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 * Finally, the nfsd_mutex also protects some of the global variables that are 63 * accessed when nfsd starts and that are settable via the write_* routines in 64 * nfsctl.c. In particular: 65 * 66 * user_recovery_dirname 67 * user_lease_time 68 * nfsd_versions 69 */ 70 DEFINE_MUTEX(nfsd_mutex); 71 72 /* 73 * nfsd_drc_lock protects nfsd_drc_max_pages and nfsd_drc_pages_used. 74 * nfsd_drc_max_pages limits the total amount of memory available for 75 * version 4.1 DRC caches. 76 * nfsd_drc_pages_used tracks the current version 4.1 DRC memory usage. 77 */ 78 DEFINE_SPINLOCK(nfsd_drc_lock); 79 unsigned long nfsd_drc_max_mem; 80 unsigned long nfsd_drc_mem_used; 81 82 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 83 static struct svc_stat nfsd_acl_svcstats; 84 static const struct svc_version *nfsd_acl_version[] = { 85 # if defined(CONFIG_NFSD_V2_ACL) 86 [2] = &nfsd_acl_version2, 87 # endif 88 # if defined(CONFIG_NFSD_V3_ACL) 89 [3] = &nfsd_acl_version3, 90 # endif 91 }; 92 93 #define NFSD_ACL_MINVERS 2 94 #define NFSD_ACL_NRVERS ARRAY_SIZE(nfsd_acl_version) 95 96 static struct svc_program nfsd_acl_program = { 97 .pg_prog = NFS_ACL_PROGRAM, 98 .pg_nvers = NFSD_ACL_NRVERS, 99 .pg_vers = nfsd_acl_version, 100 .pg_name = "nfsacl", 101 .pg_class = "nfsd", 102 .pg_stats = &nfsd_acl_svcstats, 103 .pg_authenticate = &svc_set_client, 104 .pg_init_request = nfsd_acl_init_request, 105 .pg_rpcbind_set = nfsd_acl_rpcbind_set, 106 }; 107 108 static struct svc_stat nfsd_acl_svcstats = { 109 .program = &nfsd_acl_program, 110 }; 111 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */ 112 113 static const struct svc_version *nfsd_version[] = { 114 #if defined(CONFIG_NFSD_V2) 115 [2] = &nfsd_version2, 116 #endif 117 [3] = &nfsd_version3, 118 #if defined(CONFIG_NFSD_V4) 119 [4] = &nfsd_version4, 120 #endif 121 }; 122 123 #define NFSD_MINVERS 2 124 #define NFSD_NRVERS ARRAY_SIZE(nfsd_version) 125 126 struct svc_program nfsd_program = { 127 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 128 .pg_next = &nfsd_acl_program, 129 #endif 130 .pg_prog = NFS_PROGRAM, /* program number */ 131 .pg_nvers = NFSD_NRVERS, /* nr of entries in nfsd_version */ 132 .pg_vers = nfsd_version, /* version table */ 133 .pg_name = "nfsd", /* program name */ 134 .pg_class = "nfsd", /* authentication class */ 135 .pg_stats = &nfsd_svcstats, /* version table */ 136 .pg_authenticate = &svc_set_client, /* export authentication */ 137 .pg_init_request = nfsd_init_request, 138 .pg_rpcbind_set = nfsd_rpcbind_set, 139 }; 140 141 static bool 142 nfsd_support_version(int vers) 143 { 144 if (vers >= NFSD_MINVERS && vers < NFSD_NRVERS) 145 return nfsd_version[vers] != NULL; 146 return false; 147 } 148 149 static bool * 150 nfsd_alloc_versions(void) 151 { 152 bool *vers = kmalloc_array(NFSD_NRVERS, sizeof(bool), GFP_KERNEL); 153 unsigned i; 154 155 if (vers) { 156 /* All compiled versions are enabled by default */ 157 for (i = 0; i < NFSD_NRVERS; i++) 158 vers[i] = nfsd_support_version(i); 159 } 160 return vers; 161 } 162 163 static bool * 164 nfsd_alloc_minorversions(void) 165 { 166 bool *vers = kmalloc_array(NFSD_SUPPORTED_MINOR_VERSION + 1, 167 sizeof(bool), GFP_KERNEL); 168 unsigned i; 169 170 if (vers) { 171 /* All minor versions are enabled by default */ 172 for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++) 173 vers[i] = nfsd_support_version(4); 174 } 175 return vers; 176 } 177 178 