Loading...
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
15#include <linux/sunrpc/stats.h>
16#include <linux/sunrpc/svcsock.h>
17#include <linux/lockd/bind.h>
18#include <linux/nfsacl.h>
19#include <linux/seq_file.h>
20#include <net/net_namespace.h>
21#include "nfsd.h"
22#include "cache.h"
23#include "vfs.h"
24#include "netns.h"
25
26#define NFSDDBG_FACILITY NFSDDBG_SVC
27
28extern struct svc_program nfsd_program;
29static int nfsd(void *vrqstp);
30
31/*
32 * nfsd_mutex protects nn->nfsd_serv -- both the pointer itself and the members
33 * of the svc_serv struct. In particular, ->sv_nrthreads but also to some
34 * extent ->sv_temp_socks and ->sv_permsocks. It also protects nfsdstats.th_cnt
35 *
36 * If (out side the lock) nn->nfsd_serv is non-NULL, then it must point to a
37 * properly initialised 'struct svc_serv' with ->sv_nrthreads > 0. That number
38 * of nfsd threads must exist and each must listed in ->sp_all_threads in each
39 * entry of ->sv_pools[].
40 *
41 * Transitions of the thread count between zero and non-zero are of particular
42 * interest since the svc_serv needs to be created and initialized at that
43 * point, or freed.
44 *
45 * Finally, the nfsd_mutex also protects some of the global variables that are
46 * accessed when nfsd starts and that are settable via the write_* routines in
47 * nfsctl.c. In particular:
48 *
49 * user_recovery_dirname
50 * user_lease_time
51 * nfsd_versions
52 */
53DEFINE_MUTEX(nfsd_mutex);
54
55/*
56 * nfsd_drc_lock protects nfsd_drc_max_pages and nfsd_drc_pages_used.
57 * nfsd_drc_max_pages limits the total amount of memory available for
58 * version 4.1 DRC caches.
59 * nfsd_drc_pages_used tracks the current version 4.1 DRC memory usage.
60 */
61spinlock_t nfsd_drc_lock;
62unsigned long nfsd_drc_max_mem;
63unsigned long nfsd_drc_mem_used;
64
65#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
66static struct svc_stat nfsd_acl_svcstats;
67static struct svc_version * nfsd_acl_version[] = {
68 [2] = &nfsd_acl_version2,
69 [3] = &nfsd_acl_version3,
70};
71
72#define NFSD_ACL_MINVERS 2
73#define NFSD_ACL_NRVERS ARRAY_SIZE(nfsd_acl_version)
74static struct svc_version *nfsd_acl_versions[NFSD_ACL_NRVERS];
75
76static struct svc_program nfsd_acl_program = {
77 .pg_prog = NFS_ACL_PROGRAM,
78 .pg_nvers = NFSD_ACL_NRVERS,
79 .pg_vers = nfsd_acl_versions,
80 .pg_name = "nfsacl",
81 .pg_class = "nfsd",
82 .pg_stats = &nfsd_acl_svcstats,
83 .pg_authenticate = &svc_set_client,
84};
85
86static struct svc_stat nfsd_acl_svcstats = {
87 .program = &nfsd_acl_program,
88};
89#endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
90
91static struct svc_version * nfsd_version[] = {
92 [2] = &nfsd_version2,
93#if defined(CONFIG_NFSD_V3)
94 [3] = &nfsd_version3,
95#endif
96#if defined(CONFIG_NFSD_V4)
97 [4] = &nfsd_version4,
98#endif
99};
100
101#define NFSD_MINVERS 2
102#define NFSD_NRVERS ARRAY_SIZE(nfsd_version)
103static struct svc_version *nfsd_versions[NFSD_NRVERS];
104
105struct svc_program nfsd_program = {
106#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
107 .pg_next = &nfsd_acl_program,
108#endif
109 .pg_prog = NFS_PROGRAM, /* program number */
110 .pg_nvers = NFSD_NRVERS, /* nr of entries in nfsd_version */
111 .pg_vers = nfsd_versions, /* version table */
112 .pg_name = "nfsd", /* program name */
113 .pg_class = "nfsd", /* authentication class */
114 .pg_stats = &nfsd_svcstats, /* version table */
115 .pg_authenticate = &svc_set_client, /* export authentication */
116
117};
118
119static bool nfsd_supported_minorversions[NFSD_SUPPORTED_MINOR_VERSION + 1] = {
120 [0] = 1,
121 [1] = 1,
122};
123
124int nfsd_vers(int vers, enum vers_op change)
125{
126 if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS)
127 return 0;
128 switch(change) {
129 case NFSD_SET:
130 nfsd_versions[vers] = nfsd_version[vers];
131#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
132 if (vers < NFSD_ACL_NRVERS)
133 nfsd_acl_versions[vers] = nfsd_acl_version[vers];
134#endif
135 break;
136 case NFSD_CLEAR:
137 nfsd_versions[vers] = NULL;
138#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
139 if (vers < NFSD_ACL_NRVERS)
140 nfsd_acl_versions[vers] = NULL;
141#endif
142 break;
143 case NFSD_TEST:
144 return nfsd_versions[vers] != NULL;
145 case NFSD_AVAIL:
146 return nfsd_version[vers] != NULL;
147 }
148 return 0;
149}
150
151int nfsd_minorversion(u32 minorversion, enum vers_op change)
152{
153 if (minorversion > NFSD_SUPPORTED_MINOR_VERSION)
154 return -1;
155 switch(change) {
156 case NFSD_SET:
157 nfsd_supported_minorversions[minorversion] = true;
158 break;
159 case NFSD_CLEAR:
160 nfsd_supported_minorversions[minorversion] = false;
161 break;
162 case NFSD_TEST:
163 return nfsd_supported_minorversions[minorversion];
164 case NFSD_AVAIL:
165 return minorversion <= NFSD_SUPPORTED_MINOR_VERSION;
166 }
167 return 0;
168}
169
170/*
171 * Maximum number of nfsd processes
172 */
173#define NFSD_MAXSERVS 8192
174
175int nfsd_nrthreads(struct net *net)
176{
177 int rv = 0;
178 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
179
180 mutex_lock(&nfsd_mutex);
181 if (nn->nfsd_serv)
182 rv = nn->nfsd_serv->sv_nrthreads;
183 mutex_unlock(&nfsd_mutex);
184 return rv;
185}
186
187static int nfsd_init_socks(struct net *net)
188{
189 int error;
190 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
191
192 if (!list_empty(&nn->nfsd_serv->sv_permsocks))
193 return 0;
194
195 error = svc_create_xprt(nn->nfsd_serv, "udp", net, PF_INET, NFS_PORT,
196 SVC_SOCK_DEFAULTS);
197 if (error < 0)
198 return error;
199
200 error = svc_create_xprt(nn->nfsd_serv, "tcp", net, PF_INET, NFS_PORT,
201 SVC_SOCK_DEFAULTS);
202 if (error < 0)
203 return error;
204
205 return 0;
206}
207
208static int nfsd_users = 0;
209
210static int nfsd_startup_generic(int nrservs)
211{
212 int ret;
213
214 if (nfsd_users++)
215 return 0;
216
217 /*
218 * Readahead param cache - will no-op if it already exists.
