bonding: 802.3ad: make aggregator_identifier bond-private

aggregator_identifier is used to assign unique aggregator identifiers
to aggregators of a bond during device enslaving.

aggregator_identifier is currently a global variable that is zeroed in
bond_3ad_initialize().

This sequence will lead to duplicate aggregator identifiers for eth1 and eth3:

create bond0
change bond0 mode to 802.3ad
enslave eth0 to bond0 		//eth0 gets agg id 1
enslave eth1 to bond0 		//eth1 gets agg id 2
create bond1
change bond1 mode to 802.3ad
enslave eth2 to bond1		//aggregator_identifier is reset to 0
				//eth2 gets agg id 1
enslave eth3 to bond0 		//eth3 gets agg id 2

Fix this by making aggregator_identifier private to the bond.

Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Acked-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bonding/bond_3ad.c

@@ -1796,8 +1796,6 @@ void bond_3ad_initiate_agg_selection(struct bonding *bond, int timeout)
 	BOND_AD_INFO(bond).agg_select_timer = timeout;
 }
 
-static u16 aggregator_identifier;
-
 /**
  * bond_3ad_initialize - initialize a bond's 802.3ad parameters and structures
  * @bond: bonding struct to work on
@@ -1811,7 +1809,7 @@ void bond_3ad_initialize(struct bonding *bond, u16 tick_resolution)
 	if (!MAC_ADDRESS_EQUAL(&(BOND_AD_INFO(bond).system.sys_mac_addr),
 				bond->dev->dev_addr)) {
 
-		aggregator_identifier = 0;
+		BOND_AD_INFO(bond).aggregator_identifier = 0;
 
 		BOND_AD_INFO(bond).system.sys_priority = 0xFFFF;
 		BOND_AD_INFO(bond).system.sys_mac_addr = *((struct mac_addr *)bond->dev->dev_addr);
@@ -1880,7 +1878,7 @@ void bond_3ad_bind_slave(struct slave *slave)
 		ad_initialize_agg(aggregator);
 
 		aggregator->aggregator_mac_address = *((struct mac_addr *)bond->dev->dev_addr);
-		aggregator->aggregator_identifier = (++aggregator_identifier);
+		aggregator->aggregator_identifier = ++BOND_AD_INFO(bond).aggregator_identifier;
 		aggregator->slave = slave;
 		aggregator->is_active = 0;
 		aggregator->num_of_ports = 0;

drivers/net/bonding/bond_3ad.h

@@ -253,6 +253,7 @@ struct ad_system {
 struct ad_bond_info {
 	struct ad_system system;	    /* 802.3ad system structure */
 	u32 agg_select_timer;	    // Timer to select aggregator after all adapter's hand shakes
+	u16 aggregator_identifier;
 };
 
 struct ad_slave_info {