[PATCH] knfsd: add a callback for when last rpc thread finishes
[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
29 #include <linux/sunrpc/types.h>
30 #include <linux/sunrpc/stats.h>
31 #include <linux/sunrpc/clnt.h>
32 #include <linux/sunrpc/svc.h>
33 #include <linux/sunrpc/svcsock.h>
34 #include <linux/lockd/lockd.h>
35 #include <linux/nfs.h>
36
37 #define NLMDBG_FACILITY         NLMDBG_SVC
38 #define LOCKD_BUFSIZE           (1024 + NLMSVC_XDRSIZE)
39 #define ALLOWED_SIGS            (sigmask(SIGKILL))
40
41 static struct svc_program       nlmsvc_program;
42
43 struct nlmsvc_binding *         nlmsvc_ops;
44 EXPORT_SYMBOL(nlmsvc_ops);
45
46 static DEFINE_MUTEX(nlmsvc_mutex);
47 static unsigned int             nlmsvc_users;
48 static pid_t                    nlmsvc_pid;
49 int                             nlmsvc_grace_period;
50 unsigned long                   nlmsvc_timeout;
51
52 static DECLARE_COMPLETION(lockd_start_done);
53 static DECLARE_WAIT_QUEUE_HEAD(lockd_exit);
54
55 /*
56  * These can be set at insmod time (useful for NFS as root filesystem),
57  * and also changed through the sysctl interface.  -- Jamie Lokier, Aug 2003
58  */
59 static unsigned long            nlm_grace_period;
60 static unsigned long            nlm_timeout = LOCKD_DFLT_TIMEO;
61 static int                      nlm_udpport, nlm_tcpport;
62
63 /*
64  * Constants needed for the sysctl interface.
65  */
66 static const unsigned long      nlm_grace_period_min = 0;
67 static const unsigned long      nlm_grace_period_max = 240;
68 static const unsigned long      nlm_timeout_min = 3;
69 static const unsigned long      nlm_timeout_max = 20;
70 static const int                nlm_port_min = 0, nlm_port_max = 65535;
71
72 static struct ctl_table_header * nlm_sysctl_table;
73
74 static unsigned long set_grace_period(void)
75 {
76         unsigned long grace_period;
77
78         /* Note: nlm_timeout should always be nonzero */
79         if (nlm_grace_period)
80                 grace_period = ((nlm_grace_period + nlm_timeout - 1)
81                                 / nlm_timeout) * nlm_timeout * HZ;
82         else
83                 grace_period = nlm_timeout * 5 * HZ;
84         nlmsvc_grace_period = 1;
85         return grace_period + jiffies;
86 }
87
88 static inline void clear_grace_period(void)
89 {
90         nlmsvc_grace_period = 0;
91 }
92
93 /*
94  * This is the lockd kernel thread
95  */
96 static void
97 lockd(struct svc_rqst *rqstp)
98 {
99         struct svc_serv *serv = rqstp->rq_server;
100         int             err = 0;
101         unsigned long grace_period_expire;
102
103         /* Lock module and set up kernel thread */
104         /* lockd_up is waiting for us to startup, so will
105          * be holding a reference to this module, so it
106          * is safe to just claim another reference
107          */
108         __module_get(THIS_MODULE);
109         lock_kernel();
110
111         /*
112          * Let our maker know we're running.
113          */
114         nlmsvc_pid = current->pid;
115         complete(&lockd_start_done);
116
117         daemonize("lockd");
118
119         /* Process request with signals blocked, but allow SIGKILL.  */
120         allow_signal(SIGKILL);
121
122         /* kick rpciod */
123         rpciod_up();
124
125         dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
126
127         if (!nlm_timeout)
128                 nlm_timeout = LOCKD_DFLT_TIMEO;
129         nlmsvc_timeout = nlm_timeout * HZ;
130
131         grace_period_expire = set_grace_period();
132
133         /*
134          * The main request loop. We don't terminate until the last
135          * NFS mount or NFS daemon has gone away, and we've been sent a
136          * signal, or else another process has taken over our job.
137          */
138         while ((nlmsvc_users || !signalled()) && nlmsvc_pid == current->pid) {
139                 long timeout = MAX_SCHEDULE_TIMEOUT;
140
141                 if (signalled()) {
142                         flush_signals(current);
143                         if (nlmsvc_ops) {
144                                 nlmsvc_invalidate_all();
145                                 grace_period_expire = set_grace_period();
146                         }
147                 }
148
149                 /*
150                  * Retry any blocked locks that have been notified by
151                  * the VFS. Don't do this during grace period.
