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 static struct svc_version * nfsd_version[] = { 68 [2] = &nfsd_version2, 69 #if defined(CONFIG_NFSD_V3) 70 [3] = &nfsd_version3, 71 #endif 72 #if defined(CONFIG_NFSD_V4) 73 [4] = &nfsd_version4, 74 #endif 75 }; 76 77 #define NFSD_MINVERS 2 78 #define NFSD_NRVERS (sizeof(nfsd_version)/sizeof(nfsd_version[0])) 79 static struct svc_version *nfsd_versions[NFSD_NRVERS]; 80 81 struct svc_program nfsd_program = { 82 .pg_prog = NFS_PROGRAM, /* program number */ 83 .pg_nvers = NFSD_NRVERS, /* nr of entries in nfsd_version */ 84 .pg_vers = nfsd_versions, /* version table */ 85 .pg_name = "nfsd", /* program name */ 86 .pg_class = "nfsd", /* authentication class */ 87 .pg_stats = &nfsd_svcstats, /* version table */ 88 .pg_authenticate = &svc_set_client, /* export authentication */ 89 90 }; 91 92 /* 93 * Maximum number of nfsd processes 94 */ 95 #define NFSD_MAXSERVS 8192 96 97 int nfsd_nrthreads(void) 98 { 99 if (nfsd_serv == NULL) 100 return 0; 101 else 102 return nfsd_serv->sv_nrthreads; 103 } 104 105 int 106 nfsd_svc(unsigned short port, int nrservs) 107 { 108 int error; 109 int none_left, found_one, i; 110 struct list_head *victim; 111 112 lock_kernel(); 113 dprintk("nfsd: creating service: vers 0x%x\n", 114 nfsd_versbits); 115 error = -EINVAL; 116 if (nrservs <= 0) 117 nrservs = 0; 118 if (nrservs > NFSD_MAXSERVS) 119 nrservs = NFSD_MAXSERVS; 120 121 /* Readahead param cache - will no-op if it already exists */ 122 error = nfsd_racache_init(2*nrservs); 123 if (error<0) 124 goto out; 125 error = nfs4_state_start(); 126 if (error<0) 127 goto out; 128 if (!nfsd_serv) { 129 /* 130 * Use the nfsd_ctlbits to define which 131 * versions that will be advertised. 132 * If nfsd_ctlbits doesn't list any version, 133 * export them all. 134 */ 135 found_one = 0; 136 137 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) { 138 if (NFSCTL_VERISSET(nfsd_versbits, i)) { 139 nfsd_program.pg_vers[i] = nfsd_version[i]; 140 found_one = 1; 141 } else 142 nfsd_program.pg_vers[i] = NULL; 143 } 144 145 if (!found_one) { 146 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) 147 nfsd_program.pg_vers[i] = nfsd_version[i]; 148 } 149 150 atomic_set(&nfsd_busy, 0); 151 error = -ENOMEM; 152 nfsd_serv = svc_create(&nfsd_program, NFSD_BUFSIZE); 153 if (nfsd_serv == NULL) 154 goto out; 155 error = svc_makesock(nfsd_serv, IPPROTO_UDP, port); 156 if (error < 0) 157 goto failure; 158 159 #ifdef CONFIG_NFSD_TCP 160 error = svc_makesock(nfsd_serv, IPPROTO_TCP, port); 161 if (error < 0) 162 goto failure; 163 #endif 164 do_gettimeofday(&nfssvc_boot); /* record boot time */ 165 } else 166 nfsd_serv->sv_nrthreads++; 167 nrservs -= (nfsd_serv->sv_nrthreads-1); 168 while (nrservs > 0) { 169 nrservs--; 170 __module_get(THIS_MODULE); 171 error = svc_create_thread(nfsd, nfsd_serv); 172 if (error < 0) { 173 module_put(THIS_MODULE); 174 break; 175 } 176 } 177 victim = nfsd_list.next; 178 while (nrservs < 0 && victim != &nfsd_list) { 179 struct nfsd_list *nl = 180 list_entry(victim,struct nfsd_list, list); 181 victim = victim->next; 182 send_sig(SIG_NOCLEAN, nl->task, 1); 183 nrservs++; 184 } 185 failure: 186 none_left = (nfsd_serv->sv_nrthreads == 1); 187 svc_destroy(nfsd_serv); /* Release server */ 188 if (none_left) { 189 nfsd_serv = NULL; 190 nfsd_racache_shutdown(); 