summaryrefslogtreecommitdiff
path: root/fs/lockd/svc.c
blob: 71a30b416d1a279561ed04d011cac3e7ee4fb360 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
/*
 * linux/fs/lockd/svc.c
 *
 * This is the central lockd service.
 *
 * FIXME: Separate the lockd NFS server functionality from the lockd NFS
 * 	  client functionality. Oh why didn't Sun create two separate
 *	  services in the first place?
 *
 * Authors:	Olaf Kirch (okir@monad.swb.de)
 *
 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sysctl.h>
#include <linux/moduleparam.h>

#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/in.h>
#include <linux/uio.h>
#include <linux/slab.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>

#include <linux/sunrpc/types.h>
#include <linux/sunrpc/stats.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/lockd/lockd.h>
#include <linux/nfs.h>

#define NLMDBG_FACILITY		NLMDBG_SVC
#define LOCKD_BUFSIZE		(1024 + NLMSVC_XDRSIZE)
#define ALLOWED_SIGS		(sigmask(SIGKILL))

static struct svc_program	nlmsvc_program;

struct nlmsvc_binding *		nlmsvc_ops;
EXPORT_SYMBOL(nlmsvc_ops);

static DECLARE_MUTEX(nlmsvc_sema);
static unsigned int		nlmsvc_users;
static pid_t			nlmsvc_pid;
int				nlmsvc_grace_period;
unsigned long			nlmsvc_timeout;

static DECLARE_MUTEX_LOCKED(lockd_start);
static DECLARE_WAIT_QUEUE_HEAD(lockd_exit);

/*
 * These can be set at insmod time (useful for NFS as root filesystem),
 * and also changed through the sysctl interface.  -- Jamie Lokier, Aug 2003
 */
static unsigned long		nlm_grace_period;
static unsigned long		nlm_timeout = LOCKD_DFLT_TIMEO;
static int			nlm_udpport, nlm_tcpport;

/*
 * Constants needed for the sysctl interface.
 */
static const unsigned long	nlm_grace_period_min = 0;
static const unsigned long	nlm_grace_period_max = 240;
static const unsigned long	nlm_timeout_min = 3;
static const unsigned long	nlm_timeout_max = 20;
static const int		nlm_port_min = 0, nlm_port_max = 65535;

static struct ctl_table_header * nlm_sysctl_table;

static unsigned long set_grace_period(void)
{
	unsigned long grace_period;

	/* Note: nlm_timeout should always be nonzero */
	if (nlm_grace_period)
		grace_period = ((nlm_grace_period + nlm_timeout - 1)
				/ nlm_timeout) * nlm_timeout * HZ;
	else
		grace_period = nlm_timeout * 5 * HZ;
	nlmsvc_grace_period = 1;
	return grace_period + jiffies;
}

static inline void clear_grace_period(void)
{
	nlmsvc_grace_period = 0;
}

/*
 * This is the lockd kernel thread
 */
static void
lockd(struct svc_rqst *rqstp)
{
	struct svc_serv	*serv = rqstp->rq_server;
	int		err = 0;
	unsigned long grace_period_expire;

	/* Lock module and set up kernel thread */
	/* lockd_up is waiting for us to startup, so will
	 * be holding a reference to this module, so it
	 * is safe to just claim another reference
	 */
	__module_get(THIS_MODULE);
	lock_kernel();

	/*
	 * Let our maker know we're running.
	 */
	nlmsvc_pid = current->pid;
	up(&lockd_start);

	daemonize("lockd");

	/* Process request with signals blocked, but allow SIGKILL.  */
	allow_signal(SIGKILL);

	/* kick rpciod */
	rpciod_up();

	dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");

	if (!nlm_timeout)
		nlm_timeout = LOCKD_DFLT_TIMEO;
	nlmsvc_timeout = nlm_timeout * HZ;

	grace_period_expire = set_grace_period();

	/*
	 * The main request loop. We don't terminate until the last
	 * NFS mount or NFS daemon has gone away, and we've been sent a
	 * signal, or else another process has taken over our job.
	 */
	while ((nlmsvc_users || !signalled()) && nlmsvc_pid == current->pid) {
		long timeout = MAX_SCHEDULE_TIMEOUT;

		if (signalled()) {
			flush_signals(current);
			if (nlmsvc_ops) {
				nlmsvc_invalidate_all();
				grace_period_expire = set_grace_period();
			}
		}

		/*
		 * Retry any blocked locks that have been notified by
		 * the VFS. Don't do this during grace period.
		 * (Theoretically, there shouldn't even be blocked locks
		 * during grace period).
		 */
		if (!nlmsvc_grace_period) {
			timeout = nlmsvc_retry_blocked();
		} else if (time_before(grace_period_expire, jiffies))
			clear_grace_period();

		/*
		 * Find a socket with data available and call its
		 * recvfrom routine.
		 */
		err = svc_recv(serv, rqstp, timeout);
		if (err == -EAGAIN || err == -EINTR)
			continue;
		if (err < 0) {
			printk(KERN_WARNING
			       "lockd: terminating on error %d\n",
			       -err);
			break;
		}

		dprintk("lockd: request from %08x\n",
			(unsigned)ntohl(rqstp->rq_addr.sin_addr.s_addr));

		svc_process(serv, rqstp);

