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 C744AC2BB55 for ; Thu, 16 Apr 2020 15:46:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A18F622244 for ; Thu, 16 Apr 2020 15:46:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587052017; bh=Ip3KPfQ0SRI7lGjO5hzhDrLGc6+mzqfsJbkAD61X9t0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=hXwzAbvOd1bjoifoY7Kqf2gmwSUXkmVkPxTwi/aQLDRgNYI75efjmkc6jspvMqQSo pekRxN/TuyGWRxaB98fEYPufyKDBU2NCfx1YPFXaryzc4ZYs3Awn97BHKMXX6X73Oe NRgW8L8xmOWks3LJMGTrBWDVyD3t0G1mSLO8MeYo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2896719AbgDPPqs (ORCPT ); Thu, 16 Apr 2020 11:46:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:45754 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2896320AbgDPNeP (ORCPT ); Thu, 16 Apr 2020 09:34:15 -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 5E235221EB; Thu, 16 Apr 2020 13:34:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587044054; bh=Ip3KPfQ0SRI7lGjO5hzhDrLGc6+mzqfsJbkAD61X9t0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sRNzn49X7Tbc/yLjkz5mSg/w0lM1sFmU78R8lO2/UnEJ8TegX9AQcpXD3s4IX9Kea Q6KCpVTJYI6zTWIoYnm8TgYvif0qDyuv+WKNywKxolAIXtHnaZ0fLUjzTr8X19JKPT W9pBmAhuYAmq/dcQuOB9/cM1YT4yVaUCi8fDdXRI= 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 5.5 061/257] gfs2: Dont demote a glock until its revokes are written Date: Thu, 16 Apr 2020 15:21:52 +0200 Message-Id: <20200416131333.575756859@linuxfoundation.org> X-Mailer: git-send-email 2.26.1 In-Reply-To: <20200416131325.891903893@linuxfoundation.org> References: <20200416131325.891903893@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 b7123de7c180e..a5e145d4e9916 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