFFS_TRACE_OS,
+                        "yaffs_readdir: entry . ino %d",
+                        (int)inode->i_ino);
+                yaffs_gross_unlock(dev);
+                if (filldir(dirent, ".", 1, offset, inode->i_ino, DT_DIR) < 0) {
+                        yaffs_gross_lock(dev);
+                        goto out;
+                }
+                yaffs_gross_lock(dev);
+                offset++;
+                f->f_pos++;
+        }
+        if (offset == 1) {
+                yaffs_trace(YAFFS_TRACE_OS,
+                        "yaffs_readdir: entry .. ino %d",
+                        (int)f->f_dentry->d_parent->d_inode->i_ino);
+                yaffs_gross_unlock(dev);
+                if (filldir(dirent, "..", 2, offset,
+                            f->f_dentry->d_parent->d_inode->i_ino,
+                            DT_DIR) < 0) {
+                        yaffs_gross_lock(dev);
+                        goto out;
+                }
+                yaffs_gross_lock(dev);
+                offset++;
+                f->f_pos++;
+        }
+
+        curoffs = 1;
+
+        /* If the directory has changed since the open or last call to
+           readdir, rewind to after the 2 canned entries. */
+        if (f->f_version != inode->i_version) {
+                offset = 2;
+                f->f_pos = offset;
+                f->f_version = inode->i_version;
+        }
+
+        while (sc->next_return) {
+                curoffs++;
+                l = sc->next_return;
+                if (curoffs >= offset) {
+                        int this_inode = yaffs_get_obj_inode(l);
+                        int this_type = yaffs_get_obj_type(l);
+
+                        yaffs_get_obj_name(l, name, YAFFS_MAX_NAME_LENGTH + 1);
+                        yaffs_trace(YAFFS_TRACE_OS,
+                                "yaffs_readdir: %s inode %d",
+                                name, yaffs_get_obj_inode(l));
+
+                        yaffs_gross_unlock(dev);
+
+                        if (filldir(dirent,
+                                    name,
+                                    strlen(name),
+                                    offset, this_inode, this_type) < 0) {
+                                yaffs_gross_lock(dev);
+                                goto out;
+                        }
+
+                        yaffs_gross_lock(dev);
+
+                        offset++;
+                        f->f_pos++;
+                }
+                yaffs_search_advance(sc);
+        }
+
+out:
+        yaffs_search_end(sc);
+        yaffs_dev_to_lc(dev)->readdir_process = NULL;
+        yaffs_gross_unlock(dev);
+
+        return ret_val;
+}
+
+static const struct file_operations yaffs_dir_operations = {
+        .read = generic_read_dir,
+        .readdir = yaffs_readdir,
+        .fsync = yaffs_sync_object,
+        .llseek = generic_file_llseek,
+};
+
+
+
+static int yaffs_file_flush(struct file *file, fl_owner_t id)
+{
+        struct yaffs_obj *obj = yaffs_dentry_to_obj(file->f_dentry);
+
+        struct yaffs_dev *dev = obj->my_dev;
+
+        yaffs_trace(YAFFS_TRACE_OS,
+                "yaffs_file_flush object %d (%s)",
+                obj->obj_id, obj->dirty ? "dirty" : "clean");
+
+        yaffs_gross_lock(dev);
+
+        yaffs_flush_file(obj, 1, 0);
+
+        yaffs_gross_unlock(dev);
+
+        return 0;
+}
+
+static const struct file_operations yaffs_file_operations = {
+        .read = do_sync_read,
+        .write = do_sync_write,
+        .aio_read = generic_file_aio_read,
+        .aio_write = generic_file_aio_write,
+        .mmap = generic_file_mmap,
+        .flush = yaffs_file_flush,
+        .fsync = yaffs_sync_object,
+        .splice_read = generic_file_splice_read,
+        .splice_write = generic_file_splice_write,
+        .llseek = generic_file_llseek,
+};
+
+
+/* ExportFS support */
+static struct inode *yaffs2_nfs_get_inode(struct super_block *sb, uint64_t ino,
+                                          uint32_t generation)
+{
+        return yaffs_iget(sb, ino);
+}
+
+static struct dentry *yaffs2_fh_to_dentry(struct super_block *sb,
+                                          struct fid *fid, int fh_len,
+                                          int fh_type)
+{
+        return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
+                                    yaffs2_nfs_get_inode);
+}
+
+static struct dentry *yaffs2_fh_to_parent(struct super_block *sb,
+                                          struct fid *fid, int fh_len,
+                                          int fh_type)
+{
+        return generic_fh_to_parent(sb, fid, fh_len, fh_type,
+                                    yaffs2_nfs_get_inode);
+}
+
+struct dentry *yaffs2_get_parent(struct dentry *dentry)
+{
+
+        struct super_block *sb = dentry->d_inode->i_sb;
+        struct dentry *parent = ERR_PTR(-ENOENT);
+        struct inode *inode;
+        unsigned long parent_ino;
+        struct yaffs_obj *d_obj;
+        struct yaffs_obj *parent_obj;
+
+        d_obj = yaffs_inode_to_obj(dentry->d_inode);
+
+        if (d_obj) {
+                parent_obj = d_obj->parent;
+                if (parent_obj) {
+                        parent_ino = yaffs_get_obj_inode(parent_obj);
+                        inode = yaffs_iget(sb, parent_ino);
+
+                        if (IS_ERR(inode)) {
+                                parent = ERR_CAST(inode);
+                        } else {
+                                parent = d_obtain_alias(inode);
+                                if (!IS_ERR(parent)) {
+                                        parent = ERR_PTR(-ENOMEM);
+                                        iput(inode);
+                                }
+                        }
+                }
+        }
+
+        return parent;
+}
+
+/* Just declare a zero structure as a NULL value implies
+ * using the default functions of exportfs.
+ */
+
+static struct export_operations yaffs_export_ops = {
+        .fh_to_dentry = yaffs2_fh_to_dentry,
+        .fh_to_parent = yaffs2_fh_to_parent,
+        .get_parent = yaffs2_get_parent,
+};
+
+
+/*-----------------------------------------------------------------*/
+
+static int yaffs_readlink(struct dentry *dentry, char __user * buffer,
+                          int buflen)
+{
+        unsigned char *alias;
+        int ret;
+
+        struct yaffs_dev *dev = yaffs_dentry_to_obj(dentry)->my_dev;
+
+        yaffs_gross_lock(dev);
+
+        alias = yaffs_get_symlink_alias(yaffs_dentry_to_obj(dentry));
+
+        yaffs_gross_unlock(dev);
+
+        if (!alias)
+                return -ENOMEM;
+
+        ret = vfs_readlink(dentry, buffer, buflen, alias);
+        kfree(alias);
+        return ret;
+}
+
+static void *yaffs_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+        unsigned char *alias;
+        void *ret;
+        struct yaffs_dev *dev = yaffs_dentry_to_obj(dentry)->my_dev;
+
+        yaffs_gross_lock(dev);
+
+        alias = yaffs_get_symlink_alias(yaffs_dentry_to_obj(dentry));
+        yaffs_gross_unlock(dev);
+
+        if (!alias) {
+                ret = ERR_PTR(-ENOMEM);
+                goto out;
+        }
+
+        nd_set_link(nd, alias);
+        ret = (void *)alias;
+out:
+        return ret;
+}
+
+void yaffs_put_link(struct dentry *dentry, struct nameidata *nd, void *alias)
+{
+        kfree(alias);
+}
+
+
+static void yaffs_unstitch_obj(struct inode *inode, struct yaffs_obj *obj)
+{
+        /* Clear the association between the inode and
+         * the struct yaffs_obj.
+         */
+        obj->my_inode = NULL;
+        yaffs_inode_to_obj_lv(inode) = NULL;
+
+        /* If the object freeing was deferred, then the real
+         * free happens now.
+         * This should fix the inode inconsistency problem.
+         */
+        yaffs_handle_defered_free(obj);
+}
+
+/* yaffs_evict_inode combines into one operation what was previously done in
+ * yaffs_clear_inode() and yaffs_delete_inode()
+ *
+ */
+static void yaffs_evict_inode(struct inode *inode)
+{
+        struct yaffs_obj *obj;
+        struct yaffs_dev *dev;
+        int deleteme = 0;
+
+        obj = yaffs_inode_to_obj(inode);
+
+        yaffs_trace(YAFFS_TRACE_OS,
+                "yaffs_evict_inode: ino %d, count %d %s",
+                (int)inode->i_ino,
+                atomic_read(&inode->i_count),
+                obj ? "object exists" : "null object");
+
+        if (!inode->i_nlink && !is_bad_inode(inode))
+                deleteme = 1;
+        truncate_inode_pages(&inode->i_data, 0);
+        end_writeback(inode);
+
+        if (deleteme && obj) {
+                dev = obj->my_dev;
+                yaffs_gross_lock(dev);
+                yaffs_del_obj(obj);
+                yaffs_gross_unlock(dev);
+        }
+        if (obj) {
+                dev = obj->my_dev;
+                yaffs_gross_lock(dev);
+                yaffs_unstitch_obj(inode, obj);
+                yaffs_gross_unlock(dev);
+        }
+
+}
+
+static void yaffs_touch_super(struct yaffs_dev *dev)
+{
+        struct super_block *sb = yaffs_dev_to_lc(dev)->super;
+
+        yaffs_trace(YAFFS_TRACE_OS, "yaffs_touch_super() sb = %p", sb);
+        if (sb)
+                sb->s_dirt = 1;
+}
+
+static int yaffs_readpage_nolock(struct file *f, struct page *pg)
+{
+        /* Lifted from jffs2 */
+
+        struct yaffs_obj *obj;
+        unsigned char *pg_buf;
+        int ret;
+
+        struct yaffs_dev *dev;
+
+        yaffs_trace(YAFFS_TRACE_OS,
+                "yaffs_readpage_nolock at %08x, size %08x",
+                (unsigned)(pg->index << PAGE_CACHE_SHIFT),
+                (unsigned)PAGE_CACHE_SIZE);
+
+        obj = yaffs_dentry_to_obj(f->f_dentry);
+
+        dev = obj->my_dev;
+
+        BUG_ON(!PageLocked(pg));
+
+        pg_buf = kmap(pg);
+        /* FIXME: Can kmap fail? */
+
+        yaffs_gross_lock(dev);
+
+        ret = yaffs_file_rd(obj, pg_buf,
+                            pg->index << PAGE_CACHE_SHIFT, PAGE_CACHE_SIZE);
+
+        yaffs_gross_unlock(dev);
+
+        if (ret >= 0)
+                ret = 0;
+
+        if (ret) {
+                ClearPageUptodate(pg);
+                SetPageError(pg);
+        } else {
+                SetPageUptodate(pg);
+                ClearPageError(pg);
+        }
+
+        flush_dcache_page(pg);
+        kunmap(pg);
+
+        yaffs_trace(YAFFS_TRACE_OS, "yaffs_readpage_nolock done");
+        return ret;
+}
+
+static int yaffs_readpage_unlock(struct file *f, struct page *pg)
+{
+        int ret = yaffs_readpage_nolock(f, pg);
+        UnlockPage(pg);
+        return ret;
+}
+
+static int yaffs_readpage(struct file *f, struct page *pg)
+{
+        int ret;
+
+        yaffs_trace(YAFFS_TRACE_OS, "yaffs_readpage");
+        ret = yaffs_readpage_unlock(f, pg);
+        yaffs_trace(YAFFS_TRACE_OS, "yaffs_readpage done");
+        return ret;
+}
+
+/* writepage inspired by/stolen from smbfs */
+
+static int yaffs_writepage(struct page *page, struct writeback_control *wbc)
+{
+        struct yaffs_dev *dev;
+        struct address_space *mapping = page->mapping;
+        struct inode *inode;
+        unsigned long end_index;
+        char *buffer;
+        struct yaffs_obj *obj;
+        int n_written = 0;
+        unsigned n_bytes;
+        loff_t i_size;
+
+        if (!mapping)
+                BUG();
+        inode = mapping->host;
+        if (!inode)
+                BUG();
+        i_size = i_size_read(inode);
+
+        end_index = i_size >> PAGE_CACHE_SHIFT;
+
+        if (page->index < end_index)
+                n_bytes = PAGE_CACHE_SIZE;
+        else {
+                n_bytes = i_size & (PAGE_CACHE_SIZE - 1);
+
+                if (page->index > end_index || !n_bytes) {
+                        yaffs_trace(YAFFS_TRACE_OS,
+                                "yaffs_writepage at %08x, inode size = %08x!!!",
+                                (unsigned)(page->index << PAGE_CACHE_SHIFT),
+                                (unsigned)inode->i_size);
+                        yaffs_trace(YAFFS_TRACE_OS,
+                          "                -> don't care!!");
+
+                        zero_user_segment(page, 0, PAGE_CACHE_SIZE);
+                        set_page_writeback(page);
+                        unlock_page(page);
+                        end_page_writeback(page);
+                        return 0;
+                }
+        }
+
+        if (n_bytes != PAGE_CACHE_SIZE)
+                zero_user_segment(page, n_bytes, PAGE_CACHE_SIZE);
+
+        get_page(page);
+
+        buffer = kmap(page);
+
+        obj = yaffs_inode_to_obj(inode);
+        dev = obj->my_dev;
+        yaffs_gross_lock(dev);
+
+        yaffs_trace(YAFFS_TRACE_OS,
+                "yaffs_writepage at %08x, size %08x",
+                (unsigned)(page->index << PAGE_CACHE_SHIFT), n_bytes);
+        yaffs_trace(YAFFS_TRACE_OS,
+                "writepag0: obj = %05x, ino = %05x",
+                (int)obj->variant.file_variant.file_size, (int)inode->i_size);
+
+        n_written = yaffs_wr_file(obj, buffer,
+                                  page->index << PAGE_CACHE_SHIFT, n_bytes, 0);
+
+        yaffs_touch_super(dev);
+
+        yaffs_trace(YAFFS_TRACE_OS,
+                "writepag1: obj = %05x, ino = %05x",
+                (int)obj->variant.file_variant.file_size, (int)inode->i_size);
+
+        yaffs_gross_unlock(dev);
+
+        kunmap(page);
+        set_page_writeback(page);
+        unlock_page(page);
+        end_page_writeback(page);
+        put_page(page);
+
+        return (n_written == n_bytes) ? 0 : -ENOSPC;
+}
+
+/* Space holding and freeing is done to ensure we have space available for 
+ * write_begin/end.
+ * For now we just assume few parallel writes and check against a small
+ * number.
+ * Todo: need to do this with a counter to handle parallel reads better.
