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 #include <linux/siphash.h>
16
17 #include <linux/sunrpc/stats.h>
18 #include <linux/sunrpc/svcsock.h>
19 #include <linux/sunrpc/svc_xprt.h>
20 #include <linux/lockd/bind.h>
21 #include <linux/nfsacl.h>
22 #include <linux/nfslocalio.h>
23 #include <linux/seq_file.h>
24 #include <linux/inetdevice.h>
25 #include <net/addrconf.h>
26 #include <net/ipv6.h>
27 #include <net/net_namespace.h>
28 #include "nfsd.h"
29 #include "cache.h"
30 #include "vfs.h"
31 #include "netns.h"
32 #include "filecache.h"
33
34 #include "trace.h"
35
36 #define NFSDDBG_FACILITY NFSDDBG_SVC
37
38 atomic_t nfsd_th_cnt = ATOMIC_INIT(0);
39 static int nfsd(void *vrqstp);
40 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
41 static int nfsd_acl_rpcbind_set(struct net *,
42 const struct svc_program *,
43 u32, int,
44 unsigned short,
45 unsigned short);
46 static __be32 nfsd_acl_init_request(struct svc_rqst *,
47 const struct svc_program *,
48 struct svc_process_info *);
49 #endif
50 static int nfsd_rpcbind_set(struct net *,
51 const struct svc_program *,
52 u32, int,
53 unsigned short,
54 unsigned short);
55 static __be32 nfsd_init_request(struct svc_rqst *,
56 const struct svc_program *,
57 struct svc_process_info *);
58
59 /*
60 * nfsd_mutex protects nn->nfsd_serv -- both the pointer itself and some members
61 * of the svc_serv struct such as ->sv_temp_socks and ->sv_permsocks.
62 *
63 * Finally, the nfsd_mutex also protects some of the global variables that are
64 * accessed when nfsd starts and that are settable via the write_* routines in
65 * nfsctl.c. In particular:
66 *
67 * user_recovery_dirname
68 * user_lease_time
69 * nfsd_versions
70 */
71 DEFINE_MUTEX(nfsd_mutex);
72
73 /*
74 * nfsd_drc_lock protects nfsd_drc_max_pages and nfsd_drc_pages_used.
75 * nfsd_drc_max_pages limits the total amount of memory available for
76 * version 4.1 DRC caches.
77 * nfsd_drc_pages_used tracks the current version 4.1 DRC memory usage.
78 */
79 DEFINE_SPINLOCK(nfsd_drc_lock);
80 unsigned long nfsd_drc_max_mem;
81 unsigned long nfsd_drc_mem_used;
82
83 #if IS_ENABLED(CONFIG_NFS_LOCALIO)
84 static const struct svc_version *localio_versions[] = {
85 [1] = &localio_version1,
86 };
87
88 #define NFSD_LOCALIO_NRVERS ARRAY_SIZE(localio_versions)
89
90 #endif /* CONFIG_NFS_LOCALIO */
91
92 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
93 static const struct svc_version *nfsd_acl_version[] = {
94 # if defined(CONFIG_NFSD_V2_ACL)
95 [2] = &nfsd_acl_version2,
96 # endif
97 # if defined(CONFIG_NFSD_V3_ACL)
98 [3] = &nfsd_acl_version3,
99 # endif
100 };
101
102 #define NFSD_ACL_MINVERS 2
103 #define NFSD_ACL_NRVERS ARRAY_SIZE(nfsd_acl_version)
104
105 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
106
107 static const struct svc_version *nfsd_version[NFSD_MAXVERS+1] = {
108 #if defined(CONFIG_NFSD_V2)
109 [2] = &nfsd_version2,
110 #endif
111 [3] = &nfsd_version3,
112 #if defined(CONFIG_NFSD_V4)
113 [4] = &nfsd_version4,
114 #endif
115 };
116
117 struct svc_program nfsd_programs[] = {
118 {
119 .pg_prog = NFS_PROGRAM, /* program number */
120 .pg_nvers = NFSD_MAXVERS+1, /* nr of entries in nfsd_version */
121 .pg_vers = nfsd_version, /* version table */
122 .pg_name = "nfsd", /* program name */
123 .pg_class = "nfsd", /* authentication class */
124 .pg_authenticate = svc_set_client, /* export authentication */
125 .pg_init_request = nfsd_init_request,
126 .pg_rpcbind_set = nfsd_rpcbind_set,
127 },
128 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
129 {
130 .pg_prog = NFS_ACL_PROGRAM,
131 .pg_nvers = NFSD_ACL_NRVERS,
132 .pg_vers = nfsd_acl_version,
