lockd: introduce new function to encode private argument in SM_MON requests
[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/freezer.h>
29
30 #include <linux/sunrpc/types.h>
31 #include <linux/sunrpc/stats.h>
32 #include <linux/sunrpc/clnt.h>
33 #include <linux/sunrpc/svc.h>
34 #include <linux/sunrpc/svcsock.h>
35 #include <net/ip.h>
36 #include <linux/lockd/lockd.h>
37 #include <linux/lockd/sm_inter.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
44 static struct svc_program       nlmsvc_program;
45
46 struct nlmsvc_binding *         nlmsvc_ops;
47 EXPORT_SYMBOL(nlmsvc_ops);
48
49 static DEFINE_MUTEX(nlmsvc_mutex);
50 static unsigned int             nlmsvc_users;
51 static pid_t                    nlmsvc_pid;
52 static struct svc_serv          *nlmsvc_serv;
53 int                             nlmsvc_grace_period;
54 unsigned long                   nlmsvc_timeout;
55
56 static DECLARE_COMPLETION(lockd_start_done);
57 static DECLARE_WAIT_QUEUE_HEAD(lockd_exit);
58
59 /*
60  * These can be set at insmod time (useful for NFS as root filesystem),
61  * and also changed through the sysctl interface.  -- Jamie Lokier, Aug 2003
62  */
63 static unsigned long            nlm_grace_period;
64 static unsigned long            nlm_timeout = LOCKD_DFLT_TIMEO;
65 static int                      nlm_udpport, nlm_tcpport;
66 int                             nsm_use_hostnames = 0;
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 unsigned long get_nfs_grace_period(void)
91 {
92         unsigned long lockdgrace = get_lockd_grace_period();
93         unsigned long nfsdgrace = 0;
94
95         if (nlmsvc_ops)
96                 nfsdgrace = nlmsvc_ops->get_grace_period();
97
98         return max(lockdgrace, nfsdgrace);
99 }
100 EXPORT_SYMBOL(get_nfs_grace_period);
101
102 static unsigned long set_grace_period(void)
103 {
104         nlmsvc_grace_period = 1;
105         return get_nfs_grace_period() + jiffies;
106 }
107
108 static inline void clear_grace_period(void)
109 {
110         nlmsvc_grace_period = 0;
111 }
112
113 /*
114  * This is the lockd kernel thread
115  */
116 static void
117 lockd(struct svc_rqst *rqstp)
118 {
119         int             err = 0;
120         unsigned long grace_period_expire;
121
122         /* Lock module and set up kernel thread */
123         /* lockd_up is waiting for us to startup, so will
124          * be holding a reference to this module, so it
125          * is safe to just claim another reference
126          */
127         __module_get(THIS_MODULE);
128         lock_kernel();
129
130         /*
131          * Let our maker know we're running.
132          */
133         nlmsvc_pid = current->pid;
134         nlmsvc_serv = rqstp->rq_server;
135         complete(&lockd_start_done);
136
137         daemonize("lockd");
138         set_freezable();
139
140         /* Process request with signals blocked, but allow SIGKILL.  */
141         allow_signal(SIGKILL);
142
143         dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
144
145         if (!nlm_timeout)
146                 nlm_timeout = LOCKD_DFLT_TIMEO;
147         nlmsvc_timeout = nlm_timeout * HZ;
148
149         grace_period_expire = set_grace_period();
150
151         /*
152          * The main request loop. We don't terminate until the last
153          * NFS mount or NFS daemon has gone away, and we've been sent a
154          * signal, or else another process has taken over our job.
155          */
156         while ((nlmsvc_users || !signalled()) && nlmsvc_pid == current->pid) {
157                 long timeout = MAX_SCHEDULE_TIMEOUT;
158                 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
159
160                 if (signalled()) {
161                         flush_signals(current);
162                         if (nlmsvc_ops) {
163                                 nlmsvc_invalidate_all();
164                                 grace_period_expire = set_grace_period();
165                         }
166                 }
167
168                 /*
169                  * Retry any blocked locks that have been notified by
170                  * the VFS. Don't do this during grace period.
171                  * (Theoretically, there shouldn't even be blocked locks
172                  * during grace period).
173                  */
174                 if (!nlmsvc_grace_period) {
175                         timeout = nlmsvc_retry_blocked();
176                 } else if (time_before(grace_period_expire, jiffies))
177                         clear_grace_period();
178
179                 /*
180                  * Find a socket with data available and call its
181                  * recvfrom routine.
