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=-16.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,TVD_PH_BODY_ACCOUNTS_PRE, URIBL_BLOCKED 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 7E20BC433B4 for ; Fri, 21 May 2021 00:35:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 56C0E60C3E for ; Fri, 21 May 2021 00:35:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235134AbhEUAgX (ORCPT ); Thu, 20 May 2021 20:36:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:33212 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235124AbhEUAgX (ORCPT ); Thu, 20 May 2021 20:36:23 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id CCE936138C; Fri, 21 May 2021 00:35:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1621557300; bh=GLncOGGwb3gF7djb+Xy6GdHGh0Mw4oLFEwu9yRqp/MY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=uTzWAxXgCCv0fu+YzRi21NNudq0LnPll4jqI4VnpoOasK6nZ5iyKohZiGQJBooaIS wJBnwkfcbyqgXmwVU1+CXFe9Huk1Qe3sE1VARNtprQaIIG68If6EIZwp3eS0Mb06bg 8xMFIPI8kwNEpRahx3l/HZtn1gl8viNd5WQFR+CdZDhqzcJcrJUCSXx39a4w6ZjzuK +hvmh0GjOeUoyJU6aL6L62MJIbJFLvw0cDqWr+OHpm8Vwdk2bYGLmLXbS5QvVdP7dt GbDhxlIukLO7o0ZoNL6nFliBkgUZWh/2ucfhnKSxphsWrMj12lF4HnIGFxm3CWjKO7 odFD8iQwnqr8Q== Date: Thu, 20 May 2021 17:35:00 -0700 From: "Darrick J. Wong" To: Dave Chinner Cc: linux-xfs@vger.kernel.org Subject: Re: [PATCH 14/39] xfs: embed the xlog_op_header in the unmount record Message-ID: <20210521003500.GI9675@magnolia> References: <20210519121317.585244-1-david@fromorbit.com> <20210519121317.585244-15-david@fromorbit.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210519121317.585244-15-david@fromorbit.com> Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Wed, May 19, 2021 at 10:12:52PM +1000, 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 I love me some BUILD_BUG_ON, so Reviewed-by: Darrick J. Wong --D > --- > fs/xfs/xfs_log.c | 39 ++++++++++++++++++++++++++++----------- > 1 file changed, 28 insertions(+), 11 deletions(-) > > diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c > index 981cd6f8f0ff..e7a135ffa66f 100644 > --- a/fs/xfs/xfs_log.c > +++ b/fs/xfs/xfs_log.c > @@ -800,12 +800,22 @@ 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 = { > + .ophdr = { > + .oh_clientid = XFS_LOG, > + .oh_tid = cpu_to_be32(ticket->t_tid), > + .oh_flags = XLOG_UNMOUNT_TRANS, > + }, > + .ulf = { > + .magic = XLOG_UNMOUNT_TYPE, > + }, > }; > struct xfs_log_iovec reg = { > - .i_addr = &ulf, > - .i_len = sizeof(ulf), > + .i_addr = &unmount_rec, > + .i_len = sizeof(unmount_rec), > .i_type = XLOG_REG_TYPE_UNMOUNT, > }; > struct xfs_log_vec vec = { > @@ -813,8 +823,12 @@ xlog_write_unmount_record( > .lv_iovecp = ®, > }; > > + BUILD_BUG_ON((sizeof(struct xlog_op_header) + > + sizeof(struct xfs_unmount_log_format)) != > + sizeof(unmount_rec)); > + > /* account for space used by record data */ > - ticket->t_curr_res -= sizeof(ulf); > + ticket->t_curr_res -= sizeof(unmount_rec); > > /* > * For external log devices, we need to flush the data device cache > @@ -2145,6 +2159,8 @@ xlog_write_calc_vec_length( > > /* Don't account for regions with embedded ophdrs */ > if (optype && headers > 0) { > + if (optype & XLOG_UNMOUNT_TRANS) > + headers--; > if (optype & XLOG_START_TRANS) { > ASSERT(headers >= 2); > headers -= 2; > @@ -2359,12 +2375,11 @@ xlog_write( > > /* > * If this is a commit or unmount transaction, we don't need a start > - * record to be written. We do, however, have to account for the > - * commit or unmount header that gets written. Hence we always have > - * to account for an extra xlog_op_header here for commit and unmount > - * records. > + * record to be written. We do, however, have to account for the commit > + * header that gets written. Hence we always have to account for an > + * extra xlog_op_header here for commit records. > */ > - if (optype & (XLOG_COMMIT_TRANS | XLOG_UNMOUNT_TRANS)) > + if (optype & XLOG_COMMIT_TRANS) > ticket->t_curr_res -= sizeof(struct xlog_op_header); > if (ticket->t_curr_res < 0) { > xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES, > @@ -2424,6 +2439,8 @@ xlog_write( > ophdr = reg->i_addr; > if (index) > optype &= ~XLOG_START_TRANS; > + } else if (optype & XLOG_UNMOUNT_TRANS) { > + ophdr = reg->i_addr; > } else { > ophdr = xlog_write_setup_ophdr(log, ptr, > ticket, optype); > @@ -2454,7 +2471,7 @@ xlog_write( > /* > * Copy region. > * > - * Commit and unmount records just log an opheader, so > + * Commit records just log an opheader, so > * we can have empty payloads with no data region to > * copy. Hence we only copy the payload if the vector > * says it has data to copy. > -- > 2.31.1 >