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 #include <linux/siphash.h> 16 17 #include <linux/sunrpc/stats.h> 18 #include <linux/sunrpc/svcsock.h> 19 #include <linux/sunrpc/svc_xprt.h> 20 #include <linux/lockd/bind.h> 21 #include <linux/nfsacl.h> 22 #include <linux/seq_file.h> 23 #include <linux/inetdevice.h> 24 #include <net/addrconf.h> 25 #include <net/ipv6.h> 26 #include <net/net_namespace.h> 27 #include "nfsd.h" 28 #include "cache.h" 29 #include "vfs.h" 30 #include "netns.h" 31 #include "filecache.h" 32 33 #include "trace.h" 34 35 #define NFSDDBG_FACILITY NFSDDBG_SVC 36 37 extern struct svc_program nfsd_program; 38 static int nfsd(void *vrqstp); 39 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 40 static int nfsd_acl_rpcbind_set(struct net *, 41 const struct svc_program *, 42 u32, int, 43 unsigned short, 44 unsigned short); 45 static __be32 nfsd_acl_init_request(struct svc_rqst *, 46 const struct svc_program *, 47 struct svc_process_info *); 48 #endif 49 static int nfsd_rpcbind_set(struct net *, 50 const struct svc_program *, 51 u32, int, 52 unsigned short, 53 unsigned short); 54 static __be32 nfsd_init_request(struct svc_rqst *, 55 const struct svc_program *, 56 struct svc_process_info *); 57 58 /* 59 * nfsd_mutex protects nn->nfsd_serv -- both the pointer itself and some members 60 * of the svc_serv struct such as ->sv_temp_socks and ->sv_permsocks. 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 (unless 64 * nn->keep_active is set). That number of nfsd threads must 65 * exist and each must be listed in ->sp_all_threads in some entry of 66 * ->sv_pools[]. 67 * 68 * Each active thread holds a counted reference on nn->nfsd_serv, as does 69 * the nn->keep_active flag and various transient calls to svc_get(). 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 # if defined(CONFIG_NFSD_V2_ACL) 95 [2] = &nfsd_acl_version2, 96 # endif 97 # if defined(CONFIG_NFSD_V3_ACL) 98 [3] = &nfsd_acl_version3, 99 # endif 100 }; 101 102 #define NFSD_ACL_MINVERS 2 103 #define NFSD_ACL_NRVERS ARRAY_SIZE(nfsd_acl_version) 104 105 static struct svc_program nfsd_acl_program = { 106 .pg_prog = NFS_ACL_PROGRAM, 107 .pg_nvers = NFSD_ACL_NRVERS, 108 .pg_vers = nfsd_acl_version, 109 .pg_name = "nfsacl", 110 .pg_class = "nfsd", 111 .pg_stats = &nfsd_acl_svcstats, 112 .pg_authenticate = &svc_set_client, 113 .pg_init_request = nfsd_acl_init_request, 114 .pg_rpcbind_set = nfsd_acl_rpcbind_set, 115 }; 116 117 static struct svc_stat nfsd_acl_svcstats = { 118 .program = &nfsd_acl_program, 119 }; 120 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */ 121 122 static const struct svc_version *nfsd_version[] = { 123 #if defined(CONFIG_NFSD_V2) 124 [2] = &nfsd_version2, 125 #endif 126 [3] = &nfsd_version3, 127 #if defined(CONFIG_NFSD_V4) 128 [4] = &nfsd_version4, 129 #endif 130 }; 131 132 #define NFSD_MINVERS 2 133 #define NFSD_NRVERS ARRAY_SIZE(nfsd_version) 134 135 struct svc_program nfsd_program = { 136 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 137 .pg_next = &nfsd_acl_program, 138 #endif 139 .pg_prog = NFS_PROGRAM, /* program number */ 140 .pg_nvers = NFSD_NRVERS, /* nr of entries in nfsd_version */ 141 .pg_vers = nfsd_version, /* version table */ 142 .pg_name = "nfsd", /* program name */ 143 .pg_class = "nfsd", /* authentication class */ 144 .pg_stats = &nfsd_svcstats, /* version table */ 145 .pg_authenticate = &svc_set_client, /* export authentication */ 146 .pg_init_request = nfsd_init_request, 147 .pg_rpcbind_set = nfsd_rpcbind_set, 148 }; 149 150 static bool 151 nfsd_support_version(int vers) 152 { 153 if (vers >= NFSD_MINVERS && vers < NFSD_NRVERS) 154 return nfsd_version[vers] != NULL; 155 return false; 156 } 157 158 static bool * 159 nfsd_alloc_versions(void) 160 { 161 bool *vers = kmalloc_array(NFSD_NRVERS, sizeof(bool), GFP_KERNEL); 