133 .pg_name = "nfsacl",
134 .pg_class = "nfsd",
135 .pg_authenticate = svc_set_client,
136 .pg_init_request = nfsd_acl_init_request,
137 .pg_rpcbind_set = nfsd_acl_rpcbind_set,
138 },
139 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
140 #if IS_ENABLED(CONFIG_NFS_LOCALIO)
141 {
142 .pg_prog = NFS_LOCALIO_PROGRAM,
143 .pg_nvers = NFSD_LOCALIO_NRVERS,
144 .pg_vers = localio_versions,
145 .pg_name = "nfslocalio",
146 .pg_class = "nfsd",
147 .pg_authenticate = svc_set_client,
148 .pg_init_request = svc_generic_init_request,
149 .pg_rpcbind_set = svc_generic_rpcbind_set,
150 }
151 #endif /* CONFIG_NFS_LOCALIO */
152 };
153
nfsd_support_version(int vers)154 bool nfsd_support_version(int vers)
155 {
156 if (vers >= NFSD_MINVERS && vers <= NFSD_MAXVERS)
157 return nfsd_version[vers] != NULL;
158 return false;
159 }
160
nfsd_vers(struct nfsd_net * nn,int vers,enum vers_op change)161 int nfsd_vers(struct nfsd_net *nn, int vers, enum vers_op change)
162 {
163 if (vers < NFSD_MINVERS || vers > NFSD_MAXVERS)
164 return 0;
165 switch(change) {
166 case NFSD_SET:
167 nn->nfsd_versions[vers] = nfsd_support_version(vers);
168 break;
169 case NFSD_CLEAR:
170 nn->nfsd_versions[vers] = false;
171 break;
172 case NFSD_TEST:
173 return nn->nfsd_versions[vers];
174 case NFSD_AVAIL:
175 return nfsd_support_version(vers);
176 }
177 return 0;
178 }
179
180 static void
nfsd_adjust_nfsd_versions4(struct nfsd_net * nn)181 nfsd_adjust_nfsd_versions4(struct nfsd_net *nn)
182 {
183 unsigned i;
184
185 for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++) {
186 if (nn->nfsd4_minorversions[i])
187 return;
188 }
189 nfsd_vers(nn, 4, NFSD_CLEAR);
190 }
191
nfsd_minorversion(struct nfsd_net * nn,u32 minorversion,enum vers_op change)192 int nfsd_minorversion(struct nfsd_net *nn, u32 minorversion, enum vers_op change)
193 {
194 if (minorversion > NFSD_SUPPORTED_MINOR_VERSION &&
195 change != NFSD_AVAIL)
196 return -1;
197
198 switch(change) {
199 case NFSD_SET:
200 nfsd_vers(nn, 4, NFSD_SET);
201 nn->nfsd4_minorversions[minorversion] =
202 nfsd_vers(nn, 4, NFSD_TEST);
203 break;
204 case NFSD_CLEAR:
205 nn->nfsd4_minorversions[minorversion] = false;
206 nfsd_adjust_nfsd_versions4(nn);
207 break;
208 case NFSD_TEST:
209 return nn->nfsd4_minorversions[minorversion];
210 case NFSD_AVAIL:
211 return minorversion <= NFSD_SUPPORTED_MINOR_VERSION &&
212 nfsd_vers(nn, 4, NFSD_AVAIL);
213 }
214 return 0;
215 }
216
nfsd_serv_try_get(struct net * net)217 bool nfsd_serv_try_get(struct net *net) __must_hold(rcu)
218 {
219 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
220
221 return (nn && percpu_ref_tryget_live(&nn->nfsd_serv_ref));
222 }
223
nfsd_serv_put(struct net * net)224 void nfsd_serv_put(struct net *net) __must_hold(rcu)
225 {
226 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
227
228 percpu_ref_put(&nn->nfsd_serv_ref);
229 }
230
nfsd_serv_done(struct percpu_ref * ref)231 static void nfsd_serv_done(struct percpu_ref *ref)
232 {
233 struct nfsd_net *nn = container_of(ref, struct nfsd_net, nfsd_serv_ref);
234
235 complete(&nn->nfsd_serv_confirm_done);
236 }
237
nfsd_serv_free(struct percpu_ref * ref)238 static void nfsd_serv_free(struct percpu_ref *ref)
239 {
240 struct nfsd_net *nn = container_of(ref, struct nfsd_net, nfsd_serv_ref);
241
242 complete(&nn->nfsd_serv_free_done);
243 }
244
245 /*
246 * Maximum number of nfsd processes
247 */
248 #define NFSD_MAXSERVS 8192
249
nfsd_nrthreads(struct net * net)250 int nfsd_nrthreads(struct net *net)
251 {
252 int rv = 0;
253 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
254
255 mutex_lock(&nfsd_mutex);
256 if (nn->nfsd_serv)
