[RFC] server's statd and lockd will not sync after its nfslock restart

[Mi Jinlong <mijinlong@cn.fujitsu.com>]

Hi,

When testing the NLM at the latest kernel(2.6.32),  i find a bug.
When a client hold locks, after server restart its nfslock service, 
server's statd will not synchronize with lockd.
If server restart nfslock twice or more, client's lock will be lost.

Test process:

  Step1: client open nfs file.
  Step2: client using fcntl to get lock.
  Step3: server restart it's nfslock service.

After step3, server's lockd records client holding locks, but statd's 
/var/lib/nfs/statd/sm/ directory is empty. It means statd and lockd are 
not sync. If server restart it's nfslock again, client's locks will be lost.

The Primary Reason:

  At step3, when client's reclaimed lock request is sent to server, 
client's host(the host struct) is reused but not be re-monitored at
server's lockd. After that, statd and lockd are not sync.

Question:

In my opinion, if lockd is allowed reuseing the client's host, it should
send a SM_MON to statd when reuse. If not allowed, the client's host should 
be destroyed immediately.
 
What should lockd to do?  Reuse ? Destroy ? Or some other action?


thanks,

Mi Jinlong