IB/cm: Fix stale connection detection

The ib_cm can incorrectly detect a stale connection (a new connection
request for a QPN that is already connected) as a duplicate connection
request.  Separate the handling of potential duplicate REQs from stale
connections.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 14 insertions, 11 deletions

diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c
index e840434a96d8..40c004a2697e 100644
--- a/drivers/infiniband/core/cm.c
+++ b/drivers/infiniband/core/cm.c
@@ -1297,26 +1297,29 @@ static struct cm_id_private * cm_match_req(struct cm_work *work,
 
         req_msg = (struct cm_req_msg *)work->mad_recv_wc->recv_buf.mad;
 
-        /* Check for duplicate REQ and stale connections. */
+        /* Check for possible duplicate REQ. */
         spin_lock_irqsave(&cm.lock, flags);
         timewait_info = cm_insert_remote_id(cm_id_priv->timewait_info);
-        if (!timewait_info)
-                timewait_info = cm_insert_remote_qpn(cm_id_priv->timewait_info);
-
         if (timewait_info) {
                 cur_cm_id_priv = cm_get_id(timewait_info->work.local_id,
                                            timewait_info->work.remote_id);
-                cm_cleanup_timewait(cm_id_priv->timewait_info);
                 spin_unlock_irqrestore(&cm.lock, flags);
                 if (cur_cm_id_priv) {
                         cm_dup_req_handler(work, cur_cm_id_priv);
                         cm_deref_id(cur_cm_id_priv);
-                } else
-                        cm_issue_rej(work->port, work->mad_recv_wc,
-                                     IB_CM_REJ_STALE_CONN, CM_MSG_RESPONSE_REQ,
-                                     NULL, 0);
-                listen_cm_id_priv = NULL;
-                goto out;
+                }
+                return NULL;
+        }
+
+        /* Check for stale connections. */
+        timewait_info = cm_insert_remote_qpn(cm_id_priv->timewait_info);
+        if (timewait_info) {
+                cm_cleanup_timewait(cm_id_priv->timewait_info);
+                spin_unlock_irqrestore(&cm.lock, flags);
+                cm_issue_rej(work->port, work->mad_recv_wc,
+                             IB_CM_REJ_STALE_CONN, CM_MSG_RESPONSE_REQ,
+                             NULL, 0);
+                return NULL;
         }
 
         /* Find matching listen request. */