From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S968673AbcA0V4L (ORCPT ); Wed, 27 Jan 2016 16:56:11 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:42606 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754928AbcA0Ugi (ORCPT ); Wed, 27 Jan 2016 15:36:38 -0500 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Nikolay Borisov , Mike Snitzer , Kamal Mostafa Subject: [PATCH 4.2.y-ckt 036/268] dm thin: fix race condition when destroying thin pool workqueue Date: Wed, 27 Jan 2016 12:31:37 -0800 Message-Id: <1453926929-17663-37-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1453926929-17663-1-git-send-email-kamal@canonical.com> References: <1453926929-17663-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 4.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.2.8-ckt3 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ 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: Kamal Mostafa --- drivers/md/dm-thin.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index 3efdddb..d6602ed 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -3507,8 +3507,8 @@ static void pool_postsuspend(struct dm_target *ti) 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); } -- 1.9.1