1 files changed, 306 insertions, 165 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 71d3ecd5db79..2a9ffd528dd1 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -371,6 +371,34 @@ static int ext4_block_to_path(struct inode *inode,
         return n;
 }
 
+static int __ext4_check_blockref(const char *function, struct inode *inode,
+                                 __le32 *p, unsigned int max) {
+
+        unsigned int maxblocks = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es);
+        __le32 *bref = p;
+        while (bref < p+max) {
+                if (unlikely(le32_to_cpu(*bref) >= maxblocks)) {
+                        ext4_error(inode->i_sb, function,
+                                   "block reference %u >= max (%u) "
+                                   "in inode #%lu, offset=%d",
+                                   le32_to_cpu(*bref), maxblocks,
+                                   inode->i_ino, (int)(bref-p));
+                        return -EIO;
+                }
+                bref++;
+        }
+        return 0;
+}
+
+
+#define ext4_check_indirect_blockref(inode, bh)                         \
+        __ext4_check_blockref(__func__, inode, (__le32 *)(bh)->b_data,  \
+                              EXT4_ADDR_PER_BLOCK((inode)->i_sb))
+
+#define ext4_check_inode_blockref(inode)                                \
+        __ext4_check_blockref(__func__, inode, EXT4_I(inode)->i_data,   \
+                              EXT4_NDIR_BLOCKS)
+
 /**
  *      ext4_get_branch - read the chain of indirect blocks leading to data
  *      @inode: inode in question
@@ -415,9 +443,22 @@ static Indirect *ext4_get_branch(struct inode *inode, int depth,
         if (!p->key)
                 goto no_block;
         while (--depth) {
-                bh = sb_bread(sb, le32_to_cpu(p->key));
-                if (!bh)
+                bh = sb_getblk(sb, le32_to_cpu(p->key));
+                if (unlikely(!bh))
                         goto failure;
+                  
+                if (!bh_uptodate_or_lock(bh)) {
+                        if (bh_submit_read(bh) < 0) {
+                                put_bh(bh);
+                                goto failure;
+                        }
+                        /* validate block references */
+                        if (ext4_check_indirect_blockref(inode, bh)) {
+                                put_bh(bh);
+                                goto failure;
+                        }
+                }
+                
                 add_chain(++p, bh, (__le32 *)bh->b_data + *++offsets);
                 /* Reader: end */
                 if (!p->key)
@@ -459,6 +500,8 @@ static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind)
         ext4_fsblk_t bg_start;
         ext4_fsblk_t last_block;
         ext4_grpblk_t colour;
+        ext4_group_t block_group;
+        int flex_size = ext4_flex_bg_size(EXT4_SB(inode->i_sb));
 
         /* Try to find previous block */
         for (p = ind->p - 1; p >= start; p--) {
@@ -474,9 +517,22 @@ static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind)
          * It is going to be referred to from the inode itself? OK, just put it
          * into the same cylinder group then.
          */
-        bg_start = ext4_group_first_block_no(inode->i_sb, ei->i_block_group);
+        block_group = ei->i_block_group;
+        if (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) {
+                block_group &= ~(flex_size-1);
+                if (S_ISREG(inode->i_mode))
+                        block_group++;
+        }
+        bg_start = ext4_group_first_block_no(inode->i_sb, block_group);
         last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1;
 
+        /*
+         * If we are doing delayed allocation, we don't need take
+         * colour into account.
+         */
+        if (test_opt(inode->i_sb, DELALLOC))
+                return bg_start;
+
         if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block)
                 colour = (current->pid % 16) *
                         (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16);
@@ -1052,9 +1108,16 @@ static void ext4_da_update_reserve_space(struct inode *inode, int used)
         /*
          * free those over-booking quota for metadata blocks
          */
-
         if (mdb_free)
                 vfs_dq_release_reservation_block(inode, mdb_free);
+
+        /*
+         * If we have done all the pending block allocations and if
+         * there aren't any writers on the inode, we can discard the
+         * inode's preallocations.
+         */
+        if (!total && (atomic_read(&inode->i_writecount) == 0))
+                ext4_discard_preallocations(inode);
 }
 
 /*
@@ -1086,6 +1149,7 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
         int retval;
 
         clear_buffer_mapped(bh);
+        clear_buffer_unwritten(bh);
 
         /*
          * Try to see if we can get  the block without requesting
@@ -1116,6 +1180,18 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
                 return retval;
 
