From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cong Wang Subject: [Patch net-next v2] act_mirred: get rid of mirred_list_lock spinlock Date: Tue, 5 Dec 2017 16:17:27 -0800 Message-ID: <20171206001727.25731-2-xiyou.wangcong@gmail.com> References: <20171206001727.25731-1-xiyou.wangcong@gmail.com> Cc: Cong Wang , Eric Dumazet , Jiri Pirko , Jamal Hadi Salim To: netdev@vger.kernel.org Return-path: Received: from mail-pg0-f68.google.com ([74.125.83.68]:36258 "EHLO mail-pg0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753044AbdLFARl (ORCPT ); Tue, 5 Dec 2017 19:17:41 -0500 Received: by mail-pg0-f68.google.com with SMTP id k134so1392067pga.3 for ; Tue, 05 Dec 2017 16:17:41 -0800 (PST) In-Reply-To: <20171206001727.25731-1-xiyou.wangcong@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: TC actions are no longer freed in RCU callbacks and we should always have RTNL lock, so this spinlock is no longer needed. Cc: Eric Dumazet Cc: Jiri Pirko Cc: Jamal Hadi Salim Signed-off-by: Cong Wang --- net/sched/act_mirred.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-) diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c index ff497909c0ad..cee2d413bf57 100644 --- a/net/sched/act_mirred.c +++ b/net/sched/act_mirred.c @@ -29,7 +29,6 @@ #include static LIST_HEAD(mirred_list); -static DEFINE_SPINLOCK(mirred_list_lock); static bool tcf_mirred_is_act_redirect(int action) { @@ -55,13 +54,10 @@ static void tcf_mirred_release(struct tc_action *a) struct tcf_mirred *m = to_mirred(a); struct net_device *dev; - /* We could be called either in a RCU callback or with RTNL lock held. */ - spin_lock_bh(&mirred_list_lock); list_del(&m->tcfm_list); - dev = rcu_dereference_protected(m->tcfm_dev, 1); + dev = rtnl_dereference(m->tcfm_dev); if (dev) dev_put(dev); - spin_unlock_bh(&mirred_list_lock); } static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = { @@ -147,9 +143,7 @@ static int tcf_mirred_init(struct net *net, struct nlattr *nla, } if (ret == ACT_P_CREATED) { - spin_lock_bh(&mirred_list_lock); list_add(&m->tcfm_list, &mirred_list); - spin_unlock_bh(&mirred_list_lock); tcf_idr_insert(tn, *a); } @@ -293,7 +287,6 @@ static int mirred_device_event(struct notifier_block *unused, ASSERT_RTNL(); if (event == NETDEV_UNREGISTER) { - spin_lock_bh(&mirred_list_lock); list_for_each_entry(m, &mirred_list, tcfm_list) { if (rcu_access_pointer(m->tcfm_dev) == dev) { dev_put(dev); @@ -303,7 +296,6 @@ static int mirred_device_event(struct notifier_block *unused, RCU_INIT_POINTER(m->tcfm_dev, NULL); } } - spin_unlock_bh(&mirred_list_lock); } return NOTIFY_DONE; -- 2.13.0