From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cong Wang Subject: [Patch net 04/16] net_sched: use tcf_queue_work() in cgroup filter Date: Thu, 26 Oct 2017 18:24:31 -0700 Message-ID: <20171027012443.3306-5-xiyou.wangcong@gmail.com> References: <20171027012443.3306-1-xiyou.wangcong@gmail.com> Cc: Chris Mi , Cong Wang , Daniel Borkmann , Jiri Pirko , John Fastabend , Jamal Hadi Salim , "Paul E. McKenney" To: netdev@vger.kernel.org Return-path: Received: from mail-pf0-f195.google.com ([209.85.192.195]:45018 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751961AbdJ0BZD (ORCPT ); Thu, 26 Oct 2017 21:25:03 -0400 Received: by mail-pf0-f195.google.com with SMTP id x7so3784151pfa.1 for ; Thu, 26 Oct 2017 18:25:03 -0700 (PDT) In-Reply-To: <20171027012443.3306-1-xiyou.wangcong@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: Defer the tcf_exts_destroy() in RCU callback to tc filter workqueue and get RTNL lock. Reported-by: Chris Mi Cc: Daniel Borkmann Cc: Jiri Pirko Cc: John Fastabend Cc: Jamal Hadi Salim Cc: "Paul E. McKenney" Signed-off-by: Cong Wang --- net/sched/cls_cgroup.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c index d48452f87975..a97e069bee89 100644 --- a/net/sched/cls_cgroup.c +++ b/net/sched/cls_cgroup.c @@ -23,7 +23,10 @@ struct cls_cgroup_head { struct tcf_exts exts; struct tcf_ematch_tree ematches; struct tcf_proto *tp; - struct rcu_head rcu; + union { + struct work_struct work; + struct rcu_head rcu; + }; }; static int cls_cgroup_classify(struct sk_buff *skb, const struct tcf_proto *tp, @@ -57,15 +60,26 @@ static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = { [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED }, }; +static void cls_cgroup_destroy_work(struct work_struct *work) +{ + struct cls_cgroup_head *head = container_of(work, + struct cls_cgroup_head, + work); + rtnl_lock(); + tcf_exts_destroy(&head->exts); + tcf_em_tree_destroy(&head->ematches); + kfree(head); + rtnl_unlock(); +} + static void cls_cgroup_destroy_rcu(struct rcu_head *root) { struct cls_cgroup_head *head = container_of(root, struct cls_cgroup_head, rcu); - tcf_exts_destroy(&head->exts); - tcf_em_tree_destroy(&head->ematches); - kfree(head); + INIT_WORK(&head->work, cls_cgroup_destroy_work); + tcf_queue_work(&head->work); } static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb, -- 2.13.0