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1/*
2 * Central processing for nfsd.
3 *
4 * Authors: Olaf Kirch (okir@monad.swb.de)
5 *
6 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
7 */
8
9#include <linux/sched.h>
10#include <linux/freezer.h>
11#include <linux/module.h>
12#include <linux/fs_struct.h>
13#include <linux/swap.h>
14#include <linux/nsproxy.h>
15
16#include <linux/sunrpc/stats.h>
17#include <linux/sunrpc/svcsock.h>
18#include <linux/lockd/bind.h>
19#include <linux/nfsacl.h>
20#include <linux/seq_file.h>
21#include <net/net_namespace.h>
22#include "nfsd.h"
23#include "cache.h"
24#include "vfs.h"
25
26#define NFSDDBG_FACILITY NFSDDBG_SVC
27
28extern struct svc_program nfsd_program;
29static int nfsd(void *vrqstp);
30struct timeval nfssvc_boot;
31
32/*
33 * nfsd_mutex protects nfsd_serv -- both the pointer itself and the members
34 * of the svc_serv struct. In particular, ->sv_nrthreads but also to some
35 * extent ->sv_temp_socks and ->sv_permsocks. It also protects nfsdstats.th_cnt
36 *
37 * If (out side the lock) nfsd_serv is non-NULL, then it must point to a
38 * properly initialised 'struct svc_serv' with ->sv_nrthreads > 0. That number
39 * of nfsd threads must exist and each must listed in ->sp_all_threads in each
40 * entry of ->sv_pools[].
41 *
42 * Transitions of the thread count between zero and non-zero are of particular
43 * interest since the svc_serv needs to be created and initialized at that
44 * point, or freed.
45 *
46 * Finally, the nfsd_mutex also protects some of the global variables that are
47 * accessed when nfsd starts and that are settable via the write_* routines in
48 * nfsctl.c. In particular:
49 *
50 * user_recovery_dirname
51 * user_lease_time
52 * nfsd_versions
53 */
54DEFINE_MUTEX(nfsd_mutex);
55struct svc_serv *nfsd_serv;
56
57/*
58 * nfsd_drc_lock protects nfsd_drc_max_pages and nfsd_drc_pages_used.
59 * nfsd_drc_max_pages limits the total amount of memory available for
60 * version 4.1 DRC caches.
61 * nfsd_drc_pages_used tracks the current version 4.1 DRC memory usage.
62 */
63spinlock_t nfsd_drc_lock;
64unsigned int nfsd_drc_max_mem;
65unsigned int nfsd_drc_mem_used;
66
67#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
68static struct svc_stat nfsd_acl_svcstats;
69static struct svc_version * nfsd_acl_version[] = {
70 [2] = &nfsd_acl_version2,
71 [3] = &nfsd_acl_version3,
72};
73
74#define NFSD_ACL_MINVERS 2
75#define NFSD_ACL_NRVERS ARRAY_SIZE(nfsd_acl_version)
76static struct svc_version *nfsd_acl_versions[NFSD_ACL_NRVERS];
77
78static struct svc_program nfsd_acl_program = {
79 .pg_prog = NFS_ACL_PROGRAM,
80 .pg_nvers = NFSD_ACL_NRVERS,
81 .pg_vers = nfsd_acl_versions,
82 .pg_name = "nfsacl",
83 .pg_class = "nfsd",
84 .pg_stats = &nfsd_acl_svcstats,
85 .pg_authenticate = &svc_set_client,
86};
87
88static struct svc_stat nfsd_acl_svcstats = {
89 .program = &nfsd_acl_program,
90};
91#endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
92
93static struct svc_version * nfsd_version[] = {
94 [2] = &nfsd_version2,
95#if defined(CONFIG_NFSD_V3)
96 [3] = &nfsd_version3,
97#endif
98#if defined(CONFIG_NFSD_V4)
99 [4] = &nfsd_version4,
100#endif
101};
102
103#define NFSD_MINVERS 2
104#define NFSD_NRVERS ARRAY_SIZE(nfsd_version)
105static struct svc_version *nfsd_versions[NFSD_NRVERS];
106
107struct svc_program nfsd_program = {
108#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
109 .pg_next = &nfsd_acl_program,
