fs: introduce some page/buffer invariants
[linux-2.6-block.git] / fs / nfsd / nfssvc.c
CommitLineData
1da177e4
LT
1/*
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
1da177e4 11#include <linux/module.h>
e8edc6e0 12#include <linux/sched.h>
1da177e4
LT
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>
70c3b76c 32#include <linux/nfsd/syscall.h>
1da177e4 33#include <linux/lockd/bind.h>
a257cdd0 34#include <linux/nfsacl.h>
1da177e4
LT
35
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;
70c3b76c 55 struct svc_serv *nfsd_serv;
1da177e4
LT
56static atomic_t nfsd_busy;
57static unsigned long nfsd_last_call;
58static DEFINE_SPINLOCK(nfsd_call_lock);
59
3fb803a9
AG
60#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
61static struct svc_stat nfsd_acl_svcstats;
62static struct svc_version * nfsd_acl_version[] = {
63 [2] = &nfsd_acl_version2,
64 [3] = &nfsd_acl_version3,
65};
66
67#define NFSD_ACL_MINVERS 2
e8c96f8c 68#define NFSD_ACL_NRVERS ARRAY_SIZE(nfsd_acl_version)
3fb803a9
AG
69static struct svc_version *nfsd_acl_versions[NFSD_ACL_NRVERS];
70
71static struct svc_program nfsd_acl_program = {
72 .pg_prog = NFS_ACL_PROGRAM,
73 .pg_nvers = NFSD_ACL_NRVERS,
74 .pg_vers = nfsd_acl_versions,
1a8eff6d 75 .pg_name = "nfsacl",
3fb803a9
AG
76 .pg_class = "nfsd",
77 .pg_stats = &nfsd_acl_svcstats,
78 .pg_authenticate = &svc_set_client,
79};
80
81static struct svc_stat nfsd_acl_svcstats = {
82 .program = &nfsd_acl_program,
83};
84#endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
85
70c3b76c
N
86static struct svc_version * nfsd_version[] = {
87 [2] = &nfsd_version2,
88#if defined(CONFIG_NFSD_V3)
89 [3] = &nfsd_version3,
90#endif
91#if defined(CONFIG_NFSD_V4)
92 [4] = &nfsd_version4,
93#endif
94};
95
96#define NFSD_MINVERS 2
e8c96f8c 97#define NFSD_NRVERS ARRAY_SIZE(nfsd_version)
70c3b76c
N
98static struct svc_version *nfsd_versions[NFSD_NRVERS];
99
100struct svc_program nfsd_program = {
3fb803a9
AG
101#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
102 .pg_next = &nfsd_acl_program,
103#endif
70c3b76c
N
104 .pg_prog = NFS_PROGRAM, /* program number */
105 .pg_nvers = NFSD_NRVERS, /* nr of entries in nfsd_version */
106 .pg_vers = nfsd_versions, /* version table */
107 .pg_name = "nfsd", /* program name */
108 .pg_class = "nfsd", /* authentication class */
109 .pg_stats = &nfsd_svcstats, /* version table */
110 .pg_authenticate = &svc_set_client, /* export authentication */
111
112};
113
6658d3a7
N
114int nfsd_vers(int vers, enum vers_op change)
115{
116 if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS)
117 return -1;
118 switch(change) {
119 case NFSD_SET:
120 nfsd_versions[vers] = nfsd_version[vers];
6658d3a7
N
121#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
122 if (vers < NFSD_ACL_NRVERS)
1a8eff6d 123 nfsd_acl_versions[vers] = nfsd_acl_version[vers];
6658d3a7 124#endif
1a8eff6d 125 break;
6658d3a7
N
126 case NFSD_CLEAR:
127 nfsd_versions[vers] = NULL;
128#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
129 if (vers < NFSD_ACL_NRVERS)
1a8eff6d 130 nfsd_acl_versions[vers] = NULL;
6658d3a7
N
131#endif
132 break;
133 case NFSD_TEST:
134 return nfsd_versions[vers] != NULL;
135 case NFSD_AVAIL:
136 return nfsd_version[vers] != NULL;
137 }
138 return 0;
139}
1da177e4
LT
140/*
141 * Maximum number of nfsd processes
142 */
143#define NFSD_MAXSERVS 8192
144
145int nfsd_nrthreads(void)
146{
147 if (nfsd_serv == NULL)
148 return 0;
149 else
150 return nfsd_serv->sv_nrthreads;
151}
152
bc591ccf
N
153static int killsig; /* signal that was used to kill last nfsd */
154static void nfsd_last_thread(struct svc_serv *serv)
155{
156 /* When last nfsd thread exits we need to do some clean-up */
24e36663
N
157 struct svc_sock *svsk;
158 list_for_each_entry(svsk, &serv->sv_permsocks, sk_list)
159 lockd_down();
bc591ccf
N
160 nfsd_serv = NULL;
161 nfsd_racache_shutdown();
