[openib-general] [PATCH] address handle refrences in ipoib_multicast.c

[Michael S. Tsirkin]

Multiple ipoib_neigh structures on mcast->neigh_list may point to the same ah.
Handle this in ipoib_multicast.c, in the same way as it is handled in
ipoib_main.c for struct ipoib_path.

Signed-off-by: Eli Cohen <eli at mellanox.co.il>
Signed-off-by: Michael S. Tsirkin <mst at mellanox.co.il>

Index: openib/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
===================================================================
--- openib/drivers/infiniband/ulp/ipoib/ipoib_multicast.c	(revision 4523)
+++ openib/drivers/infiniband/ulp/ipoib/ipoib_multicast.c	(working copy)
@@ -95,8 +95,6 @@ static void ipoib_mcast_free(struct ipoi
 	struct ipoib_dev_priv *priv = netdev_priv(dev);
 	struct ipoib_neigh *neigh, *tmp;
 	unsigned long flags;
-	LIST_HEAD(ah_list);
-	struct ipoib_ah *ah, *tah;
 
 	ipoib_dbg_mcast(netdev_priv(dev),
 			"deleting multicast group " IPOIB_GID_FMT "\n",
@@ -105,8 +103,14 @@ static void ipoib_mcast_free(struct ipoi
 	spin_lock_irqsave(&priv->lock, flags);
 
 	list_for_each_entry_safe(neigh, tmp, &mcast->neigh_list, list) {
+		/*
+		 * It's safe to call ipoib_put_ah() inside priv->lock
+		 * here, because we know that mcast->ah will always
+		 * hold one more reference, so ipoib_put_ah() will
+		 * never do more than decrement the ref count.
+		 */
 		if (neigh->ah)
-			list_add_tail(&neigh->ah->list, &ah_list);
+			ipoib_put_ah(neigh->ah);
 		*to_ipoib_neigh(neigh->neighbour) = NULL;
 		neigh->neighbour->ops->destructor = NULL;
 		kfree(neigh);
@@ -114,9 +118,6 @@ static void ipoib_mcast_free(struct ipoi
 
 	spin_unlock_irqrestore(&priv->lock, flags);
 
-	list_for_each_entry_safe(ah, tah, &ah_list, list)
-		ipoib_put_ah(ah);
-
 	if (mcast->ah)
 		ipoib_put_ah(mcast->ah);
 

-- 
MST