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/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> 32 #include <linux/nfsd/syscall.h> 33 #include <linux/lockd/bind.h> 34 #include <linux/nfsacl.h> 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 52 extern struct svc_program nfsd_program; 53 static void nfsd(struct svc_rqst *rqstp); 54 struct timeval nfssvc_boot; 55 struct svc_serv *nfsd_serv; 56 static atomic_t nfsd_busy; 57 static unsigned long nfsd_last_call; 58 static DEFINE_SPINLOCK(nfsd_call_lock); 59 60 struct nfsd_list { 61 struct list_head list; 62 struct task_struct *task; 63 }; 64 static struct list_head nfsd_list = LIST_HEAD_INIT(nfsd_list); 65 66 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 67 static struct svc_stat nfsd_acl_svcstats; 68 static struct svc_version * nfsd_acl_version[] = { 69 [2] = &nfsd_acl_version2, 70 [3] = &nfsd_acl_version3, 71 }; 72 73 #define NFSD_ACL_MINVERS 2 74 #define NFSD_ACL_NRVERS ARRAY_SIZE(nfsd_acl_version) 75 static struct svc_version *nfsd_acl_versions[NFSD_ACL_NRVERS]; 76 77 static 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 87 static 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 92 static 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 2 103 #define NFSD_NRVERS ARRAY_SIZE(nfsd_version) 104 static struct svc_version *nfsd_versions[NFSD_NRVERS]; 105 106 struct svc_program nfsd_program = { 107 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 108 .pg_next = &nfsd_acl_program, 109 #endif 110 .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 }; 119 120 /* 121 * Maximum number of nfsd processes 122 */ 123 #define NFSD_MAXSERVS 8192 124 125 int nfsd_nrthreads(void) 126 { 127 if (nfsd_serv == NULL) 128 return 0; 129 else 130 return nfsd_serv->sv_nrthreads; 131 } 132 133 int 134 nfsd_svc(unsigned short port, int nrservs) 135 { 136 int error; 137 int none_left, found_one, i; 138 struct list_head *victim; 139 140 lock_kernel(); 141 dprintk("nfsd: creating service: vers 0x%x\n", 142 nfsd_versbits); 143 error = -EINVAL; 144 if (nrservs <= 0) 145 nrservs = 0; 146 if (nrservs > NFSD_MAXSERVS) 147 nrservs = NFSD_MAXSERVS; 148 149 /* Readahead param cache - will no-op if it already exists */ 150 error = nfsd_racache_init(2*nrservs); 151 if (error<0) 152 goto out; 153 error = nfs4_state_start(); 154 if (error<0) 155 goto out; 156 if (!nfsd_serv) { 157 /* 158 * Use the nfsd_ctlbits to define which 159 * versions that will be advertised. 160 * If nfsd_ctlbits doesn't list any version, 161 * export them all. 162 */ 163 found_one = 0; 164 165 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) { 166 if (NFSCTL_VERISSET(nfsd_versbits, i)) { 167 nfsd_program.pg_vers[i] = nfsd_version[i]; 168 found_one = 1; 169 } else 170 nfsd_program.pg_vers[i] = NULL; 171 } 172 173 if (!found_one) { 174 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) 175 nfsd_program.pg_vers[i] = nfsd_version[i]; 176 } 177 178 179 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 180 found_one = 0; 181 182 for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) { 183 if (NFSCTL_VERISSET(nfsd_versbits, i)) { 184 nfsd_acl_program.pg_vers[i] = 185 nfsd_acl_version[i]; 186 found_one = 1; 187 } else 188 nfsd_acl_program.pg_vers[i] = NULL; 189 } 190 191 if (!found_one) { 192 for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) 193 nfsd_acl_program.pg_vers[i] = 194 nfsd_acl_version[i]; 195 } 196 #endif 197 198 atomic_set(&nfsd_busy, 0); 