IB/mad: Don't send response for failed MADs

Commit 0b307043049f ("IB/mad: Return error response for unsupported
MADs") does not failed MADs (eg those that return
IB_MAD_RESULT_FAILURE) properly -- these MADs should be silently
discarded. (We should not force the lower-layer drivers to return
SUCCESS | CONSUMED in this case, since the MAD is NOT successful).
Unsupported MADs are not failures -- they return SUCCESS, but with an
"unsupported error" status value inside the response MAD.

Reviewed-by: Hal Rosenstock <hal@mellanox.com>
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>

diff --git a/drivers/infiniband/core/mad.c b/drivers/infiniband/core/mad.c
index 1c73d8a..b0d0bc8 100644 (file)
--- a/drivers/infiniband/core/mad.c
+++ b/drivers/infiniband/core/mad.c
@@ -1871,6 +1871,7 @@ static void ib_mad_recv_done_handler(struct ib_mad_port_private *port_priv,
        struct ib_mad_list_head *mad_list;
        struct ib_mad_agent_private *mad_agent;
        int port_num;
+       int ret = IB_MAD_RESULT_SUCCESS;
 
        mad_list = (struct ib_mad_list_head *)(unsigned long)wc->wr_id;
        qp_info = mad_list->mad_queue->qp_info;
@@ -1954,8 +1955,6 @@ static void ib_mad_recv_done_handler(struct ib_mad_port_private *port_priv,
 local:
        /* Give driver "right of first refusal" on incoming MAD */
        if (port_priv->device->process_mad) {
-               int ret;
-
                ret = port_priv->device->process_mad(port_priv->device, 0,
                                                     port_priv->port_num,
                                                     wc, &recv->grh,
@@ -1983,7 +1982,8 @@ local:
                 * or via recv_handler in ib_mad_complete_recv()
                 */
                recv = NULL;
-       } else if (generate_unmatched_resp(recv, response)) {
+       } else if ((ret & IB_MAD_RESULT_SUCCESS) &&
+                  generate_unmatched_resp(recv, response)) {
                agent_send_response(&response->mad.mad, &recv->grh, wc,
                                    port_priv->device, port_num, qp_info->qp->qp_num);
        }