         /*
+         * When we call get_blocks without the create flag, the
+         * BH_Unwritten flag could have gotten set if the blocks
+         * requested were part of a uninitialized extent.  We need to
+         * clear this flag now that we are committed to convert all or
+         * part of the uninitialized extent to be an initialized
+         * extent.  This is because we need to avoid the combination
+         * of BH_Unwritten and BH_Mapped flags being simultaneously
+         * set on the buffer_head.
+         */
+        clear_buffer_unwritten(bh);
+
+        /*
          * New blocks allocate and/or writing to uninitialized extent
          * will possibly result in updating i_data, so we take
          * the write lock of i_data_sem, and call get_blocks()
@@ -1688,9 +1764,10 @@ static void ext4_da_page_release_reservation(struct page *page,
 
 struct mpage_da_data {
         struct inode *inode;
-        struct buffer_head lbh;                 /* extent of blocks */
+        sector_t b_blocknr;             /* start block number of extent */
+        size_t b_size;                  /* size of extent */
+        unsigned long b_state;          /* state of the extent */
         unsigned long first_page, next_page;    /* extent of pages */
-        get_block_t *get_block;
         struct writeback_control *wbc;
         int io_done;
         int pages_written;
@@ -1704,7 +1781,6 @@ struct mpage_da_data {
  * @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.
@@ -1724,7 +1800,7 @@ static int mpage_da_submit_io(struct mpage_da_data *mpd)
         /*
          * We need to start from the first_page to the next_page - 1
          * to make sure we also write the mapped dirty buffer_heads.
-         * If we look at mpd->lbh.b_blocknr we would only be looking
+         * If we look at mpd->b_blocknr we would only be looking
          * at the currently mapped buffer_heads.
          */
         index = mpd->first_page;
@@ -1914,68 +1990,111 @@ static void ext4_print_free_blocks(struct inode *inode)
         return;
 }
 
+#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();
+        BUG_ON(!handle);
+        ret = ext4_get_blocks_wrap(handle, inode, iblock, max_blocks,
+                                   bh_result, create, 0, EXT4_DELALLOC_RSVED);
+        if (ret <= 0)
+                return ret;
+
+        bh_result->b_size = (ret << inode->i_blkbits);
+
+        if (ext4_should_order_data(inode)) {
+                int retval;
+                retval = ext4_jbd2_file_inode(handle, inode);
+                if (retval)
+                        /*
+                         * Failed to add inode for ordered mode. Don't
+                         * update file size
+                         */
+                        return retval;
+        }
+
+        /*
+         * 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) {
+                ext4_update_i_disksize(inode, disksize);
+                ret = ext4_mark_inode_dirty(handle, inode);
+                return ret;
+        }
+        return 0;
+}
+
 /*
  * mpage_da_map_blocks - go through given space
  *
- * @mpd->lbh - bh describing space
- * @mpd->get_block - the filesystem's block mapper function
+ * @mpd - bh describing space
  *
  * The function skips space we know is already mapped to disk blocks.
  *
  */
-static int  mpage_da_map_blocks(struct mpage_da_data *mpd)
+static int mpage_da_map_blocks(struct mpage_da_data *mpd)
 {
         int err = 0;
         struct buffer_head new;
-        struct buffer_head *lbh = &mpd->lbh;
         sector_t next;
 
         /*
          * We consider only non-mapped and non-allocated blocks
          */
-        if (buffer_mapped(lbh) && !buffer_delay(lbh))
+        if ((mpd->b_state  & (1 << BH_Mapped)) &&
+            !(mpd->b_state & (1 << BH_Delay)))
                 return 0;
-        new.b_state = lbh->b_state;
+        new.b_state = mpd->b_state;
         new.b_blocknr = 0;
-        new.b_size = lbh->b_size;
-        next = lbh->b_blocknr;
+        new.b_size = mpd->b_size;
+        next = mpd->b_blocknr;
         /*
          * If we didn't accumulate anything
          * to write simply return
          */
         if (!new.b_size)
                 return 0;
-        err = mpd->get_block(mpd->inode, next, &new, 1);
-        if (err) {
 
