1 /* 2 * Central processing for nfsd. 3 * 4 * Authors: Olaf Kirch (okir@monad.swb.de) 5 * 6 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de> 7 */ 8 9 #include <linux/sched/signal.h> 10 #include <linux/freezer.h> 11 #include <linux/module.h> 12 #include <linux/fs_struct.h> 13 #include <linux/swap.h> 14 15 #include <linux/sunrpc/stats.h> 16 #include <linux/sunrpc/svcsock.h> 17 #include <linux/sunrpc/svc_xprt.h> 18 #include <linux/lockd/bind.h> 19 #include <linux/nfsacl.h> 20 #include <linux/seq_file.h> 21 #include <linux/inetdevice.h> 22 #include <net/addrconf.h> 23 #include <net/ipv6.h> 24 #include <net/net_namespace.h> 25 #include "nfsd.h" 26 #include "cache.h" 27 #include "vfs.h" 28 #include "netns.h" 29 30 #define NFSDDBG_FACILITY NFSDDBG_SVC 31 32 extern struct svc_program nfsd_program; 33 static int nfsd(void *vrqstp); 34 35 /* 36 * nfsd_mutex protects nn->nfsd_serv -- both the pointer itself and the members 37 * of the svc_serv struct. In particular, ->sv_nrthreads but also to some 38 * extent ->sv_temp_socks and ->sv_permsocks. It also protects nfsdstats.th_cnt 39 * 40 * If (out side the lock) nn->nfsd_serv is non-NULL, then it must point to a 41 * properly initialised 'struct svc_serv' with ->sv_nrthreads > 0. That number 42 * of nfsd threads must exist and each must listed in ->sp_all_threads in each 43 * entry of ->sv_pools[]. 44 * 45 * Transitions of the thread count between zero and non-zero are of particular 46 * interest since the svc_serv needs to be created and initialized at that 47 * point, or freed. 48 * 49 * Finally, the nfsd_mutex also protects some of the global variables that are 50 * accessed when nfsd starts and that are settable via the write_* routines in 51 * nfsctl.c. In particular: 52 * 53 * user_recovery_dirname 54 * user_lease_time 55 * nfsd_versions 56 */ 57 DEFINE_MUTEX(nfsd_mutex); 58 59 /* 60 * nfsd_drc_lock protects nfsd_drc_max_pages and nfsd_drc_pages_used. 61 * nfsd_drc_max_pages limits the total amount of memory available for 62 * version 4.1 DRC caches. 63 * nfsd_drc_pages_used tracks the current version 4.1 DRC memory usage. 64 */ 65 spinlock_t nfsd_drc_lock; 66 unsigned long nfsd_drc_max_mem; 67 unsigned long nfsd_drc_mem_used; 68 69 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 70 static struct svc_stat nfsd_acl_svcstats; 71 static struct svc_version * nfsd_acl_version[] = { 72 [2] = &nfsd_acl_version2, 73 [3] = &nfsd_acl_version3, 74 }; 75 76 #define NFSD_ACL_MINVERS 2 77 #define NFSD_ACL_NRVERS ARRAY_SIZE(nfsd_acl_version) 78 static struct svc_version *nfsd_acl_versions[NFSD_ACL_NRVERS]; 79 80 static struct svc_program nfsd_acl_program = { 81 .pg_prog = NFS_ACL_PROGRAM, 82 .pg_nvers = NFSD_ACL_NRVERS, 83 .pg_vers = nfsd_acl_versions, 84 .pg_name = "nfsacl", 85 .pg_class = "nfsd", 86 .pg_stats = &nfsd_acl_svcstats, 87 .pg_authenticate = &svc_set_client, 88 }; 89 90 static struct svc_stat nfsd_acl_svcstats = { 91 .program = &nfsd_acl_program, 92 }; 93 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */ 94 95 static struct svc_version * nfsd_version[] = { 96 [2] = &nfsd_version2, 97 #if defined(CONFIG_NFSD_V3) 98 [3] = &nfsd_version3, 99 #endif 100 #if defined(CONFIG_NFSD_V4) 101 [4] = &nfsd_version4, 102 #endif 103 }; 104 105 #define NFSD_MINVERS 2 106 #define NFSD_NRVERS ARRAY_SIZE(nfsd_version) 