?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
mm-only debug patch...
[mmotm.git] / fs / nfsd / nfssvc.c
blob67ea83eedd43eb7b69e896e1db54f8fd995a0d9e
1 /*
2 * linux/fs/nfsd/nfssvc.c
3 *
4 * Central processing for nfsd.
5 *
6 * Authors: Olaf Kirch (okir@monad.swb.de)
7 *
8 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
9 */
10
11 #include <linux/module.h>
12 #include <linux/sched.h>
13 #include <linux/time.h>
14 #include <linux/errno.h>
15 #include <linux/nfs.h>
16 #include <linux/in.h>
17 #include <linux/uio.h>
18 #include <linux/unistd.h>
19 #include <linux/slab.h>
20 #include <linux/smp.h>
21 #include <linux/freezer.h>
22 #include <linux/fs_struct.h>
23 #include <linux/kthread.h>
24 #include <linux/swap.h>
25
26 #include <linux/sunrpc/types.h>
27 #include <linux/sunrpc/stats.h>
28 #include <linux/sunrpc/svc.h>
29 #include <linux/sunrpc/svcsock.h>
30 #include <linux/sunrpc/cache.h>
31 #include <linux/nfsd/nfsd.h>
32 #include <linux/nfsd/stats.h>
33 #include <linux/nfsd/cache.h>
34 #include <linux/nfsd/syscall.h>
35 #include <linux/lockd/bind.h>
36 #include <linux/nfsacl.h>
37 #include <linux/seq_file.h>
38
39 #define NFSDDBG_FACILITY NFSDDBG_SVC
40
41 extern struct svc_program nfsd_program;
42 static int nfsd(void *vrqstp);
43 struct timeval nfssvc_boot;
44
45 /*
46 * nfsd_mutex protects nfsd_serv -- both the pointer itself and the members
47 * of the svc_serv struct. In particular, ->sv_nrthreads but also to some
48 * extent ->sv_temp_socks and ->sv_permsocks. It also protects nfsdstats.th_cnt
49 *
50 * If (out side the lock) nfsd_serv is non-NULL, then it must point to a
51 * properly initialised 'struct svc_serv' with ->sv_nrthreads > 0. That number
52 * of nfsd threads must exist and each must listed in ->sp_all_threads in each
53 * entry of ->sv_pools[].
54 *
55 * Transitions of the thread count between zero and non-zero are of particular
56 * interest since the svc_serv needs to be created and initialized at that
57 * point, or freed.
58 *
59 * Finally, the nfsd_mutex also protects some of the global variables that are
60 * accessed when nfsd starts and that are settable via the write_* routines in
61 * nfsctl.c. In particular:
62 *
63 * user_recovery_dirname
64 * user_lease_time
65 * nfsd_versions
66 */
67 DEFINE_MUTEX(nfsd_mutex);
68 struct svc_serv *nfsd_serv;
69
70 /*
71 * nfsd_drc_lock protects nfsd_drc_max_pages and nfsd_drc_pages_used.
72 * nfsd_drc_max_pages limits the total amount of memory available for
73 * version 4.1 DRC caches.
74 * nfsd_drc_pages_used tracks the current version 4.1 DRC memory usage.
75 */
76 spinlock_t nfsd_drc_lock;
77 unsigned int nfsd_drc_max_mem;
78 unsigned int nfsd_drc_mem_used;
79
80 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
81 static struct svc_stat nfsd_acl_svcstats;
82 static struct svc_version * nfsd_acl_version[] = {
83 [2] = &nfsd_acl_version2,
84 [3] = &nfsd_acl_version3,
85 };
86
87 #define NFSD_ACL_MINVERS 2
88 #define NFSD_ACL_NRVERS ARRAY_SIZE(nfsd_acl_version)
89 static struct svc_version *nfsd_acl_versions[NFSD_ACL_NRVERS];
90
91 static struct svc_program nfsd_acl_program = {
92 .pg_prog = NFS_ACL_PROGRAM,
93 .pg_nvers = NFSD_ACL_NRVERS,
94 .pg_vers = nfsd_acl_versions,
95 .pg_name = "nfsacl",
96 .pg_class = "nfsd",
97 .pg_stats = &nfsd_acl_svcstats,
98 .pg_authenticate = &svc_set_client,
99 };
100
101 static struct svc_stat nfsd_acl_svcstats = {
102 .program = &nfsd_acl_program,
103 };
104 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
105
106 static struct svc_version * nfsd_version[] = {
107 [2] = &nfsd_version2,
108 #if defined(CONFIG_NFSD_V3)
109 [3] = &nfsd_version3,
110 #endif
111 #if defined(CONFIG_NFSD_V4)
112 [4] = &nfsd_version4,
113 #endif
114 };
115
116 #define NFSD_MINVERS 2
117 #define NFSD_NRVERS ARRAY_SIZE(nfsd_version)
118 static struct svc_version *nfsd_versions[NFSD_NRVERS];
119
120 struct svc_program nfsd_program = {
121 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
122 .pg_next = &nfsd_acl_program,
123 #endif
124 .pg_prog = NFS_PROGRAM, /* program number */
125 .pg_nvers = NFSD_NRVERS, /* nr of entries in nfsd_version */
126 .pg_vers = nfsd_versions, /* version table */
127 .pg_name = "nfsd", /* program name */
128 .pg_class = "nfsd", /* authentication class */
129 .pg_stats = &nfsd_svcstats, /* version table */
130 .pg_authenticate = &svc_set_client, /* export authentication */
131
132 };
133
134 u32 nfsd_supported_minorversion;
135
136 int nfsd_vers(int vers, enum vers_op change)
137 {
138 if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS)
139 return -1;
140 switch(change) {
141 case NFSD_SET:
142 nfsd_versions[vers] = nfsd_version[vers];
143 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
144 if (vers < NFSD_ACL_NRVERS)
145 nfsd_acl_versions[vers] = nfsd_acl_version[vers];
146 #endif
147 break;
148 case NFSD_CLEAR:
149 nfsd_versions[vers] = NULL;
150 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
151 if (vers < NFSD_ACL_NRVERS)
152 nfsd_acl_versions[vers] = NULL;
153 #endif
154 break;
155 case NFSD_TEST:
156 return nfsd_versions[vers] != NULL;
157 case NFSD_AVAIL:
158 return nfsd_version[vers] != NULL;
159 }
160 return 0;
161 }
162
163 int nfsd_minorversion(u32 minorversion, enum vers_op change)
164 {
165 if (minorversion > NFSD_SUPPORTED_MINOR_VERSION)
166 return -1;
167 switch(change) {
168 case NFSD_SET:
169 nfsd_supported_minorversion = minorversion;
170 break;
171 case NFSD_CLEAR:
172 if (minorversion == 0)
173 return -1;
174 nfsd_supported_minorversion = minorversion - 1;
175 break;
176 case NFSD_TEST:
177 return minorversion <= nfsd_supported_minorversion;
178 case NFSD_AVAIL:
179 return minorversion <= NFSD_SUPPORTED_MINOR_VERSION;
180 }
181 return 0;
182 }
183
184 /*
185 * Maximum number of nfsd processes
186 */
187 #define NFSD_MAXSERVS 8192
188
189 int nfsd_nrthreads(void)
190 {
191 int rv = 0;
192 mutex_lock(&nfsd_mutex);
193 if (nfsd_serv)
194 rv = nfsd_serv->sv_nrthreads;
195 mutex_unlock(&nfsd_mutex);
196 return rv;
197 }
198
199 static void nfsd_last_thread(struct svc_serv *serv)
200 {
201 /* When last nfsd thread exits we need to do some clean-up */
202 struct svc_xprt *xprt;
203 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list)
204 lockd_down();
205 nfsd_serv = NULL;
206 nfsd_racache_shutdown();
207 nfs4_state_shutdown();
208
209 printk(KERN_WARNING "nfsd: last server has exited, flushing export "
210 "cache\n");
211 nfsd_export_flush();
212 }
213
214 void nfsd_reset_versions(void)
215 {
216 int found_one = 0;
217 int i;
218
219 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) {
220 if (nfsd_program.pg_vers[i])
221 found_one = 1;
222 }
223
224 if (!found_one) {
225 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++)
226 nfsd_program.pg_vers[i] = nfsd_version[i];
227 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
228 for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++)
229 nfsd_acl_program.pg_vers[i] =
230 nfsd_acl_version[i];
231 #endif
232 }
233 }
234
235 /*
236 * Each session guarantees a negotiated per slot memory cache for replies
237 * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated
238 * NFSv4.1 server might want to use more memory for a DRC than a machine
239 * with mutiple services.
