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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/nfsd/nfssvc.c
3 *
4 * Central processing for nfsd.
5 *
6 * Authors: Olaf Kirch (okir@monad.swb.de)
7 *
8 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
9 */
10
Linus Torvalds1da177e2005-04-16 15:20:36 -070011#include <linux/module.h>
12
13#include <linux/time.h>
14#include <linux/errno.h>
15#include <linux/nfs.h>
16#include <linux/in.h>
17#include <linux/uio.h>
18#include <linux/unistd.h>
19#include <linux/slab.h>
20#include <linux/smp.h>
21#include <linux/smp_lock.h>
22#include <linux/fs_struct.h>
23
24#include <linux/sunrpc/types.h>
25#include <linux/sunrpc/stats.h>
26#include <linux/sunrpc/svc.h>
27#include <linux/sunrpc/svcsock.h>
28#include <linux/sunrpc/cache.h>
29#include <linux/nfsd/nfsd.h>
30#include <linux/nfsd/stats.h>
31#include <linux/nfsd/cache.h>
NeilBrown70c3b762005-11-07 01:00:25 -080032#include <linux/nfsd/syscall.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033#include <linux/lockd/bind.h>
Andreas Gruenbachera257cdd2005-06-22 17:16:26 +000034#include <linux/nfsacl.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035
36#define NFSDDBG_FACILITY NFSDDBG_SVC
37
38/* these signals will be delivered to an nfsd thread
39 * when handling a request
40 */
41#define ALLOWED_SIGS (sigmask(SIGKILL))
42/* these signals will be delivered to an nfsd thread
43 * when not handling a request. i.e. when waiting
44 */
45#define SHUTDOWN_SIGS (sigmask(SIGKILL) | sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT))
46/* if the last thread dies with SIGHUP, then the exports table is
47 * left unchanged ( like 2.4-{0-9} ). Any other signal will clear
48 * the exports table (like 2.2).
49 */
50#define SIG_NOCLEAN SIGHUP
51
52extern struct svc_program nfsd_program;
53static void nfsd(struct svc_rqst *rqstp);
54struct timeval nfssvc_boot;
NeilBrown70c3b762005-11-07 01:00:25 -080055 struct svc_serv *nfsd_serv;
Linus Torvalds1da177e2005-04-16 15:20:36 -070056static atomic_t nfsd_busy;
57static unsigned long nfsd_last_call;
58static DEFINE_SPINLOCK(nfsd_call_lock);
59
60struct nfsd_list {
61 struct list_head list;
62 struct task_struct *task;
63};
64static struct list_head nfsd_list = LIST_HEAD_INIT(nfsd_list);
65
Andreas Gruenbacher3fb803a2006-02-01 03:04:34 -080066#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
67static struct svc_stat nfsd_acl_svcstats;
68static struct svc_version * nfsd_acl_version[] = {
69 [2] = &nfsd_acl_version2,
70 [3] = &nfsd_acl_version3,
71};
72
73#define NFSD_ACL_MINVERS 2
Tobias Klausere8c96f82006-03-24 03:15:34 -080074#define NFSD_ACL_NRVERS ARRAY_SIZE(nfsd_acl_version)
Andreas Gruenbacher3fb803a2006-02-01 03:04:34 -080075static struct svc_version *nfsd_acl_versions[NFSD_ACL_NRVERS];
76
77static struct svc_program nfsd_acl_program = {
78 .pg_prog = NFS_ACL_PROGRAM,
79 .pg_nvers = NFSD_ACL_NRVERS,
80 .pg_vers = nfsd_acl_versions,
81 .pg_name = "nfsd",
82 .pg_class = "nfsd",
83 .pg_stats = &nfsd_acl_svcstats,
84 .pg_authenticate = &svc_set_client,
85};
86
87static struct svc_stat nfsd_acl_svcstats = {
88 .program = &nfsd_acl_program,
89};
90#endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
91
NeilBrown70c3b762005-11-07 01:00:25 -080092static struct svc_version * nfsd_version[] = {
93 [2] = &nfsd_version2,
94#if defined(CONFIG_NFSD_V3)
95 [3] = &nfsd_version3,
96#endif
97#if defined(CONFIG_NFSD_V4)
98 [4] = &nfsd_version4,
99#endif
100};
101
102#define NFSD_MINVERS 2
Tobias Klausere8c96f82006-03-24 03:15:34 -0800103#define NFSD_NRVERS ARRAY_SIZE(nfsd_version)
NeilBrown70c3b762005-11-07 01:00:25 -0800104static struct svc_version *nfsd_versions[NFSD_NRVERS];
105
106struct svc_program nfsd_program = {
