Laravel - 重定向到控制器

Question

I keep getting: Unknown action [HomeController@showHome]

Route:

Route::get('/', ['before' => 'checkUserFilter'], 'HomeController@showHome');
Route::get('/createUser', 'UserController@createUser');

Filter:

Route::filter('checkUserFilter', function() 
{
    if (Auth::guest()) 
    {
        return Redirect::action('UserController@createUser');
    }  

});

Controller:

userController

public function createUser()
{
   // removed everything else, the return redirect action isn't working.

  return Redirect::action('HomeController@showHome');
}

homeController

public function showHome()
{
    return View::make('home');
}

When a user loads the webpage, the filter checks if he's a guest or not, if he is, go to the createUser method in UserController.php. It creates the user, but it doesn't redirect back to HomeController. How can I stop the above error so it redirect back to the HomeController?

I also have another question: What would be a better way to place the return redirection action, besides in the method? I would like it if I can use this same method for multiple things, for example create a user in the admin control panel.