From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754797Ab1AGRKq (ORCPT ); Fri, 7 Jan 2011 12:10:46 -0500 Received: from lennier.cc.vt.edu ([198.82.162.213]:38661 "EHLO lennier.cc.vt.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754551Ab1AGRKp (ORCPT ); Fri, 7 Jan 2011 12:10:45 -0500 X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.3-dev To: Nick Piggin Cc: Alexander Viro , Joel Becker , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: 2.6.37-next - kernel BUG at fs/dcache.c:1363 In-Reply-To: Your message of "Fri, 07 Jan 2011 00:12:09 +1100." From: Valdis.Kletnieks@vt.edu References: <8679.1294247741@localhost> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1294420240_4860P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Fri, 07 Jan 2011 12:10:40 -0500 Message-ID: <25743.1294420240@localhost> X-Mirapoint-Received-SPF: 198.82.161.152 auth3.smtp.vt.edu Valdis.Kletnieks@vt.edu 2 pass X-Mirapoint-IP-Reputation: reputation=neutral-1, source=Fixed, refid=n/a, actions=MAILHURDLE SPF TAG X-Junkmail-Status: score=10/50, host=vivi.cc.vt.edu X-Junkmail-Signature-Raw: score=unknown, refid=str=0001.0A020208.4D274911.001B,ss=1,fgs=0, ip=0.0.0.0, so=2010-07-22 22:03:31, dmn=2009-09-10 00:05:08, mode=single engine X-Junkmail-IWF: false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --==_Exmh_1294420240_4860P Content-Type: text/plain; charset=us-ascii On Fri, 07 Jan 2011 00:12:09 +1100, Nick Piggin said: > > Thanks. It actually passed in a dentry that appears to have already been > > used for something. This is not exactly a nice thing for a filesystem to do > > and probably indicates an underlying bug anyway (or at least something > > the vfs doesn't guarantee the safety of). > > > > Taking a look now. > > This patch fixes it here > config fs: avoid switching ->d_op on live dentry > Switching d_op on a live dentry is racy in general, so avoid it. In this case > it is a negative dentry, which is safer, but there are still concurrent ops > which may be called on d_op in that case (eg. d_revalidate). So in general > a filesystem may not do this. Fix configfs so as not to do this. Confirming this patch fixes the crash I was seeing, so now I'm off to try to finish bisecting my way through the other issue I was seeing... --==_Exmh_1294420240_4860P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Exmh version 2.5 07/13/2001 iD8DBQFNJ0kQcC3lWbTT17ARAqcWAJ905Ah+tLCIHfpcQMP6hWKEJozdKACgrzKg gjAD5amG+0mBWYq1k/g70sc= =QVXC -----END PGP SIGNATURE----- --==_Exmh_1294420240_4860P--