[ofa-general] [PATCH v3] ipoib: do not join broadcast group if interface is brought down

[Yossi Etigin]

Because ipoib_workqueue is not flushed when ipoib interface is brought down,
ipoib_mcast_join() may trigger a join to the broadcast group after priv->broadcast
was set to NULL (during cleanup). This will cause ipoib to be joined to the
broadcast group when interface is down.
As a side effect, this breaks the optimization of setting qkey only when joining
the broadcast group.

Signed-off-by: Yossi Etigin <yosefe at voltaire.com>

--

Changes from v1:
 - Put checks in places where was assumed priv->broadcast != NULL.

Changes from v2:
 - Put a lock around the NULL check in ipoib_mcast_join_task.

Fix bugzilla 1370.

---
 drivers/infiniband/ulp/ipoib/ipoib_multicast.c |   16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

Index: b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
===================================================================
--- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c	2008-12-31 09:56:22.000000000 +0200
+++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c	2008-12-31 09:57:13.000000000 +0200
@@ -502,7 +502,7 @@ static void ipoib_mcast_join(struct net_
 		IB_SA_MCMEMBER_REC_PKEY		|
 		IB_SA_MCMEMBER_REC_JOIN_STATE;
 
-	if (create) {
+	if (create && priv->broadcast) {
 		comp_mask |=
 			IB_SA_MCMEMBER_REC_QKEY			|
 			IB_SA_MCMEMBER_REC_MTU_SELECTOR		|
@@ -570,7 +570,8 @@ void ipoib_mcast_join_task(struct work_s
 			ipoib_warn(priv, "ib_query_port failed\n");
 	}
 
-	if (!priv->broadcast) {
+	rtnl_lock();
+	if (test_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags) && !priv->broadcast) {
 		struct ipoib_mcast *broadcast;
 
 		broadcast = ipoib_mcast_alloc(dev, 1);
@@ -581,6 +582,7 @@ void ipoib_mcast_join_task(struct work_s
 				queue_delayed_work(ipoib_workqueue,
 						   &priv->mcast_join_task, HZ);
 			mutex_unlock(&mcast_mutex);
+			rtnl_unlock();
 			return;
 		}
 
@@ -592,12 +594,17 @@ void ipoib_mcast_join_task(struct work_s
 		__ipoib_mcast_add(dev, priv->broadcast);
 		spin_unlock_irq(&priv->lock);
 	}
+	rtnl_unlock();
 
-	if (!test_bit(IPOIB_MCAST_FLAG_ATTACHED, &priv->broadcast->flags)) {
+	spin_lock_irq(&priv->lock);
+	if (priv->broadcast &&
+	    !test_bit(IPOIB_MCAST_FLAG_ATTACHED, &priv->broadcast->flags)) {
 		if (!test_bit(IPOIB_MCAST_FLAG_BUSY, &priv->broadcast->flags))
 			ipoib_mcast_join(dev, priv->broadcast, 0);
+		spin_unlock_irq(&priv->lock);
 		return;
 	}
+	spin_unlock_irq(&priv->lock);
 
 	while (1) {
 		struct ipoib_mcast *mcast = NULL;
@@ -622,7 +629,8 @@ void ipoib_mcast_join_task(struct work_s
 		return;
 	}
 
-	priv->mcast_mtu = IPOIB_UD_MTU(ib_mtu_enum_to_int(priv->broadcast->mcmember.mtu));
+	if (priv->broadcast)
+		priv->mcast_mtu = IPOIB_UD_MTU(ib_mtu_enum_to_int(priv->broadcast->mcmember.mtu));
 
 	if (!ipoib_cm_admin_enabled(dev)) {
 		rtnl_lock();

-- 
--Yossi