[PATCH v2 net-next 13/14] rtnetlink: Return int from rtnl_af_register().

[Kuniyuki Iwashima <kuniyu@amazon.com>]

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 <kuniyu@amazon.com>
---
Cc: Roopa Prabhu <roopa@nvidia.com>
Cc: Nikolay Aleksandrov <razor@blackwall.org>
Cc: David Ahern <dsahern@kernel.org>
Cc: Jeremy Kerr <jk@codeconstruct.com.au>
Cc: Matt Johnston <matt@codeconstruct.com.au>
---
 include/net/rtnetlink.h |  2 +-
 net/bridge/br_netlink.c |  6 +++++-
 net/core/rtnetlink.c    |  4 +++-
 net/ipv4/devinet.c      |  3 ++-
 net/ipv6/addrconf.c     |  5 ++++-
 net/mctp/device.c       | 16 +++++++++++-----
 net/mpls/af_mpls.c      |  5 ++++-
 7 files changed, 30 insertions(+), 11 deletions(-)

diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
index 1a6aa5ca74f3..969138ae2f4b 100644
--- a/include/net/rtnetlink.h
+++ b/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[]);
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 6b97ae47f855..3e0f47203f2a 100644
--- a/net/bridge/br_netlink.c
+++ b/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;
 }
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 445e6ffed75e..70b663aca209 100644
--- a/net/core/rtnetlink.c
+++ b/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);
 
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index d81fff93d208..2152d8cfa2dc 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -2812,7 +2812,8 @@ 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);
 }
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index ac8645ad2537..d0a99710d65d 100644
--- a/net/ipv6/addrconf.c
+++ b/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);
diff --git a/net/mctp/device.c b/net/mctp/device.c
index 85cc5f31f1e7..3d75b919995d 100644
--- a/net/mctp/device.c
+++ b/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;
 }
 
diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index a0573847bc55..1f63b32d76d6 100644
--- a/net/mpls/af_mpls.c
+++ b/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);
-- 
2.39.5 (Apple Git-154)