110#endif
111 .pg_prog = NFS_PROGRAM, /* program number */
112 .pg_nvers = NFSD_NRVERS, /* nr of entries in nfsd_version */
113 .pg_vers = nfsd_versions, /* version table */
114 .pg_name = "nfsd", /* program name */
115 .pg_class = "nfsd", /* authentication class */
116 .pg_stats = &nfsd_svcstats, /* version table */
117 .pg_authenticate = &svc_set_client, /* export authentication */
118
119};
120
121u32 nfsd_supported_minorversion;
122
123int nfsd_vers(int vers, enum vers_op change)
124{
125 if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS)
126 return 0;
127 switch(change) {
128 case NFSD_SET:
129 nfsd_versions[vers] = nfsd_version[vers];
130#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
131 if (vers < NFSD_ACL_NRVERS)
132 nfsd_acl_versions[vers] = nfsd_acl_version[vers];
133#endif
134 break;
135 case NFSD_CLEAR:
136 nfsd_versions[vers] = NULL;
137#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
138 if (vers < NFSD_ACL_NRVERS)
139 nfsd_acl_versions[vers] = NULL;
140#endif
141 break;
142 case NFSD_TEST:
143 return nfsd_versions[vers] != NULL;
144 case NFSD_AVAIL:
145 return nfsd_version[vers] != NULL;
146 }
147 return 0;
148}
149
150int nfsd_minorversion(u32 minorversion, enum vers_op change)
151{
152 if (minorversion > NFSD_SUPPORTED_MINOR_VERSION)
153 return -1;
154 switch(change) {
155 case NFSD_SET:
156 nfsd_supported_minorversion = minorversion;
157 break;
158 case NFSD_CLEAR:
159 if (minorversion == 0)
160 return -1;
161 nfsd_supported_minorversion = minorversion - 1;
162 break;
163 case NFSD_TEST:
164 return minorversion <= nfsd_supported_minorversion;
165 case NFSD_AVAIL:
166 return minorversion <= NFSD_SUPPORTED_MINOR_VERSION;
167 }
168 return 0;
169}
170
171/*
172 * Maximum number of nfsd processes
173 */
174#define NFSD_MAXSERVS 8192
175
176int nfsd_nrthreads(void)
177{
178 int rv = 0;
179 mutex_lock(&nfsd_mutex);
180 if (nfsd_serv)
181 rv = nfsd_serv->sv_nrthreads;
182 mutex_unlock(&nfsd_mutex);
183 return rv;
184}
185
186static int nfsd_init_socks(int port)
187{
188 int error;
189 if (!list_empty(&nfsd_serv->sv_permsocks))
190 return 0;
191
192 error = svc_create_xprt(nfsd_serv, "udp", &init_net, PF_INET, port,
193 SVC_SOCK_DEFAULTS);
194 if (error < 0)
195 return error;
196
197 error = svc_create_xprt(nfsd_serv, "tcp", &init_net, PF_INET, port,
198 SVC_SOCK_DEFAULTS);
199 if (error < 0)
200 return error;
201
202 return 0;
203}
204
205static bool nfsd_up = false;
206
207static int nfsd_startup(unsigned short port, int nrservs)
208{
209 int ret;
210
211 if (nfsd_up)
212 return 0;
213 /*
214 * Readahead param cache - will no-op if it already exists.
215 * (Note therefore results will be suboptimal if number of
216 * threads is modified after nfsd start.)
217 */
218 ret = nfsd_racache_init(2*nrservs);
219 if (ret)
220 return ret;
221 ret = nfsd_init_socks(port);
222 if (ret)
223 goto out_racache;
224 ret = lockd_up(&init_net);
225 if (ret)
226 goto out_racache;
227 ret = nfs4_state_start();
228 if (ret)
229 goto out_lockd;
230 nfsd_up = true;
231 return 0;
232out_lockd:
233 lockd_down(&init_net);
234out_racache:
235 nfsd_racache_shutdown();
236 return ret;
237}
238
239static void nfsd_shutdown(void)
240{
241 /*
242 * write_ports can create the server without actually starting
243 * any threads--if we get shut down before any threads are
244 * started, then nfsd_last_thread will be run before any of this
245 * other initialization has been done.
