Re: [PATCH] xfs: add regression test for swapext reflux

[Christoph Hellwig <hch@infradead.org>]

On Sat, Oct 10, 2026 at 03:57:19PM -0500, Eric Sandeen wrote:
> > 
> > And, uh, you could turn on exchrange in your test config like I do,
> > especially seeing as it's been enabled by default for a year.
> Sure. Lots of people run xfstests, sometimes even on older releases! If this test is
> specifically designed to test something that requires exchrange, it could make sure
> it sets up the test to do that whenever possible, even if not default or in an
> environment var.
> 
> I'm not actually sure what the overarching fstests philosophy is here, though.

There's not overall philosophy, and that's a bit of a problem.

Whenver we have tests and the config specifying mkfs options, there's
a chance of conflict, and we're very inconsistent in dealing with them.
I think this test would probably also run into that if someone were
testing say a v4 fs config.

I've tried a few things to clear this up, but it's all been bandaids
so far.  I think the only clean way to deal with this would be to
split test into difference categories:

  1) "macro" tests, using TEST_DIR and SCRATCH_DEV using paramters in
     the config, and not specifying their own mkfs overrides
  2) "micro" tests using SCRATCH_DEV using their own paramters, but
     not those from the enviroment
  3) "supermicro" test using their own synthetic loop/scsi_debug/etc
     device not using the option from the config file.  Or at least
     using new and different options just applying to those tests

Getting this right will be a lot of work, though.