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1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Central processing for nfsd.
4 *
5 * Authors: Olaf Kirch (okir@monad.swb.de)
6 *
7 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
8 */
9
10 #include <linux/sched/signal.h>
11 #include <linux/freezer.h>
12 #include <linux/module.h>
13 #include <linux/fs_struct.h>
14 #include <linux/swap.h>
15
16 #include <linux/sunrpc/stats.h>
17 #include <linux/sunrpc/svcsock.h>
18 #include <linux/sunrpc/svc_xprt.h>
19 #include <linux/lockd/bind.h>
20 #include <linux/nfsacl.h>
21 #include <linux/seq_file.h>
22 #include <linux/inetdevice.h>
23 #include <net/addrconf.h>
24 #include <net/ipv6.h>
25 #include <net/net_namespace.h>
26 #include "nfsd.h"
27 #include "cache.h"
28 #include "vfs.h"
29 #include "netns.h"
30 #include "filecache.h"
31
32 #include "trace.h"
33
34 #define NFSDDBG_FACILITY NFSDDBG_SVC
35
36 extern struct svc_program nfsd_program;
37 static int nfsd(void *vrqstp);
38 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
39 static int nfsd_acl_rpcbind_set(struct net *,
40 const struct svc_program *,
41 u32, int,
42 unsigned short,
43 unsigned short);
44 static __be32 nfsd_acl_init_request(struct svc_rqst *,
45 const struct svc_program *,
46 struct svc_process_info *);
47 #endif
48 static int nfsd_rpcbind_set(struct net *,
49 const struct svc_program *,
50 u32, int,
51 unsigned short,
52 unsigned short);
53 static __be32 nfsd_init_request(struct svc_rqst *,
54 const struct svc_program *,
55 struct svc_process_info *);
56
57 /*
58 * nfsd_mutex protects nn->nfsd_serv -- both the pointer itself and the members
59 * of the svc_serv struct. In particular, ->sv_nrthreads but also to some
60 * extent ->sv_temp_socks and ->sv_permsocks. It also protects nfsdstats.th_cnt
61 *
62 * If (out side the lock) nn->nfsd_serv is non-NULL, then it must point to a
63 * properly initialised 'struct svc_serv' with ->sv_nrthreads > 0. That number
64 * of nfsd threads must exist and each must listed in ->sp_all_threads in each
65 * entry of ->sv_pools[].
66 *
67 * Transitions of the thread count between zero and non-zero are of particular
68 * interest since the svc_serv needs to be created and initialized at that
69 * point, or freed.
70 *
71 * Finally, the nfsd_mutex also protects some of the global variables that are
72 * accessed when nfsd starts and that are settable via the write_* routines in
73 * nfsctl.c. In particular:
74 *
75 * user_recovery_dirname
76 * user_lease_time
77 * nfsd_versions
78 */
79 DEFINE_MUTEX(nfsd_mutex);
80
81 /*
82 * nfsd_drc_lock protects nfsd_drc_max_pages and nfsd_drc_pages_used.
83 * nfsd_drc_max_pages limits the total amount of memory available for
84 * version 4.1 DRC caches.
85 * nfsd_drc_pages_used tracks the current version 4.1 DRC memory usage.
86 */
87 spinlock_t nfsd_drc_lock;
88 unsigned long nfsd_drc_max_mem;
89 unsigned long nfsd_drc_mem_used;
90
91 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
92 static struct svc_stat nfsd_acl_svcstats;
93 static const struct svc_version *nfsd_acl_version[] = {
94 [2] = &nfsd_acl_version2,
95 [3] = &nfsd_acl_version3,
96 };
97
98 #define NFSD_ACL_MINVERS 2
99 #define NFSD_ACL_NRVERS ARRAY_SIZE(nfsd_acl_version)
100
101 static struct svc_program nfsd_acl_program = {
102 .pg_prog = NFS_ACL_PROGRAM,
103 .pg_nvers = NFSD_ACL_NRVERS,
104 .pg_vers = nfsd_acl_version,
105 .pg_name = "nfsacl",
106 .pg_class = "nfsd",
107 .pg_stats = &nfsd_acl_svcstats,
108 .pg_authenticate = &svc_set_client,
109 .pg_init_request = nfsd_acl_init_request,
110 .pg_rpcbind_set = nfsd_acl_rpcbind_set,
111 };
112
113 static struct svc_stat nfsd_acl_svcstats = {
114 .program = &nfsd_acl_program,
115 };
116 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
117
118 static const struct svc_version *nfsd_version[] = {