199 error = -ENOMEM; 200 nfsd_serv = svc_create(&nfsd_program, NFSD_BUFSIZE); 201 if (nfsd_serv == NULL) 202 goto out; 203 error = svc_makesock(nfsd_serv, IPPROTO_UDP, port); 204 if (error < 0) 205 goto failure; 206 207 #ifdef CONFIG_NFSD_TCP 208 error = svc_makesock(nfsd_serv, IPPROTO_TCP, port); 209 if (error < 0) 210 goto failure; 211 #endif 212 do_gettimeofday(&nfssvc_boot); /* record boot time */ 213 } else 214 nfsd_serv->sv_nrthreads++; 215 nrservs -= (nfsd_serv->sv_nrthreads-1); 216 while (nrservs > 0) { 217 nrservs--; 218 __module_get(THIS_MODULE); 219 error = svc_create_thread(nfsd, nfsd_serv); 220 if (error < 0) { 221 module_put(THIS_MODULE); 222 break; 223 } 224 } 225 victim = nfsd_list.next; 226 while (nrservs < 0 && victim != &nfsd_list) { 227 struct nfsd_list *nl = 228 list_entry(victim,struct nfsd_list, list); 229 victim = victim->next; 230 send_sig(SIG_NOCLEAN, nl->task, 1); 231 nrservs++; 232 } 233 failure: 234 none_left = (nfsd_serv->sv_nrthreads == 1); 235 svc_destroy(nfsd_serv); /* Release server */ 236 if (none_left) { 237 nfsd_serv = NULL; 238 nfsd_racache_shutdown(); 239 nfs4_state_shutdown(); 240 } 241 out: 242 unlock_kernel(); 243 return error; 244 } 245 246 static inline void 247 update_thread_usage(int busy_threads) 248 { 249 unsigned long prev_call; 250 unsigned long diff; 251 int decile; 252 253 spin_lock(&nfsd_call_lock); 254 prev_call = nfsd_last_call; 255 nfsd_last_call = jiffies; 256 decile = busy_threads*10/nfsdstats.th_cnt; 257 if (decile>0 && decile <= 10) { 258 diff = nfsd_last_call - prev_call; 259 if ( (nfsdstats.th_usage[decile-1] += diff) >= NFSD_USAGE_WRAP) 260 nfsdstats.th_usage[decile-1] -= NFSD_USAGE_WRAP; 261 if (decile == 10) 262 nfsdstats.th_fullcnt++; 263 } 264 spin_unlock(&nfsd_call_lock); 265 } 266 267 /* 268 * This is the NFS server kernel thread 269 */ 270 static void 271 nfsd(struct svc_rqst *rqstp) 272 { 273 struct svc_serv *serv = rqstp->rq_server; 274 struct fs_struct *fsp; 275 int err; 276 struct nfsd_list me; 277 sigset_t shutdown_mask, allowed_mask; 278 279 /* Lock module and set up kernel thread */ 280 lock_kernel(); 281 daemonize("nfsd"); 282 283 /* After daemonize() this kernel thread shares current->fs 284 * with the init process. We need to create files with a 285 * umask of 0 instead of init's umask. */ 286 fsp = copy_fs_struct(current->fs); 287 if (!fsp) { 288 printk("Unable to start nfsd thread: out of memory\n"); 289 goto out; 290 } 291 exit_fs(current); 292 current->fs = fsp; 293 current->fs->umask = 0; 294 295 siginitsetinv(&shutdown_mask, SHUTDOWN_SIGS); 296 siginitsetinv(&allowed_mask, ALLOWED_SIGS); 297 298 nfsdstats.th_cnt++; 299 300 lockd_up(); /* start lockd */ 301 302 me.task = current; 303 list_add(&me.list, &nfsd_list); 304 305 unlock_kernel(); 306 307 /* 308 * We want less throttling in balance_dirty_pages() so that nfs to 309 * localhost doesn't cause nfsd to lock up due to all the client's 310 * dirty pages. 311 */ 312 current->flags |= PF_LESS_THROTTLE; 313 314 /* 315 * The main request loop 316 */ 317 for (;;) { 318 /* Block all but the shutdown signals */ 319 sigprocmask(SIG_SETMASK, &shutdown_mask, NULL); 320 321 /* 322 * Find a socket with data available and call its 323 * recvfrom routine. 