162 unsigned i; 163 164 if (vers) { 165 /* All compiled versions are enabled by default */ 166 for (i = 0; i < NFSD_NRVERS; i++) 167 vers[i] = nfsd_support_version(i); 168 } 169 return vers; 170 } 171 172 static bool * 173 nfsd_alloc_minorversions(void) 174 { 175 bool *vers = kmalloc_array(NFSD_SUPPORTED_MINOR_VERSION + 1, 176 sizeof(bool), GFP_KERNEL); 177 unsigned i; 178 179 if (vers) { 180 /* All minor versions are enabled by default */ 181 for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++) 182 vers[i] = nfsd_support_version(4); 183 } 184 return vers; 185 } 186 187 void 188 nfsd_netns_free_versions(struct nfsd_net *nn) 189 { 190 kfree(nn->nfsd_versions); 191 kfree(nn->nfsd4_minorversions); 192 nn->nfsd_versions = NULL; 193 nn->nfsd4_minorversions = NULL; 194 } 195 196 static void 197 nfsd_netns_init_versions(struct nfsd_net *nn) 198 { 199 if (!nn->nfsd_versions) { 200 nn->nfsd_versions = nfsd_alloc_versions(); 201 nn->nfsd4_minorversions = nfsd_alloc_minorversions(); 202 if (!nn->nfsd_versions || !nn->nfsd4_minorversions) 203 nfsd_netns_free_versions(nn); 204 } 205 } 206 207 int nfsd_vers(struct nfsd_net *nn, int vers, enum vers_op change) 208 { 209 if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS) 210 return 0; 211 switch(change) { 212 case NFSD_SET: 213 if (nn->nfsd_versions) 214 nn->nfsd_versions[vers] = nfsd_support_version(vers); 215 break; 216 case NFSD_CLEAR: 217 nfsd_netns_init_versions(nn); 218 if (nn->nfsd_versions) 219 nn->nfsd_versions[vers] = false; 220 break; 221 case NFSD_TEST: 222 if (nn->nfsd_versions) 223 return nn->nfsd_versions[vers]; 224 fallthrough; 225 case NFSD_AVAIL: 226 return nfsd_support_version(vers); 227 } 228 return 0; 229 } 230 231 static void 232 nfsd_adjust_nfsd_versions4(struct nfsd_net *nn) 233 { 234 unsigned i; 235 236 for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++) { 237 if (nn->nfsd4_minorversions[i]) 238 return; 239 } 240 nfsd_vers(nn, 4, NFSD_CLEAR); 241 } 242 243 int nfsd_minorversion(struct nfsd_net *nn, u32 minorversion, enum vers_op change) 244 { 245 if (minorversion > NFSD_SUPPORTED_MINOR_VERSION && 246 change != NFSD_AVAIL) 247 return -1; 248 249 switch(change) { 250 case NFSD_SET: 251 if (nn->nfsd4_minorversions) { 252 nfsd_vers(nn, 4, NFSD_SET); 253 nn->nfsd4_minorversions[minorversion] = 254 nfsd_vers(nn, 4, NFSD_TEST); 255 } 256 break; 257 case NFSD_CLEAR: 258 nfsd_netns_init_versions(nn); 259 if (nn->nfsd4_minorversions) { 260 nn->nfsd4_minorversions[minorversion] = false; 261 nfsd_adjust_nfsd_versions4(nn); 262 } 263 break; 264 case NFSD_TEST: 265 if (nn->nfsd4_minorversions) 266 return nn->nfsd4_minorversions[minorversion]; 267 return nfsd_vers(nn, 4, NFSD_TEST); 268 case NFSD_AVAIL: 269 return minorversion <= NFSD_SUPPORTED_MINOR_VERSION && 270 nfsd_vers(nn, 4, NFSD_AVAIL); 271 } 272 return 0; 273 } 274 275 /* 276 * Maximum number of nfsd processes 277 */ 278 #define NFSD_MAXSERVS 8192 279 280 int nfsd_nrthreads(struct net *net) 281 { 282 int rv = 0; 283 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 284 285 mutex_lock(&nfsd_mutex); 286 if (nn->nfsd_serv) 287 rv = nn->nfsd_serv->sv_nrthreads; 288 mutex_unlock(&nfsd_mutex); 289 return rv; 290 } 291 292 static int nfsd_init_socks(struct net *net, const struct cred *cred) 293 { 294 int error; 295 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 296 297 if (!list_empty(&nn->nfsd_serv->sv_permsocks)) 298 return 0; 299 300 error = svc_xprt_create(nn->nfsd_serv, "udp", net, PF_INET, NFS_PORT, 301 SVC_SOCK_DEFAULTS, cred); 302 if (error < 0) 303 return error; 304 305 error = svc_xprt_create(nn->nfsd_serv, "tcp", net, PF_INET, NFS_PORT, 306 SVC_SOCK_DEFAULTS, cred); 307 if (error < 0) 308 return error; 309 310 return 0; 311 } 312 313 static int nfsd_users = 0; 314 315 static int nfsd_startup_generic(void) 