[PATCH] nfsd: sign conversion obscuring errors in nfsd_set_posix_acl()
[linux-2.6] / fs / nfsd / nfssvc.c
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
11 #include <linux/config.h>
12 #include <linux/module.h>
13
14 #include <linux/time.h>
15 #include <linux/errno.h>
16 #include <linux/nfs.h>
17 #include <linux/in.h>
18 #include <linux/uio.h>
19 #include <linux/unistd.h>
20 #include <linux/slab.h>
21 #include <linux/smp.h>
22 #include <linux/smp_lock.h>
23 #include <linux/fs_struct.h>
24
25 #include <linux/sunrpc/types.h>
26 #include <linux/sunrpc/stats.h>
27 #include <linux/sunrpc/svc.h>
28 #include <linux/sunrpc/svcsock.h>
29 #include <linux/sunrpc/cache.h>
30 #include <linux/nfsd/nfsd.h>
31 #include <linux/nfsd/stats.h>
32 #include <linux/nfsd/cache.h>
33 #include <linux/nfsd/syscall.h>
34 #include <linux/lockd/bind.h>
35 #include <linux/nfsacl.h>
36
37 #define NFSDDBG_FACILITY        NFSDDBG_SVC
38
39 /* these signals will be delivered to an nfsd thread 
40  * when handling a request
41  */
42 #define ALLOWED_SIGS    (sigmask(SIGKILL))
43 /* these signals will be delivered to an nfsd thread
44  * when not handling a request. i.e. when waiting
45  */
46 #define SHUTDOWN_SIGS   (sigmask(SIGKILL) | sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT))
47 /* if the last thread dies with SIGHUP, then the exports table is
48  * left unchanged ( like 2.4-{0-9} ).  Any other signal will clear
49  * the exports table (like 2.2).
50  */
51 #define SIG_NOCLEAN     SIGHUP
52
53 extern struct svc_program       nfsd_program;
54 static void                     nfsd(struct svc_rqst *rqstp);
55 struct timeval                  nfssvc_boot;
56        struct svc_serv          *nfsd_serv;
57 static atomic_t                 nfsd_busy;
58 static unsigned long            nfsd_last_call;
59 static DEFINE_SPINLOCK(nfsd_call_lock);
60
61 struct nfsd_list {
62         struct list_head        list;
63         struct task_struct      *task;
64 };
65 static struct list_head nfsd_list = LIST_HEAD_INIT(nfsd_list);
66
67 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
68 static struct svc_stat  nfsd_acl_svcstats;
69 static 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)
76 static struct svc_version *nfsd_acl_versions[NFSD_ACL_NRVERS];
77
78 static 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                = "nfsd",
83         .pg_class               = "nfsd",
84         .pg_stats               = &nfsd_acl_svcstats,
85         .pg_authenticate        = &svc_set_client,
86 };
87
88 static 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
93 static 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)
105 static struct svc_version *nfsd_versions[NFSD_NRVERS];
106
107 struct 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
121 /*
122  * Maximum number of nfsd processes
123  */
124 #define NFSD_MAXSERVS           8192
125
126 int nfsd_nrthreads(void)
127 {
128         if (nfsd_serv == NULL)
129                 return 0;
130         else
131                 return nfsd_serv->sv_nrthreads;
132 }
133
134 int
135 nfsd_svc(unsigned short port, int nrservs)
136 {
137         int     error;
138         int     none_left, found_one, i;
139         struct list_head *victim;
140         
141         lock_kernel();
142         dprintk("nfsd: creating service: vers 0x%x\n",
143                 nfsd_versbits);
144         error = -EINVAL;
145         if (nrservs <= 0)
146                 nrservs = 0;
147         if (nrservs > NFSD_MAXSERVS)
148                 nrservs = NFSD_MAXSERVS;
149         
150         /* Readahead param cache - will no-op if it already exists */
151         error = nfsd_racache_init(2*nrservs);
152         if (error<0)
153                 goto out;
154         error = nfs4_state_start();
155         if (error<0)
156                 goto out;
157         if (!nfsd_serv) {
158                 /*
159                  * Use the nfsd_ctlbits to define which
160                  * versions that will be advertised.
161                  * If nfsd_ctlbits doesn't list any version,
162                  * export them all.