+ */
+
+static ssize_t yaffs_hold_space(struct file *f)
+{
+        struct yaffs_obj *obj;
+        struct yaffs_dev *dev;
+
+        int n_free_chunks;
+
+        obj = yaffs_dentry_to_obj(f->f_dentry);
+
+        dev = obj->my_dev;
+
+        yaffs_gross_lock(dev);
+
+        n_free_chunks = yaffs_get_n_free_chunks(dev);
+
+        yaffs_gross_unlock(dev);
+
+        return (n_free_chunks > 20) ? 1 : 0;
+}
+
+static void yaffs_release_space(struct file *f)
+{
+        struct yaffs_obj *obj;
+        struct yaffs_dev *dev;
+
+        obj = yaffs_dentry_to_obj(f->f_dentry);
+
+        dev = obj->my_dev;
+
+        yaffs_gross_lock(dev);
+
+        yaffs_gross_unlock(dev);
+}
+
+static int yaffs_write_begin(struct file *filp, struct address_space *mapping,
+                             loff_t pos, unsigned len, unsigned flags,
+                             struct page **pagep, void **fsdata)
+{
+        struct page *pg = NULL;
+        pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+
+        int ret = 0;
+        int space_held = 0;
+
+        /* Get a page */
+        pg = grab_cache_page_write_begin(mapping, index, flags);
+
+        *pagep = pg;
+        if (!pg) {
+                ret = -ENOMEM;
+                goto out;
+        }
+        yaffs_trace(YAFFS_TRACE_OS,
+                "start yaffs_write_begin index %d(%x) uptodate %d",
+                (int)index, (int)index, Page_Uptodate(pg) ? 1 : 0);
+
+        /* Get fs space */
+        space_held = yaffs_hold_space(filp);
+
+        if (!space_held) {
+                ret = -ENOSPC;
+                goto out;
+        }
+
+        /* Update page if required */
+
+        if (!Page_Uptodate(pg))
+                ret = yaffs_readpage_nolock(filp, pg);
+
+        if (ret)
+                goto out;
+
+        /* Happy path return */
+        yaffs_trace(YAFFS_TRACE_OS, "end yaffs_write_begin - ok");
+
+        return 0;
+
+out:
+        yaffs_trace(YAFFS_TRACE_OS,
+                "end yaffs_write_begin fail returning %d", ret);
+        if (space_held)
+                yaffs_release_space(filp);
+        if (pg) {
+                unlock_page(pg);
+                page_cache_release(pg);
+        }
+        return ret;
+}
+
+static ssize_t yaffs_file_write(struct file *f, const char *buf, size_t n,
+                                loff_t * pos)
+{
+        struct yaffs_obj *obj;
+        int n_written, ipos;
+        struct inode *inode;
+        struct yaffs_dev *dev;
+
+        obj = yaffs_dentry_to_obj(f->f_dentry);
+
+        dev = obj->my_dev;
+
+        yaffs_gross_lock(dev);
+
+        inode = f->f_dentry->d_inode;
+
+        if (!S_ISBLK(inode->i_mode) && f->f_flags & O_APPEND)
+                ipos = inode->i_size;
+        else
+                ipos = *pos;
+
+        if (!obj)
+                yaffs_trace(YAFFS_TRACE_OS,
+                        "yaffs_file_write: hey obj is null!");
+        else
+                yaffs_trace(YAFFS_TRACE_OS,
+                        "yaffs_file_write about to write writing %u(%x) bytes to object %d at %d(%x)",
+                        (unsigned)n, (unsigned)n, obj->obj_id, ipos, ipos);
+
+        n_written = yaffs_wr_file(obj, buf, ipos, n, 0);
+
+        yaffs_touch_super(dev);
+
+        yaffs_trace(YAFFS_TRACE_OS,
+                "yaffs_file_write: %d(%x) bytes written",
+                (unsigned)n, (unsigned)n);
+
+        if (n_written > 0) {
+                ipos += n_written;
+                *pos = ipos;
+                if (ipos > inode->i_size) {
+                        inode->i_size = ipos;
+                        inode->i_blocks = (ipos + 511) >> 9;
+
+                        yaffs_trace(YAFFS_TRACE_OS,
+                                "yaffs_file_write size updated to %d bytes, %d blocks",
+                                ipos, (int)(inode->i_blocks));
+                }
+
+        }
+        yaffs_gross_unlock(dev);
+        return (n_written == 0) && (n > 0) ? -ENOSPC : n_written;
+}
+
+static int yaffs_write_end(struct file *filp, struct address_space *mapping,
+                           loff_t pos, unsigned len, unsigned copied,
+                           struct page *pg, void *fsdadata)
+{
+        int ret = 0;
+        void *addr, *kva;
+        uint32_t offset_into_page = pos & (PAGE_CACHE_SIZE - 1);
+
+        kva = kmap(pg);
+        addr = kva + offset_into_page;
+
+        yaffs_trace(YAFFS_TRACE_OS,
+                "yaffs_write_end addr %p pos %x n_bytes %d",
+                addr, (unsigned)pos, copied);
+
+        ret = yaffs_file_write(filp, addr, copied, &pos);
+
+        if (ret != copied) {
+                yaffs_trace(YAFFS_TRACE_OS,
+                        "yaffs_write_end not same size ret %d  copied %d",
+                        ret, copied);
+                SetPageError(pg);
+        }
+
+        kunmap(pg);
+
+        yaffs_release_space(filp);
+        unlock_page(pg);
+        page_cache_release(pg);
+        return ret;
+}
+
+static int yaffs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+        struct yaffs_dev *dev = yaffs_dentry_to_obj(dentry)->my_dev;
+        struct super_block *sb = dentry->d_sb;
+
+        yaffs_trace(YAFFS_TRACE_OS, "yaffs_statfs");
+
+        yaffs_gross_lock(dev);
+
+        buf->f_type = YAFFS_MAGIC;
+        buf->f_bsize = sb->s_blocksize;
+        buf->f_namelen = 255;
+
+        if (dev->data_bytes_per_chunk & (dev->data_bytes_per_chunk - 1)) {
+                /* Do this if chunk size is not a power of 2 */
+
+                uint64_t bytes_in_dev;
+                uint64_t bytes_free;
+
+                bytes_in_dev =
+                    ((uint64_t)
+                     ((dev->param.end_block - dev->param.start_block +
+                       1))) * ((uint64_t) (dev->param.chunks_per_block *
+                                           dev->data_bytes_per_chunk));
+
+                do_div(bytes_in_dev, sb->s_blocksize);  /* bytes_in_dev becomes the number of blocks */
+                buf->f_blocks = bytes_in_dev;
+
+                bytes_free = ((uint64_t) (yaffs_get_n_free_chunks(dev))) *
+                    ((uint64_t) (dev->data_bytes_per_chunk));
+
+                do_div(bytes_free, sb->s_blocksize);
+
+                buf->f_bfree = bytes_free;
+
+        } else if (sb->s_blocksize > dev->data_bytes_per_chunk) {
+
+                buf->f_blocks =
+                    (dev->param.end_block - dev->param.start_block + 1) *
+                    dev->param.chunks_per_block /
+                    (sb->s_blocksize / dev->data_bytes_per_chunk);
+                buf->f_bfree =
+                    yaffs_get_n_free_chunks(dev) /
+                    (sb->s_blocksize / dev->data_bytes_per_chunk);
+        } else {
+                buf->f_blocks =
+                    (dev->param.end_block - dev->param.start_block + 1) *
+                    dev->param.chunks_per_block *
+                    (dev->data_bytes_per_chunk / sb->s_blocksize);
+
+                buf->f_bfree =
+                    yaffs_get_n_free_chunks(dev) *
+                    (dev->data_bytes_per_chunk / sb->s_blocksize);
+        }
+
+        buf->f_files = 0;
+        buf->f_ffree = 0;
+        buf->f_bavail = buf->f_bfree;
+
+        yaffs_gross_unlock(dev);
+        return 0;
+}
+
+static void yaffs_flush_inodes(struct super_block *sb)
+{
+        struct inode *iptr;
+        struct yaffs_obj *obj;
+
+        list_for_each_entry(iptr, &sb->s_inodes, i_sb_list) {
+                obj = yaffs_inode_to_obj(iptr);
+                if (obj) {
+                        yaffs_trace(YAFFS_TRACE_OS,
+                                "flushing obj %d", obj->obj_id);
+                        yaffs_flush_file(obj, 1, 0);
+                }
+        }
+}
+
+static void yaffs_flush_super(struct super_block *sb, int do_checkpoint)
+{
+        struct yaffs_dev *dev = yaffs_super_to_dev(sb);
+        if (!dev)
+                return;
+
+        yaffs_flush_inodes(sb);
+        yaffs_update_dirty_dirs(dev);
+        yaffs_flush_whole_cache(dev);
+        if (do_checkpoint)
+                yaffs_checkpoint_save(dev);
+}
+
+static unsigned yaffs_bg_gc_urgency(struct yaffs_dev *dev)
+{
+        unsigned erased_chunks =
+            dev->n_erased_blocks * dev->param.chunks_per_block;
+        struct yaffs_linux_context *context = yaffs_dev_to_lc(dev);
+        unsigned scattered = 0; /* Free chunks not in an erased block */
+
+        if (erased_chunks < dev->n_free_chunks)
+                scattered = (dev->n_free_chunks - erased_chunks);
+
+        if (!context->bg_running)
+                return 0;
+        else if (scattered < (dev->param.chunks_per_block * 2))
+                return 0;
+        else if (erased_chunks > dev->n_free_chunks / 2)
+                return 0;
+        else if (erased_chunks > dev->n_free_chunks / 4)
+                return 1;
+        else
+                return 2;
+}
+
+static int yaffs_do_sync_fs(struct super_block *sb, int request_checkpoint)
+{
+
+        struct yaffs_dev *dev = yaffs_super_to_dev(sb);
+        unsigned int oneshot_checkpoint = (yaffs_auto_checkpoint & 4);
+        unsigned gc_urgent = yaffs_bg_gc_urgency(dev);
+        int do_checkpoint;
+
+        yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC | YAFFS_TRACE_BACKGROUND,
+                "yaffs_do_sync_fs: gc-urgency %d %s %s%s",
+                gc_urgent,
+                sb->s_dirt ? "dirty" : "clean",
+                request_checkpoint ? "checkpoint requested" : "no checkpoint",
+                oneshot_checkpoint ? " one-shot" : "");
+
+        yaffs_gross_lock(dev);
+        do_checkpoint = ((request_checkpoint && !gc_urgent) ||
+                         oneshot_checkpoint) && !dev->is_checkpointed;
+
+        if (sb->s_dirt || do_checkpoint) {
+                yaffs_flush_super(sb, !dev->is_checkpointed && do_checkpoint);
+                sb->s_dirt = 0;
+                if (oneshot_checkpoint)
+                        yaffs_auto_checkpoint &= ~4;
+        }
+        yaffs_gross_unlock(dev);
+
+        return 0;
+}
+
+/*
+ * yaffs background thread functions .
+ * yaffs_bg_thread_fn() the thread function
+ * yaffs_bg_start() launches the background thread.
+ * yaffs_bg_stop() cleans up the background thread.
+ *
+ * NB: 
+ * The thread should only run after the yaffs is initialised
+ * The thread should be stopped before yaffs is unmounted.
+ * The thread should not do any writing while the fs is in read only.
+ */
+
+void yaffs_background_waker(unsigned long data)
+{
+        wake_up_process((struct task_struct *)data);
+}
+
+static int yaffs_bg_thread_fn(void *data)
+{
+        struct yaffs_dev *dev = (struct yaffs_dev *)data;
+        struct yaffs_linux_context *context = yaffs_dev_to_lc(dev);
+        unsigned long now = jiffies;
+        unsigned long next_dir_update = now;
+        unsigned long next_gc = now;
+        unsigned long expires;
+        unsigned int urgency;
+
+        int gc_result;
+        struct timer_list timer;
+
+        yaffs_trace(YAFFS_TRACE_BACKGROUND,
+                "yaffs_background starting for dev %p", (void *)dev);
+
+        set_freezable();
+        while (context->bg_running) {
+                yaffs_trace(YAFFS_TRACE_BACKGROUND, "yaffs_background");
+
+                if (kthread_should_stop())
+                        break;
+
+                if (try_to_freeze())
+                        continue;
+
+                yaffs_gross_lock(dev);
+
+                now = jiffies;
+
+                if (time_after(now, next_dir_update) && yaffs_bg_enable) {
+                        yaffs_update_dirty_dirs(dev);
+                        next_dir_update = now + HZ;
+                }
+
+                if (time_after(now, next_gc) && yaffs_bg_enable) {
+                        if (!dev->is_checkpointed) {
+                                urgency = yaffs_bg_gc_urgency(dev);
+                                gc_result = yaffs_bg_gc(dev, urgency);
+                                if (urgency > 1)
+                                        next_gc = now + HZ / 20 + 1;
+                                else if (urgency > 0)
+                                        next_gc = now + HZ / 10 + 1;
+                                else
+                                        next_gc = now + HZ * 2;
+                        } else  {
+                                /*
+                                 * gc not running so set to next_dir_update
+                                 * to cut down on wake ups
+                                 */
+                                next_gc = next_dir_update;
+                        }
+                }
+                yaffs_gross_unlock(dev);
+                expires = next_dir_update;
+                if (time_before(next_gc, expires))
+                        expires = next_gc;
+                if (time_before(expires, now))
+                        expires = now + HZ;
+
+                Y_INIT_TIMER(&timer);
+                timer.expires = expires + 1;
+                timer.data = (unsigned long)current;
+                timer.function = yaffs_background_waker;
+
+                set_current_state(TASK_INTERRUPTIBLE);
+                add_timer(&timer);
+                schedule();
+                del_timer_sync(&timer);
+        }
+
+        return 0;
+}
+
+static int yaffs_bg_start(struct yaffs_dev *dev)
+{
+        int retval = 0;
+        struct yaffs_linux_context *context = yaffs_dev_to_lc(dev);
+
+        if (dev->read_only)
+                return -1;
+
+        context->bg_running = 1;
+
+        context->bg_thread = kthread_run(yaffs_bg_thread_fn,
+                                         (void *)dev, "yaffs-bg-%d",
+                                         context->mount_id);
+
+        if (IS_ERR(context->bg_thread)) {
+                retval = PTR_ERR(context->bg_thread);
+                context->bg_thread = NULL;
+                context->bg_running = 0;
+        }
+        return retval;
+}
+
+static void yaffs_bg_stop(struct yaffs_dev *dev)
+{
+        struct yaffs_linux_context *ctxt = yaffs_dev_to_lc(dev);
+
+        ctxt->bg_running = 0;
+
+        if (ctxt->bg_thread) {
+                kthread_stop(ctxt->bg_thread);
+                ctxt->bg_thread = NULL;
+        }
+}
+
+static void yaffs_write_super(struct super_block *sb)
+{
+        unsigned request_checkpoint = (yaffs_auto_checkpoint >= 2);
+
+        yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC | YAFFS_TRACE_BACKGROUND,
+                "yaffs_write_super%s",
+                request_checkpoint ? " checkpt" : "");
+
+        yaffs_do_sync_fs(sb, request_checkpoint);
+
+}
+
+static int yaffs_sync_fs(struct super_block *sb, int wait)
+{
+        unsigned request_checkpoint = (yaffs_auto_checkpoint >= 1);
+
+        yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC,
+                "yaffs_sync_fs%s", request_checkpoint ? " checkpt" : "");
+
+        yaffs_do_sync_fs(sb, request_checkpoint);
+
+        return 0;
+}
+
+
+static LIST_HEAD(yaffs_context_list);
+struct mutex yaffs_context_lock;
+
+
+
+struct yaffs_options {
+        int inband_tags;
+        int skip_checkpoint_read;
+        int skip_checkpoint_write;
+        int no_cache;
+        int tags_ecc_on;
+        int tags_ecc_overridden;
+        int lazy_loading_enabled;
+        int lazy_loading_overridden;
+        int empty_lost_and_found;
+        int empty_lost_and_found_overridden;
+};
+
+#define MAX_OPT_LEN 30
+static int yaffs_parse_options(struct yaffs_options *options,
+                               const char *options_str)
+{
+        char cur_opt[MAX_OPT_LEN + 1];
+        int p;
+        int error = 0;
+
+        /* Parse through the options which is a comma seperated list */
+
+        while (options_str && *options_str && !error) {
+                memset(cur_opt, 0, MAX_OPT_LEN + 1);
+                p = 0;
+
+                while (*options_str == ',')
+                        options_str++;
+
+                while (*options_str && *options_str != ',') {
+                        if (p < MAX_OPT_LEN) {
+                                cur_opt[p] = *options_str;
+                                p++;
+                        }
+                        options_str++;
+                }
+
+                if (!strcmp(cur_opt, "inband-tags")) {
+                        options->inband_tags = 1;
+                } else if (!strcmp(cur_opt, "tags-ecc-off")) {
+                        options->tags_ecc_on = 0;
+                        options->tags_ecc_overridden = 1;
+                } else if (!strcmp(cur_opt, "tags-ecc-on")) {
+                        options->tags_ecc_on = 1;
+                        options->tags_ecc_overridden = 1;
+                } else if (!strcmp(cur_opt, "lazy-loading-off")) {
+                        options->lazy_loading_enabled = 0;
+                        options->lazy_loading_overridden = 1;
+                } else if (!strcmp(cur_opt, "lazy-loading-on")) {
+                        options->lazy_loading_enabled = 1;
+                        options->lazy_loading_overridden = 1;
+                } else if (!strcmp(cur_opt, "empty-lost-and-found-off")) {
+                        options->empty_lost_and_found = 0;
+                        options->empty_lost_and_found_overridden = 1;
+                } else if (!strcmp(cur_opt, "empty-lost-and-found-on")) {
+                        options->empty_lost_and_found = 1;
+                        options->empty_lost_and_found_overridden = 1;
+                } else if (!strcmp(cur_opt, "no-cache")) {
+                        options->no_cache = 1;
+                } else if (!strcmp(cur_opt, "no-checkpoint-read")) {
+                        options->skip_checkpoint_read = 1;
+                } else if (!strcmp(cur_opt, "no-checkpoint-write")) {
+                        options->skip_checkpoint_write = 1;
+                } else if (!strcmp(cur_opt, "no-checkpoint")) {
+                        options->skip_checkpoint_read = 1;
+                        options->skip_checkpoint_write = 1;
+                } else {
+                        printk(KERN_INFO "yaffs: Bad mount option \"%s\"\n",
+                               cur_opt);
+                        error = 1;
+                }
+        }
+
+        return error;
+}
+
+static struct address_space_operations yaffs_file_address_operations = {
+        .readpage = yaffs_readpage,
+        .writepage = yaffs_writepage,
+        .write_begin = yaffs_write_begin,
+        .write_end = yaffs_write_end,
+};
+
+
+
+static const struct inode_operations yaffs_file_inode_operations = {
+        .setattr = yaffs_setattr,
+#ifdef CONFIG_YAFFS_XATTR
+        .setxattr = yaffs_setxattr,
+        .getxattr = yaffs_getxattr,
+        .listxattr = yaffs_listxattr,
+        .removexattr = yaffs_removexattr,
+#endif
+};
+
+static const struct inode_operations yaffs_symlink_inode_operations = {
+        .readlink = yaffs_readlink,
+        .follow_link = yaffs_follow_link,