162 nfs4_state_shutdown();
163
164 printk(KERN_WARNING "nfsd: last server has exited\n");
165 if (killsig != SIG_NOCLEAN) {
166 printk(KERN_WARNING "nfsd: unexporting all filesystems\n");
167 nfsd_export_flush();
168 }
169}
6658d3a7
N
170
171void nfsd_reset_versions(void)
172{
173 int found_one = 0;
174 int i;
175
176 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) {
177 if (nfsd_program.pg_vers[i])
178 found_one = 1;
179 }
180
181 if (!found_one) {
182 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++)
183 nfsd_program.pg_vers[i] = nfsd_version[i];
184#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
185 for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++)
186 nfsd_acl_program.pg_vers[i] =
187 nfsd_acl_version[i];
188#endif
189 }
190}
191
b41b66d6 192int nfsd_create_serv(void)
02a375f0
N
193{
194 int err = 0;
195 lock_kernel();
196 if (nfsd_serv) {
9a24ab57 197 svc_get(nfsd_serv);
02a375f0
N
198 unlock_kernel();
199 return 0;
200 }
596bbe53
N
201 if (nfsd_max_blksize == 0) {
202 /* choose a suitable default */
203 struct sysinfo i;
204 si_meminfo(&i);
205 /* Aim for 1/4096 of memory per thread
206 * This gives 1MB on 4Gig machines
207 * But only uses 32K on 128M machines.
208 * Bottom out at 8K on 32M and smaller.
209 * Of course, this is only a default.
210 */
211 nfsd_max_blksize = NFSSVC_MAXBLKSIZE;
44c55600 212 i.totalram <<= PAGE_SHIFT - 12;
596bbe53
N
213 while (nfsd_max_blksize > i.totalram &&
214 nfsd_max_blksize >= 8*1024*2)
215 nfsd_max_blksize /= 2;
216 }
02a375f0
N
217
218 atomic_set(&nfsd_busy, 0);
596bbe53 219 nfsd_serv = svc_create_pooled(&nfsd_program,
c6b0a9f8 220 nfsd_max_blksize,
eec09661
GB
221 nfsd_last_thread,
222 nfsd, SIG_NOCLEAN, THIS_MODULE);
02a375f0
N
223 if (nfsd_serv == NULL)
224 err = -ENOMEM;
02a375f0
N
225 unlock_kernel();
226 do_gettimeofday(&nfssvc_boot); /* record boot time */
227 return err;
228}
229
230static int nfsd_init_socks(int port)
231{
232 int error;
233 if (!list_empty(&nfsd_serv->sv_permsocks))
234 return 0;
235
02a375f0 236 error = lockd_up(IPPROTO_UDP);
4a3ae42d 237 if (error >= 0) {
482fb94e
CL
238 error = svc_makesock(nfsd_serv, IPPROTO_UDP, port,
239 SVC_SOCK_DEFAULTS);
4a3ae42d
N
240 if (error < 0)
241 lockd_down();
242 }
02a375f0
N
243 if (error < 0)
244 return error;
245
246#ifdef CONFIG_NFSD_TCP
02a375f0 247 error = lockd_up(IPPROTO_TCP);
4a3ae42d 248 if (error >= 0) {
482fb94e
CL
249 error = svc_makesock(nfsd_serv, IPPROTO_TCP, port,
250 SVC_SOCK_DEFAULTS);
4a3ae42d
N
251 if (error < 0)
252 lockd_down();
253 }
02a375f0
N
254 if (error < 0)
255 return error;
256#endif
257 return 0;
258}
259
eed2965a
GB
260int nfsd_nrpools(void)
261{
262 if (nfsd_serv == NULL)
263 return 0;
264 else
265 return nfsd_serv->sv_nrpools;
266}
267
268int nfsd_get_nrthreads(int n, int *nthreads)
269{
270 int i = 0;
271
272 if (nfsd_serv != NULL) {
273 for (i = 0; i < nfsd_serv->sv_nrpools && i < n; i++)
274 nthreads[i] = nfsd_serv->sv_pools[i].sp_nrthreads;
275 }
276
277 return 0;
278}
279
280int nfsd_set_nrthreads(int n, int *nthreads)
281{
282 int i = 0;
283 int tot = 0;
284 int err = 0;
285
286 if (nfsd_serv == NULL || n <= 0)
287 return 0;
288
289 if (n > nfsd_serv->sv_nrpools)
290 n = nfsd_serv->sv_nrpools;
291
292 /* enforce a global maximum number of threads */
293 tot = 0;
294 for (i = 0; i < n; i++) {
295 if (nthreads[i] > NFSD_MAXSERVS)
296 nthreads[i] = NFSD_MAXSERVS;
297 tot += nthreads[i];
298 }
299 if (tot > NFSD_MAXSERVS) {
300 /* total too large: scale down requested numbers */
301 for (i = 0; i < n && tot > 0; i++) {
302 int new = nthreads[i] * NFSD_MAXSERVS / tot;
303 tot -= (nthreads[i] - new);
304 nthreads[i] = new;
305 }
306 for (i = 0; i < n && tot > 0; i++) {
307 nthreads[i]--;
308 tot--;
309 }
310 }
311
312 /*
313 * There must always be a thread in pool 0; the admin
314 * can't shut down NFS completely using pool_threads.
