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| author | Calvin Owens <calvinowens@fb.com> | 2017-04-03 12:22:29 -0700 |
|---|---|---|
| committer | Darrick J. Wong <darrick.wong@oracle.com> | 2017-04-03 12:22:29 -0700 |
| commit | 3dd09d5a8589c640abb49cfcf92b4ed669eafad1 (patch) | |
| tree | 712c9512bb707959f129c31ac1637c47f30180e3 /fs/xfs | |
| parent | 78420281a9d74014af7616958806c3aba056319e (diff) | |
| download | linux-3dd09d5a8589c640abb49cfcf92b4ed669eafad1.tar.bz2 | |
xfs: Honor FALLOC_FL_KEEP_SIZE when punching ends of files
When punching past EOF on XFS, fallocate(mode=PUNCH_HOLE|KEEP_SIZE) will
round the file size up to the nearest multiple of PAGE_SIZE:
calvinow@vm-disks/generic-xfs-1 ~$ dd if=/dev/urandom of=test bs=2048 count=1
calvinow@vm-disks/generic-xfs-1 ~$ stat test
Size: 2048 Blocks: 8 IO Block: 4096 regular file
calvinow@vm-disks/generic-xfs-1 ~$ fallocate -n -l 2048 -o 2048 -p test
calvinow@vm-disks/generic-xfs-1 ~$ stat test
Size: 4096 Blocks: 8 IO Block: 4096 regular file
Commit 3c2bdc912a1cc050 ("xfs: kill xfs_zero_remaining_bytes") replaced
xfs_zero_remaining_bytes() with calls to iomap helpers. The new helpers
don't enforce that [pos,offset) lies strictly on [0,i_size) when being
called from xfs_free_file_space(), so by "leaking" these ranges into
xfs_zero_range() we get this buggy behavior.
Fix this by reintroducing the checks xfs_zero_remaining_bytes() did
against i_size at the bottom of xfs_free_file_space().
Reported-by: Aaron Gao <gzh@fb.com>
Fixes: 3c2bdc912a1cc050 ("xfs: kill xfs_zero_remaining_bytes")
Cc: Christoph Hellwig <hch@lst.de>
Cc: Brian Foster <bfoster@redhat.com>
Cc: <stable@vger.kernel.org> # 4.8+
Signed-off-by: Calvin Owens <calvinowens@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Diffstat (limited to 'fs/xfs')
| -rw-r--r-- | fs/xfs/xfs_bmap_util.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c index 8b75dcea5966..828532ce0adc 100644 --- a/fs/xfs/xfs_bmap_util.c +++ b/fs/xfs/xfs_bmap_util.c @@ -1311,8 +1311,16 @@ xfs_free_file_space( /* * Now that we've unmap all full blocks we'll have to zero out any * partial block at the beginning and/or end. xfs_zero_range is - * smart enough to skip any holes, including those we just created. + * smart enough to skip any holes, including those we just created, + * but we must take care not to zero beyond EOF and enlarge i_size. */ + + if (offset >= XFS_ISIZE(ip)) + return 0; + + if (offset + len > XFS_ISIZE(ip)) + len = XFS_ISIZE(ip) - offset; + return xfs_zero_range(ip, offset, len, NULL); } |