+        .put_link = yaffs_put_link,
+        .setattr = yaffs_setattr,
+#ifdef CONFIG_YAFFS_XATTR
+        .setxattr = yaffs_setxattr,
+        .getxattr = yaffs_getxattr,
+        .listxattr = yaffs_listxattr,
+        .removexattr = yaffs_removexattr,
+#endif
+};
+
+static void yaffs_fill_inode_from_obj(struct inode *inode,
+                                      struct yaffs_obj *obj)
+{
+        if (inode && obj) {
+
+                /* Check mode against the variant type and attempt to repair if broken. */
+                u32 mode = obj->yst_mode;
+                switch (obj->variant_type) {
+                case YAFFS_OBJECT_TYPE_FILE:
+                        if (!S_ISREG(mode)) {
+                                obj->yst_mode &= ~S_IFMT;
+                                obj->yst_mode |= S_IFREG;
+                        }
+
+                        break;
+                case YAFFS_OBJECT_TYPE_SYMLINK:
+                        if (!S_ISLNK(mode)) {
+                                obj->yst_mode &= ~S_IFMT;
+                                obj->yst_mode |= S_IFLNK;
+                        }
+
+                        break;
+                case YAFFS_OBJECT_TYPE_DIRECTORY:
+                        if (!S_ISDIR(mode)) {
+                                obj->yst_mode &= ~S_IFMT;
+                                obj->yst_mode |= S_IFDIR;
+                        }
+
+                        break;
+                case YAFFS_OBJECT_TYPE_UNKNOWN:
+                case YAFFS_OBJECT_TYPE_HARDLINK:
+                case YAFFS_OBJECT_TYPE_SPECIAL:
+                default:
+                        /* TODO? */
+                        break;
+                }
+
+                inode->i_flags |= S_NOATIME;
+
+                inode->i_ino = obj->obj_id;
+                inode->i_mode = obj->yst_mode;
+                inode->i_uid = obj->yst_uid;
+                inode->i_gid = obj->yst_gid;
+
+                inode->i_rdev = old_decode_dev(obj->yst_rdev);
+
+                inode->i_atime.tv_sec = (time_t) (obj->yst_atime);
+                inode->i_atime.tv_nsec = 0;
+                inode->i_mtime.tv_sec = (time_t) obj->yst_mtime;
+                inode->i_mtime.tv_nsec = 0;
+                inode->i_ctime.tv_sec = (time_t) obj->yst_ctime;
+                inode->i_ctime.tv_nsec = 0;
+                inode->i_size = yaffs_get_obj_length(obj);
+                inode->i_blocks = (inode->i_size + 511) >> 9;
+
+                inode->i_nlink = yaffs_get_obj_link_count(obj);
+
+                yaffs_trace(YAFFS_TRACE_OS,
+                        "yaffs_fill_inode mode %x uid %d gid %d size %d count %d",
+                        inode->i_mode, inode->i_uid, inode->i_gid,
+                        (int)inode->i_size, atomic_read(&inode->i_count));
+
+                switch (obj->yst_mode & S_IFMT) {
+                default:        /* fifo, device or socket */
+                        init_special_inode(inode, obj->yst_mode,
+                                           old_decode_dev(obj->yst_rdev));
+                        break;
+                case S_IFREG:   /* file */
+                        inode->i_op = &yaffs_file_inode_operations;
+                        inode->i_fop = &yaffs_file_operations;
+                        inode->i_mapping->a_ops =
+                            &yaffs_file_address_operations;
+                        break;
+                case S_IFDIR:   /* directory */
+                        inode->i_op = &yaffs_dir_inode_operations;
+                        inode->i_fop = &yaffs_dir_operations;
+                        break;
+                case S_IFLNK:   /* symlink */
+                        inode->i_op = &yaffs_symlink_inode_operations;
+                        break;
+                }
+
+                yaffs_inode_to_obj_lv(inode) = obj;
+
+                obj->my_inode = inode;
+
+        } else {
+                yaffs_trace(YAFFS_TRACE_OS,
+                        "yaffs_fill_inode invalid parameters");
+        }
+}
+
+static void yaffs_put_super(struct super_block *sb)
+{
+        struct yaffs_dev *dev = yaffs_super_to_dev(sb);
+
+        yaffs_trace(YAFFS_TRACE_OS, "yaffs_put_super");
+
+        yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_BACKGROUND,
+                "Shutting down yaffs background thread");
+        yaffs_bg_stop(dev);
+        yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_BACKGROUND,
+                "yaffs background thread shut down");
+
+        yaffs_gross_lock(dev);
+
+        yaffs_flush_super(sb, 1);
+
+        if (yaffs_dev_to_lc(dev)->put_super_fn)
+                yaffs_dev_to_lc(dev)->put_super_fn(sb);
+
+        yaffs_deinitialise(dev);
+
+        yaffs_gross_unlock(dev);
+        mutex_lock(&yaffs_context_lock);
+        list_del_init(&(yaffs_dev_to_lc(dev)->context_list));
+        mutex_unlock(&yaffs_context_lock);
+
+        if (yaffs_dev_to_lc(dev)->spare_buffer) {
+                kfree(yaffs_dev_to_lc(dev)->spare_buffer);
+                yaffs_dev_to_lc(dev)->spare_buffer = NULL;
+        }
+
+        kfree(dev);
+}
+
+static void yaffs_mtd_put_super(struct super_block *sb)
+{
+        struct mtd_info *mtd = yaffs_dev_to_mtd(yaffs_super_to_dev(sb));
+
+        if (mtd->sync)
+                mtd->sync(mtd);
+
+        put_mtd_device(mtd);
+}
+
+static const struct super_operations yaffs_super_ops = {
+        .statfs = yaffs_statfs,
+        .put_super = yaffs_put_super,
+        .evict_inode = yaffs_evict_inode,
+        .sync_fs = yaffs_sync_fs,
+        .write_super = yaffs_write_super,
+};
+
+static struct super_block *yaffs_internal_read_super(int yaffs_version,
+                                                     struct super_block *sb,
+                                                     void *data, int silent)
+{
+        int n_blocks;
+        struct inode *inode = NULL;
+        struct dentry *root;
+        struct yaffs_dev *dev = 0;
+        char devname_buf[BDEVNAME_SIZE + 1];
+        struct mtd_info *mtd;
+        int err;
+        char *data_str = (char *)data;
+        struct yaffs_linux_context *context = NULL;
+        struct yaffs_param *param;
+
+        int read_only = 0;
+
+        struct yaffs_options options;
+
+        unsigned mount_id;
+        int found;
+        struct yaffs_linux_context *context_iterator;
+        struct list_head *l;
+
+        sb->s_magic = YAFFS_MAGIC;
+        sb->s_op = &yaffs_super_ops;
+        sb->s_flags |= MS_NOATIME;
+
+        read_only = ((sb->s_flags & MS_RDONLY) != 0);
+
+        sb->s_export_op = &yaffs_export_ops;
+
+        if (!sb)
+                printk(KERN_INFO "yaffs: sb is NULL\n");
+        else if (!sb->s_dev)
+                printk(KERN_INFO "yaffs: sb->s_dev is NULL\n");
+        else if (!yaffs_devname(sb, devname_buf))
+                printk(KERN_INFO "yaffs: devname is NULL\n");
+        else
+                printk(KERN_INFO "yaffs: dev is %d name is \"%s\" %s\n",
+                       sb->s_dev,
+                       yaffs_devname(sb, devname_buf), read_only ? "ro" : "rw");
+
+        if (!data_str)
+                data_str = "";
+
+        printk(KERN_INFO "yaffs: passed flags \"%s\"\n", data_str);
+
+        memset(&options, 0, sizeof(options));
+
+        if (yaffs_parse_options(&options, data_str)) {
+                /* Option parsing failed */
+                return NULL;
+        }
+
+        sb->s_blocksize = PAGE_CACHE_SIZE;
+        sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+
+        yaffs_trace(YAFFS_TRACE_OS,
+                "yaffs_read_super: Using yaffs%d", yaffs_version);
+        yaffs_trace(YAFFS_TRACE_OS,
+                "yaffs_read_super: block size %d", (int)(sb->s_blocksize));
+
+        yaffs_trace(YAFFS_TRACE_ALWAYS,
+                "Attempting MTD mount of %u.%u,\"%s\"",
+                MAJOR(sb->s_dev), MINOR(sb->s_dev),
+                yaffs_devname(sb, devname_buf));
+
+        /* Check it's an mtd device..... */
+        if (MAJOR(sb->s_dev) != MTD_BLOCK_MAJOR)
+                return NULL;    /* This isn't an mtd device */
+
+        /* Get the device */
+        mtd = get_mtd_device(NULL, MINOR(sb->s_dev));
+        if (!mtd) {
+                yaffs_trace(YAFFS_TRACE_ALWAYS,
+                        "MTD device #%u doesn't appear to exist",
+                        MINOR(sb->s_dev));
+                return NULL;
+        }
+        /* Check it's NAND */
+        if (mtd->type != MTD_NANDFLASH) {
+                yaffs_trace(YAFFS_TRACE_ALWAYS,
+                        "MTD device is not NAND it's type %d",
+                        mtd->type);
+                return NULL;
+        }
+
+        yaffs_trace(YAFFS_TRACE_OS, " erase %p", mtd->erase);
+        yaffs_trace(YAFFS_TRACE_OS, " read %p", mtd->read);
+        yaffs_trace(YAFFS_TRACE_OS, " write %p", mtd->write);
+        yaffs_trace(YAFFS_TRACE_OS, " readoob %p", mtd->read_oob);
+        yaffs_trace(YAFFS_TRACE_OS, " writeoob %p", mtd->write_oob);
+        yaffs_trace(YAFFS_TRACE_OS, " block_isbad %p", mtd->block_isbad);
+        yaffs_trace(YAFFS_TRACE_OS, " block_markbad %p", mtd->block_markbad);
+        yaffs_trace(YAFFS_TRACE_OS, " %s %d", WRITE_SIZE_STR, WRITE_SIZE(mtd));
+        yaffs_trace(YAFFS_TRACE_OS, " oobsize %d", mtd->oobsize);
+        yaffs_trace(YAFFS_TRACE_OS, " erasesize %d", mtd->erasesize);
+        yaffs_trace(YAFFS_TRACE_OS, " size %lld", mtd->size);
+
+#ifdef CONFIG_YAFFS_AUTO_YAFFS2
+
+        if (yaffs_version == 1 && WRITE_SIZE(mtd) >= 2048) {
+                yaffs_trace(YAFFS_TRACE_ALWAYS, "auto selecting yaffs2");
+                yaffs_version = 2;
+        }
+
+        /* Added NCB 26/5/2006 for completeness */
+        if (yaffs_version == 2 && !options.inband_tags
+            && WRITE_SIZE(mtd) == 512) {
+                yaffs_trace(YAFFS_TRACE_ALWAYS, "auto selecting yaffs1");
+                yaffs_version = 1;
+        }
+#endif
+
+        if (yaffs_version == 2) {
+                /* Check for version 2 style functions */
+                if (!mtd->erase ||
+                    !mtd->block_isbad ||
+                    !mtd->block_markbad ||
+                    !mtd->read ||
+                    !mtd->write || !mtd->read_oob || !mtd->write_oob) {
+                        yaffs_trace(YAFFS_TRACE_ALWAYS,
+                                "MTD device does not support required functions");
+                        return NULL;
+                }
+
+                if ((WRITE_SIZE(mtd) < YAFFS_MIN_YAFFS2_CHUNK_SIZE ||
+                     mtd->oobsize < YAFFS_MIN_YAFFS2_SPARE_SIZE) &&
+                    !options.inband_tags) {
+                        yaffs_trace(YAFFS_TRACE_ALWAYS,
+                                "MTD device does not have the right page sizes");
+                        return NULL;
+                }
+        } else {
+                /* Check for V1 style functions */
+                if (!mtd->erase ||
+                    !mtd->read ||
+                    !mtd->write || !mtd->read_oob || !mtd->write_oob) {
+                        yaffs_trace(YAFFS_TRACE_ALWAYS,
+                                "MTD device does not support required functions");
+                        return NULL;
+                }
+
+                if (WRITE_SIZE(mtd) < YAFFS_BYTES_PER_CHUNK ||
+                    mtd->oobsize != YAFFS_BYTES_PER_SPARE) {
+                        yaffs_trace(YAFFS_TRACE_ALWAYS,
+                                "MTD device does not support have the right page sizes");
+                        return NULL;
+                }
+        }
+
+        /* OK, so if we got here, we have an MTD that's NAND and looks
+         * like it has the right capabilities
+         * Set the struct yaffs_dev up for mtd
+         */
+
+        if (!read_only && !(mtd->flags & MTD_WRITEABLE)) {
+                read_only = 1;
+                printk(KERN_INFO
+                       "yaffs: mtd is read only, setting superblock read only");
+                sb->s_flags |= MS_RDONLY;
+        }
+
+        dev = kmalloc(sizeof(struct yaffs_dev), GFP_KERNEL);
+        context = kmalloc(sizeof(struct yaffs_linux_context), GFP_KERNEL);
+
+        if (!dev || !context) {
+                if (dev)
+                        kfree(dev);
+                if (context)
+                        kfree(context);
+                dev = NULL;
+                context = NULL;
+        }
+
+        if (!dev) {
+                /* Deep shit could not allocate device structure */
+                yaffs_trace(YAFFS_TRACE_ALWAYS,
+                        "yaffs_read_super failed trying to allocate yaffs_dev");
+                return NULL;
+        }
+        memset(dev, 0, sizeof(struct yaffs_dev));
+        param = &(dev->param);
+
+        memset(context, 0, sizeof(struct yaffs_linux_context));
+        dev->os_context = context;
+        INIT_LIST_HEAD(&(context->context_list));
+        context->dev = dev;
+        context->super = sb;
+
+        dev->read_only = read_only;
+
+        sb->s_fs_info = dev;
+
+        dev->driver_context = mtd;
+        param->name = mtd->name;
+
+        /* Set up the memory size parameters.... */
+
+        n_blocks =
+            YCALCBLOCKS(mtd->size,
+                        (YAFFS_CHUNKS_PER_BLOCK * YAFFS_BYTES_PER_CHUNK));
+
+        param->start_block = 0;
+        param->end_block = n_blocks - 1;
+        param->chunks_per_block = YAFFS_CHUNKS_PER_BLOCK;
+        param->total_bytes_per_chunk = YAFFS_BYTES_PER_CHUNK;
+        param->n_reserved_blocks = 5;
+        param->n_caches = (options.no_cache) ? 0 : 10;
+        param->inband_tags = options.inband_tags;
+
+#ifdef CONFIG_YAFFS_DISABLE_LAZY_LOAD
+        param->disable_lazy_load = 1;
+#endif
+#ifdef CONFIG_YAFFS_XATTR
+        param->enable_xattr = 1;
+#endif
+        if (options.lazy_loading_overridden)
+                param->disable_lazy_load = !options.lazy_loading_enabled;
+
+#ifdef CONFIG_YAFFS_DISABLE_TAGS_ECC
+        param->no_tags_ecc = 1;
+#endif
+
+#ifdef CONFIG_YAFFS_DISABLE_BACKGROUND
+#else
+        param->defered_dir_update = 1;
+#endif
+
+        if (options.tags_ecc_overridden)
+                param->no_tags_ecc = !options.tags_ecc_on;
+
+#ifdef CONFIG_YAFFS_EMPTY_LOST_AND_FOUND
+        param->empty_lost_n_found = 1;
+#endif
+
+#ifdef CONFIG_YAFFS_DISABLE_BLOCK_REFRESHING
+        param->refresh_period = 0;
+#else
+        param->refresh_period = 500;
+#endif
+
+#ifdef CONFIG_YAFFS_ALWAYS_CHECK_CHUNK_ERASED
+        param->always_check_erased = 1;
+#endif
+
+        if (options.empty_lost_and_found_overridden)
+                param->empty_lost_n_found = options.empty_lost_and_found;
+
+        /* ... and the functions. */
+        if (yaffs_version == 2) {
+                param->write_chunk_tags_fn = nandmtd2_write_chunk_tags;
+                param->read_chunk_tags_fn = nandmtd2_read_chunk_tags;
+                param->bad_block_fn = nandmtd2_mark_block_bad;
+                param->query_block_fn = nandmtd2_query_block;
+                yaffs_dev_to_lc(dev)->spare_buffer = 
+                                kmalloc(mtd->oobsize, GFP_NOFS);
+                param->is_yaffs2 = 1;
+                param->total_bytes_per_chunk = mtd->writesize;
+                param->chunks_per_block = mtd->erasesize / mtd->writesize;
+                n_blocks = YCALCBLOCKS(mtd->size, mtd->erasesize);
+
+                param->start_block = 0;
+                param->end_block = n_blocks - 1;
+        } else {
+                /* use the MTD interface in yaffs_mtdif1.c */
+                param->write_chunk_tags_fn = nandmtd1_write_chunk_tags;
+                param->read_chunk_tags_fn = nandmtd1_read_chunk_tags;
+                param->bad_block_fn = nandmtd1_mark_block_bad;
+                param->query_block_fn = nandmtd1_query_block;
+                param->is_yaffs2 = 0;
+        }
+        /* ... and common functions */
+        param->erase_fn = nandmtd_erase_block;
+        param->initialise_flash_fn = nandmtd_initialise;
+
+        yaffs_dev_to_lc(dev)->put_super_fn = yaffs_mtd_put_super;
+
+        param->sb_dirty_fn = yaffs_touch_super;
+        param->gc_control = yaffs_gc_control_callback;
+
+        yaffs_dev_to_lc(dev)->super = sb;
+
+#ifndef CONFIG_YAFFS_DOES_ECC
+        param->use_nand_ecc = 1;
+#endif
+
+        param->skip_checkpt_rd = options.skip_checkpoint_read;
+        param->skip_checkpt_wr = options.skip_checkpoint_write;
+
+        mutex_lock(&yaffs_context_lock);
+        /* Get a mount id */
+        found = 0;
+        for (mount_id = 0; !found; mount_id++) {
+                found = 1;
+                list_for_each(l, &yaffs_context_list) {
+                        context_iterator =
+                            list_entry(l, struct yaffs_linux_context,
+                                       context_list);
+                        if (context_iterator->mount_id == mount_id)
+                                found = 0;
+                }
+        }
+        context->mount_id = mount_id;
+
+        list_add_tail(&(yaffs_dev_to_lc(dev)->context_list),
+                      &yaffs_context_list);
+        mutex_unlock(&yaffs_context_lock);
+
+        /* Directory search handling... */
+        INIT_LIST_HEAD(&(yaffs_dev_to_lc(dev)->search_contexts));
+        param->remove_obj_fn = yaffs_remove_obj_callback;
+
+        mutex_init(&(yaffs_dev_to_lc(dev)->gross_lock));
+
+        yaffs_gross_lock(dev);
+
+        err = yaffs_guts_initialise(dev);
+
+        yaffs_trace(YAFFS_TRACE_OS,
+                "yaffs_read_super: guts initialised %s",
+                (err == YAFFS_OK) ? "OK" : "FAILED");
+
+        if (err == YAFFS_OK)
+                yaffs_bg_start(dev);
+
+        if (!context->bg_thread)
+                param->defered_dir_update = 0;
+
+        /* Release lock before yaffs_get_inode() */
+        yaffs_gross_unlock(dev);
+
+        /* Create root inode */
+        if (err == YAFFS_OK)
+                inode = yaffs_get_inode(sb, S_IFDIR | 0755, 0, yaffs_root(dev));
+
+        if (!inode)
+                return NULL;
+
+        inode->i_op = &yaffs_dir_inode_operations;
+        inode->i_fop = &yaffs_dir_operations;
+
+        yaffs_trace(YAFFS_TRACE_OS, "yaffs_read_super: got root inode");
+
+        root = d_alloc_root(inode);
+
+        yaffs_trace(YAFFS_TRACE_OS, "yaffs_read_super: d_alloc_root done");
+
+        if (!root) {
+                iput(inode);
+                return NULL;
+        }
+        sb->s_root = root;
+        sb->s_dirt = !dev->is_checkpointed;
+        yaffs_trace(YAFFS_TRACE_ALWAYS,
+                "yaffs_read_super: is_checkpointed %d",
+                dev->is_checkpointed);
+
+        yaffs_trace(YAFFS_TRACE_OS, "yaffs_read_super: done");
+        return sb;
+}
+
+static int yaffs_internal_read_super_mtd(struct super_block *sb, void *data,
+                                         int silent)
+{
+        return yaffs_internal_read_super(1, sb, data, silent) ? 0 : -EINVAL;
+}
+
