1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Central processing for nfsd. 4 * 5 * Authors: Olaf Kirch (okir@monad.swb.de) 6 * 7 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de> 8 */ 9 10 #include <linux/sched/signal.h> 11 #include <linux/freezer.h> 12 #include <linux/module.h> 13 #include <linux/fs_struct.h> 14 #include <linux/swap.h> 15 16 #include <linux/sunrpc/stats.h> 17 #include <linux/sunrpc/svcsock.h> 18 #include <linux/sunrpc/svc_xprt.h> 19 #include <linux/lockd/bind.h> 20 #include <linux/nfsacl.h> 21 #include <linux/seq_file.h> 22 #include <linux/inetdevice.h> 23 #include <net/addrconf.h> 24 #include <net/ipv6.h> 25 #include <net/net_namespace.h> 26 #include "nfsd.h" 27 #include "cache.h" 28 #include "vfs.h" 29 #include "netns.h" 30 #include "filecache.h" 31 32 #include "trace.h" 33 34 #define NFSDDBG_FACILITY NFSDDBG_SVC 35 36 extern struct svc_program nfsd_program; 37 static int nfsd(void *vrqstp); 38 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 39 static int nfsd_acl_rpcbind_set(struct net *, 40 const struct svc_program *, 41 u32, int, 42 unsigned short, 43 unsigned short); 44 static __be32 nfsd_acl_init_request(struct svc_rqst *, 45 const struct svc_program *, 46 struct svc_process_info *); 47 #endif 48 static int nfsd_rpcbind_set(struct net *, 49 const struct svc_program *, 50 u32, int, 51 unsigned short, 52 unsigned short); 53 static __be32 nfsd_init_request(struct svc_rqst *, 54 const struct svc_program *, 55 struct svc_process_info *); 56 57 /* 58 * nfsd_mutex protects nn->nfsd_serv -- both the pointer itself and the members 59 * of the svc_serv struct. In particular, ->sv_nrthreads but also to some 60 * extent ->sv_temp_socks and ->sv_permsocks. It also protects nfsdstats.th_cnt 61 * 62 * If (out side the lock) nn->nfsd_serv is non-NULL, then it must point to a 63 * properly initialised 'struct svc_serv' with ->sv_nrthreads > 0. That number 64 * of nfsd threads must exist and each must listed in ->sp_all_threads in each 65 * entry of ->sv_pools[]. 66 * 67 * Transitions of the thread count between zero and non-zero are of particular 68 * interest since the svc_serv needs to be created and initialized at that 69 * point, or freed. 70 * 71 * Finally, the nfsd_mutex also protects some of the global variables that are 72 * accessed when nfsd starts and that are settable via the write_* routines in 73 * nfsctl.c. In particular: 74 * 75 * user_recovery_dirname 76 * user_lease_time 77 * nfsd_versions 78 */ 79 DEFINE_MUTEX(nfsd_mutex); 80 81 /* 82 * nfsd_drc_lock protects nfsd_drc_max_pages and nfsd_drc_pages_used. 83 * nfsd_drc_max_pages limits the total amount of memory available for 84 * version 4.1 DRC caches. 85 * nfsd_drc_pages_used tracks the current version 4.1 DRC memory usage. 86 */ 87 DEFINE_SPINLOCK(nfsd_drc_lock); 88 unsigned long nfsd_drc_max_mem; 89 unsigned long nfsd_drc_mem_used; 90 91 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 92 static struct svc_stat nfsd_acl_svcstats; 93 static const struct svc_version *nfsd_acl_version[] = { 94 [2] = &nfsd_acl_version2, 95 [3] = &nfsd_acl_version3, 96 }; 97 98 #define NFSD_ACL_MINVERS 2 99 #define NFSD_ACL_NRVERS ARRAY_SIZE(nfsd_acl_version) 100 101 static struct svc_program nfsd_acl_program = { 102 .pg_prog = NFS_ACL_PROGRAM, 103 .pg_nvers = NFSD_ACL_NRVERS, 104 .pg_vers = nfsd_acl_version, 105 .pg_name = "nfsacl", 106 .pg_class = "nfsd", 107 .pg_stats = &nfsd_acl_svcstats, 108 .pg_authenticate = &svc_set_client, 109 .pg_init_request = nfsd_acl_init_request, 110 .pg_rpcbind_set = nfsd_acl_rpcbind_set, 111 }; 112 113 static struct svc_stat nfsd_acl_svcstats = { 114 .program = &nfsd_acl_program, 115 }; 116 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */ 117 118 static const struct svc_version *nfsd_version[] = { 119 [2] = &nfsd_version2, 120 #if