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 97233C55189 for ; Wed, 22 Apr 2020 10:58:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6811920775 for ; Wed, 22 Apr 2020 10:58:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587553116; bh=69OB8wXKOxwKkXELlIwaMk0gi4EzRqKoBvI16VoEw8s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0dIRNFFGUPCwAus9DFeMg1Zb9Ro6QdtA5UHTPX5CrSInrPQ+RlzRDxX8GkVcrrnaM 1ZWH3MHRvt9XWmRD0bOABemcD5LOMQLmmSbxVzCPhnIunmYKCmUx1wSxnW9x/hhhhr B93rjBSNdsiQUM8QI7XztZKAGObMre4BjDcv1V8k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732279AbgDVK6f (ORCPT ); Wed, 22 Apr 2020 06:58:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:54064 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727898AbgDVKD5 (ORCPT ); Wed, 22 Apr 2020 06:03:57 -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 0A46120784; Wed, 22 Apr 2020 10:03:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587549836; bh=69OB8wXKOxwKkXELlIwaMk0gi4EzRqKoBvI16VoEw8s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nrzKVCLNaW72WGqdY5OwNqNBZ67uYDTsy7/fkGrpcKvLDQGbAZ2zGLWYh3wp/H8hH oDmny2orozccCWDHKYAF8PjgXA3GRHHhif0hFN3yuCGxhc1Vx773sHrAvZdOV9oeqb AHv+BtrArl/4eVwrKe2h4BIaOWrvYpg8EGAdm2Bs= 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 4.9 009/125] gfs2: Dont demote a glock until its revokes are written Date: Wed, 22 Apr 2020 11:55:26 +0200 Message-Id: <20200422095034.472542332@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200422095032.909124119@linuxfoundation.org> References: <20200422095032.909124119@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 efd44d5645d83..adc1a97cfe96d 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -548,6 +548,9 @@ __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