107 static struct svc_version *nfsd_versions[NFSD_NRVERS]; 108 109 struct svc_program nfsd_program = { 110 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 111 .pg_next = &nfsd_acl_program, 112 #endif 113 .pg_prog = NFS_PROGRAM, /* program number */ 114 .pg_nvers = NFSD_NRVERS, /* nr of entries in nfsd_version */ 115 .pg_vers = nfsd_versions, /* version table */ 116 .pg_name = "nfsd", /* program name */ 117 .pg_class = "nfsd", /* authentication class */ 118 .pg_stats = &nfsd_svcstats, /* version table */ 119 .pg_authenticate = &svc_set_client, /* export authentication */ 120 121 }; 122 123 static bool nfsd_supported_minorversions[NFSD_SUPPORTED_MINOR_VERSION + 1] = { 124 [0] = 1, 125 [1] = 1, 126 [2] = 1, 127 }; 128 129 int nfsd_vers(int vers, enum vers_op change) 130 { 131 if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS) 132 return 0; 133 switch(change) { 134 case NFSD_SET: 135 nfsd_versions[vers] = nfsd_version[vers]; 136 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 137 if (vers < NFSD_ACL_NRVERS) 138 nfsd_acl_versions[vers] = nfsd_acl_version[vers]; 139 #endif 140 break; 141 case NFSD_CLEAR: 142 nfsd_versions[vers] = NULL; 143 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 144 if (vers < NFSD_ACL_NRVERS) 145 nfsd_acl_versions[vers] = NULL; 146 #endif 147 break; 148 case NFSD_TEST: 149 return nfsd_versions[vers] != NULL; 150 case NFSD_AVAIL: 151 return nfsd_version[vers] != NULL; 152 } 153 return 0; 154 } 155 156 static void 157 nfsd_adjust_nfsd_versions4(void) 158 { 159 unsigned i; 160 161 for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++) { 162 if (nfsd_supported_minorversions[i]) 163 return; 164 } 165 nfsd_vers(4, NFSD_CLEAR); 166 } 167 168 int nfsd_minorversion(u32 minorversion, enum vers_op change) 169 { 170 if (minorversion > NFSD_SUPPORTED_MINOR_VERSION) 171 return -1; 172 switch(change) { 173 case NFSD_SET: 174 nfsd_supported_minorversions[minorversion] = true; 175 nfsd_vers(4, NFSD_SET); 176 break; 177 case NFSD_CLEAR: 178 nfsd_supported_minorversions[minorversion] = false; 179 nfsd_adjust_nfsd_versions4(); 180 break; 181 case NFSD_TEST: 182 return nfsd_supported_minorversions[minorversion]; 183 case NFSD_AVAIL: 184 return minorversion <= NFSD_SUPPORTED_MINOR_VERSION; 185 } 186 return 0; 187 } 188 189 /* 190 * Maximum number of nfsd processes 191 */ 192 #define NFSD_MAXSERVS 8192 193 194 int nfsd_nrthreads(struct net *net) 195 { 196 int rv = 0; 197 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 198 199 mutex_lock(&nfsd_mutex); 200 if (nn->nfsd_serv) 201 rv = nn->nfsd_serv->sv_nrthreads; 202 mutex_unlock(&nfsd_mutex); 203 return rv; 204 } 205 206 static int nfsd_init_socks(struct net *net) 207 { 208 int error; 209 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 210 211 if (!list_empty(&nn->nfsd_serv->sv_permsocks)) 212 return 0; 213 214 error = svc_create_xprt(nn->nfsd_serv, "udp", net, PF_INET, NFS_PORT, 215 SVC_SOCK_DEFAULTS); 216 if (error < 0) 217 return error; 218 219 error = svc_create_xprt(nn->nfsd_serv, "tcp", net, PF_INET, NFS_PORT, 220 SVC_SOCK_DEFAULTS); 221 if (error < 0) 222 return error; 223 224 return 0; 225 } 226 227 static int nfsd_users = 0; 228 229 static int nfsd_startup_generic(int nrservs) 230 { 231 int ret; 232 233 if (nfsd_users++) 234 return 0; 235 236 /* 237 * Readahead param cache - will no-op if it already exists. 