From patchwork Tue Jul 12 20:09:13 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dai Ngo X-Patchwork-Id: 12915618 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 2B687C43334 for ; Tue, 12 Jul 2022 20:09:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230473AbiGLUJ0 (ORCPT ); Tue, 12 Jul 2022 16:09:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50196 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233538AbiGLUJZ (ORCPT ); Tue, 12 Jul 2022 16:09:25 -0400 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C84D9BB7ED for ; Tue, 12 Jul 2022 13:09:23 -0700 (PDT) Received: from pps.filterd (m0246630.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 26CJYDPY023232 for ; Tue, 12 Jul 2022 20:09:23 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references; s=corp-2021-07-09; bh=NorEoZ7YcHJUo3tPOR/iLN5QIR8q5nMqggpd7EF22m0=; b=sDZzNfDwKezpujj7bu7HQSoIPsl61jae63hTaLJO8ipIrLpJK33fTCVZqefFVp5goI+l hRRAySPW5yg4HP2ce4/b3EtfySqt2U5NiCV4kbDRt/ElGvJFZhMu+91jQVXYdXdvXV77 BST6MCb8yZZ5RIDaUxs717pJDP/8c+DFi7nf4RQ0Q9oTDCLRTSqxeztVStZ0Rmg14xoH SQFNrY6Syg8Oez/FarAkOn+DCK4qSUOmTg4TWBGchYVbg7NTk///nMwoPaFy7kvlkDvW 625SIRnUgLStpSWls4z0tKieDnjN6Gz8y6JQgUYkdd4nLk4Tw3K4IOG95dai/RZb5rTx 6Q== Received: from iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta02.appoci.oracle.com [147.154.18.20]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3h71r17yeb-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Tue, 12 Jul 2022 20:09:22 +0000 Received: from pps.filterd (iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (8.16.1.2/8.16.1.2) with SMTP id 26CK1Ken019906 for ; Tue, 12 Jul 2022 20:09:16 GMT Received: from pps.reinject (localhost [127.0.0.1]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com with ESMTP id 3h70449sqd-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Tue, 12 Jul 2022 20:09:16 +0000 Received: from iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 26CK9EDf003044 for ; Tue, 12 Jul 2022 20:09:16 GMT Received: from ca-common-hq.us.oracle.com (ca-common-hq.us.oracle.com [10.211.9.209]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com with ESMTP id 3h70449snp-3; Tue, 12 Jul 2022 20:09:16 +0000 From: Dai Ngo To: chuck.lever@oracle.com Cc: linux-nfs@vger.kernel.org Subject: [PATCH 2/2] NFSD: limit the number of v4 clients to 4096 per 4GB of system memory Date: Tue, 12 Jul 2022 13:09:13 -0700 Message-Id: <1657656553-16493-3-git-send-email-dai.ngo@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1657656553-16493-1-git-send-email-dai.ngo@oracle.com> References: <1657656553-16493-1-git-send-email-dai.ngo@oracle.com> X-Proofpoint-ORIG-GUID: 3jsAQZZ1QIi_Ns2IOZyyFdtGa4eHyS0s X-Proofpoint-GUID: 3jsAQZZ1QIi_Ns2IOZyyFdtGa4eHyS0s Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Currently there is no limit on how many v4 clients are supported by the system. This can be a problem in systems with small memory configuration to function properly when a very large number of clients exist that creates memory shortage conditions. This patch enforces a limit of 4096 NFSv4 clients, including courtesy clients, per 4GB of system memory. When the number of the clients reaches the limit, requests that create new clients are returned with NFS4ERR_DELAY. The laundromat detects this condition and removes older courtesy clients. Due to the overhead of the upcall to remove the client record, the maximun number of clients