-                /* If get block returns with error
-                 * we simply return. Later writepage
-                 * will redirty the page and writepages
-                 * will find the dirty page again
+        err = ext4_da_get_block_write(mpd->inode, next, &new, 1);
+        if (err) {
+                /*
+                 * If get block returns with error we simply
+                 * return. Later writepage will redirty the page and
+                 * writepages will find the dirty page again
                  */
                 if (err == -EAGAIN)
                         return 0;
 
                 if (err == -ENOSPC &&
-                                ext4_count_free_blocks(mpd->inode->i_sb)) {
+                    ext4_count_free_blocks(mpd->inode->i_sb)) {
                         mpd->retval = err;
                         return 0;
                 }
 
                 /*
-                 * get block failure will cause us
-                 * to loop in writepages. Because
-                 * a_ops->writepage won't be able to
-                 * make progress. The page will be redirtied
-                 * by writepage and writepages will again
-                 * try to write the same.
+                 * get block failure will cause us to loop in
+                 * writepages, because a_ops->writepage won't be able
+                 * to make progress. The page will be redirtied by
+                 * writepage and writepages will again try to write
+                 * the same.
                  */
                 printk(KERN_EMERG "%s block allocation failed for inode %lu "
                                   "at logical offset %llu with max blocks "
                                   "%zd with error %d\n",
                                   __func__, mpd->inode->i_ino,
                                   (unsigned long long)next,
-                                  lbh->b_size >> mpd->inode->i_blkbits, err);
+                                  mpd->b_size >> mpd->inode->i_blkbits, err);
                 printk(KERN_EMERG "This should not happen.!! "
                                         "Data will be lost\n");
                 if (err == -ENOSPC) {
@@ -1983,7 +2102,7 @@ static int  mpage_da_map_blocks(struct mpage_da_data *mpd)
                 }
                 /* invlaidate all the pages */
                 ext4_da_block_invalidatepages(mpd, next,
-                                lbh->b_size >> mpd->inode->i_blkbits);
+                                mpd->b_size >> mpd->inode->i_blkbits);
                 return err;
         }
         BUG_ON(new.b_size == 0);
@@ -1995,7 +2114,8 @@ static int  mpage_da_map_blocks(struct mpage_da_data *mpd)
          * If blocks are delayed marked, we need to
          * put actual blocknr and drop delayed bit
          */
-        if (buffer_delay(lbh) || buffer_unwritten(lbh))
+        if ((mpd->b_state & (1 << BH_Delay)) ||
+            (mpd->b_state & (1 << BH_Unwritten)))
                 mpage_put_bnr_to_bhs(mpd, next, &new);
 
         return 0;
@@ -2014,12 +2134,11 @@ static int  mpage_da_map_blocks(struct mpage_da_data *mpd)
  * 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)
+                                   sector_t logical, size_t b_size,
+                                   unsigned long b_state)
 {
         sector_t next;
-        size_t b_size = bh->b_size;
-        struct buffer_head *lbh = &mpd->lbh;
-        int nrblocks = lbh->b_size >> mpd->inode->i_blkbits;
+        int nrblocks = mpd->b_size >> mpd->inode->i_blkbits;
 
         /* check if thereserved journal credits might overflow */
         if (!(EXT4_I(mpd->inode)->i_flags & EXT4_EXTENTS_FL)) {
@@ -2046,19 +2165,19 @@ static void mpage_add_bh_to_extent(struct mpage_da_data *mpd,
         /*
          * First block in the extent
          */
-        if (lbh->b_size == 0) {
-                lbh->b_blocknr = logical;
-                lbh->b_size = b_size;
-                lbh->b_state = bh->b_state & BH_FLAGS;
+        if (mpd->b_size == 0) {
+                mpd->b_blocknr = logical;
+                mpd->b_size = b_size;
+                mpd->b_state = b_state & BH_FLAGS;
                 return;
         }
 
-        next = lbh->b_blocknr + nrblocks;
+        next = mpd->b_blocknr + nrblocks;
         /*
          * Can we merge the block to our big extent?
          */
-        if (logical == next && (bh->b_state & BH_FLAGS) == lbh->b_state) {
-                lbh->b_size += b_size;
+        if (logical == next && (b_state & BH_FLAGS) == mpd->b_state) {
+                mpd->b_size += b_size;
                 return;
         }
 
