bonding: split bond_set_slave_link_state into two parts

Split the function into two (a) propose (b) commit phase without
changing the semantics for the original API.
Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/bonding.h

@@ -154,6 +154,7 @@ struct slave {
 	unsigned long last_rx;
 	unsigned long target_last_arp_rx[BOND_MAX_ARP_TARGETS];
 	s8     link;		/* one of BOND_LINK_XXXX */
+	s8     link_new_state;	/* one of BOND_LINK_XXXX */
 	s8     new_link;
 	u8     backup:1,   /* indicates backup slave. Value corresponds with
 			      BOND_STATE_ACTIVE and BOND_STATE_BACKUP */
@@ -504,13 +505,17 @@ static inline bool bond_is_slave_inactive(struct slave *slave)
 	return slave->inactive;
 }
 
-static inline void bond_set_slave_link_state(struct slave *slave, int state,
-					     bool notify)
+static inline void bond_propose_link_state(struct slave *slave, int state)
+{
+	slave->link_new_state = state;
+}
+
+static inline void bond_commit_link_state(struct slave *slave, bool notify)
 {
-	if (slave->link == state)
+	if (slave->link == slave->link_new_state)
 		return;
 
-	slave->link = state;
+	slave->link = slave->link_new_state;
 	if (notify) {
 		bond_queue_slave_event(slave);
 		bond_lower_state_changed(slave);
@@ -523,6 +528,13 @@ static inline void bond_set_slave_link_state(struct slave *slave, int state,
 	}
 }
 
+static inline void bond_set_slave_link_state(struct slave *slave, int state,
+					     bool notify)
+{
+	bond_propose_link_state(slave, state);
+	bond_commit_link_state(slave, notify);
+}
+
 static inline void bond_slave_link_notify(struct bonding *bond)
 {
 	struct list_head *iter;