257 rv = nn->nfsd_serv->sv_nrthreads;
258 mutex_unlock(&nfsd_mutex);
259 return rv;
260 }
261
nfsd_init_socks(struct net * net,const struct cred * cred)262 static int nfsd_init_socks(struct net *net, const struct cred *cred)
263 {
264 int error;
265 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
266
267 if (!list_empty(&nn->nfsd_serv->sv_permsocks))
268 return 0;
269
270 error = svc_xprt_create(nn->nfsd_serv, "udp", net, PF_INET, NFS_PORT,
271 SVC_SOCK_DEFAULTS, cred);
272 if (error < 0)
273 return error;
274
275 error = svc_xprt_create(nn->nfsd_serv, "tcp", net, PF_INET, NFS_PORT,
276 SVC_SOCK_DEFAULTS, cred);
277 if (error < 0)
278 return error;
279
280 return 0;
281 }
282
283 static int nfsd_users = 0;
284
nfsd_startup_generic(void)285 static int nfsd_startup_generic(void)
286 {
287 int ret;
288
289 if (nfsd_users++)
290 return 0;
291
292 ret = nfsd_file_cache_init();
293 if (ret)
294 goto dec_users;
295
296 ret = nfs4_state_start();
297 if (ret)
298 goto out_file_cache;
299 return 0;
300
301 out_file_cache:
302 nfsd_file_cache_shutdown();
303 dec_users:
304 nfsd_users--;
305 return ret;
306 }
307
nfsd_shutdown_generic(void)308 static void nfsd_shutdown_generic(void)
309 {
310 if (--nfsd_users)
311 return;
312
313 nfs4_state_shutdown();
314 nfsd_file_cache_shutdown();
315 }
316
nfsd_needs_lockd(struct nfsd_net * nn)317 static bool nfsd_needs_lockd(struct nfsd_net *nn)
318 {
319 return nfsd_vers(nn, 2, NFSD_TEST) || nfsd_vers(nn, 3, NFSD_TEST);
320 }
321
322 /**
323 * nfsd_copy_write_verifier - Atomically copy a write verifier
324 * @verf: buffer in which to receive the verifier cookie
325 * @nn: NFS net namespace
326 *
327 * This function provides a wait-free mechanism for copying the
328 * namespace's write verifier without tearing it.
329 */
nfsd_copy_write_verifier(__be32 verf[2],struct nfsd_net * nn)330 void nfsd_copy_write_verifier(__be32 verf[2], struct nfsd_net *nn)
331 {
332 unsigned int seq;
333
334 do {
335 seq = read_seqbegin(&nn->writeverf_lock);
336 memcpy(verf, nn->writeverf, sizeof(nn->writeverf));
337 } while (read_seqretry(&nn->writeverf_lock, seq));
338 }
339
nfsd_reset_write_verifier_locked(struct nfsd_net * nn)340 static void nfsd_reset_write_verifier_locked(struct nfsd_net *nn)
341 {
342 struct timespec64 now;
343 u64 verf;
344
345 /*
346 * Because the time value is hashed, y2038 time_t overflow
347 * is irrelevant in this usage.
348 */
349 ktime_get_raw_ts64(&now);
350 verf = siphash_2u64(now.tv_sec, now.tv_nsec, &nn->siphash_key);
351 memcpy(nn->writeverf, &verf, sizeof(nn->writeverf));
352 }
353
354 /**
355 * nfsd_reset_write_verifier - Generate a new write verifier
356 * @nn: NFS net namespace
357 *
358 * This function updates the ->writeverf field of @nn. This field
359 * contains an opaque cookie that, according to Section 18.32.3 of
360 * RFC 8881, "the client can use to determine whether a server has
361 * changed instance state (e.g., server restart) between a call to
362 * WRITE and a subsequent call to either WRITE or COMMIT. This
363 * cookie MUST be unchanged during a single instance of the NFSv4.1
364 * server and MUST be unique between instances of the NFSv4.1
365 * server."
366 */
nfsd_reset_write_verifier(struct nfsd_net * nn)367 void nfsd_reset_write_verifier(struct nfsd_net *nn)
368 {
369 write_seqlock(&nn->writeverf_lock);
370 nfsd_reset_write_verifier_locked(nn);
371 write_sequnlock(&nn->writeverf_lock);
372 }
373
374 /*
375 * Crank up a set of per-namespace resources for a new NFSD instance,
376 * including lockd, a duplicate reply cache, an open file cache
377 * instance, and a cache of NFSv4 state objects.
