nfsd4: check for negative dentry before use in nfsv4 readdir
[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
LT
37#include <linux/lockd/lockd.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
44static struct svc_program nlmsvc_program;
45
46struct nlmsvc_binding * nlmsvc_ops;
2de59872 47EXPORT_SYMBOL_GPL(nlmsvc_ops);
1da177e4 48
353ab6e9 49static DEFINE_MUTEX(nlmsvc_mutex);
1da177e4 50static unsigned int nlmsvc_users;
d751a7cd 51static struct task_struct *nlmsvc_task;
abd1ec4e 52static struct svc_rqst *nlmsvc_rqst;
1da177e4
LT
53unsigned long nlmsvc_timeout;
54
1da177e4
LT
55/*
56 * These can be set at insmod time (useful for NFS as root filesystem),
57 * and also changed through the sysctl interface. -- Jamie Lokier, Aug 2003
58 */
59static unsigned long nlm_grace_period;
60static unsigned long nlm_timeout = LOCKD_DFLT_TIMEO;
61static int nlm_udpport, nlm_tcpport;
62
c72a476b
JL
63/* RLIM_NOFILE defaults to 1024. That seems like a reasonable default here. */
64static unsigned int nlm_max_connections = 1024;
65
1da177e4
LT
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
af558e33
BF
88static struct lock_manager lockd_manager = {
89};
9a8db97e 90
c8ab5f2a 91static void grace_ender(struct work_struct *not_used)
9a8db97e 92{
af558e33 93 locks_end_grace(&lockd_manager);
1da177e4
LT
94}
95
c8ab5f2a
BF
96static DECLARE_DELAYED_WORK(grace_period_end, grace_ender);
97
98static void set_grace_period(void)
1da177e4 99{
af558e33 100 unsigned long grace_period = get_lockd_grace_period();
c8ab5f2a 101
af558e33 102 locks_start_grace(&lockd_manager);
c8ab5f2a
BF
103 cancel_delayed_work_sync(&grace_period_end);
104 schedule_delayed_work(&grace_period_end, grace_period);
1da177e4
LT
105}
106
107/*
108 * This is the lockd kernel thread
109 */
d751a7cd
JL
110static int
111lockd(void *vrqstp)
1da177e4 112{
f97c650d 113 int err = 0, preverr = 0;
d751a7cd 114 struct svc_rqst *rqstp = vrqstp;
1da177e4 115
d751a7cd 116 /* try_to_freeze() is called from svc_recv() */
83144186 117 set_freezable();
1da177e4 118
d751a7cd 119 /* Allow SIGKILL to tell lockd to drop all of its locks */
1da177e4
LT
120 allow_signal(SIGKILL);
121
1da177e4
LT
122 dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
123
d751a7cd
JL
124 /*
125 * FIXME: it would be nice if lockd didn't spend its entire life
126 * running under the BKL. At the very least, it would be good to
127 * have someone clarify what it's intended to protect here. I've
128 * seen some handwavy posts about posix locking needing to be
129 * done under the BKL, but it's far from clear.
130 */
131 lock_kernel();
132
1da177e4
LT
133 if (!nlm_timeout)
134 nlm_timeout = LOCKD_DFLT_TIMEO;
135 nlmsvc_timeout = nlm_timeout * HZ;
136
c8ab5f2a 137 set_grace_period();
1da177e4
LT
138
139 /*
140 * The main request loop. We don't terminate until the last
d751a7cd 141 * NFS mount or NFS daemon has gone away.
1da177e4 142 */
d751a7cd 143 while (!kthread_should_stop()) {
1da177e4 144 long timeout = MAX_SCHEDULE_TIMEOUT;
5216a8e7 145 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
1da177e4 146
c72a476b
JL
147 /* update sv_maxconn if it has changed */
148 rqstp->rq_server->sv_maxconn = nlm_max_connections;
149
1da177e4
LT
150 if (signalled()) {
151 flush_signals(current);
152 if (nlmsvc_ops) {
153 nlmsvc_invalidate_all();
c8ab5f2a 154 set_grace_period();
1da177e4 155 }
d751a7cd 156 continue;
1da177e4
LT
157 }
158
8fafa900
BF
159 timeout = nlmsvc_retry_blocked();
160
1da177e4
LT
161 /*
162 * Find a socket with data available and call its
163 * recvfrom routine.
