5bd9bf0fa9df09121f8c190d7e47ec8ef7871ede
[linux-2.6.git] / fs / lockd / svc.c
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/kthread.h>
29 #include <linux/freezer.h>
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>
36 #include <net/ip.h>
37 #include <linux/lockd/lockd.h>
38 #include <linux/lockd/sm_inter.h>
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
45 static struct svc_program       nlmsvc_program;
46
47 struct nlmsvc_binding *         nlmsvc_ops;
48 EXPORT_SYMBOL(nlmsvc_ops);
49
50 static DEFINE_MUTEX(nlmsvc_mutex);
51 static unsigned int             nlmsvc_users;
52 static struct task_struct       *nlmsvc_task;
53 static struct svc_rqst          *nlmsvc_rqst;
54 int                             nlmsvc_grace_period;
55 unsigned long                   nlmsvc_timeout;
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  */
61 static unsigned long            nlm_grace_period;
62 static unsigned long            nlm_timeout = LOCKD_DFLT_TIMEO;
63 static int                      nlm_udpport, nlm_tcpport;
64 int                             nsm_use_hostnames = 0;
65
66 /*
67  * Constants needed for the sysctl interface.
68  */
69 static const unsigned long      nlm_grace_period_min = 0;
70 static const unsigned long      nlm_grace_period_max = 240;
71 static const unsigned long      nlm_timeout_min = 3;
72 static const unsigned long      nlm_timeout_max = 20;
73 static const int                nlm_port_min = 0, nlm_port_max = 65535;
74
75 #ifdef CONFIG_SYSCTL
76 static struct ctl_table_header * nlm_sysctl_table;
77 #endif
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 int
115 lockd(void *vrqstp)
116 {
117         int             err = 0, preverr = 0;
118         struct svc_rqst *rqstp = vrqstp;
119         unsigned long grace_period_expire;
120
121         /* try_to_freeze() is called from svc_recv() */
122         set_freezable();
123
124         /* Allow SIGKILL to tell lockd to drop all of its locks */
125         allow_signal(SIGKILL);
126
127         dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
128
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
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
146          * NFS mount or NFS daemon has gone away.
147          */
148         while (!kthread_should_stop()) {
149                 long timeout = MAX_SCHEDULE_TIMEOUT;
150                 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
151
152                 if (signalled()) {
153                         flush_signals(current);
154                         if (nlmsvc_ops) {
155                                 nlmsvc_invalidate_all();
156                                 grace_period_expire = set_grace_period();
157                         }
158                         continue;
159                 }
160
161                 /*
162                  * Retry any blocked locks that have been notified by
163                  * the VFS. Don't do this during grace period.
164                  * (Theoretically, there shouldn't even be blocked locks
165                  * during grace period).
166                  */
167                 if (!nlmsvc_grace_period) {
168                         timeout = nlmsvc_retry_blocked();
169                 } else if (time_before(grace_period_expire, jiffies))
170                         clear_grace_period();
171
172                 /*
173                  * Find a socket with data available and call its
174                  * recvfrom routine.
175                  */
176                 err = svc_recv(rqstp, timeout);
177                 if (err == -EAGAIN || err == -EINTR) {
178                         preverr = err;
179                         continue;
180                 }
181                 if (err < 0) {
182                         if (err != preverr) {
183                                 printk(KERN_WARNING "%s: unexpected error "
184                                         "from svc_recv (%d)\n", __func__, err);
185                                 preverr = err;
186                         }
187                         schedule_timeout_interruptible(HZ);
188                         continue;
189                 }
190                 preverr = err;
191
192                 dprintk("lockd: request from %s\n",
193                                 svc_print_addr(rqstp, buf, sizeof(buf)));
194
195                 svc_process(rqstp);
196         }
197         flush_signals(current);
198         if (nlmsvc_ops)
199                 nlmsvc_invalidate_all();
200         nlm_shutdown_hosts();
201         unlock_kernel();
202         return 0;
203 }
204
205 /*
206  * Make any sockets that are needed but not present.
