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/nfslocalio.h> 23 #include <linux/seq_file.h> 24 #include <linux/inetdevice.h> 25 #include <net/addrconf.h> 26 #include <net/ipv6.h> 27 #include <net/net_namespace.h> 28 #include "nfsd.h" 29 #include "cache.h" 30 #include "vfs.h" 31 #include "netns.h" 32 #include "filecache.h" 33 34 #include "trace.h" 35 36 #define NFSDDBG_FACILITY NFSDDBG_SVC 37 38 atomic_t nfsd_th_cnt = ATOMIC_INIT(0); 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 #if IS_ENABLED(CONFIG_NFS_LOCALIO) 74 static const struct svc_version *localio_versions[] = { 75 [1] = &localio_version1, 76 }; 77 78 #define NFSD_LOCALIO_NRVERS ARRAY_SIZE(localio_versions) 79 80 #endif /* CONFIG_NFS_LOCALIO */ 81 82 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 83 static const struct svc_version *nfsd_acl_version[] = { 84 # if defined(CONFIG_NFSD_V2_ACL) 85 [2] = &nfsd_acl_version2, 86 # endif 87 # if defined(CONFIG_NFSD_V3_ACL) 88 [3] = &nfsd_acl_version3, 89 # endif 90 }; 91 92 #define NFSD_ACL_MINVERS 2 93 #define NFSD_ACL_NRVERS ARRAY_SIZE(nfsd_acl_version) 94 95 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */ 96 97 static const struct svc_version *nfsd_version[NFSD_MAXVERS+1] = { 98 #if defined(CONFIG_NFSD_V2) 99 [2] = &nfsd_version2, 100 #endif 101 [3] = &nfsd_version3, 102 #if defined(CONFIG_NFSD_V4) 103 [4] = &nfsd_version4, 104 #endif 105 }; 106 107 struct svc_program nfsd_programs[] = { 108 { 109 .pg_prog = NFS_PROGRAM, /* program number */ 110 .pg_nvers = NFSD_MAXVERS+1, /* nr of entries in nfsd_version */ 111 .pg_vers = nfsd_version, /* version table */ 112 .pg_name = "nfsd", /* program name */ 113 .pg_class = "nfsd", /* authentication class */ 114 .pg_authenticate = svc_set_client, /* export authentication */ 115 .pg_init_request = nfsd_init_request, 116 .pg_rpcbind_set = nfsd_rpcbind_set, 117 }, 118 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 119 { 120 .pg_prog = NFS_ACL_PROGRAM, 121 .pg_nvers = NFSD_ACL_NRVERS, 122 .pg_vers = nfsd_acl_version, 123 .pg_name = "nfsacl", 124 .pg_class = "nfsd", 125 .pg_authenticate = svc_set_client, 126 .pg_init_request = nfsd_acl_init_request, 127 .pg_rpcbind_set = nfsd_acl_rpcbind_set, 128 }, 129 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */ 130 #if IS_ENABLED(CONFIG_NFS_LOCALIO) 131 { 132 .pg_prog = NFS_LOCALIO_PROGRAM, 133 .pg_nvers = NFSD_LOCALIO_NRVERS, 134 .pg_vers = localio_versions, 135 .pg_name = "nfslocalio", 136 .pg_class = "nfsd", 137 .pg_authenticate = svc_set_client, 138 .pg_init_request = svc_generic_init_request, 139 .pg_rpcbind_set = svc_generic_rpcbind_set, 140 } 141 #endif /* CONFIG_NFS_LOCALIO */ 142 }; 143 144 bool nfsd_support_version(int vers) 145 { 146 if (vers >= NFSD_MINVERS && vers <= NFSD_MAXVERS) 147 return nfsd_version[vers] != NULL; 148 return false; 149 } 150 151 int nfsd_vers(struct nfsd_net *nn, int vers, enum vers_op change) 152 { 153 if (vers < NFSD_MINVERS || vers > NFSD_MAXVERS) 154 return 0; 155 switch(change) { 156 case NFSD_SET: 157 nn->nfsd_versions[vers] = nfsd_support_version(vers); 158 break; 159 case NFSD_CLEAR: 160 nn->nfsd_versions[vers] = false; 161 break; 162 case NFSD_TEST: 163 return nn->nfsd_versions[vers]; 164 case NFSD_AVAIL: 165 return nfsd_support_version(vers); 166 } 167 return 0; 168 } 169 170 static void 171 nfsd_adjust_nfsd_versions4(struct nfsd_net *nn) 172 { 173 unsigned i; 174 175 for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++) { 176 if (nn->nfsd4_minorversions[i]) 177 return; 178 } 179 nfsd_vers(nn, 4, NFSD_CLEAR); 180 } 181 182 int nfsd_minorversion(struct nfsd_net *nn, u32 minorversion, enum vers_op change) 183 { 184 if (minorversion > NFSD_SUPPORTED_MINOR_VERSION && 185 change != NFSD_AVAIL) 186 return -1; 187 188 switch(change) { 189 case NFSD_SET: 190 nfsd_vers(nn, 4, NFSD_SET); 191 nn->nfsd4_minorversions[minorversion] = 192 nfsd_vers(nn, 4, NFSD_TEST); 193 break; 194 case NFSD_CLEAR: 195 nn->nfsd4_minorversions[minorversion] = false; 196 nfsd_adjust_nfsd_versions4(nn); 197 break; 198 case NFSD_TEST: 199 return nn->nfsd4_minorversions[minorversion]; 200 case NFSD_AVAIL: 201 return minorversion <= NFSD_SUPPORTED_MINOR_VERSION && 202 nfsd_vers(nn, 4, NFSD_AVAIL); 203 } 204 return 0; 205 } 206 207 bool nfsd_net_try_get(struct net *net) __must_hold(rcu) 208 { 209 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 210 211 return (nn && percpu_ref_tryget_live(&nn->nfsd_net_ref)); 212 } 213 214 void nfsd_net_put(struct net *net) __must_hold(rcu) 215 { 216 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 217 218 percpu_ref_put(&nn->nfsd_net_ref); 219 } 220 221 static void nfsd_net_done(struct percpu_ref *ref) 222 { 223 struct nfsd_net *nn = container_of(ref, struct nfsd_net, nfsd_net_ref); 224 225 complete(&nn->nfsd_net_confirm_done); 226 } 227 228 static void nfsd_net_free(struct percpu_ref *ref) 229 { 230 struct nfsd_net *nn = container_of(ref, struct nfsd_net, nfsd_net_ref); 231 232 complete(&nn->nfsd_net_free_done); 233 } 234 235 /* 236 * Maximum number of nfsd processes 237 */ 238 #define NFSD_MAXSERVS 8192 239 240 int nfsd_nrthreads(struct net *net) 241 { 242 int rv = 0; 243 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 244 245 mutex_lock(&nfsd_mutex); 246 if (nn->nfsd_serv) 247 rv = nn->nfsd_serv->sv_nrthreads; 248 mutex_unlock(&nfsd_mutex); 249 return rv; 250 } 251 252 static int nfsd_users = 0; 253 254 static int nfsd_startup_generic(void) 255 { 256 int ret; 257 258 if (nfsd_users++) 259 return 0; 260 261 ret = nfsd_file_cache_init(); 262 if (ret) 263 goto dec_users; 264 265 ret = nfs4_state_start(); 266 if (ret) 267 goto out_file_cache; 268 return 0; 269 270 out_file_cache: 271 nfsd_file_cache_shutdown(); 272 dec_users: 273 nfsd_users--; 274 return ret; 275 } 276 277 static void nfsd_shutdown_generic(void) 278 { 279 if (--nfsd_users) 280 return; 281 282 nfs4_state_shutdown(); 283 nfsd_file_cache_shutdown(); 284 } 285 286 static bool nfsd_needs_lockd(struct nfsd_net *nn) 287 { 288 return nfsd_vers(nn, 2, NFSD_TEST) || nfsd_vers(nn, 3, NFSD_TEST); 289 } 290 291 /** 292 * nfsd_copy_write_verifier - Atomically copy a write verifier 293 * @verf: buffer in which to receive the verifier cookie 294 * @nn: NFS net namespace 295 * 296 * This function provides a wait-free mechanism for copying the 297 * namespace's write verifier without tearing it. 298 */ 299 void nfsd_copy_write_verifier(__be32 verf[2], struct nfsd_net *nn) 300 { 301 unsigned int seq; 302 303 do { 304 seq = read_seqbegin(&nn->writeverf_lock); 305 memcpy(verf, nn->writeverf, sizeof(nn->writeverf)); 306 } while (read_seqretry(&nn->writeverf_lock, seq)); 307 } 308 309 static void nfsd_reset_write_verifier_locked(struct nfsd_net *nn) 310 { 311 struct timespec64 now; 312 u64 verf; 313 314 /* 315 * Because the time value is hashed, y2038 time_t overflow 316 * is irrelevant in this usage. 