Hi all,

There are a ton of improvements to the XFS fuzzing code in this update.
We start by disabling by default two parts of the fuzz testing that
don't lead to predictable golden output: fuzzing with the 'random' verb,
and fuzzing the 'LSN' field.

Next, we refactor the inner fuzzing loop so that each of the four repair
strategies are broken out into separate functions, as well as the
post-repair attempts to modify the filesystem.

The next five patches after that modify each of the functions that we
split out in the previous patches to make what those functions do much
more clear.  We also revise the strategies a bit so that they more
accurately reflect the intended usage patterns of the repair programs.

Next, we strengthen other parts of the fuzzing -- we make the
post-repair modification exercises a bit more strenuous, add an
evaluation of xfs_check vs. xfs_repair, and make it possible to check
the xfs health reporting system.

Finally, we improve the array handling of the xfs fuzz tests so that we
actually know about array indices as a first class concept, instead of
the current mucking around we do with regular expressions.

If you're going to start using this mess, you probably ought to just
pull from my git trees, which are linked below.

This is an extraordinary way to destroy everything.  Enjoy!
Comments and questions are, as always, welcome.

--D

fstests git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfstests-dev.git/log/?h=fuzzer-improvements
---
 common/fuzzy  |  461 +++++++++++++++++++++++++++++++++++++++++++--------------
 common/xfs    |   38 +++++
 tests/xfs/357 |    2 
 3 files changed, 386 insertions(+), 115 deletions(-)