Populating ref to the parent using Mongoose and displaying complete parent after authentication with passportjs

I have the following schema for user and sp. sp is short for service provider. Service provider is a user, it has a reference to user. I am trying to signup and singin using PassportJS module of NodeJS. I have been able to signup an sp and I could see the data persisted in MongoDB collections in users and sps collections, but I am not able to display the complete data of sp on the profile page. I get to display only its user data. For example, I don't see the sp's spname data in the profile page after authentication.

Following is some of the code:

Schema for user:

var userSchema = mongoose.Schema({
        ip: String,
        local            : {
            email        : String,
            password     : String
        }
        name: String ,
        created: { type: Date, default: Date.now },
    })
    .plugin(mongooseRole, {
        roles: ['public', 'user', 'sp', 'admin'],
        accessLevels: {
            'public': ['public', 'user', 'sp', 'admin'],
            'anon': ['public'],
            'user': ['user', 'admin'],
            'sp': ['sp', 'admin'],
            'admin': ['admin']
    }
});
var User = mongoose.model("User", userSchema);

Schema for sp:

var spSchema = mongoose.Schema({
    user: { type: Schema.ObjectId, ref: 'User' },
    spname: String,
});
var SP = mongoose.model("SP", spSchema);

PassportJS code for logging in:

//serialization/deserialization code
    // used to serialize the user for the session
    passport.serializeUser(function(user, done) {
        done(null, user.id);
    });

    // used to deserialize the user
    passport.deserializeUser(function(id, done) {
        User.findById(id, function(err, user) {
            done(err, user);
        });
    });


//authentication code
    passport.use('local-login', new LocalStrategy({
            usernameField : 'email',
            passwordField : 'password',
            passReqToCallback : true
        },
        function(req, email, password, done) {

            User.findOne({ 'local.email' :  email }, function(err, user) {

                if(user.role == 'sp') {
                    SP.findOne({ user: user._id }).populate('user').exec(function(err, sp) {
                        if (err)
                            return done(err);
                        if (!sp.user)
                            return done(null, false, req.flash('loginMessage', 'No sp user found.')); 

                        if (!sp.user.validPassword(password))
                            return done(null, false, req.flash('loginMessage', 'Oops! Wrong password.')); 
                        return done(null, sp);
                    });
                } 

                if (err)
                    return done(err);

                if (!user)
                    return done(null, false, req.flash('loginMessage', 'No user found.')); 

                if (!user.validPassword(password))
                    return done(null, false, req.flash('loginMessage', 'Oops! Wrong password.')); 

                return done(null, user);
            });

        }));

Displaying the profile:

app.get('/profile', isLoggedIn, function (req, res) {

    res.render('profile', {
        user: req.user
    });
});

profile.ejs

<%= user %>

Could somebody help me with what should I be doing to display the whole sp object with all its data?

You're only querying User schema while deserializing. You need to deserialize sp if you want it. I'm not entirely sure about your situation but it seems that you're either authenticating a User or an SP, in which case you should similarly either deserializing User or SP (if User returns empty). Something like this maybe:

// used to deserialize the user
passport.deserializeUser(function(id, done) {
    User.findById(id, function(err, user) {
        if (user.role == 'sp')
            SP.findOne({user: user_id}).populate('user').exec(function(err, sp) {
                done(err, sp);
            });
        else done(err, user);
    });
});