From: Cong Wang <xiyou.wangcong@gmail.com>
Date: Tue, 5 Dec 2017 16:17:27 -0800
Subject: act_mirred: get rid of mirred_list_lock spinlock
Patch-mainline: v4.16-rc1
Git-commit: 4bee00eb25a7b487706d17926db4679ae8f0e411
References: bsc#1109837
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 <eric.dumazet@gmail.com>
Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
net/sched/act_mirred.c | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)
--- a/net/sched/act_mirred.c
+++ b/net/sched/act_mirred.c
@@ -29,7 +29,6 @@
#include <net/tc_act/tc_mirred.h>
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
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 *n
}
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 no
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 no
RCU_INIT_POINTER(m->tcfm_dev, NULL);
}
}
- spin_unlock_bh(&mirred_list_lock);
}
return NOTIFY_DONE;