Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755560AbcCAXza (ORCPT ); Tue, 1 Mar 2016 18:55:30 -0500 Received: from mail177-1.suw61.mandrillapp.com ([198.2.177.1]:23733 "EHLO mail177-1.suw61.mandrillapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753803AbcCAXzO (ORCPT ); Tue, 1 Mar 2016 18:55:14 -0500 From: Greg Kroah-Hartman Subject: [PATCH 4.4 070/342] dm thin: fix race condition when destroying thin pool workqueue X-Mailer: git-send-email 2.7.2 To: Cc: Greg Kroah-Hartman , , Nikolay Borisov , Mike Snitzer Message-Id: <20160301234530.263866834@linuxfoundation.org> In-Reply-To: <20160301234527.990448862@linuxfoundation.org> References: <20160301234527.990448862@linuxfoundation.org> X-Report-Abuse: Please forward a copy of this message, including all headers, to abuse@mandrill.com X-Report-Abuse: You can also report abuse here: http://mandrillapp.com/contact/abuse?id=30481620.44501ad07cb949bd867f44e74499333f X-Mandrill-User: md_30481620 Date: Tue, 01 Mar 2016 23:54:07 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1404 Lines: 38 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nikolay Borisov commit 18d03e8c25f173f4107a40d0b8c24defb6ed69f3 upstream. When a thin pool is being destroyed delayed work items are cancelled using cancel_delayed_work(), which doesn't guarantee that on return the delayed item isn't running. This can cause the work item to requeue itself on an already destroyed workqueue. Fix this by using cancel_delayed_work_sync() which guarantees that on return the work item is not running anymore. Fixes: 905e51b39a555 ("dm thin: commit outstanding data every second") Fixes: 85ad643b7e7e5 ("dm thin: add timeout to stop out-of-data-space mode holding IO forever") Signed-off-by: Nikolay Borisov Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-thin.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -3453,8 +3453,8 @@ static void pool_postsuspend(struct dm_t struct pool_c *pt = ti->private; struct pool *pool = pt->pool; - cancel_delayed_work(&pool->waker); - cancel_delayed_work(&pool->no_space_timeout); + cancel_delayed_work_sync(&pool->waker); + cancel_delayed_work_sync(&pool->no_space_timeout); flush_workqueue(pool->wq); (void) commit(pool); }