246 */
247 if (!nfsd_up)
248 return;
249 nfs4_state_shutdown();
250 lockd_down(&init_net);
251 nfsd_racache_shutdown();
252 nfsd_up = false;
253}
254
255static void nfsd_last_thread(struct svc_serv *serv, struct net *net)
256{
257 nfsd_shutdown();
258
259 svc_rpcb_cleanup(serv, net);
260
261 printk(KERN_WARNING "nfsd: last server has exited, flushing export "
262 "cache\n");
263 nfsd_export_flush(net);
264}
265
266void nfsd_reset_versions(void)
267{
268 int found_one = 0;
269 int i;
270
271 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) {
272 if (nfsd_program.pg_vers[i])
273 found_one = 1;
274 }
275
276 if (!found_one) {
277 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++)
278 nfsd_program.pg_vers[i] = nfsd_version[i];
279#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
280 for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++)
281 nfsd_acl_program.pg_vers[i] =
282 nfsd_acl_version[i];
283#endif
284 }
285}
286
287/*
288 * Each session guarantees a negotiated per slot memory cache for replies
289 * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated
290 * NFSv4.1 server might want to use more memory for a DRC than a machine
291 * with mutiple services.
292 *
293 * Impose a hard limit on the number of pages for the DRC which varies
294 * according to the machines free pages. This is of course only a default.
295 *
296 * For now this is a #defined shift which could be under admin control
297 * in the future.
298 */
299static void set_max_drc(void)
300{
301 #define NFSD_DRC_SIZE_SHIFT 10
302 nfsd_drc_max_mem = (nr_free_buffer_pages()
303 >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE;
304 nfsd_drc_mem_used = 0;
305 spin_lock_init(&nfsd_drc_lock);
306 dprintk("%s nfsd_drc_max_mem %u \n", __func__, nfsd_drc_max_mem);
307}
308
309static int nfsd_get_default_max_blksize(void)
310{
311 struct sysinfo i;
312 unsigned long long target;
313 unsigned long ret;
314
315 si_meminfo(&i);
316 target = (i.totalram - i.totalhigh) << PAGE_SHIFT;
317 /*
318 * Aim for 1/4096 of memory per thread This gives 1MB on 4Gig
319 * machines, but only uses 32K on 128M machines. Bottom out at
320 * 8K on 32M and smaller. Of course, this is only a default.
321 */
322 target >>= 12;
323
324 ret = NFSSVC_MAXBLKSIZE;
325 while (ret > target && ret >= 8*1024*2)
326 ret /= 2;
327 return ret;
328}
329
330int nfsd_create_serv(void)
331{
332 int error;
333 struct net *net = current->nsproxy->net_ns;
334
335 WARN_ON(!mutex_is_locked(&nfsd_mutex));
336 if (nfsd_serv) {
337 svc_get(nfsd_serv);
338 return 0;
339 }
340 if (nfsd_max_blksize == 0)
341 nfsd_max_blksize = nfsd_get_default_max_blksize();
342 nfsd_reset_versions();
343 nfsd_serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize,
344 nfsd_last_thread, nfsd, THIS_MODULE);
345 if (nfsd_serv == NULL)
346 return -ENOMEM;
347
348 error = svc_bind(nfsd_serv, net);
349 if (error < 0) {
350 svc_destroy(nfsd_serv);
351 return error;
352 }
353
354 set_max_drc();
355 do_gettimeofday(&nfssvc_boot); /* record boot time */
356 return 0;
357}
358
359int nfsd_nrpools(void)
360{
361 if (nfsd_serv == NULL)
362 return 0;
363 else
364 return nfsd_serv->sv_nrpools;
365}
366
367int nfsd_get_nrthreads(int n, int *nthreads)
368{
369 int i = 0;
370
371 if (nfsd_serv != NULL) {
372 for (i = 0; i < nfsd_serv->sv_nrpools && i < n; i++)
373 nthreads[i] = nfsd_serv->sv_pools[i].sp_nrthreads;
374 }
375
376 return 0;
377}
378
379int nfsd_set_nrthreads(int n, int *nthreads)
380{
381 int i = 0;
382 int tot = 0;
383 int err = 0;
384 struct net *net = &init_net;
385
386 WARN_ON(!mutex_is_locked(&nfsd_mutex));
387
388 if (nfsd_serv == NULL || n <= 0)
389 return 0;
390
391 if (n > nfsd_serv->sv_nrpools)
392 n = nfsd_serv->sv_nrpools;
393
394 /* enforce a global maximum number of threads */
395 tot = 0;
396 for (i = 0; i < n; i++) {
397 if (nthreads[i] > NFSD_MAXSERVS)
398 nthreads[i] = NFSD_MAXSERVS;
399 tot += nthreads[i];
400 }
401 if (tot > NFSD_MAXSERVS) {
402 /* total too large: scale down requested numbers */
403 for (i = 0; i < n && tot > 0; i++) {
404 int new = nthreads[i] * NFSD_MAXSERVS / tot;
405 tot -= (nthreads[i] - new);
406 nthreads[i] = new;
407 }
408 for (i = 0; i < n && tot > 0; i++) {
409 nthreads[i]--;
410 tot--;
411 }
412 }
413
414 /*
415 * There must always be a thread in pool 0; the admin
416 * can't shut down NFS completely using pool_threads.
