ruby - Stack Level Too Deep Error In Rails -

i'm getting error in rails , there's no other information me figure out why.

systemstackerror in usercontroller#students stack level deep 

my user controller follows

class usercontroller < applicationcontroller   before_filter :authenticate_user!, :except => [:show, :students, :mentors]   ...   def students     @users = student.where(:verify_code => 'verified')   end end 

even when remove @users line error persists.

edit: error seems happen every single route aside devise_for :users , to_root, means user controller.

user model

require 'json' require 'socket'  class user < activerecord::base   serialize :roles   devise :database_authenticatable, :registerable,     :recoverable, :rememberable, :trackable, :validatable   validates :ign, :server, :roles, :presence => true   validate :summoner_exists   validate :valid_roles   attr_accessible :email, :password, :password_confirmation, :remember_me, :ign, :server, :tier, :roles, :type     def valid_roles     valid_role_array = ['top', 'mid', 'jungle', 'ad carry', 'support']     self.roles.each |role|        unless valid_role_array.include?(role)         self.roles.delete(role)       end     end   end    def summoner_verified?     return self.verify_code == 'verified'   end    def summoner_verify     rune_pages = shurima_api(self.server, 'rune_pages', self.acctid)     unless rune_pages       return false     else       rune_pages.each |page|         if (page['name'] == self.verify_code)           self.verify_code = 'verified'           self.save           return true         end       end     end     return false   end    def summoner_exists     json = shurima_api(self.server, 'summoner', self.ign)     unless json       errors.add(:ign, "the summoner name \"#{self.ign}\" doesn't exist on #{self.server}")     else       self.summonerid = json['summonerid']       self.acctid = json['acctid']       self.verify_code = array.new(10){rand(36).to_s(36)}.join       eligible_to_mentor     end   end    def eligible_to_mentor     leagues = shurima_api(self.server, 'leagues', self.summonerid)     unless leagues       errors.add(:ign, "that summoner doesn't seem meet requirements become mentor. make sure you're @ least in platinum league")       return false     end     leagues.each |league|        if (league['queue'] == 'ranked_solo_5x5')         self.tier = league['tier']       end     end     eligible_tiers = ['platinum', 'diamond', 'challenger']     if (self.type == 'mentor' && !eligible_tiers.include?(self.tier))       errors.add(:mentor, "mentors must @ least platinum.")     end   end    def shurima_api(server, method, args)     host, port = 'ip removed', 714     tcpsocket.open(host, port) |socket|       ready = io.select([socket], [socket], nil, 8)       return false unless ready       socket.puts server + "&" + method + "&" + args.to_s       message = socket.gets.chomp       if message == '"unknown error"'         return false       end       return json.parse(message)     end   end end 

i ended fixing renaming request method request_mentor because causing infinite loop.