diff options
| author | Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> | 2009-06-02 08:07:56 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-06-15 09:40:36 -0700 |
| commit | b0b1dd413d407ba6879e8286a10c5781f2f2ec5e (patch) | |
| tree | 1a74e0db2a5b69d6703e45f161add8b7347f1812 | |
| parent | c3cde774f78f1519cf07c2ca2aee9e13e3185220 (diff) | |
ext4: Fix sub-block zeroing for writes into preallocated extents
(cherry picked from commit 9c1ee184a30394e54165fa4c15923cabd952c106)
We need to mark the buffer_head mapping preallocated space as new
during write_begin. Otherwise we don't zero out the page cache content
properly for a partial write. This will cause file corruption with
preallocation.
Now that we mark the buffer_head new we also need to have a valid
buffer_head blocknr so that unmap_underlying_metadata() unmaps the
correct block.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | fs/ext4/extents.c | 2 | ||||
| -rw-r--r-- | fs/ext4/inode.c | 7 |
2 files changed, 9 insertions, 0 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index e0aa4fe4f59..6af5a50276a 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -2776,6 +2776,8 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, if (allocated > max_blocks) allocated = max_blocks; set_buffer_unwritten(bh_result); + bh_result->b_bdev = inode->i_sb->s_bdev; + bh_result->b_blocknr = newblock; goto out2; } diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 64a7c4635cd..03be1225944 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -2246,6 +2246,13 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock, set_buffer_delay(bh_result); } else if (ret > 0) { bh_result->b_size = (ret << inode->i_blkbits); + /* + * 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. + */ + if (buffer_unwritten(bh_result)) + set_buffer_new(bh_result); ret = 0; } |