ovs-ctl.in: Restore interfaces and ofports for userspace restarts.

When we upgrade from pre-1.9 to 1.10 or later branches, when just
the user space daemons are restarted, with the older kernel module
intact, datapaths are recreated.

This results in loosing the internal interface states like ip addresses,
routing table entries etc. Also, the 'ofport' value of the older interfaces
change.

With this patch we restore the interface states, ofport values etc,
when "ovs-ctl restart" or "/etc/init.d/openvswitch[-switch] restart
--save-flows" is called. The later command is automatically called
when debian packages are installed.

Signed-off-by: Gurucharan Shetty <gshetty@nicira.com>

utilities/ovs-ctl.in

@@ -285,8 +285,6 @@ save_ofports_if_required () {
             action "Saving ofport values" ovs_save save-ofports \
                 "${script_ofports}"
             ;;
-        *)
-            ;;
     esac
 }
 
@@ -315,7 +313,7 @@ restore_interfaces () {
         level=err
     fi
     log="logger -p daemon.$level -t ovs-save"
-    $log "force-reload-kmod interface restore script exited with status $rc:"
+    $log "interface restore script exited with status $rc:"
     $log -f "$script_interfaces"
 }
 
@@ -379,13 +377,25 @@ force_reload_kmod () {
 ## restart ##
 ## ------- ##
 
+save_interfaces_if_required () {
+    # Save interfaces if we are upgrading from a pre-1.10 branch.
+    case `ovs-appctl version | sed 1q` in
+        "ovs-vswitchd (Open vSwitch) 1."[0-9].*)
+            ifaces=`internal_interfaces`
+            action "Detected internal interfaces: $ifaces" true
+            if action "Saving interface configuration" save_interfaces; then
+                chmod +x "$script_interfaces"
+            fi
+            ;;
+    esac
+}
+
 restart () {
     if daemon_is_running ovsdb-server && daemon_is_running ovs-vswitchd; then
-        script_flows=`mktemp`
-        trap 'rm -f "${script_flows}"' 0
-
-        action "Saving flows" ovs_save save-flows "${script_flows}" \
-            script_flows
+        init_restore_scripts
+        save_interfaces_if_required
+        action "Saving flows" ovs_save save-flows "${script_flows}"
+        save_ofports_if_required
     fi
 
     # Restart the database first, since a large database may take a
@@ -393,11 +403,18 @@ restart () {
     stop_ovsdb
     start_ovsdb
 
+    # Restore of ofports, if required, should happen before vswitchd is
+    # restarted.
+    restore_ofports
+
     stop_forwarding
     start_forwarding
 
-    # Restore the saved flows. Do not return error if restore fails.
-    restore_flows || true
+    # Restore the saved flows.
+    restore_flows
+
+    # Restore the interfaces if required. Return true even if restore fails.
+    restore_interfaces || true
 }
 
 ## --------------- ##