IB/cma: Add debug messages to error flows

index cf1edfa..6535f09 100644
@@ -3409,6 +3409,8 @@ static void cm_process_send_error(struct ib_mad_send_buf *msg,
 	if (msg != cm_id_priv->msg || state != cm_id_priv->id.state)
 		goto discard;
 
+	pr_debug_ratelimited("CM: failed sending MAD in state %d. (%s)\n",
+			     state, ib_wc_status_msg(wc_status));
 	switch (state) {
 	case IB_CM_REQ_SENT:
 	case IB_CM_MRA_REQ_RCVD:

index e7dcfac..847c5ad 100644
@@ -1689,6 +1689,7 @@ static int cma_rep_recv(struct rdma_id_private *id_priv)
 
 	return 0;
 reject:
+	pr_debug_ratelimited("RDMA CM: CONNECT_ERROR: failed to handle reply. status %d\n", ret);
 	cma_modify_qp_err(id_priv);
 	ib_send_cm_rej(id_priv->cm_id.ib, IB_CM_REJ_CONSUMER_DEFINED,
 		       NULL, 0, NULL, 0);

@@ -1760,6 +1761,8 @@ static int cma_ib_handler(struct ib_cm_id *cm_id, struct ib_cm_event *ib_event)
 		/* ignore event */
 		goto out;
 	case IB_CM_REJ_RECEIVED:
+		pr_debug_ratelimited("RDMA CM: REJECTED: %s\n", rdma_reject_msg(&id_priv->id,
+										ib_event->param.rej_rcvd.reason));
 		cma_modify_qp_err(id_priv);
 		event.status = ib_event->param.rej_rcvd.reason;
 		event.event = RDMA_CM_EVENT_REJECTED;

@@ -2285,6 +2288,8 @@ static void cma_query_handler(int status, struct ib_sa_path_rec *path_rec,
 		work->new_state = RDMA_CM_ADDR_RESOLVED;
 		work->event.event = RDMA_CM_EVENT_ROUTE_ERROR;
 		work->event.status = status;
+		pr_debug_ratelimited("RDMA CM: ROUTE_ERROR: failed to query path. status %d\n",
+				     status);
 	}
 
 	queue_work(cma_wq, &work->work);

@@ -2720,8 +2725,14 @@ static void addr_handler(int status, struct sockaddr *src_addr,
 		goto out;
 
 	memcpy(cma_src_addr(id_priv), src_addr, rdma_addr_size(src_addr));
-	if (!status && !id_priv->cma_dev)
+	if (!status && !id_priv->cma_dev) {
 		status = cma_acquire_dev(id_priv, NULL);
+		if (status)
+			pr_debug_ratelimited("RDMA CM: ADDR_ERROR: failed to acquire device. status %d\n",
+					     status);
+	} else {
+		pr_debug_ratelimited("RDMA CM: ADDR_ERROR: failed to resolve IP. status %d\n", status);
+	}
 
 	if (status) {
 		if (!cma_comp_exch(id_priv, RDMA_CM_ADDR_RESOLVED,

@@ -3307,10 +3318,13 @@ static int cma_sidr_rep_handler(struct ib_cm_id *cm_id,
 		if (rep->status != IB_SIDR_SUCCESS) {
 			event.event = RDMA_CM_EVENT_UNREACHABLE;
 			event.status = ib_event->param.sidr_rep_rcvd.status;
+			pr_debug_ratelimited("RDMA CM: UNREACHABLE: bad SIDR reply. status %d\n",
+					     event.status);
 			break;
 		}
 		ret = cma_set_qkey(id_priv, rep->qkey);
 		if (ret) {
+			pr_debug_ratelimited("RDMA CM: ADDR_ERROR: failed to set qkey. status %d\n", ret);
 			event.event = RDMA_CM_EVENT_ADDR_ERROR;
 			event.status = ret;
 			break;

@@ -3759,10 +3773,17 @@ static int cma_ib_mc_handler(int status, struct ib_sa_multicast *multicast)
 
 	if (!status)
 		status = cma_set_qkey(id_priv, be32_to_cpu(multicast->rec.qkey));
+	else
+		pr_debug_ratelimited("RDMA CM: MULTICAST_ERROR: failed to join multicast. status %d\n",
+				     status);
 	mutex_lock(&id_priv->qp_mutex);
-	if (!status && id_priv->id.qp)
+	if (!status && id_priv->id.qp) {
 		status = ib_attach_mcast(id_priv->id.qp, &multicast->rec.mgid,
 					 be16_to_cpu(multicast->rec.mlid));
+		if (!status)
+			pr_debug_ratelimited("RDMA CM: MULTICAST_ERROR: failed to attach QP. status %d\n",
+					     status);
+	}
 	mutex_unlock(&id_priv->qp_mutex);
 
