def METHOD_NAME(self):
    result = []
    for app in cache.get_apps():
        model_list = cache.get_models(app)
        for model in model_list:
            file_fields = [
                field.name
                for field in model._meta.fields
                if field.get_internal_type() == 'FileField'
            ]
            if len(file_fields) > 0:
                files = model.objects.all().values_list(*file_fields)
                result.extend(
                    [
                        split_name(file)[0]
                        for file in itertools.chain.from_iterable(files)
                        if file
                    ]
                )
    return result