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Date: Fri, 15 Apr 2011 14:48:26 -0700
Message-ID: <BANLkTimNkLZzeRRMyFSp+m8WWtqp_zjFCg@mail.gmail.com>
Subject: Re: Unionmount status?
From: Hugh Dickins <hughd@google.com>
To: Miklos Szeredi <miklos@szeredi.hu>
Cc: Michal Suchanek <hramrach@centrum.cz>, Jiri Kosina <jkosina@suse.cz>,
        Ric Wheeler <ricwheeler@gmail.com>, linux-fsdevel@vger.kernel.org,
        linux-kernel@vger.kernel.org, David Howells <dhowells@redhat.com>,
        Ian Kent <ikent@redhat.com>, Jeff Moyer <jmoyer@redhat.com>,
        Christoph Hellwig <hch@infradead.org>, Eric Paris <eparis@redhat.com>,
        James Morris <jmorris@namei.org>
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On Fri, Apr 15, 2011 at 5:29 AM, Miklos Szeredi <miklos@szeredi.hu> wrote:
> On Fri, Apr 15, 2011 at 1:51 PM, Michal Suchanek <hramrach@centrum.cz> wrote:
>> On 15 April 2011 13:31, Miklos Szeredi <miklos@szeredi.hu> wrote:
>>> On Fri, Apr 15, 2011 at 1:22 PM, Michal Suchanek <hramrach@centrum.cz> wrote:
>>>>
>>>> Cleaning up temporary files...
>>>> [    nn.nnnnnn] overlayfs: ERROR - failed to whiteout 'motd'
>>>> find: cannot delete `./motd': Operation not supported
>>>
>>> What is the upper filesystem type?  Is xattr support enabled?
>>>
>>
>> The upper filesystem is tmpfs and there is not option regarding XATTR
>> in the config.
>
> Apparently tmpfs does not support generic xattr.  I understand why
> tmpfs is an attractive choice for an upper filesystem, so this should
> be addressed.
>
> I see two options here:
>
> 1) implement generic xattr in tmpfs
> 2) take whiteout/opaque support from union mounts and use that
>
> Both have advantages and disadvantages.
>
> Any thoughts?

Please get together with Eric: he's having trouble whipping up
enthusiasm for his tmpfs xattr patch, he and I would both appreciate
your support (and if I've persuaded him to leave out a part of it that
you would need, join forces to call me an idiot).  Mainly I'm hoping
to hear from hch and jmorris on it, being xattr-illiterate myself.

https://lkml.org/lkml/2011/3/29/302

Hugh