rtnetlink: Add rtnl_net_lock_killable().

rtnl_lock_killable() is used only in register_netdev()
and will be converted to per-netns RTNL.

Let's unexport it and add the corresponding helper.

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

Author: q2ven

include/linux/rtnetlink.h

@@ -102,6 +102,7 @@ void __rtnl_net_unlock(struct net *net);
 void rtnl_net_lock(struct net *net);
 void rtnl_net_unlock(struct net *net);
 int rtnl_net_trylock(struct net *net);
+int rtnl_net_lock_killable(struct net *net);
 int rtnl_net_lock_cmp_fn(const struct lockdep_map *a, const struct lockdep_map *b);
 
 bool rtnl_net_is_locked(struct net *net);
@@ -138,6 +139,11 @@ static inline int rtnl_net_trylock(struct net *net)
 	return rtnl_trylock();
 }
 
+static inline int rtnl_net_lock_killable(struct net *net)
+{
+	return rtnl_lock_killable();
+}
+
 static inline void ASSERT_RTNL_NET(struct net *net)
 {
 	ASSERT_RTNL();

net/core/rtnetlink.c

@@ -84,7 +84,6 @@ int rtnl_lock_killable(void)
 {
 	return mutex_lock_killable(&rtnl_mutex);
 }
-EXPORT_SYMBOL(rtnl_lock_killable);
 
 static struct sk_buff *defer_kfree_skb_list;
 void rtnl_kfree_skbs(struct sk_buff *head, struct sk_buff *tail)
@@ -221,6 +220,16 @@ int rtnl_net_trylock(struct net *net)
 }
 EXPORT_SYMBOL(rtnl_net_trylock);
 
+int rtnl_net_lock_killable(struct net *net)
+{
+	int ret = rtnl_lock_killable();
+
+	if (!ret)
+		__rtnl_net_lock(net);
+
+	return ret;
+}
+
 static int rtnl_net_cmp_locks(const struct net *net_a, const struct net *net_b)
 {
 	if (net_eq(net_a, net_b))