207  * If nlm_udpport or nlm_tcpport were set as module
208  * options, make those sockets unconditionally
209  */
210 static int make_socks(struct svc_serv *serv, int proto)
211 {
212         static int warned;
213         struct svc_xprt *xprt;
214         int err = 0;
215
216         if (proto == IPPROTO_UDP || nlm_udpport) {
217                 xprt = svc_find_xprt(serv, "udp", 0, 0);
218                 if (!xprt)
219                         err = svc_create_xprt(serv, "udp", nlm_udpport,
220                                               SVC_SOCK_DEFAULTS);
221                 else
222                         svc_xprt_put(xprt);
223         }
224         if (err >= 0 && (proto == IPPROTO_TCP || nlm_tcpport)) {
225                 xprt = svc_find_xprt(serv, "tcp", 0, 0);
226                 if (!xprt)
227                         err = svc_create_xprt(serv, "tcp", nlm_tcpport,
228                                               SVC_SOCK_DEFAULTS);
229                 else
230                         svc_xprt_put(xprt);
231         }
232         if (err >= 0) {
233                 warned = 0;
234                 err = 0;
235         } else if (warned++ == 0)
236                 printk(KERN_WARNING
237                        "lockd_up: makesock failed, error=%d\n", err);
238         return err;
239 }
240
241 /*
242  * Bring up the lockd process if it's not already up.
243  */
244 int
245 lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
246 {
247         struct svc_serv *serv;
248         int             error = 0;
249
250         mutex_lock(&nlmsvc_mutex);
251         /*
252          * Check whether we're already up and running.
253          */
254         if (nlmsvc_rqst) {
255                 if (proto)
256                         error = make_socks(nlmsvc_rqst->rq_server, proto);
257                 goto out;
258         }
259
260         /*
261          * Sanity check: if there's no pid,
262          * we should be the first user ...
263          */
264         if (nlmsvc_users)
265                 printk(KERN_WARNING
266                         "lockd_up: no pid, %d users??\n", nlmsvc_users);
267
268         error = -ENOMEM;
269         serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL);
270         if (!serv) {
271                 printk(KERN_WARNING "lockd_up: create service failed\n");
272                 goto out;
273         }
274
275         if ((error = make_socks(serv, proto)) < 0)
276                 goto destroy_and_out;
277
278         /*
279          * Create the kernel thread and wait for it to start.
280          */
281         nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0]);
282         if (IS_ERR(nlmsvc_rqst)) {
283                 error = PTR_ERR(nlmsvc_rqst);
284                 nlmsvc_rqst = NULL;
285                 printk(KERN_WARNING
286                         "lockd_up: svc_rqst allocation failed, error=%d\n",
287                         error);
288                 goto destroy_and_out;
289         }
290
291         svc_sock_update_bufs(serv);
292
293         nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, serv->sv_name);
294         if (IS_ERR(nlmsvc_task)) {
295                 error = PTR_ERR(nlmsvc_task);
296                 svc_exit_thread(nlmsvc_rqst);
297                 nlmsvc_task = NULL;
298                 nlmsvc_rqst = NULL;
299                 printk(KERN_WARNING
300                         "lockd_up: kthread_run failed, error=%d\n", error);
301                 goto destroy_and_out;
302         }
303
304         /*
305          * Note: svc_serv structures have an initial use count of 1,
306          * so we exit through here on both success and failure.
307          */
308 destroy_and_out:
309         svc_destroy(serv);
310 out:
311         if (!error)
312                 nlmsvc_users++;
313         mutex_unlock(&nlmsvc_mutex);
314         return error;
315 }
316 EXPORT_SYMBOL(lockd_up);
317
318 /*
319  * Decrement the user count and bring down lockd if we're the last.
320  */
321 void
322 lockd_down(void)
323 {
324         mutex_lock(&nlmsvc_mutex);
325         if (nlmsvc_users) {
326                 if (--nlmsvc_users)
327                         goto out;
328         } else {
329                 printk(KERN_ERR "lockd_down: no users! task=%p\n",
330                         nlmsvc_task);
331                 BUG();
332         }
333
334         if (!nlmsvc_task) {
335                 printk(KERN_ERR "lockd_down: no lockd running.\n");
336                 BUG();
337         }
338         kthread_stop(nlmsvc_task);
339         svc_exit_thread(nlmsvc_rqst);
340         nlmsvc_task = NULL;
341         nlmsvc_rqst = NULL;
342 out:
343         mutex_unlock(&nlmsvc_mutex);
344 }
345 EXPORT_SYMBOL(lockd_down);
346
347 #ifdef CONFIG_SYSCTL
348
349 /*
350  * Sysctl parameters (same as module parameters, different interface).
