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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
16#include <linux/sunrpc/stats.h>
17#include <linux/sunrpc/svcsock.h>
18#include <linux/sunrpc/svc_xprt.h>
19#include <linux/lockd/bind.h>
20#include <linux/nfsacl.h>
21#include <linux/seq_file.h>
22#include <linux/inetdevice.h>
23#include <net/addrconf.h>
24#include <net/ipv6.h>
25#include <net/net_namespace.h>
26#include "nfsd.h"
27#include "cache.h"
28#include "vfs.h"
29#include "netns.h"
30
31#define NFSDDBG_FACILITY NFSDDBG_SVC
32
33extern struct svc_program nfsd_program;
34static int nfsd(void *vrqstp);
35
36/*
37 * nfsd_mutex protects nn->nfsd_serv -- both the pointer itself and the members
38 * of the svc_serv struct. In particular, ->sv_nrthreads but also to some
39 * extent ->sv_temp_socks and ->sv_permsocks. It also protects nfsdstats.th_cnt
40 *
41 * If (out side the lock) nn->nfsd_serv is non-NULL, then it must point to a
42 * properly initialised 'struct svc_serv' with ->sv_nrthreads > 0. That number
43 * of nfsd threads must exist and each must listed in ->sp_all_threads in each
44 * entry of ->sv_pools[].
45 *
46 * Transitions of the thread count between zero and non-zero are of particular
47 * interest since the svc_serv needs to be created and initialized at that
48 * point, or freed.
49 *
50 * Finally, the nfsd_mutex also protects some of the global variables that are
51 * accessed when nfsd starts and that are settable via the write_* routines in
52 * nfsctl.c. In particular:
53 *
54 * user_recovery_dirname
55 * user_lease_time
56 * nfsd_versions
57 */
58DEFINE_MUTEX(nfsd_mutex);
59
60/*
61 * nfsd_drc_lock protects nfsd_drc_max_pages and nfsd_drc_pages_used.
62 * nfsd_drc_max_pages limits the total amount of memory available for
63 * version 4.1 DRC caches.
64 * nfsd_drc_pages_used tracks the current version 4.1 DRC memory usage.
65 */
66spinlock_t nfsd_drc_lock;
67unsigned long nfsd_drc_max_mem;
68unsigned long nfsd_drc_mem_used;
69
70#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
71static struct svc_stat nfsd_acl_svcstats;
72static const struct svc_version *nfsd_acl_version[] = {
73 [2] = &nfsd_acl_version2,
74 [3] = &nfsd_acl_version3,
75};
76
77#define NFSD_ACL_MINVERS 2
78#define NFSD_ACL_NRVERS ARRAY_SIZE(nfsd_acl_version)
79static const struct svc_version *nfsd_acl_versions[NFSD_ACL_NRVERS];
80
81static struct svc_program nfsd_acl_program = {
82 .pg_prog = NFS_ACL_PROGRAM,
83 .pg_nvers = NFSD_ACL_NRVERS,
84 .pg_vers = nfsd_acl_versions,
85 .pg_name = "nfsacl",
86 .pg_class = "nfsd",
87 .pg_stats = &nfsd_acl_svcstats,
88 .pg_authenticate = &svc_set_client,
89};
90
91static struct svc_stat nfsd_acl_svcstats = {
92 .program = &nfsd_acl_program,
93};
94#endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
95
96static const struct svc_version *nfsd_version[] = {
97 [2] = &nfsd_version2,
98#if defined(CONFIG_NFSD_V3)
99 [3] = &nfsd_version3,
100#endif
101#if defined(CONFIG_NFSD_V4)
102 [4] = &nfsd_version4,
103#endif
104};
105
106#define NFSD_MINVERS 2
107#define NFSD_NRVERS ARRAY_SIZE(nfsd_version)
108static const struct svc_version *nfsd_versions[NFSD_NRVERS];
109
110struct svc_program nfsd_program = {
111#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
112 .pg_next = &nfsd_acl_program,
