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| author | Eric Sandeen <sandeen@redhat.com> | 2018-08-02 13:09:27 -0700 |
|---|---|---|
| committer | Darrick J. Wong <darrick.wong@oracle.com> | 2018-08-02 13:09:27 -0700 |
| commit | 79b3dbe4adb3420e74cf755b4beb5d2b43d5928d (patch) | |
| tree | d49aae11f8919138e3a43ef830e6bd68fd4e89bf /fs/iomap.c | |
| parent | d4a34e16555708bab5b67e679a95f055d8ef9882 (diff) | |
| download | lwn-79b3dbe4adb3420e74cf755b4beb5d2b43d5928d.tar.gz lwn-79b3dbe4adb3420e74cf755b4beb5d2b43d5928d.zip | |
fs: fix iomap_bmap position calculation
The position calculation in iomap_bmap() shifts bno the wrong way,
so we don't progress properly and end up re-mapping block zero
over and over, yielding an unchanging physical block range as the
logical block advances:
# filefrag -Be file
ext: logical_offset: physical_offset: length: expected: flags:
0: 0.. 0: 21.. 21: 1: merged
1: 1.. 1: 21.. 21: 1: 22: merged
Discontinuity: Block 1 is at 21 (was 22)
2: 2.. 2: 21.. 21: 1: 22: merged
Discontinuity: Block 2 is at 21 (was 22)
3: 3.. 3: 21.. 21: 1: 22: merged
This breaks the FIBMAP interface for anyone using it (XFS), which
in turn breaks LILO, zipl, etc.
Bug-actually-spotted-by: Darrick J. Wong <darrick.wong@oracle.com>
Fixes: 89eb1906a953 ("iomap: add an iomap-based bmap implementation")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Diffstat (limited to 'fs/iomap.c')
| -rw-r--r-- | fs/iomap.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/iomap.c b/fs/iomap.c index 77397b5a96ef..0d0bd8845586 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -1443,7 +1443,7 @@ iomap_bmap(struct address_space *mapping, sector_t bno, const struct iomap_ops *ops) { struct inode *inode = mapping->host; - loff_t pos = bno >> inode->i_blkbits; + loff_t pos = bno << inode->i_blkbits; unsigned blocksize = i_blocksize(inode); if (filemap_write_and_wait(mapping)) |