Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751106AbXAIGpI (ORCPT ); Tue, 9 Jan 2007 01:45:08 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751107AbXAIGpI (ORCPT ); Tue, 9 Jan 2007 01:45:08 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:49616 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751106AbXAIGpH (ORCPT ); Tue, 9 Jan 2007 01:45:07 -0500 Date: Tue, 9 Jan 2007 07:41:13 +0100 From: Ingo Molnar To: Andrew Morton Cc: David Chinner , linux-kernel Mailing List , xfs@oss.sgi.com, Arjan van de Ven , Peter Zijlstra Subject: Re: xfs_file_ioctl / xfs_freeze: BUG: warning at kernel/mutex-debug.c:80/debug_mutex_unlock() Message-ID: <20070109064113.GB5569@elte.hu> References: <20070104001420.GA32440@m.safari.iki.fi> <20070107213734.GS44411608@melbourne.sgi.com> <20070108155636.a68dce33.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070108155636.a68dce33.akpm@osdl.org> User-Agent: Mutt/1.4.2.2i X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -2.6 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.6 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.0.3 -2.6 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 862 Lines: 21 * Andrew Morton wrote: > > Revert bd_mount_mutex back to a semaphore so that xfs_freeze -f > > /mnt/newtest; xfs_freeze -u /mnt/newtest works safely and doesn't > > produce lockdep warnings. > > Sad. The alternative would be to implement > mutex_unlock_dont_warn_if_a_different_task_did_it(). Ingo? Possible? i'd like to avoid it as much as i'd like to avoid having to add spin_unlock_dont_warn_if_a_different_task_did_it(). Unlocking by a different task is usually a sign of messy locking and bugs lurking. Is it really true that XFS's use of bd_mount_mutex is safe and justified? Ingo - 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/