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 void nfsd_last_thread(struct net *net) 546 { 547 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 548 struct svc_serv *serv = nn->nfsd_serv; 549 550 spin_lock(&nfsd_notifier_lock); 551 nn->nfsd_serv = NULL; 552 spin_unlock(&nfsd_notifier_lock); 553 554 /* check if the notifier still has clients */ 555 if (atomic_dec_return(&nfsd_notifier_refcount) == 0) { 556 unregister_inetaddr_notifier(&nfsd_inetaddr_notifier); 557 #if IS_ENABLED(CONFIG_IPV6) 558 unregister_inet6addr_notifier(&nfsd_inet6addr_notifier); 559 #endif 560 } 561 562 svc_xprt_destroy_all(serv, net); 563 564 /* 565 * write_ports can create the server without actually starting 566 * any threads--if we get shut down before any threads are 567 * started, then nfsd_last_thread will be run before any of this 568 * other initialization has been done except the rpcb information. 569 */ 570 svc_rpcb_cleanup(serv, net); 571 if (!nn->nfsd_net_up) 572 return; 573 574 nfsd_shutdown_net(net); 575 nfsd_export_flush(net); 576 } 577 578 void nfsd_reset_versions(struct nfsd_net *nn) 579 { 580 int i; 581 582 for (i = 0; i < NFSD_NRVERS; i++) 583 if (nfsd_vers(nn, i, NFSD_TEST)) 584 return; 585 586 for (i = 0; i < NFSD_NRVERS; i++) 587 if (i != 4) 588 nfsd_vers(nn, i, NFSD_SET); 589 else { 590 int minor = 0; 591 while (nfsd_minorversion(nn, minor, NFSD_SET) >= 0) 592 minor++; 593 } 594 } 595 596 /* 597 * Each session guarantees a negotiated per slot memory cache for replies 598 * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated 599 * NFSv4.1 server might want to use more memory for a DRC than a machine 600 * with mutiple services. 601 * 602 * Impose a hard limit on the number of pages for the DRC which varies 603 * according to the machines free pages. This is of course only a default. 604 * 605 * For now this is a #defined shift which could be under admin control 606 * in the future. 607 */ 608 static void set_max_drc(void) 609 { 610 #define NFSD_DRC_SIZE_SHIFT 7 611 nfsd_drc_max_mem = (nr_free_buffer_pages() 612 >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE; 613 nfsd_drc_mem_used = 0; 614 dprintk("%s nfsd_drc_max_mem %lu \n", __func__, nfsd_drc_max_mem); 615 } 616 617 static int nfsd_get_default_max_blksize(void) 618 { 619 struct sysinfo i; 620 unsigned long long target; 621 unsigned long ret; 622 623 si_meminfo(&i); 624 target = (i.totalram - i.totalhigh) << PAGE_SHIFT; 625 /* 626 * Aim for 1/4096 of memory per thread This gives 1MB on 4Gig 627 * machines, but only uses 32K on 128M machines. Bottom out at 628 * 8K on 32M and smaller. Of course, this is only a default. 629 */ 630 target >>= 12; 631 632 ret = NFSSVC_MAXBLKSIZE; 633 while (ret > target && ret >= 8*1024*2) 634 ret /= 2; 635 return ret; 636 } 637 638 void nfsd_shutdown_threads(struct net *net) 639 { 640 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 641 struct svc_serv *serv; 642 643 mutex_lock(&nfsd_mutex); 644 serv = nn->nfsd_serv; 645 if (serv == NULL) { 646 mutex_unlock(&nfsd_mutex); 647 return; 648 } 649 650 svc_get(serv); 651 /* Kill outstanding nfsd threads */ 652 svc_set_num_threads(serv, NULL, 0); 653 nfsd_last_thread(net); 654 svc_put(serv); 655 mutex_unlock(&nfsd_mutex); 656 } 657 658 bool i_am_nfsd(void) 659 { 660 return kthread_func(current) == nfsd; 661 } 662 663 int nfsd_create_serv(struct net *net) 664 { 665 int error; 666 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 667 struct svc_serv *serv; 668 669 WARN_ON(!mutex_is_locked(&nfsd_mutex)); 670 if (nn->nfsd_serv) { 671 svc_get(nn->nfsd_serv); 672 return 0; 673 } 674 if (nfsd_max_blksize == 0) 675 nfsd_max_blksize = nfsd_get_default_max_blksize(); 676 nfsd_reset_versions(nn); 677 serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize, nfsd); 678 if (serv == NULL) 679 return -ENOMEM; 680 681 serv->sv_maxconn = nn->max_connections; 682 error = svc_bind(serv, net); 683 if (error < 0) { 684 svc_put(serv); 