NFS deadlock (unkillable nfsd and no mounts work)

[Andriy Gapon]

on 05/11/2010 07:35 Josh Carroll said the following:
> Greetings!
> 
> I'm having a problem with nfsd hanging and not serving mount points,
> during which time it can not not be killed. This problem started
> happening sometime after November 2nd, since kernel from 11/2 sources
> does not exhibit this problem.
> 
> The current kernel I'm running is via SVN I just grabbed this evening
> (around 5pm PDT on November 4th), but I was having the same problem
> yesterday around 9pm PDT after a csup yesterday (I switched to SVN
> today to rule out a stale /usr/src from an out of sync cvsup  mirror).
>  Here are the svn details:
> 
> Path: /usr/src
> URL: svn://svn.freebsd.org/base/stable/8
> Repository Root: svn://svn.freebsd.org/base
> Repository UUID: ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
> Revision: 214807
> Node Kind: directory
> Schedule: normal
> Last Changed Author: jhb
> Last Changed Rev: 214791
> Last Changed Date: 2010-11-04 10:25:31 -0700 (Thu, 04 Nov 2010)
> 
> uname -a:
> 
> FreeBSD 8.1-STABLE FreeBSD 8.1-STABLE #0 r214807: Thu Nov  4 17:13:05
> PDT 2010     root at pflog.net:/usr/obj/usr/src/sys/PFLOG  amd64
> 
> I have a Popcorn Hour, and as soon as I try to connect to my NFS mount
> with it, it hangs on the Popcorn Hour, then eventually pops up a
> message that says "Request cannot be processed". Likewise if I try to
> mount it from my macbook, it hangs then later just says operation
> timed out or something like that, after it hangs for quite a while.
> 
> During this hang, there is nothing in /var/log indicating a problem
> nor any other indications something is wrong, except that none of my
> NFS mounts work and the nfsd process will not die.
> 
> When I try to reboot the server, I wind up having to fsck all my
> drives (except the ZFS one), since nfsd will not die. Even kill -9
> doesn't kill it (it's showing as in the D state):
> 
> root 444 0.0 0.0 5812 1384 ?? D   9:30PM  0:00.00 nfsd: server (nfsd)

You can try 'procstat -kk <pid>' next time this happens.


-- 
Andriy Gapon