Permission denied problem

[J. Bruce Fields]

On Thu, Jun 14, 2007 at 04:43:03PM -0400, Avishay Traeger wrote:
> I came across the following error while running a random read benchmark
> using krb5p.  I had 6 client machines, each running 4 processes.  Each
> process was reading from its own 1GB file that was in its own directory.
> During the run, one of the reads failed, and perror() printed
> "Permission denied".  This was pretty strange, since the benchmark had
> been running for some time.
> 
> Then:
> $ umount /n/test
> (this succeeded with no problem)
> $ ls /n/test 
> ls: /n/test: Permission denied
> $ ll /n/
> ?--------- ? ?        ?       ?            ? /n/test
> $ umount /n/test
> umount: /n/test: device is busy
> 
> Running the 'mount' command does not show the NFSv4 mount.  However, if
> I cat /proc/mounts:
> v4server:/ /n/test nfs4 rw,vers=4,rsize=131072,wsize=131072,hard,intr,
> proto=tcp,timeo=600,retrans=3,sec=krb5p,addr=v4server 0 0
> 
> This does not happen every time I run the benchmark, but I have seen it
> three times.  Let me know if you need any more information.

What kernel version was this?

--b.