I applied the patch. For testing I have started a "rm -rf" on a large
directory tree. dmesg reports:
nfs server 172.18.86.13:/vol/vol_bsd_2: is alive again
nfs server 172.18.86.13:/vol/vol_bsd_2: not responding
nfs server 172.18.86.13:/vol/vol_bsd_2: not responding
nfs server 172.18.86.13:/vol/vol_bsd_2: not responding
nfs server 172.18.86.13:/vol/vol_bsd_2: not responding
nfs server 172.18.86.13:/vol/vol_bsd_2: is alive again
nfs server 172.18.86.13:/vol/vol_bsd_2: not responding
nfs server 172.18.86.13:/vol/vol_bsd_2: is alive again
...