113#endif
114 .pg_prog = NFS_PROGRAM, /* program number */
115 .pg_nvers = NFSD_NRVERS, /* nr of entries in nfsd_version */
116 .pg_vers = nfsd_versions, /* version table */
117 .pg_name = "nfsd", /* program name */
118 .pg_class = "nfsd", /* authentication class */
119 .pg_stats = &nfsd_svcstats, /* version table */
120 .pg_authenticate = &svc_set_client, /* export authentication */
121
122};
123
124static bool nfsd_supported_minorversions[NFSD_SUPPORTED_MINOR_VERSION + 1] = {
125 [0] = 1,
126 [1] = 1,
127 [2] = 1,
128};
129
130int nfsd_vers(int vers, enum vers_op change)
131{
132 if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS)
133 return 0;
134 switch(change) {
135 case NFSD_SET:
136 nfsd_versions[vers] = nfsd_version[vers];
137#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
138 if (vers < NFSD_ACL_NRVERS)
139 nfsd_acl_versions[vers] = nfsd_acl_version[vers];
140#endif
141 break;
142 case NFSD_CLEAR:
143 nfsd_versions[vers] = NULL;
144#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
145 if (vers < NFSD_ACL_NRVERS)
146 nfsd_acl_versions[vers] = NULL;
147#endif
148 break;
149 case NFSD_TEST:
150 return nfsd_versions[vers] != NULL;
151 case NFSD_AVAIL:
152 return nfsd_version[vers] != NULL;
153 }
154 return 0;
155}
156
157static void
158nfsd_adjust_nfsd_versions4(void)
159{
160 unsigned i;
161
162 for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++) {
163 if (nfsd_supported_minorversions[i])
164 return;
165 }
166 nfsd_vers(4, NFSD_CLEAR);
167}
168
169int nfsd_minorversion(u32 minorversion, enum vers_op change)
170{
171 if (minorversion > NFSD_SUPPORTED_MINOR_VERSION &&
172 change != NFSD_AVAIL)
173 return -1;
174 switch(change) {
175 case NFSD_SET:
176 nfsd_supported_minorversions[minorversion] = true;
177 nfsd_vers(4, NFSD_SET);
178 break;
179 case NFSD_CLEAR:
180 nfsd_supported_minorversions[minorversion] = false;
181 nfsd_adjust_nfsd_versions4();
182 break;
183 case NFSD_TEST:
184 return nfsd_supported_minorversions[minorversion];
185 case NFSD_AVAIL:
186 return minorversion <= NFSD_SUPPORTED_MINOR_VERSION;
187 }
188 return 0;
189}
190
191/*
192 * Maximum number of nfsd processes
193 */
194#define NFSD_MAXSERVS 8192
195
196int nfsd_nrthreads(struct net *net)
197{
198 int rv = 0;
199 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
200
201 mutex_lock(&nfsd_mutex);
202 if (nn->nfsd_serv)
203 rv = nn->nfsd_serv->sv_nrthreads;
204 mutex_unlock(&nfsd_mutex);
205 return rv;
206}
207
208static int nfsd_init_socks(struct net *net)
209{
210 int error;
211 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
212
213 if (!list_empty(&nn->nfsd_serv->sv_permsocks))
214 return 0;
215
216 error = svc_create_xprt(nn->nfsd_serv, "udp", net, PF_INET, NFS_PORT,
217 SVC_SOCK_DEFAULTS);
218 if (error < 0)
219 return error;
220
221 error = svc_create_xprt(nn->nfsd_serv, "tcp", net, PF_INET, NFS_PORT,
222 SVC_SOCK_DEFAULTS);
223 if (error < 0)
224 return error;
225
226 return 0;
227}
228
229static int nfsd_users = 0;
230
231static int nfsd_startup_generic(int nrservs)
232{
233 int ret;
234
235 if (nfsd_users++)
236 return 0;
237
238 /*
239 * Readahead param cache - will no-op if it already exists.
240 * (Note therefore results will be suboptimal if number of
241 * threads is modified after nfsd start.)