119 [2] = &nfsd_version2,
120 #if defined(CONFIG_NFSD_V3)
121 [3] = &nfsd_version3,
122 #endif
123 #if defined(CONFIG_NFSD_V4)
124 [4] = &nfsd_version4,
125 #endif
126 };
127
128 #define NFSD_MINVERS 2
129 #define NFSD_NRVERS ARRAY_SIZE(nfsd_version)
130
131 struct svc_program nfsd_program = {
132 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
133 .pg_next = &nfsd_acl_program,
134 #endif
135 .pg_prog = NFS_PROGRAM, /* program number */
136 .pg_nvers = NFSD_NRVERS, /* nr of entries in nfsd_version */
137 .pg_vers = nfsd_version, /* version table */
138 .pg_name = "nfsd", /* program name */
139 .pg_class = "nfsd", /* authentication class */
140 .pg_stats = &nfsd_svcstats, /* version table */
141 .pg_authenticate = &svc_set_client, /* export authentication */
142 .pg_init_request = nfsd_init_request,
143 .pg_rpcbind_set = nfsd_rpcbind_set,
144 };
145
146 static bool
147 nfsd_support_version(int vers)
148 {
149 if (vers >= NFSD_MINVERS && vers < NFSD_NRVERS)
150 return nfsd_version[vers] != NULL;
151 return false;
152 }
153
154 static bool *
155 nfsd_alloc_versions(void)
156 {
157 bool *vers = kmalloc_array(NFSD_NRVERS, sizeof(bool), GFP_KERNEL);
158 unsigned i;
159
160 if (vers) {
161 /* All compiled versions are enabled by default */
162 for (i = 0; i < NFSD_NRVERS; i++)
163 vers[i] = nfsd_support_version(i);
164 }
165 return vers;
166 }
167
168 static bool *
169 nfsd_alloc_minorversions(void)
170 {
171 bool *vers = kmalloc_array(NFSD_SUPPORTED_MINOR_VERSION + 1,
172 sizeof(bool), GFP_KERNEL);
173 unsigned i;
174
175 if (vers) {
176 /* All minor versions are enabled by default */
177 for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++)
178 vers[i] = nfsd_support_version(4);
179 }
180 return vers;
181 }
182
183 void
184 nfsd_netns_free_versions(struct nfsd_net *nn)
185 {
186 kfree(nn->nfsd_versions);
187 kfree(nn->nfsd4_minorversions);
188 nn->nfsd_versions = NULL;
189 nn->nfsd4_minorversions = NULL;
190 }
191
192 static void
193 nfsd_netns_init_versions(struct nfsd_net *nn)
194 {
195 if (!nn->nfsd_versions) {
196 nn->nfsd_versions = nfsd_alloc_versions();
197 nn->nfsd4_minorversions = nfsd_alloc_minorversions();
198 if (!nn->nfsd_versions || !nn->nfsd4_minorversions)
199 nfsd_netns_free_versions(nn);
200 }
201 }
202
203 int nfsd_vers(struct nfsd_net *nn, int vers, enum vers_op change)
204 {
205 if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS)
206 return 0;
207 switch(change) {
208 case NFSD_SET:
209 if (nn->nfsd_versions)
210 nn->nfsd_versions[vers] = nfsd_support_version(vers);
211 break;
212 case NFSD_CLEAR:
213 nfsd_netns_init_versions(nn);
214 if (nn->nfsd_versions)
215 nn->nfsd_versions[vers] = false;
216 break;
217 case NFSD_TEST:
218 if (nn->nfsd_versions)
219 return nn->nfsd_versions[vers];
220 fallthrough;
221 case NFSD_AVAIL:
222 return nfsd_support_version(vers);
223 }
224 return 0;
225 }
226
227 static void
228 nfsd_adjust_nfsd_versions4(struct nfsd_net *nn)
229 {
230 unsigned i;
231
232 for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++) {
233 if (nn->nfsd4_minorversions[i])
234 return;
235 }
236 nfsd_vers(nn, 4, NFSD_CLEAR);
237 }
238
239 int nfsd_minorversion(struct nfsd_net *nn, u32 minorversion, enum vers_op change)
240 {
241 if (minorversion > NFSD_SUPPORTED_MINOR_VERSION &&
242 change != NFSD_AVAIL)
243 return -1;
244
245 switch(change) {
246 case NFSD_SET:
247 if (nn->nfsd4_minorversions) {
248 nfsd_vers(nn, 4, NFSD_SET);
249 nn->nfsd4_minorversions[minorversion] =
250 nfsd_vers(nn, 4, NFSD_TEST);
251 }
252 break;
253 case NFSD_CLEAR:
254 nfsd_netns_init_versions(nn);
255 if (nn->nfsd4_minorversions) {
256 nn->nfsd4_minorversions[minorversion] = false;
257 nfsd_adjust_nfsd_versions4(nn);
258 }
259 break;
260 case NFSD_TEST:
261 if (nn->nfsd4_minorversions)
