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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 | ||
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> | |
27 | #include <linux/mutex.h> | |
28 | #include <linux/freezer.h> | |
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> | |
35 | #include <net/ip.h> | |
36 | #include <linux/lockd/lockd.h> | |
37 | #include <linux/lockd/sm_inter.h> | |
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 | ||
44 | static struct svc_program nlmsvc_program; | |
45 | ||
46 | struct nlmsvc_binding * nlmsvc_ops; | |
47 | EXPORT_SYMBOL(nlmsvc_ops); | |
48 | ||
49 | static DEFINE_MUTEX(nlmsvc_mutex); | |
50 | static unsigned int nlmsvc_users; | |
51 | static pid_t nlmsvc_pid; | |
52 | static struct svc_serv *nlmsvc_serv; | |
53 | int nlmsvc_grace_period; | |
54 | unsigned long nlmsvc_timeout; | |
55 | ||
56 | static DECLARE_COMPLETION(lockd_start_done); | |
57 | static 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 | */ | |
63 | static unsigned long nlm_grace_period; | |
64 | static unsigned long nlm_timeout = LOCKD_DFLT_TIMEO; | |
65 | static int nlm_udpport, nlm_tcpport; | |
66 | int nsm_use_hostnames = 0; | |
67 | ||
68 | /* | |
69 | * Constants needed for the sysctl interface. | |
70 | */ | |
71 | static const unsigned long nlm_grace_period_min = 0; | |
72 | static const unsigned long nlm_grace_period_max = 240; | |
73 | static const unsigned long nlm_timeout_min = 3; | |
74 | static const unsigned long nlm_timeout_max = 20; | |
75 | static const int nlm_port_min = 0, nlm_port_max = 65535; | |
76 | ||
77 | static struct ctl_table_header * nlm_sysctl_table; | |
78 | ||
79 | static unsigned long get_lockd_grace_period(void) | |
80 | { | |
81 | /* Note: nlm_timeout should always be nonzero */ | |
82 | if (nlm_grace_period) | |
83 | return roundup(nlm_grace_period, nlm_timeout) * HZ; | |
84 | else | |
85 | return nlm_timeout * 5 * HZ; | |
86 | } | |
87 | ||
88 | unsigned 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 | } | |
98 | EXPORT_SYMBOL(get_nfs_grace_period); | |
99 | ||
100 | static unsigned long set_grace_period(void) | |
101 | { | |
102 | nlmsvc_grace_period = 1; | |
103 | return get_nfs_grace_period() + jiffies; | |
104 | } | |
105 | ||
106 | static inline void clear_grace_period(void) | |
107 | { | |
108 | nlmsvc_grace_period = 0; | |
109 | } | |
110 | ||
111 | /* | |
112 | * This is the lockd kernel thread | |
113 | */ | |
114 | static void | |
115 | lockd(struct svc_rqst *rqstp) | |
116 | { | |
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; | |
132 | nlmsvc_serv = rqstp->rq_server; | |
133 | complete(&lockd_start_done); | |
134 | ||
135 | daemonize("lockd"); | |
136 | set_freezable(); | |
137 | ||
138 | /* Process request with signals blocked, but allow SIGKILL. */ | |
139 | allow_signal(SIGKILL); | |
140 | ||
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; | |
156 | RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]); | |
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 | */ | |
181 | err = svc_recv(rqstp, timeout); | |
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 | ||
191 | dprintk("lockd: request from %s\n", | |
192 | svc_print_addr(rqstp, buf, sizeof(buf))); | |
193 | ||
194 | svc_process(rqstp); | |
195 | } | |
196 | ||
197 | flush_signals(current); | |
198 | ||
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; | |
208 | nlmsvc_serv = NULL; | |
209 | } else | |
210 | printk(KERN_DEBUG | |
211 | "lockd: new process, skipping host shutdown\n"); | |
212 | wake_up(&lockd_exit); | |
213 | ||
214 | /* Exit the RPC thread */ | |
215 | svc_exit_thread(rqstp); | |
216 | ||
217 | /* Release module */ | |
218 | unlock_kernel(); | |
219 | module_put_and_exit(0); | |
220 | } | |
221 | ||
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 | */ | |
227 | static int make_socks(struct svc_serv *serv, int proto) | |
228 | { | |
229 | static int warned; | |
230 | struct svc_xprt *xprt; | |
231 | int err = 0; | |
232 | ||
233 | if (proto == IPPROTO_UDP || nlm_udpport) { | |
234 | xprt = svc_find_xprt(serv, "udp", 0, 0); | |
235 | if (!xprt) | |
236 | err = svc_create_xprt(serv, "udp", nlm_udpport, | |
237 | SVC_SOCK_DEFAULTS); | |
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) | |
244 | err = svc_create_xprt(serv, "tcp", nlm_tcpport, | |
245 | SVC_SOCK_DEFAULTS); | |
246 | else | |
247 | svc_xprt_put(xprt); | |
248 | } | |
249 | if (err >= 0) { | |
250 | warned = 0; | |
251 | err = 0; | |
252 | } else if (warned++ == 0) | |
253 | printk(KERN_WARNING | |
254 | "lockd_up: makesock failed, error=%d\n", err); | |
255 | return err; | |
256 | } | |
257 | ||
258 | /* | |
259 | * Bring up the lockd process if it's not already up. | |
260 | */ | |
261 | int | |
262 | lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */ | |
263 | { | |
264 | struct svc_serv * serv; | |
265 | int error = 0; | |
266 | ||
267 | mutex_lock(&nlmsvc_mutex); | |
268 | /* | |
