From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161311AbWASKEq (ORCPT ); Thu, 19 Jan 2006 05:04:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161313AbWASKEq (ORCPT ); Thu, 19 Jan 2006 05:04:46 -0500 Received: from mail.suse.de ([195.135.220.2]:18379 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S1161311AbWASKEp (ORCPT ); Thu, 19 Jan 2006 05:04:45 -0500 Date: Thu, 19 Jan 2006 11:04:44 +0100 From: Jan Blunck To: Kirill Korotaev Cc: Olaf Hering , linux-kernel@vger.kernel.org, Andrew Morton Subject: Re: [PATCH] Busy inodes after unmount, be more verbose in generic_shutdown_super Message-ID: <20060119100443.GD10267@hasse.suse.de> References: <20060116223431.GA24841@suse.de> <43CC2AF8.4050802@sw.ru> <20060118224953.GA31364@hasse.suse.de> <43CF6170.3050608@sw.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <43CF6170.3050608@sw.ru> "From: jblunck@suse.de" User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 19, Kirill Korotaev wrote: > This patch has nothing to do with vfsmount references and doesn't hide > anything. It just adds syncronization barrier between do_umount() and > shrink_dcache() since the latter can work with dentries/inodes without > holding locks. > > So if you think there is something wrong with it, please, be more specific. > You can only unmount a file system if there are no references to the vfsmount object anymore. Since shrink_dcache*() is called after checking the refcount of vfsmount while unmounting the file system, it isn't possible to hold a reference to a dentry (and therefore call dput()) after this point in time. Therefore your reference counting on the vfsmount is wrong which is the root case for your problem of busy inodes. Regards, Jan -- Jan Blunck jblunck@suse.de SuSE LINUX AG - A Novell company Maxfeldstr. 5 +49-911-74053-608 D-90409 Nürnberg http://www.suse.de