locks: allow lockd to process blocked locks during grace period
[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>
d751a7cd 28#include <linux/kthread.h>
83144186 29#include <linux/freezer.h>
1da177e4
LT
30
31#include <linux/sunrpc/types.h>
32#include <linux/sunrpc/stats.h>
33#include <linux/sunrpc/clnt.h>
34#include <linux/sunrpc/svc.h>
35#include <linux/sunrpc/svcsock.h>
24e36663 36#include <net/ip.h>
1da177e4 37#include <linux/lockd/lockd.h>
460f5cac 38#include <linux/lockd/sm_inter.h>
1da177e4
LT
39#include <linux/nfs.h>
40
41#define NLMDBG_FACILITY NLMDBG_SVC
42#define LOCKD_BUFSIZE (1024 + NLMSVC_XDRSIZE)
43#define ALLOWED_SIGS (sigmask(SIGKILL))
44
45static struct svc_program nlmsvc_program;
46
47struct nlmsvc_binding * nlmsvc_ops;
48EXPORT_SYMBOL(nlmsvc_ops);
49
353ab6e9 50static DEFINE_MUTEX(nlmsvc_mutex);
1da177e4 51static unsigned int nlmsvc_users;
d751a7cd 52static struct task_struct *nlmsvc_task;
abd1ec4e 53static struct svc_rqst *nlmsvc_rqst;
1da177e4
LT
54int nlmsvc_grace_period;
55unsigned long nlmsvc_timeout;
56
1da177e4
LT
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;
abd1f500 64int nsm_use_hostnames = 0;
1da177e4
LT
65
66/*
67 * Constants needed for the sysctl interface.
68 */
69static const unsigned long nlm_grace_period_min = 0;
70static const unsigned long nlm_grace_period_max = 240;
71static const unsigned long nlm_timeout_min = 3;
72static const unsigned long nlm_timeout_max = 20;
73static const int nlm_port_min = 0, nlm_port_max = 65535;
74
90d5b180 75#ifdef CONFIG_SYSCTL
1da177e4 76static struct ctl_table_header * nlm_sysctl_table;
90d5b180 77#endif
1da177e4 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 */
d751a7cd
JL
114static int
115lockd(void *vrqstp)
1da177e4 116{
f97c650d 117 int err = 0, preverr = 0;
d751a7cd 118 struct svc_rqst *rqstp = vrqstp;
1da177e4
LT
119 unsigned long grace_period_expire;
120
d751a7cd 121 /* try_to_freeze() is called from svc_recv() */
83144186 122 set_freezable();
1da177e4 123
d751a7cd 124 /* Allow SIGKILL to tell lockd to drop all of its locks */
1da177e4
LT
125 allow_signal(SIGKILL);
126
1da177e4
LT
127 dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
128
d751a7cd
JL
129 /*
130 * FIXME: it would be nice if lockd didn't spend its entire life
131 * running under the BKL. At the very least, it would be good to
132 * have someone clarify what it's intended to protect here. I've
133 * seen some handwavy posts about posix locking needing to be
134 * done under the BKL, but it's far from clear.
135 */
136 lock_kernel();
137
1da177e4
LT
138 if (!nlm_timeout)
139 nlm_timeout = LOCKD_DFLT_TIMEO;
140 nlmsvc_timeout = nlm_timeout * HZ;
141
142 grace_period_expire = set_grace_period();
143
144 /*
145 * The main request loop. We don't terminate until the last
d751a7cd 146 * NFS mount or NFS daemon has gone away.
1da177e4 147 */
d751a7cd 148 while (!kthread_should_stop()) {
1da177e4 149 long timeout = MAX_SCHEDULE_TIMEOUT;
5216a8e7 150 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
1da177e4
LT
151
152 if (signalled()) {
153 flush_signals(current);
154 if (nlmsvc_ops) {
155 nlmsvc_invalidate_all();
156 grace_period_expire = set_grace_period();
157 }
d751a7cd 158 continue;
1da177e4
LT
159 }
160
8fafa900
BF
161 timeout = nlmsvc_retry_blocked();
162
163 if (time_before(grace_period_expire, jiffies))
1da177e4
LT
164 clear_grace_period();
165
166 /*
167 * Find a socket with data available and call its
168 * recvfrom routine.