240 *
241 * Impose a hard limit on the number of pages for the DRC which varies
242 * according to the machines free pages. This is of course only a default.
243 *
244 * For now this is a #defined shift which could be under admin control
245 * in the future.
246 */
247 static void set_max_drc(void)
248 {
249 #define NFSD_DRC_SIZE_SHIFT 10
250 nfsd_drc_max_mem = (nr_free_buffer_pages()
251 >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE;
252 nfsd_drc_mem_used = 0;
253 spin_lock_init(&nfsd_drc_lock);
254 dprintk("%s nfsd_drc_max_mem %u \n", __func__, nfsd_drc_max_mem);
255 }
256
257 int nfsd_create_serv(void)
258 {
259 int err = 0;
260
261 WARN_ON(!mutex_is_locked(&nfsd_mutex));
262 if (nfsd_serv) {
263 svc_get(nfsd_serv);
264 return 0;
265 }
266 if (nfsd_max_blksize == 0) {
267 /* choose a suitable default */
268 struct sysinfo i;
269 si_meminfo(&i);
270 /* Aim for 1/4096 of memory per thread
271 * This gives 1MB on 4Gig machines
272 * But only uses 32K on 128M machines.
273 * Bottom out at 8K on 32M and smaller.
274 * Of course, this is only a default.
275 */
276 nfsd_max_blksize = NFSSVC_MAXBLKSIZE;
277 i.totalram <<= PAGE_SHIFT - 12;
278 while (nfsd_max_blksize > i.totalram &&
279 nfsd_max_blksize >= 8*1024*2)
280 nfsd_max_blksize /= 2;
281 }
282
283 nfsd_serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize,
284 nfsd_last_thread, nfsd, THIS_MODULE);
285 if (nfsd_serv == NULL)
286 err = -ENOMEM;
287 else
288 set_max_drc();
289
290 do_gettimeofday(&nfssvc_boot); /* record boot time */
291 return err;
292 }
293
294 static int nfsd_init_socks(int port)
295 {
296 int error;
297 if (!list_empty(&nfsd_serv->sv_permsocks))
298 return 0;
299
300 error = svc_create_xprt(nfsd_serv, "udp", PF_INET, port,
301 SVC_SOCK_DEFAULTS);
302 if (error < 0)
303 return error;
304
305 error = lockd_up();
306 if (error < 0)
307 return error;
308
309 error = svc_create_xprt(nfsd_serv, "tcp", PF_INET, port,
310 SVC_SOCK_DEFAULTS);
311 if (error < 0)
312 return error;
313
314 error = lockd_up();
315 if (error < 0)
316 return error;
317
318 return 0;
319 }
320
321 int nfsd_nrpools(void)
322 {
323 if (nfsd_serv == NULL)
324 return 0;
325 else
326 return nfsd_serv->sv_nrpools;
327 }
328
329 int nfsd_get_nrthreads(int n, int *nthreads)
330 {
331 int i = 0;
332
333 if (nfsd_serv != NULL) {
334 for (i = 0; i < nfsd_serv->sv_nrpools && i < n; i++)
335 nthreads[i] = nfsd_serv->sv_pools[i].sp_nrthreads;
336 }
337
338 return 0;
339 }
340
341 int nfsd_set_nrthreads(int n, int *nthreads)
342 {
343 int i = 0;
344 int tot = 0;
345 int err = 0;
346
347 WARN_ON(!mutex_is_locked(&nfsd_mutex));
348
349 if (nfsd_serv == NULL || n <= 0)
350 return 0;
351
352 if (n > nfsd_serv->sv_nrpools)
353 n = nfsd_serv->sv_nrpools;
354
355 /* enforce a global maximum number of threads */
356 tot = 0;
357 for (i = 0; i < n; i++) {
358 if (nthreads[i] > NFSD_MAXSERVS)
359 nthreads[i] = NFSD_MAXSERVS;
360 tot += nthreads[i];
361 }
362 if (tot > NFSD_MAXSERVS) {
363 /* total too large: scale down requested numbers */
364 for (i = 0; i < n && tot > 0; i++) {
365 int new = nthreads[i] * NFSD_MAXSERVS / tot;
366 tot -= (nthreads[i] - new);
367 nthreads[i] = new;
368 }
369 for (i = 0; i < n && tot > 0; i++) {
370 nthreads[i]--;
371 tot--;
372 }
373 }
374
375 /*
376 * There must always be a thread in pool 0; the admin
377 * can't shut down NFS completely using pool_threads.