Andreas Gruenbacher3fb803a2006-02-01 03:04:34 -0800107#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
108 .pg_next = &nfsd_acl_program,
109#endif
NeilBrown70c3b762005-11-07 01:00:25 -0800110 .pg_prog = NFS_PROGRAM, /* program number */
111 .pg_nvers = NFSD_NRVERS, /* nr of entries in nfsd_version */
112 .pg_vers = nfsd_versions, /* version table */
113 .pg_name = "nfsd", /* program name */
114 .pg_class = "nfsd", /* authentication class */
115 .pg_stats = &nfsd_svcstats, /* version table */
116 .pg_authenticate = &svc_set_client, /* export authentication */
117
118};
119
NeilBrown6658d3a2006-10-02 02:17:46 -0700120int nfsd_vers(int vers, enum vers_op change)
121{
122 if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS)
123 return -1;
124 switch(change) {
125 case NFSD_SET:
126 nfsd_versions[vers] = nfsd_version[vers];
127 break;
128#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
129 if (vers < NFSD_ACL_NRVERS)
130 nfsd_acl_version[vers] = nfsd_acl_version[vers];
131#endif
132 case NFSD_CLEAR:
133 nfsd_versions[vers] = NULL;
134#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
135 if (vers < NFSD_ACL_NRVERS)
136 nfsd_acl_version[vers] = NULL;
137#endif
138 break;
139 case NFSD_TEST:
140 return nfsd_versions[vers] != NULL;
141 case NFSD_AVAIL:
142 return nfsd_version[vers] != NULL;
143 }
144 return 0;
145}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146/*
147 * Maximum number of nfsd processes
148 */
149#define NFSD_MAXSERVS 8192
150
151int nfsd_nrthreads(void)
152{
153 if (nfsd_serv == NULL)
154 return 0;
155 else
156 return nfsd_serv->sv_nrthreads;
157}
158
NeilBrownbc591cc2006-10-02 02:17:44 -0700159static int killsig; /* signal that was used to kill last nfsd */
160static void nfsd_last_thread(struct svc_serv *serv)
161{
162 /* When last nfsd thread exits we need to do some clean-up */
NeilBrown24e36662006-10-02 02:17:45 -0700163 struct svc_sock *svsk;
164 list_for_each_entry(svsk, &serv->sv_permsocks, sk_list)
165 lockd_down();
NeilBrownbc591cc2006-10-02 02:17:44 -0700166 nfsd_serv = NULL;
167 nfsd_racache_shutdown();
168 nfs4_state_shutdown();
169
170 printk(KERN_WARNING "nfsd: last server has exited\n");
171 if (killsig != SIG_NOCLEAN) {
172 printk(KERN_WARNING "nfsd: unexporting all filesystems\n");
173 nfsd_export_flush();
174 }
175}
NeilBrown6658d3a2006-10-02 02:17:46 -0700176
177void nfsd_reset_versions(void)
178{
179 int found_one = 0;
180 int i;
181
182 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) {
183 if (nfsd_program.pg_vers[i])
184 found_one = 1;
185 }
186
187 if (!found_one) {
188 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++)
189 nfsd_program.pg_vers[i] = nfsd_version[i];
190#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
191 for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++)
192 nfsd_acl_program.pg_vers[i] =
193 nfsd_acl_version[i];
194#endif
195 }
196}
197
NeilBrown02a375f2006-10-02 02:17:46 -0700198static int nfsd_create_serv(void)
199{
200 int err = 0;
201 lock_kernel();
202 if (nfsd_serv) {
203 nfsd_serv->sv_nrthreads++;
204 unlock_kernel();
205 return 0;
206 }
207
208 atomic_set(&nfsd_busy, 0);
209 nfsd_serv = svc_create(&nfsd_program, NFSD_BUFSIZE,
210 nfsd_last_thread);
211 if (nfsd_serv == NULL)
212 err = -ENOMEM;
213 else
214 nfsd_serv->sv_nrthreads++;
215 unlock_kernel();
216 do_gettimeofday(&nfssvc_boot); /* record boot time */
217 return err;
218}
219
220static int nfsd_init_socks(int port)
221{
222 int error;
223 if (!list_empty(&nfsd_serv->sv_permsocks))
224 return 0;
225
226 error = svc_makesock(nfsd_serv, IPPROTO_UDP, port);
227 if (error < 0)
228 return error;
229 error = lockd_up(IPPROTO_UDP);
230 if (error < 0)
231 return error;
232
233#ifdef CONFIG_NFSD_TCP