316 { 317 int ret; 318 319 if (nfsd_users++) 320 return 0; 321 322 ret = nfsd_file_cache_init(); 323 if (ret) 324 goto dec_users; 325 326 ret = nfs4_state_start(); 327 if (ret) 328 goto out_file_cache; 329 return 0; 330 331 out_file_cache: 332 nfsd_file_cache_shutdown(); 333 dec_users: 334 nfsd_users--; 335 return ret; 336 } 337 338 static void nfsd_shutdown_generic(void) 339 { 340 if (--nfsd_users) 341 return; 342 343 nfs4_state_shutdown(); 344 nfsd_file_cache_shutdown(); 345 } 346 347 static bool nfsd_needs_lockd(struct nfsd_net *nn) 348 { 349 return nfsd_vers(nn, 2, NFSD_TEST) || nfsd_vers(nn, 3, NFSD_TEST); 350 } 351 352 /** 353 * nfsd_copy_write_verifier - Atomically copy a write verifier 354 * @verf: buffer in which to receive the verifier cookie 355 * @nn: NFS net namespace 356 * 357 * This function provides a wait-free mechanism for copying the 358 * namespace's write verifier without tearing it. 359 */ 360 void nfsd_copy_write_verifier(__be32 verf[2], struct nfsd_net *nn) 361 { 362 int seq = 0; 363 364 do { 365 read_seqbegin_or_lock(&nn->writeverf_lock, &seq); 366 memcpy(verf, nn->writeverf, sizeof(nn->writeverf)); 367 } while (need_seqretry(&nn->writeverf_lock, seq)); 368 done_seqretry(&nn->writeverf_lock, seq); 369 } 370 371 static void nfsd_reset_write_verifier_locked(struct nfsd_net *nn) 372 { 373 struct timespec64 now; 374 u64 verf; 375 376 /* 377 * Because the time value is hashed, y2038 time_t overflow 378 * is irrelevant in this usage. 379 */ 380 ktime_get_raw_ts64(&now); 381 verf = siphash_2u64(now.tv_sec, now.tv_nsec, &nn->siphash_key); 382 memcpy(nn->writeverf, &verf, sizeof(nn->writeverf)); 383 } 384 385 /** 386 * nfsd_reset_write_verifier - Generate a new write verifier 387 * @nn: NFS net namespace 388 * 389 * This function updates the ->writeverf field of @nn. This field 390 * contains an opaque cookie that, according to Section 18.32.3 of 391 * RFC 8881, "the client can use to determine whether a server has 392 * changed instance state (e.g., server restart) between a call to 393 * WRITE and a subsequent call to either WRITE or COMMIT. This 394 * cookie MUST be unchanged during a single instance of the NFSv4.1 395 * server and MUST be unique between instances of the NFSv4.1 396 * server." 397 */ 398 void nfsd_reset_write_verifier(struct nfsd_net *nn) 399 { 400 write_seqlock(&nn->writeverf_lock); 401 nfsd_reset_write_verifier_locked(nn); 402 write_sequnlock(&nn->writeverf_lock); 403 } 404 405 /* 406 * Crank up a set of per-namespace resources for a new NFSD instance, 407 * including lockd, a duplicate reply cache, an open file cache 408 * instance, and a cache of NFSv4 state objects. 409 */ 410 static int nfsd_startup_net(struct net *net, const struct cred *cred) 411 { 412 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 413 int ret; 414 415 if (nn->nfsd_net_up) 416 return 0; 417 418 ret = nfsd_startup_generic(); 419 if (ret) 420 return ret; 421 ret = nfsd_init_socks(net, cred); 422 if (ret) 423 goto out_socks; 424 425 if (nfsd_needs_lockd(nn) && !nn->lockd_up) { 426 ret = lockd_up(net, cred); 427 if (ret) 428 goto out_socks; 429 nn->lockd_up = true; 430 } 431 432 ret = nfsd_file_cache_start_net(net); 433 if (ret) 434 goto out_lockd; 435 436 ret = nfsd_reply_cache_init(nn); 437 if (ret) 438 goto out_filecache; 439 440 ret = nfs4_state_start_net(net); 441 if (ret) 442 goto out_reply_cache; 443 444 #ifdef CONFIG_NFSD_V4_2_INTER_SSC 445 nfsd4_ssc_init_umount_work(nn); 446 #endif 447 nn->nfsd_net_up = true; 448 return 0; 449 450 out_reply_cache: 451 nfsd_reply_cache_shutdown(nn); 452 out_filecache: 453 nfsd_file_cache_shutdown_net(net); 454 out_lockd: 455 if (nn->lockd_up) { 456 lockd_down(net); 457 nn->lockd_up = false; 458 } 459 out_socks: 460 nfsd_shutdown_generic(); 461 return ret; 462 } 463 464 static