From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (Postfix) with ESMTP id 48D327F69 for ; Thu, 19 Feb 2015 16:32:28 -0600 (CST) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by relay1.corp.sgi.com (Postfix) with ESMTP id 3542D8F804C for ; Thu, 19 Feb 2015 14:32:28 -0800 (PST) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by cuda.sgi.com with ESMTP id szXwpFehOY2b4LiV (version=TLSv1 cipher=AES256-SHA bits=256 verify=NO) for ; Thu, 19 Feb 2015 14:32:27 -0800 (PST) Message-ID: <54E66477.5060600@redhat.com> Date: Thu, 19 Feb 2015 17:32:23 -0500 From: Don Dutile MIME-Version: 1.0 Subject: Re: [PATCH RFC] fs: xfs: Fix xfs_trans_read_buf event tracing References: <7fb3278485ca5d8b48cd1ba980be6cc11dafc11b.1424352124.git.panand@redhat.com> <54E611BA.7010806@sandeen.net> In-Reply-To: <54E611BA.7010806@sandeen.net> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Eric Sandeen , Pratyush Anand , david@fromorbit.com, xfs@oss.sgi.com Cc: jbastian@redhat.com On 02/19/2015 11:39 AM, Eric Sandeen wrote: > On 2/19/15 7:24 AM, Pratyush Anand wrote: >> My root file system is xfs. As soon as I enable event for >> xfs_trans_read_buf `echo xfs:xfs_trans_read_buf >> >> /sys/kernel/debug/tracing/set_event`, I see a kernel panic. >> >> A little bit of debugging shows that bp->b_fspriv is NULL many a time >> when trace_xfs_trans_read_buf(bp->b_fspriv) is called. >> >> I do not have any idea about xfs filesystem. So, I am not sure, if it >> is expected to have bp->b_fspriv = NULL at this location. >> >> This patch fixes the issue, until we have a better fix. > > What kernel did you hit this on? What did the backtrace look like? > > I've been unable to reproduce the problem so far. > > Thanks, > -Eric > RHELSA snap7 kernel (that's RHEL Server for ARM; 3.19-based). Thanks for everyone's attention. Pratyush has provided a link to the upstream patch, that we have to pull into our kernel. >> Signed-off-by: Pratyush Anand >> --- >> fs/xfs/xfs_trans_buf.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/fs/xfs/xfs_trans_buf.c b/fs/xfs/xfs_trans_buf.c >> index 0a4d4ab6d9a9..0b67a20643bf 100644 >> --- a/fs/xfs/xfs_trans_buf.c >> +++ b/fs/xfs/xfs_trans_buf.c >> @@ -329,7 +329,8 @@ xfs_trans_read_buf_map( >> >> if (tp) >> _xfs_trans_bjoin(tp, bp, 1); >> - trace_xfs_trans_read_buf(bp->b_fspriv); >> + if (bp->b_fspriv) >> + trace_xfs_trans_read_buf(bp->b_fspriv); >> *bpp = bp; >> return 0; >> >> > _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs