Revert "net_sched: hold netns refcnt for each action"

This reverts commit ceffcc5e25.
If we hold that refcnt, the netns can never be destroyed until
all actions are destroyed by user, this breaks our netns design
which we expect all actions are destroyed when we destroy the
whole netns.

Cc: Lucas Bates <lucasb@mojatatu.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/act_api.h

@@ -14,7 +14,6 @@
 struct tcf_idrinfo {
 	spinlock_t	lock;
 	struct idr	action_idr;
-	struct net	*net;
 };
 
 struct tc_action_ops;
@@ -106,7 +105,7 @@ struct tc_action_net {
 
 static inline
 int tc_action_net_init(struct tc_action_net *tn,
-		       const struct tc_action_ops *ops, struct net *net)
+		       const struct tc_action_ops *ops)
 {
 	int err = 0;
 
@@ -114,7 +113,6 @@ int tc_action_net_init(struct tc_action_net *tn,
 	if (!tn->idrinfo)
 		return -ENOMEM;
 	tn->ops = ops;
-	tn->idrinfo->net = net;
 	spin_lock_init(&tn->idrinfo->lock);
 	idr_init(&tn->idrinfo->action_idr);
 	return err;

net/sched/act_api.c

@@ -78,7 +78,6 @@ static void tcf_idr_remove(struct tcf_idrinfo *idrinfo, struct tc_action *p)
 	spin_lock_bh(&idrinfo->lock);
 	idr_remove_ext(&idrinfo->action_idr, p->tcfa_index);
 	spin_unlock_bh(&idrinfo->lock);
-	put_net(idrinfo->net);
 	gen_kill_estimator(&p->tcfa_rate_est);
 	free_tcf(p);
 }
@@ -337,7 +336,6 @@ int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
 	p->idrinfo = idrinfo;
 	p->ops = ops;
 	INIT_LIST_HEAD(&p->list);
-	get_net(idrinfo->net);
 	*a = p;
 	return 0;
 }

net/sched/act_bpf.c

@@ -398,7 +398,7 @@ static __net_init int bpf_init_net(struct net *net)
 {
 	struct tc_action_net *tn = net_generic(net, bpf_net_id);
 
-	return tc_action_net_init(tn, &act_bpf_ops, net);
+	return tc_action_net_init(tn, &act_bpf_ops);
 }
 
 static void __net_exit bpf_exit_net(struct net *net)

net/sched/act_connmark.c

@@ -206,7 +206,7 @@ static __net_init int connmark_init_net(struct net *net)
 {
 	struct tc_action_net *tn = net_generic(net, connmark_net_id);
 
-	return tc_action_net_init(tn, &act_connmark_ops, net);
+	return tc_action_net_init(tn, &act_connmark_ops);
 }
 
 static void __net_exit connmark_exit_net(struct net *net)

net/sched/act_csum.c

@@ -626,7 +626,7 @@ static __net_init int csum_init_net(struct net *net)
 {
 	struct tc_action_net *tn = net_generic(net, csum_net_id);
 
-	return tc_action_net_init(tn, &act_csum_ops, net);
+	return tc_action_net_init(tn, &act_csum_ops);
 }
 
 static void __net_exit csum_exit_net(struct net *net)

net/sched/act_gact.c

@@ -232,7 +232,7 @@ static __net_init int gact_init_net(struct net *net)
 {
 	struct tc_action_net *tn = net_generic(net, gact_net_id);
 
-	return tc_action_net_init(tn, &act_gact_ops, net);
+	return tc_action_net_init(tn, &act_gact_ops);
 }
 
 static void __net_exit gact_exit_net(struct net *net)

net/sched/act_ife.c

@@ -818,7 +818,7 @@ static __net_init int ife_init_net(struct net *net)
 {
 	struct tc_action_net *tn = net_generic(net, ife_net_id);
 
-	return tc_action_net_init(tn, &act_ife_ops, net);
+	return tc_action_net_init(tn, &act_ife_ops);
 }
 
 static void __net_exit ife_exit_net(struct net *net)

net/sched/act_ipt.c

@@ -334,7 +334,7 @@ static __net_init int ipt_init_net(struct net *net)
 {
 	struct tc_action_net *tn = net_generic(net, ipt_net_id);
 
-	return tc_action_net_init(tn, &act_ipt_ops, net);
+	return tc_action_net_init(tn, &act_ipt_ops);
 }
 
 static void __net_exit ipt_exit_net(struct net *net)
@@ -384,7 +384,7 @@ static __net_init int xt_init_net(struct net *net)
 {
 	struct tc_action_net *tn = net_generic(net, xt_net_id);
 