void nfsd_shutdown_net(struct net *net) 465 { 466 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 467 468 nfs4_state_shutdown_net(net); 469 nfsd_reply_cache_shutdown(nn); 470 nfsd_file_cache_shutdown_net(net); 471 if (nn->lockd_up) { 472 lockd_down(net); 473 nn->lockd_up = false; 474 } 475 nn->nfsd_net_up = false; 476 nfsd_shutdown_generic(); 477 } 478 479 static DEFINE_SPINLOCK(nfsd_notifier_lock); 480 static int nfsd_inetaddr_event(struct notifier_block *this, unsigned long event, 481 void *ptr) 482 { 483 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 484 struct net_device *dev = ifa->ifa_dev->dev; 485 struct net *net = dev_net(dev); 486 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 487 struct sockaddr_in sin; 488 489 if (event != NETDEV_DOWN || !nn->nfsd_serv) 490 goto out; 491 492 spin_lock(&nfsd_notifier_lock); 493 if (nn->nfsd_serv) { 494 dprintk("nfsd_inetaddr_event: removed %pI4\n", &ifa->ifa_local); 495 sin.sin_family = AF_INET; 496 sin.sin_addr.s_addr = ifa->ifa_local; 497 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin); 498 } 499 spin_unlock(&nfsd_notifier_lock); 500 501 out: 502 return NOTIFY_DONE; 503 } 504 505 static struct notifier_block nfsd_inetaddr_notifier = { 506 .notifier_call = nfsd_inetaddr_event, 507 }; 508 509 #if IS_ENABLED(CONFIG_IPV6) 510 static int nfsd_inet6addr_event(struct notifier_block *this, 511 unsigned long event, void *ptr) 512 { 513 struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr; 514 struct net_device *dev = ifa->idev->dev; 515 struct net *net = dev_net(dev); 516 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 517 struct sockaddr_in6 sin6; 518 519 if (event != NETDEV_DOWN || !nn->nfsd_serv) 520 goto out; 521 522 spin_lock(&nfsd_notifier_lock); 523 if (nn->nfsd_serv) { 524 dprintk("nfsd_inet6addr_event: removed %pI6\n", &ifa->addr); 525 sin6.sin6_family = AF_INET6; 526 sin6.sin6_addr = ifa->addr; 527 if (ipv6_addr_type(&sin6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 528 sin6.sin6_scope_id = ifa->idev->dev->ifindex; 529 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin6); 530 } 531 spin_unlock(&nfsd_notifier_lock); 532 533 out: 534 return NOTIFY_DONE; 535 } 536 537 static struct notifier_block nfsd_inet6addr_notifier = { 538 .notifier_call = nfsd_inet6addr_event, 539 }; 540 #endif 541 542 /* Only used under nfsd_mutex, so this atomic may be overkill: */ 543 static atomic_t nfsd_notifier_refcount = ATOMIC_INIT(0); 544 545 static void nfsd_last_thread(struct svc_serv *serv, struct net *net) 546 { 547 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 548 549 /* check if the notifier still has clients */ 550 if (atomic_dec_return(&nfsd_notifier_refcount) == 0) { 551 unregister_inetaddr_notifier(&nfsd_inetaddr_notifier); 552 #if IS_ENABLED(CONFIG_IPV6) 553 unregister_inet6addr_notifier(&nfsd_inet6addr_notifier); 554 #endif 555 } 556 557 /* 558 * write_ports can create the server without actually starting 559 * any threads--if we get shut down before any threads are 560 * started, then nfsd_last_thread will be run before any of this 561 * other initialization has been done except the rpcb information. 562 */ 563 svc_rpcb_cleanup(serv, net); 564 if (!nn->nfsd_net_up) 565 return; 566 567 nfsd_shutdown_net(net); 568 pr_info("nfsd: last server has exited, flushing export cache\n"); 569 nfsd_export_flush(net); 570 } 571 572 void nfsd_reset_versions(struct nfsd_net *nn) 573 { 574 int i; 575 576 for (i = 0; i < NFSD_NRVERS; i++) 577 if (nfsd_vers(nn, i, NFSD_TEST)) 578 return; 579 580 for (i = 0; i < NFSD_NRVERS; i++) 581 if (i != 4) 582 nfsd_vers(nn, i, NFSD_SET); 583 else { 584 int minor = 0; 585 while (nfsd_minorversion(nn, minor, NFSD_SET) >= 0) 586 minor++; 587 } 588 } 589 590 /* 591 * Each session guarantees a negotiated per slot memory cache for replies 592 * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated 593 * NFSv4.1 server might want to use more memory for a DRC than a machine 594 * with mutiple services. 