+static int yaffs_read_super(struct file_system_type *fs,
+                            int flags, const char *dev_name,
+                            void *data, struct vfsmount *mnt)
+{
+
+        return get_sb_bdev(fs, flags, dev_name, data,
+                           yaffs_internal_read_super_mtd, mnt);
+}
+
+static struct file_system_type yaffs_fs_type = {
+        .owner = THIS_MODULE,
+        .name = "yaffs",
+        .get_sb = yaffs_read_super,
+        .kill_sb = kill_block_super,
+        .fs_flags = FS_REQUIRES_DEV,
+};
+
+#ifdef CONFIG_YAFFS_YAFFS2
+
+static int yaffs2_internal_read_super_mtd(struct super_block *sb, void *data,
+                                          int silent)
+{
+        return yaffs_internal_read_super(2, sb, data, silent) ? 0 : -EINVAL;
+}
+
+static int yaffs2_read_super(struct file_system_type *fs,
+                             int flags, const char *dev_name, void *data,
+                             struct vfsmount *mnt)
+{
+        return get_sb_bdev(fs, flags, dev_name, data,
+                           yaffs2_internal_read_super_mtd, mnt);
+}
+
+static struct file_system_type yaffs2_fs_type = {
+        .owner = THIS_MODULE,
+        .name = "yaffs2",
+        .get_sb = yaffs2_read_super,
+        .kill_sb = kill_block_super,
+        .fs_flags = FS_REQUIRES_DEV,
+};
+#endif /* CONFIG_YAFFS_YAFFS2 */
+
+static struct proc_dir_entry *my_proc_entry;
+
+static char *yaffs_dump_dev_part0(char *buf, struct yaffs_dev *dev)
+{
+        struct yaffs_param *param = &dev->param;
+        buf += sprintf(buf, "start_block........... %d\n", param->start_block);
+        buf += sprintf(buf, "end_block............. %d\n", param->end_block);
+        buf += sprintf(buf, "total_bytes_per_chunk. %d\n",
+                        param->total_bytes_per_chunk);
+        buf += sprintf(buf, "use_nand_ecc.......... %d\n",
+                        param->use_nand_ecc);
+        buf += sprintf(buf, "no_tags_ecc........... %d\n", param->no_tags_ecc);
+        buf += sprintf(buf, "is_yaffs2............. %d\n", param->is_yaffs2);
+        buf += sprintf(buf, "inband_tags........... %d\n", param->inband_tags);
+        buf += sprintf(buf, "empty_lost_n_found.... %d\n",
+                        param->empty_lost_n_found);
+        buf += sprintf(buf, "disable_lazy_load..... %d\n",
+                        param->disable_lazy_load);
+        buf += sprintf(buf, "refresh_period........ %d\n",
+                        param->refresh_period);
+        buf += sprintf(buf, "n_caches.............. %d\n", param->n_caches);
+        buf += sprintf(buf, "n_reserved_blocks..... %d\n",
+                        param->n_reserved_blocks);
+        buf += sprintf(buf, "always_check_erased... %d\n",
+                        param->always_check_erased);
+
+        return buf;
+}
+
+static char *yaffs_dump_dev_part1(char *buf, struct yaffs_dev *dev)
+{
+        buf +=
+            sprintf(buf, "data_bytes_per_chunk.. %d\n",
+                    dev->data_bytes_per_chunk);
+        buf += sprintf(buf, "chunk_grp_bits........ %d\n", dev->chunk_grp_bits);
+        buf += sprintf(buf, "chunk_grp_size........ %d\n", dev->chunk_grp_size);
+        buf +=
+            sprintf(buf, "n_erased_blocks....... %d\n", dev->n_erased_blocks);
+        buf +=
+            sprintf(buf, "blocks_in_checkpt..... %d\n", dev->blocks_in_checkpt);
+        buf += sprintf(buf, "\n");
+        buf += sprintf(buf, "n_tnodes.............. %d\n", dev->n_tnodes);
+        buf += sprintf(buf, "n_obj................. %d\n", dev->n_obj);
+        buf += sprintf(buf, "n_free_chunks......... %d\n", dev->n_free_chunks);
+        buf += sprintf(buf, "\n");
+        buf += sprintf(buf, "n_page_writes......... %u\n", dev->n_page_writes);
+        buf += sprintf(buf, "n_page_reads.......... %u\n", dev->n_page_reads);
+        buf += sprintf(buf, "n_erasures............ %u\n", dev->n_erasures);
+        buf += sprintf(buf, "n_gc_copies........... %u\n", dev->n_gc_copies);
+        buf += sprintf(buf, "all_gcs............... %u\n", dev->all_gcs);
+        buf +=
+            sprintf(buf, "passive_gc_count...... %u\n", dev->passive_gc_count);
+        buf +=
+            sprintf(buf, "oldest_dirty_gc_count. %u\n",
+                    dev->oldest_dirty_gc_count);
+        buf += sprintf(buf, "n_gc_blocks........... %u\n", dev->n_gc_blocks);
+        buf += sprintf(buf, "bg_gcs................ %u\n", dev->bg_gcs);
+        buf +=
+            sprintf(buf, "n_retired_writes...... %u\n", dev->n_retired_writes);
+        buf +=
+            sprintf(buf, "n_retired_blocks...... %u\n", dev->n_retired_blocks);
+        buf += sprintf(buf, "n_ecc_fixed........... %u\n", dev->n_ecc_fixed);
+        buf += sprintf(buf, "n_ecc_unfixed......... %u\n", dev->n_ecc_unfixed);
+        buf +=
+            sprintf(buf, "n_tags_ecc_fixed...... %u\n", dev->n_tags_ecc_fixed);
+        buf +=
+            sprintf(buf, "n_tags_ecc_unfixed.... %u\n",
+                    dev->n_tags_ecc_unfixed);
+        buf += sprintf(buf, "cache_hits............ %u\n", dev->cache_hits);
+        buf +=
+            sprintf(buf, "n_deleted_files....... %u\n", dev->n_deleted_files);
+        buf +=
+            sprintf(buf, "n_unlinked_files...... %u\n", dev->n_unlinked_files);
+        buf += sprintf(buf, "refresh_count......... %u\n", dev->refresh_count);
+        buf += sprintf(buf, "n_bg_deletions........ %u\n", dev->n_bg_deletions);
+
+        return buf;
+}
+
+static int yaffs_proc_read(char *page,
+                           char **start,
+                           off_t offset, int count, int *eof, void *data)
+{
+        struct list_head *item;
+        char *buf = page;
+        int step = offset;
+        int n = 0;
+
+        /* Get proc_file_read() to step 'offset' by one on each sucessive call.
+         * We use 'offset' (*ppos) to indicate where we are in dev_list.
+         * This also assumes the user has posted a read buffer large
+         * enough to hold the complete output; but that's life in /proc.
+         */
+
+        *(int *)start = 1;
+
+        /* Print header first */
+        if (step == 0)
+                buf += sprintf(buf, "YAFFS built:" __DATE__ " " __TIME__ "\n");
+        else if (step == 1)
+                buf += sprintf(buf, "\n");
+        else {
+                step -= 2;
+
+                mutex_lock(&yaffs_context_lock);
+
+                /* Locate and print the Nth entry.  Order N-squared but N is small. */
+                list_for_each(item, &yaffs_context_list) {
+                        struct yaffs_linux_context *dc =
+                            list_entry(item, struct yaffs_linux_context,
+                                       context_list);
+                        struct yaffs_dev *dev = dc->dev;
+
+                        if (n < (step & ~1)) {
+                                n += 2;
+                                continue;
+                        }
+                        if ((step & 1) == 0) {
+                                buf +=
+                                    sprintf(buf, "\nDevice %d \"%s\"\n", n,
+                                            dev->param.name);
+                                buf = yaffs_dump_dev_part0(buf, dev);
+                        } else {
+                                buf = yaffs_dump_dev_part1(buf, dev);
+                        }
+
+                        break;
+                }
+                mutex_unlock(&yaffs_context_lock);
+        }
+
+        return buf - page < count ? buf - page : count;
+}
+
+
+/**
+ * Set the verbosity of the warnings and error messages.
+ *
+ * Note that the names can only be a..z or _ with the current code.
+ */
+
+static struct {
+        char *mask_name;
+        unsigned mask_bitfield;
+} mask_flags[] = {
+        {"allocate", YAFFS_TRACE_ALLOCATE}, 
+        {"always", YAFFS_TRACE_ALWAYS},
+        {"background", YAFFS_TRACE_BACKGROUND},
+        {"bad_blocks", YAFFS_TRACE_BAD_BLOCKS},
+        {"buffers", YAFFS_TRACE_BUFFERS},
+        {"bug", YAFFS_TRACE_BUG},
+        {"checkpt", YAFFS_TRACE_CHECKPOINT},
+        {"deletion", YAFFS_TRACE_DELETION},
+        {"erase", YAFFS_TRACE_ERASE},
+        {"error", YAFFS_TRACE_ERROR},
+        {"gc_detail", YAFFS_TRACE_GC_DETAIL},
+        {"gc", YAFFS_TRACE_GC},
+        {"lock", YAFFS_TRACE_LOCK},
+        {"mtd", YAFFS_TRACE_MTD},
+        {"nandaccess", YAFFS_TRACE_NANDACCESS},
+        {"os", YAFFS_TRACE_OS},
+        {"scan_debug", YAFFS_TRACE_SCAN_DEBUG},
+        {"scan", YAFFS_TRACE_SCAN},
+        {"mount", YAFFS_TRACE_MOUNT},
+        {"tracing", YAFFS_TRACE_TRACING},
+        {"sync", YAFFS_TRACE_SYNC},
+        {"write", YAFFS_TRACE_WRITE},
+        {"verify", YAFFS_TRACE_VERIFY},
+        {"verify_nand", YAFFS_TRACE_VERIFY_NAND},
+        {"verify_full", YAFFS_TRACE_VERIFY_FULL},
+        {"verify_all", YAFFS_TRACE_VERIFY_ALL},
+        {"all", 0xffffffff},
+        {"none", 0},
+        {NULL, 0},
+};
+
+#define MAX_MASK_NAME_LENGTH 40
+static int yaffs_proc_write_trace_options(struct file *file, const char *buf,
+                                          unsigned long count, void *data)
+{
+        unsigned rg = 0, mask_bitfield;
+        char *end;
+        char *mask_name;
+        const char *x;
+        char substring[MAX_MASK_NAME_LENGTH + 1];
+        int i;
+        int done = 0;
+        int add, len = 0;
+        int pos = 0;
+
+        rg = yaffs_trace_mask;
+
+        while (!done && (pos < count)) {
+                done = 1;
+                while ((pos < count) && isspace(buf[pos]))
+                        pos++;
+
+                switch (buf[pos]) {
+                case '+':
+                case '-':
+                case '=':
+                        add = buf[pos];
+                        pos++;
+                        break;
+
+                default:
+                        add = ' ';
+                        break;
+                }
+                mask_name = NULL;
+
+                mask_bitfield = simple_strtoul(buf + pos, &end, 0);
+
+                if (end > buf + pos) {
+                        mask_name = "numeral";
+                        len = end - (buf + pos);
+                        pos += len;
+                        done = 0;
+                } else {
+                        for (x = buf + pos, i = 0;
+                             (*x == '_' || (*x >= 'a' && *x <= 'z')) &&
+                             i < MAX_MASK_NAME_LENGTH; x++, i++, pos++)
+                                substring[i] = *x;
+                        substring[i] = '\0';
+
+                        for (i = 0; mask_flags[i].mask_name != NULL; i++) {
+                                if (strcmp(substring, mask_flags[i].mask_name)
+                                    == 0) {
+                                        mask_name = mask_flags[i].mask_name;
+                                        mask_bitfield =
+                                            mask_flags[i].mask_bitfield;
+                                        done = 0;
+                                        break;
+                                }
+                        }
+                }
+
+                if (mask_name != NULL) {
+                        done = 0;
+                        switch (add) {
+                        case '-':
+                                rg &= ~mask_bitfield;
+                                break;
+                        case '+':
+                                rg |= mask_bitfield;
+                                break;
+                        case '=':
+                                rg = mask_bitfield;
+                                break;
+                        default:
+                                rg |= mask_bitfield;
+                                break;
+                        }
+                }
+        }
+
+        yaffs_trace_mask = rg | YAFFS_TRACE_ALWAYS;
+
+        printk(KERN_DEBUG "new trace = 0x%08X\n", yaffs_trace_mask);
+
+        if (rg & YAFFS_TRACE_ALWAYS) {
+                for (i = 0; mask_flags[i].mask_name != NULL; i++) {
+                        char flag;
+                        flag = ((rg & mask_flags[i].mask_bitfield) ==
+                                mask_flags[i].mask_bitfield) ? '+' : '-';
+                        printk(KERN_DEBUG "%c%s\n", flag,
+                               mask_flags[i].mask_name);
+                }
+        }
+
+        return count;
+}
+
+static int yaffs_proc_write(struct file *file, const char *buf,
+                            unsigned long count, void *data)
+{
+        return yaffs_proc_write_trace_options(file, buf, count, data);
+}
+
+/* Stuff to handle installation of file systems */
+struct file_system_to_install {
+        struct file_system_type *fst;
+        int installed;
+};
+
+static struct file_system_to_install fs_to_install[] = {
+        {&yaffs_fs_type, 0},
+        {&yaffs2_fs_type, 0},
+        {NULL, 0}
+};
+
+static int __init init_yaffs_fs(void)
+{
+        int error = 0;
+        struct file_system_to_install *fsinst;
+
+        yaffs_trace(YAFFS_TRACE_ALWAYS,
+                "yaffs built " __DATE__ " " __TIME__ " Installing.");
+
+#ifdef CONFIG_YAFFS_ALWAYS_CHECK_CHUNK_ERASED
+        yaffs_trace(YAFFS_TRACE_ALWAYS,
+                "\n\nYAFFS-WARNING CONFIG_YAFFS_ALWAYS_CHECK_CHUNK_ERASED selected.\n\n\n");
+#endif
+
+        mutex_init(&yaffs_context_lock);
+
+        /* Install the proc_fs entries */
+        my_proc_entry = create_proc_entry("yaffs",
+                                          S_IRUGO | S_IFREG, YPROC_ROOT);
+
+        if (my_proc_entry) {
+                my_proc_entry->write_proc = yaffs_proc_write;
+                my_proc_entry->read_proc = yaffs_proc_read;
+                my_proc_entry->data = NULL;
+        } else {
+                return -ENOMEM;
+        }
+
+
+        /* Now add the file system entries */
+
+        fsinst = fs_to_install;
+
+        while (fsinst->fst && !error) {
+                error = register_filesystem(fsinst->fst);
+                if (!error)
+                        fsinst->installed = 1;
+                fsinst++;
+        }
+
+        /* Any errors? uninstall  */
+        if (error) {
+                fsinst = fs_to_install;
+
+                while (fsinst->fst) {
+                        if (fsinst->installed) {
+                                unregister_filesystem(fsinst->fst);
+                                fsinst->installed = 0;
+                        }
+                        fsinst++;
+                }
+        }
+
+        return error;
+}
+
+static void __exit exit_yaffs_fs(void)
+{
+
+        struct file_system_to_install *fsinst;
+
+        yaffs_trace(YAFFS_TRACE_ALWAYS,
+                "yaffs built " __DATE__ " " __TIME__ " removing.");
+
+        remove_proc_entry("yaffs", YPROC_ROOT);
+
+        fsinst = fs_to_install;
+
+        while (fsinst->fst) {
+                if (fsinst->installed) {
+                        unregister_filesystem(fsinst->fst);
+                        fsinst->installed = 0;
+                }
+                fsinst++;
+        }
+}
+
+module_init(init_yaffs_fs)
+    module_exit(exit_yaffs_fs)
+
+    MODULE_DESCRIPTION("YAFFS2 - a NAND specific flash file system");
+MODULE_AUTHOR("Charles Manning, Aleph One Ltd., 2002-2010");
+MODULE_LICENSE("GPL");
diff --git a/fs/yaffs2/yaffs_yaffs1.c b/fs/yaffs2/yaffs_yaffs1.c
new file mode 100644
index 00000000000..9eb60308254
--- /dev/null
+++ b/fs/yaffs2/yaffs_yaffs1.c
@@ -0,0 +1,433 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_yaffs1.h"
+#include "yportenv.h"
+#include "yaffs_trace.h"
+#include "yaffs_bitmap.h"
+#include "yaffs_getblockinfo.h"
+#include "yaffs_nand.h"
+#include "yaffs_attribs.h"
+
+int yaffs1_scan(struct yaffs_dev *dev)
+{
+        struct yaffs_ext_tags tags;
+        int blk;
+        int result;
+
+        int chunk;
+        int c;
+        int deleted;
+        enum yaffs_block_state state;
+        struct yaffs_obj *hard_list = NULL;
+        struct yaffs_block_info *bi;
+        u32 seq_number;
+        struct yaffs_obj_hdr *oh;
+        struct yaffs_obj *in;
+        struct yaffs_obj *parent;
+
+        int alloc_failed = 0;
+
+        struct yaffs_shadow_fixer *shadow_fixers = NULL;
+
+        u8 *chunk_data;
+
+        yaffs_trace(YAFFS_TRACE_SCAN,
+                "yaffs1_scan starts  intstartblk %d intendblk %d...",
+                dev->internal_start_block, dev->internal_end_block);
+
+        chunk_data = yaffs_get_temp_buffer(dev, __LINE__);
+
+        dev->seq_number = YAFFS_LOWEST_SEQUENCE_NUMBER;
+
+        /* Scan all the blocks to determine their state */
+        bi = dev->block_info;
+        for (blk = dev->internal_start_block; blk <= dev->internal_end_block;
+             blk++) {
+                yaffs_clear_chunk_bits(dev, blk);
+                bi->pages_in_use = 0;
+                bi->soft_del_pages = 0;
+
+                yaffs_query_init_block_state(dev, blk, &state, &seq_number);
+
+                bi->block_state = state;
+                bi->seq_number = seq_number;
+
+                if (bi->seq_number == YAFFS_SEQUENCE_BAD_BLOCK)
+                        bi->block_state = state = YAFFS_BLOCK_STATE_DEAD;
+
+                yaffs_trace(YAFFS_TRACE_SCAN_DEBUG,
+                        "Block scanning block %d state %d seq %d",
+                        blk, state, seq_number);
+
+                if (state == YAFFS_BLOCK_STATE_DEAD) {
+                        yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
+                                "block %d is bad", blk);
+                } else if (state == YAFFS_BLOCK_STATE_EMPTY) {
+                        yaffs_trace(YAFFS_TRACE_SCAN_DEBUG, "Block empty ");
+                        dev->n_erased_blocks++;
+                        dev->n_free_chunks += dev->param.chunks_per_block;
+                }
+                bi++;
+        }
+
+        /* For each block.... */
+        for (blk = dev->internal_start_block;
+             !alloc_failed && blk <= dev->internal_end_block; blk++) {
+
+                cond_resched();
+
+                bi = yaffs_get_block_info(dev, blk);
+                state = bi->block_state;
+
+                deleted = 0;
+
+                /* For each chunk in each block that needs scanning.... */
+                for (c = 0; !alloc_failed && c < dev->param.chunks_per_block &&
+                     state == YAFFS_BLOCK_STATE_NEEDS_SCANNING; c++) {
+                        /* Read the tags and decide what to do */
+                        chunk = blk * dev->param.chunks_per_block + c;
+
+                        result = yaffs_rd_chunk_tags_nand(dev, chunk, NULL,
+                                                          &tags);
+
+                        /* Let's have a good look at this chunk... */
+
+                        if (tags.ecc_result == YAFFS_ECC_RESULT_UNFIXED
+                            || tags.is_deleted) {
+                                /* YAFFS1 only...