219 * (Note therefore results will be suboptimal if number of
220 * threads is modified after nfsd start.)
221 */
222 ret = nfsd_racache_init(2*nrservs);
223 if (ret)
224 return ret;
225 ret = nfs4_state_start();
226 if (ret)
227 goto out_racache;
228 return 0;
229
230out_racache:
231 nfsd_racache_shutdown();
232 return ret;
233}
234
235static void nfsd_shutdown_generic(void)
236{
237 if (--nfsd_users)
238 return;
239
240 nfs4_state_shutdown();
241 nfsd_racache_shutdown();
242}
243
244static bool nfsd_needs_lockd(void)
245{
246#if defined(CONFIG_NFSD_V3)
247 return (nfsd_versions[2] != NULL) || (nfsd_versions[3] != NULL);
248#else
249 return (nfsd_versions[2] != NULL);
250#endif
251}
252
253static int nfsd_startup_net(int nrservs, struct net *net)
254{
255 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
256 int ret;
257
258 if (nn->nfsd_net_up)
259 return 0;
260
261 ret = nfsd_startup_generic(nrservs);
262 if (ret)
263 return ret;
264 ret = nfsd_init_socks(net);
265 if (ret)
266 goto out_socks;
267
268 if (nfsd_needs_lockd() && !nn->lockd_up) {
269 ret = lockd_up(net);
270 if (ret)
271 goto out_socks;
272 nn->lockd_up = 1;
273 }
274
275 ret = nfs4_state_start_net(net);
276 if (ret)
277 goto out_lockd;
278
279 nn->nfsd_net_up = true;
280 return 0;
281
282out_lockd:
283 if (nn->lockd_up) {
284 lockd_down(net);
285 nn->lockd_up = 0;
286 }
287out_socks:
288 nfsd_shutdown_generic();
289 return ret;
290}
291
292static void nfsd_shutdown_net(struct net *net)
293{
294 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
295
296 nfs4_state_shutdown_net(net);
297 if (nn->lockd_up) {
298 lockd_down(net);
299 nn->lockd_up = 0;
300 }
301 nn->nfsd_net_up = false;
302 nfsd_shutdown_generic();
303}
304
305static void nfsd_last_thread(struct svc_serv *serv, struct net *net)
306{
307 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
308
309 /*
310 * write_ports can create the server without actually starting
311 * any threads--if we get shut down before any threads are
312 * started, then nfsd_last_thread will be run before any of this
313 * other initialization has been done.
314 */
315 if (!nn->nfsd_net_up)
316 return;
317 nfsd_shutdown_net(net);
318
319 svc_rpcb_cleanup(serv, net);
320
321 printk(KERN_WARNING "nfsd: last server has exited, flushing export "
322 "cache\n");
323 nfsd_export_flush(net);
324}
325
326void nfsd_reset_versions(void)
327{
328 int found_one = 0;
329 int i;
330
331 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) {
332 if (nfsd_program.pg_vers[i])
333 found_one = 1;
334 }
335
336 if (!found_one) {
337 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++)
338 nfsd_program.pg_vers[i] = nfsd_version[i];
339#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
340 for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++)
341 nfsd_acl_program.pg_vers[i] =
342 nfsd_acl_version[i];
343#endif
344 }
345}
346
347/*
348 * Each session guarantees a negotiated per slot memory cache for replies
349 * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated
350 * NFSv4.1 server might want to use more memory for a DRC than a machine
351 * with mutiple services.
352 *
353 * Impose a hard limit on the number of pages for the DRC which varies
354 * according to the machines free pages. This is of course only a default.
355 *
356 * For now this is a #defined shift which could be under admin control
357 * in the future.
358 */
359static void set_max_drc(void)
360{
361 #define NFSD_DRC_SIZE_SHIFT 10
362 nfsd_drc_max_mem = (nr_free_buffer_pages()
363 >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE;
364 nfsd_drc_mem_used = 0;
365 spin_lock_init(&nfsd_drc_lock);
366 dprintk("%s nfsd_drc_max_mem %lu \n", __func__, nfsd_drc_max_mem);
367}
368
369static int nfsd_get_default_max_blksize(void)
370{
371 struct sysinfo i;
372 unsigned long long target;
373 unsigned long ret;
374
375 si_meminfo(&i);
376 target = (i.totalram - i.totalhigh) << PAGE_SHIFT;
377 /*
378 * Aim for 1/4096 of memory per thread This gives 1MB on 4Gig
379 * machines, but only uses 32K on 128M machines. Bottom out at
380 * 8K on 32M and smaller. Of course, this is only a default.
381 */
382 target >>= 12;
383
384 ret = NFSSVC_MAXBLKSIZE;
385 while (ret > target && ret >= 8*1024*2)
386 ret /= 2;
387 return ret;
388}
389
390int nfsd_create_serv(struct net *net)
391{
392 int error;
393 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
394
395 WARN_ON(!mutex_is_locked(&nfsd_mutex));
396 if (nn->nfsd_serv) {
397 svc_get(nn->nfsd_serv);
398 return 0;
399 }
400 if (nfsd_max_blksize == 0)
401 nfsd_max_blksize = nfsd_get_default_max_blksize();
402 nfsd_reset_versions();
403 nn->nfsd_serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize,
404 nfsd_last_thread, nfsd, THIS_MODULE);
405 if (nn->nfsd_serv == NULL)
406 return -ENOMEM;
407
408 error = svc_bind(nn->nfsd_serv, net);
409 if (error < 0) {
410 svc_destroy(nn->nfsd_serv);
411 return error;
412 }
413
414 set_max_drc();
415 do_gettimeofday(&nn->nfssvc_boot); /* record boot time */
416 return 0;
417}
418
419int nfsd_nrpools(struct net *net)
420{
421 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
422
423 if (nn->nfsd_serv == NULL)
424 return 0;
425 else
426 return nn->nfsd_serv->sv_nrpools;
427}
428
429int nfsd_get_nrthreads(int n, int *nthreads, struct net *net)
430{
431 int i = 0;
432 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
433
434 if (nn->nfsd_serv != NULL) {
435 for (i = 0; i < nn->nfsd_serv->sv_nrpools && i < n; i++)
436 nthreads[i] = nn->nfsd_serv->sv_pools[i].sp_nrthreads;
437 }
438
439 return 0;
440}
441
442void nfsd_destroy(struct net *net)
443{
444 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
445 int destroy = (nn->nfsd_serv->sv_nrthreads == 1);
446
447 if (destroy)
448 svc_shutdown_net(nn->nfsd_serv, net);
449 svc_destroy(nn->nfsd_serv);
450 if (destroy)
451 nn->nfsd_serv = NULL;
452}
453
454int nfsd_set_nrthreads(int n, int *nthreads, struct net *net)
455{
456 int i = 0;
457 int tot = 0;
458 int err = 0;
459 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
460
461 WARN_ON(!mutex_is_locked(&nfsd_mutex));
462
463 if (nn->nfsd_serv == NULL || n <= 0)
464 return 0;
465
466 if (n > nn->nfsd_serv->sv_nrpools)
467 n = nn->nfsd_serv->sv_nrpools;
468
469 /* enforce a global maximum number of threads */
470 tot = 0;
471 for (i = 0; i < n; i++) {
472 if (nthreads[i] > NFSD_MAXSERVS)
473 nthreads[i] = NFSD_MAXSERVS;
474 tot += nthreads[i];
475 }
476 if (tot > NFSD_MAXSERVS) {
477 /* total too large: scale down requested numbers */
478 for (i = 0; i < n && tot > 0; i++) {
479 int new = nthreads[i] * NFSD_MAXSERVS / tot;
480 tot -= (nthreads[i] - new);
481 nthreads[i] = new;
482 }
483 for (i = 0; i < n && tot > 0; i++) {
484 nthreads[i]--;
485 tot--;
486 }
487 }
488
489 /*
490 * There must always be a thread in pool 0; the admin
491 * can't shut down NFS completely using pool_threads.
