From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 5 Jul 2001 10:39:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 5 Jul 2001 10:39:37 -0400 Received: from penguin.e-mind.com ([195.223.140.120]:21520 "EHLO penguin.e-mind.com") by vger.kernel.org with ESMTP id ; Thu, 5 Jul 2001 10:39:35 -0400 Date: Thu, 5 Jul 2001 16:37:16 +0200 From: Andrea Arcangeli To: Andrew Morton Cc: Dan Kegel , "linux-kernel@vger.kernel.org" Subject: Re: O_DIRECT please; Sybase 12.5 Message-ID: <20010705163716.R17051@athlon.random> In-Reply-To: <3B3C4CB4.6B3D2B2F@kegel.com>, <3B3C4CB4.6B3D2B2F@kegel.com>; <20010705155350.O17051@athlon.random> <3B44797F.DD9EAC99@uow.edu.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3B44797F.DD9EAC99@uow.edu.au>; from andrewm@uow.edu.au on Fri, Jul 06, 2001 at 12:28:15AM +1000 X-GnuPG-Key-URL: http://e-mind.com/~andrea/aa.gnupg.asc X-PGP-Key-URL: http://e-mind.com/~andrea/aa.asc Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 06, 2001 at 12:28:15AM +1000, Andrew Morton wrote: > ext3 journals data. That's unique and it breaks things (or rather, > things break it). It'd be trivial to support O_DIRECT in ext3's > writeback mode (metadata-only), but nobody uses that. I thought everybody uses metadata-only to avoid killing data-write performance. So I thought it was ok to at first support O_DIRECT only for metadata journaling, doing that should be a three liner as you said and that is what I expected. > >From a quick look it seems that we'll need fs-private implementations > of generic_direct_IO() and brw_kiovec() at least. brw_kiovec is called by generic_direct_IO, so yes, all you need is a private generic_direct_IO implementation to deal with the journaled data writes. > I'll take a closer look. OK, thanks! Andrea