378 */
nfsd_startup_net(struct net * net,const struct cred * cred)379 static int nfsd_startup_net(struct net *net, const struct cred *cred)
380 {
381 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
382 int ret;
383
384 if (nn->nfsd_net_up)
385 return 0;
386
387 ret = nfsd_startup_generic();
388 if (ret)
389 return ret;
390 ret = nfsd_init_socks(net, cred);
391 if (ret)
392 goto out_socks;
393
394 if (nfsd_needs_lockd(nn) && !nn->lockd_up) {
395 ret = lockd_up(net, cred);
396 if (ret)
397 goto out_socks;
398 nn->lockd_up = true;
399 }
400
401 ret = nfsd_file_cache_start_net(net);
402 if (ret)
403 goto out_lockd;
404
405 ret = nfsd_reply_cache_init(nn);
406 if (ret)
407 goto out_filecache;
408
409 ret = nfs4_state_start_net(net);
410 if (ret)
411 goto out_reply_cache;
412
413 #ifdef CONFIG_NFSD_V4_2_INTER_SSC
414 nfsd4_ssc_init_umount_work(nn);
415 #endif
416 nn->nfsd_net_up = true;
417 return 0;
418
419 out_reply_cache:
420 nfsd_reply_cache_shutdown(nn);
421 out_filecache:
422 nfsd_file_cache_shutdown_net(net);
423 out_lockd:
424 if (nn->lockd_up) {
425 lockd_down(net);
426 nn->lockd_up = false;
427 }
428 out_socks:
429 nfsd_shutdown_generic();
430 return ret;
431 }
432
nfsd_shutdown_net(struct net * net)433 static void nfsd_shutdown_net(struct net *net)
434 {
435 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
436
437 if (!nn->nfsd_net_up)
438 return;
439 nfsd_export_flush(net);
440 nfs4_state_shutdown_net(net);
441 nfsd_reply_cache_shutdown(nn);
442 nfsd_file_cache_shutdown_net(net);
443 if (nn->lockd_up) {
444 lockd_down(net);
445 nn->lockd_up = false;
446 }
447 percpu_ref_exit(&nn->nfsd_serv_ref);
448 nn->nfsd_net_up = false;
449 nfsd_shutdown_generic();
450 }
451
452 static DEFINE_SPINLOCK(nfsd_notifier_lock);
nfsd_inetaddr_event(struct notifier_block * this,unsigned long event,void * ptr)453 static int nfsd_inetaddr_event(struct notifier_block *this, unsigned long event,
454 void *ptr)
455 {
456 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
457 struct net_device *dev = ifa->ifa_dev->dev;
458 struct net *net = dev_net(dev);
459 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
460 struct sockaddr_in sin;
461
462 if (event != NETDEV_DOWN || !nn->nfsd_serv)
463 goto out;
464
465 spin_lock(&nfsd_notifier_lock);
466 if (nn->nfsd_serv) {
467 dprintk("nfsd_inetaddr_event: removed %pI4\n", &ifa->ifa_local);
468 sin.sin_family = AF_INET;
469 sin.sin_addr.s_addr = ifa->ifa_local;
470 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin);
471 }
472 spin_unlock(&nfsd_notifier_lock);
473
474 out:
475 return NOTIFY_DONE;
476 }
477
478 static struct notifier_block nfsd_inetaddr_notifier = {
479 .notifier_call = nfsd_inetaddr_event,
480 };
481
482 #if IS_ENABLED(CONFIG_IPV6)
nfsd_inet6addr_event(struct notifier_block * this,unsigned long event,void * ptr)483 static int nfsd_inet6addr_event(struct notifier_block *this,
484 unsigned long event, void *ptr)
485 {
486 struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
487 struct net_device *dev = ifa->idev->dev;
488 struct net *net = dev_net(dev);
489 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
490 struct sockaddr_in6 sin6;
491
492 if (event != NETDEV_DOWN || !nn->nfsd_serv)
493 goto out;
494
495 spin_lock(&nfsd_notifier_lock);
496 if (nn->nfsd_serv) {
497 dprintk("nfsd_inet6addr_event: removed %pI6\n", &ifa->addr);
498 sin6.sin6_family = AF_INET6;
499 sin6.sin6_addr = ifa->addr;
500 if (ipv6_addr_type(&sin6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
501 sin6.sin6_scope_id = ifa->idev->dev->ifindex;
502 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin6);
503 }
504 spin_unlock(&nfsd_notifier_lock);
505
506 out:
507 return NOTIFY_DONE;
508 }
509
510 static struct notifier_block nfsd_inet6addr_notifier = {
511 .notifier_call = nfsd_inet6addr_event,
512 };
513 #endif
514
515 /* Only used under nfsd_mutex, so this atomic may be overkill: */
516 static atomic_t nfsd_notifier_refcount = ATOMIC_INIT(0);
517
518 /**
519 * nfsd_destroy_serv - tear down NFSD's svc_serv for a namespace
520 * @net: network namespace the NFS service is associated with
521 */
nfsd_destroy_serv(struct net * net)522 void nfsd_destroy_serv(struct net *net)
523 {
524 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
525 struct svc_serv *serv = nn->nfsd_serv;
526
527 lockdep_assert_held(&nfsd_mutex);
528
529 percpu_ref_kill_and_confirm(&nn->nfsd_serv_ref, nfsd_serv_done);
530 wait_for_completion(&nn->nfsd_serv_confirm_done);
531 wait_for_completion(&nn->nfsd_serv_free_done);
532 /* percpu_ref_exit is called in nfsd_shutdown_net */
533
534 spin_lock(&nfsd_notifier_lock);
535 nn->nfsd_serv = NULL;
536 spin_unlock(&nfsd_notifier_lock);
537
538 /* check if the notifier still has clients */
539 if (atomic_dec_return(&nfsd_notifier_refcount) == 0) {
540 unregister_inetaddr_notifier(&nfsd_inetaddr_notifier);
541 #if IS_ENABLED(CONFIG_IPV6)
542 unregister_inet6addr_notifier(&nfsd_inet6addr_notifier);
543 #endif
544 }
545
546 svc_xprt_destroy_all(serv, net);
547
548 /*
549 * write_ports can create the server without actually starting
550 * any threads--if we get shut down before any threads are
551 * started, then nfsd_destroy_serv will be run before any of this
552 * other initialization has been done except the rpcb information.
