SUNRPC: have svc_recv() check kthread_should_stop()
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / lockd / svc.c
CommitLineData
1da177e4
LT
1/*
2 * linux/fs/lockd/svc.c
3 *
4 * This is the central lockd service.
5 *
6 * FIXME: Separate the lockd NFS server functionality from the lockd NFS
7 * client functionality. Oh why didn't Sun create two separate
8 * services in the first place?
9 *
10 * Authors: Olaf Kirch (okir@monad.swb.de)
11 *
12 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
13 */
14
1da177e4
LT
15#include <linux/module.h>
16#include <linux/init.h>
17#include <linux/sysctl.h>
18#include <linux/moduleparam.h>
19
20#include <linux/sched.h>
21#include <linux/errno.h>
22#include <linux/in.h>
23#include <linux/uio.h>
24#include <linux/slab.h>
25#include <linux/smp.h>
26#include <linux/smp_lock.h>
353ab6e9 27#include <linux/mutex.h>
83144186 28#include <linux/freezer.h>
1da177e4
LT
29
30#include <linux/sunrpc/types.h>
31#include <linux/sunrpc/stats.h>
32#include <linux/sunrpc/clnt.h>
33#include <linux/sunrpc/svc.h>
34#include <linux/sunrpc/svcsock.h>
24e36663 35#include <net/ip.h>
1da177e4 36#include <linux/lockd/lockd.h>
460f5cac 37#include <linux/lockd/sm_inter.h>
1da177e4
LT
38#include <linux/nfs.h>
39
40#define NLMDBG_FACILITY NLMDBG_SVC
41#define LOCKD_BUFSIZE (1024 + NLMSVC_XDRSIZE)
42#define ALLOWED_SIGS (sigmask(SIGKILL))
43
44static struct svc_program nlmsvc_program;
45
46struct nlmsvc_binding * nlmsvc_ops;
47EXPORT_SYMBOL(nlmsvc_ops);
48
353ab6e9 49static DEFINE_MUTEX(nlmsvc_mutex);
1da177e4
LT
50static unsigned int nlmsvc_users;
51static pid_t nlmsvc_pid;
24e36663 52static struct svc_serv *nlmsvc_serv;
1da177e4
LT
53int nlmsvc_grace_period;
54unsigned long nlmsvc_timeout;
55
353ab6e9 56static DECLARE_COMPLETION(lockd_start_done);
1da177e4
LT
57static DECLARE_WAIT_QUEUE_HEAD(lockd_exit);
58
59/*
60 * These can be set at insmod time (useful for NFS as root filesystem),
61 * and also changed through the sysctl interface. -- Jamie Lokier, Aug 2003
62 */
63static unsigned long nlm_grace_period;
64static unsigned long nlm_timeout = LOCKD_DFLT_TIMEO;
65static int nlm_udpport, nlm_tcpport;
abd1f500 66int nsm_use_hostnames = 0;
1da177e4
LT
67
68/*
69 * Constants needed for the sysctl interface.
70 */
71static const unsigned long nlm_grace_period_min = 0;
72static const unsigned long nlm_grace_period_max = 240;
73static const unsigned long nlm_timeout_min = 3;
74static const unsigned long nlm_timeout_max = 20;
75static const int nlm_port_min = 0, nlm_port_max = 65535;
76
77static struct ctl_table_header * nlm_sysctl_table;
78
9a8db97e 79static unsigned long get_lockd_grace_period(void)
1da177e4 80{
1da177e4
LT
81 /* Note: nlm_timeout should always be nonzero */
82 if (nlm_grace_period)
9a8db97e 83 return roundup(nlm_grace_period, nlm_timeout) * HZ;
1da177e4 84 else
9a8db97e
ME
85 return nlm_timeout * 5 * HZ;
86}
87
88unsigned long get_nfs_grace_period(void)
89{
90 unsigned long lockdgrace = get_lockd_grace_period();
91 unsigned long nfsdgrace = 0;
92
93 if (nlmsvc_ops)
94 nfsdgrace = nlmsvc_ops->get_grace_period();
95
96 return max(lockdgrace, nfsdgrace);
97}
98EXPORT_SYMBOL(get_nfs_grace_period);
99
100static unsigned long set_grace_period(void)
101{
1da177e4 102 nlmsvc_grace_period = 1;
9a8db97e 103 return get_nfs_grace_period() + jiffies;
1da177e4
LT
104}
105
106static inline void clear_grace_period(void)
107{
108 nlmsvc_grace_period = 0;
109}
110
111/*
112 * This is the lockd kernel thread
113 */
114static void
115lockd(struct svc_rqst *rqstp)
116{
1da177e4
LT
117 int err = 0;
118 unsigned long grace_period_expire;
119
120 /* Lock module and set up kernel thread */
121 /* lockd_up is waiting for us to startup, so will
122 * be holding a reference to this module, so it
123 * is safe to just claim another reference
124 */
125 __module_get(THIS_MODULE);
126 lock_kernel();
127
128 /*
129 * Let our maker know we're running.