234 error = svc_makesock(nfsd_serv, IPPROTO_TCP, port);
235 if (error < 0)
236 return error;
237 error = lockd_up(IPPROTO_TCP);
238 if (error < 0)
239 return error;
240#endif
241 return 0;
242}
243
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244int
245nfsd_svc(unsigned short port, int nrservs)
246{
247 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 struct list_head *victim;
249
250 lock_kernel();
NeilBrown6658d3a2006-10-02 02:17:46 -0700251 dprintk("nfsd: creating service\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 error = -EINVAL;
253 if (nrservs <= 0)
254 nrservs = 0;
255 if (nrservs > NFSD_MAXSERVS)
256 nrservs = NFSD_MAXSERVS;
257
258 /* Readahead param cache - will no-op if it already exists */
259 error = nfsd_racache_init(2*nrservs);
260 if (error<0)
261 goto out;
NeilBrown76a35502005-06-23 22:03:26 -0700262 error = nfs4_state_start();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 if (error<0)
264 goto out;
Andreas Gruenbacher3fb803a2006-02-01 03:04:34 -0800265
NeilBrown02a375f2006-10-02 02:17:46 -0700266 nfsd_reset_versions();
267
268 error = nfsd_create_serv();
269
270 if (error)
271 goto out;
272 error = nfsd_init_socks(port);
273 if (error)
274 goto failure;
275
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 nrservs -= (nfsd_serv->sv_nrthreads-1);
277 while (nrservs > 0) {
278 nrservs--;
279 __module_get(THIS_MODULE);
280 error = svc_create_thread(nfsd, nfsd_serv);
281 if (error < 0) {
282 module_put(THIS_MODULE);
283 break;
284 }
285 }
286 victim = nfsd_list.next;
287 while (nrservs < 0 && victim != &nfsd_list) {
288 struct nfsd_list *nl =
289 list_entry(victim,struct nfsd_list, list);
290 victim = victim->next;
291 send_sig(SIG_NOCLEAN, nl->task, 1);
292 nrservs++;
293 }
294 failure:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295 svc_destroy(nfsd_serv); /* Release server */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 out:
297 unlock_kernel();
298 return error;
299}
300
301static inline void
302update_thread_usage(int busy_threads)
303{
304 unsigned long prev_call;
305 unsigned long diff;
306 int decile;
307
308 spin_lock(&nfsd_call_lock);
309 prev_call = nfsd_last_call;
310 nfsd_last_call = jiffies;
311 decile = busy_threads*10/nfsdstats.th_cnt;
312 if (decile>0 && decile <= 10) {
313 diff = nfsd_last_call - prev_call;
314 if ( (nfsdstats.th_usage[decile-1] += diff) >= NFSD_USAGE_WRAP)
315 nfsdstats.th_usage[decile-1] -= NFSD_USAGE_WRAP;
316 if (decile == 10)
317 nfsdstats.th_fullcnt++;
318 }
319 spin_unlock(&nfsd_call_lock);
320}
321
322/*
323 * This is the NFS server kernel thread
324 */
325static void
326nfsd(struct svc_rqst *rqstp)
327{
328 struct svc_serv *serv = rqstp->rq_server;
329 struct fs_struct *fsp;
330 int err;
331 struct nfsd_list me;
332 sigset_t shutdown_mask, allowed_mask;
333
334 /* Lock module and set up kernel thread */
335 lock_kernel();
336 daemonize("nfsd");
337
338 /* After daemonize() this kernel thread shares current->fs
339 * with the init process. We need to create files with a
340 * umask of 0 instead of init's umask. */
341 fsp = copy_fs_struct(current->fs);
342 if (!fsp) {
343 printk("Unable to start nfsd thread: out of memory\n");
344 goto out;
345 }
346 exit_fs(current);
347 current->fs = fsp;
348 current->fs->umask = 0;
349
350 siginitsetinv(&shutdown_mask, SHUTDOWN_SIGS);
351 siginitsetinv(&allowed_mask, ALLOWED_SIGS);
352
353 nfsdstats.th_cnt++;
354
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355 me.task = current;
356 list_add(&me.list, &nfsd_list);
357
358 unlock_kernel();
359
360 /*
361 * We want less throttling in balance_dirty_pages() so that nfs to
362 * localhost doesn't cause nfsd to lock up due to all the client's
363 * dirty pages.
