From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760565AbXGKGTG (ORCPT ); Wed, 11 Jul 2007 02:19:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756007AbXGKGSx (ORCPT ); Wed, 11 Jul 2007 02:18:53 -0400 Received: from e33.co.us.ibm.com ([32.97.110.151]:47884 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755997AbXGKGSv (ORCPT ); Wed, 11 Jul 2007 02:18:51 -0400 Subject: Re: [EXT4 set 4][PATCH 1/5] i_version:64 bit inode version From: Mingming Cao Reply-To: cmm@us.ibm.com To: Andrew Morton Cc: Neil Brown , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ext4@vger.kernel.org, nfsv4@linux-nfs.org In-Reply-To: <20070710221721.23c46edf.akpm@linux-foundation.org> References: <1183275424.4010.126.camel@localhost.localdomain> <20070710163038.ceb2ae94.akpm@linux-foundation.org> <1184105380.3759.65.camel@localhost.localdomain> <20070710182237.e2f88bf3.akpm@linux-foundation.org> <18068.19667.942363.686858@notabene.brown> <1184119748.20193.37.camel@localhost.localdomain> <20070710221721.23c46edf.akpm@linux-foundation.org> Content-Type: text/plain Organization: IBM Linux Technology Center Date: Tue, 10 Jul 2007 23:18:50 -0400 Message-Id: <1184123930.20193.61.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.8.0 (2.8.0-33.el5) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2007-07-10 at 22:17 -0700, Andrew Morton wrote: > On Tue, 10 Jul 2007 22:09:08 -0400 Mingming Cao wrote: > > > David Chinneer pointed that we need to journal the version number > > updates together with the operations that causes the change of the inode > > version number, in order to survive server crashes so clients won't see > > the counter go backwards. > > > > So increment i_version in fs code is probably the place to ensure the > > inode version changes are stored to disk. It's seems update the ext4 > > inode version in every ext4_mark_inode_dirty() is the easiest way. > > That still makes us dependent upon _something_ changing the inode. For > overwrites the only something is mtime. > > If we don't want to have a peculiar dependency upon s_time_gran=1e9 (and > I don't think we do) then I guess we'll need new code in or around > file_update_time() to do this. do you mean mark inode dirty all the times in file_update_time()? Not sure about the overhead for ext3/4. Mingming