NSM: Move NSM-related XDR data structures to lockd's xdr.h
[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_GPL(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 unsigned long                   nlmsvc_timeout;
55
56 /*
57  * These can be set at insmod time (useful for NFS as root filesystem),
58  * and also changed through the sysctl interface.  -- Jamie Lokier, Aug 2003
59  */
60 static unsigned long            nlm_grace_period;
61 static unsigned long            nlm_timeout = LOCKD_DFLT_TIMEO;
62 static int                      nlm_udpport, nlm_tcpport;
63 int                             nsm_use_hostnames = 0;
64
65 /* RLIM_NOFILE defaults to 1024. That seems like a reasonable default here. */
66 static unsigned int             nlm_max_connections = 1024;
67
68 /*
69  * Constants needed for the sysctl interface.
70  */
71 static const unsigned long      nlm_grace_period_min = 0;
72 static const unsigned long      nlm_grace_period_max = 240;
73 static const unsigned long      nlm_timeout_min = 3;
74 static const unsigned long      nlm_timeout_max = 20;
75 static const int                nlm_port_min = 0, nlm_port_max = 65535;
76
77 #ifdef CONFIG_SYSCTL
78 static struct ctl_table_header * nlm_sysctl_table;
79 #endif
80
81 static unsigned long get_lockd_grace_period(void)
82 {
83         /* Note: nlm_timeout should always be nonzero */
84         if (nlm_grace_period)
85                 return roundup(nlm_grace_period, nlm_timeout) * HZ;
86         else
87                 return nlm_timeout * 5 * HZ;
88 }
89
90 static struct lock_manager lockd_manager = {
91 };
92
93 static void grace_ender(struct work_struct *not_used)
94 {
95         locks_end_grace(&lockd_manager);
96 }
97
98 static DECLARE_DELAYED_WORK(grace_period_end, grace_ender);
99
100 static void set_grace_period(void)
101 {
102         unsigned long grace_period = get_lockd_grace_period();
103
104         locks_start_grace(&lockd_manager);
105         cancel_delayed_work_sync(&grace_period_end);
106         schedule_delayed_work(&grace_period_end, grace_period);
107 }
108
109 /*
110  * This is the lockd kernel thread
111  */
112 static int
113 lockd(void *vrqstp)
114 {
115         int             err = 0, preverr = 0;
116         struct svc_rqst *rqstp = vrqstp;
117
118         /* try_to_freeze() is called from svc_recv() */
119         set_freezable();
120
121         /* Allow SIGKILL to tell lockd to drop all of its locks */
122         allow_signal(SIGKILL);
123
124         dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
125
126         /*
127          * FIXME: it would be nice if lockd didn't spend its entire life
128          * running under the BKL. At the very least, it would be good to
129          * have someone clarify what it's intended to protect here. I've
130          * seen some handwavy posts about posix locking needing to be
131          * done under the BKL, but it's far from clear.
132          */
133         lock_kernel();
134
135         if (!nlm_timeout)
136                 nlm_timeout = LOCKD_DFLT_TIMEO;
137         nlmsvc_timeout = nlm_timeout * HZ;
138
139         set_grace_period();
140
141         /*
142          * The main request loop. We don't terminate until the last
143          * NFS mount or NFS daemon has gone away.
144          */
145         while (!kthread_should_stop()) {
146                 long timeout = MAX_SCHEDULE_TIMEOUT;
147                 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
148
149                 /* update sv_maxconn if it has changed */
150                 rqstp->rq_server->sv_maxconn = nlm_max_connections;
151
152                 if (signalled()) {
153                         flush_signals(current);
154                         if (nlmsvc_ops) {
155                                 nlmsvc_invalidate_all();
156                                 set_grace_period();
157                         }
158                         continue;
159                 }
160
161                 timeout = nlmsvc_retry_blocked();
162
163                 /*
164                  * Find a socket with data available and call its
165                  * recvfrom routine.
166                  */
167                 err = svc_recv(rqstp, timeout);
168                 if (err == -EAGAIN || err == -EINTR) {
169                         preverr = err;
170                         continue;
171                 }
172                 if (err < 0) {
173                         if (err != preverr) {
174                                 printk(KERN_WARNING "%s: unexpected error "
175                                         "from svc_recv (%d)\n", __func__, err);
176                                 preverr = err;
177                         }
178                         schedule_timeout_interruptible(HZ);
179                         continue;
180                 }
181                 preverr = err;
182
183                 dprintk("lockd: request from %s\n",
184                                 svc_print_addr(rqstp, buf, sizeof(buf)));
185
186                 svc_process(rqstp);
187         }
188         flush_signals(current);
189         cancel_delayed_work_sync(&grace_period_end);
190         locks_end_grace(&lockd_manager);
191         if (nlmsvc_ops)
192                 nlmsvc_invalidate_all();
193         nlm_shutdown_hosts();
194         unlock_kernel();
195         return 0;
196 }
197
198 /*
199  * Ensure there are active UDP and TCP listeners for lockd.
