ceph_make_fpos
ctx->pos = ceph_make_fpos(frag,
loff_t new_pos = ceph_make_fpos(ceph_frag_value(frag),
ctx->pos = ceph_make_fpos(frag, dfi->next_offset,
rde->offset = ceph_make_fpos(hash, fpos_offset++, true);
rde->offset = ceph_make_fpos(frag, fpos_offset++, false);
extern loff_t ceph_make_fpos(unsigned high, unsigned off, bool hash_order);