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[NFSD_MAXVERS+1] = { 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 struct svc_program nfsd_program = { 120 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 121 .pg_next = &nfsd_acl_program, 122 #endif 123 .pg_prog = NFS_PROGRAM, /* program number */ 124 .pg_nvers = NFSD_MAXVERS+1, /* nr of entries in nfsd_version */ 125 .pg_vers = nfsd_version, /* version table */ 126 .pg_name = "nfsd", /* program name */ 127 .pg_class = "nfsd", /* authentication class */ 128 .pg_authenticate = &svc_set_client, /* export authentication */ 129 .pg_init_request = nfsd_init_request, 130 .pg_rpcbind_set = nfsd_rpcbind_set, 131 }; 132 133 bool nfsd_support_version(int vers) 134 { 135 if (vers >= NFSD_MINVERS && vers <= NFSD_MAXVERS) 136 return nfsd_version[vers] != NULL; 137 return false; 138 } 139 140 int nfsd_vers(struct nfsd_net *nn, int vers, enum vers_op change) 141 { 142 if (vers < NFSD_MINVERS || vers > NFSD_MAXVERS) 143 return 0; 144 switch(change) { 145 case NFSD_SET: 146 nn->nfsd_versions[vers] = nfsd_support_version(vers); 147 break; 148 case NFSD_CLEAR: 149 nn->nfsd_versions[vers] = false; 150 break; 151 case NFSD_TEST: 152 return nn->nfsd_versions[vers]; 153 case NFSD_AVAIL: 154 return nfsd_support_version(vers); 155 } 156 return 0; 157 } 158 159 static void 160 nfsd_adjust_nfsd_versions4(struct nfsd_net *nn) 161 { 162 unsigned i; 163 164 for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++) { 165 if (nn->nfsd4_minorversions[i]) 166 return; 167 } 168 nfsd_vers(nn, 4, NFSD_CLEAR); 169 } 170 171 int nfsd_minorversion(struct nfsd_net *nn, u32 minorversion, enum vers_op change) 172 { 173 if (minorversion > NFSD_SUPPORTED_MINOR_VERSION && 174 change != NFSD_AVAIL) 175 return -1; 176 177 switch(change) { 178 case NFSD_SET: 179 nfsd_vers(nn, 4, NFSD_SET); 180 nn->nfsd4_minorversions[minorversion] = 181 nfsd_vers(nn, 4, NFSD_TEST); 182 break; 183 case NFSD_CLEAR: 184 nn->nfsd4_minorversions[minorversion] = false; 185 nfsd_adjust_nfsd_versions4(nn); 186 break; 187 case NFSD_TEST: 188 return nn->nfsd4_minorversions[minorversion]; 189 case NFSD_AVAIL: 190 return minorversion <= NFSD_SUPPORTED_MINOR_VERSION && 191 nfsd_vers(nn, 4, NFSD_AVAIL); 192 } 193 return 0; 194 } 195 196 /* 197 * Maximum number of nfsd processes 198 */ 199 #define NFSD_MAXSERVS 8192 200 201 int nfsd_nrthreads(struct net *net) 202 { 203 int rv = 0; 204 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 205 206 mutex_lock(&nfsd_mutex); 207 if (nn->nfsd_serv) 208 rv = nn->nfsd_serv->sv_nrthreads; 209 mutex_unlock(&nfsd_mutex); 210 return rv; 211 } 212 213 static int nfsd_init_socks(struct net *net, const struct cred *cred) 214 { 215 int error; 216 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 217 218 if (!list_empty(&nn->nfsd_serv->sv_permsocks)) 219 return 0; 220 221 error = svc_xprt_create(nn->nfsd_serv, "udp", net, PF_INET, NFS_PORT, 222 SVC_SOCK_DEFAULTS, cred); 223 if (error < 0) 224 return error; 225 226 error = svc_xprt_create(nn->nfsd_serv, "tcp", net, PF_INET, NFS_PORT, 227 SVC_SOCK_DEFAULTS, cred); 228 if (error < 0) 229 return error; 230 231 return 0; 232 } 233 234 static int nfsd_users = 0; 235 236 static int nfsd_startup_generic(void) 237 { 238 int ret; 239 240 if (nfsd_users++) 241 return 0; 242 243 ret = nfsd_file_cache_init(); 244 if (ret) 245 goto dec_users; 246 247 ret = nfs4_state_start(); 248 if (ret) 249 goto out_file_cache; 250 return 0; 251 252 out_file_cache: 253 nfsd_file_cache_shutdown(); 254 dec_users: 255 nfsd_users--; 256 return ret; 257 } 258 259 static void nfsd_shutdown_generic(void) 260 { 261 if (--nfsd_users) 262 return; 263 264 nfs4_state_shutdown(); 265 nfsd_file_cache_shutdown(); 266 } 267 268 static bool nfsd_needs_lockd(struct nfsd_net *nn) 269 { 270 return nfsd_vers(nn, 2, NFSD_TEST) || nfsd_vers(nn, 3, NFSD_TEST); 271 } 272 273 /** 274 * nfsd_copy_write_verifier - Atomically copy a write verifier 275 * @verf: buffer in which to receive the verifier cookie 276 * @nn: NFS net namespace 277 * 278 * This function provides a wait-free mechanism for copying the 279 * namespace's write verifier without tearing it. 280 */ 281 void nfsd_copy_write_verifier(__be32 verf[2], struct nfsd_net *nn) 282 { 283 unsigned int seq; 284 285 do { 286 seq = read_seqbegin(&nn->writeverf_lock); 287 memcpy(verf, nn->writeverf, sizeof(nn->writeverf)); 288 } while (read_seqretry(&nn->writeverf_lock, seq)); 289 } 290 291 static void nfsd_reset_write_verifier_locked(struct nfsd_net *nn) 292 { 293 struct timespec64 now; 294 u64 verf; 295 296 /* 297 * Because the time value is hashed, y2038 time_t overflow 298 * is irrelevant in this usage. 299 */ 300 ktime_get_raw_ts64(&now); 301 verf = siphash_2u64(now.tv_sec, now.tv_nsec, &nn->siphash_key); 302 memcpy(nn->writeverf, &verf, sizeof(nn->writeverf)); 303 } 304 305 /** 306 * nfsd_reset_write_verifier - Generate a new write verifier 307 * @nn: NFS net namespace 308 * 309 * This function updates the ->writeverf field of @nn. This field 310 * contains an opaque cookie that, according to Section 18.32.3 of 311 * RFC 8881, "the client can use to determine whether a server has 312 * changed instance state (e.g., server restart) between a call to 313 * WRITE and a subsequent call to either WRITE or COMMIT. This 314 * cookie MUST be unchanged during a single instance of the NFSv4.1 315 * server and MUST be unique between instances of the NFSv4.1 316 * server." 317 */ 318 void nfsd_reset_write_verifier(struct nfsd_net *nn) 319 { 320 write_seqlock(&nn->writeverf_lock); 321 nfsd_reset_write_verifier_locked(nn); 322 write_sequnlock(&nn->writeverf_lock); 323 } 324 325 /* 326 * Crank up a set of per-namespace resources for a new NFSD instance, 327 * including lockd, a duplicate reply cache, an open file cache 328 * instance, and a cache of NFSv4 state objects. 329 */ 330 static int nfsd_startup_net(struct net *net, const struct cred *cred) 331 { 332 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 333 int ret; 334 335 if (nn->nfsd_net_up) 336 return 0; 337 338 ret = nfsd_startup_generic(); 339 if (ret) 340 return ret; 341 ret = nfsd_init_socks(net, cred); 342 if (ret) 343 goto out_socks; 344 345 if (nfsd_needs_lockd(nn) && !nn->lockd_up) { 346 ret = lockd_up(net, cred); 347 if (ret) 348 goto out_socks; 349 nn->lockd_up = true; 350 } 351 352 ret = nfsd_file_cache_start_net(net); 353 if (ret) 354 goto out_lockd; 355 356 ret = nfsd_reply_cache_init(nn); 357 if (ret) 358 goto out_filecache; 359 360 ret = nfs4_state_start_net(net); 361 if (ret) 362 goto out_reply_cache; 363 364 #ifdef CONFIG_NFSD_V4_2_INTER_SSC 365 nfsd4_ssc_init_umount_work(nn); 366 #endif 367 nn->nfsd_net_up = true; 368 return 0; 369 370 out_reply_cache: 371 nfsd_reply_cache_shutdown(nn); 372 out_filecache: 373 nfsd_file_cache_shutdown_net(net); 374 out_lockd: 375 if (nn->lockd_up) { 376 lockd_down(net); 377 nn->lockd_up = false; 378 } 379 out_socks: 380 nfsd_shutdown_generic(); 381 return ret; 382 } 383 384 static void nfsd_shutdown_net(struct net *net) 385 { 386 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 387 388 nfs4_state_shutdown_net(net); 389 nfsd_reply_cache_shutdown(nn); 390 nfsd_file_cache_shutdown_net(net); 391 if (nn->lockd_up) { 