182                  */
183                 err = svc_recv(rqstp, timeout);
184                 if (err == -EAGAIN || err == -EINTR)
185                         continue;
186                 if (err < 0) {
187                         printk(KERN_WARNING
188                                "lockd: terminating on error %d\n",
189                                -err);
190                         break;
191                 }
192
193                 dprintk("lockd: request from %s\n",
194                                 svc_print_addr(rqstp, buf, sizeof(buf)));
195
196                 svc_process(rqstp);
197         }
198
199         flush_signals(current);
200
201         /*
202          * Check whether there's a new lockd process before
203          * shutting down the hosts and clearing the slot.
204          */
205         if (!nlmsvc_pid || current->pid == nlmsvc_pid) {
206                 if (nlmsvc_ops)
207                         nlmsvc_invalidate_all();
208                 nlm_shutdown_hosts();
209                 nlmsvc_pid = 0;
210                 nlmsvc_serv = NULL;
211         } else
212                 printk(KERN_DEBUG
213                         "lockd: new process, skipping host shutdown\n");
214         wake_up(&lockd_exit);
215
216         /* Exit the RPC thread */
217         svc_exit_thread(rqstp);
218
219         /* Release module */
220         unlock_kernel();
221         module_put_and_exit(0);
222 }
223
224 /*
225  * Make any sockets that are needed but not present.
226  * If nlm_udpport or nlm_tcpport were set as module
227  * options, make those sockets unconditionally
228  */
229 static int make_socks(struct svc_serv *serv, int proto)
230 {
231         static int warned;
232         struct svc_xprt *xprt;
233         int err = 0;
234
235         if (proto == IPPROTO_UDP || nlm_udpport) {
236                 xprt = svc_find_xprt(serv, "udp", 0, 0);
237                 if (!xprt)
238                         err = svc_create_xprt(serv, "udp", nlm_udpport,
239                                               SVC_SOCK_DEFAULTS);
240                 else
241                         svc_xprt_put(xprt);
242         }
243         if (err >= 0 && (proto == IPPROTO_TCP || nlm_tcpport)) {
244                 xprt = svc_find_xprt(serv, "tcp", 0, 0);
245                 if (!xprt)
246                         err = svc_create_xprt(serv, "tcp", nlm_tcpport,
247                                               SVC_SOCK_DEFAULTS);
248                 else
249                         svc_xprt_put(xprt);
250         }
251         if (err >= 0) {
252                 warned = 0;
253                 err = 0;
254         } else if (warned++ == 0)
255                 printk(KERN_WARNING
256                        "lockd_up: makesock failed, error=%d\n", err);
257         return err;
258 }
259
260 /*
261  * Bring up the lockd process if it's not already up.
262  */
263 int
264 lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
265 {
266         struct svc_serv *       serv;
267         int                     error = 0;
268
269         mutex_lock(&nlmsvc_mutex);
270         /*
271          * Check whether we're already up and running.
272          */
273         if (nlmsvc_pid) {
274                 if (proto)
275                         error = make_socks(nlmsvc_serv, proto);
276                 goto out;
277         }
278
279         /*
280          * Sanity check: if there's no pid,
281          * we should be the first user ...
282          */
283         if (nlmsvc_users)
284                 printk(KERN_WARNING
285                         "lockd_up: no pid, %d users??\n", nlmsvc_users);
286
287         error = -ENOMEM;
288         serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL);
289         if (!serv) {
290                 printk(KERN_WARNING "lockd_up: create service failed\n");
291                 goto out;
292         }
293
294         if ((error = make_socks(serv, proto)) < 0)
295                 goto destroy_and_out;
296
297         /*
298          * Create the kernel thread and wait for it to start.
299          */
300         error = svc_create_thread(lockd, serv);
301         if (error) {
302                 printk(KERN_WARNING
303                         "lockd_up: create thread failed, error=%d\n", error);
304                 goto destroy_and_out;
305         }
306         wait_for_completion(&lockd_start_done);
307
308         /*
309          * Note: svc_serv structures have an initial use count of 1,
310          * so we exit through here on both success and failure.
311          */
312 destroy_and_out:
313         svc_destroy(serv);
314 out:
315         if (!error)
316                 nlmsvc_users++;
317         mutex_unlock(&nlmsvc_mutex);
318         return error;
319 }
320 EXPORT_SYMBOL(lockd_up);
321
322 /*
323  * Decrement the user count and bring down lockd if we're the last.
324  */
325 void
326 lockd_down(void)
327 {
328         static int warned;
329
330         mutex_lock(&nlmsvc_mutex);
331         if (nlmsvc_users) {
332                 if (--nlmsvc_users)
333                         goto out;
334         } else
335                 printk(KERN_WARNING "lockd_down: no users! pid=%d\n", nlmsvc_pid);
336
337         if (!nlmsvc_pid) {
338                 if (warned++ == 0)
339                         printk(KERN_WARNING "lockd_down: no lockd running.\n"); 
340                 goto out;
341         }
342         warned = 0;
343
344         kill_proc(nlmsvc_pid, SIGKILL, 1);
345         /*
346          * Wait for the lockd process to exit, but since we're holding
347          * the lockd semaphore, we can't wait around forever ...
