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(*verf)); 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 static int nfsd_startup_net(struct net *net, const struct cred *cred) 406 { 407 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 408 int ret; 409 410 if (nn->nfsd_net_up) 411 return 0; 412 413 ret = nfsd_startup_generic(); 414 if (ret) 415 return ret; 416 ret = nfsd_init_socks(net, cred); 417 if (ret) 418 goto out_socks; 419 420 if (nfsd_needs_lockd(nn) && !nn->lockd_up) { 421 ret = lockd_up(net, cred); 422 if (ret) 423 goto out_socks; 424 nn->lockd_up = true; 425 } 426 427 ret = nfsd_file_cache_start_net(net); 428 if (ret) 429 goto out_lockd; 430 ret = nfs4_state_start_net(net); 431 if (ret) 432 goto out_filecache; 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_filecache: 441 nfsd_file_cache_shutdown_net(net); 442 out_lockd: 443 if (nn->lockd_up) { 444 lockd_down(net); 445 nn->lockd_up = false; 446 } 447 out_socks: 448 nfsd_shutdown_generic(); 449 return ret; 450 } 451 452 static void nfsd_shutdown_net(struct net *net) 453 { 454 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 455 456 nfsd_file_cache_shutdown_net(net); 457 nfs4_state_shutdown_net(net); 458 if (nn->lockd_up) { 459 lockd_down(net); 460 nn->lockd_up = false; 461 } 462 nn->nfsd_net_up = false; 463 nfsd_shutdown_generic(); 464 } 465 466 static DEFINE_SPINLOCK(nfsd_notifier_lock); 467 static int nfsd_inetaddr_event(struct notifier_block *this, unsigned long event, 468 void *ptr) 469 { 470 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 471 struct net_device *dev = ifa->ifa_dev->dev; 472 struct net *net = dev_net(dev); 473 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 474 struct sockaddr_in sin; 475 476 if (event != NETDEV_DOWN || !nn->nfsd_serv) 477 goto out; 478 479 spin_lock(&nfsd_notifier_lock); 480 if (nn->nfsd_serv) { 481 dprintk("nfsd_inetaddr_event: removed %pI4\n", &ifa->ifa_local); 482 sin.sin_family = AF_INET; 483 sin.sin_addr.s_addr = ifa->ifa_local; 484 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin); 485 } 486 spin_unlock(&nfsd_notifier_lock); 487 488 out: 489 return NOTIFY_DONE; 490 } 491 492 static struct notifier_block nfsd_inetaddr_notifier = { 493 .notifier_call = nfsd_inetaddr_event, 494 }; 495 496 #if IS_ENABLED(CONFIG_IPV6) 497 static int nfsd_inet6addr_event(struct notifier_block *this, 498 unsigned long event, void *ptr) 499 { 500 struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr; 501 struct net_device *dev = ifa->idev->dev; 502 struct net *net = dev_net(dev); 503 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 504 struct sockaddr_in6 sin6; 505 506 if (event != NETDEV_DOWN || !nn->nfsd_serv) 507 goto out; 508 509 spin_lock(&nfsd_notifier_lock); 510 if (nn->nfsd_serv) { 511 dprintk("nfsd_inet6addr_event: removed %pI6\n", &ifa->addr); 512 sin6.sin6_family = AF_INET6; 513 sin6.sin6_addr = ifa->addr; 514 if (ipv6_addr_type(&sin6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 515 sin6.sin6_scope_id = ifa->idev->dev->ifindex; 516 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin6); 517 } 518 spin_unlock(&nfsd_notifier_lock); 519 520 out: 521 return NOTIFY_DONE; 522 } 523 524 static struct notifier_block nfsd_inet6addr_notifier = { 525 .notifier_call = nfsd_inet6addr_event, 526 }; 527 #endif 528 529 /* Only used under nfsd_mutex, so this atomic may be overkill: */ 530 static atomic_t nfsd_notifier_refcount = ATOMIC_INIT(0); 531 532 static void nfsd_last_thread(struct svc_serv *serv, struct net *net) 533 { 534 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 535 536 /* check if the notifier still has clients */ 537 if (atomic_dec_return(&nfsd_notifier_refcount) == 0) { 538 unregister_inetaddr_notifier(&nfsd_inetaddr_notifier); 539 #if IS_ENABLED(CONFIG_IPV6) 540 unregister_inet6addr_notifier(&nfsd_inet6addr_notifier); 541 #endif 542 } 543 544 /* 545 * write_ports can create the server without actually starting 546 * any threads--if we get shut down before any threads are 547 * started, then nfsd_last_thread will be run before any of this 548 * other initialization has been done except the rpcb information. 549 */ 550 svc_rpcb_cleanup(serv, net); 551 if (!nn->nfsd_net_up) 552 return; 553 554 nfsd_shutdown_net(net); 555 pr_info("nfsd: last server has exited, flushing export cache\n"); 556 nfsd_export_flush(net); 557 } 558 559 void nfsd_reset_versions(struct nfsd_net *nn) 560 { 561 int i; 562 563 for (i = 0; i < NFSD_NRVERS; i++) 564 if (nfsd_vers(nn, i, NFSD_TEST)) 565 return; 566 567 for (i = 0; i < NFSD_NRVERS; i++) 568 if (i != 4) 569 nfsd_vers(nn, i, NFSD_SET); 570 else { 571 int minor = 0; 572 while (nfsd_minorversion(nn, minor, NFSD_SET) >= 0) 573 minor++; 574 } 575 } 576 577 /* 578 * Each session guarantees a negotiated per slot memory cache for replies 579 * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated 580 * NFSv4.1 server might want to use more memory for a DRC than a machine 581 * with mutiple services. 582 * 583 * Impose a hard limit on the number of pages for the DRC which varies 584 * according to the machines free pages. This is of course only a default. 585 * 586 * For now this is a #defined shift which could be under admin control 587 * in the future. 588 */ 589 static void set_max_drc(void) 590 { 591 #define NFSD_DRC_SIZE_SHIFT 7 592 nfsd_drc_max_mem = (nr_free_buffer_pages() 593 >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE; 594 nfsd_drc_mem_used = 0; 595 dprintk("%s nfsd_drc_max_mem %lu \n", __func__, nfsd_drc_max_mem); 596 } 597 598 static int nfsd_get_default_max_blksize(void) 599 { 600 struct sysinfo i; 601 unsigned long long target; 602 unsigned long ret; 603 604 si_meminfo(&i); 605 target = (i.totalram - i.totalhigh) << PAGE_SHIFT; 606 /* 607 * Aim for 1/4096 of memory per thread This gives 1MB on 4Gig 608 * machines, but only uses 32K on 128M machines. Bottom out at 609 * 8K on 32M and smaller. Of course, this is only a default. 610 */ 611 target >>= 12; 612 613 ret = NFSSVC_MAXBLKSIZE; 614 while (ret > target && ret >= 8*1024*2) 615 ret /= 2; 616 return ret; 617 } 618 619 void nfsd_shutdown_threads(struct net *net) 620 { 621 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 622 struct svc_serv *serv; 623 624 mutex_lock(&nfsd_mutex); 625 serv = nn->nfsd_serv; 626 if (serv == NULL) { 627 mutex_unlock(&nfsd_mutex); 628 return; 629 } 630 631 svc_get(serv); 632 /* Kill outstanding nfsd threads */ 633 svc_set_num_threads(serv, NULL, 0); 634 nfsd_put(net); 635 mutex_unlock(&nfsd_mutex); 636 } 637 638 bool i_am_nfsd(void) 639 { 640 return kthread_func(current) == nfsd; 641 } 642 643 int nfsd_create_serv(struct net *net) 644 { 645 int error; 646 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 647 struct svc_serv *serv; 648 