392 lockd_down(net); 393 nn->lockd_up = false; 394 } 395 nn->nfsd_net_up = false; 396 nfsd_shutdown_generic(); 397 } 398 399 static DEFINE_SPINLOCK(nfsd_notifier_lock); 400 static int nfsd_inetaddr_event(struct notifier_block *this, unsigned long event, 401 void *ptr) 402 { 403 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 404 struct net_device *dev = ifa->ifa_dev->dev; 405 struct net *net = dev_net(dev); 406 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 407 struct sockaddr_in sin; 408 409 if (event != NETDEV_DOWN || !nn->nfsd_serv) 410 goto out; 411 412 spin_lock(&nfsd_notifier_lock); 413 if (nn->nfsd_serv) { 414 dprintk("nfsd_inetaddr_event: removed %pI4\n", &ifa->ifa_local); 415 sin.sin_family = AF_INET; 416 sin.sin_addr.s_addr = ifa->ifa_local; 417 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin); 418 } 419 spin_unlock(&nfsd_notifier_lock); 420 421 out: 422 return NOTIFY_DONE; 423 } 424 425 static struct notifier_block nfsd_inetaddr_notifier = { 426 .notifier_call = nfsd_inetaddr_event, 427 }; 428 429 #if IS_ENABLED(CONFIG_IPV6) 430 static int nfsd_inet6addr_event(struct notifier_block *this, 431 unsigned long event, void *ptr) 432 { 433 struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr; 434 struct net_device *dev = ifa->idev->dev; 435 struct net *net = dev_net(dev); 436 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 437 struct sockaddr_in6 sin6; 438 439 if (event != NETDEV_DOWN || !nn->nfsd_serv) 440 goto out; 441 442 spin_lock(&nfsd_notifier_lock); 443 if (nn->nfsd_serv) { 444 dprintk("nfsd_inet6addr_event: removed %pI6\n", &ifa->addr); 445 sin6.sin6_family = AF_INET6; 446 sin6.sin6_addr = ifa->addr; 447 if (ipv6_addr_type(&sin6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 448 sin6.sin6_scope_id = ifa->idev->dev->ifindex; 449 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin6); 450 } 451 spin_unlock(&nfsd_notifier_lock); 452 453 out: 454 return NOTIFY_DONE; 455 } 456 457 static struct notifier_block nfsd_inet6addr_notifier = { 458 .notifier_call = nfsd_inet6addr_event, 459 }; 460 #endif 461 462 /* Only used under nfsd_mutex, so this atomic may be overkill: */ 463 static atomic_t nfsd_notifier_refcount = ATOMIC_INIT(0); 464 465 /** 466 * nfsd_destroy_serv - tear down NFSD's svc_serv for a namespace 467 * @net: network namespace the NFS service is associated with 468 */ 469 void nfsd_destroy_serv(struct net *net) 470 { 471 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 472 struct svc_serv *serv = nn->nfsd_serv; 473 474 spin_lock(&nfsd_notifier_lock); 475 nn->nfsd_serv = NULL; 476 spin_unlock(&nfsd_notifier_lock); 477 478 /* check if the notifier still has clients */ 479 if (atomic_dec_return(&nfsd_notifier_refcount) == 0) { 480 unregister_inetaddr_notifier(&nfsd_inetaddr_notifier); 481 #if IS_ENABLED(CONFIG_IPV6) 482 unregister_inet6addr_notifier(&nfsd_inet6addr_notifier); 483 #endif 484 } 485 486 svc_xprt_destroy_all(serv, net); 487 488 /* 489 * write_ports can create the server without actually starting 490 * any threads--if we get shut down before any threads are 491 * started, then nfsd_destroy_serv will be run before any of this 492 * other initialization has been done except the rpcb information. 