+                                 * A deleted chunk
+                                 */
+                                deleted++;
+                                dev->n_free_chunks++;
+                                /*T((" %d %d deleted\n",blk,c)); */
+                        } else if (!tags.chunk_used) {
+                                /* An unassigned chunk in the block
+                                 * This means that either the block is empty or
+                                 * this is the one being allocated from
+                                 */
+
+                                if (c == 0) {
+                                        /* We're looking at the first chunk in the block so the block is unused */
+                                        state = YAFFS_BLOCK_STATE_EMPTY;
+                                        dev->n_erased_blocks++;
+                                } else {
+                                        /* this is the block being allocated from */
+                                        yaffs_trace(YAFFS_TRACE_SCAN,
+                                                " Allocating from %d %d",
+                                                blk, c);
+                                        state = YAFFS_BLOCK_STATE_ALLOCATING;
+                                        dev->alloc_block = blk;
+                                        dev->alloc_page = c;
+                                        dev->alloc_block_finder = blk;
+                                        /* Set block finder here to encourage the allocator to go forth from here. */
+
+                                }
+
+                                dev->n_free_chunks +=
+                                    (dev->param.chunks_per_block - c);
+                        } else if (tags.chunk_id > 0) {
+                                /* chunk_id > 0 so it is a data chunk... */
+                                unsigned int endpos;
+
+                                yaffs_set_chunk_bit(dev, blk, c);
+                                bi->pages_in_use++;
+
+                                in = yaffs_find_or_create_by_number(dev,
+                                                                    tags.obj_id,
+                                                                    YAFFS_OBJECT_TYPE_FILE);
+                                /* PutChunkIntoFile checks for a clash (two data chunks with
+                                 * the same chunk_id).
+                                 */
+
+                                if (!in)
+                                        alloc_failed = 1;
+
+                                if (in) {
+                                        if (!yaffs_put_chunk_in_file
+                                            (in, tags.chunk_id, chunk, 1))
+                                                alloc_failed = 1;
+                                }
+
+                                endpos =
+                                    (tags.chunk_id -
+                                     1) * dev->data_bytes_per_chunk +
+                                    tags.n_bytes;
+                                if (in
+                                    && in->variant_type ==
+                                    YAFFS_OBJECT_TYPE_FILE
+                                    && in->variant.file_variant.scanned_size <
+                                    endpos) {
+                                        in->variant.file_variant.scanned_size =
+                                            endpos;
+                                        if (!dev->param.use_header_file_size) {
+                                                in->variant.
+                                                    file_variant.file_size =
+                                                    in->variant.
+                                                    file_variant.scanned_size;
+                                        }
+
+                                }
+                                /* T((" %d %d data %d %d\n",blk,c,tags.obj_id,tags.chunk_id));   */
+                        } else {
+                                /* chunk_id == 0, so it is an ObjectHeader.
+                                 * Thus, we read in the object header and make the object
+                                 */
+                                yaffs_set_chunk_bit(dev, blk, c);
+                                bi->pages_in_use++;
+
+                                result = yaffs_rd_chunk_tags_nand(dev, chunk,
+                                                                  chunk_data,
+                                                                  NULL);
+
+                                oh = (struct yaffs_obj_hdr *)chunk_data;
+
+                                in = yaffs_find_by_number(dev, tags.obj_id);
+                                if (in && in->variant_type != oh->type) {
+                                        /* This should not happen, but somehow
+                                         * Wev'e ended up with an obj_id that has been reused but not yet
+                                         * deleted, and worse still it has changed type. Delete the old object.
+                                         */
+
+                                        yaffs_del_obj(in);
+
+                                        in = 0;
+                                }
+
+                                in = yaffs_find_or_create_by_number(dev,
+                                                                    tags.obj_id,
+                                                                    oh->type);
+
+                                if (!in)
+                                        alloc_failed = 1;
+
+                                if (in && oh->shadows_obj > 0) {
+
+                                        struct yaffs_shadow_fixer *fixer;
+                                        fixer =
+                                                kmalloc(sizeof
+                                                (struct yaffs_shadow_fixer),
+                                                GFP_NOFS);
+                                        if (fixer) {
+                                                fixer->next = shadow_fixers;
+                                                shadow_fixers = fixer;
+                                                fixer->obj_id = tags.obj_id;
+                                                fixer->shadowed_id =
+                                                    oh->shadows_obj;
+                                                yaffs_trace(YAFFS_TRACE_SCAN,
+                                                        " Shadow fixer: %d shadows %d",
+                                                        fixer->obj_id,
+                                                        fixer->shadowed_id);
+
+                                        }
+
+                                }
+
+                                if (in && in->valid) {
+                                        /* We have already filled this one. We have a duplicate and need to resolve it. */
+
+                                        unsigned existing_serial = in->serial;
+                                        unsigned new_serial =
+                                            tags.serial_number;
+
+                                        if (((existing_serial + 1) & 3) ==
+                                            new_serial) {
+                                                /* Use new one - destroy the exisiting one */
+                                                yaffs_chunk_del(dev,
+                                                                in->hdr_chunk,
+                                                                1, __LINE__);
+                                                in->valid = 0;
+                                        } else {
+                                                /* Use existing - destroy this one. */
+                                                yaffs_chunk_del(dev, chunk, 1,
+                                                                __LINE__);
+                                        }
+                                }
+
+                                if (in && !in->valid &&
+                                    (tags.obj_id == YAFFS_OBJECTID_ROOT ||
+                                     tags.obj_id ==
+                                     YAFFS_OBJECTID_LOSTNFOUND)) {
+                                        /* We only load some info, don't fiddle with directory structure */
+                                        in->valid = 1;
+                                        in->variant_type = oh->type;
+
+                                        in->yst_mode = oh->yst_mode;
+                                        yaffs_load_attribs(in, oh);
+                                        in->hdr_chunk = chunk;
+                                        in->serial = tags.serial_number;
+
+                                } else if (in && !in->valid) {
+                                        /* we need to load this info */
+
+                                        in->valid = 1;
+                                        in->variant_type = oh->type;
+
+                                        in->yst_mode = oh->yst_mode;
+                                        yaffs_load_attribs(in, oh);
+                                        in->hdr_chunk = chunk;
+                                        in->serial = tags.serial_number;
+
+                                        yaffs_set_obj_name_from_oh(in, oh);
+                                        in->dirty = 0;
+
+                                        /* directory stuff...
+                                         * hook up to parent
+                                         */
+
+                                        parent =
+                                            yaffs_find_or_create_by_number
+                                            (dev, oh->parent_obj_id,
+                                             YAFFS_OBJECT_TYPE_DIRECTORY);
+                                        if (!parent)
+                                                alloc_failed = 1;
+                                        if (parent && parent->variant_type ==
+                                            YAFFS_OBJECT_TYPE_UNKNOWN) {
+                                                /* Set up as a directory */
+                                                parent->variant_type =
+                                                    YAFFS_OBJECT_TYPE_DIRECTORY;
+                                                INIT_LIST_HEAD(&parent->
+                                                               variant.dir_variant.children);
+                                        } else if (!parent
+                                                   || parent->variant_type !=
+                                                   YAFFS_OBJECT_TYPE_DIRECTORY) {
+                                                /* Hoosterman, another problem....
+                                                 * We're trying to use a non-directory as a directory
+                                                 */
+
+                                                yaffs_trace(YAFFS_TRACE_ERROR,
+                                                        "yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found."
+                                                        );
+                                                parent = dev->lost_n_found;
+                                        }
+
+                                        yaffs_add_obj_to_dir(parent, in);
+
+                                        if (0 && (parent == dev->del_dir ||
+                                                  parent ==
+                                                  dev->unlinked_dir)) {
+                                                in->deleted = 1;        /* If it is unlinked at start up then it wants deleting */
+                                                dev->n_deleted_files++;
+                                        }
+                                        /* Note re hardlinks.
+                                         * Since we might scan a hardlink before its equivalent object is scanned
+                                         * we put them all in a list.
+                                         * After scanning is complete, we should have all the objects, so we run through this
+                                         * list and fix up all the chains.
+                                         */
+
+                                        switch (in->variant_type) {
+                                        case YAFFS_OBJECT_TYPE_UNKNOWN:
+                                                /* Todo got a problem */
+                                                break;
+                                        case YAFFS_OBJECT_TYPE_FILE:
+                                                if (dev->param.
+                                                    use_header_file_size)
+
+                                                        in->variant.
+                                                            file_variant.file_size
+                                                            = oh->file_size;
+
+                                                break;
+                                        case YAFFS_OBJECT_TYPE_HARDLINK:
+                                                in->variant.
+                                                    hardlink_variant.equiv_id =
+                                                    oh->equiv_id;
+                                                in->hard_links.next =
+                                                    (struct list_head *)
+                                                    hard_list;
+                                                hard_list = in;
+                                                break;
+                                        case YAFFS_OBJECT_TYPE_DIRECTORY:
+                                                /* Do nothing */
+                                                break;
+                                        case YAFFS_OBJECT_TYPE_SPECIAL:
+                                                /* Do nothing */
+                                                break;
+                                        case YAFFS_OBJECT_TYPE_SYMLINK:
+                                                in->variant.symlink_variant.
+                                                    alias =
+                                                    yaffs_clone_str(oh->alias);
+                                                if (!in->variant.
+                                                    symlink_variant.alias)
+                                                        alloc_failed = 1;
+                                                break;
+                                        }
+
+                                }
+                        }
+                }
+
+                if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
+                        /* If we got this far while scanning, then the block is fully allocated. */
+                        state = YAFFS_BLOCK_STATE_FULL;
+                }
+
+                if (state == YAFFS_BLOCK_STATE_ALLOCATING) {
+                        /* If the block was partially allocated then treat it as fully allocated. */
+                        state = YAFFS_BLOCK_STATE_FULL;
+                        dev->alloc_block = -1;
+                }
+
+                bi->block_state = state;
+
+                /* Now let's see if it was dirty */
+                if (bi->pages_in_use == 0 &&
+                    !bi->has_shrink_hdr &&
+                    bi->block_state == YAFFS_BLOCK_STATE_FULL) {
+                        yaffs_block_became_dirty(dev, blk);
+                }
+
+        }
+
+        /* Ok, we've done all the scanning.
+         * Fix up the hard link chains.
+         * We should now have scanned all the objects, now it's time to add these
+         * hardlinks.
+         */
+
+        yaffs_link_fixup(dev, hard_list);
+
+        /* Fix up any shadowed objects */
+        {
+                struct yaffs_shadow_fixer *fixer;
+                struct yaffs_obj *obj;
+
+                while (shadow_fixers) {
+                        fixer = shadow_fixers;
+                        shadow_fixers = fixer->next;
+                        /* Complete the rename transaction by deleting the shadowed object
+                         * then setting the object header to unshadowed.
+                         */
+                        obj = yaffs_find_by_number(dev, fixer->shadowed_id);
+                        if (obj)
+                                yaffs_del_obj(obj);
+
+                        obj = yaffs_find_by_number(dev, fixer->obj_id);
+
+                        if (obj)
+                                yaffs_update_oh(obj, NULL, 1, 0, 0, NULL);
+
+                        kfree(fixer);
+                }
+        }
+
+        yaffs_release_temp_buffer(dev, chunk_data, __LINE__);
+
+        if (alloc_failed)
+                return YAFFS_FAIL;
+
+        yaffs_trace(YAFFS_TRACE_SCAN, "yaffs1_scan ends");
+
+        return YAFFS_OK;
+}
diff --git a/fs/yaffs2/yaffs_yaffs1.h b/fs/yaffs2/yaffs_yaffs1.h
new file mode 100644
index 00000000000..db23e04973b
--- /dev/null
+++ b/fs/yaffs2/yaffs_yaffs1.h
@@ -0,0 +1,22 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_YAFFS1_H__
+#define __YAFFS_YAFFS1_H__
+
+#include "yaffs_guts.h"
+int yaffs1_scan(struct yaffs_dev *dev);
+
+#endif
diff --git a/fs/yaffs2/yaffs_yaffs2.c b/fs/yaffs2/yaffs_yaffs2.c
new file mode 100644
index 00000000000..33397af7003
--- /dev/null
+++ b/fs/yaffs2/yaffs_yaffs2.c
@@ -0,0 +1,1598 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_guts.h"
+#include "yaffs_trace.h"
+#include "yaffs_yaffs2.h"
+#include "yaffs_checkptrw.h"
+#include "yaffs_bitmap.h"
+#include "yaffs_nand.h"
+#include "yaffs_getblockinfo.h"
+#include "yaffs_verify.h"
+#include "yaffs_attribs.h"
+
+/*
+ * Checkpoints are really no benefit on very small partitions.
+ *
+ * To save space on small partitions don't bother with checkpoints unless
+ * the partition is at least this big.
+ */
+#define YAFFS_CHECKPOINT_MIN_BLOCKS 60
+
+#define YAFFS_SMALL_HOLE_THRESHOLD 4
+
+/*
+ * Oldest Dirty Sequence Number handling.
+ */
+
+/* yaffs_calc_oldest_dirty_seq()
+ * yaffs2_find_oldest_dirty_seq()
+ * Calculate the oldest dirty sequence number if we don't know it.
+ */
+void yaffs_calc_oldest_dirty_seq(struct yaffs_dev *dev)
+{
+        int i;
+        unsigned seq;
+        unsigned block_no = 0;
+        struct yaffs_block_info *b;
+
+        if (!dev->param.is_yaffs2)
+                return;
+
+        /* Find the oldest dirty sequence number. */
+        seq = dev->seq_number + 1;
+        b = dev->block_info;
+        for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
+                if (b->block_state == YAFFS_BLOCK_STATE_FULL &&
+                    (b->pages_in_use - b->soft_del_pages) <
+                    dev->param.chunks_per_block && b->seq_number < seq) {
+                        seq = b->seq_number;
+                        block_no = i;
+                }
+                b++;
+        }
+
+        if (block_no) {
+                dev->oldest_dirty_seq = seq;
+                dev->oldest_dirty_block = block_no;
+        }
+
+}
+
+void yaffs2_find_oldest_dirty_seq(struct yaffs_dev *dev)
+{
+        if (!dev->param.is_yaffs2)
+                return;
+
+        if (!dev->oldest_dirty_seq)
+                yaffs_calc_oldest_dirty_seq(dev);
+}
+
+/*
+ * yaffs_clear_oldest_dirty_seq()
+ * Called when a block is erased or marked bad. (ie. when its seq_number
+ * becomes invalid). If the value matches the oldest then we clear 
+ * dev->oldest_dirty_seq to force its recomputation.
+ */
+void yaffs2_clear_oldest_dirty_seq(struct yaffs_dev *dev,
+                                   struct yaffs_block_info *bi)
+{
+
+        if (!dev->param.is_yaffs2)
+                return;
+
+        if (!bi || bi->seq_number == dev->oldest_dirty_seq) {
+                dev->oldest_dirty_seq = 0;
+                dev->oldest_dirty_block = 0;
+        }
+}
+
+/*
+ * yaffs2_update_oldest_dirty_seq()
+ * Update the oldest dirty sequence number whenever we dirty a block.
+ * Only do this if the oldest_dirty_seq is actually being tracked.
