Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
[linux-2.6] / 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 static struct ctl_table_header * nlm_sysctl_table;
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 void
115 lockd(struct svc_rqst *rqstp)
116 {
117         int             err = 0;
118         unsigned long grace_period_expire;
119
120         /* Lock module and set up kernel thread */
121         /* lockd_up is waiting for us to startup, so will
122          * be holding a reference to this module, so it
123          * is safe to just claim another reference
124          */
125         __module_get(THIS_MODULE);
126         lock_kernel();
127
128         /*
129          * Let our maker know we're running.
130          */
131         nlmsvc_pid = current->pid;
132         nlmsvc_serv = rqstp->rq_server;
133         complete(&lockd_start_done);
134
135         daemonize("lockd");
136         set_freezable();
137
138         /* Process request with signals blocked, but allow SIGKILL.  */
139         allow_signal(SIGKILL);
140
141         dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
142
143         if (!nlm_timeout)
144                 nlm_timeout = LOCKD_DFLT_TIMEO;
145         nlmsvc_timeout = nlm_timeout * HZ;
146
147         grace_period_expire = set_grace_period();
148
149         /*
150          * The main request loop. We don't terminate until the last
151          * NFS mount or NFS daemon has gone away, and we've been sent a
152          * signal, or else another process has taken over our job.
153          */
154         while ((nlmsvc_users || !signalled()) && nlmsvc_pid == current->pid) {
155                 long timeout = MAX_SCHEDULE_TIMEOUT;
156                 char buf[RPC_MAX_ADDRBUFLEN];
157
158                 if (signalled()) {
159                         flush_signals(current);
160                         if (nlmsvc_ops) {
161                                 nlmsvc_invalidate_all();
162                                 grace_period_expire = set_grace_period();
163                         }
164                 }
165
166                 /*
167                  * Retry any blocked locks that have been notified by
168                  * the VFS. Don't do this during grace period.
169                  * (Theoretically, there shouldn't even be blocked locks
170                  * during grace period).
171                  */
172                 if (!nlmsvc_grace_period) {
173                         timeout = nlmsvc_retry_blocked();
174                 } else if (time_before(grace_period_expire, jiffies))
175                         clear_grace_period();
176
177                 /*
178                  * Find a socket with data available and call its
179                  * recvfrom routine.
180                  */
181                 err = svc_recv(rqstp, timeout);
182                 if (err == -EAGAIN || err == -EINTR)
183                         continue;
184                 if (err < 0) {
185                         printk(KERN_WARNING
186                                "lockd: terminating on error %d\n",
187                                -err);
188                         break;
189                 }
190
191                 dprintk("lockd: request from %s\n",
192                                 svc_print_addr(rqstp, buf, sizeof(buf)));
193
194                 svc_process(rqstp);
195         }
196
197         flush_signals(current);
198
199         /*
200          * Check whether there's a new lockd process before
201          * shutting down the hosts and clearing the slot.
202          */
203         if (!nlmsvc_pid || current->pid == nlmsvc_pid) {
204                 if (nlmsvc_ops)
205                         nlmsvc_invalidate_all();
206                 nlm_shutdown_hosts();
207                 nlmsvc_pid = 0;
208                 nlmsvc_serv = NULL;
209         } else
210                 printk(KERN_DEBUG
211                         "lockd: new process, skipping host shutdown\n");
212         wake_up(&lockd_exit);
213
214         /* Exit the RPC thread */
215         svc_exit_thread(rqstp);
216
217         /* Release module */
218         unlock_kernel();
219         module_put_and_exit(0);
220 }
221
222
223 static int find_socket(struct svc_serv *serv, int proto)
224 {
225         struct svc_sock *svsk;
226         int found = 0;
227         list_for_each_entry(svsk, &serv->sv_permsocks, sk_list)
228                 if (svsk->sk_sk->sk_protocol == proto) {
229                         found = 1;
230                         break;
231                 }
232         return found;
233 }
234
235 /*
236  * Make any sockets that are needed but not present.
237  * If nlm_udpport or nlm_tcpport were set as module
238  * options, make those sockets unconditionally
239  */
240 static int make_socks(struct svc_serv *serv, int proto)
241 {
242         static int warned;
243         int err = 0;
244
245         if (proto == IPPROTO_UDP || nlm_udpport)
246                 if (!find_socket(serv, IPPROTO_UDP))
247                         err = svc_makesock(serv, IPPROTO_UDP, nlm_udpport,
248                                                 SVC_SOCK_DEFAULTS);
249         if (err >= 0 && (proto == IPPROTO_TCP || nlm_tcpport))
250                 if (!find_socket(serv, IPPROTO_TCP))
251                         err = svc_makesock(serv, IPPROTO_TCP, nlm_tcpport,
252                                                 SVC_SOCK_DEFAULTS);
253
254         if (err >= 0) {
255                 warned = 0;
256                 err = 0;
257         } else if (warned++ == 0)
258                 printk(KERN_WARNING
259                        "lockd_up: makesock failed, error=%d\n", err);
260         return err;
261 }
262
263 /*
264  * Bring up the lockd process if it's not already up.
265  */
266 int
267 lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
268 {
269         struct svc_serv *       serv;
270         int                     error = 0;
271
272         mutex_lock(&nlmsvc_mutex);
273         /*
274          * Check whether we're already up and running.
275          */
276         if (nlmsvc_pid) {
277                 if (proto)
278                         error = make_socks(nlmsvc_serv, proto);
279                 goto out;
280         }
281
282         /*
283          * Sanity check: if there's no pid,
284          * we should be the first user ...
285          */
286         if (nlmsvc_users)
287                 printk(KERN_WARNING
288                         "lockd_up: no pid, %d users??\n", nlmsvc_users);
289
290         error = -ENOMEM;
291         serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL);
292         if (!serv) {
293                 printk(KERN_WARNING "lockd_up: create service failed\n");
294                 goto out;
295         }
296
297         if ((error = make_socks(serv, proto)) < 0)
298                 goto destroy_and_out;
299
300         /*
301          * Create the kernel thread and wait for it to start.
302          */
303         error = svc_create_thread(lockd, serv);
304         if (error) {
305                 printk(KERN_WARNING
306                         "lockd_up: create thread failed, error=%d\n", error);
307                 goto destroy_and_out;
308         }
309         wait_for_completion(&lockd_start_done);
310
311         /*
312          * Note: svc_serv structures have an initial use count of 1,
313          * so we exit through here on both success and failure.
314          */
315 destroy_and_out:
316         svc_destroy(serv);
317 out:
318         if (!error)
319                 nlmsvc_users++;
320         mutex_unlock(&nlmsvc_mutex);
321         return error;
322 }
323 EXPORT_SYMBOL(lockd_up);
324
325 /*
326  * Decrement the user count and bring down lockd if we're the last.
327  */
328 void
329 lockd_down(void)
330 {
331         static int warned;
332
333         mutex_lock(&nlmsvc_mutex);
334         if (nlmsvc_users) {
335                 if (--nlmsvc_users)
336                         goto out;
337         } else
338                 printk(KERN_WARNING "lockd_down: no users! pid=%d\n", nlmsvc_pid);
339
340         if (!nlmsvc_pid) {
341                 if (warned++ == 0)
342                         printk(KERN_WARNING "lockd_down: no lockd running.\n"); 
343                 goto out;
344         }
345         warned = 0;
346
347         kill_proc(nlmsvc_pid, SIGKILL, 1);
348         /*
349          * Wait for the lockd process to exit, but since we're holding
350          * the lockd semaphore, we can't wait around forever ...
351          */
352         clear_thread_flag(TIF_SIGPENDING);
353         interruptible_sleep_on_timeout(&lockd_exit, HZ);
354         if (nlmsvc_pid) {
355                 printk(KERN_WARNING 
356                         "lockd_down: lockd failed to exit, clearing pid\n");
357                 nlmsvc_pid = 0;
358         }
359         spin_lock_irq(&current->sighand->siglock);
360         recalc_sigpending();
361         spin_unlock_irq(&current->sighand->siglock);
362 out:
363         mutex_unlock(&nlmsvc_mutex);
364 }
365 EXPORT_SYMBOL(lockd_down);
366
367 /*
368  * Sysctl parameters (same as module parameters, different interface).
