librdmacm/cm: override default responder_resources with user value

By default, the responder_resources parameter is set to that received
in a connection request.  The passive side may override this value
when accepting the connection.  Use the value provided by the passive
side when transitioning the QP to RTR state, rather than the value
given in the connect request.  Without this change, the RTR transition
may fail if the passive side supports fewer responder_resources than
that in the request.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>

diff --git a/src/cma.c b/src/cma.c
index 00ea394d0e103755bf8e374108d4c6ba88a7c076..751ca9dfed69cec85a2a5e3432c6fb442bd65ff9 100644 (file)
--- a/src/cma.c
+++ b/src/cma.c
@@ -611,7 +611,8 @@ static int rdma_init_qp_attr(struct rdma_cm_id *id, struct ibv_qp_attr *qp_attr,
        return 0;
 }
 
-static int ucma_modify_qp_rtr(struct rdma_cm_id *id)
+static int ucma_modify_qp_rtr(struct rdma_cm_id *id,
+                             struct rdma_conn_param *conn_param)
 {
        struct ibv_qp_attr qp_attr;
        int qp_attr_mask, ret;
@@ -634,6 +635,8 @@ static int ucma_modify_qp_rtr(struct rdma_cm_id *id)
        if (ret)
                return ret;
 
+       if (conn_param)
+               qp_attr.max_dest_rd_atomic = conn_param->responder_resources;
        return ibv_modify_qp(id->qp, &qp_attr, qp_attr_mask);
 }
 
@@ -911,7 +914,7 @@ int rdma_accept(struct rdma_cm_id *id, struct rdma_conn_param *conn_param)
                return ret;
 
        if (!ucma_is_ud_ps(id->ps)) {
-               ret = ucma_modify_qp_rtr(id);
+               ret = ucma_modify_qp_rtr(id, conn_param);
                if (ret)
                        return ret;
        }
@@ -1193,7 +1196,7 @@ static int ucma_process_conn_resp(struct cma_id_private *id_priv)
        void *msg;
        int ret, size;
 
-       ret = ucma_modify_qp_rtr(&id_priv->id);
+       ret = ucma_modify_qp_rtr(&id_priv->id, NULL);
        if (ret)
                goto err;