238 * (Note therefore results will be suboptimal if number of 239 * threads is modified after nfsd start.) 240 */ 241 ret = nfsd_racache_init(2*nrservs); 242 if (ret) 243 goto dec_users; 244 245 ret = nfs4_state_start(); 246 if (ret) 247 goto out_racache; 248 return 0; 249 250 out_racache: 251 nfsd_racache_shutdown(); 252 dec_users: 253 nfsd_users--; 254 return ret; 255 } 256 257 static void nfsd_shutdown_generic(void) 258 { 259 if (--nfsd_users) 260 return; 261 262 nfs4_state_shutdown(); 263 nfsd_racache_shutdown(); 264 } 265 266 static bool nfsd_needs_lockd(void) 267 { 268 #if defined(CONFIG_NFSD_V3) 269 return (nfsd_versions[2] != NULL) || (nfsd_versions[3] != NULL); 270 #else 271 return (nfsd_versions[2] != NULL); 272 #endif 273 } 274 275 static int nfsd_startup_net(int nrservs, struct net *net) 276 { 277 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 278 int ret; 279 280 if (nn->nfsd_net_up) 281 return 0; 282 283 ret = nfsd_startup_generic(nrservs); 284 if (ret) 285 return ret; 286 ret = nfsd_init_socks(net); 287 if (ret) 288 goto out_socks; 289 290 if (nfsd_needs_lockd() && !nn->lockd_up) { 291 ret = lockd_up(net); 292 if (ret) 293 goto out_socks; 294 nn->lockd_up = 1; 295 } 296 297 ret = nfs4_state_start_net(net); 298 if (ret) 299 goto out_lockd; 300 301 nn->nfsd_net_up = true; 302 return 0; 303 304 out_lockd: 305 if (nn->lockd_up) { 306 lockd_down(net); 307 nn->lockd_up = 0; 308 } 309 out_socks: 310 nfsd_shutdown_generic(); 311 return ret; 312 } 313 314 static void nfsd_shutdown_net(struct net *net) 315 { 316 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 317 318 nfs4_state_shutdown_net(net); 319 if (nn->lockd_up) { 320 lockd_down(net); 321 nn->lockd_up = 0; 322 } 323 nn->nfsd_net_up = false; 324 nfsd_shutdown_generic(); 325 } 326 327 static int nfsd_inetaddr_event(struct notifier_block *this, unsigned long event, 328 void *ptr) 329 { 330 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 331 struct net_device *dev = ifa->ifa_dev->dev; 332 struct net *net = dev_net(dev); 333 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 334 struct sockaddr_in sin; 335 336 if (event != NETDEV_DOWN) 337 goto out; 338 339 if (nn->nfsd_serv) { 340 dprintk("nfsd_inetaddr_event: removed %pI4\n", &ifa->ifa_local); 341 sin.sin_family = AF_INET; 342 sin.sin_addr.s_addr = ifa->ifa_local; 343 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin); 344 } 345 346 out: 347 return NOTIFY_DONE; 348 } 349 350 static struct notifier_block nfsd_inetaddr_notifier = { 351 .notifier_call = nfsd_inetaddr_event, 352 }; 353 354 #if IS_ENABLED(CONFIG_IPV6) 355 static int nfsd_inet6addr_event(struct notifier_block *this, 356 unsigned long event, void *ptr) 357 { 358 struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr; 359 struct net_device *dev = ifa->idev->dev; 360 struct net *net = dev_net(dev); 361 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 362 struct sockaddr_in6 sin6; 363 364 if (event != NETDEV_DOWN) 365 goto out; 366 367 if (nn->nfsd_serv) { 368 dprintk("nfsd_inet6addr_event: removed %pI6\n", &ifa->addr); 369 sin6.sin6_family = AF_INET6; 370 sin6.sin6_addr = ifa->addr; 371 if (ipv6_addr_type(&sin6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 372 sin6.sin6_scope_id = ifa->idev->dev->ifindex; 373 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin6); 374 } 375 376 out: 377 return NOTIFY_DONE; 378 } 379 380 static struct notifier_block nfsd_inet6addr_notifier = { 381 .notifier_call = nfsd_inet6addr_event, 382 }; 383 #endif 384 385 /* Only used under nfsd_mutex, so this atomic may be overkill: */ 386 static atomic_t nfsd_notifier_refcount = ATOMIC_INIT(0); 387 388 static void nfsd_last_thread(struct svc_serv *serv, struct net *net) 389 { 390 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 391 392 /* check if the notifier still has clients */ 393 if (atomic_dec_return(&nfsd_notifier_refcount) == 0) { 394 unregister_inetaddr_notifier(&nfsd_inetaddr_notifier); 395 #if IS_ENABLED(CONFIG_IPV6) 396 unregister_inet6addr_notifier(&nfsd_inet6addr_notifier); 397 #endif 398 } 399 400 /* 401 * write_ports can create the server without actually starting 402 * any threads--if we get shut down before any threads are 403 * started, then nfsd_last_thread will be run before any of this 404 * other initialization has been done except the rpcb information. 405 */ 406 svc_rpcb_cleanup(serv, net); 407 if (!nn->nfsd_net_up) 408 return; 409 410 nfsd_shutdown_net(net); 411 printk(KERN_WARNING "nfsd: last server has exited, flushing export " 412 "cache\n"); 413 nfsd_export_flush(net); 414 } 415 416 void nfsd_reset_versions(void) 417 { 418 int found_one = 0; 419 int i; 420 421 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) { 422 if (nfsd_program.pg_vers[i]) 423 found_one = 1; 424 } 425 426 if (!found_one) { 427 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) 428 nfsd_program.pg_vers[i] = nfsd_version[i]; 429 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 430 for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) 431 nfsd_acl_program.pg_vers[i] = 432 nfsd_acl_version[i]; 433 #endif 434 } 435 } 436 437 /* 438 * Each session guarantees a negotiated per slot memory cache for replies 439 * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated 440 * NFSv4.1 server might want to use more memory for a DRC than a machine 441 * with mutiple services. 442 * 443 * Impose a hard limit on the number of pages for the DRC which varies 444 * according to the machines free pages. This is of course only a default. 445 * 446 * For now this is a #defined shift which could be under admin control 447 * in the future. 448 */ 449 static void set_max_drc(void) 450 { 451 #define NFSD_DRC_SIZE_SHIFT 10 452 nfsd_drc_max_mem = (nr_free_buffer_pages() 453 >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE; 454 nfsd_drc_mem_used = 0; 455 spin_lock_init(&nfsd_drc_lock); 456 dprintk("%s nfsd_drc_max_mem %lu \n", __func__, nfsd_drc_max_mem); 457 } 458 459 static int nfsd_get_default_max_blksize(void) 460 { 461 struct sysinfo i; 462 unsigned long long target; 463 unsigned long ret; 464 465 si_meminfo(&i); 466 target = (i.totalram - i.totalhigh) << PAGE_SHIFT; 467 /* 468 * Aim for 1/4096 of memory per thread This gives 1MB on 4Gig 469 * machines, but only uses 32K on 128M machines. Bottom out at 470 * 8K on 32M and smaller. Of course, this is only a default. 