Ext2 Directory Index, updated

[Daniel Phillips <phillips@bonn-fries.net>]

After some considerable time letting this patch 'age', here's an update
to 2.4.18:

   http://people.nl.linux.org/~phillips/htree/htree-2.4.18

The diff to 2.4.17 was provided by Ted Ts'o, and bug hunting/fixing by
Chris Li (who has the rather interesting email address
<chrisl@gnuchina.org>).  Chris is working on the Ext3 port as well.

Bill Irwin is providing loving care and attention to the hash function, so I 
feel it's in good hands.

Known Bug:

  - highmem doesn't work (because the kmapping code is wrong)

To Do:

  - Finalize hash function.
  - Coalesce on delete.  I have to do this sooner rather than later,
    since hash bucket fragmentation leads quickly to reduced leaf
    fullness.
  - Stable telldir cookie for NFS
  - Ext2 util updates (in progress, Ted Ts'o)
  - Miscellaneous source cleanups

Because of the unfinalized hash function, this patch is still for testing 
only.

-- 
Daniel