Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (61 commits)
  ext4: Documention update for new ordered mode and delayed allocation
  ext4: do not set extents feature from the kernel
  ext4: Don't allow nonextenst mount option for large filesystem
  ext4: Enable delalloc by default.
  ext4: delayed allocation i_blocks fix for stat
  ext4: fix delalloc i_disksize early update issue
  ext4: Handle page without buffers in ext4_*_writepage()
  ext4: Add ordered mode support for delalloc
  ext4: Invert lock ordering of page_lock and transaction start in delalloc
  mm: Add range_cont mode for writeback
  ext4: delayed allocation ENOSPC handling
  percpu_counter: new function percpu_counter_sum_and_set
  ext4: Add delayed allocation support in data=writeback mode
  vfs: add hooks for ext4's delayed allocation support
  jbd2: Remove data=ordered mode support using jbd buffer heads
  ext4: Use new framework for data=ordered mode in JBD2
  jbd2: Implement data=ordered mode handling via inodes
  vfs: export filemap_fdatawrite_range()
  ext4: Fix lock inversion in ext4_ext_truncate()
  ext4: Invert the locking order of page_lock and transaction start
  ...

26 files changed, 2646 insertions, 965 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index 0f51c0f7c266..5fa1512cd9a2 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1691,11 +1691,13 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
                          */
                         clear_buffer_dirty(bh);
                         set_buffer_uptodate(bh);
-                } else if (!buffer_mapped(bh) && buffer_dirty(bh)) {
+                } else if ((!buffer_mapped(bh) || buffer_delay(bh)) &&
+                           buffer_dirty(bh)) {
                         WARN_ON(bh->b_size != blocksize);
                         err = get_block(inode, block, bh, 1);
                         if (err)
                                 goto recover;
+                        clear_buffer_delay(bh);
                         if (buffer_new(bh)) {
                                 /* blockdev mappings never come here */
                                 clear_buffer_new(bh);
@@ -1774,7 +1776,8 @@ recover:
         bh = head;
         /* Recovery: lock and submit the mapped buffers */
         do {
-                if (buffer_mapped(bh) && buffer_dirty(bh)) {
+                if (buffer_mapped(bh) && buffer_dirty(bh) &&
+                    !buffer_delay(bh)) {
                         lock_buffer(bh);
                         mark_buffer_async_write(bh);
                 } else {
@@ -2061,6 +2064,7 @@ int generic_write_end(struct file *file, struct address_space *mapping,
                         struct page *page, void *fsdata)
 {
         struct inode *inode = mapping->host;
+        int i_size_changed = 0;
 
         copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
 
@@ -2073,12 +2077,21 @@ int generic_write_end(struct file *file, struct address_space *mapping,
          */
         if (pos+copied > inode->i_size) {
                 i_size_write(inode, pos+copied);
-                mark_inode_dirty(inode);
+                i_size_changed = 1;
         }
 
         unlock_page(page);
         page_cache_release(page);
 
+        /*
+         * Don't mark the inode dirty under page lock. First, it unnecessarily
+         * makes the holding time of page lock longer. Second, it forces lock
+         * ordering of page lock and transaction start for journaling
+         * filesystems.
+         */
+        if (i_size_changed)
+                mark_inode_dirty(inode);
+
         return copied;
 }
 EXPORT_SYMBOL(generic_write_end);
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 9cc80b9cc8d8..495ab21b9832 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -47,7 +47,7 @@ static int ext4_block_in_group(struct super_block *sb, ext4_fsblk_t block,
                         ext4_group_t block_group)
 {
         ext4_group_t actual_group;
-        ext4_get_group_no_and_offset(sb, block, &actual_group, 0);
+        ext4_get_group_no_and_offset(sb, block, &actual_group, NULL);
         if (actual_group == block_group)
                 return 1;
         return 0;
@@ -121,12 +121,7 @@ unsigned ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh,
                                 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks);
                 }
         } else { /* For META_BG_BLOCK_GROUPS */
-                int group_rel = (block_group -
-                                 le32_to_cpu(sbi->s_es->s_first_meta_bg)) %
-                                EXT4_DESC_PER_BLOCK(sb);
-                if (group_rel == 0 || group_rel == 1 ||
-                    (group_rel == EXT4_DESC_PER_BLOCK(sb) - 1))
-                        bit_max += 1;
+                bit_max += ext4_bg_num_gdb(sb, block_group);
         }
 
         if (block_group == sbi->s_groups_count - 1) {
@@ -295,7 +290,7 @@ err_out:
         return 0;
 }
 /**
- * read_block_bitmap()
+ * ext4_read_block_bitmap()
  * @sb:                 super block
  * @block_group:        given block group
  *
@@ -305,7 +300,7 @@ err_out:
  * Return buffer_head on success or NULL in case of failure.
  */
 struct buffer_head *
-read_block_bitmap(struct super_block *sb, ext4_group_t block_group)
+ext4_read_block_bitmap(struct super_block *sb, ext4_group_t block_group)
 {
         struct ext4_group_desc * desc;
         struct buffer_head * bh = NULL;
@@ -409,8 +404,7 @@ restart:
                 prev = rsv;
         }
         printk("Window map complete.\n");
-        if (bad)
-                BUG();
+        BUG_ON(bad);
 }
 #define rsv_window_dump(root, verbose) \
         __rsv_window_dump((root), (verbose), __func__)
@@ -694,7 +688,7 @@ do_more:
                 count -= overflow;
         }
         brelse(bitmap_bh);
-        bitmap_bh = read_block_bitmap(sb, block_group);
+        bitmap_bh = ext4_read_block_bitmap(sb, block_group);
         if (!bitmap_bh)
                 goto error_return;
         desc = ext4_get_group_desc (sb, block_group, &gd_bh);
@@ -810,6 +804,13 @@ do_more:
         spin_unlock(sb_bgl_lock(sbi, block_group));
         percpu_counter_add(&sbi->s_freeblocks_counter, count);
 
+        if (sbi->s_log_groups_per_flex) {
+                ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
+                spin_lock(sb_bgl_lock(sbi, flex_group));
+                sbi->s_flex_groups[flex_group].free_blocks += count;
+                spin_unlock(sb_bgl_lock(sbi, flex_group));
+        }
+
         /* We dirtied the bitmap block */
         BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
         err = ext4_journal_dirty_metadata(handle, bitmap_bh);
@@ -1598,23 +1599,35 @@ out:
 
 /**
  * ext4_has_free_blocks()
- * @sbi:                in-core super block structure.
+ * @sbi:        in-core super block structure.
+ * @nblocks:    number of neeed blocks
  *
- * Check if filesystem has at least 1 free block available for allocation.
+ * Check if filesystem has free blocks available for allocation.
+ * Return the number of blocks avaible for allocation for this request
+ * On success, return nblocks
  */
-static int ext4_has_free_blocks(struct ext4_sb_info *sbi)
+ext4_fsblk_t ext4_has_free_blocks(struct ext4_sb_info *sbi,
+                                                ext4_fsblk_t nblocks)
 {
-        ext4_fsblk_t free_blocks, root_blocks;
+        ext4_fsblk_t free_blocks;
+        ext4_fsblk_t root_blocks = 0;
 
         free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
-        root_blocks = ext4_r_blocks_count(sbi->s_es);
-        if (free_blocks < root_blocks + 1 && !capable(CAP_SYS_RESOURCE) &&
+
+        if (!capable(CAP_SYS_RESOURCE) &&
                 sbi->s_resuid != current->fsuid &&
-                (sbi->s_resgid == 0 || !in_group_p (sbi->s_resgid))) {
-                return 0;
-        }
-        return 1;
-}
+                (sbi->s_resgid == 0 || !in_group_p(sbi->s_resgid)))
+                root_blocks = ext4_r_blocks_count(sbi->s_es);
+#ifdef CONFIG_SMP
+        if (free_blocks - root_blocks < FBC_BATCH)
+                free_blocks =
+                        percpu_counter_sum_and_set(&sbi->s_freeblocks_counter);
+#endif
+        if (free_blocks - root_blocks < nblocks)
+                return free_blocks - root_blocks;
+        return nblocks;
+ }
+
 
 /**
  * ext4_should_retry_alloc()
@@ -1630,7 +1643,7 @@ static int ext4_has_free_blocks(struct ext4_sb_info *sbi)
  */
 int ext4_should_retry_alloc(struct super_block *sb, int *retries)
 {
-        if (!ext4_has_free_blocks(EXT4_SB(sb)) || (*retries)++ > 3)
+        if (!ext4_has_free_blocks(EXT4_SB(sb), 1) || (*retries)++ > 3)
                 return 0;
 
         jbd_debug(1, "%s: retrying operation after ENOSPC\n", sb->s_id);
@@ -1639,20 +1652,24 @@ int ext4_should_retry_alloc(struct super_block *sb, int *retries)
 }
 
 /**
- * ext4_new_blocks_old() -- core block(s) allocation function
+ * ext4_old_new_blocks() -- core block bitmap based block allocation function
+ *
  * @handle:             handle to this transaction
  * @inode:              file inode
  * @goal:               given target block(filesystem wide)
  * @count:              target number of blocks to allocate
  * @errp:               error code
  *
- * ext4_new_blocks uses a goal block to assist allocation.  It tries to
- * allocate block(s) from the block group contains the goal block first. If that
- * fails, it will try to allocate block(s) from other block groups without
- * any specific goal block.
+ * ext4_old_new_blocks uses a goal block to assist allocation and look up
+ * the block bitmap directly to do block allocation.  It tries to
+ * allocate block(s) from the block group contains the goal block first. If
+ * that fails, it will try to allocate block(s) from other block groups
+ * without any specific goal block.
+ *
+ * This function is called when -o nomballoc mount option is enabled
  *
  */
-ext4_fsblk_t ext4_new_blocks_old(handle_t *handle, struct inode *inode,
+ext4_fsblk_t ext4_old_new_blocks(handle_t *handle, struct inode *inode,
                         ext4_fsblk_t goal, unsigned long *count, int *errp)
 {
         struct buffer_head *bitmap_bh = NULL;
@@ -1676,13 +1693,26 @@ ext4_fsblk_t ext4_new_blocks_old(handle_t *handle, struct inode *inode,
         ext4_group_t ngroups;
         unsigned long num = *count;
 
-        *errp = -ENOSPC;
         sb = inode->i_sb;
         if (!sb) {
+                *errp = -ENODEV;
                 printk("ext4_new_block: nonexistent device");
                 return 0;
         }
 
+        sbi = EXT4_SB(sb);
+        if (!EXT4_I(inode)->i_delalloc_reserved_flag) {
+                /*
+                 * With delalloc we already reserved the blocks
+                 */
+                *count = ext4_has_free_blocks(sbi, *count);
+        }
+        if (*count == 0) {
+                *errp = -ENOSPC;
+                return 0;       /*return with ENOSPC error */
+        }
+        num = *count;
+
         /*
          * Check quota for allocation of this block.
          */
@@ -1706,11 +1736,6 @@ ext4_fsblk_t ext4_new_blocks_old(handle_t *handle, struct inode *inode,
         if (block_i && ((windowsz = block_i->rsv_window_node.rsv_goal_size) > 0))
                 my_rsv = &block_i->rsv_window_node;
 
-        if (!ext4_has_free_blocks(sbi)) {
-                *errp = -ENOSPC;
-                goto out;
-        }
-
         /*
          * First, test whether the goal block is free.
          */
@@ -1734,7 +1759,7 @@ retry_alloc:
                 my_rsv = NULL;
 
         if (free_blocks > 0) {
-                bitmap_bh = read_block_bitmap(sb, group_no);
+                bitmap_bh = ext4_read_block_bitmap(sb, group_no);
                 if (!bitmap_bh)
                         goto io_error;
                 grp_alloc_blk = ext4_try_to_allocate_with_rsv(sb, handle,
@@ -1770,7 +1795,7 @@ retry_alloc:
                         continue;
 
                 brelse(bitmap_bh);
-                bitmap_bh = read_block_bitmap(sb, group_no);
+                bitmap_bh = ext4_read_block_bitmap(sb, group_no);
                 if (!bitmap_bh)
                         goto io_error;
                 /*
@@ -1882,7 +1907,15 @@ allocated:
         le16_add_cpu(&gdp->bg_free_blocks_count, -num);
         gdp->bg_checksum = ext4_group_desc_csum(sbi, group_no, gdp);
         spin_unlock(sb_bgl_lock(sbi, group_no));
-        percpu_counter_sub(&sbi->s_freeblocks_counter, num);
+        if (!EXT4_I(inode)->i_delalloc_reserved_flag)
+                percpu_counter_sub(&sbi->s_freeblocks_counter, num);
+
+        if (sbi->s_log_groups_per_flex) {
+                ext4_group_t flex_group = ext4_flex_group(sbi, group_no);
+                spin_lock(sb_bgl_lock(sbi, flex_group));
+                sbi->s_flex_groups[flex_group].free_blocks -= num;
+                spin_unlock(sb_bgl_lock(sbi, flex_group));
+        }
 
         BUFFER_TRACE(gdp_bh, "journal_dirty_metadata for group descriptor");
         err = ext4_journal_dirty_metadata(handle, gdp_bh);
@@ -1915,46 +1948,104 @@ out:
         return 0;
 }
 
-ext4_fsblk_t ext4_new_block(handle_t *handle, struct inode *inode,
-                ext4_fsblk_t goal, int *errp)
+#define EXT4_META_BLOCK 0x1
+
+static ext4_fsblk_t do_blk_alloc(handle_t *handle, struct inode *inode,
+                                ext4_lblk_t iblock, ext4_fsblk_t goal,
+                                unsigned long *count, int *errp, int flags)
 {
         struct ext4_allocation_request ar;
         ext4_fsblk_t ret;
 
         if (!test_opt(inode->i_sb, MBALLOC)) {
-                unsigned long count = 1;
-                ret = ext4_new_blocks_old(handle, inode, goal, &count, errp);
-                return ret;
+                return ext4_old_new_blocks(handle, inode, goal, count, errp);
         }
 
         memset(&ar, 0, sizeof(ar));
+        /* Fill with neighbour allocated blocks */
+
         ar.inode = inode;
         ar.goal = goal;
-        ar.len = 1;
+        ar.len = *count;
+        ar.logical = iblock;
+
+        if (S_ISREG(inode->i_mode) && !(flags & EXT4_META_BLOCK))
+                /* enable in-core preallocation for data block allocation */
+                ar.flags = EXT4_MB_HINT_DATA;
+        else
+                /* disable in-core preallocation for non-regular files */
+                ar.flags = 0;
+
         ret = ext4_mb_new_blocks(handle, &ar, errp);
+        *count = ar.len;
         return ret;
 }
 
-ext4_fsblk_t ext4_new_blocks(handle_t *handle, struct inode *inode,
+/*
+ * ext4_new_meta_blocks() -- allocate block for meta data (indexing) blocks
+ *
+ * @handle:             handle to this transaction
+ * @inode:              file inode
+ * @goal:               given target block(filesystem wide)
+ * @count:              total number of blocks need
+ * @errp:               error code
+ *
+ * Return 1st allocated block numberon success, *count stores total account
+ * error stores in errp pointer
+ */
+ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
                 ext4_fsblk_t goal, unsigned long *count, int *errp)
 {
-        struct ext4_allocation_request ar;
         ext4_fsblk_t ret;
-
-        if (!test_opt(inode->i_sb, MBALLOC)) {
-                ret = ext4_new_blocks_old(handle, inode, goal, count, errp);
-                return ret;
+        ret = do_blk_alloc(handle, inode, 0, goal,
+                                count, errp, EXT4_META_BLOCK);
+        /*
+         * Account for the allocated meta blocks
+         */
+        if (!(*errp)) {
+                spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
+                EXT4_I(inode)->i_allocated_meta_blocks += *count;
+                spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
         }
-
-        memset(&ar, 0, sizeof(ar));
-        ar.inode = inode;
-        ar.goal = goal;
-        ar.len = *count;
-        ret = ext4_mb_new_blocks(handle, &ar, errp);
-        *count = ar.len;
         return ret;
 }
 
+/*
+ * ext4_new_meta_block() -- allocate block for meta data (indexing) blocks
+ *
+ * @handle:             handle to this transaction
+ * @inode:              file inode
+ * @goal:               given target block(filesystem wide)
+ * @errp:               error code
+ *
+ * Return allocated block number on success
+ */
+ext4_fsblk_t ext4_new_meta_block(handle_t *handle, struct inode *inode,
+                ext4_fsblk_t goal, int *errp)
+{
+        unsigned long count = 1;
+        return ext4_new_meta_blocks(handle, inode, goal, &count, errp);
+}
+
+/*
+ * ext4_new_blocks() -- allocate data blocks
+ *
+ * @handle:             handle to this transaction
+ * @inode:              file inode
+ * @goal:               given target block(filesystem wide)
+ * @count:              total number of blocks need
+ * @errp:               error code
+ *
+ * Return 1st allocated block numberon success, *count stores total account
+ * error stores in errp pointer
+ */
+
+ext4_fsblk_t ext4_new_blocks(handle_t *handle, struct inode *inode,
+                                ext4_lblk_t iblock, ext4_fsblk_t goal,
+                                unsigned long *count, int *errp)
+{
+        return do_blk_alloc(handle, inode, iblock, goal, count, errp, 0);
+}
 
 /**
  * ext4_count_free_blocks() -- count filesystem free blocks
@@ -1986,7 +2077,7 @@ ext4_fsblk_t ext4_count_free_blocks(struct super_block *sb)
                         continue;
                 desc_count += le16_to_cpu(gdp->bg_free_blocks_count);
                 brelse(bitmap_bh);
-                bitmap_bh = read_block_bitmap(sb, i);
+                bitmap_bh = ext4_read_block_bitmap(sb, i);
                 if (bitmap_bh == NULL)
                         continue;
 
diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index 2bf0331ea194..d3d23d73c08b 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -129,7 +129,8 @@ static int ext4_readdir(struct file * filp,
                 struct buffer_head *bh = NULL;
 
                 map_bh.b_state = 0;
-                err = ext4_get_blocks_wrap(NULL, inode, blk, 1, &map_bh, 0, 0);
+                err = ext4_get_blocks_wrap(NULL, inode, blk, 1, &map_bh,
+                                                0, 0, 0);
                 if (err > 0) {
                         pgoff_t index = map_bh.b_blocknr >>
                                         (PAGE_CACHE_SHIFT - inode->i_blkbits);
@@ -272,7 +273,7 @@ static void free_rb_tree_fname(struct rb_root *root)
 
         while (n) {
                 /* Do the node's children first */
-                if ((n)->rb_left) {
+                if (n->rb_left) {
                         n = n->rb_left;
                         continue;
                 }
@@ -301,24 +302,18 @@ static void free_rb_tree_fname(struct rb_root *root)
                         parent->rb_right = NULL;
                 n = parent;
         }
-        root->rb_node = NULL;
 }
 
 
-static struct dir_private_info *create_dir_info(loff_t pos)
+static struct dir_private_info *ext4_htree_create_dir_info(loff_t pos)
 {
         struct dir_private_info *p;
 
-        p = kmalloc(sizeof(struct dir_private_info), GFP_KERNEL);
+        p = kzalloc(sizeof(struct dir_private_info), GFP_KERNEL);
         if (!p)
                 return NULL;
-        p->root.rb_node = NULL;
-        p->curr_node = NULL;
-        p->extra_fname = NULL;
-        p->last_pos = 0;
         p->curr_hash = pos2maj_hash(pos);
         p->curr_minor_hash = pos2min_hash(pos);
-        p->next_hash = 0;
         return p;
 }
 
@@ -433,7 +428,7 @@ static int ext4_dx_readdir(struct file * filp,
         int     ret;
 
         if (!info) {
-                info = create_dir_info(filp->f_pos);
+                info = ext4_htree_create_dir_info(filp->f_pos);
                 if (!info)
                         return -ENOMEM;
                 filp->private_data = info;
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 8158083f7ac0..303e41cf7b14 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -22,7 +22,7 @@
 #include "ext4_i.h"
 
 /*
- * The second extended filesystem constants/structures
+ * The fourth extended filesystem constants/structures
  */
 
 /*
@@ -45,7 +45,7 @@
 #define ext4_debug(f, a...)                                             \
         do {                                                            \
                 printk (KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:",       \
-                        __FILE__, __LINE__, __FUNCTION__);              \
+                        __FILE__, __LINE__, __func__);                  \
                 printk (KERN_DEBUG f, ## a);                            \
         } while (0)
 #else
@@ -74,6 +74,9 @@
 #define EXT4_MB_HINT_GOAL_ONLY          256
 /* goal is meaningful */
 #define EXT4_MB_HINT_TRY_GOAL           512
+/* blocks already pre-reserved by delayed allocation */
+#define EXT4_MB_DELALLOC_RESERVED      1024
+
 
 struct ext4_allocation_request {
         /* target inode for block we're allocating */
@@ -170,6 +173,15 @@ struct ext4_group_desc
         __u32   bg_reserved2[3];
 };
 
+/*
+ * Structure of a flex block group info
+ */
+
+struct flex_groups {
+        __u32 free_inodes;
+        __u32 free_blocks;
+};
+
 #define EXT4_BG_INODE_UNINIT    0x0001 /* Inode table/bitmap not in use */
 #define EXT4_BG_BLOCK_UNINIT    0x0002 /* Block bitmap not in use */
 #define EXT4_BG_INODE_ZEROED    0x0004 /* On-disk itable initialized to zero */
@@ -527,6 +539,7 @@ do {									       \
 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT 0x1000000 /* Journal Async Commit */
 #define EXT4_MOUNT_I_VERSION            0x2000000 /* i_version support */
 #define EXT4_MOUNT_MBALLOC              0x4000000 /* Buddy allocation support */
+#define EXT4_MOUNT_DELALLOC             0x8000000 /* Delalloc support */
 /* Compatibility, for having both ext2_fs.h and ext4_fs.h included at once */
 #ifndef _LINUX_EXT2_FS_H
 #define clear_opt(o, opt)               o &= ~EXT4_MOUNT_##opt
@@ -647,7 +660,10 @@ struct ext4_super_block {
         __le16  s_mmp_interval;         /* # seconds to wait in MMP checking */
         __le64  s_mmp_block;            /* Block for multi-mount protection */
         __le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
-        __u32   s_reserved[163];        /* Padding to the end of the block */
+        __u8    s_log_groups_per_flex;  /* FLEX_BG group size */
+        __u8    s_reserved_char_pad2;
+        __le16  s_reserved_pad;
+        __u32   s_reserved[162];        /* Padding to the end of the block */
 };
 
 #ifdef __KERNEL__
@@ -958,12 +974,17 @@ extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
                         ext4_group_t group);
-extern ext4_fsblk_t ext4_new_block (handle_t *handle, struct inode *inode,
+extern ext4_fsblk_t ext4_new_meta_block(handle_t *handle, struct inode *inode,
                         ext4_fsblk_t goal, int *errp);
-extern ext4_fsblk_t ext4_new_blocks (handle_t *handle, struct inode *inode,
+extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
                         ext4_fsblk_t goal, unsigned long *count, int *errp);
-extern ext4_fsblk_t ext4_new_blocks_old(handle_t *handle, struct inode *inode,
+extern ext4_fsblk_t ext4_new_blocks(handle_t *handle, struct inode *inode,
+                                        ext4_lblk_t iblock, ext4_fsblk_t goal,
+                                        unsigned long *count, int *errp);
+extern ext4_fsblk_t ext4_old_new_blocks(handle_t *handle, struct inode *inode,
                         ext4_fsblk_t goal, unsigned long *count, int *errp);
+extern ext4_fsblk_t ext4_has_free_blocks(struct ext4_sb_info *sbi,
+                                                ext4_fsblk_t nblocks);
 extern void ext4_free_blocks (handle_t *handle, struct inode *inode,
                         ext4_fsblk_t block, unsigned long count, int metadata);
 extern void ext4_free_blocks_sb (handle_t *handle, struct super_block *sb,
@@ -1016,9 +1037,14 @@ extern int __init init_ext4_mballoc(void);
 extern void exit_ext4_mballoc(void);
 extern void ext4_mb_free_blocks(handle_t *, struct inode *,
                 unsigned long, unsigned long, int, unsigned long *);
+extern int ext4_mb_add_more_groupinfo(struct super_block *sb,
+                ext4_group_t i, struct ext4_group_desc *desc);
+extern void ext4_mb_update_group_info(struct ext4_group_info *grp,
+                ext4_grpblk_t add);
 
 
 /* inode.c */
+void ext4_da_release_space(struct inode *inode, int used, int to_free);
 int ext4_forget(handle_t *handle, int is_metadata, struct inode *inode,
                 struct buffer_head *bh, ext4_fsblk_t blocknr);
 struct buffer_head *ext4_getblk(handle_t *, struct inode *,
@@ -1033,19 +1059,23 @@ int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
 extern struct inode *ext4_iget(struct super_block *, unsigned long);
 extern int  ext4_write_inode (struct inode *, int);
 extern int  ext4_setattr (struct dentry *, struct iattr *);
+extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
+                                struct kstat *stat);
 extern void ext4_delete_inode (struct inode *);
 extern int  ext4_sync_inode (handle_t *, struct inode *);
 extern void ext4_discard_reservation (struct inode *);
 extern void ext4_dirty_inode(struct inode *);
 extern int ext4_change_inode_journal_flag(struct inode *, int);
 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
+extern int ext4_can_truncate(struct inode *inode);
 extern void ext4_truncate (struct inode *);
 extern void ext4_set_inode_flags(struct inode *);
 extern void ext4_get_inode_flags(struct ext4_inode_info *);
 extern void ext4_set_aops(struct inode *inode);
 extern int ext4_writepage_trans_blocks(struct inode *);
-extern int ext4_block_truncate_page(handle_t *handle, struct page *page,
+extern int ext4_block_truncate_page(handle_t *handle,
                 struct address_space *mapping, loff_t from);
+extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct page *page);
 
 /* ioctl.c */
 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
@@ -1159,10 +1189,21 @@ struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
 }
 