317 */ 318 ktime_get_raw_ts64(&now); 319 verf = siphash_2u64(now.tv_sec, now.tv_nsec, &nn->siphash_key); 320 memcpy(nn->writeverf, &verf, sizeof(nn->writeverf)); 321 } 322 323 /** 324 * nfsd_reset_write_verifier - Generate a new write verifier 325 * @nn: NFS net namespace 326 * 327 * This function updates the ->writeverf field of @nn. This field 328 * contains an opaque cookie that, according to Section 18.32.3 of 329 * RFC 8881, "the client can use to determine whether a server has 330 * changed instance state (e.g., server restart) between a call to 331 * WRITE and a subsequent call to either WRITE or COMMIT. This 332 * cookie MUST be unchanged during a single instance of the NFSv4.1 333 * server and MUST be unique between instances of the NFSv4.1 334 * server." 335 */ 336 void nfsd_reset_write_verifier(struct nfsd_net *nn) 337 { 338 write_seqlock(&nn->writeverf_lock); 339 nfsd_reset_write_verifier_locked(nn); 340 write_sequnlock(&nn->writeverf_lock); 341 } 342 343 /* 344 * Crank up a set of per-namespace resources for a new NFSD instance, 345 * including lockd, a duplicate reply cache, an open file cache 346 * instance, and a cache of NFSv4 state objects. 347 */ 348 static int nfsd_startup_net(struct net *net, const struct cred *cred) 349 { 350 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 351 int ret; 352 353 if (nn->nfsd_net_up) 354 return 0; 355 356 ret = nfsd_startup_generic(); 357 if (ret) 358 return ret; 359 360 if (list_empty(&nn->nfsd_serv->sv_permsocks)) { 361 pr_warn("NFSD: Failed to start, no listeners configured.\n"); 362 ret = -EIO; 363 goto out_socks; 364 } 365 366 if (nfsd_needs_lockd(nn) && !nn->lockd_up) { 367 ret = lockd_up(net, cred); 368 if (ret) 369 goto out_socks; 370 nn->lockd_up = true; 371 } 372 373 ret = nfsd_file_cache_start_net(net); 374 if (ret) 375 goto out_lockd; 376 377 ret = nfsd_reply_cache_init(nn); 378 if (ret) 379 goto out_filecache; 380 381 #ifdef CONFIG_NFSD_V4_2_INTER_SSC 382 nfsd4_ssc_init_umount_work(nn); 383 #endif 384 ret = nfs4_state_start_net(net); 385 if (ret) 386 goto out_reply_cache; 387 388 nn->nfsd_net_up = true; 389 return 0; 390 391 out_reply_cache: 392 nfsd_reply_cache_shutdown(nn); 393 out_filecache: 394 nfsd_file_cache_shutdown_net(net); 395 out_lockd: 396 if (nn->lockd_up) { 397 lockd_down(net); 398 nn->lockd_up = false; 399 } 400 out_socks: 401 nfsd_shutdown_generic(); 402 return ret; 403 } 404 405 static void nfsd_shutdown_net(struct net *net) 406 { 407 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 408 409 if (nn->nfsd_net_up) { 410 percpu_ref_kill_and_confirm(&nn->nfsd_net_ref, nfsd_net_done); 411 wait_for_completion(&nn->nfsd_net_confirm_done); 412 413 nfsd_export_flush(net); 414 nfs4_state_shutdown_net(net); 415 nfsd_reply_cache_shutdown(nn); 416 nfsd_file_cache_shutdown_net(net); 417 if (nn->lockd_up) { 418 lockd_down(net); 419 nn->lockd_up = false; 420 } 421 wait_for_completion(&nn->nfsd_net_free_done); 422 } 423 424 percpu_ref_exit(&nn->nfsd_net_ref); 425 426 if (nn->nfsd_net_up) 427 nfsd_shutdown_generic(); 428 nn->nfsd_net_up = false; 429 } 430 431 static DEFINE_SPINLOCK(nfsd_notifier_lock); 432 static int nfsd_inetaddr_event(struct notifier_block *this, unsigned long event, 433 void *ptr) 434 { 435 struct in_ifaddr *ifa = (struct in_ifaddr *)ptr; 436 struct net_device *dev = ifa->ifa_dev->dev; 437 struct net *net = dev_net(dev); 438 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 439 struct sockaddr_in sin; 440 441 if (event != NETDEV_DOWN || !nn->nfsd_serv) 442 goto out; 443 444 spin_lock(&nfsd_notifier_lock); 445 if (nn->nfsd_serv) { 446 dprintk("nfsd_inetaddr_event: removed %pI4\n", &ifa->ifa_local); 447 sin.sin_family = AF_INET; 448 sin.sin_addr.s_addr = ifa->ifa_local; 449 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin); 