fs/nfsd/nfssvc.c

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This source file includes following definitions.
nfsd_support_version
nfsd_alloc_versions
nfsd_alloc_minorversions
nfsd_netns_free_versions
nfsd_netns_init_versions
nfsd_vers
nfsd_adjust_nfsd_versions4
nfsd_minorversion
nfsd_nrthreads
nfsd_init_socks
nfsd_startup_generic
nfsd_shutdown_generic
nfsd_needs_lockd
nfsd_copy_boot_verifier
nfsd_reset_boot_verifier_locked
nfsd_reset_boot_verifier
nfsd_startup_net
nfsd_shutdown_net
nfsd_inetaddr_event
nfsd_inet6addr_event
nfsd_last_thread
nfsd_reset_versions
set_max_drc
nfsd_get_default_max_blksize
nfsd_create_serv
nfsd_nrpools
nfsd_get_nrthreads
nfsd_destroy
nfsd_set_nrthreads
nfsd_svc
nfsd_support_acl_version
nfsd_acl_rpcbind_set
nfsd_acl_init_request
nfsd_rpcbind_set
nfsd_init_request
nfsd
map_new_errors
nfs_request_too_big
nfsd_dispatch
nfsd_pool_stats_open
nfsd_pool_stats_release
   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 
  16 #include <linux/sunrpc/stats.h>
  17 #include <linux/sunrpc/svcsock.h>
  18 #include <linux/sunrpc/svc_xprt.h>
  19 #include <linux/lockd/bind.h>
  20 #include <linux/nfsacl.h>
  21 #include <linux/seq_file.h>
  22 #include <linux/inetdevice.h>
  23 #include <net/addrconf.h>
  24 #include <net/ipv6.h>
  25 #include <net/net_namespace.h>
  26 #include "nfsd.h"
  27 #include "cache.h"
  28 #include "vfs.h"
  29 #include "netns.h"
  30 #include "filecache.h"
  31 
  32 #define NFSDDBG_FACILITY        NFSDDBG_SVC
  33 
  34 extern struct svc_program       nfsd_program;
  35 static int                      nfsd(void *vrqstp);
  36 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
  37 static int                      nfsd_acl_rpcbind_set(struct net *,
  38                                                      const struct svc_program *,
  39                                                      u32, int,
  40                                                      unsigned short,
  41                                                      unsigned short);
  42 static __be32                   nfsd_acl_init_request(struct svc_rqst *,
  43                                                 const struct svc_program *,
  44                                                 struct svc_process_info *);
  45 #endif
  46 static int                      nfsd_rpcbind_set(struct net *,
  47                                                  const struct svc_program *,
  48                                                  u32, int,
  49                                                  unsigned short,
  50                                                  unsigned short);
  51 static __be32                   nfsd_init_request(struct svc_rqst *,
  52                                                 const struct svc_program *,
  53                                                 struct svc_process_info *);
  54 
  55 /*
  56  * nfsd_mutex protects nn->nfsd_serv -- both the pointer itself and the members
  57  * of the svc_serv struct. In particular, ->sv_nrthreads but also to some
  58  * extent ->sv_temp_socks and ->sv_permsocks. It also protects nfsdstats.th_cnt
  59  *
  60  * If (out side the lock) nn->nfsd_serv is non-NULL, then it must point to a
  61  * properly initialised 'struct svc_serv' with ->sv_nrthreads > 0. That number
  62  * of nfsd threads must exist and each must listed in ->sp_all_threads in each
  63  * entry of ->sv_pools[].
  64  *
  65  * Transitions of the thread count between zero and non-zero are of particular
  66  * interest since the svc_serv needs to be created and initialized at that
  67  * point, or freed.
  68  *
  69  * Finally, the nfsd_mutex also protects some of the global variables that are
  70  * accessed when nfsd starts and that are settable via the write_* routines in
  71  * nfsctl.c. In particular:
  72  *
  73  *      user_recovery_dirname
  74  *      user_lease_time
  75  *      nfsd_versions
  76  */
  77 DEFINE_MUTEX(nfsd_mutex);
  78 
  79 /*
  80  * nfsd_drc_lock protects nfsd_drc_max_pages and nfsd_drc_pages_used.
  81  * nfsd_drc_max_pages limits the total amount of memory available for
  82  * version 4.1 DRC caches.
  83  * nfsd_drc_pages_used tracks the current version 4.1 DRC memory usage.