130 */
131 nlmsvc_pid = current->pid;
6fb2b47f 132 nlmsvc_serv = rqstp->rq_server;
353ab6e9 133 complete(&lockd_start_done);
1da177e4
LT
134
135 daemonize("lockd");
83144186 136 set_freezable();
1da177e4
LT
137
138 /* Process request with signals blocked, but allow SIGKILL. */
139 allow_signal(SIGKILL);
140
1da177e4
LT
141 dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
142
143 if (!nlm_timeout)
144 nlm_timeout = LOCKD_DFLT_TIMEO;
145 nlmsvc_timeout = nlm_timeout * HZ;
146
147 grace_period_expire = set_grace_period();
148
149 /*
150 * The main request loop. We don't terminate until the last
151 * NFS mount or NFS daemon has gone away, and we've been sent a
152 * signal, or else another process has taken over our job.
153 */
154 while ((nlmsvc_users || !signalled()) && nlmsvc_pid == current->pid) {
155 long timeout = MAX_SCHEDULE_TIMEOUT;
5216a8e7 156 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
1da177e4
LT
157
158 if (signalled()) {
159 flush_signals(current);
160 if (nlmsvc_ops) {
161 nlmsvc_invalidate_all();
162 grace_period_expire = set_grace_period();
163 }
164 }
165
166 /*
167 * Retry any blocked locks that have been notified by
168 * the VFS. Don't do this during grace period.
169 * (Theoretically, there shouldn't even be blocked locks
170 * during grace period).
171 */
172 if (!nlmsvc_grace_period) {
173 timeout = nlmsvc_retry_blocked();
174 } else if (time_before(grace_period_expire, jiffies))
175 clear_grace_period();
176
177 /*
178 * Find a socket with data available and call its
179 * recvfrom routine.
180 */
6fb2b47f 181 err = svc_recv(rqstp, timeout);
1da177e4
LT
182 if (err == -EAGAIN || err == -EINTR)
183 continue;
184 if (err < 0) {
185 printk(KERN_WARNING
186 "lockd: terminating on error %d\n",
187 -err);
188 break;
189 }
190
ad06e4bd
CL
191 dprintk("lockd: request from %s\n",
192 svc_print_addr(rqstp, buf, sizeof(buf)));
1da177e4 193
6fb2b47f 194 svc_process(rqstp);
1da177e4
LT
195 }
196
2bd61579
TM
197 flush_signals(current);
198
1da177e4
LT
199 /*
200 * Check whether there's a new lockd process before
201 * shutting down the hosts and clearing the slot.
202 */
203 if (!nlmsvc_pid || current->pid == nlmsvc_pid) {
204 if (nlmsvc_ops)
205 nlmsvc_invalidate_all();
206 nlm_shutdown_hosts();
207 nlmsvc_pid = 0;
24e36663 208 nlmsvc_serv = NULL;
1da177e4
LT
209 } else
210 printk(KERN_DEBUG
211 "lockd: new process, skipping host shutdown\n");
212 wake_up(&lockd_exit);
46be925f 213
1da177e4
LT
214 /* Exit the RPC thread */
215 svc_exit_thread(rqstp);
216
1da177e4
LT
217 /* Release module */
218 unlock_kernel();
219 module_put_and_exit(0);
220}
221
482fb94e
CL
222/*
223 * Make any sockets that are needed but not present.
