Received-SPF: pass (google.com: domain of linux-nfs-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Chuck Lever III <chuck.lever@oracle.com>
To:     Dai Ngo <dai.ngo@oracle.com>
CC:     "jlayton@kernel.org" <jlayton@kernel.org>,
        Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Subject: Re: [PATCH v6 1/2] NFSD: keep track of the number of courtesy clients
 in the system
Thread-Topic: [PATCH v6 1/2] NFSD: keep track of the number of courtesy
 clients in the system
Thread-Index: AQHYx4rDD3NcBHvjY0+YO1U0/EN4+K3eCiEA
Date:   Tue, 13 Sep 2022 23:57:41 +0000
Message-ID: <343795C8-01A5-4FCA-848D-2952773DBF50@oracle.com>
References: <1663085170-23136-1-git-send-email-dai.ngo@oracle.com>
 <1663085170-23136-2-git-send-email-dai.ngo@oracle.com>
In-Reply-To: <1663085170-23136-2-git-send-email-dai.ngo@oracle.com>
Accept-Language: en-US
Content-Language: en-US
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?3lHOqIZRHW5msOI7n7NPcyjs3ZZI+5vzgI11pWJrp5JZ/mBDVlRFGIDUuxMQ?=
 =?us-ascii?Q?cn3SUankGyAmK0MLcWn6tS2WeSfJ39ecRWvdhRBFANO5t6r8v+/NHzFTZOJm?=
 =?us-ascii?Q?v6Hp6EFqZe2UL1ml5g3HvJkO2h1WQma6XPO7XETHIkjWYEbazUPVau9BfxON?=
 =?us-ascii?Q?sbIz5lx936h83FIMhNR1nx/QlWgJUatiK/rYZEPd61KFb74+RdaQs3Clx6s2?=
 =?us-ascii?Q?n/rwAo2PY9qu3aUZIsL5sPgBnUxAwxFRO3AViE9Zxl71Zjr8FkhQiUR3Ebgu?=
 =?us-ascii?Q?cFCFdiohhRV3CKCBCkJUwjWqCUusW7D9ZVoXg/tpUhMHub7lEZ8ARZEgR2R8?=
 =?us-ascii?Q?zb8g/lFJWx24ifVzhAr5URATnxqvmi96VMqd8OtjAhS3hqGC7Vbjw5u2SHT6?=
 =?us-ascii?Q?ChcPSizbj2iRqEJxqsxdfZ7k//v2+UKEyNf/e+920hqVIEd7yh20jELroqXJ?=
 =?us-ascii?Q?HxUZWUVkQvBQalPBb4AY+fcnbq6+Gp1vLBa+9o2V+sMPte+l6GRzK27MUhps?=
 =?us-ascii?Q?qtpa9Do+Ryh2J/ms2Lnsahbz69Zzi5G+T/WDnO46f841tdTA2PPR6JaIJ6CI?=
 =?us-ascii?Q?lcJz+dOaYnWCajTTBs61+TTfCDU9Ka9fAEvI28hsbr9JN3co+zFwmNQCy5rH?=
 =?us-ascii?Q?5JESnu0fzwDNwdOjZqmOGHY9A/AWqN2CfDiAhg4Y2SiJh75KZK0c09s0yXsz?=
 =?us-ascii?Q?J3CcnP9wSgrO/aUSuFlhOPkO1rw3f3o9Xrj1bv4oVi6KLPh6PhlpyzLrv3oS?=
 =?us-ascii?Q?tmum3GHvr/ZvMwa1WC9+359MxpqNqv1pdhwwjhSYVzzGb82TSrXOLY0OmLIZ?=
 =?us-ascii?Q?qtLVYnpNDGKQPSGoKA9UnYoZPrAvhfDnKOVg/97SxhB/6P77/immTk433yMf?=
 =?us-ascii?Q?MbSBzcDr/LARaxMlqYCg5IPofEoKrTsqybWiiFZXATuZfilSRjjR062lCUPm?=
 =?us-ascii?Q?h5wU3JHaEy55EDkOzVCgsp5KmjjaYtNN/Zv2xj1YU0xISGfLMAc+uDsG212g?=
 =?us-ascii?Q?pnMhAnQgTrJ476M+b/xQqeP0pQ8VZwEqz68RqGeI4AaWF1/MbycBP6lPxtIY?=
 =?us-ascii?Q?OB0NFnHzN0kCVNIRgyyns6gzfW7+hP3fnCxnipFn6WoUTNUziuP8jOl9ZxN8?=
 =?us-ascii?Q?vTP7164xZoyG45WsET5e1Ny3LCmZbj0jWilYN2rhmZD/pziiQteX0yn2xwnl?=
 =?us-ascii?Q?Nw+oV7ftoeU+9xPkPrYZXz+RkqDl1RKYooNs8EwbA6D/9iaVjgqR+FgFKZgG?=
 =?us-ascii?Q?kao3jdjNbt75Sg3ouRl5Lglw1Z+PNVwklSL/IfNKya4GL7/m3QKjg95kTI84?=
 =?us-ascii?Q?VpADc+Mx7NPICvM3KjvthJfihisPcPmqoe0wIpKBkM088lAhWvYhS3KNRV6o?=
 =?us-ascii?Q?1yzyK95D04DtUayezAMuLArVkFN4Cm5xvlU5xiXVevxJPb2a5ooSY4vqAcH+?=
 =?us-ascii?Q?cuSPLvXlwoWWS8MnDIM3z2E7QiTr8X9VUztUv1u/8X7yoAOuz5ZQWYMK/wf2?=
 =?us-ascii?Q?lwIK4O+VJ9/vY+k7D8S9fve3eS7+hR/a6yQLHdWo3Hc89i6DlQa0cTN6F9P5?=
 =?us-ascii?Q?odSpJ3w1RRzbbagoJwtUU2j0UYHjQ1w78krfsxXXmdRdb9duj3LnMXM+KgHC?=
 =?us-ascii?Q?lA=3D=3D?=
Content-Type: text/plain; charset="us-ascii"
Content-ID: <FB1AFBF2E0D50142A1B47E3765E07F87@namprd10.prod.outlook.com>
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-OriginatorOrg: oracle.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: BN0PR10MB5128.namprd10.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 1541d3e7-5580-4804-6b04-08da95e3be91
X-MS-Exchange-CrossTenant-originalarrivaltime: 13 Sep 2022 23:57:41.3193
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: 1dhns2KCeaUc7ibv31MgOATJRjn6yOxLCNHHSae+ej4KpgYCbd3l+5YamKBVaIO+lf1sIJIgtrDWCOAhKceulA==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR10MB4558
X-Proofpoint-Virus-Version: vendor=baseguard
 engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.528,FMLib:17.11.122.1
 definitions=2022-09-13_10,2022-09-13_01,2022-06-22_01
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 mlxlogscore=999
 bulkscore=0 phishscore=0 spamscore=0 suspectscore=0 adultscore=0
 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1
 engine=8.12.0-2208220000 definitions=main-2209130111
X-Proofpoint-ORIG-GUID: wptsTtTF3l9igofmNaGXvuPvg_J94CGg
X-Proofpoint-GUID: wptsTtTF3l9igofmNaGXvuPvg_J94CGg
X-Spam-Status: No, score=-2.8 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_LOW,
        RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE,T_SCC_BODY_TEXT_LINE
        autolearn=ham autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-nfs.vger.kernel.org>
X-Mailing-List: linux-nfs@vger.kernel.org


