Getting Current User id from server

I’m trying to update a the user “photoPath” field after uploading a file using meteor-uploads.

I’m getting this error :
Error: Meteor code must always run within a Fiber. Try wrapping callbacks that you pass to non-Meteor libraries with Meteor.bindEnvironment.

server/init.js

validateFile: function(file, req) {
    Meteor.users.update( { _id: Meteor.userId() }, {$set: {"profile.photoPath": req.path}});

    return null; 
}

Any ideas?

we need full module code and entry point of this operation