svc.c 12.4 KB
Newer Older
L
Linus Torvalds 已提交
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
/*
 * 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/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>
I
Ingo Molnar 已提交
27
#include <linux/mutex.h>
L
Linus Torvalds 已提交
28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45

#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);

I
Ingo Molnar 已提交
46
static DEFINE_MUTEX(nlmsvc_mutex);
L
Linus Torvalds 已提交
47 48 49 50 51
static unsigned int		nlmsvc_users;
static pid_t			nlmsvc_pid;
int				nlmsvc_grace_period;
unsigned long			nlmsvc_timeout;

I
Ingo Molnar 已提交
52
static DECLARE_COMPLETION(lockd_start_done);
L
Linus Torvalds 已提交
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
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;
I
Ingo Molnar 已提交
115
	complete(&lockd_start_done);
L
Linus Torvalds 已提交
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

	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);

	}

181 182
	flush_signals(current);

L
Linus Torvalds 已提交
183 184 185 186 187 188 189 190 191 192 193 194 195
	/*
	 * 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);
196

L
Linus Torvalds 已提交
197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217
	/* 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;

I
Ingo Molnar 已提交
218
	mutex_lock(&nlmsvc_mutex);
L
Linus Torvalds 已提交
219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238
	/*
	 * 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;
239
	serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL);
L
Linus Torvalds 已提交
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
	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;
	}
I
Ingo Molnar 已提交
266
	wait_for_completion(&lockd_start_done);
L
Linus Torvalds 已提交
267 268 269 270 271 272 273 274

	/*
	 * 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:
I
Ingo Molnar 已提交
275
	mutex_unlock(&nlmsvc_mutex);
L
Linus Torvalds 已提交
276 277 278 279 280 281 282 283 284 285 286 287
	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;

I
Ingo Molnar 已提交
288
	mutex_lock(&nlmsvc_mutex);
L
Linus Torvalds 已提交
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
	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:
I
Ingo Molnar 已提交
318
	mutex_unlock(&nlmsvc_mutex);
L
Linus Torvalds 已提交
319 320 321 322 323 324 325 326 327 328 329 330 331 332 333
}
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,
334
		.maxlen		= sizeof(unsigned long),
L
Linus Torvalds 已提交
335 336 337 338 339 340 341 342 343
		.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,
344
		.maxlen		= sizeof(unsigned long),
L
Linus Torvalds 已提交
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
		.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;

512
#define NLM_NRVERS	ARRAY_SIZE(nlmsvc_version)
L
Linus Torvalds 已提交
513 514 515 516 517 518 519 520 521
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 */
};