471 */ 472 target >>= 12; 473 474 ret = NFSSVC_MAXBLKSIZE; 475 while (ret > target && ret >= 8*1024*2) 476 ret /= 2; 477 return ret; 478 } 479 480 static struct svc_serv_ops nfsd_thread_sv_ops = { 481 .svo_shutdown = nfsd_last_thread, 482 .svo_function = nfsd, 483 .svo_enqueue_xprt = svc_xprt_do_enqueue, 484 .svo_setup = svc_set_num_threads, 485 .svo_module = THIS_MODULE, 486 }; 487 488 int nfsd_create_serv(struct net *net) 489 { 490 int error; 491 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 492 493 WARN_ON(!mutex_is_locked(&nfsd_mutex)); 494 if (nn->nfsd_serv) { 495 svc_get(nn->nfsd_serv); 496 return 0; 497 } 498 if (nfsd_max_blksize == 0) 499 nfsd_max_blksize = nfsd_get_default_max_blksize(); 500 nfsd_reset_versions(); 501 nn->nfsd_serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize, 502 &nfsd_thread_sv_ops); 503 if (nn->nfsd_serv == NULL) 504 return -ENOMEM; 505 506 nn->nfsd_serv->sv_maxconn = nn->max_connections; 507 error = svc_bind(nn->nfsd_serv, net); 508 if (error < 0) { 509 svc_destroy(nn->nfsd_serv); 510 return error; 511 } 512 513 set_max_drc(); 514 /* check if the notifier is already set */ 515 if (atomic_inc_return(&nfsd_notifier_refcount) == 1) { 516 register_inetaddr_notifier(&nfsd_inetaddr_notifier); 517 #if IS_ENABLED(CONFIG_IPV6) 518 register_inet6addr_notifier(&nfsd_inet6addr_notifier); 519 #endif 520 } 521 do_gettimeofday(&nn->nfssvc_boot); /* record boot time */ 522 return 0; 523 } 524 525 int nfsd_nrpools(struct net *net) 526 { 527 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 528 529 if (nn->nfsd_serv == NULL) 530 return 0; 531 else 532 return nn->nfsd_serv->sv_nrpools; 533 } 534 535 int nfsd_get_nrthreads(int n, int *nthreads, struct net *net) 536 { 537 int i = 0; 538 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 539 540 if (nn->nfsd_serv != NULL) { 541 for (i = 0; i < nn->nfsd_serv->sv_nrpools && i < n; i++) 542 nthreads[i] = nn->nfsd_serv->sv_pools[i].sp_nrthreads; 543 } 544 545 return 0; 546 } 547 548 void nfsd_destroy(struct net *net) 549 { 550 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 551 int destroy = (nn->nfsd_serv->sv_nrthreads == 1); 552 553 if (destroy) 554 svc_shutdown_net(nn->nfsd_serv, net); 555 svc_destroy(nn->nfsd_serv); 556 if (destroy) 557 nn->nfsd_serv = NULL; 558 } 559 560 int nfsd_set_nrthreads(int n, int *nthreads, struct net *net) 561 { 562 int i = 0; 563 int tot = 0; 564 int err = 0; 565 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 566 567 WARN_ON(!mutex_is_locked(&nfsd_mutex)); 568 569 if (nn->nfsd_serv == NULL || n <= 0) 570 return 0; 571 572 if (n > nn->nfsd_serv->sv_nrpools) 573 n = nn->nfsd_serv->sv_nrpools; 574 575 /* enforce a global maximum number of threads */ 576 tot = 0; 577 for (i = 0; i < n; i++) { 578 nthreads[i] = min(nthreads[i], NFSD_MAXSERVS); 579 tot += nthreads[i]; 580 } 581 if (tot > NFSD_MAXSERVS) { 582 /* total too large: scale down requested numbers */ 583 for (i = 0; i < n && tot > 0; i++) { 584 int new = nthreads[i] * NFSD_MAXSERVS / tot; 585 tot -= (nthreads[i] - new); 586 nthreads[i] = new; 587 } 588 for (i = 0; i < n && tot > 0; i++) { 589 nthreads[i]--; 590 tot--; 591 } 592 } 593 594 /* 595 * There must always be a thread in pool 0; the admin 596 * can't shut down NFS completely using pool_threads. 