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-rw-r--r--fs/nfsd/nfssvc.c385
1 files changed, 385 insertions, 0 deletions
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
new file mode 100644
index 000000000000..39551657e656
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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/lockd/bind.h>
34
35#define NFSDDBG_FACILITY NFSDDBG_SVC
36
37/* these signals will be delivered to an nfsd thread
38 * when handling a request
39 */
40#define ALLOWED_SIGS (sigmask(SIGKILL))
41/* these signals will be delivered to an nfsd thread
42 * when not handling a request. i.e. when waiting
43 */
44#define SHUTDOWN_SIGS (sigmask(SIGKILL) | sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT))
45/* if the last thread dies with SIGHUP, then the exports table is
46 * left unchanged ( like 2.4-{0-9} ). Any other signal will clear
47 * the exports table (like 2.2).
48 */
49#define SIG_NOCLEAN SIGHUP
50
51extern struct svc_program nfsd_program;
52static void nfsd(struct svc_rqst *rqstp);
53struct timeval nfssvc_boot;
54static struct svc_serv *nfsd_serv;
55static atomic_t nfsd_busy;
56static unsigned long nfsd_last_call;
57static DEFINE_SPINLOCK(nfsd_call_lock);
58
59struct nfsd_list {
60 struct list_head list;
61 struct task_struct *task;
62};
63static struct list_head nfsd_list = LIST_HEAD_INIT(nfsd_list);
64
65/*
66 * Maximum number of nfsd processes
67 */
68#define NFSD_MAXSERVS 8192
69
70int nfsd_nrthreads(void)
71{
72 if (nfsd_serv == NULL)
73 return 0;
74 else
75 return nfsd_serv->sv_nrthreads;
76}
77
78int
79nfsd_svc(unsigned short port, int nrservs)
80{
81 int error;
82 int none_left;
83 struct list_head *victim;
84
85 lock_kernel();
86 dprintk("nfsd: creating service\n");
87 error = -EINVAL;
88 if (nrservs <= 0)
89 nrservs = 0;
90 if (nrservs > NFSD_MAXSERVS)
91 nrservs = NFSD_MAXSERVS;
92
93 /* Readahead param cache - will no-op if it already exists */
94 error = nfsd_racache_init(2*nrservs);
95 if (error<0)
96 goto out;
97 error = nfs4_state_init();
98 if (error<0)
99 goto out;
100 if (!nfsd_serv) {
101 atomic_set(&nfsd_busy, 0);
102 error = -ENOMEM;
103 nfsd_serv = svc_create(&nfsd_program, NFSD_BUFSIZE);
104 if (nfsd_serv == NULL)
105 goto out;
106 error = svc_makesock(nfsd_serv, IPPROTO_UDP, port);
107 if (error < 0)
108 goto failure;
109
110#ifdef CONFIG_NFSD_TCP
111 error = svc_makesock(nfsd_serv, IPPROTO_TCP, port);
112 if (error < 0)
113 goto failure;
114#endif
115 do_gettimeofday(&nfssvc_boot); /* record boot time */
116 } else
117 nfsd_serv->sv_nrthreads++;
118 nrservs -= (nfsd_serv->sv_nrthreads-1);
119 while (nrservs > 0) {
120 nrservs--;
121 __module_get(THIS_MODULE);
122 error = svc_create_thread(nfsd, nfsd_serv);
123 if (error < 0) {
124 module_put(THIS_MODULE);
125 break;
126 }
127 }
128 victim = nfsd_list.next;
129 while (nrservs < 0 && victim != &nfsd_list) {
130 struct nfsd_list *nl =
131 list_entry(victim,struct nfsd_list, list);
132 victim = victim->next;
133 send_sig(SIG_NOCLEAN, nl->task, 1);
134 nrservs++;
135 }
136 failure:
137 none_left = (nfsd_serv->sv_nrthreads == 1);
138 svc_destroy(nfsd_serv); /* Release server */
139 if (none_left) {
140 nfsd_serv = NULL;
141 nfsd_racache_shutdown();
142 nfs4_state_shutdown();
143 }
144 out:
