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 atomic_t nfsd_th_cnt = ATOMIC_INIT(0); 38 extern struct svc_program nfsd_program; 39 static int nfsd(void *vrqstp); 40 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 41 static int nfsd_acl_rpcbind_set(struct net *, 42 const struct svc_program *, 43 u32, int, 44 unsigned short, 45 unsigned short); 46 static __be32 nfsd_acl_init_request(struct svc_rqst *, 47 const struct svc_program *, 48 struct svc_process_info *); 49 #endif 50 static int nfsd_rpcbind_set(struct net *, 51 const struct svc_program *, 52 u32, int, 53 unsigned short, 54 unsigned short); 55 static __be32 nfsd_init_request(struct svc_rqst *, 56 const struct svc_program *, 57 struct svc_process_info *); 58 59 /* 60 * nfsd_mutex protects nn->nfsd_serv -- both the pointer itself and some members 61 * of the svc_serv struct such as ->sv_temp_socks and ->sv_permsocks. 62 * 63 * Finally, the nfsd_mutex also protects some of the global variables that are 64 * accessed when nfsd starts and that are settable via the write_* routines in 65 * nfsctl.c. In particular: 66 * 67 * user_recovery_dirname 68 * user_lease_time 69 * nfsd_versions 70 */ 71 DEFINE_MUTEX(nfsd_mutex); 72 73 /* 74 * nfsd_drc_lock protects nfsd_drc_max_pages and nfsd_drc_pages_used. 75 * nfsd_drc_max_pages limits the total amount of memory available for 76 * version 4.1 DRC caches. 77 * nfsd_drc_pages_used tracks the current version 4.1 DRC memory usage. 78 */ 79 DEFINE_SPINLOCK(nfsd_drc_lock); 80 unsigned long nfsd_drc_max_mem; 81 unsigned long nfsd_drc_mem_used; 82 83 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 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_authenticate = &svc_set_client, 103 .pg_init_request = nfsd_acl_init_request, 104 .pg_rpcbind_set = nfsd_acl_rpcbind_set, 105 }; 106 107 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */ 108 109 static const struct svc_version *nfsd_version[] = { 110 #if defined(CONFIG_NFSD_V2) 111 [2] = &nfsd_version2, 112 #endif 113 [3] = &nfsd_version3, 114 #if defined(CONFIG_NFSD_V4) 115 [4] = &nfsd_version4, 116 #endif 117 }; 118 119 #define NFSD_MINVERS 2 120 #define NFSD_NRVERS ARRAY_SIZE(nfsd_version) 121 122 struct svc_program nfsd_program = { 123 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 124 .pg_next = &nfsd_acl_program, 125 #endif 126 .pg_prog = NFS_PROGRAM, /* program number */ 127 .pg_nvers = NFSD_NRVERS, /* nr of entries in nfsd_version */ 128 .pg_vers = nfsd_version, /* version table */ 129 .pg_name = "nfsd", /* program name */ 130 .pg_class = "nfsd", /* authentication class */ 131 .pg_authenticate = &svc_set_client, /* export authentication */ 132 .pg_init_request = nfsd_init_request, 133 .pg_rpcbind_set = nfsd_rpcbind_set, 134 }; 135 136 bool nfsd_support_version(int vers) 137 { 138 if (vers >= NFSD_MINVERS && vers < NFSD_NRVERS) 139 return nfsd_version[vers] != NULL; 140 return false; 141 } 142 143 static bool * 144 nfsd_alloc_versions(void) 145 { 146 bool *vers = kmalloc_array(NFSD_NRVERS, sizeof(bool), GFP_KERNEL); 147 unsigned i; 148 149 if (vers) { 150 /* All compiled versions are enabled by default */ 151 for (i = 0; i < NFSD_NRVERS; i++) 152 vers[i] = nfsd_support_version(i); 153 } 154 return vers; 155 } 156 157 static bool * 158 nfsd_alloc_minorversions(void) 159 { 160 bool *vers = kmalloc_array(NFSD_SUPPORTED_MINOR_VERSION + 1, 161 sizeof(bool), GFP_KERNEL); 162 unsigned i; 163 164 if (vers) { 165 /* All minor versions are enabled by default */ 166 