void 179 nfsd_netns_free_versions(struct nfsd_net *nn) 180 { 181 kfree(nn->nfsd_versions); 182 kfree(nn->nfsd4_minorversions); 183 nn->nfsd_versions = NULL; 184 nn->nfsd4_minorversions = NULL; 185 } 186 187 static void 188 nfsd_netns_init_versions(struct nfsd_net *nn) 189 { 190 if (!nn->nfsd_versions) { 191 nn->nfsd_versions = nfsd_alloc_versions(); 192 nn->nfsd4_minorversions = nfsd_alloc_minorversions(); 193 if (!nn->nfsd_versions || !nn->nfsd4_minorversions) 194 nfsd_netns_free_versions(nn); 195 } 196 } 197 198 int nfsd_vers(struct nfsd_net *nn, int vers, enum vers_op change) 199 { 200 if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS) 201 return 0; 202 switch(change) { 203 case NFSD_SET: 204 if (nn->nfsd_versions) 205 nn->nfsd_versions[vers] = nfsd_support_version(vers); 206 break; 207 case NFSD_CLEAR: 208 nfsd_netns_init_versions(nn); 209 if (nn->nfsd_versions) 210 nn->nfsd_versions[vers] = false; 211 break; 212 case NFSD_TEST: 213 if (nn->nfsd_versions) 214 return nn->nfsd_versions[vers]; 215 fallthrough; 216 case NFSD_AVAIL: 217 return nfsd_support_version(vers); 218 } 219 return 0; 220 } 221 222 static void 223 nfsd_adjust_nfsd_versions4(struct nfsd_net *nn) 224 { 225 unsigned i; 226 227 for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++) { 228 if (nn->nfsd4_minorversions[i]) 229 return; 230 } 231 nfsd_vers(nn, 4, NFSD_CLEAR); 232 } 233 234 int nfsd_minorversion(struct nfsd_net *nn, u32 minorversion, enum vers_op change) 235 { 236 if (minorversion > NFSD_SUPPORTED_MINOR_VERSION && 237 change != NFSD_AVAIL) 238 return -1; 239 240 switch(change) { 241 case NFSD_SET: 242 if (nn->nfsd4_minorversions) { 243 nfsd_vers(nn, 4, NFSD_SET); 244 nn->nfsd4_minorversions[minorversion] = 245 nfsd_vers(nn, 4, NFSD_TEST); 246 } 247 break; 248 case NFSD_CLEAR: 249 nfsd_netns_init_versions(nn); 250 if (nn->nfsd4_minorversions) { 251 nn->nfsd4_minorversions[minorversion] = false; 252 nfsd_adjust_nfsd_versions4(nn); 253 } 254 break; 255 case NFSD_TEST: 256 if (nn->nfsd4_minorversions) 257 return nn->nfsd4_minorversions[minorversion]; 258 return nfsd_vers(nn, 4, NFSD_TEST); 259 case NFSD_AVAIL: 260 return minorversion <= NFSD_SUPPORTED_MINOR_VERSION && 261 nfsd_vers(nn, 4, NFSD_AVAIL); 262 } 263 return 0; 264 } 265 266 /* 267 * Maximum number of nfsd processes 268 */ 269 #define NFSD_MAXSERVS 8192 270 271 int nfsd_nrthreads(struct net *net) 272 { 273 int rv = 0; 274 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 275 276 mutex_lock(&nfsd_mutex); 277 if (nn->nfsd_serv) 278 rv = nn->nfsd_serv->sv_nrthreads; 279 mutex_unlock(&nfsd_mutex); 280 return rv; 281 } 282 283 static int nfsd_init_socks(struct net *net, const struct cred *cred) 284 { 285 int error; 286 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 287 288 if (!list_empty(&nn->nfsd_serv->sv_permsocks)) 289 return 0; 290 291 error = svc_xprt_create(nn->nfsd_serv, "udp", net, PF_INET, NFS_PORT, 292 SVC_SOCK_DEFAULTS, cred); 293 if (error < 0) 294 return error; 295 296 error = svc_xprt_create(nn->nfsd_serv, "tcp", net, PF_INET, NFS_PORT, 297 SVC_SOCK_DEFAULTS, cred); 298 if (error < 0) 299 return error; 300 301 return 0; 302 } 303 304 static int nfsd_users = 0; 305 306 static int nfsd_startup_generic(void) 307 { 308 int ret; 309 310 if (nfsd_users++) 311 return 0; 312 313 ret = nfsd_file_cache_init(); 314 if (ret) 315 goto dec_users; 316 317 ret = nfs4_state_start(); 318 if (ret) 319 goto out_file_cache; 320 return 0; 321 322 out_file_cache: 