+ */
+void yaffs2_update_oldest_dirty_seq(struct yaffs_dev *dev, unsigned block_no,
+                                    struct yaffs_block_info *bi)
+{
+        if (!dev->param.is_yaffs2)
+                return;
+
+        if (dev->oldest_dirty_seq) {
+                if (dev->oldest_dirty_seq > bi->seq_number) {
+                        dev->oldest_dirty_seq = bi->seq_number;
+                        dev->oldest_dirty_block = block_no;
+                }
+        }
+}
+
+int yaffs_block_ok_for_gc(struct yaffs_dev *dev, struct yaffs_block_info *bi)
+{
+
+        if (!dev->param.is_yaffs2)
+                return 1;       /* disqualification only applies to yaffs2. */
+
+        if (!bi->has_shrink_hdr)
+                return 1;       /* can gc */
+
+        yaffs2_find_oldest_dirty_seq(dev);
+
+        /* Can't do gc of this block if there are any blocks older than this one that have
+         * discarded pages.
+         */
+        return (bi->seq_number <= dev->oldest_dirty_seq);
+}
+
+/*
+ * yaffs2_find_refresh_block()
+ * periodically finds the oldest full block by sequence number for refreshing.
+ * Only for yaffs2.
+ */
+u32 yaffs2_find_refresh_block(struct yaffs_dev * dev)
+{
+        u32 b;
+
+        u32 oldest = 0;
+        u32 oldest_seq = 0;
+
+        struct yaffs_block_info *bi;
+
+        if (!dev->param.is_yaffs2)
+                return oldest;
+
+        /*
+         * If refresh period < 10 then refreshing is disabled.
+         */
+        if (dev->param.refresh_period < 10)
+                return oldest;
+
+        /*
+         * Fix broken values.
+         */
+        if (dev->refresh_skip > dev->param.refresh_period)
+                dev->refresh_skip = dev->param.refresh_period;
+
+        if (dev->refresh_skip > 0)
+                return oldest;
+
+        /*
+         * Refresh skip is now zero.
+         * We'll do a refresh this time around....
+         * Update the refresh skip and find the oldest block.
+         */
+        dev->refresh_skip = dev->param.refresh_period;
+        dev->refresh_count++;
+        bi = dev->block_info;
+        for (b = dev->internal_start_block; b <= dev->internal_end_block; b++) {
+
+                if (bi->block_state == YAFFS_BLOCK_STATE_FULL) {
+
+                        if (oldest < 1 || bi->seq_number < oldest_seq) {
+                                oldest = b;
+                                oldest_seq = bi->seq_number;
+                        }
+                }
+                bi++;
+        }
+
+        if (oldest > 0) {
+                yaffs_trace(YAFFS_TRACE_GC,
+                        "GC refresh count %d selected block %d with seq_number %d",
+                        dev->refresh_count, oldest, oldest_seq);
+        }
+
+        return oldest;
+}
+
+int yaffs2_checkpt_required(struct yaffs_dev *dev)
+{
+        int nblocks;
+
+        if (!dev->param.is_yaffs2)
+                return 0;
+
+        nblocks = dev->internal_end_block - dev->internal_start_block + 1;
+
+        return !dev->param.skip_checkpt_wr &&
+            !dev->read_only && (nblocks >= YAFFS_CHECKPOINT_MIN_BLOCKS);
+}
+
+int yaffs_calc_checkpt_blocks_required(struct yaffs_dev *dev)
+{
+        int retval;
+
+        if (!dev->param.is_yaffs2)
+                return 0;
+
+        if (!dev->checkpoint_blocks_required && yaffs2_checkpt_required(dev)) {
+                /* Not a valid value so recalculate */
+                int n_bytes = 0;
+                int n_blocks;
+                int dev_blocks =
+                    (dev->param.end_block - dev->param.start_block + 1);
+
+                n_bytes += sizeof(struct yaffs_checkpt_validity);
+                n_bytes += sizeof(struct yaffs_checkpt_dev);
+                n_bytes += dev_blocks * sizeof(struct yaffs_block_info);
+                n_bytes += dev_blocks * dev->chunk_bit_stride;
+                n_bytes +=
+                    (sizeof(struct yaffs_checkpt_obj) +
+                     sizeof(u32)) * (dev->n_obj);
+                n_bytes += (dev->tnode_size + sizeof(u32)) * (dev->n_tnodes);
+                n_bytes += sizeof(struct yaffs_checkpt_validity);
+                n_bytes += sizeof(u32); /* checksum */
+
+                /* Round up and add 2 blocks to allow for some bad blocks, so add 3 */
+
+                n_blocks =
+                    (n_bytes /
+                     (dev->data_bytes_per_chunk *
+                      dev->param.chunks_per_block)) + 3;
+
+                dev->checkpoint_blocks_required = n_blocks;
+        }
+
+        retval = dev->checkpoint_blocks_required - dev->blocks_in_checkpt;
+        if (retval < 0)
+                retval = 0;
+        return retval;
+}
+
+/*--------------------- Checkpointing --------------------*/
+
+static int yaffs2_wr_checkpt_validity_marker(struct yaffs_dev *dev, int head)
+{
+        struct yaffs_checkpt_validity cp;
+
+        memset(&cp, 0, sizeof(cp));
+
+        cp.struct_type = sizeof(cp);
+        cp.magic = YAFFS_MAGIC;
+        cp.version = YAFFS_CHECKPOINT_VERSION;
+        cp.head = (head) ? 1 : 0;
+
+        return (yaffs2_checkpt_wr(dev, &cp, sizeof(cp)) == sizeof(cp)) ? 1 : 0;
+}
+
+static int yaffs2_rd_checkpt_validity_marker(struct yaffs_dev *dev, int head)
+{
+        struct yaffs_checkpt_validity cp;
+        int ok;
+
+        ok = (yaffs2_checkpt_rd(dev, &cp, sizeof(cp)) == sizeof(cp));
+
+        if (ok)
+                ok = (cp.struct_type == sizeof(cp)) &&
+                    (cp.magic == YAFFS_MAGIC) &&
+                    (cp.version == YAFFS_CHECKPOINT_VERSION) &&
+                    (cp.head == ((head) ? 1 : 0));
+        return ok ? 1 : 0;
+}
+
+static void yaffs2_dev_to_checkpt_dev(struct yaffs_checkpt_dev *cp,
+                                      struct yaffs_dev *dev)
+{
+        cp->n_erased_blocks = dev->n_erased_blocks;
+        cp->alloc_block = dev->alloc_block;
+        cp->alloc_page = dev->alloc_page;
+        cp->n_free_chunks = dev->n_free_chunks;
+
+        cp->n_deleted_files = dev->n_deleted_files;
+        cp->n_unlinked_files = dev->n_unlinked_files;
+        cp->n_bg_deletions = dev->n_bg_deletions;
+        cp->seq_number = dev->seq_number;
+
+}
+
+static void yaffs_checkpt_dev_to_dev(struct yaffs_dev *dev,
+                                     struct yaffs_checkpt_dev *cp)
+{
+        dev->n_erased_blocks = cp->n_erased_blocks;
+        dev->alloc_block = cp->alloc_block;
+        dev->alloc_page = cp->alloc_page;
+        dev->n_free_chunks = cp->n_free_chunks;
+
+        dev->n_deleted_files = cp->n_deleted_files;
+        dev->n_unlinked_files = cp->n_unlinked_files;
+        dev->n_bg_deletions = cp->n_bg_deletions;
+        dev->seq_number = cp->seq_number;
+}
+
+static int yaffs2_wr_checkpt_dev(struct yaffs_dev *dev)
+{
+        struct yaffs_checkpt_dev cp;
+        u32 n_bytes;
+        u32 n_blocks =
+            (dev->internal_end_block - dev->internal_start_block + 1);
+
+        int ok;
+
+        /* Write device runtime values */
+        yaffs2_dev_to_checkpt_dev(&cp, dev);
+        cp.struct_type = sizeof(cp);
+
+        ok = (yaffs2_checkpt_wr(dev, &cp, sizeof(cp)) == sizeof(cp));
+
+        /* Write block info */
+        if (ok) {
+                n_bytes = n_blocks * sizeof(struct yaffs_block_info);
+                ok = (yaffs2_checkpt_wr(dev, dev->block_info, n_bytes) ==
+                      n_bytes);
+        }
+
+        /* Write chunk bits */
+        if (ok) {
+                n_bytes = n_blocks * dev->chunk_bit_stride;
+                ok = (yaffs2_checkpt_wr(dev, dev->chunk_bits, n_bytes) ==
+                      n_bytes);
+        }
+        return ok ? 1 : 0;
+
+}
+
+static int yaffs2_rd_checkpt_dev(struct yaffs_dev *dev)
+{
+        struct yaffs_checkpt_dev cp;
+        u32 n_bytes;
+        u32 n_blocks =
+            (dev->internal_end_block - dev->internal_start_block + 1);
+
+        int ok;
+
+        ok = (yaffs2_checkpt_rd(dev, &cp, sizeof(cp)) == sizeof(cp));
+        if (!ok)
+                return 0;
+
+        if (cp.struct_type != sizeof(cp))
+                return 0;
+
+        yaffs_checkpt_dev_to_dev(dev, &cp);
+
+        n_bytes = n_blocks * sizeof(struct yaffs_block_info);
+
+        ok = (yaffs2_checkpt_rd(dev, dev->block_info, n_bytes) == n_bytes);
+
+        if (!ok)
+                return 0;
+        n_bytes = n_blocks * dev->chunk_bit_stride;
+
+        ok = (yaffs2_checkpt_rd(dev, dev->chunk_bits, n_bytes) == n_bytes);
+
+        return ok ? 1 : 0;
+}
+
+static void yaffs2_obj_checkpt_obj(struct yaffs_checkpt_obj *cp,
+                                   struct yaffs_obj *obj)
+{
+
+        cp->obj_id = obj->obj_id;
+        cp->parent_id = (obj->parent) ? obj->parent->obj_id : 0;
+        cp->hdr_chunk = obj->hdr_chunk;
+        cp->variant_type = obj->variant_type;
+        cp->deleted = obj->deleted;
+        cp->soft_del = obj->soft_del;
+        cp->unlinked = obj->unlinked;
+        cp->fake = obj->fake;
+        cp->rename_allowed = obj->rename_allowed;
+        cp->unlink_allowed = obj->unlink_allowed;
+        cp->serial = obj->serial;
+        cp->n_data_chunks = obj->n_data_chunks;
+
+        if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
+                cp->size_or_equiv_obj = obj->variant.file_variant.file_size;
+        else if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK)
+                cp->size_or_equiv_obj = obj->variant.hardlink_variant.equiv_id;
+}
+
+static int taffs2_checkpt_obj_to_obj(struct yaffs_obj *obj,
+                                     struct yaffs_checkpt_obj *cp)
+{
+
+        struct yaffs_obj *parent;
+
+        if (obj->variant_type != cp->variant_type) {
+                yaffs_trace(YAFFS_TRACE_ERROR,
+                        "Checkpoint read object %d type %d chunk %d does not match existing object type %d",
+                        cp->obj_id, cp->variant_type, cp->hdr_chunk,
+                        obj->variant_type);
+                return 0;
+        }
+
+        obj->obj_id = cp->obj_id;
+
+        if (cp->parent_id)
+                parent = yaffs_find_or_create_by_number(obj->my_dev,
+                                                        cp->parent_id,
+                                                        YAFFS_OBJECT_TYPE_DIRECTORY);
+        else
+                parent = NULL;
+
+        if (parent) {
+                if (parent->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+                        yaffs_trace(YAFFS_TRACE_ALWAYS,
+                                "Checkpoint read object %d parent %d type %d chunk %d Parent type, %d, not directory",
+                                cp->obj_id, cp->parent_id,
+                                cp->variant_type, cp->hdr_chunk,
+                                parent->variant_type);
+                        return 0;
+                }
+                yaffs_add_obj_to_dir(parent, obj);
+        }
+
+        obj->hdr_chunk = cp->hdr_chunk;
+        obj->variant_type = cp->variant_type;
+        obj->deleted = cp->deleted;
+        obj->soft_del = cp->soft_del;
+        obj->unlinked = cp->unlinked;
+        obj->fake = cp->fake;
+        obj->rename_allowed = cp->rename_allowed;
+        obj->unlink_allowed = cp->unlink_allowed;
+        obj->serial = cp->serial;
+        obj->n_data_chunks = cp->n_data_chunks;
+
+        if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
+                obj->variant.file_variant.file_size = cp->size_or_equiv_obj;
+        else if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK)
+                obj->variant.hardlink_variant.equiv_id = cp->size_or_equiv_obj;
+
+        if (obj->hdr_chunk > 0)
+                obj->lazy_loaded = 1;
+        return 1;
+}
+
+static int yaffs2_checkpt_tnode_worker(struct yaffs_obj *in,
+                                       struct yaffs_tnode *tn, u32 level,
+                                       int chunk_offset)
+{
+        int i;
+        struct yaffs_dev *dev = in->my_dev;
+        int ok = 1;
+
+        if (tn) {
+                if (level > 0) {
+
+                        for (i = 0; i < YAFFS_NTNODES_INTERNAL && ok; i++) {
+                                if (tn->internal[i]) {
+                                        ok = yaffs2_checkpt_tnode_worker(in,
+                                                                         tn->
+                                                                         internal
+                                                                         [i],
+                                                                         level -
+                                                                         1,
+                                                                         (chunk_offset
+                                                                          <<
+                                                                          YAFFS_TNODES_INTERNAL_BITS)
+                                                                         + i);
+                                }
+                        }
+                } else if (level == 0) {
+                        u32 base_offset =
+                            chunk_offset << YAFFS_TNODES_LEVEL0_BITS;
+                        ok = (yaffs2_checkpt_wr
+                              (dev, &base_offset,
+                               sizeof(base_offset)) == sizeof(base_offset));
+                        if (ok)
+                                ok = (yaffs2_checkpt_wr
+                                      (dev, tn,
+                                       dev->tnode_size) == dev->tnode_size);
+                }
+        }
+
+        return ok;
+
+}
+
+static int yaffs2_wr_checkpt_tnodes(struct yaffs_obj *obj)
+{
+        u32 end_marker = ~0;
+        int ok = 1;
+
+        if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE) {
+                ok = yaffs2_checkpt_tnode_worker(obj,
+                                                 obj->variant.file_variant.top,
+                                                 obj->variant.file_variant.
+                                                 top_level, 0);
+                if (ok)
+                        ok = (yaffs2_checkpt_wr
+                              (obj->my_dev, &end_marker,
+                               sizeof(end_marker)) == sizeof(end_marker));
+        }
+
+        return ok ? 1 : 0;
+}
+
+static int yaffs2_rd_checkpt_tnodes(struct yaffs_obj *obj)
+{
+        u32 base_chunk;
+        int ok = 1;
+        struct yaffs_dev *dev = obj->my_dev;
+        struct yaffs_file_var *file_stuct_ptr = &obj->variant.file_variant;
+        struct yaffs_tnode *tn;
+        int nread = 0;
+
+        ok = (yaffs2_checkpt_rd(dev, &base_chunk, sizeof(base_chunk)) ==
+              sizeof(base_chunk));
+
+        while (ok && (~base_chunk)) {
+                nread++;
+                /* Read level 0 tnode */
+
+                tn = yaffs_get_tnode(dev);
+                if (tn) {
+                        ok = (yaffs2_checkpt_rd(dev, tn, dev->tnode_size) ==
+                              dev->tnode_size);
+                } else {
+                        ok = 0;
+                }
+
+                if (tn && ok)
+                        ok = yaffs_add_find_tnode_0(dev,
+                                                    file_stuct_ptr,
+                                                    base_chunk, tn) ? 1 : 0;
+
+                if (ok)
+                        ok = (yaffs2_checkpt_rd
+                              (dev, &base_chunk,
+                               sizeof(base_chunk)) == sizeof(base_chunk));
+
+        }
+
+        yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                "Checkpoint read tnodes %d records, last %d. ok %d",
+                nread, base_chunk, ok);
+
+        return ok ? 1 : 0;
+}
+
+static int yaffs2_wr_checkpt_objs(struct yaffs_dev *dev)
+{
+        struct yaffs_obj *obj;
+        struct yaffs_checkpt_obj cp;
+        int i;
+        int ok = 1;
+        struct list_head *lh;
+
+        /* Iterate through the objects in each hash entry,
+         * dumping them to the checkpointing stream.
