rtnetlink: Return int from rtnl_af_register().

The next patch will add init_srcu_struct() in rtnl_af_register(),
then we need to handle its error.

Let's add the error handling in advance to make the following
patch cleaner.

Signed-off-by: Kuniyuki Iwashima <[email protected]>
Reviewed-by: Matt Johnston <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

Author: q2ven

include/net/rtnetlink.h

@@ -204,7 +204,7 @@ struct rtnl_af_ops {
 	size_t			(*get_stats_af_size)(const struct net_device *dev);
 };
 
-void rtnl_af_register(struct rtnl_af_ops *ops);
+int rtnl_af_register(struct rtnl_af_ops *ops);
 void rtnl_af_unregister(struct rtnl_af_ops *ops);
 
 struct net *rtnl_link_get_net(struct net *src_net, struct nlattr *tb[]);

net/bridge/br_netlink.c

@@ -1924,7 +1924,9 @@ int __init br_netlink_init(void)
 	if (err)
 		goto out;
 
-	rtnl_af_register(&br_af_ops);
+	err = rtnl_af_register(&br_af_ops);
+	if (err)
+		goto out_vlan;
 
 	err = rtnl_link_register(&br_link_ops);
 	if (err)
@@ -1934,6 +1936,8 @@ int __init br_netlink_init(void)
 
 out_af:
 	rtnl_af_unregister(&br_af_ops);
+out_vlan:
+	br_vlan_rtnl_uninit();
 out:
 	return err;
 }

net/core/rtnetlink.c

@@ -686,11 +686,13 @@ static const struct rtnl_af_ops *rtnl_af_lookup(const int family)
  *
  * Returns 0 on success or a negative error code.
  */
-void rtnl_af_register(struct rtnl_af_ops *ops)
+int rtnl_af_register(struct rtnl_af_ops *ops)
 {
 	rtnl_lock();
 	list_add_tail_rcu(&ops->list, &rtnl_af_ops);
 	rtnl_unlock();
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(rtnl_af_register);
 

net/ipv4/devinet.c

@@ -2827,7 +2827,8 @@ void __init devinet_init(void)
 	register_pernet_subsys(&devinet_ops);
 	register_netdevice_notifier(&ip_netdev_notifier);
 
-	rtnl_af_register(&inet_af_ops);
+	if (rtnl_af_register(&inet_af_ops))
+		panic("Unable to register inet_af_ops\n");
 
 	rtnl_register_many(devinet_rtnl_msg_handlers);
 }

net/ipv6/addrconf.c

@@ -7468,7 +7468,9 @@ int __init addrconf_init(void)
 
 	addrconf_verify(&init_net);
 
-	rtnl_af_register(&inet6_ops);
+	err = rtnl_af_register(&inet6_ops);
+	if (err)
+		goto erraf;
 
 	err = rtnl_register_many(addrconf_rtnl_msg_handlers);
 	if (err)
@@ -7482,6 +7484,7 @@ int __init addrconf_init(void)
 errout:
 	rtnl_unregister_all(PF_INET6);
 	rtnl_af_unregister(&inet6_ops);
+erraf:
 	unregister_netdevice_notifier(&ipv6_dev_notf);
 errlo:
 	destroy_workqueue(addrconf_wq);

net/mctp/device.c

@@ -535,14 +535,20 @@ int __init mctp_device_init(void)
 	int err;
 
 	register_netdevice_notifier(&mctp_dev_nb);
-	rtnl_af_register(&mctp_af_ops);
+
+	err = rtnl_af_register(&mctp_af_ops);
+	if (err)
+		goto err_notifier;
 
 	err = rtnl_register_many(mctp_device_rtnl_msg_handlers);
-	if (err) {
-		rtnl_af_unregister(&mctp_af_ops);
-		unregister_netdevice_notifier(&mctp_dev_nb);
-	}
+	if (err)
+		goto err_af;
 
+	return 0;
+err_af:
+	rtnl_af_unregister(&mctp_af_ops);
+err_notifier:
+	unregister_netdevice_notifier(&mctp_dev_nb);
 	return err;
 }
 

net/mpls/af_mpls.c

@@ -2753,7 +2753,9 @@ static int __init mpls_init(void)
 
 	dev_add_pack(&mpls_packet_type);
 
-	rtnl_af_register(&mpls_af_ops);
+	err = rtnl_af_register(&mpls_af_ops);
+	if (err)
+		goto out_unregister_dev_type;
 
 	err = rtnl_register_many(mpls_rtnl_msg_handlers);
 	if (err)
@@ -2773,6 +2775,7 @@ static int __init mpls_init(void)
 	rtnl_unregister_many(mpls_rtnl_msg_handlers);
 out_unregister_rtnl_af:
 	rtnl_af_unregister(&mpls_af_ops);
+out_unregister_dev_type:
 	dev_remove_pack(&mpls_packet_type);
 out_unregister_pernet:
 	unregister_pernet_subsys(&mpls_net_ops);