Retrieve filesystem configuration, including support for specified file types.

def _get_filesystem_config(file_types):
    """Retrieve filesystem configuration, including support for specified file types.
    """
    out = "     filesystems {\n"
    for file_type in sorted(list(file_types)):
        if file_type in _FILESYSTEM_CONFIG:
            out += _FILESYSTEM_CONFIG[file_type]
    out += "      }\n"
    return out