262 return nn->nfsd4_minorversions[minorversion];
263 return nfsd_vers(nn, 4, NFSD_TEST);
264 case NFSD_AVAIL:
265 return minorversion <= NFSD_SUPPORTED_MINOR_VERSION &&
266 nfsd_vers(nn, 4, NFSD_AVAIL);
267 }
268 return 0;
269 }
270
271 /*
272 * Maximum number of nfsd processes
273 */
274 #define NFSD_MAXSERVS 8192
275
276 int nfsd_nrthreads(struct net *net)
277 {
278 int rv = 0;
279 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
280
281 mutex_lock(&nfsd_mutex);
282 if (nn->nfsd_serv)
283 rv = nn->nfsd_serv->sv_nrthreads;
284 mutex_unlock(&nfsd_mutex);
285 return rv;
286 }
287
288 static int nfsd_init_socks(struct net *net, const struct cred *cred)
289 {
290 int error;
291 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
292
293 if (!list_empty(&nn->nfsd_serv->sv_permsocks))
294 return 0;
295
296 error = svc_create_xprt(nn->nfsd_serv, "udp", net, PF_INET, NFS_PORT,
297 SVC_SOCK_DEFAULTS, cred);
298 if (error < 0)
299 return error;
300
301 error = svc_create_xprt(nn->nfsd_serv, "tcp", net, PF_INET, NFS_PORT,
302 SVC_SOCK_DEFAULTS, cred);
303 if (error < 0)
304 return error;
305
306 return 0;
307 }
308
309 static int nfsd_users = 0;
310
311 static int nfsd_startup_generic(int nrservs)
312 {
313 int ret;
314
315 if (nfsd_users++)
316 return 0;
317
318 ret = nfsd_file_cache_init();
319 if (ret)
320 goto dec_users;
321
322 ret = nfs4_state_start();
323 if (ret)
324 goto out_file_cache;
325 return 0;
326
327 out_file_cache:
328 nfsd_file_cache_shutdown();
329 dec_users:
330 nfsd_users--;
331 return ret;
332 }
333
334 static void nfsd_shutdown_generic(void)
335 {
336 if (--nfsd_users)
337 return;
338
339 nfs4_state_shutdown();
340 nfsd_file_cache_shutdown();
341 }
342
343 static bool nfsd_needs_lockd(struct nfsd_net *nn)
344 {
345 return nfsd_vers(nn, 2, NFSD_TEST) || nfsd_vers(nn, 3, NFSD_TEST);
346 }
347
348 void nfsd_copy_boot_verifier(__be32 verf[2], struct nfsd_net *nn)
349 {
350 int seq = 0;
351
352 do {
353 read_seqbegin_or_lock(&nn->boot_lock, &seq);
354 /*
355 * This is opaque to client, so no need to byte-swap. Use
356 * __force to keep sparse happy. y2038 time_t overflow is
357 * irrelevant in this usage
358 */
359 verf[0] = (__force __be32)nn->nfssvc_boot.tv_sec;
360 verf[1] = (__force __be32)nn->nfssvc_boot.tv_nsec;
361 } while (need_seqretry(&nn->boot_lock, seq));
362 done_seqretry(&nn->boot_lock, seq);
363 }
364
365 static void nfsd_reset_boot_verifier_locked(struct nfsd_net *nn)
366 {
367 ktime_get_real_ts64(&nn->nfssvc_boot);
368 }
369
370 void nfsd_reset_boot_verifier(struct nfsd_net *nn)
371 {
372 write_seqlock(&nn->boot_lock);
373 nfsd_reset_boot_verifier_locked(nn);
374 write_sequnlock(&nn->boot_lock);
375 }
376
377 static int nfsd_startup_net(int nrservs, struct net *net, const struct cred *cred)
378 {
379 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
380 int ret;
381
382 if (nn->nfsd_net_up)
383 return 0;
384
385 ret = nfsd_startup_generic(nrservs);
386 if (ret)
387 return ret;
388 ret = nfsd_init_socks(net, cred);
389 if (ret)
390 goto out_socks;
391
392 if (nfsd_needs_lockd(nn) && !nn->lockd_up) {
393 ret = lockd_up(net, cred);
394 if (ret)
395 goto out_socks;
396 nn->lockd_up = true;
397 }
398
399 ret = nfsd_file_cache_start_net(net);
400 if (ret)
401 goto out_lockd;
402 ret = nfs4_state_start_net(net);
403 if (ret)
404 goto out_filecache;
405
406 nn->nfsd_net_up = true;
407 return 0;
408
409 out_filecache:
410 nfsd_file_cache_shutdown_net(net);
411 out_lockd:
412 if (nn->lockd_up) {
413 lockd_down(net);
414 nn->lockd_up = false;
415 }
416 out_socks:
417 nfsd_shutdown_generic();
418 return ret;
419 }
420
421 static void nfsd_shutdown_net(struct net *net)
422 {
423 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
424
425 nfsd_file_cache_shutdown_net(net);
426 nfs4_state_shutdown_net(net);
427 if (nn->lockd_up) {
428 lockd_down(net);
429 nn->lockd_up = false;
430 }
431 nn->nfsd_net_up = false;
432 nfsd_shutdown_generic();
433 }
434
435 static int nfsd_inetaddr_event(struct notifier_block *this, unsigned long event,
436 void *ptr)
437 {
438 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
439 struct net_device *dev = ifa->ifa_dev->dev;
440 struct net *net = dev_net(dev);
441 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
442 struct sockaddr_in sin;
443
444 if ((event != NETDEV_DOWN) ||
445 !atomic_inc_not_zero(&nn->ntf_refcnt))
446 goto out;
447
448 if (nn->nfsd_serv) {
449 dprintk("nfsd_inetaddr_event: removed %pI4\n", &ifa->ifa_local);
450 sin.sin_family = AF_INET;
451 sin.sin_addr.s_addr = ifa->ifa_local;
452 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin);
453 }
454 atomic_dec(&nn->ntf_refcnt);
455 wake_up(&nn->ntf_wq);
456
457 out:
458 return NOTIFY_DONE;
459 }
460
461 static struct notifier_block nfsd_inetaddr_notifier = {
462 .notifier_call = nfsd_inetaddr_event,
463 };
464
465 #if IS_ENABLED(CONFIG_IPV6)
466 static int nfsd_inet6addr_event(struct notifier_block *this,
467 unsigned long event, void *ptr)
468 {
469 struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
470 struct net_device *dev = ifa->idev->dev;
471 struct net *net = dev_net(dev);
472 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
473 struct sockaddr_in6 sin6;
474
475 if ((event != NETDEV_DOWN) ||
476 !atomic_inc_not_zero(&nn->ntf_refcnt))
477 goto out;
478
479 if (nn->nfsd_serv) {
480 dprintk("nfsd_inet6addr_event: removed %pI6\n", &ifa->addr);
481 sin6.sin6_family = AF_INET6;
482 sin6.sin6_addr = ifa->addr;
483 if (ipv6_addr_type(&sin6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
484 sin6.sin6_scope_id = ifa->idev->dev->ifindex;
485 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin6);
486 }
487 atomic_dec(&nn->ntf_refcnt);
488 wake_up(&nn->ntf_wq);
489 out:
490 return NOTIFY_DONE;
491 }
492
493 static struct notifier_block nfsd_inet6addr_notifier = {
494 .notifier_call = nfsd_inet6addr_event,
495 };
496 #endif
497
498 /* Only used under nfsd_mutex, so this atomic may be overkill: */
499 static atomic_t nfsd_notifier_refcount = ATOMIC_INIT(0);
500
501 static void nfsd_last_thread(struct svc_serv *serv, struct net *net)
502 {
503 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
504
505 atomic_dec(&nn->ntf_refcnt);
506 /* check if the notifier still has clients */
507 if (atomic_dec_return(&nfsd_notifier_refcount) == 0) {
508 unregister_inetaddr_notifier(&nfsd_inetaddr_notifier);
509 #if IS_ENABLED(CONFIG_IPV6)
510 unregister_inet6addr_notifier(&nfsd_inet6addr_notifier);
511 #endif
512 }
513 wait_event(nn->ntf_wq, atomic_read(&nn->ntf_refcnt) == 0);
514
515 /*
516 * write_ports can create the server without actually starting
517 * any threads--if we get shut down before any threads are
518 * started, then nfsd_last_thread will be run before any of this
519 * other initialization has been done except the rpcb information.
520 */
521 svc_rpcb_cleanup(serv, net);
522 if (!nn->nfsd_net_up)
523 return;
524
525 nfsd_shutdown_net(net);
526 pr_info("nfsd: last server has exited, flushing export cache\n");
527 nfsd_export_flush(net);
528 }
529
530 void nfsd_reset_versions(struct nfsd_net *nn)
531 {
532 int i;
533
534 for (i = 0; i < NFSD_NRVERS; i++)
535 if (nfsd_vers(nn, i, NFSD_TEST))
536 return;
537
538 for (i = 0; i < NFSD_NRVERS; i++)
539 if (i != 4)
540 nfsd_vers(nn, i, NFSD_SET);
541 else {
542 int minor = 0;
543 while (nfsd_minorversion(nn, minor, NFSD_SET) >= 0)
544 minor++;
545 }
546 }
547
548 /*
549 * Each session guarantees a negotiated per slot memory cache for replies
550 * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated
551 * NFSv4.1 server might want to use more memory for a DRC than a machine
552 * with mutiple services.
