From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932531AbWLPShi (ORCPT ); Sat, 16 Dec 2006 13:37:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932518AbWLPShi (ORCPT ); Sat, 16 Dec 2006 13:37:38 -0500 Received: from excu-mxob-2.symantec.com ([198.6.49.23]:35514 "EHLO excu-mxob-2.symantec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932531AbWLPShh (ORCPT ); Sat, 16 Dec 2006 13:37:37 -0500 X-Greylist: delayed 1020 seconds by postgrey-1.27 at vger.kernel.org; Sat, 16 Dec 2006 13:37:37 EST X-AuditID: c6063117-a2740bb000001a74-8e-458438f51ac4 Date: Sat, 16 Dec 2006 18:20:59 +0000 (GMT) From: Hugh Dickins X-X-Sender: hugh@blonde.wat.veritas.com To: Martin Michlmayr cc: Peter Zijlstra , linux-mm@kvack.org, linux-kernel@vger.kernel.org, debian-kernel@lists.debian.org Subject: Re: Recent mm changes leading to filesystem corruption? In-Reply-To: <20061216155044.GA14681@deprecation.cyrius.com> Message-ID: References: <20061216155044.GA14681@deprecation.cyrius.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-OriginalArrivalTime: 16 Dec 2006 18:20:37.0189 (UTC) FILETIME=[E24F5F50:01C7213E] X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 16 Dec 2006, Martin Michlmayr wrote: > Debian recently applied a number of mm changes that went into 2.6.19 > to their 2.6.18 kernel for LSB 3.1 compliance (msync() had problems > before). Since then, some filesystem corruption has been observed > which can be traced back to these mm changes. Is anyone aware of > problems with these patches? Very disturbing. I'm not aware of any problem with them, and we surely wouldn't have released 2.6.19 with any known-corrupting patches in. There's some doubts about 2.6.19 itself in the links below: were it not for those, I'd suspect a mismerge of the pieces into 2.6.18, perhaps a hidden dependency on something else. I'll ponder a little, but let's CC linux-mm in case someone there has an idea. Hugh > > The patches that were applied are: > > - mm: tracking shared dirty pages > - mm: balance dirty pages > - mm: optimize the new mprotect() code a bit > - mm: small cleanup of install_page() > - mm: fixup do_wp_page() > - mm: msync() cleanup > > With these applied to 2.6.18, the Debian installer on a slow ARM > system fails because a program segfaults due to filesystem corruption: > http://bugs.debian.org/401980 This problem also occurs if you only > apply the "mm: tracking shared dirty pages" patch to 2.6.18 from the > series of 5 patches listed above. > > Another problem has been reported related to libtorrent: according to > http://bugs.debian.org/402707 someone also saw this with non-Debian > 2.6.19 but obviously it's hard to say whether the bugs are really > related. > http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=394392;msg=24 shows > some dmesg messages but again it's not 100% clear it's the same bug. > > Has anyone else seen problems or is aware of a fix to the patches > listed above that I'm unaware of? It's possible the problem only > shows up on slow systems. (The corruption is reproducible on a slow > NSLU2 ARM system with 32 MB ram, but it doesn't happen on a faster ARM > box with more RAM.) > -- > Martin Michlmayr > http://www.cyrius.com/