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 DF43EC433DF for ; Tue, 26 May 2020 19:13:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B5D4520B80 for ; Tue, 26 May 2020 19:13:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590520380; bh=9WfN8TrM9dUs8IFLzvFT0ojQuTob51q7V/MhlfmIgPM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=XqeT4X59bRoVrc5MMRYGoZh7SKqBxwl1PM7f9im8//jJnmI9ysIQYIjiDCp+41mqS zyYUmC2S1IoSvAV03r8O+uREKX4kkNwvsLZsg6ugVLw1sVTGsOfsB6er9q/Fn+upAh rVVt7BNJHOmrau55cU/64CZ3ZNiAlVIjUmcZMtyY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404185AbgEZTNA (ORCPT ); Tue, 26 May 2020 15:13:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:40188 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389413AbgEZTKx (ORCPT ); Tue, 26 May 2020 15:10:53 -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 26EA4208A7; Tue, 26 May 2020 19:10:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590520252; bh=9WfN8TrM9dUs8IFLzvFT0ojQuTob51q7V/MhlfmIgPM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=e1XkJ9vKUxs/y//L4ANLVdW9+13oaAN7GkIFWydDP/DmnJeDXAZ6xxXTBeKhScFGo mubMl248wYJRoOM2I8M2c5mZWo/VLD7IzKTi4S6zjG/FE8Ia0u+9NOOwMvVzOIiH8/ mILDW5yXw/WORs7bxlrJvx8QwFtIJhaA2ri6iLGA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bob Peterson , Sasha Levin Subject: [PATCH 5.4 080/111] Revert "gfs2: Dont demote a glock until its revokes are written" Date: Tue, 26 May 2020 20:53:38 +0200 Message-Id: <20200526183940.474966795@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200526183932.245016380@linuxfoundation.org> References: <20200526183932.245016380@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 b14c94908b1b884276a6608dea3d0b1b510338b7 ] This reverts commit df5db5f9ee112e76b5202fbc331f990a0fc316d6. This patch fixes a regression: patch df5db5f9ee112 allowed function run_queue() to bypass its call to do_xmote() if revokes were queued for the glock. That's wrong because its call to do_xmote() is what is responsible for calling the go_sync() glops functions to sync both the ail list and any revokes queued for it. By bypassing the call, gfs2 could get into a stand-off where the glock could not be demoted until its revokes are written back, but the revokes would not be written back because do_xmote() was never called. It "sort of" works, however, because there are other mechanisms like the log flush daemon (logd) that can sync the ail items and revokes, if it deems it necessary. The problem is: without file system pressure, it might never deem it necessary. Signed-off-by: Bob Peterson Signed-off-by: Sasha Levin --- fs/gfs2/glock.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index 21820a5b388f..0290a22ebccf 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -639,9 +639,6 @@ __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; -- 2.25.1