163                  */
164                 found_one = 0;
165
166                 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) {
167                         if (NFSCTL_VERISSET(nfsd_versbits, i)) {
168                                 nfsd_program.pg_vers[i] = nfsd_version[i];
169                                 found_one = 1;
170                         } else
171                                 nfsd_program.pg_vers[i] = NULL;
172                 }
173
174                 if (!found_one) {
175                         for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++)
176                                 nfsd_program.pg_vers[i] = nfsd_version[i];
177                 }
178
179
180 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
181                 found_one = 0;
182
183                 for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) {
184                         if (NFSCTL_VERISSET(nfsd_versbits, i)) {
185                                 nfsd_acl_program.pg_vers[i] =
186                                         nfsd_acl_version[i];
187                                 found_one = 1;
188                         } else
189                                 nfsd_acl_program.pg_vers[i] = NULL;
190                 }
191
192                 if (!found_one) {
193                         for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++)
194                                 nfsd_acl_program.pg_vers[i] =
195                                         nfsd_acl_version[i];
196                 }
197 #endif
198
199                 atomic_set(&nfsd_busy, 0);
200                 error = -ENOMEM;
201                 nfsd_serv = svc_create(&nfsd_program, NFSD_BUFSIZE);
202                 if (nfsd_serv == NULL)
203                         goto out;
204                 error = svc_makesock(nfsd_serv, IPPROTO_UDP, port);
205                 if (error < 0)
206                         goto failure;
207
208 #ifdef CONFIG_NFSD_TCP
209                 error = svc_makesock(nfsd_serv, IPPROTO_TCP, port);
210                 if (error < 0)
211                         goto failure;
212 #endif
213                 do_gettimeofday(&nfssvc_boot);          /* record boot time */
214         } else
215                 nfsd_serv->sv_nrthreads++;
216         nrservs -= (nfsd_serv->sv_nrthreads-1);
217         while (nrservs > 0) {
218                 nrservs--;
219                 __module_get(THIS_MODULE);
220                 error = svc_create_thread(nfsd, nfsd_serv);
221                 if (error < 0) {
222                         module_put(THIS_MODULE);
223                         break;
224                 }
225         }
226         victim = nfsd_list.next;
227         while (nrservs < 0 && victim != &nfsd_list) {
228                 struct nfsd_list *nl =
229                         list_entry(victim,struct nfsd_list, list);
230                 victim = victim->next;
231                 send_sig(SIG_NOCLEAN, nl->task, 1);
232                 nrservs++;
233         }
234  failure:
235         none_left = (nfsd_serv->sv_nrthreads == 1);
236         svc_destroy(nfsd_serv);         /* Release server */
237         if (none_left) {
238                 nfsd_serv = NULL;
239                 nfsd_racache_shutdown();
240                 nfs4_state_shutdown();
241         }
242  out:
243         unlock_kernel();
244         return error;
245 }
246
247 static inline void
248 update_thread_usage(int busy_threads)
249 {
250         unsigned long prev_call;
251         unsigned long diff;
252         int decile;
253
254         spin_lock(&nfsd_call_lock);
255         prev_call = nfsd_last_call;
256         nfsd_last_call = jiffies;
257         decile = busy_threads*10/nfsdstats.th_cnt;
258         if (decile>0 && decile <= 10) {
259                 diff = nfsd_last_call - prev_call;
260                 if ( (nfsdstats.th_usage[decile-1] += diff) >= NFSD_USAGE_WRAP)
261                         nfsdstats.th_usage[decile-1] -= NFSD_USAGE_WRAP;
262                 if (decile == 10)
263                         nfsdstats.th_fullcnt++;
264         }
265         spin_unlock(&nfsd_call_lock);
266 }
267
268 /*
269  * This is the NFS server kernel thread
270  */
271 static void
272 nfsd(struct svc_rqst *rqstp)
273 {
274         struct svc_serv *serv = rqstp->rq_server;
275         struct fs_struct *fsp;
276         int             err;
277         struct nfsd_list me;
278         sigset_t shutdown_mask, allowed_mask;
279
280         /* Lock module and set up kernel thread */
281         lock_kernel();
282         daemonize("nfsd");
283
284         /* After daemonize() this kernel thread shares current->fs
285          * with the init process. We need to create files with a
286          * umask of 0 instead of init's umask. */
287         fsp = copy_fs_struct(current->fs);
288         if (!fsp) {
289                 printk("Unable to start nfsd thread: out of memory\n");
290                 goto out;
291         }
292         exit_fs(current);
293         current->fs = fsp;
294         current->fs->umask = 0;
295
296         siginitsetinv(&shutdown_mask, SHUTDOWN_SIGS);
297         siginitsetinv(&allowed_mask, ALLOWED_SIGS);
298
299         nfsdstats.th_cnt++;
300
301         lockd_up();                             /* start lockd */
302
303         me.task = current;
304         list_add(&me.list, &nfsd_list);
305
306         unlock_kernel();
307
308         /*
309          * We want less throttling in balance_dirty_pages() so that nfs to
310          * localhost doesn't cause nfsd to lock up due to all the client's
311          * dirty pages.
312          */
313         current->flags |= PF_LESS_THROTTLE;
314
315         /*
316          * The main request loop
317          */
318         for (;;) {
319                 /* Block all but the shutdown signals */
320                 sigprocmask(SIG_SETMASK, &shutdown_mask, NULL);
321
322                 /*
323                  * Find a socket with data available and call its
324                  * recvfrom routine.
