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