378 */
379 if (nthreads[0] == 0)
380 nthreads[0] = 1;
381
382 /* apply the new numbers */
383 svc_get(nfsd_serv);
384 for (i = 0; i < n; i++) {
385 err = svc_set_num_threads(nfsd_serv, &nfsd_serv->sv_pools[i],
386 nthreads[i]);
387 if (err)
388 break;
389 }
390 svc_destroy(nfsd_serv);
391
392 return err;
393 }
394
395 int
396 nfsd_svc(unsigned short port, int nrservs)
397 {
398 int error;
399
400 mutex_lock(&nfsd_mutex);
401 dprintk("nfsd: creating service\n");
402 if (nrservs <= 0)
403 nrservs = 0;
404 if (nrservs > NFSD_MAXSERVS)
405 nrservs = NFSD_MAXSERVS;
406 error = 0;
407 if (nrservs == 0 && nfsd_serv == NULL)
408 goto out;
409
410 /* Readahead param cache - will no-op if it already exists */
411 error = nfsd_racache_init(2*nrservs);
412 if (error<0)
413 goto out;
414 error = nfs4_state_start();
415 if (error)
416 goto out;
417
418 nfsd_reset_versions();
419
420 error = nfsd_create_serv();
421
422 if (error)
423 goto out;
424 error = nfsd_init_socks(port);
425 if (error)
426 goto failure;
427
428 error = svc_set_num_threads(nfsd_serv, NULL, nrservs);
429 if (error == 0)
430 /* We are holding a reference to nfsd_serv which
431 * we don't want to count in the return value,
432 * so subtract 1
433 */
434 error = nfsd_serv->sv_nrthreads - 1;
435 failure:
436 svc_destroy(nfsd_serv); /* Release server */
437 out:
438 mutex_unlock(&nfsd_mutex);
439 return error;
440 }
441
442
443 /*
444 * This is the NFS server kernel thread
445 */
446 static int
447 nfsd(void *vrqstp)
448 {
449 struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp;
450 int err, preverr = 0;
451
452 /* Lock module and set up kernel thread */
453 mutex_lock(&nfsd_mutex);
454
455 /* At this point, the thread shares current->fs
456 * with the init process. We need to create files with a
457 * umask of 0 instead of init's umask. */
458 if (unshare_fs_struct() < 0) {
459 printk("Unable to start nfsd thread: out of memory\n");
460 goto out;
461 }
462
463 current->fs->umask = 0;
464
465 /*
466 * thread is spawned with all signals set to SIG_IGN, re-enable
467 * the ones that will bring down the thread
468 */
469 allow_signal(SIGKILL);
470 allow_signal(SIGHUP);
471 allow_signal(SIGINT);
472 allow_signal(SIGQUIT);
473
474 nfsdstats.th_cnt++;
475 mutex_unlock(&nfsd_mutex);
476
477 /*
478 * We want less throttling in balance_dirty_pages() so that nfs to
479 * localhost doesn't cause nfsd to lock up due to all the client's
480 * dirty pages.
481 */
482 current->flags |= PF_LESS_THROTTLE;
483 set_freezable();
484
485 /*
486 * The main request loop
487 */
488 for (;;) {
489 /*
490 * Find a socket with data available and call its
491 * recvfrom routine.