169 */
6fb2b47f 170 err = svc_recv(rqstp, timeout);
f97c650d
JL
171 if (err == -EAGAIN || err == -EINTR) {
172 preverr = err;
1da177e4 173 continue;
f97c650d 174 }
1da177e4 175 if (err < 0) {
f97c650d
JL
176 if (err != preverr) {
177 printk(KERN_WARNING "%s: unexpected error "
178 "from svc_recv (%d)\n", __func__, err);
179 preverr = err;
180 }
181 schedule_timeout_interruptible(HZ);
182 continue;
1da177e4 183 }
f97c650d 184 preverr = err;
1da177e4 185
ad06e4bd
CL
186 dprintk("lockd: request from %s\n",
187 svc_print_addr(rqstp, buf, sizeof(buf)));
1da177e4 188
6fb2b47f 189 svc_process(rqstp);
1da177e4 190 }
2bd61579 191 flush_signals(current);
d751a7cd
JL
192 if (nlmsvc_ops)
193 nlmsvc_invalidate_all();
194 nlm_shutdown_hosts();
d751a7cd 195 unlock_kernel();
d751a7cd 196 return 0;
1da177e4
LT
197}
198
482fb94e
CL
199/*
200 * Make any sockets that are needed but not present.
201 * If nlm_udpport or nlm_tcpport were set as module
202 * options, make those sockets unconditionally
203 */
24e36663
N
204static int make_socks(struct svc_serv *serv, int proto)
205{
482fb94e 206 static int warned;
a217813f 207 struct svc_xprt *xprt;
24e36663 208 int err = 0;
482fb94e 209
a217813f
TT
210 if (proto == IPPROTO_UDP || nlm_udpport) {
211 xprt = svc_find_xprt(serv, "udp", 0, 0);
212 if (!xprt)
d7c9f1ed
TT
213 err = svc_create_xprt(serv, "udp", nlm_udpport,
214 SVC_SOCK_DEFAULTS);
a217813f
TT
215 else
216 svc_xprt_put(xprt);
217 }
218 if (err >= 0 && (proto == IPPROTO_TCP || nlm_tcpport)) {
219 xprt = svc_find_xprt(serv, "tcp", 0, 0);
220 if (!xprt)
d7c9f1ed
TT
221 err = svc_create_xprt(serv, "tcp", nlm_tcpport,
222 SVC_SOCK_DEFAULTS);
a217813f
TT
223 else
224 svc_xprt_put(xprt);
225 }
482fb94e 226 if (err >= 0) {
7dcf91ec 227 warned = 0;
482fb94e
CL
228 err = 0;
229 } else if (warned++ == 0)
7dcf91ec
N
230 printk(KERN_WARNING
231 "lockd_up: makesock failed, error=%d\n", err);
24e36663
N
232 return err;
233}
234
1da177e4
LT
235/*
236 * Bring up the lockd process if it's not already up.
237 */
238int
24e36663 239lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
1da177e4 240{
d751a7cd 241 struct svc_serv *serv;
d751a7cd 242 int error = 0;
1da177e4 243
353ab6e9 244 mutex_lock(&nlmsvc_mutex);
1da177e4
LT
245 /*
246 * Check whether we're already up and running.
247 */
abd1ec4e 248 if (nlmsvc_rqst) {
4a3ae42d 249 if (proto)
abd1ec4e 250 error = make_socks(nlmsvc_rqst->rq_server, proto);
1da177e4 251 goto out;
24e36663 252 }
1da177e4
LT
253
254 /*
255 * Sanity check: if there's no pid,
256 * we should be the first user ...
