ipv6: ipv6_count_addresses() rcu conversion

Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv6/addrconf.c

@@ -152,7 +152,7 @@ static void ipv6_regen_rndid(struct inet6_dev *idev);
 static void ipv6_try_regen_rndid(struct inet6_dev *idev, struct in6_addr *tmpaddr);
 
 static int ipv6_generate_eui64(u8 *eui, struct net_device *dev);
-static int ipv6_count_addresses(struct inet6_dev *idev);
+static int ipv6_count_addresses(const struct inet6_dev *idev);
 static int ipv6_generate_stable_address(struct in6_addr *addr,
 					u8 dad_count,
 					const struct inet6_dev *idev);
@@ -1785,15 +1785,15 @@ int ipv6_get_lladdr(struct net_device *dev, struct in6_addr *addr,
 	return err;
 }
 
-static int ipv6_count_addresses(struct inet6_dev *idev)
+static int ipv6_count_addresses(const struct inet6_dev *idev)
 {
+	const struct inet6_ifaddr *ifp;
 	int cnt = 0;
-	struct inet6_ifaddr *ifp;
 
-	read_lock_bh(&idev->lock);
-	list_for_each_entry(ifp, &idev->addr_list, if_list)
+	rcu_read_lock();
+	list_for_each_entry_rcu(ifp, &idev->addr_list, if_list)
 		cnt++;
-	read_unlock_bh(&idev->lock);
+	rcu_read_unlock();
 	return cnt;
 }