417 */
418 if (nthreads[0] == 0)
419 nthreads[0] = 1;
420
421 /* apply the new numbers */
422 svc_get(nfsd_serv);
423 for (i = 0; i < n; i++) {
424 err = svc_set_num_threads(nfsd_serv, &nfsd_serv->sv_pools[i],
425 nthreads[i]);
426 if (err)
427 break;
428 }
429 nfsd_destroy(net);
430 return err;
431}
432
433/*
434 * Adjust the number of threads and return the new number of threads.
435 * This is also the function that starts the server if necessary, if
436 * this is the first time nrservs is nonzero.
437 */
438int
439nfsd_svc(unsigned short port, int nrservs)
440{
441 int error;
442 bool nfsd_up_before;
443 struct net *net = &init_net;
444
445 mutex_lock(&nfsd_mutex);
446 dprintk("nfsd: creating service\n");
447 if (nrservs <= 0)
448 nrservs = 0;
449 if (nrservs > NFSD_MAXSERVS)
450 nrservs = NFSD_MAXSERVS;
451 error = 0;
452 if (nrservs == 0 && nfsd_serv == NULL)
453 goto out;
454
455 error = nfsd_create_serv();
456 if (error)
457 goto out;
458
459 nfsd_up_before = nfsd_up;
460
461 error = nfsd_startup(port, nrservs);
462 if (error)
463 goto out_destroy;
464 error = svc_set_num_threads(nfsd_serv, NULL, nrservs);
465 if (error)
466 goto out_shutdown;
467 /* We are holding a reference to nfsd_serv which
468 * we don't want to count in the return value,
469 * so subtract 1
470 */
471 error = nfsd_serv->sv_nrthreads - 1;
472out_shutdown:
473 if (error < 0 && !nfsd_up_before)
474 nfsd_shutdown();
475out_destroy:
476 nfsd_destroy(net); /* Release server */
477out:
478 mutex_unlock(&nfsd_mutex);
479 return error;
480}
481
482
483/*
484 * This is the NFS server kernel thread
485 */
486static int
487nfsd(void *vrqstp)
488{
489 struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp;
490 int err, preverr = 0;
491
492 /* Lock module and set up kernel thread */
493 mutex_lock(&nfsd_mutex);
494
495 /* At this point, the thread shares current->fs
496 * with the init process. We need to create files with a
497 * umask of 0 instead of init's umask. */
498 if (unshare_fs_struct() < 0) {
499 printk("Unable to start nfsd thread: out of memory\n");
500 goto out;
501 }
502
503 current->fs->umask = 0;
504
505 /*
506 * thread is spawned with all signals set to SIG_IGN, re-enable
507 * the ones that will bring down the thread
508 */
509 allow_signal(SIGKILL);
510 allow_signal(SIGHUP);
511 allow_signal(SIGINT);
512 allow_signal(SIGQUIT);
513
514 nfsdstats.th_cnt++;
515 mutex_unlock(&nfsd_mutex);
516
517 /*
518 * We want less throttling in balance_dirty_pages() so that nfs to
519 * localhost doesn't cause nfsd to lock up due to all the client's
520 * dirty pages.
521 */
522 current->flags |= PF_LESS_THROTTLE;
523 set_freezable();
524
525 /*
526 * The main request loop
527 */
528 for (;;) {
529 /*
530 * Find a socket with data available and call its
531 * recvfrom routine.
