Merge git://git.kernel.org/pub/scm/linux/kernel/git/czankel/xtensa-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_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 /*
66  * Constants needed for the sysctl interface.
67  */
68 static const unsigned long      nlm_grace_period_min = 0;
69 static const unsigned long      nlm_grace_period_max = 240;
70 static const unsigned long      nlm_timeout_min = 3;
71 static const unsigned long      nlm_timeout_max = 20;
72 static const int                nlm_port_min = 0, nlm_port_max = 65535;
73
74 #ifdef CONFIG_SYSCTL
75 static struct ctl_table_header * nlm_sysctl_table;
76 #endif
77
78 static unsigned long get_lockd_grace_period(void)
79 {
80         /* Note: nlm_timeout should always be nonzero */
81         if (nlm_grace_period)
82                 return roundup(nlm_grace_period, nlm_timeout) * HZ;
83         else
84                 return nlm_timeout * 5 * HZ;
85 }
86
87 static struct lock_manager lockd_manager = {
88 };
89
90 static void grace_ender(struct work_struct *not_used)
91 {
92         locks_end_grace(&lockd_manager);
93 }
94
95 static DECLARE_DELAYED_WORK(grace_period_end, grace_ender);
96
97 static void set_grace_period(void)
98 {
99         unsigned long grace_period = get_lockd_grace_period();
100
101         locks_start_grace(&lockd_manager);
102         cancel_delayed_work_sync(&grace_period_end);
103         schedule_delayed_work(&grace_period_end, grace_period);
104 }
105
106 /*
107  * This is the lockd kernel thread
108  */
109 static int
110 lockd(void *vrqstp)
111 {
112         int             err = 0, preverr = 0;
113         struct svc_rqst *rqstp = vrqstp;
114
115         /* try_to_freeze() is called from svc_recv() */
116         set_freezable();
117
118         /* Allow SIGKILL to tell lockd to drop all of its locks */
119         allow_signal(SIGKILL);
120
121         dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
122
123         /*
124          * FIXME: it would be nice if lockd didn't spend its entire life
125          * running under the BKL. At the very least, it would be good to
126          * have someone clarify what it's intended to protect here. I've
127          * seen some handwavy posts about posix locking needing to be
128          * done under the BKL, but it's far from clear.
129          */
130         lock_kernel();
131
132         if (!nlm_timeout)
133                 nlm_timeout = LOCKD_DFLT_TIMEO;
134         nlmsvc_timeout = nlm_timeout * HZ;
135
136         set_grace_period();
137
138         /*
139          * The main request loop. We don't terminate until the last
140          * NFS mount or NFS daemon has gone away.
141          */
142         while (!kthread_should_stop()) {
143                 long timeout = MAX_SCHEDULE_TIMEOUT;
144                 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
145
146                 if (signalled()) {
147                         flush_signals(current);
148                         if (nlmsvc_ops) {
149                                 nlmsvc_invalidate_all();
150                                 set_grace_period();
151                         }
152                         continue;
153                 }
154
155                 timeout = nlmsvc_retry_blocked();
156
157                 /*
158                  * Find a socket with data available and call its
159                  * recvfrom routine.
160                  */
161                 err = svc_recv(rqstp, timeout);
162                 if (err == -EAGAIN || err == -EINTR) {
163                         preverr = err;
164                         continue;
165                 }
166                 if (err < 0) {
167                         if (err != preverr) {
168                                 printk(KERN_WARNING "%s: unexpected error "
169                                         "from svc_recv (%d)\n", __func__, err);
170                                 preverr = err;
171                         }
172                         schedule_timeout_interruptible(HZ);
173                         continue;
174                 }
175                 preverr = err;
176
177                 dprintk("lockd: request from %s\n",
178                                 svc_print_addr(rqstp, buf, sizeof(buf)));
179
180                 svc_process(rqstp);
181         }
182         flush_signals(current);
183         cancel_delayed_work_sync(&grace_period_end);
184         locks_end_grace(&lockd_manager);
185         if (nlmsvc_ops)
186                 nlmsvc_invalidate_all();
187         nlm_shutdown_hosts();
188         unlock_kernel();
189         return 0;
190 }
191
192 /*
193  * Ensure there are active UDP and TCP listeners for lockd.
194  *
195  * Even if we have only TCP NFS mounts and/or TCP NFSDs, some
196  * local services (such as rpc.statd) still require UDP, and
197  * some NFS servers do not yet support NLM over TCP.
198  *
199  * Returns zero if all listeners are available; otherwise a
200  * negative errno value is returned.
201  */
202 static int make_socks(struct svc_serv *serv)
203 {
204         static int warned;
205         struct svc_xprt *xprt;
206         int err = 0;
207
208         xprt = svc_find_xprt(serv, "udp", 0, 0);
209         if (!xprt)
210                 err = svc_create_xprt(serv, "udp", nlm_udpport,
211                                       SVC_SOCK_DEFAULTS);
212         else
213                 svc_xprt_put(xprt);
214         if (err >= 0) {
215                 xprt = svc_find_xprt(serv, "tcp", 0, 0);
216                 if (!xprt)
217                         err = svc_create_xprt(serv, "tcp", nlm_tcpport,
218                                               SVC_SOCK_DEFAULTS);
219                 else
220                         svc_xprt_put(xprt);
221         }
222         if (err >= 0) {
223                 warned = 0;
224                 err = 0;
225         } else if (warned++ == 0)
226                 printk(KERN_WARNING
227                        "lockd_up: makesock failed, error=%d\n", err);
228         return err;
229 }
230
231 /*
232  * Bring up the lockd process if it's not already up.
233  */
234 int lockd_up(void)
235 {
236         struct svc_serv *serv;
237         int             error = 0;
238
239         mutex_lock(&nlmsvc_mutex);
240         /*
241          * Check whether we're already up and running.
242          */
243         if (nlmsvc_rqst)
244                 goto out;
245
246         /*
247          * Sanity check: if there's no pid,
248          * we should be the first user ...
249          */
250         if (nlmsvc_users)
251                 printk(KERN_WARNING
252                         "lockd_up: no pid, %d users??\n", nlmsvc_users);
253
254         error = -ENOMEM;
255         serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, AF_INET, NULL);
256         if (!serv) {
257                 printk(KERN_WARNING "lockd_up: create service failed\n");
258                 goto out;
259         }
260
261         error = make_socks(serv);
262         if (error < 0)
263                 goto destroy_and_out;
264
265         /*
266          * Create the kernel thread and wait for it to start.
267          */
268         nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0]);
269         if (IS_ERR(nlmsvc_rqst)) {
270                 error = PTR_ERR(nlmsvc_rqst);
271                 nlmsvc_rqst = NULL;
272                 printk(KERN_WARNING
273                         "lockd_up: svc_rqst allocation failed, error=%d\n",
274                         error);
275                 goto destroy_and_out;
276         }
277
278         svc_sock_update_bufs(serv);
279
280         nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, serv->sv_name);
281         if (IS_ERR(nlmsvc_task)) {
282                 error = PTR_ERR(nlmsvc_task);
283                 svc_exit_thread(nlmsvc_rqst);
284                 nlmsvc_task = NULL;
285                 nlmsvc_rqst = NULL;
286                 printk(KERN_WARNING
287                         "lockd_up: kthread_run failed, error=%d\n", error);
288                 goto destroy_and_out;
289         }
290
291         /*
292          * Note: svc_serv structures have an initial use count of 1,
293          * so we exit through here on both success and failure.
294          */
295 destroy_and_out:
296         svc_destroy(serv);
297 out:
298         if (!error)
299                 nlmsvc_users++;
300         mutex_unlock(&nlmsvc_mutex);
301         return error;
302 }
303 EXPORT_SYMBOL_GPL(lockd_up);
304
305 /*
306  * Decrement the user count and bring down lockd if we're the last.
307  */
308 void
309 lockd_down(void)
310 {
311         mutex_lock(&nlmsvc_mutex);
312         if (nlmsvc_users) {
313                 if (--nlmsvc_users)
314                         goto out;
315         } else {
316                 printk(KERN_ERR "lockd_down: no users! task=%p\n",
317                         nlmsvc_task);
318                 BUG();
319         }
320
321         if (!nlmsvc_task) {
322                 printk(KERN_ERR "lockd_down: no lockd running.\n");
323                 BUG();
324         }
325         kthread_stop(nlmsvc_task);
326         svc_exit_thread(nlmsvc_rqst);
327         nlmsvc_task = NULL;
328         nlmsvc_rqst = NULL;
329 out:
330         mutex_unlock(&nlmsvc_mutex);
331 }
332 EXPORT_SYMBOL_GPL(lockd_down);
333
334 #ifdef CONFIG_SYSCTL
335
336 /*
337  * Sysctl parameters (same as module parameters, different interface).
