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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
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
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}