685 return error; 686 } 687 spin_lock(&nfsd_notifier_lock); 688 nn->nfsd_serv = serv; 689 spin_unlock(&nfsd_notifier_lock); 690 691 set_max_drc(); 692 /* check if the notifier is already set */ 693 if (atomic_inc_return(&nfsd_notifier_refcount) == 1) { 694 register_inetaddr_notifier(&nfsd_inetaddr_notifier); 695 #if IS_ENABLED(CONFIG_IPV6) 696 register_inet6addr_notifier(&nfsd_inet6addr_notifier); 697 #endif 698 } 699 nfsd_reset_write_verifier(nn); 700 return 0; 701 } 702 703 int nfsd_nrpools(struct net *net) 704 { 705 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 706 707 if (nn->nfsd_serv == NULL) 708 return 0; 709 else 710 return nn->nfsd_serv->sv_nrpools; 711 } 712 713 int nfsd_get_nrthreads(int n, int *nthreads, struct net *net) 714 { 715 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 716 struct svc_serv *serv = nn->nfsd_serv; 717 int i; 718 719 if (serv) 720 for (i = 0; i < serv->sv_nrpools && i < n; i++) 721 nthreads[i] = atomic_read(&serv->sv_pools[i].sp_nrthreads); 722 return 0; 723 } 724 725 int nfsd_set_nrthreads(int n, int *nthreads, struct net *net) 726 { 727 int i = 0; 728 int tot = 0; 729 int err = 0; 730 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 731 732 WARN_ON(!mutex_is_locked(&nfsd_mutex)); 733 734 if (nn->nfsd_serv == NULL || n <= 0) 735 return 0; 736 737 if (n > nn->nfsd_serv->sv_nrpools) 738 n = nn->nfsd_serv->sv_nrpools; 739 740 /* enforce a global maximum number of threads */ 741 tot = 0; 742 for (i = 0; i < n; i++) { 743 nthreads[i] = min(nthreads[i], NFSD_MAXSERVS); 744 tot += nthreads[i]; 745 } 746 if (tot > NFSD_MAXSERVS) { 747 /* total too large: scale down requested numbers */ 748 for (i = 0; i < n && tot > 0; i++) { 749 int new = nthreads[i] * NFSD_MAXSERVS / tot; 750 tot -= (nthreads[i] - new); 751 nthreads[i] = new; 752 } 753 for (i = 0; i < n && tot > 0; i++) { 754 nthreads[i]--; 755 tot--; 756 } 757 } 758 759 /* 760 * There must always be a thread in pool 0; the admin 761 * can't shut down NFS completely using pool_threads. 762 */ 763 if (nthreads[0] == 0) 764 nthreads[0] = 1; 765 766 /* apply the new numbers */ 767 svc_get(nn->nfsd_serv); 768 for (i = 0; i < n; i++) { 769 err = svc_set_num_threads(nn->nfsd_serv, 770 &nn->nfsd_serv->sv_pools[i], 771 nthreads[i]); 772 if (err) 773 break; 774 } 775 svc_put(nn->nfsd_serv); 776 return err; 777 } 778 779 /* 780 * Adjust the number of threads and return the new number of threads. 781 * This is also the function that starts the server if necessary, if 782 * this is the first time nrservs is nonzero. 783 */ 784 int 785 nfsd_svc(int nrservs, struct net *net, const struct cred *cred) 786 { 787 int error; 788 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 789 struct svc_serv *serv; 790 791 mutex_lock(&nfsd_mutex); 792 dprintk("nfsd: creating service\n"); 793 794 nrservs = max(nrservs, 0); 795 nrservs = min(nrservs, NFSD_MAXSERVS); 796 error = 0; 797 798 if (nrservs == 0 && nn->nfsd_serv == NULL) 799 goto out; 800 801 strscpy(nn->nfsd_name, utsname()->nodename, 802 sizeof(nn->nfsd_name)); 803 804 error = nfsd_create_serv(net); 805 if (error) 806 goto out; 807 serv = nn->nfsd_serv; 808 809 error = nfsd_startup_net(net, cred); 810 if (error) 811 goto out_put; 812 error = svc_set_num_threads(serv, NULL, nrservs); 813 if (error) 814 goto out_put; 815 error = serv->sv_nrthreads; 816 out_put: 817 /* Threads now hold service active */ 818 if (xchg(&nn->keep_active, 0)) 819 svc_put(serv); 820 821 if (serv->sv_nrthreads == 0) 822 nfsd_last_thread(net); 823 svc_put(serv); 824 out: 825 mutex_unlock(&nfsd_mutex); 826 return error; 827 } 828 829 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 830 static bool 831 nfsd_support_acl_version(int vers) 832 { 833 if (vers >= NFSD_ACL_MINVERS && vers < NFSD_ACL_NRVERS) 834 return nfsd_acl_version[vers] != NULL; 835 return false; 836 } 837 838 static int 839 nfsd_acl_rpcbind_set(struct net *net, const struct svc_program *progp, 