FD_ALLOCATE

;;; Force the allocation of space in a file.
  ;;; Note: This is similar to `posix_fallocate` in POSIX.
  (@interface func (export "fd_allocate")
    (param $fd $fd)
    ;;; The offset at which to start the allocation.
    (param $offset $filesize)
    ;;; The length of the area that is allocated.
    (param $len $filesize)
    (result $error (expected (error $errno)))
  )