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| author | Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> | 2009-05-13 18:36:58 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2009-05-13 18:36:58 -0400 |
| commit | 9c1ee184a30394e54165fa4c15923cabd952c106 (patch) | |
| tree | 77fee66ccc5e4aec3aeff7c7d641691b116be091 | |
| parent | 091bf7624d1c90cec9e578a18529f615213ff847 (diff) | |
| download | op-kernel-dev-9c1ee184a30394e54165fa4c15923cabd952c106.zip op-kernel-dev-9c1ee184a30394e54165fa4c15923cabd952c106.tar.gz | |
ext4: Fix sub-block zeroing for writes into preallocated extents
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>
| -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 e403321..172656c 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -2875,6 +2875,8 @@ 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 e91f978..d4b634a 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -2323,6 +2323,13 @@ 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; } |