defined(CONFIG_NFSD_V3) 121 [3] = &nfsd_version3, 122 #endif 123 #if defined(CONFIG_NFSD_V4) 124 [4] = &nfsd_version4, 125 #endif 126 }; 127 128 #define NFSD_MINVERS 2 129 #define NFSD_NRVERS ARRAY_SIZE(nfsd_version) 130 131 struct svc_program nfsd_program = { 132 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 133 .pg_next = &nfsd_acl_program, 134 #endif 135 .pg_prog = NFS_PROGRAM, /* program number */ 136 .pg_nvers = NFSD_NRVERS, /* nr of entries in nfsd_version */ 137 .pg_vers = nfsd_version, /* version table */ 138 .pg_name = "nfsd", /* program name */ 139 .pg_class = "nfsd", /* authentication class */ 140 .pg_stats = &nfsd_svcstats, /* version table */ 141 .pg_authenticate = &svc_set_client, /* export authentication */ 142 .pg_init_request = nfsd_init_request, 143 .pg_rpcbind_set = nfsd_rpcbind_set, 144 }; 145 146 static bool 147 nfsd_support_version(int vers) 148 { 149 if (vers >= NFSD_MINVERS && vers < NFSD_NRVERS) 150 return nfsd_version[vers] != NULL; 151 return false; 152 } 153 154 static bool * 155 nfsd_alloc_versions(void) 156 { 157 bool *vers = kmalloc_array(NFSD_NRVERS, sizeof(bool), GFP_KERNEL); 158 unsigned i; 159 160 if (vers) { 161 /* All compiled versions are enabled by default */ 162 for (i = 0; i < NFSD_NRVERS; i++) 163 vers[i] = nfsd_support_version(i); 164 } 165 return vers; 166 } 167 168 static bool * 169 nfsd_alloc_minorversions(void) 170 { 171 bool *vers = kmalloc_array(NFSD_SUPPORTED_MINOR_VERSION + 1, 172 sizeof(bool), GFP_KERNEL); 173 unsigned i; 174 175 if (vers) { 176 /* All minor versions are enabled by default */ 177 for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++) 178 vers[i] = nfsd_support_version(4); 179 } 180 return vers; 181 } 182 183 void 184 nfsd_netns_free_versions(struct nfsd_net *nn) 185 { 186 kfree(nn->nfsd_versions); 187 kfree(nn->nfsd4_minorversions); 188 nn->nfsd_versions = NULL; 189 nn->nfsd4_minorversions = NULL; 190 } 191 192 static void 193 nfsd_netns_init_versions(struct nfsd_net *nn) 194 { 195 if (!nn->nfsd_versions) { 196 nn->nfsd_versions = nfsd_alloc_versions(); 197 nn->nfsd4_minorversions = nfsd_alloc_minorversions(); 198 if (!nn->nfsd_versions || !nn->nfsd4_minorversions) 199 nfsd_netns_free_versions(nn); 200 } 201 } 202 203 int nfsd_vers(struct nfsd_net *nn, int vers, enum vers_op change) 204 { 205 if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS) 206 return 0; 207 switch(change) { 208 case NFSD_SET: 209 if (nn->nfsd_versions) 210 nn->nfsd_versions[vers] = nfsd_support_version(vers); 211 break; 212 case NFSD_CLEAR: 213 nfsd_netns_init_versions(nn); 214 if (nn->nfsd_versions) 215 nn->nfsd_versions[vers] = false; 216 break; 217 case NFSD_TEST: 218 if (nn->nfsd_versions) 219 return nn->nfsd_versions[vers]; 220 fallthrough; 221 case NFSD_AVAIL: 222 return nfsd_support_version(vers); 223 } 224 return 0; 225 } 226 227 static void 228 nfsd_adjust_nfsd_versions4(struct nfsd_net *nn) 229 { 230 unsigned i; 231 232 for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++) { 233 if (nn->nfsd4_minorversions[i]) 234 return; 235 } 236 nfsd_vers(nn, 4, NFSD_CLEAR); 237 } 238 239 int nfsd_minorversion(struct nfsd_net *nn, u32 minorversion, enum vers_op change) 240 { 241 if (minorversion > NFSD_SUPPORTED_MINOR_VERSION && 242 change != NFSD_AVAIL) 243 return -1; 244 245 switch(change) { 246 case NFSD_SET: 247 if (nn->nfsd4_minorversions) { 248 nfsd_vers(nn, 4, NFSD_SET); 249 nn->nfsd4_minorversions[minorversion] = 250 nfsd_vers(nn, 4, NFSD_TEST); 251 } 252 break; 253 case NFSD_CLEAR: 254 nfsd_netns_init_versions(nn); 255 if (nn->nfsd4_minorversions) { 256 nn->nfsd4_minorversions[minorversion] = false; 257 nfsd_adjust_nfsd_versions4(nn); 258 } 259 break; 260 case NFSD_TEST: 261 if (nn->nfsd4_minorversions) 262 return nn->nfsd4_minorversions[minorversion]; 263 return nfsd_vers(nn, 4, NFSD_TEST); 264 