From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay2.corp.sgi.com [137.38.102.29]) by oss.sgi.com (Postfix) with ESMTP id 822C129E15 for ; Tue, 7 May 2013 17:45:15 -0500 (CDT) Message-ID: <51898400.8000900@sgi.com> Date: Tue, 07 May 2013 17:45:20 -0500 From: Mark Tinguely MIME-Version: 1.0 Subject: Re: xfs_efi_item slab corruption. (v3.9-10936-g51a26ae) References: <20130507133707.GA18301@redhat.com> <51895025.2010709@sgi.com> <20130507190731.GA15528@redhat.com> <518954DE.4070803@sgi.com> <20130507193146.GA7539@redhat.com> <51895CD7.7040806@sgi.com> <20130507195954.GA8384@redhat.com> <51895E51.2050508@sgi.com> <20130507202217.GA9883@redhat.com> <518962FC.2060509@sgi.com> <20130507222256.GD24635@dastard> In-Reply-To: <20130507222256.GD24635@dastard> 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: Dave Chinner Cc: Dave Jones , CAI Qian , xfs@oss.sgi.com On 05/07/13 17:22, Dave Chinner wrote: > On Tue, May 07, 2013 at 03:24:28PM -0500, Mark Tinguely wrote: >> On 05/07/13 15:22, Dave Jones wrote: >>> On Tue, May 07, 2013 at 03:04:33PM -0500, Mark Tinguely wrote: >>> > On 05/07/13 14:59, Dave Jones wrote: >>> > > On Tue, May 07, 2013 at 02:58:15PM -0500, Mark Tinguely wrote: >>> > > >>> > > > > I can hit this almost instantly with fsx. I'll do a bisect, though >>> > > > > it sounds like you already have a suspect. >>> > > > > >>> > > > >>> > > > If you want to try kmem debug of Linux 3.8 that would help. >>> > > >>> > > I'm not sure what that is. >>> > >>> > Sorry, if you would test Linux 3.8 with "CONFIG_DEBUG_SLAB=y". >>> >>> Ah, done that. (I pretty much always run with it). >>> >>> This is something new. Even 3.9 was fine. It's only since >>> the recent xfs merge. >>> >>> Dave >>> >> >> git revert 666d644cd72a9ec58b353209ff191d7430f3b357 > > That won't prevent the use after free. That commit fixed a problem > that could lead to a use after free, but what we are seeing here is > that it has ultimately exposed a previously unknown issue that > causes the use after free. > > Basically what is happening is that there are two commits for the > EFD being processed, when there should only be one. I'm not sure how > this is happening yet, but these three traces came out from my debug > sequentially when running generic/006: > Sorry for the misleading statement. Yes, I agree that patch is a good thing. I meant that Dave and only Dave revert it and only to test if that patch was the change that caused the new symptom - which we know now that it is. I added some asserts and did not learn anything new except where the efi item was already freed. --Mark. _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs