[PATCH] nfsd: add lock annotations to e_start and e_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>
1da177e4
LT
28
29#include <linux/sunrpc/types.h>
30#include <linux/sunrpc/stats.h>
31#include <linux/sunrpc/clnt.h>
32#include <linux/sunrpc/svc.h>
33#include <linux/sunrpc/svcsock.h>
24e36663 34#include <net/ip.h>
1da177e4
LT
35#include <linux/lockd/lockd.h>
36#include <linux/nfs.h>
37
38#define NLMDBG_FACILITY NLMDBG_SVC
39#define LOCKD_BUFSIZE (1024 + NLMSVC_XDRSIZE)
40#define ALLOWED_SIGS (sigmask(SIGKILL))
41
42static struct svc_program nlmsvc_program;
43
44struct nlmsvc_binding * nlmsvc_ops;
45EXPORT_SYMBOL(nlmsvc_ops);
46
353ab6e9 47static DEFINE_MUTEX(nlmsvc_mutex);
1da177e4
LT
48static unsigned int nlmsvc_users;
49static pid_t nlmsvc_pid;
24e36663 50static struct svc_serv *nlmsvc_serv;
1da177e4
LT
51int nlmsvc_grace_period;
52unsigned long nlmsvc_timeout;
53
353ab6e9 54static DECLARE_COMPLETION(lockd_start_done);
1da177e4
LT
55static DECLARE_WAIT_QUEUE_HEAD(lockd_exit);
56
57/*
58 * These can be set at insmod time (useful for NFS as root filesystem),
59 * and also changed through the sysctl interface. -- Jamie Lokier, Aug 2003
60 */
61static unsigned long nlm_grace_period;
62static unsigned long nlm_timeout = LOCKD_DFLT_TIMEO;
63static int nlm_udpport, nlm_tcpport;
64
65/*
66 * Constants needed for the sysctl interface.
67 */
68static const unsigned long nlm_grace_period_min = 0;
69static const unsigned long nlm_grace_period_max = 240;
70static const unsigned long nlm_timeout_min = 3;
71static const unsigned long nlm_timeout_max = 20;
72static const int nlm_port_min = 0, nlm_port_max = 65535;
73
74static struct ctl_table_header * nlm_sysctl_table;
75
76static unsigned long set_grace_period(void)
77{
78 unsigned long grace_period;
79
80 /* Note: nlm_timeout should always be nonzero */
81 if (nlm_grace_period)
82 grace_period = ((nlm_grace_period + nlm_timeout - 1)
83 / nlm_timeout) * nlm_timeout * HZ;
84 else
85 grace_period = nlm_timeout * 5 * HZ;
86 nlmsvc_grace_period = 1;
87 return grace_period + jiffies;
88}
89
90static inline void clear_grace_period(void)
91{
92 nlmsvc_grace_period = 0;
93}
94
95/*
96 * This is the lockd kernel thread
97 */
98static void
99lockd(struct svc_rqst *rqstp)
100{
101 struct svc_serv *serv = rqstp->rq_server;
102 int err = 0;
103 unsigned long grace_period_expire;
104
105 /* Lock module and set up kernel thread */
106 /* lockd_up is waiting for us to startup, so will
107 * be holding a reference to this module, so it
108 * is safe to just claim another reference
109 */
110 __module_get(THIS_MODULE);
111 lock_kernel();
112
113 /*
114 * Let our maker know we're running.
115 */
116 nlmsvc_pid = current->pid;
24e36663 117 nlmsvc_serv = serv;
353ab6e9 118 complete(&lockd_start_done);
1da177e4
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119
120 daemonize("lockd");
121
122 /* Process request with signals blocked, but allow SIGKILL. */
123 allow_signal(SIGKILL);
124
125 /* kick rpciod */
126 rpciod_up();
127
128 dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
129
130 if (!nlm_timeout)
131 nlm_timeout = LOCKD_DFLT_TIMEO;
132 nlmsvc_timeout = nlm_timeout * HZ;
133
134 grace_period_expire = set_grace_period();
135
136 /*
137 * The main request loop. We don't terminate until the last
138 * NFS mount or NFS daemon has gone away, and we've been sent a
139 * signal, or else another process has taken over our job.
140 */
141 while ((nlmsvc_users || !signalled()) && nlmsvc_pid == current->pid) {
142 long timeout = MAX_SCHEDULE_TIMEOUT;
143
144 if (signalled()) {
145 flush_signals(current);
146 if (nlmsvc_ops) {
147 nlmsvc_invalidate_all();
148 grace_period_expire = set_grace_period();
149 }
150 }
151
152 /*
153 * Retry any blocked locks that have been notified by
154 * the VFS. Don't do this during grace period.
