From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id q3UNKJ9W048150 for ; Mon, 30 Apr 2012 18:20:19 -0500 Received: from ipmail05.adl6.internode.on.net (ipmail05.adl6.internode.on.net [150.101.137.143]) by cuda.sgi.com with ESMTP id eHRFEBvoaRzuzzXs for ; Mon, 30 Apr 2012 16:20:18 -0700 (PDT) Date: Tue, 1 May 2012 09:20:07 +1000 From: Dave Chinner Subject: Re: [PATCH 00/37] xfs: current 3.4 patch queue Message-ID: <20120430232007.GO7015@dastard> References: <1335160747-17254-1-git-send-email-david@fromorbit.com> <20120430143434.GM16881@sgi.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20120430143434.GM16881@sgi.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Ben Myers Cc: xfs@oss.sgi.com On Mon, Apr 30, 2012 at 09:34:34AM -0500, Ben Myers wrote: > While testing this patchset without Jan's freeze work, I hit this assert. > > This one rings bells for me, but I can't find where it's been reported. > > -Ben > > > [56571.411824] BUG: unable to handle kernel NULL pointer dereference at 0000000000000028 > [56571.412798] IP: [] xfs_log_space_wake+0x17/0x140 [xfs] Which is failing on this: (gdb) l *(xfs_log_space_wake+0x17) 0xffffffff81482cb7 is in xfs_log_space_wake (fs/xfs/xfs_log.c:844). 839 struct xfs_mount *mp) 840 { 841 struct log *log = mp->m_log; 842 int free_bytes; 843 844 >>>>>>> if (XLOG_FORCED_SHUTDOWN(log)) 845 return; On this offset: $ pahole fs/xfs/xfs_log.o |grep -A 6 "^struct log" struct log { struct xfs_mount * l_mp; /* 0 8 */ struct xfs_ail * l_ailp; /* 8 8 */ struct xfs_cil * l_cilp; /* 16 8 */ struct xfs_buf * l_xbuf; /* 24 8 */ struct xfs_buftarg * l_targ; /* 32 8 */ uint l_flags; /* 40 4 */ ^^^^^^^^^^^^^^^^^ So the log pointer passed is NULL. That's the first definite sign that the problems you are seeing are all a result of log buffer IO completing after the log has been torn down. Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs