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| author | Ashish Samant <ashish.samant@oracle.com> | 2016-09-19 14:44:42 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-09-19 15:36:17 -0700 |
| commit | d21c353d5e99c56cdd5b5c1183ffbcaf23b8b960 (patch) | |
| tree | d0c56ebf05ea58999b3e1ec2fae968e7ee94c05b /fs | |
| parent | d979a39d7242e0601bf9b60e89628fb8ac577179 (diff) | |
| download | linux-d21c353d5e99c56cdd5b5c1183ffbcaf23b8b960.tar.bz2 | |
ocfs2: fix start offset to ocfs2_zero_range_for_truncate()
If we punch a hole on a reflink such that following conditions are met:
1. start offset is on a cluster boundary
2. end offset is not on a cluster boundary
3. (end offset is somewhere in another extent) or
(hole range > MAX_CONTIG_BYTES(1MB)),
we dont COW the first cluster starting at the start offset. But in this
case, we were wrongly passing this cluster to
ocfs2_zero_range_for_truncate() to zero out. This will modify the
cluster in place and zero it in the source too.
Fix this by skipping this cluster in such a scenario.
To reproduce:
1. Create a random file of say 10 MB
xfs_io -c 'pwrite -b 4k 0 10M' -f 10MBfile
2. Reflink it
reflink -f 10MBfile reflnktest
3. Punch a hole at starting at cluster boundary with range greater that
1MB. You can also use a range that will put the end offset in another
extent.
fallocate -p -o 0 -l 1048615 reflnktest
4. sync
5. Check the first cluster in the source file. (It will be zeroed out).
dd if=10MBfile iflag=direct bs=<cluster size> count=1 | hexdump -C
Link: http://lkml.kernel.org/r/1470957147-14185-1-git-send-email-ashish.samant@oracle.com
Signed-off-by: Ashish Samant <ashish.samant@oracle.com>
Reported-by: Saar Maoz <saar.maoz@oracle.com>
Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Eric Ren <zren@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ocfs2/file.c | 34 |
1 files changed, 24 insertions, 10 deletions
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index 4e7b0dc22450..0b055bfb8e86 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -1506,7 +1506,8 @@ static int ocfs2_zero_partial_clusters(struct inode *inode, u64 start, u64 len) { int ret = 0; - u64 tmpend, end = start + len; + u64 tmpend = 0; + u64 end = start + len; struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); unsigned int csize = osb->s_clustersize; handle_t *handle; @@ -1538,18 +1539,31 @@ static int ocfs2_zero_partial_clusters(struct inode *inode, } /* - * We want to get the byte offset of the end of the 1st cluster. + * If start is on a cluster boundary and end is somewhere in another + * cluster, we have not COWed the cluster starting at start, unless + * end is also within the same cluster. So, in this case, we skip this + * first call to ocfs2_zero_range_for_truncate() truncate and move on + * to the next one. */ - tmpend = (u64)osb->s_clustersize + (start & ~(osb->s_clustersize - 1)); - if (tmpend > end) - tmpend = end; + if ((start & (csize - 1)) != 0) { + /* + * We want to get the byte offset of the end of the 1st + * cluster. + */ + tmpend = (u64)osb->s_clustersize + + (start & ~(osb->s_clustersize - 1)); + if (tmpend > end) + tmpend = end; - trace_ocfs2_zero_partial_clusters_range1((unsigned long long)start, - (unsigned long long)tmpend); + trace_ocfs2_zero_partial_clusters_range1( + (unsigned long long)start, + (unsigned long long)tmpend); - ret = ocfs2_zero_range_for_truncate(inode, handle, start, tmpend); - if (ret) - mlog_errno(ret); + ret = ocfs2_zero_range_for_truncate(inode, handle, start, + tmpend); + if (ret) + mlog_errno(ret); + } if (tmpend < end) { /* |