649 WARN_ON(!mutex_is_locked(&nfsd_mutex)); 650 if (nn->nfsd_serv) { 651 svc_get(nn->nfsd_serv); 652 return 0; 653 } 654 if (nfsd_max_blksize == 0) 655 nfsd_max_blksize = nfsd_get_default_max_blksize(); 656 nfsd_reset_versions(nn); 657 serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize, nfsd); 658 if (serv == NULL) 659 return -ENOMEM; 660 661 serv->sv_maxconn = nn->max_connections; 662 error = svc_bind(serv, net); 663 if (error < 0) { 664 /* NOT nfsd_put() as notifiers (see below) haven't 665 * been set up yet. 666 */ 667 svc_put(serv); 668 return error; 669 } 670 spin_lock(&nfsd_notifier_lock); 671 nn->nfsd_serv = serv; 672 spin_unlock(&nfsd_notifier_lock); 673 674 set_max_drc(); 675 /* check if the notifier is already set */ 676 if (atomic_inc_return(&nfsd_notifier_refcount) == 1) { 677 register_inetaddr_notifier(&nfsd_inetaddr_notifier); 678 #if IS_ENABLED(CONFIG_IPV6) 679 register_inet6addr_notifier(&nfsd_inet6addr_notifier); 680 #endif 681 } 682 nfsd_reset_write_verifier(nn); 683 return 0; 684 } 685 686 int nfsd_nrpools(struct net *net) 687 { 688 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 689 690 if (nn->nfsd_serv == NULL) 691 return 0; 692 else 693 return nn->nfsd_serv->sv_nrpools; 694 } 695 696 int nfsd_get_nrthreads(int n, int *nthreads, struct net *net) 697 { 698 int i = 0; 699 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 700 701 if (nn->nfsd_serv != NULL) { 702 for (i = 0; i < nn->nfsd_serv->sv_nrpools && i < n; i++) 703 nthreads[i] = nn->nfsd_serv->sv_pools[i].sp_nrthreads; 704 } 705 706 return 0; 707 } 708 709 /* This is the callback for kref_put() below. 710 * There is no code here as the first thing to be done is 711 * call svc_shutdown_net(), but we cannot get the 'net' from 712 * the kref. So do all the work when kref_put returns true. 713 */ 714 static void nfsd_noop(struct kref *ref) 715 { 716 } 717 718 void nfsd_put(struct net *net) 719 { 720 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 721 722 if (kref_put(&nn->nfsd_serv->sv_refcnt, nfsd_noop)) { 723 svc_xprt_destroy_all(nn->nfsd_serv, net); 724 nfsd_last_thread(nn->nfsd_serv, net); 725 svc_destroy(&nn->nfsd_serv->sv_refcnt); 726 spin_lock(&nfsd_notifier_lock); 727 nn->nfsd_serv = NULL; 728 spin_unlock(&nfsd_notifier_lock); 729 } 730 } 731 732 int nfsd_set_nrthreads(int n, int *nthreads, struct net *net) 733 { 734 int i = 0; 735 int tot = 0; 736 int err = 0; 737 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 738 739 WARN_ON(!mutex_is_locked(&nfsd_mutex)); 740 741 if (nn->nfsd_serv == NULL || n <= 0) 742 return 0; 743 744 if (n > nn->nfsd_serv->sv_nrpools) 745 n = nn->nfsd_serv->sv_nrpools; 746 747 /* enforce a global maximum number of threads */ 748 tot = 0; 749 for (i = 0; i < n; i++) { 750 nthreads[i] = min(nthreads[i], NFSD_MAXSERVS); 751 tot += nthreads[i]; 752 } 753 if (tot > NFSD_MAXSERVS) { 754 /* total too large: scale down requested numbers */ 755 for (i = 0; i < n && tot > 0; i++) { 756 int new = nthreads[i] * NFSD_MAXSERVS / tot; 757 tot -= (nthreads[i] - new); 758 nthreads[i] = new; 759 } 760 for (i = 0; i < n && tot > 0; i++) { 761 nthreads[i]--; 762 tot--; 763 } 764 } 765 766 /* 767 * There must always be a thread in pool 0; the admin 768 * can't shut down NFS completely using pool_threads. 