I made up a patch for anybody who's interested in ripping it apart, it's
available at the following URL:

  http://invisible.yi.org/~jmcneill/netbsd/dirpref-20010411.diff.gz

Someone needs to review the patches to ffs_vfsops.c, I quickly copied the
OpenBSD patch when I did it, and it could be (probably is) done very
wrong. The FreeBSD patch is much cleaner IMO so that should be taken into
consideration before commiting these changes.

I haven't tested booting a machine without first updating the super blocks
(using tunefs), so unless you build tunefs and use it first to tune a few
things, YMMV.

Enjoy!
Jared