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authorJan Kara <jack@suse.cz>2014-06-06 10:06:37 +0400
committerDave Chinner <david@fromorbit.com>2014-06-06 10:06:37 +0400
commit30265117ee1e23fa91920f337a3ea91207f700dc (patch)
tree92bc5cec785f90d64f8e5f42baa0ce185b0c3cfb
parent448011e2ab1c44f7990a62649580bde0da5242b5 (diff)
downloadlinux-30265117ee1e23fa91920f337a3ea91207f700dc.tar.xz
xfs: Fix rounding in xfs_alloc_fix_len()
Rounding in xfs_alloc_fix_len() is wrong. As the comment states, the result should be a number of a form (k*prod+mod) however due to sign mistake the result is different. As a result allocations on raid arrays could be misaligned in some cases. This also seems to fix occasional assertion failure: XFS_WANT_CORRUPTED_GOTO(rlen <= flen, error0) in xfs_alloc_ag_vextent_size(). Also add an assertion that the result of xfs_alloc_fix_len() is of expected form. Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
-rw-r--r--fs/xfs/xfs_alloc.c18
1 files changed, 8 insertions, 10 deletions
diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c
index 077c3417a54e..d43813267a80 100644
--- a/fs/xfs/xfs_alloc.c
+++ b/fs/xfs/xfs_alloc.c
@@ -257,16 +257,14 @@ xfs_alloc_fix_len(
k = rlen % args->prod;
if (k == args->mod)
return;
- if (k > args->mod) {
- if ((int)(rlen = rlen - k - args->mod) < (int)args->minlen)
- return;
- } else {
- if ((int)(rlen = rlen - args->prod - (args->mod - k)) <
- (int)args->minlen)
- return;
- }
- ASSERT(rlen >= args->minlen);
- ASSERT(rlen <= args->maxlen);
+ if (k > args->mod)
+ rlen = rlen - (k - args->mod);
+ else
+ rlen = rlen - args->prod + (args->mod - k);
+ if ((int)rlen < (int)args->minlen)
+ return;
+ ASSERT(rlen >= args->minlen && rlen <= args->maxlen);
+ ASSERT(rlen % args->prod == args->mod);
args->len = rlen;
}