492 */
493 while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN)
494 ;
495 if (err == -EINTR)
496 break;
497 else if (err < 0) {
498 if (err != preverr) {
499 printk(KERN_WARNING "%s: unexpected error "
500 "from svc_recv (%d)\n", __func__, -err);
501 preverr = err;
502 }
503 schedule_timeout_uninterruptible(HZ);
504 continue;
505 }
506
507
508 /* Lock the export hash tables for reading. */
509 exp_readlock();
510
511 validate_process_creds();
512 svc_process(rqstp);
513 validate_process_creds();
514
515 /* Unlock export hash tables */
516 exp_readunlock();
517 }
518
519 /* Clear signals before calling svc_exit_thread() */
520 flush_signals(current);
521
522 mutex_lock(&nfsd_mutex);
523 nfsdstats.th_cnt --;
524
525 out:
526 /* Release the thread */
527 svc_exit_thread(rqstp);
528
529 /* Release module */
530 mutex_unlock(&nfsd_mutex);
531 module_put_and_exit(0);
532 return 0;
533 }
534
535 static __be32 map_new_errors(u32 vers, __be32 nfserr)
536 {
537 if (nfserr == nfserr_jukebox && vers == 2)
538 return nfserr_dropit;
539 if (nfserr == nfserr_wrongsec && vers < 4)
540 return nfserr_acces;
541 return nfserr;
542 }
543
544 int
545 nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
546 {
547 struct svc_procedure *proc;
548 kxdrproc_t xdr;
549 __be32 nfserr;
550 __be32 *nfserrp;
551
552 dprintk("nfsd_dispatch: vers %d proc %d\n",
553 rqstp->rq_vers, rqstp->rq_proc);
554 proc = rqstp->rq_procinfo;
555
556 /* Check whether we have this call in the cache. */
557 switch (nfsd_cache_lookup(rqstp, proc->pc_cachetype)) {
558 case RC_INTR:
559 case RC_DROPIT:
560 return 0;
561 case RC_REPLY:
562 return 1;
563 case RC_DOIT:;
564 /* do it */
565 }
566
567 /* Decode arguments */
568 xdr = proc->pc_decode;
569 if (xdr && !xdr(rqstp, (__be32*)rqstp->rq_arg.head[0].iov_base,
570 rqstp->rq_argp)) {
571 dprintk("nfsd: failed to decode arguments!\n");
572 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
573 *statp = rpc_garbage_args;
574 return 1;
575 }
576
577 /* need to grab the location to store the status, as
578 * nfsv4 does some encoding while processing
579 */
580 nfserrp = rqstp->rq_res.head[0].iov_base
581 + rqstp->rq_res.head[0].iov_len;
582 rqstp->rq_res.head[0].iov_len += sizeof(__be32);
583
584 /* Now call the procedure handler, and encode NFS status. */
585 nfserr = proc->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
586 nfserr = map_new_errors(rqstp->rq_vers, nfserr);
587 if (nfserr == nfserr_dropit) {
588 dprintk("nfsd: Dropping request; may be revisited later\n");
589 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
590 return 0;
591 }
592
593 if (rqstp->rq_proc != 0)
594 *nfserrp++ = nfserr;
595
596 /* Encode result.
597 * For NFSv2, additional info is never returned in case of an error.
598 */
599 if (!(nfserr && rqstp->rq_vers == 2)) {
600 xdr = proc->pc_encode;
601 if (xdr && !xdr(rqstp, nfserrp,
602 rqstp->rq_resp)) {
603 /* Failed to encode result. Release cache entry */
604 dprintk("nfsd: failed to encode result!\n");
605 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
606 *statp = rpc_system_err;
607 return 1;
608 }
609 }
610
611 /* Store reply in cache. */
612 nfsd_cache_update(rqstp, proc->pc_cachetype, statp + 1);
613 return 1;
614 }
615
616 int nfsd_pool_stats_open(struct inode *inode, struct file *file)
617 {
618 int ret;
619 mutex_lock(&nfsd_mutex);
620 if (nfsd_serv == NULL) {
621 mutex_unlock(&nfsd_mutex);
622 return -ENODEV;
623 }
624 /* bump up the psudo refcount while traversing */
625 svc_get(nfsd_serv);
626 ret = svc_pool_stats_open(nfsd_serv, file);
627 mutex_unlock(&nfsd_mutex);
628 return ret;
629 }
630
631 int nfsd_pool_stats_release(struct inode *inode, struct file *file)
632 {
633 int ret = seq_release(inode, file);
634 mutex_lock(&nfsd_mutex);
635 /* this function really, really should have been called svc_put() */
636 svc_destroy(nfsd_serv);
637 mutex_unlock(&nfsd_mutex);
638 return ret;
639 }
mm of the moment repository