242 */
243 ret = nfsd_racache_init(2*nrservs);
244 if (ret)
245 goto dec_users;
246
247 ret = nfs4_state_start();
248 if (ret)
249 goto out_racache;
250 return 0;
251
252out_racache:
253 nfsd_racache_shutdown();
254dec_users:
255 nfsd_users--;
256 return ret;
257}
258
259static void nfsd_shutdown_generic(void)
260{
261 if (--nfsd_users)
262 return;
263
264 nfs4_state_shutdown();
265 nfsd_racache_shutdown();
266}
267
268static bool nfsd_needs_lockd(void)
269{
270#if defined(CONFIG_NFSD_V3)
271 return (nfsd_versions[2] != NULL) || (nfsd_versions[3] != NULL);
272#else
273 return (nfsd_versions[2] != NULL);
274#endif
275}
276
277static int nfsd_startup_net(int nrservs, struct net *net)
278{
279 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
280 int ret;
281
282 if (nn->nfsd_net_up)
283 return 0;
284
285 ret = nfsd_startup_generic(nrservs);
286 if (ret)
287 return ret;
288 ret = nfsd_init_socks(net);
289 if (ret)
290 goto out_socks;
291
292 if (nfsd_needs_lockd() && !nn->lockd_up) {
293 ret = lockd_up(net);
294 if (ret)
295 goto out_socks;
296 nn->lockd_up = 1;
297 }
298
299 ret = nfs4_state_start_net(net);
300 if (ret)
301 goto out_lockd;
302
303 nn->nfsd_net_up = true;
304 return 0;
305
306out_lockd:
307 if (nn->lockd_up) {
308 lockd_down(net);
309 nn->lockd_up = 0;
310 }
311out_socks:
312 nfsd_shutdown_generic();
313 return ret;
314}
315
316static void nfsd_shutdown_net(struct net *net)
317{
318 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
319
320 nfs4_state_shutdown_net(net);
321 if (nn->lockd_up) {
322 lockd_down(net);
323 nn->lockd_up = 0;
324 }
325 nn->nfsd_net_up = false;
326 nfsd_shutdown_generic();
327}
328
329static int nfsd_inetaddr_event(struct notifier_block *this, unsigned long event,
330 void *ptr)
331{
332 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
333 struct net_device *dev = ifa->ifa_dev->dev;
334 struct net *net = dev_net(dev);
335 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
336 struct sockaddr_in sin;
337
338 if ((event != NETDEV_DOWN) ||
339 !atomic_inc_not_zero(&nn->ntf_refcnt))
340 goto out;
341
342 if (nn->nfsd_serv) {
343 dprintk("nfsd_inetaddr_event: removed %pI4\n", &ifa->ifa_local);
344 sin.sin_family = AF_INET;
345 sin.sin_addr.s_addr = ifa->ifa_local;
346 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin);
347 }
348 atomic_dec(&nn->ntf_refcnt);
349 wake_up(&nn->ntf_wq);
350
351out:
352 return NOTIFY_DONE;
353}
354
355static struct notifier_block nfsd_inetaddr_notifier = {
356 .notifier_call = nfsd_inetaddr_event,
357};
358
359#if IS_ENABLED(CONFIG_IPV6)
360static int nfsd_inet6addr_event(struct notifier_block *this,
361 unsigned long event, void *ptr)
362{
363 struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
364 struct net_device *dev = ifa->idev->dev;
365 struct net *net = dev_net(dev);
366 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
367 struct sockaddr_in6 sin6;
368
369 if ((event != NETDEV_DOWN) ||
370 !atomic_inc_not_zero(&nn->ntf_refcnt))
371 goto out;
372
373 if (nn->nfsd_serv) {
374 dprintk("nfsd_inet6addr_event: removed %pI6\n", &ifa->addr);
375 sin6.sin6_family = AF_INET6;
376 sin6.sin6_addr = ifa->addr;
377 if (ipv6_addr_type(&sin6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
378 sin6.sin6_scope_id = ifa->idev->dev->ifindex;
379 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin6);
380 }
381 atomic_dec(&nn->ntf_refcnt);
382 wake_up(&nn->ntf_wq);
383out:
384 return NOTIFY_DONE;
385}
386
387static struct notifier_block nfsd_inet6addr_notifier = {
388 .notifier_call = nfsd_inet6addr_event,
389};
390#endif
391
392/* Only used under nfsd_mutex, so this atomic may be overkill: */
393static atomic_t nfsd_notifier_refcount = ATOMIC_INIT(0);
394
395static void nfsd_last_thread(struct svc_serv *serv, struct net *net)
396{
397 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
398
399 atomic_dec(&nn->ntf_refcnt);
400 /* check if the notifier still has clients */
401 if (atomic_dec_return(&nfsd_notifier_refcount) == 0) {
402 unregister_inetaddr_notifier(&nfsd_inetaddr_notifier);
403#if IS_ENABLED(CONFIG_IPV6)
404 unregister_inet6addr_notifier(&nfsd_inet6addr_notifier);
405#endif
406 }
407 wait_event(nn->ntf_wq, atomic_read(&nn->ntf_refcnt) == 0);
408
409 /*
410 * write_ports can create the server without actually starting
411 * any threads--if we get shut down before any threads are
412 * started, then nfsd_last_thread will be run before any of this
413 * other initialization has been done except the rpcb information.