493 */ 494 svc_rpcb_cleanup(serv, net); 495 if (!nn->nfsd_net_up) 496 return; 497 498 nfsd_shutdown_net(net); 499 nfsd_export_flush(net); 500 svc_destroy(&serv); 501 } 502 503 void nfsd_reset_versions(struct nfsd_net *nn) 504 { 505 int i; 506 507 for (i = 0; i <= NFSD_MAXVERS; i++) 508 if (nfsd_vers(nn, i, NFSD_TEST)) 509 return; 510 511 for (i = 0; i <= NFSD_MAXVERS; i++) 512 if (i != 4) 513 nfsd_vers(nn, i, NFSD_SET); 514 else { 515 int minor = 0; 516 while (nfsd_minorversion(nn, minor, NFSD_SET) >= 0) 517 minor++; 518 } 519 } 520 521 /* 522 * Each session guarantees a negotiated per slot memory cache for replies 523 * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated 524 * NFSv4.1 server might want to use more memory for a DRC than a machine 525 * with mutiple services. 526 * 527 * Impose a hard limit on the number of pages for the DRC which varies 528 * according to the machines free pages. This is of course only a default. 529 * 530 * For now this is a #defined shift which could be under admin control 531 * in the future. 532 */ 533 static void set_max_drc(void) 534 { 535 #define NFSD_DRC_SIZE_SHIFT 7 536 nfsd_drc_max_mem = (nr_free_buffer_pages() 537 >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE; 538 nfsd_drc_mem_used = 0; 539 dprintk("%s nfsd_drc_max_mem %lu \n", __func__, nfsd_drc_max_mem); 540 } 541 542 static int nfsd_get_default_max_blksize(void) 543 { 544 struct sysinfo i; 545 unsigned long long target; 546 unsigned long ret; 547 548 si_meminfo(&i); 549 target = (i.totalram - i.totalhigh) << PAGE_SHIFT; 550 /* 551 * Aim for 1/4096 of memory per thread This gives 1MB on 4Gig 552 * machines, but only uses 32K on 128M machines. Bottom out at 553 * 8K on 32M and smaller. Of course, this is only a default. 554 */ 555 target >>= 12; 556 557 ret = NFSSVC_MAXBLKSIZE; 558 while (ret > target && ret >= 8*1024*2) 559 ret /= 2; 560 return ret; 561 } 562 563 void nfsd_shutdown_threads(struct net *net) 564 { 565 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 566 struct svc_serv *serv; 567 568 mutex_lock(&nfsd_mutex); 569 serv = nn->nfsd_serv; 570 if (serv == NULL) { 571 mutex_unlock(&nfsd_mutex); 572 return; 573 } 574 575 /* Kill outstanding nfsd threads */ 576 svc_set_num_threads(serv, NULL, 0); 577 nfsd_destroy_serv(net); 578 mutex_unlock(&nfsd_mutex); 579 } 580 581 struct svc_rqst *nfsd_current_rqst(void) 582 { 583 if (kthread_func(current) == nfsd) 584 return kthread_data(current); 585 return NULL; 586 } 587 588 int nfsd_create_serv(struct net *net) 589 { 590 int error; 591 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 592 struct svc_serv *serv; 593 594 WARN_ON(!mutex_is_locked(&nfsd_mutex)); 595 if (nn->nfsd_serv) 596 return 0; 597 598 if (nfsd_max_blksize == 0) 599 nfsd_max_blksize = nfsd_get_default_max_blksize(); 600 nfsd_reset_versions(nn); 601 serv = svc_create_pooled(&nfsd_program, &nn->nfsd_svcstats, 602 nfsd_max_blksize, nfsd); 603 if (serv == NULL) 604 return -ENOMEM; 605 606 serv->sv_maxconn = nn->max_connections; 607 error = svc_bind(serv, net); 608 if (error < 0) { 609 svc_destroy(&serv); 610 return error; 611 } 612 spin_lock(&nfsd_notifier_lock); 613 nn->nfsd_serv = serv; 614 spin_unlock(&nfsd_notifier_lock); 615 616 set_max_drc(); 617 /* check if the notifier is already set */ 618 if (atomic_inc_return(&nfsd_notifier_refcount) == 1) { 619 register_inetaddr_notifier(&nfsd_inetaddr_notifier); 620 #if IS_ENABLED(CONFIG_IPV6) 621 register_inet6addr_notifier(&nfsd_inet6addr_notifier); 622 #endif 623 } 624 nfsd_reset_write_verifier(nn); 625 return 0; 626 } 627 628 int nfsd_nrpools(struct net *net) 629 { 630 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 631 632 if (nn->nfsd_serv == NULL) 633 return 0; 634 else 635 return nn->nfsd_serv->sv_nrpools; 636 } 637 638 int nfsd_get_nrthreads(int n, int *nthreads, struct net *net) 639 { 640 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 641 struct svc_serv *serv = nn->nfsd_serv; 642 int i; 643 644 if (serv) 645 for (i = 0; i < serv->sv_nrpools && i < n; i++) 646 nthreads[i] = serv->sv_pools[i].sp_nrthreads; 647 return 0; 648 } 649 650 /** 651 * nfsd_set_nrthreads - set the number of running threads in the net's service 652 * @n: number of array members in @nthreads 653 * @nthreads: array of thread counts for each pool 654 * @net: network namespace to operate within 655 * 656 * This function alters the number of running threads for the given network 657 * namespace in each pool. If passed an array longer then the number of pools 658 * the extra pool settings are ignored. If passed an array shorter than the 659 * number of pools, the missing values are interpreted as 0's. 660 * 661 * Returns 0 on success or a negative errno on error. 662 */ 663 int nfsd_set_nrthreads(int n, int *nthreads, struct net *net) 664 { 665 int i = 0; 666 int tot = 0; 667 int err = 0; 668 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 669 670 lockdep_assert_held(&nfsd_mutex); 671 672 if (nn->nfsd_serv == NULL || n <= 0) 673 return 0; 674 675 /* 676 * Special case: When n == 1, pass in NULL for the pool, so that the 677 * change is distributed equally among them. 678 */ 679 if (n == 1) 680 return svc_set_num_threads(nn->nfsd_serv, NULL, nthreads[0]); 681 682 if (n > nn->nfsd_serv->sv_nrpools) 683 n = nn->nfsd_serv->sv_nrpools; 684 685 /* enforce a global maximum number of threads */ 686 tot = 0; 687 for (i = 0; i < n; i++) { 688 nthreads[i] = min(nthreads[i], NFSD_MAXSERVS); 689 tot += nthreads[i]; 690 } 691 if (tot > NFSD_MAXSERVS) { 692 /* total too large: scale down requested numbers */ 693 for (i = 0; i < n && tot > 0; i++) { 694 int new = nthreads[i] * NFSD_MAXSERVS / tot; 695 tot -= (nthreads[i] - new); 696 nthreads[i] = new; 697 } 698 for (i = 0; i < n && tot > 0; i++) { 699 nthreads[i]--; 700 tot--; 701 } 702 } 703 704 /* apply the new numbers */ 705 for (i = 0; i < n; i++) { 706 err = svc_set_num_threads(nn->nfsd_serv, 707 &nn->nfsd_serv->sv_pools[i], 708 nthreads[i]); 709 if (err) 710 goto out; 711 } 712 713 /* Anything undefined in array is considered to be 0 */ 714 for (i = n; i < nn->nfsd_serv->sv_nrpools; ++i) { 715 err = svc_set_num_threads(nn->nfsd_serv, 716 &nn->nfsd_serv->sv_pools[i], 717 0); 718 if (err) 719 goto out; 720 } 721 out: 722 return err; 723 } 724 725 /** 726 * nfsd_svc: start up or shut down the nfsd server 727 * @n: number of array members in @nthreads 728 * @nthreads: array of thread counts for each pool 729 * @net: network namespace to operate within 730 * @cred: credentials to use for xprt creation 731 * @scope: server scope value (defaults to nodename) 732 * 733 * Adjust the number of threads in each pool and return the new 734 * total number of threads in the service. 735 */ 736 int 737 nfsd_svc(int n, int *nthreads, struct net *net, const struct cred *cred, const char *scope) 738 { 739 int error; 740 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 741 struct svc_serv *serv; 742 743 lockdep_assert_held(&nfsd_mutex); 744 745 dprintk("nfsd: creating service\n"); 746 747 strscpy(nn->nfsd_name, scope ? scope : utsname()->nodename, 748 sizeof(nn->nfsd_name)); 749 750 error = nfsd_create_serv(net); 751 if (error) 752 goto out; 753 serv = nn->nfsd_serv; 754 755 error = nfsd_startup_net(net, cred); 756 if (error) 757 goto out_put; 758 error = nfsd_set_nrthreads(n, nthreads, net); 759 if (error) 760 goto out_put; 761 error = serv->sv_nrthreads; 762 out_put: 763 if (serv->sv_nrthreads == 0) 764 nfsd_destroy_serv(net); 765 out: 766 return error; 767 } 768 769 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 770 static bool 771 nfsd_support_acl_version(int vers) 