553 */
554 svc_rpcb_cleanup(serv, net);
555
556 nfsd_shutdown_net(net);
557 svc_destroy(&serv);
558 }
559
nfsd_reset_versions(struct nfsd_net * nn)560 void nfsd_reset_versions(struct nfsd_net *nn)
561 {
562 int i;
563
564 for (i = 0; i <= NFSD_MAXVERS; i++)
565 if (nfsd_vers(nn, i, NFSD_TEST))
566 return;
567
568 for (i = 0; i <= NFSD_MAXVERS; i++)
569 if (i != 4)
570 nfsd_vers(nn, i, NFSD_SET);
571 else {
572 int minor = 0;
573 while (nfsd_minorversion(nn, minor, NFSD_SET) >= 0)
574 minor++;
575 }
576 }
577
578 /*
579 * Each session guarantees a negotiated per slot memory cache for replies
580 * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated
581 * NFSv4.1 server might want to use more memory for a DRC than a machine
582 * with mutiple services.
583 *
584 * Impose a hard limit on the number of pages for the DRC which varies
585 * according to the machines free pages. This is of course only a default.
586 *
587 * For now this is a #defined shift which could be under admin control
588 * in the future.
589 */
set_max_drc(void)590 static void set_max_drc(void)
591 {
592 #define NFSD_DRC_SIZE_SHIFT 7
593 nfsd_drc_max_mem = (nr_free_buffer_pages()
594 >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE;
595 nfsd_drc_mem_used = 0;
596 dprintk("%s nfsd_drc_max_mem %lu \n", __func__, nfsd_drc_max_mem);
597 }
598
nfsd_get_default_max_blksize(void)599 static int nfsd_get_default_max_blksize(void)
600 {
601 struct sysinfo i;
602 unsigned long long target;
603 unsigned long ret;
604
605 si_meminfo(&i);
606 target = (i.totalram - i.totalhigh) << PAGE_SHIFT;
607 /*
608 * Aim for 1/4096 of memory per thread This gives 1MB on 4Gig
609 * machines, but only uses 32K on 128M machines. Bottom out at
610 * 8K on 32M and smaller. Of course, this is only a default.
611 */
612 target >>= 12;
613
614 ret = NFSSVC_MAXBLKSIZE;
615 while (ret > target && ret >= 8*1024*2)
616 ret /= 2;
617 return ret;
618 }
619
nfsd_shutdown_threads(struct net * net)620 void nfsd_shutdown_threads(struct net *net)
621 {
622 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
623 struct svc_serv *serv;
624
625 mutex_lock(&nfsd_mutex);
626 serv = nn->nfsd_serv;
627 if (serv == NULL) {
628 mutex_unlock(&nfsd_mutex);
629 return;
630 }
631
632 /* Kill outstanding nfsd threads */
633 svc_set_num_threads(serv, NULL, 0);
634 nfsd_destroy_serv(net);
635 mutex_unlock(&nfsd_mutex);
636 }
637
nfsd_current_rqst(void)638 struct svc_rqst *nfsd_current_rqst(void)
639 {
640 if (kthread_func(current) == nfsd)
641 return kthread_data(current);
642 return NULL;
643 }
644
nfsd_create_serv(struct net * net)645 int nfsd_create_serv(struct net *net)
646 {
647 int error;
648 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
649 struct svc_serv *serv;
650
651 WARN_ON(!mutex_is_locked(&nfsd_mutex));
652 if (nn->nfsd_serv)
653 return 0;
654
655 error = percpu_ref_init(&nn->nfsd_serv_ref, nfsd_serv_free,
656 0, GFP_KERNEL);
657 if (error)
658 return error;
659 init_completion(&nn->nfsd_serv_free_done);
660 init_completion(&nn->nfsd_serv_confirm_done);
661
662 if (nfsd_max_blksize == 0)
663 nfsd_max_blksize = nfsd_get_default_max_blksize();
664 nfsd_reset_versions(nn);
665 serv = svc_create_pooled(nfsd_programs, ARRAY_SIZE(nfsd_programs),
666 &nn->nfsd_svcstats,
667 nfsd_max_blksize, nfsd);
668 if (serv == NULL)
669 return -ENOMEM;
670
671 serv->sv_maxconn = nn->max_connections;
672 error = svc_bind(serv, net);
673 if (error < 0) {
674 svc_destroy(&serv);
675 return error;
676 }
677 spin_lock(&nfsd_notifier_lock);
678 nn->nfsd_serv = serv;
679 spin_unlock(&nfsd_notifier_lock);
680
681 set_max_drc();