	}

	flush_signals(current);

	/*
	 * Check whether there's a new lockd process before
	 * shutting down the hosts and clearing the slot.
	 */
	if (!nlmsvc_pid || current->pid == nlmsvc_pid) {
		if (nlmsvc_ops)
			nlmsvc_invalidate_all();
		nlm_shutdown_hosts();
		nlmsvc_pid = 0;
	} else
		printk(KERN_DEBUG
			"lockd: new process, skipping host shutdown\n");
	wake_up(&lockd_exit);

	/* Exit the RPC thread */
	svc_exit_thread(rqstp);

	/* release rpciod */
	rpciod_down();

	/* Release module */
	unlock_kernel();
	module_put_and_exit(0);
}

/*
 * Bring up the lockd process if it's not already up.
 */
int
lockd_up(void)
{
	static int		warned;
	struct svc_serv *	serv;
	int			error = 0;

	down(&nlmsvc_sema);
	/*
	 * Unconditionally increment the user count ... this is
	 * the number of clients who _want_ a lockd process.
	 */
	nlmsvc_users++; 
	/*
	 * Check whether we're already up and running.
	 */
	if (nlmsvc_pid)
		goto out;

	/*
	 * Sanity check: if there's no pid,
	 * we should be the first user ...
	 */
	if (nlmsvc_users > 1)
		printk(KERN_WARNING
			"lockd_up: no pid, %d users??\n", nlmsvc_users);

	error = -ENOMEM;
	serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE);
	if (!serv) {
		printk(KERN_WARNING "lockd_up: create service failed\n");
		goto out;
	}

	if ((error = svc_makesock(serv, IPPROTO_UDP, nlm_udpport)) < 0 
#ifdef CONFIG_NFSD_TCP
	 || (error = svc_makesock(serv, IPPROTO_TCP, nlm_tcpport)) < 0
#endif
		) {
		if (warned++ == 0) 
			printk(KERN_WARNING
				"lockd_up: makesock failed, error=%d\n", error);
		goto destroy_and_out;
	} 
	warned = 0;

	/*
	 * Create the kernel thread and wait for it to start.
	 */
	error = svc_create_thread(lockd, serv);
	if (error) {
		printk(KERN_WARNING
			"lockd_up: create thread failed, error=%d\n", error);
		goto destroy_and_out;
	}
	down(&lockd_start);

	/*
	 * Note: svc_serv structures have an initial use count of 1,
	 * so we exit through here on both success and failure.
	 */
destroy_and_out:
	svc_destroy(serv);
out:
	up(&nlmsvc_sema);
	return error;
}
EXPORT_SYMBOL(lockd_up);

/*
 * Decrement the user count and bring down lockd if we're the last.
 */
void
lockd_down(void)
{
	static int warned;

	down(&nlmsvc_sema);
	if (nlmsvc_users) {
		if (--nlmsvc_users)
			goto out;
	} else
		printk(KERN_WARNING "lockd_down: no users! pid=%d\n", nlmsvc_pid);

	if (!nlmsvc_pid) {
		if (warned++ == 0)
			printk(KERN_WARNING "lockd_down: no lockd running.\n"); 
		goto out;
	}
	warned = 0;

	kill_proc(nlmsvc_pid, SIGKILL, 1);
	/*
	 * Wait for the lockd process to exit, but since we're holding
	 * the lockd semaphore, we can't wait around forever ...
	 */
	clear_thread_flag(TIF_SIGPENDING);
	interruptible_sleep_on_timeout(&lockd_exit, HZ);
	if (nlmsvc_pid) {
		printk(KERN_WARNING 
			"lockd_down: lockd failed to exit, clearing pid\n");
		nlmsvc_pid = 0;
	}
	spin_lock_irq(&current->sighand->siglock);
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);
out:
	up(&nlmsvc_sema);
}
EXPORT_SYMBOL(lockd_down);

/*
 * Sysctl parameters (same as module parameters, different interface).
 */

/* Something that isn't CTL_ANY, CTL_NONE or a value that may clash. */
#define CTL_UNNUMBERED		-2

static ctl_table nlm_sysctls[] = {
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "nlm_grace_period",
		.data		= &nlm_grace_period,
		.maxlen		= sizeof(unsigned long),
		.mode		= 0644,
		.proc_handler	= &proc_doulongvec_minmax,
		.extra1		= (unsigned long *) &nlm_grace_period_min,
		.extra2		= (unsigned long *) &nlm_grace_period_max,
	},
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "nlm_timeout",
		.data		= &nlm_timeout,
		.maxlen		= sizeof(unsigned long),
		.mode		= 0644,
		.proc_handler	= &proc_doulongvec_minmax,
		.extra1		= (unsigned long *) &nlm_timeout_min,
		.extra2		= (unsigned long *) &nlm_timeout_max,
	},
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "nlm_udpport",
		.data		= &nlm_udpport,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_minmax,
		.extra1		= (int *) &nlm_port_min,
		.extra2		= (int *) &nlm_port_max,
	},
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "nlm_tcpport",
		.data		= &nlm_tcpport,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_minmax,
		.extra1		= (int *) &nlm_port_min,
		.extra2		= (int *) &nlm_port_max,
	},
	{ .ctl_name = 0 }
};

static ctl_table nlm_sysctl_dir[] = {
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "nfs",
		.mode		= 0555,
		.child		= nlm_sysctls,
	},
	{ .ctl_name = 0 }
};

static ctl_table nlm_sysctl_root[] = {
	{
		.ctl_name	= CTL_FS,
		.procname	= "fs",
		.mode		= 0555,
		.child		= nlm_sysctl_dir,
	},
	{ .ctl_name = 0 }
};

