routine file_get_storage_info (
    file: file_t;
    RPT
    out ports: portarray_t, dealloc;
    out ints: intarray_t, dealloc;
    out offsets: off_array_t, dealloc;
    out data: data_t, dealloc);

Return information on the storage used to hold this file. See the comment for enum file_storage_class in <hurd/hurd_types.h> the details.