595 * 596 * Impose a hard limit on the number of pages for the DRC which varies 597 * according to the machines free pages. This is of course only a default. 598 * 599 * For now this is a #defined shift which could be under admin control 600 * in the future. 601 */ 602 static void set_max_drc(void) 603 { 604 #define NFSD_DRC_SIZE_SHIFT 7 605 nfsd_drc_max_mem = (nr_free_buffer_pages() 606 >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE; 607 nfsd_drc_mem_used = 0; 608 dprintk("%s nfsd_drc_max_mem %lu \n", __func__, nfsd_drc_max_mem); 609 } 610 611 static int nfsd_get_default_max_blksize(void) 612 { 613 struct sysinfo i; 614 unsigned long long target; 615 unsigned long ret; 616 617 si_meminfo(&i); 618 target = (i.totalram - i.totalhigh) << PAGE_SHIFT; 619 /* 620 * Aim for 1/4096 of memory per thread This gives 1MB on 4Gig 621 * machines, but only uses 32K on 128M machines. Bottom out at 622 * 8K on 32M and smaller. Of course, this is only a default. 623 */ 624 target >>= 12; 625 626 ret = NFSSVC_MAXBLKSIZE; 627 while (ret > target && ret >= 8*1024*2) 628 ret /= 2; 629 return ret; 630 } 631 632 void nfsd_shutdown_threads(struct net *net) 633 { 634 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 635 struct svc_serv *serv; 636 637 mutex_lock(&nfsd_mutex); 638 serv = nn->nfsd_serv; 639 if (serv == NULL) { 640 mutex_unlock(&nfsd_mutex); 641 return; 642 } 643 644 svc_get(serv); 645 /* Kill outstanding nfsd threads */ 646 svc_set_num_threads(serv, NULL, 0); 647 nfsd_put(net); 648 mutex_unlock(&nfsd_mutex); 649 } 650 651 bool i_am_nfsd(void) 652 { 653 return kthread_func(current) == nfsd; 654 } 655 656 int nfsd_create_serv(struct net *net) 657 { 658 int error; 659 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 660 struct svc_serv *serv; 661 662 WARN_ON(!mutex_is_locked(&nfsd_mutex)); 663 if (nn->nfsd_serv) { 664 svc_get(nn->nfsd_serv); 665 return 0; 666 } 667 if (nfsd_max_blksize == 0) 668 nfsd_max_blksize = nfsd_get_default_max_blksize(); 669 nfsd_reset_versions(nn); 670 serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize, nfsd); 671 if (serv == NULL) 672 return -ENOMEM; 673 674 serv->sv_maxconn = nn->max_connections; 675 error = svc_bind(serv, net); 676 if (error < 0) { 677 /* NOT nfsd_put() as notifiers (see below) haven't 678 * been set up yet. 679 */ 680 svc_put(serv); 681 return error; 682 } 683 spin_lock(&nfsd_notifier_lock); 684 nn->nfsd_serv = serv; 685 spin_unlock(&nfsd_notifier_lock); 686 687 set_max_drc(); 688 /* check if the notifier is already set */ 689 if (atomic_inc_return(&nfsd_notifier_refcount) == 1) { 690 register_inetaddr_notifier(&nfsd_inetaddr_notifier); 691 #if IS_ENABLED(CONFIG_IPV6) 692 register_inet6addr_notifier(&nfsd_inet6addr_notifier); 693 #endif 694 } 695 nfsd_reset_write_verifier(nn); 696 return 0; 697 } 698 699 int nfsd_nrpools(struct net *net) 700 { 701 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 702 703 if (nn->nfsd_serv == NULL) 704 return 0; 705 else 706 return nn->nfsd_serv->sv_nrpools; 707 } 708 709 int nfsd_get_nrthreads(int n, int *nthreads, struct net *net) 710 { 711 int i = 0; 712 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 713 714 if (nn->nfsd_serv != NULL) { 715 for (i = 0; i < nn->nfsd_serv->sv_nrpools && i < n; i++) 716 nthreads[i] = nn->nfsd_serv->sv_pools[i].sp_nrthreads; 717 } 718 719 return 0; 720 } 721 722 /* This is the callback for kref_put() below. 