152                  * (Theoretically, there shouldn't even be blocked locks
153                  * during grace period).
154                  */
155                 if (!nlmsvc_grace_period) {
156                         timeout = nlmsvc_retry_blocked();
157                 } else if (time_before(grace_period_expire, jiffies))
158                         clear_grace_period();
159
160                 /*
161                  * Find a socket with data available and call its
162                  * recvfrom routine.
163                  */
164                 err = svc_recv(serv, rqstp, timeout);
165                 if (err == -EAGAIN || err == -EINTR)
166                         continue;
167                 if (err < 0) {
168                         printk(KERN_WARNING
169                                "lockd: terminating on error %d\n",
170                                -err);
171                         break;
172                 }
173
174                 dprintk("lockd: request from %08x\n",
175                         (unsigned)ntohl(rqstp->rq_addr.sin_addr.s_addr));
176
177                 svc_process(serv, rqstp);
178
179         }
180
181         flush_signals(current);
182
183         /*
184          * Check whether there's a new lockd process before
185          * shutting down the hosts and clearing the slot.
186          */
187         if (!nlmsvc_pid || current->pid == nlmsvc_pid) {
188                 if (nlmsvc_ops)
189                         nlmsvc_invalidate_all();
190                 nlm_shutdown_hosts();
191                 nlmsvc_pid = 0;
192         } else
193                 printk(KERN_DEBUG
194                         "lockd: new process, skipping host shutdown\n");
195         wake_up(&lockd_exit);
196
197         /* Exit the RPC thread */
198         svc_exit_thread(rqstp);
199
200         /* release rpciod */
201         rpciod_down();
202
203         /* Release module */
204         unlock_kernel();
205         module_put_and_exit(0);
206 }
207
208 /*
209  * Bring up the lockd process if it's not already up.
210  */
211 int
212 lockd_up(void)
213 {
214         static int              warned;
215         struct svc_serv *       serv;
216         int                     error = 0;
217
218         mutex_lock(&nlmsvc_mutex);
219         /*
220          * Unconditionally increment the user count ... this is
221          * the number of clients who _want_ a lockd process.
222          */
223         nlmsvc_users++; 
224         /*
225          * Check whether we're already up and running.
226          */
227         if (nlmsvc_pid)
228                 goto out;
229
230         /*
231          * Sanity check: if there's no pid,
232          * we should be the first user ...
233          */
234         if (nlmsvc_users > 1)
235                 printk(KERN_WARNING
236                         "lockd_up: no pid, %d users??\n", nlmsvc_users);
237
238         error = -ENOMEM;
239         serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL);
240         if (!serv) {
241                 printk(KERN_WARNING "lockd_up: create service failed\n");
242                 goto out;
243         }
244
245         if ((error = svc_makesock(serv, IPPROTO_UDP, nlm_udpport)) < 0 
246 #ifdef CONFIG_NFSD_TCP
247          || (error = svc_makesock(serv, IPPROTO_TCP, nlm_tcpport)) < 0
248 #endif
249                 ) {
250                 if (warned++ == 0) 
251                         printk(KERN_WARNING
252                                 "lockd_up: makesock failed, error=%d\n", error);
253                 goto destroy_and_out;
254         } 
255         warned = 0;
256
257         /*
258          * Create the kernel thread and wait for it to start.
259          */
260         error = svc_create_thread(lockd, serv);
261         if (error) {
262                 printk(KERN_WARNING
263                         "lockd_up: create thread failed, error=%d\n", error);
264                 goto destroy_and_out;
265         }
266         wait_for_completion(&lockd_start_done);
267
268         /*
269          * Note: svc_serv structures have an initial use count of 1,
270          * so we exit through here on both success and failure.
271          */
272 destroy_and_out:
273         svc_destroy(serv);
274 out:
275         mutex_unlock(&nlmsvc_mutex);
276         return error;
277 }
278 EXPORT_SYMBOL(lockd_up);
279
280 /*
281  * Decrement the user count and bring down lockd if we're the last.