323 nfsd_file_cache_shutdown(); 324 dec_users: 325 nfsd_users--; 326 return ret; 327 } 328 329 static void nfsd_shutdown_generic(void) 330 { 331 if (--nfsd_users) 332 return; 333 334 nfs4_state_shutdown(); 335 nfsd_file_cache_shutdown(); 336 } 337 338 static bool nfsd_needs_lockd(struct nfsd_net *nn) 339 { 340 return nfsd_vers(nn, 2, NFSD_TEST) || nfsd_vers(nn, 3, NFSD_TEST); 341 } 342 343 /** 344 * nfsd_copy_write_verifier - Atomically copy a write verifier 345 * @verf: buffer in which to receive the verifier cookie 346 * @nn: NFS net namespace 347 * 348 * This function provides a wait-free mechanism for copying the 349 * namespace's write verifier without tearing it. 350 */ 351 void nfsd_copy_write_verifier(__be32 verf[2], struct nfsd_net *nn) 352 { 353 unsigned int seq; 354 355 do { 356 seq = read_seqbegin(&nn->writeverf_lock); 357 memcpy(verf, nn->writeverf, sizeof(nn->writeverf)); 358 } while (read_seqretry(&nn->writeverf_lock, seq)); 359 } 360 361 static void nfsd_reset_write_verifier_locked(struct nfsd_net *nn) 362 { 363 struct timespec64 now; 364 u64 verf; 365 366 /* 367 * Because the time value is hashed, y2038 time_t overflow 368 * is irrelevant in this usage. 369 */ 370 ktime_get_raw_ts64(&now); 371 verf = siphash_2u64(now.tv_sec, now.tv_nsec, &nn->siphash_key); 372 memcpy(nn->writeverf, &verf, sizeof(nn->writeverf)); 373 } 374 375 /** 376 * nfsd_reset_write_verifier - Generate a new write verifier 377 * @nn: NFS net namespace 378 * 379 * This function updates the ->writeverf field of @nn. This field 380 * contains an opaque cookie that, according to Section 18.32.3 of 381 * RFC 8881, "the client can use to determine whether a server has 382 * changed instance state (e.g., server restart) between a call to 383 * WRITE and a subsequent call to either WRITE or COMMIT. This 384 * cookie MUST be unchanged during a single instance of the NFSv4.1 385 * server and MUST be unique between instances of the NFSv4.1 386 * server." 387 */ 388 void nfsd_reset_write_verifier(struct nfsd_net *nn) 389 { 390 write_seqlock(&nn->writeverf_lock); 391 nfsd_reset_write_verifier_locked(nn); 392 write_sequnlock(&nn->writeverf_lock); 393 } 394 395 /* 396 * Crank up a set of per-namespace resources for a new NFSD instance, 397 * including lockd, a duplicate reply cache, an open file cache 398 * instance, and a cache of NFSv4 state objects. 399 */ 400 static int nfsd_startup_net(struct net *net, const struct cred *cred) 401 { 402 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 403 int ret; 404 405 if (nn->nfsd_net_up) 406 return 0; 407 408 ret = nfsd_startup_generic(); 409 if (ret) 410 return ret; 411 ret = nfsd_init_socks(net, cred); 412 if (ret) 413 goto out_socks; 414 415 if (nfsd_needs_lockd(nn) && !nn->lockd_up) { 416 ret = lockd_up(net, cred); 417 if (ret) 418 goto out_socks; 419 nn->lockd_up = true; 420 } 421 422 ret = nfsd_file_cache_start_net(net); 423 if (ret) 424 goto out_lockd; 425 426 ret = nfsd_reply_cache_init(nn); 427 if (ret) 428 goto out_filecache; 429 430 ret = nfs4_state_start_net(net); 431 if (ret) 432 goto out_reply_cache; 433 434 #ifdef CONFIG_NFSD_V4_2_INTER_SSC 435 nfsd4_ssc_init_umount_work(nn); 436 #endif 437 nn->nfsd_net_up = true; 438 return 0; 439 440 out_reply_cache: 441 nfsd_reply_cache_shutdown(nn); 442 out_filecache: 443 nfsd_file_cache_shutdown_net(net); 444 out_lockd: 445 if (nn->lockd_up) { 446 lockd_down(net); 447 nn->lockd_up = false; 448 } 449 out_socks: 450 nfsd_shutdown_generic(); 