4 files changed, 27 insertions, 1 deletions

diff --git a/drivers/infiniband/ulp/ipoib/ipoib.h b/drivers/infiniband/ulp/ipoib/ipoib.h
index 4f7d9b48df64..9dbfcc0ab577 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib.h
+++ b/drivers/infiniband/ulp/ipoib/ipoib.h
@@ -478,6 +478,7 @@ void ipoib_send(struct net_device *dev, struct sk_buff *skb,
 		struct ipoib_ah *address, u32 qpn);
 void ipoib_reap_ah(struct work_struct *work);
 
+struct ipoib_path *__path_find(struct net_device *dev, void *gid);
 void ipoib_mark_paths_invalid(struct net_device *dev);
 void ipoib_flush_paths(struct net_device *dev);
 int ipoib_check_sm_sendonly_fullmember_support(struct ipoib_dev_priv *priv);
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_cm.c b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
index 951d9abcca8b..4ad297d3de89 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_cm.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
@@ -1318,6 +1318,8 @@ void ipoib_cm_destroy_tx(struct ipoib_cm_tx *tx)
 	}
 }
 
+#define QPN_AND_OPTIONS_OFFSET	4
+
 static void ipoib_cm_tx_start(struct work_struct *work)
 {
 	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
@@ -1326,6 +1328,7 @@ static void ipoib_cm_tx_start(struct work_struct *work)
 	struct ipoib_neigh *neigh;
 	struct ipoib_cm_tx *p;
 	unsigned long flags;
+	struct ipoib_path *path;
 	int ret;
 
 	struct ib_sa_path_rec pathrec;
@@ -1338,7 +1341,19 @@ static void ipoib_cm_tx_start(struct work_struct *work)
 		p = list_entry(priv->cm.start_list.next, typeof(*p), list);
 		list_del_init(&p->list);
 		neigh = p->neigh;
+
 		qpn = IPOIB_QPN(neigh->daddr);
+		/*
+		 * As long as the search is with these 2 locks,
+		 * path existence indicates its validity.
+		 */
+		path = __path_find(dev, neigh->daddr + QPN_AND_OPTIONS_OFFSET);
+		if (!path) {
+			pr_info("%s ignore not valid path %pI6\n",
+				__func__,
+				neigh->daddr + QPN_AND_OPTIONS_OFFSET);
+			goto free_neigh;
+		}
 		memcpy(&pathrec, &p->path->pathrec, sizeof pathrec);
 
 		spin_unlock_irqrestore(&priv->lock, flags);
@@ -1350,6 +1365,7 @@ static void ipoib_cm_tx_start(struct work_struct *work)
 		spin_lock_irqsave(&priv->lock, flags);
 
 		if (ret) {
+free_neigh:
 			neigh = p->neigh;
 			if (neigh) {
 				neigh->cm = NULL;
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_ib.c b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
index dc6d241b9406..be11d5d5b8c1 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_ib.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
@@ -1161,8 +1161,17 @@ static void __ipoib_ib_dev_flush(struct ipoib_dev_priv *priv,
 	}
 
 	if (level == IPOIB_FLUSH_LIGHT) {
+		int oper_up;
 		ipoib_mark_paths_invalid(dev);
+		/* Set IPoIB operation as down to prevent races between:
+		 * the flush flow which leaves MCG and on the fly joins
+		 * which can happen during that time. mcast restart task
+		 * should deal with join requests we missed.
+		 */
+		oper_up = test_and_clear_bit(IPOIB_FLAG_OPER_UP, &priv->flags);
 		ipoib_mcast_dev_flush(dev);
+		if (oper_up)
+			set_bit(IPOIB_FLAG_OPER_UP, &priv->flags);
 		ipoib_flush_ah(dev);
 	}
 
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index 74bcaa064226..cc1c1b062ea5 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -485,7 +485,7 @@ int ipoib_set_mode(struct net_device *dev, const char *buf)
 	return -EINVAL;
 }
 
-static struct ipoib_path *__path_find(struct net_device *dev, void *gid)
+struct ipoib_path *__path_find(struct net_device *dev, void *gid)
 {
 	struct ipoib_dev_priv *priv = netdev_priv(dev);
 	struct rb_node *n = priv->path_tree.rb_node;