723 * There is no code here as the first thing to be done is 724 * call svc_shutdown_net(), but we cannot get the 'net' from 725 * the kref. So do all the work when kref_put returns true. 726 */ 727 static void nfsd_noop(struct kref *ref) 728 { 729 } 730 731 void nfsd_put(struct net *net) 732 { 733 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 734 735 if (kref_put(&nn->nfsd_serv->sv_refcnt, nfsd_noop)) { 736 svc_xprt_destroy_all(nn->nfsd_serv, net); 737 nfsd_last_thread(nn->nfsd_serv, net); 738 svc_destroy(&nn->nfsd_serv->sv_refcnt); 739 spin_lock(&nfsd_notifier_lock); 740 nn->nfsd_serv = NULL; 741 spin_unlock(&nfsd_notifier_lock); 742 } 743 } 744 745 int nfsd_set_nrthreads(int n, int *nthreads, struct net *net) 746 { 747 int i = 0; 748 int tot = 0; 749 int err = 0; 750 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 751 752 WARN_ON(!mutex_is_locked(&nfsd_mutex)); 753 754 if (nn->nfsd_serv == NULL || n <= 0) 755 return 0; 756 757 if (n > nn->nfsd_serv->sv_nrpools) 758 n = nn->nfsd_serv->sv_nrpools; 759 760 /* enforce a global maximum number of threads */ 761 tot = 0; 762 for (i = 0; i < n; i++) { 763 nthreads[i] = min(nthreads[i], NFSD_MAXSERVS); 764 tot += nthreads[i]; 765 } 766 if (tot > NFSD_MAXSERVS) { 767 /* total too large: scale down requested numbers */ 768 for (i = 0; i < n && tot > 0; i++) { 769 int new = nthreads[i] * NFSD_MAXSERVS / tot; 770 tot -= (nthreads[i] - new); 771 nthreads[i] = new; 772 } 773 for (i = 0; i < n && tot > 0; i++) { 774 nthreads[i]--; 775 tot--; 776 } 777 } 778 779 /* 780 * There must always be a thread in pool 0; the admin 781 * can't shut down NFS completely using pool_threads. 782 */ 783 if (nthreads[0] == 0) 784 nthreads[0] = 1; 785 786 /* apply the new numbers */ 787 svc_get(nn->nfsd_serv); 788 for (i = 0; i < n; i++) { 789 err = svc_set_num_threads(nn->nfsd_serv, 790 &nn->nfsd_serv->sv_pools[i], 791 nthreads[i]); 792 if (err) 793 break; 794 } 795 nfsd_put(net); 796 return err; 797 } 798 799 /* 800 * Adjust the number of threads and return the new number of threads. 801 * This is also the function that starts the server if necessary, if 802 * this is the first time nrservs is nonzero. 803 */ 804 int 805 nfsd_svc(int nrservs, struct net *net, const struct cred *cred) 806 { 807 int error; 808 bool nfsd_up_before; 809 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 810 811 mutex_lock(&nfsd_mutex); 812 dprintk("nfsd: creating service\n"); 813 814 nrservs = max(nrservs, 0); 815 nrservs = min(nrservs, NFSD_MAXSERVS); 816 error = 0; 817 818 if (nrservs == 0 && nn->nfsd_serv == NULL) 819 goto out; 820 821 strscpy(nn->nfsd_name, utsname()->nodename, 822 sizeof(nn->nfsd_name)); 823 824 error = nfsd_create_serv(net); 825 if (error) 826 goto out; 827 828 nfsd_up_before = nn->nfsd_net_up; 829 830 error = nfsd_startup_net(net, cred); 831 if (error) 832 goto out_put; 833 error = svc_set_num_threads(nn->nfsd_serv, NULL, nrservs); 834 if (error) 835 goto out_shutdown; 836 error = nn->nfsd_serv->sv_nrthreads; 837 out_shutdown: 838 if (error < 0 && !nfsd_up_before) 839 nfsd_shutdown_net(net); 840 out_put: 841 /* Threads now hold service active */ 842 if (xchg(&nn->keep_active, 0)) 843 nfsd_put(net); 844 nfsd_put(net); 845 out: 846 mutex_unlock(&nfsd_mutex); 847 return error; 848 } 849 850 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 851 static bool 852 nfsd_support_acl_version(int vers) 853 { 854 if (vers >= NFSD_ACL_MINVERS && vers < NFSD_ACL_NRVERS) 855 return nfsd_acl_version[vers] != NULL; 856 return false; 857 } 858 859 static int 860 nfsd_acl_rpcbind_set(struct net *net, const struct svc_program *progp, 861 u32 version, int family, unsigned short proto, 862 unsigned short port) 863 { 864 if (!nfsd_support_acl_version(version) || 865 !nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST)) 866 return 0; 867 return svc_generic_rpcbind_set(net, progp, version, family, 868 proto, port); 869 } 870 871 static __be32 872 nfsd_acl_init_request(struct svc_rqst *rqstp, 873 const struct svc_program *progp, 874 struct