 	memset(&event, 0, sizeof event);

index 847c5ad..bd8d051 100644
@@ -2843,20 +2843,26 @@ int rdma_resolve_addr(struct rdma_cm_id *id, struct sockaddr *src_addr,
 	int ret;
 
 	id_priv = container_of(id, struct rdma_id_private, id);
+	memcpy(cma_dst_addr(id_priv), dst_addr, rdma_addr_size(dst_addr));
 	if (id_priv->state == RDMA_CM_IDLE) {
 		ret = cma_bind_addr(id, src_addr, dst_addr);
-		if (ret)
+		if (ret) {
+			memset(cma_dst_addr(id_priv), 0, rdma_addr_size(dst_addr));
 			return ret;
+		}
 	}
 
-	if (cma_family(id_priv) != dst_addr->sa_family)
+	if (cma_family(id_priv) != dst_addr->sa_family) {
+		memset(cma_dst_addr(id_priv), 0, rdma_addr_size(dst_addr));
 		return -EINVAL;
+	}
 
-	if (!cma_comp_exch(id_priv, RDMA_CM_ADDR_BOUND, RDMA_CM_ADDR_QUERY))
+	if (!cma_comp_exch(id_priv, RDMA_CM_ADDR_BOUND, RDMA_CM_ADDR_QUERY)) {
+		memset(cma_dst_addr(id_priv), 0, rdma_addr_size(dst_addr));
 		return -EINVAL;
+	}
 
 	atomic_inc(&id_priv->refcount);
-	memcpy(cma_dst_addr(id_priv), dst_addr, rdma_addr_size(dst_addr));
 	if (cma_any_addr(dst_addr)) {
 		ret = cma_resolve_loopback(id_priv);
 	} else {

@@ -2972,6 +2978,43 @@ static int cma_alloc_port(enum rdma_port_space ps,
 	return ret == -ENOSPC ? -EADDRNOTAVAIL : ret;
 }
 
+static int cma_port_is_unique(struct rdma_bind_list *bind_list,
+			      struct rdma_id_private *id_priv)
+{
+	struct rdma_id_private *cur_id;
+	struct sockaddr  *daddr = cma_dst_addr(id_priv);
+	struct sockaddr  *saddr = cma_src_addr(id_priv);
+	__be16 dport = cma_port(daddr);
+
+	hlist_for_each_entry(cur_id, &bind_list->owners, node) {
+		struct sockaddr  *cur_daddr = cma_dst_addr(cur_id);
+		struct sockaddr  *cur_saddr = cma_src_addr(cur_id);
+		__be16 cur_dport = cma_port(cur_daddr);
+
+		if (id_priv == cur_id)
+			continue;
+
+		/* different dest port -> unique */
+		if (!cma_any_port(cur_daddr) &&
+		    (dport != cur_dport))
+			continue;
+
+		/* different src address -> unique */
+		if (!cma_any_addr(saddr) &&
+		    !cma_any_addr(cur_saddr) &&
+		    cma_addr_cmp(saddr, cur_saddr))
+			continue;
+
+		/* different dst address -> unique */
+		if (!cma_any_addr(cur_daddr) &&
+		    cma_addr_cmp(daddr, cur_daddr))
+			continue;
+
+		return -EADDRNOTAVAIL;
+	}
+	return 0;
+}
+
 static int cma_alloc_any_port(enum rdma_port_space ps,
 			      struct rdma_id_private *id_priv)
 {

@@ -2984,9 +3027,19 @@ static int cma_alloc_any_port(enum rdma_port_space ps,
 	remaining = (high - low) + 1;
 	rover = prandom_u32() % remaining + low;
 retry:
-	if (last_used_port != rover &&
-	    !cma_ps_find(net, ps, (unsigned short)rover)) {
-		int ret = cma_alloc_port(ps, id_priv, rover);
+	if (last_used_port != rover) {
+		struct rdma_bind_list *bind_list;
+		int ret;
+
+		bind_list = cma_ps_find(net, ps, (unsigned short)rover);
+
+		if (!bind_list) {
+			ret = cma_alloc_port(ps, id_priv, rover);
+		} else {
+			ret = cma_port_is_unique(bind_list, id_priv);
+			if (!ret)
+				cma_bind_port(bind_list, id_priv);
+		}
 		/*
 		 * Remember previously used port number in order to avoid
 		 * re-using same port immediately after it is closed.