for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++) 167 vers[i] = nfsd_support_version(4); 168 } 169 return vers; 170 } 171 172 void 173 nfsd_netns_free_versions(struct nfsd_net *nn) 174 { 175 kfree(nn->nfsd_versions); 176 kfree(nn->nfsd4_minorversions); 177 nn->nfsd_versions = NULL; 178 nn->nfsd4_minorversions = NULL; 179 } 180 181 static void 182 nfsd_netns_init_versions(struct nfsd_net *nn) 183 { 184 if (!nn->nfsd_versions) { 185 nn->nfsd_versions = nfsd_alloc_versions(); 186 nn->nfsd4_minorversions = nfsd_alloc_minorversions(); 187 if (!nn->nfsd_versions || !nn->nfsd4_minorversions) 188 nfsd_netns_free_versions(nn); 189 } 190 } 191 192 int nfsd_vers(struct nfsd_net *nn, int vers, enum vers_op change) 193 { 194 if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS) 195 return 0; 196 switch(change) { 197 case NFSD_SET: 198 if (nn->nfsd_versions) 199 nn->nfsd_versions[vers] = nfsd_support_version(vers); 200 break; 201 case NFSD_CLEAR: 202 nfsd_netns_init_versions(nn); 203 if (nn->nfsd_versions) 204 nn->nfsd_versions[vers] = false; 205 break; 206 case NFSD_TEST: 207 if (nn->nfsd_versions) 208 return nn->nfsd_versions[vers]; 209 fallthrough; 210 case NFSD_AVAIL: 211 return nfsd_support_version(vers); 212 } 213 return 0; 214 } 215 216 static void 217 nfsd_adjust_nfsd_versions4(struct nfsd_net *nn) 218 { 219 unsigned i; 220 221 for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++) { 222 if (nn->nfsd4_minorversions[i]) 223 return; 224 } 225 nfsd_vers(nn, 4, NFSD_CLEAR); 226 } 227 228 int nfsd_minorversion(struct nfsd_net *nn, u32 minorversion, enum vers_op change) 229 { 230 if (minorversion > NFSD_SUPPORTED_MINOR_VERSION && 231 change != NFSD_AVAIL) 232 return -1; 233 234 switch(change) { 235 case NFSD_SET: 236 if (nn->nfsd4_minorversions) { 237 nfsd_vers(nn, 4, NFSD_SET); 238 nn->nfsd4_minorversions[minorversion] = 239 nfsd_vers(nn, 4, NFSD_TEST); 240 } 241 break; 242 case NFSD_CLEAR: 243 nfsd_netns_init_versions(nn); 244 if (nn->nfsd4_minorversions) { 245 nn->nfsd4_minorversions[minorversion] = false; 246 nfsd_adjust_nfsd_versions4(nn); 247 } 248 break; 249 case NFSD_TEST: 250 if (nn->nfsd4_minorversions) 251 return nn->nfsd4_minorversions[minorversion]; 252 return nfsd_vers(nn, 4, NFSD_TEST); 253 case NFSD_AVAIL: 254 return minorversion <= NFSD_SUPPORTED_MINOR_VERSION && 255 nfsd_vers(nn, 4, NFSD_AVAIL); 256 } 257 return 0; 258 } 259 260 /* 261 * Maximum number of nfsd processes 262 */ 263 #define NFSD_MAXSERVS 8192 264 265 int nfsd_nrthreads(struct net *net) 266 { 267 int rv = 0; 268 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 269 270 mutex_lock(&nfsd_mutex); 271 if (nn->nfsd_serv) 272 rv = nn->nfsd_serv->sv_nrthreads; 273 mutex_unlock(&nfsd_mutex); 274 return rv; 275 } 276 277 static int nfsd_init_socks(struct net *net, const struct cred *cred) 278 { 279 int error; 280 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 281 282 if (!list_empty(&nn->nfsd_serv->sv_permsocks)) 283 return 0; 284 285 error = svc_xprt_create(nn->nfsd_serv, "udp", net, PF_INET, NFS_PORT, 286 SVC_SOCK_DEFAULTS, cred); 287 if (error < 0) 288 return error; 289 290 error = svc_xprt_create(nn->nfsd_serv, "tcp", net, PF_INET, NFS_PORT, 291 SVC_SOCK_DEFAULTS, cred); 292 if (error < 0) 293 return error; 294 295 return 0; 296 } 297 298 static int nfsd_users = 0; 299 300 static int nfsd_startup_generic(void) 301 { 302 int ret; 303 304 if (nfsd_users++) 305 return 0; 306 307 ret = nfsd_file_cache_init(); 308 if (ret) 309 goto dec_users; 310 311 ret = nfs4_state_start(); 312 if (ret) 313 goto out_file_cache; 314 return 0; 315 316 out_file_cache: 317 nfsd_file_cache_shutdown(); 318 dec_users: 319 nfsd_users--; 320 return ret; 321 } 322 323 static void nfsd_shutdown_generic(void) 324 { 325 if (--nfsd_users) 326 return; 327 328 nfs4_state_shutdown(); 329 nfsd_file_cache_shutdown(); 330 } 331 332 static bool nfsd_needs_lockd(struct nfsd_net *nn) 333 { 334 return nfsd_vers(nn, 2, NFSD_TEST) || nfsd_vers(nn, 3, NFSD_TEST); 335 } 336 337 /** 338 * nfsd_copy_write_verifier - Atomically copy a write verifier 339 * @verf: buffer in which to receive the verifier cookie 340 * @nn: NFS net namespace 341 * 342 * This function provides a wait-free mechanism for copying the 343 * namespace's write verifier without tearing it. 344 */ 345 void nfsd_copy_write_verifier(__be32 verf[2], struct nfsd_net *nn) 346 { 347 unsigned int seq; 348 349 do { 350 seq = read_seqbegin(&nn->writeverf_lock); 351 memcpy(verf, nn->writeverf, sizeof(nn->writeverf)); 352 } while (read_seqretry(&nn->writeverf_lock, seq)); 353 } 354 355 static void nfsd_reset_write_verifier_locked(struct nfsd_net *nn) 356 { 357 struct timespec64 now; 358 u64 verf; 359 360 /* 361 * Because the time value is hashed, y2038 time_t overflow 362 * is irrelevant in this usage. 363 */ 364 ktime_get_raw_ts64(&now); 365 verf = siphash_2u64(now.tv_sec, now.tv_nsec, &nn->siphash_key); 366 memcpy(nn->writeverf, &verf, sizeof(nn->writeverf)); 367 } 368 369 /** 370 * nfsd_reset_write_verifier - Generate a new write verifier 371 * @nn: NFS net namespace 372 * 373 * This function updates the ->writeverf field of @nn. This field 374 * contains an opaque cookie that, according to Section 18.32.3 of 375 * RFC 8881, "the client can use to determine whether a server has 376 * changed instance state (e.g., server restart) between a call to 377 * WRITE and a subsequent call to either WRITE or COMMIT. This 378 * cookie MUST be unchanged during a single instance of the NFSv4.1 379 * server and MUST be unique between instances of the NFSv4.1 380 * server." 381 */ 382 void nfsd_reset_write_verifier(struct nfsd_net *nn) 383 { 384 write_seqlock(&nn->writeverf_lock); 385 nfsd_reset_write_verifier_locked(nn); 386 write_sequnlock(&nn->writeverf_lock); 387 } 388 389 /* 390 * Crank up a set of per-namespace resources for a new NFSD instance, 391 * including lockd, a duplicate reply cache, an open file cache 392 * instance, and a cache of NFSv4 state objects. 393 */ 394 static int nfsd_startup_net(struct net *net, const struct cred *cred) 395 { 396 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 397 int ret; 398 399 if (nn->nfsd_net_up) 400 return 0; 401 402 ret = nfsd_startup_generic(); 403 if (ret) 404 return ret; 405 ret = nfsd_init_socks(net, cred); 406 if (ret) 407 goto out_socks; 408 409 if (nfsd_needs_lockd(nn) && !nn->lockd_up) { 410 ret = lockd_up(net, cred); 411 if (ret) 412 goto out_socks; 413 nn->lockd_up = true; 414 } 415 416 ret = nfsd_file_cache_start_net(net); 417 if (ret) 418 goto out_lockd; 419 420 ret = nfsd_reply_cache_init(nn); 421 if (ret) 422 goto out_filecache; 423 424 ret = nfs4_state_start_net(net); 425 if (ret) 426 goto out_reply_cache; 427 428 #ifdef CONFIG_NFSD_V4_2_INTER_SSC 429 nfsd4_ssc_init_umount_work(nn); 430 #endif 431 nn->nfsd_net_up = true; 432 return 0; 433 434 out_reply_cache: 435 nfsd_reply_cache_shutdown(nn); 436 out_filecache: 437 nfsd_file_cache_shutdown_net(net); 438 out_lockd: 439 if (nn->lockd_up) { 440 lockd_down(net); 441 