Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753450Ab0F2Rwl (ORCPT ); Tue, 29 Jun 2010 13:52:41 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:55421 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753007Ab0F2Rwj (ORCPT ); Tue, 29 Jun 2010 13:52:39 -0400 MIME-Version: 1.0 In-Reply-To: <20100629174122.GN28364@laptop> References: <20100624030212.676457061@suse.de> <20100624030725.885831564@suse.de> <20100629130214.GA21410@infradead.org> <20100629145617.GG28364@laptop> <20100629174122.GN28364@laptop> Date: Tue, 29 Jun 2010 10:52:03 -0700 Message-ID: Subject: Re: [patch 02/52] fs: fix superblock iteration race From: Linus Torvalds To: Nick Piggin Cc: Christoph Hellwig , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, John Stultz , Frank Mayhar , Al Viro Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1320 Lines: 29 On Tue, Jun 29, 2010 at 10:41 AM, Nick Piggin wrote: > On Tue, Jun 29, 2010 at 10:35:47AM -0700, Linus Torvalds wrote: >> >> I'll apply it. We have a couple of oopses listed for the superblock >> iterator, and I haven't heard from Al. And the patch looks obviously >> fine, whether it's actually the cause of some of the bugs or not. > > OK. I only have managed to get it into an infininte loop but I think > it would be surely possible to oops it because the next pointer can > be uninitialised memory at that point. Look for "2.6.35-rc3 oops trying to suspend" on lkml, for example. No guarantee that it's the same thing, but it's "iterate_supers()" getting an oops when it does "down_read(&sb->s_umount)". Which really looks suspiciously like "sb" just being totally bogus, most likely because of this same issue. So I dunno, but I asked Al to look at it, and haven't heard back. Regardless, I think your patch is the right thing to do (modulo any syntactic issues - and I think your final version was the best of the lot). Linus -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/