From 7893b2491a2d5f716540ac5643d78d37a7f6628b Mon Sep 17 00:00:00 2001
From: Moni Shoua <monis@voltaire.com>
Date: Sat, 17 May 2008 21:10:12 -0700
Subject: [PATCH] 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>
---
drivers/net/bonding/bond_main.c | 23 ++++++++++++++----
drivers/net/bonding/bond_sysfs.c | 40 ++++++++++++++++++++++++++++++++
drivers/net/bonding/bonding.h | 1 +
3 files changed, 60 insertions(+), 4 deletions(-)
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 2a0039f193770d..fa3c2101fe750d 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 @@ struct bond_params bonding_defaults;
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 @@ void bond_change_active_slave(struct bonding *bond, struct slave *new_active)
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 @@ static int __bond_mii_monitor(struct bonding *bond, int have_locks)
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 @@ static int bond_check_params(struct bond_params *params)
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 @@ static int bond_check_params(struct bond_params *params)
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;
diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index 1f028579e53bd8..7a61e9a143863a 100644
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c
@@ -950,6 +950,45 @@ out:
}
static DEVICE_ATTR(lacp_rate, S_IRUGO | S_IWUSR, bonding_show_lacp, bonding_store_lacp);
+/*
+ * Show and set the number of grat ARP to send after a failover event.
+ */
+static ssize_t bonding_show_n_grat_arp(struct device *d,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct bonding *bond = to_bond(d);
+
+ return sprintf(buf, "%d\n", bond->params.num_grat_arp);
+}
+
+static ssize_t bonding_store_n_grat_arp(struct device *d,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int new_value, ret = count;
+ struct bonding *bond = to_bond(d);
+
+ if (sscanf(buf, "%d", &new_value) != 1) {
+ printk(KERN_ERR DRV_NAME
+ ": %s: no num_grat_arp value specified.\n",
+ bond->dev->name);
+ ret = -EINVAL;
+ goto out;
+ }
+ if (new_value < 0 || new_value > 255) {
+ printk(KERN_ERR DRV_NAME
+ ": %s: Invalid num_grat_arp value %d not in range 0-255; rejected.\n",
+ bond->dev->name, new_value);
+ ret = -EINVAL;
+ goto out;
+ } else {
+ bond->params.num_grat_arp = new_value;
+ }
+out:
+ return ret;
+}
+static DEVICE_ATTR(num_grat_arp, S_IRUGO | S_IWUSR, bonding_show_n_grat_arp, bonding_store_n_grat_arp);
/*
* Show and set the MII monitor interval. There are two tricky bits
* here. First, if MII monitoring is activated, then we must disable
@@ -1387,6 +1426,7 @@ static struct attribute *per_bond_attrs[] = {
&dev_attr_updelay.attr,
&dev_attr_lacp_rate.attr,
&dev_attr_xmit_hash_policy.attr,
+ &dev_attr_num_grat_arp.attr,
&dev_attr_miimon.attr,
&dev_attr_primary.attr,
&dev_attr_use_carrier.attr,
diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
index 0ce7f4ae920f3e..46a2ed507b3325 100644
--- a/drivers/net/bonding/bonding.h
+++ b/drivers/net/bonding/bonding.h
@@ -125,6 +125,7 @@ struct bond_params {
int mode;
int xmit_policy;
int miimon;
+ int num_grat_arp;
int arp_interval;
int arp_validate;
int use_carrier;
--
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