nn->lockd_up = false; 442 } 443 out_socks: 444 nfsd_shutdown_generic(); 445 return ret; 446 } 447 448 static void nfsd_shutdown_net(struct net *net) 449 { 450 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 451 452 nfs4_state_shutdown_net(net); 453 nfsd_reply_cache_shutdown(nn); 454 nfsd_file_cache_shutdown_net(net); 455 if (nn->lockd_up) { 456 lockd_down(net); 457 nn->lockd_up = false; 458 } 459 nn->nfsd_net_up = false; 460 nfsd_shutdown_generic(); 461 } 462 463 static DEFINE_SPINLOCK(nfsd_notifier_lock); 464 static int nfsd_inetaddr_event(struct notifier_block *this, unsigned long event, 465 void *ptr) 466 { 467 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 468 struct net_device *dev = ifa->ifa_dev->dev; 469 struct net *net = dev_net(dev); 470 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 471 struct sockaddr_in sin; 472 473 if (event != NETDEV_DOWN || !nn->nfsd_serv) 474 goto out; 475 476 spin_lock(&nfsd_notifier_lock); 477 if (nn->nfsd_serv) { 478 dprintk("nfsd_inetaddr_event: removed %pI4\n", &ifa->ifa_local); 479 sin.sin_family = AF_INET; 480 sin.sin_addr.s_addr = ifa->ifa_local; 481 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin); 482 } 483 spin_unlock(&nfsd_notifier_lock); 484 485 out: 486 return NOTIFY_DONE; 487 } 488 489 static struct notifier_block nfsd_inetaddr_notifier = { 490 .notifier_call = nfsd_inetaddr_event, 491 }; 492 493 #if IS_ENABLED(CONFIG_IPV6) 494 static int nfsd_inet6addr_event(struct notifier_block *this, 495 unsigned long event, void *ptr) 496 { 497 struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr; 498 struct net_device *dev = ifa->idev->dev; 499 struct net *net = dev_net(dev); 500 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 501 struct sockaddr_in6 sin6; 502 503 if (event != NETDEV_DOWN || !nn->nfsd_serv) 504 goto out; 505 506 spin_lock(&nfsd_notifier_lock); 507 if (nn->nfsd_serv) { 508 dprintk("nfsd_inet6addr_event: removed %pI6\n", &ifa->addr); 509 sin6.sin6_family = AF_INET6; 510 sin6.sin6_addr = ifa->addr; 511 if (ipv6_addr_type(&sin6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 512 sin6.sin6_scope_id = ifa->idev->dev->ifindex; 513 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin6); 514 } 515 spin_unlock(&nfsd_notifier_lock); 516 517 out: 518 return NOTIFY_DONE; 519 } 520 521 static struct notifier_block nfsd_inet6addr_notifier = { 522 .notifier_call = nfsd_inet6addr_event, 523 }; 524 #endif 525 526 /* Only used under nfsd_mutex, so this atomic may be overkill: */ 527 static atomic_t nfsd_notifier_refcount = ATOMIC_INIT(0); 528 529 /** 530 * nfsd_destroy_serv - tear down NFSD's svc_serv for a namespace 531 * @net: network namespace the NFS service is associated with 532 */ 533 void nfsd_destroy_serv(struct net *net) 534 { 535 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 536 struct svc_serv *serv = nn->nfsd_serv; 537 538 spin_lock(&nfsd_notifier_lock); 539 nn->nfsd_serv = NULL; 540 spin_unlock(&nfsd_notifier_lock); 541 542 /* check if the notifier still has clients */ 543 if (atomic_dec_return(&nfsd_notifier_refcount) == 0) { 544 unregister_inetaddr_notifier(&nfsd_inetaddr_notifier); 545 #if IS_ENABLED(CONFIG_IPV6) 546 unregister_inet6addr_notifier(&nfsd_inet6addr_notifier); 547 #endif 548 } 549 550 svc_xprt_destroy_all(serv, net); 551 552 /* 553 * write_ports can create the server without actually starting 554 * any threads--if we get shut down before any threads are 555 * started, then nfsd_destroy_serv will be run before any of this 556 * other initialization has been done except the rpcb information. 