348          */
349         clear_thread_flag(TIF_SIGPENDING);
350         interruptible_sleep_on_timeout(&lockd_exit, HZ);
351         if (nlmsvc_pid) {
352                 printk(KERN_WARNING 
353                         "lockd_down: lockd failed to exit, clearing pid\n");
354                 nlmsvc_pid = 0;
355         }
356         spin_lock_irq(&current->sighand->siglock);
357         recalc_sigpending();
358         spin_unlock_irq(&current->sighand->siglock);
359 out:
360         mutex_unlock(&nlmsvc_mutex);
361 }
362 EXPORT_SYMBOL(lockd_down);
363
364 #ifdef CONFIG_SYSCTL
365
366 /*
367  * Sysctl parameters (same as module parameters, different interface).
368  */
369
370 static ctl_table nlm_sysctls[] = {
371         {
372                 .ctl_name       = CTL_UNNUMBERED,
373                 .procname       = "nlm_grace_period",
374                 .data           = &nlm_grace_period,
375                 .maxlen         = sizeof(unsigned long),
376                 .mode           = 0644,
377                 .proc_handler   = &proc_doulongvec_minmax,
378                 .extra1         = (unsigned long *) &nlm_grace_period_min,
379                 .extra2         = (unsigned long *) &nlm_grace_period_max,
380         },
381         {
382                 .ctl_name       = CTL_UNNUMBERED,
383                 .procname       = "nlm_timeout",
384                 .data           = &nlm_timeout,
385                 .maxlen         = sizeof(unsigned long),
386                 .mode           = 0644,
387                 .proc_handler   = &proc_doulongvec_minmax,
388                 .extra1         = (unsigned long *) &nlm_timeout_min,
389                 .extra2         = (unsigned long *) &nlm_timeout_max,
390         },
391         {
392                 .ctl_name       = CTL_UNNUMBERED,
393                 .procname       = "nlm_udpport",
394                 .data           = &nlm_udpport,
395                 .maxlen         = sizeof(int),
396                 .mode           = 0644,
397                 .proc_handler   = &proc_dointvec_minmax,
398                 .extra1         = (int *) &nlm_port_min,
399                 .extra2         = (int *) &nlm_port_max,
400         },
401         {
402                 .ctl_name       = CTL_UNNUMBERED,
403                 .procname       = "nlm_tcpport",
404                 .data           = &nlm_tcpport,
405                 .maxlen         = sizeof(int),
406                 .mode           = 0644,
407                 .proc_handler   = &proc_dointvec_minmax,
408                 .extra1         = (int *) &nlm_port_min,
409                 .extra2         = (int *) &nlm_port_max,
410         },
411         {
412                 .ctl_name       = CTL_UNNUMBERED,
413                 .procname       = "nsm_use_hostnames",
414                 .data           = &nsm_use_hostnames,
415                 .maxlen         = sizeof(int),
416                 .mode           = 0644,
417                 .proc_handler   = &proc_dointvec,
418         },
419         {
420                 .ctl_name       = CTL_UNNUMBERED,
421                 .procname       = "nsm_local_state",
422                 .data           = &nsm_local_state,
423                 .maxlen         = sizeof(int),
424                 .mode           = 0644,
425                 .proc_handler   = &proc_dointvec,
426         },
427         { .ctl_name = 0 }
428 };
429
430 static ctl_table nlm_sysctl_dir[] = {
431         {
432                 .ctl_name       = CTL_UNNUMBERED,
433                 .procname       = "nfs",
434                 .mode           = 0555,
435                 .child          = nlm_sysctls,
436         },
437         { .ctl_name = 0 }
438 };
439
440 static ctl_table nlm_sysctl_root[] = {
441         {
442                 .ctl_name       = CTL_FS,
443                 .procname       = "fs",
444                 .mode           = 0555,
445                 .child          = nlm_sysctl_dir,
446         },
447         { .ctl_name = 0 }
448 };
449
450 #endif  /* CONFIG_SYSCTL */
451
452 /*
453  * Module (and sysfs) parameters.
