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>

1 files changed, 26 insertions, 0 deletions

diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index 935406aa5f0c..4059bfc73dbf 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,