597 */ 598 if (nthreads[0] == 0) 599 nthreads[0] = 1; 600 601 /* apply the new numbers */ 602 svc_get(nn->nfsd_serv); 603 for (i = 0; i < n; i++) { 604 err = nn->nfsd_serv->sv_ops->svo_setup(nn->nfsd_serv, 605 &nn->nfsd_serv->sv_pools[i], nthreads[i]); 606 if (err) 607 break; 608 } 609 nfsd_destroy(net); 610 return err; 611 } 612 613 /* 614 * Adjust the number of threads and return the new number of threads. 615 * This is also the function that starts the server if necessary, if 616 * this is the first time nrservs is nonzero. 617 */ 618 int 619 nfsd_svc(int nrservs, struct net *net) 620 { 621 int error; 622 bool nfsd_up_before; 623 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 624 625 mutex_lock(&nfsd_mutex); 626 dprintk("nfsd: creating service\n"); 627 628 nrservs = max(nrservs, 0); 629 nrservs = min(nrservs, NFSD_MAXSERVS); 630 error = 0; 631 632 if (nrservs == 0 && nn->nfsd_serv == NULL) 633 goto out; 634 635 error = nfsd_create_serv(net); 636 if (error) 637 goto out; 638 639 nfsd_up_before = nn->nfsd_net_up; 640 641 error = nfsd_startup_net(nrservs, net); 642 if (error) 643 goto out_destroy; 644 error = nn->nfsd_serv->sv_ops->svo_setup(nn->nfsd_serv, 645 NULL, nrservs); 646 if (error) 647 goto out_shutdown; 648 /* We are holding a reference to nn->nfsd_serv which 649 * we don't want to count in the return value, 650 * so subtract 1 651 */ 652 error = nn->nfsd_serv->sv_nrthreads - 1; 653 out_shutdown: 654 if (error < 0 && !nfsd_up_before) 655 nfsd_shutdown_net(net); 656 out_destroy: 657 nfsd_destroy(net); /* Release server */ 658 out: 659 mutex_unlock(&nfsd_mutex); 660 return error; 661 } 662 663 664 /* 665 * This is the NFS server kernel thread 666 */ 667 static int 668 nfsd(void *vrqstp) 669 { 670 struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp; 671 struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list); 672 struct net *net = perm_sock->xpt_net; 673 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 674 int err; 675 676 /* Lock module and set up kernel thread */ 677 mutex_lock(&nfsd_mutex); 678 679 /* At this point, the thread shares current->fs 680 * with the init process. We need to create files with the 681 * umask as defined by the client instead of init's umask. */ 682 if (unshare_fs_struct() < 0) { 683 printk("Unable to start nfsd thread: out of memory\n"); 684 goto out; 685 } 686 687 current->fs->umask = 0; 688 689 /* 690 * thread is spawned with all signals set to SIG_IGN, re-enable 691 * the ones that will bring down the thread 692 */ 693 allow_signal(SIGKILL); 694 allow_signal(SIGHUP); 695 allow_signal(SIGINT); 696 allow_signal(SIGQUIT); 697 698 nfsdstats.th_cnt++; 699 mutex_unlock(&nfsd_mutex); 700 701 set_freezable(); 702 703 /* 704 * The main request loop 705 */ 706 for (;;) { 707 /* Update sv_maxconn if it has changed */ 708 rqstp->rq_server->sv_maxconn = nn->max_connections; 709 710 /* 711 * Find a socket with data available and call its 712 * recvfrom routine. 713 */ 714 while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN) 715 ; 716 if (err == -EINTR) 717 break; 718 validate_process_creds(); 719 svc_process(rqstp); 720 validate_process_creds(); 721 } 722 723 /* Clear signals before calling svc_exit_thread() */ 724 flush_signals(current); 725 726 mutex_lock(&nfsd_mutex); 727 nfsdstats.th_cnt --; 728 729 out: 730 rqstp->rq_server = NULL; 731 732 /* Release the thread */ 733 svc_exit_thread(rqstp); 734 735 nfsd_destroy(net); 736 737 /* Release module */ 738 mutex_unlock(&nfsd_mutex); 739 