351  */
352
353 static ctl_table nlm_sysctls[] = {
354         {
355                 .ctl_name       = CTL_UNNUMBERED,
356                 .procname       = "nlm_grace_period",
357                 .data           = &nlm_grace_period,
358                 .maxlen         = sizeof(unsigned long),
359                 .mode           = 0644,
360                 .proc_handler   = &proc_doulongvec_minmax,
361                 .extra1         = (unsigned long *) &nlm_grace_period_min,
362                 .extra2         = (unsigned long *) &nlm_grace_period_max,
363         },
364         {
365                 .ctl_name       = CTL_UNNUMBERED,
366                 .procname       = "nlm_timeout",
367                 .data           = &nlm_timeout,
368                 .maxlen         = sizeof(unsigned long),
369                 .mode           = 0644,
370                 .proc_handler   = &proc_doulongvec_minmax,
371                 .extra1         = (unsigned long *) &nlm_timeout_min,
372                 .extra2         = (unsigned long *) &nlm_timeout_max,
373         },
374         {
375                 .ctl_name       = CTL_UNNUMBERED,
376                 .procname       = "nlm_udpport",
377                 .data           = &nlm_udpport,
378                 .maxlen         = sizeof(int),
379                 .mode           = 0644,
380                 .proc_handler   = &proc_dointvec_minmax,
381                 .extra1         = (int *) &nlm_port_min,
382                 .extra2         = (int *) &nlm_port_max,
383         },
384         {
385                 .ctl_name       = CTL_UNNUMBERED,
386                 .procname       = "nlm_tcpport",
387                 .data           = &nlm_tcpport,
388                 .maxlen         = sizeof(int),
389                 .mode           = 0644,
390                 .proc_handler   = &proc_dointvec_minmax,
391                 .extra1         = (int *) &nlm_port_min,
392                 .extra2         = (int *) &nlm_port_max,
393         },
394         {
395                 .ctl_name       = CTL_UNNUMBERED,
396                 .procname       = "nsm_use_hostnames",
397                 .data           = &nsm_use_hostnames,
398                 .maxlen         = sizeof(int),
399                 .mode           = 0644,
400                 .proc_handler   = &proc_dointvec,
401         },
402         {
403                 .ctl_name       = CTL_UNNUMBERED,
404                 .procname       = "nsm_local_state",
405                 .data           = &nsm_local_state,
406                 .maxlen         = sizeof(int),
407                 .mode           = 0644,
408                 .proc_handler   = &proc_dointvec,
409         },
410         { .ctl_name = 0 }
411 };
412
413 static ctl_table nlm_sysctl_dir[] = {
414         {
415                 .ctl_name       = CTL_UNNUMBERED,
416                 .procname       = "nfs",
417                 .mode           = 0555,
418                 .child          = nlm_sysctls,
419         },
420         { .ctl_name = 0 }
421 };
422
423 static ctl_table nlm_sysctl_root[] = {
424         {
425                 .ctl_name       = CTL_FS,
426                 .procname       = "fs",
427                 .mode           = 0555,
428                 .child          = nlm_sysctl_dir,
429         },
430         { .ctl_name = 0 }
431 };
432
433 #endif  /* CONFIG_SYSCTL */
434
435 /*
436  * Module (and sysfs) parameters.