+         */
+
+        for (i = 0; ok && i < YAFFS_NOBJECT_BUCKETS; i++) {
+                list_for_each(lh, &dev->obj_bucket[i].list) {
+                        if (lh) {
+                                obj =
+                                    list_entry(lh, struct yaffs_obj, hash_link);
+                                if (!obj->defered_free) {
+                                        yaffs2_obj_checkpt_obj(&cp, obj);
+                                        cp.struct_type = sizeof(cp);
+
+                                        yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                                                "Checkpoint write object %d parent %d type %d chunk %d obj addr %p",
+                                                cp.obj_id, cp.parent_id,
+                                                cp.variant_type, cp.hdr_chunk, obj);
+
+                                        ok = (yaffs2_checkpt_wr
+                                              (dev, &cp,
+                                               sizeof(cp)) == sizeof(cp));
+
+                                        if (ok
+                                            && obj->variant_type ==
+                                            YAFFS_OBJECT_TYPE_FILE)
+                                                ok = yaffs2_wr_checkpt_tnodes
+                                                    (obj);
+                                }
+                        }
+                }
+        }
+
+        /* Dump end of list */
+        memset(&cp, 0xFF, sizeof(struct yaffs_checkpt_obj));
+        cp.struct_type = sizeof(cp);
+
+        if (ok)
+                ok = (yaffs2_checkpt_wr(dev, &cp, sizeof(cp)) == sizeof(cp));
+
+        return ok ? 1 : 0;
+}
+
+static int yaffs2_rd_checkpt_objs(struct yaffs_dev *dev)
+{
+        struct yaffs_obj *obj;
+        struct yaffs_checkpt_obj cp;
+        int ok = 1;
+        int done = 0;
+        struct yaffs_obj *hard_list = NULL;
+
+        while (ok && !done) {
+                ok = (yaffs2_checkpt_rd(dev, &cp, sizeof(cp)) == sizeof(cp));
+                if (cp.struct_type != sizeof(cp)) {
+                        yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                                "struct size %d instead of %d ok %d",
+                                cp.struct_type, (int)sizeof(cp), ok);
+                        ok = 0;
+                }
+
+                yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                        "Checkpoint read object %d parent %d type %d chunk %d ",
+                        cp.obj_id, cp.parent_id, cp.variant_type,
+                        cp.hdr_chunk);
+
+                if (ok && cp.obj_id == ~0) {
+                        done = 1;
+                } else if (ok) {
+                        obj =
+                            yaffs_find_or_create_by_number(dev, cp.obj_id,
+                                                           cp.variant_type);
+                        if (obj) {
+                                ok = taffs2_checkpt_obj_to_obj(obj, &cp);
+                                if (!ok)
+                                        break;
+                                if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE) {
+                                        ok = yaffs2_rd_checkpt_tnodes(obj);
+                                } else if (obj->variant_type ==
+                                           YAFFS_OBJECT_TYPE_HARDLINK) {
+                                        obj->hard_links.next =
+                                            (struct list_head *)hard_list;
+                                        hard_list = obj;
+                                }
+                        } else {
+                                ok = 0;
+                        }
+                }
+        }
+
+        if (ok)
+                yaffs_link_fixup(dev, hard_list);
+
+        return ok ? 1 : 0;
+}
+
+static int yaffs2_wr_checkpt_sum(struct yaffs_dev *dev)
+{
+        u32 checkpt_sum;
+        int ok;
+
+        yaffs2_get_checkpt_sum(dev, &checkpt_sum);
+
+        ok = (yaffs2_checkpt_wr(dev, &checkpt_sum, sizeof(checkpt_sum)) ==
+              sizeof(checkpt_sum));
+
+        if (!ok)
+                return 0;
+
+        return 1;
+}
+
+static int yaffs2_rd_checkpt_sum(struct yaffs_dev *dev)
+{
+        u32 checkpt_sum0;
+        u32 checkpt_sum1;
+        int ok;
+
+        yaffs2_get_checkpt_sum(dev, &checkpt_sum0);
+
+        ok = (yaffs2_checkpt_rd(dev, &checkpt_sum1, sizeof(checkpt_sum1)) ==
+              sizeof(checkpt_sum1));
+
+        if (!ok)
+                return 0;
+
+        if (checkpt_sum0 != checkpt_sum1)
+                return 0;
+
+        return 1;
+}
+
+static int yaffs2_wr_checkpt_data(struct yaffs_dev *dev)
+{
+        int ok = 1;
+
+        if (!yaffs2_checkpt_required(dev)) {
+                yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                        "skipping checkpoint write");
+                ok = 0;
+        }
+
+        if (ok)
+                ok = yaffs2_checkpt_open(dev, 1);
+
+        if (ok) {
+                yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                        "write checkpoint validity");
+                ok = yaffs2_wr_checkpt_validity_marker(dev, 1);
+        }
+        if (ok) {
+                yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                        "write checkpoint device");
+                ok = yaffs2_wr_checkpt_dev(dev);
+        }
+        if (ok) {
+                yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                        "write checkpoint objects");
+                ok = yaffs2_wr_checkpt_objs(dev);
+        }
+        if (ok) {
+                yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                        "write checkpoint validity");
+                ok = yaffs2_wr_checkpt_validity_marker(dev, 0);
+        }
+
+        if (ok)
+                ok = yaffs2_wr_checkpt_sum(dev);
+
+        if (!yaffs_checkpt_close(dev))
+                ok = 0;
+
+        if (ok)
+                dev->is_checkpointed = 1;
+        else
+                dev->is_checkpointed = 0;
+
+        return dev->is_checkpointed;
+}
+
+static int yaffs2_rd_checkpt_data(struct yaffs_dev *dev)
+{
+        int ok = 1;
+
+        if (!dev->param.is_yaffs2)
+                ok = 0;
+
+        if (ok && dev->param.skip_checkpt_rd) {
+                yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                        "skipping checkpoint read");
+                ok = 0;
+        }
+
+        if (ok)
+                ok = yaffs2_checkpt_open(dev, 0); /* open for read */
+
+        if (ok) {
+                yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                        "read checkpoint validity");
+                ok = yaffs2_rd_checkpt_validity_marker(dev, 1);
+        }
+        if (ok) {
+                yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                        "read checkpoint device");
+                ok = yaffs2_rd_checkpt_dev(dev);
+        }
+        if (ok) {
+                yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                        "read checkpoint objects");
+                ok = yaffs2_rd_checkpt_objs(dev);
+        }
+        if (ok) {
+                yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                        "read checkpoint validity");
+                ok = yaffs2_rd_checkpt_validity_marker(dev, 0);
+        }
+
+        if (ok) {
+                ok = yaffs2_rd_checkpt_sum(dev);
+                yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                        "read checkpoint checksum %d", ok);
+        }
+
+        if (!yaffs_checkpt_close(dev))
+                ok = 0;
+
+        if (ok)
+                dev->is_checkpointed = 1;
+        else
+                dev->is_checkpointed = 0;
+
+        return ok ? 1 : 0;
+
+}
+
+void yaffs2_checkpt_invalidate(struct yaffs_dev *dev)
+{
+        if (dev->is_checkpointed || dev->blocks_in_checkpt > 0) {
+                dev->is_checkpointed = 0;
+                yaffs2_checkpt_invalidate_stream(dev);
+        }
+        if (dev->param.sb_dirty_fn)
+                dev->param.sb_dirty_fn(dev);
+}
+
+int yaffs_checkpoint_save(struct yaffs_dev *dev)
+{
+
+        yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                "save entry: is_checkpointed %d",
+                dev->is_checkpointed);
+
+        yaffs_verify_objects(dev);
+        yaffs_verify_blocks(dev);
+        yaffs_verify_free_chunks(dev);
+
+        if (!dev->is_checkpointed) {
+                yaffs2_checkpt_invalidate(dev);
+                yaffs2_wr_checkpt_data(dev);
+        }
+
+        yaffs_trace(YAFFS_TRACE_CHECKPOINT | YAFFS_TRACE_MOUNT,
+                "save exit: is_checkpointed %d",
+                dev->is_checkpointed);
+
+        return dev->is_checkpointed;
+}
+
+int yaffs2_checkpt_restore(struct yaffs_dev *dev)
+{
+        int retval;
+        yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                "restore entry: is_checkpointed %d",
+                dev->is_checkpointed);
+
+        retval = yaffs2_rd_checkpt_data(dev);
+
+        if (dev->is_checkpointed) {
+                yaffs_verify_objects(dev);
+                yaffs_verify_blocks(dev);
+                yaffs_verify_free_chunks(dev);
+        }
+
+        yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                "restore exit: is_checkpointed %d",
+                dev->is_checkpointed);
+
+        return retval;
+}
+
+int yaffs2_handle_hole(struct yaffs_obj *obj, loff_t new_size)
+{
+        /* if new_size > old_file_size.
+         * We're going to be writing a hole.
+         * If the hole is small then write zeros otherwise write a start of hole marker.
+         */
+
+        loff_t old_file_size;
+        int increase;
+        int small_hole;
+        int result = YAFFS_OK;
+        struct yaffs_dev *dev = NULL;
+
+        u8 *local_buffer = NULL;
+
+        int small_increase_ok = 0;
+
+        if (!obj)
+                return YAFFS_FAIL;
+
+        if (obj->variant_type != YAFFS_OBJECT_TYPE_FILE)
+                return YAFFS_FAIL;
+
+        dev = obj->my_dev;
+
+        /* Bail out if not yaffs2 mode */
+        if (!dev->param.is_yaffs2)
+                return YAFFS_OK;
+
+        old_file_size = obj->variant.file_variant.file_size;
+
+        if (new_size <= old_file_size)
+                return YAFFS_OK;
+
+        increase = new_size - old_file_size;
+
+        if (increase < YAFFS_SMALL_HOLE_THRESHOLD * dev->data_bytes_per_chunk &&
+            yaffs_check_alloc_available(dev, YAFFS_SMALL_HOLE_THRESHOLD + 1))
+                small_hole = 1;
+        else
+                small_hole = 0;
+
+        if (small_hole)
+                local_buffer = yaffs_get_temp_buffer(dev, __LINE__);
+
+        if (local_buffer) {
+                /* fill hole with zero bytes */
+                int pos = old_file_size;
+                int this_write;
+                int written;
+                memset(local_buffer, 0, dev->data_bytes_per_chunk);
+                small_increase_ok = 1;
+
+                while (increase > 0 && small_increase_ok) {
+                        this_write = increase;
+                        if (this_write > dev->data_bytes_per_chunk)
+                                this_write = dev->data_bytes_per_chunk;
+                        written =
+                            yaffs_do_file_wr(obj, local_buffer, pos, this_write,
+                                             0);
+                        if (written == this_write) {
+                                pos += this_write;
+                                increase -= this_write;
+                        } else {
+                                small_increase_ok = 0;
+                        }
+                }
+
+                yaffs_release_temp_buffer(dev, local_buffer, __LINE__);
+
+                /* If we were out of space then reverse any chunks we've added */
+                if (!small_increase_ok)
+                        yaffs_resize_file_down(obj, old_file_size);
+        }
+
+        if (!small_increase_ok &&
+            obj->parent &&
+            obj->parent->obj_id != YAFFS_OBJECTID_UNLINKED &&
+            obj->parent->obj_id != YAFFS_OBJECTID_DELETED) {
+                /* Write a hole start header with the old file size */
+                yaffs_update_oh(obj, NULL, 0, 1, 0, NULL);
+        }
+
+        return result;
+
+}
+
+struct yaffs_block_index {
+        int seq;
+        int block;
+};
+
+static int yaffs2_ybicmp(const void *a, const void *b)
+{
+        int aseq = ((struct yaffs_block_index *)a)->seq;
+        int bseq = ((struct yaffs_block_index *)b)->seq;
+        int ablock = ((struct yaffs_block_index *)a)->block;
+        int bblock = ((struct yaffs_block_index *)b)->block;
+        if (aseq == bseq)
+                return ablock - bblock;
+        else
+                return aseq - bseq;
+}
+
+int yaffs2_scan_backwards(struct yaffs_dev *dev)
+{
+        struct yaffs_ext_tags tags;
+        int blk;
+        int block_iter;
+        int start_iter;
+        int end_iter;
+        int n_to_scan = 0;
+
+        int chunk;
+        int result;
+        int c;
+        int deleted;
+        enum yaffs_block_state state;
+        struct yaffs_obj *hard_list = NULL;
+        struct yaffs_block_info *bi;
+        u32 seq_number;
+        struct yaffs_obj_hdr *oh;
+        struct yaffs_obj *in;
+        struct yaffs_obj *parent;
+        int n_blocks = dev->internal_end_block - dev->internal_start_block + 1;
+        int is_unlinked;
+        u8 *chunk_data;
+
+        int file_size;
+        int is_shrink;
+        int found_chunks;
+        int equiv_id;
+        int alloc_failed = 0;
+
+        struct yaffs_block_index *block_index = NULL;
+        int alt_block_index = 0;
+
+        yaffs_trace(YAFFS_TRACE_SCAN,
+                "yaffs2_scan_backwards starts  intstartblk %d intendblk %d...",
+                dev->internal_start_block, dev->internal_end_block);
+
+        dev->seq_number = YAFFS_LOWEST_SEQUENCE_NUMBER;
+
+        block_index = kmalloc(n_blocks * sizeof(struct yaffs_block_index),
+                        GFP_NOFS);
+
+        if (!block_index) {
+                block_index =
+                    vmalloc(n_blocks * sizeof(struct yaffs_block_index));
+                alt_block_index = 1;
+        }
+
+        if (!block_index) {
+                yaffs_trace(YAFFS_TRACE_SCAN,
+                        "yaffs2_scan_backwards() could not allocate block index!"
+                        );
+                return YAFFS_FAIL;
+        }
+
+        dev->blocks_in_checkpt = 0;
+
+        chunk_data = yaffs_get_temp_buffer(dev, __LINE__);
+
+        /* Scan all the blocks to determine their state */
+        bi = dev->block_info;
+        for (blk = dev->internal_start_block; blk <= dev->internal_end_block;
+             blk++) {
+                yaffs_clear_chunk_bits(dev, blk);
+                bi->pages_in_use = 0;
+                bi->soft_del_pages = 0;
+
+                yaffs_query_init_block_state(dev, blk, &state, &seq_number);
+
+                bi->block_state = state;
+                bi->seq_number = seq_number;
+
+                if (bi->seq_number == YAFFS_SEQUENCE_CHECKPOINT_DATA)
+                        bi->block_state = state = YAFFS_BLOCK_STATE_CHECKPOINT;
+                if (bi->seq_number == YAFFS_SEQUENCE_BAD_BLOCK)
+                        bi->block_state = state = YAFFS_BLOCK_STATE_DEAD;
+
+                yaffs_trace(YAFFS_TRACE_SCAN_DEBUG,
+                        "Block scanning block %d state %d seq %d",
+                        blk, state, seq_number);
+
+                if (state == YAFFS_BLOCK_STATE_CHECKPOINT) {
+                        dev->blocks_in_checkpt++;
+
+                } else if (state == YAFFS_BLOCK_STATE_DEAD) {
+                        yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
+                                "block %d is bad", blk);
+                } else if (state == YAFFS_BLOCK_STATE_EMPTY) {
+                        yaffs_trace(YAFFS_TRACE_SCAN_DEBUG, "Block empty ");
+                        dev->n_erased_blocks++;
+                        dev->n_free_chunks += dev->param.chunks_per_block;
+                } else if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
+
+                        /* Determine the highest sequence number */
+                        if (seq_number >= YAFFS_LOWEST_SEQUENCE_NUMBER &&
+                            seq_number < YAFFS_HIGHEST_SEQUENCE_NUMBER) {
+
+                                block_index[n_to_scan].seq = seq_number;
+                                block_index[n_to_scan].block = blk;
+
+                                n_to_scan++;
+
+                                if (seq_number >= dev->seq_number)
+                                        dev->seq_number = seq_number;
+                        } else {
+                                /* TODO: Nasty sequence number! */
+                                yaffs_trace(YAFFS_TRACE_SCAN,
+                                        "Block scanning block %d has bad sequence number %d",
+                                        blk, seq_number);
+
+                        }
+                }
+                bi++;
+        }
+
+        yaffs_trace(YAFFS_TRACE_SCAN, "%d blocks to be sorted...", n_to_scan);
+
+        cond_resched();
+
+        /* Sort the blocks by sequence number */
+        sort(block_index, n_to_scan, sizeof(struct yaffs_block_index),
+                   yaffs2_ybicmp, NULL);
+
+        cond_resched();
+
+        yaffs_trace(YAFFS_TRACE_SCAN, "...done");
+
+        /* Now scan the blocks looking at the data. */
+        start_iter = 0;
+        end_iter = n_to_scan - 1;
+        yaffs_trace(YAFFS_TRACE_SCAN_DEBUG, "%d blocks to scan", n_to_scan);
+
+        /* For each block.... backwards */
+        for (block_iter = end_iter; !alloc_failed && block_iter >= start_iter;
+             block_iter--) {
+                /* Cooperative multitasking! This loop can run for so
+                   long that watchdog timers expire. */
+                cond_resched();
+
+                /* get the block to scan in the correct order */
+                blk = block_index[block_iter].block;
+
+                bi = yaffs_get_block_info(dev, blk);
+
+                state = bi->block_state;
+
+                deleted = 0;
+
+                /* For each chunk in each block that needs scanning.... */
+                found_chunks = 0;
+                for (c = dev->param.chunks_per_block - 1;
+                     !alloc_failed && c >= 0 &&
+                     (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING ||
+                      state == YAFFS_BLOCK_STATE_ALLOCATING); c--) {
+                        /* Scan backwards...
+                         * Read the tags and decide what to do
+                         */
+
+                        chunk = blk * dev->param.chunks_per_block + c;
+
+                        result = yaffs_rd_chunk_tags_nand(dev, chunk, NULL,
+                                                          &tags);
+
+                        /* Let's have a good look at this chunk... */
+
+                        if (!tags.chunk_used) {
+                                /* An unassigned chunk in the block.
+                                 * If there are used chunks after this one, then
+                                 * it is a chunk that was skipped due to failing the erased
+                                 * check. Just skip it so that it can be deleted.
+                                 * But, more typically, We get here when this is an unallocated
+                                 * chunk and his means that either the block is empty or
+                                 * this is the one being allocated from
+                                 */
+
+                                if (found_chunks) {
+                                        /* This is a chunk that was skipped due to failing the erased check */
+                                } else if (c == 0) {
+                                        /* We're looking at the first chunk in the block so the block is unused */
+                                        state = YAFFS_BLOCK_STATE_EMPTY;
+                                        dev->n_erased_blocks++;
+                                } else {
+                                        if (state ==
+                                            YAFFS_BLOCK_STATE_NEEDS_SCANNING
+                                            || state ==
+                                            YAFFS_BLOCK_STATE_ALLOCATING) {
+                                                if (dev->seq_number ==
+                                                    bi->seq_number) {
+                                                        /* this is the block being allocated from */
+
+                                                        yaffs_trace(YAFFS_TRACE_SCAN,
+                                                                " Allocating from %d %d",
+                                                                blk, c);
+
+                                                        state =
+                                                            YAFFS_BLOCK_STATE_ALLOCATING;
+                                                        dev->alloc_block = blk;
+                                                        dev->alloc_page = c;
+                                                        dev->
+                                                            alloc_block_finder =
+                                                            blk;
+                                                } else {
+                                                        /* This is a partially written block that is not
+                                                         * the current allocation block.