 
+static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
+                                             ext4_group_t block_group)
+{
+        return block_group >> sbi->s_log_groups_per_flex;
+}
+
+static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
+{
+        return 1 << sbi->s_log_groups_per_flex;
+}
+
 #define ext4_std_error(sb, errno)                               \
 do {                                                            \
         if ((errno))                                            \
-                __ext4_std_error((sb), __FUNCTION__, (errno));  \
+                __ext4_std_error((sb), __func__, (errno));      \
 } while (0)
 
 /*
@@ -1191,7 +1232,7 @@ extern int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
                         ext4_lblk_t iblock,
                         unsigned long max_blocks, struct buffer_head *bh_result,
                         int create, int extend_disksize);
-extern void ext4_ext_truncate(struct inode *, struct page *);
+extern void ext4_ext_truncate(struct inode *);
 extern void ext4_ext_init(struct super_block *);
 extern void ext4_ext_release(struct super_block *);
 extern long ext4_fallocate(struct inode *inode, int mode, loff_t offset,
@@ -1199,7 +1240,7 @@ extern long ext4_fallocate(struct inode *inode, int mode, loff_t offset,
 extern int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode,
                         sector_t block, unsigned long max_blocks,
                         struct buffer_head *bh, int create,
-                        int extend_disksize);
+                        int extend_disksize, int flag);
 #endif  /* __KERNEL__ */
 
 #endif  /* _EXT4_H */
diff --git a/fs/ext4/ext4_extents.h b/fs/ext4/ext4_extents.h
index 75333b595fab..6c166c0a54b7 100644
--- a/fs/ext4/ext4_extents.h
+++ b/fs/ext4/ext4_extents.h
@@ -212,6 +212,7 @@ static inline int ext4_ext_get_actual_len(struct ext4_extent *ext)
                 (le16_to_cpu(ext->ee_len) - EXT_INIT_MAX_LEN));
 }
 
+extern int ext4_ext_calc_metadata_amount(struct inode *inode, int blocks);
 extern ext4_fsblk_t idx_pblock(struct ext4_extent_idx *);
 extern void ext4_ext_store_pblock(struct ext4_extent *, ext4_fsblk_t);
 extern int ext4_extent_tree_init(handle_t *, struct inode *);
diff --git a/fs/ext4/ext4_i.h b/fs/ext4/ext4_i.h
index 26a4ae255d79..ef7409f0e7e4 100644
--- a/fs/ext4/ext4_i.h
+++ b/fs/ext4/ext4_i.h
@@ -79,7 +79,7 @@ struct ext4_ext_cache {
 };
 
 /*
- * third extended file system inode data in memory
+ * fourth extended file system inode data in memory
  */
 struct ext4_inode_info {
         __le32  i_data[15];     /* unconverted */
@@ -150,6 +150,7 @@ struct ext4_inode_info {
          */
         struct rw_semaphore i_data_sem;
         struct inode vfs_inode;
+        struct jbd2_inode jinode;
 
         unsigned long i_ext_generation;
         struct ext4_ext_cache i_cached_extent;
@@ -162,6 +163,13 @@ struct ext4_inode_info {
         /* mballoc */
         struct list_head i_prealloc_list;
         spinlock_t i_prealloc_lock;
+
+        /* allocation reservation info for delalloc */
+        unsigned long i_reserved_data_blocks;
+        unsigned long i_reserved_meta_blocks;
+        unsigned long i_allocated_meta_blocks;
+        unsigned short i_delalloc_reserved_flag;
+        spinlock_t i_block_reservation_lock;
 };
 
 #endif  /* _EXT4_I */
diff --git a/fs/ext4/ext4_jbd2.h b/fs/ext4/ext4_jbd2.h
index 9255a7d28b24..eb8bc3afe6e9 100644
--- a/fs/ext4/ext4_jbd2.h
+++ b/fs/ext4/ext4_jbd2.h
@@ -142,19 +142,17 @@ int __ext4_journal_dirty_metadata(const char *where,
                                 handle_t *handle, struct buffer_head *bh);
 
 #define ext4_journal_get_undo_access(handle, bh) \
-        __ext4_journal_get_undo_access(__FUNCTION__, (handle), (bh))
+        __ext4_journal_get_undo_access(__func__, (handle), (bh))
 #define ext4_journal_get_write_access(handle, bh) \
-        __ext4_journal_get_write_access(__FUNCTION__, (handle), (bh))
+        __ext4_journal_get_write_access(__func__, (handle), (bh))
 #define ext4_journal_revoke(handle, blocknr, bh) \
-        __ext4_journal_revoke(__FUNCTION__, (handle), (blocknr), (bh))
+        __ext4_journal_revoke(__func__, (handle), (blocknr), (bh))
 #define ext4_journal_get_create_access(handle, bh) \
-        __ext4_journal_get_create_access(__FUNCTION__, (handle), (bh))
+        __ext4_journal_get_create_access(__func__, (handle), (bh))
 #define ext4_journal_dirty_metadata(handle, bh) \
-        __ext4_journal_dirty_metadata(__FUNCTION__, (handle), (bh))
+        __ext4_journal_dirty_metadata(__func__, (handle), (bh))
 #define ext4_journal_forget(handle, bh) \
-        __ext4_journal_forget(__FUNCTION__, (handle), (bh))
-
-int ext4_journal_dirty_data(handle_t *handle, struct buffer_head *bh);
+        __ext4_journal_forget(__func__, (handle), (bh))
 
 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks);
 int __ext4_journal_stop(const char *where, handle_t *handle);
@@ -165,7 +163,7 @@ static inline handle_t *ext4_journal_start(struct inode *inode, int nblocks)
 }
 
 #define ext4_journal_stop(handle) \
-        __ext4_journal_stop(__FUNCTION__, (handle))
+        __ext4_journal_stop(__func__, (handle))
 
 static inline handle_t *ext4_journal_current_handle(void)
 {
@@ -192,6 +190,11 @@ static inline int ext4_journal_force_commit(journal_t *journal)
         return jbd2_journal_force_commit(journal);
 }
 
+static inline int ext4_jbd2_file_inode(handle_t *handle, struct inode *inode)
+{
+        return jbd2_journal_file_inode(handle, &EXT4_I(inode)->jinode);
+}
+
 /* super.c */
 int ext4_force_commit(struct super_block *sb);
 
diff --git a/fs/ext4/ext4_sb.h b/fs/ext4/ext4_sb.h
index 5802e69f2191..6300226d5531 100644
--- a/fs/ext4/ext4_sb.h
+++ b/fs/ext4/ext4_sb.h
@@ -25,7 +25,7 @@
 #include <linux/rbtree.h>
 
 /*
- * third extended-fs super-block data in memory
+ * fourth extended-fs super-block data in memory
  */
 struct ext4_sb_info {
         unsigned long s_desc_size;      /* Size of a group descriptor in bytes */
@@ -143,6 +143,9 @@ struct ext4_sb_info {
 
         /* locality groups */
         struct ext4_locality_group *s_locality_groups;
+
+        unsigned int s_log_groups_per_flex;
+        struct flex_groups *s_flex_groups;
 };
 
 #endif  /* _EXT4_SB */
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 47929c4e3dae..42c4c0c892ed 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -92,17 +92,16 @@ static void ext4_idx_store_pblock(struct ext4_extent_idx *ix, ext4_fsblk_t pb)
         ix->ei_leaf_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff);
 }
 
-static handle_t *ext4_ext_journal_restart(handle_t *handle, int needed)
+static int ext4_ext_journal_restart(handle_t *handle, int needed)
 {
         int err;
 
         if (handle->h_buffer_credits > needed)
-                return handle;
-        if (!ext4_journal_extend(handle, needed))
-                return handle;
-        err = ext4_journal_restart(handle, needed);
-
-        return handle;
+                return 0;
+        err = ext4_journal_extend(handle, needed);
+        if (err)
+                return err;
+        return ext4_journal_restart(handle, needed);
 }
 
 /*
@@ -180,15 +179,18 @@ static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
         return bg_start + colour + block;
 }
 
+/*
+ * Allocation for a meta data block
+ */
 static ext4_fsblk_t
-ext4_ext_new_block(handle_t *handle, struct inode *inode,
+ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
                         struct ext4_ext_path *path,
                         struct ext4_extent *ex, int *err)
 {
         ext4_fsblk_t goal, newblock;
 
         goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
-        newblock = ext4_new_block(handle, inode, goal, err);
+        newblock = ext4_new_meta_block(handle, inode, goal, err);
         return newblock;
 }
 
@@ -246,6 +248,36 @@ static int ext4_ext_space_root_idx(struct inode *inode)
         return size;
 }
 
+/*
+ * Calculate the number of metadata blocks needed
+ * to allocate @blocks
+ * Worse case is one block per extent
+ */
+int ext4_ext_calc_metadata_amount(struct inode *inode, int blocks)
+{
+        int lcap, icap, rcap, leafs, idxs, num;
+        int newextents = blocks;
+
+        rcap = ext4_ext_space_root_idx(inode);
+        lcap = ext4_ext_space_block(inode);
+        icap = ext4_ext_space_block_idx(inode);
+
+        /* number of new leaf blocks needed */
+        num = leafs = (newextents + lcap - 1) / lcap;
+
+        /*
+         * Worse case, we need separate index block(s)
+         * to link all new leaf blocks
+         */
+        idxs = (leafs + icap - 1) / icap;
+        do {
+                num += idxs;
+                idxs = (idxs + icap - 1) / icap;
+        } while (idxs > rcap);
+
+        return num;
+}
+
 static int
 ext4_ext_max_entries(struct inode *inode, int depth)
 {
@@ -524,6 +556,7 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
                 alloc = 1;
         }
         path[0].p_hdr = eh;
+        path[0].p_bh = NULL;
 
         i = depth;
         /* walk through the tree */
@@ -552,12 +585,14 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
         }
 
         path[ppos].p_depth = i;
-        path[ppos].p_hdr = eh;
         path[ppos].p_ext = NULL;
         path[ppos].p_idx = NULL;
 
         /* find extent */
         ext4_ext_binsearch(inode, path + ppos, block);
+        /* if not an empty leaf */
+        if (path[ppos].p_ext)
+                path[ppos].p_block = ext_pblock(path[ppos].p_ext);
 
         ext4_ext_show_path(inode, path);
 
@@ -688,7 +723,8 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
         /* allocate all needed blocks */
         ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
         for (a = 0; a < depth - at; a++) {
-                newblock = ext4_ext_new_block(handle, inode, path, newext, &err);
+                newblock = ext4_ext_new_meta_block(handle, inode, path,
+                                                   newext, &err);
                 if (newblock == 0)
                         goto cleanup;
                 ablocks[a] = newblock;
@@ -884,7 +920,7 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
         ext4_fsblk_t newblock;
         int err = 0;
 
-        newblock = ext4_ext_new_block(handle, inode, path, newext, &err);
+        newblock = ext4_ext_new_meta_block(handle, inode, path, newext, &err);
         if (newblock == 0)
                 return err;
 
@@ -981,6 +1017,8 @@ repeat:
                 /* if we found index with free entry, then use that
                  * entry: create all needed subtree and add new leaf */
                 err = ext4_ext_split(handle, inode, path, newext, i);
+                if (err)
+                        goto out;
 
                 /* refill path */
                 ext4_ext_drop_refs(path);
@@ -1883,11 +1921,9 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
                 credits += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb);
 #endif
 
-                handle = ext4_ext_journal_restart(handle, credits);
-                if (IS_ERR(handle)) {
-                        err = PTR_ERR(handle);
+                err = ext4_ext_journal_restart(handle, credits);
+                if (err)
                         goto out;
-                }
 
                 err = ext4_ext_get_access(handle, inode, path + depth);
                 if (err)
@@ -2529,6 +2565,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
         int err = 0, depth, ret;
         unsigned long allocated = 0;
         struct ext4_allocation_request ar;
+        loff_t disksize;
 
         __clear_bit(BH_New, &bh_result->b_state);
         ext_debug("blocks %u/%lu requested for inode %u\n",
@@ -2616,8 +2653,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
                                  */
                                 if (allocated > max_blocks)
                                         allocated = max_blocks;
-                                /* mark the buffer unwritten */
-                                __set_bit(BH_Unwritten, &bh_result->b_state);
+                                set_buffer_unwritten(bh_result);
                                 goto out2;
                         }
 
@@ -2716,14 +2752,19 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
                 goto out2;
         }
 
-        if (extend_disksize && inode->i_size > EXT4_I(inode)->i_disksize)
-                EXT4_I(inode)->i_disksize = inode->i_size;
-
         /* previous routine could use block we allocated */
         newblock = ext_pblock(&newex);
         allocated = ext4_ext_get_actual_len(&newex);
 outnew:
-        __set_bit(BH_New, &bh_result->b_state);
+        if (extend_disksize) {
+                disksize = ((loff_t) iblock + ar.len) << inode->i_blkbits;
+                if (disksize > i_size_read(inode))
+                        disksize = i_size_read(inode);
+                if (disksize > EXT4_I(inode)->i_disksize)
+                        EXT4_I(inode)->i_disksize = disksize;
+        }
+
+        set_buffer_new(bh_result);
 
         /* Cache only when it is _not_ an uninitialized extent */
         if (create != EXT4_CREATE_UNINITIALIZED_EXT)
@@ -2733,7 +2774,7 @@ out:
         if (allocated > max_blocks)
                 allocated = max_blocks;
         ext4_ext_show_leaf(inode, path);
-        __set_bit(BH_Mapped, &bh_result->b_state);
+        set_buffer_mapped(bh_result);
         bh_result->b_bdev = inode->i_sb->s_bdev;
         bh_result->b_blocknr = newblock;
 out2:
@@ -2744,7 +2785,7 @@ out2:
         return err ? err : allocated;
 }
 
-void ext4_ext_truncate(struct inode * inode, struct page *page)
+void ext4_ext_truncate(struct inode *inode)
 {
         struct address_space *mapping = inode->i_mapping;
         struct super_block *sb = inode->i_sb;
@@ -2757,18 +2798,14 @@ void ext4_ext_truncate(struct inode * inode, struct page *page)
          */
         err = ext4_writepage_trans_blocks(inode) + 3;
         handle = ext4_journal_start(inode, err);
-        if (IS_ERR(handle)) {
-                if (page) {
-                        clear_highpage(page);
-                        flush_dcache_page(page);
-                        unlock_page(page);
-                        page_cache_release(page);
-                }
+        if (IS_ERR(handle))
                 return;
-        }
 
-        if (page)
-                ext4_block_truncate_page(handle, page, mapping, inode->i_size);
+        if (inode->i_size & (sb->s_blocksize - 1))
+                ext4_block_truncate_page(handle, mapping, inode->i_size);
+
+        if (ext4_orphan_add(handle, inode))
+                goto out_stop;
 
         down_write(&EXT4_I(inode)->i_data_sem);
         ext4_ext_invalidate_cache(inode);
@@ -2780,8 +2817,6 @@ void ext4_ext_truncate(struct inode * inode, struct page *page)
          * Probably we need not scan at all,
          * because page truncation is enough.
          */
-        if (ext4_orphan_add(handle, inode))
-                goto out_stop;
 
         /* we have to know where to truncate from in crash case */
         EXT4_I(inode)->i_disksize = inode->i_size;
@@ -2798,6 +2833,7 @@ void ext4_ext_truncate(struct inode * inode, struct page *page)
                 handle->h_sync = 1;
 
 out_stop:
+        up_write(&EXT4_I(inode)->i_data_sem);
         /*
          * If this was a simple ftruncate() and the file will remain alive,
          * then we need to clear up the orphan record which we created above.
@@ -2808,7 +2844,6 @@ out_stop:
         if (inode->i_nlink)
                 ext4_orphan_del(handle, inode);
 
-        up_write(&EXT4_I(inode)->i_data_sem);
         inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
         ext4_mark_inode_dirty(handle, inode);
         ext4_journal_stop(handle);
@@ -2911,7 +2946,7 @@ retry:
                 }
                 ret = ext4_get_blocks_wrap(handle, inode, block,
                                           max_blocks, &map_bh,
-                                          EXT4_CREATE_UNINITIALIZED_EXT, 0);
+                                          EXT4_CREATE_UNINITIALIZED_EXT, 0, 0);
                 if (ret <= 0) {
 #ifdef EXT4FS_DEBUG
                         WARN_ON(ret <= 0);
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 4159be6366ab..430eb7978db4 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -123,6 +123,23 @@ force_commit:
         return ret;
 }
 
+static struct vm_operations_struct ext4_file_vm_ops = {
+        .fault          = filemap_fault,
+        .page_mkwrite   = ext4_page_mkwrite,
+};
+
+static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+        struct address_space *mapping = file->f_mapping;
+
+        if (!mapping->a_ops->readpage)
+                return -ENOEXEC;
+        file_accessed(file);
+        vma->vm_ops = &ext4_file_vm_ops;
+        vma->vm_flags |= VM_CAN_NONLINEAR;
+        return 0;
+}
+
 const struct file_operations ext4_file_operations = {
         .llseek         = generic_file_llseek,
         .read           = do_sync_read,
@@ -133,7 +150,7 @@ const struct file_operations ext4_file_operations = {
 #ifdef CONFIG_COMPAT
         .compat_ioctl   = ext4_compat_ioctl,
 #endif
-        .mmap           = generic_file_mmap,
+        .mmap           = ext4_file_mmap,
         .open           = generic_file_open,
         .release        = ext4_release_file,
         .fsync          = ext4_sync_file,
@@ -144,6 +161,7 @@ const struct file_operations ext4_file_operations = {
 const struct inode_operations ext4_file_inode_operations = {
         .truncate       = ext4_truncate,
         .setattr        = ext4_setattr,
+        .getattr        = ext4_getattr,
 #ifdef CONFIG_EXT4DEV_FS_XATTR
         .setxattr       = generic_setxattr,
         .getxattr       = generic_getxattr,
diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c
index 1c8ba48d4f8d..a45c3737ad31 100644
--- a/fs/ext4/fsync.c
+++ b/fs/ext4/fsync.c
@@ -27,6 +27,7 @@
 #include <linux/sched.h>
 #include <linux/writeback.h>
 #include <linux/jbd2.h>
+#include <linux/blkdev.h>
 #include "ext4.h"
 #include "ext4_jbd2.h"
 
@@ -45,6 +46,7 @@
 int ext4_sync_file(struct file * file, struct dentry *dentry, int datasync)
 {
         struct inode *inode = dentry->d_inode;
+        journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
         int ret = 0;
 
         J_ASSERT(ext4_journal_current_handle() == NULL);
@@ -85,6 +87,8 @@ int ext4_sync_file(struct file * file, struct dentry *dentry, int datasync)
                         .nr_to_write = 0, /* sys_fsync did this */
                 };
                 ret = sync_inode(inode, &wbc);
+                if (journal && (journal->j_flags & JBD2_BARRIER))
+                        blkdev_issue_flush(inode->i_sb->s_bdev, NULL);
         }
 out:
         return ret;
diff --git a/fs/ext4/group.h b/fs/ext4/group.h
index 7eb0604e7eea..c2c0a8d06d0e 100644
--- a/fs/ext4/group.h
+++ b/fs/ext4/group.h
@@ -13,7 +13,7 @@ extern __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 group,
                                    struct ext4_group_desc *gdp);
 extern int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 group,
                                        struct ext4_group_desc *gdp);
-struct buffer_head *read_block_bitmap(struct super_block *sb,
+struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
                                       ext4_group_t block_group);
 extern unsigned ext4_init_block_bitmap(struct super_block *sb,
                                        struct buffer_head *bh,
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index c6efbab0c801..a92eb305344f 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -157,6 +157,7 @@ void ext4_free_inode (handle_t *handle, struct inode * inode)
         struct ext4_super_block * es;
         struct ext4_sb_info *sbi;
         int fatal = 0, err;
+        ext4_group_t flex_group;
 
         if (atomic_read(&inode->i_count) > 1) {
                 printk ("ext4_free_inode: inode has count=%d\n",
@@ -232,6 +233,12 @@ void ext4_free_inode (handle_t *handle, struct inode * inode)
                         if (is_directory)
                                 percpu_counter_dec(&sbi->s_dirs_counter);
 
+                        if (sbi->s_log_groups_per_flex) {
+                                flex_group = ext4_flex_group(sbi, block_group);
+                                spin_lock(sb_bgl_lock(sbi, flex_group));
+                                sbi->s_flex_groups[flex_group].free_inodes++;
+                                spin_unlock(sb_bgl_lock(sbi, flex_group));
+                        }
                 }
                 BUFFER_TRACE(bh2, "call ext4_journal_dirty_metadata");
                 err = ext4_journal_dirty_metadata(handle, bh2);
@@ -286,6 +293,80 @@ static int find_group_dir(struct super_block *sb, struct inode *parent,
         return ret;
 }
 
+#define free_block_ratio 10
+
+static int find_group_flex(struct super_block *sb, struct inode *parent,
+                           ext4_group_t *best_group)
+{
+        struct ext4_sb_info *sbi = EXT4_SB(sb);
+        struct ext4_group_desc *desc;
+        struct buffer_head *bh;
+        struct flex_groups *flex_group = sbi->s_flex_groups;
+        ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
+        ext4_group_t parent_fbg_group = ext4_flex_group(sbi, parent_group);
+        ext4_group_t ngroups = sbi->s_groups_count;
+        int flex_size = ext4_flex_bg_size(sbi);
+        ext4_group_t best_flex = parent_fbg_group;
+        int blocks_per_flex = sbi->s_blocks_per_group * flex_size;
+        int flexbg_free_blocks;
+        int flex_freeb_ratio;
+        ext4_group_t n_fbg_groups;
+        ext4_group_t i;
+
+        n_fbg_groups = (sbi->s_groups_count + flex_size - 1) >>
+                sbi->s_log_groups_per_flex;
+
+find_close_to_parent:
+        flexbg_free_blocks = flex_group[best_flex].free_blocks;
+        flex_freeb_ratio = flexbg_free_blocks * 100 / blocks_per_flex;
+        if (flex_group[best_flex].free_inodes &&
+            flex_freeb_ratio > free_block_ratio)
+                goto found_flexbg;
+
+        if (best_flex && best_flex == parent_fbg_group) {
+                best_flex--;
+                goto find_close_to_parent;
+        }
+
+        for (i = 0; i < n_fbg_groups; i++) {
+                if (i == parent_fbg_group || i == parent_fbg_group - 1)
+                        continue;
+
+                flexbg_free_blocks = flex_group[i].free_blocks;
+                flex_freeb_ratio = flexbg_free_blocks * 100 / blocks_per_flex;
+
+                if (flex_freeb_ratio > free_block_ratio &&
+                    flex_group[i].free_inodes) {
+                        best_flex = i;
+                        goto found_flexbg;
+                }
+
+                if (best_flex < 0 ||
+                    (flex_group[i].free_blocks >
+                     flex_group[best_flex].free_blocks &&
+                     flex_group[i].free_inodes))
+                        best_flex = i;
+        }
+
+        if (!flex_group[best_flex].free_inodes ||
+            !flex_group[best_flex].free_blocks)
+                return -1;
+
+found_flexbg:
+        for (i = best_flex * flex_size; i < ngroups &&
+                     i < (best_flex + 1) * flex_size; i++) {
+                desc = ext4_get_group_desc(sb, i, &bh);
+                if (le16_to_cpu(desc->bg_free_inodes_count)) {
+                        *best_group = i;
+                        goto out;
+                }
+        }
+
+        return -1;
+out:
+        return 0;
+}
+
 /*
  * Orlov's allocator for directories.
  *
@@ -501,6 +582,7 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode * dir, int mode)
         struct inode *ret;
         ext4_group_t i;
         int free = 0;
+        ext4_group_t flex_group;
 
         /* Cannot create files in a deleted directory */
         if (!dir || !dir->i_nlink)
@@ -514,6 +596,12 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode * dir, int mode)
 
         sbi = EXT4_SB(sb);
         es = sbi->s_es;
+
+        if (sbi->s_log_groups_per_flex) {
+                ret2 = find_group_flex(sb, dir, &group);
+                goto got_group;
+        }
+
         if (S_ISDIR(mode)) {
                 if (test_opt (sb, OLDALLOC))
                         ret2 = find_group_dir(sb, dir, &group);
@@ -522,6 +610,7 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode * dir, int mode)
         } else
                 ret2 = find_group_other(sb, dir, &group);
 
+got_group:
         err = -ENOSPC;
         if (ret2 == -1)
                 goto out;
@@ -600,7 +689,7 @@ got:
         /* We may have to initialize the block bitmap if it isn't already */
         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
             gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
-                struct buffer_head *block_bh = read_block_bitmap(sb, group);
+                struct buffer_head *block_bh = ext4_read_block_bitmap(sb, group);
 
                 BUFFER_TRACE(block_bh, "get block bitmap access");
                 err = ext4_journal_get_write_access(handle, block_bh);
@@ -676,6 +765,13 @@ got:
                 percpu_counter_inc(&sbi->s_dirs_counter);
         sb->s_dirt = 1;
 
+        if (sbi->s_log_groups_per_flex) {
+                flex_group = ext4_flex_group(sbi, group);
+                spin_lock(sb_bgl_lock(sbi, flex_group));
+                sbi->s_flex_groups[flex_group].free_inodes--;
+                spin_unlock(sb_bgl_lock(sbi, flex_group));
+        }
+
         inode->i_uid = current->fsuid;
         if (test_opt (sb, GRPID))
                 inode->i_gid = dir->i_gid;
@@ -740,14 +836,10 @@ got:
                 goto fail_free_drop;
 
         if (test_opt(sb, EXTENTS)) {
-                /* set extent flag only for diretory, file and normal symlink*/
+                /* set extent flag only for directory, file and normal symlink*/
                 if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) {
                         EXT4_I(inode)->i_flags |= EXT4_EXTENTS_FL;
                         ext4_ext_tree_init(handle, inode);
-                        err = ext4_update_incompat_feature(handle, sb,
-                                        EXT4_FEATURE_INCOMPAT_EXTENTS);
-                        if (err)
-                                goto fail_free_drop;
                 }
         }
 