450 } 451 spin_unlock(&nfsd_notifier_lock); 452 453 out: 454 return NOTIFY_DONE; 455 } 456 457 static struct notifier_block nfsd_inetaddr_notifier = { 458 .notifier_call = nfsd_inetaddr_event, 459 }; 460 461 #if IS_ENABLED(CONFIG_IPV6) 462 static int nfsd_inet6addr_event(struct notifier_block *this, 463 unsigned long event, void *ptr) 464 { 465 struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr; 466 struct net_device *dev = ifa->idev->dev; 467 struct net *net = dev_net(dev); 468 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 469 struct sockaddr_in6 sin6; 470 471 if (event != NETDEV_DOWN || !nn->nfsd_serv) 472 goto out; 473 474 spin_lock(&nfsd_notifier_lock); 475 if (nn->nfsd_serv) { 476 dprintk("nfsd_inet6addr_event: removed %pI6\n", &ifa->addr); 477 sin6.sin6_family = AF_INET6; 478 sin6.sin6_addr = ifa->addr; 479 if (ipv6_addr_type(&sin6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 480 sin6.sin6_scope_id = ifa->idev->dev->ifindex; 481 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin6); 482 } 483 spin_unlock(&nfsd_notifier_lock); 484 485 out: 486 return NOTIFY_DONE; 487 } 488 489 static struct notifier_block nfsd_inet6addr_notifier = { 490 .notifier_call = nfsd_inet6addr_event, 491 }; 492 #endif 493 494 /* Only used under nfsd_mutex, so this atomic may be overkill: */ 495 static atomic_t nfsd_notifier_refcount = ATOMIC_INIT(0); 496 497 /** 498 * nfsd_destroy_serv - tear down NFSD's svc_serv for a namespace 499 * @net: network namespace the NFS service is associated with 500 */ 501 void nfsd_destroy_serv(struct net *net) 502 { 503 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 504 struct svc_serv *serv = nn->nfsd_serv; 505 506 lockdep_assert_held(&nfsd_mutex); 507 508 spin_lock(&nfsd_notifier_lock); 509 nn->nfsd_serv = NULL; 510 spin_unlock(&nfsd_notifier_lock); 511 512 /* check if the notifier still has clients */ 513 if (atomic_dec_return(&nfsd_notifier_refcount) == 0) { 514 unregister_inetaddr_notifier(&nfsd_inetaddr_notifier); 515 #if IS_ENABLED(CONFIG_IPV6) 516 unregister_inet6addr_notifier(&nfsd_inet6addr_notifier); 517 #endif 518 } 519 520 /* 521 * write_ports can create the server without actually starting 522 * any threads. If we get shut down before any threads are 523 * started, then nfsd_destroy_serv will be run before any of this 524 * other initialization has been done except the rpcb information. 525 */ 526 svc_xprt_destroy_all(serv, net, true); 527 nfsd_shutdown_net(net); 528 svc_destroy(&serv); 529 } 530 531 void nfsd_reset_versions(struct nfsd_net *nn) 532 { 533 int i; 534 535 for (i = 0; i <= NFSD_MAXVERS; i++) 536 if (nfsd_vers(nn, i, NFSD_TEST)) 537 return; 538 539 for (i = 0; i <= NFSD_MAXVERS; i++) 540 if (i != 4) 541 nfsd_vers(nn, i, NFSD_SET); 542 else { 543 int minor = 0; 544 while (nfsd_minorversion(nn, minor, NFSD_SET) >= 0) 545 minor++; 546 } 547 } 548 549 static int nfsd_get_default_max_blksize(void) 550 { 551 struct sysinfo i; 552 unsigned long long target; 553 unsigned long ret; 554 555 si_meminfo(&i); 556 target = (i.totalram - i.totalhigh) << PAGE_SHIFT; 557 /* 558 * Aim for 1/4096 of memory per thread This gives 1MB on 4Gig 559 * machines, but only uses 32K on 128M machines. Bottom out at 560 * 8K on 32M and smaller. Of course, this is only a default. 