From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752483AbZIOW3U (ORCPT ); Tue, 15 Sep 2009 18:29:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752105AbZIOW3P (ORCPT ); Tue, 15 Sep 2009 18:29:15 -0400 Received: from cantor2.suse.de ([195.135.220.15]:51029 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751772AbZIOW3O (ORCPT ); Tue, 15 Sep 2009 18:29:14 -0400 Date: Tue, 15 Sep 2009 15:25:11 -0700 From: Greg KH To: Dan Williams Cc: Neil Brown , Dave Jones , Linux Kernel , Hans de Goede Subject: Re: 2.6.31rc5 RAID10 lockdep report - sysfs_nofity_dirent locking issue Message-ID: <20090915222511.GA13600@suse.de> References: <20090804141425.GA2831@redhat.com> <58e2e493d0855face4e7d3fbf7ee65b9.squirrel@neil.brown.name> <20090804212404.GA26390@suse.de> <19066.28054.65288.171564@notabene.brown> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 15, 2009 at 03:12:07PM -0700, Dan Williams wrote: > On Wed, Aug 5, 2009 at 10:43 PM, Neil Brown wrote: > > On Tuesday August 4, gregkh@suse.de wrote: > >> > > >> > Greg: does that look right?  If so I'll add a changelog entry and > >> > submit it properly (after at least a compile test...) > >> > >> Yes, it looks correct, if it passes your tests :) > > > > Thanks. > > I've tested it and documented it now and so am happy to submit it. > > Thanks, > > NeilBrown > > > > > > From: NeilBrown > > Date: Thu, 6 Aug 2009 15:42:08 +1000 > > Subject: [PATCH] Allow sysfs_notify_dirent to be called from interrupt context. > > > > sysfs_notify_dirent is a simple atomic operation that can be used to > > alert user-space that new data can be read from a sysfs attribute. > > > > Unfortunately is cannot currently be called from non-process context > > because of it's use of spin_lock which is sometimes taken with > > interrupt enabled. > > > > So change all lockers of sysfs_open_dirent_lock to disable interrupts, > > thus making sysfs_notify_dirent safe to be called from non-process > > context (as drivers/md does in md_safemode_timeout). > > > > sysfs_get_open_dirent is (documented as being) only called from > > process context, so it uses spin_lock_irq.  Other places > > use spin_lock_irqsave. > > > > The usage for sysfs_notify_dirent in md_safemode_timeout was > > introduced in 2.6.28, so this patch is suitable for that and more > > recent kernels. > > > > Cc: stable@kernel.org > > Signed-off-by: NeilBrown > > --- > > Greg? > > Looks like this never made it upstream, and now Hans is hitting this > in his tests. Ok, I don't have this in my queue, so someone needs to resubmit it and tell me what kernel trees it should be applicable for. thanks, greg k-h