Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-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/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_serv          *nlmsvc_serv;
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
198         flush_signals(current);
199         if (nlmsvc_ops)
200                 nlmsvc_invalidate_all();
201         nlm_shutdown_hosts();
202
203         unlock_kernel();
204
205         nlmsvc_task = NULL;
206         nlmsvc_serv = NULL;
207
208         /* Exit the RPC thread */
209         svc_exit_thread(rqstp);
210
211         return 0;
212 }
213
214 /*
215  * Make any sockets that are needed but not present.
216  * If nlm_udpport or nlm_tcpport were set as module
217  * options, make those sockets unconditionally
218  */
219 static int make_socks(struct svc_serv *serv, int proto)
220 {
221         static int warned;
222         struct svc_xprt *xprt;
223         int err = 0;
224
225         if (proto == IPPROTO_UDP || nlm_udpport) {
226                 xprt = svc_find_xprt(serv, "udp", 0, 0);
227                 if (!xprt)
228                         err = svc_create_xprt(serv, "udp", nlm_udpport,
229                                               SVC_SOCK_DEFAULTS);
230                 else
231                         svc_xprt_put(xprt);
232         }
233         if (err >= 0 && (proto == IPPROTO_TCP || nlm_tcpport)) {
234                 xprt = svc_find_xprt(serv, "tcp", 0, 0);
235                 if (!xprt)
236                         err = svc_create_xprt(serv, "tcp", nlm_tcpport,
237                                               SVC_SOCK_DEFAULTS);
238                 else
239                         svc_xprt_put(xprt);
240         }
241         if (err >= 0) {
242                 warned = 0;
243                 err = 0;
244         } else if (warned++ == 0)
245                 printk(KERN_WARNING
246                        "lockd_up: makesock failed, error=%d\n", err);
247         return err;
248 }
249
250 /*
251  * Bring up the lockd process if it's not already up.
252  */
253 int
254 lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
255 {
256         struct svc_serv *serv;
257         struct svc_rqst *rqstp;
258         int             error = 0;
259
260         mutex_lock(&nlmsvc_mutex);
261         /*
262          * Check whether we're already up and running.
263          */
264         if (nlmsvc_serv) {
265                 if (proto)
266                         error = make_socks(nlmsvc_serv, proto);
267                 goto out;
268         }
269
270         /*
271          * Sanity check: if there's no pid,
272          * we should be the first user ...
273          */
274         if (nlmsvc_users)
275                 printk(KERN_WARNING
276                         "lockd_up: no pid, %d users??\n", nlmsvc_users);
277
278         error = -ENOMEM;
279         serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL);
280         if (!serv) {
281                 printk(KERN_WARNING "lockd_up: create service failed\n");
282                 goto out;
283         }
284
285         if ((error = make_socks(serv, proto)) < 0)
286                 goto destroy_and_out;
287
288         /*
289          * Create the kernel thread and wait for it to start.
290          */
291         rqstp = svc_prepare_thread(serv, &serv->sv_pools[0]);
292         if (IS_ERR(rqstp)) {
293                 error = PTR_ERR(rqstp);
294                 printk(KERN_WARNING
295                         "lockd_up: svc_rqst allocation failed, error=%d\n",
296                         error);
297                 goto destroy_and_out;
298         }
299
300         svc_sock_update_bufs(serv);
301         nlmsvc_serv = rqstp->rq_server;
302
303         nlmsvc_task = kthread_run(lockd, rqstp, serv->sv_name);
304         if (IS_ERR(nlmsvc_task)) {
305                 error = PTR_ERR(nlmsvc_task);
306                 nlmsvc_task = NULL;
307                 nlmsvc_serv = NULL;
308                 printk(KERN_WARNING
309                         "lockd_up: kthread_run failed, error=%d\n", error);
310                 svc_exit_thread(rqstp);
311                 goto destroy_and_out;
312         }
313
314         /*
315          * Note: svc_serv structures have an initial use count of 1,
316          * so we exit through here on both success and failure.
317          */
318 destroy_and_out:
319         svc_destroy(serv);
320 out:
321         if (!error)
322                 nlmsvc_users++;
323         mutex_unlock(&nlmsvc_mutex);
324         return error;
325 }
326 EXPORT_SYMBOL(lockd_up);
327
328 /*
329  * Decrement the user count and bring down lockd if we're the last.
