From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 1 Jun 2002 16:11:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 1 Jun 2002 16:11:27 -0400 Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:27398 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id ; Sat, 1 Jun 2002 16:11:23 -0400 Message-ID: <3CF92B1D.E466B743@zip.com.au> Date: Sat, 01 Jun 2002 13:14:21 -0700 From: Andrew Morton X-Mailer: Mozilla 4.79 [en] (X11; U; Linux 2.4.19-pre9 i686) X-Accept-Language: en MIME-Version: 1.0 To: Andreas Dilger CC: Linus Torvalds , lkml Subject: Re: [patch 9/16] direct-to-BIO writeback for writeback-mode ext3 In-Reply-To: <3CF88903.E253A075@zip.com.au> <20020601191514.GA7905@turbolinux.com> 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 Andreas Dilger wrote: > > On Jun 01, 2002 01:42 -0700, Andrew Morton wrote: > > Turn on direct-to-BIO writeback for ext3 in data=writeback mode. > > A minor note on this (especially minor since I believe data=journal > doesn't even work in 2.5), but you should probably also change the > address ops in ext3/ioctl.c if you enable/disable per-inode data > journaling. hrm. Actually, changing journalling mode against a file while modifications are happening against it is almost certain to explode if the timing is right. ISTR that we have seen bug reports against this on ext3-users. This is just waaaay too hard to do. But we can fix it by doing the opposite: create three separate a_ops instances, one for each journalling mode. Assign it at new_inode/read_inode time. This way, we don't have to do the `ext3_should_journal_data()' tests all over the place and we just don't care if someone diddles the journalling mode while the file is otherwise in use. Another one for my todo list.. -