@@ -2087,7 +2206,7 @@ static int __mpage_da_writepage(struct page *page,
 {
         struct mpage_da_data *mpd = data;
         struct inode *inode = mpd->inode;
-        struct buffer_head *bh, *head, fake;
+        struct buffer_head *bh, *head;
         sector_t logical;
 
         if (mpd->io_done) {
@@ -2129,9 +2248,9 @@ static int __mpage_da_writepage(struct page *page,
                 /*
                  * ... and blocks
                  */
-                mpd->lbh.b_size = 0;
-                mpd->lbh.b_state = 0;
-                mpd->lbh.b_blocknr = 0;
+                mpd->b_size = 0;
+                mpd->b_state = 0;
+                mpd->b_blocknr = 0;
         }
 
         mpd->next_page = page->index + 1;
@@ -2139,16 +2258,8 @@ static int __mpage_da_writepage(struct page *page,
                   (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);
+                mpage_add_bh_to_extent(mpd, logical, PAGE_CACHE_SIZE,
+                                       (1 << BH_Dirty) | (1 << BH_Uptodate));
                 if (mpd->io_done)
                         return MPAGE_DA_EXTENT_TAIL;
         } else {
@@ -2166,8 +2277,10 @@ static int __mpage_da_writepage(struct page *page,
                          * with the page in ext4_da_writepage
                          */
                         if (buffer_dirty(bh) &&
-                                (!buffer_mapped(bh) || buffer_delay(bh))) {
-                                mpage_add_bh_to_extent(mpd, logical, bh);
+                            (!buffer_mapped(bh) || buffer_delay(bh))) {
+                                mpage_add_bh_to_extent(mpd, logical,
+                                                       bh->b_size,
+                                                       bh->b_state);
                                 if (mpd->io_done)
                                         return MPAGE_DA_EXTENT_TAIL;
                         } else if (buffer_dirty(bh) && (buffer_mapped(bh))) {
@@ -2179,9 +2292,8 @@ static int __mpage_da_writepage(struct page *page,
                                  * unmapped buffer_head later we need to
                                  * use the b_state flag of that buffer_head.
                                  */
-                                if (mpd->lbh.b_size == 0)
-                                        mpd->lbh.b_state =
-                                                bh->b_state & BH_FLAGS;
+                                if (mpd->b_size == 0)
+                                        mpd->b_state = bh->b_state & BH_FLAGS;
                         }
                         logical++;
                 } while ((bh = bh->b_this_page) != head);
@@ -2191,51 +2303,6 @@ static int __mpage_da_writepage(struct page *page,
 }
 
 /*
- * 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.
- */
-static int mpage_da_writepages(struct address_space *mapping,
-                               struct writeback_control *wbc,
-                               struct mpage_da_data *mpd)
-{
-        int ret;
-
-        if (!mpd->get_block)
-                return generic_writepages(mapping, wbc);
-
-        mpd->lbh.b_size = 0;
-        mpd->lbh.b_state = 0;
-        mpd->lbh.b_blocknr = 0;
-        mpd->first_page = 0;
-        mpd->next_page = 0;
-        mpd->io_done = 0;
-        mpd->pages_written = 0;
-        mpd->retval = 0;
-
-        ret = write_cache_pages(mapping, wbc, __mpage_da_writepage, mpd);
-        /*
-         * Handle last extent of pages
-         */
-        if (!mpd->io_done && mpd->next_page != mpd->first_page) {
-                if (mpage_da_map_blocks(mpd) == 0)
-                        mpage_da_submit_io(mpd);
-
-                mpd->io_done = 1;
-                ret = MPAGE_DA_EXTENT_TAIL;
-        }
-        wbc->nr_to_write -= mpd->pages_written;
-        return ret;
-}
-
-/*
  * this is a special callback for ->write_begin() only
  * it's intention is to return mapped block or reserve space
  */
@@ -2243,6 +2310,10 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
                                   struct buffer_head *bh_result, int create)
 {
         int ret = 0;
+        sector_t invalid_block = ~((sector_t) 0xffff);
+
+        if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es))
+                invalid_block = ~0;
 
         BUG_ON(create == 0);
         BUG_ON(bh_result->b_size != inode->i_sb->s_blocksize);
@@ -2264,59 +2335,21 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
                         /* not enough space to reserve */
                         return ret;
 
