} else {
if (r->end + diff > r->sz) r->end = r->sz - diff;
rearrange_sectors(r, r->start + diff, r->start, r->end - r->start);
} else {
if (r->end + diff > r->sz) r->end = r->sz - diff;
rearrange_sectors(r, r->start + diff, r->start, r->end - r->start);