@@ -817,6 +909,14 @@ struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
         if (IS_ERR(inode))
                 goto iget_failed;
 
+        /*
+         * If the orphans has i_nlinks > 0 then it should be able to be
+         * truncated, otherwise it won't be removed from the orphan list
+         * during processing and an infinite loop will result.
+         */
+        if (inode->i_nlink && !ext4_can_truncate(inode))
+                goto bad_orphan;
+
         if (NEXT_ORPHAN(inode) > max_ino)
                 goto bad_orphan;
         brelse(bitmap_bh);
@@ -838,6 +938,7 @@ bad_orphan:
                 printk(KERN_NOTICE "NEXT_ORPHAN(inode)=%u\n",
                        NEXT_ORPHAN(inode));
                 printk(KERN_NOTICE "max_ino=%lu\n", max_ino);
+                printk(KERN_NOTICE "i_nlink=%u\n", inode->i_nlink);
                 /* Avoid freeing blocks if we got a bad deleted inode */
                 if (inode->i_nlink == 0)
                         inode->i_blocks = 0;
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 8d9707746413..8ca2763df091 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -32,12 +32,23 @@
 #include <linux/string.h>
 #include <linux/buffer_head.h>
 #include <linux/writeback.h>
+#include <linux/pagevec.h>
 #include <linux/mpage.h>
 #include <linux/uio.h>
 #include <linux/bio.h>
 #include "ext4_jbd2.h"
 #include "xattr.h"
 #include "acl.h"
+#include "ext4_extents.h"
+
+static inline int ext4_begin_ordered_truncate(struct inode *inode,
+                                              loff_t new_size)
+{
+        return jbd2_journal_begin_ordered_truncate(&EXT4_I(inode)->jinode,
+                                                   new_size);
+}
+
+static void ext4_invalidatepage(struct page *page, unsigned long offset);
 
 /*
  * Test whether an inode is a fast symlink.
@@ -181,6 +192,8 @@ void ext4_delete_inode (struct inode * inode)
 {
         handle_t *handle;
 
+        if (ext4_should_order_data(inode))
+                ext4_begin_ordered_truncate(inode, 0);
         truncate_inode_pages(&inode->i_data, 0);
 
         if (is_bad_inode(inode))
@@ -508,11 +521,12 @@ static int ext4_blks_to_allocate(Indirect *branch, int k, unsigned long blks,
  *              direct blocks
  */
 static int ext4_alloc_blocks(handle_t *handle, struct inode *inode,
-                        ext4_fsblk_t goal, int indirect_blks, int blks,
-                        ext4_fsblk_t new_blocks[4], int *err)
+                                ext4_lblk_t iblock, ext4_fsblk_t goal,
+                                int indirect_blks, int blks,
+                                ext4_fsblk_t new_blocks[4], int *err)
 {
         int target, i;
-        unsigned long count = 0;
+        unsigned long count = 0, blk_allocated = 0;
         int index = 0;
         ext4_fsblk_t current_block = 0;
         int ret = 0;
@@ -525,12 +539,13 @@ static int ext4_alloc_blocks(handle_t *handle, struct inode *inode,
          * the first direct block of this branch.  That's the
          * minimum number of blocks need to allocate(required)
          */
-        target = blks + indirect_blks;
-
-        while (1) {
+        /* first we try to allocate the indirect blocks */
+        target = indirect_blks;
+        while (target > 0) {
                 count = target;
                 /* allocating blocks for indirect blocks and direct blocks */
-                current_block = ext4_new_blocks(handle,inode,goal,&count,err);
+                current_block = ext4_new_meta_blocks(handle, inode,
+                                                        goal, &count, err);
                 if (*err)
                         goto failed_out;
 
@@ -540,16 +555,48 @@ static int ext4_alloc_blocks(handle_t *handle, struct inode *inode,
                         new_blocks[index++] = current_block++;
                         count--;
                 }
-
-                if (count > 0)
+                if (count > 0) {
+                        /*
+                         * save the new block number
+                         * for the first direct block
+                         */
+                        new_blocks[index] = current_block;
+                        printk(KERN_INFO "%s returned more blocks than "
+                                                "requested\n", __func__);
+                        WARN_ON(1);
                         break;
+                }
         }
 
-        /* save the new block number for the first direct block */
-        new_blocks[index] = current_block;
-
+        target = blks - count ;
+        blk_allocated = count;
+        if (!target)
+                goto allocated;
+        /* Now allocate data blocks */
+        count = target;
+        /* allocating blocks for data blocks */
+        current_block = ext4_new_blocks(handle, inode, iblock,
+                                                goal, &count, err);
+        if (*err && (target == blks)) {
+                /*
+                 * if the allocation failed and we didn't allocate
+                 * any blocks before
+                 */
+                goto failed_out;
+        }
+        if (!*err) {
+                if (target == blks) {
+                /*
+                 * save the new block number
+                 * for the first direct block
+                 */
+                        new_blocks[index] = current_block;
+                }
+                blk_allocated += count;
+        }
+allocated:
         /* total number of blocks allocated for direct blocks */
-        ret = count;
+        ret = blk_allocated;
         *err = 0;
         return ret;
 failed_out:
@@ -584,8 +631,9 @@ failed_out:
  *      as described above and return 0.
  */
 static int ext4_alloc_branch(handle_t *handle, struct inode *inode,
-                        int indirect_blks, int *blks, ext4_fsblk_t goal,
-                        ext4_lblk_t *offsets, Indirect *branch)
+                                ext4_lblk_t iblock, int indirect_blks,
+                                int *blks, ext4_fsblk_t goal,
+                                ext4_lblk_t *offsets, Indirect *branch)
 {
         int blocksize = inode->i_sb->s_blocksize;
         int i, n = 0;
@@ -595,7 +643,7 @@ static int ext4_alloc_branch(handle_t *handle, struct inode *inode,
         ext4_fsblk_t new_blocks[4];
         ext4_fsblk_t current_block;
 
-        num = ext4_alloc_blocks(handle, inode, goal, indirect_blks,
+        num = ext4_alloc_blocks(handle, inode, iblock, goal, indirect_blks,
                                 *blks, new_blocks, &err);
         if (err)
                 return err;
@@ -799,6 +847,7 @@ int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
         struct ext4_inode_info *ei = EXT4_I(inode);
         int count = 0;
         ext4_fsblk_t first_block = 0;
+        loff_t disksize;
 
 
         J_ASSERT(!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL));
@@ -855,8 +904,9 @@ int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
         /*
          * Block out ext4_truncate while we alter the tree
          */
-        err = ext4_alloc_branch(handle, inode, indirect_blks, &count, goal,
-                                offsets + (partial - chain), partial);
+        err = ext4_alloc_branch(handle, inode, iblock, indirect_blks,
+                                        &count, goal,
+                                        offsets + (partial - chain), partial);
 
         /*
          * The ext4_splice_branch call will free and forget any buffers
@@ -873,8 +923,13 @@ int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
          * protect it if you're about to implement concurrent
          * ext4_get_block() -bzzz
         */
-        if (!err && extend_disksize && inode->i_size > ei->i_disksize)
-                ei->i_disksize = inode->i_size;
+        if (!err && extend_disksize) {
+                disksize = ((loff_t) iblock + count) << inode->i_blkbits;
+                if (disksize > i_size_read(inode))
+                        disksize = i_size_read(inode);
+                if (disksize > ei->i_disksize)
+                        ei->i_disksize = disksize;
+        }
         if (err)
                 goto cleanup;
 
@@ -934,7 +989,7 @@ out:
  */
 int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
                         unsigned long max_blocks, struct buffer_head *bh,
-                        int create, int extend_disksize)
+                        int create, int extend_disksize, int flag)
 {
         int retval;
 
@@ -975,6 +1030,15 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
          * with create == 1 flag.
          */
         down_write((&EXT4_I(inode)->i_data_sem));
+
+        /*
+         * if the caller is from delayed allocation writeout path
+         * we have already reserved fs blocks for allocation
+         * let the underlying get_block() function know to
+         * avoid double accounting
+         */
+        if (flag)
+                EXT4_I(inode)->i_delalloc_reserved_flag = 1;
         /*
          * We need to check for EXT4 here because migrate
          * could have changed the inode type in between
@@ -996,6 +1060,18 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
                                                         ~EXT4_EXT_MIGRATE;
                 }
         }
+
+        if (flag) {
+                EXT4_I(inode)->i_delalloc_reserved_flag = 0;
+                /*
+                 * Update reserved blocks/metadata blocks
+                 * after successful block allocation
+                 * which were deferred till now
+                 */
+                if ((retval > 0) && buffer_delay(bh))
+                        ext4_da_release_space(inode, retval, 0);
+        }
+
         up_write((&EXT4_I(inode)->i_data_sem));
         return retval;
 }
@@ -1021,7 +1097,7 @@ static int ext4_get_block(struct inode *inode, sector_t iblock,
         }
 
         ret = ext4_get_blocks_wrap(handle, inode, iblock,
-                                        max_blocks, bh_result, create, 0);
+                                        max_blocks, bh_result, create, 0, 0);
         if (ret > 0) {
                 bh_result->b_size = (ret << inode->i_blkbits);
                 ret = 0;
@@ -1047,7 +1123,7 @@ struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
         dummy.b_blocknr = -1000;
         buffer_trace_init(&dummy.b_history);
         err = ext4_get_blocks_wrap(handle, inode, block, 1,
-                                        &dummy, create, 1);
+                                        &dummy, create, 1, 0);
         /*
          * ext4_get_blocks_handle() returns number of blocks
          * mapped. 0 in case of a HOLE.
@@ -1203,19 +1279,20 @@ static int ext4_write_begin(struct file *file, struct address_space *mapping,
         to = from + len;
 
 retry:
-        page = __grab_cache_page(mapping, index);
-        if (!page)
-                return -ENOMEM;
-        *pagep = page;
-
         handle = ext4_journal_start(inode, needed_blocks);
         if (IS_ERR(handle)) {
-                unlock_page(page);
-                page_cache_release(page);
                 ret = PTR_ERR(handle);
                 goto out;
         }
 
+        page = __grab_cache_page(mapping, index);
+        if (!page) {
+                ext4_journal_stop(handle);
+                ret = -ENOMEM;
+                goto out;
+        }
+        *pagep = page;
+
         ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
                                                         ext4_get_block);
 
@@ -1225,8 +1302,8 @@ retry:
         }
 
         if (ret) {
-                ext4_journal_stop(handle);
                 unlock_page(page);
+                ext4_journal_stop(handle);
                 page_cache_release(page);
         }
 
@@ -1236,15 +1313,6 @@ out:
         return ret;
 }
 
-int ext4_journal_dirty_data(handle_t *handle, struct buffer_head *bh)
-{
-        int err = jbd2_journal_dirty_data(handle, bh);
-        if (err)
-                ext4_journal_abort_handle(__func__, __func__,
-                                                bh, handle, err);
-        return err;
-}
-
 /* For write_end() in data=journal mode */
 static int write_end_fn(handle_t *handle, struct buffer_head *bh)
 {
@@ -1255,29 +1323,6 @@ static int write_end_fn(handle_t *handle, struct buffer_head *bh)
 }
 
 /*
- * Generic write_end handler for ordered and writeback ext4 journal modes.
- * We can't use generic_write_end, because that unlocks the page and we need to
- * unlock the page after ext4_journal_stop, but ext4_journal_stop must run
- * after block_write_end.
- */
-static int ext4_generic_write_end(struct file *file,
-                                struct address_space *mapping,
-                                loff_t pos, unsigned len, unsigned copied,
-                                struct page *page, void *fsdata)
-{
-        struct inode *inode = file->f_mapping->host;
-
-        copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
-
-        if (pos+copied > inode->i_size) {
-                i_size_write(inode, pos+copied);
-                mark_inode_dirty(inode);
-        }
-
-        return copied;
-}
-
-/*
  * We need to pick up the new inode size which generic_commit_write gave us
  * `file' can be NULL - eg, when called from page_symlink().
  *
@@ -1290,15 +1335,14 @@ static int ext4_ordered_write_end(struct file *file,
                                 struct page *page, void *fsdata)
 {
         handle_t *handle = ext4_journal_current_handle();
-        struct inode *inode = file->f_mapping->host;
+        struct inode *inode = mapping->host;
         unsigned from, to;
         int ret = 0, ret2;
 
         from = pos & (PAGE_CACHE_SIZE - 1);
         to = from + len;
 
-        ret = walk_page_buffers(handle, page_buffers(page),
-                from, to, NULL, ext4_journal_dirty_data);
+        ret = ext4_jbd2_file_inode(handle, inode);
 
         if (ret == 0) {
                 /*
@@ -1311,7 +1355,7 @@ static int ext4_ordered_write_end(struct file *file,
                 new_i_size = pos + copied;
                 if (new_i_size > EXT4_I(inode)->i_disksize)
                         EXT4_I(inode)->i_disksize = new_i_size;
-                ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
+                ret2 = generic_write_end(file, mapping, pos, len, copied,
                                                         page, fsdata);
                 copied = ret2;
                 if (ret2 < 0)
@@ -1320,8 +1364,6 @@ static int ext4_ordered_write_end(struct file *file,
         ret2 = ext4_journal_stop(handle);
         if (!ret)
                 ret = ret2;
-        unlock_page(page);
-        page_cache_release(page);
 
         return ret ? ret : copied;
 }
@@ -1332,7 +1374,7 @@ static int ext4_writeback_write_end(struct file *file,
                                 struct page *page, void *fsdata)
 {
         handle_t *handle = ext4_journal_current_handle();
-        struct inode *inode = file->f_mapping->host;
+        struct inode *inode = mapping->host;
         int ret = 0, ret2;
         loff_t new_i_size;
 
@@ -1340,7 +1382,7 @@ static int ext4_writeback_write_end(struct file *file,
         if (new_i_size > EXT4_I(inode)->i_disksize)
                 EXT4_I(inode)->i_disksize = new_i_size;
 
-        ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
+        ret2 = generic_write_end(file, mapping, pos, len, copied,
                                                         page, fsdata);
         copied = ret2;
         if (ret2 < 0)
@@ -1349,8 +1391,6 @@ static int ext4_writeback_write_end(struct file *file,
         ret2 = ext4_journal_stop(handle);
         if (!ret)
                 ret = ret2;
-        unlock_page(page);
-        page_cache_release(page);
 
         return ret ? ret : copied;
 }
@@ -1389,14 +1429,965 @@ static int ext4_journalled_write_end(struct file *file,
                         ret = ret2;
         }
 
+        unlock_page(page);
         ret2 = ext4_journal_stop(handle);
         if (!ret)
                 ret = ret2;
-        unlock_page(page);
         page_cache_release(page);
 
