bhyve can also make use of fspacectl(2) to implement BOP_DELETE with
hole-punching. Since it is not desirable to do zero-filling for large
DEALLOCATE/UNMAP range, candelete is not set if pathconf(2) indicates
that the underlying file system does not support native
VOP_DEALLOCATE(9).
Submitted by: Ka Ho Ng <khng@freebsdfoundation.org>
Sponsored by: The FreeBSD Foundation