451 return ret; 452 } 453 454 static void nfsd_shutdown_net(struct net *net) 455 { 456 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 457 458 nfs4_state_shutdown_net(net); 459 nfsd_reply_cache_shutdown(nn); 460 nfsd_file_cache_shutdown_net(net); 461 if (nn->lockd_up) { 462 lockd_down(net); 463 nn->lockd_up = false; 464 } 465 nn->nfsd_net_up = false; 466 nfsd_shutdown_generic(); 467 } 468 469 static DEFINE_SPINLOCK(nfsd_notifier_lock); 470 static int nfsd_inetaddr_event(struct notifier_block *this, unsigned long event, 471 void *ptr) 472 { 473 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 474 struct net_device *dev = ifa->ifa_dev->dev; 475 struct net *net = dev_net(dev); 476 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 477 struct sockaddr_in sin; 478 479 if (event != NETDEV_DOWN || !nn->nfsd_serv) 480 goto out; 481 482 spin_lock(&nfsd_notifier_lock); 483 if (nn->nfsd_serv) { 484 dprintk("nfsd_inetaddr_event: removed %pI4\n", &ifa->ifa_local); 485 sin.sin_family = AF_INET; 486 sin.sin_addr.s_addr = ifa->ifa_local; 487 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin); 488 } 489 spin_unlock(&nfsd_notifier_lock); 490 491 out: 492 return NOTIFY_DONE; 493 } 494 495 static struct notifier_block nfsd_inetaddr_notifier = { 496 .notifier_call = nfsd_inetaddr_event, 497 }; 498 499 #if IS_ENABLED(CONFIG_IPV6) 500 static int nfsd_inet6addr_event(struct notifier_block *this, 501 unsigned long event, void *ptr) 502 { 503 struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr; 504 struct net_device *dev = ifa->idev->dev; 505 struct net *net = dev_net(dev); 506 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 507 struct sockaddr_in6 sin6; 508 509 if (event != NETDEV_DOWN || !nn->nfsd_serv) 510 goto out; 511 512 spin_lock(&nfsd_notifier_lock); 513 if (nn->nfsd_serv) { 514 dprintk("nfsd_inet6addr_event: removed %pI6\n", &ifa->addr); 515 sin6.sin6_family = AF_INET6; 516 sin6.sin6_addr = ifa->addr; 517 if (ipv6_addr_type(&sin6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 518 sin6.sin6_scope_id = ifa->idev->dev->ifindex; 519 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin6); 520 } 521 spin_unlock(&nfsd_notifier_lock); 522 523 out: 524 return NOTIFY_DONE; 525 } 526 527 static struct notifier_block nfsd_inet6addr_notifier = { 528 .notifier_call = nfsd_inet6addr_event, 529 }; 530 #endif 531 532 /* Only used under nfsd_mutex, so this atomic may be overkill: */ 533 static atomic_t nfsd_notifier_refcount = ATOMIC_INIT(0); 534 535 /** 536 * nfsd_destroy_serv - tear down NFSD's svc_serv for a namespace 537 * @net: network namespace the NFS service is associated with 538 */ 539 void nfsd_destroy_serv(struct net *net) 540 { 541 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 542 struct svc_serv *serv = nn->nfsd_serv; 543 544 spin_lock(&nfsd_notifier_lock); 545 nn->nfsd_serv = NULL; 546 spin_unlock(&nfsd_notifier_lock); 547 548 /* check if the notifier still has clients */ 549 if (atomic_dec_return(&nfsd_notifier_refcount) == 0) { 550 unregister_inetaddr_notifier(&nfsd_inetaddr_notifier); 551 #if IS_ENABLED(CONFIG_IPV6) 552 unregister_inet6addr_notifier(&nfsd_inet6addr_notifier); 553 #endif 554 } 555 556 svc_xprt_destroy_all(serv, net); 557 558 /* 559 * write_ports can create the server without actually starting 560 * any threads--if we get shut down before any threads are 561 * started, then nfsd_destroy_serv will be run before any of this 562 * other initialization has been done except the rpcb information. 