From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756057AbXD0QVN (ORCPT ); Fri, 27 Apr 2007 12:21:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756064AbXD0QVN (ORCPT ); Fri, 27 Apr 2007 12:21:13 -0400 Received: from ns2.suse.de ([195.135.220.15]:52483 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756062AbXD0QVL (ORCPT ); Fri, 27 Apr 2007 12:21:11 -0400 Message-ID: <463222F5.7080209@suse.de> Date: Fri, 27 Apr 2007 12:21:09 -0400 From: Jeff Mahoney User-Agent: Thunderbird 1.5.0.10 (X11/20060911) MIME-Version: 1.0 To: Jeff Mahoney Cc: Takashi Iwai , Andrew Morton , David Brownell , Linux Kernel list , reiserfs-dev@namesys.com Subject: Re: 2.6.21 reiserfs -- cicular locking? References: <200704261640.15068.david-b@pacbell.net> <20070426224408.fd525b46.akpm@linux-foundation.org> <4631D9CD.4050106@suse.com> <463213FD.3060401@suse.com> In-Reply-To: <463213FD.3060401@suse.com> X-Enigmail-Version: 0.94.0.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Jeff Mahoney wrote: > Takashi Iwai wrote: >>> At Fri, 27 Apr 2007 07:09:01 -0400, >>> Jeff Mahoney wrote: >>>> -----BEGIN PGP SIGNED MESSAGE----- >>>> Hash: SHA1 >>>> >>>> Takashi Iwai wrote: >>>>> At Fri, 27 Apr 2007 12:09:03 +0200, >>>>> I wrote: >>>>>> I got a similar bug right now at the fresh boot of 2.6.21. >>>>>> >>>>>> >>>>>> ReiserFS: sda2: found reiserfs format "3.6" with standard journal >>>>>> ReiserFS: sda2: using ordered data mode >>>>>> ReiserFS: sda2: journal params: device sda2, size 8192, journal first block 18, max trans len 1024, max batch 900, max commit age 30, max trans age 30 >>>>>> ReiserFS: sda2: checking transaction log (sda2) >>>>>> ReiserFS: sda2: Using r5 hash to sort names >>>>>> ReiserFS: sda2: Removing [3613 1354701 0x0 SD]..done >>>>>> ReiserFS: sda2: There were 1 uncompleted unlinks/truncates. Completed >>>>>> >>>>>> ======================================================= >>>>>> [ INFO: possible circular locking dependency detected ] >>>>>> 2.6.21-work #1 >>>>>> ------------------------------------------------------- >>>>>> mktemp/1459 is trying to acquire lock: >>>>>> (&REISERFS_I(inode)->xattr_sem){..--}, at: [] reiserfs_cache_default_acl+0x2a/0x9c [reiserfs] >>>>>> >>>>>> but task is already holding lock: >>>>>> (&inode->i_mutex){--..}, at: [] open_namei+0xe2/0x5a2 >>>>>> >>>>>> which lock already depends on the new lock. >>>>> The message disappears when I revert the patch: >>>>> >>>>> commit 9b7f375505f5611efb562065b57814b28a81abc3 >>>>> Author: Jeff Mahoney >>>>> Date: Mon Apr 23 14:41:17 2007 -0700 >>>>> >>>>> reiserfs: fix xattr root locking/refcount bug >>>>> >>>>> >>>>> So, likely a newly introduced bug after rc7... >>>> I got a message with a trace similar to this from Vladimir before I >>>> submitted that patch. I'm not sure how to annotate this, since the >>>> xattr_sem can never be taken in the manner described. Internal inodes >>>> are protected by I_PRIVATE. >>> Hm, then maybe my case was just a coincidence. >>> >>> FWIW, I can reproduce the deadlock warning at each time I boot >>> non-patched 2.6.21, and after reverting the patch, it disappeared. > > Ok, so I took another look at the report Vladimir sent me. The trace he > ran into was in the delete inode path, but was still a race between the > xattr_sem and the inode sem. Since we're locking the xattr root on the > xattr read path now, this condition arises more freqently, but it's > really the same one he reported. > > I'm using the default openSUSE config, which doesn't enable mutex > debugging. I'll rebuild with it, and hopefully come up with a way to > kill the warning. I still didn't get the warning, but can you try this and let me know if it fixes it? - -Jeff - --- a/fs/reiserfs/xattr.c 2007-04-22 10:53:10.000000000 -0400 +++ b/fs/reiserfs/xattr.c 2007-04-27 12:09:02.000000000 -0400 @@ -68,7 +68,7 @@ if (!privroot) return ERR_PTR(-ENODATA); - - mutex_lock(&privroot->d_inode->i_mutex); + mutex_lock_nested(&privroot->d_inode->i_mutex, I_MUTEX_XATTR); if (REISERFS_SB(sb)->xattr_root) { xaroot = dget(REISERFS_SB(sb)->xattr_root); goto out; - -- Jeff Mahoney SUSE Labs -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iD8DBQFGMiL1LPWxlyuTD7IRAuwoAKCob0DLVBcmeOApOr9vA5cVFRwBewCfTU/U jwIjK+Uy4RfXKsag5Uamzew= =svba -----END PGP SIGNATURE-----