Re: [PATCH v2 6/6] xfs/260: Move xfs/260 to generic

Ira Weiny
2020-06-23T18:08:04Z

On Tue, Jun 23, 2020 at 04:51:31PM +0800, Xiao Yang wrote:
> On 2020/6/19 23:15, Ira Weiny wrote:
> > On Thu, Jun 18, 2020 at 11:35:56PM +0800, Xiao Yang wrote:
> > > On 6/18/20 5:48 AM, Ira Weiny wrote:
> > > > On Wed, Jun 17, 2020 at 05:32:04PM +0800, Xiao Yang wrote:
> > > > > From: Xiao Yang<yangx.jy@cn.fujitsu.com>

[snip]

> > > > }
> > > > @@ -124,17 +151,11 @@ do_tests()
> > > > # make xfs aligned for PMD fault testing
> > > > _scratch_mkfs_geom $(_get_hugepagesize) 1>> $seqres.full 2>&1
> > > > -# mount with dax option
> > > > -_scratch_mount "-o dax"
> > > > -
> Hi Ira,
>
> Why do you want to remove this combination(i.e. test per-inode DAX flag
> under mounting with dax option) ?
> Is it because mounting with dax option ignore FS_XFLAG_DAX flag?
> I think it is a reasonable combination. :-)

Yes running with the DAX mount option really does not test anything IMO.

>
> > > > tsize=$((128 * 1024 * 1024))
> > > > -do_tests
> > > > -_scratch_unmount
> > > > -
> > > > # mount again without dax option
> > > > export MOUNT_OPTIONS=""
> > > > -_scratch_mount
> > > > +_scratch_mount "-o dax=inode"
> > > > do_tests
> > > > # success, all done
>
> Could we keep _scratch_mount without dax so that this test can run on both
> old and new kernel?
> See the following reasons:
> 1) FS_XFLAG_DAX was introduced by commit 58f88ca("xfs: introduce per-inode
> DAX enablement") since 2017.
> 2) _scratch_mount with dax=inode is equal to _scratch_mount without dax.

I suppose that would be ok. But being generic what happens when this runs on
FS's which don't have the FS_XFLAG_DAX flag? is it ignored?

FWIW I believe that any FS (which includes older kernels) which do not support
dax=inode have no need for this test to run. The use of FS_XFLAG_DAX on older
xfs does not do anything and simply does not exist elsewhere. Only FS's which
support dax=inode have behavior which needs to be tested IMO.

Ira

>
> Best Regards,
> Xiao Yang
> >
> > .
> >
>
>
>