bonding: Rework / fix multiple gratuitous ARP support

	Support for sending multiple gratuitous ARPs during failovers
was added by commit:

commit 7893b2491a2d5f716540ac5643d78d37a7f6628b
Author: Moni Shoua <monis@voltaire.com>
Date:   Sat May 17 21:10:12 2008 -0700

    bonding: Send more than one gratuitous ARP when slave takes over

	This change modifies that support to remove duplicated code,
add support for ARP monitor (the original only supported miimon), clear
the grat ARP counter in bond_close (lest a later "ifconfig up" immediately
start spewing ARPs), and add documentation for the module parameter.

	Also updated driver version to 3.3.0.

Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 22 insertions, 20 deletions

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 925402bcdf4d..3b6d66a8ab98 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1195,14 +1195,7 @@ void bond_change_active_slave(struct bonding *bond, struct slave *new_active)
 						      old_active);
 
 			bond->send_grat_arp = bond->params.num_grat_arp;
-			if (!test_bit(__LINK_STATE_LINKWATCH_PENDING,
-					&bond->curr_active_slave->dev->state)) {
-				bond_send_gratuitous_arp(bond);
-				bond->send_grat_arp--;
-			} else {
-				dprintk("delaying gratuitous arp on %s\n",
-					bond->curr_active_slave->dev->name);
-			}
+			bond_send_gratuitous_arp(bond);
 
 			write_unlock_bh(&bond->curr_slave_lock);
 			read_unlock(&bond->lock);
@@ -2241,17 +2234,6 @@ static int __bond_mii_monitor(struct bonding *bond, int have_locks)
 	 * program could monitor the link itself if needed.
 	 */
 
-	if (bond->send_grat_arp) {
-		if (bond->curr_active_slave && test_bit(__LINK_STATE_LINKWATCH_PENDING,
-				&bond->curr_active_slave->dev->state))
-			dprintk("Needs to send gratuitous arp but not yet\n");
-		else {
-			dprintk("sending delayed gratuitous arp on on %s\n",
-				bond->curr_active_slave->dev->name);
-			bond_send_gratuitous_arp(bond);
-			bond->send_grat_arp--;
-		}
-	}
 	read_lock(&bond->curr_slave_lock);
 	oldcurrent = bond->curr_active_slave;
 	read_unlock(&bond->curr_slave_lock);
@@ -2492,6 +2474,13 @@ void bond_mii_monitor(struct work_struct *work)
 		read_unlock(&bond->lock);
 		return;
 	}
+
+	if (bond->send_grat_arp) {
+		read_lock(&bond->curr_slave_lock);
+		bond_send_gratuitous_arp(bond);
+		read_unlock(&bond->curr_slave_lock);
+	}
+
 	if (__bond_mii_monitor(bond, 0)) {
 		read_unlock(&bond->lock);
 		rtnl_lock();
@@ -2657,6 +2646,8 @@ static void bond_arp_send_all(struct bonding *bond, struct slave *slave)
 /*
  * Kick out a gratuitous ARP for an IP on the bonding master plus one
  * for each VLAN above us.
+ *
+ * Caller must hold curr_slave_lock for read or better
  */
 static void bond_send_gratuitous_arp(struct bonding *bond)
 {
@@ -2666,9 +2657,13 @@ static void bond_send_gratuitous_arp(struct bonding *bond)
 
 	dprintk("bond_send_grat_arp: bond %s slave %s\n", bond->dev->name,
 				slave ? slave->dev->name : "NULL");
-	if (!slave)
+
+	if (!slave || !bond->send_grat_arp ||
+	    test_bit(__LINK_STATE_LINKWATCH_PENDING, &slave->dev->state))
 		return;
 
+	bond->send_grat_arp--;
+
 	if (bond->master_ip) {
 		bond_arp_send(slave->dev, ARPOP_REPLY, bond->master_ip,
 				bond->master_ip, 0);
@@ -3172,6 +3167,12 @@ void bond_activebackup_arp_mon(struct work_struct *work)
 	if (bond->slave_cnt == 0)
 		goto re_arm;
 
+	if (bond->send_grat_arp) {
+		read_lock(&bond->curr_slave_lock);
+		bond_send_gratuitous_arp(bond);
+		read_unlock(&bond->curr_slave_lock);
+	}
+
 	if (bond_ab_arp_inspect(bond, delta_in_ticks)) {
 		read_unlock(&bond->lock);
 		rtnl_lock();
@@ -3846,6 +3847,7 @@ static int bond_close(struct net_device *bond_dev)
 
 	write_lock_bh(&bond->lock);
 
+	bond->send_grat_arp = 0;
 
 	/* signal timers not to re-arm */
 	bond->kill_timers = 1;