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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,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 070FEC76186 for ; Mon, 29 Jul 2019 19:45:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C5DC8205F4 for ; Mon, 29 Jul 2019 19:45:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564429508; bh=pHc7wbZC2CQyPwbypAX1PB3PGUIUAQS/3zqsA9hgQkg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=IPBdPxpTm/CieLpLicGVaS1fcnMl4Pjl8uDcfNVpkqH8k5ASKWPtqXMQVPDIwdyH7 9pFWQVJug+9bHVf2nZ+f+F8Txpf2DvZhGzBH4BN6gOybquMZ2e9KMXty/Q1s/GyQGz aEa9jXfDih6Gii7UEI7EOshRsNECo5s3qxRL0BEs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389907AbfG2TpI (ORCPT ); Mon, 29 Jul 2019 15:45:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:33730 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389827AbfG2TpC (ORCPT ); Mon, 29 Jul 2019 15:45:02 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 0890220C01; Mon, 29 Jul 2019 19:45:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564429501; bh=pHc7wbZC2CQyPwbypAX1PB3PGUIUAQS/3zqsA9hgQkg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xYoYaEXc/ySqtsvWWTmJJ4sZ0zb2bdynSeIQQYNw+WzVfHJa2BNnbAMtKnrxJuBGd Q4rmIlEfS5BvQis6BjB4wwzQWIAK5iOMlTGHXwZibRemtnMqMvilTvJcd9/r1l0x93 8yIMb+WoE2To8kDJCBw0Q5e0r1RfJoWDpz5mt+Y4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Windsor , David Teigland , Sasha Levin Subject: [PATCH 4.19 079/113] dlm: check if workqueues are NULL before flushing/destroying Date: Mon, 29 Jul 2019 21:22:46 +0200 Message-Id: <20190729190714.519242769@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190729190655.455345569@linuxfoundation.org> References: <20190729190655.455345569@linuxfoundation.org> User-Agent: quilt/0.66 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 [ Upstream commit b355516f450703c9015316e429b66a93dfff0e6f ] If the DLM lowcomms stack is shut down before any DLM traffic can be generated, flush_workqueue() and destroy_workqueue() can be called on empty send and/or recv workqueues. Insert guard conditionals to only call flush_workqueue() and destroy_workqueue() on workqueues that are not NULL. Signed-off-by: David Windsor Signed-off-by: David Teigland Signed-off-by: Sasha Levin --- fs/dlm/lowcomms.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c index a5e4a221435c..a93ebffe84b3 100644 --- a/fs/dlm/lowcomms.c +++ b/fs/dlm/lowcomms.c @@ -1630,8 +1630,10 @@ static void clean_writequeues(void) static void work_stop(void) { - destroy_workqueue(recv_workqueue); - destroy_workqueue(send_workqueue); + if (recv_workqueue) + destroy_workqueue(recv_workqueue); + if (send_workqueue) + destroy_workqueue(send_workqueue); } static int work_start(void) @@ -1691,13 +1693,17 @@ static void work_flush(void) struct hlist_node *n; struct connection *con; - flush_workqueue(recv_workqueue); - flush_workqueue(send_workqueue); + if (recv_workqueue) + flush_workqueue(recv_workqueue); + if (send_workqueue) + flush_workqueue(send_workqueue); do { ok = 1; foreach_conn(stop_conn); - flush_workqueue(recv_workqueue); - flush_workqueue(send_workqueue); + if (recv_workqueue) + flush_workqueue(recv_workqueue); + if (send_workqueue) + flush_workqueue(send_workqueue); for (i = 0; i < CONN_HASH_SIZE && ok; i++) { hlist_for_each_entry_safe(con, n, &connection_hash[i], list) { -- 2.20.1