492 */
493 if (nthreads[0] == 0)
494 nthreads[0] = 1;
495
496 /* apply the new numbers */
497 svc_get(nn->nfsd_serv);
498 for (i = 0; i < n; i++) {
499 err = svc_set_num_threads(nn->nfsd_serv, &nn->nfsd_serv->sv_pools[i],
500 nthreads[i]);
501 if (err)
502 break;
503 }
504 nfsd_destroy(net);
505 return err;
506}
507
508/*
509 * Adjust the number of threads and return the new number of threads.
510 * This is also the function that starts the server if necessary, if
511 * this is the first time nrservs is nonzero.
512 */
513int
514nfsd_svc(int nrservs, struct net *net)
515{
516 int error;
517 bool nfsd_up_before;
518 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
519
520 mutex_lock(&nfsd_mutex);
521 dprintk("nfsd: creating service\n");
522 if (nrservs <= 0)
523 nrservs = 0;
524 if (nrservs > NFSD_MAXSERVS)
525 nrservs = NFSD_MAXSERVS;
526 error = 0;
527 if (nrservs == 0 && nn->nfsd_serv == NULL)
528 goto out;
529
530 error = nfsd_create_serv(net);
531 if (error)
532 goto out;
533
534 nfsd_up_before = nn->nfsd_net_up;
535
536 error = nfsd_startup_net(nrservs, net);
537 if (error)
538 goto out_destroy;
539 error = svc_set_num_threads(nn->nfsd_serv, NULL, nrservs);
540 if (error)
541 goto out_shutdown;
542 /* We are holding a reference to nn->nfsd_serv which
543 * we don't want to count in the return value,
544 * so subtract 1
545 */
546 error = nn->nfsd_serv->sv_nrthreads - 1;
547out_shutdown:
548 if (error < 0 && !nfsd_up_before)
549 nfsd_shutdown_net(net);
550out_destroy:
551 nfsd_destroy(net); /* Release server */
552out:
553 mutex_unlock(&nfsd_mutex);
554 return error;
555}
556
557
558/*
559 * This is the NFS server kernel thread
560 */
561static int
562nfsd(void *vrqstp)
563{
564 struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp;
565 struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list);
566 struct net *net = perm_sock->xpt_net;
567 int err;
568
569 /* Lock module and set up kernel thread */
570 mutex_lock(&nfsd_mutex);
571
572 /* At this point, the thread shares current->fs
573 * with the init process. We need to create files with a
574 * umask of 0 instead of init's umask. */
575 if (unshare_fs_struct() < 0) {
576 printk("Unable to start nfsd thread: out of memory\n");
577 goto out;
578 }
579
580 current->fs->umask = 0;
581
582 /*
583 * thread is spawned with all signals set to SIG_IGN, re-enable
584 * the ones that will bring down the thread
585 */
586 allow_signal(SIGKILL);
587 allow_signal(SIGHUP);
588 allow_signal(SIGINT);
589 allow_signal(SIGQUIT);
590
591 nfsdstats.th_cnt++;
592 mutex_unlock(&nfsd_mutex);
593
594 /*
595 * We want less throttling in balance_dirty_pages() so that nfs to
596 * localhost doesn't cause nfsd to lock up due to all the client's
597 * dirty pages.
598 */
599 current->flags |= PF_LESS_THROTTLE;
600 set_freezable();
601
602 /*
603 * The main request loop
604 */
605 for (;;) {
606 /*
607 * Find a socket with data available and call its
608 * recvfrom routine.
609 */
610 while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN)
611 ;
612 if (err == -EINTR)
613 break;
614 validate_process_creds();
615 svc_process(rqstp);
616 validate_process_creds();
617 }
618
619 /* Clear signals before calling svc_exit_thread() */
620 flush_signals(current);
621
622 mutex_lock(&nfsd_mutex);
623 nfsdstats.th_cnt --;
624
625out:
626 rqstp->rq_server = NULL;
627
628 /* Release the thread */
629 svc_exit_thread(rqstp);
630
631 nfsd_destroy(net);
632
633 /* Release module */
634 mutex_unlock(&nfsd_mutex);
635 module_put_and_exit(0);
636 return 0;
637}
638
639static __be32 map_new_errors(u32 vers, __be32 nfserr)
640{
641 if (nfserr == nfserr_jukebox && vers == 2)
642 return nfserr_dropit;
643 if (nfserr == nfserr_wrongsec && vers < 4)
644 return nfserr_acces;
645 return nfserr;
646}
647
648int
649nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
650{
651 struct svc_procedure *proc;
652 kxdrproc_t xdr;
653 __be32 nfserr;
654 __be32 *nfserrp;
655
656 dprintk("nfsd_dispatch: vers %d proc %d\n",
657 rqstp->rq_vers, rqstp->rq_proc);
658 proc = rqstp->rq_procinfo;
659
660 /*
661 * Give the xdr decoder a chance to change this if it wants
662 * (necessary in the NFSv4.0 compound case)
663 */
664 rqstp->rq_cachetype = proc->pc_cachetype;
665 /* Decode arguments */
666 xdr = proc->pc_decode;
667 if (xdr && !xdr(rqstp, (__be32*)rqstp->rq_arg.head[0].iov_base,
668 rqstp->rq_argp)) {
669 dprintk("nfsd: failed to decode arguments!\n");
670 *statp = rpc_garbage_args;
671 return 1;
672 }
673
674 /* Check whether we have this call in the cache. */
675 switch (nfsd_cache_lookup(rqstp)) {
676 case RC_DROPIT:
677 return 0;
678 case RC_REPLY:
679 return 1;
680 case RC_DOIT:;
681 /* do it */
682 }
683
684 /* need to grab the location to store the status, as
685 * nfsv4 does some encoding while processing
686 */
687 nfserrp = rqstp->rq_res.head[0].iov_base
688 + rqstp->rq_res.head[0].iov_len;
689 rqstp->rq_res.head[0].iov_len += sizeof(__be32);
690
691 /* Now call the procedure handler, and encode NFS status. */
692 nfserr = proc->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
693 nfserr = map_new_errors(rqstp->rq_vers, nfserr);
694 if (nfserr == nfserr_dropit || rqstp->rq_dropme) {
695 dprintk("nfsd: Dropping request; may be revisited later\n");
696 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
697 return 0;
698 }
699
700 if (rqstp->rq_proc != 0)
701 *nfserrp++ = nfserr;
702
703 /* Encode result.
