Re: [RFC PATCH v2 1/3] common/xfs: add a _require_xfs_shrink helper

[Gao Xiang <hsiangkao@redhat.com>]

Hi Zorro,

On Fri, Mar 12, 2021 at 11:25:06PM +0800, Zorro Lang wrote:
> On Fri, Mar 12, 2021 at 09:22:58PM +0800, Gao Xiang wrote:
> > In order to detect whether the current kernel supports XFS shrinking.
> > 
> > Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
> > ---
> > use -D1 rather than -D0 since xfs_growfs would report unchanged size
> > instead.
> > 
> >  common/xfs | 10 ++++++++++
> >  1 file changed, 10 insertions(+)
> > 
> > diff --git a/common/xfs b/common/xfs
> > index 2156749d..326edacc 100644
> > --- a/common/xfs
> > +++ b/common/xfs
> > @@ -432,6 +432,16 @@ _supports_xfs_scrub()
> >  	return 0
> >  }
> >  
> > +_require_xfs_shrink()
> > +{
> > +	_scratch_mkfs_xfs >/dev/null 2>&1
> > +
> > +	_scratch_mount
> > +	$XFS_GROWFS_PROG -D1 "$SCRATCH_MNT" 2>&1 | grep -q 'Invalid argument' || { \
> > +		_scratch_unmount; _notrun "kernel does not support shrinking"; }
> 	        ^^^^
> 		I think this unmount isn't necessary, due to after "_notrun" the
> 		$SCRATCH_DEV will be umounted "automatically".

I didn't dig into it more. Just follow _require_xfs_scratch_rmapbt().

If it's not necessary (assumed ./check does that), will update it in
the next version. Thanks for your suggestion.

Thanks,
Gao Xiang