ipv4, ipv6, bonding: Restore control over number of peer notifications

For backward compatibility, we should retain the module parameters and
sysfs attributes to control the number of peer notifications
(gratuitous ARPs and unsolicited NAs) sent after bonding failover.
Also, it is possible for failover to take place even though the new
active slave does not have link up, and in that case the peer
notification should be deferred until it does.

Change ipv4 and ipv6 so they do not automatically send peer
notifications on bonding failover.

Change the bonding driver to send separate NETDEV_NOTIFY_PEERS
notifications when the link is up, as many times as requested.  Since
it does not directly control which protocols send notifications, make
num_grat_arp and num_unsol_na aliases for a single parameter.  Bump
the bonding version number and update its documentation.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Acked-by: Brian Haley <brian.haley@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 89 insertions, 2 deletions

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 66d9dc6..22bd03b 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -89,6 +89,7 @@
 
 static int max_bonds	= BOND_DEFAULT_MAX_BONDS;
 static int tx_queues	= BOND_DEFAULT_TX_QUEUES;
+static int num_peer_notif = 1;
 static int miimon	= BOND_LINK_MON_INTERV;
 static int updelay;
 static int downdelay;
@@ -111,6 +112,10 @@ module_param(max_bonds, int, 0);
 MODULE_PARM_DESC(max_bonds, "Max number of bonded devices");
 module_param(tx_queues, int, 0);
 MODULE_PARM_DESC(tx_queues, "Max number of transmit queues (default = 16)");
+module_param_named(num_grat_arp, num_peer_notif, int, 0644);
+MODULE_PARM_DESC(num_grat_arp, "Number of peer notifications to send on failover event (alias of num_unsol_na)");
+module_param_named(num_unsol_na, num_peer_notif, int, 0644);
+MODULE_PARM_DESC(num_unsol_na, "Number of peer notifications to send on failover event (alias of num_grat_arp)");
 module_param(miimon, int, 0);
 MODULE_PARM_DESC(miimon, "Link check interval in milliseconds");
 module_param(updelay, int, 0);
@@ -1082,6 +1087,21 @@ static struct slave *bond_find_best_slave(struct bonding *bond)
 	return bestslave;
 }
 
+static bool bond_should_notify_peers(struct bonding *bond)
+{
+	struct slave *slave = bond->curr_active_slave;
+
+	pr_debug("bond_should_notify_peers: bond %s slave %s\n",
+		 bond->dev->name, slave ? slave->dev->name : "NULL");
+
+	if (!slave || !bond->send_peer_notif ||
+	    test_bit(__LINK_STATE_LINKWATCH_PENDING, &slave->dev->state))
+		return false;
+
+	bond->send_peer_notif--;
+	return true;
+}
+
 /**
  * change_active_interface - change the active slave into the specified one
  * @bond: our bonding struct
@@ -1149,16 +1169,28 @@ void bond_change_active_slave(struct bonding *bond, struct slave *new_active)
 			bond_set_slave_inactive_flags(old_active);
 
 		if (new_active) {
+			bool should_notify_peers = false;
+
 			bond_set_slave_active_flags(new_active);
 
 			if (bond->params.fail_over_mac)
 				bond_do_fail_over_mac(bond, new_active,
 						      old_active);
 
+			if (netif_running(bond->dev)) {
+				bond->send_peer_notif =
+					bond->params.num_peer_notif;
+				should_notify_peers =
+					bond_should_notify_peers(bond);
+			}
+
 			write_unlock_bh(&bond->curr_slave_lock);
 			read_unlock(&bond->lock);
 
 			netdev_bonding_change(bond->dev, NETDEV_BONDING_FAILOVER);
+			if (should_notify_peers)
+				netdev_bonding_change(bond->dev,
+						      NETDEV_NOTIFY_PEERS);
 
 			read_lock(&bond->lock);
 			write_lock_bh(&bond->curr_slave_lock);
@@ -2556,6 +2588,7 @@ void bond_mii_monitor(struct work_struct *work)
 {
 	struct bonding *bond = container_of(work, struct bonding,
 					    mii_work.work);
+	bool should_notify_peers = false;
 
 	read_lock(&bond->lock);
 	if (bond->kill_timers)
@@ -2564,6 +2597,8 @@ void bond_mii_monitor(struct work_struct *work)
 	if (bond->slave_cnt == 0)
 		goto re_arm;
 
+	should_notify_peers = bond_should_notify_peers(bond);
+
 	if (bond_miimon_inspect(bond)) {
 		read_unlock(&bond->lock);
 		rtnl_lock();
@@ -2582,6 +2617,12 @@ re_arm:
 				   msecs_to_jiffies(bond->params.miimon));
 out:
 	read_unlock(&bond->lock);
+
+	if (should_notify_peers) {
+		rtnl_lock();
+		netdev_bonding_change(bond->dev, NETDEV_NOTIFY_PEERS);
+		rtnl_unlock();
+	}
 }
 
 static __be32 bond_glean_dev_ip(struct net_device *dev)
@@ -3154,6 +3195,7 @@ void bond_activebackup_arp_mon(struct work_struct *work)
 {
 	struct bonding *bond = container_of(work, struct bonding,
 					    arp_work.work);
+	bool should_notify_peers = false;
 	int delta_in_ticks;
 
 	read_lock(&bond->lock);
@@ -3166,6 +3208,8 @@ void bond_activebackup_arp_mon(struct work_struct *work)
 	if (bond->slave_cnt == 0)
 		goto re_arm;
 
