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=-16.3 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 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 A454DC433E0 for ; Tue, 9 Mar 2021 02:40:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6827E614A7 for ; Tue, 9 Mar 2021 02:40:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229599AbhCICjm (ORCPT ); Mon, 8 Mar 2021 21:39:42 -0500 Received: from mail.kernel.org ([198.145.29.99]:45296 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229575AbhCICj2 (ORCPT ); Mon, 8 Mar 2021 21:39:28 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0BBED6527B; Tue, 9 Mar 2021 02:39:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1615257568; bh=0bUyVV22GlM3d/cucTC6G5WHjXLZZcQ1v4yU2w2Tf7k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Y0aJswrqiUkf2Bt8JA2w6+lvaLK1rPm8WOHUHRdjedxxu8vrF2RBcg9cA6EziZBJt N89l8ZfMMM0H0W5STTbBBPy5IhzwkeNJHyXa8jXQQOmjWs9T8JO/22iyMPUfuXRiGd 74axJ+XESdlm4oxhwtUXQY0YkRP7I4v9yYVK4wnWTA46M3uuTIGcJvMYE8HCur6ZHu QXUsbIvTWjw2rMAHQknYBj/BgaCqhLXoCTS9NKnx1oPk+mg0u31iwHZPH/LOuli2N0 NKIOAQhbCqdVz1UiqhxP09mHG2wXi1XiprJHOqZAS4N9X9i4KoeG1Z/bOmtIp9UVJW cQrgHusP8ElPg== Date: Mon, 8 Mar 2021 18:39:27 -0800 From: "Darrick J. Wong" To: Dave Chinner Cc: linux-xfs@vger.kernel.org Subject: Re: [PATCH 28/45] xfs: introduce xlog_write_single() Message-ID: <20210309023927.GP3419940@magnolia> References: <20210305051143.182133-1-david@fromorbit.com> <20210305051143.182133-29-david@fromorbit.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210305051143.182133-29-david@fromorbit.com> Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Fri, Mar 05, 2021 at 04:11:26PM +1100, Dave Chinner wrote: > From: Dave Chinner > > Introduce an optimised version of xlog_write() that is used when the > entire write will fit in a single iclog. This greatly simplifies the > implementation of writing a log vector chain into an iclog, and sets > the ground work for a much more understandable xlog_write() > implementation. > > Signed-off-by: Dave Chinner > --- > fs/xfs/xfs_log.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 56 insertions(+), 1 deletion(-) > > diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c > index 22f97914ab99..590c1e6db475 100644 > --- a/fs/xfs/xfs_log.c > +++ b/fs/xfs/xfs_log.c > @@ -2214,6 +2214,52 @@ xlog_write_copy_finish( > return error; > } > > +/* > + * Write log vectors into a single iclog which is guaranteed by the caller > + * to have enough space to write the entire log vector into. Return the number > + * of log vectors written into the iclog. > + */ > +static int > +xlog_write_single( > + struct xfs_log_vec *log_vector, > + struct xlog_ticket *ticket, > + struct xlog_in_core *iclog, > + uint32_t log_offset, > + uint32_t len) > +{ > + struct xfs_log_vec *lv = log_vector; > + void *ptr; > + int index = 0; > + int record_cnt = 0; Any reason these (and the return type) can't be unsigned? I don't think negative indices or record counts have any meaning, right? Otherwise this looks ok to me. --D > + > + ASSERT(log_offset + len <= iclog->ic_size); > + > + ptr = iclog->ic_datap + log_offset; > + for (lv = log_vector; lv; lv = lv->lv_next) { > + /* > + * Ordered log vectors have no regions to write so this > + * loop will naturally skip them. > + */ > + for (index = 0; index < lv->lv_niovecs; index++) { > + struct xfs_log_iovec *reg = &lv->lv_iovecp[index]; > + struct xlog_op_header *ophdr = reg->i_addr; > + > + ASSERT(reg->i_len % sizeof(int32_t) == 0); > + ASSERT((unsigned long)ptr % sizeof(int32_t) == 0); > + > + ophdr->oh_tid = cpu_to_be32(ticket->t_tid); > + ophdr->oh_len = cpu_to_be32(reg->i_len - > + sizeof(struct xlog_op_header)); > + memcpy(ptr, reg->i_addr, reg->i_len); > + xlog_write_adv_cnt(&ptr, &len, &log_offset, reg->i_len); > + record_cnt++; > + } > + } > + ASSERT(len == 0); > + return record_cnt; > +} > + > + > /* > * Write some region out to in-core log > * > @@ -2294,7 +2340,6 @@ xlog_write( > return error; > > ASSERT(log_offset <= iclog->ic_size - 1); > - ptr = iclog->ic_datap + log_offset; > > /* Start_lsn is the first lsn written to. */ > if (start_lsn && !*start_lsn) > @@ -2311,10 +2356,20 @@ xlog_write( > XLOG_ICL_NEED_FUA); > } > > + /* If this is a single iclog write, go fast... */ > + if (!contwr && lv == log_vector) { > + record_cnt = xlog_write_single(lv, ticket, iclog, > + log_offset, len); > + len = 0; > + data_cnt = len; > + break; > + } > + > /* > * This loop writes out as many regions as can fit in the amount > * of space which was allocated by xlog_state_get_iclog_space(). > */ > + ptr = iclog->ic_datap + log_offset; > while (lv && (!lv->lv_niovecs || index < lv->lv_niovecs)) { > struct xfs_log_iovec *reg; > struct xlog_op_header *ophdr; > -- > 2.28.0 >