NFS: don't let nfs_callback_svc exit on unexpected svc_recv errors (try #2)
[linux-2.6-block.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;
24e36663 53static struct svc_serv *nlmsvc_serv;
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
75static struct ctl_table_header * nlm_sysctl_table;
76
9a8db97e 77static unsigned long get_lockd_grace_period(void)
1da177e4 78{
1da177e4
LT
79 /* Note: nlm_timeout should always be nonzero */
80 if (nlm_grace_period)
9a8db97e 81 return roundup(nlm_grace_period, nlm_timeout) * HZ;
1da177e4 82 else
9a8db97e
ME
83 return nlm_timeout * 5 * HZ;
84}
85
86unsigned long get_nfs_grace_period(void)
87{
88 unsigned long lockdgrace = get_lockd_grace_period();
89 unsigned long nfsdgrace = 0;
90
91 if (nlmsvc_ops)
92 nfsdgrace = nlmsvc_ops->get_grace_period();
93
94 return max(lockdgrace, nfsdgrace);
95}
96EXPORT_SYMBOL(get_nfs_grace_period);
97
98static unsigned long set_grace_period(void)
99{
1da177e4 100 nlmsvc_grace_period = 1;
9a8db97e 101 return get_nfs_grace_period() + jiffies;
1da177e4
LT
102}
103
104static inline void clear_grace_period(void)
105{
106 nlmsvc_grace_period = 0;
107}
108
109/*
110 * This is the lockd kernel thread
111 */
d751a7cd
JL
112static int
113lockd(void *vrqstp)
1da177e4 114{
1da177e4 115 int err = 0;
d751a7cd 116 struct svc_rqst *rqstp = vrqstp;
1da177e4
LT
117 unsigned long grace_period_expire;
118
d751a7cd 119 /* try_to_freeze() is called from svc_recv() */
83144186 120 set_freezable();
1da177e4 121
d751a7cd 122 /* Allow SIGKILL to tell lockd to drop all of its locks */
1da177e4
LT
123 allow_signal(SIGKILL);
124
1da177e4
LT
125 dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
126
d751a7cd
JL
127 /*
128 * FIXME: it would be nice if lockd didn't spend its entire life
129 * running under the BKL. At the very least, it would be good to
130 * have someone clarify what it's intended to protect here. I've
131 * seen some handwavy posts about posix locking needing to be
132 * done under the BKL, but it's far from clear.
133 */
134 lock_kernel();
135
1da177e4
LT
136 if (!nlm_timeout)
137 nlm_timeout = LOCKD_DFLT_TIMEO;
138 nlmsvc_timeout = nlm_timeout * HZ;
139
140 grace_period_expire = set_grace_period();
141
142 /*
143 * The main request loop. We don't terminate until the last
d751a7cd 144 * NFS mount or NFS daemon has gone away.
1da177e4 145 */
d751a7cd 146 while (!kthread_should_stop()) {
1da177e4 147 long timeout = MAX_SCHEDULE_TIMEOUT;
5216a8e7 148 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
1da177e4
LT
149
150 if (signalled()) {
151 flush_signals(current);
152 if (nlmsvc_ops) {
153 nlmsvc_invalidate_all();
154 grace_period_expire = set_grace_period();
155 }
d751a7cd 156 continue;
1da177e4
LT
157 }
158
159 /*
160 * Retry any blocked locks that have been notified by
161 * the VFS. Don't do this during grace period.
162 * (Theoretically, there shouldn't even be blocked locks
163 * during grace period).
164 */
165 if (!nlmsvc_grace_period) {
166 timeout = nlmsvc_retry_blocked();
167 } else if (time_before(grace_period_expire, jiffies))
168 clear_grace_period();
169
170 /*
171 * Find a socket with data available and call its
172 * recvfrom routine.
173 */
6fb2b47f 174 err = svc_recv(rqstp, timeout);
1da177e4
LT
175 if (err == -EAGAIN || err == -EINTR)
176 continue;
177 if (err < 0) {
178 printk(KERN_WARNING
179 "lockd: terminating on error %d\n",
180 -err);
181 break;
182 }
183
ad06e4bd
CL
184 dprintk("lockd: request from %s\n",
185 svc_print_addr(rqstp, buf, sizeof(buf)));
1da177e4 186
6fb2b47f 187 svc_process(rqstp);
1da177e4
LT
188 }
189
2bd61579 190 flush_signals(current);
d751a7cd
JL
191 if (nlmsvc_ops)
192 nlmsvc_invalidate_all();
193 nlm_shutdown_hosts();
2bd61579 194
d751a7cd
JL
195 unlock_kernel();
196
197 nlmsvc_task = NULL;
198 nlmsvc_serv = NULL;
46be925f 199
1da177e4
LT
200 /* Exit the RPC thread */
201 svc_exit_thread(rqstp);
202
d751a7cd 203 return 0;
1da177e4
LT
204}
205
482fb94e
CL
206/*
207 * Make any sockets that are needed but not present.
208 * If nlm_udpport or nlm_tcpport were set as module
209 * options, make those sockets unconditionally
210 */
24e36663
N
211static int make_socks(struct svc_serv *serv, int proto)
212{
482fb94e 213 static int warned;
a217813f 214 struct svc_xprt *xprt;
24e36663 215 int err = 0;
482fb94e 216
a217813f
TT
217 if (proto == IPPROTO_UDP || nlm_udpport) {
218 xprt = svc_find_xprt(serv, "udp", 0, 0);
219 if (!xprt)
d7c9f1ed
TT
220 err = svc_create_xprt(serv, "udp", nlm_udpport,
221 SVC_SOCK_DEFAULTS);
a217813f
TT
222 else
223 svc_xprt_put(xprt);
224 }
225 if (err >= 0 && (proto == IPPROTO_TCP || nlm_tcpport)) {
226 xprt = svc_find_xprt(serv, "tcp", 0, 0);
227 if (!xprt)
d7c9f1ed
TT
228 err = svc_create_xprt(serv, "tcp", nlm_tcpport,
229 SVC_SOCK_DEFAULTS);
a217813f
TT
230 else
231 svc_xprt_put(xprt);
232 }
482fb94e 233 if (err >= 0) {
7dcf91ec 234 warned = 0;
482fb94e
CL
235 err = 0;
236 } else if (warned++ == 0)
7dcf91ec
N
237 printk(KERN_WARNING
238 "lockd_up: makesock failed, error=%d\n", err);
24e36663
N
239 return err;
240}
241
1da177e4
LT
242/*
243 * Bring up the lockd process if it's not already up.
244 */
245int
24e36663 246lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
1da177e4 247{
d751a7cd
JL
248 struct svc_serv *serv;
249 struct svc_rqst *rqstp;
250 int error = 0;
1da177e4 251
353ab6e9 252 mutex_lock(&nlmsvc_mutex);
1da177e4
LT
253 /*
254 * Check whether we're already up and running.
255 */
d751a7cd 256 if (nlmsvc_serv) {
4a3ae42d
N
257 if (proto)
258 error = make_socks(nlmsvc_serv, proto);
1da177e4 259 goto out;
24e36663 260 }
1da177e4
LT
261
262 /*
263 * Sanity check: if there's no pid,
264 * we should be the first user ...
265 */
4a3ae42d 266 if (nlmsvc_users)
1da177e4
LT
267 printk(KERN_WARNING
268 "lockd_up: no pid, %d users??\n", nlmsvc_users);
269
270 error = -ENOMEM;
bc591ccf 271 serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL);
1da177e4
LT
272 if (!serv) {
273 printk(KERN_WARNING "lockd_up: create service failed\n");
274 goto out;
275 }
276
7dcf91ec 277 if ((error = make_socks(serv, proto)) < 0)
1da177e4 278 goto destroy_and_out;
1da177e4
LT
279
280 /*
281 * Create the kernel thread and wait for it to start.