  84  */
  85 spinlock_t      nfsd_drc_lock;
  86 unsigned long   nfsd_drc_max_mem;
  87 unsigned long   nfsd_drc_mem_used;
  88 
  89 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
  90 static struct svc_stat  nfsd_acl_svcstats;
  91 static const struct svc_version *nfsd_acl_version[] = {
  92         [2] = &nfsd_acl_version2,
  93         [3] = &nfsd_acl_version3,
  94 };
  95 
  96 #define NFSD_ACL_MINVERS            2
  97 #define NFSD_ACL_NRVERS         ARRAY_SIZE(nfsd_acl_version)
  98 
  99 static struct svc_program       nfsd_acl_program = {
 100         .pg_prog                = NFS_ACL_PROGRAM,
 101         .pg_nvers               = NFSD_ACL_NRVERS,
 102         .pg_vers                = nfsd_acl_version,
 103         .pg_name                = "nfsacl",
 104         .pg_class               = "nfsd",
 105         .pg_stats               = &nfsd_acl_svcstats,
 106         .pg_authenticate        = &svc_set_client,
 107         .pg_init_request        = nfsd_acl_init_request,
 108         .pg_rpcbind_set         = nfsd_acl_rpcbind_set,
 109 };
 110 
 111 static struct svc_stat  nfsd_acl_svcstats = {
 112         .program        = &nfsd_acl_program,
 113 };
 114 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
 115 
 116 static const struct svc_version *nfsd_version[] = {
 117         [2] = &nfsd_version2,
 118 #if defined(CONFIG_NFSD_V3)
 119         [3] = &nfsd_version3,
 120 #endif
 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_create_xprt(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_create_xprt(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(int nrservs)
 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 void nfsd_copy_boot_verifier(__be32 verf[2], struct nfsd_net *nn)
 347 {
 348         int seq = 0;
 349 
 350         do {
 351                 read_seqbegin_or_lock(&nn->boot_lock, &seq);
 352                 /*
 353                  * This is opaque to client, so no need to byte-swap. Use
 354                  * __force to keep sparse happy. y2038 time_t overflow is
 355                  * irrelevant in this usage
 356                  */
 357                 verf[0] = (__force __be32)nn->nfssvc_boot.tv_sec;
 358                 verf[1] = (__force __be32)nn->nfssvc_boot.tv_nsec;
 359         } while (need_seqretry(&nn->boot_lock, seq));
 360         done_seqretry(&nn->boot_lock, seq);
 361 }
 362 
 363 static void nfsd_reset_boot_verifier_locked(struct nfsd_net *nn)
 364 {
 365         ktime_get_real_ts64(&nn->nfssvc_boot);
 366 }
 367 
 368 void nfsd_reset_boot_verifier(struct nfsd_net *nn)
 369 {
 370         write_seqlock(&nn->boot_lock);
 371         nfsd_reset_boot_verifier_locked(nn);
 372         write_sequnlock(&nn->boot_lock);
 373 }
 374 
 375 static int nfsd_startup_net(int nrservs, struct net *net, const struct cred *cred)
 376 {
 377         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 378         int ret;
 379 
 380         if (nn->nfsd_net_up)
 381                 return 0;
 382 
 383         ret = nfsd_startup_generic(nrservs);
 384         if (ret)
 385                 return ret;
 386         ret = nfsd_init_socks(net, cred);
 387         if (ret)
 388                 goto out_socks;
 389 
 390         if (nfsd_needs_lockd(nn) && !nn->lockd_up) {
 391                 ret = lockd_up(net, cred);
 392                 if (ret)
 393                         goto out_socks;
 394                 nn->lockd_up = 1;
 395         }
 396 
 397         ret = nfs4_state_start_net(net);
 398         if (ret)
 399                 goto out_lockd;
 400 
 401         nn->nfsd_net_up = true;
 402         return 0;
 403 
 404 out_lockd:
 405         if (nn->lockd_up) {
 406                 lockd_down(net);
 407                 nn->lockd_up = 0;
 408         }
 409 out_socks:
 410         nfsd_shutdown_generic();
 411         return ret;
 412 }
 413 
 414 static void nfsd_shutdown_net(struct net *net)
