From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757800Ab0E0RFe (ORCPT ); Thu, 27 May 2010 13:05:34 -0400 Received: from hera.kernel.org ([140.211.167.34]:39042 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756665Ab0E0RFd (ORCPT ); Thu, 27 May 2010 13:05:33 -0400 Message-ID: <4BFEA5CF.2070002@kernel.org> Date: Thu, 27 May 2010 19:03:11 +0200 From: Tejun Heo User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.9.1.9) Gecko/20100317 Thunderbird/3.0.4 MIME-Version: 1.0 To: =?ISO-8859-1?Q?Am=E9rico_Wang?= CC: David Howells , davem@davemloft.net, jens.axboe@oracle.com, linux-kernel@vger.kernel.org, torvalds@osdl.org, viro@ZenIV.linux.org.uk, akpm@linux-foundation.org Subject: Re: [PATCH] fs: run emergency remount on dedicated workqueue References: <25328.1274886067@redhat.com> <4BFE4203.5010803@kernel.org> <20100527145807.GB3600@hack> In-Reply-To: <20100527145807.GB3600@hack> X-Enigmail-Version: 1.0.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Thu, 27 May 2010 17:03:12 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/27/2010 04:59 PM, Américo Wang wrote: > On Thu, May 27, 2010 at 11:57:23AM +0200, Tejun Heo wrote: >> Commit fa4b9074cd8428958c2adf9dc0c831f46e27c193 made s_umount depend >> on keventd; however, emergency remount schedules works to keventd >> which grabs s_umount creating a circular dependency. Run emergency >> remount on a separate workqueue to break it. >> > > I have a stupid question, why using workqueue instead of > calling do_remount_sb() directly in emergency_remount()? > Avoid blocking emergency_remount()? Umm... because it's called from interrupt handler? Right? -- tejun