769 */ 770 if (nthreads[0] == 0) 771 nthreads[0] = 1; 772 773 /* apply the new numbers */ 774 svc_get(nn->nfsd_serv); 775 for (i = 0; i < n; i++) { 776 err = svc_set_num_threads(nn->nfsd_serv, 777 &nn->nfsd_serv->sv_pools[i], 778 nthreads[i]); 779 if (err) 780 break; 781 } 782 nfsd_put(net); 783 return err; 784 } 785 786 /* 787 * Adjust the number of threads and return the new number of threads. 788 * This is also the function that starts the server if necessary, if 789 * this is the first time nrservs is nonzero. 790 */ 791 int 792 nfsd_svc(int nrservs, struct net *net, const struct cred *cred) 793 { 794 int error; 795 bool nfsd_up_before; 796 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 797 798 mutex_lock(&nfsd_mutex); 799 dprintk("nfsd: creating service\n"); 800 801 nrservs = max(nrservs, 0); 802 nrservs = min(nrservs, NFSD_MAXSERVS); 803 error = 0; 804 805 if (nrservs == 0 && nn->nfsd_serv == NULL) 806 goto out; 807 808 strscpy(nn->nfsd_name, utsname()->nodename, 809 sizeof(nn->nfsd_name)); 810 811 error = nfsd_create_serv(net); 812 if (error) 813 goto out; 814 815 nfsd_up_before = nn->nfsd_net_up; 816 817 error = nfsd_startup_net(net, cred); 818 if (error) 819 goto out_put; 820 error = svc_set_num_threads(nn->nfsd_serv, NULL, nrservs); 821 if (error) 822 goto out_shutdown; 823 error = nn->nfsd_serv->sv_nrthreads; 824 out_shutdown: 825 if (error < 0 && !nfsd_up_before) 826 nfsd_shutdown_net(net); 827 out_put: 828 /* Threads now hold service active */ 829 if (xchg(&nn->keep_active, 0)) 830 nfsd_put(net); 831 nfsd_put(net); 832 out: 833 mutex_unlock(&nfsd_mutex); 834 return error; 835 } 836 837 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 838 static bool 839 nfsd_support_acl_version(int vers) 840 { 841 if (vers >= NFSD_ACL_MINVERS && vers < NFSD_ACL_NRVERS) 842 return nfsd_acl_version[vers] != NULL; 843 return false; 844 } 845 846 static int 847 nfsd_acl_rpcbind_set(struct net *net, const struct svc_program *progp, 848 u32 version, int family, unsigned short proto, 849 unsigned short port) 850 { 851 if (!nfsd_support_acl_version(version) || 852 !nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST)) 853 return 0; 854 return svc_generic_rpcbind_set(net, progp, version, family, 855 proto, port); 856 } 857 858 static __be32 859 nfsd_acl_init_request(struct svc_rqst *rqstp, 860 const struct svc_program *progp, 861 struct svc_process_info *ret) 862 { 863 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); 864 int i; 865 866 if (likely(nfsd_support_acl_version(rqstp->rq_vers) && 867 nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST))) 868 return svc_generic_init_request(rqstp, progp, ret); 869 870 ret->mismatch.lovers = NFSD_ACL_NRVERS; 871 for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) { 872 if (nfsd_support_acl_version(rqstp->rq_vers) && 873 nfsd_vers(nn, i, NFSD_TEST)) { 874 ret->mismatch.lovers = i; 875 break; 876 } 877 } 878 if (ret->mismatch.lovers == NFSD_ACL_NRVERS) 879 return rpc_prog_unavail; 880 ret->mismatch.hivers = NFSD_ACL_MINVERS; 881 for (i = NFSD_ACL_NRVERS - 1; i >= NFSD_ACL_MINVERS; i--) { 882 if (nfsd_support_acl_version(rqstp->rq_vers) && 883 nfsd_vers(nn, i, NFSD_TEST)) { 884 ret->mismatch.hivers = i; 885 break; 886 } 887 } 888 return rpc_prog_mismatch; 889 } 890 #endif 891 892 static int 893 nfsd_rpcbind_set(struct net *net, const struct svc_program *progp, 894 u32 version, int family, unsigned short proto, 895 unsigned short port) 896 { 897 if (!nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST)) 898 return 0; 899 return svc_generic_rpcbind_set(net, progp, version, family, 900 proto, port); 901 } 902 903 static __be32 904 nfsd_init_request(struct svc_rqst *rqstp, 905 const struct svc_program *progp, 906 struct svc_process_info *ret) 907 { 908 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); 909 int i; 910 911 if (likely(nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST))) 912 return svc_generic_init_request(rqstp, progp, ret); 913 914 ret->mismatch.lovers = NFSD_NRVERS; 915 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) { 916 if (nfsd_vers(nn, i, NFSD_TEST)) { 917 ret->mismatch.lovers = i; 918 break; 919 } 920 } 921 if (ret->mismatch.lovers == NFSD_NRVERS) 922 return rpc_prog_unavail; 923 ret->mismatch.hivers = NFSD_MINVERS; 924 for (i = NFSD_NRVERS - 1; i >= NFSD_MINVERS; i--) { 925 if (nfsd_vers(nn, i, NFSD_TEST)) { 926 ret->mismatch.hivers = i; 927 break; 928 } 929 } 930 return rpc_prog_mismatch; 931 } 932 933 /* 934 * This is the NFS server kernel thread 935 */ 936 static int 937 nfsd(void *vrqstp) 938 { 939 struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp; 940 struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list); 941 struct net *net = perm_sock->xpt_net; 942 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 943 int err; 944 945 /* At this point, the thread shares current->fs 946 * with the init process. We need to create files with the 947 * umask as defined by the client instead of init's umask. */ 948 if (unshare_fs_struct() < 0) { 949 printk("Unable to start nfsd thread: out of memory\n"); 950 goto out; 951 } 952 953 current->fs->umask = 0; 954 955 /* 956 * thread is spawned with all signals set to SIG_IGN, re-enable 957 * the ones that will bring down the thread 958 */ 959 allow_signal(SIGKILL); 960 allow_signal(SIGHUP); 961 allow_signal(SIGINT); 962 allow_signal(SIGQUIT); 963 964 atomic_inc(&nfsdstats.th_cnt); 965 966 set_freezable(); 967 968 /* 969 * The main request loop 970 */ 971 for (;;) { 972 /* Update sv_maxconn if it has changed */ 973 rqstp->rq_server->sv_maxconn = nn->max_connections; 974 975 /* 976 * Find a socket with data available and call its 977 * recvfrom routine. 978 */ 979 while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN) 980 ; 981 if (err == -EINTR) 982 break; 983 validate_process_creds(); 984 svc_process(rqstp); 985 validate_process_creds(); 986 } 987 988 /* Clear signals before calling svc_exit_thread() */ 989 flush_signals(current); 990 991 atomic_dec(&nfsdstats.th_cnt); 992 993 out: 994 /* Take an extra ref so that the svc_put in svc_exit_thread() 995 * doesn't call svc_destroy() 996 */ 997 svc_get(nn->nfsd_serv); 998 999 /* Release the thread */ 1000 svc_exit_thread(rqstp); 1001 1002 /* We need to drop a ref, but may not drop the last reference 1003 * without holding nfsd_mutex, and we cannot wait for nfsd_mutex as that 1004 * could deadlock with nfsd_shutdown_threads() waiting for us. 1005 * So three options are: 1006 * - drop a non-final reference, 1007 * - get the mutex without waiting 1008 * - sleep briefly andd try the above again 1009 */ 1010 while (!svc_put_not_last(nn->nfsd_serv)) { 1011 if (mutex_trylock(&nfsd_mutex)) { 1012 nfsd_put(net); 1013 mutex_unlock(&nfsd_mutex); 1014 break; 1015 } 1016 msleep(20); 1017 } 1018 1019 return 0; 1020 } 1021 1022 /** 1023 * nfsd_dispatch - Process an NFS or NFSACL Request 1024 * @rqstp: incoming request 1025 * @statp: pointer to location of accept_stat field in RPC Reply buffer 1026 * 1027 * This RPC dispatcher integrates the NFS server's duplicate reply cache. 