On Thu, Apr 28, 2022 at 03:58:25PM +1000, Dave Chinner wrote:
> On Thu, Apr 28, 2022 at 12:53:13PM +0800, Zorro Lang wrote:
> > On Wed, Apr 27, 2022 at 03:44:58PM -0400, Theodore Ts'o wrote:
> > > On Thu, Apr 28, 2022 at 01:19:23AM +0800, Zorro Lang wrote:
> > > > I just noticed that _scratch_mkfs_sized() and _scratch_mkfs_blocksized() both use
> > > > _scratch_mkfs_xfs for XFS, I'm wondering if ext4 would like to use _scratch_mkfs_ext4()
> > > > or even use _scratch_mkfs() directly in these two functions. Then you can do something
> > > > likes:
> > > > MKFS_OPTIONS="$MKFS_OPTIONS -F -O quota"
> > > > _scratch_mkfs_blocksized 1024
> > > > or:
> > > > MKFS_OPTIONS="$MKFS_OPTIONS -F -O quota" _scratch_mkfs_blocksized 1024
> > >
> > > I'd prefer to keep changing _scratch_mkfs_sized and
> > > _scatch_mkfs_blocksized to use _scratch_mfks_ext4 as a separate
> > > commit. It makes sense to do that, but it does mean some behavioral
> > > changes; specifically in the external log case,
> > > "_scratch_mkfs_blocksized" will now create a file system using an
> > > external log. It's probably a good change, but there is some testing
> > > I'd like to do first before makinig that change and I don't have time
> > > for it.
> >
> > Sure, totally agree :)
> >
> > >
> > > > We just provide a helper to avoid someone forget 'dax', I don't object someone would
> > > > like to "exclude dax" by explicit method :) So if you don't have much time to do this
> > > > change, you can just do what you said above, then I'll take another time/chance to
> > > > change _scratch_mkfs_* things.
> > >
> > > Hmm, one thing which I noticed when searching through things. xfs/432
> > > does this:
> > >
> > > _scratch_mkfs -b size=1k -n size=64k > "$seqres.full" 2>&1
> > >
> > > So in {gce,kvm}-xfstests we have an exclude file entry in
> > > .../fs/xfs/cfg/dax.exclude:
> > >
> > > # This test formats a file system with a 1k block size, which is not
> > > # compatible with DAX (at least with systems with a 4k page size).
> > > xfs/432
> > >
> > > ... in order to suppress a test failure.
> > >
> > > Arguably we should add an "_exclude_scratch_mount_option dax" to this
> > > test, as opposed to having an explicit test exclusion in my test
> > > runner. Or we figure out how to change xfs/432 to use
> > > _scratch_mkfs_blocksized. So there is a lot of cleanup that can be
> > > done here, and I suspect we should do this work incrementally. :-)
> >
> > Thanks for finding that, yes, we can do a cleanup later, if you have
> > a failed testing list welcome to provide to be references :)
> >
> > >
> > > > Maybe we should think about let all _scratch_mkfs_*[1] helpers use _scratch_mkfs
> > > > consistently. But that will change and affect too many things. I don't want to break
> > > > fundamental code too much, might be better to let each fs help to change and test
> > > > that bit by bit, when they need :)
> > >
> > > Yep. :-)
> > >
> > > - Ted
> > >
> > > P.S. Here's something else that should probably be moved from my test
> > > runner into xfstests. Again from .../xfs/cfg/dax.exclude:
> > >
> > > # mkfs.xfs options which now includes reflink, and reflink is not
> > > # compatible with DAX
> > > xfs/032
> > > xfs/205
> > > xfs/294
> >
> > Yes, xfs reflink can't work with DAX now, I don't know if it *will*, maybe
> > Darrick knows more details.
>
> The DAX+reflink patches are almost ready to be merged - everything
> has been reviewed and if I get updated patches in the next week or
> two that address all the remaining concerns I'll probably merge
> them.
Thanks, good to know that. So we don't need to concern DAX+reflink test cases.
>
> > > Maybe _scratch_mkfs_xfs should be parsing the output of mkfs.xfs to
> > > see if reflink is enabled, and then automatically asserting an
> > > "_exclude_scratch_mount_option dax", perhaps?
>
> The time to do this was about 4 years ago, not right now when we are
> potentially within a couple of weeks of actually landing the support
> for this functionality in the dev tree and need the fstests
> infrastructure to explicitly support this configuration....
Sure, we'll give it a regression testing too, when DAX+reflink is ready.
>
> Cheers,
>
> Dave.
> --
> Dave Chinner
> david@xxxxxxxxxxxxx
>
