Re: [PATCH v2] btrfs: Add test that checks rmdir(2) can delete a subvolume

[Eryu Guan <guaneryu@gmail.com>]

On Fri, Apr 27, 2018 at 06:26:35PM +0200, David Sterba wrote:
> On Fri, Apr 27, 2018 at 05:02:45PM +0900, Misono Tomohiro wrote:
> > Add btrfs test that checks "rmdir" or "rm -r" command can delete a
> > subvolume like an ordinary drectory.
> > 
> > This behavior has been restricted long time but becomes allowed by
> > following patch in the kernel:
> >   btrfs: Allow rmdir(2) to delete an empty subvolume
> 
> AFAICS this test will fail on older kernels, eg. stable versions, but
> this is not a bug that needs to be fixed by backporting patches. The
> usual way is to use the expunges, but as this is a feature coverage, I
> think the test should detect if the kernel has the feature at all.
> Similar to the fallocate modes etc.

Agreed, if the change is treated as a behavior change not a bug on old
kernels, we probably need a way to detect the case and _notrun if kernel
doesn't support it.

> 
> For the test itself, the scenarios look sufficient, so
> Reviewed-by: David Sterba <dsterba@suse.com>

Thanks for the review!

Eryu