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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 DB81FC55189 for ; Wed, 22 Apr 2020 11:03:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B7B012076E for ; Wed, 22 Apr 2020 11:03:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587553422; bh=QKMcaEVYytCyf1hqsXW7L2gDGVX8IfnY0Ttlq6wcg+E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=TXTu6e/M+THOhSy9yaBRcdbc1v527UeWhoNJ/yuXvN4B8GXps2G+ZIEhHOz11oESD HjDppa07ms3euZC5rBPVbSaVPLRdh7XKxaf/Z6ivJfaSFBMbnBMcgTbRh6GnIKD0wQ Fo6Zbw8t1EhoAYqaoON7OFIFdjwT12q086Fvp9Go= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732496AbgDVLDl (ORCPT ); Wed, 22 Apr 2020 07:03:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:46292 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726478AbgDVJ7i (ORCPT ); Wed, 22 Apr 2020 05:59:38 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 433642076E; Wed, 22 Apr 2020 09:59:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587549577; bh=QKMcaEVYytCyf1hqsXW7L2gDGVX8IfnY0Ttlq6wcg+E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NK9czYVYaZ4YexBI9IQp/ROnMU/dELh1vgbI52k82u3TquggE0xCbHrI/3UGDMUVS bBLxBL04m6GTPL7JkwmDSy7/ddiCOdrB8Wmu1QDQyEb7ZA2zfayYe8ngvRyIXF6ehS JWcbI16c+pPYxjgQhwVmQ2RZg8OwBARAyhjvDeX0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bob Peterson , Andreas Gruenbacher , Sasha Levin Subject: [PATCH 4.4 008/100] gfs2: Dont demote a glock until its revokes are written Date: Wed, 22 Apr 2020 11:55:38 +0200 Message-Id: <20200422095024.209082810@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200422095022.476101261@linuxfoundation.org> References: <20200422095022.476101261@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Bob Peterson [ Upstream commit df5db5f9ee112e76b5202fbc331f990a0fc316d6 ] Before this patch, run_queue would demote glocks based on whether there are any more holders. But if the glock has pending revokes that haven't been written to the media, giving up the glock might end in file system corruption if the revokes never get written due to io errors, node crashes and fences, etc. In that case, another node will replay the metadata blocks associated with the glock, but because the revoke was never written, it could replay that block even though the glock had since been granted to another node who might have made changes. This patch changes the logic in run_queue so that it never demotes a glock until its count of pending revokes reaches zero. Signed-off-by: Bob Peterson Reviewed-by: Andreas Gruenbacher Signed-off-by: Sasha Levin --- fs/gfs2/glock.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index 1eb737c466ddc..f80ffccb03160 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -541,6 +541,9 @@ __acquires(&gl->gl_lockref.lock) goto out_unlock; if (nonblock) goto out_sched; + smp_mb(); + if (atomic_read(&gl->gl_revokes) != 0) + goto out_sched; set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags); GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE); gl->gl_target = gl->gl_demote_state; -- 2.20.1