704 * For NFSv2, additional info is never returned in case of an error.
705 */
706 if (!(nfserr && rqstp->rq_vers == 2)) {
707 xdr = proc->pc_encode;
708 if (xdr && !xdr(rqstp, nfserrp,
709 rqstp->rq_resp)) {
710 /* Failed to encode result. Release cache entry */
711 dprintk("nfsd: failed to encode result!\n");
712 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
713 *statp = rpc_system_err;
714 return 1;
715 }
716 }
717
718 /* Store reply in cache. */
719 nfsd_cache_update(rqstp, rqstp->rq_cachetype, statp + 1);
720 return 1;
721}
722
723int nfsd_pool_stats_open(struct inode *inode, struct file *file)
724{
725 int ret;
726 struct nfsd_net *nn = net_generic(inode->i_sb->s_fs_info, nfsd_net_id);
727
728 mutex_lock(&nfsd_mutex);
729 if (nn->nfsd_serv == NULL) {
730 mutex_unlock(&nfsd_mutex);
731 return -ENODEV;
732 }
733 /* bump up the psudo refcount while traversing */
734 svc_get(nn->nfsd_serv);
735 ret = svc_pool_stats_open(nn->nfsd_serv, file);
736 mutex_unlock(&nfsd_mutex);
737 return ret;
738}
739
740int nfsd_pool_stats_release(struct inode *inode, struct file *file)
741{
742 int ret = seq_release(inode, file);
743 struct net *net = inode->i_sb->s_fs_info;
744
745 mutex_lock(&nfsd_mutex);
746 /* this function really, really should have been called svc_put() */
747 nfsd_destroy(net);
748 mutex_unlock(&nfsd_mutex);
749 return ret;
750}
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
37extern struct svc_program nfsd_program;
38static int nfsd(void *vrqstp);
39#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
40static int nfsd_acl_rpcbind_set(struct net *,
41 const struct svc_program *,
42 u32, int,
43 unsigned short,
44 unsigned short);
45static __be32 nfsd_acl_init_request(struct svc_rqst *,
46 const struct svc_program *,
47 struct svc_process_info *);
48#endif
49static int nfsd_rpcbind_set(struct net *,
50 const struct svc_program *,
51 u32, int,
52 unsigned short,
53 unsigned short);
54static __be32 nfsd_init_request(struct svc_rqst *,
55 const struct svc_program *,
56 struct svc_process_info *);
57
58/*
59 * nfsd_mutex protects nn->nfsd_serv -- both the pointer itself and some members
60 * of the svc_serv struct such as ->sv_temp_socks and ->sv_permsocks.
61 *
62 * Finally, the nfsd_mutex also protects some of the global variables that are
63 * accessed when nfsd starts and that are settable via the write_* routines in
64 * nfsctl.c. In particular:
65 *
66 * user_recovery_dirname
67 * user_lease_time
68 * nfsd_versions
69 */
70DEFINE_MUTEX(nfsd_mutex);
71
72/*
73 * nfsd_drc_lock protects nfsd_drc_max_pages and nfsd_drc_pages_used.
74 * nfsd_drc_max_pages limits the total amount of memory available for
75 * version 4.1 DRC caches.
76 * nfsd_drc_pages_used tracks the current version 4.1 DRC memory usage.
77 */
78DEFINE_SPINLOCK(nfsd_drc_lock);
79unsigned long nfsd_drc_max_mem;
80unsigned long nfsd_drc_mem_used;
81
82#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
83static struct svc_stat nfsd_acl_svcstats;
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_stats = &nfsd_acl_svcstats,
103 .pg_authenticate = &svc_set_client,
104 .pg_init_request = nfsd_acl_init_request,
105 .pg_rpcbind_set = nfsd_acl_rpcbind_set,
106};
107
108static struct svc_stat nfsd_acl_svcstats = {
109 .program = &nfsd_acl_program,
110};
111#endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
112
113static const struct svc_version *nfsd_version[] = {
114#if defined(CONFIG_NFSD_V2)
115 [2] = &nfsd_version2,
116#endif
117 [3] = &nfsd_version3,
118#if defined(CONFIG_NFSD_V4)
119 [4] = &nfsd_version4,
120#endif
121};
122
123#define NFSD_MINVERS 2
124#define NFSD_NRVERS ARRAY_SIZE(nfsd_version)
125
126struct svc_program nfsd_program = {
127#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
128 .pg_next = &nfsd_acl_program,
129#endif
130 .pg_prog = NFS_PROGRAM, /* program number */
131 .pg_nvers = NFSD_NRVERS, /* nr of entries in nfsd_version */
132 .pg_vers = nfsd_version, /* version table */
133 .pg_name = "nfsd", /* program name */
134 .pg_class = "nfsd", /* authentication class */
135 .pg_stats = &nfsd_svcstats, /* version table */
136 .pg_authenticate = &svc_set_client, /* export authentication */
137 .pg_init_request = nfsd_init_request,
138 .pg_rpcbind_set = nfsd_rpcbind_set,
139};
140
141static bool
142nfsd_support_version(int vers)
143{
144 if (vers >= NFSD_MINVERS && vers < NFSD_NRVERS)
145 return nfsd_version[vers] != NULL;
146 return false;
147}
148
149static bool *
150nfsd_alloc_versions(void)
151{
152 bool *vers = kmalloc_array(NFSD_NRVERS, sizeof(bool), GFP_KERNEL);
153 unsigned i;
154
155 if (vers) {
156 /* All compiled versions are enabled by default */
157 for (i = 0; i < NFSD_NRVERS; i++)
158 vers[i] = nfsd_support_version(i);
159 }
160 return vers;
161}
162
163static bool *
164nfsd_alloc_minorversions(void)
165{
166 bool *vers = kmalloc_array(NFSD_SUPPORTED_MINOR_VERSION + 1,
167 sizeof(bool), GFP_KERNEL);
168 unsigned i;
169
170 if (vers) {
171 /* All minor versions are enabled by default */
172 for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++)
173 vers[i] = nfsd_support_version(4);
174 }
175 return vers;
176}
177
178void
179nfsd_netns_free_versions(struct nfsd_net *nn)
180{
181 kfree(nn->nfsd_versions);
182 kfree(nn->nfsd4_minorversions);
183 nn->nfsd_versions = NULL;
184 nn->nfsd4_minorversions = NULL;
185}
186
187static void
188nfsd_netns_init_versions(struct nfsd_net *nn)
189{
190 if (!nn->nfsd_versions) {