563 */ 564 svc_rpcb_cleanup(serv, net); 565 if (!nn->nfsd_net_up) 566 return; 567 568 nfsd_shutdown_net(net); 569 nfsd_export_flush(net); 570 svc_destroy(&serv); 571 } 572 573 void nfsd_reset_versions(struct nfsd_net *nn) 574 { 575 int i; 576 577 for (i = 0; i < NFSD_NRVERS; i++) 578 if (nfsd_vers(nn, i, NFSD_TEST)) 579 return; 580 581 for (i = 0; i < NFSD_NRVERS; i++) 582 if (i != 4) 583 nfsd_vers(nn, i, NFSD_SET); 584 else { 585 int minor = 0; 586 while (nfsd_minorversion(nn, minor, NFSD_SET) >= 0) 587 minor++; 588 } 589 } 590 591 /* 592 * Each session guarantees a negotiated per slot memory cache for replies 593 * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated 594 * NFSv4.1 server might want to use more memory for a DRC than a machine 595 * with mutiple services. 596 * 597 * Impose a hard limit on the number of pages for the DRC which varies 598 * according to the machines free pages. This is of course only a default. 599 * 600 * For now this is a #defined shift which could be under admin control 601 * in the future. 602 */ 603 static void set_max_drc(void) 604 { 605 #define NFSD_DRC_SIZE_SHIFT 7 606 nfsd_drc_max_mem = (nr_free_buffer_pages() 607 >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE; 608 nfsd_drc_mem_used = 0; 609 dprintk("%s nfsd_drc_max_mem %lu \n", __func__, nfsd_drc_max_mem); 610 } 611 612 static int nfsd_get_default_max_blksize(void) 613 { 614 struct sysinfo i; 615 unsigned long long target; 616 unsigned long ret; 617 618 si_meminfo(&i); 619 target = (i.totalram - i.totalhigh) << PAGE_SHIFT; 620 /* 621 * Aim for 1/4096 of memory per thread This gives 1MB on 4Gig 622 * machines, but only uses 32K on 128M machines. Bottom out at 623 * 8K on 32M and smaller. Of course, this is only a default. 624 */ 625 target >>= 12; 626 627 ret = NFSSVC_MAXBLKSIZE; 628 while (ret > target && ret >= 8*1024*2) 629 ret /= 2; 630 return ret; 631 } 632 633 void nfsd_shutdown_threads(struct net *net) 634 { 635 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 636 struct svc_serv *serv; 637 638 mutex_lock(&nfsd_mutex); 639 serv = nn->nfsd_serv; 640 if (serv == NULL) { 641 mutex_unlock(&nfsd_mutex); 642 return; 643 } 644 645 /* Kill outstanding nfsd threads */ 646 svc_set_num_threads(serv, NULL, 0); 647 nfsd_destroy_serv(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 return 0; 665 666 if (nfsd_max_blksize == 0) 667 nfsd_max_blksize = nfsd_get_default_max_blksize(); 668 nfsd_reset_versions(nn); 669 serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize, nfsd); 670 if (serv == NULL) 671 return -ENOMEM; 672 673 serv->sv_maxconn = nn->max_connections; 674 error = svc_bind(serv, net); 675 if (error < 0) { 676 svc_destroy(&serv); 677 return error; 678 } 679 spin_lock(&nfsd_notifier_lock); 680 nn->nfsd_info.mutex = &nfsd_mutex; 681 nn->nfsd_serv = serv; 682 spin_unlock(&nfsd_notifier_lock); 683 684 set_max_drc(); 685 /* check if the notifier is already set */ 686 if (atomic_inc_return(&nfsd_notifier_refcount) == 1) { 687 register_inetaddr_notifier(&nfsd_inetaddr_notifier); 688 #if IS_ENABLED(CONFIG_IPV6) 689 register_inet6addr_notifier(&nfsd_inet6addr_notifier); 690 #endif 691 } 692 nfsd_reset_write_verifier(nn); 693 return 0; 694 } 695 696 int nfsd_nrpools(struct net *net) 697 { 698 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 699 700 if (nn->nfsd_serv == NULL) 701 return 0; 702 else 703 return nn->nfsd_serv->sv_nrpools; 704 } 705 