IPoIB: Don't drop multicast sends when they can be queued
When set_multicast_list() is called the multicast task is restarted
and the IPOIB_MCAST_STARTED bit is cleared. As a result for some
window of time, multicast packets are not transmitted nor queued but
rather dropped by ipoib_mcast_send(). These dropped packets are
painful in two cases:
- bonding fail-over which both calls set_multicast_list() on the new
active slave and sends Gratuitous ARP through that slave.
- IP_DROP_MEMBERSHIP code which both calls set_multicast_list() on the
device and issues IGMP leave.
In both these cases, depending on the scheduling of the IPoIB
multicast task, the packets would be dropped. As a result, in the
bonding case, the failover would not be detected by the peers until
their neighbour is renewed the neighbour (which takes a few tens of
seconds). In the IGMP case, the IP router doesn't get an IGMP leave
and would only learn on that from further probes on the group (also a
delay of at least a few tens of seconds).
Fix this by allowing transmission (or queuing) depending on the
IPOIB_FLAG_OPER_UP flag instead of the IPOIB_MCAST_STARTED flag.
Signed-off-by: Olga Shern <olgas@voltaire.com>
Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
index 2628339..31a53c5 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
@@ -650,7 +650,7 @@
*/
spin_lock(&priv->lock);
- if (!test_bit(IPOIB_MCAST_STARTED, &priv->flags) ||
+ if (!test_bit(IPOIB_FLAG_OPER_UP, &priv->flags) ||
!priv->broadcast ||
!test_bit(IPOIB_MCAST_FLAG_ATTACHED, &priv->broadcast->flags)) {
++dev->stats.tx_dropped;