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

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

J. Bruce Fields :
> On Tue, Dec 15, 2009 at 06:02:11PM +0800, Mi Jinlong wrote:
>> 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.
> 
> I don't know what you mean; what did you actually do in step 3?

  I use command "service nfslock restart" at server.

  I mean, after server restart nfslock service, lockd and statd are not synchronizing.
  Because, after nfslock restart, server go into grace_period, and client's 
  reclaimed lock request will be processed by lockd. At this, client's host(the host struct)
  will be reused which is created before nfslock restart, but, the lockd don't 
  send a SM_MON to statd.

  After locks are reclaimed, server's lockd records client hold locks, but statd don't 
  monitor client.

 thanks,
 Mi Jinlong

> 
> --b.
> 
>> 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
>>
> 
> 

-- 
Regards
Mi Jinlong