561 */ 562 target >>= 12; 563 564 ret = NFSSVC_DEFBLKSIZE; 565 while (ret > target && ret >= 8*1024*2) 566 ret /= 2; 567 return ret; 568 } 569 570 void nfsd_shutdown_threads(struct net *net) 571 { 572 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 573 struct svc_serv *serv; 574 575 mutex_lock(&nfsd_mutex); 576 serv = nn->nfsd_serv; 577 if (serv == NULL) { 578 mutex_unlock(&nfsd_mutex); 579 return; 580 } 581 582 /* Kill outstanding nfsd threads */ 583 svc_set_num_threads(serv, 0, 0); 584 nfsd_destroy_serv(net); 585 mutex_unlock(&nfsd_mutex); 586 } 587 588 struct svc_rqst *nfsd_current_rqst(void) 589 { 590 if (kthread_func(current) == nfsd) 591 return kthread_data(current); 592 return NULL; 593 } 594 595 int nfsd_create_serv(struct net *net) 596 { 597 int error; 598 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 599 struct svc_serv *serv; 600 601 WARN_ON(!mutex_is_locked(&nfsd_mutex)); 602 if (nn->nfsd_serv) 603 return 0; 604 605 error = percpu_ref_init(&nn->nfsd_net_ref, nfsd_net_free, 606 0, GFP_KERNEL); 607 if (error) 608 return error; 609 init_completion(&nn->nfsd_net_free_done); 610 init_completion(&nn->nfsd_net_confirm_done); 611 612 if (nfsd_max_blksize == 0) 613 nfsd_max_blksize = nfsd_get_default_max_blksize(); 614 nfsd_reset_versions(nn); 615 serv = svc_create_pooled(nfsd_programs, ARRAY_SIZE(nfsd_programs), 616 &nn->nfsd_svcstats, 617 nfsd_max_blksize, nfsd); 618 if (serv == NULL) { 619 percpu_ref_exit(&nn->nfsd_net_ref); 620 return -ENOMEM; 621 } 622 623 error = svc_bind(serv, net); 624 if (error < 0) { 625 svc_destroy(&serv); 626 percpu_ref_exit(&nn->nfsd_net_ref); 627 return error; 628 } 629 spin_lock(&nfsd_notifier_lock); 630 nn->nfsd_serv = serv; 631 spin_unlock(&nfsd_notifier_lock); 632 633 /* check if the notifier is already set */ 634 if (atomic_inc_return(&nfsd_notifier_refcount) == 1) { 635 register_inetaddr_notifier(&nfsd_inetaddr_notifier); 636 #if IS_ENABLED(CONFIG_IPV6) 637 register_inet6addr_notifier(&nfsd_inet6addr_notifier); 638 #endif 639 } 640 nfsd_reset_write_verifier(nn); 641 return 0; 642 } 643 644 int nfsd_nrpools(struct net *net) 645 { 646 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 647 648 if (nn->nfsd_serv == NULL) 649 return 0; 650 else 651 return nn->nfsd_serv->sv_nrpools; 652 } 653 654 int nfsd_get_nrthreads(int n, int *nthreads, struct net *net) 655 { 656 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 657 struct svc_serv *serv = nn->nfsd_serv; 658 int i; 659 660 if (serv) 661 for (i = 0; i < serv->sv_nrpools && i < n; i++) 662 nthreads[i] = serv->sv_pools[i].sp_nrthreads; 663 return 0; 664 } 665 666 /** 667 * nfsd_set_nrthreads - set the number of running threads in the net's service 668 * @n: number of array members in @nthreads 669 * @nthreads: array of thread counts for each pool 670 * @net: network namespace to operate within 671 * 672 * This function alters the number of running threads for the given network 673 * namespace in each pool. If passed an array longer then the number of pools 674 * the extra pool settings are ignored. If passed an array shorter than the 675 * number of pools, the missing values are interpreted as 0's. 676 * 677 * Returns 0 on success or a negative errno on error. 678 */ 679 int nfsd_set_nrthreads(int n, int *nthreads, struct net *net) 680 { 681 int i = 0; 682 int tot = 0; 683 int err = 0; 684 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 685 686 lockdep_assert_held(&nfsd_mutex); 687 688 if (nn->nfsd_serv == NULL || n <= 0) 689 return 0; 690 691 /* Special case: When n == 1, distribute threads equally among pools. */ 692 if (n == 1) 693 return svc_set_num_threads(nn->nfsd_serv, nn->min_threads, nthreads[0]); 694 695 if (n > nn->nfsd_serv->sv_nrpools) 696 n = nn->nfsd_serv->sv_nrpools; 697 698 /* enforce a global maximum