Nodejs - Access Middleware Object - Multer-S3

Question

I am using the multer and multer-s3 modules to bulk upload multiple files, but after the files are uploaded, I would like to access the newly imported files to then be used within my page, but I can't seem to figure out the best way to access the object that would contain the information related to these files. Should I set the cb to the req object?

Here is my current setup:

var upload = multer({
        storage: multerS3({
            s3: s3,
            bucket: options.Bucket,
            contentType: multerS3.AUTO_CONTENT_TYPE,
            acl: options.ACL,
            key: function(req, file, cb){
                var fileNameFormatted = file.originalname.replace(/\s+/g, '-').toLowerCase();
                cb(null, req.user.organizationId + '/' + uploadDate + '/' + fileNameFormatted);
                req.data = cb;
            }
        })
});

appRoutes.post('/sign', upload.array('fileUpload', 5), function(req, res){  

    console.log('This is a upload ' + JSON.stringify(req.data));

});

File Input:

<input type="file" id="file-input" name="fileUpload[]" multiple>

jQuery triggering route:

$("#file-input").on('change', function(){
        var files = $(this).get(0).files;

        if (files.length > 0){
            var formData = new FormData();

            for(var i = 0; i < files.length; i++){
                var file = files[i];
                console.log(files[i]);
                formData.append('fileUpload', file, file.name);
            }

            $.ajax({
                url: '/sign',
                type: 'POST',
                data: formData,
                processData: false,
                contentType: false,
                success: function(data){
                  console.log('upload successful! ' + data);
                },
                error: function(error){
                    console.log('error ' + JSON.stringify(error));
                }
            });
        }
    });

req.data returns undefined