200  *
201  * Even if we have only TCP NFS mounts and/or TCP NFSDs, some
202  * local services (such as rpc.statd) still require UDP, and
203  * some NFS servers do not yet support NLM over TCP.
204  *
205  * Returns zero if all listeners are available; otherwise a
206  * negative errno value is returned.
207  */
208 static int make_socks(struct svc_serv *serv)
209 {
210         static int warned;
211         struct svc_xprt *xprt;
212         int err = 0;
213
214         xprt = svc_find_xprt(serv, "udp", 0, 0);
215         if (!xprt)
216                 err = svc_create_xprt(serv, "udp", nlm_udpport,
217                                       SVC_SOCK_DEFAULTS);
218         else
219                 svc_xprt_put(xprt);
220         if (err >= 0) {
221                 xprt = svc_find_xprt(serv, "tcp", 0, 0);
222                 if (!xprt)
223                         err = svc_create_xprt(serv, "tcp", nlm_tcpport,
224                                               SVC_SOCK_DEFAULTS);
225                 else
226                         svc_xprt_put(xprt);
227         }
228         if (err >= 0) {
229                 warned = 0;
230                 err = 0;
231         } else if (warned++ == 0)
232                 printk(KERN_WARNING
233                        "lockd_up: makesock failed, error=%d\n", err);
234         return err;
235 }
236
237 /*
238  * Bring up the lockd process if it's not already up.
239  */
240 int lockd_up(void)
241 {
242         struct svc_serv *serv;
243         int             error = 0;
244
245         mutex_lock(&nlmsvc_mutex);
246         /*
247          * Check whether we're already up and running.
248          */
249         if (nlmsvc_rqst)
250                 goto out;
251
252         /*
253          * Sanity check: if there's no pid,
254          * we should be the first user ...
255          */
256         if (nlmsvc_users)
257                 printk(KERN_WARNING
258                         "lockd_up: no pid, %d users??\n", nlmsvc_users);
259
260         error = -ENOMEM;
261         serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, AF_INET, NULL);
262         if (!serv) {
263                 printk(KERN_WARNING "lockd_up: create service failed\n");
264                 goto out;
265         }
266
267         error = make_socks(serv);
268         if (error < 0)
269                 goto destroy_and_out;
270
271         /*
272          * Create the kernel thread and wait for it to start.
273          */
274         nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0]);
275         if (IS_ERR(nlmsvc_rqst)) {
276                 error = PTR_ERR(nlmsvc_rqst);
277                 nlmsvc_rqst = NULL;
278                 printk(KERN_WARNING
279                         "lockd_up: svc_rqst allocation failed, error=%d\n",
280                         error);
281                 goto destroy_and_out;
282         }
283
284         svc_sock_update_bufs(serv);
285         serv->sv_maxconn = nlm_max_connections;
286
287         nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, serv->sv_name);
288         if (IS_ERR(nlmsvc_task)) {
289                 error = PTR_ERR(nlmsvc_task);
290                 svc_exit_thread(nlmsvc_rqst);
291                 nlmsvc_task = NULL;
292                 nlmsvc_rqst = NULL;
293                 printk(KERN_WARNING
294                         "lockd_up: kthread_run failed, error=%d\n", error);
295                 goto destroy_and_out;
296         }
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          */
302 destroy_and_out:
303         svc_destroy(serv);
304 out:
305         if (!error)
306                 nlmsvc_users++;
307         mutex_unlock(&nlmsvc_mutex);
308         return error;
309 }
310 EXPORT_SYMBOL_GPL(lockd_up);
311
312 /*
313  * Decrement the user count and bring down lockd if we're the last.
314  */
315 void
316 lockd_down(void)
317 {
318         mutex_lock(&nlmsvc_mutex);
319         if (nlmsvc_users) {
320                 if (--nlmsvc_users)
321                         goto out;
322         } else {
323                 printk(KERN_ERR "lockd_down: no users! task=%p\n",
324                         nlmsvc_task);
325                 BUG();
326         }
327
328         if (!nlmsvc_task) {
329                 printk(KERN_ERR "lockd_down: no lockd running.\n");
330                 BUG();
331         }
332         kthread_stop(nlmsvc_task);
333         svc_exit_thread(nlmsvc_rqst);
334         nlmsvc_task = NULL;
335         nlmsvc_rqst = NULL;
336 out:
337         mutex_unlock(&nlmsvc_mutex);
338 }
339 EXPORT_SYMBOL_GPL(lockd_down);
340
341 #ifdef CONFIG_SYSCTL
342
343 /*
344  * Sysctl parameters (same as module parameters, different interface).