191 nn->nfsd_versions = nfsd_alloc_versions();
192 nn->nfsd4_minorversions = nfsd_alloc_minorversions();
193 if (!nn->nfsd_versions || !nn->nfsd4_minorversions)
194 nfsd_netns_free_versions(nn);
195 }
196}
197
198int nfsd_vers(struct nfsd_net *nn, int vers, enum vers_op change)
199{
200 if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS)
201 return 0;
202 switch(change) {
203 case NFSD_SET:
204 if (nn->nfsd_versions)
205 nn->nfsd_versions[vers] = nfsd_support_version(vers);
206 break;
207 case NFSD_CLEAR:
208 nfsd_netns_init_versions(nn);
209 if (nn->nfsd_versions)
210 nn->nfsd_versions[vers] = false;
211 break;
212 case NFSD_TEST:
213 if (nn->nfsd_versions)
214 return nn->nfsd_versions[vers];
215 fallthrough;
216 case NFSD_AVAIL:
217 return nfsd_support_version(vers);
218 }
219 return 0;
220}
221
222static void
223nfsd_adjust_nfsd_versions4(struct nfsd_net *nn)
224{
225 unsigned i;
226
227 for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++) {
228 if (nn->nfsd4_minorversions[i])
229 return;
230 }
231 nfsd_vers(nn, 4, NFSD_CLEAR);
232}
233
234int nfsd_minorversion(struct nfsd_net *nn, u32 minorversion, enum vers_op change)
235{
236 if (minorversion > NFSD_SUPPORTED_MINOR_VERSION &&
237 change != NFSD_AVAIL)
238 return -1;
239
240 switch(change) {
241 case NFSD_SET:
242 if (nn->nfsd4_minorversions) {
243 nfsd_vers(nn, 4, NFSD_SET);
244 nn->nfsd4_minorversions[minorversion] =
245 nfsd_vers(nn, 4, NFSD_TEST);
246 }
247 break;
248 case NFSD_CLEAR:
249 nfsd_netns_init_versions(nn);
250 if (nn->nfsd4_minorversions) {
251 nn->nfsd4_minorversions[minorversion] = false;
252 nfsd_adjust_nfsd_versions4(nn);
253 }
254 break;
255 case NFSD_TEST:
256 if (nn->nfsd4_minorversions)
257 return nn->nfsd4_minorversions[minorversion];
258 return nfsd_vers(nn, 4, NFSD_TEST);
259 case NFSD_AVAIL:
260 return minorversion <= NFSD_SUPPORTED_MINOR_VERSION &&
261 nfsd_vers(nn, 4, NFSD_AVAIL);
262 }
263 return 0;
264}
265
266/*
267 * Maximum number of nfsd processes
268 */
269#define NFSD_MAXSERVS 8192
270
271int nfsd_nrthreads(struct net *net)
272{
273 int rv = 0;
274 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
275
276 mutex_lock(&nfsd_mutex);
277 if (nn->nfsd_serv)
278 rv = nn->nfsd_serv->sv_nrthreads;
279 mutex_unlock(&nfsd_mutex);
280 return rv;
281}
282
283static int nfsd_init_socks(struct net *net, const struct cred *cred)
284{
285 int error;
286 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
287
288 if (!list_empty(&nn->nfsd_serv->sv_permsocks))
289 return 0;
290
291 error = svc_xprt_create(nn->nfsd_serv, "udp", net, PF_INET, NFS_PORT,
292 SVC_SOCK_DEFAULTS, cred);
293 if (error < 0)
294 return error;
295
296 error = svc_xprt_create(nn->nfsd_serv, "tcp", net, PF_INET, NFS_PORT,
297 SVC_SOCK_DEFAULTS, cred);
298 if (error < 0)
299 return error;
300
301 return 0;
302}
303
304static int nfsd_users = 0;
305
306static int nfsd_startup_generic(void)
307{
308 int ret;
309
310 if (nfsd_users++)
311 return 0;
312
313 ret = nfsd_file_cache_init();
314 if (ret)
315 goto dec_users;
316
317 ret = nfs4_state_start();
318 if (ret)
319 goto out_file_cache;
320 return 0;
321
322out_file_cache:
323 nfsd_file_cache_shutdown();
324dec_users:
325 nfsd_users--;
326 return ret;
327}
328
329static void nfsd_shutdown_generic(void)
330{
331 if (--nfsd_users)
332 return;
333
334 nfs4_state_shutdown();
335 nfsd_file_cache_shutdown();
336}
337
338static bool nfsd_needs_lockd(struct nfsd_net *nn)
339{
340 return nfsd_vers(nn, 2, NFSD_TEST) || nfsd_vers(nn, 3, NFSD_TEST);
341}
342
343/**
344 * nfsd_copy_write_verifier - Atomically copy a write verifier
345 * @verf: buffer in which to receive the verifier cookie
346 * @nn: NFS net namespace
347 *
348 * This function provides a wait-free mechanism for copying the
349 * namespace's write verifier without tearing it.
350 */
351void nfsd_copy_write_verifier(__be32 verf[2], struct nfsd_net *nn)
352{
353 unsigned int seq;
354
355 do {
356 seq = read_seqbegin(&nn->writeverf_lock);
357 memcpy(verf, nn->writeverf, sizeof(nn->writeverf));
358 } while (read_seqretry(&nn->writeverf_lock, seq));
359}
360
361static void nfsd_reset_write_verifier_locked(struct nfsd_net *nn)
362{
363 struct timespec64 now;
364 u64 verf;
365
366 /*
367 * Because the time value is hashed, y2038 time_t overflow
368 * is irrelevant in this usage.
369 */
370 ktime_get_raw_ts64(&now);
371 verf = siphash_2u64(now.tv_sec, now.tv_nsec, &nn->siphash_key);
372 memcpy(nn->writeverf, &verf, sizeof(nn->writeverf));
373}
374
375/**
376 * nfsd_reset_write_verifier - Generate a new write verifier
377 * @nn: NFS net namespace
378 *
379 * This function updates the ->writeverf field of @nn. This field
380 * contains an opaque cookie that, according to Section 18.32.3 of
381 * RFC 8881, "the client can use to determine whether a server has
382 * changed instance state (e.g., server restart) between a call to
383 * WRITE and a subsequent call to either WRITE or COMMIT. This
384 * cookie MUST be unchanged during a single instance of the NFSv4.1
385 * server and MUST be unique between instances of the NFSv4.1
386 * server."
387 */
388void nfsd_reset_write_verifier(struct nfsd_net *nn)
389{
390 write_seqlock(&nn->writeverf_lock);
391 nfsd_reset_write_verifier_locked(nn);
392 write_sequnlock(&nn->writeverf_lock);
393}
394
395/*
396 * Crank up a set of per-namespace resources for a new NFSD instance,
397 * including lockd, a duplicate reply cache, an open file cache
398 * instance, and a cache of NFSv4 state objects.
