From patchwork Wed Apr 27 08:52:47 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dai Ngo X-Patchwork-Id: 12828473 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 A090AC433F5 for ; Wed, 27 Apr 2022 08:53:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235765AbiD0I4V (ORCPT ); Wed, 27 Apr 2022 04:56:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44934 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231802AbiD0I4P (ORCPT ); Wed, 27 Apr 2022 04:56:15 -0400 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E415D1AE030; Wed, 27 Apr 2022 01:53:04 -0700 (PDT) Received: from pps.filterd (m0246617.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 23R8V0PV025784; Wed, 27 Apr 2022 08:53:01 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=kQDrEX1cOZkNPBvdGjqW8/aRbDdYw6z9OFMCQBq1aqg=; b=Ejf/+kMoV+VX3fOF/ZY3yMMS5CmJ4jzsQ9wKUfCzLHUpXVxsL5CayO/3HEftmPHasEJS TlMbTN9RTopJST7ON80Fbt2yLomdyfAvvDl9C6Q6QO7wnON4NI4NvS7B66U+JsbY9czJ v3X6kKnHGlKoMRZLvBiMHHiHQxQlwTTK5e3t//9A3altWa97lVW5rZfzoOSwANNPy/zE D2hc9HGHDb6kZdHjaomWxvbwUGoZvtxXutLwXeuL7N8QV11CdykoKx03H4JzlZzdGaOz Ri34Ni4mTFl4dQNoHbPp/HW8/MElsbVCvc+m1BGTBGdkdun5tPlLGyuoJi328bPT66Yd 3Q== Received: from iadpaimrmta01.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta01.appoci.oracle.com [130.35.100.223]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3fmb1mrfjw-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 27 Apr 2022 08:53:01 +0000 Received: from pps.filterd (iadpaimrmta01.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta01.imrmtpd1.prodappiadaev1.oraclevcn.com (8.16.1.2/8.16.1.2) with SMTP id 23R8kYfG001350; Wed, 27 Apr 2022 08:52:59 GMT Received: from pps.reinject (localhost [127.0.0.1]) by iadpaimrmta01.imrmtpd1.prodappiadaev1.oraclevcn.com with ESMTP id 3fp5ykfxnm-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 27 Apr 2022 08:52:59 +0000 Received: from iadpaimrmta01.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta01.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 23R8ligs005778; Wed, 27 Apr 2022 08:52:59 GMT Received: from ca-common-hq.us.oracle.com (ca-common-hq.us.oracle.com [10.211.9.209]) by iadpaimrmta01.imrmtpd1.prodappiadaev1.oraclevcn.com with ESMTP id 3fp5ykfxme-2; Wed, 27 Apr 2022 08:52:59 +0000 From: Dai Ngo To: chuck.lever@oracle.com, bfields@fieldses.org Cc: jlayton@redhat.com, viro@zeniv.linux.org.uk, linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH RFC v22 1/7] NFSD: add courteous server support for thread with only delegation Date: Wed, 27 Apr 2022 01:52:47 -0700 Message-Id: <1651049573-29552-2-git-send-email-dai.ngo@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1651049573-29552-1-git-send-email-dai.ngo@oracle.com> References: <1651049573-29552-1-git-send-email-dai.ngo@oracle.com> X-Proofpoint-GUID: gzPCpcRG7MbasYSN4uhM6b62YEydYbzX X-Proofpoint-ORIG-GUID: gzPCpcRG7MbasYSN4uhM6b62YEydYbzX Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org This patch provides courteous server support for delegation only. Only expired client with delegation but no conflict and no open or lock state is allowed to be in COURTESY state. Delegation conflict with COURTESY/EXPIRABLE client is resolved by setting it to EXPIRABLE, queue work for the laundromat and return delay to the caller. Conflict is resolved when the laudromat runs and expires the EXIRABLE client while the NFS client retries the OPEN request. Local thread request that gets conflict is doing the retry in _break_lease. Client in COURTESY or EXPIRABLE state is allowed to reconnect and continues to have access to its state. Access to the nfs4_client by the reconnecting thread and the laundromat is