772 { 773 if (vers >= NFSD_ACL_MINVERS && vers < NFSD_ACL_NRVERS) 774 return nfsd_acl_version[vers] != NULL; 775 return false; 776 } 777 778 static int 779 nfsd_acl_rpcbind_set(struct net *net, const struct svc_program *progp, 780 u32 version, int family, unsigned short proto, 781 unsigned short port) 782 { 783 if (!nfsd_support_acl_version(version) || 784 !nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST)) 785 return 0; 786 return svc_generic_rpcbind_set(net, progp, version, family, 787 proto, port); 788 } 789 790 static __be32 791 nfsd_acl_init_request(struct svc_rqst *rqstp, 792 const struct svc_program *progp, 793 struct svc_process_info *ret) 794 { 795 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); 796 int i; 797 798 if (likely(nfsd_support_acl_version(rqstp->rq_vers) && 799 nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST))) 800 return svc_generic_init_request(rqstp, progp, ret); 801 802 ret->mismatch.lovers = NFSD_ACL_NRVERS; 803 for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) { 804 if (nfsd_support_acl_version(rqstp->rq_vers) && 805 nfsd_vers(nn, i, NFSD_TEST)) { 806 ret->mismatch.lovers = i; 807 break; 808 } 809 } 810 if (ret->mismatch.lovers == NFSD_ACL_NRVERS) 811 return rpc_prog_unavail; 812 ret->mismatch.hivers = NFSD_ACL_MINVERS; 813 for (i = NFSD_ACL_NRVERS - 1; i >= NFSD_ACL_MINVERS; i--) { 814 if (nfsd_support_acl_version(rqstp->rq_vers) && 815 nfsd_vers(nn, i, NFSD_TEST)) { 816 ret->mismatch.hivers = i; 817 break; 818 } 819 } 820 return rpc_prog_mismatch; 821 } 822 #endif 823 824 static int 825 nfsd_rpcbind_set(struct net *net, const struct svc_program *progp, 826 u32 version, int family, unsigned short proto, 827 unsigned short port) 828 { 829 if (!nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST)) 830 return 0; 831 return svc_generic_rpcbind_set(net, progp, version, family, 832 proto, port); 833 } 834 835 static __be32 836 nfsd_init_request(struct svc_rqst *rqstp, 837 const struct svc_program *progp, 838 struct svc_process_info *ret) 839 { 840 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); 841 int i; 842 843 if (likely(nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST))) 844 return svc_generic_init_request(rqstp, progp, ret); 845 846 ret->mismatch.lovers = NFSD_MAXVERS + 1; 847 for (i = NFSD_MINVERS; i <= NFSD_MAXVERS; i++) { 848 if (nfsd_vers(nn, i, NFSD_TEST)) { 849 ret->mismatch.lovers = i; 850 break; 851 } 852 } 853 if (ret->mismatch.lovers > NFSD_MAXVERS) 854 return rpc_prog_unavail; 855 ret->mismatch.hivers = NFSD_MINVERS; 856 for (i = NFSD_MAXVERS; i >= NFSD_MINVERS; i--) { 857 if (nfsd_vers(nn, i, NFSD_TEST)) { 858 ret->mismatch.hivers = i; 859 break; 860 } 861 } 862 return rpc_prog_mismatch; 863 } 864 865 /* 866 * This is the NFS server kernel thread 867 */ 868 static int 869 nfsd(void *vrqstp) 870 { 871 struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp; 872 struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list); 873 struct net *net = perm_sock->xpt_net; 874 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 875 876 /* At this point, the thread shares current->fs 877 * with the init process. We need to create files with the 878 * umask as defined by the client instead of init's umask. 879 */ 880 svc_thread_init_status(rqstp, unshare_fs_struct()); 881 882 current->fs->umask = 0; 883 884 atomic_inc(&nfsd_th_cnt); 885 886 set_freezable(); 887 888 /* 889 * The main request loop 890 */ 891 while (!svc_thread_should_stop(rqstp)) { 892 /* Update sv_maxconn if it has changed */ 893 rqstp->rq_server->sv_maxconn = nn->max_connections; 894 895 svc_recv(rqstp); 896 897 nfsd_file_net_dispose(nn); 898 } 899 900 atomic_dec(&nfsd_th_cnt); 901 902 /* Release the thread */ 903 svc_exit_thread(rqstp); 904 return 0; 905 } 906 907 /** 908 * nfsd_dispatch - Process an NFS or NFSACL Request 909 * @rqstp: incoming request 910 * 911 * This RPC dispatcher integrates the NFS server's duplicate reply cache. 