399 */
400static int nfsd_startup_net(struct net *net, const struct cred *cred)
401{
402 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
403 int ret;
404
405 if (nn->nfsd_net_up)
406 return 0;
407
408 ret = nfsd_startup_generic();
409 if (ret)
410 return ret;
411 ret = nfsd_init_socks(net, cred);
412 if (ret)
413 goto out_socks;
414
415 if (nfsd_needs_lockd(nn) && !nn->lockd_up) {
416 ret = lockd_up(net, cred);
417 if (ret)
418 goto out_socks;
419 nn->lockd_up = true;
420 }
421
422 ret = nfsd_file_cache_start_net(net);
423 if (ret)
424 goto out_lockd;
425
426 ret = nfsd_reply_cache_init(nn);
427 if (ret)
428 goto out_filecache;
429
430 ret = nfs4_state_start_net(net);
431 if (ret)
432 goto out_reply_cache;
433
434#ifdef CONFIG_NFSD_V4_2_INTER_SSC
435 nfsd4_ssc_init_umount_work(nn);
436#endif
437 nn->nfsd_net_up = true;
438 return 0;
439
440out_reply_cache:
441 nfsd_reply_cache_shutdown(nn);
442out_filecache:
443 nfsd_file_cache_shutdown_net(net);
444out_lockd:
445 if (nn->lockd_up) {
446 lockd_down(net);
447 nn->lockd_up = false;
448 }
449out_socks:
450 nfsd_shutdown_generic();
451 return ret;
452}
453
454static void nfsd_shutdown_net(struct net *net)
455{
456 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
457
458 nfs4_state_shutdown_net(net);
459 nfsd_reply_cache_shutdown(nn);
460 nfsd_file_cache_shutdown_net(net);
461 if (nn->lockd_up) {
462 lockd_down(net);
463 nn->lockd_up = false;
464 }
465 nn->nfsd_net_up = false;
466 nfsd_shutdown_generic();
467}
468
469static DEFINE_SPINLOCK(nfsd_notifier_lock);
470static int nfsd_inetaddr_event(struct notifier_block *this, unsigned long event,
471 void *ptr)
472{
473 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
474 struct net_device *dev = ifa->ifa_dev->dev;
475 struct net *net = dev_net(dev);
476 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
477 struct sockaddr_in sin;
478
479 if (event != NETDEV_DOWN || !nn->nfsd_serv)
480 goto out;
481
482 spin_lock(&nfsd_notifier_lock);
483 if (nn->nfsd_serv) {
484 dprintk("nfsd_inetaddr_event: removed %pI4\n", &ifa->ifa_local);
485 sin.sin_family = AF_INET;
486 sin.sin_addr.s_addr = ifa->ifa_local;
487 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin);
488 }
489 spin_unlock(&nfsd_notifier_lock);
490
491out:
492 return NOTIFY_DONE;
493}
494
495static struct notifier_block nfsd_inetaddr_notifier = {
496 .notifier_call = nfsd_inetaddr_event,
497};
498
499#if IS_ENABLED(CONFIG_IPV6)
500static int nfsd_inet6addr_event(struct notifier_block *this,
501 unsigned long event, void *ptr)
502{
503 struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
504 struct net_device *dev = ifa->idev->dev;
505 struct net *net = dev_net(dev);
506 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
507 struct sockaddr_in6 sin6;
508
509 if (event != NETDEV_DOWN || !nn->nfsd_serv)
510 goto out;
511
512 spin_lock(&nfsd_notifier_lock);
513 if (nn->nfsd_serv) {
514 dprintk("nfsd_inet6addr_event: removed %pI6\n", &ifa->addr);
515 sin6.sin6_family = AF_INET6;
516 sin6.sin6_addr = ifa->addr;
517 if (ipv6_addr_type(&sin6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
518 sin6.sin6_scope_id = ifa->idev->dev->ifindex;
519 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin6);
520 }
521 spin_unlock(&nfsd_notifier_lock);
522
523out:
524 return NOTIFY_DONE;
525}
526
527static struct notifier_block nfsd_inet6addr_notifier = {
528 .notifier_call = nfsd_inet6addr_event,
529};
530#endif
531
532/* Only used under nfsd_mutex, so this atomic may be overkill: */
533static atomic_t nfsd_notifier_refcount = ATOMIC_INIT(0);
534
535/**
536 * nfsd_destroy_serv - tear down NFSD's svc_serv for a namespace
537 * @net: network namespace the NFS service is associated with
538 */
539void nfsd_destroy_serv(struct net *net)
540{
541 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
542 struct svc_serv *serv = nn->nfsd_serv;
543
544 spin_lock(&nfsd_notifier_lock);
545 nn->nfsd_serv = NULL;
546 spin_unlock(&nfsd_notifier_lock);
547
548 /* check if the notifier still has clients */
549 if (atomic_dec_return(&nfsd_notifier_refcount) == 0) {
550 unregister_inetaddr_notifier(&nfsd_inetaddr_notifier);
551#if IS_ENABLED(CONFIG_IPV6)
552 unregister_inet6addr_notifier(&nfsd_inet6addr_notifier);
553#endif
554 }
555
556 svc_xprt_destroy_all(serv, net);
557
558 /*
559 * write_ports can create the server without actually starting
560 * any threads--if we get shut down before any threads are
561 * started, then nfsd_destroy_serv will be run before any of this
562 * other initialization has been done except the rpcb information.
563 */
564 svc_rpcb_cleanup(serv, net);
565 if (!nn->nfsd_net_up)
566 return;
567
568 nfsd_shutdown_net(net);
569 nfsd_export_flush(net);
570 svc_destroy(&serv);
571}
572
573void nfsd_reset_versions(struct nfsd_net *nn)
574{
575 int i;
576
577 for (i = 0; i < NFSD_NRVERS; i++)
578 if (nfsd_vers(nn, i, NFSD_TEST))
579 return;
580
581 for (i = 0; i < NFSD_NRVERS; i++)
582 if (i != 4)
583 nfsd_vers(nn, i, NFSD_SET);
584 else {
585 int minor = 0;
586 while (nfsd_minorversion(nn, minor, NFSD_SET) >= 0)
587 minor++;
588 }
589}
590
591/*
592 * Each session guarantees a negotiated per slot memory cache for replies
593 * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated
594 * NFSv4.1 server might want to use more memory for a DRC than a machine
595 * with mutiple services.
596 *
597 * Impose a hard limit on the number of pages for the DRC which varies
598 * according to the machines free pages. This is of course only a default.
599 *
600 * For now this is a #defined shift which could be under admin control
601 * in the future.
602 */
603static void set_max_drc(void)
604{
605 #define NFSD_DRC_SIZE_SHIFT 7
606 nfsd_drc_max_mem = (nr_free_buffer_pages()
607 >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE;
608 nfsd_drc_mem_used = 0;
609 dprintk("%s nfsd_drc_max_mem %lu \n", __func__, nfsd_drc_max_mem);
610}
611
612static int nfsd_get_default_max_blksize(void)
613{
614 struct sysinfo i;
615 unsigned long long target;
616 unsigned long ret;
617
618 si_meminfo(&i);
619 target = (i.totalram - i.totalhigh) << PAGE_SHIFT;
620 /*
621 * Aim for 1/4096 of memory per thread This gives 1MB on 4Gig
622 * machines, but only uses 32K on 128M machines. Bottom out at
623 * 8K on 32M and smaller. Of course, this is only a default.