224 * If nlm_udpport or nlm_tcpport were set as module
225 * options, make those sockets unconditionally
226 */
24e36663
N
227static int make_socks(struct svc_serv *serv, int proto)
228{
482fb94e 229 static int warned;
a217813f 230 struct svc_xprt *xprt;
24e36663 231 int err = 0;
482fb94e 232
a217813f
TT
233 if (proto == IPPROTO_UDP || nlm_udpport) {
234 xprt = svc_find_xprt(serv, "udp", 0, 0);
235 if (!xprt)
d7c9f1ed
TT
236 err = svc_create_xprt(serv, "udp", nlm_udpport,
237 SVC_SOCK_DEFAULTS);
a217813f
TT
238 else
239 svc_xprt_put(xprt);
240 }
241 if (err >= 0 && (proto == IPPROTO_TCP || nlm_tcpport)) {
242 xprt = svc_find_xprt(serv, "tcp", 0, 0);
243 if (!xprt)
d7c9f1ed
TT
244 err = svc_create_xprt(serv, "tcp", nlm_tcpport,
245 SVC_SOCK_DEFAULTS);
a217813f
TT
246 else
247 svc_xprt_put(xprt);
248 }
482fb94e 249 if (err >= 0) {
7dcf91ec 250 warned = 0;
482fb94e
CL
251 err = 0;
252 } else if (warned++ == 0)
7dcf91ec
N
253 printk(KERN_WARNING
254 "lockd_up: makesock failed, error=%d\n", err);
24e36663
N
255 return err;
256}
257
1da177e4
LT
258/*
259 * Bring up the lockd process if it's not already up.
260 */
261int
24e36663 262lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
1da177e4 263{
1da177e4
LT
264 struct svc_serv * serv;
265 int error = 0;
266
353ab6e9 267 mutex_lock(&nlmsvc_mutex);
1da177e4
LT
268 /*
269 * Check whether we're already up and running.
270 */
24e36663 271 if (nlmsvc_pid) {
4a3ae42d
N
272 if (proto)
273 error = make_socks(nlmsvc_serv, proto);
1da177e4 274 goto out;
24e36663 275 }
1da177e4
LT
276
277 /*
278 * Sanity check: if there's no pid,
279 * we should be the first user ...
280 */
4a3ae42d 281 if (nlmsvc_users)
1da177e4
LT
282 printk(KERN_WARNING
283 "lockd_up: no pid, %d users??\n", nlmsvc_users);
284
285 error = -ENOMEM;
bc591ccf 286 serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL);
1da177e4
LT
287 if (!serv) {
288 printk(KERN_WARNING "lockd_up: create service failed\n");
289 goto out;
290 }
291
7dcf91ec 292 if ((error = make_socks(serv, proto)) < 0)
1da177e4 293 goto destroy_and_out;
1da177e4
LT
294
295 /*
296 * Create the kernel thread and wait for it to start.
297 */
298 error = svc_create_thread(lockd, serv);
299 if (error) {
300 printk(KERN_WARNING
301 "lockd_up: create thread failed, error=%d\n", error);
302 goto destroy_and_out;
303 }
353ab6e9 304 wait_for_completion(&lockd_start_done);
1da177e4
LT
305
306 /*
307 * Note: svc_serv structures have an initial use count of 1,
308 * so we exit through here on both success and failure.
309 */
310destroy_and_out:
311 svc_destroy(serv);
312out:
4a3ae42d
N
313 if (!error)
314 nlmsvc_users++;
353ab6e9 315 mutex_unlock(&nlmsvc_mutex);
1da177e4
LT
316 return error;
317}
318EXPORT_SYMBOL(lockd_up);
319
320/*
321 * Decrement the user count and bring down lockd if we're the last.
322 */
323void
324lockd_down(void)
325{
326 static int warned;
327
353ab6e9 328 mutex_lock(&nlmsvc_mutex);
1da177e4
LT
329 if (nlmsvc_users) {
330 if (--nlmsvc_users)
331 goto out;
332 } else
333 printk(KERN_WARNING "lockd_down: no users! pid=%d\n", nlmsvc_pid);
334
335 if (!nlmsvc_pid) {
336 if (warned++ == 0)
337 printk(KERN_WARNING "lockd_down: no lockd running.\n");
338 goto out;
339 }
340 warned = 0;
341
342 kill_proc(nlmsvc_pid, SIGKILL, 1);
343 /*
344 * Wait for the lockd process to exit, but since we're holding
345 * the lockd semaphore, we can't wait around forever ...
