xref: /linux/fs/lockd/svc.c (revision a64917bc2e9b1e0aa716b783c4ec879fdd280300)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * linux/fs/lockd/svc.c
4  *
5  * This is the central lockd service.
6  *
7  * FIXME: Separate the lockd NFS server functionality from the lockd NFS
8  * 	  client functionality. Oh why didn't Sun create two separate
9  *	  services in the first place?
10  *
11  * Authors:	Olaf Kirch (okir@monad.swb.de)
12  *
13  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
14  */
15 
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/sysctl.h>
19 #include <linux/moduleparam.h>
20 
21 #include <linux/sched/signal.h>
22 #include <linux/errno.h>
23 #include <linux/in.h>
24 #include <linux/uio.h>
25 #include <linux/smp.h>
26 #include <linux/mutex.h>
27 #include <linux/kthread.h>
28 #include <linux/freezer.h>
29 #include <linux/inetdevice.h>
30 
31 #include <linux/sunrpc/types.h>
32 #include <linux/sunrpc/stats.h>
33 #include <linux/sunrpc/clnt.h>
34 #include <linux/sunrpc/svc.h>
35 #include <linux/sunrpc/svcsock.h>
36 #include <linux/sunrpc/svc_xprt.h>
37 #include <net/ip.h>
38 #include <net/addrconf.h>
39 #include <net/ipv6.h>
40 #include <linux/lockd/lockd.h>
41 #include <linux/nfs.h>
42 
43 #include "netns.h"
44 #include "procfs.h"
45 
46 #define NLMDBG_FACILITY		NLMDBG_SVC
47 #define LOCKD_BUFSIZE		(1024 + NLMSVC_XDRSIZE)
48 #define ALLOWED_SIGS		(sigmask(SIGKILL))
49 
50 static struct svc_program	nlmsvc_program;
51 
52 const struct nlmsvc_binding	*nlmsvc_ops;
53 EXPORT_SYMBOL_GPL(nlmsvc_ops);
54 
55 static DEFINE_MUTEX(nlmsvc_mutex);
56 static unsigned int		nlmsvc_users;
57 static struct task_struct	*nlmsvc_task;
58 static struct svc_rqst		*nlmsvc_rqst;
59 unsigned long			nlmsvc_timeout;
60 
61 static atomic_t nlm_ntf_refcnt = ATOMIC_INIT(0);
62 static DECLARE_WAIT_QUEUE_HEAD(nlm_ntf_wq);
63 
64 unsigned int lockd_net_id;
65 
66 /*
67  * These can be set at insmod time (useful for NFS as root filesystem),
68  * and also changed through the sysctl interface.  -- Jamie Lokier, Aug 2003
69  */
70 static unsigned long		nlm_grace_period;
71 static unsigned long		nlm_timeout = LOCKD_DFLT_TIMEO;
72 static int			nlm_udpport, nlm_tcpport;
73 
74 /* RLIM_NOFILE defaults to 1024. That seems like a reasonable default here. */
75 static unsigned int		nlm_max_connections = 1024;
76 
77 /*
78  * Constants needed for the sysctl interface.
