Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935533AbXEVWk5 (ORCPT ); Tue, 22 May 2007 18:40:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761287AbXEVWku (ORCPT ); Tue, 22 May 2007 18:40:50 -0400 Received: from canuck.infradead.org ([209.217.80.40]:54393 "EHLO canuck.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760079AbXEVWkt (ORCPT ); Tue, 22 May 2007 18:40:49 -0400 Date: Tue, 22 May 2007 15:38:41 -0700 From: Greg KH To: Maneesh Soni Cc: Tejun Heo , Andrew Morton , Clemens Schwaighofer , linux-kernel , Dipankar Sarma , Chuck Ebbert Subject: Re: [PATCH 2/2] sysfs: fix race condition around sd->s_dentry, take#2 Message-ID: <20070522223841.GB2874@kroah.com> References: <20070516082935.fe112ab5.akpm@linux-foundation.org> <464B2605.9040200@gmail.com> <20070516091346.3c76cb46.akpm@linux-foundation.org> <464B4DE4.9060100@gmail.com> <20070517120423.GE17712@kroah.com> <20070517173912.GA14370@in.ibm.com> <464C95AB.3020209@gmail.com> <464C9801.8000606@gmail.com> <464C9BEA.7060309@gmail.com> <20070521050101.GC9214@in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070521050101.GC9214@in.ibm.com> User-Agent: Mutt/1.5.15 (2007-04-06) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1451 Lines: 34 On Mon, May 21, 2007 at 10:31:01AM +0530, Maneesh Soni wrote: > On Thu, May 17, 2007 at 08:16:10PM +0200, Tejun Heo wrote: > > Allowing attribute and symlink dentries to be reclaimed means > > sd->s_dentry can change dynamically. However, updates to the field > > are unsynchronized leading to race conditions. This patch adds > > sysfs_lock and use it to synchronize updates to sd->s_dentry. > > > > Due to the locking around ->d_iput, the check in sysfs_drop_dentry() > > is complex. sysfs_lock only protect sd->s_dentry pointer itself. The > > validity of the dentry is protected by dcache_lock, so whether dentry > > is alive or not can only be tested while holding both locks. > > > > This is minimal backport of sysfs_drop_dentry() rewrite in devel > > branch. > > > > DONT APPLY JUST YET > > Looks ok to me.. I have tested it it but unfortunately I couldn't > recreate the race without the patch also. It would be helpful if > people actually seeing the race, provide the test results. > > Greg, please merge this one once we have some test results. Can someone just resend it after those test results are in, with the proper signed-off-by, so I know it's safe to apply? thanks, greg k-h - 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/