164 */
6fb2b47f 165 err = svc_recv(rqstp, timeout);
f97c650d
JL
166 if (err == -EAGAIN || err == -EINTR) {
167 preverr = err;
1da177e4 168 continue;
f97c650d 169 }
1da177e4 170 if (err < 0) {
f97c650d
JL
171 if (err != preverr) {
172 printk(KERN_WARNING "%s: unexpected error "
173 "from svc_recv (%d)\n", __func__, err);
174 preverr = err;
175 }
176 schedule_timeout_interruptible(HZ);
177 continue;
1da177e4 178 }
f97c650d 179 preverr = err;
1da177e4 180
ad06e4bd
CL
181 dprintk("lockd: request from %s\n",
182 svc_print_addr(rqstp, buf, sizeof(buf)));
1da177e4 183
6fb2b47f 184 svc_process(rqstp);
1da177e4 185 }
2bd61579 186 flush_signals(current);
c8ab5f2a 187 cancel_delayed_work_sync(&grace_period_end);
2c5e7615 188 locks_end_grace(&lockd_manager);
d751a7cd
JL
189 if (nlmsvc_ops)
190 nlmsvc_invalidate_all();
191 nlm_shutdown_hosts();
d751a7cd 192 unlock_kernel();
d751a7cd 193 return 0;
1da177e4
LT
194}
195
eb16e907
CL
196static int create_lockd_listener(struct svc_serv *serv, const char *name,
197 const int family, const unsigned short port)
d3fe5ea7
CL
198{
199 struct svc_xprt *xprt;
200
eb16e907 201 xprt = svc_find_xprt(serv, name, family, 0);
d3fe5ea7 202 if (xprt == NULL)
eb16e907
CL
203 return svc_create_xprt(serv, name, family, port,
204 SVC_SOCK_DEFAULTS);
d3fe5ea7
CL
205 svc_xprt_put(xprt);
206 return 0;
207}
208
eb16e907
CL
209static int create_lockd_family(struct svc_serv *serv, const int family)
210{
211 int err;
212
213 err = create_lockd_listener(serv, "udp", family, nlm_udpport);
214 if (err < 0)
215 return err;
216
217 return create_lockd_listener(serv, "tcp", family, nlm_tcpport);
218}
219
482fb94e 220/*
8c3916f4
CL
221 * Ensure there are active UDP and TCP listeners for lockd.
222 *
223 * Even if we have only TCP NFS mounts and/or TCP NFSDs, some
224 * local services (such as rpc.statd) still require UDP, and
225 * some NFS servers do not yet support NLM over TCP.
226 *
227 * Returns zero if all listeners are available; otherwise a
228 * negative errno value is returned.
482fb94e 229 */
8c3916f4 230static int make_socks(struct svc_serv *serv)
24e36663 231{
482fb94e 232 static int warned;
0dba7c2a 233 int err;
482fb94e 234
eb16e907 235 err = create_lockd_family(serv, PF_INET);
0dba7c2a
CL
236 if (err < 0)
237 goto out_err;
238
eb16e907
CL
239#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
240 err = create_lockd_family(serv, PF_INET6);
241 if (err < 0 && err != -EAFNOSUPPORT)
0dba7c2a 242 goto out_err;
eb16e907 243#endif /* CONFIG_IPV6 || CONFIG_IPV6_MODULE */
0dba7c2a
CL
244
245 warned = 0;
246 return 0;
247
248out_err:
249 if (warned++ == 0)
7dcf91ec 250 printk(KERN_WARNING
0dba7c2a 251 "lockd_up: makesock failed, error=%d\n", err);
24e36663
N
252 return err;
253}
254
1da177e4
LT
255/*
256 * Bring up the lockd process if it's not already up.