the laundromat removes on each run is limited to 128. This is done to ensure the laundromat can still process other tasks in a timely manner. Since there is now a limit of the number of clients, the 24-hr idle time limit of courtesy client is no longer needed and was removed. Signed-off-by: Dai Ngo --- fs/nfsd/netns.h | 1 + fs/nfsd/nfs4state.c | 17 +++++++++++++---- fs/nfsd/nfsctl.c | 8 ++++++++ 3 files changed, 22 insertions(+), 4 deletions(-) diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h index ce864f001a3e..8d72b302a49c 100644 --- a/fs/nfsd/netns.h +++ b/fs/nfsd/netns.h @@ -191,6 +191,7 @@ struct nfsd_net { siphash_key_t siphash_key; atomic_t nfs4_client_count; + unsigned int nfs4_max_clients; }; /* 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 30e16d9e8657..e54db346dc00 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -126,6 +126,7 @@ static const struct nfsd4_callback_ops nfsd4_cb_recall_ops; static const struct nfsd4_callback_ops nfsd4_cb_notify_lock_ops; static struct workqueue_struct *laundry_wq; +#define NFSD_CLIENT_MAX_TRIM_PER_RUN 128 int nfsd4_create_laundry_wq(void) { @@ -2059,6 +2060,8 @@ static struct nfs4_client *alloc_client(struct xdr_netobj name, struct nfs4_client *clp; int i; + if (atomic_read(&nn->nfs4_client_count) >= nn->nfs4_max_clients) + return NULL; clp = kmem_cache_zalloc(client_slab, GFP_KERNEL); if (clp == NULL) return NULL; @@ -5796,9 +5799,12 @@ static void nfs4_get_client_reaplist(struct nfsd_net *nn, struct list_head *reaplist, struct laundry_time *lt) { + unsigned int maxreap = 0, reapcnt = 0; struct list_head *pos, *next; struct nfs4_client *clp; + if (atomic_read(&nn->nfs4_client_count) >= nn->nfs4_max_clients) + maxreap = NFSD_CLIENT_MAX_TRIM_PER_RUN; INIT_LIST_HEAD(reaplist); spin_lock(&nn->client_lock); list_for_each_safe(pos, next, &nn->client_lru) { @@ -5809,14 +5815,17 @@ nfs4_get_client_reaplist(struct nfsd_net *nn, struct list_head *reaplist, break; if (!atomic_read(&clp->cl_rpc_users)) clp->cl_state = NFSD4_COURTESY; - if (!client_has_state(clp) || - ktime_get_boottime_seconds() >= - (clp->cl_time + NFSD_COURTESY_CLIENT_TIMEOUT)) + if (!client_has_state(clp)) goto exp_client; if (nfs4_anylock_blockers(clp)) { exp_client: - if (!mark_client_expired_locked(clp)) + if (!mark_client_expired_locked(clp)) { list_add(&clp->cl_lru, reaplist); + reapcnt++; + } + } else { + if (reapcnt < maxreap) + goto exp_client; } } spin_unlock(&nn->client_lock); diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 547f4c4b9668..223659e15af3 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -96,6 +96,8 @@ static ssize_t (*const write_op[])(struct file *, char *, size_t) = { #endif }; +#define NFS4_MAX_CLIENTS_PER_4GB 4096 + static ssize_t nfsctl_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos) { ino_t ino = file_inode(file)->i_ino; @@ -1462,6 +1464,8 @@ unsigned int nfsd_net_id; static __net_init int nfsd_init_net(struct net *net) { int retval; + unsigned long lowmem; + struct sysinfo si; struct nfsd_net *nn = net_generic(net, nfsd_net_id); retval = nfsd_export_init(net); @@ -1488,6 +1492,10 @@ static __net_init int nfsd_init_net(struct net *net) seqlock_init(&nn->writeverf_lock); atomic_set(&nn->nfs4_client_count, 0); + si_meminfo(&si); + lowmem = (si.totalram - si.totalhigh) * si.mem_unit; + nn->nfs4_max_clients = (((lowmem * 100) >> 32) * + NFS4_MAX_CLIENTS_PER_4GB) / 100; return 0;