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