282  */
283 void
284 lockd_down(void)
285 {
286         static int warned;
287
288         mutex_lock(&nlmsvc_mutex);
289         if (nlmsvc_users) {
290                 if (--nlmsvc_users)
291                         goto out;
292         } else
293                 printk(KERN_WARNING "lockd_down: no users! pid=%d\n", nlmsvc_pid);
294
295         if (!nlmsvc_pid) {
296                 if (warned++ == 0)
297                         printk(KERN_WARNING "lockd_down: no lockd running.\n"); 
298                 goto out;
299         }
300         warned = 0;
301
302         kill_proc(nlmsvc_pid, SIGKILL, 1);
303         /*
304          * Wait for the lockd process to exit, but since we're holding
305          * the lockd semaphore, we can't wait around forever ...
306          */
307         clear_thread_flag(TIF_SIGPENDING);
308         interruptible_sleep_on_timeout(&lockd_exit, HZ);
309         if (nlmsvc_pid) {
310                 printk(KERN_WARNING 
311                         "lockd_down: lockd failed to exit, clearing pid\n");
312                 nlmsvc_pid = 0;
313         }
314         spin_lock_irq(&current->sighand->siglock);
315         recalc_sigpending();
316         spin_unlock_irq(&current->sighand->siglock);
317 out:
318         mutex_unlock(&nlmsvc_mutex);
319 }
320 EXPORT_SYMBOL(lockd_down);
321
322 /*
323  * Sysctl parameters (same as module parameters, different interface).
324  */
325
326 /* Something that isn't CTL_ANY, CTL_NONE or a value that may clash. */
327 #define CTL_UNNUMBERED          -2
328
329 static ctl_table nlm_sysctls[] = {
330         {
331                 .ctl_name       = CTL_UNNUMBERED,
332                 .procname       = "nlm_grace_period",
333                 .data           = &nlm_grace_period,
334                 .maxlen         = sizeof(unsigned long),
335                 .mode           = 0644,
336                 .proc_handler   = &proc_doulongvec_minmax,
337                 .extra1         = (unsigned long *) &nlm_grace_period_min,
338                 .extra2         = (unsigned long *) &nlm_grace_period_max,
339         },
340         {
341                 .ctl_name       = CTL_UNNUMBERED,
342                 .procname       = "nlm_timeout",
343                 .data           = &nlm_timeout,
344                 .maxlen         = sizeof(unsigned long),
345                 .mode           = 0644,
346                 .proc_handler   = &proc_doulongvec_minmax,
347                 .extra1         = (unsigned long *) &nlm_timeout_min,
348                 .extra2         = (unsigned long *) &nlm_timeout_max,
349         },
350         {
351                 .ctl_name       = CTL_UNNUMBERED,
352                 .procname       = "nlm_udpport",
353                 .data           = &nlm_udpport,
354                 .maxlen         = sizeof(int),
355                 .mode           = 0644,
356                 .proc_handler   = &proc_dointvec_minmax,
357                 .extra1         = (int *) &nlm_port_min,
358                 .extra2         = (int *) &nlm_port_max,
359         },
360         {
361                 .ctl_name       = CTL_UNNUMBERED,
362                 .procname       = "nlm_tcpport",
363                 .data           = &nlm_tcpport,
364                 .maxlen         = sizeof(int),
365                 .mode           = 0644,
366                 .proc_handler   = &proc_dointvec_minmax,
367                 .extra1         = (int *) &nlm_port_min,
368                 .extra2         = (int *) &nlm_port_max,
369         },
370         { .ctl_name = 0 }
371 };
372
373 static ctl_table nlm_sysctl_dir[] = {
374         {
375                 .ctl_name       = CTL_UNNUMBERED,
376                 .procname       = "nfs",
377                 .mode           = 0555,
378                 .child          = nlm_sysctls,
379         },
380         { .ctl_name = 0 }
381 };
382
383 static ctl_table nlm_sysctl_root[] = {
384         {
385                 .ctl_name       = CTL_FS,
386                 .procname       = "fs",
387                 .mode           = 0555,
388                 .child          = nlm_sysctl_dir,
389         },
390         { .ctl_name = 0 }
391 };
392
393 /*
394  * Module (and driverfs) parameters.
