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=-16.0 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, 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 05857C4332B for ; Tue, 12 Jan 2021 15:35:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D1E7323132 for ; Tue, 12 Jan 2021 15:35:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387648AbhALPfU (ORCPT ); Tue, 12 Jan 2021 10:35:20 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:56874 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390169AbhALPfT (ORCPT ); Tue, 12 Jan 2021 10:35:19 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1610465632; 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=d+8am/m3tezG92qp7H/Fxn99xKqSmRQsQyWg2ExJTpc=; b=KBcaWRBCLf/SkI1eySY55TXjktotpZ4tCL4prcVqIWekYe6SBxeEUhRUGFMcSR4bSXLHqK Pc3i3E+Ouh+1bB/SY3QXufhdIpHAWKndZMdnwipVS+Cx9g1ugPc8/LLd08oXdItaN1SQzf gzEfxKPNNDRL2LSHLEQ+8YFvqBLN91I= 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-342-yNZgbp2vPrGpxqczeEcHNQ-1; Tue, 12 Jan 2021 10:33:51 -0500 X-MC-Unique: yNZgbp2vPrGpxqczeEcHNQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0C3A9180E461; Tue, 12 Jan 2021 15:33:50 +0000 (UTC) Received: from bfoster (ovpn-114-23.rdu2.redhat.com [10.10.114.23]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 996C01F0; Tue, 12 Jan 2021 15:33:49 +0000 (UTC) Date: Tue, 12 Jan 2021 10:33:47 -0500 From: Brian Foster To: Christoph Hellwig Cc: linux-xfs@vger.kernel.org Subject: Re: [PATCH 1/2] xfs: refactor xfs_file_fsync Message-ID: <20210112153347.GB1137163@bfoster> References: <20210111161544.1414409-1-hch@lst.de> <20210111161544.1414409-2-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210111161544.1414409-2-hch@lst.de> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Mon, Jan 11, 2021 at 05:15:43PM +0100, Christoph Hellwig wrote: > Factor out the log syncing logic into two helpers to make the code easier > to read and more maintainable. > > Signed-off-by: Christoph Hellwig > --- Looks fine, though it might be nice to find some commonality with xfs_log_force_inode(): Reviewed-by: Brian Foster > fs/xfs/xfs_file.c | 81 +++++++++++++++++++++++++++++------------------ > 1 file changed, 50 insertions(+), 31 deletions(-) > > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c > index 5b0f93f738372d..414d856e2e755a 100644 > --- a/fs/xfs/xfs_file.c > +++ b/fs/xfs/xfs_file.c > @@ -118,6 +118,54 @@ xfs_dir_fsync( > return xfs_log_force_inode(ip); > } > > +static xfs_lsn_t > +xfs_fsync_lsn( > + struct xfs_inode *ip, > + bool datasync) > +{ > + if (!xfs_ipincount(ip)) > + return 0; > + if (datasync && !(ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP)) > + return 0; > + return ip->i_itemp->ili_last_lsn; > +} > + > +/* > + * All metadata updates are logged, which means that we just have to flush the > + * log up to the latest LSN that touched the inode. > + * > + * If we have concurrent fsync/fdatasync() calls, we need them to all block on > + * the log force before we clear the ili_fsync_fields field. This ensures that > + * we don't get a racing sync operation that does not wait for the metadata to > + * hit the journal before returning. If we race with clearing ili_fsync_fields, > + * then all that will happen is the log force will do nothing as the lsn will > + * already be on disk. We can't race with setting ili_fsync_fields because that > + * is done under XFS_ILOCK_EXCL, and that can't happen because we hold the lock > + * shared until after the ili_fsync_fields is cleared. > + */ > +static int > +xfs_fsync_flush_log( > + struct xfs_inode *ip, > + bool datasync, > + int *log_flushed) > +{ > + int error = 0; > + xfs_lsn_t lsn; > + > + xfs_ilock(ip, XFS_ILOCK_SHARED); > + lsn = xfs_fsync_lsn(ip, datasync); > + if (lsn) { > + error = xfs_log_force_lsn(ip->i_mount, lsn, XFS_LOG_SYNC, > + log_flushed); > + > + spin_lock(&ip->i_itemp->ili_lock); > + ip->i_itemp->ili_fsync_fields = 0; > + spin_unlock(&ip->i_itemp->ili_lock); > + } > + xfs_iunlock(ip, XFS_ILOCK_SHARED); > + return error; > +} > + > STATIC int > xfs_file_fsync( > struct file *file, > @@ -125,13 +173,10 @@ xfs_file_fsync( > loff_t end, > int datasync) > { > - struct inode *inode = file->f_mapping->host; > - struct xfs_inode *ip = XFS_I(inode); > - struct xfs_inode_log_item *iip = ip->i_itemp; > + struct xfs_inode *ip = XFS_I(file->f_mapping->host); > struct xfs_mount *mp = ip->i_mount; > int error = 0; > int log_flushed = 0; > - xfs_lsn_t lsn = 0; > > trace_xfs_file_fsync(ip); > > @@ -155,33 +200,7 @@ xfs_file_fsync( > else if (mp->m_logdev_targp != mp->m_ddev_targp) > xfs_blkdev_issue_flush(mp->m_ddev_targp); > > - /* > - * All metadata updates are logged, which means that we just have to > - * flush the log up to the latest LSN that touched the inode. If we have > - * concurrent fsync/fdatasync() calls, we need them to all block on the > - * log force before we clear the ili_fsync_fields field. This ensures > - * that we don't get a racing sync operation that does not wait for the > - * metadata to hit the journal before returning. If we race with > - * clearing the ili_fsync_fields, then all that will happen is the log > - * force will do nothing as the lsn will already be on disk. We can't > - * race with setting ili_fsync_fields because that is done under > - * XFS_ILOCK_EXCL, and that can't happen because we hold the lock shared > - * until after the ili_fsync_fields is cleared. > - */ > - xfs_ilock(ip, XFS_ILOCK_SHARED); > - if (xfs_ipincount(ip)) { > - if (!datasync || > - (iip->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP)) > - lsn = iip->ili_last_lsn; > - } > - > - if (lsn) { > - error = xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, &log_flushed); > - spin_lock(&iip->ili_lock); > - iip->ili_fsync_fields = 0; > - spin_unlock(&iip->ili_lock); > - } > - xfs_iunlock(ip, XFS_ILOCK_SHARED); > + error = xfs_fsync_flush_log(ip, datasync, &log_flushed); > > /* > * If we only have a single device, and the log force about was > -- > 2.29.2 >