From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932635AbYETVln (ORCPT ); Tue, 20 May 2008 17:41:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761717AbYETVlf (ORCPT ); Tue, 20 May 2008 17:41:35 -0400 Received: from agminet01.oracle.com ([141.146.126.228]:17110 "EHLO agminet01.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759703AbYETVle (ORCPT ); Tue, 20 May 2008 17:41:34 -0400 Date: Tue, 20 May 2008 14:41:15 -0700 From: Joel Becker To: Louis Rilling Cc: linux-kernel@vger.kernel.org, ocfs2-devel@oss.oracle.com Subject: Re: [Ocfs2-devel] [RFC][PATCH 0/3] configfs: Make nested default groups lockdep-friendly Message-ID: <20080520214115.GF26609@mail.oracle.com> Mail-Followup-To: Louis Rilling , linux-kernel@vger.kernel.org, ocfs2-devel@oss.oracle.com References: <20080520163320.025971210@kerlabs.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080520163320.025971210@kerlabs.com> X-Burt-Line: Trees are cool. X-Red-Smith: Ninety feet between bases is perhaps as close as man has ever come to perfection. User-Agent: Mutt/1.5.17+20080114 (2008-01-14) X-Brightmail-Tracker: AAAAAQAAAAI= X-Brightmail-Tracker: AAAAAQAAAAI= X-Whitelist: TRUE X-Whitelist: TRUE Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 20, 2008 at 06:33:20PM +0200, Louis Rilling wrote: > The following patches fix lockdep warnings resulting from (correct) recursive > locking in configfs. > > Current lockdep annotations for inode mutexes in configfs are lockdep-friendly > provided that: > 1/ config_groups have at most one level of default groups (see > configfs_attach_group()), > 2/ config_groups having default groups are never removed (see > configfs_detach_prep()). > > Since lockdep does not handle such correct recursion, the idea is to insert > lockdep_off()/lockdep_on() for inode mutexes as soon as the level of recursion > of the I_MUTEX_PARENT -> I_MUTEX_CHILD dependency pattern increases. Hmm, this is definitely a more readable solution than the previous, but I'm also with Arjan that it's scary :-) Joel -- "Ninety feet between bases is perhaps as close as man has ever come to perfection." - Red Smith Joel Becker Principal Software Developer Oracle E-mail: joel.becker@oracle.com Phone: (650) 506-8127