706 int nfsd_get_nrthreads(int n, int *nthreads, struct net *net) 707 { 708 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 709 struct svc_serv *serv = nn->nfsd_serv; 710 int i; 711 712 if (serv) 713 for (i = 0; i < serv->sv_nrpools && i < n; i++) 714 nthreads[i] = atomic_read(&serv->sv_pools[i].sp_nrthreads); 715 return 0; 716 } 717 718 int nfsd_set_nrthreads(int n, int *nthreads, struct net *net) 719 { 720 int i = 0; 721 int tot = 0; 722 int err = 0; 723 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 724 725 WARN_ON(!mutex_is_locked(&nfsd_mutex)); 726 727 if (nn->nfsd_serv == NULL || n <= 0) 728 return 0; 729 730 if (n > nn->nfsd_serv->sv_nrpools) 731 n = nn->nfsd_serv->sv_nrpools; 732 733 /* enforce a global maximum number of threads */ 734 tot = 0; 735 for (i = 0; i < n; i++) { 736 nthreads[i] = min(nthreads[i], NFSD_MAXSERVS); 737 tot += nthreads[i]; 738 } 739 if (tot > NFSD_MAXSERVS) { 740 /* total too large: scale down requested numbers */ 741 for (i = 0; i < n && tot > 0; i++) { 742 int new = nthreads[i] * NFSD_MAXSERVS / tot; 743 tot -= (nthreads[i] - new); 744 nthreads[i] = new; 745 } 746 for (i = 0; i < n && tot > 0; i++) { 747 nthreads[i]--; 748 tot--; 749 } 750 } 751 752 /* 753 * There must always be a thread in pool 0; the admin 754 * can't shut down NFS completely using pool_threads. 755 */ 756 if (nthreads[0] == 0) 757 nthreads[0] = 1; 758 759 /* apply the new numbers */ 760 for (i = 0; i < n; i++) { 761 err = svc_set_num_threads(nn->nfsd_serv, 762 &nn->nfsd_serv->sv_pools[i], 763 nthreads[i]); 764 if (err) 765 break; 766 } 767 return err; 768 } 769 770 /* 771 * Adjust the number of threads and return the new number of threads. 772 * This is also the function that starts the server if necessary, if 773 * this is the first time nrservs is nonzero. 774 */ 775 int 776 nfsd_svc(int nrservs, struct net *net, const struct cred *cred) 777 { 778 int error; 779 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 780 struct svc_serv *serv; 781 782 mutex_lock(&nfsd_mutex); 783 dprintk("nfsd: creating service\n"); 784 785 nrservs = max(nrservs, 0); 786 nrservs = min(nrservs, NFSD_MAXSERVS); 787 error = 0; 788 789 if (nrservs == 0 && nn->nfsd_serv == NULL) 790 goto out; 791 792 strscpy(nn->nfsd_name, utsname()->nodename, 793 sizeof(nn->nfsd_name)); 794 795 error = nfsd_create_serv(net); 796 if (error) 797 goto out; 798 serv = nn->nfsd_serv; 799 800 error = nfsd_startup_net(net, cred); 801 if (error) 802 goto out_put; 803 error = svc_set_num_threads(serv, NULL, nrservs); 804 if (error) 805 goto out_put; 806 error = serv->sv_nrthreads; 807 out_put: 808 if (serv->sv_nrthreads == 0) 809 nfsd_destroy_serv(net); 810 out: 811 mutex_unlock(&nfsd_mutex); 812 return error; 813 } 814 815 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 816 static bool 817 nfsd_support_acl_version(int vers) 818 { 819 if (vers >= NFSD_ACL_MINVERS && vers < NFSD_ACL_NRVERS) 820 return nfsd_acl_version[vers] != NULL; 821 return false; 822 } 823 824 static int 825 nfsd_acl_rpcbind_set(struct net *net, const struct svc_program *progp, 826 u32 version, int family, unsigned short proto, 827 unsigned short port) 828 { 829 if (!nfsd_support_acl_version(version) || 830 !nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST)) 831 return 0; 832 return svc_generic_rpcbind_set(net, progp, version, family, 833 proto, port); 834 } 835 836 static __be32 837 nfsd_acl_init_request(struct svc_rqst *rqstp, 838 const struct