282 */
d751a7cd
JL
283 rqstp = svc_prepare_thread(serv, &serv->sv_pools[0]);
284 if (IS_ERR(rqstp)) {
285 error = PTR_ERR(rqstp);
286 printk(KERN_WARNING
287 "lockd_up: svc_rqst allocation failed, error=%d\n",
288 error);
289 goto destroy_and_out;
290 }
291
292 svc_sock_update_bufs(serv);
293 nlmsvc_serv = rqstp->rq_server;
294
295 nlmsvc_task = kthread_run(lockd, rqstp, serv->sv_name);
296 if (IS_ERR(nlmsvc_task)) {
297 error = PTR_ERR(nlmsvc_task);
298 nlmsvc_task = NULL;
299 nlmsvc_serv = NULL;
1da177e4 300 printk(KERN_WARNING
d751a7cd
JL
301 "lockd_up: kthread_run failed, error=%d\n", error);
302 svc_exit_thread(rqstp);
1da177e4
LT
303 goto destroy_and_out;
304 }
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{
353ab6e9 326 mutex_lock(&nlmsvc_mutex);
1da177e4
LT
327 if (nlmsvc_users) {
328 if (--nlmsvc_users)
329 goto out;
d751a7cd
JL
330 } else {
331 printk(KERN_ERR "lockd_down: no users! task=%p\n",
332 nlmsvc_task);
333 BUG();
1da177e4 334 }
1da177e4 335
d751a7cd
JL
336 if (!nlmsvc_task) {
337 printk(KERN_ERR "lockd_down: no lockd running.\n");
338 BUG();
1da177e4 339 }
d751a7cd 340 kthread_stop(nlmsvc_task);
1da177e4 341out:
353ab6e9 342 mutex_unlock(&nlmsvc_mutex);
1da177e4
LT
343}
344EXPORT_SYMBOL(lockd_down);
345
346/*
347 * Sysctl parameters (same as module parameters, different interface).
348 */
349
1da177e4
LT
350static ctl_table nlm_sysctls[] = {
351 {
352 .ctl_name = CTL_UNNUMBERED,
353 .procname = "nlm_grace_period",
354 .data = &nlm_grace_period,
7ee91ec1 355 .maxlen = sizeof(unsigned long),
1da177e4
LT
356 .mode = 0644,
357 .proc_handler = &proc_doulongvec_minmax,
358 .extra1 = (unsigned long *) &nlm_grace_period_min,
359 .extra2 = (unsigned long *) &nlm_grace_period_max,
360 },
361 {
362 .ctl_name = CTL_UNNUMBERED,
363 .procname = "nlm_timeout",
364 .data = &nlm_timeout,
7ee91ec1 365 .maxlen = sizeof(unsigned long),
1da177e4
LT
366 .mode = 0644,
367 .proc_handler = &proc_doulongvec_minmax,
368 .extra1 = (unsigned long *) &nlm_timeout_min,
369 .extra2 = (unsigned long *) &nlm_timeout_max,
370 },
371 {
372 .ctl_name = CTL_UNNUMBERED,
373 .procname = "nlm_udpport",
374 .data = &nlm_udpport,
375 .maxlen = sizeof(int),
376 .mode = 0644,
377 .proc_handler = &proc_dointvec_minmax,
378 .extra1 = (int *) &nlm_port_min,
379 .extra2 = (int *) &nlm_port_max,
380 },
381 {
382 .ctl_name = CTL_UNNUMBERED,
383 .procname = "nlm_tcpport",
384 .data = &nlm_tcpport,
385 .maxlen = sizeof(int),
386 .mode = 0644,
387 .proc_handler = &proc_dointvec_minmax,
388 .extra1 = (int *) &nlm_port_min,
389 .extra2 = (int *) &nlm_port_max,
390 },
abd1f500
OK
391 {
392 .ctl_name = CTL_UNNUMBERED,
393 .procname = "nsm_use_hostnames",
394 .data = &nsm_use_hostnames,
395 .maxlen = sizeof(int),
396 .mode = 0644,
397 .proc_handler = &proc_dointvec,
398 },
460f5cac
OK
399 {
400 .ctl_name = CTL_UNNUMBERED,
401 .procname = "nsm_local_state",
402 .data = &nsm_local_state,
403 .maxlen = sizeof(int),
404 .mode = 0644,
405 .proc_handler = &proc_dointvec,
406 },
1da177e4
LT
407 { .ctl_name = 0 }
408};
409
410static ctl_table nlm_sysctl_dir[] = {
411 {
412 .ctl_name = CTL_UNNUMBERED,
413 .procname = "nfs",
414 .mode = 0555,
415 .child = nlm_sysctls,
416 },
417 { .ctl_name = 0 }
418};
419
420static ctl_table nlm_sysctl_root[] = {
421 {
422 .ctl_name = CTL_FS,
423 .procname = "fs",
424 .mode = 0555,
425 .child = nlm_sysctl_dir,
426 },
427 { .ctl_name = 0 }
428};
429
430/*
405ae7d3 431 * Module (and sysfs) parameters.
