Rails 3 + Devise: Change password manually

edit.html.erb

<%= form_for :user, :url => password_path do |f| %>
   <p><%= f.label :current_password, "Current password" %><br />
   <%= f.password_field :current_password %></p>

  <p><%= f.label :password, "New password" %><br />
  <%= f.password_field :password %></p>

  <p><%= f.label :password_confirmation, "Confirm new password" %><br />
  <%= f.password_field :password_confirmation %></p>

  <p><%= f.submit "Change my password" %></p>
<% end %>

passwords_controller.rb

class PasswordsController < ApplicationController
  before_filter :authenticate_user!

  def edit
    @user = current_user
  end

  def update
    @user = current_user

    # Devise::Models::DatabaseAuthenticatable#update_with_password
    # Update record attributes when :current_password matches, otherwise returns error on :current_password.
    # It also automatically rejects :password and :password_confirmation if they are blank.
    if @user.update_with_password(params[:user])
      
      # Sign in the user bypassing validation in case his password changed
      sign_in @user, :bypass => true
      
      redirect_to root_path, :notice => "Your Password has been updated!"
    else

      flash[:alert] = @user.errors.full_messages.join("<br />")
      render :edit

    end
  end
end

routes.rb

devise_for :users ,:controllers => {:passwords => "passwords"} do
  resources :passwords
end

Same here.