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=-9.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,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 BCE8FECDE46 for ; Thu, 25 Oct 2018 14:20:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7A0D82147A for ; Thu, 25 Oct 2018 14:20:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="ckeHRf5C" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7A0D82147A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.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 S1731043AbeJYWxZ (ORCPT ); Thu, 25 Oct 2018 18:53:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:35902 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730997AbeJYWxX (ORCPT ); Thu, 25 Oct 2018 18:53:23 -0400 Received: from sasha-vm.mshome.net (unknown [167.98.65.38]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BAA1F20848; Thu, 25 Oct 2018 14:20:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1540477225; bh=0sQ+f8bVoklB/YfLYu6NQqSR0Jjp1YogOt9E1kNBgAY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ckeHRf5CyWs8Ed86CeF1S+fKQvu5pYGiO7sFx4xO+fBECSqGs4m+cVzhMfp7/qHHw adDtYRjK+EFmZcinUO60k8rrQ2q5dVEB6gI2BYr3ONnC8T0IBHfXFkkMdNn1krc2WK /WEQmC8pQFNHWgUhwUnqPVsIhij2rWKu9aEy84sk= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Junichi Nomura , Mike Snitzer , Sasha Levin Subject: [PATCH AUTOSEL 3.18 60/98] dm: fix AB-BA deadlock in __dm_destroy() Date: Thu, 25 Oct 2018 10:18:15 -0400 Message-Id: <20181025141853.214051-60-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181025141853.214051-1-sashal@kernel.org> References: <20181025141853.214051-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Junichi Nomura [ Upstream commit 2a708cff93f1845b9239bc7d6310aef54e716c6a ] __dm_destroy() takes io_barrier SRCU lock (dm_get_live_table) and suspend_lock in reverse order. Doing so can cause AB-BA deadlock: __dm_destroy dm_swap_table --------------------------------------------------- mutex_lock(suspend_lock) dm_get_live_table() srcu_read_lock(io_barrier) dm_sync_table() synchronize_srcu(io_barrier) .. waiting for dm_put_live_table() mutex_lock(suspend_lock) .. waiting for suspend_lock Fix this by taking the locks in proper order. Signed-off-by: Jun'ichi Nomura Fixes: ab7c7bb6f4ab ("dm: hold suspend_lock while suspending device during device deletion") Acked-by: Mikulas Patocka Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin --- drivers/md/dm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 1d08dc6fa0b5..00c86ff3c721 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -2599,14 +2599,14 @@ static void __dm_destroy(struct mapped_device *md, bool wait) * do not race with internal suspend. */ mutex_lock(&md->suspend_lock); + map = dm_get_live_table(md, &srcu_idx); if (!dm_suspended_md(md)) { dm_table_presuspend_targets(map); dm_table_postsuspend_targets(map); } - mutex_unlock(&md->suspend_lock); - /* dm_put_live_table must be before msleep, otherwise deadlock is possible */ dm_put_live_table(md, srcu_idx); + mutex_unlock(&md->suspend_lock); /* * Rare, but there may be I/O requests still going to complete, -- 2.17.1