79  */
80 static const unsigned long	nlm_grace_period_min = 0;
81 static const unsigned long	nlm_grace_period_max = 240;
82 static const unsigned long	nlm_timeout_min = 3;
83 static const unsigned long	nlm_timeout_max = 20;
84 static const int		nlm_port_min = 0, nlm_port_max = 65535;
85 
86 #ifdef CONFIG_SYSCTL
87 static struct ctl_table_header * nlm_sysctl_table;
88 #endif
89 
90 static unsigned long get_lockd_grace_period(void)
91 {
92 	/* Note: nlm_timeout should always be nonzero */
93 	if (nlm_grace_period)
94 		return roundup(nlm_grace_period, nlm_timeout) * HZ;
95 	else
96 		return nlm_timeout * 5 * HZ;
97 }
98 
99 static void grace_ender(struct work_struct *grace)
100 {
101 	struct delayed_work *dwork = to_delayed_work(grace);
102 	struct lockd_net *ln = container_of(dwork, struct lockd_net,
103 					    grace_period_end);
104 
105 	locks_end_grace(&ln->lockd_manager);
106 }
107 
108 static void set_grace_period(struct net *net)
109 {
110 	unsigned long grace_period = get_lockd_grace_period();
111 	struct lockd_net *ln = net_generic(net, lockd_net_id);
112 
113 	locks_start_grace(net, &ln->lockd_manager);
114 	cancel_delayed_work_sync(&ln->grace_period_end);
115 	schedule_delayed_work(&ln->grace_period_end, grace_period);
116 }
117 
118 static void restart_grace(void)
119 {
120 	if (nlmsvc_ops) {
121 		struct net *net = &init_net;
122 		struct lockd_net *ln = net_generic(net, lockd_net_id);
123 
124 		cancel_delayed_work_sync(&ln->grace_period_end);
125 		locks_end_grace(&ln->lockd_manager);
126 		nlmsvc_invalidate_all();
127 		set_grace_period(net);
128 	}
129 }
130 
131 /*
132  * This is the lockd kernel thread
133  */
134 static int
135 lockd(void *vrqstp)
136 {
137 	int		err = 0;
138 	struct svc_rqst *rqstp = vrqstp;
139 	struct net *net = &init_net;
140 	struct lockd_net *ln = net_generic(net, lockd_net_id);
141 
142 	/* try_to_freeze() is called from svc_recv() */
143 	set_freezable();
144 
145 	/* Allow SIGKILL to tell lockd to drop all of its locks */
146 	allow_signal(SIGKILL);
147 
148 	dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
149 
150 	/*
151 	 * The main request loop. We don't terminate until the last
152 	 * NFS mount or NFS daemon has gone away.
153 	 */
154 	while (!kthread_should_stop()) {
155 		long timeout = MAX_SCHEDULE_TIMEOUT;
156 		RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
157 
158 		/* update sv_maxconn if it has changed */
159 		rqstp->rq_server->sv_maxconn = nlm_max_connections;
160 
161 		if (signalled()) {
162 			flush_signals(current);
163 			restart_grace();
164 			continue;
165 		}
166 
167 		timeout = nlmsvc_retry_blocked();
168 
169 		/*
170 		 * Find a socket with data available and call its
171 		 * recvfrom routine.
172 		 */
173 		err = svc_recv(rqstp, timeout);
174 		if (err == -EAGAIN || err == -EINTR)
175 			continue;
176 		dprintk("lockd: request from %s\n",
177 				svc_print_addr(rqstp, buf, sizeof(buf)));
178 
179 		svc_process(rqstp);
180 	}
181 	flush_signals(current);
182 	if (nlmsvc_ops)
183 		nlmsvc_invalidate_all();
184 	nlm_shutdown_hosts();
185 	cancel_delayed_work_sync(&ln->grace_period_end);
186 	locks_end_grace(&ln->lockd_manager);
187 	return 0;
188 }
189 
190 static int create_lockd_listener(struct svc_serv *serv, const char *name,
191 				 struct net *net, const int family,
192 				 const unsigned short port,
193 				 const struct cred *cred)
194 {
195 	struct svc_xprt *xprt;
196 
197 	xprt = svc_find_xprt(serv, name, net, family, 0);
198 	if (xprt == NULL)
199 		return svc_create_xprt(serv, name, net, family, port,
200 						SVC_SOCK_DEFAULTS, cred);
201 	svc_xprt_put(xprt);
202 	return 0;
203 }
204 
205 static int create_lockd_family(struct svc_serv *serv, struct net *net,
206 			       const int family, const struct cred *cred)
207 {
208 	int err;
209 
210 	err = create_lockd_listener(serv, "udp", net, family, nlm_udpport,
211 			cred);
212 	if (err < 0)
213 		return err;
214 
215 	return create_lockd_listener(serv, "tcp", net, family, nlm_tcpport,
216 			cred);
217 }
218 
219 /*
220  * Ensure there are active UDP and TCP listeners for lockd.
