do not hold the lock after controller has started

This enables controller to be able to create new watches after it has started.
This is required for cases where you are writing some meta-controller
which discovers new types to watch during the reconcilation.

pkg/internal/controller/controller.go

@@ -124,7 +124,6 @@ func (c *Controller) Watch(src source.Source, evthdler handler.EventHandler, prc
 // Start implements controller.Controller
 func (c *Controller) Start(stop <-chan struct{}) error {
 	c.mu.Lock()
-	defer c.mu.Unlock()
 
 	// TODO(pwittrock): Reconsider HandleCrash
 	defer utilruntime.HandleCrash()
@@ -142,6 +141,7 @@ func (c *Controller) Start(stop <-chan struct{}) error {
 		// Leaving it here because that could happen in the future
 		err := fmt.Errorf("failed to wait for %s caches to sync", c.Name)
 		log.Error(err, "Could not wait for Cache to sync", "Controller", c.Name)
+		c.mu.Unlock()
 		return err
 	}
 
@@ -160,6 +160,7 @@ func (c *Controller) Start(stop <-chan struct{}) error {
 	}
 
 	c.Started = true
+	c.mu.Unlock()
 
 	<-stop
 	log.Info("Stopping workers", "Controller", c.Name)