[PATCH] IB/ipath: enforce device resource limits

These limits are somewhat artificial in that we don't actually have any
device limits.  However, the verbs layer expects that such limits exist
and are enforced, so we make up arbitrary (but sensible) limits.

Signed-off-by: Robert Walsh <robert.walsh@qlogic.com>
Signed-off-by: Bryan O'Sullivan <bryan.osullivan@qlogic.com>
Cc: "Michael S. Tsirkin" <mst@mellanox.co.il>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 30 insertions, 6 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_verbs_mcast.c b/drivers/infiniband/hw/ipath/ipath_verbs_mcast.c
index 996bbb05c396..ee0e1d96d723 100644
--- a/drivers/infiniband/hw/ipath/ipath_verbs_mcast.c
+++ b/drivers/infiniband/hw/ipath/ipath_verbs_mcast.c
@@ -93,6 +93,7 @@ static struct ipath_mcast *ipath_mcast_alloc(union ib_gid *mgid)
 	INIT_LIST_HEAD(&mcast->qp_list);
 	init_waitqueue_head(&mcast->wait);
 	atomic_set(&mcast->refcount, 0);
+	mcast->n_attached = 0;
 
 bail:
 	return mcast;
@@ -158,7 +159,8 @@ bail:
  * the table but the QP was added.  Return ESRCH if the QP was already
  * attached and neither structure was added.
  */
-static int ipath_mcast_add(struct ipath_mcast *mcast,
+static int ipath_mcast_add(struct ipath_ibdev *dev,
+			   struct ipath_mcast *mcast,
 			   struct ipath_mcast_qp *mqp)
 {
 	struct rb_node **n = &mcast_tree.rb_node;
@@ -189,34 +191,47 @@ static int ipath_mcast_add(struct ipath_mcast *mcast,
 		/* Search the QP list to see if this is already there. */
 		list_for_each_entry_rcu(p, &tmcast->qp_list, list) {
 			if (p->qp == mqp->qp) {
-				spin_unlock_irqrestore(&mcast_lock, flags);
 				ret = ESRCH;
 				goto bail;
 			}
 		}
+		if (tmcast->n_attached == ib_ipath_max_mcast_qp_attached) {
+			ret = ENOMEM;
+			goto bail;
+		}
+
+		tmcast->n_attached++;
+
 		list_add_tail_rcu(&mqp->list, &tmcast->qp_list);
-		spin_unlock_irqrestore(&mcast_lock, flags);
 		ret = EEXIST;
 		goto bail;
 	}
 
+	if (dev->n_mcast_grps_allocated == ib_ipath_max_mcast_grps) {
+		ret = ENOMEM;
+		goto bail;
+	}
+
+	dev->n_mcast_grps_allocated++;
+
 	list_add_tail_rcu(&mqp->list, &mcast->qp_list);
 
 	atomic_inc(&mcast->refcount);
 	rb_link_node(&mcast->rb_node, pn, n);
 	rb_insert_color(&mcast->rb_node, &mcast_tree);
 
-	spin_unlock_irqrestore(&mcast_lock, flags);
-
 	ret = 0;
 
 bail:
+	spin_unlock_irqrestore(&mcast_lock, flags);
+
 	return ret;
 }
 
 int ipath_multicast_attach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
 {
 	struct ipath_qp *qp = to_iqp(ibqp);
+	struct ipath_ibdev *dev = to_idev(ibqp->device);
 	struct ipath_mcast *mcast;
 	struct ipath_mcast_qp *mqp;
 	int ret;
@@ -236,7 +251,7 @@ int ipath_multicast_attach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
 		ret = -ENOMEM;
 		goto bail;
 	}
-	switch (ipath_mcast_add(mcast, mqp)) {
+	switch (ipath_mcast_add(dev, mcast, mqp)) {
 	case ESRCH:
 		/* Neither was used: can't attach the same QP twice. */
 		ipath_mcast_qp_free(mqp);
@@ -246,6 +261,12 @@ int ipath_multicast_attach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
 	case EEXIST:		/* The mcast wasn't used */
 		ipath_mcast_free(mcast);
 		break;
+	case ENOMEM:
+		/* Exceeded the maximum number of mcast groups. */
+		ipath_mcast_qp_free(mqp);
+		ipath_mcast_free(mcast);
+		ret = -ENOMEM;
+		goto bail;
 	default:
 		break;
 	}
@@ -259,6 +280,7 @@ bail:
 int ipath_multicast_detach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
 {
 	struct ipath_qp *qp = to_iqp(ibqp);
+	struct ipath_ibdev *dev = to_idev(ibqp->device);
 	struct ipath_mcast *mcast = NULL;
 	struct ipath_mcast_qp *p, *tmp;
 	struct rb_node *n;
@@ -297,6 +319,7 @@ int ipath_multicast_detach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
 		 * link until we are sure there are no list walkers.
 		 */
 		list_del_rcu(&p->list);
+		mcast->n_attached--;
 
 		/* If this was the last attached QP, remove the GID too. */
 		if (list_empty(&mcast->qp_list)) {
@@ -320,6 +343,7 @@ int ipath_multicast_detach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
 		atomic_dec(&mcast->refcount);
 		wait_event(mcast->wait, !atomic_read(&mcast->refcount));
 		ipath_mcast_free(mcast);
+		dev->n_mcast_grps_allocated--;
 	}
 
 	ret = 0;