221  *
222  * Even if we have only TCP NFS mounts and/or TCP NFSDs, some
223  * local services (such as rpc.statd) still require UDP, and
224  * some NFS servers do not yet support NLM over TCP.
225  *
226  * Returns zero if all listeners are available; otherwise a
227  * negative errno value is returned.
228  */
229 static int make_socks(struct svc_serv *serv, struct net *net,
230 		const struct cred *cred)
231 {
232 	static int warned;
233 	int err;
234 
235 	err = create_lockd_family(serv, net, PF_INET, cred);
236 	if (err < 0)
237 		goto out_err;
238 
239 	err = create_lockd_family(serv, net, PF_INET6, cred);
240 	if (err < 0 && err != -EAFNOSUPPORT)
241 		goto out_err;
242 
243 	warned = 0;
244 	return 0;
245 
246 out_err:
247 	if (warned++ == 0)
248 		printk(KERN_WARNING
249 			"lockd_up: makesock failed, error=%d\n", err);
250 	svc_shutdown_net(serv, net);
251 	return err;
252 }
253 
254 static int lockd_up_net(struct svc_serv *serv, struct net *net,
255 		const struct cred *cred)
256 {
257 	struct lockd_net *ln = net_generic(net, lockd_net_id);
258 	int error;
259 
260 	if (ln->nlmsvc_users++)
261 		return 0;
262 
263 	error = svc_bind(serv, net);
264 	if (error)
265 		goto err_bind;
266 
267 	error = make_socks(serv, net, cred);
268 	if (error < 0)
269 		goto err_bind;
270 	set_grace_period(net);
271 	dprintk("%s: per-net data created; net=%x\n", __func__, net->ns.inum);
272 	return 0;
273 
274 err_bind:
275 	ln->nlmsvc_users--;
276 	return error;
277 }
278 
279 static void lockd_down_net(struct svc_serv *serv, struct net *net)
280 {
281 	struct lockd_net *ln = net_generic(net, lockd_net_id);
282 
283 	if (ln->nlmsvc_users) {
284 		if (--ln->nlmsvc_users == 0) {
285 			nlm_shutdown_hosts_net(net);
286 			cancel_delayed_work_sync(&ln->grace_period_end);
287 			locks_end_grace(&ln->lockd_manager);
288 			svc_shutdown_net(serv, net);
289 			dprintk("%s: per-net data destroyed; net=%x\n",
290 				__func__, net->ns.inum);
291 		}
292 	} else {
293 		pr_err("%s: no users! task=%p, net=%x\n",
294 			__func__, nlmsvc_task, net->ns.inum);
295 		BUG();
296 	}
297 }
298 
299 static int lockd_inetaddr_event(struct notifier_block *this,
300 	unsigned long event, void *ptr)
301 {
302 	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
303 	struct sockaddr_in sin;
304 
305 	if ((event != NETDEV_DOWN) ||
306 	    !atomic_inc_not_zero(&nlm_ntf_refcnt))
307 		goto out;
308 
309 	if (nlmsvc_rqst) {
310 		dprintk("lockd_inetaddr_event: removed %pI4\n",
311 			&ifa->ifa_local);
312 		sin.sin_family = AF_INET;
313 		sin.sin_addr.s_addr = ifa->ifa_local;
314 		svc_age_temp_xprts_now(nlmsvc_rqst->rq_server,
315 			(struct sockaddr *)&sin);
316 	}
317 	atomic_dec(&nlm_ntf_refcnt);
318 	wake_up(&nlm_ntf_wq);
319 
320 out:
321 	return NOTIFY_DONE;
322 }
323 
324 static struct notifier_block lockd_inetaddr_notifier = {
325 	.notifier_call = lockd_inetaddr_event,
326 };
327 
328 #if IS_ENABLED(CONFIG_IPV6)
329 static int lockd_inet6addr_event(struct notifier_block *this,