369  */
370
371 static ctl_table nlm_sysctls[] = {
372         {
373                 .ctl_name       = CTL_UNNUMBERED,
374                 .procname       = "nlm_grace_period",
375                 .data           = &nlm_grace_period,
376                 .maxlen         = sizeof(unsigned long),
377                 .mode           = 0644,
378                 .proc_handler   = &proc_doulongvec_minmax,
379                 .extra1         = (unsigned long *) &nlm_grace_period_min,
380                 .extra2         = (unsigned long *) &nlm_grace_period_max,
381         },
382         {
383                 .ctl_name       = CTL_UNNUMBERED,
384                 .procname       = "nlm_timeout",
385                 .data           = &nlm_timeout,
386                 .maxlen         = sizeof(unsigned long),
387                 .mode           = 0644,
388                 .proc_handler   = &proc_doulongvec_minmax,
389                 .extra1         = (unsigned long *) &nlm_timeout_min,
390                 .extra2         = (unsigned long *) &nlm_timeout_max,
391         },
392         {
393                 .ctl_name       = CTL_UNNUMBERED,
394                 .procname       = "nlm_udpport",
395                 .data           = &nlm_udpport,
396                 .maxlen         = sizeof(int),
397                 .mode           = 0644,
398                 .proc_handler   = &proc_dointvec_minmax,
399                 .extra1         = (int *) &nlm_port_min,
400                 .extra2         = (int *) &nlm_port_max,
401         },
402         {
403                 .ctl_name       = CTL_UNNUMBERED,
404                 .procname       = "nlm_tcpport",
405                 .data           = &nlm_tcpport,
406                 .maxlen         = sizeof(int),
407                 .mode           = 0644,
408                 .proc_handler   = &proc_dointvec_minmax,
409                 .extra1         = (int *) &nlm_port_min,
410                 .extra2         = (int *) &nlm_port_max,
411         },
412         {
413                 .ctl_name       = CTL_UNNUMBERED,
414                 .procname       = "nsm_use_hostnames",
415                 .data           = &nsm_use_hostnames,
416                 .maxlen         = sizeof(int),
417                 .mode           = 0644,
418                 .proc_handler   = &proc_dointvec,
419         },
420         {
421                 .ctl_name       = CTL_UNNUMBERED,
422                 .procname       = "nsm_local_state",
423                 .data           = &nsm_local_state,
424                 .maxlen         = sizeof(int),
425                 .mode           = 0644,
426                 .proc_handler   = &proc_dointvec,
427         },
428         { .ctl_name = 0 }
429 };
430
431 static ctl_table nlm_sysctl_dir[] = {
432         {
433                 .ctl_name       = CTL_UNNUMBERED,
434                 .procname       = "nfs",
435                 .mode           = 0555,
436                 .child          = nlm_sysctls,
437         },
438         { .ctl_name = 0 }
439 };
440
441 static ctl_table nlm_sysctl_root[] = {
442         {
443                 .ctl_name       = CTL_FS,
444                 .procname       = "fs",
445                 .mode           = 0555,
446                 .child          = nlm_sysctl_dir,
447         },
448         { .ctl_name = 0 }
449 };
450
451 /*
452  * Module (and sysfs) parameters.