682 /* check if the notifier is already set */
683 if (atomic_inc_return(&nfsd_notifier_refcount) == 1) {
684 register_inetaddr_notifier(&nfsd_inetaddr_notifier);
685 #if IS_ENABLED(CONFIG_IPV6)
686 register_inet6addr_notifier(&nfsd_inet6addr_notifier);
687 #endif
688 }
689 nfsd_reset_write_verifier(nn);
690 return 0;
691 }
692
nfsd_nrpools(struct net * net)693 int nfsd_nrpools(struct net *net)
694 {
695 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
696
697 if (nn->nfsd_serv == NULL)
698 return 0;
699 else
700 return nn->nfsd_serv->sv_nrpools;
701 }
702
nfsd_get_nrthreads(int n,int * nthreads,struct net * net)703 int nfsd_get_nrthreads(int n, int *nthreads, struct net *net)
704 {
705 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
706 struct svc_serv *serv = nn->nfsd_serv;
707 int i;
708
709 if (serv)
710 for (i = 0; i < serv->sv_nrpools && i < n; i++)
711 nthreads[i] = serv->sv_pools[i].sp_nrthreads;
712 return 0;
713 }
714
715 /**
716 * nfsd_set_nrthreads - set the number of running threads in the net's service
717 * @n: number of array members in @nthreads
718 * @nthreads: array of thread counts for each pool
719 * @net: network namespace to operate within
720 *
721 * This function alters the number of running threads for the given network
722 * namespace in each pool. If passed an array longer then the number of pools
723 * the extra pool settings are ignored. If passed an array shorter than the
724 * number of pools, the missing values are interpreted as 0's.
725 *
726 * Returns 0 on success or a negative errno on error.
727 */
nfsd_set_nrthreads(int n,int * nthreads,struct net * net)728 int nfsd_set_nrthreads(int n, int *nthreads, struct net *net)
729 {
730 int i = 0;
731 int tot = 0;
732 int err = 0;
733 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
734
735 lockdep_assert_held(&nfsd_mutex);
736
737 if (nn->nfsd_serv == NULL || n <= 0)
738 return 0;
739
740 /*
741 * Special case: When n == 1, pass in NULL for the pool, so that the
742 * change is distributed equally among them.
743 */
744 if (n == 1)
745 return svc_set_num_threads(nn->nfsd_serv, NULL, nthreads[0]);
746
747 if (n > nn->nfsd_serv->sv_nrpools)
748 n = nn->nfsd_serv->sv_nrpools;
749
750 /* enforce a global maximum number of threads */
751 tot = 0;
752 for (i = 0; i < n; i++) {
753 nthreads[i] = min(nthreads[i], NFSD_MAXSERVS);
754 tot += nthreads[i];
755 }
756 if (tot > NFSD_MAXSERVS) {
757 /* total too large: scale down requested numbers */
758 for (i = 0; i < n && tot > 0; i++) {
759 int new = nthreads[i] * NFSD_MAXSERVS / tot;
760 tot -= (nthreads[i] - new);
761 nthreads[i] = new;
762 }
763 for (i = 0; i < n && tot > 0; i++) {
764 nthreads[i]--;
765 tot--;
766 }
767 }
768
769 /* apply the new numbers */
770 for (i = 0; i < n; i++) {
771 err = svc_set_num_threads(nn->nfsd_serv,
772 &nn->nfsd_serv->sv_pools[i],
773 nthreads[i]);
774 if (err)
775 goto out;
776 }
777
778 /* Anything undefined in array is considered to be 0 */
779 for (i = n; i < nn->nfsd_serv->sv_nrpools; ++i) {
780 err = svc_set_num_threads(nn->nfsd_serv,
781 &nn->nfsd_serv->sv_pools[i],
782 0);
783 if (err)
784 goto out;
785 }
786 out:
787 return err;
788 }
789
790 /**
791 * nfsd_svc: start up or shut down the nfsd server
792 * @n: number of array members in @nthreads
793 * @nthreads: array of thread counts for each pool
794 * @net: network namespace to operate within
795 * @cred: credentials to use for xprt creation
796 * @scope: server scope value (defaults to nodename)
797 *
798 * Adjust the number of threads in each pool and return the new
799 * total number of threads in the service.
