From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 24 Sep 2001 10:37:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 24 Sep 2001 10:37:17 -0400 Received: from chunnel.redhat.com ([199.183.24.220]:61684 "EHLO sisko.scot.redhat.com") by vger.kernel.org with ESMTP id ; Mon, 24 Sep 2001 10:37:10 -0400 Date: Mon, 24 Sep 2001 15:37:00 +0100 From: "Stephen C. Tweedie" To: Beau Kuiper , linux-kernel@vger.kernel.org, tovarlds@transmeta.com, Stephen Tweedie Subject: Re: [PATCH] Significant performace improvements on reiserfs systems, kupdated bugfixes Message-ID: <20010924153700.B13817@redhat.com> In-Reply-To: <20010921152627.C13862@emma1.emma.line.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <20010921152627.C13862@emma1.emma.line.org>; from matthias.andree@stud.uni-dortmund.de on Fri, Sep 21, 2001 at 03:26:27PM +0200 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Fri, Sep 21, 2001 at 03:26:27PM +0200, Matthias Andree wrote: > Be careful! MTAs rely on this behaviour on fsync(). The official > consensus on ReiserFS and ext3 on current Linux 2.4.x kernels (x >= 9) > is that "any synchronous operation flushes all pending operations", and > if that is changed, you MUST make sure that the changed ReiserFS/ext3fs > still make all the guarantees that softupdated BSD file systems make, > lest you want people to run their mail queues off "sync" disks. Reiserfs and ext3 have their own IO ordering --- they don't commit transactions until the log writes for _all_ of the blocks in those transactions have been acknowledged. Reordering outstanding IOs won't affect the fsync guarantees at all. --Stephen