-	return tc_action_net_init(tn, &act_xt_ops, net);
+	return tc_action_net_init(tn, &act_xt_ops);
 }
 
 static void __net_exit xt_exit_net(struct net *net)

net/sched/act_mirred.c

@@ -343,7 +343,7 @@ static __net_init int mirred_init_net(struct net *net)
 {
 	struct tc_action_net *tn = net_generic(net, mirred_net_id);
 
-	return tc_action_net_init(tn, &act_mirred_ops, net);
+	return tc_action_net_init(tn, &act_mirred_ops);
 }
 
 static void __net_exit mirred_exit_net(struct net *net)

net/sched/act_nat.c

@@ -307,7 +307,7 @@ static __net_init int nat_init_net(struct net *net)
 {
 	struct tc_action_net *tn = net_generic(net, nat_net_id);
 
-	return tc_action_net_init(tn, &act_nat_ops, net);
+	return tc_action_net_init(tn, &act_nat_ops);
 }
 
 static void __net_exit nat_exit_net(struct net *net)

net/sched/act_pedit.c

@@ -450,7 +450,7 @@ static __net_init int pedit_init_net(struct net *net)
 {
 	struct tc_action_net *tn = net_generic(net, pedit_net_id);
 
-	return tc_action_net_init(tn, &act_pedit_ops, net);
+	return tc_action_net_init(tn, &act_pedit_ops);
 }
 
 static void __net_exit pedit_exit_net(struct net *net)

net/sched/act_police.c

@@ -331,7 +331,7 @@ static __net_init int police_init_net(struct net *net)
 {
 	struct tc_action_net *tn = net_generic(net, police_net_id);
 
-	return tc_action_net_init(tn, &act_police_ops, net);
+	return tc_action_net_init(tn, &act_police_ops);
 }
 
 static void __net_exit police_exit_net(struct net *net)

net/sched/act_sample.c

@@ -240,7 +240,7 @@ static __net_init int sample_init_net(struct net *net)
 {
 	struct tc_action_net *tn = net_generic(net, sample_net_id);
 
-	return tc_action_net_init(tn, &act_sample_ops, net);
+	return tc_action_net_init(tn, &act_sample_ops);
 }
 
 static void __net_exit sample_exit_net(struct net *net)

net/sched/act_simple.c

@@ -201,7 +201,7 @@ static __net_init int simp_init_net(struct net *net)
 {
 	struct tc_action_net *tn = net_generic(net, simp_net_id);
 
-	return tc_action_net_init(tn, &act_simp_ops, net);
+	return tc_action_net_init(tn, &act_simp_ops);
 }
 
 static void __net_exit simp_exit_net(struct net *net)

net/sched/act_skbedit.c

@@ -238,7 +238,7 @@ static __net_init int skbedit_init_net(struct net *net)
 {
 	struct tc_action_net *tn = net_generic(net, skbedit_net_id);
 
-	return tc_action_net_init(tn, &act_skbedit_ops, net);
+	return tc_action_net_init(tn, &act_skbedit_ops);
 }
 
 static void __net_exit skbedit_exit_net(struct net *net)

net/sched/act_skbmod.c

@@ -263,7 +263,7 @@ static __net_init int skbmod_init_net(struct net *net)
 {
 	struct tc_action_net *tn = net_generic(net, skbmod_net_id);
 
-	return tc_action_net_init(tn, &act_skbmod_ops, net);
+	return tc_action_net_init(tn, &act_skbmod_ops);
 }
 
 static void __net_exit skbmod_exit_net(struct net *net)

net/sched/act_tunnel_key.c

@@ -322,7 +322,7 @@ static __net_init int tunnel_key_init_net(struct net *net)
 {
 	struct tc_action_net *tn = net_generic(net, tunnel_key_net_id);
 
-	return tc_action_net_init(tn, &act_tunnel_key_ops, net);
+	return tc_action_net_init(tn, &act_tunnel_key_ops);
 }
 
 static void __net_exit tunnel_key_exit_net(struct net *net)

net/sched/act_vlan.c

@@ -269,7 +269,7 @@ static __net_init int vlan_init_net(struct net *net)
 {
 	struct tc_action_net *tn = net_generic(net, vlan_net_id);
 
-	return tc_action_net_init(tn, &act_vlan_ops, net);
+	return tc_action_net_init(tn, &act_vlan_ops);
 }
 
 static void __net_exit vlan_exit_net(struct net *net)