svc_process_info *ret) 875 { 876 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); 877 int i; 878 879 if (likely(nfsd_support_acl_version(rqstp->rq_vers) && 880 nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST))) 881 return svc_generic_init_request(rqstp, progp, ret); 882 883 ret->mismatch.lovers = NFSD_ACL_NRVERS; 884 for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) { 885 if (nfsd_support_acl_version(rqstp->rq_vers) && 886 nfsd_vers(nn, i, NFSD_TEST)) { 887 ret->mismatch.lovers = i; 888 break; 889 } 890 } 891 if (ret->mismatch.lovers == NFSD_ACL_NRVERS) 892 return rpc_prog_unavail; 893 ret->mismatch.hivers = NFSD_ACL_MINVERS; 894 for (i = NFSD_ACL_NRVERS - 1; i >= NFSD_ACL_MINVERS; i--) { 895 if (nfsd_support_acl_version(rqstp->rq_vers) && 896 nfsd_vers(nn, i, NFSD_TEST)) { 897 ret->mismatch.hivers = i; 898 break; 899 } 900 } 901 return rpc_prog_mismatch; 902 } 903 #endif 904 905 static int 906 nfsd_rpcbind_set(struct net *net, const struct svc_program *progp, 907 u32 version, int family, unsigned short proto, 908 unsigned short port) 909 { 910 if (!nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST)) 911 return 0; 912 return svc_generic_rpcbind_set(net, progp, version, family, 913 proto, port); 914 } 915 916 static __be32 917 nfsd_init_request(struct svc_rqst *rqstp, 918 const struct svc_program *progp, 919 struct svc_process_info *ret) 920 { 921 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); 922 int i; 923 924 if (likely(nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST))) 925 return svc_generic_init_request(rqstp, progp, ret); 926 927 ret->mismatch.lovers = NFSD_NRVERS; 928 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) { 929 if (nfsd_vers(nn, i, NFSD_TEST)) { 930 ret->mismatch.lovers = i; 931 break; 932 } 933 } 934 if (ret->mismatch.lovers == NFSD_NRVERS) 935 return rpc_prog_unavail; 936 ret->mismatch.hivers = NFSD_MINVERS; 937 for (i = NFSD_NRVERS - 1; i >= NFSD_MINVERS; i--) { 938 if (nfsd_vers(nn, i, NFSD_TEST)) { 939 ret->mismatch.hivers = i; 940 break; 941 } 942 } 943 return rpc_prog_mismatch; 944 } 945 946 /* 947 * This is the NFS server kernel thread 948 */ 949 static int 950 nfsd(void *vrqstp) 951 { 952 struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp; 953 struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list); 954 struct net *net = perm_sock->xpt_net; 955 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 956 int err; 957 958 /* At this point, the thread shares current->fs 959 * with the init process. We need to create files with the 960 * umask as defined by the client instead of init's umask. */ 961 if (unshare_fs_struct() < 0) { 962 printk("Unable to start nfsd thread: out of memory\n"); 963 goto out; 964 } 965 966 current->fs->umask = 0; 967 968 /* 969 * thread is spawned with all signals set to SIG_IGN, re-enable 970 * the ones that will bring down the thread 971 */ 972 allow_signal(SIGKILL); 973 allow_signal(SIGHUP); 974 allow_signal(SIGINT); 975 allow_signal(SIGQUIT); 976 977 atomic_inc(&nfsdstats.th_cnt); 978 979 set_freezable(); 980 981 /* 982 * The main request loop 983 */ 984 for (;;) { 985 /* Update sv_maxconn if it has changed */ 986 rqstp->rq_server->sv_maxconn = nn->max_connections; 987 988 /* 989 * Find a socket with data available and call its 990 * recvfrom routine. 