557 */ 558 svc_rpcb_cleanup(serv, net); 559 if (!nn->nfsd_net_up) 560 return; 561 562 nfsd_shutdown_net(net); 563 nfsd_export_flush(net); 564 svc_destroy(&serv); 565 } 566 567 void nfsd_reset_versions(struct nfsd_net *nn) 568 { 569 int i; 570 571 for (i = 0; i < NFSD_NRVERS; i++) 572 if (nfsd_vers(nn, i, NFSD_TEST)) 573 return; 574 575 for (i = 0; i < NFSD_NRVERS; i++) 576 if (i != 4) 577 nfsd_vers(nn, i, NFSD_SET); 578 else { 579 int minor = 0; 580 while (nfsd_minorversion(nn, minor, NFSD_SET) >= 0) 581 minor++; 582 } 583 } 584 585 /* 586 * Each session guarantees a negotiated per slot memory cache for replies 587 * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated 588 * NFSv4.1 server might want to use more memory for a DRC than a machine 589 * with mutiple services. 590 * 591 * Impose a hard limit on the number of pages for the DRC which varies 592 * according to the machines free pages. This is of course only a default. 593 * 594 * For now this is a #defined shift which could be under admin control 595 * in the future. 596 */ 597 static void set_max_drc(void) 598 { 599 #define NFSD_DRC_SIZE_SHIFT 7 600 nfsd_drc_max_mem = (nr_free_buffer_pages() 601 >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE; 602 nfsd_drc_mem_used = 0; 603 dprintk("%s nfsd_drc_max_mem %lu \n", __func__, nfsd_drc_max_mem); 604 } 605 606 static int nfsd_get_default_max_blksize(void) 607 { 608 struct sysinfo i; 609 unsigned long long target; 610 unsigned long ret; 611 612 si_meminfo(&i); 613 target = (i.totalram - i.totalhigh) << PAGE_SHIFT; 614 /* 615 * Aim for 1/4096 of memory per thread This gives 1MB on 4Gig 616 * machines, but only uses 32K on 128M machines. Bottom out at 617 * 8K on 32M and smaller. Of course, this is only a default. 618 */ 619 target >>= 12; 620 621 ret = NFSSVC_MAXBLKSIZE; 622 while (ret > target && ret >= 8*1024*2) 623 ret /= 2; 624 return ret; 625 } 626 627 void nfsd_shutdown_threads(struct net *net) 628 { 629 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 630 struct svc_serv *serv; 631 632 mutex_lock(&nfsd_mutex); 633 serv = nn->nfsd_serv; 634 if (serv == NULL) { 635 mutex_unlock(&nfsd_mutex); 636 return; 637 } 638 639 /* Kill outstanding nfsd threads */ 640 svc_set_num_threads(serv, NULL, 0); 641 nfsd_destroy_serv(net); 642 mutex_unlock(&nfsd_mutex); 643 } 644 645 bool i_am_nfsd(void) 646 { 647 return kthread_func(current) == nfsd; 648 } 649 650 int nfsd_create_serv(struct net *net) 651 { 652 int error; 653 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 654 struct svc_serv *serv; 655 656 WARN_ON(!mutex_is_locked(&nfsd_mutex)); 657 if (nn->nfsd_serv) 658 return 0; 659 660 if (nfsd_max_blksize == 0) 661 nfsd_max_blksize = nfsd_get_default_max_blksize(); 662 nfsd_reset_versions(nn); 663 serv = svc_create_pooled(&nfsd_program, &nn->nfsd_svcstats, 664 nfsd_max_blksize, nfsd); 665 if (serv == NULL) 666 return -ENOMEM; 667 668 serv->sv_maxconn = nn->max_connections; 669 error = svc_bind(serv, net); 670 if (error < 0) { 671 svc_destroy(&serv); 672 return error; 673 } 674 spin_lock(&nfsd_notifier_lock); 675 nn->nfsd_info.mutex = &nfsd_mutex; 676 nn->nfsd_serv = serv; 677 spin_unlock(&nfsd_notifier_lock); 678 679 set_max_drc(); 680 /* check if the notifier is already set */ 681 if (atomic_inc_return(&nfsd_notifier_refcount) == 1) { 682 register_inetaddr_notifier(&nfsd_inetaddr_notifier); 683 #if IS_ENABLED(CONFIG_IPV6) 684 