330 	unsigned long event, void *ptr)
331 {
332 	struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
333 	struct sockaddr_in6 sin6;
334 
335 	if ((event != NETDEV_DOWN) ||
336 	    !atomic_inc_not_zero(&nlm_ntf_refcnt))
337 		goto out;
338 
339 	if (nlmsvc_rqst) {
340 		dprintk("lockd_inet6addr_event: removed %pI6\n", &ifa->addr);
341 		sin6.sin6_family = AF_INET6;
342 		sin6.sin6_addr = ifa->addr;
343 		if (ipv6_addr_type(&sin6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
344 			sin6.sin6_scope_id = ifa->idev->dev->ifindex;
345 		svc_age_temp_xprts_now(nlmsvc_rqst->rq_server,
346 			(struct sockaddr *)&sin6);
347 	}
348 	atomic_dec(&nlm_ntf_refcnt);
349 	wake_up(&nlm_ntf_wq);
350 
351 out:
352 	return NOTIFY_DONE;
353 }
354 
355 static struct notifier_block lockd_inet6addr_notifier = {
356 	.notifier_call = lockd_inet6addr_event,
357 };
358 #endif
359 
360 static void lockd_unregister_notifiers(void)
361 {
362 	unregister_inetaddr_notifier(&lockd_inetaddr_notifier);
363 #if IS_ENABLED(CONFIG_IPV6)
364 	unregister_inet6addr_notifier(&lockd_inet6addr_notifier);
365 #endif
366 	wait_event(nlm_ntf_wq, atomic_read(&nlm_ntf_refcnt) == 0);
367 }
368 
369 static void lockd_svc_exit_thread(void)
370 {
371 	atomic_dec(&nlm_ntf_refcnt);
372 	lockd_unregister_notifiers();
373 	svc_exit_thread(nlmsvc_rqst);
374 }
375 
376 static int lockd_start_svc(struct svc_serv *serv)
377 {
378 	int error;
379 
380 	if (nlmsvc_rqst)
381 		return 0;
382 
383 	/*
384 	 * Create the kernel thread and wait for it to start.
385 	 */
386 	nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
387 	if (IS_ERR(nlmsvc_rqst)) {
388 		error = PTR_ERR(nlmsvc_rqst);
389 		printk(KERN_WARNING
390 			"lockd_up: svc_rqst allocation failed, error=%d\n",
391 			error);
392 		lockd_unregister_notifiers();
393 		goto out_rqst;
394 	}
395 
396 	atomic_inc(&nlm_ntf_refcnt);
397 	svc_sock_update_bufs(serv);
398 	serv->sv_maxconn = nlm_max_connections;
399 
400 	nlmsvc_task = kthread_create(lockd, nlmsvc_rqst, "%s", serv->sv_name);
401 	if (IS_ERR(nlmsvc_task)) {
402 		error = PTR_ERR(nlmsvc_task);
403 		printk(KERN_WARNING
404 			"lockd_up: kthread_run failed, error=%d\n", error);
405 		goto out_task;
406 	}
407 	nlmsvc_rqst->rq_task = nlmsvc_task;
408 	wake_up_process(nlmsvc_task);
409 
410 	dprintk("lockd_up: service started\n");
411 	return 0;
412 
413 out_task:
414 	lockd_svc_exit_thread();
415 	nlmsvc_task = NULL;
416 out_rqst:
417 	nlmsvc_rqst = NULL;
418 	return error;
419 }
420 
421 static const struct svc_serv_ops lockd_sv_ops = {
422 	.svo_shutdown		= svc_rpcb_cleanup,
423 	.svo_enqueue_xprt	= svc_xprt_do_enqueue,
424 };
425 
426 static struct svc_serv *lockd_create_svc(void)
427 {
428 	struct svc_serv *serv;
429 
430 	/*
431 	 * Check whether we're already up and running.
432 	 */
433 	if (nlmsvc_rqst) {
434 		/*
435 		 * Note: increase service usage, because later in case of error
436 		 * svc_destroy() will be called.
