From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay3.corp.sgi.com [198.149.34.15]) by oss.sgi.com (Postfix) with ESMTP id 9D7DA7F7D for ; Thu, 5 Feb 2015 22:47:05 -0600 (CST) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by relay3.corp.sgi.com (Postfix) with ESMTP id 385B9AC001 for ; Thu, 5 Feb 2015 20:47:04 -0800 (PST) Received: from ipmail07.adl2.internode.on.net (ipmail07.adl2.internode.on.net [150.101.137.131]) by cuda.sgi.com with ESMTP id SJaAWVfhoviGLwWX for ; Thu, 05 Feb 2015 20:47:02 -0800 (PST) From: Dave Chinner Subject: [PATCH] xfs: only trace buffer items if they exist Date: Fri, 6 Feb 2015 15:46:48 +1100 Message-Id: <1423198008-30748-1-git-send-email-david@fromorbit.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: xfs@oss.sgi.com Cc: y@disappointment.disaster From: Dave Chinner 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 --- 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 _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs