ovn-controller: Fix releasing wrong vif

When binding an OVS interface to a logical port, if external_ids:iface-id is
set within the same transaction as adding the interface to a bridge,
ovn-controller is usually initially notified of ovs interface change with
ofport == 0.
If the lport was already bound to a different interface, the ofport=0
notification caused an unexpected release of the interface.

Signed-off-by: Xavier Simonart <xsimonar@redhat.com>
Acked-by: Han Zhou <hzhou@ovn.org>
Signed-off-by: Numan Siddique <numans@ovn.org>
(cherry picked from commit a2f80ce)

controller/binding.c

@@ -1958,6 +1958,23 @@ consider_iface_release(const struct ovsrec_interface *iface_rec,
     struct shash *binding_lports = &b_ctx_out->lbinding_data->lports;
 
     lbinding = local_binding_find(local_bindings, iface_id);
+
+   if (lbinding) {
+        int64_t ofport = iface_rec->n_ofport ? *iface_rec->ofport : 0;
+        if (lbinding->iface != iface_rec && !ofport) {
+            /* If external_ids:iface-id is set within the same transaction
+             * as adding an interface to a bridge, ovn-controller is
+             * usually initially notified of ovs interface changes with
+             * ofport == 0. If the lport was bound to a different interface
+             * we do not want to release it.
+             */
+            VLOG_DBG("Not releasing lport %s as %s was claimed "
+                     "and %s was never bound)", iface_id, lbinding->iface ?
+                     lbinding->iface->name : "", iface_rec->name);
+            return true;
+        }
+    }
+
     struct binding_lport *b_lport =
         local_binding_get_primary_or_localport_lport(lbinding);
     if (is_binding_lport_this_chassis(b_lport, b_ctx_in->chassis_rec)) {