553 *
554 * Impose a hard limit on the number of pages for the DRC which varies
555 * according to the machines free pages. This is of course only a default.
556 *
557 * For now this is a #defined shift which could be under admin control
558 * in the future.
559 */
560 static void set_max_drc(void)
561 {
562 #define NFSD_DRC_SIZE_SHIFT 7
563 nfsd_drc_max_mem = (nr_free_buffer_pages()
564 >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE;
565 nfsd_drc_mem_used = 0;
566 spin_lock_init(&nfsd_drc_lock);
567 dprintk("%s nfsd_drc_max_mem %lu \n", __func__, nfsd_drc_max_mem);
568 }
569
570 static int nfsd_get_default_max_blksize(void)
571 {
572 struct sysinfo i;
573 unsigned long long target;
574 unsigned long ret;
575
576 si_meminfo(&i);
577 target = (i.totalram - i.totalhigh) << PAGE_SHIFT;
578 /*
579 * Aim for 1/4096 of memory per thread This gives 1MB on 4Gig
580 * machines, but only uses 32K on 128M machines. Bottom out at
581 * 8K on 32M and smaller. Of course, this is only a default.
582 */
583 target >>= 12;
584
585 ret = NFSSVC_MAXBLKSIZE;
586 while (ret > target && ret >= 8*1024*2)
587 ret /= 2;
588 return ret;
589 }
590
591 static const struct svc_serv_ops nfsd_thread_sv_ops = {
592 .svo_shutdown = nfsd_last_thread,
593 .svo_function = nfsd,
594 .svo_enqueue_xprt = svc_xprt_do_enqueue,
595 .svo_setup = svc_set_num_threads,
596 .svo_module = THIS_MODULE,
597 };
598
599 bool i_am_nfsd(void)
600 {
601 return kthread_func(current) == nfsd;
602 }
603
604 int nfsd_create_serv(struct net *net)
605 {
606 int error;
607 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
608
609 WARN_ON(!mutex_is_locked(&nfsd_mutex));
610 if (nn->nfsd_serv) {
611 svc_get(nn->nfsd_serv);
612 return 0;
613 }
614 if (nfsd_max_blksize == 0)
615 nfsd_max_blksize = nfsd_get_default_max_blksize();
616 nfsd_reset_versions(nn);
617 nn->nfsd_serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize,
618 &nfsd_thread_sv_ops);
619 if (nn->nfsd_serv == NULL)
620 return -ENOMEM;
621
622 nn->nfsd_serv->sv_maxconn = nn->max_connections;
623 error = svc_bind(nn->nfsd_serv, net);
624 if (error < 0) {
625 svc_destroy(nn->nfsd_serv);
626 return error;
627 }
628
629 set_max_drc();
630 /* check if the notifier is already set */
631 if (atomic_inc_return(&nfsd_notifier_refcount) == 1) {
632 register_inetaddr_notifier(&nfsd_inetaddr_notifier);
633 #if IS_ENABLED(CONFIG_IPV6)
634 register_inet6addr_notifier(&nfsd_inet6addr_notifier);
635 #endif
636 }
637 atomic_inc(&nn->ntf_refcnt);
638 nfsd_reset_boot_verifier(nn);
639 return 0;
640 }
641
642 int nfsd_nrpools(struct net *net)
643 {
644 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
645
646 if (nn->nfsd_serv == NULL)
647 return 0;
648 else
649 return nn->nfsd_serv->sv_nrpools;
650 }
651
652 int nfsd_get_nrthreads(int n, int *nthreads, struct net *net)
653 {
654 int i = 0;
655 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
656
657 if (nn->nfsd_serv != NULL) {
658 for (i = 0; i < nn->nfsd_serv->sv_nrpools && i < n; i++)
659 nthreads[i] = nn->nfsd_serv->sv_pools[i].sp_nrthreads;
660 }
661
662 return 0;
663 }
664
665 void nfsd_destroy(struct net *net)
666 {
667 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
668 int destroy = (nn->nfsd_serv->sv_nrthreads == 1);
669
670 if (destroy)
671 svc_shutdown_net(nn->nfsd_serv, net);
672 svc_destroy(nn->nfsd_serv);
673 if (destroy)
674 nn->nfsd_serv = NULL;
675 }
676
677 int nfsd_set_nrthreads(int n, int *nthreads, struct net *net)
678 {
679 int i = 0;
680 int tot = 0;
681 int err = 0;
682 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
683
684 WARN_ON(!mutex_is_locked(&nfsd_mutex));
685
686 if (nn->nfsd_serv == NULL || n <= 0)
687 return 0;
688
689 if (n > nn->nfsd_serv->sv_nrpools)
690 n = nn->nfsd_serv->sv_nrpools;
691
692 /* enforce a global maximum number of threads */
693 tot = 0;
694 for (i = 0; i < n; i++) {
695 nthreads[i] = min(nthreads[i], NFSD_MAXSERVS);
696 tot += nthreads[i];
697 }
698 if (tot > NFSD_MAXSERVS) {
699 /* total too large: scale down requested numbers */
700 for (i = 0; i < n && tot > 0; i++) {
701 int new = nthreads[i] * NFSD_MAXSERVS / tot;
702 tot -= (nthreads[i] - new);
703 nthreads[i] = new;
704 }
705 for (i = 0; i < n && tot > 0; i++) {
706 nthreads[i]--;
707 tot--;
708 }
709 }
710
711 /*
712 * There must always be a thread in pool 0; the admin
713 * can't shut down NFS completely using pool_threads.
