From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751224AbWGKLxl (ORCPT ); Tue, 11 Jul 2006 07:53:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751230AbWGKLxl (ORCPT ); Tue, 11 Jul 2006 07:53:41 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:32953 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S1751224AbWGKLxl (ORCPT ); Tue, 11 Jul 2006 07:53:41 -0400 Subject: Re: e1000 vs nfs/net circular locking report From: Arjan van de Ven To: Jens Axboe Cc: linux-kernel@vger.kernel.org, john.ronciak@intel.com, jesse.brandeburg@intel.com, trond.myklebust@fys.uio.no In-Reply-To: <20060711115143.GB4113@suse.de> References: <20060711115143.GB4113@suse.de> Content-Type: text/plain Date: Tue, 11 Jul 2006 13:53:37 +0200 Message-Id: <1152618818.3128.36.camel@laptopd505.fenrus.org> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-2.fc4) Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2006-07-11 at 13:51 +0200, Jens Axboe wrote: > Hi, > > Upon cd'ing to an nfs mounted directory, I received this report. It's > perfectly reproducible. this patch (about to be merged in mainline) should fix it From: Arjan van de Ven Subject: fix false positives by giving sysfs inodes their own lock class sysfs has a different i_mutex lock order behavior for i_mutex than the other filesystems; sysfs i_mutex is called in many places with subsystem locks held. At the same time, many of the VFS locking rules do not apply to sysfs at all (cross directory rename for example). To untangle this mess (which gives false positives in lockdep), we're giving sysfs inodes their own class for i_mutex. Signed-off-by: Arjan van de Ven Index: linux-2.6.18-rc1/fs/sysfs/inode.c =================================================================== --- linux-2.6.18-rc1.orig/fs/sysfs/inode.c +++ linux-2.6.18-rc1/fs/sysfs/inode.c @@ -109,6 +109,17 @@ static inline void set_inode_attr(struct inode->i_ctime = iattr->ia_ctime; } + +/* + * sysfs has a different i_mutex lock order behavior for i_mutex than other + * filesystems; sysfs i_mutex is called in many places with subsystem locks + * held. At the same time, many of the VFS locking rules do not apply to + * sysfs at all (cross directory rename for example). To untangle this mess + * (which gives false positives in lockdep), we're giving sysfs inodes their + * own class for i_mutex. + */ +static struct lock_class_key sysfs_inode_imutex_key; + struct inode * sysfs_new_inode(mode_t mode, struct sysfs_dirent * sd) { struct inode * inode = new_inode(sysfs_sb); @@ -118,6 +129,7 @@ struct inode * sysfs_new_inode(mode_t mo inode->i_mapping->a_ops = &sysfs_aops; inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info; inode->i_op = &sysfs_inode_operations; + lockdep_set_class(&inode->i_mutex, &sysfs_inode_imutex_key); if (sd->s_iattr) { /* sysfs_dirent has non-default attributes