345  */
346
347 static ctl_table nlm_sysctls[] = {
348         {
349                 .ctl_name       = CTL_UNNUMBERED,
350                 .procname       = "nlm_grace_period",
351                 .data           = &nlm_grace_period,
352                 .maxlen         = sizeof(unsigned long),
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,
362                 .maxlen         = sizeof(unsigned long),
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         },
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         },
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         },
404         { .ctl_name = 0 }
405 };
406
407 static 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
417 static 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
427 #endif  /* CONFIG_SYSCTL */
428
429 /*
430  * Module (and sysfs) parameters.
431  */
432
433 #define param_set_min_max(name, type, which_strtol, min, max)           \
434 static 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
444 static 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
456 static 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
476 param_set_min_max(port, int, simple_strtol, 0, 65535)
477 param_set_min_max(grace_period, unsigned long, simple_strtoul,
478                   nlm_grace_period_min, nlm_grace_period_max)
479 param_set_min_max(timeout, unsigned long, simple_strtoul,
480                   nlm_timeout_min, nlm_timeout_max)
481
482 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
483 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
484 MODULE_LICENSE("GPL");
485
486 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
487                   &nlm_grace_period, 0644);
488 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
489                   &nlm_timeout, 0644);
490 module_param_call(nlm_udpport, param_set_port, param_get_int,
491                   &nlm_udpport, 0644);
492 module_param_call(nlm_tcpport, param_set_port, param_get_int,
493                   &nlm_tcpport, 0644);
494 module_param(nsm_use_hostnames, bool, 0644);
495 module_param(nlm_max_connections, uint, 0644);
496
497 /*
498  * Initialising and terminating the module.
499  */
500
501 static int __init init_nlm(void)
502 {
503 #ifdef CONFIG_SYSCTL
504         nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
505         return nlm_sysctl_table ? 0 : -ENOMEM;
506 #else
507         return 0;
508 #endif
509 }
510
511 static void __exit exit_nlm(void)
512 {
513         /* FIXME: delete all NLM clients */
514         nlm_shutdown_hosts();
515 #ifdef CONFIG_SYSCTL
516         unregister_sysctl_table(nlm_sysctl_table);
517 #endif
518 }
519
520 module_init(init_nlm);
521 module_exit(exit_nlm);
522
523 /*
524  * Define NLM program and procedures
525  */
526 static struct svc_version       nlmsvc_version1 = {
527                 .vs_vers        = 1,
528                 .vs_nproc       = 17,
529                 .vs_proc        = nlmsvc_procedures,
530                 .vs_xdrsize     = NLMSVC_XDRSIZE,
531 };
532 static struct svc_version       nlmsvc_version3 = {
533                 .vs_vers        = 3,
534                 .vs_nproc       = 24,
535                 .vs_proc        = nlmsvc_procedures,
536                 .vs_xdrsize     = NLMSVC_XDRSIZE,
537 };
538 #ifdef CONFIG_LOCKD_V4
539 static struct svc_version       nlmsvc_version4 = {
540                 .vs_vers        = 4,
541                 .vs_nproc       = 24,
542                 .vs_proc        = nlmsvc_procedures4,
543                 .vs_xdrsize     = NLMSVC_XDRSIZE,
544 };
545 #endif
546 static struct svc_version *     nlmsvc_version[] = {
547         [1] = &nlmsvc_version1,
548         [3] = &nlmsvc_version3,
549 #ifdef CONFIG_LOCKD_V4
550         [4] = &nlmsvc_version4,
551 #endif
552 };
553
554 static struct svc_stat          nlmsvc_stats;
555
556 #define NLM_NRVERS      ARRAY_SIZE(nlmsvc_version)
557 static struct svc_program       nlmsvc_program = {
558         .pg_prog                = NLM_PROGRAM,          /* program number */
559         .pg_nvers               = NLM_NRVERS,           /* number of entries in nlmsvc_version */
560         .pg_vers                = nlmsvc_version,       /* version table */
561         .pg_name                = "lockd",              /* service name */
562         .pg_class               = "nfsd",               /* share authentication with nfsd */
563         .pg_stats               = &nlmsvc_stats,        /* stats table */
564         .pg_authenticate = &lockd_authenticate  /* export authentication */
565 };