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From: Miklos Szeredi <miklos@szeredi.hu>
Date: Fri, 24 Aug 2018 19:08:00 +0200
Message-ID: <CAJfpegvgvmC_d4OndH=drW4Xoo=Q892O_+YDV9VTGS6CGmmjBQ@mail.gmail.com>
Subject: Re: [git pull] new mount API
To: Andy Lutomirski <luto@amacapital.net>
Cc: David Howells <dhowells@redhat.com>,
        "Theodore Y. Ts'o" <tytso@mit.edu>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Linux FS Devel <linux-fsdevel@vger.kernel.org>,
        Linux API <linux-api@vger.kernel.org>
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On Fri, Aug 24, 2018 at 5:09 PM, Andy Lutomirski <luto@amacapital.net> wrot=
e:
>
>> On Aug 24, 2018, at 8:02 AM, Miklos Szeredi <miklos@szeredi.hu> wrote:
>>
>>> On Fri, Aug 24, 2018 at 4:49 PM, Andy Lutomirski <luto@amacapital.net> =
wrote:
>>>
>>>
>>>>> On Aug 24, 2018, at 2:45 AM, David Howells <dhowells@redhat.com> wrot=
e:
>>>>
>>>>
>>>>
>>>> The problem is that "exclusivity" isn't necessarily an easy thing to d=
efine.
>>>> Take nfs4 and btrfs for example.  They creating a backing superblock t=
hat the
>>>> actual node is derived from (though in different ways).  How do you de=
fine
>>>> what "exclusive" means in their case?
>>>>
>>>
>>> I would argue that =E2=80=9Cexclusive=E2=80=9D means =E2=80=9Csemantica=
lly equivalent to getting a fully independent instance.=E2=80=9D
>>
>> The only way to get semantically equivalent instance is to create a
>> fully independent instance.  See reconfigure (nee remount).
>>
>>
>
> Hmm. Is it that case in the current patchset that you can do CMD_CREATE a=
nd reconfigure the result and some *other* existing mount will change?  If =
so, that=E2=80=99s rather unfriendly to users.

Exactly.

Thanks,
Miklos