346 */
347 clear_thread_flag(TIF_SIGPENDING);
348 interruptible_sleep_on_timeout(&lockd_exit, HZ);
349 if (nlmsvc_pid) {
350 printk(KERN_WARNING
351 "lockd_down: lockd failed to exit, clearing pid\n");
352 nlmsvc_pid = 0;
353 }
354 spin_lock_irq(&current->sighand->siglock);
355 recalc_sigpending();
356 spin_unlock_irq(&current->sighand->siglock);
357out:
353ab6e9 358 mutex_unlock(&nlmsvc_mutex);
1da177e4
LT
359}
360EXPORT_SYMBOL(lockd_down);
361
362/*
363 * Sysctl parameters (same as module parameters, different interface).
364 */
365
1da177e4
LT
366static ctl_table nlm_sysctls[] = {
367 {
368 .ctl_name = CTL_UNNUMBERED,
369 .procname = "nlm_grace_period",
370 .data = &nlm_grace_period,
7ee91ec1 371 .maxlen = sizeof(unsigned long),
1da177e4
LT
372 .mode = 0644,
373 .proc_handler = &proc_doulongvec_minmax,
374 .extra1 = (unsigned long *) &nlm_grace_period_min,
375 .extra2 = (unsigned long *) &nlm_grace_period_max,
376 },
377 {
378 .ctl_name = CTL_UNNUMBERED,
379 .procname = "nlm_timeout",
380 .data = &nlm_timeout,
7ee91ec1 381 .maxlen = sizeof(unsigned long),
1da177e4
LT
382 .mode = 0644,
383 .proc_handler = &proc_doulongvec_minmax,
384 .extra1 = (unsigned long *) &nlm_timeout_min,
385 .extra2 = (unsigned long *) &nlm_timeout_max,
386 },
387 {
388 .ctl_name = CTL_UNNUMBERED,
389 .procname = "nlm_udpport",
390 .data = &nlm_udpport,
391 .maxlen = sizeof(int),
392 .mode = 0644,
393 .proc_handler = &proc_dointvec_minmax,
394 .extra1 = (int *) &nlm_port_min,
395 .extra2 = (int *) &nlm_port_max,
396 },
397 {
398 .ctl_name = CTL_UNNUMBERED,
399 .procname = "nlm_tcpport",
400 .data = &nlm_tcpport,
401 .maxlen = sizeof(int),
402 .mode = 0644,
403 .proc_handler = &proc_dointvec_minmax,
404 .extra1 = (int *) &nlm_port_min,
405 .extra2 = (int *) &nlm_port_max,
406 },
abd1f500
OK
407 {
408 .ctl_name = CTL_UNNUMBERED,
409 .procname = "nsm_use_hostnames",
410 .data = &nsm_use_hostnames,
411 .maxlen = sizeof(int),
412 .mode = 0644,
413 .proc_handler = &proc_dointvec,
414 },
460f5cac
OK
415 {
416 .ctl_name = CTL_UNNUMBERED,
417 .procname = "nsm_local_state",
418 .data = &nsm_local_state,
419 .maxlen = sizeof(int),
420 .mode = 0644,
421 .proc_handler = &proc_dointvec,
422 },
1da177e4
LT
423 { .ctl_name = 0 }
424};
425
426static ctl_table nlm_sysctl_dir[] = {
427 {
428 .ctl_name = CTL_UNNUMBERED,
429 .procname = "nfs",
430 .mode = 0555,
431 .child = nlm_sysctls,
432 },
433 { .ctl_name = 0 }
434};
435
436static ctl_table nlm_sysctl_root[] = {
437 {
438 .ctl_name = CTL_FS,
439 .procname = "fs",
440 .mode = 0555,
441 .child = nlm_sysctl_dir,
442 },
443 { .ctl_name = 0 }
444};
445
446/*
405ae7d3 447 * Module (and sysfs) parameters.
