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From:   Chuck Lever III <chuck.lever@oracle.com>
To:     Bruce Fields <bfields@fieldses.org>
CC:     Dai Ngo <dai.ngo@oracle.com>, Jeff Layton <jlayton@redhat.com>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Linux NFS Mailing List <linux-nfs@vger.kernel.org>,
        "linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH RFC v18 02/11] NFSD: Add courtesy client state, macro and
 spinlock to support courteous server
Thread-Topic: [PATCH RFC v18 02/11] NFSD: Add courtesy client state, macro and
 spinlock to support courteous server
Thread-Index: AQHYQAGu2vXHyzFxzEOK5co/7sorDqzWiKwAgAAI/wCAAALWgIAAHqSAgAAFbQCAAA7/AIAABI+AgAACqACAAADAgIAABWQA
Date:   Tue, 29 Mar 2022 20:20:45 +0000
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> On Mar 29, 2022, at 4:01 PM, Bruce Fields <bfields@fieldses.org> wrote:
>=20
> 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".
>>=20
>> Dai, would you add
>>=20
>> +enum courtesy_client_state {
>>>>> 	NFSD4_CLIENT_ACTIVE =3D 0,
>> +	NFSD4_CLIENT_COURTESY,
>> +	NFSD4_CLIENT_EXPIRED,
>> +	NFSD4_CLIENT_RECONNECTED,
>> +};
>>=20
>> And set cl_cs_client_state to ACTIVE where the client is
>> allowed to transition back to being active?
>=20
> I'm not clear then what the RECONNECTED->ACTIVE transition would be.
>=20
> 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