+	should_notify_peers = bond_should_notify_peers(bond);
+
 	if (bond_ab_arp_inspect(bond, delta_in_ticks)) {
 		read_unlock(&bond->lock);
 		rtnl_lock();
@@ -3185,6 +3229,12 @@ re_arm:
 		queue_delayed_work(bond->wq, &bond->arp_work, delta_in_ticks);
 out:
 	read_unlock(&bond->lock);
+
+	if (should_notify_peers) {
+		rtnl_lock();
+		netdev_bonding_change(bond->dev, NETDEV_NOTIFY_PEERS);
+		rtnl_unlock();
+	}
 }
 
 /*-------------------------- netdev event handling --------------------------*/
@@ -3494,6 +3544,8 @@ static int bond_close(struct net_device *bond_dev)
 
 	write_lock_bh(&bond->lock);
 
+	bond->send_peer_notif = 0;
+
 	/* signal timers not to re-arm */
 	bond->kill_timers = 1;
 
@@ -4571,6 +4623,12 @@ static int bond_check_params(struct bond_params *params)
 		use_carrier = 1;
 	}
 
+	if (num_peer_notif < 0 || num_peer_notif > 255) {
+		pr_warning("Warning: num_grat_arp/num_unsol_na (%d) not in range 0-255 so it was reset to 1\n",
+			   num_peer_notif);
+		num_peer_notif = 1;
+	}
+
 	/* reset values for 802.3ad */
 	if (bond_mode == BOND_MODE_8023AD) {
 		if (!miimon) {
@@ -4760,6 +4818,7 @@ static int bond_check_params(struct bond_params *params)
 	params->mode = bond_mode;
 	params->xmit_policy = xmit_hashtype;
 	params->miimon = miimon;
+	params->num_peer_notif = num_peer_notif;
 	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 935406a..4059bfc 100644
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c
@@ -869,6 +869,30 @@ static DEVICE_ATTR(ad_select, S_IRUGO | S_IWUSR,
 		   bonding_show_ad_select, bonding_store_ad_select);
 
 /*
+ * Show and set the number of peer notifications to send after a failover event.
+ */
+static ssize_t bonding_show_num_peer_notif(struct device *d,
+					   struct device_attribute *attr,
+					   char *buf)
+{
+	struct bonding *bond = to_bond(d);
+	return sprintf(buf, "%d\n", bond->params.num_peer_notif);
+}
+
+static ssize_t bonding_store_num_peer_notif(struct device *d,
+					    struct device_attribute *attr,
+					    const char *buf, size_t count)
+{
+	struct bonding *bond = to_bond(d);
+	int err = kstrtou8(buf, 10, &bond->params.num_peer_notif);
+	return err ? err : count;
+}
+static DEVICE_ATTR(num_grat_arp, S_IRUGO | S_IWUSR,
+		   bonding_show_num_peer_notif, bonding_store_num_peer_notif);
+static DEVICE_ATTR(num_unsol_na, S_IRUGO | S_IWUSR,
+		   bonding_show_num_peer_notif, bonding_store_num_peer_notif);
+
+/*
  * Show and set the MII monitor interval.  There are two tricky bits
  * here.  First, if MII monitoring is activated, then we must disable
  * ARP monitoring.  Second, if the timer isn't running, we must
@@ -1566,6 +1590,8 @@ static struct attribute *per_bond_attrs[] = {
 	&dev_attr_lacp_rate.attr,
 	&dev_attr_ad_select.attr,
 	&dev_attr_xmit_hash_policy.attr,
+	&dev_attr_num_grat_arp.attr,
+	&dev_attr_num_unsol_na.attr,
 	&dev_attr_miimon.attr,
 	&dev_attr_primary.attr,
 	&dev_attr_primary_reselect.attr,
diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
index 85fb822..d08362e 100644
--- a/drivers/net/bonding/bonding.h
+++ b/drivers/net/bonding/bonding.h
@@ -24,8 +24,8 @@
 #include "bond_3ad.h"
 #include "bond_alb.h"
 
-#define DRV_VERSION	"3.7.0"
-#define DRV_RELDATE	"June 2, 2010"
+#define DRV_VERSION	"3.7.1"
+#define DRV_RELDATE	"April 27, 2011"
 #define DRV_NAME	"bonding"
 #define DRV_DESCRIPTION	"Ethernet Channel Bonding Driver"
 
@@ -149,6 +149,7 @@ struct bond_params {
 	int mode;
 	int xmit_policy;
 	int miimon;
+	u8 num_peer_notif;
 	int arp_interval;
 	int arp_validate;
 	int use_carrier;
@@ -231,6 +232,7 @@ struct bonding {
 	rwlock_t lock;
 	rwlock_t curr_slave_lock;
 	s8       kill_timers;
+	u8	 send_peer_notif;
 	s8	 setup_by_slave;
 	s8       igmp_retrans;
 #ifdef CONFIG_PROC_FS