800 */
801 int
nfsd_svc(int n,int * nthreads,struct net * net,const struct cred * cred,const char * scope)802 nfsd_svc(int n, int *nthreads, struct net *net, const struct cred *cred, const char *scope)
803 {
804 int error;
805 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
806 struct svc_serv *serv;
807
808 lockdep_assert_held(&nfsd_mutex);
809
810 dprintk("nfsd: creating service\n");
811
812 strscpy(nn->nfsd_name, scope ? scope : utsname()->nodename,
813 sizeof(nn->nfsd_name));
814
815 error = nfsd_create_serv(net);
816 if (error)
817 goto out;
818 serv = nn->nfsd_serv;
819
820 error = nfsd_startup_net(net, cred);
821 if (error)
822 goto out_put;
823 error = nfsd_set_nrthreads(n, nthreads, net);
824 if (error)
825 goto out_put;
826 error = serv->sv_nrthreads;
827 out_put:
828 if (serv->sv_nrthreads == 0)
829 nfsd_destroy_serv(net);
830 out:
831 return error;
832 }
833
834 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
835 static bool
nfsd_support_acl_version(int vers)836 nfsd_support_acl_version(int vers)
837 {
838 if (vers >= NFSD_ACL_MINVERS && vers < NFSD_ACL_NRVERS)
839 return nfsd_acl_version[vers] != NULL;
840 return false;
841 }
842
843 static int
nfsd_acl_rpcbind_set(struct net * net,const struct svc_program * progp,u32 version,int family,unsigned short proto,unsigned short port)844 nfsd_acl_rpcbind_set(struct net *net, const struct svc_program *progp,
845 u32 version, int family, unsigned short proto,
846 unsigned short port)
847 {
848 if (!nfsd_support_acl_version(version) ||
849 !nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST))
850 return 0;
851 return svc_generic_rpcbind_set(net, progp, version, family,
852 proto, port);
853 }
854
855 static __be32
nfsd_acl_init_request(struct svc_rqst * rqstp,const struct svc_program * progp,struct svc_process_info * ret)856 nfsd_acl_init_request(struct svc_rqst *rqstp,
857 const struct svc_program *progp,
858 struct svc_process_info *ret)
859 {
860 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
861 int i;
862
863 if (likely(nfsd_support_acl_version(rqstp->rq_vers) &&
864 nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST)))
865 return svc_generic_init_request(rqstp, progp, ret);
866
867 ret->mismatch.lovers = NFSD_ACL_NRVERS;
868 for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) {
869 if (nfsd_support_acl_version(rqstp->rq_vers) &&
870 nfsd_vers(nn, i, NFSD_TEST)) {
871 ret->mismatch.lovers = i;
872 break;
873 }
874 }
875 if (ret->mismatch.lovers == NFSD_ACL_NRVERS)
876 return rpc_prog_unavail;
877 ret->mismatch.hivers = NFSD_ACL_MINVERS;
878 for (i = NFSD_ACL_NRVERS - 1; i >= NFSD_ACL_MINVERS; i--) {
879 if (nfsd_support_acl_version(rqstp->rq_vers) &&
880 nfsd_vers(nn, i, NFSD_TEST)) {
881 ret->mismatch.hivers = i;
882 break;
883 }
884 }
885 return rpc_prog_mismatch;
886 }
887 #endif
888
889 static int
nfsd_rpcbind_set(struct net * net,const struct svc_program * progp,u32 version,int family,unsigned short proto,unsigned short port)890 nfsd_rpcbind_set(struct net *net, const struct svc_program *progp,
891 u32 version, int family, unsigned short proto,
892 unsigned short port)
893 {
894 if (!nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST))
895 return 0;
896 return svc_generic_rpcbind_set(net, progp, version, family,
897 proto, port);
898 }
899
900 static __be32
nfsd_init_request(struct svc_rqst * rqstp,const struct svc_program * progp,struct svc_process_info * ret)901 nfsd_init_request(struct svc_rqst *rqstp,
902 const struct svc_program *progp,
903 struct svc_process_info *ret)
904 {
905 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
906 int i;
907
908 if (likely(nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST)))
909 return svc_generic_init_request(rqstp, progp, ret);
910
911 ret->mismatch.lovers = NFSD_MAXVERS + 1;
912 for (i = NFSD_MINVERS; i <= NFSD_MAXVERS; i++) {
913 if (nfsd_vers(nn, i, NFSD_TEST)) {
914 ret->mismatch.lovers = i;
915 break;
916 }
917 }
918 if (ret->mismatch.lovers > NFSD_MAXVERS)
919 return rpc_prog_unavail;
920 ret->mismatch.hivers = NFSD_MINVERS;
921 for (i = NFSD_MAXVERS; i >= NFSD_MINVERS; i--) {
922 if (nfsd_vers(nn, i, NFSD_TEST)) {
923 ret->mismatch.hivers = i;
924 break;
925 }
926 }
927 return rpc_prog_mismatch;
928 }
929
930 /*
931 * This is the NFS server kernel thread
932 */
933 static int
nfsd(void * vrqstp)934 nfsd(void *vrqstp)
935 {
936 struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp;
937 struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list);
938 struct net *net = perm_sock->xpt_net;
939 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
940
941 /* At this point, the thread shares current->fs
942 * with the init process. We need to create files with the
943 * umask as defined by the client instead of init's umask.
