librdmacm: Ack the pending event in sync UD connection

[ Upstream commit 9a0fc3a ]

When the server accepts a UD connection request in sync mode,
the event needs to be acked, otherwise destroying the
listening id would get stuck because there is a pending event.
For RC, the event is acked in ucma_complete().

Fixes: 332b203 ("librdmacm: Do not wait in rdma_accept for UD QPs")
Signed-off-by: Oren Sidi <osidi@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Sean Hefty <shefty@nvidia.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: Nicolas Morey <nmorey@suse.com>

librdmacm/cma.c

@@ -1953,8 +1953,14 @@ int rdma_accept(struct rdma_cm_id *id, struct rdma_conn_param *conn_param)
 		return (ret >= 0) ? ERR(ENODATA) : -1;
 	}
 
-	if (ucma_is_ud_qp(id->qp_type))
+	if (ucma_is_ud_qp(id->qp_type)) {
+		if (id_priv->sync && id_priv->id.event) {
+			rdma_ack_cm_event(id_priv->id.event);
+			id_priv->id.event = NULL;
+		}
+
 		return 0;
+	}
 
 	return ucma_complete(id);
 }