> On Sep 13, 2022, at 9:06 AM, Dai Ngo <dai.ngo@oracle.com> wrote:
>=20
> Add counter nfs4_courtesy_client_count to nfsd_net to keep track
> of the number of courtesy clients in the system.
>=20
> Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
> ---
> fs/nfsd/netns.h     |  2 ++
> fs/nfsd/nfs4state.c | 17 ++++++++++++++++-
> 2 files changed, 18 insertions(+), 1 deletion(-)
>=20
> diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
> index ffe17743cc74..55c7006d6109 100644
> --- a/fs/nfsd/netns.h
> +++ b/fs/nfsd/netns.h
> @@ -192,6 +192,8 @@ struct nfsd_net {
>=20
> 	atomic_t		nfs4_client_count;
> 	int			nfs4_max_clients;
> +
> +	atomic_t		nfsd_courtesy_clients;
> };
>=20
> /* Simple check to find out if a given net was properly initialized */
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index c5d199d7e6b4..3af4fc5241b2 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -160,6 +160,13 @@ static bool is_client_expired(struct nfs4_client *cl=
p)
> 	return clp->cl_time =3D=3D 0;
> }
>=20
> +static inline void nfsd4_decr_courtesy_client_count(struct nfsd_net *nn,
> +					struct nfs4_client *clp)