437  */
438
439 #define param_set_min_max(name, type, which_strtol, min, max)           \
440 static int param_set_##name(const char *val, struct kernel_param *kp)   \
441 {                                                                       \
442         char *endp;                                                     \
443         __typeof__(type) num = which_strtol(val, &endp, 0);             \
444         if (endp == val || *endp || num < (min) || num > (max))         \
445                 return -EINVAL;                                         \
446         *((int *) kp->arg) = num;                                       \
447         return 0;                                                       \
448 }
449
450 static inline int is_callback(u32 proc)
451 {
452         return proc == NLMPROC_GRANTED
453                 || proc == NLMPROC_GRANTED_MSG
454                 || proc == NLMPROC_TEST_RES
455                 || proc == NLMPROC_LOCK_RES
456                 || proc == NLMPROC_CANCEL_RES
457                 || proc == NLMPROC_UNLOCK_RES
458                 || proc == NLMPROC_NSM_NOTIFY;
459 }
460
461
462 static int lockd_authenticate(struct svc_rqst *rqstp)
463 {
464         rqstp->rq_client = NULL;
465         switch (rqstp->rq_authop->flavour) {
466                 case RPC_AUTH_NULL:
467                 case RPC_AUTH_UNIX:
468                         if (rqstp->rq_proc == 0)
469                                 return SVC_OK;
470                         if (is_callback(rqstp->rq_proc)) {
471                                 /* Leave it to individual procedures to
472                                  * call nlmsvc_lookup_host(rqstp)
473                                  */
474                                 return SVC_OK;
475                         }
476                         return svc_set_client(rqstp);
477         }
478         return SVC_DENIED;
479 }
480
481
482 param_set_min_max(port, int, simple_strtol, 0, 65535)
483 param_set_min_max(grace_period, unsigned long, simple_strtoul,
484                   nlm_grace_period_min, nlm_grace_period_max)
485 param_set_min_max(timeout, unsigned long, simple_strtoul,
486                   nlm_timeout_min, nlm_timeout_max)
487
488 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
489 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
490 MODULE_LICENSE("GPL");
491
492 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
493                   &nlm_grace_period, 0644);
494 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
495                   &nlm_timeout, 0644);
496 module_param_call(nlm_udpport, param_set_port, param_get_int,
497                   &nlm_udpport, 0644);
498 module_param_call(nlm_tcpport, param_set_port, param_get_int,
499                   &nlm_tcpport, 0644);
500 module_param(nsm_use_hostnames, bool, 0644);
501
502 /*
503  * Initialising and terminating the module.
504  */
505
506 static int __init init_nlm(void)
507 {
508 #ifdef CONFIG_SYSCTL
509         nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
510         return nlm_sysctl_table ? 0 : -ENOMEM;
511 #else
512         return 0;
513 #endif
514 }
515
516 static void __exit exit_nlm(void)
517 {
518         /* FIXME: delete all NLM clients */
519         nlm_shutdown_hosts();
520 #ifdef CONFIG_SYSCTL
521         unregister_sysctl_table(nlm_sysctl_table);
522 #endif
523 }
524
525 module_init(init_nlm);
526 module_exit(exit_nlm);
527
528 /*
529  * Define NLM program and procedures
530  */
531 static struct svc_version       nlmsvc_version1 = {
532                 .vs_vers        = 1,
533                 .vs_nproc       = 17,
534                 .vs_proc        = nlmsvc_procedures,
535                 .vs_xdrsize     = NLMSVC_XDRSIZE,
536 };
537 static struct svc_version       nlmsvc_version3 = {
538                 .vs_vers        = 3,
539                 .vs_nproc       = 24,
540                 .vs_proc        = nlmsvc_procedures,
541                 .vs_xdrsize     = NLMSVC_XDRSIZE,
542 };
543 #ifdef CONFIG_LOCKD_V4
544 static struct svc_version       nlmsvc_version4 = {
545                 .vs_vers        = 4,
546                 .vs_nproc       = 24,
547                 .vs_proc        = nlmsvc_procedures4,
548                 .vs_xdrsize     = NLMSVC_XDRSIZE,
549 };
550 #endif
551 static struct svc_version *     nlmsvc_version[] = {
552         [1] = &nlmsvc_version1,
553         [3] = &nlmsvc_version3,
554 #ifdef CONFIG_LOCKD_V4
555         [4] = &nlmsvc_version4,
556 #endif
557 };
558
559 static struct svc_stat          nlmsvc_stats;
560
561 #define NLM_NRVERS      ARRAY_SIZE(nlmsvc_version)
562 static struct svc_program       nlmsvc_program = {
563         .pg_prog                = NLM_PROGRAM,          /* program number */
564         .pg_nvers               = NLM_NRVERS,           /* number of entries in nlmsvc_version */
565         .pg_vers                = nlmsvc_version,       /* version table */
566         .pg_name                = "lockd",              /* service name */
567         .pg_class               = "nfsd",               /* share authentication with nfsd */
568         .pg_stats               = &nlmsvc_stats,        /* stats table */
569         .pg_authenticate = &lockd_authenticate  /* export authentication */
570 };