364 */
365 current->flags |= PF_LESS_THROTTLE;
366
367 /*
368 * The main request loop
369 */
370 for (;;) {
371 /* Block all but the shutdown signals */
372 sigprocmask(SIG_SETMASK, &shutdown_mask, NULL);
373
374 /*
375 * Find a socket with data available and call its
376 * recvfrom routine.
377 */
378 while ((err = svc_recv(serv, rqstp,
379 60*60*HZ)) == -EAGAIN)
380 ;
381 if (err < 0)
382 break;
383 update_thread_usage(atomic_read(&nfsd_busy));
384 atomic_inc(&nfsd_busy);
385
386 /* Lock the export hash tables for reading. */
387 exp_readlock();
388
389 /* Process request with signals blocked. */
390 sigprocmask(SIG_SETMASK, &allowed_mask, NULL);
391
392 svc_process(serv, rqstp);
393
394 /* Unlock export hash tables */
395 exp_readunlock();
396 update_thread_usage(atomic_read(&nfsd_busy));
397 atomic_dec(&nfsd_busy);
398 }
399
400 if (err != -EINTR) {
401 printk(KERN_WARNING "nfsd: terminating on error %d\n", -err);
402 } else {
403 unsigned int signo;
404
405 for (signo = 1; signo <= _NSIG; signo++)
406 if (sigismember(&current->pending.signal, signo) &&
407 !sigismember(&current->blocked, signo))
408 break;
NeilBrownbc591cc2006-10-02 02:17:44 -0700409 killsig = signo;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410 }
NeilBrown24e36662006-10-02 02:17:45 -0700411 /* Clear signals before calling svc_exit_thread() */
NeilBrown9e4160522005-04-16 15:26:37 -0700412 flush_signals(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413
414 lock_kernel();
415
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416 list_del(&me.list);
417 nfsdstats.th_cnt --;
418
419out:
420 /* Release the thread */
421 svc_exit_thread(rqstp);
422
423 /* Release module */
Steven Rostedtc4f92db2005-08-17 14:25:23 -0400424 unlock_kernel();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 module_put_and_exit(0);
426}
427
428int
429nfsd_dispatch(struct svc_rqst *rqstp, u32 *statp)
430{
431 struct svc_procedure *proc;
432 kxdrproc_t xdr;
433 u32 nfserr;
434 u32 *nfserrp;
435
436 dprintk("nfsd_dispatch: vers %d proc %d\n",
437 rqstp->rq_vers, rqstp->rq_proc);
438 proc = rqstp->rq_procinfo;
439
440 /* Check whether we have this call in the cache. */
441 switch (nfsd_cache_lookup(rqstp, proc->pc_cachetype)) {
442 case RC_INTR:
443 case RC_DROPIT:
444 return 0;
445 case RC_REPLY:
446 return 1;
447 case RC_DOIT:;
448 /* do it */
449 }
450
451 /* Decode arguments */
452 xdr = proc->pc_decode;
453 if (xdr && !xdr(rqstp, (u32*)rqstp->rq_arg.head[0].iov_base,
454 rqstp->rq_argp)) {
455 dprintk("nfsd: failed to decode arguments!\n");
456 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
457 *statp = rpc_garbage_args;
458 return 1;
459 }
460
461 /* need to grab the location to store the status, as
462 * nfsv4 does some encoding while processing
463 */
464 nfserrp = rqstp->rq_res.head[0].iov_base
465 + rqstp->rq_res.head[0].iov_len;
466 rqstp->rq_res.head[0].iov_len += sizeof(u32);
467
468 /* Now call the procedure handler, and encode NFS status. */
469 nfserr = proc->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
470 if (nfserr == nfserr_jukebox && rqstp->rq_vers == 2)
471 nfserr = nfserr_dropit;
472 if (nfserr == nfserr_dropit) {
473 dprintk("nfsd: Dropping request due to malloc failure!\n");
474 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
475 return 0;
476 }
477
478 if (rqstp->rq_proc != 0)
479 *nfserrp++ = nfserr;
480
481 /* Encode result.
482 * For NFSv2, additional info is never returned in case of an error.
483 */
484 if (!(nfserr && rqstp->rq_vers == 2)) {
485 xdr = proc->pc_encode;
486 if (xdr && !xdr(rqstp, nfserrp,
487 rqstp->rq_resp)) {
488 /* Failed to encode result. Release cache entry */
489 dprintk("nfsd: failed to encode result!\n");
490 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
491 *statp = rpc_system_err;
492 return 1;
493 }
494 }
495
496 /* Store reply in cache. */
497 nfsd_cache_update(rqstp, proc->pc_cachetype, statp + 1);
498 return 1;
499}