257 */
4a3ae42d 258 if (nlmsvc_users)
1da177e4
LT
259 printk(KERN_WARNING
260 "lockd_up: no pid, %d users??\n", nlmsvc_users);
261
262 error = -ENOMEM;
e851db5b 263 serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, AF_INET, NULL);
1da177e4
LT
264 if (!serv) {
265 printk(KERN_WARNING "lockd_up: create service failed\n");
266 goto out;
267 }
268
7dcf91ec 269 if ((error = make_socks(serv, proto)) < 0)
1da177e4 270 goto destroy_and_out;
1da177e4
LT
271
272 /*
273 * Create the kernel thread and wait for it to start.
274 */
abd1ec4e
JL
275 nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0]);
276 if (IS_ERR(nlmsvc_rqst)) {
277 error = PTR_ERR(nlmsvc_rqst);
278 nlmsvc_rqst = NULL;
d751a7cd
JL
279 printk(KERN_WARNING
280 "lockd_up: svc_rqst allocation failed, error=%d\n",
281 error);
282 goto destroy_and_out;
283 }
284
285 svc_sock_update_bufs(serv);
d751a7cd 286
abd1ec4e 287 nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, serv->sv_name);
d751a7cd
JL
288 if (IS_ERR(nlmsvc_task)) {
289 error = PTR_ERR(nlmsvc_task);
abd1ec4e 290 svc_exit_thread(nlmsvc_rqst);
d751a7cd 291 nlmsvc_task = NULL;
abd1ec4e 292 nlmsvc_rqst = NULL;
1da177e4 293 printk(KERN_WARNING
d751a7cd 294 "lockd_up: kthread_run failed, error=%d\n", error);
1da177e4
LT
295 goto destroy_and_out;
296 }
1da177e4
LT
297
298 /*
299 * Note: svc_serv structures have an initial use count of 1,
300 * so we exit through here on both success and failure.
301 */
302destroy_and_out:
303 svc_destroy(serv);
304out:
4a3ae42d
N
305 if (!error)
306 nlmsvc_users++;
353ab6e9 307 mutex_unlock(&nlmsvc_mutex);
1da177e4
LT
308 return error;
309}
310EXPORT_SYMBOL(lockd_up);
311
312/*
313 * Decrement the user count and bring down lockd if we're the last.
314 */
315void
316lockd_down(void)
317{
353ab6e9 318 mutex_lock(&nlmsvc_mutex);
1da177e4
LT
319 if (nlmsvc_users) {
320 if (--nlmsvc_users)
321 goto out;
d751a7cd
JL
322 } else {
323 printk(KERN_ERR "lockd_down: no users! task=%p\n",
324 nlmsvc_task);
325 BUG();
1da177e4 326 }
1da177e4 327
d751a7cd
JL
328 if (!nlmsvc_task) {
329 printk(KERN_ERR "lockd_down: no lockd running.\n");
330 BUG();
1da177e4 331 }
d751a7cd 332 kthread_stop(nlmsvc_task);
abd1ec4e
JL
333 svc_exit_thread(nlmsvc_rqst);
334 nlmsvc_task = NULL;
335 nlmsvc_rqst = NULL;
1da177e4 336out:
353ab6e9 337 mutex_unlock(&nlmsvc_mutex);
1da177e4
LT
338}
339EXPORT_SYMBOL(lockd_down);
340
90d5b180
CL
341#ifdef CONFIG_SYSCTL
342
1da177e4
LT
343/*
344 * Sysctl parameters (same as module parameters, different interface).