-                map_bh(bh_result, inode->i_sb, 0);
+                map_bh(bh_result, inode->i_sb, invalid_block);
                 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();
-        BUG_ON(!handle);
-        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);
-
-                if (ext4_should_order_data(inode)) {
-                        int retval;
-                        retval = ext4_jbd2_file_inode(handle, inode);
-                        if (retval)
-                                /*
-                                 * Failed to add inode for ordered
-                                 * mode. Don't update file size
-                                 */
-                                return retval;
-                }
-
                 /*
-                 * Update on-disk size along with block allocation
-                 * we don't use 'extend_disksize' as size may change
-                 * within already allocated block -bzzz
+                 * With sub-block writes into unwritten extents
+                 * we also need to mark the buffer as new so that
+                 * the unwritten parts of the buffer gets correctly zeroed.
                  */
-                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) {
-                        ext4_update_i_disksize(inode, disksize);
-                        ret = ext4_mark_inode_dirty(handle, inode);
-                        return ret;
-                }
+                if (buffer_unwritten(bh_result))
+                        set_buffer_new(bh_result);
                 ret = 0;
         }
+
         return ret;
 }
 
@@ -2569,8 +2602,38 @@ retry:
                         dump_stack();
                         goto out_writepages;
                 }
-                mpd.get_block = ext4_da_get_block_write;
-                ret = mpage_da_writepages(mapping, wbc, &mpd);
+
+                /*
+                 * Now call __mpage_da_writepage to find the next
+                 * contiguous region of logical blocks that need
+                 * blocks to be allocated by ext4.  We don't actually
+                 * submit the blocks for I/O here, even though
+                 * write_cache_pages thinks it will, and will set the
+                 * pages as clean for write before calling
+                 * __mpage_da_writepage().
+                 */
+                mpd.b_size = 0;
+                mpd.b_state = 0;
+                mpd.b_blocknr = 0;
+                mpd.first_page = 0;
+                mpd.next_page = 0;
+                mpd.io_done = 0;
+                mpd.pages_written = 0;
+                mpd.retval = 0;
+                ret = write_cache_pages(mapping, wbc, __mpage_da_writepage,
+                                        &mpd);
+                /*
+                 * If we have a contigous extent of pages and we
+                 * haven't done the I/O yet, map the blocks and submit
+                 * them for I/O.
+                 */
+                if (!mpd.io_done && mpd.next_page != mpd.first_page) {
+                        if (mpage_da_map_blocks(&mpd) == 0)
+                                mpage_da_submit_io(&mpd);
+                        mpd.io_done = 1;
+                        ret = MPAGE_DA_EXTENT_TAIL;
+                }
+                wbc->nr_to_write -= mpd.pages_written;
 
                 ext4_journal_stop(handle);
 
@@ -2846,6 +2909,48 @@ out:
         return;
 }
 
+/*
+ * Force all delayed allocation blocks to be allocated for a given inode.
+ */
+int ext4_alloc_da_blocks(struct inode *inode)
+{
+        if (!EXT4_I(inode)->i_reserved_data_blocks &&
+            !EXT4_I(inode)->i_reserved_meta_blocks)
+                return 0;
+
+        /*
+         * We do something simple for now.  The filemap_flush() will
+         * also start triggering a write of the data blocks, which is
+         * not strictly speaking necessary (and for users of
+         * laptop_mode, not even desirable).  However, to do otherwise
+         * would require replicating code paths in:
+         * 
+         * ext4_da_writepages() ->
+         *    write_cache_pages() ---> (via passed in callback function)
+         *        __mpage_da_writepage() -->
+         *           mpage_add_bh_to_extent()
+         *           mpage_da_map_blocks()
+         *
+         * The problem is that write_cache_pages(), located in
+         * mm/page-writeback.c, marks pages clean in preparation for
+         * doing I/O, which is not desirable if we're not planning on
+         * doing I/O at all.
+         *
+         * We could call write_cache_pages(), and then redirty all of
+         * the pages by calling redirty_page_for_writeback() but that
+         * would be ugly in the extreme.  So instead we would need to
+         * replicate parts of the code in the above functions,
+         * simplifying them becuase we wouldn't actually intend to
+         * write out the pages, but rather only collect contiguous
+         * logical block extents, call the multi-block allocator, and
+         * then update the buffer heads with the block allocations.
+         * 
+         * For now, though, we'll cheat by calling filemap_flush(),
+         * which will map the blocks, and start the I/O, but not
+         * actually wait for the I/O to complete.
+         */
+        return filemap_flush(inode->i_mapping);
+}
 
 /*
  * bmap() is special.  It gets used by applications such as lilo and by
@@ -3868,6 +3973,9 @@ void ext4_truncate(struct inode *inode)
         if (!ext4_can_truncate(inode))
                 return;
 
