[PATCHSET,v24.0,00/24] fstests: improve xfs fuzzing

Message

Darrick J. Wong Dec. 30, 2022, 10:19 p.m. UTC

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, 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.  This splitting makes it
much easier to fix some longstanding problems with the fuzzer logic.  We
also revise the strategies a bit so that they more accurately reflect
the intended usage patterns of the repair programs.

Then, strengthen other parts of the fuzzing -- we make the post-repair
modification exercises a bit more strenuous by running fsstress on the
repaired fs; adding an evaluation of xfs_check vs.  xfs_repair; and
making it possible to check the xfs health reporting system.  The
xfs_check changes were key to disabling it in fstests in 2021.

Finally, 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  |  513 ++++++++++++++++++++++++++++++++++++++++++++-------------
 common/xfs    |   80 +++++++++
 tests/xfs/354 |    7 +
 tests/xfs/355 |    7 +
 tests/xfs/358 |    5 -
 tests/xfs/359 |    5 -
 tests/xfs/360 |    5 -
 tests/xfs/361 |    5 -
 tests/xfs/362 |    5 -
 tests/xfs/363 |    5 -
 tests/xfs/364 |    5 -
 tests/xfs/365 |    5 -
 tests/xfs/366 |    5 -
 tests/xfs/367 |    5 -
 tests/xfs/368 |    5 -
 tests/xfs/369 |    5 -
 tests/xfs/370 |    5 -
 tests/xfs/371 |    5 -
 tests/xfs/372 |    5 -
 tests/xfs/373 |    7 +
 tests/xfs/410 |    5 -
 tests/xfs/411 |    5 -
 tests/xfs/455 |    7 +
 tests/xfs/457 |    5 -
 tests/xfs/458 |    5 -
 tests/xfs/459 |    5 -
 tests/xfs/460 |    5 -
 tests/xfs/461 |    5 -
 tests/xfs/462 |    5 -
 tests/xfs/463 |    5 -
 tests/xfs/464 |    7 +
 tests/xfs/483 |    5 -
 32 files changed, 606 insertions(+), 147 deletions(-)