/*
 * Module (and driverfs) parameters.
 */

#define param_set_min_max(name, type, which_strtol, min, max)		\
static int param_set_##name(const char *val, struct kernel_param *kp)	\
{									\
	char *endp;							\
	__typeof__(type) num = which_strtol(val, &endp, 0);		\
	if (endp == val || *endp || num < (min) || num > (max))		\
		return -EINVAL;						\
	*((int *) kp->arg) = num;					\
	return 0;							\
}

static inline int is_callback(u32 proc)
{
	return proc == NLMPROC_GRANTED
		|| proc == NLMPROC_GRANTED_MSG
		|| proc == NLMPROC_TEST_RES
		|| proc == NLMPROC_LOCK_RES
		|| proc == NLMPROC_CANCEL_RES
		|| proc == NLMPROC_UNLOCK_RES
		|| proc == NLMPROC_NSM_NOTIFY;
}


static int lockd_authenticate(struct svc_rqst *rqstp)
{
	rqstp->rq_client = NULL;
	switch (rqstp->rq_authop->flavour) {
		case RPC_AUTH_NULL:
		case RPC_AUTH_UNIX:
			if (rqstp->rq_proc == 0)
				return SVC_OK;
			if (is_callback(rqstp->rq_proc)) {
				/* Leave it to individual procedures to
				 * call nlmsvc_lookup_host(rqstp)
				 */
				return SVC_OK;
			}
			return svc_set_client(rqstp);
	}
	return SVC_DENIED;
}


param_set_min_max(port, int, simple_strtol, 0, 65535)
param_set_min_max(grace_period, unsigned long, simple_strtoul,
		  nlm_grace_period_min, nlm_grace_period_max)
param_set_min_max(timeout, unsigned long, simple_strtoul,
		  nlm_timeout_min, nlm_timeout_max)

MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
MODULE_LICENSE("GPL");

module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
		  &nlm_grace_period, 0644);
module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
		  &nlm_timeout, 0644);
module_param_call(nlm_udpport, param_set_port, param_get_int,
		  &nlm_udpport, 0644);
module_param_call(nlm_tcpport, param_set_port, param_get_int,
		  &nlm_tcpport, 0644);

/*
 * Initialising and terminating the module.
 */

static int __init init_nlm(void)
{
	nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root, 0);
	return nlm_sysctl_table ? 0 : -ENOMEM;
}

static void __exit exit_nlm(void)
{
	/* FIXME: delete all NLM clients */
	nlm_shutdown_hosts();
	unregister_sysctl_table(nlm_sysctl_table);
}

module_init(init_nlm);
module_exit(exit_nlm);

/*
 * Define NLM program and procedures
 */
static struct svc_version	nlmsvc_version1 = {
		.vs_vers	= 1,
		.vs_nproc	= 17,
		.vs_proc	= nlmsvc_procedures,
		.vs_xdrsize	= NLMSVC_XDRSIZE,
};
static struct svc_version	nlmsvc_version3 = {
		.vs_vers	= 3,
		.vs_nproc	= 24,
		.vs_proc	= nlmsvc_procedures,
		.vs_xdrsize	= NLMSVC_XDRSIZE,
};
#ifdef CONFIG_LOCKD_V4
static struct svc_version	nlmsvc_version4 = {
		.vs_vers	= 4,
		.vs_nproc	= 24,
		.vs_proc	= nlmsvc_procedures4,
		.vs_xdrsize	= NLMSVC_XDRSIZE,
};
#endif
static struct svc_version *	nlmsvc_version[] = {
	[1] = &nlmsvc_version1,
	[3] = &nlmsvc_version3,
#ifdef CONFIG_LOCKD_V4
	[4] = &nlmsvc_version4,
#endif
};

static struct svc_stat		nlmsvc_stats;

#define NLM_NRVERS	(sizeof(nlmsvc_version)/sizeof(nlmsvc_version[0]))
static struct svc_program	nlmsvc_program = {
	.pg_prog		= NLM_PROGRAM,		/* program number */
	.pg_nvers		= NLM_NRVERS,		/* number of entries in nlmsvc_version */
	.pg_vers		= nlmsvc_version,	/* version table */
	.pg_name		= "lockd",		/* service name */
	.pg_class		= "nfsd",		/* share authentication with nfsd */
	.pg_stats		= &nlmsvc_stats,	/* stats table */
	.pg_authenticate = &lockd_authenticate	/* export authentication */
};