532 */
533 while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN)
534 ;
535 if (err == -EINTR)
536 break;
537 else if (err < 0) {
538 if (err != preverr) {
539 printk(KERN_WARNING "%s: unexpected error "
540 "from svc_recv (%d)\n", __func__, -err);
541 preverr = err;
542 }
543 schedule_timeout_uninterruptible(HZ);
544 continue;
545 }
546
547 validate_process_creds();
548 svc_process(rqstp);
549 validate_process_creds();
550 }
551
552 /* Clear signals before calling svc_exit_thread() */
553 flush_signals(current);
554
555 mutex_lock(&nfsd_mutex);
556 nfsdstats.th_cnt --;
557
558out:
559 rqstp->rq_server = NULL;
560
561 /* Release the thread */
562 svc_exit_thread(rqstp);
563
564 nfsd_destroy(&init_net);
565
566 /* Release module */
567 mutex_unlock(&nfsd_mutex);
568 module_put_and_exit(0);
569 return 0;
570}
571
572static __be32 map_new_errors(u32 vers, __be32 nfserr)
573{
574 if (nfserr == nfserr_jukebox && vers == 2)
575 return nfserr_dropit;
576 if (nfserr == nfserr_wrongsec && vers < 4)
577 return nfserr_acces;
578 return nfserr;
579}
580
581int
582nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
583{
584 struct svc_procedure *proc;
585 kxdrproc_t xdr;
586 __be32 nfserr;
587 __be32 *nfserrp;
588
589 dprintk("nfsd_dispatch: vers %d proc %d\n",
590 rqstp->rq_vers, rqstp->rq_proc);
591 proc = rqstp->rq_procinfo;
592
593 /*
594 * Give the xdr decoder a chance to change this if it wants
595 * (necessary in the NFSv4.0 compound case)
596 */
597 rqstp->rq_cachetype = proc->pc_cachetype;
598 /* Decode arguments */
599 xdr = proc->pc_decode;
600 if (xdr && !xdr(rqstp, (__be32*)rqstp->rq_arg.head[0].iov_base,
601 rqstp->rq_argp)) {
602 dprintk("nfsd: failed to decode arguments!\n");
603 *statp = rpc_garbage_args;
604 return 1;
605 }
606
607 /* Check whether we have this call in the cache. */
608 switch (nfsd_cache_lookup(rqstp)) {
609 case RC_INTR:
610 case RC_DROPIT:
611 return 0;
612 case RC_REPLY:
613 return 1;
614 case RC_DOIT:;
615 /* do it */
616 }
617
618 /* need to grab the location to store the status, as
619 * nfsv4 does some encoding while processing
620 */
621 nfserrp = rqstp->rq_res.head[0].iov_base
622 + rqstp->rq_res.head[0].iov_len;
623 rqstp->rq_res.head[0].iov_len += sizeof(__be32);
624
625 /* Now call the procedure handler, and encode NFS status. */
626 nfserr = proc->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
627 nfserr = map_new_errors(rqstp->rq_vers, nfserr);
628 if (nfserr == nfserr_dropit || rqstp->rq_dropme) {
629 dprintk("nfsd: Dropping request; may be revisited later\n");
630 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
631 return 0;
632 }
633
634 if (rqstp->rq_proc != 0)
635 *nfserrp++ = nfserr;
636
637 /* Encode result.
638 * For NFSv2, additional info is never returned in case of an error.
639 */
640 if (!(nfserr && rqstp->rq_vers == 2)) {
641 xdr = proc->pc_encode;
642 if (xdr && !xdr(rqstp, nfserrp,
643 rqstp->rq_resp)) {
644 /* Failed to encode result. Release cache entry */
645 dprintk("nfsd: failed to encode result!\n");
646 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
647 *statp = rpc_system_err;
648 return 1;
649 }
650 }
651
652 /* Store reply in cache. */
653 nfsd_cache_update(rqstp, proc->pc_cachetype, statp + 1);
654 return 1;
655}
656
657int nfsd_pool_stats_open(struct inode *inode, struct file *file)
658{
659 int ret;
660 mutex_lock(&nfsd_mutex);
661 if (nfsd_serv == NULL) {
662 mutex_unlock(&nfsd_mutex);
663 return -ENODEV;
664 }
665 /* bump up the psudo refcount while traversing */
666 svc_get(nfsd_serv);
667 ret = svc_pool_stats_open(nfsd_serv, file);
668 mutex_unlock(&nfsd_mutex);
669 return ret;
670}
671
672int nfsd_pool_stats_release(struct inode *inode, struct file *file)
673{
674 int ret = seq_release(inode, file);
675 struct net *net = &init_net;
676
677 mutex_lock(&nfsd_mutex);
678 /* this function really, really should have been called svc_put() */
679 nfsd_destroy(net);
680 mutex_unlock(&nfsd_mutex);
681 return ret;
682}
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, 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(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 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(4);
169 }
170 return vers;
171}
172
173void
174nfsd_netns_free_versions(struct nfsd_net *nn)
175{
176 kfree(nn->nfsd_versions);
177 kfree(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, 4, 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, 4, NFSD_SET);
239 nn->nfsd4_minorversions[minorversion] =
240 nfsd_vers(nn, 4, 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, 4, NFSD_TEST);
254 case NFSD_AVAIL:
255 return minorversion <= NFSD_SUPPORTED_MINOR_VERSION &&
256 nfsd_vers(nn, 4, 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, nfsd_net_id);
270
271 mutex_lock(&nfsd_mutex);
272 if (nn->nfsd_serv)
273 rv = nn->nfsd_serv->sv_nrthreads;
274 mutex_unlock(&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, nfsd_net_id);