155 * (Theoretically, there shouldn't even be blocked locks
156 * during grace period).
157 */
158 if (!nlmsvc_grace_period) {
159 timeout = nlmsvc_retry_blocked();
160 } else if (time_before(grace_period_expire, jiffies))
161 clear_grace_period();
162
163 /*
164 * Find a socket with data available and call its
165 * recvfrom routine.
166 */
167 err = svc_recv(serv, rqstp, timeout);
168 if (err == -EAGAIN || err == -EINTR)
169 continue;
170 if (err < 0) {
171 printk(KERN_WARNING
172 "lockd: terminating on error %d\n",
173 -err);
174 break;
175 }
176
177 dprintk("lockd: request from %08x\n",
178 (unsigned)ntohl(rqstp->rq_addr.sin_addr.s_addr));
179
180 svc_process(serv, rqstp);
181
182 }
183
2bd61579
TM
184 flush_signals(current);
185
1da177e4
LT
186 /*
187 * Check whether there's a new lockd process before
188 * shutting down the hosts and clearing the slot.
189 */
190 if (!nlmsvc_pid || current->pid == nlmsvc_pid) {
191 if (nlmsvc_ops)
192 nlmsvc_invalidate_all();
193 nlm_shutdown_hosts();
194 nlmsvc_pid = 0;
24e36663 195 nlmsvc_serv = NULL;
1da177e4
LT
196 } else
197 printk(KERN_DEBUG
198 "lockd: new process, skipping host shutdown\n");
199 wake_up(&lockd_exit);
46be925f 200
1da177e4
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201 /* Exit the RPC thread */
202 svc_exit_thread(rqstp);
203
204 /* release rpciod */
205 rpciod_down();
206
207 /* Release module */
208 unlock_kernel();
209 module_put_and_exit(0);
210}
211
24e36663
N
212
213static int find_socket(struct svc_serv *serv, int proto)
214{
215 struct svc_sock *svsk;
216 int found = 0;
217 list_for_each_entry(svsk, &serv->sv_permsocks, sk_list)
218 if (svsk->sk_sk->sk_protocol == proto) {
219 found = 1;
220 break;
221 }
222 return found;
223}
224
225static int make_socks(struct svc_serv *serv, int proto)
226{
227 /* Make any sockets that are needed but not present.
228 * If nlm_udpport or nlm_tcpport were set as module
229 * options, make those sockets unconditionally
230 */
231 int err = 0;
232 if (proto == IPPROTO_UDP || nlm_udpport)
233 if (!find_socket(serv, IPPROTO_UDP))
234 err = svc_makesock(serv, IPPROTO_UDP, nlm_udpport);
235 if (err)
236 return err;
237 if (proto == IPPROTO_TCP || nlm_tcpport)
238 if (!find_socket(serv, IPPROTO_TCP))
239 err= svc_makesock(serv, IPPROTO_TCP, nlm_tcpport);
240 return err;
241}
242
1da177e4
LT
243/*
244 * Bring up the lockd process if it's not already up.
245 */
246int
24e36663 247lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
1da177e4
LT
248{
249 static int warned;
250 struct svc_serv * serv;
251 int error = 0;
252
353ab6e9 253 mutex_lock(&nlmsvc_mutex);
1da177e4
LT
254 /*
255 * Unconditionally increment the user count ... this is
256 * the number of clients who _want_ a lockd process.
257 */
258 nlmsvc_users++;
259 /*
260 * Check whether we're already up and running.
261 */
24e36663
N
262 if (nlmsvc_pid) {
263 error = make_socks(nlmsvc_serv, proto);
1da177e4 264 goto out;
24e36663 265 }
1da177e4
LT
266
267 /*
268 * Sanity check: if there's no pid,
269 * we should be the first user ...
270 */
271 if (nlmsvc_users > 1)
272 printk(KERN_WARNING
273 "lockd_up: no pid, %d users??\n", nlmsvc_users);
274
275 error = -ENOMEM;
bc591ccf 276 serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL);
1da177e4
LT
277 if (!serv) {
278 printk(KERN_WARNING "lockd_up: create service failed\n");
279 goto out;
280 }
281
24e36663 282 if ((error = make_socks(serv, proto)) < 0) {
1da177e4
LT
283 if (warned++ == 0)
284 printk(KERN_WARNING
285 "lockd_up: makesock failed, error=%d\n", error);
286 goto destroy_and_out;
287 }
288 warned = 0;
289
290 /*
291 * Create the kernel thread and wait for it to start.