case NFSD_AVAIL: 265 return minorversion <= NFSD_SUPPORTED_MINOR_VERSION && 266 nfsd_vers(nn, 4, NFSD_AVAIL); 267 } 268 return 0; 269 } 270 271 /* 272 * Maximum number of nfsd processes 273 */ 274 #define NFSD_MAXSERVS 8192 275 276 int nfsd_nrthreads(struct net *net) 277 { 278 int rv = 0; 279 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 280 281 mutex_lock(&nfsd_mutex); 282 if (nn->nfsd_serv) 283 rv = nn->nfsd_serv->sv_nrthreads; 284 mutex_unlock(&nfsd_mutex); 285 return rv; 286 } 287 288 static int nfsd_init_socks(struct net *net, const struct cred *cred) 289 { 290 int error; 291 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 292 293 if (!list_empty(&nn->nfsd_serv->sv_permsocks)) 294 return 0; 295 296 error = svc_create_xprt(nn->nfsd_serv, "udp", net, PF_INET, NFS_PORT, 297 SVC_SOCK_DEFAULTS, cred); 298 if (error < 0) 299 return error; 300 301 error = svc_create_xprt(nn->nfsd_serv, "tcp", net, PF_INET, NFS_PORT, 302 SVC_SOCK_DEFAULTS, cred); 303 if (error < 0) 304 return error; 305 306 return 0; 307 } 308 309 static int nfsd_users = 0; 310 311 static int nfsd_startup_generic(void) 312 { 313 int ret; 314 315 if (nfsd_users++) 316 return 0; 317 318 ret = nfsd_file_cache_init(); 319 if (ret) 320 goto dec_users; 321 322 ret = nfs4_state_start(); 323 if (ret) 324 goto out_file_cache; 325 return 0; 326 327 out_file_cache: 328 nfsd_file_cache_shutdown(); 329 dec_users: 330 nfsd_users--; 331 return ret; 332 } 333 334 static void nfsd_shutdown_generic(void) 335 { 336 if (--nfsd_users) 337 return; 338 339 nfs4_state_shutdown(); 340 nfsd_file_cache_shutdown(); 341 } 342 343 static bool nfsd_needs_lockd(struct nfsd_net *nn) 344 { 345 return nfsd_vers(nn, 2, NFSD_TEST) || nfsd_vers(nn, 3, NFSD_TEST); 346 } 347 348 void nfsd_copy_boot_verifier(__be32 verf[2], struct nfsd_net *nn) 349 { 350 int seq = 0; 351 352 do { 353 read_seqbegin_or_lock(&nn->boot_lock, &seq); 354 /* 355 * This is opaque to client, so no need to byte-swap. Use 356 * __force to keep sparse happy. y2038 time_t overflow is 357 * irrelevant in this usage 358 */ 359 verf[0] = (__force __be32)nn->nfssvc_boot.tv_sec; 360 verf[1] = (__force __be32)nn->nfssvc_boot.tv_nsec; 361 } while (need_seqretry(&nn->boot_lock, seq)); 362 done_seqretry(&nn->boot_lock, seq); 363 } 364 365 static void nfsd_reset_boot_verifier_locked(struct nfsd_net *nn) 366 { 367 ktime_get_real_ts64(&nn->nfssvc_boot); 368 } 369 370 void nfsd_reset_boot_verifier(struct nfsd_net *nn) 371 { 372 write_seqlock(&nn->boot_lock); 373 nfsd_reset_boot_verifier_locked(nn); 374 write_sequnlock(&nn->boot_lock); 375 } 376 377 static int nfsd_startup_net(struct net *net, const struct cred *cred) 378 { 379 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 380 int ret; 381 382 if (nn->nfsd_net_up) 383 return 0; 384 385 ret = nfsd_startup_generic(); 386 if (ret) 387 return ret; 388 ret = nfsd_init_socks(net, cred); 389 if (ret) 390 goto out_socks; 391 392 if (nfsd_needs_lockd(nn) && !nn->lockd_up) { 393 ret = lockd_up(net, cred); 394 if (ret) 395 goto out_socks; 396 nn->lockd_up = true; 397 } 398 399 ret = nfsd_file_cache_start_net(net); 400 if (ret) 401 goto out_lockd; 402 ret = nfs4_state_start_net(net); 403 if (ret) 404 goto out_filecache; 405 406 #ifdef CONFIG_NFSD_V4_2_INTER_SSC 407 nfsd4_ssc_init_umount_work(nn); 408 #endif 409 nn->nfsd_net_up = true; 410 return 0; 411 412 out_filecache: 413 nfsd_file_cache_shutdown_net(net); 414 out_lockd: 415 if (nn->lockd_up) { 416 lockd_down(net); 417 nn->lockd_up = false; 418 } 419 out_socks: 420 nfsd_shutdown_generic(); 421 return ret; 422 } 423 424 static void nfsd_shutdown_net(struct net *net) 425 { 426 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 427 428 nfsd_file_cache_shutdown_net(net); 429 nfs4_state_shutdown_net(net); 430 if (nn->lockd_up) { 431 lockd_down(net); 432 nn->lockd_up = false; 433 } 434 nn->nfsd_net_up = false; 435 nfsd_shutdown_generic(); 436 } 437 438 static int nfsd_inetaddr_event(struct notifier_block *this, unsigned long event, 439 void *ptr) 440 { 441 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 442 struct net_device *dev = ifa->ifa_dev->dev; 443 struct net *net = dev_net(dev); 444 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 445 struct sockaddr_in sin; 446 447 if ((event != NETDEV_DOWN) || 448 !atomic_inc_not_zero(&nn->ntf_refcnt)) 449 goto out; 450 451 if (nn->nfsd_serv) { 452 dprintk("nfsd_inetaddr_event: removed %pI4\n", &ifa->ifa_local); 453 sin.sin_family = AF_INET; 454 sin.sin_addr.s_addr = ifa->ifa_local; 455 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin); 456 } 457 atomic_dec(&nn->ntf_refcnt); 458 wake_up(&nn->ntf_wq); 459 460 out: 461 return NOTIFY_DONE; 462 } 463 464 static struct notifier_block nfsd_inetaddr_notifier = { 465 .notifier_call = nfsd_inetaddr_event, 466 }; 467 468 #if IS_ENABLED(CONFIG_IPV6) 469 static int nfsd_inet6addr_event(struct notifier_block *this, 470 unsigned long event, void *ptr) 471 { 472 struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr; 473 struct net_device *dev = ifa->idev->dev; 474 struct net *net = dev_net(dev); 475 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 476 struct sockaddr_in6 sin6; 477 478 if ((event != NETDEV_DOWN) || 479 !atomic_inc_not_zero(&nn->ntf_refcnt)) 480 goto out; 481 482 if (nn->nfsd_serv) { 483 dprintk("nfsd_inet6addr_event: removed %pI6\n", &ifa->addr); 484 sin6.sin6_family = AF_INET6; 485 sin6.sin6_addr = ifa->addr; 486 if (ipv6_addr_type(&sin6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 487 sin6.sin6_scope_id = ifa->idev->dev->ifindex; 488 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin6); 489 } 490 atomic_dec(&nn->ntf_refcnt); 491 wake_up(&nn->ntf_wq); 492 out: 493 return NOTIFY_DONE; 494 } 495 496 static struct notifier_block nfsd_inet6addr_notifier = { 497 .notifier_call = nfsd_inet6addr_event, 498 }; 499 #endif 500 501 /* Only used under nfsd_mutex, so this atomic may be overkill: */ 502 static atomic_t nfsd_notifier_refcount = ATOMIC_INIT(0); 503 504 static void nfsd_last_thread(struct svc_serv *serv, struct net *net) 505 { 506 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 507 508 atomic_dec(&nn->ntf_refcnt); 509 /* check if the notifier still has clients */ 510 if (atomic_dec_return(&nfsd_notifier_refcount) == 0) { 511 unregister_inetaddr_notifier(&nfsd_inetaddr_notifier); 512 #if IS_ENABLED(CONFIG_IPV6) 513 unregister_inet6addr_notifier(&nfsd_inet6addr_notifier); 514 #endif 515 } 516 wait_event(nn->ntf_wq, atomic_read(&nn->ntf_refcnt) == 0); 517 518 /* 519 * write_ports can create the server without actually starting 520 * any threads--if we get shut down before any threads are 521 * started, then nfsd_last_thread will be run before any of this 522 * other initialization has been done except the rpcb information. 523 */ 524 svc_rpcb_cleanup(serv, net); 525 if (!nn->nfsd_net_up) 526 return; 527 528 nfsd_shutdown_net(net); 529 pr_info("nfsd: last server has exited, flushing export cache\n"); 530 nfsd_export_flush(net); 531 } 532 533 void nfsd_reset_versions(struct nfsd_net *nn) 534 { 535 int i; 536 537 for (i = 0; i < NFSD_NRVERS; i++) 538 if (nfsd_vers(nn, i, NFSD_TEST)) 539 return; 540 541 for (i = 0; i < NFSD_NRVERS; i++) 542 if (i != 4) 543 nfsd_vers(nn, i, NFSD_SET); 544 else { 545 int minor = 0; 546 while (nfsd_minorversion(nn, minor, NFSD_SET) >= 0) 547 minor++; 548 } 549 } 550 551 /* 552 * Each session guarantees a negotiated per slot memory cache for replies 553 * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated 554 * NFSv4.1 server might want to use more memory for a DRC than a machine 555 * with mutiple services. 