bonding: implement lower state change propagation

Let netdev notifier listeners know about link and slave state change.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/bonding.h b/include/net/bonding.h
index 1df4377..ee6c520 100644
--- a/include/net/bonding.h
+++ b/include/net/bonding.h
@@ -247,6 +247,7 @@
 	((struct slave *) rtnl_dereference(dev->rx_handler_data))
 
 void bond_queue_slave_event(struct slave *slave);
+void bond_lower_state_changed(struct slave *slave);
 
 struct bond_vlan_tag {
 	__be16		vlan_proto;
@@ -328,6 +329,7 @@
 	if (slave->backup) {
 		slave->backup = 0;
 		bond_queue_slave_event(slave);
+		bond_lower_state_changed(slave);
 		rtmsg_ifinfo(RTM_NEWLINK, slave->dev, 0, GFP_ATOMIC);
 	}
 }
@@ -337,6 +339,7 @@
 	if (!slave->backup) {
 		slave->backup = 1;
 		bond_queue_slave_event(slave);
+		bond_lower_state_changed(slave);
 		rtmsg_ifinfo(RTM_NEWLINK, slave->dev, 0, GFP_ATOMIC);
 	}
 }
@@ -349,6 +352,7 @@
 
 	slave->backup = slave_state;
 	if (notify) {
+		bond_lower_state_changed(slave);
 		rtmsg_ifinfo(RTM_NEWLINK, slave->dev, 0, GFP_ATOMIC);
 		bond_queue_slave_event(slave);
 		slave->should_notify = 0;
@@ -380,6 +384,7 @@
 
 	bond_for_each_slave(bond, tmp, iter) {
 		if (tmp->should_notify) {
+			bond_lower_state_changed(tmp);
 			rtmsg_ifinfo(RTM_NEWLINK, tmp->dev, 0, GFP_ATOMIC);
 			tmp->should_notify = 0;
 		}
@@ -514,6 +519,7 @@
 	slave->link = state;
 	if (notify) {
 		bond_queue_slave_event(slave);
+		bond_lower_state_changed(slave);
 		slave->should_notify_link = 0;
 	} else {
 		if (slave->should_notify_link)
@@ -531,6 +537,7 @@
 	bond_for_each_slave(bond, tmp, iter) {
 		if (tmp->should_notify_link) {
 			bond_queue_slave_event(tmp);
+			bond_lower_state_changed(tmp);
 			tmp->should_notify_link = 0;
 		}
 	}