number of threads */ 699 tot = 0; 700 for (i = 0; i < n; i++) { 701 nthreads[i] = min(nthreads[i], NFSD_MAXSERVS); 702 tot += nthreads[i]; 703 } 704 if (tot > NFSD_MAXSERVS) { 705 /* total too large: scale down requested numbers */ 706 for (i = 0; i < n && tot > 0; i++) { 707 int new = nthreads[i] * NFSD_MAXSERVS / tot; 708 tot -= (nthreads[i] - new); 709 nthreads[i] = new; 710 } 711 for (i = 0; i < n && tot > 0; i++) { 712 nthreads[i]--; 713 tot--; 714 } 715 } 716 717 /* apply the new numbers */ 718 for (i = 0; i < n; i++) { 719 err = svc_set_pool_threads(nn->nfsd_serv, 720 &nn->nfsd_serv->sv_pools[i], 721 nn->min_threads, nthreads[i]); 722 if (err) 723 goto out; 724 } 725 726 /* Anything undefined in array is considered to be 0 */ 727 for (i = n; i < nn->nfsd_serv->sv_nrpools; ++i) { 728 err = svc_set_pool_threads(nn->nfsd_serv, 729 &nn->nfsd_serv->sv_pools[i], 730 0, 0); 731 if (err) 732 goto out; 733 } 734 out: 735 return err; 736 } 737 738 /** 739 * nfsd_svc: start up or shut down the nfsd server 740 * @n: number of array members in @nthreads 741 * @nthreads: array of thread counts for each pool 742 * @net: network namespace to operate within 743 * @cred: credentials to use for xprt creation 744 * @scope: server scope value (defaults to nodename) 745 * 746 * Adjust the number of threads in each pool and return the new 747 * total number of threads in the service. 748 */ 749 int 750 nfsd_svc(int n, int *nthreads, struct net *net, const struct cred *cred, const char *scope) 751 { 752 int error; 753 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 754 struct svc_serv *serv; 755 756 lockdep_assert_held(&nfsd_mutex); 757 758 dprintk("nfsd: creating service\n"); 759 760 strscpy(nn->nfsd_name, scope ? scope : utsname()->nodename, 761 sizeof(nn->nfsd_name)); 762 763 error = nfsd_create_serv(net); 764 if (error) 765 goto out; 766 serv = nn->nfsd_serv; 767 768 error = nfsd_startup_net(net, cred); 769 if (error) 770 goto out_put; 771 error = nfsd_set_nrthreads(n, nthreads, net); 772 if (error) 773 goto out_put; 774 error = serv->sv_nrthreads; 775 out_put: 776 if (serv->sv_nrthreads == 0) 777 nfsd_destroy_serv(net); 778 out: 779 return error; 780 } 781 782 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 783 static bool 784 nfsd_support_acl_version(int vers) 785 { 786 if (vers >= NFSD_ACL_MINVERS && vers < NFSD_ACL_NRVERS) 787 return nfsd_acl_version[vers] != NULL; 788 return false; 789 } 790 791 static int 792 nfsd_acl_rpcbind_set(struct net *net, const struct svc_program *progp, 793 u32 version, int family, unsigned short proto, 794 unsigned short port) 795 { 796 if (!nfsd_support_acl_version(version) || 797 !nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST)) 798 return 0; 799 return svc_generic_rpcbind_set(net, progp, version, family, 800 proto, port); 801 } 802 803 static __be32 804 nfsd_acl_init_request(struct svc_rqst *rqstp, 805 const struct svc_program *progp, 806 struct svc_process_info *ret) 807 { 808 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); 809 int i; 810 811 if (likely(nfsd_support_acl_version(rqstp->rq_vers) && 812 nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST))) 813 return svc_generic_init_request(rqstp, progp, ret); 814 815 ret->mismatch.lovers = NFSD_ACL_NRVERS; 816 for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) { 817 if (nfsd_support_acl_version(rqstp->rq_vers) && 818 nfsd_vers(nn, i, NFSD_TEST)) { 819 ret->mismatch.lovers = i; 820 break; 821 } 822 } 823 if (ret->mismatch.lovers == NFSD_ACL_NRVERS) 824 return rpc_prog_unavail; 