714 */
715 if (nthreads[0] == 0)
716 nthreads[0] = 1;
717
718 /* apply the new numbers */
719 svc_get(nn->nfsd_serv);
720 for (i = 0; i < n; i++) {
721 err = nn->nfsd_serv->sv_ops->svo_setup(nn->nfsd_serv,
722 &nn->nfsd_serv->sv_pools[i], nthreads[i]);
723 if (err)
724 break;
725 }
726 nfsd_destroy(net);
727 return err;
728 }
729
730 /*
731 * Adjust the number of threads and return the new number of threads.
732 * This is also the function that starts the server if necessary, if
733 * this is the first time nrservs is nonzero.
734 */
735 int
736 nfsd_svc(int nrservs, struct net *net, const struct cred *cred)
737 {
738 int error;
739 bool nfsd_up_before;
740 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
741
742 mutex_lock(&nfsd_mutex);
743 dprintk("nfsd: creating service\n");
744
745 nrservs = max(nrservs, 0);
746 nrservs = min(nrservs, NFSD_MAXSERVS);
747 error = 0;
748
749 if (nrservs == 0 && nn->nfsd_serv == NULL)
750 goto out;
751
752 strlcpy(nn->nfsd_name, utsname()->nodename,
753 sizeof(nn->nfsd_name));
754
755 error = nfsd_create_serv(net);
756 if (error)
757 goto out;
758
759 nfsd_up_before = nn->nfsd_net_up;
760
761 error = nfsd_startup_net(nrservs, net, cred);
762 if (error)
763 goto out_destroy;
764 error = nn->nfsd_serv->sv_ops->svo_setup(nn->nfsd_serv,
765 NULL, nrservs);
766 if (error)
767 goto out_shutdown;
768 /* We are holding a reference to nn->nfsd_serv which
769 * we don't want to count in the return value,
770 * so subtract 1
771 */
772 error = nn->nfsd_serv->sv_nrthreads - 1;
773 out_shutdown:
774 if (error < 0 && !nfsd_up_before)
775 nfsd_shutdown_net(net);
776 out_destroy:
777 nfsd_destroy(net); /* Release server */
778 out:
779 mutex_unlock(&nfsd_mutex);
780 return error;
781 }
782
783 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
784 static bool
785 nfsd_support_acl_version(int vers)
786 {
787 if (vers >= NFSD_ACL_MINVERS && vers < NFSD_ACL_NRVERS)
788 return nfsd_acl_version[vers] != NULL;
789 return false;
790 }
791
792 static int
793 nfsd_acl_rpcbind_set(struct net *net, const struct svc_program *progp,
794 u32 version, int family, unsigned short proto,
795 unsigned short port)
796 {
797 if (!nfsd_support_acl_version(version) ||
798 !nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST))
799 return 0;
800 return svc_generic_rpcbind_set(net, progp, version, family,
801 proto, port);
802 }
803
804 static __be32
805 nfsd_acl_init_request(struct svc_rqst *rqstp,
806 const struct svc_program *progp,
807 struct svc_process_info *ret)
808 {
809 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
810 int i;
811
812 if (likely(nfsd_support_acl_version(rqstp->rq_vers) &&
813 nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST)))
814 return svc_generic_init_request(rqstp, progp, ret);
815
816 ret->mismatch.lovers = NFSD_ACL_NRVERS;
817 for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) {
818 if (nfsd_support_acl_version(rqstp->rq_vers) &&
819 nfsd_vers(nn, i, NFSD_TEST)) {
820 ret->mismatch.lovers = i;
821 break;
822 }
823 }
824 if (ret->mismatch.lovers == NFSD_ACL_NRVERS)
825 return rpc_prog_unavail;
826 ret->mismatch.hivers = NFSD_ACL_MINVERS;
827 for (i = NFSD_ACL_NRVERS - 1; i >= NFSD_ACL_MINVERS; i--) {
828 if (nfsd_support_acl_version(rqstp->rq_vers) &&
829 nfsd_vers(nn, i, NFSD_TEST)) {
830 ret->mismatch.hivers = i;
831 break;
832 }
833 }
834 return rpc_prog_mismatch;
835 }
836 #endif
837
838 static int
839 nfsd_rpcbind_set(struct net *net, const struct svc_program *progp,
840 u32 version, int family, unsigned short proto,
841 unsigned short port)
842 {
843 if (!nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST))
844 return 0;
845 return svc_generic_rpcbind_set(net, progp, version, family,
846 proto, port);
847 }
848
849 static __be32
850 nfsd_init_request(struct svc_rqst *rqstp,
851 const struct svc_program *progp,
852 struct svc_process_info *ret)
853 {
