Re: [PATCH] xfs/XXX: Add xfs/XXX

[Darrick J. Wong]

On Mon, Apr 13, 2020 at 07:11:46PM +0300, Amir Goldstein wrote:
> > >
> > > But the kernel patch suggests that there is an intention to make
> > > this behavior also applicable to ext4??
> > > If that is the case I would recommend making this a generic tests
> > > which requires filesystem support for -o dax=XXX
> >
> > I have a patch set for ext4 which is not quite passing this.  I'm not sure what
> > is going on yet.
> >
> > Once that is working I was going to move this to generic.  (The documentation
> > in the kernel patch set also reflects ext4 being different from xfs for the
> > time being.)
> 
> IMO, if ext4 maintainer is on board with the plan to make this behavior of
> ext4 then it is best to add this test as generic from the start.
> Any other filesystems that may tag along later?

I was under the impression that any test can go in generic/ so long as
it isn't using fs-specific interfaces (e.g. xfs error injection), even
if not all filesystems actually support the functionality being examined
by the test.

> >
> > This is mainly because I'm not sure if ext4 will make 5.8 or not.  Would you
> > prefer making this generic now?  I assume there is some way to mark generic
> > tests for a subset of FS's?  I have not figured that out yet.
> >
> 
> There is a way, _supported_fs, see the tests/shared/*,
> but the idea it to get rid of those in favor of feature tests such as
> _require_scratch_dax
> 
> I believe it should be trivial to implement
> _require_scratch_dax_never

Agreed, though I would name the helper to make it clear that it's
checking the dax mount options (e.g. "_require_scratch_dax_mountopt")
because "never" is a little subtle here.

> Thanks,
> Amir.