315 */
316 if (nthreads[0] == 0)
317 nthreads[0] = 1;
318
319 /* apply the new numbers */
320 lock_kernel();
321 svc_get(nfsd_serv);
322 for (i = 0; i < n; i++) {
323 err = svc_set_num_threads(nfsd_serv, &nfsd_serv->sv_pools[i],
324 nthreads[i]);
325 if (err)
326 break;
327 }
328 svc_destroy(nfsd_serv);
329 unlock_kernel();
330
331 return err;
332}
333
1da177e4
LT
334int
335nfsd_svc(unsigned short port, int nrservs)
336{
337 int error;
1da177e4
LT
338
339 lock_kernel();
6658d3a7 340 dprintk("nfsd: creating service\n");
1da177e4
LT
341 error = -EINVAL;
342 if (nrservs <= 0)
343 nrservs = 0;
344 if (nrservs > NFSD_MAXSERVS)
345 nrservs = NFSD_MAXSERVS;
346
347 /* Readahead param cache - will no-op if it already exists */
348 error = nfsd_racache_init(2*nrservs);
349 if (error<0)
350 goto out;
76a3550e 351 error = nfs4_state_start();
1da177e4
LT
352 if (error<0)
353 goto out;
02a375f0
N
354
355 nfsd_reset_versions();
356
357 error = nfsd_create_serv();
358
359 if (error)
360 goto out;
361 error = nfsd_init_socks(port);
362 if (error)
363 goto failure;
364
eec09661 365 error = svc_set_num_threads(nfsd_serv, NULL, nrservs);
1da177e4 366 failure:
1da177e4 367 svc_destroy(nfsd_serv); /* Release server */
1da177e4
LT
368 out:
369 unlock_kernel();
370 return error;
371}
372
373static inline void
374update_thread_usage(int busy_threads)
375{
376 unsigned long prev_call;
377 unsigned long diff;
378 int decile;
379
380 spin_lock(&nfsd_call_lock);
381 prev_call = nfsd_last_call;
382 nfsd_last_call = jiffies;
383 decile = busy_threads*10/nfsdstats.th_cnt;
384 if (decile>0 && decile <= 10) {
385 diff = nfsd_last_call - prev_call;
386 if ( (nfsdstats.th_usage[decile-1] += diff) >= NFSD_USAGE_WRAP)
387 nfsdstats.th_usage[decile-1] -= NFSD_USAGE_WRAP;
388 if (decile == 10)
389 nfsdstats.th_fullcnt++;
390 }
391 spin_unlock(&nfsd_call_lock);
392}
393
394/*
395 * This is the NFS server kernel thread
396 */
397static void
398nfsd(struct svc_rqst *rqstp)
399{
1da177e4
LT
400 struct fs_struct *fsp;
401 int err;
1da177e4
LT
402 sigset_t shutdown_mask, allowed_mask;
403
404 /* Lock module and set up kernel thread */
405 lock_kernel();
406 daemonize("nfsd");
407
408 /* After daemonize() this kernel thread shares current->fs
409 * with the init process. We need to create files with a
410 * umask of 0 instead of init's umask. */
411 fsp = copy_fs_struct(current->fs);
412 if (!fsp) {
413 printk("Unable to start nfsd thread: out of memory\n");
414 goto out;
415 }
416 exit_fs(current);
417 current->fs = fsp;
418 current->fs->umask = 0;
419
420 siginitsetinv(&shutdown_mask, SHUTDOWN_SIGS);
421 siginitsetinv(&allowed_mask, ALLOWED_SIGS);
422
423 nfsdstats.th_cnt++;
424
eec09661 425 rqstp->rq_task = current;
1da177e4
LT
426
427 unlock_kernel();
428
429 /*
430 * We want less throttling in balance_dirty_pages() so that nfs to
431 * localhost doesn't cause nfsd to lock up due to all the client's
432 * dirty pages.