437 		 */
438 		svc_get(nlmsvc_rqst->rq_server);
439 		return nlmsvc_rqst->rq_server;
440 	}
441 
442 	/*
443 	 * Sanity check: if there's no pid,
444 	 * we should be the first user ...
445 	 */
446 	if (nlmsvc_users)
447 		printk(KERN_WARNING
448 			"lockd_up: no pid, %d users??\n", nlmsvc_users);
449 
450 	if (!nlm_timeout)
451 		nlm_timeout = LOCKD_DFLT_TIMEO;
452 	nlmsvc_timeout = nlm_timeout * HZ;
453 
454 	serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, &lockd_sv_ops);
455 	if (!serv) {
456 		printk(KERN_WARNING "lockd_up: create service failed\n");
457 		return ERR_PTR(-ENOMEM);
458 	}
459 	register_inetaddr_notifier(&lockd_inetaddr_notifier);
460 #if IS_ENABLED(CONFIG_IPV6)
461 	register_inet6addr_notifier(&lockd_inet6addr_notifier);
462 #endif
463 	dprintk("lockd_up: service created\n");
464 	return serv;
465 }
466 
467 /*
468  * Bring up the lockd process if it's not already up.
469  */
470 int lockd_up(struct net *net, const struct cred *cred)
471 {
472 	struct svc_serv *serv;
473 	int error;
474 
475 	mutex_lock(&nlmsvc_mutex);
476 
477 	serv = lockd_create_svc();
478 	if (IS_ERR(serv)) {
479 		error = PTR_ERR(serv);
480 		goto err_create;
481 	}
482 
483 	error = lockd_up_net(serv, net, cred);
484 	if (error < 0) {
485 		lockd_unregister_notifiers();
486 		goto err_put;
487 	}
488 
489 	error = lockd_start_svc(serv);
490 	if (error < 0) {
491 		lockd_down_net(serv, net);
492 		goto err_put;
493 	}
494 	nlmsvc_users++;
495 	/*
496 	 * Note: svc_serv structures have an initial use count of 1,
497 	 * so we exit through here on both success and failure.
498 	 */
499 err_put:
500 	svc_destroy(serv);
501 err_create:
502 	mutex_unlock(&nlmsvc_mutex);
503 	return error;
504 }
505 EXPORT_SYMBOL_GPL(lockd_up);
506 
507 /*
508  * Decrement the user count and bring down lockd if we're the last.
509  */
510 void
511 lockd_down(struct net *net)
512 {
513 	mutex_lock(&nlmsvc_mutex);
514 	lockd_down_net(nlmsvc_rqst->rq_server, net);
515 	if (nlmsvc_users) {
516 		if (--nlmsvc_users)
517 			goto out;
518 	} else {
519 		printk(KERN_ERR "lockd_down: no users! task=%p\n",
520 			nlmsvc_task);
521 		BUG();
522 	}
523 
524 	if (!nlmsvc_task) {
525 		printk(KERN_ERR "lockd_down: no lockd running.\n");
526 		BUG();
527 	}
528 	kthread_stop(nlmsvc_task);
529 	dprintk("lockd_down: service stopped\n");
530 	lockd_svc_exit_thread();
531 	dprintk("lockd_down: service destroyed\n");
532 	nlmsvc_task = NULL;
533 	nlmsvc_rqst = NULL;
534 out:
535 	mutex_unlock(&nlmsvc_mutex);
536 }
537 EXPORT_SYMBOL_GPL(lockd_down);
538 
539 #ifdef CONFIG_SYSCTL
540 
541 /*
542  * Sysctl parameters (same as module parameters, different interface).
