Undefined method `name' for nil:NilClass for search form

I am creating search form, and I have created search controller and other controller named as user. Here is the code of search_controller

def search
  if params[:q]
    @users = User.q(params[:q]).order("created_at DESC").paginate(page: params[:page])
  else
    @users = User.all.order('created_at DESC').paginate(page: params[:page])
  end
end

Here is the search form

<%= form_tag search_path, :method => 'get' do %>
  <%= text_field_tag :q, params[:q] %>
  <%= submit_tag "Search", :name => nil %>
<% end %>

But when I search I am getting undefined method 'name' for nil:NilClass error.

class UsersController < ApplicationController
  before_action :logged_in_user, only: [:index, :edit, :destroy] 

  def index
    @users = User.paginate(page: params[:page])
  end

  def show
    @user = User.find(params[:id])
    @archings = @user.archings.paginate(page: params[:page])
  end

  def new
    @user = User.new
  end

  def destroy
    User.find(params[:id]).destroy
    flash[:success] = "User deleted"
    redirect_to users_url
  end

  def create
    @user = User.new(user_params)
    if @user.save
      log_in @user
      flash[:success] = "Welcome to the Arch"
      redirect_to @user
    else
      render 'new'
    end
  end

  def edit
    @user = User.find(params[:id])
  end

  private

    def user_params
      params.require(:user).permit(:name, :email, :password,
                                   :password_confirmation)
    end

   def logged_in_user
      unless logged_in?
    store_location
        flash[:danger] = "Please log in."
        redirect_to login_url
      end

 end
end

Can anyone tell me where I am doing mistake?

PS: I am beginner and new to rails and ruby.

via Chebli Mohamed