257 */
26a41409 258int lockd_up(void)
1da177e4 259{
d751a7cd 260 struct svc_serv *serv;
d751a7cd 261 int error = 0;
1da177e4 262
353ab6e9 263 mutex_lock(&nlmsvc_mutex);
1da177e4
LT
264 /*
265 * Check whether we're already up and running.
266 */
8c3916f4 267 if (nlmsvc_rqst)
1da177e4
LT
268 goto out;
269
270 /*
271 * Sanity check: if there's no pid,
272 * we should be the first user ...
273 */
4a3ae42d 274 if (nlmsvc_users)
1da177e4
LT
275 printk(KERN_WARNING
276 "lockd_up: no pid, %d users??\n", nlmsvc_users);
277
278 error = -ENOMEM;
49a9072f 279 serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL);
1da177e4
LT
280 if (!serv) {
281 printk(KERN_WARNING "lockd_up: create service failed\n");
282 goto out;
283 }
284
8c3916f4
CL
285 error = make_socks(serv);
286 if (error < 0)
1da177e4 287 goto destroy_and_out;
1da177e4
LT
288
289 /*
290 * Create the kernel thread and wait for it to start.
291 */
abd1ec4e
JL
292 nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0]);
293 if (IS_ERR(nlmsvc_rqst)) {
294 error = PTR_ERR(nlmsvc_rqst);
295 nlmsvc_rqst = NULL;
d751a7cd
JL
296 printk(KERN_WARNING
297 "lockd_up: svc_rqst allocation failed, error=%d\n",
298 error);
299 goto destroy_and_out;
300 }
301
302 svc_sock_update_bufs(serv);
c72a476b 303 serv->sv_maxconn = nlm_max_connections;
d751a7cd 304
abd1ec4e 305 nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, serv->sv_name);
d751a7cd
JL
306 if (IS_ERR(nlmsvc_task)) {
307 error = PTR_ERR(nlmsvc_task);
abd1ec4e 308 svc_exit_thread(nlmsvc_rqst);
d751a7cd 309 nlmsvc_task = NULL;
abd1ec4e 310 nlmsvc_rqst = NULL;
1da177e4 311 printk(KERN_WARNING
d751a7cd 312 "lockd_up: kthread_run failed, error=%d\n", error);
1da177e4
LT
313 goto destroy_and_out;
314 }
1da177e4
LT
315
316 /*
317 * Note: svc_serv structures have an initial use count of 1,
318 * so we exit through here on both success and failure.
319 */
320destroy_and_out:
321 svc_destroy(serv);
322out:
4a3ae42d
N
323 if (!error)
324 nlmsvc_users++;
353ab6e9 325 mutex_unlock(&nlmsvc_mutex);
1da177e4
LT
326 return error;
327}
2de59872 328EXPORT_SYMBOL_GPL(lockd_up);
1da177e4
LT
329
330/*
331 * Decrement the user count and bring down lockd if we're the last.
332 */
333void
334lockd_down(void)
335{
353ab6e9 336 mutex_lock(&nlmsvc_mutex);
1da177e4
LT
337 if (nlmsvc_users) {
338 if (--nlmsvc_users)
339 goto out;
d751a7cd
JL
340 } else {
341 printk(KERN_ERR "lockd_down: no users! task=%p\n",
342 nlmsvc_task);
343 BUG();
1da177e4 344 }
1da177e4 345
d751a7cd
JL
346 if (!nlmsvc_task) {
347 printk(KERN_ERR "lockd_down: no lockd running.\n");
348 BUG();
1da177e4 349 }
d751a7cd 350 kthread_stop(nlmsvc_task);
abd1ec4e
JL
351 svc_exit_thread(nlmsvc_rqst);
352 nlmsvc_task = NULL;
353 nlmsvc_rqst = NULL;
1da177e4 354out:
353ab6e9 355 mutex_unlock(&nlmsvc_mutex);
1da177e4 356}
2de59872 357EXPORT_SYMBOL_GPL(lockd_down);
1da177e4 358
90d5b180
CL
359#ifdef CONFIG_SYSCTL
360
1da177e4
LT
361/*
362 * Sysctl parameters (same as module parameters, different interface).