338  */
339
340 static ctl_table nlm_sysctls[] = {
341         {
342                 .ctl_name       = CTL_UNNUMBERED,
343                 .procname       = "nlm_grace_period",
344                 .data           = &nlm_grace_period,
345                 .maxlen         = sizeof(unsigned long),
346                 .mode           = 0644,
347                 .proc_handler   = &proc_doulongvec_minmax,
348                 .extra1         = (unsigned long *) &nlm_grace_period_min,
349                 .extra2         = (unsigned long *) &nlm_grace_period_max,
350         },
351         {
352                 .ctl_name       = CTL_UNNUMBERED,
353                 .procname       = "nlm_timeout",
354                 .data           = &nlm_timeout,
355                 .maxlen         = sizeof(unsigned long),
356                 .mode           = 0644,
357                 .proc_handler   = &proc_doulongvec_minmax,
358                 .extra1         = (unsigned long *) &nlm_timeout_min,
359                 .extra2         = (unsigned long *) &nlm_timeout_max,
360         },
361         {
362                 .ctl_name       = CTL_UNNUMBERED,
363                 .procname       = "nlm_udpport",
364                 .data           = &nlm_udpport,
365                 .maxlen         = sizeof(int),
366                 .mode           = 0644,
367                 .proc_handler   = &proc_dointvec_minmax,
368                 .extra1         = (int *) &nlm_port_min,
369                 .extra2         = (int *) &nlm_port_max,
370         },
371         {
372                 .ctl_name       = CTL_UNNUMBERED,
373                 .procname       = "nlm_tcpport",
374                 .data           = &nlm_tcpport,
375                 .maxlen         = sizeof(int),
376                 .mode           = 0644,
377                 .proc_handler   = &proc_dointvec_minmax,
378                 .extra1         = (int *) &nlm_port_min,
379                 .extra2         = (int *) &nlm_port_max,
380         },
381         {
382                 .ctl_name       = CTL_UNNUMBERED,
383                 .procname       = "nsm_use_hostnames",
384                 .data           = &nsm_use_hostnames,
385                 .maxlen         = sizeof(int),
386                 .mode           = 0644,
387                 .proc_handler   = &proc_dointvec,
388         },
389         {
390                 .ctl_name       = CTL_UNNUMBERED,
391                 .procname       = "nsm_local_state",
392                 .data           = &nsm_local_state,
393                 .maxlen         = sizeof(int),
394                 .mode           = 0644,
395                 .proc_handler   = &proc_dointvec,
396         },
397         { .ctl_name = 0 }
398 };
399
400 static ctl_table nlm_sysctl_dir[] = {
401         {
402                 .ctl_name       = CTL_UNNUMBERED,
403                 .procname       = "nfs",
404                 .mode           = 0555,
405                 .child          = nlm_sysctls,
406         },
407         { .ctl_name = 0 }
408 };
409
410 static ctl_table nlm_sysctl_root[] = {
411         {
412                 .ctl_name       = CTL_FS,
413                 .procname       = "fs",
414                 .mode           = 0555,
415                 .child          = nlm_sysctl_dir,
416         },
417         { .ctl_name = 0 }
418 };
419
420 #endif  /* CONFIG_SYSCTL */
421
422 /*
423  * Module (and sysfs) parameters.