 415 {
 416         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 417 
 418         nfsd_file_cache_purge(net);
 419         nfs4_state_shutdown_net(net);
 420         if (nn->lockd_up) {
 421                 lockd_down(net);
 422                 nn->lockd_up = 0;
 423         }
 424         nn->nfsd_net_up = false;
 425         nfsd_shutdown_generic();
 426 }
 427 
 428 static int nfsd_inetaddr_event(struct notifier_block *this, unsigned long event,
 429         void *ptr)
 430 {
 431         struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
 432         struct net_device *dev = ifa->ifa_dev->dev;
 433         struct net *net = dev_net(dev);
 434         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 435         struct sockaddr_in sin;
 436 
 437         if ((event != NETDEV_DOWN) ||
 438             !atomic_inc_not_zero(&nn->ntf_refcnt))
 439                 goto out;
 440 
 441         if (nn->nfsd_serv) {
 442                 dprintk("nfsd_inetaddr_event: removed %pI4\n", &ifa->ifa_local);
 443                 sin.sin_family = AF_INET;
 444                 sin.sin_addr.s_addr = ifa->ifa_local;
 445                 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin);
 446         }
 447         atomic_dec(&nn->ntf_refcnt);
 448         wake_up(&nn->ntf_wq);
 449 
 450 out:
 451         return NOTIFY_DONE;
 452 }
 453 
 454 static struct notifier_block nfsd_inetaddr_notifier = {
 455         .notifier_call = nfsd_inetaddr_event,
 456 };
 457 
 458 #if IS_ENABLED(CONFIG_IPV6)
 459 static int nfsd_inet6addr_event(struct notifier_block *this,
 460         unsigned long event, void *ptr)
 461 {
 462         struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
 463         struct net_device *dev = ifa->idev->dev;
 464         struct net *net = dev_net(dev);
 465         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 466         struct sockaddr_in6 sin6;
 467 
 468         if ((event != NETDEV_DOWN) ||
 469             !atomic_inc_not_zero(&nn->ntf_refcnt))
 470                 goto out;
 471 
 472         if (nn->nfsd_serv) {
 473                 dprintk("nfsd_inet6addr_event: removed %pI6\n", &ifa->addr);
 474                 sin6.sin6_family = AF_INET6;
 475                 sin6.sin6_addr = ifa->addr;
 476                 if (ipv6_addr_type(&sin6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 477                         sin6.sin6_scope_id = ifa->idev->dev->ifindex;
 478                 svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin6);
 479         }
 480         atomic_dec(&nn->ntf_refcnt);
 481         wake_up(&nn->ntf_wq);
 482 out:
 483         return NOTIFY_DONE;
 484 }
 485 
 486 static struct notifier_block nfsd_inet6addr_notifier = {
 487         .notifier_call = nfsd_inet6addr_event,
 488 };
 489 #endif
 490 
 491 /* Only used under nfsd_mutex, so this atomic may be overkill: */
 492 static atomic_t nfsd_notifier_refcount = ATOMIC_INIT(0);
 493 
 494 static void nfsd_last_thread(struct svc_serv *serv, struct net *net)
 495 {
 496         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 497 
 498         atomic_dec(&nn->ntf_refcnt);
 499         /* check if the notifier still has clients */
 500         if (atomic_dec_return(&nfsd_notifier_refcount) == 0) {
 501                 unregister_inetaddr_notifier(&nfsd_inetaddr_notifier);
 502 #if IS_ENABLED(CONFIG_IPV6)
 503                 unregister_inet6addr_notifier(&nfsd_inet6addr_notifier);
 504 #endif
 505         }
 506         wait_event(nn->ntf_wq, atomic_read(&nn->ntf_refcnt) == 0);
 507 
 508         /*
 509          * write_ports can create the server without actually starting
 510          * any threads--if we get shut down before any threads are
 511          * started, then nfsd_last_thread will be run before any of this
 512          * other initialization has been done except the rpcb information.
