Date:        Fri, 17 Sep 1999 22:24:45 -0700 (PDT)
    From:        Todd Whitesel <toddpw@best.com>
    Message-ID:  <199909180524.WAA15452@shell17.ba.best.com>

  | The packing syscall would fail gracefully if
  | it would have to move the directory slot across any other readdir()
  | pointers.

That would be a challenge.   "any other readdir() pointers" is
file[*].f_offset - kernels have never kept back pointes from inodes
(vnodes) to file *'s.    Now that one might be manageable, one more
list (or even, since this would not be a very frequent operation, just
a scan of the file[]) - but finding the readdir() pointers on NFS clients
would be a more interesting challenge to overcome.

kre