145 unlock_kernel();
146 return error;
147}
148
149static inline void
150update_thread_usage(int busy_threads)
151{
152 unsigned long prev_call;
153 unsigned long diff;
154 int decile;
155
156 spin_lock(&nfsd_call_lock);
157 prev_call = nfsd_last_call;
158 nfsd_last_call = jiffies;
159 decile = busy_threads*10/nfsdstats.th_cnt;
160 if (decile>0 && decile <= 10) {
161 diff = nfsd_last_call - prev_call;
162 if ( (nfsdstats.th_usage[decile-1] += diff) >= NFSD_USAGE_WRAP)
163 nfsdstats.th_usage[decile-1] -= NFSD_USAGE_WRAP;
164 if (decile == 10)
165 nfsdstats.th_fullcnt++;
166 }
167 spin_unlock(&nfsd_call_lock);
168}
169
170/*
171 * This is the NFS server kernel thread
172 */
173static void
174nfsd(struct svc_rqst *rqstp)
175{
176 struct svc_serv *serv = rqstp->rq_server;
177 struct fs_struct *fsp;
178 int err;
179 struct nfsd_list me;
180 sigset_t shutdown_mask, allowed_mask;
181
182 /* Lock module and set up kernel thread */
183 lock_kernel();
184 daemonize("nfsd");
185
186 /* After daemonize() this kernel thread shares current->fs
187 * with the init process. We need to create files with a
188 * umask of 0 instead of init's umask. */
189 fsp = copy_fs_struct(current->fs);
190 if (!fsp) {
191 printk("Unable to start nfsd thread: out of memory\n");
192 goto out;
193 }
194 exit_fs(current);
195 current->fs = fsp;
196 current->fs->umask = 0;
197
198 siginitsetinv(&shutdown_mask, SHUTDOWN_SIGS);
199 siginitsetinv(&allowed_mask, ALLOWED_SIGS);
200
201 nfsdstats.th_cnt++;
202
203 lockd_up(); /* start lockd */
204
205 me.task = current;
206 list_add(&me.list, &nfsd_list);
207
208 unlock_kernel();
209
210 /*
211 * We want less throttling in balance_dirty_pages() so that nfs to
212 * localhost doesn't cause nfsd to lock up due to all the client's
213 * dirty pages.
214 */
215 current->flags |= PF_LESS_THROTTLE;
216
217 /*
218 * The main request loop
219 */
220 for (;;) {
221 /* Block all but the shutdown signals */
222 sigprocmask(SIG_SETMASK, &shutdown_mask, NULL);
223
224 /*
225 * Find a socket with data available and call its
226 * recvfrom routine.
227 */
228 while ((err = svc_recv(serv, rqstp,
229 60*60*HZ)) == -EAGAIN)
230 ;
231 if (err < 0)
232 break;
233 update_thread_usage(atomic_read(&nfsd_busy));
234 atomic_inc(&nfsd_busy);
235
236 /* Lock the export hash tables for reading. */
237 exp_readlock();
238
239 /* Process request with signals blocked. */
240 sigprocmask(SIG_SETMASK, &allowed_mask, NULL);
241
242 svc_process(serv, rqstp);
243
244 /* Unlock export hash tables */
245 exp_readunlock();
246 update_thread_usage(atomic_read(&nfsd_busy));
247 atomic_dec(&nfsd_busy);
248 }
249
250 if (err != -EINTR) {
251 printk(KERN_WARNING "nfsd: terminating on error %d\n", -err);
252 } else {
253 unsigned int signo;
254
255 for (signo = 1; signo <= _NSIG; signo++)
256 if (sigismember(&current->pending.signal, signo) &&
257 !sigismember(&current->blocked, signo))
258 break;
259 err = signo;
260 }
261
262 lock_kernel();
263
264 /* Release lockd */
265 lockd_down();
266
267 /* Check if this is last thread */
268 if (serv->sv_nrthreads==1) {
269
270 printk(KERN_WARNING "nfsd: last server has exited\n");
271 if (err != SIG_NOCLEAN) {
272 printk(KERN_WARNING "nfsd: unexporting all filesystems\n");
273 nfsd_export_flush();
274 }