module_put_and_exit(0); 740 return 0; 741 } 742 743 static __be32 map_new_errors(u32 vers, __be32 nfserr) 744 { 745 if (nfserr == nfserr_jukebox && vers == 2) 746 return nfserr_dropit; 747 if (nfserr == nfserr_wrongsec && vers < 4) 748 return nfserr_acces; 749 return nfserr; 750 } 751 752 int 753 nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp) 754 { 755 struct svc_procedure *proc; 756 kxdrproc_t xdr; 757 __be32 nfserr; 758 __be32 *nfserrp; 759 760 dprintk("nfsd_dispatch: vers %d proc %d\n", 761 rqstp->rq_vers, rqstp->rq_proc); 762 proc = rqstp->rq_procinfo; 763 764 /* 765 * Give the xdr decoder a chance to change this if it wants 766 * (necessary in the NFSv4.0 compound case) 767 */ 768 rqstp->rq_cachetype = proc->pc_cachetype; 769 /* Decode arguments */ 770 xdr = proc->pc_decode; 771 if (xdr && !xdr(rqstp, (__be32*)rqstp->rq_arg.head[0].iov_base, 772 rqstp->rq_argp)) { 773 dprintk("nfsd: failed to decode arguments!\n"); 774 *statp = rpc_garbage_args; 775 return 1; 776 } 777 778 /* Check whether we have this call in the cache. */ 779 switch (nfsd_cache_lookup(rqstp)) { 780 case RC_DROPIT: 781 return 0; 782 case RC_REPLY: 783 return 1; 784 case RC_DOIT:; 785 /* do it */ 786 } 787 788 /* need to grab the location to store the status, as 789 * nfsv4 does some encoding while processing 790 */ 791 nfserrp = rqstp->rq_res.head[0].iov_base 792 + rqstp->rq_res.head[0].iov_len; 793 rqstp->rq_res.head[0].iov_len += sizeof(__be32); 794 795 /* Now call the procedure handler, and encode NFS status. */ 796 nfserr = proc->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp); 797 nfserr = map_new_errors(rqstp->rq_vers, nfserr); 798 if (nfserr == nfserr_dropit || test_bit(RQ_DROPME, &rqstp->rq_flags)) { 799 dprintk("nfsd: Dropping request; may be revisited later\n"); 800 nfsd_cache_update(rqstp, RC_NOCACHE, NULL); 801 return 0; 802 } 803 804 if (rqstp->rq_proc != 0) 805 *nfserrp++ = nfserr; 806 807 /* Encode result. 808 * For NFSv2, additional info is never returned in case of an error. 809 */ 810 if (!(nfserr && rqstp->rq_vers == 2)) { 811 xdr = proc->pc_encode; 812 if (xdr && !xdr(rqstp, nfserrp, 813 rqstp->rq_resp)) { 814 /* Failed to encode result. Release cache entry */ 815 dprintk("nfsd: failed to encode result!\n"); 816 nfsd_cache_update(rqstp, RC_NOCACHE, NULL); 817 *statp = rpc_system_err; 818 return 1; 819 } 820 } 821 822 /* Store reply in cache. */ 823 nfsd_cache_update(rqstp, rqstp->rq_cachetype, statp + 1); 824 return 1; 825 } 826 827 int nfsd_pool_stats_open(struct inode *inode, struct file *file) 828 { 829 int ret; 830 struct nfsd_net *nn = net_generic(inode->i_sb->s_fs_info, nfsd_net_id); 831 832 mutex_lock(&nfsd_mutex); 833 if (nn->nfsd_serv == NULL) { 834 mutex_unlock(&nfsd_mutex); 835 return -ENODEV; 836 } 837 /* bump up the psudo refcount while traversing */ 838 svc_get(nn->nfsd_serv); 839 ret = svc_pool_stats_open(nn->nfsd_serv, file); 840 mutex_unlock(&nfsd_mutex); 841 return ret; 842 } 843 844 int nfsd_pool_stats_release(struct inode *inode, struct file *file) 845 { 846 int ret = seq_release(inode, file); 847 struct net *net = inode->i_sb->s_fs_info; 848 849 mutex_lock(&nfsd_mutex); 850 /* this function really, really should have been called svc_put() */ 851 nfsd_destroy(net); 852 mutex_unlock(&nfsd_mutex); 853 return ret; 854 } 855