453  */
454
455 #define param_set_min_max(name, type, which_strtol, min, max)           \
456 static int param_set_##name(const char *val, struct kernel_param *kp)   \
457 {                                                                       \
458         char *endp;                                                     \
459         __typeof__(type) num = which_strtol(val, &endp, 0);             \
460         if (endp == val || *endp || num < (min) || num > (max))         \
461                 return -EINVAL;                                         \
462         *((int *) kp->arg) = num;                                       \
463         return 0;                                                       \
464 }
465
466 static inline int is_callback(u32 proc)
467 {
468         return proc == NLMPROC_GRANTED
469                 || proc == NLMPROC_GRANTED_MSG
470                 || proc == NLMPROC_TEST_RES
471                 || proc == NLMPROC_LOCK_RES
472                 || proc == NLMPROC_CANCEL_RES
473                 || proc == NLMPROC_UNLOCK_RES
474                 || proc == NLMPROC_NSM_NOTIFY;
475 }
476
477
478 static int lockd_authenticate(struct svc_rqst *rqstp)
479 {
480         rqstp->rq_client = NULL;
481         switch (rqstp->rq_authop->flavour) {
482                 case RPC_AUTH_NULL:
483                 case RPC_AUTH_UNIX:
484                         if (rqstp->rq_proc == 0)
485                                 return SVC_OK;
486                         if (is_callback(rqstp->rq_proc)) {
487                                 /* Leave it to individual procedures to
488                                  * call nlmsvc_lookup_host(rqstp)
489                                  */
490                                 return SVC_OK;
491                         }
492                         return svc_set_client(rqstp);
493         }
494         return SVC_DENIED;
495 }
496
497
498 param_set_min_max(port, int, simple_strtol, 0, 65535)
499 param_set_min_max(grace_period, unsigned long, simple_strtoul,
500                   nlm_grace_period_min, nlm_grace_period_max)
501 param_set_min_max(timeout, unsigned long, simple_strtoul,
502                   nlm_timeout_min, nlm_timeout_max)
503
504 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
505 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
506 MODULE_LICENSE("GPL");
507
508 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
509                   &nlm_grace_period, 0644);
510 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
511                   &nlm_timeout, 0644);
512 module_param_call(nlm_udpport, param_set_port, param_get_int,
513                   &nlm_udpport, 0644);
514 module_param_call(nlm_tcpport, param_set_port, param_get_int,
515                   &nlm_tcpport, 0644);
516 module_param(nsm_use_hostnames, bool, 0644);
517
518 /*
519  * Initialising and terminating the module.
520  */
521
522 static int __init init_nlm(void)
523 {
524         nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
525         return nlm_sysctl_table ? 0 : -ENOMEM;
526 }
527
528 static void __exit exit_nlm(void)
529 {
530         /* FIXME: delete all NLM clients */
531         nlm_shutdown_hosts();
532         unregister_sysctl_table(nlm_sysctl_table);
533 }
534
535 module_init(init_nlm);
536 module_exit(exit_nlm);
537
538 /*
539  * Define NLM program and procedures
540  */
541 static struct svc_version       nlmsvc_version1 = {
542                 .vs_vers        = 1,
543                 .vs_nproc       = 17,
544                 .vs_proc        = nlmsvc_procedures,
545                 .vs_xdrsize     = NLMSVC_XDRSIZE,
546 };
547 static struct svc_version       nlmsvc_version3 = {
548                 .vs_vers        = 3,
549                 .vs_nproc       = 24,
550                 .vs_proc        = nlmsvc_procedures,
551                 .vs_xdrsize     = NLMSVC_XDRSIZE,
552 };
553 #ifdef CONFIG_LOCKD_V4
554 static struct svc_version       nlmsvc_version4 = {
555                 .vs_vers        = 4,
556                 .vs_nproc       = 24,
557                 .vs_proc        = nlmsvc_procedures4,
558                 .vs_xdrsize     = NLMSVC_XDRSIZE,
559 };
560 #endif
561 static struct svc_version *     nlmsvc_version[] = {
562         [1] = &nlmsvc_version1,
563         [3] = &nlmsvc_version3,
564 #ifdef CONFIG_LOCKD_V4
565         [4] = &nlmsvc_version4,
566 #endif
567 };
568
569 static struct svc_stat          nlmsvc_stats;
570
571 #define NLM_NRVERS      ARRAY_SIZE(nlmsvc_version)
572 static struct svc_program       nlmsvc_program = {
573         .pg_prog                = NLM_PROGRAM,          /* program number */
574         .pg_nvers               = NLM_NRVERS,           /* number of entries in nlmsvc_version */
575         .pg_vers                = nlmsvc_version,       /* version table */
576         .pg_name                = "lockd",              /* service name */
577         .pg_class               = "nfsd",               /* share authentication with nfsd */
578         .pg_stats               = &nlmsvc_stats,        /* stats table */
579         .pg_authenticate = &lockd_authenticate  /* export authentication */
580 };