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=-12.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 21D2DC00A89 for ; Tue, 3 Nov 2020 03:29:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C258D223FD for ; Tue, 3 Nov 2020 03:29:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727265AbgKCD3S (ORCPT ); Mon, 2 Nov 2020 22:29:18 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:6737 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725952AbgKCD3S (ORCPT ); Mon, 2 Nov 2020 22:29:18 -0500 Received: from DGGEMS405-HUB.china.huawei.com (unknown [172.30.72.58]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4CQFd43f75zkdnT; Tue, 3 Nov 2020 11:29:12 +0800 (CST) Received: from localhost.localdomain (10.69.192.58) by DGGEMS405-HUB.china.huawei.com (10.3.19.205) with Microsoft SMTP Server id 14.3.487.0; Tue, 3 Nov 2020 11:29:07 +0800 From: Yunsheng Lin To: , CC: , , , , , , , , , , , , , Subject: [PATCH stable] net: sch_generic: fix the missing new qdisc assignment bug Date: Tue, 3 Nov 2020 11:25:38 +0800 Message-ID: <1604373938-211588-1-git-send-email-linyunsheng@huawei.com> X-Mailer: git-send-email 2.8.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.69.192.58] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org commit 2fb541c862c9 ("net: sch_generic: aviod concurrent reset and enqueue op for lockless qdisc") When the above upstream commit is backported to stable kernel, one assignment is missing, which causes two problems reported by Joakim and Vishwanath, see [1] and [2]. So add the assignment back to fix it. 1. https://www.spinics.net/lists/netdev/msg693916.html 2. https://www.spinics.net/lists/netdev/msg695131.html Fixes: 749cc0b0c7f3 ("net: sch_generic: aviod concurrent reset and enqueue op for lockless qdisc") Signed-off-by: Yunsheng Lin --- net/sched/sch_generic.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 0e275e1..6e6147a 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -1127,10 +1127,13 @@ static void dev_deactivate_queue(struct net_device *dev, void *_qdisc_default) { struct Qdisc *qdisc = rtnl_dereference(dev_queue->qdisc); + struct Qdisc *qdisc_default = _qdisc_default; if (qdisc) { if (!(qdisc->flags & TCQ_F_BUILTIN)) set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state); + + rcu_assign_pointer(dev_queue->qdisc, qdisc_default); } } -- 2.7.4