register_inet6addr_notifier(&nfsd_inet6addr_notifier); 685 #endif 686 } 687 nfsd_reset_write_verifier(nn); 688 return 0; 689 } 690 691 int nfsd_nrpools(struct net *net) 692 { 693 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 694 695 if (nn->nfsd_serv == NULL) 696 return 0; 697 else 698 return nn->nfsd_serv->sv_nrpools; 699 } 700 701 int nfsd_get_nrthreads(int n, int *nthreads, struct net *net) 702 { 703 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 704 struct svc_serv *serv = nn->nfsd_serv; 705 int i; 706 707 if (serv) 708 for (i = 0; i < serv->sv_nrpools && i < n; i++) 709 nthreads[i] = atomic_read(&serv->sv_pools[i].sp_nrthreads); 710 return 0; 711 } 712 713 int nfsd_set_nrthreads(int n, int *nthreads, struct net *net) 714 { 715 int i = 0; 716 int tot = 0; 717 int err = 0; 718 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 719 720 WARN_ON(!mutex_is_locked(&nfsd_mutex)); 721 722 if (nn->nfsd_serv == NULL || n <= 0) 723 return 0; 724 725 if (n > nn->nfsd_serv->sv_nrpools) 726 n = nn->nfsd_serv->sv_nrpools; 727 728 /* enforce a global maximum number of threads */ 729 tot = 0; 730 for (i = 0; i < n; i++) { 731 nthreads[i] = min(nthreads[i], NFSD_MAXSERVS); 732 tot += nthreads[i]; 733 } 734 if (tot > NFSD_MAXSERVS) { 735 /* total too large: scale down requested numbers */ 736 for (i = 0; i < n && tot > 0; i++) { 737 int new = nthreads[i] * NFSD_MAXSERVS / tot; 738 tot -= (nthreads[i] - new); 739 nthreads[i] = new; 740 } 741 for (i = 0; i < n && tot > 0; i++) { 742 nthreads[i]--; 743 tot--; 744 } 745 } 746 747 /* 748 * There must always be a thread in pool 0; the admin 749 * can't shut down NFS completely using pool_threads. 750 */ 751 if (nthreads[0] == 0) 752 nthreads[0] = 1; 753 754 /* apply the new numbers */ 755 for (i = 0; i < n; i++) { 756 err = svc_set_num_threads(nn->nfsd_serv, 757 &nn->nfsd_serv->sv_pools[i], 758 nthreads[i]); 759 if (err) 760 break; 761 } 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, const char *scope) 772 { 773 int error; 774 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 775 struct svc_serv *serv; 776 777 lockdep_assert_held(&nfsd_mutex); 778 779 dprintk("nfsd: creating service\n"); 780 781 nrservs = max(nrservs, 0); 782 nrservs = min(nrservs, NFSD_MAXSERVS); 783 error = 0; 784 785 if (nrservs == 0 && nn->nfsd_serv == NULL) 786 goto out; 787 788 strscpy(nn->nfsd_name, scope ? scope : utsname()->nodename, 789 sizeof(nn->nfsd_name)); 790 791 error = nfsd_create_serv(net); 792 if (error) 793 goto out; 794 serv = nn->nfsd_serv; 795 796 error = nfsd_startup_net(net, cred); 797 if (error) 798 goto out_put; 799 error = svc_set_num_threads(serv, NULL, nrservs); 800 if (error) 801 goto out_put; 802 error = serv->sv_nrthreads; 803 out_put: 804 if (serv->sv_nrthreads == 0) 805 nfsd_destroy_serv(net); 806 out: 807 return error; 808 } 809 810 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 811 static bool 812 nfsd_support_acl_version(int vers) 813 { 814 if (vers >= NFSD_ACL_MINVERS && vers < NFSD_ACL_NRVERS) 815 return nfsd_acl_version[vers] != NULL; 816 return false; 817 } 818 819 static int 820 nfsd_acl_rpcbind_set(struct net *net, const struct svc_program *progp, 821 u32 version, int family, unsigned short proto, 822 unsigned short port) 823 { 824 if (!nfsd_support_acl_version(version) || 825 !nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST)) 826 return 0; 827 return svc_generic_rpcbind_set(net, progp, version, family, 828 proto, port); 829 } 830 831 static __be32 832 nfsd_acl_init_request(struct