+                                                         */
+
+                                                        yaffs_trace(YAFFS_TRACE_SCAN,
+                                                                "Partially written block %d detected",
+                                                                blk);
+                                                }
+                                        }
+                                }
+
+                                dev->n_free_chunks++;
+
+                        } else if (tags.ecc_result == YAFFS_ECC_RESULT_UNFIXED) {
+                                yaffs_trace(YAFFS_TRACE_SCAN,
+                                        " Unfixed ECC in chunk(%d:%d), chunk ignored",
+                                        blk, c);
+
+                                dev->n_free_chunks++;
+
+                        } else if (tags.obj_id > YAFFS_MAX_OBJECT_ID ||
+                                   tags.chunk_id > YAFFS_MAX_CHUNK_ID ||
+                                   (tags.chunk_id > 0
+                                    && tags.n_bytes > dev->data_bytes_per_chunk)
+                                   || tags.seq_number != bi->seq_number) {
+                                yaffs_trace(YAFFS_TRACE_SCAN,
+                                        "Chunk (%d:%d) with bad tags:obj = %d, chunk_id = %d, n_bytes = %d, ignored",
+                                        blk, c, tags.obj_id,
+                                        tags.chunk_id, tags.n_bytes);
+
+                                dev->n_free_chunks++;
+
+                        } else if (tags.chunk_id > 0) {
+                                /* chunk_id > 0 so it is a data chunk... */
+                                unsigned int endpos;
+                                u32 chunk_base =
+                                    (tags.chunk_id -
+                                     1) * dev->data_bytes_per_chunk;
+
+                                found_chunks = 1;
+
+                                yaffs_set_chunk_bit(dev, blk, c);
+                                bi->pages_in_use++;
+
+                                in = yaffs_find_or_create_by_number(dev,
+                                                                    tags.obj_id,
+                                                                    YAFFS_OBJECT_TYPE_FILE);
+                                if (!in) {
+                                        /* Out of memory */
+                                        alloc_failed = 1;
+                                }
+
+                                if (in &&
+                                    in->variant_type == YAFFS_OBJECT_TYPE_FILE
+                                    && chunk_base <
+                                    in->variant.file_variant.shrink_size) {
+                                        /* This has not been invalidated by a resize */
+                                        if (!yaffs_put_chunk_in_file
+                                            (in, tags.chunk_id, chunk, -1)) {
+                                                alloc_failed = 1;
+                                        }
+
+                                        /* File size is calculated by looking at the data chunks if we have not
+                                         * seen an object header yet. Stop this practice once we find an object header.
+                                         */
+                                        endpos = chunk_base + tags.n_bytes;
+
+                                        if (!in->valid &&       /* have not got an object header yet */
+                                            in->variant.file_variant.
+                                            scanned_size < endpos) {
+                                                in->variant.file_variant.
+                                                    scanned_size = endpos;
+                                                in->variant.file_variant.
+                                                    file_size = endpos;
+                                        }
+
+                                } else if (in) {
+                                        /* This chunk has been invalidated by a resize, or a past file deletion
+                                         * so delete the chunk*/
+                                        yaffs_chunk_del(dev, chunk, 1,
+                                                        __LINE__);
+
+                                }
+                        } else {
+                                /* chunk_id == 0, so it is an ObjectHeader.
+                                 * Thus, we read in the object header and make the object
+                                 */
+                                found_chunks = 1;
+
+                                yaffs_set_chunk_bit(dev, blk, c);
+                                bi->pages_in_use++;
+
+                                oh = NULL;
+                                in = NULL;
+
+                                if (tags.extra_available) {
+                                        in = yaffs_find_or_create_by_number(dev,
+                                                                            tags.
+                                                                            obj_id,
+                                                                            tags.
+                                                                            extra_obj_type);
+                                        if (!in)
+                                                alloc_failed = 1;
+                                }
+
+                                if (!in ||
+                                    (!in->valid && dev->param.disable_lazy_load)
+                                    || tags.extra_shadows || (!in->valid
+                                                              && (tags.obj_id ==
+                                                                  YAFFS_OBJECTID_ROOT
+                                                                  || tags.
+                                                                  obj_id ==
+                                                                  YAFFS_OBJECTID_LOSTNFOUND)))
+                                {
+
+                                        /* If we don't have  valid info then we need to read the chunk
+                                         * TODO In future we can probably defer reading the chunk and
+                                         * living with invalid data until needed.
+                                         */
+
+                                        result = yaffs_rd_chunk_tags_nand(dev,
+                                                                          chunk,
+                                                                          chunk_data,
+                                                                          NULL);
+
+                                        oh = (struct yaffs_obj_hdr *)chunk_data;
+
+                                        if (dev->param.inband_tags) {
+                                                /* Fix up the header if they got corrupted by inband tags */
+                                                oh->shadows_obj =
+                                                    oh->inband_shadowed_obj_id;
+                                                oh->is_shrink =
+                                                    oh->inband_is_shrink;
+                                        }
+
+                                        if (!in) {
+                                                in = yaffs_find_or_create_by_number(dev, tags.obj_id, oh->type);
+                                                if (!in)
+                                                        alloc_failed = 1;
+                                        }
+
+                                }
+
+                                if (!in) {
+                                        /* TODO Hoosterman we have a problem! */
+                                        yaffs_trace(YAFFS_TRACE_ERROR,
+                                                "yaffs tragedy: Could not make object for object  %d at chunk %d during scan",
+                                                tags.obj_id, chunk);
+                                        continue;
+                                }
+
+                                if (in->valid) {
+                                        /* We have already filled this one.
+                                         * We have a duplicate that will be discarded, but
+                                         * we first have to suck out resize info if it is a file.
+                                         */
+
+                                        if ((in->variant_type ==
+                                             YAFFS_OBJECT_TYPE_FILE) && ((oh
+                                                                          &&
+                                                                          oh->
+                                                                          type
+                                                                          ==
+                                                                          YAFFS_OBJECT_TYPE_FILE)
+                                                                         ||
+                                                                         (tags.
+                                                                          extra_available
+                                                                          &&
+                                                                          tags.
+                                                                          extra_obj_type
+                                                                          ==
+                                                                          YAFFS_OBJECT_TYPE_FILE)))
+                                        {
+                                                u32 this_size =
+                                                    (oh) ? oh->
+                                                    file_size :
+                                                    tags.extra_length;
+                                                u32 parent_obj_id =
+                                                    (oh) ? oh->parent_obj_id :
+                                                    tags.extra_parent_id;
+
+                                                is_shrink =
+                                                    (oh) ? oh->
+                                                    is_shrink :
+                                                    tags.extra_is_shrink;
+
+                                                /* If it is deleted (unlinked at start also means deleted)
+                                                 * we treat the file size as being zeroed at this point.
+                                                 */
+                                                if (parent_obj_id ==
+                                                    YAFFS_OBJECTID_DELETED
+                                                    || parent_obj_id ==
+                                                    YAFFS_OBJECTID_UNLINKED) {
+                                                        this_size = 0;
+                                                        is_shrink = 1;
+                                                }
+
+                                                if (is_shrink
+                                                    && in->variant.file_variant.
+                                                    shrink_size > this_size)
+                                                        in->variant.
+                                                            file_variant.
+                                                            shrink_size =
+                                                            this_size;
+
+                                                if (is_shrink)
+                                                        bi->has_shrink_hdr = 1;
+
+                                        }
+                                        /* Use existing - destroy this one. */
+                                        yaffs_chunk_del(dev, chunk, 1,
+                                                        __LINE__);
+
+                                }
+
+                                if (!in->valid && in->variant_type !=
+                                    (oh ? oh->type : tags.extra_obj_type))
+                                        yaffs_trace(YAFFS_TRACE_ERROR,
+                                                "yaffs tragedy: Bad object type, %d != %d, for object %d at chunk %d during scan",
+                                                oh ?
+                                                oh->type : tags.extra_obj_type,
+                                                in->variant_type, tags.obj_id,
+                                                chunk);
+
+                                if (!in->valid &&
+                                    (tags.obj_id == YAFFS_OBJECTID_ROOT ||
+                                     tags.obj_id ==
+                                     YAFFS_OBJECTID_LOSTNFOUND)) {
+                                        /* We only load some info, don't fiddle with directory structure */
+                                        in->valid = 1;
+
+                                        if (oh) {
+
+                                                in->yst_mode = oh->yst_mode;
+                                                yaffs_load_attribs(in, oh);
+                                                in->lazy_loaded = 0;
+                                        } else {
+                                                in->lazy_loaded = 1;
+                                        }
+                                        in->hdr_chunk = chunk;
+
+                                } else if (!in->valid) {
+                                        /* we need to load this info */
+
+                                        in->valid = 1;
+                                        in->hdr_chunk = chunk;
+
+                                        if (oh) {
+                                                in->variant_type = oh->type;
+
+                                                in->yst_mode = oh->yst_mode;
+                                                yaffs_load_attribs(in, oh);
+
+                                                if (oh->shadows_obj > 0)
+                                                        yaffs_handle_shadowed_obj
+                                                            (dev,
+                                                             oh->shadows_obj,
+                                                             1);
+
+                                                yaffs_set_obj_name_from_oh(in,
+                                                                           oh);
+                                                parent =
+                                                    yaffs_find_or_create_by_number
+                                                    (dev, oh->parent_obj_id,
+                                                     YAFFS_OBJECT_TYPE_DIRECTORY);
+
+                                                file_size = oh->file_size;
+                                                is_shrink = oh->is_shrink;
+                                                equiv_id = oh->equiv_id;
+
+                                        } else {
+                                                in->variant_type =
+                                                    tags.extra_obj_type;
+                                                parent =
+                                                    yaffs_find_or_create_by_number
+                                                    (dev, tags.extra_parent_id,
+                                                     YAFFS_OBJECT_TYPE_DIRECTORY);
+                                                file_size = tags.extra_length;
+                                                is_shrink =
+                                                    tags.extra_is_shrink;
+                                                equiv_id = tags.extra_equiv_id;
+                                                in->lazy_loaded = 1;
+
+                                        }
+                                        in->dirty = 0;
+
+                                        if (!parent)
+                                                alloc_failed = 1;
+
+                                        /* directory stuff...
+                                         * hook up to parent
+                                         */
+
+                                        if (parent && parent->variant_type ==
+                                            YAFFS_OBJECT_TYPE_UNKNOWN) {
+                                                /* Set up as a directory */
+                                                parent->variant_type =
+                                                    YAFFS_OBJECT_TYPE_DIRECTORY;
+                                                INIT_LIST_HEAD(&parent->
+                                                               variant.dir_variant.children);
+                                        } else if (!parent
+                                                   || parent->variant_type !=
+                                                   YAFFS_OBJECT_TYPE_DIRECTORY) {
+                                                /* Hoosterman, another problem....
+                                                 * We're trying to use a non-directory as a directory
+                                                 */
+
+                                                yaffs_trace(YAFFS_TRACE_ERROR,
+                                                        "yaffs tragedy: attempting to use non-directory as a directory in scan. Put in lost+found."
+                                                        );
+                                                parent = dev->lost_n_found;
+                                        }
+
+                                        yaffs_add_obj_to_dir(parent, in);
+
+                                        is_unlinked = (parent == dev->del_dir)
+                                            || (parent == dev->unlinked_dir);
+
+                                        if (is_shrink) {
+                                                /* Mark the block as having a shrink header */
+                                                bi->has_shrink_hdr = 1;
+                                        }
+
+                                        /* Note re hardlinks.
+                                         * Since we might scan a hardlink before its equivalent object is scanned
+                                         * we put them all in a list.
+                                         * After scanning is complete, we should have all the objects, so we run
+                                         * through this list and fix up all the chains.
+                                         */
+
+                                        switch (in->variant_type) {
+                                        case YAFFS_OBJECT_TYPE_UNKNOWN:
+                                                /* Todo got a problem */
+                                                break;
+                                        case YAFFS_OBJECT_TYPE_FILE:
+
+                                                if (in->variant.
+                                                    file_variant.scanned_size <
+                                                    file_size) {
+                                                        /* This covers the case where the file size is greater
+                                                         * than where the data is
+                                                         * This will happen if the file is resized to be larger
+                                                         * than its current data extents.
+                                                         */
+                                                        in->variant.
+                                                            file_variant.
+                                                            file_size =
+                                                            file_size;
+                                                        in->variant.
+                                                            file_variant.
+                                                            scanned_size =
+                                                            file_size;
+                                                }
+
+                                                if (in->variant.file_variant.
+                                                    shrink_size > file_size)
+                                                        in->variant.
+                                                            file_variant.
+                                                            shrink_size =
+                                                            file_size;
+
+                                                break;
+                                        case YAFFS_OBJECT_TYPE_HARDLINK:
+                                                if (!is_unlinked) {
+                                                        in->variant.
+                                                            hardlink_variant.
+                                                            equiv_id = equiv_id;
+                                                        in->hard_links.next =
+                                                            (struct list_head *)
+                                                            hard_list;
+                                                        hard_list = in;
+                                                }
+                                                break;
+                                        case YAFFS_OBJECT_TYPE_DIRECTORY:
+                                                /* Do nothing */
+                                                break;
+                                        case YAFFS_OBJECT_TYPE_SPECIAL:
+                                                /* Do nothing */
+                                                break;
+                                        case YAFFS_OBJECT_TYPE_SYMLINK:
+                                                if (oh) {
+                                                        in->variant.
+                                                            symlink_variant.
+                                                            alias =
+                                                            yaffs_clone_str(oh->
+                                                                            alias);
+                                                        if (!in->variant.
+                                                            symlink_variant.
+                                                            alias)
+                                                                alloc_failed =
+                                                                    1;
+                                                }
+                                                break;
+                                        }
+
+                                }
+
+                        }
+
+                }               /* End of scanning for each chunk */
+
+                if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
+                        /* If we got this far while scanning, then the block is fully allocated. */
+                        state = YAFFS_BLOCK_STATE_FULL;
+                }
+
+                bi->block_state = state;
+
+                /* Now let's see if it was dirty */
+                if (bi->pages_in_use == 0 &&
+                    !bi->has_shrink_hdr &&
+                    bi->block_state == YAFFS_BLOCK_STATE_FULL) {
+                        yaffs_block_became_dirty(dev, blk);
+                }
+
+        }
+
+        yaffs_skip_rest_of_block(dev);
+
+        if (alt_block_index)
+                vfree(block_index);
+        else
+                kfree(block_index);
+
+        /* Ok, we've done all the scanning.
+         * Fix up the hard link chains.
+         * We should now have scanned all the objects, now it's time to add these
+         * hardlinks.
+         */
+        yaffs_link_fixup(dev, hard_list);
+
+        yaffs_release_temp_buffer(dev, chunk_data, __LINE__);
+
+        if (alloc_failed)
+                return YAFFS_FAIL;
+
+        yaffs_trace(YAFFS_TRACE_SCAN, "yaffs2_scan_backwards ends");
+
+        return YAFFS_OK;
+}
diff --git a/fs/yaffs2/yaffs_yaffs2.h b/fs/yaffs2/yaffs_yaffs2.h
new file mode 100644
index 00000000000..e1a9287fc50
--- /dev/null
+++ b/fs/yaffs2/yaffs_yaffs2.h
@@ -0,0 +1,39 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_YAFFS2_H__
+#define __YAFFS_YAFFS2_H__
+
+#include "yaffs_guts.h"
+
+void yaffs_calc_oldest_dirty_seq(struct yaffs_dev *dev);
+void yaffs2_find_oldest_dirty_seq(struct yaffs_dev *dev);
+void yaffs2_clear_oldest_dirty_seq(struct yaffs_dev *dev,
+                                   struct yaffs_block_info *bi);
+void yaffs2_update_oldest_dirty_seq(struct yaffs_dev *dev, unsigned block_no,
+                                    struct yaffs_block_info *bi);
+int yaffs_block_ok_for_gc(struct yaffs_dev *dev, struct yaffs_block_info *bi);
+u32 yaffs2_find_refresh_block(struct yaffs_dev *dev);
+int yaffs2_checkpt_required(struct yaffs_dev *dev);
+int yaffs_calc_checkpt_blocks_required(struct yaffs_dev *dev);
+
+void yaffs2_checkpt_invalidate(struct yaffs_dev *dev);
+int yaffs2_checkpt_save(struct yaffs_dev *dev);
+int yaffs2_checkpt_restore(struct yaffs_dev *dev);
+
+int yaffs2_handle_hole(struct yaffs_obj *obj, loff_t new_size);
+int yaffs2_scan_backwards(struct yaffs_dev *dev);
+
+#endif
diff --git a/fs/yaffs2/yportenv.h b/fs/yaffs2/yportenv.h
new file mode 100644
index 00000000000..8183425448c
--- /dev/null
+++ b/fs/yaffs2/yportenv.h
@@ -0,0 +1,70 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2010 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YPORTENV_LINUX_H__
+#define __YPORTENV_LINUX_H__
+
+#include <linux/version.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/xattr.h>
+#include <linux/list.h>
+#include <linux/types.h>
+#include <linux/fs.h>
+#include <linux/stat.h>
+#include <linux/sort.h>
+#include <linux/bitops.h>
+
+#define YCHAR char
+#define YUCHAR unsigned char
+#define _Y(x)     x
+
+#define YAFFS_LOSTNFOUND_NAME           "lost+found"
+#define YAFFS_LOSTNFOUND_PREFIX         "obj"
+
+
+#define YAFFS_ROOT_MODE                 0755
+#define YAFFS_LOSTNFOUND_MODE           0700
+
+#define Y_CURRENT_TIME CURRENT_TIME.tv_sec
+#define Y_TIME_CONVERT(x) (x).tv_sec
+
+#define compile_time_assertion(assertion) \
+        ({ int x = __builtin_choose_expr(assertion, 0, (void)0); (void) x; })
+
+
+#ifndef Y_DUMP_STACK
+#define Y_DUMP_STACK() dump_stack()
+#endif
+
+#define yaffs_trace(msk, fmt, ...) do { \
+        if(yaffs_trace_mask & (msk)) \
+                printk(KERN_DEBUG "yaffs: " fmt "\n", ##__VA_ARGS__); \
+} while(0)
+
+#ifndef YBUG
+#define YBUG() do {\
+        yaffs_trace(YAFFS_TRACE_BUG,\
+                "bug " __FILE__ " %d",\
+                __LINE__);\
+        Y_DUMP_STACK();\
+} while (0)
+#endif
+
+#endif