543  */
544 
545 static struct ctl_table nlm_sysctls[] = {
546 	{
547 		.procname	= "nlm_grace_period",
548 		.data		= &nlm_grace_period,
549 		.maxlen		= sizeof(unsigned long),
550 		.mode		= 0644,
551 		.proc_handler	= proc_doulongvec_minmax,
552 		.extra1		= (unsigned long *) &nlm_grace_period_min,
553 		.extra2		= (unsigned long *) &nlm_grace_period_max,
554 	},
555 	{
556 		.procname	= "nlm_timeout",
557 		.data		= &nlm_timeout,
558 		.maxlen		= sizeof(unsigned long),
559 		.mode		= 0644,
560 		.proc_handler	= proc_doulongvec_minmax,
561 		.extra1		= (unsigned long *) &nlm_timeout_min,
562 		.extra2		= (unsigned long *) &nlm_timeout_max,
563 	},
564 	{
565 		.procname	= "nlm_udpport",
566 		.data		= &nlm_udpport,
567 		.maxlen		= sizeof(int),
568 		.mode		= 0644,
569 		.proc_handler	= proc_dointvec_minmax,
570 		.extra1		= (int *) &nlm_port_min,
571 		.extra2		= (int *) &nlm_port_max,
572 	},
573 	{
574 		.procname	= "nlm_tcpport",
575 		.data		= &nlm_tcpport,
576 		.maxlen		= sizeof(int),
577 		.mode		= 0644,
578 		.proc_handler	= proc_dointvec_minmax,
579 		.extra1		= (int *) &nlm_port_min,
580 		.extra2		= (int *) &nlm_port_max,
581 	},
582 	{
583 		.procname	= "nsm_use_hostnames",
584 		.data		= &nsm_use_hostnames,
585 		.maxlen		= sizeof(int),
586 		.mode		= 0644,
587 		.proc_handler	= proc_dobool,
588 	},
589 	{
590 		.procname	= "nsm_local_state",
591 		.data		= &nsm_local_state,
592 		.maxlen		= sizeof(int),
593 		.mode		= 0644,
594 		.proc_handler	= proc_dointvec,
595 	},
596 	{ }
597 };
598 
599 static struct ctl_table nlm_sysctl_dir[] = {
600 	{
601 		.procname	= "nfs",
602 		.mode		= 0555,
603 		.child		= nlm_sysctls,
604 	},
605 	{ }
606 };
607 
608 static struct ctl_table nlm_sysctl_root[] = {
609 	{
610 		.procname	= "fs",
611 		.mode		= 0555,
612 		.child		= nlm_sysctl_dir,
613 	},
614 	{ }
615 };
616 
617 #endif	/* CONFIG_SYSCTL */
618 
619 /*
620  * Module (and sysfs) parameters.
621  */
622 
623 #define param_set_min_max(name, type, which_strtol, min, max)		\
624 static int param_set_##name(const char *val, const struct kernel_param *kp) \
625 {									\
626 	char *endp;							\
627 	__typeof__(type) num = which_strtol(val, &endp, 0);		\
628 	if (endp == val || *endp || num < (min) || num > (max))		\
629 		return -EINVAL;						\
630 	*((type *) kp->arg) = num;					\
631 	return 0;							\
632 }
633 
634 static inline int is_callback(u32 proc)
635 {
636 	return proc == NLMPROC_GRANTED
637 		|| proc == NLMPROC_GRANTED_MSG
638 		|| proc == NLMPROC_TEST_RES
639 		|| proc == NLMPROC_LOCK_RES
640 		|| proc == NLMPROC_CANCEL_RES
641 		|| proc == NLMPROC_UNLOCK_RES
642 		|| proc == NLMPROC_NSM_NOTIFY;
643 }
644 
645 
646 static int lockd_authenticate(struct svc_rqst *rqstp)
647 {
648 	rqstp->rq_client = NULL;
649 	switch (rqstp->rq_authop->flavour) {
650 		case RPC_AUTH_NULL:
651 		case RPC_AUTH_UNIX:
652 			rqstp->rq_auth_stat = rpc_auth_ok;
653 			if (rqstp->rq_proc == 0)
654 				return SVC_OK;
655 			if (is_callback(rqstp->rq_proc)) {
656 				/* Leave it to individual procedures to