serialized via the client_lock. Signed-off-by: Dai Ngo --- fs/nfsd/nfs4state.c | 86 +++++++++++++++++++++++++++++++++++++++++++++-------- fs/nfsd/nfsd.h | 1 + fs/nfsd/state.h | 32 ++++++++++++++++++++ 3 files changed, 106 insertions(+), 13 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 234e852fcdfa..216bd77a8764 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -125,6 +125,8 @@ static void free_session(struct nfsd4_session *); 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; + static bool is_session_dead(struct nfsd4_session *ses) { return ses->se_flags & NFS4_SESSION_DEAD; @@ -152,6 +154,7 @@ static __be32 get_client_locked(struct nfs4_client *clp) if (is_client_expired(clp)) return nfserr_expired; atomic_inc(&clp->cl_rpc_users); + clp->cl_state = NFSD4_ACTIVE; return nfs_ok; } @@ -172,6 +175,7 @@ renew_client_locked(struct nfs4_client *clp) list_move_tail(&clp->cl_lru, &nn->client_lru); clp->cl_time = ktime_get_boottime_seconds(); + clp->cl_state = NFSD4_ACTIVE; } static void put_client_renew_locked(struct nfs4_client *clp) @@ -2004,6 +2008,7 @@ static struct nfs4_client *alloc_client(struct xdr_netobj name) idr_init(&clp->cl_stateids); atomic_set(&clp->cl_rpc_users, 0); clp->cl_cb_state = NFSD4_CB_UNKNOWN; + clp->cl_state = NFSD4_ACTIVE; INIT_LIST_HEAD(&clp->cl_idhash); INIT_LIST_HEAD(&clp->cl_openowners); INIT_LIST_HEAD(&clp->cl_delegations); @@ -4694,9 +4699,16 @@ nfsd_break_deleg_cb(struct file_lock *fl) bool ret = false; struct nfs4_delegation *dp = (struct nfs4_delegation *)fl->fl_owner; struct nfs4_file *fp = dp->dl_stid.sc_file; + struct nfs4_client *clp = dp->dl_stid.sc_client; + struct nfsd_net *nn; trace_nfsd_cb_recall(&dp->dl_stid); + if (!try_to_expire_client(clp)) { + nn = net_generic(clp->net, nfsd_net_id); + mod_delayed_work(laundry_wq, &nn->laundromat_work, 0); + } + /* * We don't want the locks code to timeout the lease for us; * we'll remove it ourself if a delegation isn't returned @@ -5605,6 +5617,65 @@ static void nfsd4_ssc_expire_umount(struct nfsd_net *nn) } #endif +/* + * place holder for now, no check for lock blockers yet + */ +static bool +nfs4_anylock_blockers(struct nfs4_client *clp) +{ + /* + * don't want to check for delegation conflict here since + * we need the state_lock for it. The laundromat willexpire + * COURTESY later when checking for delegation recall timeout. + */ + return false; +} + +static bool client_has_state_tmp(struct nfs4_client *clp) +{ + if (!list_empty(&clp->cl_delegations) && + !client_has_openowners(clp) && + list_empty(&clp->async_copies)) + return true; + return false; +} + +static void +nfs4_get_client_reaplist(struct nfsd_net *nn, struct list_head *reaplist, + struct laundry_time *lt) +{ + struct list_head *pos, *next; + struct nfs4_client *clp; + bool cour; + + INIT_LIST_HEAD(reaplist); + spin_lock(&nn->client_lock); + list_for_each_safe(pos, next, &nn->client_lru) { + clp = list_entry(pos, struct nfs4_client, cl_lru); + if (clp->cl_state == NFSD4_EXPIRABLE) + goto exp_client; + if (!state_expired(lt, clp->cl_time)) + break; + if (!client_has_state_tmp(clp)) + goto exp_client; + cour = (clp->cl_state == NFSD4_COURTESY); + if (cour && ktime_get_boottime_seconds() >= + (clp->cl_time + NFSD_COURTESY_CLIENT_TIMEOUT)) { + goto exp_client; + } + if (nfs4_anylock_blockers(clp)) { +exp_client: + if (mark_client_expired_locked(clp)) + continue; + list_add(&clp->cl_lru, reaplist); + continue; + } + if (!cour) + cmpxchg(&clp->cl_state, NFSD4_ACTIVE, NFSD4_COURTESY); + } + spin_unlock(&nn->client_lock); +} + static time64_t nfs4_laundromat(struct nfsd_net *nn) { @@ -5627,7 +5698,6 @@ nfs4_laundromat(struct nfsd_net *nn) goto