944 */
945 svc_thread_init_status(rqstp, unshare_fs_struct());
946
947 current->fs->umask = 0;
948
949 atomic_inc(&nfsd_th_cnt);
950
951 set_freezable();
952
953 /*
954 * The main request loop
955 */
956 while (!svc_thread_should_stop(rqstp)) {
957 /* Update sv_maxconn if it has changed */
958 rqstp->rq_server->sv_maxconn = nn->max_connections;
959
960 svc_recv(rqstp);
961
962 nfsd_file_net_dispose(nn);
963 }
964
965 atomic_dec(&nfsd_th_cnt);
966
967 /* Release the thread */
968 svc_exit_thread(rqstp);
969 return 0;
970 }
971
972 /**
973 * nfsd_dispatch - Process an NFS or NFSACL or LOCALIO Request
974 * @rqstp: incoming request
975 *
976 * This RPC dispatcher integrates the NFS server's duplicate reply cache.
977 *
978 * Return values:
979 * %0: Processing complete; do not send a Reply
980 * %1: Processing complete; send Reply in rqstp->rq_res
981 */
nfsd_dispatch(struct svc_rqst * rqstp)982 int nfsd_dispatch(struct svc_rqst *rqstp)
983 {
984 const struct svc_procedure *proc = rqstp->rq_procinfo;
985 __be32 *statp = rqstp->rq_accept_statp;
986 struct nfsd_cacherep *rp;
987 unsigned int start, len;
988 __be32 *nfs_reply;
989
990 /*
991 * Give the xdr decoder a chance to change this if it wants
992 * (necessary in the NFSv4.0 compound case)
993 */
994 rqstp->rq_cachetype = proc->pc_cachetype;
995
996 /*
997 * ->pc_decode advances the argument stream past the NFS
998 * Call header, so grab the header's starting location and
999 * size now for the call to nfsd_cache_lookup().
1000 */
1001 start = xdr_stream_pos(&rqstp->rq_arg_stream);
1002 len = xdr_stream_remaining(&rqstp->rq_arg_stream);
1003 if (!proc->pc_decode(rqstp, &rqstp->rq_arg_stream))
1004 goto out_decode_err;
1005
1006 /*
1007 * Release rq_status_counter setting it to an odd value after the rpc
1008 * request has been properly parsed. rq_status_counter is used to
1009 * notify the consumers if the rqstp fields are stable
1010 * (rq_status_counter is odd) or not meaningful (rq_status_counter
1011 * is even).
1012 */
1013 smp_store_release(&rqstp->rq_status_counter, rqstp->rq_status_counter | 1);
1014
1015 rp = NULL;
1016 switch (nfsd_cache_lookup(rqstp, start, len, &rp)) {
1017 case RC_DOIT:
1018 break;
1019 case RC_REPLY:
1020 goto out_cached_reply;
1021 case RC_DROPIT:
1022 goto out_dropit;
1023 }
1024
1025 nfs_reply = xdr_inline_decode(&rqstp->rq_res_stream, 0);
1026 *statp = proc->pc_func(rqstp);
1027 if (test_bit(RQ_DROPME, &rqstp->rq_flags))
1028 goto out_update_drop;
1029
1030 if (!proc->pc_encode(rqstp, &rqstp->rq_res_stream))
1031 goto out_encode_err;
1032
1033 /*
1034 * Release rq_status_counter setting it to an even value after the rpc
1035 * request has been properly processed.
1036 */
1037 smp_store_release(&rqstp->rq_status_counter, rqstp->rq_status_counter + 1);
1038
1039 nfsd_cache_update(rqstp, rp, rqstp->rq_cachetype, nfs_reply);
1040 out_cached_reply:
1041 return 1;
1042
1043 out_decode_err:
1044 trace_nfsd_garbage_args_err(rqstp);
1045 *statp = rpc_garbage_args;
1046 return 1;
1047
1048 out_update_drop:
1049 nfsd_cache_update(rqstp, rp, RC_NOCACHE, NULL);
1050 out_dropit:
1051 return 0;
1052
1053 out_encode_err:
1054 trace_nfsd_cant_encode_err(rqstp);
1055 nfsd_cache_update(rqstp, rp, RC_NOCACHE, NULL);
1056 *statp = rpc_system_err;
1057 return 1;
1058 }
1059
1060 /**
1061 * nfssvc_decode_voidarg - Decode void arguments
1062 * @rqstp: Server RPC transaction context
1063 * @xdr: XDR stream positioned at arguments to decode
1064 *
1065 * Return values:
1066 * %false: Arguments were not valid
1067 * %true: Decoding was successful
1068 */
nfssvc_decode_voidarg(struct svc_rqst * rqstp,struct xdr_stream * xdr)1069 bool nfssvc_decode_voidarg(struct svc_rqst *rqstp, struct xdr_stream *xdr)
1070 {
1071 return true;
1072 }
1073
1074 /**
1075 * nfssvc_encode_voidres - Encode void results
1076 * @rqstp: Server RPC transaction context
1077 * @xdr: XDR stream into which to encode results
1078 *
1079 * Return values:
1080 * %false: Local error while encoding
1081 * %true: Encoding was successful
1082 */
nfssvc_encode_voidres(struct svc_rqst * rqstp,struct xdr_stream * xdr)1083 bool nfssvc_encode_voidres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
1084 {
1085 return true;
1086 }
1087