854 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
855 int i;
856
857 if (likely(nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST)))
858 return svc_generic_init_request(rqstp, progp, ret);
859
860 ret->mismatch.lovers = NFSD_NRVERS;
861 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) {
862 if (nfsd_vers(nn, i, NFSD_TEST)) {
863 ret->mismatch.lovers = i;
864 break;
865 }
866 }
867 if (ret->mismatch.lovers == NFSD_NRVERS)
868 return rpc_prog_unavail;
869 ret->mismatch.hivers = NFSD_MINVERS;
870 for (i = NFSD_NRVERS - 1; i >= NFSD_MINVERS; i--) {
871 if (nfsd_vers(nn, i, NFSD_TEST)) {
872 ret->mismatch.hivers = i;
873 break;
874 }
875 }
876 return rpc_prog_mismatch;
877 }
878
879 /*
880 * This is the NFS server kernel thread
881 */
882 static int
883 nfsd(void *vrqstp)
884 {
885 struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp;
886 struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list);
887 struct net *net = perm_sock->xpt_net;
888 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
889 int err;
890
891 /* Lock module and set up kernel thread */
892 mutex_lock(&nfsd_mutex);
893
894 /* At this point, the thread shares current->fs
895 * with the init process. We need to create files with the
896 * umask as defined by the client instead of init's umask. */
897 if (unshare_fs_struct() < 0) {
898 printk("Unable to start nfsd thread: out of memory\n");
899 goto out;
900 }
901
902 current->fs->umask = 0;
903
904 /*
905 * thread is spawned with all signals set to SIG_IGN, re-enable
906 * the ones that will bring down the thread
907 */
908 allow_signal(SIGKILL);
909 allow_signal(SIGHUP);
910 allow_signal(SIGINT);
911 allow_signal(SIGQUIT);
912
913 nfsdstats.th_cnt++;
914 mutex_unlock(&nfsd_mutex);
915
916 set_freezable();
917
918 /*
919 * The main request loop
920 */
921 for (;;) {
922 /* Update sv_maxconn if it has changed */
923 rqstp->rq_server->sv_maxconn = nn->max_connections;
924
925 /*
926 * Find a socket with data available and call its
927 * recvfrom routine.
928 */
929 while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN)
930 ;
931 if (err == -EINTR)
932 break;
933 validate_process_creds();
934 svc_process(rqstp);
935 validate_process_creds();
936 }
937
938 /* Clear signals before calling svc_exit_thread() */
939 flush_signals(current);
940
941 mutex_lock(&nfsd_mutex);
942 nfsdstats.th_cnt --;
943
944 out:
945 rqstp->rq_server = NULL;
946
947 /* Release the thread */
948 svc_exit_thread(rqstp);
949
950 nfsd_destroy(net);
951
952 /* Release module */
953 mutex_unlock(&nfsd_mutex);
954 module_put_and_exit(0);
955 return 0;
956 }
957
958 /*
959 * A write procedure can have a large argument, and a read procedure can
960 * have a large reply, but no NFSv2 or NFSv3 procedure has argument and
961 * reply that can both be larger than a page. The xdr code has taken
962 * advantage of this assumption to be a sloppy about bounds checking in
963 * some cases. Pending a rewrite of the NFSv2/v3 xdr code to fix that
964 * problem, we enforce these assumptions here:
965 */
966 static bool nfs_request_too_big(struct svc_rqst *rqstp,
967 const struct svc_procedure *proc)
968 {
969 /*
970 * The ACL code has more careful bounds-checking and is not
971 * susceptible to this problem:
972 */
973 if (rqstp->rq_prog != NFS_PROGRAM)
974 return false;
975 /*
976 * Ditto NFSv4 (which can in theory have argument and reply both
977 * more than a page):
978 */
979 if (rqstp->rq_vers >= 4)
980 return false;
981 /* The reply will be small, we're OK: */
982 if (proc->pc_xdrressize > 0 &&
983 proc->pc_xdrressize < XDR_QUADLEN(PAGE_SIZE))
984 return false;
985
986 return rqstp->rq_arg.len > PAGE_SIZE;
987 }
988
989 /**
990 * nfsd_dispatch - Process an NFS or NFSACL Request
991 * @rqstp: incoming request
992 * @statp: pointer to location of accept_stat field in RPC Reply buffer
993 *
994 * This RPC dispatcher integrates the NFS server's duplicate reply cache.