624 */
625 target >>= 12;
626
627 ret = NFSSVC_MAXBLKSIZE;
628 while (ret > target && ret >= 8*1024*2)
629 ret /= 2;
630 return ret;
631}
632
633void nfsd_shutdown_threads(struct net *net)
634{
635 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
636 struct svc_serv *serv;
637
638 mutex_lock(&nfsd_mutex);
639 serv = nn->nfsd_serv;
640 if (serv == NULL) {
641 mutex_unlock(&nfsd_mutex);
642 return;
643 }
644
645 /* Kill outstanding nfsd threads */
646 svc_set_num_threads(serv, NULL, 0);
647 nfsd_destroy_serv(net);
648 mutex_unlock(&nfsd_mutex);
649}
650
651bool i_am_nfsd(void)
652{
653 return kthread_func(current) == nfsd;
654}
655
656int nfsd_create_serv(struct net *net)
657{
658 int error;
659 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
660 struct svc_serv *serv;
661
662 WARN_ON(!mutex_is_locked(&nfsd_mutex));
663 if (nn->nfsd_serv)
664 return 0;
665
666 if (nfsd_max_blksize == 0)
667 nfsd_max_blksize = nfsd_get_default_max_blksize();
668 nfsd_reset_versions(nn);
669 serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize, nfsd);
670 if (serv == NULL)
671 return -ENOMEM;
672
673 serv->sv_maxconn = nn->max_connections;
674 error = svc_bind(serv, net);
675 if (error < 0) {
676 svc_destroy(&serv);
677 return error;
678 }
679 spin_lock(&nfsd_notifier_lock);
680 nn->nfsd_info.mutex = &nfsd_mutex;
681 nn->nfsd_serv = serv;
682 spin_unlock(&nfsd_notifier_lock);
683
684 set_max_drc();
685 /* check if the notifier is already set */
686 if (atomic_inc_return(&nfsd_notifier_refcount) == 1) {
687 register_inetaddr_notifier(&nfsd_inetaddr_notifier);
688#if IS_ENABLED(CONFIG_IPV6)
689 register_inet6addr_notifier(&nfsd_inet6addr_notifier);
690#endif
691 }
692 nfsd_reset_write_verifier(nn);
693 return 0;
694}
695
696int nfsd_nrpools(struct net *net)
697{
698 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
699
700 if (nn->nfsd_serv == NULL)
701 return 0;
702 else
703 return nn->nfsd_serv->sv_nrpools;
704}
705
706int nfsd_get_nrthreads(int n, int *nthreads, struct net *net)
707{
708 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
709 struct svc_serv *serv = nn->nfsd_serv;
710 int i;
711
712 if (serv)
713 for (i = 0; i < serv->sv_nrpools && i < n; i++)
714 nthreads[i] = atomic_read(&serv->sv_pools[i].sp_nrthreads);
715 return 0;
716}
717
718int nfsd_set_nrthreads(int n, int *nthreads, struct net *net)
719{
720 int i = 0;
721 int tot = 0;
722 int err = 0;
723 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
724
725 WARN_ON(!mutex_is_locked(&nfsd_mutex));
726
727 if (nn->nfsd_serv == NULL || n <= 0)
728 return 0;
729
730 if (n > nn->nfsd_serv->sv_nrpools)
731 n = nn->nfsd_serv->sv_nrpools;
732
733 /* enforce a global maximum number of threads */
734 tot = 0;
735 for (i = 0; i < n; i++) {
736 nthreads[i] = min(nthreads[i], NFSD_MAXSERVS);
737 tot += nthreads[i];
738 }
739 if (tot > NFSD_MAXSERVS) {
740 /* total too large: scale down requested numbers */
741 for (i = 0; i < n && tot > 0; i++) {
742 int new = nthreads[i] * NFSD_MAXSERVS / tot;
743 tot -= (nthreads[i] - new);
744 nthreads[i] = new;
745 }
746 for (i = 0; i < n && tot > 0; i++) {
747 nthreads[i]--;
748 tot--;
749 }
750 }
751
752 /*
753 * There must always be a thread in pool 0; the admin
754 * can't shut down NFS completely using pool_threads.
755 */
756 if (nthreads[0] == 0)
757 nthreads[0] = 1;
758
759 /* apply the new numbers */
760 for (i = 0; i < n; i++) {
761 err = svc_set_num_threads(nn->nfsd_serv,
762 &nn->nfsd_serv->sv_pools[i],
763 nthreads[i]);
764 if (err)
765 break;
766 }
767 return err;
768}
769
770/*
771 * Adjust the number of threads and return the new number of threads.
772 * This is also the function that starts the server if necessary, if
773 * this is the first time nrservs is nonzero.
774 */
775int
776nfsd_svc(int nrservs, struct net *net, const struct cred *cred)
777{
778 int error;
779 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
780 struct svc_serv *serv;
781
782 mutex_lock(&nfsd_mutex);
783 dprintk("nfsd: creating service\n");
784
785 nrservs = max(nrservs, 0);
786 nrservs = min(nrservs, NFSD_MAXSERVS);
787 error = 0;
788
789 if (nrservs == 0 && nn->nfsd_serv == NULL)
790 goto out;
791
792 strscpy(nn->nfsd_name, utsname()->nodename,
793 sizeof(nn->nfsd_name));
794
795 error = nfsd_create_serv(net);
796 if (error)
797 goto out;
798 serv = nn->nfsd_serv;
799
800 error = nfsd_startup_net(net, cred);
801 if (error)
802 goto out_put;
803 error = svc_set_num_threads(serv, NULL, nrservs);
804 if (error)
805 goto out_put;
806 error = serv->sv_nrthreads;
807out_put:
808 if (serv->sv_nrthreads == 0)
809 nfsd_destroy_serv(net);
810out:
811 mutex_unlock(&nfsd_mutex);
812 return error;
813}
814
815#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
816static bool
817nfsd_support_acl_version(int vers)
818{
819 if (vers >= NFSD_ACL_MINVERS && vers < NFSD_ACL_NRVERS)
820 return nfsd_acl_version[vers] != NULL;
821 return false;
822}
823
824static int
825nfsd_acl_rpcbind_set(struct net *net, const struct svc_program *progp,
826 u32 version, int family, unsigned short proto,
827 unsigned short port)
828{
829 if (!nfsd_support_acl_version(version) ||
830 !nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST))
831 return 0;
832 return svc_generic_rpcbind_set(net, progp, version, family,
833 proto, port);
834}
835
836static __be32
837nfsd_acl_init_request(struct svc_rqst *rqstp,
838 const struct svc_program *progp,
839 struct svc_process_info *ret)
840{
841 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
842 int i;
843
844 if (likely(nfsd_support_acl_version(rqstp->rq_vers) &&
845 nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST)))
846 return svc_generic_init_request(rqstp, progp, ret);
847
848 ret->mismatch.lovers = NFSD_ACL_NRVERS;
849 for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) {
850 if (nfsd_support_acl_version(rqstp->rq_vers) &&
851 nfsd_vers(nn, i, NFSD_TEST)) {
852 ret->mismatch.lovers = i;
853 break;
854 }
855 }
856 if (ret->mismatch.lovers == NFSD_ACL_NRVERS)
857 return rpc_prog_unavail;
858 ret->mismatch.hivers = NFSD_ACL_MINVERS;
859 for (i = NFSD_ACL_NRVERS - 1; i >= NFSD_ACL_MINVERS; i--) {
