bonding: Send more than one gratuitous ARP when slave takes over
With IPoIB, reception of gratuitous ARP by neighboring hosts
is essential for a successful change of slaves in case of failure.
Otherwise, they won't learn about the HW address change and need
to wait a long time until the neighboring system gives up and sends
an ARP request to learn the new HW address. This patch decreases
the chance for a lost of a gratuitous ARP packet by sending it more
than once. The number retries is configurable and can be set with a
module param.
Signed-off-by: Moni Shoua <monis@voltaire.com>
Acked-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 2a0039f..fa3c210 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -88,6 +88,7 @@
#define BOND_LINK_ARP_INTERV 0
static int max_bonds = BOND_DEFAULT_MAX_BONDS;
+static int num_grat_arp = 1;
static int miimon = BOND_LINK_MON_INTERV;
static int updelay = 0;
static int downdelay = 0;
@@ -104,6 +105,8 @@
module_param(max_bonds, int, 0);
MODULE_PARM_DESC(max_bonds, "Max number of bonded devices");
+module_param(num_grat_arp, int, 0644);
+MODULE_PARM_DESC(num_grat_arp, "Number of gratuitous ARP packets to send on failover event");
module_param(miimon, int, 0);
MODULE_PARM_DESC(miimon, "Link check interval in milliseconds");
module_param(updelay, int, 0);
@@ -1109,14 +1112,18 @@
if (new_active && bond->params.fail_over_mac)
memcpy(bond->dev->dev_addr, new_active->dev->dev_addr,
new_active->dev->addr_len);
+ bond->send_grat_arp = bond->params.num_grat_arp;
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);
+ } else {
+ if (bond->send_grat_arp > 0) {
+ bond_send_gratuitous_arp(bond);
+ bond->send_grat_arp--;
+ }
+ }
}
}
@@ -2144,7 +2151,7 @@
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;
+ bond->send_grat_arp--;
}
}
read_lock(&bond->curr_slave_lock);
@@ -4626,6 +4633,13 @@
use_carrier = 1;
}
+ if (num_grat_arp < 0 || num_grat_arp > 255) {
+ printk(KERN_WARNING DRV_NAME
+ ": Warning: num_grat_arp (%d) not in range 0-255 so it "
+ "was reset to 1 \n", num_grat_arp);
+ num_grat_arp = 1;
+ }
+
/* reset values for 802.3ad */
if (bond_mode == BOND_MODE_8023AD) {
if (!miimon) {
@@ -4813,6 +4827,7 @@
params->mode = bond_mode;
params->xmit_policy = xmit_hashtype;
params->miimon = miimon;
+ params->num_grat_arp = num_grat_arp;
params->arp_interval = arp_interval;
params->arp_validate = arp_validate_value;
params->updelay = updelay;