414 */
415 svc_rpcb_cleanup(serv, net);
416 if (!nn->nfsd_net_up)
417 return;
418
419 nfsd_shutdown_net(net);
420 printk(KERN_WARNING "nfsd: last server has exited, flushing export "
421 "cache\n");
422 nfsd_export_flush(net);
423}
424
425void nfsd_reset_versions(void)
426{
427 int i;
428
429 for (i = 0; i < NFSD_NRVERS; i++)
430 if (nfsd_vers(i, NFSD_TEST))
431 return;
432
433 for (i = 0; i < NFSD_NRVERS; i++)
434 if (i != 4)
435 nfsd_vers(i, NFSD_SET);
436 else {
437 int minor = 0;
438 while (nfsd_minorversion(minor, NFSD_SET) >= 0)
439 minor++;
440 }
441}
442
443/*
444 * Each session guarantees a negotiated per slot memory cache for replies
445 * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated
446 * NFSv4.1 server might want to use more memory for a DRC than a machine
447 * with mutiple services.
448 *
449 * Impose a hard limit on the number of pages for the DRC which varies
450 * according to the machines free pages. This is of course only a default.
451 *
452 * For now this is a #defined shift which could be under admin control
453 * in the future.
454 */
455static void set_max_drc(void)
456{
457 #define NFSD_DRC_SIZE_SHIFT 7
458 nfsd_drc_max_mem = (nr_free_buffer_pages()
459 >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE;
460 nfsd_drc_mem_used = 0;
461 spin_lock_init(&nfsd_drc_lock);
462 dprintk("%s nfsd_drc_max_mem %lu \n", __func__, nfsd_drc_max_mem);
463}
464
465static int nfsd_get_default_max_blksize(void)
466{
467 struct sysinfo i;
468 unsigned long long target;
469 unsigned long ret;
470
471 si_meminfo(&i);
472 target = (i.totalram - i.totalhigh) << PAGE_SHIFT;
473 /*
474 * Aim for 1/4096 of memory per thread This gives 1MB on 4Gig
475 * machines, but only uses 32K on 128M machines. Bottom out at
476 * 8K on 32M and smaller. Of course, this is only a default.
