Re: [PATCH] xfstests: Ensure cmdline geometry puts mkfs.xfs into multidisk mode

Dave Chinner
2012-12-09T23:48:51Z

On Sat, Dec 08, 2012 at 10:27:47AM -0600, Eric Sandeen wrote:
> On 12/8/12 6:00 AM, Christoph Hellwig wrote:
> > On Thu, Dec 06, 2012 at 04:02:16PM -0600, Eric Sandeen wrote:
> >> Ensure that when mkfs.xfs is invoked with commandline geometry, it
> >> triggers multidisk mode and creates more AGs.
> >>
> >> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> >
> > Looks good,
> >
> > Reviewed-by: Christoph Hellwig <hch@lst.de>
>
> Thanks
>
> >> Maybe this should also test device-specified geometry, but not sure
> >> how to do that easily within xfstests, any ideas?
> >
> > That would involved scsi_debug so that we could set them up. We had
> > several ideas how to use scsi debug for these sort of tests but never
> > really bothered to do it. If you have some spare cycles I'd love to see
> > this sort of tests.
>
> scsi_debug won't report geometry on its own today; we'd need to assemble
> something out of scsi_debug luns I'm afraid, so it gets even more involved.
>
> We do have a little bit of scsi_debug framework in xfstests today, though,
> so if scsi_debug grew the capability it'd be easy to add.

Does it really need scsi for this? To mkfs.xfs, all devices look the
same, so if you want to make random geometries, wouldn't playing
games with llopback devices and DM be sufficient?

Cheers,

Dave.
--
Dave Chinner
david@fromorbit.com