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 F0103C433E0 for ; Tue, 26 May 2020 19:02:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C162D208A7 for ; Tue, 26 May 2020 19:02:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590519723; bh=NMEBRsZuFeSwo6hyj6E/8Y3EaRKS6l+MKMDuJjdmF6c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=XZt+B2kETtLeunRHoCq5lVlFA0ko7F36SLfWDLIRMPvt8UNatzCmbl0rh9Bx/nCfy 96W10Hf9eBlsKKqVyUlTw1Bf4RvF490f+b8YukV28KV2Ymwf9g73PdQIioXBro4pGM lmqgzpF4hpwVXUE1Z4GjqVPFJdUY5JPs8RNJWsf0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403821AbgEZTCD (ORCPT ); Tue, 26 May 2020 15:02:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:56608 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390372AbgEZTCA (ORCPT ); Tue, 26 May 2020 15:02:00 -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 C68F620849; Tue, 26 May 2020 19:01:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590519719; bh=NMEBRsZuFeSwo6hyj6E/8Y3EaRKS6l+MKMDuJjdmF6c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YZlg6efFfNouyQveS4vdKa3hCLCrUQkJQ+vi210yHqOsC/jmndcor7bI6gglnTZHW NXA86N0fqtTFevrQ+9kiIVXI6mPGrk8kkYrrACJUpNlufhDFS0OrMJpHEJaaZ2pe1y wBfnPfNUjDkaYCKI9XuOzsShu6yuuiX0oZGOSnFU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bob Peterson , Sasha Levin Subject: [PATCH 4.14 49/59] Revert "gfs2: Dont demote a glock until its revokes are written" Date: Tue, 26 May 2020 20:53:34 +0200 Message-Id: <20200526183922.400590870@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200526183907.123822792@linuxfoundation.org> References: <20200526183907.123822792@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 1e2ff4b32c79..aea1ed0aebd0 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -636,9 +636,6 @@ __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