325                  */
326                 while ((err = svc_recv(serv, rqstp,
327                                        60*60*HZ)) == -EAGAIN)
328                         ;
329                 if (err < 0)
330                         break;
331                 update_thread_usage(atomic_read(&nfsd_busy));
332                 atomic_inc(&nfsd_busy);
333
334                 /* Lock the export hash tables for reading. */
335                 exp_readlock();
336
337                 /* Process request with signals blocked.  */
338                 sigprocmask(SIG_SETMASK, &allowed_mask, NULL);
339
340                 svc_process(serv, rqstp);
341
342                 /* Unlock export hash tables */
343                 exp_readunlock();
344                 update_thread_usage(atomic_read(&nfsd_busy));
345                 atomic_dec(&nfsd_busy);
346         }
347
348         if (err != -EINTR) {
349                 printk(KERN_WARNING "nfsd: terminating on error %d\n", -err);
350         } else {
351                 unsigned int    signo;
352
353                 for (signo = 1; signo <= _NSIG; signo++)
354                         if (sigismember(&current->pending.signal, signo) &&
355                             !sigismember(&current->blocked, signo))
356                                 break;
357                 err = signo;
358         }
359         /* Clear signals before calling lockd_down() and svc_exit_thread() */
360         flush_signals(current);
361
362         lock_kernel();
363
364         /* Release lockd */
365         lockd_down();
366
367         /* Check if this is last thread */
368         if (serv->sv_nrthreads==1) {
369                 
370                 printk(KERN_WARNING "nfsd: last server has exited\n");
371                 if (err != SIG_NOCLEAN) {
372                         printk(KERN_WARNING "nfsd: unexporting all filesystems\n");
373                         nfsd_export_flush();
374                 }
375                 nfsd_serv = NULL;
376                 nfsd_racache_shutdown();        /* release read-ahead cache */
377                 nfs4_state_shutdown();
378         }
379         list_del(&me.list);
380         nfsdstats.th_cnt --;
381
382 out:
383         /* Release the thread */
384         svc_exit_thread(rqstp);
385
386         /* Release module */
387         unlock_kernel();
388         module_put_and_exit(0);
389 }
390
391 int
392 nfsd_dispatch(struct svc_rqst *rqstp, u32 *statp)
393 {
394         struct svc_procedure    *proc;
395         kxdrproc_t              xdr;
396         u32                     nfserr;
397         u32                     *nfserrp;
398
399         dprintk("nfsd_dispatch: vers %d proc %d\n",
400                                 rqstp->rq_vers, rqstp->rq_proc);
401         proc = rqstp->rq_procinfo;
402
403         /* Check whether we have this call in the cache. */
404         switch (nfsd_cache_lookup(rqstp, proc->pc_cachetype)) {
405         case RC_INTR:
406         case RC_DROPIT:
407                 return 0;
408         case RC_REPLY:
409                 return 1;
410         case RC_DOIT:;
411                 /* do it */
412         }
413
414         /* Decode arguments */
415         xdr = proc->pc_decode;
416         if (xdr && !xdr(rqstp, (u32*)rqstp->rq_arg.head[0].iov_base,
417                         rqstp->rq_argp)) {
418                 dprintk("nfsd: failed to decode arguments!\n");
419                 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
420                 *statp = rpc_garbage_args;
421                 return 1;
422         }
423
424         /* need to grab the location to store the status, as
425          * nfsv4 does some encoding while processing 
426          */
427         nfserrp = rqstp->rq_res.head[0].iov_base
428                 + rqstp->rq_res.head[0].iov_len;
429         rqstp->rq_res.head[0].iov_len += sizeof(u32);
430
431         /* Now call the procedure handler, and encode NFS status. */
432         nfserr = proc->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
433         if (nfserr == nfserr_jukebox && rqstp->rq_vers == 2)
434                 nfserr = nfserr_dropit;
435         if (nfserr == nfserr_dropit) {
436                 dprintk("nfsd: Dropping request due to malloc failure!\n");
437                 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
438                 return 0;
439         }
440
441         if (rqstp->rq_proc != 0)
442                 *nfserrp++ = nfserr;
443
444         /* Encode result.
445          * For NFSv2, additional info is never returned in case of an error.
446          */
447         if (!(nfserr && rqstp->rq_vers == 2)) {
448                 xdr = proc->pc_encode;
449                 if (xdr && !xdr(rqstp, nfserrp,
450                                 rqstp->rq_resp)) {
451                         /* Failed to encode result. Release cache entry */
452                         dprintk("nfsd: failed to encode result!\n");
453                         nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
454                         *statp = rpc_system_err;
455                         return 1;
456                 }
457         }
458
459         /* Store reply in cache. */
460         nfsd_cache_update(rqstp, proc->pc_cachetype, statp + 1);
461         return 1;
462 }