 513          */
 514         svc_rpcb_cleanup(serv, net);
 515         if (!nn->nfsd_net_up)
 516                 return;
 517 
 518         nfsd_shutdown_net(net);
 519         printk(KERN_WARNING "nfsd: last server has exited, flushing export "
 520                             "cache\n");
 521         nfsd_export_flush(net);
 522 }
 523 
 524 void nfsd_reset_versions(struct nfsd_net *nn)
 525 {
 526         int i;
 527 
 528         for (i = 0; i < NFSD_NRVERS; i++)
 529                 if (nfsd_vers(nn, i, NFSD_TEST))
 530                         return;
 531 
 532         for (i = 0; i < NFSD_NRVERS; i++)
 533                 if (i != 4)
 534                         nfsd_vers(nn, i, NFSD_SET);
 535                 else {
 536                         int minor = 0;
 537                         while (nfsd_minorversion(nn, minor, NFSD_SET) >= 0)
 538                                 minor++;
 539                 }
 540 }
 541 
 542 /*
 543  * Each session guarantees a negotiated per slot memory cache for replies
 544  * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated
 545  * NFSv4.1 server might want to use more memory for a DRC than a machine
 546  * with mutiple services.
 547  *
 548  * Impose a hard limit on the number of pages for the DRC which varies
 549  * according to the machines free pages. This is of course only a default.
 550  *
 551  * For now this is a #defined shift which could be under admin control
 552  * in the future.
 553  */
 554 static void set_max_drc(void)
 555 {
 556         #define NFSD_DRC_SIZE_SHIFT     7
 557         nfsd_drc_max_mem = (nr_free_buffer_pages()
 558                                         >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE;
 559         nfsd_drc_mem_used = 0;
 560         spin_lock_init(&nfsd_drc_lock);
 561         dprintk("%s nfsd_drc_max_mem %lu \n", __func__, nfsd_drc_max_mem);
 562 }
 563 
 564 static int nfsd_get_default_max_blksize(void)
 565 {
 566         struct sysinfo i;
 567         unsigned long long target;
 568         unsigned long ret;
 569 
 570         si_meminfo(&i);
 571         target = (i.totalram - i.totalhigh) << PAGE_SHIFT;
 572         /*
 573          * Aim for 1/4096 of memory per thread This gives 1MB on 4Gig
 574          * machines, but only uses 32K on 128M machines.  Bottom out at
 575          * 8K on 32M and smaller.  Of course, this is only a default.
 576          */
 577         target >>= 12;
 578 
 579         ret = NFSSVC_MAXBLKSIZE;
 580         while (ret > target && ret >= 8*1024*2)
 581                 ret /= 2;
 582         return ret;
 583 }
 584 
 585 static const struct svc_serv_ops nfsd_thread_sv_ops = {
 586         .svo_shutdown           = nfsd_last_thread,
 587         .svo_function           = nfsd,
 588         .svo_enqueue_xprt       = svc_xprt_do_enqueue,
 589         .svo_setup              = svc_set_num_threads,
 590         .svo_module             = THIS_MODULE,
 591 };
 592 
 593 int nfsd_create_serv(struct net *net)
 594 {
 595         int error;
 596         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 597 
 598         WARN_ON(!mutex_is_locked(&nfsd_mutex));
 599         if (nn->nfsd_serv) {
 600                 svc_get(nn->nfsd_serv);
 601                 return 0;
 602         }
 603         if (nfsd_max_blksize == 0)
 604                 nfsd_max_blksize = nfsd_get_default_max_blksize();
 605         nfsd_reset_versions(nn);
 606         nn->nfsd_serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize,
 607                                                 &nfsd_thread_sv_ops);
 608         if (nn->nfsd_serv == NULL)
 609                 return -ENOMEM;
 610 
 611         nn->nfsd_serv->sv_maxconn = nn->max_connections;
 612         error = svc_bind(nn->nfsd_serv, net);
 613         if (error < 0) {
 614                 svc_destroy(nn->nfsd_serv);
 615                 return error;
 616         }
 617 
 618         set_max_drc();
 619         /* check if the notifier is already set */
 620         if (atomic_inc_return(&nfsd_notifier_refcount) == 1) {
 621                 register_inetaddr_notifier(&nfsd_inetaddr_notifier);
 622 #if IS_ENABLED(CONFIG_IPV6)
 623                 register_inet6addr_notifier(&nfsd_inet6addr_notifier);
 624 #endif
 625         }
 626         atomic_inc(&nn->ntf_refcnt);
 627         nfsd_reset_boot_verifier(nn);
 628         return 0;
 629 }
 630 
 631 int nfsd_nrpools(struct net *net)
