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=-6.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 8E4D6C677D4 for ; Mon, 8 Oct 2018 18:51:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 54FF52087D for ; Mon, 8 Oct 2018 18:51:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="cbWp3Soe" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 54FF52087D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732441AbeJICFE (ORCPT ); Mon, 8 Oct 2018 22:05:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:55100 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732099AbeJICFE (ORCPT ); Mon, 8 Oct 2018 22:05:04 -0400 Received: from localhost (ip-213-127-77-176.ip.prioritytelecom.net [213.127.77.176]) (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 ED87A2087D; Mon, 8 Oct 2018 18:51:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1539024716; bh=g4EHOwaHPfqBFHJI5i9AB1PZvDWmnbg/QZwdfy/YhAw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cbWp3SoeCmlZjR9S6c8qKlF3SxJ4OBZIS8ZGDGLK5mcrXIDPZqviclHbs5HWGVxm2 bVn20IMCc7BrglbdmRhk1DRQHdLWxzkn2DySElKUv3Af1zzaEIN6Hzt5/rdHIIEeZX lO1/1ICmLGGtC7aqra2N/fsIihc+u6ZQz4ODXB5k= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Heinz Mauelshagen , Mike Snitzer , Sasha Levin Subject: [PATCH 4.18 113/168] dm raid: fix stripe adding reshape deadlock Date: Mon, 8 Oct 2018 20:31:33 +0200 Message-Id: <20181008175624.344860454@linuxfoundation.org> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20181008175620.043587728@linuxfoundation.org> References: <20181008175620.043587728@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review 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 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Heinz Mauelshagen [ Upstream commit 644e2537fdc77baeeefc829524937bca64329f82 ] When initiating a stripe adding reshape, a deadlock between md_stop_writes() waiting for the sync thread to stop and the running sync thread waiting for inactive stripes occurs (this frequently happens on single-core but rarely on multi-core systems). Fix this deadlock by setting MD_RECOVERY_WAIT to have the main MD resynchronization thread worker (md_do_sync()) bail out when initiating the reshape via constructor arguments. Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-raid.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -3869,14 +3869,13 @@ static int rs_start_reshape(struct raid_ struct mddev *mddev = &rs->md; struct md_personality *pers = mddev->pers; + /* Don't allow the sync thread to work until the table gets reloaded. */ + set_bit(MD_RECOVERY_WAIT, &mddev->recovery); + r = rs_setup_reshape(rs); if (r) return r; - /* Need to be resumed to be able to start reshape, recovery is frozen until raid_resume() though */ - if (test_and_clear_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) - mddev_resume(mddev); - /* * Check any reshape constraints enforced by the personalility * @@ -3900,10 +3899,6 @@ static int rs_start_reshape(struct raid_ } } - /* Suspend because a resume will happen in raid_resume() */ - set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags); - mddev_suspend(mddev); - /* * Now reshape got set up, update superblocks to * reflect the fact so that a table reload will