From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760080AbXGRLRL (ORCPT ); Wed, 18 Jul 2007 07:17:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751521AbXGRLQ5 (ORCPT ); Wed, 18 Jul 2007 07:16:57 -0400 Received: from mtagate4.uk.ibm.com ([195.212.29.137]:53407 "EHLO mtagate4.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752088AbXGRLQ4 (ORCPT ); Wed, 18 Jul 2007 07:16:56 -0400 Date: Wed, 18 Jul 2007 13:16:46 +0200 From: Cornelia Huck To: Tejun Heo Cc: Gabriel C , Satyam Sharma , Linux Kernel Mailing List , Christoph Lameter , gregkh@suse.de, miles.lane@gmail.com Subject: Re: [PATCH] sysfs: kill an extra put in sysfs_create_link() failure path Message-ID: <20070718131646.2c9cdab0@gondolin.boeblingen.de.ibm.com> In-Reply-To: <20070718071445.GI23568@htj.dyndns.org> References: <469A5C94.7030201@googlemail.com> <469A9D5D.10509@googlemail.com> <469B61C8.8010902@googlemail.com> <469BB7B8.3060002@gmail.com> <469BB9CA.6090500@googlemail.com> <469BC2D6.5090008@googlemail.com> <469BC34C.4080107@googlemail.com> <20070718071445.GI23568@htj.dyndns.org> Organization: IBM Deutschland Entwicklung GmbH X-Mailer: Claws Mail 2.10.0 (GTK+ 2.10.13; i486-pc-linux-gnu) X-Legal: IBM Deutschland Entwicklung GmbH Vorsitzender des Aufsichtsrats: Johann Weihen =?ISO-8859-15?Q?Gesch=E4ftsf=FChrung:?= Herbert Kircher Sitz der Gesellschaft: =?ISO-8859-15?Q?B=F6blingen?= Registergericht: Amtsgericht Stuttgart, HRB 243294 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 18 Jul 2007 16:14:45 +0900, Tejun Heo wrote: > There is a subtle bug in sysfs_create_link() failure path. When > symlink creation fails because there's already a node with the same > name, the target sysfs_dirent is put twice - once by failure path of > sysfs_create_link() and once more when the symlink is released. > > Fix it by making only the symlink node responsible for putting > target_sd. > > Signed-off-by: Tejun Heo > --- > Gabriel, Miles, please verify this fixes your problem. Thanks. > > fs/sysfs/symlink.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c > index 2f86e04..d056e96 100644 > --- a/fs/sysfs/symlink.c > +++ b/fs/sysfs/symlink.c > @@ -86,7 +86,9 @@ int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char > sd = sysfs_new_dirent(name, S_IFLNK|S_IRWXUGO, SYSFS_KOBJ_LINK); > if (!sd) > goto out_put; > + > sd->s_elem.symlink.target_sd = target_sd; > + target_sd = NULL; /* reference is now owned by the symlink */ > > sysfs_addrm_start(&acxt, parent_sd); > A subtle bug indeed. The patch looks sane to me. Reviewed-by: Cornelia Huck