363 */
364
1da177e4
LT
365static ctl_table nlm_sysctls[] = {
366 {
367 .ctl_name = CTL_UNNUMBERED,
368 .procname = "nlm_grace_period",
369 .data = &nlm_grace_period,
7ee91ec1 370 .maxlen = sizeof(unsigned long),
1da177e4
LT
371 .mode = 0644,
372 .proc_handler = &proc_doulongvec_minmax,
373 .extra1 = (unsigned long *) &nlm_grace_period_min,
374 .extra2 = (unsigned long *) &nlm_grace_period_max,
375 },
376 {
377 .ctl_name = CTL_UNNUMBERED,
378 .procname = "nlm_timeout",
379 .data = &nlm_timeout,
7ee91ec1 380 .maxlen = sizeof(unsigned long),
1da177e4
LT
381 .mode = 0644,
382 .proc_handler = &proc_doulongvec_minmax,
383 .extra1 = (unsigned long *) &nlm_timeout_min,
384 .extra2 = (unsigned long *) &nlm_timeout_max,
385 },
386 {
387 .ctl_name = CTL_UNNUMBERED,
388 .procname = "nlm_udpport",
389 .data = &nlm_udpport,
390 .maxlen = sizeof(int),
391 .mode = 0644,
392 .proc_handler = &proc_dointvec_minmax,
393 .extra1 = (int *) &nlm_port_min,
394 .extra2 = (int *) &nlm_port_max,
395 },
396 {
397 .ctl_name = CTL_UNNUMBERED,
398 .procname = "nlm_tcpport",
399 .data = &nlm_tcpport,
400 .maxlen = sizeof(int),
401 .mode = 0644,
402 .proc_handler = &proc_dointvec_minmax,
403 .extra1 = (int *) &nlm_port_min,
404 .extra2 = (int *) &nlm_port_max,
405 },
abd1f500
OK
406 {
407 .ctl_name = CTL_UNNUMBERED,
408 .procname = "nsm_use_hostnames",
409 .data = &nsm_use_hostnames,
410 .maxlen = sizeof(int),
411 .mode = 0644,
412 .proc_handler = &proc_dointvec,
413 },
460f5cac
OK
414 {
415 .ctl_name = CTL_UNNUMBERED,
416 .procname = "nsm_local_state",
417 .data = &nsm_local_state,
418 .maxlen = sizeof(int),
419 .mode = 0644,
420 .proc_handler = &proc_dointvec,
421 },
1da177e4
LT
422 { .ctl_name = 0 }
423};
424
425static ctl_table nlm_sysctl_dir[] = {
426 {
427 .ctl_name = CTL_UNNUMBERED,
428 .procname = "nfs",
429 .mode = 0555,
430 .child = nlm_sysctls,
431 },
432 { .ctl_name = 0 }
433};
434
435static ctl_table nlm_sysctl_root[] = {
436 {
437 .ctl_name = CTL_FS,
438 .procname = "fs",
439 .mode = 0555,
440 .child = nlm_sysctl_dir,
441 },
442 { .ctl_name = 0 }
443};
444
90d5b180
CL
445#endif /* CONFIG_SYSCTL */
446
1da177e4 447/*
405ae7d3 448 * Module (and sysfs) parameters.
