bonding: options: remove bond->lock usage

We're safe to remove the bond->lock use from the arp targets because
arp_rcv_probe no longer acquires bond->lock, only rcu_read_lock.
Also setting the primary slave is safe because noone uses the bond->lock
as a syncing mechanism for that anymore.

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bonding/bond_options.c

@@ -955,14 +955,7 @@ static int _bond_option_arp_ip_target_add(struct bonding *bond, __be32 target)
 
 static int bond_option_arp_ip_target_add(struct bonding *bond, __be32 target)
 {
-	int ret;
-
-	/* not to race with bond_arp_rcv */
-	write_lock_bh(&bond->lock);
-	ret = _bond_option_arp_ip_target_add(bond, target);
-	write_unlock_bh(&bond->lock);
-
-	return ret;
+	return _bond_option_arp_ip_target_add(bond, target);
 }
 
 static int bond_option_arp_ip_target_rem(struct bonding *bond, __be32 target)
@@ -991,9 +984,6 @@ static int bond_option_arp_ip_target_rem(struct bonding *bond, __be32 target)
 
 	netdev_info(bond->dev, "Removing ARP target %pI4\n", &target);
 
-	/* not to race with bond_arp_rcv */
-	write_lock_bh(&bond->lock);
-
 	bond_for_each_slave(bond, slave, iter) {
 		targets_rx = slave->target_last_arp_rx;
 		for (i = ind; (i < BOND_MAX_ARP_TARGETS-1) && targets[i+1]; i++)
@@ -1004,8 +994,6 @@ static int bond_option_arp_ip_target_rem(struct bonding *bond, __be32 target)
 		targets[i] = targets[i+1];
 	targets[i] = 0;
 
-	write_unlock_bh(&bond->lock);
-
 	return 0;
 }
 
@@ -1013,11 +1001,8 @@ void bond_option_arp_ip_targets_clear(struct bonding *bond)
 {
 	int i;
 
-	/* not to race with bond_arp_rcv */
-	write_lock_bh(&bond->lock);
 	for (i = 0; i < BOND_MAX_ARP_TARGETS; i++)
 		_bond_options_arp_ip_target_set(bond, i, 0, 0);
-	write_unlock_bh(&bond->lock);
 }
 
 static int bond_option_arp_ip_targets_set(struct bonding *bond,
@@ -1081,7 +1066,6 @@ static int bond_option_primary_set(struct bonding *bond,
 	struct slave *slave;
 
 	block_netpoll_tx();
-	read_lock(&bond->lock);
 	write_lock_bh(&bond->curr_slave_lock);
 
 	p = strchr(primary, '\n');
@@ -1120,7 +1104,6 @@ static int bond_option_primary_set(struct bonding *bond,
 
 out:
 	write_unlock_bh(&bond->curr_slave_lock);
-	read_unlock(&bond->lock);
 	unblock_netpoll_tx();
 
 	return 0;