282
283 if (!list_empty(&nn->nfsd_serv->sv_permsocks))
284 return 0;
285
286 error = svc_xprt_create(nn->nfsd_serv, "udp", net, PF_INET, NFS_PORT,
287 SVC_SOCK_DEFAULTS, cred);
288 if (error < 0)
289 return error;
290
291 error = svc_xprt_create(nn->nfsd_serv, "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, 2, NFSD_TEST) || nfsd_vers(nn, 3, 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(&nn->writeverf_lock);
352 memcpy(verf, nn->writeverf, sizeof(nn->writeverf));
353 } while (read_seqretry(&nn->writeverf_lock, 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(&now);
366 verf = siphash_2u64(now.tv_sec, now.tv_nsec, &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(&nn->writeverf_lock);
386 nfsd_reset_write_verifier_locked(nn);
387 write_sequnlock(&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, 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, 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, nfsd_net_id);
472 struct sockaddr_in sin;
473
474 if (event != NETDEV_DOWN || !nn->nfsd_serv)
475 goto out;
476
477 spin_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(&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, nfsd_net_id);
502 struct sockaddr_in6 sin6;
503
504 if (event != NETDEV_DOWN || !nn->nfsd_serv)
505 goto out;
506
507 spin_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(&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(&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, nfsd_net_id);
537 struct svc_serv *serv = nn->nfsd_serv;
538
539 spin_lock(&nfsd_notifier_lock);
540 nn->nfsd_serv = NULL;
541 spin_unlock(&nfsd_notifier_lock);
542
543 /* check if the notifier still has clients */
544 if (atomic_dec_return(&nfsd_notifier_refcount) == 0) {
545 unregister_inetaddr_notifier(&nfsd_inetaddr_notifier);
546#if IS_ENABLED(CONFIG_IPV6)
547 unregister_inet6addr_notifier(&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(&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, i, NFSD_TEST))
574 return;
575
576 for (i = 0; i < NFSD_NRVERS; i++)
577 if (i != 4)
578 nfsd_vers(nn, i, NFSD_SET);
579 else {
580 int minor = 0;
581 while (nfsd_minorversion(nn, minor, 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(&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, 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(&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(&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, 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(&nfsd_program, &nn->nfsd_svcstats,
665 nfsd_max_blksize, 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(&serv);
673 return error;
674 }
675 spin_lock(&nfsd_notifier_lock);
676 nn->nfsd_info.mutex = &nfsd_mutex;
677 nn->nfsd_serv = serv;
678 spin_unlock(&nfsd_notifier_lock);
679
680 set_max_drc();
681 /* check if the notifier is already set */
682 if (atomic_inc_return(&nfsd_notifier_refcount) == 1) {
683 register_inetaddr_notifier(&nfsd_inetaddr_notifier);
684#if IS_ENABLED(CONFIG_IPV6)
685 register_inet6addr_notifier(&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, 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, 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(&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, 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, 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(&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(version) ||
826 !nfsd_vers(net_generic(net, nfsd_net_id), version, 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), 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, 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(rqstp->rq_vers) &&
847 nfsd_vers(nn, i, 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(rqstp->rq_vers) &&
857 nfsd_vers(nn, i, 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(net_generic(net, nfsd_net_id), version, 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), 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, ret);
887
888 ret->mismatch.lovers = NFSD_NRVERS;
889 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) {
890 if (nfsd_vers(nn, i, 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, i, 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, 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(&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(&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(&rqstp->rq_arg_stream);
982 len = xdr_stream_remaining(&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, &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(&rqstp->rq_res_stream, 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, rqstp->rq_cachetype, 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, 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, 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(inode->i_sb->s_fs_info, nfsd_net_id);
1071
1072 return svc_pool_stats_open(&nn->nfsd_info, file);
1073}