show error flash on failed file stuffs

app/controllers/users_controller.rb

@@ -5,17 +5,15 @@ class UsersController < ApplicationController
   def show
   end
 
-  def edit
-  end
-
   def update
     if @user.update_attributes(user_params)
       flash[:success] = "Successfully updated!"
-      redirect_to @user
     else
+      flash[:error] = "Update failed!"
+      # TODO form errors?
       @user.reload
-      render 'edit'
     end
+    redirect_to @user
   end
 
   def edit_dagschotel
@@ -38,7 +36,7 @@ class UsersController < ApplicationController
   private
 
     def user_params
-      params.require(:user).permit(:avatar, :private, :dagschotel_id)
+      params.fetch(:user, {}).permit(:avatar, :private, :dagschotel_id)
     end
 
     def init

config/routes.rb

@@ -17,7 +17,7 @@ Rails.application.routes.draw do
     end
   end
 
-  resources :users, only: [:show] do
+  resources :users, only: [:show, :update] do
     resources :orders, only: [:new, :create, :destroy]
     member do
       get 'quickpay'               => 'users#quickpay'