860 if (nfsd_support_acl_version(rqstp->rq_vers) &&
861 nfsd_vers(nn, i, NFSD_TEST)) {
862 ret->mismatch.hivers = i;
863 break;
864 }
865 }
866 return rpc_prog_mismatch;
867}
868#endif
869
870static int
871nfsd_rpcbind_set(struct net *net, const struct svc_program *progp,
872 u32 version, int family, unsigned short proto,
873 unsigned short port)
874{
875 if (!nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST))
876 return 0;
877 return svc_generic_rpcbind_set(net, progp, version, family,
878 proto, port);
879}
880
881static __be32
882nfsd_init_request(struct svc_rqst *rqstp,
883 const struct svc_program *progp,
884 struct svc_process_info *ret)
885{
886 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
887 int i;
888
889 if (likely(nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST)))
890 return svc_generic_init_request(rqstp, progp, ret);
891
892 ret->mismatch.lovers = NFSD_NRVERS;
893 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) {
894 if (nfsd_vers(nn, i, NFSD_TEST)) {
895 ret->mismatch.lovers = i;
896 break;
897 }
898 }
899 if (ret->mismatch.lovers == NFSD_NRVERS)
900 return rpc_prog_unavail;
901 ret->mismatch.hivers = NFSD_MINVERS;
902 for (i = NFSD_NRVERS - 1; i >= NFSD_MINVERS; i--) {
903 if (nfsd_vers(nn, i, NFSD_TEST)) {
904 ret->mismatch.hivers = i;
905 break;
906 }
907 }
908 return rpc_prog_mismatch;
909}
910
911/*
912 * This is the NFS server kernel thread
913 */
914static int
915nfsd(void *vrqstp)
916{
917 struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp;
918 struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list);
919 struct net *net = perm_sock->xpt_net;
920 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
921
922 /* At this point, the thread shares current->fs
923 * with the init process. We need to create files with the
924 * umask as defined by the client instead of init's umask. */
925 if (unshare_fs_struct() < 0) {
926 printk("Unable to start nfsd thread: out of memory\n");
927 goto out;
928 }
929
930 current->fs->umask = 0;
931
932 atomic_inc(&nfsdstats.th_cnt);
933
934 set_freezable();
935
936 /*
937 * The main request loop
938 */
939 while (!svc_thread_should_stop(rqstp)) {
940 /* Update sv_maxconn if it has changed */
941 rqstp->rq_server->sv_maxconn = nn->max_connections;
942
943 svc_recv(rqstp);
944 }
945
946 atomic_dec(&nfsdstats.th_cnt);
947
948out:
949 /* Release the thread */
950 svc_exit_thread(rqstp);
951 return 0;
952}
953
954/**
955 * nfsd_dispatch - Process an NFS or NFSACL Request
956 * @rqstp: incoming request
957 *
958 * This RPC dispatcher integrates the NFS server's duplicate reply cache.
959 *
960 * Return values:
961 * %0: Processing complete; do not send a Reply
962 * %1: Processing complete; send Reply in rqstp->rq_res
963 */
964int nfsd_dispatch(struct svc_rqst *rqstp)
965{
966 const struct svc_procedure *proc = rqstp->rq_procinfo;
967 __be32 *statp = rqstp->rq_accept_statp;
968 struct nfsd_cacherep *rp;
969 unsigned int start, len;
970 __be32 *nfs_reply;
971
972 /*
973 * Give the xdr decoder a chance to change this if it wants
974 * (necessary in the NFSv4.0 compound case)
975 */
976 rqstp->rq_cachetype = proc->pc_cachetype;
977
978 /*
979 * ->pc_decode advances the argument stream past the NFS
980 * Call header, so grab the header's starting location and
981 * size now for the call to nfsd_cache_lookup().
982 */
983 start = xdr_stream_pos(&rqstp->rq_arg_stream);
984 len = xdr_stream_remaining(&rqstp->rq_arg_stream);
985 if (!proc->pc_decode(rqstp, &rqstp->rq_arg_stream))
986 goto out_decode_err;
987
988 /*
989 * Release rq_status_counter setting it to an odd value after the rpc
990 * request has been properly parsed. rq_status_counter is used to
991 * notify the consumers if the rqstp fields are stable
992 * (rq_status_counter is odd) or not meaningful (rq_status_counter
993 * is even).
994 */
995 smp_store_release(&rqstp->rq_status_counter, rqstp->rq_status_counter | 1);
996
997 rp = NULL;
998 switch (nfsd_cache_lookup(rqstp, start, len, &rp)) {
999 case RC_DOIT:
1000 break;
1001 case RC_REPLY:
1002 goto out_cached_reply;
1003 case RC_DROPIT:
1004 goto out_dropit;
1005 }
1006
1007 nfs_reply = xdr_inline_decode(&rqstp->rq_res_stream, 0);
1008 *statp = proc->pc_func(rqstp);
1009 if (test_bit(RQ_DROPME, &rqstp->rq_flags))
1010 goto out_update_drop;
1011
1012 if (!proc->pc_encode(rqstp, &rqstp->rq_res_stream))
1013 goto out_encode_err;
1014
1015 /*
1016 * Release rq_status_counter setting it to an even value after the rpc
1017 * request has been properly processed.
1018 */
1019 smp_store_release(&rqstp->rq_status_counter, rqstp->rq_status_counter + 1);
1020
1021 nfsd_cache_update(rqstp, rp, rqstp->rq_cachetype, nfs_reply);
1022out_cached_reply:
1023 return 1;
1024
1025out_decode_err:
1026 trace_nfsd_garbage_args_err(rqstp);
1027 *statp = rpc_garbage_args;
1028 return 1;
1029
1030out_update_drop:
1031 nfsd_cache_update(rqstp, rp, RC_NOCACHE, NULL);
1032out_dropit:
1033 return 0;
1034
1035out_encode_err:
1036 trace_nfsd_cant_encode_err(rqstp);
1037 nfsd_cache_update(rqstp, rp, RC_NOCACHE, NULL);
1038 *statp = rpc_system_err;
1039 return 1;
1040}
1041
1042/**
1043 * nfssvc_decode_voidarg - Decode void arguments
1044 * @rqstp: Server RPC transaction context
1045 * @xdr: XDR stream positioned at arguments to decode
1046 *
1047 * Return values:
1048 * %false: Arguments were not valid
1049 * %true: Decoding was successful
1050 */
1051bool nfssvc_decode_voidarg(struct svc_rqst *rqstp, struct xdr_stream *xdr)
1052{
1053 return true;
1054}
1055
1056/**
1057 * nfssvc_encode_voidres - Encode void results
1058 * @rqstp: Server RPC transaction context
1059 * @xdr: XDR stream into which to encode results
1060 *
1061 * Return values:
1062 * %false: Local error while encoding
1063 * %true: Encoding was successful
1064 */
1065bool nfssvc_encode_voidres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
1066{
1067 return true;
1068}
1069
1070int nfsd_pool_stats_open(struct inode *inode, struct file *file)
1071{
1072 struct nfsd_net *nn = net_generic(inode->i_sb->s_fs_info, nfsd_net_id);
1073
1074 return svc_pool_stats_open(&nn->nfsd_info, file);
1075}