From patchwork Fri Sep 14 14:26:00 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislav Kinsbursky X-Patchwork-Id: 1459171 Return-Path: X-Original-To: patchwork-linux-nfs@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id 3ED8740220 for ; Fri, 14 Sep 2012 14:34:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757499Ab2INOdD (ORCPT ); Fri, 14 Sep 2012 10:33:03 -0400 Received: from mailhub.sw.ru ([195.214.232.25]:16651 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757454Ab2INOdA (ORCPT ); Fri, 14 Sep 2012 10:33:00 -0400 Received: from localhost.localdomain ([10.30.21.131]) by relay.sw.ru (8.13.4/8.13.4) with ESMTP id q8EEWnvG008395; Fri, 14 Sep 2012 18:32:49 +0400 (MSK) Subject: [PATCH 2/3] lockd: per-net NSM client creation and destruction helpers introduced To: Trond.Myklebust@netapp.com From: Stanislav Kinsbursky Cc: bfields@fieldses.org, linux-nfs@vger.kernel.org, devel@openvz.org, linux-kernel@vger.kernel.org, jlayton@redhat.com Date: Fri, 14 Sep 2012 18:26:00 +0400 Message-ID: <20120914142600.10835.70696.stgit@localhost.localdomain> In-Reply-To: <20120914140811.10835.81465.stgit@localhost.localdomain> References: <20120914140811.10835.81465.stgit@localhost.localdomain> User-Agent: StGit/0.16 MIME-Version: 1.0 Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org NSM RPC client can be required on NFSv3 umount, when child reaper is dying (and destroying it's mount namespace). It means, that current nsproxy is set to NULL already, but creation of RPC client requires UTS namespace for gaining hostname string. This patch introduces reference counted NFS RPC clients creation and destruction helpers (similar to RPCBIND RPC clients). Signed-off-by: Stanislav Kinsbursky Cc: --- fs/lockd/mon.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++ fs/lockd/netns.h | 4 ++++ fs/lockd/svc.c | 1 + 3 files changed, 52 insertions(+), 0 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c index c6186fb..77e07fe 100644 --- a/fs/lockd/mon.c +++ b/fs/lockd/mon.c @@ -19,6 +19,8 @@ #include +#include "netns.h" + #define NLMDBG_FACILITY NLMDBG_MONITOR #define NSM_PROGRAM 100024 #define NSM_VERSION 1 @@ -83,6 +85,51 @@ static struct rpc_clnt *nsm_create(struct net *net) return rpc_create(&args); } +__maybe_unused static struct rpc_clnt *nsm_client_get(struct net *net) +{ + static DEFINE_MUTEX(nsm_create_mutex); + struct rpc_clnt *clnt; + struct lockd_net *ln = net_generic(net, lockd_net_id); + + spin_lock(&ln->nsm_clnt_lock); + if (ln->nsm_users) { + ln->nsm_users++; + clnt = ln->nsm_clnt; + spin_unlock(&ln->nsm_clnt_lock); + goto out; + } + spin_unlock(&ln->nsm_clnt_lock); + + mutex_lock(&nsm_create_mutex); + clnt = nsm_create(net); + if (!IS_ERR(clnt)) { + ln->nsm_clnt = clnt; + smp_wmb(); + ln->nsm_users = 1; + } + mutex_unlock(&nsm_create_mutex); +out: + return clnt; +} + +__maybe_unused static void nsm_client_put(struct net *net) +{ + struct lockd_net *ln = net_generic(net, lockd_net_id); + struct rpc_clnt *clnt = ln->nsm_clnt; + int shutdown = 0; + + spin_lock(&ln->nsm_clnt_lock); + if (ln->nsm_users) { + if (--ln->nsm_users) + ln->nsm_clnt = NULL; + shutdown = !ln->nsm_users; + } + spin_unlock(&ln->nsm_clnt_lock); + + if (shutdown) + rpc_shutdown_client(clnt); +} + static int nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res, struct net *net) { diff --git a/fs/lockd/netns.h b/fs/lockd/netns.h index 4eee248..5010b55 100644 --- a/fs/lockd/netns.h +++ b/fs/lockd/netns.h @@ -12,6 +12,10 @@ struct lockd_net { struct delayed_work grace_period_end; struct lock_manager lockd_manager; struct list_head grace_list; + + spinlock_t nsm_clnt_lock; + unsigned int nsm_users; + struct rpc_clnt *nsm_clnt; }; extern int lockd_net_id; diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c index 31a63f8..7e35587 100644 --- a/fs/lockd/svc.c +++ b/fs/lockd/svc.c @@ -596,6 +596,7 @@ static int lockd_init_net(struct net *net) INIT_DELAYED_WORK(&ln->grace_period_end, grace_ender); INIT_LIST_HEAD(&ln->grace_list); + spin_lock_init(&ln->nsm_clnt_lock); return 0; }