477 */
478 target >>= 12;
479
480 ret = NFSSVC_MAXBLKSIZE;
481 while (ret > target && ret >= 8*1024*2)
482 ret /= 2;
483 return ret;
484}
485
486static const struct svc_serv_ops nfsd_thread_sv_ops = {
487 .svo_shutdown = nfsd_last_thread,
488 .svo_function = nfsd,
489 .svo_enqueue_xprt = svc_xprt_do_enqueue,
490 .svo_setup = svc_set_num_threads,
491 .svo_module = THIS_MODULE,
492};
493
494int nfsd_create_serv(struct net *net)
495{
496 int error;
497 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
498
499 WARN_ON(!mutex_is_locked(&nfsd_mutex));
500 if (nn->nfsd_serv) {
501 svc_get(nn->nfsd_serv);
502 return 0;
503 }
504 if (nfsd_max_blksize == 0)
505 nfsd_max_blksize = nfsd_get_default_max_blksize();
506 nfsd_reset_versions();
507 nn->nfsd_serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize,
508 &nfsd_thread_sv_ops);
509 if (nn->nfsd_serv == NULL)
510 return -ENOMEM;
511
512 nn->nfsd_serv->sv_maxconn = nn->max_connections;
513 error = svc_bind(nn->nfsd_serv, net);
514 if (error < 0) {
515 svc_destroy(nn->nfsd_serv);
516 return error;
517 }
518
519 set_max_drc();
520 /* check if the notifier is already set */
521 if (atomic_inc_return(&nfsd_notifier_refcount) == 1) {
522 register_inetaddr_notifier(&nfsd_inetaddr_notifier);
523#if IS_ENABLED(CONFIG_IPV6)
524 register_inet6addr_notifier(&nfsd_inet6addr_notifier);
525#endif
526 }
527 atomic_inc(&nn->ntf_refcnt);
528 ktime_get_real_ts64(&nn->nfssvc_boot); /* record boot time */
529 return 0;
530}
531
532int nfsd_nrpools(struct net *net)
533{
534 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
535
536 if (nn->nfsd_serv == NULL)
537 return 0;
538 else
539 return nn->nfsd_serv->sv_nrpools;
540}
541
542int nfsd_get_nrthreads(int n, int *nthreads, struct net *net)
543{
544 int i = 0;
545 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
546
547 if (nn->nfsd_serv != NULL) {
548 for (i = 0; i < nn->nfsd_serv->sv_nrpools && i < n; i++)
549 nthreads[i] = nn->nfsd_serv->sv_pools[i].sp_nrthreads;
550 }
551
552 return 0;
553}
554
555void nfsd_destroy(struct net *net)
556{
557 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
558 int destroy = (nn->nfsd_serv->sv_nrthreads == 1);
559
560 if (destroy)
561 svc_shutdown_net(nn->nfsd_serv, net);
562 svc_destroy(nn->nfsd_serv);
563 if (destroy)
564 nn->nfsd_serv = NULL;
565}
566
567int nfsd_set_nrthreads(int n, int *nthreads, struct net *net)
568{
569 int i = 0;
570 int tot = 0;
571 int err = 0;
572 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
573
574 WARN_ON(!mutex_is_locked(&nfsd_mutex));
575
576 if (nn->nfsd_serv == NULL || n <= 0)
577 return 0;
578
579 if (n > nn->nfsd_serv->sv_nrpools)
580 n = nn->nfsd_serv->sv_nrpools;
581
582 /* enforce a global maximum number of threads */
583 tot = 0;
584 for (i = 0; i < n; i++) {
585 nthreads[i] = min(nthreads[i], NFSD_MAXSERVS);
586 tot += nthreads[i];
587 }
588 if (tot > NFSD_MAXSERVS) {
589 /* total too large: scale down requested numbers */
590 for (i = 0; i < n && tot > 0; i++) {
591 int new = nthreads[i] * NFSD_MAXSERVS / tot;
592 tot -= (nthreads[i] - new);
593 nthreads[i] = new;
594 }
595 for (i = 0; i < n && tot > 0; i++) {
596 nthreads[i]--;
597 tot--;
598 }
599 }
600
601 /*
602 * There must always be a thread in pool 0; the admin
603 * can't shut down NFS completely using pool_threads.
604 */
605 if (nthreads[0] == 0)
606 nthreads[0] = 1;
607
608 /* apply the new numbers */
609 svc_get(nn->nfsd_serv);
610 for (i = 0; i < n; i++) {
611 err = nn->nfsd_serv->sv_ops->svo_setup(nn->nfsd_serv,
612 &nn->nfsd_serv->sv_pools[i], nthreads[i]);
613 if (err)
614 break;
615 }
616 nfsd_destroy(net);
617 return err;
618}
619
620/*
621 * Adjust the number of threads and return the new number of threads.
622 * This is also the function that starts the server if necessary, if
623 * this is the first time nrservs is nonzero.