1da177e4
LT
449 */
450
451#define param_set_min_max(name, type, which_strtol, min, max) \
452static int param_set_##name(const char *val, struct kernel_param *kp) \
453{ \
454 char *endp; \
455 __typeof__(type) num = which_strtol(val, &endp, 0); \
456 if (endp == val || *endp || num < (min) || num > (max)) \
457 return -EINVAL; \
458 *((int *) kp->arg) = num; \
459 return 0; \
460}
461
462static inline int is_callback(u32 proc)
463{
464 return proc == NLMPROC_GRANTED
465 || proc == NLMPROC_GRANTED_MSG
466 || proc == NLMPROC_TEST_RES
467 || proc == NLMPROC_LOCK_RES
468 || proc == NLMPROC_CANCEL_RES
469 || proc == NLMPROC_UNLOCK_RES
470 || proc == NLMPROC_NSM_NOTIFY;
471}
472
473
474static int lockd_authenticate(struct svc_rqst *rqstp)
475{
476 rqstp->rq_client = NULL;
477 switch (rqstp->rq_authop->flavour) {
478 case RPC_AUTH_NULL:
479 case RPC_AUTH_UNIX:
480 if (rqstp->rq_proc == 0)
481 return SVC_OK;
482 if (is_callback(rqstp->rq_proc)) {
483 /* Leave it to individual procedures to
484 * call nlmsvc_lookup_host(rqstp)
485 */
486 return SVC_OK;
487 }
488 return svc_set_client(rqstp);
489 }
490 return SVC_DENIED;
491}
492
493
494param_set_min_max(port, int, simple_strtol, 0, 65535)
495param_set_min_max(grace_period, unsigned long, simple_strtoul,
496 nlm_grace_period_min, nlm_grace_period_max)
497param_set_min_max(timeout, unsigned long, simple_strtoul,
498 nlm_timeout_min, nlm_timeout_max)
499
500MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
501MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
502MODULE_LICENSE("GPL");
503
504module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
505 &nlm_grace_period, 0644);
506module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
507 &nlm_timeout, 0644);
508module_param_call(nlm_udpport, param_set_port, param_get_int,
509 &nlm_udpport, 0644);
510module_param_call(nlm_tcpport, param_set_port, param_get_int,
511 &nlm_tcpport, 0644);
abd1f500 512module_param(nsm_use_hostnames, bool, 0644);
c72a476b 513module_param(nlm_max_connections, uint, 0644);
1da177e4
LT
514
515/*
516 * Initialising and terminating the module.
517 */
518
519static int __init init_nlm(void)
520{
90d5b180 521#ifdef CONFIG_SYSCTL
0b4d4147 522 nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
1da177e4 523 return nlm_sysctl_table ? 0 : -ENOMEM;
90d5b180
CL
524#else
525 return 0;
526#endif
1da177e4
LT
527}
528
529static void __exit exit_nlm(void)
530{
531 /* FIXME: delete all NLM clients */
532 nlm_shutdown_hosts();
90d5b180 533#ifdef CONFIG_SYSCTL
1da177e4 534 unregister_sysctl_table(nlm_sysctl_table);
90d5b180 535#endif
1da177e4
LT
536}
537
538module_init(init_nlm);
539module_exit(exit_nlm);
540
541/*
542 * Define NLM program and procedures
543 */
544static struct svc_version nlmsvc_version1 = {
545 .vs_vers = 1,
546 .vs_nproc = 17,
547 .vs_proc = nlmsvc_procedures,
548 .vs_xdrsize = NLMSVC_XDRSIZE,
549};
550static struct svc_version nlmsvc_version3 = {
551 .vs_vers = 3,
552 .vs_nproc = 24,
553 .vs_proc = nlmsvc_procedures,
554 .vs_xdrsize = NLMSVC_XDRSIZE,
555};
556#ifdef CONFIG_LOCKD_V4
557static struct svc_version nlmsvc_version4 = {
558 .vs_vers = 4,
559 .vs_nproc = 24,
560 .vs_proc = nlmsvc_procedures4,
561 .vs_xdrsize = NLMSVC_XDRSIZE,
562};
563#endif
564static struct svc_version * nlmsvc_version[] = {
565 [1] = &nlmsvc_version1,
566 [3] = &nlmsvc_version3,
567#ifdef CONFIG_LOCKD_V4
568 [4] = &nlmsvc_version4,
569#endif
570};
571
572static struct svc_stat nlmsvc_stats;
573
e8c96f8c 574#define NLM_NRVERS ARRAY_SIZE(nlmsvc_version)
1da177e4
LT
575static struct svc_program nlmsvc_program = {
576 .pg_prog = NLM_PROGRAM, /* program number */
577 .pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */
578 .pg_vers = nlmsvc_version, /* version table */
579 .pg_name = "lockd", /* service name */
580 .pg_class = "nfsd", /* share authentication with nfsd */
581 .pg_stats = &nlmsvc_stats, /* stats table */
582 .pg_authenticate = &lockd_authenticate /* export authentication */
583};