191 nfs4_state_shutdown(); 192 } 193 out: 194 unlock_kernel(); 195 return error; 196 } 197 198 static inline void 199 update_thread_usage(int busy_threads) 200 { 201 unsigned long prev_call; 202 unsigned long diff; 203 int decile; 204 205 spin_lock(&nfsd_call_lock); 206 prev_call = nfsd_last_call; 207 nfsd_last_call = jiffies; 208 decile = busy_threads*10/nfsdstats.th_cnt; 209 if (decile>0 && decile <= 10) { 210 diff = nfsd_last_call - prev_call; 211 if ( (nfsdstats.th_usage[decile-1] += diff) >= NFSD_USAGE_WRAP) 212 nfsdstats.th_usage[decile-1] -= NFSD_USAGE_WRAP; 213 if (decile == 10) 214 nfsdstats.th_fullcnt++; 215 } 216 spin_unlock(&nfsd_call_lock); 217 } 218 219 /* 220 * This is the NFS server kernel thread 221 */ 222 static void 223 nfsd(struct svc_rqst *rqstp) 224 { 225 struct svc_serv *serv = rqstp->rq_server; 226 struct fs_struct *fsp; 227 int err; 228 struct nfsd_list me; 229 sigset_t shutdown_mask, allowed_mask; 230 231 /* Lock module and set up kernel thread */ 232 lock_kernel(); 233 daemonize("nfsd"); 234 235 /* After daemonize() this kernel thread shares current->fs 236 * with the init process. We need to create files with a 237 * umask of 0 instead of init's umask. */ 238 fsp = copy_fs_struct(current->fs); 239 if (!fsp) { 240 printk("Unable to start nfsd thread: out of memory\n"); 241 goto out; 242 } 243 exit_fs(current); 244 current->fs = fsp; 245 current->fs->umask = 0; 246 247 siginitsetinv(&shutdown_mask, SHUTDOWN_SIGS); 248 siginitsetinv(&allowed_mask, ALLOWED_SIGS); 249 250 nfsdstats.th_cnt++; 251 252 lockd_up(); /* start lockd */ 253 254 me.task = current; 255 list_add(&me.list, &nfsd_list); 256 257 unlock_kernel(); 258 259 /* 260 * We want less throttling in balance_dirty_pages() so that nfs to 261 * localhost doesn't cause nfsd to lock up due to all the client's 262 * dirty pages. 263 */ 264 current->flags |= PF_LESS_THROTTLE; 265 266 /* 267 * The main request loop 268 */ 269 for (;;) { 270 /* Block all but the shutdown signals */ 271 sigprocmask(SIG_SETMASK, &shutdown_mask, NULL); 272 273 /* 274 * Find a socket with data available and call its 275 * recvfrom routine. 276 */ 277 while ((err = svc_recv(serv, rqstp, 278 60*60*HZ)) == -EAGAIN) 279 ; 280 if (err < 0) 281 break; 282 update_thread_usage(atomic_read(&nfsd_busy)); 283 atomic_inc(&nfsd_busy); 284 285 /* Lock the export hash tables for reading. */ 286 exp_readlock(); 287 288 /* Process request with signals blocked. */ 289 sigprocmask(SIG_SETMASK, &allowed_mask, NULL); 290 291 svc_process(serv, rqstp); 292 293 /* Unlock export hash tables */ 294 exp_readunlock(); 295 update_thread_usage(atomic_read(&nfsd_busy)); 296 atomic_dec(&nfsd_busy); 297 } 298 299 if (err != -EINTR) { 300 printk(KERN_WARNING "nfsd: terminating on error %d\n", -err); 301 } else { 302 unsigned int signo; 303 304 for (signo = 1; signo <= _NSIG; signo++) 305 if (sigismember(¤t->pending.signal, signo) && 306 !sigismember(¤t->blocked, signo)) 307 break; 308 err = signo; 309 } 310 /* Clear signals before calling lockd_down() and svc_exit_thread() */ 311 flush_signals(current); 312 313 lock_kernel(); 314 315 /* Release lockd */ 316 lockd_down(); 317 318 /* Check if this is last thread */ 319 if (serv->sv_nrthreads==1) { 320 321 printk(KERN_WARNING "nfsd: last server has exited\n"); 322 if (err != SIG_NOCLEAN) { 323 printk(KERN_WARNING "nfsd: unexporting all filesystems\n"); 324 nfsd_export_flush(); 325 } 326 nfsd_serv = NULL; 327 nfsd_racache_shutdown(); /* release read-ahead cache */ 328 nfs4_state_shutdown(); 329 } 330 list_del(&me.list); 331 nfsdstats.th_cnt --; 332 333 out: 334 /* Release the thread */ 335 svc_exit_thread(rqstp); 336 337 /* Release module */ 338 unlock_kernel(); 339 module_put_and_exit(0); 340 } 341 342 int 343 nfsd_dispatch(struct svc_rqst *rqstp, u32 *statp) 344 { 345 struct svc_procedure *proc; 346 kxdrproc_t xdr; 347 u32 nfserr; 348 u32 *nfserrp; 349 350 dprintk("nfsd_dispatch: vers %d proc %d\n", 351 rqstp->rq_vers, rqstp->rq_proc); 352 proc = rqstp->rq_procinfo; 353 354 /* Check whether we have this call in the cache. */ 355 switch (nfsd_cache_lookup(rqstp, proc->pc_cachetype)) { 356 case RC_INTR: 357 case RC_DROPIT: 358 return 0; 359 case RC_REPLY: 360 return 1; 361 case RC_DOIT:; 362 /* do it */ 363 } 364 365 /* Decode arguments */ 366 xdr = proc->pc_decode; 367 if (xdr && !xdr(rqstp, (u32*)rqstp->rq_arg.head[0].iov_base, 368 rqstp->rq_argp)) { 369 dprintk("nfsd: failed to decode arguments!\n"); 370 nfsd_cache_update(rqstp, RC_NOCACHE, NULL); 371 *statp = rpc_garbage_args; 372 return 1; 373 } 374 375 /* need to grab the location to store the status, as 376 * nfsv4 does some encoding while processing 377 */ 378 nfserrp = rqstp->rq_res.head[0].iov_base 379 + rqstp->rq_res.head[0].iov_len; 380 rqstp->rq_res.head[0].iov_len += sizeof(u32); 381 382 /* Now call the procedure handler, and encode NFS status. */ 383 nfserr = proc->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp); 384 if (nfserr == nfserr_jukebox && rqstp->rq_vers == 2) 385 nfserr = nfserr_dropit; 386 if (nfserr == nfserr_dropit) { 387 dprintk("nfsd: Dropping request due to malloc failure!\n"); 388 nfsd_cache_update(rqstp, RC_NOCACHE, NULL); 389 return 0; 390 } 391 392 if (rqstp->rq_proc != 0) 393 *nfserrp++ = nfserr; 394 395 /* Encode result. 396 * For NFSv2, additional info is never returned in case of an error. 397 */ 398 if (!(nfserr && rqstp->rq_vers == 2)) { 399 xdr = proc->pc_encode; 400 if (xdr && !xdr(rqstp, nfserrp, 401 rqstp->rq_resp)) { 402 /* Failed to encode result. Release cache entry */ 403 dprintk("nfsd: failed to encode result!\n"); 404 nfsd_cache_update(rqstp, RC_NOCACHE, NULL); 405 *statp = rpc_system_err; 406 return 1; 407 } 408 } 409 410 /* Store reply in cache. */ 411 nfsd_cache_update(rqstp, proc->pc_cachetype, statp + 1); 412 return 1; 413 } 414 415 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 416 static struct svc_stat nfsd_acl_svcstats; 417 static struct svc_version * nfsd_acl_version[] = { 418 [2] = &nfsd_acl_version2, 419 [3] = &nfsd_acl_version3, 420 }; 421 422 #define NFSD_ACL_NRVERS (sizeof(nfsd_acl_version)/sizeof(nfsd_acl_version[0])) 423 static struct svc_program nfsd_acl_program = { 424 .pg_prog = NFS_ACL_PROGRAM, 425 .pg_nvers = NFSD_ACL_NRVERS, 426 .pg_vers = nfsd_acl_version, 427 .pg_name = "nfsd", 428 .pg_class = "nfsd", 429 .pg_stats = &nfsd_acl_svcstats, 430 .pg_authenticate = &svc_set_client, 431 }; 432 433 static struct svc_stat nfsd_acl_svcstats = { 434 .program = &nfsd_acl_program, 435 }; 436 437 #define nfsd_acl_program_p &nfsd_acl_program 438 #else 439 #define nfsd_acl_program_p NULL 440 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */ 441