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| author | Jan Kara <jack@suse.cz> | 2023-01-23 14:18:47 +0100 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2023-01-26 16:46:35 +0100 |
| commit | 36ec52ea038b18a53e198116ef7d7e70c87db046 (patch) | |
| tree | ccc09721412b9051dc357523b5a175fcd8bf4e6e /fs/udf | |
| parent | 36580ed08776224f25f9a34ede6eed7a4e11aed8 (diff) | |
| download | lwn-36ec52ea038b18a53e198116ef7d7e70c87db046.tar.gz lwn-36ec52ea038b18a53e198116ef7d7e70c87db046.zip | |
udf: Fix file corruption when appending just after end of preallocated extent
When we append new block just after the end of preallocated extent, the
code in inode_getblk() wrongly determined we're going to use the
preallocated extent which resulted in adding block into a wrong logical
offset in the file. Sequence like this manifests it:
xfs_io -f -c "pwrite 0x2cacf 0xd122" -c "truncate 0x2dd6f" \
-c "pwrite 0x27fd9 0x69a9" -c "pwrite 0x32981 0x7244" <file>
The code that determined the use of preallocated extent is actually
stale because udf_do_extend_file() does not create preallocation anymore
so after calling that function we are sure there's no usable
preallocation. Just remove the faulty condition.
CC: stable@vger.kernel.org
Fixes: 16d055656814 ("udf: Discard preallocation before extending file with a hole")
Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/udf')
| -rw-r--r-- | fs/udf/inode.c | 24 |
1 files changed, 11 insertions, 13 deletions
diff --git a/fs/udf/inode.c b/fs/udf/inode.c index 356e15daef18..51deada8b928 100644 --- a/fs/udf/inode.c +++ b/fs/udf/inode.c @@ -742,19 +742,17 @@ static int inode_getblk(struct inode *inode, struct udf_map_rq *map) c = 0; offset = 0; count += ret; - /* We are not covered by a preallocated extent? */ - if ((laarr[0].extLength & UDF_EXTENT_FLAG_MASK) != - EXT_NOT_RECORDED_ALLOCATED) { - /* Is there any real extent? - otherwise we overwrite - * the fake one... */ - if (count) - c = !c; - laarr[c].extLength = EXT_NOT_RECORDED_NOT_ALLOCATED | - inode->i_sb->s_blocksize; - memset(&laarr[c].extLocation, 0x00, - sizeof(struct kernel_lb_addr)); - count++; - } + /* + * Is there any real extent? - otherwise we overwrite the fake + * one... + */ + if (count) + c = !c; + laarr[c].extLength = EXT_NOT_RECORDED_NOT_ALLOCATED | + inode->i_sb->s_blocksize; + memset(&laarr[c].extLocation, 0x00, + sizeof(struct kernel_lb_addr)); + count++; endnum = c + 1; lastblock = 1; } else { |