825 ret->mismatch.hivers = NFSD_ACL_MINVERS; 826 for (i = NFSD_ACL_NRVERS - 1; i >= NFSD_ACL_MINVERS; i--) { 827 if (nfsd_support_acl_version(rqstp->rq_vers) && 828 nfsd_vers(nn, i, NFSD_TEST)) { 829 ret->mismatch.hivers = i; 830 break; 831 } 832 } 833 return rpc_prog_mismatch; 834 } 835 #endif 836 837 static int 838 nfsd_rpcbind_set(struct net *net, const struct svc_program *progp, 839 u32 version, int family, unsigned short proto, 840 unsigned short port) 841 { 842 if (!nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST)) 843 return 0; 844 return svc_generic_rpcbind_set(net, progp, version, family, 845 proto, port); 846 } 847 848 static __be32 849 nfsd_init_request(struct svc_rqst *rqstp, 850 const struct svc_program *progp, 851 struct svc_process_info *ret) 852 { 853 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); 854 int i; 855 856 if (likely(nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST))) 857 return svc_generic_init_request(rqstp, progp, ret); 858 859 ret->mismatch.lovers = NFSD_MAXVERS + 1; 860 for (i = NFSD_MINVERS; i <= NFSD_MAXVERS; i++) { 861 if (nfsd_vers(nn, i, NFSD_TEST)) { 862 ret->mismatch.lovers = i; 863 break; 864 } 865 } 866 if (ret->mismatch.lovers > NFSD_MAXVERS) 867 return rpc_prog_unavail; 868 ret->mismatch.hivers = NFSD_MINVERS; 869 for (i = NFSD_MAXVERS; i >= NFSD_MINVERS; i--) { 870 if (nfsd_vers(nn, i, NFSD_TEST)) { 871 ret->mismatch.hivers = i; 872 break; 873 } 874 } 875 return rpc_prog_mismatch; 876 } 877 878 /* 879 * This is the NFS server kernel thread 880 */ 881 static int 882 nfsd(void *vrqstp) 883 { 884 struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp; 885 struct svc_pool *pool = rqstp->rq_pool; 886 struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list); 887 struct net *net = perm_sock->xpt_net; 888 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 889 bool have_mutex = false; 890 891 /* At this point, the thread shares current->fs 892 * with the init process. We need to create files with the 893 * umask as defined by the client instead of init's umask. 894 */ 895 svc_thread_init_status(rqstp, unshare_fs_struct()); 896 897 current->fs->umask = 0; 898 899 atomic_inc(&nfsd_th_cnt); 900 901 set_freezable(); 902 903 /* 904 * The main request loop 905 */ 906 while (!svc_thread_should_stop(rqstp)) { 907 switch (svc_recv(rqstp, 5 * HZ)) { 908 case -ETIMEDOUT: 909 /* No work arrived within the timeout window */ 910 if (mutex_trylock(&nfsd_mutex)) { 911 if (pool->sp_nrthreads > pool->sp_nrthrmin) { 912 trace_nfsd_dynthread_kill(net, pool); 913 set_bit(RQ_VICTIM, &rqstp->rq_flags); 914 have_mutex = true; 915 } else { 916 mutex_unlock(&nfsd_mutex); 917 } 918 } else { 919 trace_nfsd_dynthread_trylock_fail(net, pool); 920 } 921 break; 922 case -EBUSY: 923 /* No idle threads; consider spawning another */ 924 if (pool->sp_nrthreads < pool->sp_nrthrmax) { 925 if (mutex_trylock(&nfsd_mutex)) { 926 if (pool->sp_nrthreads < pool->sp_nrthrmax) { 927 int ret; 928 929 trace_nfsd_dynthread_start(net, pool); 930 ret = svc_new_thread(rqstp->rq_server, pool); 931 if (ret) 932 pr_notice_ratelimited("%s: unable to spawn new thread: %d\n", 933 __func__, ret); 934 } 935 mutex_unlock(&nfsd_mutex); 936 } else { 937 trace_nfsd_dynthread_trylock_fail(net, pool); 938 } 939 } 940 clear_bit(SP_TASK_STARTING, &pool->sp_flags); 941 break; 942 default: 943 break; 944 } 945 nfsd_file_net_dispose(nn); 946 } 947 948 atomic_dec(&nfsd_th_cnt); 949 950 /* Release the thread */ 951 svc_exit_thread(rqstp); 952 if (have_mutex) 953 mutex_unlock(&nfsd_mutex); 954 return 0; 955 } 956 957 /** 958 * nfsd_dispatch - Process an NFS or NFSACL or LOCALIO Request 959 * @rqstp: incoming request 960 * 961 * This RPC dispatcher integrates the NFS server's duplicate reply cache. 