995 *
996 * Return values:
997 * %0: Processing complete; do not send a Reply
998 * %1: Processing complete; send Reply in rqstp->rq_res
999 */
1000 int nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
1001 {
1002 const struct svc_procedure *proc = rqstp->rq_procinfo;
1003 struct kvec *argv = &rqstp->rq_arg.head[0];
1004 struct kvec *resv = &rqstp->rq_res.head[0];
1005 __be32 *p;
1006
1007 if (nfs_request_too_big(rqstp, proc))
1008 goto out_decode_err;
1009
1010 /*
1011 * Give the xdr decoder a chance to change this if it wants
1012 * (necessary in the NFSv4.0 compound case)
1013 */
1014 rqstp->rq_cachetype = proc->pc_cachetype;
1015
1016 svcxdr_init_decode(rqstp);
1017 if (!proc->pc_decode(rqstp, argv->iov_base))
1018 goto out_decode_err;
1019
1020 switch (nfsd_cache_lookup(rqstp)) {
1021 case RC_DOIT:
1022 break;
1023 case RC_REPLY:
1024 goto out_cached_reply;
1025 case RC_DROPIT:
1026 goto out_dropit;
1027 }
1028
1029 /*
1030 * Need to grab the location to store the status, as
1031 * NFSv4 does some encoding while processing
1032 */
1033 p = resv->iov_base + resv->iov_len;
1034 resv->iov_len += sizeof(__be32);
1035
1036 *statp = proc->pc_func(rqstp);
1037 if (*statp == rpc_drop_reply || test_bit(RQ_DROPME, &rqstp->rq_flags))
1038 goto out_update_drop;
1039
1040 if (!proc->pc_encode(rqstp, p))
1041 goto out_encode_err;
1042
1043 nfsd_cache_update(rqstp, rqstp->rq_cachetype, statp + 1);
1044 out_cached_reply:
1045 return 1;
1046
1047 out_decode_err:
1048 trace_nfsd_garbage_args_err(rqstp);
1049 *statp = rpc_garbage_args;
1050 return 1;
1051
1052 out_update_drop:
1053 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
1054 out_dropit:
1055 return 0;
1056
1057 out_encode_err:
1058 trace_nfsd_cant_encode_err(rqstp);
1059 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
1060 *statp = rpc_system_err;
1061 return 1;
1062 }
1063
1064 /**
1065 * nfssvc_decode_voidarg - Decode void arguments
1066 * @rqstp: Server RPC transaction context
1067 * @p: buffer containing arguments to decode
1068 *
1069 * Return values:
1070 * %0: Arguments were not valid
1071 * %1: Decoding was successful
1072 */
1073 int nfssvc_decode_voidarg(struct svc_rqst *rqstp, __be32 *p)
1074 {
1075 return 1;
1076 }
1077
1078 /**
1079 * nfssvc_encode_voidres - Encode void results
1080 * @rqstp: Server RPC transaction context
1081 * @p: buffer in which to encode results
1082 *
1083 * Return values:
1084 * %0: Local error while encoding
1085 * %1: Encoding was successful
1086 */
1087 int nfssvc_encode_voidres(struct svc_rqst *rqstp, __be32 *p)
1088 {
1089 return xdr_ressize_check(rqstp, p);
1090 }
1091
1092 int nfsd_pool_stats_open(struct inode *inode, struct file *file)
1093 {
1094 int ret;
1095 struct nfsd_net *nn = net_generic(inode->i_sb->s_fs_info, nfsd_net_id);
1096
1097 mutex_lock(&nfsd_mutex);
1098 if (nn->nfsd_serv == NULL) {
1099 mutex_unlock(&nfsd_mutex);
1100 return -ENODEV;
1101 }
1102 /* bump up the psudo refcount while traversing */
1103 svc_get(nn->nfsd_serv);
1104 ret = svc_pool_stats_open(nn->nfsd_serv, file);
1105 mutex_unlock(&nfsd_mutex);
1106 return ret;
1107 }
1108
1109 int nfsd_pool_stats_release(struct inode *inode, struct file *file)
1110 {
1111 int ret = seq_release(inode, file);
1112 struct net *net = inode->i_sb->s_fs_info;
1113
1114 mutex_lock(&nfsd_mutex);
1115 /* this function really, really should have been called svc_put() */
1116 nfsd_destroy(net);
1117 mutex_unlock(&nfsd_mutex);
1118 return ret;
1119 }