324 */ 325 while ((err = svc_recv(serv, rqstp, 326 60*60*HZ)) == -EAGAIN) 327 ; 328 if (err < 0) 329 break; 330 update_thread_usage(atomic_read(&nfsd_busy)); 331 atomic_inc(&nfsd_busy); 332 333 /* Lock the export hash tables for reading. */ 334 exp_readlock(); 335 336 /* Process request with signals blocked. */ 337 sigprocmask(SIG_SETMASK, &allowed_mask, NULL); 338 339 svc_process(serv, rqstp); 340 341 /* Unlock export hash tables */ 342 exp_readunlock(); 343 update_thread_usage(atomic_read(&nfsd_busy)); 344 atomic_dec(&nfsd_busy); 345 } 346 347 if (err != -EINTR) { 348 printk(KERN_WARNING "nfsd: terminating on error %d\n", -err); 349 } else { 350 unsigned int signo; 351 352 for (signo = 1; signo <= _NSIG; signo++) 353 if (sigismember(¤t->pending.signal, signo) && 354 !sigismember(¤t->blocked, signo)) 355 break; 356 err = signo; 357 } 358 /* Clear signals before calling lockd_down() and svc_exit_thread() */ 359 flush_signals(current); 360 361 lock_kernel(); 362 363 /* Release lockd */ 364 lockd_down(); 365 366 /* Check if this is last thread */ 367 if (serv->sv_nrthreads==1) { 368 369 printk(KERN_WARNING "nfsd: last server has exited\n"); 370 if (err != SIG_NOCLEAN) { 371 printk(KERN_WARNING "nfsd: unexporting all filesystems\n"); 372 nfsd_export_flush(); 373 } 374 nfsd_serv = NULL; 375 nfsd_racache_shutdown(); /* release read-ahead cache */ 376 nfs4_state_shutdown(); 377 } 378 list_del(&me.list); 379 nfsdstats.th_cnt --; 380 381 out: 382 /* Release the thread */ 383 svc_exit_thread(rqstp); 384 385 /* Release module */ 386 unlock_kernel(); 387 module_put_and_exit(0); 388 } 389 390 int 391 nfsd_dispatch(struct svc_rqst *rqstp, u32 *statp) 392 { 393 struct svc_procedure *proc; 394 kxdrproc_t xdr; 395 u32 nfserr; 396 u32 *nfserrp; 397 398 dprintk("nfsd_dispatch: vers %d proc %d\n", 399 rqstp->rq_vers, rqstp->rq_proc); 400 proc = rqstp->rq_procinfo; 401 402 /* Check whether we have this call in the cache. */ 403 switch (nfsd_cache_lookup(rqstp, proc->pc_cachetype)) { 404 case RC_INTR: 405 case RC_DROPIT: 406 return 0; 407 case RC_REPLY: 408 return 1; 409 case RC_DOIT:; 410 /* do it */ 411 } 412 413 /* Decode arguments */ 414 xdr = proc->pc_decode; 415 if (xdr && !xdr(rqstp, (u32*)rqstp->rq_arg.head[0].iov_base, 416 rqstp->rq_argp)) { 417 dprintk("nfsd: failed to decode arguments!\n"); 418 nfsd_cache_update(rqstp, RC_NOCACHE, NULL); 419 *statp = rpc_garbage_args; 420 return 1; 421 } 422 423 /* need to grab the location to store the status, as 424 * nfsv4 does some encoding while processing 425 */ 426 nfserrp = rqstp->rq_res.head[0].iov_base 427 + rqstp->rq_res.head[0].iov_len; 428 rqstp->rq_res.head[0].iov_len += sizeof(u32); 429 430 /* Now call the procedure handler, and encode NFS status. */ 431 nfserr = proc->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp); 432 if (nfserr == nfserr_jukebox && rqstp->rq_vers == 2) 433 nfserr = nfserr_dropit; 434 if (nfserr == nfserr_dropit) { 435 dprintk("nfsd: Dropping request due to malloc failure!\n"); 436 nfsd_cache_update(rqstp, RC_NOCACHE, NULL); 437 return 0; 438 } 439 440 if (rqstp->rq_proc != 0) 441 *nfserrp++ = nfserr; 442 443 /* Encode result. 444 * For NFSv2, additional info is never returned in case of an error. 445 */ 446 if (!(nfserr && rqstp->rq_vers == 2)) { 447 xdr = proc->pc_encode; 448 if (xdr && !xdr(rqstp, nfserrp, 449 rqstp->rq_resp)) { 450 /* Failed to encode result. Release cache entry */ 451 dprintk("nfsd: failed to encode result!\n"); 452 nfsd_cache_update(rqstp, RC_NOCACHE, NULL); 453 *statp = rpc_system_err; 454 return 1; 455 } 456 } 457 458 /* Store reply in cache. */ 459 nfsd_cache_update(rqstp, proc->pc_cachetype, statp + 1); 460 return 1; 461 } 462