From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756279AbaF3QBg (ORCPT ); Mon, 30 Jun 2014 12:01:36 -0400 Received: from zimbra13.linbit.com ([212.69.166.240]:50033 "EHLO zimbra13.linbit.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754500AbaF3PxM (ORCPT ); Mon, 30 Jun 2014 11:53:12 -0400 From: Philipp Reisner To: linux-kernel@vger.kernel.org, Jens Axboe Cc: drbd-dev@lists.linbit.com Subject: [PATCH 08/18] drbd: fix a race stopping the worker thread Date: Mon, 30 Jun 2014 17:52:57 +0200 Message-Id: <1404143587-24344-9-git-send-email-philipp.reisner@linbit.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1404143587-24344-1-git-send-email-philipp.reisner@linbit.com> References: <1404143587-24344-1-git-send-email-philipp.reisner@linbit.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lars Ellenberg We may implicitly call drbd_send() from inside wait_for_work(), via maybe_send_barrier(). If the "stop" signal was send just before that, drbd_send() would call flush_signals(), and we would run an unbounded schedule() afterwards. Fix: check for thread_state == RUNNING before we schedule() Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- drivers/block/drbd/drbd_worker.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c index 5915885..47bc840 100644 --- a/drivers/block/drbd/drbd_worker.c +++ b/drivers/block/drbd/drbd_worker.c @@ -1930,6 +1930,9 @@ static void wait_for_work(struct drbd_connection *connection, struct list_head * if (send_barrier) maybe_send_barrier(connection, connection->send.current_epoch_nr + 1); + /* drbd_send() may have called flush_signals() */ + if (get_t_state(&connection->worker) != RUNNING) + break; schedule(); /* may be woken up for other things but new work, too, * e.g. if the current epoch got closed. -- 1.9.1