From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761080AbXGCXcV (ORCPT ); Tue, 3 Jul 2007 19:32:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755041AbXGCXcL (ORCPT ); Tue, 3 Jul 2007 19:32:11 -0400 Received: from 74-0-229-162.T1.lbdsl.net ([74.0.229.162]:36333 "EHLO mail.clusterfs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754018AbXGCXcJ (ORCPT ); Tue, 3 Jul 2007 19:32:09 -0400 Date: Tue, 3 Jul 2007 17:32:00 -0600 From: Andreas Dilger To: "J. Bruce Fields" Cc: Mingming Cao , linux-fsdevel@vger.kernel.org, Trond Myklebust , 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: <20070703233200.GL6578@schatzie.adilger.int> Mail-Followup-To: "J. Bruce Fields" , Mingming Cao , linux-fsdevel@vger.kernel.org, Trond Myklebust , linux-kernel@vger.kernel.org, linux-ext4@vger.kernel.org, nfsv4@linux-nfs.org References: <1183275424.4010.126.camel@localhost.localdomain> <1183388313.3864.35.camel@localhost.localdomain> <20070703221522.GE14074@fieldses.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070703221522.GE14074@fieldses.org> User-Agent: Mutt/1.4.1i X-GPG-Key: 1024D/0D35BED6 X-GPG-Fingerprint: 7A37 5D79 BF1B CECA D44F 8A29 A488 39F5 0D35 BED6 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Jul 03, 2007 18:15 -0400, J. Bruce Fields wrote: > How will nfsd tell whether it can really on a given filesystem's > i_version, or whether it should fall back on ctime? Good question. > > As to performance concerns that raise before the inode version counter > > (at least for ext4) is done inside ext4_mark_inode_dirty), so there is > > no extra IO work to store this counter to disk. > > So what's the motivation for the "noversion" mount option? Lustre needs to be able to control the version number directly (version number needs to be ordered between all inodes, is set by Lustre to be a transaction number). Instead of trying to incorporate this unused code into ext4 we just turn off the ext4 version code and let Lustre control this directly. It may even be that NFSv4 will need to control the version numbers itself... Cheers, Andreas -- Andreas Dilger Principal Software Engineer Cluster File Systems, Inc.