svc_rqst *rqstp, 833 const struct svc_program *progp, 834 struct svc_process_info *ret) 835 { 836 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); 837 int i; 838 839 if (likely(nfsd_support_acl_version(rqstp->rq_vers) && 840 nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST))) 841 return svc_generic_init_request(rqstp, progp, ret); 842 843 ret->mismatch.lovers = NFSD_ACL_NRVERS; 844 for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) { 845 if (nfsd_support_acl_version(rqstp->rq_vers) && 846 nfsd_vers(nn, i, NFSD_TEST)) { 847 ret->mismatch.lovers = i; 848 break; 849 } 850 } 851 if (ret->mismatch.lovers == NFSD_ACL_NRVERS) 852 return rpc_prog_unavail; 853 ret->mismatch.hivers = NFSD_ACL_MINVERS; 854 for (i = NFSD_ACL_NRVERS - 1; i >= NFSD_ACL_MINVERS; i--) { 855 if (nfsd_support_acl_version(rqstp->rq_vers) && 856 nfsd_vers(nn, i, NFSD_TEST)) { 857 ret->mismatch.hivers = i; 858 break; 859 } 860 } 861 return rpc_prog_mismatch; 862 } 863 #endif 864 865 static int 866 nfsd_rpcbind_set(struct net *net, const struct svc_program *progp, 867 u32 version, int family, unsigned short proto, 868 unsigned short port) 869 { 870 if (!nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST)) 871 return 0; 872 return svc_generic_rpcbind_set(net, progp, version, family, 873 proto, port); 874 } 875 876 static __be32 877 nfsd_init_request(struct svc_rqst *rqstp, 878 const struct svc_program *progp, 879 struct svc_process_info *ret) 880 { 881 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); 882 int i; 883 884 if (likely(nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST))) 885 return svc_generic_init_request(rqstp, progp, ret); 886 887 ret->mismatch.lovers = NFSD_NRVERS; 888 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) { 889 if (nfsd_vers(nn, i, NFSD_TEST)) { 890 ret->mismatch.lovers = i; 891 break; 892 } 893 } 894 if (ret->mismatch.lovers == NFSD_NRVERS) 895 return rpc_prog_unavail; 896 ret->mismatch.hivers = NFSD_MINVERS; 897 for (i = NFSD_NRVERS - 1; i >= NFSD_MINVERS; i--) { 898 if (nfsd_vers(nn, i, NFSD_TEST)) { 899 ret->mismatch.hivers = i; 900 break; 901 } 902 } 903 return rpc_prog_mismatch; 904 } 905 906 /* 907 * This is the NFS server kernel thread 908 */ 909 static int 910 nfsd(void *vrqstp) 911 { 912 struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp; 913 struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list); 914 struct net *net = perm_sock->xpt_net; 915 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 916 917 /* At this point, the thread shares current->fs 918 * with the init process. We need to create files with the 919 * umask as defined by the client instead of init's umask. */ 920 if (unshare_fs_struct() < 0) { 921 printk("Unable to start nfsd thread: out of memory\n"); 922 goto out; 923 } 924 925 current->fs->umask = 0; 926 927 atomic_inc(&nfsd_th_cnt); 928 929 set_freezable(); 930 931 /* 932 * The main request loop 933 */ 934 while (!svc_thread_should_stop(rqstp)) { 935 /* Update sv_maxconn if it has changed */ 936 rqstp->rq_server->sv_maxconn = nn->max_connections; 937 938 svc_recv(rqstp); 939 940 nfsd_file_net_dispose(nn); 941 } 942 943 atomic_dec(&nfsd_th_cnt); 944 945 out: 946 /* Release the thread */ 947 svc_exit_thread(rqstp); 948 return 0; 949 } 950 951 /** 952 * nfsd_dispatch - Process an NFS or NFSACL Request 953 * @rqstp: incoming request 954 * 955 * This RPC dispatcher integrates the NFS server's duplicate reply cache. 