345 */
346
1da177e4
LT
347static ctl_table nlm_sysctls[] = {
348 {
349 .ctl_name = CTL_UNNUMBERED,
350 .procname = "nlm_grace_period",
351 .data = &nlm_grace_period,
7ee91ec1 352 .maxlen = sizeof(unsigned long),
1da177e4
LT
353 .mode = 0644,
354 .proc_handler = &proc_doulongvec_minmax,
355 .extra1 = (unsigned long *) &nlm_grace_period_min,
356 .extra2 = (unsigned long *) &nlm_grace_period_max,
357 },
358 {
359 .ctl_name = CTL_UNNUMBERED,
360 .procname = "nlm_timeout",
361 .data = &nlm_timeout,
7ee91ec1 362 .maxlen = sizeof(unsigned long),
1da177e4
LT
363 .mode = 0644,
364 .proc_handler = &proc_doulongvec_minmax,
365 .extra1 = (unsigned long *) &nlm_timeout_min,
366 .extra2 = (unsigned long *) &nlm_timeout_max,
367 },
368 {
369 .ctl_name = CTL_UNNUMBERED,
370 .procname = "nlm_udpport",
371 .data = &nlm_udpport,
372 .maxlen = sizeof(int),
373 .mode = 0644,
374 .proc_handler = &proc_dointvec_minmax,
375 .extra1 = (int *) &nlm_port_min,
376 .extra2 = (int *) &nlm_port_max,
377 },
378 {
379 .ctl_name = CTL_UNNUMBERED,
380 .procname = "nlm_tcpport",
381 .data = &nlm_tcpport,
382 .maxlen = sizeof(int),
383 .mode = 0644,
384 .proc_handler = &proc_dointvec_minmax,
385 .extra1 = (int *) &nlm_port_min,
386 .extra2 = (int *) &nlm_port_max,
387 },
abd1f500
OK
388 {
389 .ctl_name = CTL_UNNUMBERED,
390 .procname = "nsm_use_hostnames",
391 .data = &nsm_use_hostnames,
392 .maxlen = sizeof(int),
393 .mode = 0644,
394 .proc_handler = &proc_dointvec,
395 },
460f5cac
OK
396 {
397 .ctl_name = CTL_UNNUMBERED,
398 .procname = "nsm_local_state",
399 .data = &nsm_local_state,
400 .maxlen = sizeof(int),
401 .mode = 0644,
402 .proc_handler = &proc_dointvec,
403 },
1da177e4
LT
404 { .ctl_name = 0 }
405};
406
407static ctl_table nlm_sysctl_dir[] = {
408 {
409 .ctl_name = CTL_UNNUMBERED,
410 .procname = "nfs",
411 .mode = 0555,
412 .child = nlm_sysctls,
413 },
414 { .ctl_name = 0 }
415};
416
417static ctl_table nlm_sysctl_root[] = {
418 {
419 .ctl_name = CTL_FS,
420 .procname = "fs",
421 .mode = 0555,
422 .child = nlm_sysctl_dir,
423 },
424 { .ctl_name = 0 }
425};
426
90d5b180
CL
427#endif /* CONFIG_SYSCTL */
428
1da177e4 429/*
405ae7d3 430 * Module (and sysfs) parameters.
