NetBSD-5.0.2/tests/fs/tmpfs/README

The tests in this directory where written at the same time tmpfs was
developed.  This is why, if you follow the order of tests in the Atffile,
you will notice that they start checking the most basic things and end
checking the less common ones.  Furthermore, tests try not to use features
tested by further tests in the lists.

However, the above is not the most appropriate testing procedure when you
have a working file system because some separation in test programs does
not make sense afterwards.

Many of the tests here are applicable to any file system.  They should be
refactored to be reusable on any mounted file system, which could also
remove the need to do the mount/unmount steps in each and every test case.

Possibly take a look at the file system tests in FreeBSD.  They seem to be
much more complete, even though they are written in Perl and therefore not
directly usable.