556 * 557 * Impose a hard limit on the number of pages for the DRC which varies 558 * according to the machines free pages. This is of course only a default. 559 * 560 * For now this is a #defined shift which could be under admin control 561 * in the future. 562 */ 563 static void set_max_drc(void) 564 { 565 #define NFSD_DRC_SIZE_SHIFT 7 566 nfsd_drc_max_mem = (nr_free_buffer_pages() 567 >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE; 568 nfsd_drc_mem_used = 0; 569 dprintk("%s nfsd_drc_max_mem %lu \n", __func__, nfsd_drc_max_mem); 570 } 571 572 static int nfsd_get_default_max_blksize(void) 573 { 574 struct sysinfo i; 575 unsigned long long target; 576 unsigned long ret; 577 578 si_meminfo(&i); 579 target = (i.totalram - i.totalhigh) << PAGE_SHIFT; 580 /* 581 * Aim for 1/4096 of memory per thread This gives 1MB on 4Gig 582 * machines, but only uses 32K on 128M machines. Bottom out at 583 * 8K on 32M and smaller. Of course, this is only a default. 584 */ 585 target >>= 12; 586 587 ret = NFSSVC_MAXBLKSIZE; 588 while (ret > target && ret >= 8*1024*2) 589 ret /= 2; 590 return ret; 591 } 592 593 static const struct svc_serv_ops nfsd_thread_sv_ops = { 594 .svo_shutdown = nfsd_last_thread, 595 .svo_function = nfsd, 596 .svo_enqueue_xprt = svc_xprt_do_enqueue, 597 .svo_setup = svc_set_num_threads, 598 .svo_module = THIS_MODULE, 599 }; 600 601 static void nfsd_complete_shutdown(struct net *net) 602 { 603 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 604 605 WARN_ON(!mutex_is_locked(&nfsd_mutex)); 606 607 nn->nfsd_serv = NULL; 608 complete(&nn->nfsd_shutdown_complete); 609 } 610 611 void nfsd_shutdown_threads(struct net *net) 612 { 613 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 614 struct svc_serv *serv; 615 616 mutex_lock(&nfsd_mutex); 617 serv = nn->nfsd_serv; 618 if (serv == NULL) { 619 mutex_unlock(&nfsd_mutex); 620 return; 621 } 622 623 svc_get(serv); 624 /* Kill outstanding nfsd threads */ 625 serv->sv_ops->svo_setup(serv, NULL, 0); 626 nfsd_destroy(net); 627 mutex_unlock(&nfsd_mutex); 628 /* Wait for shutdown of nfsd_serv to complete */ 629 wait_for_completion(&nn->nfsd_shutdown_complete); 630 } 631 632 bool i_am_nfsd(void) 633 { 634 return kthread_func(current) == nfsd; 635 } 636 637 int nfsd_create_serv(struct net *net) 638 { 639 int error; 640 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 641 642 WARN_ON(!mutex_is_locked(&nfsd_mutex)); 643 if (nn->nfsd_serv) { 644 svc_get(nn->nfsd_serv); 645 return 0; 646 } 647 if (nfsd_max_blksize == 0) 648 nfsd_max_blksize = nfsd_get_default_max_blksize(); 649 nfsd_reset_versions(nn); 650 nn->nfsd_serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize, 651 &nfsd_thread_sv_ops); 652 if (nn->nfsd_serv == NULL) 653 return -ENOMEM; 654 init_completion(&nn->nfsd_shutdown_complete); 655 656 nn->nfsd_serv->sv_maxconn = nn->max_connections; 657 error = svc_bind(nn->nfsd_serv, net); 658 if (error < 0) { 659 svc_destroy(nn->nfsd_serv); 660 nfsd_complete_shutdown(net); 661 return error; 662 } 663 664 set_max_drc(); 665 /* check if the notifier is already set */ 666 if (atomic_inc_return(&nfsd_notifier_refcount) == 1) { 667 register_inetaddr_notifier(&nfsd_inetaddr_notifier); 668 #if IS_ENABLED(CONFIG_IPV6) 669 register_inet6addr_notifier(&nfsd_inet6addr_notifier); 670 #endif 671 } 672 atomic_inc(&nn->ntf_refcnt); 673 nfsd_reset_boot_verifier(nn); 674 return 0; 675 } 676 677 int nfsd_nrpools(struct net *net) 678 { 679 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 680 681 if (nn->nfsd_serv == NULL) 682 return 0; 683 else 684 return nn->nfsd_serv->sv_nrpools; 685 } 686 687 int nfsd_get_nrthreads(int n, int *nthreads, struct net *net) 688 { 689 int i = 0; 690 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 691 692 if (nn->nfsd_serv != NULL) { 693 for (i = 0; i < nn->nfsd_serv->sv_nrpools && i < n; i++) 694 