Re: cvs update hangs 'amd' in tstile when 'firefox' is running

["John D. Baker" <jdbaker%mylinuxisp.com@localhost>]

On Fri, 12 Feb 2016 01:19:59 +0000 (UTC), christos%astron.com@localhost (Christos
Zoulas) wrote:

> So the problem is when nfs unmounts.  You should be able to reproduce
> it

>   mount foo:/foo /foo
>   cd /foo
>   umount /foo

> And now umount is stuck and never returns EBUSY. Is that true?

On the machine in question, already stuck via 'amd', yes, attempts
to unmount an arbitrary "hard"-mounted NFS file system hangs.

On another client which is not stuck, the above sequence does indeed
produce:

  $ cd /x
  $ sudo umount /x
  umount: /x: Device busy

and continues to operate normally.  I tried this during a cvs update.
A couple of times there was an slight delay, but it eventually reported
"Device busy" each time.

> I don't think that firefox or the syncher and involved in the lossage
> but seem to be victims of it.

That may be. but so far, only under these circumstances do I experience
the problem.  As long as firefox is not running, or at least not operating
on files on an amd-managed NFS mount, 'amd' can unmount/remount the file
system while 'cvs update' is running on the file server--it just takes
it a while to respond (although I have had cases where it satisfied a
mount from an alternate location).

> I am not an FS locking expert though, Hannken!!!  Help :-)

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