 632 {
 633         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 634 
 635         if (nn->nfsd_serv == NULL)
 636                 return 0;
 637         else
 638                 return nn->nfsd_serv->sv_nrpools;
 639 }
 640 
 641 int nfsd_get_nrthreads(int n, int *nthreads, struct net *net)
 642 {
 643         int i = 0;
 644         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 645 
 646         if (nn->nfsd_serv != NULL) {
 647                 for (i = 0; i < nn->nfsd_serv->sv_nrpools && i < n; i++)
 648                         nthreads[i] = nn->nfsd_serv->sv_pools[i].sp_nrthreads;
 649         }
 650 
 651         return 0;
 652 }
 653 
 654 void nfsd_destroy(struct net *net)
 655 {
 656         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 657         int destroy = (nn->nfsd_serv->sv_nrthreads == 1);
 658 
 659         if (destroy)
 660                 svc_shutdown_net(nn->nfsd_serv, net);
 661         svc_destroy(nn->nfsd_serv);
 662         if (destroy)
 663                 nn->nfsd_serv = NULL;
 664 }
 665 
 666 int nfsd_set_nrthreads(int n, int *nthreads, struct net *net)
 667 {
 668         int i = 0;
 669         int tot = 0;
 670         int err = 0;
 671         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 672 
 673         WARN_ON(!mutex_is_locked(&nfsd_mutex));
 674 
 675         if (nn->nfsd_serv == NULL || n <= 0)
 676                 return 0;
 677 
 678         if (n > nn->nfsd_serv->sv_nrpools)
 679                 n = nn->nfsd_serv->sv_nrpools;
 680 
 681         /* enforce a global maximum number of threads */
 682         tot = 0;
 683         for (i = 0; i < n; i++) {
 684                 nthreads[i] = min(nthreads[i], NFSD_MAXSERVS);
 685                 tot += nthreads[i];
 686         }
 687         if (tot > NFSD_MAXSERVS) {
 688                 /* total too large: scale down requested numbers */
 689                 for (i = 0; i < n && tot > 0; i++) {
 690                         int new = nthreads[i] * NFSD_MAXSERVS / tot;
 691                         tot -= (nthreads[i] - new);
 692                         nthreads[i] = new;
 693                 }
 694                 for (i = 0; i < n && tot > 0; i++) {
 695                         nthreads[i]--;
 696                         tot--;
 697                 }
 698         }
 699 
 700         /*
 701          * There must always be a thread in pool 0; the admin
 702          * can't shut down NFS completely using pool_threads.
 703          */
 704         if (nthreads[0] == 0)
 705                 nthreads[0] = 1;
 706 
 707         /* apply the new numbers */
 708         svc_get(nn->nfsd_serv);
 709         for (i = 0; i < n; i++) {
 710                 err = nn->nfsd_serv->sv_ops->svo_setup(nn->nfsd_serv,
 711                                 &nn->nfsd_serv->sv_pools[i], nthreads[i]);
 712                 if (err)
 713                         break;
 714         }
 715         nfsd_destroy(net);
 716         return err;
 717 }
 718 
 719 /*
 720  * Adjust the number of threads and return the new number of threads.
 721  * This is also the function that starts the server if necessary, if
 722  * this is the first time nrservs is nonzero.
 723  */
 724 int
 725 nfsd_svc(int nrservs, struct net *net, const struct cred *cred)
 726 {
 727         int     error;
 728         bool    nfsd_up_before;
 729         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 730 
 731         mutex_lock(&nfsd_mutex);
 732         dprintk("nfsd: creating service\n");
 733 
 734         nrservs = max(nrservs, 0);
 735         nrservs = min(nrservs, NFSD_MAXSERVS);
 736         error = 0;
 737 
 738         if (nrservs == 0 && nn->nfsd_serv == NULL)
 739                 goto out;
 740 
 741         error = nfsd_create_serv(net);
 742         if (error)
 743                 goto out;
 744 
 745         nfsd_up_before = nn->nfsd_net_up;
 746 
 747         error = nfsd_startup_net(nrservs, net, cred);
 748         if (error)
 749                 goto out_destroy;
 750         error = nn->nfsd_serv->sv_ops->svo_setup(nn->nfsd_serv,
 751                         NULL, nrservs);
 752         if (error)
 753                 goto out_shutdown;
 754         /* We are holding a reference to nn->nfsd_serv which
 755          * we don't want to count in the return value,
 756          * so subtract 1
 757          */
 758         error = nn->nfsd_serv->sv_nrthreads - 1;