Nit: The usual naming scheme is "dec" for helpers like this
rather than "decr".

Also "inline" is not necessary here since this helper is used
only in the same source file where it is defined. The compiler
will figure out when to inline it.


> +{
> +	if (clp->cl_state !=3D NFSD4_ACTIVE)
> +		atomic_add_unless(&nn->nfsd_courtesy_clients, -1, 0);
> +}
> +
> static __be32 get_client_locked(struct nfs4_client *clp)
> {
> 	struct nfsd_net *nn =3D net_generic(clp->net, nfsd_net_id);
> @@ -169,6 +176,7 @@ static __be32 get_client_locked(struct nfs4_client *c=
lp)
> 	if (is_client_expired(clp))
> 		return nfserr_expired;
> 	atomic_inc(&clp->cl_rpc_users);
> +	nfsd4_decr_courtesy_client_count(nn, clp);
> 	clp->cl_state =3D NFSD4_ACTIVE;
> 	return nfs_ok;
> }
> @@ -190,6 +198,7 @@ renew_client_locked(struct nfs4_client *clp)
>=20
> 	list_move_tail(&clp->cl_lru, &nn->client_lru);
> 	clp->cl_time =3D ktime_get_boottime_seconds();
> +	nfsd4_decr_courtesy_client_count(nn, clp);
> 	clp->cl_state =3D NFSD4_ACTIVE;
> }
>=20
> @@ -2233,6 +2242,7 @@ __destroy_client(struct nfs4_client *clp)
> 	if (clp->cl_cb_conn.cb_xprt)
> 		svc_xprt_put(clp->cl_cb_conn.cb_xprt);
> 	atomic_add_unless(&nn->nfs4_client_count, -1, 0);
> +	nfsd4_decr_courtesy_client_count(nn, clp);
> 	free_client(clp);
> 	wake_up_all(&expiry_wq);
> }
> @@ -4356,6 +4366,8 @@ void nfsd4_init_leases_net(struct nfsd_net *nn)
> 	max_clients =3D (u64)si.totalram * si.mem_unit / (1024 * 1024 * 1024);
> 	max_clients *=3D NFS4_CLIENTS_PER_GB;
> 	nn->nfs4_max_clients =3D max_t(int, max_clients, NFS4_CLIENTS_PER_GB);
> +
> +	atomic_set(&nn->nfsd_courtesy_clients, 0);
> }
>=20
> static void init_nfs4_replay(struct nfs4_replay *rp)
> @@ -5878,8 +5890,11 @@ nfs4_get_client_reaplist(struct nfsd_net *nn, stru=
ct list_head *reaplist,
> 			goto exp_client;
> 		if (!state_expired(lt, clp->cl_time))
> 			break;
> -		if (!atomic_read(&clp->cl_rpc_users))
> +		if (!atomic_read(&clp->cl_rpc_users)) {
> +			if (clp->cl_state =3D=3D NFSD4_ACTIVE)
> +				atomic_inc(&nn->nfsd_courtesy_clients);
> 			clp->cl_state =3D NFSD4_COURTESY;
> +		}
> 		if (!client_has_state(clp))
> 			goto exp_client;
> 		if (!nfs4_anylock_blockers(clp))
> --=20
> 2.9.5
>=20

--
Chuck Lever