From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756824AbYFQKnQ (ORCPT ); Tue, 17 Jun 2008 06:43:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754257AbYFQKnD (ORCPT ); Tue, 17 Jun 2008 06:43:03 -0400 Received: from bohort.kerlabs.com ([62.160.40.57]:41142 "EHLO bohort.kerlabs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754064AbYFQKnB (ORCPT ); Tue, 17 Jun 2008 06:43:01 -0400 Date: Tue, 17 Jun 2008 12:42:59 +0200 From: Louis Rilling To: Joel.Becker@oracle.com Cc: linux-kernel@vger.kernel.org, ocfs2-devel@oss.oracle.com Subject: Re: [PATCH][BUGFIX] configfs: Fix symlink() to a removing item Message-ID: <20080617104259.GX30804@localhost> Reply-To: Louis.Rilling@kerlabs.com References: <20080616180911.GV30804@localhost> <20080616222900.GD6441@mail.oracle.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=_bohort-26428-1213699290-0001-2" Content-Disposition: inline In-Reply-To: <20080616222900.GD6441@mail.oracle.com> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is a MIME-formatted message. If you see this text it means that your E-mail software does not support MIME-formatted messages. --=_bohort-26428-1213699290-0001-2 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Jun 16, 2008 at 03:29:00PM -0700, Joel Becker wrote: > On Mon, Jun 16, 2008 at 08:09:11PM +0200, Louis Rilling wrote: > > This patch introduces a similar (weird?) behavior as with mkdir failure= s making > > rmdir fail: if symlink() races with rmdir() of the parent directory (or= its > > youngest user-created ancestor if parent is a default group) or rmdir()= of the > > target directory, and then fails in configfs_create(), this can make th= e racing > > rmdir() fail despite the concerned directory having no user-created ent= ry (resp. > > no symlink pointing to it or one of its default groups) in the end. > > If this behavior is found unacceptable, I'll submit a fix in the same s= pirit as > > the racing mkdir() fix. >=20 > Ahh, but you can't wait on the mutex like you do in mkdir(), > because they're not ordered - it can race rename again. Yes I can. In the mkdir() case, rmdir() waits on the mutex of one of the de= fault groups. The symlink case will be handled the same. The difference is that w= hile mkdir() tags the parent with CONFIGFS_USET_IN_MKDIR, symlink() will tag bot= h the parent and the target with CONFIGFS_USET_IN_SYMLINK. [ We can actually merg= e the two flags in something like CONFIGFS_USET_ATTACHING. ] Since tagging requir= es only to take configfs_dirent_lock, there will be no deadlock. I'll send a patch later. Louis --=20 Dr Louis Rilling Kerlabs Skype: louis.rilling Batiment Germanium Phone: (+33|0) 6 80 89 08 23 80 avenue des Buttes de Coesmes http://www.kerlabs.com/ 35700 Rennes --=_bohort-26428-1213699290-0001-2 Content-Type: application/pgp-signature; name="signature.asc" Content-Transfer-Encoding: 7bit Content-Description: Digital signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQFIV5UzVKcRuvQ9Q1QRAncpAJ9xN2elFXJiDP+fNhC9P8jNr/VSoQCfU3rh uF8lY7+0uJB9h9zFXyoFKGU= =iEJF -----END PGP SIGNATURE----- --=_bohort-26428-1213699290-0001-2--