+        if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
+                ei->i_state |= EXT4_STATE_DA_ALLOC_CLOSE;
+
         if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
                 ext4_ext_truncate(inode);
                 return;
@@ -4110,12 +4218,7 @@ make_io:
                         unsigned num;
 
                         table = ext4_inode_table(sb, gdp);
-                        /* Make sure s_inode_readahead_blks is a power of 2 */
-                        while (EXT4_SB(sb)->s_inode_readahead_blks &
-                               (EXT4_SB(sb)->s_inode_readahead_blks-1))
-                                EXT4_SB(sb)->s_inode_readahead_blks = 
-                                   (EXT4_SB(sb)->s_inode_readahead_blks &
-                                    (EXT4_SB(sb)->s_inode_readahead_blks-1));
+                        /* s_inode_readahead_blks is always a power of 2 */
                         b = block & ~(EXT4_SB(sb)->s_inode_readahead_blks-1);
                         if (table > b)
                                 b = table;
@@ -4278,15 +4381,14 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
         ei->i_flags = le32_to_cpu(raw_inode->i_flags);
         inode->i_blocks = ext4_inode_blocks(raw_inode, ei);
         ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo);
-        if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
-            cpu_to_le32(EXT4_OS_HURD)) {
+        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT))
                 ei->i_file_acl |=
                         ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
-        }
         inode->i_size = ext4_isize(raw_inode);
         ei->i_disksize = inode->i_size;
         inode->i_generation = le32_to_cpu(raw_inode->i_generation);
         ei->i_block_group = iloc.block_group;
+        ei->i_last_alloc_group = ~0;
         /*
          * NOTE! The in-memory inode i_data array is in little-endian order
          * even on big-endian machines: we do NOT byteswap the block numbers!
@@ -4329,6 +4431,34 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
                         (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
         }
 
+        ret = 0;
+        if (ei->i_file_acl &&
+            ((ei->i_file_acl < 
+              (le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) +
+               EXT4_SB(sb)->s_gdb_count)) ||
+             (ei->i_file_acl >= ext4_blocks_count(EXT4_SB(sb)->s_es)))) {
+                ext4_error(sb, __func__,
+                           "bad extended attribute block %llu in inode #%lu",
+                           ei->i_file_acl, inode->i_ino);
+                ret = -EIO;
+                goto bad_inode;
+        } else if (ei->i_flags & EXT4_EXTENTS_FL) {
+                if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+                    (S_ISLNK(inode->i_mode) &&
+                     !ext4_inode_is_fast_symlink(inode)))
+                        /* Validate extent which is part of inode */
+                        ret = ext4_ext_check_inode(inode);
+        } else if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+                   (S_ISLNK(inode->i_mode) &&
+                    !ext4_inode_is_fast_symlink(inode))) {
+                /* Validate block references which are part of inode */
+                ret = ext4_check_inode_blockref(inode);
+        }
+        if (ret) {
+                brelse(bh);
+                goto bad_inode;
+        }
+
         if (S_ISREG(inode->i_mode)) {
                 inode->i_op = &ext4_file_inode_operations;
                 inode->i_fop = &ext4_file_operations;
@@ -4345,7 +4475,8 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
                         inode->i_op = &ext4_symlink_inode_operations;
                         ext4_set_aops(inode);
                 }
-        } else {
+        } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
+              S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
                 inode->i_op = &ext4_special_inode_operations;
                 if (raw_inode->i_block[0])
                         init_special_inode(inode, inode->i_mode,
@@ -4353,6 +4484,13 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
                 else
                         init_special_inode(inode, inode->i_mode,
                            new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
+        } else {
+                brelse(bh);
+                ret = -EIO;
+                ext4_error(inode->i_sb, __func__, 
+                           "bogus i_mode (%o) for inode=%lu",
+                           inode->i_mode, inode->i_ino);
+                goto bad_inode;
         }
         brelse(iloc.bh);
         ext4_set_inode_flags(inode);
@@ -5146,8 +5284,9 @@ 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)
+int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
+        struct page *page = vmf->page;
         loff_t size;
         unsigned long len;
         int ret = -EINVAL;
@@ -5199,6 +5338,8 @@ int ext4_page_mkwrite(struct vm_area_struct *vma, struct page *page)
                 goto out_unlock;
         ret = 0;
 out_unlock:
+        if (ret)
+                ret = VM_FAULT_SIGBUS;
         up_read(&inode->i_alloc_sem);
         return ret;
 }