330  */
331 void
332 lockd_down(void)
333 {
334         mutex_lock(&nlmsvc_mutex);
335         if (nlmsvc_users) {
336                 if (--nlmsvc_users)
337                         goto out;
338         } else {
339                 printk(KERN_ERR "lockd_down: no users! task=%p\n",
340                         nlmsvc_task);
341                 BUG();
342         }
343
344         if (!nlmsvc_task) {
345                 printk(KERN_ERR "lockd_down: no lockd running.\n");
346                 BUG();
347         }
348         kthread_stop(nlmsvc_task);
349 out:
350         mutex_unlock(&nlmsvc_mutex);
351 }
352 EXPORT_SYMBOL(lockd_down);
353
354 #ifdef CONFIG_SYSCTL
355
356 /*
357  * Sysctl parameters (same as module parameters, different interface).
358  */
359
360 static ctl_table nlm_sysctls[] = {
361         {
362                 .ctl_name       = CTL_UNNUMBERED,
363                 .procname       = "nlm_grace_period",
364                 .data           = &nlm_grace_period,
365                 .maxlen         = sizeof(unsigned long),
366                 .mode           = 0644,
367                 .proc_handler   = &proc_doulongvec_minmax,
368                 .extra1         = (unsigned long *) &nlm_grace_period_min,
369                 .extra2         = (unsigned long *) &nlm_grace_period_max,
370         },
371         {
372                 .ctl_name       = CTL_UNNUMBERED,
373                 .procname       = "nlm_timeout",
374                 .data           = &nlm_timeout,
375                 .maxlen         = sizeof(unsigned long),
376                 .mode           = 0644,
377                 .proc_handler   = &proc_doulongvec_minmax,
378                 .extra1         = (unsigned long *) &nlm_timeout_min,
379                 .extra2         = (unsigned long *) &nlm_timeout_max,
380         },
381         {
382                 .ctl_name       = CTL_UNNUMBERED,
383                 .procname       = "nlm_udpport",
384                 .data           = &nlm_udpport,
385                 .maxlen         = sizeof(int),
386                 .mode           = 0644,
387                 .proc_handler   = &proc_dointvec_minmax,
388                 .extra1         = (int *) &nlm_port_min,
389                 .extra2         = (int *) &nlm_port_max,
390         },
391         {
392                 .ctl_name       = CTL_UNNUMBERED,
393                 .procname       = "nlm_tcpport",
394                 .data           = &nlm_tcpport,
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       = "nsm_use_hostnames",
404                 .data           = &nsm_use_hostnames,
405                 .maxlen         = sizeof(int),
406                 .mode           = 0644,
407                 .proc_handler   = &proc_dointvec,
408         },
409         {
410                 .ctl_name       = CTL_UNNUMBERED,
411                 .procname       = "nsm_local_state",
412                 .data           = &nsm_local_state,
413                 .maxlen         = sizeof(int),
414                 .mode           = 0644,
415                 .proc_handler   = &proc_dointvec,
416         },
417         { .ctl_name = 0 }
418 };
419
420 static ctl_table nlm_sysctl_dir[] = {
421         {
422                 .ctl_name       = CTL_UNNUMBERED,
423                 .procname       = "nfs",
424                 .mode           = 0555,
425                 .child          = nlm_sysctls,
426         },
427         { .ctl_name = 0 }
428 };
429
430 static ctl_table nlm_sysctl_root[] = {
431         {
432                 .ctl_name       = CTL_FS,
433                 .procname       = "fs",
434                 .mode           = 0555,
435                 .child          = nlm_sysctl_dir,
436         },
437         { .ctl_name = 0 }
438 };
439
440 #endif  /* CONFIG_SYSCTL */
441
442 /*
443  * Module (and sysfs) parameters.
