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

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source code of linux/fs/nfsd/nfssvc.c