1da177e4
LT
448 */
449
450#define param_set_min_max(name, type, which_strtol, min, max) \
451static int param_set_##name(const char *val, struct kernel_param *kp) \
452{ \
453 char *endp; \
454 __typeof__(type) num = which_strtol(val, &endp, 0); \
455 if (endp == val || *endp || num < (min) || num > (max)) \
456 return -EINVAL; \
457 *((int *) kp->arg) = num; \
458 return 0; \
459}
460
461static inline int is_callback(u32 proc)
462{
463 return proc == NLMPROC_GRANTED
464 || proc == NLMPROC_GRANTED_MSG
465 || proc == NLMPROC_TEST_RES
466 || proc == NLMPROC_LOCK_RES
467 || proc == NLMPROC_CANCEL_RES
468 || proc == NLMPROC_UNLOCK_RES
469 || proc == NLMPROC_NSM_NOTIFY;
470}
471
472
473static int lockd_authenticate(struct svc_rqst *rqstp)
474{
475 rqstp->rq_client = NULL;
476 switch (rqstp->rq_authop->flavour) {
477 case RPC_AUTH_NULL:
478 case RPC_AUTH_UNIX:
479 if (rqstp->rq_proc == 0)
480 return SVC_OK;
481 if (is_callback(rqstp->rq_proc)) {
482 /* Leave it to individual procedures to
483 * call nlmsvc_lookup_host(rqstp)
484 */
485 return SVC_OK;
486 }
487 return svc_set_client(rqstp);
488 }
489 return SVC_DENIED;
490}
491
492
493param_set_min_max(port, int, simple_strtol, 0, 65535)
494param_set_min_max(grace_period, unsigned long, simple_strtoul,
495 nlm_grace_period_min, nlm_grace_period_max)
496param_set_min_max(timeout, unsigned long, simple_strtoul,
497 nlm_timeout_min, nlm_timeout_max)
498
499MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
500MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
501MODULE_LICENSE("GPL");
502
503module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
504 &nlm_grace_period, 0644);
505module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
506 &nlm_timeout, 0644);
507module_param_call(nlm_udpport, param_set_port, param_get_int,
508 &nlm_udpport, 0644);
509module_param_call(nlm_tcpport, param_set_port, param_get_int,
510 &nlm_tcpport, 0644);
abd1f500 511module_param(nsm_use_hostnames, bool, 0644);
1da177e4
LT
512
513/*
514 * Initialising and terminating the module.
515 */
516
517static int __init init_nlm(void)
518{
0b4d4147 519 nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
1da177e4
LT
520 return nlm_sysctl_table ? 0 : -ENOMEM;
521}
522
523static void __exit exit_nlm(void)
524{
525 /* FIXME: delete all NLM clients */
526 nlm_shutdown_hosts();
527 unregister_sysctl_table(nlm_sysctl_table);
528}
529
530module_init(init_nlm);
531module_exit(exit_nlm);
532
533/*
534 * Define NLM program and procedures
535 */
536static struct svc_version nlmsvc_version1 = {
537 .vs_vers = 1,
538 .vs_nproc = 17,
539 .vs_proc = nlmsvc_procedures,
540 .vs_xdrsize = NLMSVC_XDRSIZE,
541};
542static struct svc_version nlmsvc_version3 = {
543 .vs_vers = 3,
544 .vs_nproc = 24,
545 .vs_proc = nlmsvc_procedures,
546 .vs_xdrsize = NLMSVC_XDRSIZE,
547};
548#ifdef CONFIG_LOCKD_V4
549static struct svc_version nlmsvc_version4 = {
550 .vs_vers = 4,
551 .vs_nproc = 24,
552 .vs_proc = nlmsvc_procedures4,
553 .vs_xdrsize = NLMSVC_XDRSIZE,
554};
555#endif
556static struct svc_version * nlmsvc_version[] = {
557 [1] = &nlmsvc_version1,
558 [3] = &nlmsvc_version3,
559#ifdef CONFIG_LOCKD_V4
560 [4] = &nlmsvc_version4,
561#endif
562};
563
564static struct svc_stat nlmsvc_stats;
565
e8c96f8c 566#define NLM_NRVERS ARRAY_SIZE(nlmsvc_version)
1da177e4
LT
567static struct svc_program nlmsvc_program = {
568 .pg_prog = NLM_PROGRAM, /* program number */
569 .pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */
570 .pg_vers = nlmsvc_version, /* version table */
571 .pg_name = "lockd", /* service name */
572 .pg_class = "nfsd", /* share authentication with nfsd */
573 .pg_stats = &nlmsvc_stats, /* stats table */
574 .pg_authenticate = &lockd_authenticate /* export authentication */
575};