Thread (2 messages) 2 messages, 2 authors, 2017-11-28

Re: [PATCH] xfs: calculate correct offset in xfs_scrub_quota_item

From: Darrick J. Wong <hidden>
Date: 2017-11-28 02:21:00

On Mon, Nov 27, 2017 at 06:04:55PM -0600, Eric Sandeen wrote:
It's only used for tracepoints so it's relatively harmless,
but the offset is calculated incorrectly in xfs_scrub_quota_item.

qi_dqperchunk is the nr. of dquots per "chunk" which we have
conveniently *cough* defined to always be 1 FSB.  Therefore 
block_offset * qi_dqperchunk == first id in that chunk,
and so offset = id / qi_dqperchunk

id * dqperchunk is ... meaningless.

Fixes-coverity-id: 1423965
Fixes: c2fc338c ("xfs: scrub quota information")
Signed-off-by: Eric Sandeen <redacted>
Looks ok, will test
Reviewed-by: Darrick J. Wong <redacted>
quoted hunk ↗ jump to hunk
---

compile-tested only
diff --git a/fs/xfs/scrub/quota.c b/fs/xfs/scrub/quota.c
index 8e58ba8..2eac160 100644
--- a/fs/xfs/scrub/quota.c
+++ b/fs/xfs/scrub/quota.c
@@ -107,7 +107,7 @@
 	unsigned long long		rcount;
 	xfs_ino_t			fs_icount;
 
-	offset = id * qi->qi_dqperchunk;
+	offset = id / qi->qi_dqperchunk;
 
 	/*
 	 * We fed $id and DQNEXT into the xfs_qm_dqget call, which means
--
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