         return ret ? ret : copied;
 }
+/*
+ * Calculate the number of metadata blocks need to reserve
+ * to allocate @blocks for non extent file based file
+ */
+static int ext4_indirect_calc_metadata_amount(struct inode *inode, int blocks)
+{
+        int icap = EXT4_ADDR_PER_BLOCK(inode->i_sb);
+        int ind_blks, dind_blks, tind_blks;
+
+        /* number of new indirect blocks needed */
+        ind_blks = (blocks + icap - 1) / icap;
+
+        dind_blks = (ind_blks + icap - 1) / icap;
+
+        tind_blks = 1;
+
+        return ind_blks + dind_blks + tind_blks;
+}
+
+/*
+ * Calculate the number of metadata blocks need to reserve
+ * to allocate given number of blocks
+ */
+static int ext4_calc_metadata_amount(struct inode *inode, int blocks)
+{
+        if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)
+                return ext4_ext_calc_metadata_amount(inode, blocks);
+
+        return ext4_indirect_calc_metadata_amount(inode, blocks);
+}
+
+static int ext4_da_reserve_space(struct inode *inode, int nrblocks)
+{
+       struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+       unsigned long md_needed, mdblocks, total = 0;
+
+        /*
+         * recalculate the amount of metadata blocks to reserve
+         * in order to allocate nrblocks
+         * worse case is one extent per block
+         */
+        spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
+        total = EXT4_I(inode)->i_reserved_data_blocks + nrblocks;
+        mdblocks = ext4_calc_metadata_amount(inode, total);
+        BUG_ON(mdblocks < EXT4_I(inode)->i_reserved_meta_blocks);
+
+        md_needed = mdblocks - EXT4_I(inode)->i_reserved_meta_blocks;
+        total = md_needed + nrblocks;
+
+        if (ext4_has_free_blocks(sbi, total) < total) {
+                spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+                return -ENOSPC;
+        }
+
+        /* reduce fs free blocks counter */
+        percpu_counter_sub(&sbi->s_freeblocks_counter, total);
+
+        EXT4_I(inode)->i_reserved_data_blocks += nrblocks;
+        EXT4_I(inode)->i_reserved_meta_blocks = mdblocks;
+
+        spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+        return 0;       /* success */
+}
+
+void ext4_da_release_space(struct inode *inode, int used, int to_free)
+{
+        struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+        int total, mdb, mdb_free, release;
+
+        spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
+        /* recalculate the number of metablocks still need to be reserved */
+        total = EXT4_I(inode)->i_reserved_data_blocks - used - to_free;
+        mdb = ext4_calc_metadata_amount(inode, total);
+
+        /* figure out how many metablocks to release */
+        BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
+        mdb_free = EXT4_I(inode)->i_reserved_meta_blocks - mdb;
+
+        /* Account for allocated meta_blocks */
+        mdb_free -= EXT4_I(inode)->i_allocated_meta_blocks;
+
+        release = to_free + mdb_free;
+
+        /* update fs free blocks counter for truncate case */
+        percpu_counter_add(&sbi->s_freeblocks_counter, release);
+
+        /* update per-inode reservations */
+        BUG_ON(used + to_free > EXT4_I(inode)->i_reserved_data_blocks);
+        EXT4_I(inode)->i_reserved_data_blocks -= (used + to_free);
+
+        BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
+        EXT4_I(inode)->i_reserved_meta_blocks = mdb;
+        EXT4_I(inode)->i_allocated_meta_blocks = 0;
+        spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+}
+
+static void ext4_da_page_release_reservation(struct page *page,
+                                                unsigned long offset)
+{
+        int to_release = 0;
+        struct buffer_head *head, *bh;
+        unsigned int curr_off = 0;
+
+        head = page_buffers(page);
+        bh = head;
+        do {
+                unsigned int next_off = curr_off + bh->b_size;
+
+                if ((offset <= curr_off) && (buffer_delay(bh))) {
+                        to_release++;
+                        clear_buffer_delay(bh);
+                }
+                curr_off = next_off;
+        } while ((bh = bh->b_this_page) != head);
+        ext4_da_release_space(page->mapping->host, 0, to_release);
+}
+
+/*
+ * Delayed allocation stuff
+ */
+
+struct mpage_da_data {
+        struct inode *inode;
+        struct buffer_head lbh;                 /* extent of blocks */
+        unsigned long first_page, next_page;    /* extent of pages */
+        get_block_t *get_block;
+        struct writeback_control *wbc;
+};
+
+/*
+ * mpage_da_submit_io - walks through extent of pages and try to write
+ * them with __mpage_writepage()
+ *
+ * @mpd->inode: inode
+ * @mpd->first_page: first page of the extent
+ * @mpd->next_page: page after the last page of the extent
+ * @mpd->get_block: the filesystem's block mapper function
+ *
+ * By the time mpage_da_submit_io() is called we expect all blocks
+ * to be allocated. this may be wrong if allocation failed.
+ *
+ * As pages are already locked by write_cache_pages(), we can't use it
+ */
+static int mpage_da_submit_io(struct mpage_da_data *mpd)
+{
+        struct address_space *mapping = mpd->inode->i_mapping;
+        struct mpage_data mpd_pp = {
+                .bio = NULL,
+                .last_block_in_bio = 0,
+                .get_block = mpd->get_block,
+                .use_writepage = 1,
+        };
+        int ret = 0, err, nr_pages, i;
+        unsigned long index, end;
+        struct pagevec pvec;
+
+        BUG_ON(mpd->next_page <= mpd->first_page);
+
+        pagevec_init(&pvec, 0);
+        index = mpd->first_page;
+        end = mpd->next_page - 1;
+
+        while (index <= end) {
+                /* XXX: optimize tail */
+                nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
+                if (nr_pages == 0)
+                        break;
+                for (i = 0; i < nr_pages; i++) {
+                        struct page *page = pvec.pages[i];
+
+                        index = page->index;
+                        if (index > end)
+                                break;
+                        index++;
+
+                        err = __mpage_writepage(page, mpd->wbc, &mpd_pp);
+
+                        /*
+                         * In error case, we have to continue because
+                         * remaining pages are still locked
+                         * XXX: unlock and re-dirty them?
+                         */
+                        if (ret == 0)
+                                ret = err;
+                }
+                pagevec_release(&pvec);
+        }
+        if (mpd_pp.bio)
+                mpage_bio_submit(WRITE, mpd_pp.bio);
+
+        return ret;
+}
+
+/*
+ * mpage_put_bnr_to_bhs - walk blocks and assign them actual numbers
+ *
+ * @mpd->inode - inode to walk through
+ * @exbh->b_blocknr - first block on a disk
+ * @exbh->b_size - amount of space in bytes
+ * @logical - first logical block to start assignment with
+ *
+ * the function goes through all passed space and put actual disk
+ * block numbers into buffer heads, dropping BH_Delay
+ */
+static void mpage_put_bnr_to_bhs(struct mpage_da_data *mpd, sector_t logical,
+                                 struct buffer_head *exbh)
+{
+        struct inode *inode = mpd->inode;
+        struct address_space *mapping = inode->i_mapping;
+        int blocks = exbh->b_size >> inode->i_blkbits;
+        sector_t pblock = exbh->b_blocknr, cur_logical;
+        struct buffer_head *head, *bh;
+        unsigned long index, end;
+        struct pagevec pvec;
+        int nr_pages, i;
+
+        index = logical >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
+        end = (logical + blocks - 1) >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
+        cur_logical = index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
+
+        pagevec_init(&pvec, 0);
+
+        while (index <= end) {
+                /* XXX: optimize tail */
+                nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
+                if (nr_pages == 0)
+                        break;
+                for (i = 0; i < nr_pages; i++) {
+                        struct page *page = pvec.pages[i];
+
+                        index = page->index;
+                        if (index > end)
+                                break;
+                        index++;
+
+                        BUG_ON(!PageLocked(page));
+                        BUG_ON(PageWriteback(page));
+                        BUG_ON(!page_has_buffers(page));
+
+                        bh = page_buffers(page);
+                        head = bh;
+
+                        /* skip blocks out of the range */
+                        do {
+                                if (cur_logical >= logical)
+                                        break;
+                                cur_logical++;
+                        } while ((bh = bh->b_this_page) != head);
+
+                        do {
+                                if (cur_logical >= logical + blocks)
+                                        break;
+                                if (buffer_delay(bh)) {
+                                        bh->b_blocknr = pblock;
+                                        clear_buffer_delay(bh);
+                                } else if (buffer_mapped(bh))
+                                        BUG_ON(bh->b_blocknr != pblock);
+
+                                cur_logical++;
+                                pblock++;
+                        } while ((bh = bh->b_this_page) != head);
+                }
+                pagevec_release(&pvec);
+        }
+}
+
+
+/*
+ * __unmap_underlying_blocks - just a helper function to unmap
+ * set of blocks described by @bh
+ */
+static inline void __unmap_underlying_blocks(struct inode *inode,
+                                             struct buffer_head *bh)
+{
+        struct block_device *bdev = inode->i_sb->s_bdev;
+        int blocks, i;
+
+        blocks = bh->b_size >> inode->i_blkbits;
+        for (i = 0; i < blocks; i++)
+                unmap_underlying_metadata(bdev, bh->b_blocknr + i);
+}
+
+/*
+ * mpage_da_map_blocks - go through given space
+ *
+ * @mpd->lbh - bh describing space
+ * @mpd->get_block - the filesystem's block mapper function
+ *
+ * The function skips space we know is already mapped to disk blocks.
+ *
+ * The function ignores errors ->get_block() returns, thus real
+ * error handling is postponed to __mpage_writepage()
+ */
+static void mpage_da_map_blocks(struct mpage_da_data *mpd)
+{
+        struct buffer_head *lbh = &mpd->lbh;
+        int err = 0, remain = lbh->b_size;
+        sector_t next = lbh->b_blocknr;
+        struct buffer_head new;
+
+        /*
+         * We consider only non-mapped and non-allocated blocks
+         */
+        if (buffer_mapped(lbh) && !buffer_delay(lbh))
+                return;
+
+        while (remain) {
+                new.b_state = lbh->b_state;
+                new.b_blocknr = 0;
+                new.b_size = remain;
+                err = mpd->get_block(mpd->inode, next, &new, 1);
+                if (err) {
+                        /*
+                         * Rather than implement own error handling
+                         * here, we just leave remaining blocks
+                         * unallocated and try again with ->writepage()
+                         */
+                        break;
+                }
+                BUG_ON(new.b_size == 0);
+
+                if (buffer_new(&new))
+                        __unmap_underlying_blocks(mpd->inode, &new);
+
+                /*
+                 * If blocks are delayed marked, we need to
+                 * put actual blocknr and drop delayed bit
+                 */
+                if (buffer_delay(lbh))
+                        mpage_put_bnr_to_bhs(mpd, next, &new);
+
+                /* go for the remaining blocks */
+                next += new.b_size >> mpd->inode->i_blkbits;
+                remain -= new.b_size;
+        }
+}
+
+#define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | (1 << BH_Delay))
+
+/*
+ * mpage_add_bh_to_extent - try to add one more block to extent of blocks
+ *
+ * @mpd->lbh - extent of blocks
+ * @logical - logical number of the block in the file
+ * @bh - bh of the block (used to access block's state)
+ *
+ * the function is used to collect contig. blocks in same state
+ */
+static void mpage_add_bh_to_extent(struct mpage_da_data *mpd,
+                                   sector_t logical, struct buffer_head *bh)
+{
+        struct buffer_head *lbh = &mpd->lbh;
+        sector_t next;
+
+        next = lbh->b_blocknr + (lbh->b_size >> mpd->inode->i_blkbits);
+
+        /*
+         * First block in the extent
+         */
+        if (lbh->b_size == 0) {
+                lbh->b_blocknr = logical;
+                lbh->b_size = bh->b_size;
+                lbh->b_state = bh->b_state & BH_FLAGS;
+                return;
+        }
+
+        /*
+         * Can we merge the block to our big extent?
+         */
+        if (logical == next && (bh->b_state & BH_FLAGS) == lbh->b_state) {
+                lbh->b_size += bh->b_size;
+                return;
+        }
+
+        /*
+         * We couldn't merge the block to our extent, so we
+         * need to flush current  extent and start new one
+         */
+        mpage_da_map_blocks(mpd);
+
+        /*
+         * Now start a new extent
+         */
+        lbh->b_size = bh->b_size;
+        lbh->b_state = bh->b_state & BH_FLAGS;
+        lbh->b_blocknr = logical;
+}
+
+/*
+ * __mpage_da_writepage - finds extent of pages and blocks
+ *
+ * @page: page to consider
+ * @wbc: not used, we just follow rules
+ * @data: context
+ *
+ * The function finds extents of pages and scan them for all blocks.
+ */
+static int __mpage_da_writepage(struct page *page,
+                                struct writeback_control *wbc, void *data)
+{
+        struct mpage_da_data *mpd = data;
+        struct inode *inode = mpd->inode;
+        struct buffer_head *bh, *head, fake;
+        sector_t logical;
+
+        /*
+         * Can we merge this page to current extent?
+         */
+        if (mpd->next_page != page->index) {
+                /*
+                 * Nope, we can't. So, we map non-allocated blocks
+                 * and start IO on them using __mpage_writepage()
+                 */
+                if (mpd->next_page != mpd->first_page) {
+                        mpage_da_map_blocks(mpd);
+                        mpage_da_submit_io(mpd);
+                }
+
+                /*
+                 * Start next extent of pages ...
+                 */
+                mpd->first_page = page->index;
+
+                /*
+                 * ... and blocks
+                 */
+                mpd->lbh.b_size = 0;
+                mpd->lbh.b_state = 0;
+                mpd->lbh.b_blocknr = 0;
+        }
+
+        mpd->next_page = page->index + 1;
+        logical = (sector_t) page->index <<
+                  (PAGE_CACHE_SHIFT - inode->i_blkbits);
+
+        if (!page_has_buffers(page)) {
+                /*
+                 * There is no attached buffer heads yet (mmap?)
+                 * we treat the page asfull of dirty blocks
+                 */
+                bh = &fake;
+                bh->b_size = PAGE_CACHE_SIZE;
+                bh->b_state = 0;
+                set_buffer_dirty(bh);
+                set_buffer_uptodate(bh);
+                mpage_add_bh_to_extent(mpd, logical, bh);
+        } else {
+                /*
+                 * Page with regular buffer heads, just add all dirty ones
+                 */
+                head = page_buffers(page);
+                bh = head;
+                do {
+                        BUG_ON(buffer_locked(bh));
+                        if (buffer_dirty(bh))
+                                mpage_add_bh_to_extent(mpd, logical, bh);
+                        logical++;
+                } while ((bh = bh->b_this_page) != head);
+        }
+
+        return 0;
+}
+
+/*
+ * mpage_da_writepages - walk the list of dirty pages of the given
+ * address space, allocates non-allocated blocks, maps newly-allocated
+ * blocks to existing bhs and issue IO them
+ *
+ * @mapping: address space structure to write
+ * @wbc: subtract the number of written pages from *@wbc->nr_to_write
+ * @get_block: the filesystem's block mapper function.
+ *
+ * This is a library function, which implements the writepages()
+ * address_space_operation.
+ *
+ * In order to avoid duplication of logic that deals with partial pages,
+ * multiple bio per page, etc, we find non-allocated blocks, allocate
+ * them with minimal calls to ->get_block() and re-use __mpage_writepage()
+ *
+ * It's important that we call __mpage_writepage() only once for each
+ * involved page, otherwise we'd have to implement more complicated logic
+ * to deal with pages w/o PG_lock or w/ PG_writeback and so on.
+ *
+ * See comments to mpage_writepages()
+ */
+static int mpage_da_writepages(struct address_space *mapping,
+                               struct writeback_control *wbc,
+                               get_block_t get_block)
+{
+        struct mpage_da_data mpd;
+        int ret;
+
+        if (!get_block)
+                return generic_writepages(mapping, wbc);
+
+        mpd.wbc = wbc;
+        mpd.inode = mapping->host;
+        mpd.lbh.b_size = 0;
+        mpd.lbh.b_state = 0;
+        mpd.lbh.b_blocknr = 0;
+        mpd.first_page = 0;
+        mpd.next_page = 0;
+        mpd.get_block = get_block;
+
+        ret = write_cache_pages(mapping, wbc, __mpage_da_writepage, &mpd);
+
+        /*
+         * Handle last extent of pages
+         */
+        if (mpd.next_page != mpd.first_page) {
+                mpage_da_map_blocks(&mpd);
+                mpage_da_submit_io(&mpd);
+        }
+
+        return ret;
+}
+
+/*
+ * this is a special callback for ->write_begin() only
+ * it's intention is to return mapped block or reserve space
+ */
+static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
+                                  struct buffer_head *bh_result, int create)
+{
+        int ret = 0;
+
+        BUG_ON(create == 0);
+        BUG_ON(bh_result->b_size != inode->i_sb->s_blocksize);
+
+        /*
+         * first, we need to know whether the block is allocated already
+         * preallocated blocks are unmapped but should treated
+         * the same as allocated blocks.
+         */
+        ret = ext4_get_blocks_wrap(NULL, inode, iblock, 1,  bh_result, 0, 0, 0);
+        if ((ret == 0) && !buffer_delay(bh_result)) {
+                /* the block isn't (pre)allocated yet, let's reserve space */
+                /*
+                 * XXX: __block_prepare_write() unmaps passed block,
+                 * is it OK?
+                 */
+                ret = ext4_da_reserve_space(inode, 1);
+                if (ret)
+                        /* not enough space to reserve */
+                        return ret;
+
+                map_bh(bh_result, inode->i_sb, 0);
+                set_buffer_new(bh_result);
+                set_buffer_delay(bh_result);
+        } else if (ret > 0) {
+                bh_result->b_size = (ret << inode->i_blkbits);
+                ret = 0;
+        }
+
+        return ret;
+}
+#define         EXT4_DELALLOC_RSVED     1
+static int ext4_da_get_block_write(struct inode *inode, sector_t iblock,
+                                   struct buffer_head *bh_result, int create)
+{
+        int ret;
+        unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
+        loff_t disksize = EXT4_I(inode)->i_disksize;
+        handle_t *handle = NULL;
+
+        handle = ext4_journal_current_handle();
+        if (!handle) {
+                ret = ext4_get_blocks_wrap(handle, inode, iblock, max_blocks,
+                                   bh_result, 0, 0, 0);
+                BUG_ON(!ret);
+        } else {
+                ret = ext4_get_blocks_wrap(handle, inode, iblock, max_blocks,
+                                   bh_result, create, 0, EXT4_DELALLOC_RSVED);
+        }
+
+        if (ret > 0) {
+                bh_result->b_size = (ret << inode->i_blkbits);
+
+                /*
+                 * Update on-disk size along with block allocation
+                 * we don't use 'extend_disksize' as size may change
+                 * within already allocated block -bzzz
+                 */
+                disksize = ((loff_t) iblock + ret) << inode->i_blkbits;
+                if (disksize > i_size_read(inode))
+                        disksize = i_size_read(inode);
+                if (disksize > EXT4_I(inode)->i_disksize) {
+                        /*
+                         * XXX: replace with spinlock if seen contended -bzzz
+                         */
+                        down_write(&EXT4_I(inode)->i_data_sem);
+                        if (disksize > EXT4_I(inode)->i_disksize)
+                                EXT4_I(inode)->i_disksize = disksize;
+                        up_write(&EXT4_I(inode)->i_data_sem);
+
+                        if (EXT4_I(inode)->i_disksize == disksize) {
+                                ret = ext4_mark_inode_dirty(handle, inode);
+                                return ret;
+                        }
+                }
+                ret = 0;
+        }
+        return ret;
+}
+
+static int ext4_bh_unmapped_or_delay(handle_t *handle, struct buffer_head *bh)
+{
+        /*
+         * unmapped buffer is possible for holes.
+         * delay buffer is possible with delayed allocation
+         */
+        return ((!buffer_mapped(bh) || buffer_delay(bh)) && buffer_dirty(bh));
+}
+
+static int ext4_normal_get_block_write(struct inode *inode, sector_t iblock,
+                                   struct buffer_head *bh_result, int create)
+{
+        int ret = 0;
+        unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
+
+        /*
+         * we don't want to do block allocation in writepage
+         * so call get_block_wrap with create = 0
+         */
+        ret = ext4_get_blocks_wrap(NULL, inode, iblock, max_blocks,
+                                   bh_result, 0, 0, 0);
+        if (ret > 0) {
+                bh_result->b_size = (ret << inode->i_blkbits);
+                ret = 0;
+        }
+        return ret;
+}
+
+/*
+ * get called vi ext4_da_writepages after taking page lock (have journal handle)
+ * get called via journal_submit_inode_data_buffers (no journal handle)
+ * get called via shrink_page_list via pdflush (no journal handle)
+ * or grab_page_cache when doing write_begin (have journal handle)
+ */
+static int ext4_da_writepage(struct page *page,
+                                struct writeback_control *wbc)
+{
+        int ret = 0;
+        loff_t size;
+        unsigned long len;
+        struct buffer_head *page_bufs;
+        struct inode *inode = page->mapping->host;
+
+        size = i_size_read(inode);
+        if (page->index == size >> PAGE_CACHE_SHIFT)
+                len = size & ~PAGE_CACHE_MASK;
+        else
+                len = PAGE_CACHE_SIZE;
+
+        if (page_has_buffers(page)) {
+                page_bufs = page_buffers(page);
+                if (walk_page_buffers(NULL, page_bufs, 0, len, NULL,
+                                        ext4_bh_unmapped_or_delay)) {
+                        /*
+                         * 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.
+                         * If we don't have mapping block we just ignore
+                         * them. We can also reach here via shrink_page_list
+                         */
+                        redirty_page_for_writepage(wbc, page);
+                        unlock_page(page);
+                        return 0;
+                }
+        } else {
+                /*
+                 * The test for page_has_buffers() is subtle:
+                 * We know the page is dirty but it lost buffers. That means
+                 * that at some moment in time after write_begin()/write_end()
+                 * has been called all buffers have been clean and thus they
+                 * must have been written at least once. So they are all
+                 * mapped and we can happily proceed with mapping them
+                 * and writing the page.
+                 *
+                 * Try to initialize the buffer_heads and check whether
+                 * all are mapped and non delay. We don't want to
+                 * do block allocation here.
+                 */
+                ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
+                                                ext4_normal_get_block_write);
+                if (!ret) {
+                        page_bufs = page_buffers(page);
+                        /* check whether all are mapped and non delay */
+                        if (walk_page_buffers(NULL, page_bufs, 0, len, NULL,
+                                                ext4_bh_unmapped_or_delay)) {
+                                redirty_page_for_writepage(wbc, page);
+                                unlock_page(page);
+                                return 0;
+                        }
+                } else {
+                        /*
+                         * We can't do block allocation here
+                         * so just redity the page and unlock
+                         * and return
+                         */
+                        redirty_page_for_writepage(wbc, page);
+                        unlock_page(page);
+                        return 0;
+                }
+        }
+
+        if (test_opt(inode->i_sb, NOBH) && ext4_should_writeback_data(inode))
+                ret = nobh_writepage(page, ext4_normal_get_block_write, wbc);
+        else
+                ret = block_write_full_page(page,
+                                                ext4_normal_get_block_write,
+                                                wbc);
+
+        return ret;
+}
+
+/*
+ * For now just follow the DIO way to estimate the max credits
+ * needed to write out EXT4_MAX_WRITEBACK_PAGES.
+ * todo: need to calculate the max credits need for
+ * extent based files, currently the DIO credits is based on
+ * indirect-blocks mapping way.
+ *
+ * Probably should have a generic way to calculate credits
+ * for DIO, writepages, and truncate
+ */
+#define EXT4_MAX_WRITEBACK_PAGES      DIO_MAX_BLOCKS
+#define EXT4_MAX_WRITEBACK_CREDITS    DIO_CREDITS
+
+static int ext4_da_writepages(struct address_space *mapping,
+                                struct writeback_control *wbc)
+{
+        struct inode *inode = mapping->host;
+        handle_t *handle = NULL;
+        int needed_blocks;
+        int ret = 0;
+        long to_write;
+        loff_t range_start = 0;
+
+        /*
+         * No pages to write? This is mainly a kludge to avoid starting
+         * a transaction for special inodes like journal inode on last iput()
+         * because that could violate lock ordering on umount
+         */
+        if (!mapping->nrpages)
+                return 0;
+
+        /*
+         * Estimate the worse case needed credits to write out
+         * EXT4_MAX_BUF_BLOCKS pages
+         */
+        needed_blocks = EXT4_MAX_WRITEBACK_CREDITS;
+
+        to_write = wbc->nr_to_write;
+        if (!wbc->range_cyclic) {
+                /*
+                 * If range_cyclic is not set force range_cont
+                 * and save the old writeback_index
+                 */
+                wbc->range_cont = 1;
+                range_start =  wbc->range_start;
+        }
+
+        while (!ret && to_write) {
+                /* start a new transaction*/
+                handle = ext4_journal_start(inode, needed_blocks);
+                if (IS_ERR(handle)) {
+                        ret = PTR_ERR(handle);
+                        goto out_writepages;
+                }
+                if (ext4_should_order_data(inode)) {
+                        /*
+                         * With ordered mode we need to add
+                         * the inode to the journal handle
+                         * when we do block allocation.
+                         */
+                        ret = ext4_jbd2_file_inode(handle, inode);
+                        if (ret) {
+                                ext4_journal_stop(handle);
+                                goto out_writepages;
+                        }
+
+                }
+                /*
+                 * set the max dirty pages could be write at a time
+                 * to fit into the reserved transaction credits
+                 */
+                if (wbc->nr_to_write > EXT4_MAX_WRITEBACK_PAGES)
+                        wbc->nr_to_write = EXT4_MAX_WRITEBACK_PAGES;
+
+                to_write -= wbc->nr_to_write;
+                ret = mpage_da_writepages(mapping, wbc,
+                                                ext4_da_get_block_write);
+                ext4_journal_stop(handle);
+                if (wbc->nr_to_write) {
+                        /*
+                         * There is no more writeout needed
+                         * or we requested for a noblocking writeout
+                         * and we found the device congested
+                         */
+                        to_write += wbc->nr_to_write;
+                        break;
+                }
+                wbc->nr_to_write = to_write;
+        }
+
+out_writepages:
+        wbc->nr_to_write = to_write;
+        if (range_start)
+                wbc->range_start = range_start;
+        return ret;
+}
+
+static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
+                                loff_t pos, unsigned len, unsigned flags,
+                                struct page **pagep, void **fsdata)
+{
+        int ret, retries = 0;
+        struct page *page;
+        pgoff_t index;
+        unsigned from, to;
+        struct inode *inode = mapping->host;
+        handle_t *handle;
+
+        index = pos >> PAGE_CACHE_SHIFT;
+        from = pos & (PAGE_CACHE_SIZE - 1);
+        to = from + len;
+
+retry:
+        /*
+         * With delayed allocation, we don't log the i_disksize update
+         * if there is delayed block allocation. But we still need
+         * to journalling the i_disksize update if writes to the end
+         * of file which has an already mapped buffer.
+         */
+        handle = ext4_journal_start(inode, 1);
+        if (IS_ERR(handle)) {
+                ret = PTR_ERR(handle);
+                goto out;
+        }
+
+        page = __grab_cache_page(mapping, index);
+        if (!page)
+                return -ENOMEM;
+        *pagep = page;
+
+        ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+                                                        ext4_da_get_block_prep);
+        if (ret < 0) {
+                unlock_page(page);
+                ext4_journal_stop(handle);
+                page_cache_release(page);
+        }
+
+        if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
+                goto retry;
+out:
+        return ret;
+}
+
+/*
+ * Check if we should update i_disksize
+ * when write to the end of file but not require block allocation
+ */
+static int ext4_da_should_update_i_disksize(struct page *page,
+                                         unsigned long offset)
+{
+        struct buffer_head *bh;
+        struct inode *inode = page->mapping->host;
+        unsigned int idx;
+        int i;
+
+        bh = page_buffers(page);
+        idx = offset >> inode->i_blkbits;
+
+        for (i=0; i < idx; i++)
+                bh = bh->b_this_page;
+
+        if (!buffer_mapped(bh) || (buffer_delay(bh)))
+                return 0;
+        return 1;
+}
+
+static int ext4_da_write_end(struct file *file,
+                                struct address_space *mapping,
+                                loff_t pos, unsigned len, unsigned copied,
+                                struct page *page, void *fsdata)
+{
+        struct inode *inode = mapping->host;
+        int ret = 0, ret2;
+        handle_t *handle = ext4_journal_current_handle();
+        loff_t new_i_size;
+        unsigned long start, end;
+
+        start = pos & (PAGE_CACHE_SIZE - 1);
+        end = start + copied -1;
+
+        /*
+         * generic_write_end() will run mark_inode_dirty() if i_size
+         * changes.  So let's piggyback the i_disksize mark_inode_dirty
+         * into that.
+         */
+
+        new_i_size = pos + copied;
+        if (new_i_size > EXT4_I(inode)->i_disksize) {
+                if (ext4_da_should_update_i_disksize(page, end)) {
+                        down_write(&EXT4_I(inode)->i_data_sem);
+                        if (new_i_size > EXT4_I(inode)->i_disksize) {
+                                /*
+                                 * Updating i_disksize when extending file
+                                 * without needing block allocation
+                                 */
+                                if (ext4_should_order_data(inode))
+                                        ret = ext4_jbd2_file_inode(handle,
+                                                                   inode);
+
+                                EXT4_I(inode)->i_disksize = new_i_size;
+                        }
+                        up_write(&EXT4_I(inode)->i_data_sem);
+                }
+        }
+        ret2 = generic_write_end(file, mapping, pos, len, copied,
+                                                        page, fsdata);
+        copied = ret2;
+        if (ret2 < 0)
+                ret = ret2;
+        ret2 = ext4_journal_stop(handle);
+        if (!ret)
+                ret = ret2;
+
+        return ret ? ret : copied;
+}
+
+static void ext4_da_invalidatepage(struct page *page, unsigned long offset)
+{
+        /*
+         * Drop reserved blocks
+         */
+        BUG_ON(!PageLocked(page));
+        if (!page_has_buffers(page))
+                goto out;
+
+        ext4_da_page_release_reservation(page, offset);
+
+out:
+        ext4_invalidatepage(page, offset);
+
+        return;
+}
+
 
 /*
  * bmap() is special.  It gets used by applications such as lilo and by
@@ -1418,6 +2409,16 @@ static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
         journal_t *journal;
         int err;
 
+        if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
+                        test_opt(inode->i_sb, DELALLOC)) {
+                /*
+                 * With delalloc we want to sync the file
+                 * so that we can make sure we allocate
+                 * blocks for file
+                 */
+                filemap_write_and_wait(mapping);
+        }
+
         if (EXT4_I(inode)->i_state & EXT4_STATE_JDATA) {
                 /*
                  * This is a REALLY heavyweight approach, but the use of
@@ -1462,21 +2463,17 @@ static int bput_one(handle_t *handle, struct buffer_head *bh)
         return 0;
 }
 
-static int jbd2_journal_dirty_data_fn(handle_t *handle, struct buffer_head *bh)
-{
-        if (buffer_mapped(bh))
-                return ext4_journal_dirty_data(handle, bh);
-        return 0;
-}
-
 /*
- * Note that we always start a transaction even if we're not journalling
- * data.  This is to preserve ordering: any hole instantiation within
- * __block_write_full_page -> ext4_get_block() should be journalled
- * along with the data so we don't crash and then get metadata which
- * refers to old data.
+ * Note that we don't need to start a transaction unless we're journaling data
+ * because we should have holes filled from ext4_page_mkwrite(). We even don't
+ * need to file the inode to the transaction's list in ordered mode because if
+ * we are writing back data added by write(), the inode is already there and if
+ * we are writing back data modified via mmap(), noone guarantees in which
+ * transaction the data will hit the disk. In case we are journaling data, we
+ * cannot start transaction directly because transaction start ranks above page
+ * lock so we have to do some magic.
  *
- * In all journalling modes block_write_full_page() will start the I/O.
+ * In all journaling modes block_write_full_page() will start the I/O.
  *
  * Problem:
  *
@@ -1518,105 +2515,103 @@ static int jbd2_journal_dirty_data_fn(handle_t *handle, struct buffer_head *bh)
  * disastrous.  Any write() or metadata operation will sync the fs for
  * us.
  *
- * AKPM2: if all the page's buffers are mapped to disk and !data=journal,
- * we don't need to open a transaction here.
  */
-static int ext4_ordered_writepage(struct page *page,
+static int __ext4_normal_writepage(struct page *page,
                                 struct writeback_control *wbc)
 {
         struct inode *inode = page->mapping->host;
-        struct buffer_head *page_bufs;
-        handle_t *handle = NULL;
-        int ret = 0;
-        int err;
-
-        J_ASSERT(PageLocked(page));
-
-        /*
-         * We give up here if we're reentered, because it might be for a
-         * different filesystem.
-         */
-        if (ext4_journal_current_handle())
-                goto out_fail;
 
-        handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
+        if (test_opt(inode->i_sb, NOBH))
+                return nobh_writepage(page,
+                                        ext4_normal_get_block_write, wbc);
+        else
+                return block_write_full_page(page,
+                                                ext4_normal_get_block_write,
+                                                wbc);
+}
 
-        if (IS_ERR(handle)) {
-                ret = PTR_ERR(handle);
-                goto out_fail;
-        }
+static int ext4_normal_writepage(struct page *page,
+                                struct writeback_control *wbc)
+{
+        struct inode *inode = page->mapping->host;
+        loff_t size = i_size_read(inode);
+        loff_t len;
 
-        if (!page_has_buffers(page)) {
-                create_empty_buffers(page, inode->i_sb->s_blocksize,
-                                (1 << BH_Dirty)|(1 << BH_Uptodate));
+        J_ASSERT(PageLocked(page));
+        if (page->index == size >> PAGE_CACHE_SHIFT)
+                len = size & ~PAGE_CACHE_MASK;
+        else
+                len = PAGE_CACHE_SIZE;
+
+        if (page_has_buffers(page)) {
+                /* if page has buffers it should all be mapped
+                 * and allocated. If there are not buffers attached
+                 * to the page we know the page is dirty but it lost
+                 * buffers. That means that at some moment in time
+                 * after write_begin() / write_end() has been called
+                 * all buffers have been clean and thus they must have been
+                 * written at least once. So they are all mapped and we can
+                 * happily proceed with mapping them and writing the page.
+                 */
+                BUG_ON(walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
+                                        ext4_bh_unmapped_or_delay));
         }
-        page_bufs = page_buffers(page);
-        walk_page_buffers(handle, page_bufs, 0,
-                        PAGE_CACHE_SIZE, NULL, bget_one);
-
-        ret = block_write_full_page(page, ext4_get_block, wbc);
 
-        /*
-         * The page can become unlocked at any point now, and
-         * truncate can then come in and change things.  So we
-         * can't touch *page from now on.  But *page_bufs is
-         * safe due to elevated refcount.
-         */
+        if (!ext4_journal_current_handle())
+                return __ext4_normal_writepage(page, wbc);
 
-        /*
-         * And attach them to the current transaction.  But only if
-         * block_write_full_page() succeeded.  Otherwise they are unmapped,
-         * and generally junk.
-         */
-        if (ret == 0) {
-                err = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE,
-                                        NULL, jbd2_journal_dirty_data_fn);
-                if (!ret)
-                        ret = err;
-        }
-        walk_page_buffers(handle, page_bufs, 0,
-                        PAGE_CACHE_SIZE, NULL, bput_one);
-        err = ext4_journal_stop(handle);
-        if (!ret)
-                ret = err;
-        return ret;
-
-out_fail:
         redirty_page_for_writepage(wbc, page);
         unlock_page(page);
-        return ret;
+        return 0;
 }
 
-static int ext4_writeback_writepage(struct page *page,
+static int __ext4_journalled_writepage(struct page *page,
                                 struct writeback_control *wbc)
 {
-        struct inode *inode = page->mapping->host;
+        struct address_space *mapping = page->mapping;
+        struct inode *inode = mapping->host;
+        struct buffer_head *page_bufs;
         handle_t *handle = NULL;
         int ret = 0;
         int err;
 
-        if (ext4_journal_current_handle())
-                goto out_fail;
+        ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
+                                        ext4_normal_get_block_write);
+        if (ret != 0)
+                goto out_unlock;
+
+        page_bufs = page_buffers(page);
+        walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE, NULL,
+                                                                bget_one);
+        /* As soon as we unlock the page, it can go away, but we have
+         * references to buffers so we are safe */
+        unlock_page(page);
 
         handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
         if (IS_ERR(handle)) {
                 ret = PTR_ERR(handle);
-                goto out_fail;
+                goto out;
         }
 
-        if (test_opt(inode->i_sb, NOBH) && ext4_should_writeback_data(inode))
-                ret = nobh_writepage(page, ext4_get_block, wbc);
-        else
-                ret = block_write_full_page(page, ext4_get_block, wbc);
+        ret = walk_page_buffers(handle, page_bufs, 0,
+                        PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
 
+        err = walk_page_buffers(handle, page_bufs, 0,
+                                PAGE_CACHE_SIZE, NULL, write_end_fn);
+        if (ret == 0)
+                ret = err;
         err = ext4_journal_stop(handle);
         if (!ret)
                 ret = err;
-        return ret;
 