912 * 913 * Return values: 914 * %0: Processing complete; do not send a Reply 915 * %1: Processing complete; send Reply in rqstp->rq_res 916 */ 917 int nfsd_dispatch(struct svc_rqst *rqstp) 918 { 919 const struct svc_procedure *proc = rqstp->rq_procinfo; 920 __be32 *statp = rqstp->rq_accept_statp; 921 struct nfsd_cacherep *rp; 922 unsigned int start, len; 923 __be32 *nfs_reply; 924 925 /* 926 * Give the xdr decoder a chance to change this if it wants 927 * (necessary in the NFSv4.0 compound case) 928 */ 929 rqstp->rq_cachetype = proc->pc_cachetype; 930 931 /* 932 * ->pc_decode advances the argument stream past the NFS 933 * Call header, so grab the header's starting location and 934 * size now for the call to nfsd_cache_lookup(). 935 */ 936 start = xdr_stream_pos(&rqstp->rq_arg_stream); 937 len = xdr_stream_remaining(&rqstp->rq_arg_stream); 938 if (!proc->pc_decode(rqstp, &rqstp->rq_arg_stream)) 939 goto out_decode_err; 940 941 /* 942 * Release rq_status_counter setting it to an odd value after the rpc 943 * request has been properly parsed. rq_status_counter is used to 944 * notify the consumers if the rqstp fields are stable 945 * (rq_status_counter is odd) or not meaningful (rq_status_counter 946 * is even). 947 */ 948 smp_store_release(&rqstp->rq_status_counter, rqstp->rq_status_counter | 1); 949 950 rp = NULL; 951 switch (nfsd_cache_lookup(rqstp, start, len, &rp)) { 952 case RC_DOIT: 953 break; 954 case RC_REPLY: 955 goto out_cached_reply; 956 case RC_DROPIT: 957 goto out_dropit; 958 } 959 960 nfs_reply = xdr_inline_decode(&rqstp->rq_res_stream, 0); 961 *statp = proc->pc_func(rqstp); 962 if (test_bit(RQ_DROPME, &rqstp->rq_flags)) 963 goto out_update_drop; 964 965 if (!proc->pc_encode(rqstp, &rqstp->rq_res_stream)) 966 goto out_encode_err; 967 968 /* 969 * Release rq_status_counter setting it to an even value after the rpc 970 * request has been properly processed. 971 */ 972 smp_store_release(&rqstp->rq_status_counter, rqstp->rq_status_counter + 1); 973 974 nfsd_cache_update(rqstp, rp, rqstp->rq_cachetype, nfs_reply); 975 out_cached_reply: 976 return 1; 977 978 out_decode_err: 979 trace_nfsd_garbage_args_err(rqstp); 980 *statp = rpc_garbage_args; 981 return 1; 982 983 out_update_drop: 984 nfsd_cache_update(rqstp, rp, RC_NOCACHE, NULL); 985 out_dropit: 986 return 0; 987 988 out_encode_err: 989 trace_nfsd_cant_encode_err(rqstp); 990 nfsd_cache_update(rqstp, rp, RC_NOCACHE, NULL); 991 *statp = rpc_system_err; 992 return 1; 993 } 994 995 /** 996 * nfssvc_decode_voidarg - Decode void arguments 997 * @rqstp: Server RPC transaction context 998 * @xdr: XDR stream positioned at arguments to decode 999 * 1000 * Return values: 1001 * %false: Arguments were not valid 1002 * %true: Decoding was successful 1003 */ 1004 bool nfssvc_decode_voidarg(struct svc_rqst *rqstp, struct xdr_stream *xdr) 1005 { 1006 return true; 1007 } 1008 1009 /** 1010 * nfssvc_encode_voidres - Encode void results 1011 * @rqstp: Server RPC transaction context 1012 * @xdr: XDR stream into which to encode results 1013 * 1014 * Return values: 1015 * %false: Local error while encoding 1016 * %true: Encoding was successful 1017 */ 1018 bool nfssvc_encode_voidres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 1019 { 1020 return true; 1021 } 1022