svc_program *progp, 839 struct svc_process_info *ret) 840 { 841 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); 842 int i; 843 844 if (likely(nfsd_support_acl_version(rqstp->rq_vers) && 845 nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST))) 846 return svc_generic_init_request(rqstp, progp, ret); 847 848 ret->mismatch.lovers = NFSD_ACL_NRVERS; 849 for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) { 850 if (nfsd_support_acl_version(rqstp->rq_vers) && 851 nfsd_vers(nn, i, NFSD_TEST)) { 852 ret->mismatch.lovers = i; 853 break; 854 } 855 } 856 if (ret->mismatch.lovers == NFSD_ACL_NRVERS) 857 return rpc_prog_unavail; 858 ret->mismatch.hivers = NFSD_ACL_MINVERS; 859 for (i = NFSD_ACL_NRVERS - 1; i >= NFSD_ACL_MINVERS; i--) { 860 if (nfsd_support_acl_version(rqstp->rq_vers) && 861 nfsd_vers(nn, i, NFSD_TEST)) { 862 ret->mismatch.hivers = i; 863 break; 864 } 865 } 866 return rpc_prog_mismatch; 867 } 868 #endif 869 870 static int 871 nfsd_rpcbind_set(struct net *net, const struct svc_program *progp, 872 u32 version, int family, unsigned short proto, 873 unsigned short port) 874 { 875 if (!nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST)) 876 return 0; 877 return svc_generic_rpcbind_set(net, progp, version, family, 878 proto, port); 879 } 880 881 static __be32 882 nfsd_init_request(struct svc_rqst *rqstp, 883 const struct svc_program *progp, 884 struct svc_process_info *ret) 885 { 886 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); 887 int i; 888 889 if (likely(nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST))) 890 return svc_generic_init_request(rqstp, progp, ret); 891 892 ret->mismatch.lovers = NFSD_NRVERS; 893 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) { 894 if (nfsd_vers(nn, i, NFSD_TEST)) { 895 ret->mismatch.lovers = i; 896 break; 897 } 898 } 899 if (ret->mismatch.lovers == NFSD_NRVERS) 900 return rpc_prog_unavail; 901 ret->mismatch.hivers = NFSD_MINVERS; 902 for (i = NFSD_NRVERS - 1; i >= NFSD_MINVERS; i--) { 903 if (nfsd_vers(nn, i, NFSD_TEST)) { 904 ret->mismatch.hivers = i; 905 break; 906 } 907 } 908 return rpc_prog_mismatch; 909 } 910 911 /* 912 * This is the NFS server kernel thread 913 */ 914 static int 915 nfsd(void *vrqstp) 916 { 917 struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp; 918 struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list); 919 struct net *net = perm_sock->xpt_net; 920 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 921 922 /* At this point, the thread shares current->fs 923 * with the init process. We need to create files with the 924 * umask as defined by the client instead of init's umask. */ 925 if (unshare_fs_struct() < 0) { 926 printk("Unable to start nfsd thread: out of memory\n"); 927 goto out; 928 } 929 930 current->fs->umask = 0; 931 932 atomic_inc(&nfsdstats.th_cnt); 933 934 set_freezable(); 935 936 /* 937 * The main request loop 938 */ 939 while (!svc_thread_should_stop(rqstp)) { 940 /* Update sv_maxconn if it has changed */ 941 rqstp->rq_server->sv_maxconn = nn->max_connections; 942 943 svc_recv(rqstp); 944 } 945 946 atomic_dec(&nfsdstats.th_cnt); 947 948 out: 949 /* Release the thread */ 950 svc_exit_thread(rqstp); 951 return 0; 952 } 953 954 /** 955 * nfsd_dispatch - Process an NFS or NFSACL Request 956 * @rqstp: incoming request 957 * 958 * This RPC dispatcher integrates the NFS server's duplicate reply cache. 