3 files changed, 54 insertions, 2 deletions

diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c
index 7ef14b3c5bee..38f240e104ce 100644
--- a/fs/lockd/mon.c
+++ b/fs/lockd/mon.c
@@ -19,6 +19,8 @@
 
 #include <asm/unaligned.h>
 
+#include "netns.h"
+
 #define NLMDBG_FACILITY         NLMDBG_MONITOR
 #define NSM_PROGRAM             100024
 #define NSM_VERSION             1
@@ -70,7 +72,7 @@ static struct rpc_clnt *nsm_create(struct net *net)
         };
         struct rpc_create_args args = {
                 .net                    = net,
-                .protocol               = XPRT_TRANSPORT_UDP,
+                .protocol               = XPRT_TRANSPORT_TCP,
                 .address                = (struct sockaddr *)&sin,
                 .addrsize               = sizeof(sin),
                 .servername             = "rpc.statd",
@@ -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)
 {
@@ -111,7 +158,7 @@ static int nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res,
         memset(res, 0, sizeof(*res));
 
         msg.rpc_proc = &clnt->cl_procinfo[proc];
-        status = rpc_call_sync(clnt, &msg, 0);
+        status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFTCONN);
         if (status < 0)
                 dprintk("lockd: NSM upcall RPC failed, status=%d\n",
                                 status);
diff --git a/fs/lockd/netns.h b/fs/lockd/netns.h
index 4eee248ba96e..5010b55628b4 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 31a63f87b806..7e355870d519 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;
 }