444  */
445
446 #define param_set_min_max(name, type, which_strtol, min, max)           \
447 static int param_set_##name(const char *val, struct kernel_param *kp)   \
448 {                                                                       \
449         char *endp;                                                     \
450         __typeof__(type) num = which_strtol(val, &endp, 0);             \
451         if (endp == val || *endp || num < (min) || num > (max))         \
452                 return -EINVAL;                                         \
453         *((int *) kp->arg) = num;                                       \
454         return 0;                                                       \
455 }
456
457 static inline int is_callback(u32 proc)
458 {
459         return proc == NLMPROC_GRANTED
460                 || proc == NLMPROC_GRANTED_MSG
461                 || proc == NLMPROC_TEST_RES
462                 || proc == NLMPROC_LOCK_RES
463                 || proc == NLMPROC_CANCEL_RES
464                 || proc == NLMPROC_UNLOCK_RES
465                 || proc == NLMPROC_NSM_NOTIFY;
466 }
467
468
469 static int lockd_authenticate(struct svc_rqst *rqstp)
470 {
471         rqstp->rq_client = NULL;
472         switch (rqstp->rq_authop->flavour) {
473                 case RPC_AUTH_NULL:
474                 case RPC_AUTH_UNIX:
475                         if (rqstp->rq_proc == 0)
476                                 return SVC_OK;
477                         if (is_callback(rqstp->rq_proc)) {
478                                 /* Leave it to individual procedures to
479                                  * call nlmsvc_lookup_host(rqstp)
480                                  */
481                                 return SVC_OK;
482                         }
483                         return svc_set_client(rqstp);
484         }
485         return SVC_DENIED;
486 }
487
488
489 param_set_min_max(port, int, simple_strtol, 0, 65535)
490 param_set_min_max(grace_period, unsigned long, simple_strtoul,
491                   nlm_grace_period_min, nlm_grace_period_max)
492 param_set_min_max(timeout, unsigned long, simple_strtoul,
493                   nlm_timeout_min, nlm_timeout_max)
494
495 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
496 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
497 MODULE_LICENSE("GPL");
498
499 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
500                   &nlm_grace_period, 0644);
501 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
502                   &nlm_timeout, 0644);
503 module_param_call(nlm_udpport, param_set_port, param_get_int,
504                   &nlm_udpport, 0644);
505 module_param_call(nlm_tcpport, param_set_port, param_get_int,
506                   &nlm_tcpport, 0644);
507 module_param(nsm_use_hostnames, bool, 0644);
508
509 /*
510  * Initialising and terminating the module.
511  */
512
513 static int __init init_nlm(void)
514 {
515 #ifdef CONFIG_SYSCTL
516         nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
517         return nlm_sysctl_table ? 0 : -ENOMEM;
518 #else
519         return 0;
520 #endif
521 }
522
523 static void __exit exit_nlm(void)
524 {
525         /* FIXME: delete all NLM clients */
526         nlm_shutdown_hosts();
527 #ifdef CONFIG_SYSCTL
528         unregister_sysctl_table(nlm_sysctl_table);
529 #endif
530 }
531
532 module_init(init_nlm);
533 module_exit(exit_nlm);
534
535 /*
536  * Define NLM program and procedures
537  */
538 static struct svc_version       nlmsvc_version1 = {
539                 .vs_vers        = 1,
540                 .vs_nproc       = 17,
541                 .vs_proc        = nlmsvc_procedures,
542                 .vs_xdrsize     = NLMSVC_XDRSIZE,
543 };
544 static struct svc_version       nlmsvc_version3 = {
545                 .vs_vers        = 3,
546                 .vs_nproc       = 24,
547                 .vs_proc        = nlmsvc_procedures,
548                 .vs_xdrsize     = NLMSVC_XDRSIZE,
549 };
550 #ifdef CONFIG_LOCKD_V4
551 static struct svc_version       nlmsvc_version4 = {
552                 .vs_vers        = 4,
553                 .vs_nproc       = 24,
554                 .vs_proc        = nlmsvc_procedures4,
555                 .vs_xdrsize     = NLMSVC_XDRSIZE,
556 };
557 #endif
558 static struct svc_version *     nlmsvc_version[] = {
559         [1] = &nlmsvc_version1,
560         [3] = &nlmsvc_version3,
561 #ifdef CONFIG_LOCKD_V4
562         [4] = &nlmsvc_version4,
563 #endif
564 };
565
566 static struct svc_stat          nlmsvc_stats;
567
568 #define NLM_NRVERS      ARRAY_SIZE(nlmsvc_version)
569 static struct svc_program       nlmsvc_program = {
570         .pg_prog                = NLM_PROGRAM,          /* program number */
571         .pg_nvers               = NLM_NRVERS,           /* number of entries in nlmsvc_version */
572         .pg_vers                = nlmsvc_version,       /* version table */
573         .pg_name                = "lockd",              /* service name */
574         .pg_class               = "nfsd",               /* share authentication with nfsd */
575         .pg_stats               = &nlmsvc_stats,        /* stats table */
576         .pg_authenticate = &lockd_authenticate  /* export authentication */
577 };