fixing "umount -f" for the NFS client

[Benjamin Kaduk]

On Wed, 4 Sep 2013, Rick Macklem wrote:

> Benjamin Kaduk wrote:
>>
>> 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.
>>
> There are spares vfs ops in 10/current, but not in stable/9. An MFC will
> result in a VFS ABI change. (Since 10.0 hasn't been released yet, I didn't
> use one of the recently added spares.)

Oh, right, I was looking at 10/current.

Unless there are pressing calls for the feature in the stable branches, 
it's probably best to hold off on the MFC, then.  OpenAFS has encountered 
a few KBI incompatibilities over the years (mostly in the networking bits, 
if I remember correctly), and we can deal in the future, but not having to 
is nice.

Thanks,

Ben