Good times with md, ReiserFS, and /usr unmountable

[Ken Teague <kteague@pobox.com>]

Greetings,

Debian Etch
AMD64
multi-disk
ReiserFS

Came in to find /dev/md6 wasn't mounted after rebooting the box.  Tried
to run fsck on it, but fsck.reiserfs was missing because reiserfsprogs
wasn't installed.  I can't apt-get or dpkg because those tools reside
under /usr.  This leads to a few questions and possible solutions:

1. Why isn't reiserfsprogs a dependency of the kernel image that has
support for it?  Shouldn't all file system tools be dependent if the
kernel being pushed out to the box supports said file system?  How can
one fix a file system if they don't have the correct tools to do so?

2. Why is apt-get and dpkg under /usr?  Shouldn't they belong under
/sbin?  If they were, I'd have access to those tools and would be able
to dpkg -i reiserfsprogs.  I'm going to assume that dependencies for
dpkg and apt-get require a lot of stuff that is located under /usr, and
those dependencies have no place to be in /sbin.

I understand this is -devel and not the standard mailing list where I
should ask for support, but any info on how I can recover from this
would be greatly appreciated.

- Ken