From patchwork Thu Jun 26 19:11:50 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 4430221 Return-Path: X-Original-To: patchwork-linux-nfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id D3933BEEAA for ; Thu, 26 Jun 2014 19:14:06 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id C228A2024D for ; Thu, 26 Jun 2014 19:14:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AE038201BB for ; Thu, 26 Jun 2014 19:14:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750974AbaFZTOC (ORCPT ); Thu, 26 Jun 2014 15:14:02 -0400 Received: from mail-qg0-f41.google.com ([209.85.192.41]:35635 "EHLO mail-qg0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750832AbaFZTOB (ORCPT ); Thu, 26 Jun 2014 15:14:01 -0400 Received: by mail-qg0-f41.google.com with SMTP id i50so3481253qgf.14 for ; Thu, 26 Jun 2014 12:14:00 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references; bh=mdQQI2Zq/NGHD3i50tGDhIfkPOXt29iMzkXahZmS+LY=; b=RAiVBDSOj08qhvqZe4a0PNwvpoHh/guJC5EkGXe8sF6hLHiMqr/f1iCR5WkbKNiUa2 bQvR9vofjjqfBeme9B2AjjNbKYlKCSAmPWgwNTavRKi3bpdl3LVPDGMDjw2tFRpQRMYJ lQYtewyMyECoUK/JhSDhpKWKTMaIklQAhJVFqe98b43xy2BzMlskb/1FD5aVa74F5YAB kiaMAigL0X7fOD60G4P/0UJQthQW8gnwSvfkGb8wKzCOclceVQf1XSe0fx9m3o9G+7OF hRLyQ15FG9R5w/ZCd5yb1JRSKRR/YMPKd5AxMHs68dnzX9UwOHAFq1YyBIhhhJVVJ5Iq qfAw== X-Gm-Message-State: ALoCoQlbkhpw//NK7mXfBxFpggdE5JXSz0Px3uFkeJrcaPfg/FxA/WGPsmqNYZ8WuWKwPyEpyTvd X-Received: by 10.224.13.139 with SMTP id c11mr25502791qaa.77.1403810040759; Thu, 26 Jun 2014 12:14:00 -0700 (PDT) Received: from tlielax.poochiereds.net ([2001:470:8:d63:3a60:77ff:fe93:a95d]) by mx.google.com with ESMTPSA id 88sm4763039qgh.5.2014.06.26.12.13.59 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 26 Jun 2014 12:13:59 -0700 (PDT) From: Jeff Layton To: bfields@fieldses.org Cc: linux-nfs@vger.kernel.org Subject: [PATCH v2 010/117] nfsd: Avoid taking state_lock while holding inode lock in nfsd_break_one_deleg Date: Thu, 26 Jun 2014 15:11:50 -0400 Message-Id: <1403810017-16062-11-git-send-email-jlayton@primarydata.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1403810017-16062-1-git-send-email-jlayton@primarydata.com> References: <1403810017-16062-1-git-send-email-jlayton@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP state_lock is a heavily contended global lock. We don't want to grab that while simultaneously holding the inode->i_lock. Add a new per-nfs4_file lock that we can use to protect the per-nfs4_file delegation list. Hold that while walking the list in the break_deleg callback and queue the workqueue job for each one. The workqueue job can then take the state_lock and do the list manipulations without the i_lock being held prior to starting the rpc call. Signed-off-by: Trond Myklebust Signed-off-by: Jeff Layton Reviewed-by: Christoph Hellwig --- fs/nfsd/nfs4callback.c | 22 ++++++++++++++++++---- fs/nfsd/nfs4state.c | 43 ++++++++++++++++++++++++++++--------------- fs/nfsd/state.h | 2 ++ 3 files changed, 48 insertions(+), 19 deletions(-) diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c index 00cb9b7a75f6..771323ae1b33 100644 --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -1014,9 +1014,8 @@ static void nfsd4_process_cb_update(struct nfsd4_callback *cb) run_nfsd4_cb(cb); } -static void nfsd4_do_callback_rpc(struct work_struct *w) +static void nfsd4_run_callback_rpc(struct nfsd4_callback *cb) { - struct nfsd4_callback *cb = container_of(w, struct nfsd4_callback, cb_work); struct nfs4_client *clp = cb->cb_clp; struct rpc_clnt *clnt; @@ -1034,6 +1033,22 @@ static void nfsd4_do_callback_rpc(struct work_struct *w) cb->cb_ops, cb); } +static void nfsd4_do_callback_rpc(struct work_struct *w) +{ + struct nfsd4_callback *cb = container_of(w, struct nfsd4_callback, + cb_work); + nfsd4_run_callback_rpc(cb); +} + +static void nfsd4_do_cb_recall(struct work_struct *w) +{ + struct nfsd4_callback *cb = container_of(w, struct nfsd4_callback, + cb_work); + + nfsd4_prepare_cb_recall(cb->cb_op); + nfsd4_run_callback_rpc(cb); +} + void nfsd4_cb_recall(struct nfs4_delegation *dp) { struct nfsd4_callback *cb = &dp->dl_recall; @@ -1050,8 +1065,7 @@ void nfsd4_cb_recall(struct nfs4_delegation *dp) INIT_LIST_HEAD(&cb->cb_per_client); cb->cb_done = true; - - INIT_WORK(&cb->cb_work, nfsd4_do_callback_rpc); + INIT_WORK(&cb->cb_work, nfsd4_do_cb_recall); run_nfsd4_cb(&dp->dl_recall); } diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index b49b46b0ce23..461229a01963 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -513,7 +513,9 @@ hash_delegation_locked(struct nfs4_delegation *dp, struct nfs4_file *fp) lockdep_assert_held(&state_lock); dp->dl_stid.sc_type = NFS4_DELEG_STID; + spin_lock(&fp->fi_lock); list_add(&dp->dl_perfile, &fp->fi_delegations); + spin_unlock(&fp->fi_lock); list_add(&dp->dl_perclnt, &dp->dl_stid.sc_client->cl_delegations); } @@ -521,14 +523,18 @@ hash_delegation_locked(struct nfs4_delegation *dp, struct nfs4_file *fp) static void unhash_delegation(struct nfs4_delegation *dp) { + struct nfs4_file *fp = dp->dl_file; + spin_lock(&state_lock); list_del_init(&dp->dl_perclnt); - list_del_init(&dp->dl_perfile); list_del_init(&dp->dl_recall_lru); + spin_lock(&fp->fi_lock); + list_del_init(&dp->dl_perfile); + spin_unlock(&fp->fi_lock); spin_unlock(&state_lock); - if (dp->dl_file) { - nfs4_put_deleg_lease(dp->dl_file); - put_nfs4_file(dp->dl_file); + if (fp) { + nfs4_put_deleg_lease(fp); + put_nfs4_file(fp); dp->dl_file = NULL; } } @@ -2612,6 +2618,7 @@ static void nfsd4_init_file(struct nfs4_file *fp, struct inode *ino) lockdep_assert_held(&state_lock); atomic_set(&fp->fi_ref, 1); + spin_lock_init(&fp->fi_lock); INIT_LIST_HEAD(&fp->fi_stateids); INIT_LIST_HEAD(&fp->fi_delegations); ihold(ino); @@ -2857,26 +2864,32 @@ out: return ret; } -static void nfsd_break_one_deleg(struct nfs4_delegation *dp) +void nfsd4_prepare_cb_recall(struct nfs4_delegation *dp) { struct nfs4_client *clp = dp->dl_stid.sc_client; struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id); - lockdep_assert_held(&state_lock); + /* + * We can't do this in nfsd_break_deleg_cb because it is + * already holding inode->i_lock + */ + spin_lock(&state_lock); + if (list_empty(&dp->dl_recall_lru)) { + dp->dl_time = get_seconds(); + list_add_tail(&dp->dl_recall_lru, &nn->del_recall_lru); + } + spin_unlock(&state_lock); +} + +static void nfsd_break_one_deleg(struct nfs4_delegation *dp) +{ /* We're assuming the state code never drops its reference * without first removing the lease. Since we're in this lease * callback (and since the lease code is serialized by the kernel * lock) we know the server hasn't removed the lease yet, we know * it's safe to take a reference: */ atomic_inc(&dp->dl_count); - - list_add_tail(&dp->dl_recall_lru, &nn->del_recall_lru); - - /* Only place dl_time is set; protected by i_lock: */ - dp->dl_time = get_seconds(); - block_delegations(&dp->dl_fh); - nfsd4_cb_recall(dp); } @@ -2901,11 +2914,11 @@ static void nfsd_break_deleg_cb(struct file_lock *fl) */ fl->fl_break_time = 0; - spin_lock(&state_lock); fp->fi_had_conflict = true; + spin_lock(&fp->fi_lock); list_for_each_entry(dp, &fp->fi_delegations, dl_perfile) nfsd_break_one_deleg(dp); - spin_unlock(&state_lock); + spin_unlock(&fp->fi_lock); } static diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index 9447f86f2778..7d6ba06c1abe 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -382,6 +382,7 @@ static inline struct nfs4_lockowner * lockowner(struct nfs4_stateowner *so) /* nfs4_file: a file opened by some number of (open) nfs4_stateowners. */ struct nfs4_file { atomic_t fi_ref; + spinlock_t fi_lock; struct hlist_node fi_hash; /* hash by "struct inode *" */ struct list_head fi_stateids; struct list_head fi_delegations; @@ -471,6 +472,7 @@ extern void nfsd4_cb_recall(struct nfs4_delegation *dp); extern int nfsd4_create_callback_queue(void); extern void nfsd4_destroy_callback_queue(void); extern void nfsd4_shutdown_callback(struct nfs4_client *); +extern void nfsd4_prepare_cb_recall(struct nfs4_delegation *dp); extern void nfs4_put_delegation(struct nfs4_delegation *dp); extern struct nfs4_client_reclaim *nfs4_client_to_reclaim(const char *name, struct nfsd_net *nn);