server.js

function logAndNext() {
    app.get('log').pageRequested({ ip : ip, pos : req.session.pos, page : req.url, method : req.method }, function(err) {
        if (err) throw err;
        next();
    });
}
if (!req.session.pos) {
    app.get('db').getPosByIp(ip, function(err, pos) {
        req.session.pos = pos;
        logAndNext();
    });
} else {
    logAndNext();
}