From 97460df37ea3335ca11562568932c9f9facfecdb Mon Sep 17 00:00:00 2001 From: Eli Cohen Date: Tue, 10 Jan 2006 07:43:02 -0800 Subject: [PATCH] IPoIB: Fix address handle refcounting for multicast groups Multiple ipoib_neigh structures on mcast->neigh_list may point to the same ah. This means that ipoib_mcast_free() can't just make a list of ah structs to free, since this might end up trying to add the same ah to the list more than once. 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 Signed-off-by: Michael S. Tsirkin Signed-off-by: Roland Dreier --- drivers/infiniband/ulp/ipoib/ipoib_multicast.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c index 6c6db759e79e..03b2ca64a40c 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c @@ -97,8 +97,6 @@ static void ipoib_mcast_free(struct ipoib_mcast *mcast) 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", @@ -107,8 +105,14 @@ static void ipoib_mcast_free(struct ipoib_mcast *mcast) 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); @@ -116,9 +120,6 @@ static void ipoib_mcast_free(struct ipoib_mcast *mcast) 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);