275 nfsd_serv = NULL;
276 nfsd_racache_shutdown(); /* release read-ahead cache */
277 nfs4_state_shutdown();
278 }
279 list_del(&me.list);
280 nfsdstats.th_cnt --;
281
282out:
283 /* Release the thread */
284 svc_exit_thread(rqstp);
285
286 /* Release module */
287 module_put_and_exit(0);
288}
289
290int
291nfsd_dispatch(struct svc_rqst *rqstp, u32 *statp)
292{
293 struct svc_procedure *proc;
294 kxdrproc_t xdr;
295 u32 nfserr;
296 u32 *nfserrp;
297
298 dprintk("nfsd_dispatch: vers %d proc %d\n",
299 rqstp->rq_vers, rqstp->rq_proc);
300 proc = rqstp->rq_procinfo;
301
302 /* Check whether we have this call in the cache. */
303 switch (nfsd_cache_lookup(rqstp, proc->pc_cachetype)) {
304 case RC_INTR:
305 case RC_DROPIT:
306 return 0;
307 case RC_REPLY:
308 return 1;
309 case RC_DOIT:;
310 /* do it */
311 }
312
313 /* Decode arguments */
314 xdr = proc->pc_decode;
315 if (xdr && !xdr(rqstp, (u32*)rqstp->rq_arg.head[0].iov_base,
316 rqstp->rq_argp)) {
317 dprintk("nfsd: failed to decode arguments!\n");
318 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
319 *statp = rpc_garbage_args;
320 return 1;
321 }
322
323 /* need to grab the location to store the status, as
324 * nfsv4 does some encoding while processing
325 */
326 nfserrp = rqstp->rq_res.head[0].iov_base
327 + rqstp->rq_res.head[0].iov_len;
328 rqstp->rq_res.head[0].iov_len += sizeof(u32);
329
330 /* Now call the procedure handler, and encode NFS status. */
331 nfserr = proc->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
332 if (nfserr == nfserr_jukebox && rqstp->rq_vers == 2)
333 nfserr = nfserr_dropit;
334 if (nfserr == nfserr_dropit) {
335 dprintk("nfsd: Dropping request due to malloc failure!\n");
336 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
337 return 0;
338 }
339
340 if (rqstp->rq_proc != 0)
341 *nfserrp++ = nfserr;
342
343 /* Encode result.
344 * For NFSv2, additional info is never returned in case of an error.
345 */
346 if (!(nfserr && rqstp->rq_vers == 2)) {
347 xdr = proc->pc_encode;
348 if (xdr && !xdr(rqstp, nfserrp,
349 rqstp->rq_resp)) {
350 /* Failed to encode result. Release cache entry */
351 dprintk("nfsd: failed to encode result!\n");
352 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
353 *statp = rpc_system_err;
354 return 1;
355 }
356 }
357
358 /* Store reply in cache. */
359 nfsd_cache_update(rqstp, proc->pc_cachetype, statp + 1);
360 return 1;
361}
362
363extern struct svc_version nfsd_version2, nfsd_version3, nfsd_version4;
364
365static struct svc_version * nfsd_version[] = {
366 [2] = &nfsd_version2,
367#if defined(CONFIG_NFSD_V3)
368 [3] = &nfsd_version3,
369#endif
370#if defined(CONFIG_NFSD_V4)
371 [4] = &nfsd_version4,
372#endif
373};
374
375#define NFSD_NRVERS (sizeof(nfsd_version)/sizeof(nfsd_version[0]))
376struct svc_program nfsd_program = {
377 .pg_prog = NFS_PROGRAM, /* program number */
378 .pg_nvers = NFSD_NRVERS, /* nr of entries in nfsd_version */
379 .pg_vers = nfsd_version, /* version table */
380 .pg_name = "nfsd", /* program name */
381 .pg_class = "nfsd", /* authentication class */
382 .pg_stats = &nfsd_svcstats, /* version table */
383 .pg_authenticate = &svc_set_client, /* export authentication */
384
385};
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-16 11:26:10 -0500