net: Kill hold_net release_net

hold_net and release_net were an idea that turned out to be useless.
The code has been disabled since 2008.  Kill the code it is long past due.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 5 insertions, 35 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 962ee9d..39fe369 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6841,8 +6841,6 @@ void free_netdev(struct net_device *dev)
 {
 	struct napi_struct *p, *n;
 
-	release_net(dev_net(dev));
-
 	netif_free_tx_queues(dev);
 #ifdef CONFIG_SYSFS
 	kvfree(dev->_rx);
diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c
index b55677f..68ea695 100644
--- a/net/core/fib_rules.c
+++ b/net/core/fib_rules.c
@@ -31,7 +31,7 @@ int fib_default_rule_add(struct fib_rules_ops *ops,
 	r->pref = pref;
 	r->table = table;
 	r->flags = flags;
-	r->fr_net = hold_net(ops->fro_net);
+	r->fr_net = ops->fro_net;
 
 	r->suppress_prefixlen = -1;
 	r->suppress_ifgroup = -1;
@@ -116,7 +116,6 @@ static int __fib_rules_register(struct fib_rules_ops *ops)
 		if (ops->family == o->family)
 			goto errout;
 
-	hold_net(net);
 	list_add_tail_rcu(&ops->list, &net->rules_ops);
 	err = 0;
 errout:
@@ -160,15 +159,6 @@ static void fib_rules_cleanup_ops(struct fib_rules_ops *ops)
 	}
 }
 
-static void fib_rules_put_rcu(struct rcu_head *head)
-{
-	struct fib_rules_ops *ops = container_of(head, struct fib_rules_ops, rcu);
-	struct net *net = ops->fro_net;
-
-	release_net(net);
-	kfree(ops);
-}
-
 void fib_rules_unregister(struct fib_rules_ops *ops)
 {
 	struct net *net = ops->fro_net;
@@ -178,7 +168,7 @@ void fib_rules_unregister(struct fib_rules_ops *ops)
 	fib_rules_cleanup_ops(ops);
 	spin_unlock(&net->rules_mod_lock);
 
-	call_rcu(&ops->rcu, fib_rules_put_rcu);
+	kfree_rcu(ops, rcu);
 }
 EXPORT_SYMBOL_GPL(fib_rules_unregister);
 
@@ -303,7 +293,7 @@ static int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh)
 		err = -ENOMEM;
 		goto errout;
 	}
-	rule->fr_net = hold_net(net);
+	rule->fr_net = net;
 
 	if (tb[FRA_PRIORITY])
 		rule->pref = nla_get_u32(tb[FRA_PRIORITY]);
@@ -423,7 +413,6 @@ static int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh)
 	return 0;
 
 errout_free:
-	release_net(rule->fr_net);
 	kfree(rule);
 errout:
 	rules_ops_put(ops);
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index ad07990..0e8b32e 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -591,7 +591,7 @@ struct pneigh_entry * pneigh_lookup(struct neigh_table *tbl,
 	if (!n)
 		goto out;
 
-	write_pnet(&n->net, hold_net(net));
+	write_pnet(&n->net, net);
 	memcpy(n->key, pkey, key_len);
 	n->dev = dev;
 	if (dev)
@@ -600,7 +600,6 @@ struct pneigh_entry * pneigh_lookup(struct neigh_table *tbl,
 	if (tbl->pconstructor && tbl->pconstructor(n)) {
 		if (dev)
 			dev_put(dev);
-		release_net(net);
 		kfree(n);
 		n = NULL;
 		goto out;
@@ -634,7 +633,6 @@ int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *pkey,
 				tbl->pdestructor(n);
 			if (n->dev)
 				dev_put(n->dev);
-			release_net(pneigh_net(n));
 			kfree(n);
 			return 0;
 		}
@@ -657,7 +655,6 @@ static int pneigh_ifdown(struct neigh_table *tbl, struct net_device *dev)
 					tbl->pdestructor(n);
 				if (n->dev)
 					dev_put(n->dev);
-				release_net(pneigh_net(n));
 				kfree(n);
 				continue;
 			}
@@ -1428,11 +1425,10 @@ struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
 				neigh_rand_reach_time(NEIGH_VAR(p, BASE_REACHABLE_TIME));
 		dev_hold(dev);
 		p->dev = dev;
-		write_pnet(&p->net, hold_net(net));
+		write_pnet(&p->net, net);
 		p->sysctl_table = NULL;
 
 		if (ops->ndo_neigh_setup && ops->ndo_neigh_setup(dev, p)) {
-			release_net(net);
 			dev_put(dev);
 			kfree(p);
 			return NULL;
@@ -1472,7 +1468,6 @@ EXPORT_SYMBOL(neigh_parms_release);
 
 static void neigh_parms_destroy(struct neigh_parms *parms)
 {
-	release_net(neigh_parms_net(parms));
 	kfree(parms);
 }
 
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index cb5290b..e5e96b0 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -236,10 +236,6 @@ static __net_init int setup_net(struct net *net, struct user_namespace *user_ns)
 	net->user_ns = user_ns;
 	idr_init(&net->netns_ids);
 
-#ifdef NETNS_REFCNT_DEBUG
-	atomic_set(&net->use_count, 0);
-#endif
-
 	list_for_each_entry(ops, &pernet_list, list) {
 		error = ops_init(ops, net);
 		if (error < 0)
@@ -294,13 +290,6 @@ out_free:
 
 static void net_free(struct net *net)
 {
-#ifdef NETNS_REFCNT_DEBUG
-	if (unlikely(atomic_read(&net->use_count) != 0)) {
-		pr_emerg("network namespace not free! Usage: %d\n",
-			 atomic_read(&net->use_count));
-		return;
-	}
-#endif
 	kfree(rcu_access_pointer(net->gen));
 	kmem_cache_free(net_cachep, net);
 }
diff --git a/net/core/sock.c b/net/core/sock.c
index a9a9c2f..c8842f2 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1455,7 +1455,6 @@ void sk_release_kernel(struct sock *sk)
 
 	sock_hold(sk);
 	sock_release(sk->sk_socket);
-	release_net(sock_net(sk));
 	sock_net_set(sk, get_net(&init_net));
 	sock_put(sk);
 }