From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 56FFCECAAD2 for ; Mon, 29 Aug 2022 16:48:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229510AbiH2Qsm (ORCPT ); Mon, 29 Aug 2022 12:48:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37198 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229916AbiH2Qsj (ORCPT ); Mon, 29 Aug 2022 12:48:39 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9C8048168D for ; Mon, 29 Aug 2022 09:48:38 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 4123F6123F for ; Mon, 29 Aug 2022 16:48:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 38ADBC433C1; Mon, 29 Aug 2022 16:48:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1661791717; bh=VW8Z9xzYpgHUmD0wSVjM5z8pwUw/DB6zVmpeOH27le4=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=RYEjNGTVEX+4HwjT8/K6DGINQTaxLVIDhCvySh2FKyFwNRhWxMXnhFvNqy/UgGY2S rR52Y3WNdIw9Xt3pGCblI67rSVX2zX8RSdChnGkSWjKOi6VFi9yFY7FN5UgBo9sQse qT9eL53YIz+rwX9E5OF3zNn1gNGFse8jDx+9fmZ+dv0Hm5jB3GknbrnyDOi0qJnId8 j+8hnjiswaWQu9sjWC3IIF8ClYTj8b3qtKgLT3NzTyZeNiiUEVOP7xrUmf6SEN+MS4 34hjZCvYPLHza+BtMezRVKLnK0NFC8UD3hTLD7clm+W93YGIf9WyWELE1l/kDHC+bU apB1rlvKfWdSw== Message-ID: Subject: Re: [PATCH v2 1/2] NFSD: keep track of the number of courtesy clients in the system From: Jeff Layton To: Dai Ngo , chuck.lever@oracle.com Cc: linux-nfs@vger.kernel.org Date: Mon, 29 Aug 2022 12:48:35 -0400 In-Reply-To: <1661734063-22023-2-git-send-email-dai.ngo@oracle.com> References: <1661734063-22023-1-git-send-email-dai.ngo@oracle.com> <1661734063-22023-2-git-send-email-dai.ngo@oracle.com> Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.44.4 (3.44.4-1.fc36) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org On Sun, 2022-08-28 at 17:47 -0700, Dai Ngo wrote: > 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 > --- > fs/nfsd/netns.h | 2 ++ > fs/nfsd/nfs4state.c | 20 +++++++++++++++----- > 2 files changed, 17 insertions(+), 5 deletions(-) >=20 > diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h > index ffe17743cc74..2695dff1378a 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_client_count; > }; > =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..3d8d7ebb5b91 100644 > --- a/fs/nfsd/nfs4state.c > +++ b/fs/nfsd/nfs4state.c > @@ -169,7 +169,8 @@ static __be32 get_client_locked(struct nfs4_client *c= lp) > if (is_client_expired(clp)) > return nfserr_expired; > atomic_inc(&clp->cl_rpc_users); > - clp->cl_state =3D NFSD4_ACTIVE; > + if (xchg(&clp->cl_state, NFSD4_ACTIVE) !=3D NFSD4_ACTIVE) The xchg calls seem like overkill. The cl_state is protected by the nn->client_lock. Nothing else can race in and change it here. > + atomic_add_unless(&nn->nfsd_courtesy_client_count, -1, 0); > return nfs_ok; > } > =20 > @@ -190,7 +191,8 @@ 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(); > - clp->cl_state =3D NFSD4_ACTIVE; > + if (xchg(&clp->cl_state, NFSD4_ACTIVE) !=3D NFSD4_ACTIVE) > + atomic_add_unless(&nn->nfsd_courtesy_client_count, -1, 0); > } > =20 > static void put_client_renew_locked(struct nfs4_client *clp) > @@ -2233,6 +2235,8 @@ __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); > + if (clp->cl_state !=3D NFSD4_ACTIVE) > + atomic_add_unless(&nn->nfsd_courtesy_client_count, -1, 0); > free_client(clp); > wake_up_all(&expiry_wq); > } > @@ -4356,6 +4360,8 @@ 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_client_count, 0); > } > =20 > static void init_nfs4_replay(struct nfs4_replay *rp) > @@ -5864,7 +5870,7 @@ static void > nfs4_get_client_reaplist(struct nfsd_net *nn, struct list_head *reaplist= , > struct laundry_time *lt) > { > - unsigned int maxreap, reapcnt =3D 0; > + unsigned int oldstate, maxreap, reapcnt =3D 0; > struct list_head *pos, *next; > struct nfs4_client *clp; > =20 > @@ -5878,8 +5884,12 @@ 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)) > - clp->cl_state =3D NFSD4_COURTESY; > + oldstate =3D NFSD4_ACTIVE; > + if (!atomic_read(&clp->cl_rpc_users)) { > + oldstate =3D xchg(&clp->cl_state, NFSD4_COURTESY); > + if (oldstate =3D=3D NFSD4_ACTIVE) > + atomic_inc(&nn->nfsd_courtesy_client_count); > + } > if (!client_has_state(clp)) > goto exp_client; > if (!nfs4_anylock_blockers(clp)) --=20 Jeff Layton