840 u32 version, int family, unsigned short proto, 841 unsigned short port) 842 { 843 if (!nfsd_support_acl_version(version) || 844 !nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST)) 845 return 0; 846 return svc_generic_rpcbind_set(net, progp, version, family, 847 proto, port); 848 } 849 850 static __be32 851 nfsd_acl_init_request(struct svc_rqst *rqstp, 852 const struct svc_program *progp, 853 struct svc_process_info *ret) 854 { 855 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); 856 int i; 857 858 if (likely(nfsd_support_acl_version(rqstp->rq_vers) && 859 nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST))) 860 return svc_generic_init_request(rqstp, progp, ret); 861 862 ret->mismatch.lovers = NFSD_ACL_NRVERS; 863 for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) { 864 if (nfsd_support_acl_version(rqstp->rq_vers) && 865 nfsd_vers(nn, i, NFSD_TEST)) { 866 ret->mismatch.lovers = i; 867 break; 868 } 869 } 870 if (ret->mismatch.lovers == NFSD_ACL_NRVERS) 871 return rpc_prog_unavail; 872 ret->mismatch.hivers = NFSD_ACL_MINVERS; 873 for (i = NFSD_ACL_NRVERS - 1; i >= NFSD_ACL_MINVERS; i--) { 874 if (nfsd_support_acl_version(rqstp->rq_vers) && 875 nfsd_vers(nn, i, NFSD_TEST)) { 876 ret->mismatch.hivers = i; 877 break; 878 } 879 } 880 return rpc_prog_mismatch; 881 } 882 #endif 883 884 static int 885 nfsd_rpcbind_set(struct net *net, const struct svc_program *progp, 886 u32 version, int family, unsigned short proto, 887 unsigned short port) 888 { 889 if (!nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST)) 890 return 0; 891 return svc_generic_rpcbind_set(net, progp, version, family, 892 proto, port); 893 } 894 895 static __be32 896 nfsd_init_request(struct svc_rqst *rqstp, 897 const struct svc_program *progp, 898 struct svc_process_info *ret) 899 { 900 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); 901 int i; 902 903 if (likely(nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST))) 904 return svc_generic_init_request(rqstp, progp, ret); 905 906 ret->mismatch.lovers = NFSD_NRVERS; 907 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) { 908 if (nfsd_vers(nn, i, NFSD_TEST)) { 909 ret->mismatch.lovers = i; 910 break; 911 } 912 } 913 if (ret->mismatch.lovers == NFSD_NRVERS) 914 return rpc_prog_unavail; 915 ret->mismatch.hivers = NFSD_MINVERS; 916 for (i = NFSD_NRVERS - 1; i >= NFSD_MINVERS; i--) { 917 if (nfsd_vers(nn, i, NFSD_TEST)) { 918 ret->mismatch.hivers = i; 919 break; 920 } 921 } 922 return rpc_prog_mismatch; 923 } 924 925 /* 926 * This is the NFS server kernel thread 927 */ 928 static int 929 nfsd(void *vrqstp) 930 { 931 struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp; 932 struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list); 933 struct net *net = perm_sock->xpt_net; 934 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 935 936 /* At this point, the thread shares current->fs 937 * with the init process. We need to create files with the 938 * umask as defined by the client instead of init's umask. */ 939 if (unshare_fs_struct() < 0) { 940 printk("Unable to start nfsd thread: out of memory\n"); 941 goto out; 942 } 943 944 current->fs->umask = 0; 945 946 atomic_inc(&nfsdstats.th_cnt); 947 948 set_freezable(); 949 950 /* 951 * The main request loop 952 */ 953 while (!svc_thread_should_stop(rqstp)) { 954 /* Update sv_maxconn if it has changed */ 955 rqstp->rq_server->sv_maxconn = nn->max_connections; 956 957 svc_recv(rqstp); 958 } 959 960 atomic_dec(&nfsdstats.th_cnt); 961 962 out: 963 /* Release the thread */ 964 svc_exit_thread(rqstp); 965 return 0; 966 } 967 968 /** 969 * nfsd_dispatch - Process an NFS or NFSACL Request 970 * @rqstp: incoming request 971 * 972 * This RPC dispatcher integrates the NFS server's duplicate reply cache. 