From: Andrew Morton Subject: Re: [EXT4 set 4][PATCH 1/5] i_version:64 bit inode version Date: Tue, 10 Jul 2007 22:17:21 -0700 Message-ID: <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> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, nfsv4@linux-nfs.org, linux-kernel@vger.kernel.org To: cmm@us.ibm.com Return-path: In-Reply-To: <1184119748.20193.37.camel@localhost.localdomain> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: nfsv4-bounces@linux-nfs.org Errors-To: nfsv4-bounces@linux-nfs.org List-Id: linux-ext4.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.