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=-15.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 72A4FC433DB for ; Thu, 21 Jan 2021 17:19:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 36E2E23A57 for ; Thu, 21 Jan 2021 17:19:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388719AbhAURTQ (ORCPT ); Thu, 21 Jan 2021 12:19:16 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:21768 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388415AbhAURSp (ORCPT ); Thu, 21 Jan 2021 12:18:45 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611249438; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=/9Yf0tNkOs0Ufdc2O09r9i+VpSs7YIdRvxnWSwiCEYY=; b=UY/2vkYozjgo6BhdmzZ9hVNME82khwetpFzWo/enFteBaHn1aXP3RPIxppDb2uIzWkP0mk T0OheRww70iHYBPTXzZezJPpEov64ZTRoxDZ8zrX7wIUfeovTXVhfjatwuIfSz3rGLe7vM JdnZmjtTm4cLrRwEZcJfmWk16mmU3yk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-173-jnJeN-YfMyK2DttsAU0v4A-1; Thu, 21 Jan 2021 12:17:15 -0500 X-MC-Unique: jnJeN-YfMyK2DttsAU0v4A-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7C1DA18C89DE; Thu, 21 Jan 2021 17:17:14 +0000 (UTC) Received: from redhat.com (ovpn-113-255.rdu2.redhat.com [10.10.113.255]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 084435D9C6; Thu, 21 Jan 2021 17:17:13 +0000 (UTC) Date: Thu, 21 Jan 2021 11:17:12 -0600 From: Bill O'Donnell To: "Darrick J. Wong" Cc: Brian Foster , linux-xfs@vger.kernel.org Subject: Re: [PATCH 1/9] xfs: sync lazy sb accounting on quiesce of read-only mounts Message-ID: <20210121171712.GA1372309@redhat.com> References: <20210106174127.805660-1-bfoster@redhat.com> <20210106174127.805660-2-bfoster@redhat.com> <20210121150827.GA1118971@redhat.com> <20210121164933.GA1282159@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210121164933.GA1282159@magnolia> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Thu, Jan 21, 2021 at 08:49:33AM -0800, Darrick J. Wong wrote: > On Thu, Jan 21, 2021 at 09:08:27AM -0600, Bill O'Donnell wrote: > > On Wed, Jan 06, 2021 at 12:41:19PM -0500, Brian Foster wrote: > > > xfs_log_sbcount() syncs the superblock specifically to accumulate > > > the in-core percpu superblock counters and commit them to disk. This > > > is required to maintain filesystem consistency across quiesce > > > (freeze, read-only mount/remount) or unmount when lazy superblock > > > accounting is enabled because individual transactions do not update > > > the superblock directly. > > > > > > This mechanism works as expected for writable mounts, but > > > xfs_log_sbcount() skips the update for read-only mounts. Read-only > > > mounts otherwise still allow log recovery and write out an unmount > > > record during log quiesce. If a read-only mount performs log > > > recovery, it can modify the in-core superblock counters and write an > > > unmount record when the filesystem unmounts without ever syncing the > > > in-core counters. This leaves the filesystem with a clean log but in > > > an inconsistent state with regard to lazy sb counters. > > > > > > Update xfs_log_sbcount() to use the same logic > > > xfs_log_unmount_write() uses to determine when to write an unmount > > > record. We can drop the freeze state check because the update is > > > already allowed during the freezing process and no context calls > > > this function on an already frozen fs. This ensures that lazy > > > accounting is always synced before the log is cleaned. Refactor this > > > logic into a new helper to distinguish between a writable filesystem > > > and a writable log. Specifically, the log is writable unless the > > > filesystem is mounted with the norecovery mount option, the > > > underlying log device is read-only, or the filesystem is shutdown. > > > > > > Signed-off-by: Brian Foster > > > Reviewed-by: Gao Xiang > > > > works for me. > > Reviewed-by: Bill O'Donnell > > Does this also apply to the v3 series that Brian just sent? I only used this patch 1/9, as that was all I was focusing on. > > --D > > > > > > --- > > > fs/xfs/xfs_log.c | 28 ++++++++++++++++++++-------- > > > fs/xfs/xfs_log.h | 1 + > > > fs/xfs/xfs_mount.c | 3 +-- > > > 3 files changed, 22 insertions(+), 10 deletions(-) > > > > > > diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c > > > index fa2d05e65ff1..b445e63cbc3c 100644 > > > --- a/fs/xfs/xfs_log.c > > > +++ b/fs/xfs/xfs_log.c > > > @@ -347,6 +347,25 @@ xlog_tic_add_region(xlog_ticket_t *tic, uint len, uint type) > > > tic->t_res_num++; > > > } > > > > > > +bool > > > +xfs_log_writable( > > > + struct xfs_mount *mp) > > > +{ > > > + /* > > > + * Never write to the log on norecovery mounts, if the block device is > > > + * read-only, or if the filesystem is shutdown. Read-only mounts still > > > + * allow internal writes for log recovery and unmount purposes, so don't > > > + * restrict that case here. > > > + */ > > > + if (mp->m_flags & XFS_MOUNT_NORECOVERY) > > > + return false; > > > + if (xfs_readonly_buftarg(mp->m_log->l_targ)) > > > + return false; > > > + if (XFS_FORCED_SHUTDOWN(mp)) > > > + return false; > > > + return true; > > > +} > > > + > > > /* > > > * Replenish the byte reservation required by moving the grant write head. > > > */ > > > @@ -886,15 +905,8 @@ xfs_log_unmount_write( > > > { > > > struct xlog *log = mp->m_log; > > > > > > - /* > > > - * Don't write out unmount record on norecovery mounts or ro devices. > > > - * Or, if we are doing a forced umount (typically because of IO errors). > > > - */ > > > - if (mp->m_flags & XFS_MOUNT_NORECOVERY || > > > - xfs_readonly_buftarg(log->l_targ)) { > > > - ASSERT(mp->m_flags & XFS_MOUNT_RDONLY); > > > + if (!xfs_log_writable(mp)) > > > return; > > > - } > > > > > > xfs_log_force(mp, XFS_LOG_SYNC); > > > > > > diff --git a/fs/xfs/xfs_log.h b/fs/xfs/xfs_log.h > > > index 58c3fcbec94a..98c913da7587 100644 > > > --- a/fs/xfs/xfs_log.h > > > +++ b/fs/xfs/xfs_log.h > > > @@ -127,6 +127,7 @@ int xfs_log_reserve(struct xfs_mount *mp, > > > int xfs_log_regrant(struct xfs_mount *mp, struct xlog_ticket *tic); > > > void xfs_log_unmount(struct xfs_mount *mp); > > > int xfs_log_force_umount(struct xfs_mount *mp, int logerror); > > > +bool xfs_log_writable(struct xfs_mount *mp); > > > > > > struct xlog_ticket *xfs_log_ticket_get(struct xlog_ticket *ticket); > > > void xfs_log_ticket_put(struct xlog_ticket *ticket); > > > diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c > > > index 7110507a2b6b..a62b8a574409 100644 > > > --- a/fs/xfs/xfs_mount.c > > > +++ b/fs/xfs/xfs_mount.c > > > @@ -1176,8 +1176,7 @@ xfs_fs_writable( > > > int > > > xfs_log_sbcount(xfs_mount_t *mp) > > > { > > > - /* allow this to proceed during the freeze sequence... */ > > > - if (!xfs_fs_writable(mp, SB_FREEZE_COMPLETE)) > > > + if (!xfs_log_writable(mp)) > > > return 0; > > > > > > /* > > > -- > > > 2.26.2 > > > > > >