Lockd: shutdown NLM hosts in network namespace context

Lockd now managed in network namespace context. And this patch introduces
network namespace related NLM hosts shutdown in case of releasing per-net Lockd
resources.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/lockd/host.c

@@ -565,12 +565,8 @@ void nlm_host_rebooted(const struct nlm_reboot *info)
 	nsm_release(nsm);
 }
 
-/*
- * Shut down the hosts module.
- * Note that this routine is called only at server shutdown time.
- */
 void
-nlm_shutdown_hosts(void)
+nlm_shutdown_hosts_net(struct net *net)
 {
 	struct hlist_head *chain;
 	struct hlist_node *pos;
@@ -582,6 +578,8 @@ nlm_shutdown_hosts(void)
 	/* First, make all hosts eligible for gc */
 	dprintk("lockd: nuking all hosts...\n");
 	for_each_host(host, pos, chain, nlm_server_hosts) {
+		if (net && host->net != net)
+			continue;
 		host->h_expires = jiffies - 1;
 		if (host->h_rpcclnt) {
 			rpc_shutdown_client(host->h_rpcclnt);
@@ -592,15 +590,29 @@ nlm_shutdown_hosts(void)
 	/* Then, perform a garbage collection pass */
 	nlm_gc_hosts();
 	mutex_unlock(&nlm_host_mutex);
+}
+
+/*
+ * Shut down the hosts module.
+ * Note that this routine is called only at server shutdown time.
+ */
+void
+nlm_shutdown_hosts(void)
+{
+	struct hlist_head *chain;
+	struct hlist_node *pos;
+	struct nlm_host	*host;
+
+	nlm_shutdown_hosts_net(NULL);
 
 	/* complain if any hosts are left */
 	if (nrhosts != 0) {
 		printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
 		dprintk("lockd: %lu hosts left:\n", nrhosts);
 		for_each_host(host, pos, chain, nlm_server_hosts) {
-			dprintk("       %s (cnt %d use %d exp %ld)\n",
+			dprintk("       %s (cnt %d use %d exp %ld net %p)\n",
 				host->h_name, atomic_read(&host->h_count),
-				host->h_inuse, host->h_expires);
+				host->h_inuse, host->h_expires, host->net);
 		}
 	}
 }

fs/lockd/svc.c

@@ -281,8 +281,10 @@ static void lockd_down_net(struct net *net)
 	struct svc_serv *serv = nlmsvc_rqst->rq_server;
 
 	if (ln->nlmsvc_users) {
-		if (--ln->nlmsvc_users == 0)
+		if (--ln->nlmsvc_users == 0) {
+			nlm_shutdown_hosts_net(net);
 			svc_shutdown_net(serv, net);
+		}
 	} else {
 		printk(KERN_ERR "lockd_down_net: no users! task=%p, net=%p\n",
 				nlmsvc_task, net);

include/linux/lockd/lockd.h

@@ -234,6 +234,7 @@ struct rpc_clnt * nlm_bind_host(struct nlm_host *);
 void		  nlm_rebind_host(struct nlm_host *);
 struct nlm_host * nlm_get_host(struct nlm_host *);
 void		  nlm_shutdown_hosts(void);
+void		  nlm_shutdown_hosts_net(struct net *net);
 void		  nlm_host_rebooted(const struct nlm_reboot *);
 
 /*