net/bonding: Delay sending of gratuitous ARP to avoid failure

Delay sending a gratuitous_arp when LINK_STATE_LINKWATCH_PENDING bit
in dev->state field is on. This improves the chances for the arp packet to
be transmitted.

Signed-off-by: Moni Shoua <monis at voltaire.com>
Acked-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

2 files changed, 22 insertions, 3 deletions

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 7be23364a9d6..19fd35175a77 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1103,8 +1103,14 @@ void bond_change_active_slave(struct bonding *bond, struct slave *new_active)
                 if (new_active && !bond->do_set_mac_addr)
                         memcpy(bond->dev->dev_addr,  new_active->dev->dev_addr,
                                 new_active->dev->addr_len);
-
-                bond_send_gratuitous_arp(bond);
+                if (bond->curr_active_slave &&
+                        test_bit(__LINK_STATE_LINKWATCH_PENDING,
+                                        &bond->curr_active_slave->dev->state)) {
+                        dprintk("delaying gratuitous arp on %s\n",
+                                bond->curr_active_slave->dev->name);
+                        bond->send_grat_arp = 1;
+                } else
+                        bond_send_gratuitous_arp(bond);
         }
 }
 
@@ -2073,6 +2079,17 @@ void bond_mii_monitor(struct net_device *bond_dev)
          * 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 = 0;
+                }
+        }
         read_lock(&bond->curr_slave_lock);
         oldcurrent = bond->curr_active_slave;
         read_unlock(&bond->curr_slave_lock);
@@ -2474,7 +2491,7 @@ static void bond_send_gratuitous_arp(struct bonding *bond)
 
         if (bond->master_ip) {
                 bond_arp_send(slave->dev, ARPOP_REPLY, bond->master_ip,
-                                  bond->master_ip, 0);
+                                bond->master_ip, 0);
         }
 
         list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
@@ -4280,6 +4297,7 @@ static int bond_init(struct net_device *bond_dev, struct bond_params *params)
         bond->current_arp_slave = NULL;
         bond->primary_slave = NULL;
         bond->dev = bond_dev;
+        bond->send_grat_arp = 0;
         INIT_LIST_HEAD(&bond->vlan_list);
 
         /* Initialize the device entry points */
diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
index ad9c632f88e4..e0e06a84b5b9 100644
--- a/drivers/net/bonding/bonding.h
+++ b/drivers/net/bonding/bonding.h
@@ -187,6 +187,7 @@ struct bonding {
         struct   timer_list arp_timer;
         s8       kill_timers;
         s8       do_set_mac_addr;
+        s8       send_grat_arp;
         struct   net_device_stats stats;
 #ifdef CONFIG_PROC_FS
         struct   proc_dir_entry *proc_entry;