657 				 * call nlmsvc_lookup_host(rqstp)
658 				 */
659 				return SVC_OK;
660 			}
661 			return svc_set_client(rqstp);
662 	}
663 	rqstp->rq_auth_stat = rpc_autherr_badcred;
664 	return SVC_DENIED;
665 }
666 
667 
668 param_set_min_max(port, int, simple_strtol, 0, 65535)
669 param_set_min_max(grace_period, unsigned long, simple_strtoul,
670 		  nlm_grace_period_min, nlm_grace_period_max)
671 param_set_min_max(timeout, unsigned long, simple_strtoul,
672 		  nlm_timeout_min, nlm_timeout_max)
673 
674 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
675 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
676 MODULE_LICENSE("GPL");
677 
678 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
679 		  &nlm_grace_period, 0644);
680 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
681 		  &nlm_timeout, 0644);
682 module_param_call(nlm_udpport, param_set_port, param_get_int,
683 		  &nlm_udpport, 0644);
684 module_param_call(nlm_tcpport, param_set_port, param_get_int,
685 		  &nlm_tcpport, 0644);
686 module_param(nsm_use_hostnames, bool, 0644);
687 module_param(nlm_max_connections, uint, 0644);
688 
689 static int lockd_init_net(struct net *net)
690 {
691 	struct lockd_net *ln = net_generic(net, lockd_net_id);
692 
693 	INIT_DELAYED_WORK(&ln->grace_period_end, grace_ender);
694 	INIT_LIST_HEAD(&ln->lockd_manager.list);
695 	ln->lockd_manager.block_opens = false;
696 	INIT_LIST_HEAD(&ln->nsm_handles);
697 	return 0;
698 }
699 
700 static void lockd_exit_net(struct net *net)
701 {
702 	struct lockd_net *ln = net_generic(net, lockd_net_id);
703 
704 	WARN_ONCE(!list_empty(&ln->lockd_manager.list),
705 		  "net %x %s: lockd_manager.list is not empty\n",
706 		  net->ns.inum, __func__);
707 	WARN_ONCE(!list_empty(&ln->nsm_handles),
708 		  "net %x %s: nsm_handles list is not empty\n",
709 		  net->ns.inum, __func__);
710 	WARN_ONCE(delayed_work_pending(&ln->grace_period_end),
711 		  "net %x %s: grace_period_end was not cancelled\n",
712 		  net->ns.inum, __func__);
713 }
714 
715 static struct pernet_operations lockd_net_ops = {
716 	.init = lockd_init_net,
717 	.exit = lockd_exit_net,
718 	.id = &lockd_net_id,
719 	.size = sizeof(struct lockd_net),
720 };
721 
722 
723 /*
724  * Initialising and terminating the module.
725  */
726 
727 static int __init init_nlm(void)
728 {
729 	int err;
730 
731 #ifdef CONFIG_SYSCTL
732 	err = -ENOMEM;
733 	nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
734 	if (nlm_sysctl_table == NULL)
735 		goto err_sysctl;
736 #endif
737 	err = register_pernet_subsys(&lockd_net_ops);
738 	if (err)
739 		goto err_pernet;
740 
741 	err = lockd_create_procfs();
742 	if (err)
743 		goto err_procfs;
744 
745 	return 0;
746 
747 err_procfs:
748 	unregister_pernet_subsys(&lockd_net_ops);
749 err_pernet:
750 #ifdef CONFIG_SYSCTL
751 	unregister_sysctl_table(nlm_sysctl_table);
752 err_sysctl:
753 #endif
754 	return err;
755 }
756 
757 static void __exit exit_nlm(void)
758 {
759 	/* FIXME: delete all NLM clients */
760 	nlm_shutdown_hosts();
761 	lockd_remove_procfs();
