Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752998Ab3CUU0m (ORCPT ); Thu, 21 Mar 2013 16:26:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56116 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752947Ab3CUU0k (ORCPT ); Thu, 21 Mar 2013 16:26:40 -0400 Date: Thu, 21 Mar 2013 16:26:35 -0400 From: Dave Jones To: Linus Torvalds Cc: Al Viro , Linux Kernel Subject: Re: VFS deadlock ? Message-ID: <20130321202635.GA16406@redhat.com> Mail-Followup-To: Dave Jones , Linus Torvalds , Al Viro , Linux Kernel References: <20130321190653.GA15479@redhat.com> <20130321192935.GY21522@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1444 Lines: 35 On Thu, Mar 21, 2013 at 01:15:08PM -0700, Linus Torvalds wrote: > On Thu, Mar 21, 2013 at 12:29 PM, Al Viro wrote: > > > > #0 oddity aside, that looks very much like directory aliased by two different > > dentries. Try to add > > BUG_ON(p1->d_inode == p2->d_inode); > > just before > > mutex_lock(&p1->d_inode->i_sb->s_vfs_rename_mutex); > > and see if it triggers. > > Don't do a BUG_ON(), instead do something like > > if (WARN_ON_ONCE(p1->d_inode == p2->d_inode)) { > printk("pi=%s p2=%s\n", pi->d_name, p2->d_name); > mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT); > return NULL; > } those are qstr's, so I used d_name.name, right ? > so that we actually see where it is. I'm assuming it's some sysfs oddity again.. I'd be surprised actually, I've got sysfs excluded from its list of victim files, due to unrelated issues still unresolved. So unless it followed a symlink into sys from somewhere in /proc or /dev... It took a few hours to reproduce last time, I'll increase the number of child processes to see if I can trigger it faster now that I have the debug stuff in there. Dave -- 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/