nthreads[i] = nn->nfsd_serv->sv_pools[i].sp_nrthreads; 695 } 696 697 return 0; 698 } 699 700 void nfsd_destroy(struct net *net) 701 { 702 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 703 int destroy = (nn->nfsd_serv->sv_nrthreads == 1); 704 705 if (destroy) 706 svc_shutdown_net(nn->nfsd_serv, net); 707 svc_destroy(nn->nfsd_serv); 708 if (destroy) 709 nfsd_complete_shutdown(net); 710 } 711 712 int nfsd_set_nrthreads(int n, int *nthreads, struct net *net) 713 { 714 int i = 0; 715 int tot = 0; 716 int err = 0; 717 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 718 719 WARN_ON(!mutex_is_locked(&nfsd_mutex)); 720 721 if (nn->nfsd_serv == NULL || n <= 0) 722 return 0; 723 724 if (n > nn->nfsd_serv->sv_nrpools) 725 n = nn->nfsd_serv->sv_nrpools; 726 727 /* enforce a global maximum number of threads */ 728 tot = 0; 729 for (i = 0; i < n; i++) { 730 nthreads[i] = min(nthreads[i], NFSD_MAXSERVS); 731 tot += nthreads[i]; 732 } 733 if (tot > NFSD_MAXSERVS) { 734 /* total too large: scale down requested numbers */ 735 for (i = 0; i < n && tot > 0; i++) { 736 int new = nthreads[i] * NFSD_MAXSERVS / tot; 737 tot -= (nthreads[i] - new); 738 nthreads[i] = new; 739 } 740 for (i = 0; i < n && tot > 0; i++) { 741 nthreads[i]--; 742 tot--; 743 } 744 } 745 746 /* 747 * There must always be a thread in pool 0; the admin 748 * can't shut down NFS completely using pool_threads. 749 */ 750 if (nthreads[0] == 0) 751 nthreads[0] = 1; 752 753 /* apply the new numbers */ 754 svc_get(nn->nfsd_serv); 755 for (i = 0; i < n; i++) { 756 err = nn->nfsd_serv->sv_ops->svo_setup(nn->nfsd_serv, 757 &nn->nfsd_serv->sv_pools[i], nthreads[i]); 758 if (err) 759 break; 760 } 761 nfsd_destroy(net); 762 return err; 763 } 764 765 /* 766 * Adjust the number of threads and return the new number of threads. 767 * This is also the function that starts the server if necessary, if 768 * this is the first time nrservs is nonzero. 769 */ 770 int 771 nfsd_svc(int nrservs, struct net *net, const struct cred *cred) 772 { 773 int error; 774 bool nfsd_up_before; 775 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 776 777 mutex_lock(&nfsd_mutex); 778 dprintk("nfsd: creating service\n"); 779 780 nrservs = max(nrservs, 0); 781 nrservs = min(nrservs, NFSD_MAXSERVS); 782 error = 0; 783 784 if (nrservs == 0 && nn->nfsd_serv == NULL) 785 goto out; 786 787 strlcpy(nn->nfsd_name, utsname()->nodename, 788 sizeof(nn->nfsd_name)); 789 790 error = nfsd_create_serv(net); 791 if (error) 792 goto out; 793 794 nfsd_up_before = nn->nfsd_net_up; 795 796 error = nfsd_startup_net(net, cred); 797 if (error) 798 goto out_destroy; 799 error = nn->nfsd_serv->sv_ops->svo_setup(nn->nfsd_serv, 800 NULL, nrservs); 801 if (error) 802 goto out_shutdown; 803 /* We are holding a reference to nn->nfsd_serv which 804 * we don't want to count in the return value, 805 * so subtract 1 806 */ 807 error = nn->nfsd_serv->sv_nrthreads - 1; 808 out_shutdown: 809 if (error < 0 && !nfsd_up_before) 810 nfsd_shutdown_net(net); 811 out_destroy: 812 nfsd_destroy(net); /* Release server */ 813 out: 814 mutex_unlock(&nfsd_mutex); 815 return error; 816 } 817 818 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 819 static bool 820 nfsd_support_acl_version(int vers) 821 { 822 if (vers >= NFSD_ACL_MINVERS && vers < NFSD_ACL_NRVERS) 823 return nfsd_acl_version[vers] != NULL; 824 return false; 825 } 826 827 static int 828 nfsd_acl_rpcbind_set(struct net *net, const struct svc_program *progp, 829 u32 version, int family, unsigned short proto, 830 unsigned short port) 831 { 832 if (!nfsd_support_acl_version(version) || 833 !nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST)) 834 return 0; 835 return svc_generic_rpcbind_set(net, progp, version, family, 836 proto, port); 837 } 838 839 static __be32 840 nfsd_acl_init_request(struct svc_rqst *rqstp, 841 const struct