From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 037EFC433E0 for ; Thu, 11 Mar 2021 02:55:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B61A664FC0 for ; Thu, 11 Mar 2021 02:55:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229624AbhCKCy6 (ORCPT ); Wed, 10 Mar 2021 21:54:58 -0500 Received: from mail108.syd.optusnet.com.au ([211.29.132.59]:55250 "EHLO mail108.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229469AbhCKCy2 (ORCPT ); Wed, 10 Mar 2021 21:54:28 -0500 Received: from dread.disaster.area (pa49-181-239-12.pa.nsw.optusnet.com.au [49.181.239.12]) by mail108.syd.optusnet.com.au (Postfix) with ESMTPS id 5DCED1AE924; Thu, 11 Mar 2021 13:54:26 +1100 (AEDT) Received: from dave by dread.disaster.area with local (Exim 4.92.3) (envelope-from ) id 1lKBSz-0017mZ-Iy; Thu, 11 Mar 2021 13:54:25 +1100 Date: Thu, 11 Mar 2021 13:54:25 +1100 From: Dave Chinner To: "Darrick J. Wong" Cc: linux-xfs@vger.kernel.org Subject: Re: [PATCH 21/45] xfs: embed the xlog_op_header in the unmount record Message-ID: <20210311025425.GJ74031@dread.disaster.area> References: <20210305051143.182133-1-david@fromorbit.com> <20210305051143.182133-22-david@fromorbit.com> <20210309001523.GH3419940@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210309001523.GH3419940@magnolia> X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.3 cv=YKPhNiOx c=1 sm=1 tr=0 cx=a_idp_d a=gO82wUwQTSpaJfP49aMSow==:117 a=gO82wUwQTSpaJfP49aMSow==:17 a=kj9zAlcOel0A:10 a=dESyimp9J3IA:10 a=20KFwNOVAAAA:8 a=7-415B0cAAAA:8 a=dUU8WNNNTr0vn8zOWOcA:9 a=CjuIK1q_8ugA:10 a=biEYGPWJfzWAr4FL6Ov7:22 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Mon, Mar 08, 2021 at 04:15:23PM -0800, Darrick J. Wong wrote: > On Fri, Mar 05, 2021 at 04:11:19PM +1100, Dave Chinner wrote: > > From: Dave Chinner > > > > Remove another case where xlog_write() has to prepend an opheader to > > a log transaction. The unmount record + ophdr is smaller than the > > minimum amount of space guaranteed to be free in an iclog (2 * > > sizeof(ophdr)) and so we don't have to care about an unmount record > > being split across 2 iclogs. > > > > Signed-off-by: Dave Chinner > > Reviewed-by: Christoph Hellwig > > --- > > fs/xfs/xfs_log.c | 35 ++++++++++++++++++++++++----------- > > 1 file changed, 24 insertions(+), 11 deletions(-) > > > > diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c > > index b2f9fb1b4fed..94711b9ff007 100644 > > --- a/fs/xfs/xfs_log.c > > +++ b/fs/xfs/xfs_log.c > > @@ -798,12 +798,22 @@ xlog_write_unmount_record( > > struct xlog *log, > > struct xlog_ticket *ticket) > > { > > - struct xfs_unmount_log_format ulf = { > > - .magic = XLOG_UNMOUNT_TYPE, > > + struct { > > + struct xlog_op_header ophdr; > > + struct xfs_unmount_log_format ulf; > > + } unmount_rec = { > > I wonder, should we have a BUILD_BUG_ON to confirm sizeof(umount_rec) > just in case some weird architecture injects padding between these two? > Prior to this code we formatted the op header and unmount record in > separate incore buffers and wrote them to disk with no gap, right? Yup. Easy enough to add. Cheers, Dave. -- Dave Chinner david@fromorbit.com