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=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 2EF82C2BB85 for ; Thu, 16 Apr 2020 14:23:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0FA3A2076D for ; Thu, 16 Apr 2020 14:23:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587047032; bh=KWxq6ZrFrO8jPWH9ZCMnZoxwcvM3QWIjNinxvnDkmIE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=1okUqqYl69mtdlP/jP+07S/tGdohxfeaa7Bhb84z5OUNGptaaBeqd+rTUHgI5JHgz 6NNF7wLuYgLtZ2LuFlyZDdoqRgDe1AUm0FarfLWYzImth2dbfxMN3W5hEIf99hoAqX b+tFOJV6o6zZC5PjFaIPX0JuMOzARyBDtpNn4I7E= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2442408AbgDPOTH (ORCPT ); Thu, 16 Apr 2020 10:19:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:40202 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2636312AbgDPNxn (ORCPT ); Thu, 16 Apr 2020 09:53:43 -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 DE4B620732; Thu, 16 Apr 2020 13:53:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587045222; bh=KWxq6ZrFrO8jPWH9ZCMnZoxwcvM3QWIjNinxvnDkmIE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vQMUp9AS/NEdZbbrf1pV9NKwsjqaguD/kYn1hrFJeKVYJV1cdGJmIfU2jX5wezjh/ fC0p1dDbXMYKAmA+00x2lZSh2tgubpGLT/RKMsHeXsk1ZMHdBYIbZiWmCXUDtdHJdH d4s45TXtipmOZ4SOeiMvT+jDFc635oCt5EnYf/Po= 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 5.6 045/254] gfs2: Dont demote a glock until its revokes are written Date: Thu, 16 Apr 2020 15:22:14 +0200 Message-Id: <20200416131331.520541316@linuxfoundation.org> X-Mailer: git-send-email 2.26.1 In-Reply-To: <20200416131325.804095985@linuxfoundation.org> References: <20200416131325.804095985@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 d0eceaff3cea9..19ebc6cd0f2ba 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -645,6 +645,9 @@ __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