Re: 45aebeaf4f67 "ovl: Ensure upper filesystem supports d_type" breaking Docker

[Al Viro]

On Mon, May 16, 2016 at 09:07:27AM -0400, Vivek Goyal wrote:
> So it became clear that we need a check at mount time to make sure
> d_type is supported otherwise error out. This will require users to
> do mkfs.xfs with ftype=1 to make progress.
> 
> I think new defaults for mkfs.xfs are such that ftype=1 is set. I am
> not sure which version that change was made in.

Dumb question - can we end up with empty workdir at that point?  Because
if we do, the check would appear to return a false negative, no matter
what fs supports...