 759 out_shutdown:
 760         if (error < 0 && !nfsd_up_before)
 761                 nfsd_shutdown_net(net);
 762 out_destroy:
 763         nfsd_destroy(net);              /* Release server */
 764 out:
 765         mutex_unlock(&nfsd_mutex);
 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_NRVERS;
 847         for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) {
 848                 if (nfsd_vers(nn, i, NFSD_TEST)) {
 849                         ret->mismatch.lovers = i;
 850                         break;
 851                 }
 852         }
 853         if (ret->mismatch.lovers == NFSD_NRVERS)
 854                 return rpc_prog_unavail;
 855         ret->mismatch.hivers = NFSD_MINVERS;
 856         for (i = NFSD_NRVERS - 1; 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         int err;
 876 
 877         /* Lock module and set up kernel thread */
 878         mutex_lock(&nfsd_mutex);
 879 
 880         /* At this point, the thread shares current->fs
 881          * with the init process. We need to create files with the
 882          * umask as defined by the client instead of init's umask. */
 883         if (unshare_fs_struct() < 0) {
 884                 printk("Unable to start nfsd thread: out of memory\n");
 885                 goto out;
 886         }
 887 
 888         current->fs->umask = 0;
 889 
 890         /*
 891          * thread is spawned with all signals set to SIG_IGN, re-enable
 892          * the ones that will bring down the thread
 893          */
 894         allow_signal(SIGKILL);
 895         allow_signal(SIGHUP);
 896         allow_signal(SIGINT);
 897         allow_signal(SIGQUIT);
 898 
 899         nfsdstats.th_cnt++;
 900         mutex_unlock(&nfsd_mutex);
 901 
 902         set_freezable();
 903 
 904         /*
 905          * The main request loop
 906          */
 907         for (;;) {
 908                 /* Update sv_maxconn if it has changed */
 909                 rqstp->rq_server->sv_maxconn = nn->max_connections;
 910 
 911                 /*
 912                  * Find a socket with data available and call its
 913                  * recvfrom routine.
 914                  */
 915                 while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN)
 916                         ;
 917                 if (err == -EINTR)
 918                         break;
 919                 validate_process_creds();
 920                 svc_process(rqstp);
 921                 validate_process_creds();
 922         }
 923 
 924         /* Clear signals before calling svc_exit_thread() */
 925         flush_signals(current);
 926 
 927         mutex_lock(&nfsd_mutex);
 928         nfsdstats.th_cnt --;
 929 
 930 out:
 931         rqstp->rq_server = NULL;
 932 
 933         /* Release the thread */
 934         svc_exit_thread(rqstp);
 935 
 936         nfsd_destroy(net);
 937 
 938         /* Release module */
 939         mutex_unlock(&nfsd_mutex);
 940         module_put_and_exit(0);
 941         return 0;
 942 }
 943 
 944 static __be32 map_new_errors(u32 vers, __be32 nfserr)
 945 {
 946         if (nfserr == nfserr_jukebox && vers == 2)
 947                 return nfserr_dropit;
 948         if (nfserr == nfserr_wrongsec && vers < 4)
 949                 return nfserr_acces;
 950         return nfserr;
 951 }
 952 
 953 /*
 954  * A write procedure can have a large argument, and a read procedure can
 955  * have a large reply, but no NFSv2 or NFSv3 procedure has argument and
 956  * reply that can both be larger than a page.  The xdr code has taken
 957  * advantage of this assumption to be a sloppy about bounds checking in
 958  * some cases.  Pending a rewrite of the NFSv2/v3 xdr code to fix that
 959  * problem, we enforce these assumptions here:
 960  */
 961 static bool nfs_request_too_big(struct svc_rqst *rqstp,
 962                                 const struct svc_procedure *proc)
 963 {
 964         /*
 965          * The ACL code has more careful bounds-checking and is not
 966          * susceptible to this problem:
 967          */
 968         if (rqstp->rq_prog != NFS_PROGRAM)
 969                 return false;
 970         /*
 971          * Ditto NFSv4 (which can in theory have argument and reply both
 972          * more than a page):
 973          */
 974         if (rqstp->rq_vers >= 4)
 975                 return false;
 976         /* The reply will be small, we're OK: */