762 	unregister_pernet_subsys(&lockd_net_ops);
763 #ifdef CONFIG_SYSCTL
764 	unregister_sysctl_table(nlm_sysctl_table);
765 #endif
766 }
767 
768 module_init(init_nlm);
769 module_exit(exit_nlm);
770 
771 /**
772  * nlmsvc_dispatch - Process an NLM Request
773  * @rqstp: incoming request
774  * @statp: pointer to location of accept_stat field in RPC Reply buffer
775  *
776  * Return values:
777  *  %0: Processing complete; do not send a Reply
778  *  %1: Processing complete; send Reply in rqstp->rq_res
779  */
780 static int nlmsvc_dispatch(struct svc_rqst *rqstp, __be32 *statp)
781 {
782 	const struct svc_procedure *procp = rqstp->rq_procinfo;
783 
784 	svcxdr_init_decode(rqstp);
785 	if (!procp->pc_decode(rqstp, &rqstp->rq_arg_stream))
786 		goto out_decode_err;
787 
788 	*statp = procp->pc_func(rqstp);
789 	if (*statp == rpc_drop_reply)
790 		return 0;
791 	if (*statp != rpc_success)
792 		return 1;
793 
794 	svcxdr_init_encode(rqstp);
795 	if (!procp->pc_encode(rqstp, &rqstp->rq_res_stream))
796 		goto out_encode_err;
797 
798 	return 1;
799 
800 out_decode_err:
801 	*statp = rpc_garbage_args;
802 	return 1;
803 
804 out_encode_err:
805 	*statp = rpc_system_err;
806 	return 1;
807 }
808 
809 /*
810  * Define NLM program and procedures
811  */
812 static unsigned int nlmsvc_version1_count[17];
813 static const struct svc_version	nlmsvc_version1 = {
814 	.vs_vers	= 1,
815 	.vs_nproc	= 17,
816 	.vs_proc	= nlmsvc_procedures,
817 	.vs_count	= nlmsvc_version1_count,
818 	.vs_dispatch	= nlmsvc_dispatch,
819 	.vs_xdrsize	= NLMSVC_XDRSIZE,
820 };
821 static unsigned int nlmsvc_version3_count[24];
822 static const struct svc_version	nlmsvc_version3 = {
823 	.vs_vers	= 3,
824 	.vs_nproc	= 24,
825 	.vs_proc	= nlmsvc_procedures,
826 	.vs_count	= nlmsvc_version3_count,
827 	.vs_dispatch	= nlmsvc_dispatch,
828 	.vs_xdrsize	= NLMSVC_XDRSIZE,
829 };
830 #ifdef CONFIG_LOCKD_V4
831 static unsigned int nlmsvc_version4_count[24];
832 static const struct svc_version	nlmsvc_version4 = {
833 	.vs_vers	= 4,
834 	.vs_nproc	= 24,
835 	.vs_proc	= nlmsvc_procedures4,
836 	.vs_count	= nlmsvc_version4_count,
837 	.vs_dispatch	= nlmsvc_dispatch,
838 	.vs_xdrsize	= NLMSVC_XDRSIZE,
839 };
840 #endif
841 static const struct svc_version *nlmsvc_version[] = {
842 	[1] = &nlmsvc_version1,
843 	[3] = &nlmsvc_version3,
844 #ifdef CONFIG_LOCKD_V4
845 	[4] = &nlmsvc_version4,
846 #endif
847 };
848 
849 static struct svc_stat		nlmsvc_stats;
850 
851 #define NLM_NRVERS	ARRAY_SIZE(nlmsvc_version)
852 static struct svc_program	nlmsvc_program = {
853 	.pg_prog		= NLM_PROGRAM,		/* program number */
854 	.pg_nvers		= NLM_NRVERS,		/* number of entries in nlmsvc_version */
855 	.pg_vers		= nlmsvc_version,	/* version table */
856 	.pg_name		= "lockd",		/* service name */
857 	.pg_class		= "nfsd",		/* share authentication with nfsd */
858 	.pg_stats		= &nlmsvc_stats,	/* stats table */
859 	.pg_authenticate	= &lockd_authenticate,	/* export authentication */
860 	.pg_init_request	= svc_generic_init_request,
861 	.pg_rpcbind_set		= svc_generic_rpcbind_set,
862 };
863