[ofa-general] [PATCH V2] IB/ipoib: Do not turn on carrier to a non active port

[Moni Shoua]

This patch fixes https://bugs.openfabrics.org/show_bug.cgi?id=1726
Multicast join can succeed even if IB port is down. This happens when OpenSM
runs on the same port with the requesting port. IPoIB on the other hand, calls
netif_carrier_on() when join succeeded without caring about the state of
the IB port. The result is an IPoIB interface in RUNNING state but without
active IB port to support it. If a bonding interface uses this IPoIB interface
as a slave it might not detect that this slave is almost useless and failover
functionality will be damaged.
The fix  checks the state of the IB port in the carrier_task before
calling netif_carrier_on().

Signed-off-by: Moni Shoua <monis at voltaire.com>
---
 drivers/infiniband/ulp/ipoib/ipoib_multicast.c |    7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
index 25874fc..9ace51d 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
@@ -362,12 +362,19 @@ void ipoib_mcast_carrier_on_task(struct work_struct *work)
 {
 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
 						   carrier_on_task);
+	struct ib_port_attr attr;
 
 	/*
 	 * Take rtnl_lock to avoid racing with ipoib_stop() and
 	 * turning the carrier back on while a device is being
 	 * removed.
 	 */
+
+	if (ib_query_port(priv->ca, priv->port, &attr) ||
+		attr.state != IB_PORT_ACTIVE) {
+		ipoib_dbg(priv, "wait with carrier until IB port is active\n");
+		return;
+	}
 	rtnl_lock();
 	netif_carrier_on(priv->dev);
 	rtnl_unlock();