395  */
396
397 #define param_set_min_max(name, type, which_strtol, min, max)           \
398 static int param_set_##name(const char *val, struct kernel_param *kp)   \
399 {                                                                       \
400         char *endp;                                                     \
401         __typeof__(type) num = which_strtol(val, &endp, 0);             \
402         if (endp == val || *endp || num < (min) || num > (max))         \
403                 return -EINVAL;                                         \
404         *((int *) kp->arg) = num;                                       \
405         return 0;                                                       \
406 }
407
408 static inline int is_callback(u32 proc)
409 {
410         return proc == NLMPROC_GRANTED
411                 || proc == NLMPROC_GRANTED_MSG
412                 || proc == NLMPROC_TEST_RES
413                 || proc == NLMPROC_LOCK_RES
414                 || proc == NLMPROC_CANCEL_RES
415                 || proc == NLMPROC_UNLOCK_RES
416                 || proc == NLMPROC_NSM_NOTIFY;
417 }
418
419
420 static int lockd_authenticate(struct svc_rqst *rqstp)
421 {
422         rqstp->rq_client = NULL;
423         switch (rqstp->rq_authop->flavour) {
424                 case RPC_AUTH_NULL:
425                 case RPC_AUTH_UNIX:
426                         if (rqstp->rq_proc == 0)
427                                 return SVC_OK;
428                         if (is_callback(rqstp->rq_proc)) {
429                                 /* Leave it to individual procedures to
430                                  * call nlmsvc_lookup_host(rqstp)
431                                  */
432                                 return SVC_OK;
433                         }
434                         return svc_set_client(rqstp);
435         }
436         return SVC_DENIED;
437 }
438
439
440 param_set_min_max(port, int, simple_strtol, 0, 65535)
441 param_set_min_max(grace_period, unsigned long, simple_strtoul,
442                   nlm_grace_period_min, nlm_grace_period_max)
443 param_set_min_max(timeout, unsigned long, simple_strtoul,
444                   nlm_timeout_min, nlm_timeout_max)
445
446 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
447 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
448 MODULE_LICENSE("GPL");
449
450 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
451                   &nlm_grace_period, 0644);
452 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
453                   &nlm_timeout, 0644);
454 module_param_call(nlm_udpport, param_set_port, param_get_int,
455                   &nlm_udpport, 0644);
456 module_param_call(nlm_tcpport, param_set_port, param_get_int,
457                   &nlm_tcpport, 0644);
458
459 /*
460  * Initialising and terminating the module.
461  */
462
463 static int __init init_nlm(void)
464 {
465         nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root, 0);
466         return nlm_sysctl_table ? 0 : -ENOMEM;
467 }
468
469 static void __exit exit_nlm(void)
470 {
471         /* FIXME: delete all NLM clients */
472         nlm_shutdown_hosts();
473         unregister_sysctl_table(nlm_sysctl_table);
474 }
475
476 module_init(init_nlm);
477 module_exit(exit_nlm);
478
479 /*
480  * Define NLM program and procedures
481  */
482 static struct svc_version       nlmsvc_version1 = {
483                 .vs_vers        = 1,
484                 .vs_nproc       = 17,
485                 .vs_proc        = nlmsvc_procedures,
486                 .vs_xdrsize     = NLMSVC_XDRSIZE,
487 };
488 static struct svc_version       nlmsvc_version3 = {
489                 .vs_vers        = 3,
490                 .vs_nproc       = 24,
491                 .vs_proc        = nlmsvc_procedures,
492                 .vs_xdrsize     = NLMSVC_XDRSIZE,
493 };
494 #ifdef CONFIG_LOCKD_V4
495 static struct svc_version       nlmsvc_version4 = {
496                 .vs_vers        = 4,
497                 .vs_nproc       = 24,
498                 .vs_proc        = nlmsvc_procedures4,
499                 .vs_xdrsize     = NLMSVC_XDRSIZE,
500 };
501 #endif
502 static struct svc_version *     nlmsvc_version[] = {
503         [1] = &nlmsvc_version1,
504         [3] = &nlmsvc_version3,
505 #ifdef CONFIG_LOCKD_V4
506         [4] = &nlmsvc_version4,
507 #endif
508 };
509
510 static struct svc_stat          nlmsvc_stats;
511
512 #define NLM_NRVERS      ARRAY_SIZE(nlmsvc_version)
513 static struct svc_program       nlmsvc_program = {
514         .pg_prog                = NLM_PROGRAM,          /* program number */
515         .pg_nvers               = NLM_NRVERS,           /* number of entries in nlmsvc_version */
516         .pg_vers                = nlmsvc_version,       /* version table */
517         .pg_name                = "lockd",              /* service name */
518         .pg_class               = "nfsd",               /* share authentication with nfsd */
519         .pg_stats               = &nlmsvc_stats,        /* stats table */
520         .pg_authenticate = &lockd_authenticate  /* export authentication */
521 };