624 */
625int
626nfsd_svc(int nrservs, struct net *net)
627{
628 int error;
629 bool nfsd_up_before;
630 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
631
632 mutex_lock(&nfsd_mutex);
633 dprintk("nfsd: creating service\n");
634
635 nrservs = max(nrservs, 0);
636 nrservs = min(nrservs, NFSD_MAXSERVS);
637 error = 0;
638
639 if (nrservs == 0 && nn->nfsd_serv == NULL)
640 goto out;
641
642 error = nfsd_create_serv(net);
643 if (error)
644 goto out;
645
646 nfsd_up_before = nn->nfsd_net_up;
647
648 error = nfsd_startup_net(nrservs, net);
649 if (error)
650 goto out_destroy;
651 error = nn->nfsd_serv->sv_ops->svo_setup(nn->nfsd_serv,
652 NULL, nrservs);
653 if (error)
654 goto out_shutdown;
655 /* We are holding a reference to nn->nfsd_serv which
656 * we don't want to count in the return value,
657 * so subtract 1
658 */
659 error = nn->nfsd_serv->sv_nrthreads - 1;
660out_shutdown:
661 if (error < 0 && !nfsd_up_before)
662 nfsd_shutdown_net(net);
663out_destroy:
664 nfsd_destroy(net); /* Release server */
665out:
666 mutex_unlock(&nfsd_mutex);
667 return error;
668}
669
670
671/*
672 * This is the NFS server kernel thread
673 */
674static int
675nfsd(void *vrqstp)
676{
677 struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp;
678 struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list);
679 struct net *net = perm_sock->xpt_net;
680 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
681 int err;
682
683 /* Lock module and set up kernel thread */
684 mutex_lock(&nfsd_mutex);
685
686 /* At this point, the thread shares current->fs
687 * with the init process. We need to create files with the
688 * umask as defined by the client instead of init's umask. */
689 if (unshare_fs_struct() < 0) {
690 printk("Unable to start nfsd thread: out of memory\n");
691 goto out;
692 }
693
694 current->fs->umask = 0;
695
696 /*
697 * thread is spawned with all signals set to SIG_IGN, re-enable
698 * the ones that will bring down the thread
699 */
700 allow_signal(SIGKILL);
701 allow_signal(SIGHUP);
702 allow_signal(SIGINT);
703 allow_signal(SIGQUIT);
704
705 nfsdstats.th_cnt++;
706 mutex_unlock(&nfsd_mutex);
707
708 set_freezable();
709
710 /*
711 * The main request loop
712 */
713 for (;;) {
714 /* Update sv_maxconn if it has changed */
715 rqstp->rq_server->sv_maxconn = nn->max_connections;
716
717 /*
718 * Find a socket with data available and call its
719 * recvfrom routine.
720 */
721 while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN)
722 ;
723 if (err == -EINTR)
724 break;
725 validate_process_creds();
726 svc_process(rqstp);
727 validate_process_creds();
728 }
729
730 /* Clear signals before calling svc_exit_thread() */
731 flush_signals(current);
732
733 mutex_lock(&nfsd_mutex);
734 nfsdstats.th_cnt --;
735
736out:
737 rqstp->rq_server = NULL;
738
739 /* Release the thread */
740 svc_exit_thread(rqstp);
741
742 nfsd_destroy(net);
743
744 /* Release module */
745 mutex_unlock(&nfsd_mutex);
746 module_put_and_exit(0);
747 return 0;
748}
749
750static __be32 map_new_errors(u32 vers, __be32 nfserr)
751{
752 if (nfserr == nfserr_jukebox && vers == 2)
753 return nfserr_dropit;
754 if (nfserr == nfserr_wrongsec && vers < 4)
755 return nfserr_acces;
756 return nfserr;
757}
758
759/*
760 * A write procedure can have a large argument, and a read procedure can
761 * have a large reply, but no NFSv2 or NFSv3 procedure has argument and
762 * reply that can both be larger than a page. The xdr code has taken
763 * advantage of this assumption to be a sloppy about bounds checking in
764 * some cases. Pending a rewrite of the NFSv2/v3 xdr code to fix that
765 * problem, we enforce these assumptions here:
766 */
