Re: [PATCH RFC v18 02/11] NFSD: Add courtesy client state, macro and spinlock to support courteous server

[Chuck Lever III <chuck.lever@oracle.com>]

> On Mar 29, 2022, at 4:01 PM, Bruce Fields <bfields@fieldses.org> wrote:
> 
> On Tue, Mar 29, 2022 at 07:58:46PM +0000, Chuck Lever III wrote:
>> Got it. Agreed, cl_cs_client_state should be reinitialized if
>> a courtesy client is transitioned back to "active".
>> 
>> Dai, would you add
>> 
>> +enum courtesy_client_state {
>>>>> 	NFSD4_CLIENT_ACTIVE = 0,
>> +	NFSD4_CLIENT_COURTESY,
>> +	NFSD4_CLIENT_EXPIRED,
>> +	NFSD4_CLIENT_RECONNECTED,
>> +};
>> 
>> And set cl_cs_client_state to ACTIVE where the client is
>> allowed to transition back to being active?
> 
> I'm not clear then what the RECONNECTED->ACTIVE transition would be.
> 
> My feeling is that the RECONNECTED state shouldn't exist, and that there
> should only be a transition of EXPIRED back to ACTIVE.

Audit the places that check for NFSD4_CLIENT_RECONNECTED.
Some of them will expire a reconnected client, some will
let it transition back to active. My impression from Dai
was that the server cannot transition a courtesy client
back to active in _every_ case.

If you can demonstrate that in every case where RECONNECTED
is found that a client should be transitioned to ACTIVE
rather than discarded, then yes, we should get rid of
RECONNECTED in favor of going from COURTESY -> ACTIVE.


--
Chuck Lever