fixing "umount -f" for the NFS client

[Rick Macklem]

araujo wrote:
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> 2013/9/5 Benjamin Kaduk < kaduk at mit.edu >
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> On Wed, 4 Sep 2013, Rick Macklem wrote:
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> Benjamin Kaduk wrote:
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> 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.
> 
> 
> 
> 
> Hello Guys,
> 
> 
> Is it possible to have it on 9-STABLE?
> I tried to port the changes of revision 255136 made by rmacklem@ to a
> 9.1-RELEASE but the bug is still there.
> 
> 
> Any change to make it works on 9.1, 9.2 or 9-STABLE?
> 
> The patch attached is based on 9.1-RELEASE.
> 
The patch looks ok at a glance. Note that it can take
up to 2-3minutes for a forced dismount to complete,
depending on where the threads are waiting.

If the mount is still there 5minutes after doing
"umount -f", do a "ps axhl" and post the output
of that to me. It may be getting stuck somewhere
else than where I've seen during testing.

rick

> 
> Best Regards, --
> Marcelo Araujo
> araujo at FreeBSD.org