svc_program *progp, 842 struct svc_process_info *ret) 843 { 844 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); 845 int i; 846 847 if (likely(nfsd_support_acl_version(rqstp->rq_vers) && 848 nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST))) 849 return svc_generic_init_request(rqstp, progp, ret); 850 851 ret->mismatch.lovers = NFSD_ACL_NRVERS; 852 for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) { 853 if (nfsd_support_acl_version(rqstp->rq_vers) && 854 nfsd_vers(nn, i, NFSD_TEST)) { 855 ret->mismatch.lovers = i; 856 break; 857 } 858 } 859 if (ret->mismatch.lovers == NFSD_ACL_NRVERS) 860 return rpc_prog_unavail; 861 ret->mismatch.hivers = NFSD_ACL_MINVERS; 862 for (i = NFSD_ACL_NRVERS - 1; i >= NFSD_ACL_MINVERS; i--) { 863 if (nfsd_support_acl_version(rqstp->rq_vers) && 864 nfsd_vers(nn, i, NFSD_TEST)) { 865 ret->mismatch.hivers = i; 866 break; 867 } 868 } 869 return rpc_prog_mismatch; 870 } 871 #endif 872 873 static int 874 nfsd_rpcbind_set(struct net *net, const struct svc_program *progp, 875 u32 version, int family, unsigned short proto, 876 unsigned short port) 877 { 878 if (!nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST)) 879 return 0; 880 return svc_generic_rpcbind_set(net, progp, version, family, 881 proto, port); 882 } 883 884 static __be32 885 nfsd_init_request(struct svc_rqst *rqstp, 886 const struct svc_program *progp, 887 struct svc_process_info *ret) 888 { 889 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); 890 int i; 891 892 if (likely(nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST))) 893 return svc_generic_init_request(rqstp, progp, ret); 894 895 ret->mismatch.lovers = NFSD_NRVERS; 896 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) { 897 if (nfsd_vers(nn, i, NFSD_TEST)) { 898 ret->mismatch.lovers = i; 899 break; 900 } 901 } 902 if (ret->mismatch.lovers == NFSD_NRVERS) 903 return rpc_prog_unavail; 904 ret->mismatch.hivers = NFSD_MINVERS; 905 for (i = NFSD_NRVERS - 1; i >= NFSD_MINVERS; i--) { 906 if (nfsd_vers(nn, i, NFSD_TEST)) { 907 ret->mismatch.hivers = i; 908 break; 909 } 910 } 911 return rpc_prog_mismatch; 912 } 913 914 /* 915 * This is the NFS server kernel thread 916 */ 917 static int 918 nfsd(void *vrqstp) 919 { 920 struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp; 921 struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list); 922 struct net *net = perm_sock->xpt_net; 923 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 924 int err; 925 926 /* Lock module and set up kernel thread */ 927 mutex_lock(&nfsd_mutex); 928 929 /* At this point, the thread shares current->fs 930 * with the init process. We need to create files with the 931 * umask as defined by the client instead of init's umask. */ 932 if (unshare_fs_struct() < 0) { 933 printk("Unable to start nfsd thread: out of memory\n"); 934 goto out; 935 } 936 937 current->fs->umask = 0; 938 939 /* 940 * thread is spawned with all signals set to SIG_IGN, re-enable 941 * the ones that will bring down the thread 942 */ 943 allow_signal(SIGKILL); 944 allow_signal(SIGHUP); 945 allow_signal(SIGINT); 946 allow_signal(SIGQUIT); 947 948 nfsdstats.th_cnt++; 949 mutex_unlock(&nfsd_mutex); 950 951 set_freezable(); 952 953 /* 954 * The main request loop 955 */ 956 for (;;) { 957 /* Update sv_maxconn if it has changed */ 958 rqstp->rq_server->sv_maxconn = nn->max_connections; 959 960 /* 961 * Find a socket with data available and call its 962 * recvfrom routine. 