292 */
293 error = svc_create_thread(lockd, serv);
294 if (error) {
295 printk(KERN_WARNING
296 "lockd_up: create thread failed, error=%d\n", error);
297 goto destroy_and_out;
298 }
353ab6e9 299 wait_for_completion(&lockd_start_done);
1da177e4
LT
300
301 /*
302 * Note: svc_serv structures have an initial use count of 1,
303 * so we exit through here on both success and failure.
304 */
305destroy_and_out:
306 svc_destroy(serv);
307out:
353ab6e9 308 mutex_unlock(&nlmsvc_mutex);
1da177e4
LT
309 return error;
310}
311EXPORT_SYMBOL(lockd_up);
312
313/*
314 * Decrement the user count and bring down lockd if we're the last.
315 */
316void
317lockd_down(void)
318{
319 static int warned;
320
353ab6e9 321 mutex_lock(&nlmsvc_mutex);
1da177e4
LT
322 if (nlmsvc_users) {
323 if (--nlmsvc_users)
324 goto out;
325 } else
326 printk(KERN_WARNING "lockd_down: no users! pid=%d\n", nlmsvc_pid);
327
328 if (!nlmsvc_pid) {
329 if (warned++ == 0)
330 printk(KERN_WARNING "lockd_down: no lockd running.\n");
331 goto out;
332 }
333 warned = 0;
334
335 kill_proc(nlmsvc_pid, SIGKILL, 1);
336 /*
337 * Wait for the lockd process to exit, but since we're holding
338 * the lockd semaphore, we can't wait around forever ...
339 */
340 clear_thread_flag(TIF_SIGPENDING);
341 interruptible_sleep_on_timeout(&lockd_exit, HZ);
342 if (nlmsvc_pid) {
343 printk(KERN_WARNING
344 "lockd_down: lockd failed to exit, clearing pid\n");
345 nlmsvc_pid = 0;
346 }
347 spin_lock_irq(&current->sighand->siglock);
348 recalc_sigpending();
349 spin_unlock_irq(&current->sighand->siglock);
350out:
353ab6e9 351 mutex_unlock(&nlmsvc_mutex);
1da177e4
LT
352}
353EXPORT_SYMBOL(lockd_down);
354
355/*
356 * Sysctl parameters (same as module parameters, different interface).
357 */
358
359/* Something that isn't CTL_ANY, CTL_NONE or a value that may clash. */
360#define CTL_UNNUMBERED -2
361
362static ctl_table nlm_sysctls[] = {
363 {
364 .ctl_name = CTL_UNNUMBERED,
365 .procname = "nlm_grace_period",
366 .data = &nlm_grace_period,
7ee91ec1 367 .maxlen = sizeof(unsigned long),
1da177e4
LT
368 .mode = 0644,
369 .proc_handler = &proc_doulongvec_minmax,
370 .extra1 = (unsigned long *) &nlm_grace_period_min,
371 .extra2 = (unsigned long *) &nlm_grace_period_max,
372 },
373 {
374 .ctl_name = CTL_UNNUMBERED,
375 .procname = "nlm_timeout",
376 .data = &nlm_timeout,
7ee91ec1 377 .maxlen = sizeof(unsigned long),
1da177e4
LT
378 .mode = 0644,
379 .proc_handler = &proc_doulongvec_minmax,
380 .extra1 = (unsigned long *) &nlm_timeout_min,
381 .extra2 = (unsigned long *) &nlm_timeout_max,
382 },
383 {
384 .ctl_name = CTL_UNNUMBERED,
385 .procname = "nlm_udpport",
386 .data = &nlm_udpport,
387 .maxlen = sizeof(int),
388 .mode = 0644,
389 .proc_handler = &proc_dointvec_minmax,
390 .extra1 = (int *) &nlm_port_min,
391 .extra2 = (int *) &nlm_port_max,
392 },
393 {
394 .ctl_name = CTL_UNNUMBERED,
395 .procname = "nlm_tcpport",
396 .data = &nlm_tcpport,
397 .maxlen = sizeof(int),
398 .mode = 0644,
399 .proc_handler = &proc_dointvec_minmax,
400 .extra1 = (int *) &nlm_port_min,
401 .extra2 = (int *) &nlm_port_max,
402 },
403 { .ctl_name = 0 }
404};
405
406static ctl_table nlm_sysctl_dir[] = {
407 {
408 .ctl_name = CTL_UNNUMBERED,
409 .procname = "nfs",
410 .mode = 0555,
411 .child = nlm_sysctls,
412 },
413 { .ctl_name = 0 }
414};
415
416static ctl_table nlm_sysctl_root[] = {
417 {
418 .ctl_name = CTL_FS,
419 .procname = "fs",
420 .mode = 0555,
421 .child = nlm_sysctl_dir,
422 },
423 { .ctl_name = 0 }
424};
425
426/*
427 * Module (and driverfs) parameters.