767static bool nfs_request_too_big(struct svc_rqst *rqstp,
768 const struct svc_procedure *proc)
769{
770 /*
771 * The ACL code has more careful bounds-checking and is not
772 * susceptible to this problem:
773 */
774 if (rqstp->rq_prog != NFS_PROGRAM)
775 return false;
776 /*
777 * Ditto NFSv4 (which can in theory have argument and reply both
778 * more than a page):
779 */
780 if (rqstp->rq_vers >= 4)
781 return false;
782 /* The reply will be small, we're OK: */
783 if (proc->pc_xdrressize > 0 &&
784 proc->pc_xdrressize < XDR_QUADLEN(PAGE_SIZE))
785 return false;
786
787 return rqstp->rq_arg.len > PAGE_SIZE;
788}
789
790int
791nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
792{
793 const struct svc_procedure *proc;
794 __be32 nfserr;
795 __be32 *nfserrp;
796
797 dprintk("nfsd_dispatch: vers %d proc %d\n",
798 rqstp->rq_vers, rqstp->rq_proc);
799 proc = rqstp->rq_procinfo;
800
801 if (nfs_request_too_big(rqstp, proc)) {
802 dprintk("nfsd: NFSv%d argument too large\n", rqstp->rq_vers);
803 *statp = rpc_garbage_args;
804 return 1;
805 }
806 /*
807 * Give the xdr decoder a chance to change this if it wants
808 * (necessary in the NFSv4.0 compound case)
809 */
810 rqstp->rq_cachetype = proc->pc_cachetype;
811 /* Decode arguments */
812 if (proc->pc_decode &&
813 !proc->pc_decode(rqstp, (__be32*)rqstp->rq_arg.head[0].iov_base)) {
814 dprintk("nfsd: failed to decode arguments!\n");
815 *statp = rpc_garbage_args;
816 return 1;
817 }
818
819 /* Check whether we have this call in the cache. */
820 switch (nfsd_cache_lookup(rqstp)) {
821 case RC_DROPIT:
822 return 0;
823 case RC_REPLY:
824 return 1;
825 case RC_DOIT:;
826 /* do it */
827 }
828
829 /* need to grab the location to store the status, as
830 * nfsv4 does some encoding while processing
831 */
832 nfserrp = rqstp->rq_res.head[0].iov_base
833 + rqstp->rq_res.head[0].iov_len;
834 rqstp->rq_res.head[0].iov_len += sizeof(__be32);
835
836 /* Now call the procedure handler, and encode NFS status. */
837 nfserr = proc->pc_func(rqstp);
838 nfserr = map_new_errors(rqstp->rq_vers, nfserr);
839 if (nfserr == nfserr_dropit || test_bit(RQ_DROPME, &rqstp->rq_flags)) {
840 dprintk("nfsd: Dropping request; may be revisited later\n");
841 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
842 return 0;
843 }
844
845 if (rqstp->rq_proc != 0)
846 *nfserrp++ = nfserr;
847
848 /* Encode result.
849 * For NFSv2, additional info is never returned in case of an error.
850 */
851 if (!(nfserr && rqstp->rq_vers == 2)) {
852 if (proc->pc_encode && !proc->pc_encode(rqstp, nfserrp)) {
853 /* Failed to encode result. Release cache entry */
854 dprintk("nfsd: failed to encode result!\n");
855 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
856 *statp = rpc_system_err;
857 return 1;
858 }
859 }
860
861 /* Store reply in cache. */
862 nfsd_cache_update(rqstp, rqstp->rq_cachetype, statp + 1);
863 return 1;
864}
865
866int nfsd_pool_stats_open(struct inode *inode, struct file *file)
867{
868 int ret;
869 struct nfsd_net *nn = net_generic(inode->i_sb->s_fs_info, nfsd_net_id);
870
871 mutex_lock(&nfsd_mutex);
872 if (nn->nfsd_serv == NULL) {
873 mutex_unlock(&nfsd_mutex);
874 return -ENODEV;
875 }
876 /* bump up the psudo refcount while traversing */
877 svc_get(nn->nfsd_serv);
878 ret = svc_pool_stats_open(nn->nfsd_serv, file);
879 mutex_unlock(&nfsd_mutex);
880 return ret;
881}
882
883int nfsd_pool_stats_release(struct inode *inode, struct file *file)
884{
885 int ret = seq_release(inode, file);
886 struct net *net = inode->i_sb->s_fs_info;
887
888 mutex_lock(&nfsd_mutex);
889 /* this function really, really should have been called svc_put() */
890 nfsd_destroy(net);
891 mutex_unlock(&nfsd_mutex);
892 return ret;
893}