From: Dave Chinner <david@fromorbit.com>
To: xfs@oss.sgi.com
Cc: y@disappointment.disaster
Subject: [PATCH] xfs: only trace buffer items if they exist
Date: Fri, 6 Feb 2015 15:46:48 +1100 [thread overview]
Message-ID: <1423198008-30748-1-git-send-email-david@fromorbit.com> (raw)
From: Dave Chinner <dchinner@redhat.com>
The commit 2d3d0c5 ("xfs: lobotomise xfs_trans_read_buf_map()") left
a landmine in the tracing code: trace_xfs_trans_buf_read() is now
call on all buffers that are read through this interface rather than
just buffers in transactions. For buffers outside transaction
context, bp->b_fspriv is null, and so the buf log item tracing
functions cannot be called. This causes a NULL pointer dereference
in the trace_xfs_trans_buf_read() function when tracing is turned
on.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/xfs/xfs_trans_buf.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/xfs/xfs_trans_buf.c b/fs/xfs/xfs_trans_buf.c
index 0a4d4ab..7579841 100644
--- a/fs/xfs/xfs_trans_buf.c
+++ b/fs/xfs/xfs_trans_buf.c
@@ -327,9 +327,10 @@ xfs_trans_read_buf_map(
return -EIO;
}
- if (tp)
+ if (tp) {
_xfs_trans_bjoin(tp, bp, 1);
- trace_xfs_trans_read_buf(bp->b_fspriv);
+ trace_xfs_trans_read_buf(bp->b_fspriv);
+ }
*bpp = bp;
return 0;
--
2.0.0
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next reply other threads:[~2015-02-06 4:47 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-06 4:46 Dave Chinner [this message]
2015-02-09 18:25 ` [PATCH] xfs: only trace buffer items if they exist Brian Foster
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