fixing "umount -f" for the NFS client

[Benjamin Kaduk]

On Sun, 1 Sep 2013, Rick Macklem wrote:

> Benjamin Kaduk wrote:
>> On Fri, 30 Aug 2013, Rick Macklem wrote:
>>
>>> Kostik wrote:
>>>> On Thu, Aug 29, 2013 at 07:43:34PM -0400, Rick Macklem wrote:
>>>>>>> I assume I would also need to bump __FreeBSD_version (and maybe
>>>>>>> VFS_VERSION?).
>>>>>> I think you could avoid it.
>>>>>>
>>>>> Do you mean I don't need to bump __FreeBSD_version or VFS_VERSION
>>>>> or both?
>>>> I do not see much sense in bumping either of them.
>>>> You might want to bump __FreeBSD_version when merging to stable.
>>
>> Please do bump __FreeBSD_version when merging to stable.  I will not
>> make
>> much noise about -current at the moment, as I'm behind on tracking
>> it.
>>
> Actually, I'm "on the fence" as to whether or not this one should be
> MFC'd, due to the VFS ABI breakage.
>
> Since you (well, actually OpenAFS;-) are the main guy affected by VFS
> ABI breakage these days, maybe you'd like to comment on this?
>
> Also, if anyone else has an opinion w.r.t. MFC'ng a patch that adds
> a VFS op and, therefore, breaks the VFS ABI, please feel free to comment.

Oops, this mail got lost.

I think there are spare vfsops fields, so the MFC can be done in an 
ABI-compatible way.  The new routine is for optional functionality, so it 
seems fine.

-Ben