424  */
425
426 #define param_set_min_max(name, type, which_strtol, min, max)           \
427 static int param_set_##name(const char *val, struct kernel_param *kp)   \
428 {                                                                       \
429         char *endp;                                                     \
430         __typeof__(type) num = which_strtol(val, &endp, 0);             \
431         if (endp == val || *endp || num < (min) || num > (max))         \
432                 return -EINVAL;                                         \
433         *((int *) kp->arg) = num;                                       \
434         return 0;                                                       \
435 }
436
437 static inline int is_callback(u32 proc)
438 {
439         return proc == NLMPROC_GRANTED
440                 || proc == NLMPROC_GRANTED_MSG
441                 || proc == NLMPROC_TEST_RES
442                 || proc == NLMPROC_LOCK_RES
443                 || proc == NLMPROC_CANCEL_RES
444                 || proc == NLMPROC_UNLOCK_RES
445                 || proc == NLMPROC_NSM_NOTIFY;
446 }
447
448
449 static int lockd_authenticate(struct svc_rqst *rqstp)
450 {
451         rqstp->rq_client = NULL;
452         switch (rqstp->rq_authop->flavour) {
453                 case RPC_AUTH_NULL:
454                 case RPC_AUTH_UNIX:
455                         if (rqstp->rq_proc == 0)
456                                 return SVC_OK;
457                         if (is_callback(rqstp->rq_proc)) {
458                                 /* Leave it to individual procedures to
459                                  * call nlmsvc_lookup_host(rqstp)
460                                  */
461                                 return SVC_OK;
462                         }
463                         return svc_set_client(rqstp);
464         }
465         return SVC_DENIED;
466 }
467
468
469 param_set_min_max(port, int, simple_strtol, 0, 65535)
470 param_set_min_max(grace_period, unsigned long, simple_strtoul,
471                   nlm_grace_period_min, nlm_grace_period_max)
472 param_set_min_max(timeout, unsigned long, simple_strtoul,
473                   nlm_timeout_min, nlm_timeout_max)
474
475 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
476 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
477 MODULE_LICENSE("GPL");
478
479 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
480                   &nlm_grace_period, 0644);
481 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
482                   &nlm_timeout, 0644);
483 module_param_call(nlm_udpport, param_set_port, param_get_int,
484                   &nlm_udpport, 0644);
485 module_param_call(nlm_tcpport, param_set_port, param_get_int,
486                   &nlm_tcpport, 0644);
487 module_param(nsm_use_hostnames, bool, 0644);
488
489 /*
490  * Initialising and terminating the module.
491  */
492
493 static int __init init_nlm(void)
494 {
495 #ifdef CONFIG_SYSCTL
496         nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
497         return nlm_sysctl_table ? 0 : -ENOMEM;
498 #else
499         return 0;
500 #endif
501 }
502
503 static void __exit exit_nlm(void)
504 {
505         /* FIXME: delete all NLM clients */
506         nlm_shutdown_hosts();
507 #ifdef CONFIG_SYSCTL
508         unregister_sysctl_table(nlm_sysctl_table);
509 #endif
510 }
511
512 module_init(init_nlm);
513 module_exit(exit_nlm);
514
515 /*
516  * Define NLM program and procedures
517  */
518 static struct svc_version       nlmsvc_version1 = {
519                 .vs_vers        = 1,
520                 .vs_nproc       = 17,
521                 .vs_proc        = nlmsvc_procedures,
522                 .vs_xdrsize     = NLMSVC_XDRSIZE,
523 };
524 static struct svc_version       nlmsvc_version3 = {
525                 .vs_vers        = 3,
526                 .vs_nproc       = 24,
527                 .vs_proc        = nlmsvc_procedures,
528                 .vs_xdrsize     = NLMSVC_XDRSIZE,
529 };
530 #ifdef CONFIG_LOCKD_V4
531 static struct svc_version       nlmsvc_version4 = {
532                 .vs_vers        = 4,
533                 .vs_nproc       = 24,
534                 .vs_proc        = nlmsvc_procedures4,
535                 .vs_xdrsize     = NLMSVC_XDRSIZE,
536 };
537 #endif
538 static struct svc_version *     nlmsvc_version[] = {
539         [1] = &nlmsvc_version1,
540         [3] = &nlmsvc_version3,
541 #ifdef CONFIG_LOCKD_V4
542         [4] = &nlmsvc_version4,
543 #endif
544 };
545
546 static struct svc_stat          nlmsvc_stats;
547
548 #define NLM_NRVERS      ARRAY_SIZE(nlmsvc_version)
549 static struct svc_program       nlmsvc_program = {
550         .pg_prog                = NLM_PROGRAM,          /* program number */
551         .pg_nvers               = NLM_NRVERS,           /* number of entries in nlmsvc_version */
552         .pg_vers                = nlmsvc_version,       /* version table */
553         .pg_name                = "lockd",              /* service name */
554         .pg_class               = "nfsd",               /* share authentication with nfsd */
555         .pg_stats               = &nlmsvc_stats,        /* stats table */
556         .pg_authenticate = &lockd_authenticate  /* export authentication */
557 };