IB/cm: avoid reusing local ID

Use an increasing local ID to avoid re-using identifiers while
messages may still be outstanding on the old ID.  Without this, a
quick connect-disconnect-connect sequence can fail by matching
messages for the new connection with the old connection.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/core/cm.c

@@ -308,10 +308,11 @@ static int cm_alloc_id(struct cm_id_private *cm_id_priv)
 {
 	unsigned long flags;
 	int ret;
+	static int next_id;
 
 	do {
 		spin_lock_irqsave(&cm.lock, flags);
-		ret = idr_get_new_above(&cm.local_id_table, cm_id_priv, 1,
+		ret = idr_get_new_above(&cm.local_id_table, cm_id_priv, next_id++,
 					(__force int *) &cm_id_priv->id.local_id);
 		spin_unlock_irqrestore(&cm.lock, flags);
 	} while( (ret == -EAGAIN) && idr_pre_get(&cm.local_id_table, GFP_KERNEL) );