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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 12F28C432C0 for ; Wed, 20 Nov 2019 15:42:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D90A020709 for ; Wed, 20 Nov 2019 15:42:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730367AbfKTPmR (ORCPT ); Wed, 20 Nov 2019 10:42:17 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:53016 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731850AbfKTPkU (ORCPT ); Wed, 20 Nov 2019 10:40:20 -0500 Received: from [167.98.27.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iXS5X-0004d4-GA; Wed, 20 Nov 2019 15:40:15 +0000 Received: from ben by deadeye with local (Exim 4.93-RC1) (envelope-from ) id 1iXS5V-0004Oj-Ll; Wed, 20 Nov 2019 15:40:13 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Dan Williams" , "Song Liu" , "Nigel Croxon" Date: Wed, 20 Nov 2019 15:38:30 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 80/83] md/raid: raid5 preserve the writeback action after the parity check In-Reply-To: X-SA-Exim-Connect-IP: 167.98.27.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.78-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Nigel Croxon commit b2176a1dfb518d870ee073445d27055fea64dfb8 upstream. The problem is that any 'uptodate' vs 'disks' check is not precise in this path. Put a "WARN_ON(!test_bit(R5_UPTODATE, &dev->flags)" on the device that might try to kick off writes and then skip the action. Better to prevent the raid driver from taking unexpected action *and* keep the system alive vs killing the machine with BUG_ON. Note: fixed warning reported by kbuild test robot Signed-off-by: Dan Williams Signed-off-by: Nigel Croxon Signed-off-by: Song Liu Signed-off-by: Ben Hutchings --- drivers/md/raid5.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -3385,7 +3385,7 @@ static void handle_parity_checks6(struct /* now write out any block on a failed drive, * or P or Q if they were recomputed */ - BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */ + dev = NULL; if (s->failed == 2) { dev = &sh->dev[s->failed_num[1]]; s->locked++; @@ -3410,6 +3410,14 @@ static void handle_parity_checks6(struct set_bit(R5_LOCKED, &dev->flags); set_bit(R5_Wantwrite, &dev->flags); } + if (WARN_ONCE(dev && !test_bit(R5_UPTODATE, &dev->flags), + "%s: disk%td not up to date\n", + mdname(conf->mddev), + dev - (struct r5dev *) &sh->dev)) { + clear_bit(R5_LOCKED, &dev->flags); + clear_bit(R5_Wantwrite, &dev->flags); + s->locked--; + } clear_bit(STRIPE_DEGRADED, &sh->state); set_bit(STRIPE_INSYNC, &sh->state);