1da177e4
LT
431 */
432
433#define param_set_min_max(name, type, which_strtol, min, max) \
434static int param_set_##name(const char *val, struct kernel_param *kp) \
435{ \
436 char *endp; \
437 __typeof__(type) num = which_strtol(val, &endp, 0); \
438 if (endp == val || *endp || num < (min) || num > (max)) \
439 return -EINVAL; \
440 *((int *) kp->arg) = num; \
441 return 0; \
442}
443
444static inline int is_callback(u32 proc)
445{
446 return proc == NLMPROC_GRANTED
447 || proc == NLMPROC_GRANTED_MSG
448 || proc == NLMPROC_TEST_RES
449 || proc == NLMPROC_LOCK_RES
450 || proc == NLMPROC_CANCEL_RES
451 || proc == NLMPROC_UNLOCK_RES
452 || proc == NLMPROC_NSM_NOTIFY;
453}
454
455
456static int lockd_authenticate(struct svc_rqst *rqstp)
457{
458 rqstp->rq_client = NULL;
459 switch (rqstp->rq_authop->flavour) {
460 case RPC_AUTH_NULL:
461 case RPC_AUTH_UNIX:
462 if (rqstp->rq_proc == 0)
463 return SVC_OK;
464 if (is_callback(rqstp->rq_proc)) {
465 /* Leave it to individual procedures to
466 * call nlmsvc_lookup_host(rqstp)
467 */
468 return SVC_OK;
469 }
470 return svc_set_client(rqstp);
471 }
472 return SVC_DENIED;
473}
474
475
476param_set_min_max(port, int, simple_strtol, 0, 65535)
477param_set_min_max(grace_period, unsigned long, simple_strtoul,
478 nlm_grace_period_min, nlm_grace_period_max)
479param_set_min_max(timeout, unsigned long, simple_strtoul,
480 nlm_timeout_min, nlm_timeout_max)
481
482MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
483MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
484MODULE_LICENSE("GPL");
485
486module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
487 &nlm_grace_period, 0644);
488module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
489 &nlm_timeout, 0644);
490module_param_call(nlm_udpport, param_set_port, param_get_int,
491 &nlm_udpport, 0644);
492module_param_call(nlm_tcpport, param_set_port, param_get_int,
493 &nlm_tcpport, 0644);
abd1f500 494module_param(nsm_use_hostnames, bool, 0644);
1da177e4
LT
495
496/*
497 * Initialising and terminating the module.
498 */
499
500static int __init init_nlm(void)
501{
90d5b180 502#ifdef CONFIG_SYSCTL
0b4d4147 503 nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
1da177e4 504 return nlm_sysctl_table ? 0 : -ENOMEM;
90d5b180
CL
505#else
506 return 0;
507#endif
1da177e4
LT
508}
509
510static void __exit exit_nlm(void)
511{
512 /* FIXME: delete all NLM clients */
513 nlm_shutdown_hosts();
90d5b180 514#ifdef CONFIG_SYSCTL
1da177e4 515 unregister_sysctl_table(nlm_sysctl_table);
90d5b180 516#endif
1da177e4
LT
517}
518
519module_init(init_nlm);
520module_exit(exit_nlm);
521
522/*
523 * Define NLM program and procedures
524 */
525static struct svc_version nlmsvc_version1 = {
526 .vs_vers = 1,
527 .vs_nproc = 17,
528 .vs_proc = nlmsvc_procedures,
529 .vs_xdrsize = NLMSVC_XDRSIZE,
530};
531static struct svc_version nlmsvc_version3 = {
532 .vs_vers = 3,
533 .vs_nproc = 24,
534 .vs_proc = nlmsvc_procedures,
535 .vs_xdrsize = NLMSVC_XDRSIZE,
536};
537#ifdef CONFIG_LOCKD_V4
538static struct svc_version nlmsvc_version4 = {
539 .vs_vers = 4,
540 .vs_nproc = 24,
541 .vs_proc = nlmsvc_procedures4,
542 .vs_xdrsize = NLMSVC_XDRSIZE,
543};
544#endif
545static struct svc_version * nlmsvc_version[] = {
546 [1] = &nlmsvc_version1,
547 [3] = &nlmsvc_version3,
548#ifdef CONFIG_LOCKD_V4
549 [4] = &nlmsvc_version4,
550#endif
551};
552
553static struct svc_stat nlmsvc_stats;
554
e8c96f8c 555#define NLM_NRVERS ARRAY_SIZE(nlmsvc_version)
1da177e4
LT
556static struct svc_program nlmsvc_program = {
557 .pg_prog = NLM_PROGRAM, /* program number */
558 .pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */
559 .pg_vers = nlmsvc_version, /* version table */
560 .pg_name = "lockd", /* service name */
561 .pg_class = "nfsd", /* share authentication with nfsd */
562 .pg_stats = &nlmsvc_stats, /* stats table */
563 .pg_authenticate = &lockd_authenticate /* export authentication */
564};