1da177e4
LT
432 */
433
434#define param_set_min_max(name, type, which_strtol, min, max) \
435static int param_set_##name(const char *val, struct kernel_param *kp) \
436{ \
437 char *endp; \
438 __typeof__(type) num = which_strtol(val, &endp, 0); \
439 if (endp == val || *endp || num < (min) || num > (max)) \
440 return -EINVAL; \
441 *((int *) kp->arg) = num; \
442 return 0; \
443}
444
445static inline int is_callback(u32 proc)
446{
447 return proc == NLMPROC_GRANTED
448 || proc == NLMPROC_GRANTED_MSG
449 || proc == NLMPROC_TEST_RES
450 || proc == NLMPROC_LOCK_RES
451 || proc == NLMPROC_CANCEL_RES
452 || proc == NLMPROC_UNLOCK_RES
453 || proc == NLMPROC_NSM_NOTIFY;
454}
455
456
457static int lockd_authenticate(struct svc_rqst *rqstp)
458{
459 rqstp->rq_client = NULL;
460 switch (rqstp->rq_authop->flavour) {
461 case RPC_AUTH_NULL:
462 case RPC_AUTH_UNIX:
463 if (rqstp->rq_proc == 0)
464 return SVC_OK;
465 if (is_callback(rqstp->rq_proc)) {
466 /* Leave it to individual procedures to
467 * call nlmsvc_lookup_host(rqstp)
468 */
469 return SVC_OK;
470 }
471 return svc_set_client(rqstp);
472 }
473 return SVC_DENIED;
474}
475
476
477param_set_min_max(port, int, simple_strtol, 0, 65535)
478param_set_min_max(grace_period, unsigned long, simple_strtoul,
479 nlm_grace_period_min, nlm_grace_period_max)
480param_set_min_max(timeout, unsigned long, simple_strtoul,
481 nlm_timeout_min, nlm_timeout_max)
482
483MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
484MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
485MODULE_LICENSE("GPL");
486
487module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
488 &nlm_grace_period, 0644);
489module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
490 &nlm_timeout, 0644);
491module_param_call(nlm_udpport, param_set_port, param_get_int,
492 &nlm_udpport, 0644);
493module_param_call(nlm_tcpport, param_set_port, param_get_int,
494 &nlm_tcpport, 0644);
abd1f500 495module_param(nsm_use_hostnames, bool, 0644);
1da177e4
LT
496
497/*
498 * Initialising and terminating the module.
499 */
500
501static int __init init_nlm(void)
502{
0b4d4147 503 nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
1da177e4
LT
504 return nlm_sysctl_table ? 0 : -ENOMEM;
505}
506
507static void __exit exit_nlm(void)
508{
509 /* FIXME: delete all NLM clients */
510 nlm_shutdown_hosts();
511 unregister_sysctl_table(nlm_sysctl_table);
512}
513
514module_init(init_nlm);
515module_exit(exit_nlm);
516
517/*
518 * Define NLM program and procedures
519 */
520static struct svc_version nlmsvc_version1 = {
521 .vs_vers = 1,
522 .vs_nproc = 17,
523 .vs_proc = nlmsvc_procedures,
524 .vs_xdrsize = NLMSVC_XDRSIZE,
525};
526static struct svc_version nlmsvc_version3 = {
527 .vs_vers = 3,
528 .vs_nproc = 24,
529 .vs_proc = nlmsvc_procedures,
530 .vs_xdrsize = NLMSVC_XDRSIZE,
531};
532#ifdef CONFIG_LOCKD_V4
533static struct svc_version nlmsvc_version4 = {
534 .vs_vers = 4,
535 .vs_nproc = 24,
536 .vs_proc = nlmsvc_procedures4,
537 .vs_xdrsize = NLMSVC_XDRSIZE,
538};
539#endif
540static struct svc_version * nlmsvc_version[] = {
541 [1] = &nlmsvc_version1,
542 [3] = &nlmsvc_version3,
543#ifdef CONFIG_LOCKD_V4
544 [4] = &nlmsvc_version4,
545#endif
546};
547
548static struct svc_stat nlmsvc_stats;
549
e8c96f8c 550#define NLM_NRVERS ARRAY_SIZE(nlmsvc_version)
1da177e4
LT
551static struct svc_program nlmsvc_program = {
552 .pg_prog = NLM_PROGRAM, /* program number */
553 .pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */
554 .pg_vers = nlmsvc_version, /* version table */
555 .pg_name = "lockd", /* service name */
556 .pg_class = "nfsd", /* share authentication with nfsd */
557 .pg_stats = &nlmsvc_stats, /* stats table */
558 .pg_authenticate = &lockd_authenticate /* export authentication */
559};