973 * 974 * Return values: 975 * %0: Processing complete; do not send a Reply 976 * %1: Processing complete; send Reply in rqstp->rq_res 977 */ 978 int nfsd_dispatch(struct svc_rqst *rqstp) 979 { 980 const struct svc_procedure *proc = rqstp->rq_procinfo; 981 __be32 *statp = rqstp->rq_accept_statp; 982 struct nfsd_cacherep *rp; 983 unsigned int start, len; 984 __be32 *nfs_reply; 985 986 /* 987 * Give the xdr decoder a chance to change this if it wants 988 * (necessary in the NFSv4.0 compound case) 989 */ 990 rqstp->rq_cachetype = proc->pc_cachetype; 991 992 /* 993 * ->pc_decode advances the argument stream past the NFS 994 * Call header, so grab the header's starting location and 995 * size now for the call to nfsd_cache_lookup(). 996 */ 997 start = xdr_stream_pos(&rqstp->rq_arg_stream); 998 len = xdr_stream_remaining(&rqstp->rq_arg_stream); 999 if (!proc->pc_decode(rqstp, &rqstp->rq_arg_stream)) 1000 goto out_decode_err; 1001 1002 /* 1003 * Release rq_status_counter setting it to an odd value after the rpc 1004 * request has been properly parsed. rq_status_counter is used to 1005 * notify the consumers if the rqstp fields are stable 1006 * (rq_status_counter is odd) or not meaningful (rq_status_counter 1007 * is even). 1008 */ 1009 smp_store_release(&rqstp->rq_status_counter, rqstp->rq_status_counter | 1); 1010 1011 rp = NULL; 1012 switch (nfsd_cache_lookup(rqstp, start, len, &rp)) { 1013 case RC_DOIT: 1014 break; 1015 case RC_REPLY: 1016 goto out_cached_reply; 1017 case RC_DROPIT: 1018 goto out_dropit; 1019 } 1020 1021 nfs_reply = xdr_inline_decode(&rqstp->rq_res_stream, 0); 1022 *statp = proc->pc_func(rqstp); 1023 if (test_bit(RQ_DROPME, &rqstp->rq_flags)) 1024 goto out_update_drop; 1025 1026 if (!proc->pc_encode(rqstp, &rqstp->rq_res_stream)) 1027 goto out_encode_err; 1028 1029 /* 1030 * Release rq_status_counter setting it to an even value after the rpc 1031 * request has been properly processed. 1032 */ 1033 smp_store_release(&rqstp->rq_status_counter, rqstp->rq_status_counter + 1); 1034 1035 nfsd_cache_update(rqstp, rp, rqstp->rq_cachetype, nfs_reply); 1036 out_cached_reply: 1037 return 1; 1038 1039 out_decode_err: 1040 trace_nfsd_garbage_args_err(rqstp); 1041 *statp = rpc_garbage_args; 1042 return 1; 1043 1044 out_update_drop: 1045 nfsd_cache_update(rqstp, rp, RC_NOCACHE, NULL); 1046 out_dropit: 1047 return 0; 1048 1049 out_encode_err: 1050 trace_nfsd_cant_encode_err(rqstp); 1051 nfsd_cache_update(rqstp, rp, RC_NOCACHE, NULL); 1052 *statp = rpc_system_err; 1053 return 1; 1054 } 1055 1056 /** 1057 * nfssvc_decode_voidarg - Decode void arguments 1058 * @rqstp: Server RPC transaction context 1059 * @xdr: XDR stream positioned at arguments to decode 1060 * 1061 * Return values: 1062 * %false: Arguments were not valid 1063 * %true: Decoding was successful 1064 */ 1065 bool nfssvc_decode_voidarg(struct svc_rqst *rqstp, struct xdr_stream *xdr) 1066 { 1067 return true; 1068 } 1069 1070 /** 1071 * nfssvc_encode_voidres - Encode void results 1072 * @rqstp: Server RPC transaction context 1073 * @xdr: XDR stream into which to encode results 1074 * 1075 * Return values: 1076 * %false: Local error while encoding 1077 * %true: Encoding was successful 1078 */ 1079 bool nfssvc_encode_voidres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 1080 { 1081 return true; 1082 } 1083 1084 int nfsd_pool_stats_open(struct inode *inode, struct file *file) 1085 { 1086 int ret; 1087 struct nfsd_net *nn = net_generic(inode->i_sb->s_fs_info, nfsd_net_id); 1088 1089 mutex_lock(&nfsd_mutex); 1090 if (nn->nfsd_serv == NULL) { 1091 mutex_unlock(&nfsd_mutex); 1092 return -ENODEV; 1093 } 1094 svc_get(nn->nfsd_serv); 1095 ret = svc_pool_stats_open(nn->nfsd_serv, file); 1096 mutex_unlock(&nfsd_mutex); 1097 return ret; 1098 } 1099 1100 int nfsd_pool_stats_release(struct inode *inode, struct file *file) 1101 { 1102 struct seq_file *seq = file->private_data; 1103 struct svc_serv *serv = seq->private; 1104 int ret = seq_release(inode, file); 1105 1106 mutex_lock(&nfsd_mutex); 1107 svc_put(serv); 1108 mutex_unlock(&nfsd_mutex); 1109 return ret; 1110 } 1111