433 */
434 current->flags |= PF_LESS_THROTTLE;
435
436 /*
437 * The main request loop
438 */
439 for (;;) {
440 /* Block all but the shutdown signals */
441 sigprocmask(SIG_SETMASK, &shutdown_mask, NULL);
442
443 /*
444 * Find a socket with data available and call its
445 * recvfrom routine.
446 */
6fb2b47f 447 while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN)
1da177e4
LT
448 ;
449 if (err < 0)
450 break;
451 update_thread_usage(atomic_read(&nfsd_busy));
452 atomic_inc(&nfsd_busy);
453
454 /* Lock the export hash tables for reading. */
455 exp_readlock();
456
457 /* Process request with signals blocked. */
458 sigprocmask(SIG_SETMASK, &allowed_mask, NULL);
459
6fb2b47f 460 svc_process(rqstp);
1da177e4
LT
461
462 /* Unlock export hash tables */
463 exp_readunlock();
464 update_thread_usage(atomic_read(&nfsd_busy));
465 atomic_dec(&nfsd_busy);
466 }
467
468 if (err != -EINTR) {
469 printk(KERN_WARNING "nfsd: terminating on error %d\n", -err);
470 } else {
471 unsigned int signo;
472
473 for (signo = 1; signo <= _NSIG; signo++)
474 if (sigismember(&current->pending.signal, signo) &&
475 !sigismember(&current->blocked, signo))
476 break;
bc591ccf 477 killsig = signo;
1da177e4 478 }
24e36663 479 /* Clear signals before calling svc_exit_thread() */
9e416052 480 flush_signals(current);
1da177e4
LT
481
482 lock_kernel();
483
1da177e4
LT
484 nfsdstats.th_cnt --;
485
486out:
487 /* Release the thread */
488 svc_exit_thread(rqstp);
489
490 /* Release module */
c4f92dba 491 unlock_kernel();
1da177e4
LT
492 module_put_and_exit(0);
493}
494
495int
c7afef1f 496nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
1da177e4
LT
497{
498 struct svc_procedure *proc;
499 kxdrproc_t xdr;
ad451d38
AV
500 __be32 nfserr;
501 __be32 *nfserrp;
1da177e4
LT
502
503 dprintk("nfsd_dispatch: vers %d proc %d\n",
504 rqstp->rq_vers, rqstp->rq_proc);
505 proc = rqstp->rq_procinfo;
506
507 /* Check whether we have this call in the cache. */
508 switch (nfsd_cache_lookup(rqstp, proc->pc_cachetype)) {
509 case RC_INTR:
510 case RC_DROPIT:
511 return 0;
512 case RC_REPLY:
513 return 1;
514 case RC_DOIT:;
515 /* do it */
516 }
517
518 /* Decode arguments */
519 xdr = proc->pc_decode;
ad451d38 520 if (xdr && !xdr(rqstp, (__be32*)rqstp->rq_arg.head[0].iov_base,
1da177e4
LT
521 rqstp->rq_argp)) {
522 dprintk("nfsd: failed to decode arguments!\n");
523 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
524 *statp = rpc_garbage_args;
525 return 1;
526 }
527
528 /* need to grab the location to store the status, as
529 * nfsv4 does some encoding while processing
530 */
531 nfserrp = rqstp->rq_res.head[0].iov_base
532 + rqstp->rq_res.head[0].iov_len;
ad451d38 533 rqstp->rq_res.head[0].iov_len += sizeof(__be32);
1da177e4
LT
534
535 /* Now call the procedure handler, and encode NFS status. */
536 nfserr = proc->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
537 if (nfserr == nfserr_jukebox && rqstp->rq_vers == 2)
538 nfserr = nfserr_dropit;
539 if (nfserr == nfserr_dropit) {
540 dprintk("nfsd: Dropping request due to malloc failure!\n");
541 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
542 return 0;
543 }
544
545 if (rqstp->rq_proc != 0)
546 *nfserrp++ = nfserr;
547
548 /* Encode result.
549 * For NFSv2, additional info is never returned in case of an error.
550 */
551 if (!(nfserr && rqstp->rq_vers == 2)) {
552 xdr = proc->pc_encode;
553 if (xdr && !xdr(rqstp, nfserrp,
554 rqstp->rq_resp)) {
555 /* Failed to encode result. Release cache entry */
556 dprintk("nfsd: failed to encode result!\n");
557 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
558 *statp = rpc_system_err;
559 return 1;
560 }
561 }
562
563 /* Store reply in cache. */
564 nfsd_cache_update(rqstp, proc->pc_cachetype, statp + 1);
565 return 1;
566}