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Date: Tue, 17 May 2016 07:28:29 +0100
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Vivek Goyal <vgoyal@redhat.com>
Cc: Daniel Axtens <dja@axtens.net>, linux-fsdevel@vger.kernel.org,
	linux-unionfs@vger.kernel.org, linux-kernel@vger.kernel.org,
	mpe@ellerman.id.au, mszeredi@redhat.com, dchinner@redhat.com
Subject: Re: 45aebeaf4f67 "ovl: Ensure upper filesystem supports d_type"
 breaking Docker
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 <20160516130727.GA26411@redhat.com>
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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...