269 | * Check whether we're already up and running. | |
270 | */ | |
271 | if (nlmsvc_pid) { | |
272 | if (proto) | |
273 | error = make_socks(nlmsvc_serv, proto); | |
274 | goto out; | |
275 | } | |
276 | ||
277 | /* | |
278 | * Sanity check: if there's no pid, | |
279 | * we should be the first user ... | |
280 | */ | |
281 | if (nlmsvc_users) | |
282 | printk(KERN_WARNING | |
283 | "lockd_up: no pid, %d users??\n", nlmsvc_users); | |
284 | ||
285 | error = -ENOMEM; | |
286 | serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL); | |
287 | if (!serv) { | |
288 | printk(KERN_WARNING "lockd_up: create service failed\n"); | |
289 | goto out; | |
290 | } | |
291 | ||
292 | if ((error = make_socks(serv, proto)) < 0) | |
293 | goto destroy_and_out; | |
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 | } | |
304 | wait_for_completion(&lockd_start_done); | |
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 | */ | |
310 | destroy_and_out: | |
311 | svc_destroy(serv); | |
312 | out: | |
313 | if (!error) | |
314 | nlmsvc_users++; | |
315 | mutex_unlock(&nlmsvc_mutex); | |
316 | return error; | |
317 | } | |
318 | EXPORT_SYMBOL(lockd_up); | |
319 | ||
320 | /* | |
321 | * Decrement the user count and bring down lockd if we're the last. | |
322 | */ | |
323 | void | |
324 | lockd_down(void) | |
325 | { | |
326 | static int warned; | |
327 | ||
328 | mutex_lock(&nlmsvc_mutex); | |
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(¤t->sighand->siglock); | |
355 | recalc_sigpending(); | |
356 | spin_unlock_irq(¤t->sighand->siglock); | |
357 | out: | |
358 | mutex_unlock(&nlmsvc_mutex); | |
359 | } | |
360 | EXPORT_SYMBOL(lockd_down); | |
361 | ||
362 | /* | |
363 | * Sysctl parameters (same as module parameters, different interface). | |
364 | */ | |
365 | ||
366 | static ctl_table nlm_sysctls[] = { | |
367 | { | |
368 | .ctl_name = CTL_UNNUMBERED, | |
369 | .procname = "nlm_grace_period", | |
370 | .data = &nlm_grace_period, | |
371 | .maxlen = sizeof(unsigned long), | |
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, | |
381 | .maxlen = sizeof(unsigned long), | |
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 | }, | |
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 | }, | |
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 | }, | |
423 | { .ctl_name = 0 } | |
424 | }; | |
425 | ||
426 | static 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 | ||
436 | static 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 | /* | |
447 | * Module (and sysfs) parameters. | |
448 | */ | |
449 | ||
450 | #define param_set_min_max(name, type, which_strtol, min, max) \ | |
451 | static 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 | ||
461 | static 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 | ||
473 | static 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 | ||
493 | param_set_min_max(port, int, simple_strtol, 0, 65535) | |
494 | param_set_min_max(grace_period, unsigned long, simple_strtoul, | |
495 | nlm_grace_period_min, nlm_grace_period_max) | |
496 | param_set_min_max(timeout, unsigned long, simple_strtoul, | |
497 | nlm_timeout_min, nlm_timeout_max) | |
498 | ||
499 | MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>"); | |
500 | MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION "."); | |
501 | MODULE_LICENSE("GPL"); | |
502 | ||
503 | module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong, | |
504 | &nlm_grace_period, 0644); | |
505 | module_param_call(nlm_timeout, param_set_timeout, param_get_ulong, | |
506 | &nlm_timeout, 0644); | |
507 | module_param_call(nlm_udpport, param_set_port, param_get_int, | |
508 | &nlm_udpport, 0644); | |
509 | module_param_call(nlm_tcpport, param_set_port, param_get_int, | |
510 | &nlm_tcpport, 0644); | |
511 | module_param(nsm_use_hostnames, bool, 0644); | |
512 | ||
513 | /* | |
514 | * Initialising and terminating the module. | |
515 | */ | |
516 | ||
517 | static int __init init_nlm(void) | |
518 | { | |
519 | nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root); | |
520 | return nlm_sysctl_table ? 0 : -ENOMEM; | |
521 | } | |
522 | ||
523 | static 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 | ||
530 | module_init(init_nlm); | |
531 | module_exit(exit_nlm); | |
532 | ||
533 | /* | |
534 | * Define NLM program and procedures | |
535 | */ | |
536 | static struct svc_version nlmsvc_version1 = { | |
537 | .vs_vers = 1, | |
538 | .vs_nproc = 17, | |
539 | .vs_proc = nlmsvc_procedures, | |
540 | .vs_xdrsize = NLMSVC_XDRSIZE, | |
541 | }; | |
542 | static 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 | |
549 | static 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 | |
556 | static 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 | ||
564 | static struct svc_stat nlmsvc_stats; | |
565 | ||
566 | #define NLM_NRVERS ARRAY_SIZE(nlmsvc_version) | |
567 | static 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 | }; |