ipv4, ipv6: kill ip_mc_{join, leave}_group and ipv6_sock_mc_{join, drop}

in favor of their inner __ ones, which doesn't grab rtnl.

As these functions need to operate on a locked socket, we can't be
grabbing rtnl by then. It's too late and doing so causes reversed
locking.

So this patch:
- move rtnl handling to callers instead while already fixing some
  reversed locking situations, like on vxlan and ipvs code.
- renames __ ones to not have the __ mark:
  __ip_mc_{join,leave}_group -> ip_mc_{join,leave}_group
  __ipv6_sock_mc_{join,drop} -> ipv6_sock_mc_{join,drop}

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index 1dd1fed..cbb66fd 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -132,7 +132,7 @@
 	return iv > 0 ? iv : 1;
 }
 
-int __ipv6_sock_mc_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
+int ipv6_sock_mc_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
 {
 	struct net_device *dev = NULL;
 	struct ipv6_mc_socklist *mc_lst;
@@ -199,24 +199,12 @@
 
 	return 0;
 }
-EXPORT_SYMBOL(__ipv6_sock_mc_join);
-
-int ipv6_sock_mc_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
-{
-	int ret;
-
-	rtnl_lock();
-	ret = __ipv6_sock_mc_join(sk, ifindex, addr);
-	rtnl_unlock();
-
-	return ret;
-}
 EXPORT_SYMBOL(ipv6_sock_mc_join);
 
 /*
  *	socket leave on multicast group
  */
-int __ipv6_sock_mc_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
+int ipv6_sock_mc_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
 {
 	struct ipv6_pinfo *np = inet6_sk(sk);
 	struct ipv6_mc_socklist *mc_lst;
@@ -255,18 +243,6 @@
 
 	return -EADDRNOTAVAIL;
 }
-EXPORT_SYMBOL(__ipv6_sock_mc_drop);
-
-int ipv6_sock_mc_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
-{
-	int ret;
-
-	rtnl_lock();
-	ret = __ipv6_sock_mc_drop(sk, ifindex, addr);
-	rtnl_unlock();
-
-	return ret;
-}
 EXPORT_SYMBOL(ipv6_sock_mc_drop);
 
 /* called with rcu_read_lock() */
@@ -460,7 +436,7 @@
 	read_unlock_bh(&idev->lock);
 	rcu_read_unlock();
 	if (leavegroup)
-		return ipv6_sock_mc_drop(sk, pgsr->gsr_interface, group);
+		err = ipv6_sock_mc_drop(sk, pgsr->gsr_interface, group);
 	return err;
 }