428 */
429
430#define param_set_min_max(name, type, which_strtol, min, max) \
431static int param_set_##name(const char *val, struct kernel_param *kp) \
432{ \
433 char *endp; \
434 __typeof__(type) num = which_strtol(val, &endp, 0); \
435 if (endp == val || *endp || num < (min) || num > (max)) \
436 return -EINVAL; \
437 *((int *) kp->arg) = num; \
438 return 0; \
439}
440
441static inline int is_callback(u32 proc)
442{
443 return proc == NLMPROC_GRANTED
444 || proc == NLMPROC_GRANTED_MSG
445 || proc == NLMPROC_TEST_RES
446 || proc == NLMPROC_LOCK_RES
447 || proc == NLMPROC_CANCEL_RES
448 || proc == NLMPROC_UNLOCK_RES
449 || proc == NLMPROC_NSM_NOTIFY;
450}
451
452
453static int lockd_authenticate(struct svc_rqst *rqstp)
454{
455 rqstp->rq_client = NULL;
456 switch (rqstp->rq_authop->flavour) {
457 case RPC_AUTH_NULL:
458 case RPC_AUTH_UNIX:
459 if (rqstp->rq_proc == 0)
460 return SVC_OK;
461 if (is_callback(rqstp->rq_proc)) {
462 /* Leave it to individual procedures to
463 * call nlmsvc_lookup_host(rqstp)
464 */
465 return SVC_OK;
466 }
467 return svc_set_client(rqstp);
468 }
469 return SVC_DENIED;
470}
471
472
473param_set_min_max(port, int, simple_strtol, 0, 65535)
474param_set_min_max(grace_period, unsigned long, simple_strtoul,
475 nlm_grace_period_min, nlm_grace_period_max)
476param_set_min_max(timeout, unsigned long, simple_strtoul,
477 nlm_timeout_min, nlm_timeout_max)
478
479MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
480MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
481MODULE_LICENSE("GPL");
482
483module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
484 &nlm_grace_period, 0644);
485module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
486 &nlm_timeout, 0644);
487module_param_call(nlm_udpport, param_set_port, param_get_int,
488 &nlm_udpport, 0644);
489module_param_call(nlm_tcpport, param_set_port, param_get_int,
490 &nlm_tcpport, 0644);
491
492/*
493 * Initialising and terminating the module.
494 */
495
496static int __init init_nlm(void)
497{
498 nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root, 0);
499 return nlm_sysctl_table ? 0 : -ENOMEM;
500}
501
502static void __exit exit_nlm(void)
503{
504 /* FIXME: delete all NLM clients */
505 nlm_shutdown_hosts();
506 unregister_sysctl_table(nlm_sysctl_table);
507}
508
509module_init(init_nlm);
510module_exit(exit_nlm);
511
512/*
513 * Define NLM program and procedures
514 */
515static struct svc_version nlmsvc_version1 = {
516 .vs_vers = 1,
517 .vs_nproc = 17,
518 .vs_proc = nlmsvc_procedures,
519 .vs_xdrsize = NLMSVC_XDRSIZE,
520};
521static struct svc_version nlmsvc_version3 = {
522 .vs_vers = 3,
523 .vs_nproc = 24,
524 .vs_proc = nlmsvc_procedures,
525 .vs_xdrsize = NLMSVC_XDRSIZE,
526};
527#ifdef CONFIG_LOCKD_V4
528static struct svc_version nlmsvc_version4 = {
529 .vs_vers = 4,
530 .vs_nproc = 24,
531 .vs_proc = nlmsvc_procedures4,
532 .vs_xdrsize = NLMSVC_XDRSIZE,
533};
534#endif
535static struct svc_version * nlmsvc_version[] = {
536 [1] = &nlmsvc_version1,
537 [3] = &nlmsvc_version3,
538#ifdef CONFIG_LOCKD_V4
539 [4] = &nlmsvc_version4,
540#endif
541};
542
543static struct svc_stat nlmsvc_stats;
544
e8c96f8c 545#define NLM_NRVERS ARRAY_SIZE(nlmsvc_version)
1da177e4
LT
546static struct svc_program nlmsvc_program = {
547 .pg_prog = NLM_PROGRAM, /* program number */
548 .pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */
549 .pg_vers = nlmsvc_version, /* version table */
550 .pg_name = "lockd", /* service name */
551 .pg_class = "nfsd", /* share authentication with nfsd */
552 .pg_stats = &nlmsvc_stats, /* stats table */
553 .pg_authenticate = &lockd_authenticate /* export authentication */
554};