-out_fail:
-        redirty_page_for_writepage(wbc, page);
+        walk_page_buffers(handle, page_bufs, 0,
+                                PAGE_CACHE_SIZE, NULL, bput_one);
+        EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;
+        goto out;
+
+out_unlock:
         unlock_page(page);
+out:
         return ret;
 }
 
@@ -1624,59 +2619,53 @@ static int ext4_journalled_writepage(struct page *page,
                                 struct writeback_control *wbc)
 {
         struct inode *inode = page->mapping->host;
-        handle_t *handle = NULL;
-        int ret = 0;
-        int err;
+        loff_t size = i_size_read(inode);
+        loff_t len;
 
-        if (ext4_journal_current_handle())
-                goto no_write;
+        J_ASSERT(PageLocked(page));
+        if (page->index == size >> PAGE_CACHE_SHIFT)
+                len = size & ~PAGE_CACHE_MASK;
+        else
+                len = PAGE_CACHE_SIZE;
+
+        if (page_has_buffers(page)) {
+                /* if page has buffers it should all be mapped
+                 * and allocated. If there are not buffers attached
+                 * to the page we know the page is dirty but it lost
+                 * buffers. That means that at some moment in time
+                 * after write_begin() / write_end() has been called
+                 * all buffers have been clean and thus they must have been
+                 * written at least once. So they are all mapped and we can
+                 * happily proceed with mapping them and writing the page.
+                 */
+                BUG_ON(walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
+                                        ext4_bh_unmapped_or_delay));
+        }
 
-        handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
-        if (IS_ERR(handle)) {
-                ret = PTR_ERR(handle);
+        if (ext4_journal_current_handle())
                 goto no_write;
-        }
 
-        if (!page_has_buffers(page) || PageChecked(page)) {
+        if (PageChecked(page)) {
                 /*
                  * It's mmapped pagecache.  Add buffers and journal it.  There
                  * doesn't seem much point in redirtying the page here.
                  */
                 ClearPageChecked(page);
-                ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
-                                        ext4_get_block);
-                if (ret != 0) {
-                        ext4_journal_stop(handle);
-                        goto out_unlock;
-                }
-                ret = walk_page_buffers(handle, page_buffers(page), 0,
-                        PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
-
-                err = walk_page_buffers(handle, page_buffers(page), 0,
-                                PAGE_CACHE_SIZE, NULL, write_end_fn);
-                if (ret == 0)
-                        ret = err;
-                EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;
-                unlock_page(page);
+                return __ext4_journalled_writepage(page, wbc);
         } else {
                 /*
                  * It may be a page full of checkpoint-mode buffers.  We don't
                  * really know unless we go poke around in the buffer_heads.
                  * But block_write_full_page will do the right thing.
                  */
-                ret = block_write_full_page(page, ext4_get_block, wbc);
+                return block_write_full_page(page,
+                                                ext4_normal_get_block_write,
+                                                wbc);
         }
-        err = ext4_journal_stop(handle);
-        if (!ret)
-                ret = err;
-out:
-        return ret;
-
 no_write:
         redirty_page_for_writepage(wbc, page);
-out_unlock:
         unlock_page(page);
-        goto out;
+        return 0;
 }
 
 static int ext4_readpage(struct file *file, struct page *page)
@@ -1819,7 +2808,7 @@ static int ext4_journalled_set_page_dirty(struct page *page)
 static const struct address_space_operations ext4_ordered_aops = {
         .readpage       = ext4_readpage,
         .readpages      = ext4_readpages,
-        .writepage      = ext4_ordered_writepage,
+        .writepage      = ext4_normal_writepage,
         .sync_page      = block_sync_page,
         .write_begin    = ext4_write_begin,
         .write_end      = ext4_ordered_write_end,
@@ -1833,7 +2822,7 @@ static const struct address_space_operations ext4_ordered_aops = {
 static const struct address_space_operations ext4_writeback_aops = {
         .readpage       = ext4_readpage,
         .readpages      = ext4_readpages,
-        .writepage      = ext4_writeback_writepage,
+        .writepage      = ext4_normal_writepage,
         .sync_page      = block_sync_page,
         .write_begin    = ext4_write_begin,
         .write_end      = ext4_writeback_write_end,
@@ -1857,10 +2846,31 @@ static const struct address_space_operations ext4_journalled_aops = {
         .releasepage    = ext4_releasepage,
 };
 
+static const struct address_space_operations ext4_da_aops = {
+        .readpage       = ext4_readpage,
+        .readpages      = ext4_readpages,
+        .writepage      = ext4_da_writepage,
+        .writepages     = ext4_da_writepages,
+        .sync_page      = block_sync_page,
+        .write_begin    = ext4_da_write_begin,
+        .write_end      = ext4_da_write_end,
+        .bmap           = ext4_bmap,
+        .invalidatepage = ext4_da_invalidatepage,
+        .releasepage    = ext4_releasepage,
+        .direct_IO      = ext4_direct_IO,
+        .migratepage    = buffer_migrate_page,
+};
+
 void ext4_set_aops(struct inode *inode)
 {
-        if (ext4_should_order_data(inode))
+        if (ext4_should_order_data(inode) &&
+                test_opt(inode->i_sb, DELALLOC))
+                inode->i_mapping->a_ops = &ext4_da_aops;
+        else if (ext4_should_order_data(inode))
                 inode->i_mapping->a_ops = &ext4_ordered_aops;
+        else if (ext4_should_writeback_data(inode) &&
+                 test_opt(inode->i_sb, DELALLOC))
+                inode->i_mapping->a_ops = &ext4_da_aops;
         else if (ext4_should_writeback_data(inode))
                 inode->i_mapping->a_ops = &ext4_writeback_aops;
         else
@@ -1873,7 +2883,7 @@ void ext4_set_aops(struct inode *inode)
  * This required during truncate. We need to physically zero the tail end
  * of that block so it doesn't yield old data if the file is later grown.
  */
-int ext4_block_truncate_page(handle_t *handle, struct page *page,
+int ext4_block_truncate_page(handle_t *handle,
                 struct address_space *mapping, loff_t from)
 {
         ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT;
@@ -1882,8 +2892,13 @@ int ext4_block_truncate_page(handle_t *handle, struct page *page,
         ext4_lblk_t iblock;
         struct inode *inode = mapping->host;
         struct buffer_head *bh;
+        struct page *page;
         int err = 0;
 
+        page = grab_cache_page(mapping, from >> PAGE_CACHE_SHIFT);
+        if (!page)
+                return -EINVAL;
+
         blocksize = inode->i_sb->s_blocksize;
         length = blocksize - (offset & (blocksize - 1));
         iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
@@ -1956,7 +2971,7 @@ int ext4_block_truncate_page(handle_t *handle, struct page *page,
                 err = ext4_journal_dirty_metadata(handle, bh);
         } else {
                 if (ext4_should_order_data(inode))
-                        err = ext4_journal_dirty_data(handle, bh);
+                        err = ext4_jbd2_file_inode(handle, inode);
                 mark_buffer_dirty(bh);
         }
 
@@ -2179,7 +3194,21 @@ static void ext4_free_data(handle_t *handle, struct inode *inode,
 
         if (this_bh) {
                 BUFFER_TRACE(this_bh, "call ext4_journal_dirty_metadata");
-                ext4_journal_dirty_metadata(handle, this_bh);
+
+                /*
+                 * The buffer head should have an attached journal head at this
+                 * point. However, if the data is corrupted and an indirect
+                 * block pointed to itself, it would have been detached when
+                 * the block was cleared. Check for this instead of OOPSing.
+                 */
+                if (bh2jh(this_bh))
+                        ext4_journal_dirty_metadata(handle, this_bh);
+                else
+                        ext4_error(inode->i_sb, __func__,
+                                   "circular indirect block detected, "
+                                   "inode=%lu, block=%llu",
+                                   inode->i_ino,
+                                   (unsigned long long) this_bh->b_blocknr);
         }
 }
 
@@ -2305,6 +3334,19 @@ static void ext4_free_branches(handle_t *handle, struct inode *inode,
         }
 }
 
+int ext4_can_truncate(struct inode *inode)
+{
+        if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+                return 0;
+        if (S_ISREG(inode->i_mode))
+                return 1;
+        if (S_ISDIR(inode->i_mode))
+                return 1;
+        if (S_ISLNK(inode->i_mode))
+                return !ext4_inode_is_fast_symlink(inode);
+        return 0;
+}
+
 /*
  * ext4_truncate()
  *
@@ -2347,51 +3389,25 @@ void ext4_truncate(struct inode *inode)
         int n;
         ext4_lblk_t last_block;
         unsigned blocksize = inode->i_sb->s_blocksize;
-        struct page *page;
 
-        if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
-            S_ISLNK(inode->i_mode)))
-                return;
-        if (ext4_inode_is_fast_symlink(inode))
-                return;
-        if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+        if (!ext4_can_truncate(inode))
                 return;
 
-        /*
-         * We have to lock the EOF page here, because lock_page() nests
-         * outside jbd2_journal_start().
-         */
-        if ((inode->i_size & (blocksize - 1)) == 0) {
-                /* Block boundary? Nothing to do */
-                page = NULL;
-        } else {
-                page = grab_cache_page(mapping,
-                                inode->i_size >> PAGE_CACHE_SHIFT);
-                if (!page)
-                        return;
-        }
-
         if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
-                ext4_ext_truncate(inode, page);
+                ext4_ext_truncate(inode);
                 return;
         }
 
         handle = start_transaction(inode);
-        if (IS_ERR(handle)) {
-                if (page) {
-                        clear_highpage(page);
-                        flush_dcache_page(page);
-                        unlock_page(page);
-                        page_cache_release(page);
-                }
+        if (IS_ERR(handle))
                 return;         /* AKPM: return what? */
-        }
 
         last_block = (inode->i_size + blocksize-1)
                                         >> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
 
-        if (page)
-                ext4_block_truncate_page(handle, page, mapping, inode->i_size);
+        if (inode->i_size & (blocksize - 1))
+                if (ext4_block_truncate_page(handle, mapping, inode->i_size))
+                        goto out_stop;
 
         n = ext4_block_to_path(inode, last_block, offsets, NULL);
         if (n == 0)
@@ -2410,6 +3426,11 @@ void ext4_truncate(struct inode *inode)
                 goto out_stop;
 
         /*
+         * From here we block out all ext4_get_block() callers who want to
+         * modify the block allocation tree.
+         */
+        down_write(&ei->i_data_sem);
+        /*
          * The orphan list entry will now protect us from any crash which
          * occurs before the truncate completes, so it is now safe to propagate
          * the new, shorter inode size (held for now in i_size) into the
@@ -2418,12 +3439,6 @@ void ext4_truncate(struct inode *inode)
          */
         ei->i_disksize = inode->i_size;
 
-        /*
-         * From here we block out all ext4_get_block() callers who want to
-         * modify the block allocation tree.
-         */
-        down_write(&ei->i_data_sem);
-
         if (n == 1) {           /* direct blocks */
                 ext4_free_data(handle, inode, NULL, i_data+offsets[0],
                                i_data + EXT4_NDIR_BLOCKS);
@@ -3107,7 +4122,14 @@ int ext4_write_inode(struct inode *inode, int wait)
  * be freed, so we have a strong guarantee that no future commit will
  * leave these blocks visible to the user.)
  *
- * Called with inode->sem down.
+ * Another thing we have to assure is that if we are in ordered mode
+ * and inode is still attached to the committing transaction, we must
+ * we start writeout of all the dirty pages which are being truncated.
+ * This way we are sure that all the data written in the previous
+ * transaction are already on disk (truncate waits for pages under
+ * writeback).
+ *
+ * Called with inode->i_mutex down.
  */
 int ext4_setattr(struct dentry *dentry, struct iattr *attr)
 {
@@ -3173,6 +4195,22 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
                 if (!error)
                         error = rc;
                 ext4_journal_stop(handle);
+
+                if (ext4_should_order_data(inode)) {
+                        error = ext4_begin_ordered_truncate(inode,
+                                                            attr->ia_size);
+                        if (error) {
+                                /* Do as much error cleanup as possible */
+                                handle = ext4_journal_start(inode, 3);
+                                if (IS_ERR(handle)) {
+                                        ext4_orphan_del(NULL, inode);
+                                        goto err_out;
+                                }
+                                ext4_orphan_del(handle, inode);
+                                ext4_journal_stop(handle);
+                                goto err_out;
+                        }
+                }
         }
 
         rc = inode_setattr(inode, attr);
@@ -3193,6 +4231,32 @@ err_out:
         return error;
 }
 
+int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
+                 struct kstat *stat)
+{
+        struct inode *inode;
+        unsigned long delalloc_blocks;
+
+        inode = dentry->d_inode;
+        generic_fillattr(inode, stat);
+
+        /*
+         * We can't update i_blocks if the block allocation is delayed
+         * otherwise in the case of system crash before the real block
+         * allocation is done, we will have i_blocks inconsistent with
+         * on-disk file blocks.
+         * We always keep i_blocks updated together with real
+         * allocation. But to not confuse with user, stat
+         * will return the blocks that include the delayed allocation
+         * blocks for this file.
+         */
+        spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
+        delalloc_blocks = EXT4_I(inode)->i_reserved_data_blocks;
+        spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+
+        stat->blocks += (delalloc_blocks << inode->i_sb->s_blocksize_bits)>>9;
+        return 0;
+}
 
 /*
  * How many blocks doth make a writepage()?
@@ -3506,3 +4570,64 @@ int ext4_change_inode_journal_flag(struct inode *inode, int val)
 
         return err;
 }
+
+static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
+{
+        return !buffer_mapped(bh);
+}
+
+int ext4_page_mkwrite(struct vm_area_struct *vma, struct page *page)
+{
+        loff_t size;
+        unsigned long len;
+        int ret = -EINVAL;
+        struct file *file = vma->vm_file;
+        struct inode *inode = file->f_path.dentry->d_inode;
+        struct address_space *mapping = inode->i_mapping;
+
+        /*
+         * Get i_alloc_sem to stop truncates messing with the inode. We cannot
+         * get i_mutex because we are already holding mmap_sem.
+         */
+        down_read(&inode->i_alloc_sem);
+        size = i_size_read(inode);
+        if (page->mapping != mapping || size <= page_offset(page)
+            || !PageUptodate(page)) {
+                /* page got truncated from under us? */
+                goto out_unlock;
+        }
+        ret = 0;
+        if (PageMappedToDisk(page))
+                goto out_unlock;
+
+        if (page->index == size >> PAGE_CACHE_SHIFT)
+                len = size & ~PAGE_CACHE_MASK;
+        else
+                len = PAGE_CACHE_SIZE;
+
+        if (page_has_buffers(page)) {
+                /* return if we have all the buffers mapped */
+                if (!walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
+                                       ext4_bh_unmapped))
+                        goto out_unlock;
+        }
+        /*
+         * OK, we need to fill the hole... Do write_begin write_end
+         * to do block allocation/reservation.We are not holding
+         * inode.i__mutex here. That allow * parallel write_begin,
+         * write_end call. lock_page prevent this from happening
+         * on the same page though
+         */
+        ret = mapping->a_ops->write_begin(file, mapping, page_offset(page),
+                        len, AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
+        if (ret < 0)
+                goto out_unlock;
+        ret = mapping->a_ops->write_end(file, mapping, page_offset(page),
+                        len, len, page, NULL);
+        if (ret < 0)
+                goto out_unlock;
+        ret = 0;
+out_unlock:
+        up_read(&inode->i_alloc_sem);
+        return ret;
+}
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index c9900aade150..8d141a25bbee 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -381,22 +381,28 @@ static inline void mb_clear_bit_atomic(spinlock_t *lock, int bit, void *addr)
 
 static inline int mb_find_next_zero_bit(void *addr, int max, int start)
 {
-        int fix = 0;
+        int fix = 0, ret, tmpmax;
         addr = mb_correct_addr_and_bit(&fix, addr);
-        max += fix;
+        tmpmax = max + fix;
         start += fix;
 
-        return ext4_find_next_zero_bit(addr, max, start) - fix;
+        ret = ext4_find_next_zero_bit(addr, tmpmax, start) - fix;
+        if (ret > max)
+                return max;
+        return ret;
 }
 
 static inline int mb_find_next_bit(void *addr, int max, int start)
 {
-        int fix = 0;
+        int fix = 0, ret, tmpmax;
         addr = mb_correct_addr_and_bit(&fix, addr);
-        max += fix;
+        tmpmax = max + fix;
         start += fix;
 
-        return ext4_find_next_bit(addr, max, start) - fix;
+        ret = ext4_find_next_bit(addr, tmpmax, start) - fix;
+        if (ret > max)
+                return max;
+        return ret;
 }
 
 static void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max)
@@ -803,6 +809,7 @@ static int ext4_mb_init_cache(struct page *page, char *incore)
                 if (!buffer_uptodate(bh[i]))
                         goto out;
 
+        err = 0;
         first_block = page->index * blocks_per_page;
         for (i = 0; i < blocks_per_page; i++) {
                 int group;
@@ -883,6 +890,7 @@ ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,
         int pnum;
         int poff;
         struct page *page;
+        int ret;
 
         mb_debug("load group %lu\n", group);
 
@@ -914,15 +922,21 @@ ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,
                 if (page) {
                         BUG_ON(page->mapping != inode->i_mapping);
                         if (!PageUptodate(page)) {
-                                ext4_mb_init_cache(page, NULL);
+                                ret = ext4_mb_init_cache(page, NULL);
+                                if (ret) {
+                                        unlock_page(page);
+                                        goto err;
+                                }
                                 mb_cmp_bitmaps(e4b, page_address(page) +
                                                (poff * sb->s_blocksize));
                         }
                         unlock_page(page);
                 }
         }
-        if (page == NULL || !PageUptodate(page))
+        if (page == NULL || !PageUptodate(page)) {
+                ret = -EIO;
                 goto err;
+        }
         e4b->bd_bitmap_page = page;
         e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize);
         mark_page_accessed(page);
@@ -938,14 +952,20 @@ ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,
                 page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS);
                 if (page) {
                         BUG_ON(page->mapping != inode->i_mapping);
-                        if (!PageUptodate(page))
-                                ext4_mb_init_cache(page, e4b->bd_bitmap);
-
+                        if (!PageUptodate(page)) {
+                                ret = ext4_mb_init_cache(page, e4b->bd_bitmap);
+                                if (ret) {
+                                        unlock_page(page);
+                                        goto err;
+                                }
+                        }
                         unlock_page(page);
                 }
         }
-        if (page == NULL || !PageUptodate(page))
+        if (page == NULL || !PageUptodate(page)) {
+                ret = -EIO;
                 goto err;
+        }
         e4b->bd_buddy_page = page;
         e4b->bd_buddy = page_address(page) + (poff * sb->s_blocksize);
         mark_page_accessed(page);
@@ -962,7 +982,7 @@ err:
                 page_cache_release(e4b->bd_buddy_page);
         e4b->bd_buddy = NULL;
         e4b->bd_bitmap = NULL;
-        return -EIO;
+        return ret;
 }
 
 static void ext4_mb_release_desc(struct ext4_buddy *e4b)
@@ -1031,7 +1051,7 @@ static void mb_set_bits(spinlock_t *lock, void *bm, int cur, int len)
         }
 }
 
-static int mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
+static void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
                           int first, int count)
 {
         int block = 0;
@@ -1071,11 +1091,12 @@ static int mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
                         blocknr += block;
                         blocknr +=
                             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
-
+                        ext4_unlock_group(sb, e4b->bd_group);
                         ext4_error(sb, __func__, "double-free of inode"
                                    " %lu's block %llu(bit %u in group %lu)\n",
                                    inode ? inode->i_ino : 0, blocknr, block,
                                    e4b->bd_group);
+                        ext4_lock_group(sb, e4b->bd_group);
                 }
                 mb_clear_bit(block, EXT4_MB_BITMAP(e4b));
                 e4b->bd_info->bb_counters[order]++;
@@ -1113,8 +1134,6 @@ static int mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
                 } while (1);
         }
         mb_check_buddy(e4b);
-
-        return 0;
 }
 
 static int mb_find_extent(struct ext4_buddy *e4b, int order, int block,
@@ -1730,10 +1749,6 @@ ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
                 ac->ac_g_ex.fe_start = sbi->s_mb_last_start;
                 spin_unlock(&sbi->s_md_lock);
         }
-
-        /* searching for the right group start from the goal value specified */
-        group = ac->ac_g_ex.fe_group;
-
         /* Let's just scan groups to find more-less suitable blocks */
         cr = ac->ac_2order ? 0 : 1;
         /*
@@ -1743,6 +1758,12 @@ ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
 repeat:
         for (; cr < 4 && ac->ac_status == AC_STATUS_CONTINUE; cr++) {
                 ac->ac_criteria = cr;
+                /*
+                 * searching for the right group start
+                 * from the goal value specified
+                 */
+                group = ac->ac_g_ex.fe_group;
+
                 for (i = 0; i < EXT4_SB(sb)->s_groups_count; group++, i++) {
                         struct ext4_group_info *grp;
                         struct ext4_group_desc *desc;
@@ -1963,6 +1984,8 @@ static int ext4_mb_seq_history_open(struct inode *inode, struct file *file)
         int rc;
         int size;
 
+        if (unlikely(sbi->s_mb_history == NULL))
+                return -ENOMEM;
         s = kmalloc(sizeof(*s), GFP_KERNEL);
         if (s == NULL)
                 return -ENOMEM;
@@ -2165,9 +2188,7 @@ static void ext4_mb_history_init(struct super_block *sb)
         sbi->s_mb_history_cur = 0;
         spin_lock_init(&sbi->s_mb_history_lock);
         i = sbi->s_mb_history_max * sizeof(struct ext4_mb_history);
-        sbi->s_mb_history = kmalloc(i, GFP_KERNEL);
-        if (likely(sbi->s_mb_history != NULL))
-                memset(sbi->s_mb_history, 0, i);
+        sbi->s_mb_history = kzalloc(i, GFP_KERNEL);
         /* if we can't allocate history, then we simple won't use it */
 }
 
@@ -2215,21 +2236,192 @@ ext4_mb_store_history(struct ext4_allocation_context *ac)
 #define ext4_mb_history_init(sb)
 #endif
 
+
+/* Create and initialize ext4_group_info data for the given group. */
+int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,
+                          struct ext4_group_desc *desc)
+{
+        int i, len;
+        int metalen = 0;
+        struct ext4_sb_info *sbi = EXT4_SB(sb);
+        struct ext4_group_info **meta_group_info;
+
+        /*
+         * First check if this group is the first of a reserved block.
+         * If it's true, we have to allocate a new table of pointers
+         * to ext4_group_info structures
+         */
+        if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
+                metalen = sizeof(*meta_group_info) <<
+                        EXT4_DESC_PER_BLOCK_BITS(sb);
+                meta_group_info = kmalloc(metalen, GFP_KERNEL);
+                if (meta_group_info == NULL) {
+                        printk(KERN_ERR "EXT4-fs: can't allocate mem for a "
+                               "buddy group\n");
+                        goto exit_meta_group_info;
+                }
+                sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)] =
+                        meta_group_info;
+        }
+
+        /*
+         * calculate needed size. if change bb_counters size,
+         * don't forget about ext4_mb_generate_buddy()
+         */
+        len = offsetof(typeof(**meta_group_info),
+                       bb_counters[sb->s_blocksize_bits + 2]);
+
+        meta_group_info =
+                sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)];
+        i = group & (EXT4_DESC_PER_BLOCK(sb) - 1);
+
+        meta_group_info[i] = kzalloc(len, GFP_KERNEL);
+        if (meta_group_info[i] == NULL) {
+                printk(KERN_ERR "EXT4-fs: can't allocate buddy mem\n");
+                goto exit_group_info;
+        }
+        set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT,
+                &(meta_group_info[i]->bb_state));
+
+        /*
+         * initialize bb_free to be able to skip
+         * empty groups without initialization
+         */
+        if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
+                meta_group_info[i]->bb_free =
+                        ext4_free_blocks_after_init(sb, group, desc);
+        } else {
+                meta_group_info[i]->bb_free =
+                        le16_to_cpu(desc->bg_free_blocks_count);
+        }
+
+        INIT_LIST_HEAD(&meta_group_info[i]->bb_prealloc_list);
+
+#ifdef DOUBLE_CHECK
+        {
+                struct buffer_head *bh;
+                meta_group_info[i]->bb_bitmap =
+                        kmalloc(sb->s_blocksize, GFP_KERNEL);
+                BUG_ON(meta_group_info[i]->bb_bitmap == NULL);
+                bh = ext4_read_block_bitmap(sb, group);
+                BUG_ON(bh == NULL);
+                memcpy(meta_group_info[i]->bb_bitmap, bh->b_data,
+                        sb->s_blocksize);
+                put_bh(bh);
+        }
+#endif
+
+        return 0;
+
+exit_group_info:
+        /* If a meta_group_info table has been allocated, release it now */
+        if (group % EXT4_DESC_PER_BLOCK(sb) == 0)
+                kfree(sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)]);
+exit_meta_group_info:
+        return -ENOMEM;
+} /* ext4_mb_add_groupinfo */
+
+/*
+ * Add a group to the existing groups.
+ * This function is used for online resize
+ */
+int ext4_mb_add_more_groupinfo(struct super_block *sb, ext4_group_t group,
+                               struct ext4_group_desc *desc)
+{
+        struct ext4_sb_info *sbi = EXT4_SB(sb);
+        struct inode *inode = sbi->s_buddy_cache;
+        int blocks_per_page;
+        int block;
+        int pnum;
+        struct page *page;
+        int err;
+
+        /* Add group based on group descriptor*/
+        err = ext4_mb_add_groupinfo(sb, group, desc);
+        if (err)
+                return err;
+
+        /*
+         * Cache pages containing dynamic mb_alloc datas (buddy and bitmap
+         * datas) are set not up to date so that they will be re-initilaized
+         * during the next call to ext4_mb_load_buddy
+         */
+
+        /* Set buddy page as not up to date */
+        blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize;
+        block = group * 2;
+        pnum = block / blocks_per_page;
+        page = find_get_page(inode->i_mapping, pnum);
+        if (page != NULL) {
+                ClearPageUptodate(page);
+                page_cache_release(page);
+        }
+
+        /* Set bitmap page as not up to date */
+        block++;
+        pnum = block / blocks_per_page;
+        page = find_get_page(inode->i_mapping, pnum);
+        if (page != NULL) {
+                ClearPageUptodate(page);
+                page_cache_release(page);
+        }
+
+        return 0;
+}
+
+/*
+ * Update an existing group.
+ * This function is used for online resize
+ */
+void ext4_mb_update_group_info(struct ext4_group_info *grp, ext4_grpblk_t add)
+{
+        grp->bb_free += add;
+}
+
 static int ext4_mb_init_backend(struct super_block *sb)
 {
         ext4_group_t i;
-        int j, len, metalen;
+        int metalen;
         struct ext4_sb_info *sbi = EXT4_SB(sb);
-        int num_meta_group_infos =
-                (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) >>
-                        EXT4_DESC_PER_BLOCK_BITS(sb);
+        struct ext4_super_block *es = sbi->s_es;
+        int num_meta_group_infos;
+        int num_meta_group_infos_max;
+        int array_size;
         struct ext4_group_info **meta_group_info;
+        struct ext4_group_desc *desc;
+
+        /* This is the number of blocks used by GDT */
+        num_meta_group_infos = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) -
+                                1) >> EXT4_DESC_PER_BLOCK_BITS(sb);
+
+        /*
+         * This is the total number of blocks used by GDT including
+         * the number of reserved blocks for GDT.
+         * The s_group_info array is allocated with this value
+         * to allow a clean online resize without a complex
+         * manipulation of pointer.
+         * The drawback is the unused memory when no resize
+         * occurs but it's very low in terms of pages
+         * (see comments below)
+         * Need to handle this properly when META_BG resizing is allowed
+         */
+        num_meta_group_infos_max = num_meta_group_infos +
+                                le16_to_cpu(es->s_reserved_gdt_blocks);
 