962 * 963 * Return values: 964 * %0: Processing complete; do not send a Reply 965 * %1: Processing complete; send Reply in rqstp->rq_res 966 */ 967 int nfsd_dispatch(struct svc_rqst *rqstp) 968 { 969 const struct svc_procedure *proc = rqstp->rq_procinfo; 970 __be32 *statp = rqstp->rq_accept_statp; 971 struct nfsd_cacherep *rp; 972 unsigned int start, len; 973 __be32 *nfs_reply; 974 975 /* 976 * Give the xdr decoder a chance to change this if it wants 977 * (necessary in the NFSv4.0 compound case) 978 */ 979 rqstp->rq_cachetype = proc->pc_cachetype; 980 981 /* 982 * ->pc_decode advances the argument stream past the NFS 983 * Call header, so grab the header's starting location and 984 * size now for the call to nfsd_cache_lookup(). 985 */ 986 start = xdr_stream_pos(&rqstp->rq_arg_stream); 987 len = xdr_stream_remaining(&rqstp->rq_arg_stream); 988 if (!proc->pc_decode(rqstp, &rqstp->rq_arg_stream)) 989 goto out_decode_err; 990 991 /* 992 * Release rq_status_counter setting it to an odd value after the rpc 993 * request has been properly parsed. rq_status_counter is used to 994 * notify the consumers if the rqstp fields are stable 995 * (rq_status_counter is odd) or not meaningful (rq_status_counter 996 * is even). 997 */ 998 smp_store_release(&rqstp->rq_status_counter, rqstp->rq_status_counter | 1); 999 1000 rp = NULL; 1001 switch (nfsd_cache_lookup(rqstp, start, len, &rp)) { 1002 case RC_DOIT: 1003 break; 1004 case RC_REPLY: 1005 goto out_cached_reply; 1006 case RC_DROPIT: 1007 goto out_dropit; 1008 } 1009 1010 nfs_reply = xdr_inline_decode(&rqstp->rq_res_stream, 0); 1011 *statp = proc->pc_func(rqstp); 1012 if (test_bit(RQ_DROPME, &rqstp->rq_flags)) 1013 goto out_update_drop; 1014 1015 if (!proc->pc_encode(rqstp, &rqstp->rq_res_stream)) 1016 goto out_encode_err; 1017 1018 /* 1019 * Release rq_status_counter setting it to an even value after the rpc 1020 * request has been properly processed. 1021 */ 1022 smp_store_release(&rqstp->rq_status_counter, rqstp->rq_status_counter + 1); 1023 1024 nfsd_cache_update(rqstp, rp, rqstp->rq_cachetype, nfs_reply); 1025 out_cached_reply: 1026 return 1; 1027 1028 out_decode_err: 1029 trace_nfsd_garbage_args_err(rqstp); 1030 *statp = rpc_garbage_args; 1031 return 1; 1032 1033 out_update_drop: 1034 nfsd_cache_update(rqstp, rp, RC_NOCACHE, NULL); 1035 out_dropit: 1036 return 0; 1037 1038 out_encode_err: 1039 trace_nfsd_cant_encode_err(rqstp); 1040 nfsd_cache_update(rqstp, rp, RC_NOCACHE, NULL); 1041 *statp = rpc_system_err; 1042 return 1; 1043 } 1044 1045 /** 1046 * nfssvc_decode_voidarg - Decode void arguments 1047 * @rqstp: Server RPC transaction context 1048 * @xdr: XDR stream positioned at arguments to decode 1049 * 1050 * Return values: 1051 * %false: Arguments were not valid 1052 * %true: Decoding was successful 1053 */ 1054 bool nfssvc_decode_voidarg(struct svc_rqst *rqstp, struct xdr_stream *xdr) 1055 { 1056 return true; 1057 } 1058 1059 /** 1060 * nfssvc_encode_voidres - Encode void results 1061 * @rqstp: Server RPC transaction context 1062 * @xdr: XDR stream into which to encode results 1063 * 1064 * Return values: 1065 * %false: Local error while encoding 1066 * %true: Encoding was successful 1067 */ 1068 bool nfssvc_encode_voidres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 1069 { 1070 return true; 1071 } 1072