963 */ 964 while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN) 965 ; 966 if (err == -EINTR) 967 break; 968 validate_process_creds(); 969 svc_process(rqstp); 970 validate_process_creds(); 971 } 972 973 /* Clear signals before calling svc_exit_thread() */ 974 flush_signals(current); 975 976 mutex_lock(&nfsd_mutex); 977 nfsdstats.th_cnt --; 978 979 out: 980 rqstp->rq_server = NULL; 981 982 /* Release the thread */ 983 svc_exit_thread(rqstp); 984 985 nfsd_destroy(net); 986 987 /* Release module */ 988 mutex_unlock(&nfsd_mutex); 989 module_put_and_exit(0); 990 return 0; 991 } 992 993 /** 994 * nfsd_dispatch - Process an NFS or NFSACL Request 995 * @rqstp: incoming request 996 * @statp: pointer to location of accept_stat field in RPC Reply buffer 997 * 998 * This RPC dispatcher integrates the NFS server's duplicate reply cache. 999 * 1000 * Return values: 1001 * %0: Processing complete; do not send a Reply 1002 * %1: Processing complete; send Reply in rqstp->rq_res 1003 */ 1004 int nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp) 1005 { 1006 const struct svc_procedure *proc = rqstp->rq_procinfo; 1007 struct kvec *argv = &rqstp->rq_arg.head[0]; 1008 struct kvec *resv = &rqstp->rq_res.head[0]; 1009 __be32 *p; 1010 1011 /* 1012 * Give the xdr decoder a chance to change this if it wants 1013 * (necessary in the NFSv4.0 compound case) 1014 */ 1015 rqstp->rq_cachetype = proc->pc_cachetype; 1016 1017 svcxdr_init_decode(rqstp); 1018 if (!proc->pc_decode(rqstp, argv->iov_base)) 1019 goto out_decode_err; 1020 1021 switch (nfsd_cache_lookup(rqstp)) { 1022 case RC_DOIT: 1023 break; 1024 case RC_REPLY: 1025 goto out_cached_reply; 1026 case RC_DROPIT: 1027 goto out_dropit; 1028 } 1029 1030 /* 1031 * Need to grab the location to store the status, as 1032 * NFSv4 does some encoding while processing 1033 */ 1034 p = resv->iov_base + resv->iov_len; 1035 svcxdr_init_encode(rqstp); 1036 1037 *statp = proc->pc_func(rqstp); 1038 if (*statp == rpc_drop_reply || test_bit(RQ_DROPME, &rqstp->rq_flags)) 1039 goto out_update_drop; 1040 1041 if (!proc->pc_encode(rqstp, p)) 1042 goto out_encode_err; 1043 1044 nfsd_cache_update(rqstp, rqstp->rq_cachetype, statp + 1); 1045 out_cached_reply: 1046 return 1; 1047 1048 out_decode_err: 1049 trace_nfsd_garbage_args_err(rqstp); 1050 *statp = rpc_garbage_args; 1051 return 1; 1052 1053 out_update_drop: 1054 nfsd_cache_update(rqstp, RC_NOCACHE, NULL); 1055 out_dropit: 1056 return 0; 1057 1058 out_encode_err: 1059 trace_nfsd_cant_encode_err(rqstp); 1060 nfsd_cache_update(rqstp, RC_NOCACHE, NULL); 1061 *statp = rpc_system_err; 1062 return 1; 1063 } 1064 1065 /** 1066 * nfssvc_decode_voidarg - Decode void arguments 1067 * @rqstp: Server RPC transaction context 1068 * @p: buffer containing arguments to decode 1069 * 1070 * Return values: 1071 * %0: Arguments were not valid 1072 * %1: Decoding was successful 1073 */ 1074 int nfssvc_decode_voidarg(struct svc_rqst *rqstp, __be32 *p) 1075 { 1076 return 1; 1077 } 1078 1079 /** 1080 * nfssvc_encode_voidres - Encode void results 1081 * @rqstp: Server RPC transaction context 1082 * @p: buffer in which to encode results 1083 * 1084 * Return values: 1085 * %0: Local error while encoding 1086 * %1: Encoding was successful 1087 */ 1088 int nfssvc_encode_voidres(struct svc_rqst *rqstp, __be32 *p) 1089 { 1090 return 1; 1091 } 1092 1093 int nfsd_pool_stats_open(struct inode *inode, struct file *file) 1094 { 1095 int ret; 1096 struct nfsd_net *nn = net_generic(inode->i_sb->s_fs_info, nfsd_net_id); 1097 1098 mutex_lock(&nfsd_mutex); 1099 if (nn->nfsd_serv == NULL) { 1100 mutex_unlock(&nfsd_mutex); 1101 return -ENODEV; 1102 } 1103 /* bump up the psudo refcount while traversing */ 1104 svc_get(nn->nfsd_serv); 1105 ret = svc_pool_stats_open(nn->nfsd_serv, file); 1106 mutex_unlock(&nfsd_mutex); 1107 return ret; 1108 } 1109 1110 int nfsd_pool_stats_release(struct inode *inode, struct file *file) 1111 { 1112 int ret = seq_release(inode, file); 1113 struct net *net = inode->i_sb->s_fs_info; 1114 1115 mutex_lock(&nfsd_mutex); 1116 /* this function really, really should have been called svc_put() */ 1117 nfsd_destroy(net); 1118 mutex_unlock(&nfsd_mutex); 1119 return ret; 1120 } 1121