454  */
455
456 #define param_set_min_max(name, type, which_strtol, min, max)           \
457 static int param_set_##name(const char *val, struct kernel_param *kp)   \
458 {                                                                       \
459         char *endp;                                                     \
460         __typeof__(type) num = which_strtol(val, &endp, 0);             \
461         if (endp == val || *endp || num < (min) || num > (max))         \
462                 return -EINVAL;                                         \
463         *((int *) kp->arg) = num;                                       \
464         return 0;                                                       \
465 }
466
467 static inline int is_callback(u32 proc)
468 {
469         return proc == NLMPROC_GRANTED
470                 || proc == NLMPROC_GRANTED_MSG
471                 || proc == NLMPROC_TEST_RES
472                 || proc == NLMPROC_LOCK_RES
473                 || proc == NLMPROC_CANCEL_RES
474                 || proc == NLMPROC_UNLOCK_RES
475                 || proc == NLMPROC_NSM_NOTIFY;
476 }
477
478
479 static int lockd_authenticate(struct svc_rqst *rqstp)
480 {
481         rqstp->rq_client = NULL;
482         switch (rqstp->rq_authop->flavour) {
483                 case RPC_AUTH_NULL:
484                 case RPC_AUTH_UNIX:
485                         if (rqstp->rq_proc == 0)
486                                 return SVC_OK;
487                         if (is_callback(rqstp->rq_proc)) {
488                                 /* Leave it to individual procedures to
489                                  * call nlmsvc_lookup_host(rqstp)
490                                  */
491                                 return SVC_OK;
492                         }
493                         return svc_set_client(rqstp);
494         }
495         return SVC_DENIED;
496 }
497
498
499 param_set_min_max(port, int, simple_strtol, 0, 65535)
500 param_set_min_max(grace_period, unsigned long, simple_strtoul,
501                   nlm_grace_period_min, nlm_grace_period_max)
502 param_set_min_max(timeout, unsigned long, simple_strtoul,
503                   nlm_timeout_min, nlm_timeout_max)
504
505 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
506 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
507 MODULE_LICENSE("GPL");
508
509 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
510                   &nlm_grace_period, 0644);
511 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
512                   &nlm_timeout, 0644);
513 module_param_call(nlm_udpport, param_set_port, param_get_int,
514                   &nlm_udpport, 0644);
515 module_param_call(nlm_tcpport, param_set_port, param_get_int,
516                   &nlm_tcpport, 0644);
517 module_param(nsm_use_hostnames, bool, 0644);
518
519 /*
520  * Initialising and terminating the module.
521  */
522
523 static int __init init_nlm(void)
524 {
525 #ifdef CONFIG_SYSCTL
526         nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
527         return nlm_sysctl_table ? 0 : -ENOMEM;
528 #else
529         return 0;
530 #endif
531 }
532
533 static void __exit exit_nlm(void)
534 {
535         /* FIXME: delete all NLM clients */
536         nlm_shutdown_hosts();
537 #ifdef CONFIG_SYSCTL
538         unregister_sysctl_table(nlm_sysctl_table);
539 #endif
540 }
541
542 module_init(init_nlm);
543 module_exit(exit_nlm);
544
545 /*
546  * Define NLM program and procedures
547  */
548 static struct svc_version       nlmsvc_version1 = {
549                 .vs_vers        = 1,
550                 .vs_nproc       = 17,
551                 .vs_proc        = nlmsvc_procedures,
552                 .vs_xdrsize     = NLMSVC_XDRSIZE,
553 };
554 static struct svc_version       nlmsvc_version3 = {
555                 .vs_vers        = 3,
556                 .vs_nproc       = 24,
557                 .vs_proc        = nlmsvc_procedures,
558                 .vs_xdrsize     = NLMSVC_XDRSIZE,
559 };
560 #ifdef CONFIG_LOCKD_V4
561 static struct svc_version       nlmsvc_version4 = {
562                 .vs_vers        = 4,
563                 .vs_nproc       = 24,
564                 .vs_proc        = nlmsvc_procedures4,
565                 .vs_xdrsize     = NLMSVC_XDRSIZE,
566 };
567 #endif
568 static struct svc_version *     nlmsvc_version[] = {
569         [1] = &nlmsvc_version1,
570         [3] = &nlmsvc_version3,
571 #ifdef CONFIG_LOCKD_V4
572         [4] = &nlmsvc_version4,
573 #endif
574 };
575
576 static struct svc_stat          nlmsvc_stats;
577
578 #define NLM_NRVERS      ARRAY_SIZE(nlmsvc_version)
579 static struct svc_program       nlmsvc_program = {
580         .pg_prog                = NLM_PROGRAM,          /* program number */
581         .pg_nvers               = NLM_NRVERS,           /* number of entries in nlmsvc_version */
582         .pg_vers                = nlmsvc_version,       /* version table */
583         .pg_name                = "lockd",              /* service name */
584         .pg_class               = "nfsd",               /* share authentication with nfsd */
585         .pg_stats               = &nlmsvc_stats,        /* stats table */
586         .pg_authenticate = &lockd_authenticate  /* export authentication */
587 };