+        /*
+         * array_size is the size of s_group_info array. We round it
+         * to the next power of two because this approximation is done
+         * internally by kmalloc so we can have some more memory
+         * for free here (e.g. may be used for META_BG resize).
+         */
+        array_size = 1;
+        while (array_size < sizeof(*sbi->s_group_info) *
+               num_meta_group_infos_max)
+                array_size = array_size << 1;
         /* An 8TB filesystem with 64-bit pointers requires a 4096 byte
          * kmalloc. A 128kb malloc should suffice for a 256TB filesystem.
          * So a two level scheme suffices for now. */
-        sbi->s_group_info = kmalloc(sizeof(*sbi->s_group_info) *
-                                    num_meta_group_infos, GFP_KERNEL);
+        sbi->s_group_info = kmalloc(array_size, GFP_KERNEL);
         if (sbi->s_group_info == NULL) {
                 printk(KERN_ERR "EXT4-fs: can't allocate buddy meta group\n");
                 return -ENOMEM;
@@ -2256,63 +2448,15 @@ static int ext4_mb_init_backend(struct super_block *sb)
                 sbi->s_group_info[i] = meta_group_info;
         }
 
-        /*
-         * calculate needed size. if change bb_counters size,
-         * don't forget about ext4_mb_generate_buddy()
-         */
-        len = sizeof(struct ext4_group_info);
-        len += sizeof(unsigned short) * (sb->s_blocksize_bits + 2);
         for (i = 0; i < sbi->s_groups_count; i++) {
-                struct ext4_group_desc *desc;
-
-                meta_group_info =
-                        sbi->s_group_info[i >> EXT4_DESC_PER_BLOCK_BITS(sb)];
-                j = i & (EXT4_DESC_PER_BLOCK(sb) - 1);
-
-                meta_group_info[j] = kzalloc(len, GFP_KERNEL);
-                if (meta_group_info[j] == NULL) {
-                        printk(KERN_ERR "EXT4-fs: can't allocate buddy mem\n");
-                        goto err_freebuddy;
-                }
                 desc = ext4_get_group_desc(sb, i, NULL);
                 if (desc == NULL) {
                         printk(KERN_ERR
                                 "EXT4-fs: can't read descriptor %lu\n", i);
-                        i++;
                         goto err_freebuddy;
                 }
-                memset(meta_group_info[j], 0, len);
-                set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT,
-                        &(meta_group_info[j]->bb_state));
-
-                /*
-                 * initialize bb_free to be able to skip
-                 * empty groups without initialization
-                 */
-                if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
-                        meta_group_info[j]->bb_free =
-                                ext4_free_blocks_after_init(sb, i, desc);
-                } else {
-                        meta_group_info[j]->bb_free =
-                                le16_to_cpu(desc->bg_free_blocks_count);
-                }
-
-                INIT_LIST_HEAD(&meta_group_info[j]->bb_prealloc_list);
-
-#ifdef DOUBLE_CHECK
-                {
-                        struct buffer_head *bh;
-                        meta_group_info[j]->bb_bitmap =
-                                kmalloc(sb->s_blocksize, GFP_KERNEL);
-                        BUG_ON(meta_group_info[j]->bb_bitmap == NULL);
-                        bh = read_block_bitmap(sb, i);
-                        BUG_ON(bh == NULL);
-                        memcpy(meta_group_info[j]->bb_bitmap, bh->b_data,
-                                        sb->s_blocksize);
-                        put_bh(bh);
-                }
-#endif
-
+                if (ext4_mb_add_groupinfo(sb, i, desc) != 0)
+                        goto err_freebuddy;
         }
 
         return 0;
@@ -2336,6 +2480,7 @@ int ext4_mb_init(struct super_block *sb, int needs_recovery)
         unsigned i;
         unsigned offset;
         unsigned max;
+        int ret;
 
         if (!test_opt(sb, MBALLOC))
                 return 0;
@@ -2370,12 +2515,12 @@ int ext4_mb_init(struct super_block *sb, int needs_recovery)
         } while (i <= sb->s_blocksize_bits + 1);
 
         /* init file for buddy data */
-        i = ext4_mb_init_backend(sb);
-        if (i) {
+        ret = ext4_mb_init_backend(sb);
+        if (ret != 0) {
                 clear_opt(sbi->s_mount_opt, MBALLOC);
                 kfree(sbi->s_mb_offsets);
                 kfree(sbi->s_mb_maxs);
-                return i;
+                return ret;
         }
 
         spin_lock_init(&sbi->s_md_lock);
@@ -2548,8 +2693,7 @@ ext4_mb_free_committed_blocks(struct super_block *sb)
                 ext4_lock_group(sb, md->group);
                 for (i = 0; i < md->num; i++) {
                         mb_debug(" %u", md->blocks[i]);
-                        err = mb_free_blocks(NULL, &e4b, md->blocks[i], 1);
-                        BUG_ON(err != 0);
+                        mb_free_blocks(NULL, &e4b, md->blocks[i], 1);
                 }
                 mb_debug("\n");
                 ext4_unlock_group(sb, md->group);
@@ -2575,25 +2719,24 @@ ext4_mb_free_committed_blocks(struct super_block *sb)
 
 
 
-#define MB_PROC_VALUE_READ(name)                                \
-static int ext4_mb_read_##name(char *page, char **start,        \
-                off_t off, int count, int *eof, void *data)     \
+#define MB_PROC_FOPS(name)                                      \
+static int ext4_mb_##name##_proc_show(struct seq_file *m, void *v)      \
 {                                                               \
-        struct ext4_sb_info *sbi = data;                        \
-        int len;                                                \
-        *eof = 1;                                               \
-        if (off != 0)                                           \
-                return 0;                                       \
-        len = sprintf(page, "%ld\n", sbi->s_mb_##name);         \
-        *start = page;                                          \
-        return len;                                             \
-}
-
-#define MB_PROC_VALUE_WRITE(name)                               \
-static int ext4_mb_write_##name(struct file *file,              \
-                const char __user *buf, unsigned long cnt, void *data)  \
+        struct ext4_sb_info *sbi = m->private;                  \
+                                                                \
+        seq_printf(m, "%ld\n", sbi->s_mb_##name);               \
+        return 0;                                               \
+}                                                               \
+                                                                \
+static int ext4_mb_##name##_proc_open(struct inode *inode, struct file *file)\
+{                                                               \
+        return single_open(file, ext4_mb_##name##_proc_show, PDE(inode)->data);\
+}                                                               \
+                                                                \
+static ssize_t ext4_mb_##name##_proc_write(struct file *file,   \
+                const char __user *buf, size_t cnt, loff_t *ppos)       \
 {                                                               \
-        struct ext4_sb_info *sbi = data;                        \
+        struct ext4_sb_info *sbi = PDE(file->f_path.dentry->d_inode)->data;\
         char str[32];                                           \
         long value;                                             \
         if (cnt >= sizeof(str))                                 \
@@ -2605,31 +2748,32 @@ static int ext4_mb_write_##name(struct file *file,		\
                 return -ERANGE;                                 \
         sbi->s_mb_##name = value;                               \
         return cnt;                                             \
-}
+}                                                               \
+                                                                \
+static const struct file_operations ext4_mb_##name##_proc_fops = {      \
+        .owner          = THIS_MODULE,                          \
+        .open           = ext4_mb_##name##_proc_open,           \
+        .read           = seq_read,                             \
+        .llseek         = seq_lseek,                            \
+        .release        = single_release,                       \
+        .write          = ext4_mb_##name##_proc_write,          \
+};
 
-MB_PROC_VALUE_READ(stats);
-MB_PROC_VALUE_WRITE(stats);
-MB_PROC_VALUE_READ(max_to_scan);
-MB_PROC_VALUE_WRITE(max_to_scan);
-MB_PROC_VALUE_READ(min_to_scan);
-MB_PROC_VALUE_WRITE(min_to_scan);
-MB_PROC_VALUE_READ(order2_reqs);
-MB_PROC_VALUE_WRITE(order2_reqs);
-MB_PROC_VALUE_READ(stream_request);
-MB_PROC_VALUE_WRITE(stream_request);
-MB_PROC_VALUE_READ(group_prealloc);
-MB_PROC_VALUE_WRITE(group_prealloc);
+MB_PROC_FOPS(stats);
+MB_PROC_FOPS(max_to_scan);
+MB_PROC_FOPS(min_to_scan);
+MB_PROC_FOPS(order2_reqs);
+MB_PROC_FOPS(stream_request);
+MB_PROC_FOPS(group_prealloc);
 
 #define MB_PROC_HANDLER(name, var)                                      \
 do {                                                                    \
-        proc = create_proc_entry(name, mode, sbi->s_mb_proc);           \
+        proc = proc_create_data(name, mode, sbi->s_mb_proc,             \
+                                &ext4_mb_##var##_proc_fops, sbi);       \
         if (proc == NULL) {                                             \
                 printk(KERN_ERR "EXT4-fs: can't to create %s\n", name); \
                 goto err_out;                                           \
         }                                                               \
-        proc->data = sbi;                                               \
-        proc->read_proc  = ext4_mb_read_##var ;                         \
-        proc->write_proc = ext4_mb_write_##var;                         \
 } while (0)
 
 static int ext4_mb_init_per_dev_proc(struct super_block *sb)
@@ -2639,6 +2783,10 @@ static int ext4_mb_init_per_dev_proc(struct super_block *sb)
         struct proc_dir_entry *proc;
         char devname[64];
 
+        if (proc_root_ext4 == NULL) {
+                sbi->s_mb_proc = NULL;
+                return -EINVAL;
+        }
         bdevname(sb->s_bdev, devname);
         sbi->s_mb_proc = proc_mkdir(devname, proc_root_ext4);
 
@@ -2747,7 +2895,7 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
 
 
         err = -EIO;
-        bitmap_bh = read_block_bitmap(sb, ac->ac_b_ex.fe_group);
+        bitmap_bh = ext4_read_block_bitmap(sb, ac->ac_b_ex.fe_group);
         if (!bitmap_bh)
                 goto out_err;
 
@@ -2816,7 +2964,23 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
         le16_add_cpu(&gdp->bg_free_blocks_count, -ac->ac_b_ex.fe_len);
         gdp->bg_checksum = ext4_group_desc_csum(sbi, ac->ac_b_ex.fe_group, gdp);
         spin_unlock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group));
-        percpu_counter_sub(&sbi->s_freeblocks_counter, ac->ac_b_ex.fe_len);
+
+        /*
+         * free blocks account has already be reduced/reserved
+         * at write_begin() time for delayed allocation
+         * do not double accounting
+         */
+        if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED))
+                percpu_counter_sub(&sbi->s_freeblocks_counter,
+                                        ac->ac_b_ex.fe_len);
+
+        if (sbi->s_log_groups_per_flex) {
+                ext4_group_t flex_group = ext4_flex_group(sbi,
+                                                          ac->ac_b_ex.fe_group);
+                spin_lock(sb_bgl_lock(sbi, flex_group));
+                sbi->s_flex_groups[flex_group].free_blocks -= ac->ac_b_ex.fe_len;
+                spin_unlock(sb_bgl_lock(sbi, flex_group));
+        }
 
         err = ext4_journal_dirty_metadata(handle, bitmap_bh);
         if (err)
@@ -3473,8 +3637,6 @@ ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh,
                 if (bit >= end)
                         break;
                 next = mb_find_next_bit(bitmap_bh->b_data, end, bit);
-                if (next > end)
-                        next = end;
                 start = group * EXT4_BLOCKS_PER_GROUP(sb) + bit +
                                 le32_to_cpu(sbi->s_es->s_first_data_block);
                 mb_debug("    free preallocated %u/%u in group %u\n",
@@ -3569,7 +3731,7 @@ ext4_mb_discard_group_preallocations(struct super_block *sb,
         if (list_empty(&grp->bb_prealloc_list))
                 return 0;
 
-        bitmap_bh = read_block_bitmap(sb, group);
+        bitmap_bh = ext4_read_block_bitmap(sb, group);
         if (bitmap_bh == NULL) {
                 /* error handling here */
                 ext4_mb_release_desc(&e4b);
@@ -3743,7 +3905,7 @@ repeat:
                 err = ext4_mb_load_buddy(sb, group, &e4b);
                 BUG_ON(err != 0); /* error handling here */
 
-                bitmap_bh = read_block_bitmap(sb, group);
+                bitmap_bh = ext4_read_block_bitmap(sb, group);
                 if (bitmap_bh == NULL) {
                         /* error handling here */
                         ext4_mb_release_desc(&e4b);
@@ -4011,10 +4173,21 @@ ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
         sbi = EXT4_SB(sb);
 
         if (!test_opt(sb, MBALLOC)) {
-                block = ext4_new_blocks_old(handle, ar->inode, ar->goal,
+                block = ext4_old_new_blocks(handle, ar->inode, ar->goal,
                                             &(ar->len), errp);
                 return block;
         }
+        if (!EXT4_I(ar->inode)->i_delalloc_reserved_flag) {
+                /*
+                 * With delalloc we already reserved the blocks
+                 */
+                ar->len = ext4_has_free_blocks(sbi, ar->len);
+        }
+
+        if (ar->len == 0) {
+                *errp = -ENOSPC;
+                return 0;
+        }
 
         while (ar->len && DQUOT_ALLOC_BLOCK(ar->inode, ar->len)) {
                 ar->flags |= EXT4_MB_HINT_NOPREALLOC;
@@ -4026,10 +4199,14 @@ ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
         }
         inquota = ar->len;
 
+        if (EXT4_I(ar->inode)->i_delalloc_reserved_flag)
+                ar->flags |= EXT4_MB_DELALLOC_RESERVED;
+
         ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
         if (!ac) {
+                ar->len = 0;
                 *errp = -ENOMEM;
-                return 0;
+                goto out1;
         }
 
         ext4_mb_poll_new_transaction(sb, handle);
@@ -4037,12 +4214,11 @@ ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
         *errp = ext4_mb_initialize_context(ac, ar);
         if (*errp) {
                 ar->len = 0;
-                goto out;
+                goto out2;
         }
 
         ac->ac_op = EXT4_MB_HISTORY_PREALLOC;
         if (!ext4_mb_use_preallocated(ac)) {
-
                 ac->ac_op = EXT4_MB_HISTORY_ALLOC;
                 ext4_mb_normalize_request(ac, ar);
 repeat:
@@ -4085,11 +4261,12 @@ repeat:
 
         ext4_mb_release_context(ac);
 
-out:
+out2:
+        kmem_cache_free(ext4_ac_cachep, ac);
+out1:
         if (ar->len < inquota)
                 DQUOT_FREE_BLOCK(ar->inode, inquota - ar->len);
 
-        kmem_cache_free(ext4_ac_cachep, ac);
         return block;
 }
 static void ext4_mb_poll_new_transaction(struct super_block *sb,
@@ -4242,7 +4419,7 @@ do_more:
                 overflow = bit + count - EXT4_BLOCKS_PER_GROUP(sb);
                 count -= overflow;
         }
-        bitmap_bh = read_block_bitmap(sb, block_group);
+        bitmap_bh = ext4_read_block_bitmap(sb, block_group);
         if (!bitmap_bh)
                 goto error_return;
         gdp = ext4_get_group_desc(sb, block_group, &gd_bh);
@@ -4309,10 +4486,9 @@ do_more:
                 ext4_mb_free_metadata(handle, &e4b, block_group, bit, count);
         } else {
                 ext4_lock_group(sb, block_group);
-                err = mb_free_blocks(inode, &e4b, bit, count);
+                mb_free_blocks(inode, &e4b, bit, count);
                 ext4_mb_return_to_preallocation(inode, &e4b, block, count);
                 ext4_unlock_group(sb, block_group);
-                BUG_ON(err != 0);
         }
 
         spin_lock(sb_bgl_lock(sbi, block_group));
@@ -4321,6 +4497,13 @@ do_more:
         spin_unlock(sb_bgl_lock(sbi, block_group));
         percpu_counter_add(&sbi->s_freeblocks_counter, count);
 
+        if (sbi->s_log_groups_per_flex) {
+                ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
+                spin_lock(sb_bgl_lock(sbi, flex_group));
+                sbi->s_flex_groups[flex_group].free_blocks += count;
+                spin_unlock(sb_bgl_lock(sbi, flex_group));
+        }
+
         ext4_mb_release_desc(&e4b);
 
         *freed += count;
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index ab16beaa830d..387ad98350c3 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -183,6 +183,16 @@ static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
                              struct inode *inode);
 
 /*
+ * p is at least 6 bytes before the end of page
+ */
+static inline struct ext4_dir_entry_2 *
+ext4_next_entry(struct ext4_dir_entry_2 *p)
+{
+        return (struct ext4_dir_entry_2 *)((char *)p +
+                ext4_rec_len_from_disk(p->rec_len));
+}
+
+/*
  * Future: use high four bits of block for coalesce-on-delete flags
  * Mask them off for now.
  */
@@ -231,13 +241,13 @@ static inline unsigned dx_root_limit (struct inode *dir, unsigned infosize)
 {
         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
                 EXT4_DIR_REC_LEN(2) - infosize;
-        return 0? 20: entry_space / sizeof(struct dx_entry);
+        return entry_space / sizeof(struct dx_entry);
 }
 
 static inline unsigned dx_node_limit (struct inode *dir)
 {
         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
-        return 0? 22: entry_space / sizeof(struct dx_entry);
+        return entry_space / sizeof(struct dx_entry);
 }
 
 /*
@@ -554,15 +564,6 @@ static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 
 
 /*
- * p is at least 6 bytes before the end of page
- */
-static inline struct ext4_dir_entry_2 *ext4_next_entry(struct ext4_dir_entry_2 *p)
-{
-        return (struct ext4_dir_entry_2 *)((char *)p +
-                ext4_rec_len_from_disk(p->rec_len));
-}
-
-/*
  * This function fills a red-black tree with information from a
  * directory block.  It returns the number directory entries loaded
  * into the tree.  If there is an error it is returned in err.
@@ -993,19 +994,21 @@ static struct buffer_head * ext4_dx_find_entry(struct dentry *dentry,
                 de = (struct ext4_dir_entry_2 *) bh->b_data;
                 top = (struct ext4_dir_entry_2 *) ((char *) de + sb->s_blocksize -
                                        EXT4_DIR_REC_LEN(0));
-                for (; de < top; de = ext4_next_entry(de))
-                if (ext4_match (namelen, name, de)) {
-                        if (!ext4_check_dir_entry("ext4_find_entry",
-                                                  dir, de, bh,
-                                  (block<<EXT4_BLOCK_SIZE_BITS(sb))
-                                          +((char *)de - bh->b_data))) {
-                                brelse (bh);
+                for (; de < top; de = ext4_next_entry(de)) {
+                        int off = (block << EXT4_BLOCK_SIZE_BITS(sb))
+                                  + ((char *) de - bh->b_data);
+
+                        if (!ext4_check_dir_entry(__func__, dir, de, bh, off)) {
+                                brelse(bh);
                                 *err = ERR_BAD_DX_DIR;
                                 goto errout;
                         }
-                        *res_dir = de;
-                        dx_release (frames);
-                        return bh;
+
+                        if (ext4_match(namelen, name, de)) {
+                                *res_dir = de;
+                                dx_release(frames);
+                                return bh;
+                        }
                 }
                 brelse (bh);
                 /* Check to see if we should continue to search */
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 9ff7b1c04239..f000fbe2cd93 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -866,6 +866,15 @@ int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
         gdp->bg_checksum = ext4_group_desc_csum(sbi, input->group, gdp);
 
         /*
+         * We can allocate memory for mb_alloc based on the new group
+         * descriptor
+         */
+        if (test_opt(sb, MBALLOC)) {
+                err = ext4_mb_add_more_groupinfo(sb, input->group, gdp);
+                if (err)
+                        goto exit_journal;
+        }
+        /*
          * Make the new blocks and inodes valid next.  We do this before
          * increasing the group count so that once the group is enabled,
          * all of its blocks and inodes are already valid.
@@ -957,6 +966,8 @@ int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
         handle_t *handle;
         int err;
         unsigned long freed_blocks;
+        ext4_group_t group;
+        struct ext4_group_info *grp;
 
         /* We don't need to worry about locking wrt other resizers just
          * yet: we're going to revalidate es->s_blocks_count after
@@ -988,7 +999,7 @@ int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
         }
 
         /* Handle the remaining blocks in the last group only. */
-        ext4_get_group_no_and_offset(sb, o_blocks_count, NULL, &last);
+        ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
 
         if (last == 0) {
                 ext4_warning(sb, __func__,
@@ -1060,6 +1071,45 @@ int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
                    o_blocks_count + add);
         if ((err = ext4_journal_stop(handle)))
                 goto exit_put;
+
+        /*
+         * Mark mballoc pages as not up to date so that they will be updated
+         * next time they are loaded by ext4_mb_load_buddy.
+         */
+        if (test_opt(sb, MBALLOC)) {
+                struct ext4_sb_info *sbi = EXT4_SB(sb);
+                struct inode *inode = sbi->s_buddy_cache;
+                int blocks_per_page;
+                int block;
+                int pnum;
+                struct page *page;
+
+                /* Set buddy page as not up to date */
+                blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize;
+                block = group * 2;
+                pnum = block / blocks_per_page;
+                page = find_get_page(inode->i_mapping, pnum);
+                if (page != NULL) {
+                        ClearPageUptodate(page);
+                        page_cache_release(page);
+                }
+
+                /* Set bitmap page as not up to date */
+                block++;
+                pnum = block / blocks_per_page;
+                page = find_get_page(inode->i_mapping, pnum);
+                if (page != NULL) {
+                        ClearPageUptodate(page);
+                        page_cache_release(page);
+                }
+
+                /* Get the info on the last group */
+                grp = ext4_get_group_info(sb, group);
+
+                /* Update free blocks in group info */
+                ext4_mb_update_group_info(grp, add);
+        }
+
         if (test_opt(sb, DEBUG))
                 printk(KERN_DEBUG "EXT4-fs: extended group to %llu blocks\n",
                        ext4_blocks_count(es));
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 02bf24343979..1cb371dcd609 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -506,6 +506,7 @@ static void ext4_put_super (struct super_block * sb)
         ext4_ext_release(sb);
         ext4_xattr_put_super(sb);
         jbd2_journal_destroy(sbi->s_journal);
+        sbi->s_journal = NULL;
         if (!(sb->s_flags & MS_RDONLY)) {
                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
                 es->s_state = cpu_to_le16(sbi->s_mount_state);
@@ -517,6 +518,7 @@ static void ext4_put_super (struct super_block * sb)
         for (i = 0; i < sbi->s_gdb_count; i++)
                 brelse(sbi->s_group_desc[i]);
         kfree(sbi->s_group_desc);
+        kfree(sbi->s_flex_groups);
         percpu_counter_destroy(&sbi->s_freeblocks_counter);
         percpu_counter_destroy(&sbi->s_freeinodes_counter);
         percpu_counter_destroy(&sbi->s_dirs_counter);
@@ -571,6 +573,12 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
         INIT_LIST_HEAD(&ei->i_prealloc_list);
         spin_lock_init(&ei->i_prealloc_lock);
+        jbd2_journal_init_jbd_inode(&ei->jinode, &ei->vfs_inode);
+        ei->i_reserved_data_blocks = 0;
+        ei->i_reserved_meta_blocks = 0;
+        ei->i_allocated_meta_blocks = 0;
+        ei->i_delalloc_reserved_flag = 0;
+        spin_lock_init(&(ei->i_block_reservation_lock));
         return &ei->vfs_inode;
 }
 
@@ -635,6 +643,8 @@ static void ext4_clear_inode(struct inode *inode)
         EXT4_I(inode)->i_block_alloc_info = NULL;
         if (unlikely(rsv))
                 kfree(rsv);
+        jbd2_journal_release_jbd_inode(EXT4_SB(inode->i_sb)->s_journal,
+                                       &EXT4_I(inode)->jinode);
 }
 
 static inline void ext4_show_quota_options(struct seq_file *seq, struct super_block *sb)
@@ -671,7 +681,6 @@ static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
         unsigned long def_mount_opts;
         struct super_block *sb = vfs->mnt_sb;
         struct ext4_sb_info *sbi = EXT4_SB(sb);
-        journal_t *journal = sbi->s_journal;
         struct ext4_super_block *es = sbi->s_es;
 
