dev: update __dev_notify_flags() to send rtnl msg

This patch only prepares the next one, there is no functional change.
Now, __dev_notify_flags() can also be used to notify flags changes via
rtnetlink.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/netdevice.h

@@ -2378,7 +2378,9 @@ extern int		dev_ethtool(struct net *net, struct ifreq *);
 extern unsigned int	dev_get_flags(const struct net_device *);
 extern int		__dev_change_flags(struct net_device *, unsigned int flags);
 extern int		dev_change_flags(struct net_device *, unsigned int);
-extern void		__dev_notify_flags(struct net_device *, unsigned int old_flags);
+void			__dev_notify_flags(struct net_device *,
+					   unsigned int old_flags,
+					   unsigned int gchanges);
 extern int		dev_change_name(struct net_device *, const char *);
 extern int		dev_set_alias(struct net_device *, const char *, size_t);
 extern int		dev_change_net_namespace(struct net_device *,

net/core/dev.c

@@ -5235,10 +5235,14 @@ int __dev_change_flags(struct net_device *dev, unsigned int flags)
 	return ret;
 }
 
-void __dev_notify_flags(struct net_device *dev, unsigned int old_flags)
+void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
+			unsigned int gchanges)
 {
 	unsigned int changes = dev->flags ^ old_flags;
 
+	if (gchanges)
+		rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges);
+
 	if (changes & IFF_UP) {
 		if (dev->flags & IFF_UP)
 			call_netdevice_notifiers(NETDEV_UP, dev);
@@ -5274,10 +5278,7 @@ int dev_change_flags(struct net_device *dev, unsigned int flags)
 		return ret;
 
 	changes = old_flags ^ dev->flags;
-	if (changes)
-		rtmsg_ifinfo(RTM_NEWLINK, dev, changes);
-
-	__dev_notify_flags(dev, old_flags);
+	__dev_notify_flags(dev, old_flags, changes);
 	return ret;
 }
 EXPORT_SYMBOL(dev_change_flags);

net/core/rtnetlink.c

@@ -1647,9 +1647,8 @@ int rtnl_configure_link(struct net_device *dev, const struct ifinfomsg *ifm)
 	}
 
 	dev->rtnl_link_state = RTNL_LINK_INITIALIZED;
-	rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
 
-	__dev_notify_flags(dev, old_flags);
+	__dev_notify_flags(dev, old_flags, ~0U);
 	return 0;
 }
 EXPORT_SYMBOL(rtnl_configure_link);