From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761245AbXGKFRr (ORCPT ); Wed, 11 Jul 2007 01:17:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758500AbXGKFRk (ORCPT ); Wed, 11 Jul 2007 01:17:40 -0400 Received: from smtp2.linux-foundation.org ([207.189.120.14]:35239 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757577AbXGKFRj (ORCPT ); Wed, 11 Jul 2007 01:17:39 -0400 Date: Tue, 10 Jul 2007 22:17:21 -0700 From: Andrew Morton To: cmm@us.ibm.com Cc: Neil Brown , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ext4@vger.kernel.org, nfsv4@linux-nfs.org Subject: Re: [EXT4 set 4][PATCH 1/5] i_version:64 bit inode version Message-Id: <20070710221721.23c46edf.akpm@linux-foundation.org> In-Reply-To: <1184119748.20193.37.camel@localhost.localdomain> 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> X-Mailer: Sylpheed 2.4.1 (GTK+ 2.8.17; x86_64-unknown-linux-gnu) 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 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.