         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
@@ -747,6 +756,9 @@ static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
                 seq_puts(seq, ",nomballoc");
         if (test_opt(sb, I_VERSION))
                 seq_puts(seq, ",i_version");
+        if (!test_opt(sb, DELALLOC))
+                seq_puts(seq, ",nodelalloc");
+
 
         if (sbi->s_stripe)
                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
@@ -894,7 +906,7 @@ enum {
         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
         Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
         Opt_grpquota, Opt_extents, Opt_noextents, Opt_i_version,
-        Opt_mballoc, Opt_nomballoc, Opt_stripe,
+        Opt_mballoc, Opt_nomballoc, Opt_stripe, Opt_delalloc, Opt_nodelalloc,
 };
 
 static match_table_t tokens = {
@@ -953,6 +965,8 @@ static match_table_t tokens = {
         {Opt_nomballoc, "nomballoc"},
         {Opt_stripe, "stripe=%u"},
         {Opt_resize, "resize"},
+        {Opt_delalloc, "delalloc"},
+        {Opt_nodelalloc, "nodelalloc"},
         {Opt_err, NULL},
 };
 
@@ -990,6 +1004,7 @@ static int parse_options (char *options, struct super_block *sb,
         int qtype, qfmt;
         char *qname;
 #endif
+        ext4_fsblk_t last_block;
 
         if (!options)
                 return 1;
@@ -1309,15 +1324,39 @@ set_qf_format:
                         clear_opt(sbi->s_mount_opt, NOBH);
                         break;
                 case Opt_extents:
+                        if (!EXT4_HAS_INCOMPAT_FEATURE(sb,
+                                        EXT4_FEATURE_INCOMPAT_EXTENTS)) {
+                                ext4_warning(sb, __func__,
+                                        "extents feature not enabled "
+                                        "on this filesystem, use tune2fs\n");
+                                return 0;
+                        }
                         set_opt (sbi->s_mount_opt, EXTENTS);
                         break;
                 case Opt_noextents:
+                        /*
+                         * When e2fsprogs support resizing an already existing
+                         * ext3 file system to greater than 2**32 we need to
+                         * add support to block allocator to handle growing
+                         * already existing block  mapped inode so that blocks
+                         * allocated for them fall within 2**32
+                         */
+                        last_block = ext4_blocks_count(sbi->s_es) - 1;
+                        if (last_block  > 0xffffffffULL) {
+                                printk(KERN_ERR "EXT4-fs: Filesystem too "
+                                                "large to mount with "
+                                                "-o noextents options\n");
+                                return 0;
+                        }
                         clear_opt (sbi->s_mount_opt, EXTENTS);
                         break;
                 case Opt_i_version:
                         set_opt(sbi->s_mount_opt, I_VERSION);
                         sb->s_flags |= MS_I_VERSION;
                         break;
+                case Opt_nodelalloc:
+                        clear_opt(sbi->s_mount_opt, DELALLOC);
+                        break;
                 case Opt_mballoc:
                         set_opt(sbi->s_mount_opt, MBALLOC);
                         break;
@@ -1331,6 +1370,9 @@ set_qf_format:
                                 return 0;
                         sbi->s_stripe = option;
                         break;
+                case Opt_delalloc:
+                        set_opt(sbi->s_mount_opt, DELALLOC);
+                        break;
                 default:
                         printk (KERN_ERR
                                 "EXT4-fs: Unrecognized mount option \"%s\" "
@@ -1443,6 +1485,54 @@ static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
         return res;
 }
 
+static int ext4_fill_flex_info(struct super_block *sb)
+{
+        struct ext4_sb_info *sbi = EXT4_SB(sb);
+        struct ext4_group_desc *gdp = NULL;
+        struct buffer_head *bh;
+        ext4_group_t flex_group_count;
+        ext4_group_t flex_group;
+        int groups_per_flex = 0;
+        __u64 block_bitmap = 0;
+        int i;
+
+        if (!sbi->s_es->s_log_groups_per_flex) {
+                sbi->s_log_groups_per_flex = 0;
+                return 1;
+        }
+
+        sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
+        groups_per_flex = 1 << sbi->s_log_groups_per_flex;
+
+        flex_group_count = (sbi->s_groups_count + groups_per_flex - 1) /
+                groups_per_flex;
+        sbi->s_flex_groups = kmalloc(flex_group_count *
+                                     sizeof(struct flex_groups), GFP_KERNEL);
+        if (sbi->s_flex_groups == NULL) {
+                printk(KERN_ERR "EXT4-fs: not enough memory\n");
+                goto failed;
+        }
+        memset(sbi->s_flex_groups, 0, flex_group_count *
+               sizeof(struct flex_groups));
+
+        gdp = ext4_get_group_desc(sb, 1, &bh);
+        block_bitmap = ext4_block_bitmap(sb, gdp) - 1;
+
+        for (i = 0; i < sbi->s_groups_count; i++) {
+                gdp = ext4_get_group_desc(sb, i, &bh);
+
+                flex_group = ext4_flex_group(sbi, i);
+                sbi->s_flex_groups[flex_group].free_inodes +=
+                        le16_to_cpu(gdp->bg_free_inodes_count);
+                sbi->s_flex_groups[flex_group].free_blocks +=
+                        le16_to_cpu(gdp->bg_free_blocks_count);
+        }
+
+        return 1;
+failed:
+        return 0;
+}
+
 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
                             struct ext4_group_desc *gdp)
 {
@@ -1810,8 +1900,8 @@ static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
 }
 
 static int ext4_fill_super (struct super_block *sb, void *data, int silent)
-                                __releases(kernel_sem)
-                                __acquires(kernel_sem)
+                                __releases(kernel_lock)
+                                __acquires(kernel_lock)
 
 {
         struct buffer_head * bh;
@@ -1851,11 +1941,6 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
                 goto out_fail;
         }
 
-        if (!sb_set_blocksize(sb, blocksize)) {
-                printk(KERN_ERR "EXT4-fs: bad blocksize %d.\n", blocksize);
-                goto out_fail;
-        }
-
         /*
          * The ext4 superblock will not be buffer aligned for other than 1kB
          * block sizes.  We need to calculate the offset from buffer start.
@@ -1919,15 +2004,28 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 
         /*
          * turn on extents feature by default in ext4 filesystem
-         * User -o noextents to turn it off
+         * only if feature flag already set by mkfs or tune2fs.
+         * Use -o noextents to turn it off
          */
-        set_opt(sbi->s_mount_opt, EXTENTS);
+        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
+                set_opt(sbi->s_mount_opt, EXTENTS);
+        else
+                ext4_warning(sb, __func__,
+                        "extents feature not enabled on this filesystem, "
+                        "use tune2fs.\n");
         /*
-         * turn on mballoc feature by default in ext4 filesystem
-         * User -o nomballoc to turn it off
+         * turn on mballoc code by default in ext4 filesystem
+         * Use -o nomballoc to turn it off
          */
         set_opt(sbi->s_mount_opt, MBALLOC);
 
+        /*
+         * enable delayed allocation by default
+         * Use -o nodelalloc to turn it off
+         */
+        set_opt(sbi->s_mount_opt, DELALLOC);
+
+
         if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,
                             NULL, 0))
                 goto failed_mount;
@@ -2138,6 +2236,14 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
                 printk(KERN_ERR "EXT4-fs: group descriptors corrupted!\n");
                 goto failed_mount2;
         }
+        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
+                if (!ext4_fill_flex_info(sb)) {
+                        printk(KERN_ERR
+                               "EXT4-fs: unable to initialize "
+                               "flex_bg meta info!\n");
+                        goto failed_mount2;
+                }
+
         sbi->s_gdb_count = db_count;
         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
         spin_lock_init(&sbi->s_next_gen_lock);
@@ -2358,6 +2464,13 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA ? "ordered":
                 "writeback");
 
+        if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
+                printk(KERN_WARNING "EXT4-fs: Ignoring delalloc option - "
+                                "requested data journaling mode\n");
+                clear_opt(sbi->s_mount_opt, DELALLOC);
+        } else if (test_opt(sb, DELALLOC))
+                printk(KERN_INFO "EXT4-fs: delayed allocation enabled\n");
+
         ext4_ext_init(sb);
         ext4_mb_init(sb, needs_recovery);
 
@@ -2372,6 +2485,7 @@ cantfind_ext4:
 
 failed_mount4:
         jbd2_journal_destroy(sbi->s_journal);
+        sbi->s_journal = NULL;
 failed_mount3:
         percpu_counter_destroy(&sbi->s_freeblocks_counter);
         percpu_counter_destroy(&sbi->s_freeinodes_counter);
@@ -3325,7 +3439,7 @@ static ssize_t ext4_quota_write(struct super_block *sb, int type,
                         err = ext4_journal_dirty_metadata(handle, bh);
                 else {
                         /* Always do at least ordered writes for quotas */
-                        err = ext4_journal_dirty_data(handle, bh);
+                        err = ext4_jbd2_file_inode(handle, inode);
                         mark_buffer_dirty(bh);
                 }
                 brelse(bh);
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index ff08633f398e..93c5fdcdad2e 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -810,7 +810,7 @@ inserted:
                         /* We need to allocate a new block */
                         ext4_fsblk_t goal = ext4_group_first_block_no(sb,
                                                 EXT4_I(inode)->i_block_group);
-                        ext4_fsblk_t block = ext4_new_block(handle, inode,
+                        ext4_fsblk_t block = ext4_new_meta_block(handle, inode,
                                                         goal, &error);
                         if (error)
                                 goto cleanup;
diff --git a/fs/ext4/xattr_trusted.c b/fs/ext4/xattr_trusted.c
index fff33382cadc..ac1a52cf2a37 100644
--- a/fs/ext4/xattr_trusted.c
+++ b/fs/ext4/xattr_trusted.c
@@ -13,13 +13,11 @@
 #include "ext4.h"
 #include "xattr.h"
 
-#define XATTR_TRUSTED_PREFIX "trusted."
-
 static size_t
 ext4_xattr_trusted_list(struct inode *inode, char *list, size_t list_size,
                         const char *name, size_t name_len)
 {
-        const size_t prefix_len = sizeof(XATTR_TRUSTED_PREFIX)-1;
+        const size_t prefix_len = XATTR_TRUSTED_PREFIX_LEN;
         const size_t total_len = prefix_len + name_len + 1;
 
         if (!capable(CAP_SYS_ADMIN))
diff --git a/fs/ext4/xattr_user.c b/fs/ext4/xattr_user.c
index 67be723fcc4e..d91aa61b42aa 100644
--- a/fs/ext4/xattr_user.c
+++ b/fs/ext4/xattr_user.c
@@ -12,13 +12,11 @@
 #include "ext4.h"
 #include "xattr.h"
 
-#define XATTR_USER_PREFIX "user."
-
 static size_t
 ext4_xattr_user_list(struct inode *inode, char *list, size_t list_size,
                      const char *name, size_t name_len)
 {
-        const size_t prefix_len = sizeof(XATTR_USER_PREFIX)-1;
+        const size_t prefix_len = XATTR_USER_PREFIX_LEN;
         const size_t total_len = prefix_len + name_len + 1;
 
         if (!test_opt(inode->i_sb, XATTR_USER))
diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
index 6914598022ce..91389c8aee8a 100644
--- a/fs/jbd2/checkpoint.c
+++ b/fs/jbd2/checkpoint.c
@@ -688,7 +688,6 @@ void __jbd2_journal_drop_transaction(journal_t *journal, transaction_t *transact
 
         J_ASSERT(transaction->t_state == T_FINISHED);
         J_ASSERT(transaction->t_buffers == NULL);
-        J_ASSERT(transaction->t_sync_datalist == NULL);
         J_ASSERT(transaction->t_forget == NULL);
         J_ASSERT(transaction->t_iobuf_list == NULL);
         J_ASSERT(transaction->t_shadow_list == NULL);
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index a2ed72f7ceee..f8b3be873226 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -22,6 +22,8 @@
 #include <linux/pagemap.h>
 #include <linux/jiffies.h>
 #include <linux/crc32.h>
+#include <linux/writeback.h>
+#include <linux/backing-dev.h>
 
 /*
  * Default IO end handler for temporary BJ_IO buffer_heads.
@@ -37,8 +39,8 @@ static void journal_end_buffer_io_sync(struct buffer_head *bh, int uptodate)
 }
 
 /*
- * When an ext3-ordered file is truncated, it is possible that many pages are
- * not sucessfully freed, because they are attached to a committing transaction.
+ * When an ext4 file is truncated, it is possible that some pages are not
+ * successfully freed, because they are attached to a committing transaction.
  * After the transaction commits, these pages are left on the LRU, with no
  * ->mapping, and with attached buffers.  These pages are trivially reclaimable
  * by the VM, but their apparent absence upsets the VM accounting, and it makes
@@ -80,21 +82,6 @@ nope:
 }
 
 /*
- * Try to acquire jbd_lock_bh_state() against the buffer, when j_list_lock is
- * held.  For ranking reasons we must trylock.  If we lose, schedule away and
- * return 0.  j_list_lock is dropped in this case.
- */
-static int inverted_lock(journal_t *journal, struct buffer_head *bh)
-{
-        if (!jbd_trylock_bh_state(bh)) {
-                spin_unlock(&journal->j_list_lock);
-                schedule();
-                return 0;
-        }
-        return 1;
-}
-
-/*
  * Done it all: now submit the commit record.  We should have
  * cleaned up our previous buffers by now, so if we are in abort
  * mode we can now just skip the rest of the journal write
@@ -112,6 +99,7 @@ static int journal_submit_commit_record(journal_t *journal,
         struct buffer_head *bh;
         int ret;
         int barrier_done = 0;
+        struct timespec now = current_kernel_time();
 
         if (is_journal_aborted(journal))
                 return 0;
@@ -126,6 +114,8 @@ static int journal_submit_commit_record(journal_t *journal,
         tmp->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER);
         tmp->h_blocktype = cpu_to_be32(JBD2_COMMIT_BLOCK);
         tmp->h_sequence = cpu_to_be32(commit_transaction->t_tid);
+        tmp->h_commit_sec = cpu_to_be64(now.tv_sec);
+        tmp->h_commit_nsec = cpu_to_be32(now.tv_nsec);
 
         if (JBD2_HAS_COMPAT_FEATURE(journal,
                                     JBD2_FEATURE_COMPAT_CHECKSUM)) {
@@ -197,159 +187,104 @@ static int journal_wait_on_commit_record(struct buffer_head *bh)
 }
 
 /*
- * Wait for all submitted IO to complete.
+ * write the filemap data using writepage() address_space_operations.
+ * We don't do block allocation here even for delalloc. We don't
+ * use writepages() because with dealyed allocation we may be doing
+ * block allocation in writepages().
  */
-static int journal_wait_on_locked_list(journal_t *journal,
-                                       transaction_t *commit_transaction)
+static int journal_submit_inode_data_buffers(struct address_space *mapping)
 {
-        int ret = 0;
-        struct journal_head *jh;
-
-        while (commit_transaction->t_locked_list) {
-                struct buffer_head *bh;
-
-                jh = commit_transaction->t_locked_list->b_tprev;
-                bh = jh2bh(jh);
-                get_bh(bh);
-                if (buffer_locked(bh)) {
-                        spin_unlock(&journal->j_list_lock);
-                        wait_on_buffer(bh);
-                        if (unlikely(!buffer_uptodate(bh)))
-                                ret = -EIO;
-                        spin_lock(&journal->j_list_lock);
-                }
-                if (!inverted_lock(journal, bh)) {
-                        put_bh(bh);
-                        spin_lock(&journal->j_list_lock);
-                        continue;
-                }
-                if (buffer_jbd(bh) && jh->b_jlist == BJ_Locked) {
-                        __jbd2_journal_unfile_buffer(jh);
-                        jbd_unlock_bh_state(bh);
-                        jbd2_journal_remove_journal_head(bh);
-                        put_bh(bh);
-                } else {
-                        jbd_unlock_bh_state(bh);
-                }
-                put_bh(bh);
-                cond_resched_lock(&journal->j_list_lock);
-        }
+        int ret;
+        struct writeback_control wbc = {
+                .sync_mode =  WB_SYNC_ALL,
+                .nr_to_write = mapping->nrpages * 2,
+                .range_start = 0,
+                .range_end = i_size_read(mapping->host),
+                .for_writepages = 1,
+        };
+
+        ret = generic_writepages(mapping, &wbc);
         return ret;
-  }
+}
 
-static void journal_do_submit_data(struct buffer_head **wbuf, int bufs)
+/*
+ * Submit all the data buffers of inode associated with the transaction to
+ * disk.
+ *
+ * We are in a committing transaction. Therefore no new inode can be added to
+ * our inode list. We use JI_COMMIT_RUNNING flag to protect inode we currently
+ * operate on from being released while we write out pages.
+ */
+static int journal_submit_data_buffers(journal_t *journal,
+                transaction_t *commit_transaction)
 {
-        int i;
+        struct jbd2_inode *jinode;
+        int err, ret = 0;
+        struct address_space *mapping;
 
-        for (i = 0; i < bufs; i++) {
-                wbuf[i]->b_end_io = end_buffer_write_sync;
-                /* We use-up our safety reference in submit_bh() */
-                submit_bh(WRITE, wbuf[i]);
+        spin_lock(&journal->j_list_lock);
+        list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
+                mapping = jinode->i_vfs_inode->i_mapping;
+                jinode->i_flags |= JI_COMMIT_RUNNING;
+                spin_unlock(&journal->j_list_lock);
+                /*
+                 * submit the inode data buffers. We use writepage
+                 * instead of writepages. Because writepages can do
+                 * block allocation  with delalloc. We need to write
+                 * only allocated blocks here.
+                 */
+                err = journal_submit_inode_data_buffers(mapping);
+                if (!ret)
+                        ret = err;
+                spin_lock(&journal->j_list_lock);
+                J_ASSERT(jinode->i_transaction == commit_transaction);
+                jinode->i_flags &= ~JI_COMMIT_RUNNING;
+                wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
         }
+        spin_unlock(&journal->j_list_lock);
+        return ret;
 }
 
 /*
- *  Submit all the data buffers to disk
+ * Wait for data submitted for writeout, refile inodes to proper
+ * transaction if needed.
+ *
  */
-static void journal_submit_data_buffers(journal_t *journal,
-                                transaction_t *commit_transaction)
+static int journal_finish_inode_data_buffers(journal_t *journal,
+                transaction_t *commit_transaction)
 {
-        struct journal_head *jh;
-        struct buffer_head *bh;
-        int locked;
-        int bufs = 0;
-        struct buffer_head **wbuf = journal->j_wbuf;
+        struct jbd2_inode *jinode, *next_i;
+        int err, ret = 0;
 
-        /*
-         * Whenever we unlock the journal and sleep, things can get added
-         * onto ->t_sync_datalist, so we have to keep looping back to
-         * write_out_data until we *know* that the list is empty.
-         *
-         * Cleanup any flushed data buffers from the data list.  Even in
-         * abort mode, we want to flush this out as soon as possible.
-         */
-write_out_data:
-        cond_resched();
+        /* For locking, see the comment in journal_submit_data_buffers() */
         spin_lock(&journal->j_list_lock);
+        list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
+                jinode->i_flags |= JI_COMMIT_RUNNING;
+                spin_unlock(&journal->j_list_lock);
+                err = filemap_fdatawait(jinode->i_vfs_inode->i_mapping);
+                if (!ret)
+                        ret = err;
+                spin_lock(&journal->j_list_lock);
+                jinode->i_flags &= ~JI_COMMIT_RUNNING;
+                wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
+        }
 
-        while (commit_transaction->t_sync_datalist) {
-                jh = commit_transaction->t_sync_datalist;
-                bh = jh2bh(jh);
-                locked = 0;
-
-                /* Get reference just to make sure buffer does not disappear
-                 * when we are forced to drop various locks */
-                get_bh(bh);
-                /* If the buffer is dirty, we need to submit IO and hence
-                 * we need the buffer lock. We try to lock the buffer without
-                 * blocking. If we fail, we need to drop j_list_lock and do
-                 * blocking lock_buffer().
-                 */
-                if (buffer_dirty(bh)) {
-                        if (test_set_buffer_locked(bh)) {
-                                BUFFER_TRACE(bh, "needs blocking lock");
-                                spin_unlock(&journal->j_list_lock);
-                                /* Write out all data to prevent deadlocks */
-                                journal_do_submit_data(wbuf, bufs);
-                                bufs = 0;
-                                lock_buffer(bh);
-                                spin_lock(&journal->j_list_lock);
-                        }
-                        locked = 1;
-                }
-                /* We have to get bh_state lock. Again out of order, sigh. */
-                if (!inverted_lock(journal, bh)) {
-                        jbd_lock_bh_state(bh);
-                        spin_lock(&journal->j_list_lock);
-                }
-                /* Someone already cleaned up the buffer? */
-                if (!buffer_jbd(bh)
-                        || jh->b_transaction != commit_transaction
-                        || jh->b_jlist != BJ_SyncData) {
-                        jbd_unlock_bh_state(bh);
-                        if (locked)
-                                unlock_buffer(bh);
-                        BUFFER_TRACE(bh, "already cleaned up");
-                        put_bh(bh);
-                        continue;
-                }
-                if (locked && test_clear_buffer_dirty(bh)) {
-                        BUFFER_TRACE(bh, "needs writeout, adding to array");
-                        wbuf[bufs++] = bh;
-                        __jbd2_journal_file_buffer(jh, commit_transaction,
-                                                BJ_Locked);
-                        jbd_unlock_bh_state(bh);
-                        if (bufs == journal->j_wbufsize) {
-                                spin_unlock(&journal->j_list_lock);
-                                journal_do_submit_data(wbuf, bufs);
-                                bufs = 0;
-                                goto write_out_data;
-                        }
-                } else if (!locked && buffer_locked(bh)) {
-                        __jbd2_journal_file_buffer(jh, commit_transaction,
-                                                BJ_Locked);
-                        jbd_unlock_bh_state(bh);
-                        put_bh(bh);
+        /* Now refile inode to proper lists */
+        list_for_each_entry_safe(jinode, next_i,
+                                 &commit_transaction->t_inode_list, i_list) {
+                list_del(&jinode->i_list);
+                if (jinode->i_next_transaction) {
+                        jinode->i_transaction = jinode->i_next_transaction;
+                        jinode->i_next_transaction = NULL;
+                        list_add(&jinode->i_list,
+                                &jinode->i_transaction->t_inode_list);
                 } else {
-                        BUFFER_TRACE(bh, "writeout complete: unfile");
-                        __jbd2_journal_unfile_buffer(jh);
-                        jbd_unlock_bh_state(bh);
-                        if (locked)
-                                unlock_buffer(bh);
-                        jbd2_journal_remove_journal_head(bh);
-                        /* Once for our safety reference, once for
-                         * jbd2_journal_remove_journal_head() */
-                        put_bh(bh);
-                        put_bh(bh);
-                }
-
-                if (need_resched() || spin_needbreak(&journal->j_list_lock)) {
-                        spin_unlock(&journal->j_list_lock);
-                        goto write_out_data;
+                        jinode->i_transaction = NULL;
                 }
         }
         spin_unlock(&journal->j_list_lock);
-        journal_do_submit_data(wbuf, bufs);
+
+        return ret;
 }
 
 static __u32 jbd2_checksum_data(__u32 crc32_sum, struct buffer_head *bh)
@@ -524,21 +459,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
          * Now start flushing things to disk, in the order they appear
          * on the transaction lists.  Data blocks go first.
          */
-        err = 0;
-        journal_submit_data_buffers(journal, commit_transaction);
-
-        /*
-         * Wait for all previously submitted IO to complete if commit
-         * record is to be written synchronously.
-         */
-        spin_lock(&journal->j_list_lock);
-        if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
-                JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT))
-                err = journal_wait_on_locked_list(journal,
-                                                commit_transaction);
-
-        spin_unlock(&journal->j_list_lock);
-
+        err = journal_submit_data_buffers(journal, commit_transaction);
         if (err)
                 jbd2_journal_abort(journal, err);
 
@@ -547,16 +468,6 @@ void jbd2_journal_commit_transaction(journal_t *journal)
         jbd_debug(3, "JBD: commit phase 2\n");
 
         /*
-         * If we found any dirty or locked buffers, then we should have
-         * looped back up to the write_out_data label.  If there weren't
-         * any then journal_clean_data_list should have wiped the list
-         * clean by now, so check that it is in fact empty.
-         */
-        J_ASSERT (commit_transaction->t_sync_datalist == NULL);
-
-        jbd_debug (3, "JBD: commit phase 3\n");
-
-        /*
          * Way to go: we have now written out all of the data for a
          * transaction!  Now comes the tricky part: we need to write out
          * metadata.  Loop over the transaction's entire buffer list:
@@ -574,6 +485,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
         J_ASSERT(commit_transaction->t_nr_buffers <=
                  commit_transaction->t_outstanding_credits);
 
+        err = 0;
         descriptor = NULL;
         bufs = 0;
         while (commit_transaction->t_buffers) {
@@ -748,15 +660,19 @@ start_journal_io:
                                                  &cbh, crc32_sum);
                 if (err)
                         __jbd2_journal_abort_hard(journal);
-
-                spin_lock(&journal->j_list_lock);
-                err = journal_wait_on_locked_list(journal,
-                                                commit_transaction);
-                spin_unlock(&journal->j_list_lock);
-                if (err)
-                        __jbd2_journal_abort_hard(journal);
         }
 
+        /*
+         * This is the right place to wait for data buffers both for ASYNC
+         * and !ASYNC commit. If commit is ASYNC, we need to wait only after
+         * the commit block went to disk (which happens above). If commit is
+         * SYNC, we need to wait for data buffers before we start writing
+         * commit block, which happens below in such setting.
+         */
+        err = journal_finish_inode_data_buffers(journal, commit_transaction);
+        if (err)
+                jbd2_journal_abort(journal, err);
+
         /* Lo and behold: we have just managed to send a transaction to
            the log.  Before we can commit it, wait for the IO so far to
            complete.  Control buffers being written are on the
@@ -768,7 +684,7 @@ start_journal_io:
            so we incur less scheduling load.
         */
 