 977         if (proc->pc_xdrressize > 0 &&
 978             proc->pc_xdrressize < XDR_QUADLEN(PAGE_SIZE))
 979                 return false;
 980 
 981         return rqstp->rq_arg.len > PAGE_SIZE;
 982 }
 983 
 984 int
 985 nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
 986 {
 987         const struct svc_procedure *proc;
 988         __be32                  nfserr;
 989         __be32                  *nfserrp;
 990 
 991         dprintk("nfsd_dispatch: vers %d proc %d\n",
 992                                 rqstp->rq_vers, rqstp->rq_proc);
 993         proc = rqstp->rq_procinfo;
 994 
 995         if (nfs_request_too_big(rqstp, proc)) {
 996                 dprintk("nfsd: NFSv%d argument too large\n", rqstp->rq_vers);
 997                 *statp = rpc_garbage_args;
 998                 return 1;
 999         }
1000         /*
1001          * Give the xdr decoder a chance to change this if it wants
1002          * (necessary in the NFSv4.0 compound case)
1003          */
1004         rqstp->rq_cachetype = proc->pc_cachetype;
1005         /* Decode arguments */
1006         if (proc->pc_decode &&
1007             !proc->pc_decode(rqstp, (__be32*)rqstp->rq_arg.head[0].iov_base)) {
1008                 dprintk("nfsd: failed to decode arguments!\n");
1009                 *statp = rpc_garbage_args;
1010                 return 1;
1011         }
1012 
1013         /* Check whether we have this call in the cache. */
1014         switch (nfsd_cache_lookup(rqstp)) {
1015         case RC_DROPIT:
1016                 return 0;
1017         case RC_REPLY:
1018                 return 1;
1019         case RC_DOIT:;
1020                 /* do it */
1021         }
1022 
1023         /* need to grab the location to store the status, as
1024          * nfsv4 does some encoding while processing 
1025          */
1026         nfserrp = rqstp->rq_res.head[0].iov_base
1027                 + rqstp->rq_res.head[0].iov_len;
1028         rqstp->rq_res.head[0].iov_len += sizeof(__be32);
1029 
1030         /* Now call the procedure handler, and encode NFS status. */
1031         nfserr = proc->pc_func(rqstp);
1032         nfserr = map_new_errors(rqstp->rq_vers, nfserr);
1033         if (nfserr == nfserr_dropit || test_bit(RQ_DROPME, &rqstp->rq_flags)) {
1034                 dprintk("nfsd: Dropping request; may be revisited later\n");
1035                 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
1036                 return 0;
1037         }
1038 
1039         if (rqstp->rq_proc != 0)
1040                 *nfserrp++ = nfserr;
1041 
1042         /* Encode result.
1043          * For NFSv2, additional info is never returned in case of an error.
1044          */
1045         if (!(nfserr && rqstp->rq_vers == 2)) {
1046                 if (proc->pc_encode && !proc->pc_encode(rqstp, nfserrp)) {
1047                         /* Failed to encode result. Release cache entry */
1048                         dprintk("nfsd: failed to encode result!\n");
1049                         nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
1050                         *statp = rpc_system_err;
1051                         return 1;
1052                 }
1053         }
1054 
1055         /* Store reply in cache. */
1056         nfsd_cache_update(rqstp, rqstp->rq_cachetype, statp + 1);
1057         return 1;
1058 }
1059 
1060 int nfsd_pool_stats_open(struct inode *inode, struct file *file)
1061 {
1062         int ret;
1063         struct nfsd_net *nn = net_generic(inode->i_sb->s_fs_info, nfsd_net_id);
1064 
1065         mutex_lock(&nfsd_mutex);
1066         if (nn->nfsd_serv == NULL) {
1067                 mutex_unlock(&nfsd_mutex);
1068                 return -ENODEV;
1069         }
1070         /* bump up the psudo refcount while traversing */
1071         svc_get(nn->nfsd_serv);
1072         ret = svc_pool_stats_open(nn->nfsd_serv, file);
1073         mutex_unlock(&nfsd_mutex);
1074         return ret;
1075 }
1076 
1077 int nfsd_pool_stats_release(struct inode *inode, struct file *file)
1078 {
1079         int ret = seq_release(inode, file);
1080         struct net *net = inode->i_sb->s_fs_info;
1081 
1082         mutex_lock(&nfsd_mutex);
1083         /* this function really, really should have been called svc_put() */
1084         nfsd_destroy(net);
1085         mutex_unlock(&nfsd_mutex);
1086         return ret;
1087 }
/* [<][>][^][v][top][bottom][index][help] */
root/fs/nfsd/nfssvc.c

DEFINITIONS
