Re: RFC: don't fail tests when mkfs options collide

["Theodore Ts'o" <tytso@mit.edu>]

On Mon, Jul 22, 2024 at 05:00:31PM -0700, Christoph Hellwig wrote:
> Hi all,
> 
> I've been running some tests with forced large log sizes, and forced
> sector sizes, and get a fair amount of failures because these options
> collide with options forced by the tests themselves.  The series here was
> my attempt to fix this by not failing the tests in this case but _notrun
> them and print the options that caused them to fail.

Yeah, it's a bit of a mess.  It's not been an issue for ext4 because
mkfs.ext4 allows options specified later in the command-line to
override earlier ones.

> So what could we do instead?  We might distinguish better between tests
> that just want to create a scratch file system with $MKFS_OPTIONS from
> the xfstests config, and those (file system specific ones) that want
> to force very specific file system configurations.  How do we get
> there?

There's a third possibility, which is sometimes the test might
explicitly want the mkfs options to be merged together.  For example,
in the ext4/4k configuration we have "-b 4096", while the ext4/1k
confiuration option we might have "-b 1024".  And we might want to
have that *combined* with a test which is enabling fscrypt feature, so
we can test fscrypt with a 4k block size, as well as fsvrypt with a 1k
blocksize.

That being said, that doesn't always make sense, and sometimes the
combination doesn't make any sense.

It's not clear what the best solution should be.

     	       	    	     - Ted