Re: remove _supported_fs

[Christoph Hellwig <hch@lst.de>]

On Tue, Dec 10, 2024 at 08:00:33AM -0500, Theodore Ts'o wrote:
> Hmm, instead of doing this (would require hard-coding support for ext2
> and ext3 file systems needing to use ext-common), why not just have
> special-case code which causes ext2 and ext3 file systems to include
> the ext4 group, and then we'll have _exclude_fs declaractions as
> needed for ext2 and ext3?

That's what the current tree does and what I want to get away from.
I think the diffstat alone makes it pretty clear that moving away
form that is a benefit, and it's also a lot easier to understand than
that ext2 and ext3 magically run ext4 tests.

> After all, ext3 has been removed except for the very oldest LTS
> kernels (and I dount anyone is actually testing ext3 using xfstests
> these days),

The tests also cover using ext4 as the ext3 driver.

> So it might not be worth it to move a bunch of tests and creating a
> new (somewhat ugly) group, ext4-common, IMO.

І'll let Jan speak up, but the only thing cleaner would be to drop
the ext2/3 coverage, but І don't think the extra group is too bad,
and certainly much better than what we currently have.