| [] ->
invalid_arg "linear_map_device: offset not mapped"
| (start_extent, end_extent, dev, pvoffset) :: rest ->
- eprintf "pvoffset = %Ld\n" pvoffset;
if start_extent <= offset_in_extents &&
offset_in_extents < end_extent
then dev#read (offset +^ pvoffset *^ extent_size) len