-        jbd_debug(3, "JBD: commit phase 4\n");
+        jbd_debug(3, "JBD: commit phase 3\n");
 
         /*
          * akpm: these are BJ_IO, and j_list_lock is not needed.
@@ -827,7 +743,7 @@ wait_for_iobuf:
 
         J_ASSERT (commit_transaction->t_shadow_list == NULL);
 
-        jbd_debug(3, "JBD: commit phase 5\n");
+        jbd_debug(3, "JBD: commit phase 4\n");
 
         /* Here we wait for the revoke record and descriptor record buffers */
  wait_for_ctlbuf:
@@ -854,7 +770,7 @@ wait_for_iobuf:
                 /* AKPM: bforget here */
         }
 
-        jbd_debug(3, "JBD: commit phase 6\n");
+        jbd_debug(3, "JBD: commit phase 5\n");
 
         if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
@@ -874,9 +790,9 @@ wait_for_iobuf:
            transaction can be removed from any checkpoint list it was on
            before. */
 
-        jbd_debug(3, "JBD: commit phase 7\n");
+        jbd_debug(3, "JBD: commit phase 6\n");
 
-        J_ASSERT(commit_transaction->t_sync_datalist == NULL);
+        J_ASSERT(list_empty(&commit_transaction->t_inode_list));
         J_ASSERT(commit_transaction->t_buffers == NULL);
         J_ASSERT(commit_transaction->t_checkpoint_list == NULL);
         J_ASSERT(commit_transaction->t_iobuf_list == NULL);
@@ -997,7 +913,7 @@ restart_loop:
 
         /* Done with this transaction! */
 
-        jbd_debug(3, "JBD: commit phase 8\n");
+        jbd_debug(3, "JBD: commit phase 7\n");
 
         J_ASSERT(commit_transaction->t_state == T_COMMIT);
 
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 2e24567c4a79..b26c6d9fe6ae 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -50,7 +50,6 @@ EXPORT_SYMBOL(jbd2_journal_unlock_updates);
 EXPORT_SYMBOL(jbd2_journal_get_write_access);
 EXPORT_SYMBOL(jbd2_journal_get_create_access);
 EXPORT_SYMBOL(jbd2_journal_get_undo_access);
-EXPORT_SYMBOL(jbd2_journal_dirty_data);
 EXPORT_SYMBOL(jbd2_journal_dirty_metadata);
 EXPORT_SYMBOL(jbd2_journal_release_buffer);
 EXPORT_SYMBOL(jbd2_journal_forget);
@@ -82,6 +81,10 @@ EXPORT_SYMBOL(jbd2_journal_blocks_per_page);
 EXPORT_SYMBOL(jbd2_journal_invalidatepage);
 EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers);
 EXPORT_SYMBOL(jbd2_journal_force_commit);
+EXPORT_SYMBOL(jbd2_journal_file_inode);
+EXPORT_SYMBOL(jbd2_journal_init_jbd_inode);
+EXPORT_SYMBOL(jbd2_journal_release_jbd_inode);
+EXPORT_SYMBOL(jbd2_journal_begin_ordered_truncate);
 
 static int journal_convert_superblock_v1(journal_t *, journal_superblock_t *);
 static void __journal_abort_soft (journal_t *journal, int errno);
@@ -2195,6 +2198,54 @@ void jbd2_journal_put_journal_head(struct journal_head *jh)
 }
 
 /*
+ * Initialize jbd inode head
+ */
+void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode)
+{
+        jinode->i_transaction = NULL;
+        jinode->i_next_transaction = NULL;
+        jinode->i_vfs_inode = inode;
+        jinode->i_flags = 0;
+        INIT_LIST_HEAD(&jinode->i_list);
+}
+
+/*
+ * Function to be called before we start removing inode from memory (i.e.,
+ * clear_inode() is a fine place to be called from). It removes inode from
+ * transaction's lists.
+ */
+void jbd2_journal_release_jbd_inode(journal_t *journal,
+                                    struct jbd2_inode *jinode)
+{
+        int writeout = 0;
+
+        if (!journal)
+                return;
+restart:
+        spin_lock(&journal->j_list_lock);
+        /* Is commit writing out inode - we have to wait */
+        if (jinode->i_flags & JI_COMMIT_RUNNING) {
+                wait_queue_head_t *wq;
+                DEFINE_WAIT_BIT(wait, &jinode->i_flags, __JI_COMMIT_RUNNING);
+                wq = bit_waitqueue(&jinode->i_flags, __JI_COMMIT_RUNNING);
+                prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE);
+                spin_unlock(&journal->j_list_lock);
+                schedule();
+                finish_wait(wq, &wait.wait);
+                goto restart;
+        }
+
+        /* Do we need to wait for data writeback? */
+        if (journal->j_committing_transaction == jinode->i_transaction)
+                writeout = 1;
+        if (jinode->i_transaction) {
+                list_del(&jinode->i_list);
+                jinode->i_transaction = NULL;
+        }
+        spin_unlock(&journal->j_list_lock);
+}
+
+/*
  * debugfs tunables
  */
 #ifdef CONFIG_JBD2_DEBUG
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index d6e006e67804..4f7cadbb19fa 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -41,7 +41,6 @@ static void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh);
  *      new transaction and we can't block without protecting against other
  *      processes trying to touch the journal while it is in transition.
  *
- * Called under j_state_lock
  */
 
 static transaction_t *
@@ -52,6 +51,7 @@ jbd2_get_transaction(journal_t *journal, transaction_t *transaction)
         transaction->t_tid = journal->j_transaction_sequence++;
         transaction->t_expires = jiffies + journal->j_commit_interval;
         spin_lock_init(&transaction->t_handle_lock);
+        INIT_LIST_HEAD(&transaction->t_inode_list);
 
         /* Set up the commit timer for the new transaction. */
         journal->j_commit_timer.expires = round_jiffies(transaction->t_expires);
@@ -943,183 +943,6 @@ out:
 }
 
 /**
- * int jbd2_journal_dirty_data() -  mark a buffer as containing dirty data which
- *                             needs to be flushed before we can commit the
- *                             current transaction.
- * @handle: transaction
- * @bh: bufferhead to mark
- *
- * The buffer is placed on the transaction's data list and is marked as
- * belonging to the transaction.
- *
- * Returns error number or 0 on success.
- *
- * jbd2_journal_dirty_data() can be called via page_launder->ext3_writepage
- * by kswapd.
- */
-int jbd2_journal_dirty_data(handle_t *handle, struct buffer_head *bh)
-{
-        journal_t *journal = handle->h_transaction->t_journal;
-        int need_brelse = 0;
-        struct journal_head *jh;
-
-        if (is_handle_aborted(handle))
-                return 0;
-
-        jh = jbd2_journal_add_journal_head(bh);
-        JBUFFER_TRACE(jh, "entry");
-
-        /*
-         * The buffer could *already* be dirty.  Writeout can start
-         * at any time.
-         */
-        jbd_debug(4, "jh: %p, tid:%d\n", jh, handle->h_transaction->t_tid);
-
-        /*
-         * What if the buffer is already part of a running transaction?
-         *
-         * There are two cases:
-         * 1) It is part of the current running transaction.  Refile it,
-         *    just in case we have allocated it as metadata, deallocated
-         *    it, then reallocated it as data.
-         * 2) It is part of the previous, still-committing transaction.
-         *    If all we want to do is to guarantee that the buffer will be
-         *    written to disk before this new transaction commits, then
-         *    being sure that the *previous* transaction has this same
-         *    property is sufficient for us!  Just leave it on its old
-         *    transaction.
-         *
-         * In case (2), the buffer must not already exist as metadata
-         * --- that would violate write ordering (a transaction is free
-         * to write its data at any point, even before the previous
-         * committing transaction has committed).  The caller must
-         * never, ever allow this to happen: there's nothing we can do
-         * about it in this layer.
-         */
-        jbd_lock_bh_state(bh);
-        spin_lock(&journal->j_list_lock);
-
-        /* Now that we have bh_state locked, are we really still mapped? */
-        if (!buffer_mapped(bh)) {
-                JBUFFER_TRACE(jh, "unmapped buffer, bailing out");
-                goto no_journal;
-        }
-
-        if (jh->b_transaction) {
-                JBUFFER_TRACE(jh, "has transaction");
-                if (jh->b_transaction != handle->h_transaction) {
-                        JBUFFER_TRACE(jh, "belongs to older transaction");
-                        J_ASSERT_JH(jh, jh->b_transaction ==
-                                        journal->j_committing_transaction);
-
-                        /* @@@ IS THIS TRUE  ? */
-                        /*
-                         * Not any more.  Scenario: someone does a write()
-                         * in data=journal mode.  The buffer's transaction has
-                         * moved into commit.  Then someone does another
-                         * write() to the file.  We do the frozen data copyout
-                         * and set b_next_transaction to point to j_running_t.
-                         * And while we're in that state, someone does a
-                         * writepage() in an attempt to pageout the same area
-                         * of the file via a shared mapping.  At present that
-                         * calls jbd2_journal_dirty_data(), and we get right here.
-                         * It may be too late to journal the data.  Simply
-                         * falling through to the next test will suffice: the
-                         * data will be dirty and wil be checkpointed.  The
-                         * ordering comments in the next comment block still
-                         * apply.
-                         */
-                        //J_ASSERT_JH(jh, jh->b_next_transaction == NULL);
-
-                        /*
-                         * If we're journalling data, and this buffer was
-                         * subject to a write(), it could be metadata, forget
-                         * or shadow against the committing transaction.  Now,
-                         * someone has dirtied the same darn page via a mapping
-                         * and it is being writepage()'d.
-                         * We *could* just steal the page from commit, with some
-                         * fancy locking there.  Instead, we just skip it -
-                         * don't tie the page's buffers to the new transaction
-                         * at all.
-                         * Implication: if we crash before the writepage() data
-                         * is written into the filesystem, recovery will replay
-                         * the write() data.
-                         */
-                        if (jh->b_jlist != BJ_None &&
-                                        jh->b_jlist != BJ_SyncData &&
-                                        jh->b_jlist != BJ_Locked) {
-                                JBUFFER_TRACE(jh, "Not stealing");
-                                goto no_journal;
-                        }
-
-                        /*
-                         * This buffer may be undergoing writeout in commit.  We
-                         * can't return from here and let the caller dirty it
-                         * again because that can cause the write-out loop in
-                         * commit to never terminate.
-                         */
-                        if (buffer_dirty(bh)) {
-                                get_bh(bh);
-                                spin_unlock(&journal->j_list_lock);
-                                jbd_unlock_bh_state(bh);
-                                need_brelse = 1;
-                                sync_dirty_buffer(bh);
-                                jbd_lock_bh_state(bh);
-                                spin_lock(&journal->j_list_lock);
-                                /* Since we dropped the lock... */
-                                if (!buffer_mapped(bh)) {
-                                        JBUFFER_TRACE(jh, "buffer got unmapped");
-                                        goto no_journal;
-                                }
-                                /* The buffer may become locked again at any
-                                   time if it is redirtied */
-                        }
-
-                        /* journal_clean_data_list() may have got there first */
-                        if (jh->b_transaction != NULL) {
-                                JBUFFER_TRACE(jh, "unfile from commit");
-                                __jbd2_journal_temp_unlink_buffer(jh);
-                                /* It still points to the committing
-                                 * transaction; move it to this one so
-                                 * that the refile assert checks are
-                                 * happy. */
-                                jh->b_transaction = handle->h_transaction;
-                        }
-                        /* The buffer will be refiled below */
-
-                }
-                /*
-                 * Special case --- the buffer might actually have been
-                 * allocated and then immediately deallocated in the previous,
-                 * committing transaction, so might still be left on that
-                 * transaction's metadata lists.
-                 */
-                if (jh->b_jlist != BJ_SyncData && jh->b_jlist != BJ_Locked) {
-                        JBUFFER_TRACE(jh, "not on correct data list: unfile");
-                        J_ASSERT_JH(jh, jh->b_jlist != BJ_Shadow);
-                        __jbd2_journal_temp_unlink_buffer(jh);
-                        jh->b_transaction = handle->h_transaction;
-                        JBUFFER_TRACE(jh, "file as data");
-                        __jbd2_journal_file_buffer(jh, handle->h_transaction,
-                                                BJ_SyncData);
-                }
-        } else {
-                JBUFFER_TRACE(jh, "not on a transaction");
-                __jbd2_journal_file_buffer(jh, handle->h_transaction, BJ_SyncData);
-        }
-no_journal:
-        spin_unlock(&journal->j_list_lock);
-        jbd_unlock_bh_state(bh);
-        if (need_brelse) {
-                BUFFER_TRACE(bh, "brelse");
-                __brelse(bh);
-        }
-        JBUFFER_TRACE(jh, "exit");
-        jbd2_journal_put_journal_head(jh);
-        return 0;
-}
-
-/**
  * int jbd2_journal_dirty_metadata() -  mark a buffer as containing dirty metadata
  * @handle: transaction to add buffer to.
  * @bh: buffer to mark
@@ -1541,10 +1364,10 @@ __blist_del_buffer(struct journal_head **list, struct journal_head *jh)
  * Remove a buffer from the appropriate transaction list.
  *
  * Note that this function can *change* the value of
- * bh->b_transaction->t_sync_datalist, t_buffers, t_forget,
- * t_iobuf_list, t_shadow_list, t_log_list or t_reserved_list.  If the caller
- * is holding onto a copy of one of thee pointers, it could go bad.
- * Generally the caller needs to re-read the pointer from the transaction_t.
+ * bh->b_transaction->t_buffers, t_forget, t_iobuf_list, t_shadow_list,
+ * t_log_list or t_reserved_list.  If the caller is holding onto a copy of one
+ * of these pointers, it could go bad.  Generally the caller needs to re-read
+ * the pointer from the transaction_t.
  *
  * Called under j_list_lock.  The journal may not be locked.
  */
@@ -1566,9 +1389,6 @@ void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh)
         switch (jh->b_jlist) {
         case BJ_None:
                 return;
-        case BJ_SyncData:
-                list = &transaction->t_sync_datalist;
-                break;
         case BJ_Metadata:
                 transaction->t_nr_buffers--;
                 J_ASSERT_JH(jh, transaction->t_nr_buffers >= 0);
@@ -1589,9 +1409,6 @@ void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh)
         case BJ_Reserved:
                 list = &transaction->t_reserved_list;
                 break;
-        case BJ_Locked:
-                list = &transaction->t_locked_list;
-                break;
         }
 
         __blist_del_buffer(list, jh);
@@ -1634,15 +1451,7 @@ __journal_try_to_free_buffer(journal_t *journal, struct buffer_head *bh)
                 goto out;
 
         spin_lock(&journal->j_list_lock);
-        if (jh->b_transaction != NULL && jh->b_cp_transaction == NULL) {
-                if (jh->b_jlist == BJ_SyncData || jh->b_jlist == BJ_Locked) {
-                        /* A written-back ordered data buffer */
-                        JBUFFER_TRACE(jh, "release data");
-                        __jbd2_journal_unfile_buffer(jh);
-                        jbd2_journal_remove_journal_head(bh);
-                        __brelse(bh);
-                }
-        } else if (jh->b_cp_transaction != NULL && jh->b_transaction == NULL) {
+        if (jh->b_cp_transaction != NULL && jh->b_transaction == NULL) {
                 /* written-back checkpointed metadata buffer */
                 if (jh->b_jlist == BJ_None) {
                         JBUFFER_TRACE(jh, "remove from checkpoint list");
@@ -1656,12 +1465,43 @@ out:
         return;
 }
 
+/*
+ * jbd2_journal_try_to_free_buffers() could race with
+ * jbd2_journal_commit_transaction(). The later might still hold the
+ * reference count to the buffers when inspecting them on
+ * t_syncdata_list or t_locked_list.
+ *
+ * jbd2_journal_try_to_free_buffers() will call this function to
+ * wait for the current transaction to finish syncing data buffers, before
+ * try to free that buffer.
+ *
+ * Called with journal->j_state_lock hold.
+ */
+static void jbd2_journal_wait_for_transaction_sync_data(journal_t *journal)
+{
+        transaction_t *transaction;
+        tid_t tid;
+
+        spin_lock(&journal->j_state_lock);
+        transaction = journal->j_committing_transaction;
+
+        if (!transaction) {
+                spin_unlock(&journal->j_state_lock);
+                return;
+        }
+
+        tid = transaction->t_tid;
+        spin_unlock(&journal->j_state_lock);
+        jbd2_log_wait_commit(journal, tid);
+}
 
 /**
  * int jbd2_journal_try_to_free_buffers() - try to free page buffers.
  * @journal: journal for operation
  * @page: to try and free
- * @unused_gfp_mask: unused
+ * @gfp_mask: we use the mask to detect how hard should we try to release
+ * buffers. If __GFP_WAIT and __GFP_FS is set, we wait for commit code to
+ * release the buffers.
  *
  *
  * For all the buffers on this page,
@@ -1690,9 +1530,11 @@ out:
  * journal_try_to_free_buffer() is changing its state.  But that
  * cannot happen because we never reallocate freed data as metadata
  * while the data is part of a transaction.  Yes?
+ *
+ * Return 0 on failure, 1 on success
  */
 int jbd2_journal_try_to_free_buffers(journal_t *journal,
-                                struct page *page, gfp_t unused_gfp_mask)
+                                struct page *page, gfp_t gfp_mask)
 {
         struct buffer_head *head;
         struct buffer_head *bh;
@@ -1708,7 +1550,8 @@ int jbd2_journal_try_to_free_buffers(journal_t *journal,
                 /*
                  * We take our own ref against the journal_head here to avoid
                  * having to add tons of locking around each instance of
-                 * jbd2_journal_remove_journal_head() and jbd2_journal_put_journal_head().
+                 * jbd2_journal_remove_journal_head() and
+                 * jbd2_journal_put_journal_head().
                  */
                 jh = jbd2_journal_grab_journal_head(bh);
                 if (!jh)
@@ -1721,7 +1564,28 @@ int jbd2_journal_try_to_free_buffers(journal_t *journal,
                 if (buffer_jbd(bh))
                         goto busy;
         } while ((bh = bh->b_this_page) != head);
+
         ret = try_to_free_buffers(page);
+
+        /*
+         * There are a number of places where jbd2_journal_try_to_free_buffers()
+         * could race with jbd2_journal_commit_transaction(), the later still
+         * holds the reference to the buffers to free while processing them.
+         * try_to_free_buffers() failed to free those buffers. Some of the
+         * caller of releasepage() request page buffers to be dropped, otherwise
+         * treat the fail-to-free as errors (such as generic_file_direct_IO())
+         *
+         * So, if the caller of try_to_release_page() wants the synchronous
+         * behaviour(i.e make sure buffers are dropped upon return),
+         * let's wait for the current transaction to finish flush of
+         * dirty data buffers, then try to free those buffers again,
+         * with the journal locked.
+         */
+        if (ret == 0 && (gfp_mask & __GFP_WAIT) && (gfp_mask & __GFP_FS)) {
+                jbd2_journal_wait_for_transaction_sync_data(journal);
+                ret = try_to_free_buffers(page);
+        }
+
 busy:
         return ret;
 }
@@ -1823,6 +1687,7 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh)
         if (!buffer_jbd(bh))
                 goto zap_buffer_unlocked;
 
+        /* OK, we have data buffer in journaled mode */
         spin_lock(&journal->j_state_lock);
         jbd_lock_bh_state(bh);
         spin_lock(&journal->j_list_lock);
@@ -1886,15 +1751,6 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh)
                 }
         } else if (transaction == journal->j_committing_transaction) {
                 JBUFFER_TRACE(jh, "on committing transaction");
-                if (jh->b_jlist == BJ_Locked) {
-                        /*
-                         * The buffer is on the committing transaction's locked
-                         * list.  We have the buffer locked, so I/O has
-                         * completed.  So we can nail the buffer now.
-                         */
-                        may_free = __dispose_buffer(jh, transaction);
-                        goto zap_buffer;
-                }
                 /*
                  * If it is committing, we simply cannot touch it.  We
                  * can remove it's next_transaction pointer from the
@@ -2027,9 +1883,6 @@ void __jbd2_journal_file_buffer(struct journal_head *jh,
                 J_ASSERT_JH(jh, !jh->b_committed_data);
                 J_ASSERT_JH(jh, !jh->b_frozen_data);
                 return;
-        case BJ_SyncData:
-                list = &transaction->t_sync_datalist;
-                break;
         case BJ_Metadata:
                 transaction->t_nr_buffers++;
                 list = &transaction->t_buffers;
@@ -2049,9 +1902,6 @@ void __jbd2_journal_file_buffer(struct journal_head *jh,
         case BJ_Reserved:
                 list = &transaction->t_reserved_list;
                 break;
-        case BJ_Locked:
-                list =  &transaction->t_locked_list;
-                break;
         }
 
         __blist_add_buffer(list, jh);
@@ -2141,3 +1991,88 @@ void jbd2_journal_refile_buffer(journal_t *journal, struct journal_head *jh)
         spin_unlock(&journal->j_list_lock);
         __brelse(bh);
 }
+
+/*
+ * File inode in the inode list of the handle's transaction
+ */
+int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *jinode)
+{
+        transaction_t *transaction = handle->h_transaction;
+        journal_t *journal = transaction->t_journal;
+
+        if (is_handle_aborted(handle))
+                return -EIO;
+
+        jbd_debug(4, "Adding inode %lu, tid:%d\n", jinode->i_vfs_inode->i_ino,
+                        transaction->t_tid);
+
+        /*
+         * First check whether inode isn't already on the transaction's
+         * lists without taking the lock. Note that this check is safe
+         * without the lock as we cannot race with somebody removing inode
+         * from the transaction. The reason is that we remove inode from the
+         * transaction only in journal_release_jbd_inode() and when we commit
+         * the transaction. We are guarded from the first case by holding
+         * a reference to the inode. We are safe against the second case
+         * because if jinode->i_transaction == transaction, commit code
+         * cannot touch the transaction because we hold reference to it,
+         * and if jinode->i_next_transaction == transaction, commit code
+         * will only file the inode where we want it.
+         */
+        if (jinode->i_transaction == transaction ||
+            jinode->i_next_transaction == transaction)
+                return 0;
+
+        spin_lock(&journal->j_list_lock);
+
+        if (jinode->i_transaction == transaction ||
+            jinode->i_next_transaction == transaction)
+                goto done;
+
+        /* On some different transaction's list - should be
+         * the committing one */
+        if (jinode->i_transaction) {
+                J_ASSERT(jinode->i_next_transaction == NULL);
+                J_ASSERT(jinode->i_transaction ==
+                                        journal->j_committing_transaction);
+                jinode->i_next_transaction = transaction;
+                goto done;
+        }
+        /* Not on any transaction list... */
+        J_ASSERT(!jinode->i_next_transaction);
+        jinode->i_transaction = transaction;
+        list_add(&jinode->i_list, &transaction->t_inode_list);
+done:
+        spin_unlock(&journal->j_list_lock);
+
+        return 0;
+}
+
+/*
+ * This function must be called when inode is journaled in ordered mode
+ * before truncation happens. It starts writeout of truncated part in
+ * case it is in the committing transaction so that we stand to ordered
+ * mode consistency guarantees.
+ */
+int jbd2_journal_begin_ordered_truncate(struct jbd2_inode *inode,
+                                        loff_t new_size)
+{
+        journal_t *journal;
+        transaction_t *commit_trans;
+        int ret = 0;
+
+        if (!inode->i_transaction && !inode->i_next_transaction)
+                goto out;
+        journal = inode->i_transaction->t_journal;
+        spin_lock(&journal->j_state_lock);
+        commit_trans = journal->j_committing_transaction;
+        spin_unlock(&journal->j_state_lock);
+        if (inode->i_transaction == commit_trans) {
+                ret = filemap_fdatawrite_range(inode->i_vfs_inode->i_mapping,
+                        new_size, LLONG_MAX);
+                if (ret)
+                        jbd2_journal_abort(journal, ret);
+        }
+out:
+        return ret;
+}
diff --git a/fs/mpage.c b/fs/mpage.c
index 235e4d3873a8..dbcc7af76a15 100644
--- a/fs/mpage.c
+++ b/fs/mpage.c
@@ -82,7 +82,7 @@ static void mpage_end_io_write(struct bio *bio, int err)
         bio_put(bio);
 }
 
-static struct bio *mpage_bio_submit(int rw, struct bio *bio)
+struct bio *mpage_bio_submit(int rw, struct bio *bio)
 {
         bio->bi_end_io = mpage_end_io_read;
         if (rw == WRITE)
@@ -90,6 +90,7 @@ static struct bio *mpage_bio_submit(int rw, struct bio *bio)
         submit_bio(rw, bio);
         return NULL;
 }
+EXPORT_SYMBOL(mpage_bio_submit);
 
 static struct bio *
 mpage_alloc(struct block_device *bdev,
@@ -435,15 +436,9 @@ EXPORT_SYMBOL(mpage_readpage);
  * written, so it can intelligently allocate a suitably-sized BIO.  For now,
  * just allocate full-size (16-page) BIOs.
  */
-struct mpage_data {
-        struct bio *bio;
-        sector_t last_block_in_bio;
-        get_block_t *get_block;
-        unsigned use_writepage;
-};
 
-static int __mpage_writepage(struct page *page, struct writeback_control *wbc,
-                             void *data)
+int __mpage_writepage(struct page *page, struct writeback_control *wbc,
+                      void *data)
 {
         struct mpage_data *mpd = data;
         struct bio *bio = mpd->bio;
@@ -651,6 +646,7 @@ out:
         mpd->bio = bio;
         return ret;
 }
+EXPORT_SYMBOL(__mpage_writepage);
 
 /**
  * mpage_writepages - walk the list of dirty pages of the given address space & writepage() all of them