956 * 957 * Return values: 958 * %0: Processing complete; do not send a Reply 959 * %1: Processing complete; send Reply in rqstp->rq_res 960 */ 961 int nfsd_dispatch(struct svc_rqst *rqstp) 962 { 963 const struct svc_procedure *proc = rqstp->rq_procinfo; 964 __be32 *statp = rqstp->rq_accept_statp; 965 struct nfsd_cacherep *rp; 966 unsigned int start, len; 967 __be32 *nfs_reply; 968 969 /* 970 * Give the xdr decoder a chance to change this if it wants 971 * (necessary in the NFSv4.0 compound case) 972 */ 973 rqstp->rq_cachetype = proc->pc_cachetype; 974 975 /* 976 * ->pc_decode advances the argument stream past the NFS 977 * Call header, so grab the header's starting location and 978 * size now for the call to nfsd_cache_lookup(). 979 */ 980 start = xdr_stream_pos(&rqstp->rq_arg_stream); 981 len = xdr_stream_remaining(&rqstp->rq_arg_stream); 982 if (!proc->pc_decode(rqstp, &rqstp->rq_arg_stream)) 983 goto out_decode_err; 984 985 /* 986 * Release rq_status_counter setting it to an odd value after the rpc 987 * request has been properly parsed. rq_status_counter is used to 988 * notify the consumers if the rqstp fields are stable 989 * (rq_status_counter is odd) or not meaningful (rq_status_counter 990 * is even). 991 */ 992 smp_store_release(&rqstp->rq_status_counter, rqstp->rq_status_counter | 1); 993 994 rp = NULL; 995 switch (nfsd_cache_lookup(rqstp, start, len, &rp)) { 996 case RC_DOIT: 997 break; 998 case RC_REPLY: 999 goto out_cached_reply; 1000 case RC_DROPIT: 1001 goto out_dropit; 1002 } 1003 1004 nfs_reply = xdr_inline_decode(&rqstp->rq_res_stream, 0); 1005 *statp = proc->pc_func(rqstp); 1006 if (test_bit(RQ_DROPME, &rqstp->rq_flags)) 1007 goto out_update_drop; 1008 1009 if (!proc->pc_encode(rqstp, &rqstp->rq_res_stream)) 1010 goto out_encode_err; 1011 1012 /* 1013 * Release rq_status_counter setting it to an even value after the rpc 1014 * request has been properly processed. 1015 */ 1016 smp_store_release(&rqstp->rq_status_counter, rqstp->rq_status_counter + 1); 1017 1018 nfsd_cache_update(rqstp, rp, rqstp->rq_cachetype, nfs_reply); 1019 out_cached_reply: 1020 return 1; 1021 1022 out_decode_err: 1023 trace_nfsd_garbage_args_err(rqstp); 1024 *statp = rpc_garbage_args; 1025 return 1; 1026 1027 out_update_drop: 1028 nfsd_cache_update(rqstp, rp, RC_NOCACHE, NULL); 1029 out_dropit: 1030 return 0; 1031 1032 out_encode_err: 1033 trace_nfsd_cant_encode_err(rqstp); 1034 nfsd_cache_update(rqstp, rp, RC_NOCACHE, NULL); 1035 *statp = rpc_system_err; 1036 return 1; 1037 } 1038 1039 /** 1040 * nfssvc_decode_voidarg - Decode void arguments 1041 * @rqstp: Server RPC transaction context 1042 * @xdr: XDR stream positioned at arguments to decode 1043 * 1044 * Return values: 1045 * %false: Arguments were not valid 1046 * %true: Decoding was successful 1047 */ 1048 bool nfssvc_decode_voidarg(struct svc_rqst *rqstp, struct xdr_stream *xdr) 1049 { 1050 return true; 1051 } 1052 1053 /** 1054 * nfssvc_encode_voidres - Encode void results 1055 * @rqstp: Server RPC transaction context 1056 * @xdr: XDR stream into which to encode results 1057 * 1058 * Return values: 1059 * %false: Local error while encoding 1060 * %true: Encoding was successful 1061 */ 1062 bool nfssvc_encode_voidres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 1063 { 1064 return true; 1065 } 1066 1067 int nfsd_pool_stats_open(struct inode *inode, struct file *file) 1068 { 1069 struct nfsd_net *nn = net_generic(inode->i_sb->s_fs_info, nfsd_net_id); 1070 1071 return svc_pool_stats_open(&nn->nfsd_info, file); 1072 } 1073