991 */ 992 while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN) 993 ; 994 if (err == -EINTR) 995 break; 996 validate_process_creds(); 997 svc_process(rqstp); 998 validate_process_creds(); 999 } 1000 1001 /* Clear signals before calling svc_exit_thread() */ 1002 flush_signals(current); 1003 1004 atomic_dec(&nfsdstats.th_cnt); 1005 1006 out: 1007 /* Take an extra ref so that the svc_put in svc_exit_thread() 1008 * doesn't call svc_destroy() 1009 */ 1010 svc_get(nn->nfsd_serv); 1011 1012 /* Release the thread */ 1013 svc_exit_thread(rqstp); 1014 1015 /* We need to drop a ref, but may not drop the last reference 1016 * without holding nfsd_mutex, and we cannot wait for nfsd_mutex as that 1017 * could deadlock with nfsd_shutdown_threads() waiting for us. 1018 * So three options are: 1019 * - drop a non-final reference, 1020 * - get the mutex without waiting 1021 * - sleep briefly andd try the above again 1022 */ 1023 while (!svc_put_not_last(nn->nfsd_serv)) { 1024 if (mutex_trylock(&nfsd_mutex)) { 1025 nfsd_put(net); 1026 mutex_unlock(&nfsd_mutex); 1027 break; 1028 } 1029 msleep(20); 1030 } 1031 1032 return 0; 1033 } 1034 1035 /** 1036 * nfsd_dispatch - Process an NFS or NFSACL Request 1037 * @rqstp: incoming request 1038 * 1039 * This RPC dispatcher integrates the NFS server's duplicate reply cache. 1040 * 1041 * Return values: 1042 * %0: Processing complete; do not send a Reply 1043 * %1: Processing complete; send Reply in rqstp->rq_res 1044 */ 1045 int nfsd_dispatch(struct svc_rqst *rqstp) 1046 { 1047 const struct svc_procedure *proc = rqstp->rq_procinfo; 1048 __be32 *statp = rqstp->rq_accept_statp; 1049 1050 /* 1051 * Give the xdr decoder a chance to change this if it wants 1052 * (necessary in the NFSv4.0 compound case) 1053 */ 1054 rqstp->rq_cachetype = proc->pc_cachetype; 1055 1056 if (!proc->pc_decode(rqstp, &rqstp->rq_arg_stream)) 1057 goto out_decode_err; 1058 1059 switch (nfsd_cache_lookup(rqstp)) { 1060 case RC_DOIT: 1061 break; 1062 case RC_REPLY: 1063 goto out_cached_reply; 1064 case RC_DROPIT: 1065 goto out_dropit; 1066 } 1067 1068 *statp = proc->pc_func(rqstp); 1069 if (test_bit(RQ_DROPME, &rqstp->rq_flags)) 1070 goto out_update_drop; 1071 1072 if (!proc->pc_encode(rqstp, &rqstp->rq_res_stream)) 1073 goto out_encode_err; 1074 1075 nfsd_cache_update(rqstp, rqstp->rq_cachetype, statp + 1); 1076 out_cached_reply: 1077 return 1; 1078 1079 out_decode_err: 1080 trace_nfsd_garbage_args_err(rqstp); 1081 *statp = rpc_garbage_args; 1082 return 1; 1083 1084 out_update_drop: 1085 nfsd_cache_update(rqstp, RC_NOCACHE, NULL); 1086 out_dropit: 1087 return 0; 1088 1089 out_encode_err: 1090 trace_nfsd_cant_encode_err(rqstp); 1091 nfsd_cache_update(rqstp, RC_NOCACHE, NULL); 1092 *statp = rpc_system_err; 1093 return 1; 1094 } 1095 1096 /** 1097 * nfssvc_decode_voidarg - Decode void arguments 1098 * @rqstp: Server RPC transaction context 1099 * @xdr: XDR stream positioned at arguments to decode 1100 * 1101 * Return values: 1102 * %false: Arguments were not valid 1103 * %true: Decoding was successful 1104 */ 1105 bool nfssvc_decode_voidarg(struct svc_rqst *rqstp, struct xdr_stream *xdr) 1106 { 1107 return true; 1108 } 1109 1110 /** 1111 * nfssvc_encode_voidres - Encode void results 1112 * @rqstp: Server RPC transaction context 1113 * @xdr: XDR stream into which to encode results 1114 * 1115 * Return values: 1116 * %false: Local error while encoding 1117 * %true: Encoding was successful 1118 */ 1119 bool nfssvc_encode_voidres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 1120 { 1121 return true; 1122 } 1123 1124 int nfsd_pool_stats_open(struct inode *inode, struct file *file) 1125 { 1126 int ret; 1127 struct nfsd_net *nn = net_generic(inode->i_sb->s_fs_info, nfsd_net_id); 1128 1129 mutex_lock(&nfsd_mutex); 1130 if (nn->nfsd_serv == NULL) { 1131 mutex_unlock(&nfsd_mutex); 1132 return -ENODEV; 1133 } 1134 svc_get(nn->nfsd_serv); 1135 ret = svc_pool_stats_open(nn->nfsd_serv, file); 1136 mutex_unlock(&nfsd_mutex); 1137 return ret; 1138 } 1139 1140 int nfsd_pool_stats_release(struct inode *inode, struct file *file) 1141 { 1142 int ret = seq_release(inode, file); 1143 struct net *net = inode->i_sb->s_fs_info; 1144 1145 mutex_lock(&nfsd_mutex); 1146 nfsd_put(net); 1147 mutex_unlock(&nfsd_mutex); 1148 return ret; 1149 } 1150