nfs4_reclaim_open_state: Lock reclaim failed!

[Emil Flink <emil.flink@bublar.com>]

Hi,

I'm not sure where to go with this issue so please free to point me to
a more suitable forum if necessary.

My issue is that a client mounting a NFS share frequently locks up
with massive amounts of "nfs4_reclaim_open_state: Lock reclaim
failed!" in the kernel logs. Meanwhile the NFS server does not log any
errors as far as I can tell.

I only encounter this when the client is doing a lot of I/O against
the NFS share.

To recover from this I have to kill all processes on the client using
the NFS share, unmount the NFS share and remount it.

The NFS export is mounted with:
10.0.1.203:/nfs/lxc-office on /var/lib/lxc type nfs4
(rw,noatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=10.0.1.231,local_lock=none,addr=10.0.1.203)

Both the server and the client is running up-to-date installations of
Debian 9 ("stretch"), meaning kernel 4.9.0-4 and nfs-common /
nfs-kernel-server 1.3.4-2.1.


Regards,

Emil Flink