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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 0FBDDC6377B for ; Thu, 22 Jul 2021 01:53:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DA1E661264 for ; Thu, 22 Jul 2021 01:53:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230143AbhGVBNH (ORCPT ); Wed, 21 Jul 2021 21:13:07 -0400 Received: from mail110.syd.optusnet.com.au ([211.29.132.97]:51214 "EHLO mail110.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230040AbhGVBNG (ORCPT ); Wed, 21 Jul 2021 21:13:06 -0400 Received: from dread.disaster.area (pa49-181-34-10.pa.nsw.optusnet.com.au [49.181.34.10]) by mail110.syd.optusnet.com.au (Postfix) with ESMTPS id 9D6AB100B4D for ; Thu, 22 Jul 2021 11:53:39 +1000 (AEST) Received: from discord.disaster.area ([192.168.253.110]) by dread.disaster.area with esmtp (Exim 4.92.3) (envelope-from ) id 1m6Nu6-009JQJ-Eo for linux-xfs@vger.kernel.org; Thu, 22 Jul 2021 11:53:38 +1000 Received: from dave by discord.disaster.area with local (Exim 4.94) (envelope-from ) id 1m6Nu6-00Cquj-6x for linux-xfs@vger.kernel.org; Thu, 22 Jul 2021 11:53:38 +1000 From: Dave Chinner To: linux-xfs@vger.kernel.org Subject: [PATCH 5/5] xfs: avoid unnecessary waits in xfs_log_force_lsn() Date: Thu, 22 Jul 2021 11:53:35 +1000 Message-Id: <20210722015335.3063274-6-david@fromorbit.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210722015335.3063274-1-david@fromorbit.com> References: <20210722015335.3063274-1-david@fromorbit.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.3 cv=F8MpiZpN c=1 sm=1 tr=0 a=hdaoRb6WoHYrV466vVKEyw==:117 a=hdaoRb6WoHYrV466vVKEyw==:17 a=e_q4qTt1xDgA:10 a=20KFwNOVAAAA:8 a=wpwPaxZDQMKr-q5_gskA:9 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org From: Dave Chinner Before waiting on a iclog in xfs_log_force_lsn(), we don't check to see if the iclog has already been completed and the contents on stable storage. We check for completed iclogs in xfs_log_force(), so we should do the same thing for xfs_log_force_lsn(). This fixed some random up-to-30s pauses seen in unmounting filesystems in some tests. A log force ends up waiting on completed iclog, and that doesn't then get flushed (and hence the log force get completed) until the background log worker issues a log force that flushes the iclog in question. Then the unmount unblocks and continues. Signed-off-by: Dave Chinner --- fs/xfs/xfs_log.c | 47 +++++++++++++++++++++++++++++++++++++---------- 1 file changed, 37 insertions(+), 10 deletions(-) diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index 7da42c0656e3..baee9871cd65 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -3147,6 +3147,35 @@ xlog_state_switch_iclogs( log->l_iclog = iclog->ic_next; } +/* + * Force the iclog to disk and check if the iclog has been completed before + * xlog_force_iclog() returns. This can happen on synchronous (e.g. + * pmem) or fast async storage because we drop the icloglock to issue the IO. + * If completion has already occurred, tell the caller so that it can avoid an + * unnecessary wait on the iclog. + */ +static int +xlog_force_and_check_iclog( + struct xlog_in_core *iclog, + bool *completed) +{ + xfs_lsn_t lsn = be64_to_cpu(iclog->ic_header.h_lsn); + int error; + + *completed = false; + error = xlog_force_iclog(iclog); + if (error) + return error; + + /* + * If the iclog has already been completed and reused the header LSN + * will have been rewritten by completion + */ + if (be64_to_cpu(iclog->ic_header.h_lsn) != lsn) + *completed = true; + return 0; +} + /* * Write out all data in the in-core log as of this exact moment in time. * @@ -3181,7 +3210,6 @@ xfs_log_force( { struct xlog *log = mp->m_log; struct xlog_in_core *iclog; - xfs_lsn_t lsn; XFS_STATS_INC(mp, xs_log_force); trace_xfs_log_force(mp, 0, _RET_IP_); @@ -3210,15 +3238,11 @@ xfs_log_force( } else if (iclog->ic_state == XLOG_STATE_ACTIVE) { if (atomic_read(&iclog->ic_refcnt) == 0) { /* We have exclusive access to this iclog. */ - lsn = be64_to_cpu(iclog->ic_header.h_lsn); - if (xlog_force_iclog(iclog)) + bool completed; + + if (xlog_force_and_check_iclog(iclog, &completed)) goto out_error; - /* - * If the iclog has already been completed and reused - * the header LSN will have been rewritten. Don't wait - * on these iclogs that contain future modifications. - */ - if (be64_to_cpu(iclog->ic_header.h_lsn) != lsn) + if (completed) goto out_unlock; } else { /* @@ -3258,6 +3282,7 @@ xlog_force_lsn( bool already_slept) { struct xlog_in_core *iclog; + bool completed; spin_lock(&log->l_icloglock); iclog = log->l_iclog; @@ -3295,10 +3320,12 @@ xlog_force_lsn( &log->l_icloglock); return -EAGAIN; } - if (xlog_force_iclog(iclog)) + if (xlog_force_and_check_iclog(iclog, &completed)) goto out_error; if (log_flushed) *log_flushed = 1; + if (completed) + goto out_unlock; break; case XLOG_STATE_WANT_SYNC: /* -- 2.31.1