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 90869C2BB55 for ; Thu, 16 Apr 2020 16:02:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 62F6A217D8 for ; Thu, 16 Apr 2020 16:02:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587052943; bh=JVBQ4mJiai4SFGqM9hpLiYzHjPgT+kxE4i+UwDn0DQY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Fg7fxSQhlW14k2zGhT1QsSYMJ7WLo5E7sRI4sRcdmTTNYdkvi6q4hVuuXej7IcL0Z mJPDb8YQLclajUfHwKtsyCYlKEx1VjoGTMDfc+ApodaVpxqAbVIPg090HW2EYSEIJS 4mex5KFjg8OtYgCAqCXObT6j9mnGG0G65fDBG7o0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2410709AbgDPQCW (ORCPT ); Thu, 16 Apr 2020 12:02:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:35036 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2895308AbgDPN0s (ORCPT ); Thu, 16 Apr 2020 09:26:48 -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 914DA217D8; Thu, 16 Apr 2020 13:26:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587043608; bh=JVBQ4mJiai4SFGqM9hpLiYzHjPgT+kxE4i+UwDn0DQY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fRgvZBD+SZMr8T9OcR7ZFwH47w0Iq1vHVKOSYOSwo+y7LlqGncXSQkq3s/wkyh8gw eSOmyw4OPXsdMxm3nWbJ0F9S+6PB2czQoV99gQG1kd/s8hEkrO4UfoiFs3RaOQgTcr W7fBp8B6qqb5l+Vro+NqgambpRf20tLqxO79wJUs= 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 4.19 026/146] gfs2: Dont demote a glock until its revokes are written Date: Thu, 16 Apr 2020 15:22:47 +0200 Message-Id: <20200416131246.024198134@linuxfoundation.org> X-Mailer: git-send-email 2.26.1 In-Reply-To: <20200416131242.353444678@linuxfoundation.org> References: <20200416131242.353444678@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 ccdd8c821abd7..f8a5eef3d014b 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -636,6 +636,9 @@ __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