out; } nfsd4_end_grace(nn); - INIT_LIST_HEAD(&reaplist); spin_lock(&nn->s2s_cp_lock); idr_for_each_entry(&nn->s2s_cp_stateids, cps_t, i) { @@ -5637,17 +5707,7 @@ nfs4_laundromat(struct nfsd_net *nn) _free_cpntf_state_locked(nn, cps); } spin_unlock(&nn->s2s_cp_lock); - - spin_lock(&nn->client_lock); - list_for_each_safe(pos, next, &nn->client_lru) { - clp = list_entry(pos, struct nfs4_client, cl_lru); - if (!state_expired(<, clp->cl_time)) - break; - if (mark_client_expired_locked(clp)) - continue; - list_add(&clp->cl_lru, &reaplist); - } - spin_unlock(&nn->client_lock); + nfs4_get_client_reaplist(nn, &reaplist, <); list_for_each_safe(pos, next, &reaplist) { clp = list_entry(pos, struct nfs4_client, cl_lru); trace_nfsd_clid_purged(&clp->cl_clientid); @@ -5657,6 +5717,7 @@ nfs4_laundromat(struct nfsd_net *nn) spin_lock(&state_lock); list_for_each_safe(pos, next, &nn->del_recall_lru) { dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru); + try_to_expire_client(dp->dl_stid.sc_client); if (!state_expired(<, dp->dl_time)) break; WARN_ON(!unhash_delegation_locked(dp)); @@ -5722,7 +5783,6 @@ nfs4_laundromat(struct nfsd_net *nn) return max_t(time64_t, lt.new_timeo, NFSD_LAUNDROMAT_MINTIMEOUT); } -static struct workqueue_struct *laundry_wq; static void laundromat_main(struct work_struct *); static void diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h index 4fc1fd639527..23996c6ca75e 100644 --- a/fs/nfsd/nfsd.h +++ b/fs/nfsd/nfsd.h @@ -336,6 +336,7 @@ void nfsd_lockd_shutdown(void); #define COMPOUND_ERR_SLACK_SPACE 16 /* OP_SETATTR */ #define NFSD_LAUNDROMAT_MINTIMEOUT 1 /* seconds */ +#define NFSD_COURTESY_CLIENT_TIMEOUT (24 * 60 * 60) /* seconds */ /* * The following attributes are currently not supported by the NFSv4 server: diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index 95457cfd37fc..6130376c438b 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -283,6 +283,28 @@ struct nfsd4_sessionid { #define HEXDIR_LEN 33 /* hex version of 16 byte md5 of cl_name plus '\0' */ /* + * State Meaning Where set + * -------------------------------------------------------------------------- + * | NFSD4_ACTIVE | Confirmed, active | Default | + * |------------------- ----------------------------------------------------| + * | NFSD4_COURTESY | Courtesy state. | nfs4_get_client_reaplist | + * | | Lease/lock/share | | + * | | reservation conflict | | + * | | can cause Courtesy | | + * | | client to be expired | | + * |------------------------------------------------------------------------| + * | NFSD4_EXPIRABLE | Courtesy client to be| nfs4_laundromat | + * | | expired by Laundromat| try_to_expire_client | + * | | due to conflict | | + * |------------------------------------------------------------------------| + */ +enum { + NFSD4_ACTIVE = 0, + NFSD4_COURTESY, + NFSD4_EXPIRABLE, +}; + +/* * struct nfs4_client - one per client. Clientids live here. * * The initial object created by an NFS client using SETCLIENTID (for NFSv4.0) @@ -385,6 +407,8 @@ struct nfs4_client { struct list_head async_copies; /* list of async copies */ spinlock_t async_lock; /* lock for async copies */ atomic_t cl_cb_inflight; /* Outstanding callbacks */ + + unsigned int cl_state; }; /* struct nfs4_client_reset @@ -702,4 +726,12 @@ extern void nfsd4_client_record_remove(struct nfs4_client *clp); extern int nfsd4_client_record_check(struct nfs4_client *clp); extern void nfsd4_record_grace_done(struct nfsd_net *nn); +static inline bool try_to_expire_client(struct nfs4_client *clp) +{ + bool ret; + + ret = NFSD4_ACTIVE == + cmpxchg(&clp->cl_state, NFSD4_COURTESY, NFSD4_EXPIRABLE); + return ret; +} #endif /* NFSD4_STATE_H */