959 * 960 * Return values: 961 * %0: Processing complete; do not send a Reply 962 * %1: Processing complete; send Reply in rqstp->rq_res 963 */ 964 int nfsd_dispatch(struct svc_rqst *rqstp) 965 { 966 const struct svc_procedure *proc = rqstp->rq_procinfo; 967 __be32 *statp = rqstp->rq_accept_statp; 968 struct nfsd_cacherep *rp; 969 unsigned int start, len; 970 __be32 *nfs_reply; 971 972 /* 973 * Give the xdr decoder a chance to change this if it wants 974 * (necessary in the NFSv4.0 compound case) 975 */ 976 rqstp->rq_cachetype = proc->pc_cachetype; 977 978 /* 979 * ->pc_decode advances the argument stream past the NFS 980 * Call header, so grab the header's starting location and 981 * size now for the call to nfsd_cache_lookup(). 982 */ 983 start = xdr_stream_pos(&rqstp->rq_arg_stream); 984 len = xdr_stream_remaining(&rqstp->rq_arg_stream); 985 if (!proc->pc_decode(rqstp, &rqstp->rq_arg_stream)) 986 goto out_decode_err; 987 988 /* 989 * Release rq_status_counter setting it to an odd value after the rpc 990 * request has been properly parsed. rq_status_counter is used to 991 * notify the consumers if the rqstp fields are stable 992 * (rq_status_counter is odd) or not meaningful (rq_status_counter 993 * is even). 994 */ 995 smp_store_release(&rqstp->rq_status_counter, rqstp->rq_status_counter | 1); 996 997 rp = NULL; 998 switch (nfsd_cache_lookup(rqstp, start, len, &rp)) { 999 case RC_DOIT: 1000 break; 1001 case RC_REPLY: 1002 goto out_cached_reply; 1003 case RC_DROPIT: 1004 goto out_dropit; 1005 } 1006 1007 nfs_reply = xdr_inline_decode(&rqstp->rq_res_stream, 0); 1008 *statp = proc->pc_func(rqstp); 1009 if (test_bit(RQ_DROPME, &rqstp->rq_flags)) 1010 goto out_update_drop; 1011 1012 if (!proc->pc_encode(rqstp, &rqstp->rq_res_stream)) 1013 goto out_encode_err; 1014 1015 /* 1016 * Release rq_status_counter setting it to an even value after the rpc 1017 * request has been properly processed. 1018 */ 1019 smp_store_release(&rqstp->rq_status_counter, rqstp->rq_status_counter + 1); 1020 1021 nfsd_cache_update(rqstp, rp, rqstp->rq_cachetype, nfs_reply); 1022 out_cached_reply: 1023 return 1; 1024 1025 out_decode_err: 1026 trace_nfsd_garbage_args_err(rqstp); 1027 *statp = rpc_garbage_args; 1028 return 1; 1029 1030 out_update_drop: 1031 nfsd_cache_update(rqstp, rp, RC_NOCACHE, NULL); 1032 out_dropit: 1033 return 0; 1034 1035 out_encode_err: 1036 trace_nfsd_cant_encode_err(rqstp); 1037 nfsd_cache_update(rqstp, rp, RC_NOCACHE, NULL); 1038 *statp = rpc_system_err; 1039 return 1; 1040 } 1041 1042 /** 1043 * nfssvc_decode_voidarg - Decode void arguments 1044 * @rqstp: Server RPC transaction context 1045 * @xdr: XDR stream positioned at arguments to decode 1046 * 1047 * Return values: 1048 * %false: Arguments were not valid 1049 * %true: Decoding was successful 1050 */ 1051 bool nfssvc_decode_voidarg(struct svc_rqst *rqstp, struct xdr_stream *xdr) 1052 { 1053 return true; 1054 } 1055 1056 /** 1057 * nfssvc_encode_voidres - Encode void results 1058 * @rqstp: Server RPC transaction context 1059 * @xdr: XDR stream into which to encode results 1060 * 1061 * Return values: 1062 * %false: Local error while encoding 1063 * %true: Encoding was successful 1064 */ 1065 bool nfssvc_encode_voidres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 1066 { 1067 return true; 1068 } 1069 1070 int nfsd_pool_stats_open(struct inode *inode, struct file *file) 1071 { 1072 struct nfsd_net *nn = net_generic(inode->i_sb->s_fs_info, nfsd_net_id); 1073 1074 return svc_pool_stats_open(&nn->nfsd_info, file); 1075 } 1076