1028 * 1029 * Return values: 1030 * %0: Processing complete; do not send a Reply 1031 * %1: Processing complete; send Reply in rqstp->rq_res 1032 */ 1033 int nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp) 1034 { 1035 const struct svc_procedure *proc = rqstp->rq_procinfo; 1036 1037 /* 1038 * Give the xdr decoder a chance to change this if it wants 1039 * (necessary in the NFSv4.0 compound case) 1040 */ 1041 rqstp->rq_cachetype = proc->pc_cachetype; 1042 1043 svcxdr_init_decode(rqstp); 1044 if (!proc->pc_decode(rqstp, &rqstp->rq_arg_stream)) 1045 goto out_decode_err; 1046 1047 switch (nfsd_cache_lookup(rqstp)) { 1048 case RC_DOIT: 1049 break; 1050 case RC_REPLY: 1051 goto out_cached_reply; 1052 case RC_DROPIT: 1053 goto out_dropit; 1054 } 1055 1056 /* 1057 * Need to grab the location to store the status, as 1058 * NFSv4 does some encoding while processing 1059 */ 1060 svcxdr_init_encode(rqstp); 1061 1062 *statp = proc->pc_func(rqstp); 1063 if (test_bit(RQ_DROPME, &rqstp->rq_flags)) 1064 goto out_update_drop; 1065 1066 if (!proc->pc_encode(rqstp, &rqstp->rq_res_stream)) 1067 goto out_encode_err; 1068 1069 nfsd_cache_update(rqstp, rqstp->rq_cachetype, statp + 1); 1070 out_cached_reply: 1071 return 1; 1072 1073 out_decode_err: 1074 trace_nfsd_garbage_args_err(rqstp); 1075 *statp = rpc_garbage_args; 1076 return 1; 1077 1078 out_update_drop: 1079 nfsd_cache_update(rqstp, RC_NOCACHE, NULL); 1080 out_dropit: 1081 return 0; 1082 1083 out_encode_err: 1084 trace_nfsd_cant_encode_err(rqstp); 1085 nfsd_cache_update(rqstp, RC_NOCACHE, NULL); 1086 *statp = rpc_system_err; 1087 return 1; 1088 } 1089 1090 /** 1091 * nfssvc_decode_voidarg - Decode void arguments 1092 * @rqstp: Server RPC transaction context 1093 * @xdr: XDR stream positioned at arguments to decode 1094 * 1095 * Return values: 1096 * %false: Arguments were not valid 1097 * %true: Decoding was successful 1098 */ 1099 bool nfssvc_decode_voidarg(struct svc_rqst *rqstp, struct xdr_stream *xdr) 1100 { 1101 return true; 1102 } 1103 1104 /** 1105 * nfssvc_encode_voidres - Encode void results 1106 * @rqstp: Server RPC transaction context 1107 * @xdr: XDR stream into which to encode results 1108 * 1109 * Return values: 1110 * %false: Local error while encoding 1111 * %true: Encoding was successful 1112 */ 1113 bool nfssvc_encode_voidres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 1114 { 1115 return true; 1116 } 1117 1118 int nfsd_pool_stats_open(struct inode *inode, struct file *file) 1119 { 1120 int ret; 1121 struct nfsd_net *nn = net_generic(inode->i_sb->s_fs_info, nfsd_net_id); 1122 1123 mutex_lock(&nfsd_mutex); 1124 if (nn->nfsd_serv == NULL) { 1125 mutex_unlock(&nfsd_mutex); 1126 return -ENODEV; 1127 } 1128 svc_get(nn->nfsd_serv); 1129 ret = svc_pool_stats_open(nn->nfsd_serv, file); 1130 mutex_unlock(&nfsd_mutex); 1131 return ret; 1132 } 1133 1134 int nfsd_pool_stats_release(struct inode *inode, struct file *file) 1135 { 1136 int ret = seq_release(inode, file); 1137 struct net *net = inode->i_sb->s_fs_info; 1138 1139 mutex_lock(&nfsd_mutex); 1140 nfsd_put(net); 1141 mutex_unlock(&nfsd_mutex); 1142 return ret; 1143 } 1144