1 /* 2 * Central processing for nfsd. 3 * 4 * Authors: Olaf Kirch (okir@monad.swb.de) 5 * 6 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de> 7 */ 8 9 #include <linux/sched.h> 10 #include <linux/freezer.h> 11 #include <linux/module.h> 12 #include <linux/fs_struct.h> 13 #include <linux/swap.h> 14 15 #include <linux/sunrpc/stats.h> 16 #include <linux/sunrpc/svcsock.h> 17 #include <linux/lockd/bind.h> 18 #include <linux/nfsacl.h> 19 #include <linux/seq_file.h> 20 #include <net/net_namespace.h> 21 #include "nfsd.h" 22 #include "cache.h" 23 #include "vfs.h" 24 #include "netns.h" 25 26 #define NFSDDBG_FACILITY NFSDDBG_SVC 27 28 extern struct svc_program nfsd_program; 29 static int nfsd(void *vrqstp); 30 31 /* 32 * nfsd_mutex protects nn->nfsd_serv -- both the pointer itself and the members 33 * of the svc_serv struct. In particular, ->sv_nrthreads but also to some 34 * extent ->sv_temp_socks and ->sv_permsocks. It also protects nfsdstats.th_cnt 35 * 36 * If (out side the lock) nn->nfsd_serv is non-NULL, then it must point to a 37 * properly initialised 'struct svc_serv' with ->sv_nrthreads > 0. That number 38 * of nfsd threads must exist and each must listed in ->sp_all_threads in each 39 * entry of ->sv_pools[]. 40 * 41 * Transitions of the thread count between zero and non-zero are of particular 42 * interest since the svc_serv needs to be created and initialized at that 43 * point, or freed. 44 * 45 * Finally, the nfsd_mutex also protects some of the global variables that are 46 * accessed when nfsd starts and that are settable via the write_* routines in 47 * nfsctl.c. In particular: 48 * 49 * user_recovery_dirname 50 * user_lease_time 51 * nfsd_versions 52 */ 53 DEFINE_MUTEX(nfsd_mutex); 54 55 /* 56 * nfsd_drc_lock protects nfsd_drc_max_pages and nfsd_drc_pages_used. 57 * nfsd_drc_max_pages limits the total amount of memory available for 58 * version 4.1 DRC caches. 59 * nfsd_drc_pages_used tracks the current version 4.1 DRC memory usage. 60 */ 61 spinlock_t nfsd_drc_lock; 62 unsigned long nfsd_drc_max_mem; 63 unsigned long nfsd_drc_mem_used; 64 65 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 66 static struct svc_stat nfsd_acl_svcstats; 67 static struct svc_version * nfsd_acl_version[] = { 68 [2] = &nfsd_acl_version2, 69 [3] = &nfsd_acl_version3, 70 }; 71 72 #define NFSD_ACL_MINVERS 2 73 #define NFSD_ACL_NRVERS ARRAY_SIZE(nfsd_acl_version) 74 static struct svc_version *nfsd_acl_versions[NFSD_ACL_NRVERS]; 75 76 static struct svc_program nfsd_acl_program = { 77 .pg_prog = NFS_ACL_PROGRAM, 78 .pg_nvers = NFSD_ACL_NRVERS, 79 .pg_vers = nfsd_acl_versions, 80 .pg_name = "nfsacl", 81 .pg_class = "nfsd", 82 .pg_stats = &nfsd_acl_svcstats, 83 .pg_authenticate = &svc_set_client, 84 }; 85 86 static struct svc_stat nfsd_acl_svcstats = { 87 .program = &nfsd_acl_program, 88 }; 89 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */ 90 91 static struct svc_version * nfsd_version[] = { 92 [2] = &nfsd_version2, 93 #if defined(CONFIG_NFSD_V3) 94 [3] = &nfsd_version3, 95 #endif 96 #if defined(CONFIG_NFSD_V4) 97 [4] = &nfsd_version4, 98 #endif 99 }; 100 101 #define NFSD_MINVERS 2 102 #define NFSD_NRVERS ARRAY_SIZE(nfsd_version) 103 static struct svc_version *nfsd_versions[NFSD_NRVERS]; 104 105 struct svc_program nfsd_program = { 106 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 107 .pg_next = &nfsd_acl_program, 108 #endif 109 .pg_prog = NFS_PROGRAM, /* program number */ 110 .pg_nvers = NFSD_NRVERS, /* nr of entries in nfsd_version */ 111 .pg_vers = nfsd_versions, /* version table */ 112 .pg_name = "nfsd", /* program name */ 113 .pg_class = "nfsd", /* authentication class */ 114 .pg_stats = &nfsd_svcstats, /* version table */ 115 .pg_authenticate = &svc_set_client, /* export authentication */ 116 117 }; 118 119 static bool nfsd_supported_minorversions[NFSD_SUPPORTED_MINOR_VERSION + 1] = { 120 [0] = 1, 121 [1] = 1, 122 }; 123 124 int nfsd_vers(int vers, enum vers_op change) 125 { 126 if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS) 127 return 0; 128 switch(change) { 129 case NFSD_SET: 130 nfsd_versions[vers] = nfsd_version[vers]; 131 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 132 if (vers < NFSD_ACL_NRVERS) 133 nfsd_acl_versions[vers] = nfsd_acl_version[vers]; 134 #endif 135 break; 136 case NFSD_CLEAR: 137 nfsd_versions[vers] = NULL; 138 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 139 if (vers < NFSD_ACL_NRVERS) 140 nfsd_acl_versions[vers] = NULL; 141 #endif 142 break; 143 case NFSD_TEST: 144 return nfsd_versions[vers] != NULL; 145 case NFSD_AVAIL: 146 return nfsd_version[vers] != NULL; 147 } 148 return 0; 149 } 150 151 int nfsd_minorversion(u32 minorversion, enum vers_op change) 152 { 153 if (minorversion > NFSD_SUPPORTED_MINOR_VERSION) 154 return -1; 155 switch(change) { 156 case NFSD_SET: 157 nfsd_supported_minorversions[minorversion] = true; 158 break; 159 case NFSD_CLEAR: 160 nfsd_supported_minorversions[minorversion] = false; 161 break; 162 case NFSD_TEST: 163 return nfsd_supported_minorversions[minorversion]; 164 case NFSD_AVAIL: 165 return minorversion <= NFSD_SUPPORTED_MINOR_VERSION; 166 } 167 return 0; 168 } 169 170 /* 171 * Maximum number of nfsd processes 172 */ 173 #define NFSD_MAXSERVS 8192 174 175 int nfsd_nrthreads(struct net *net) 176 { 177 int rv = 0; 178 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 179 180 mutex_lock(&nfsd_mutex); 181 if (nn->nfsd_serv) 182 rv = nn->nfsd_serv->sv_nrthreads; 183 mutex_unlock(&nfsd_mutex); 184 return rv; 185 } 186 187 static int nfsd_init_socks(struct net *net) 188 { 189 int error; 190 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 191 192 if (!list_empty(&nn->nfsd_serv->sv_permsocks)) 193 return 0; 194 195 error = svc_create_xprt(nn->nfsd_serv, "udp", net, PF_INET, NFS_PORT, 196 SVC_SOCK_DEFAULTS); 197 if (error < 0) 198 return error; 199 200 error = svc_create_xprt(nn->nfsd_serv, "tcp", net, PF_INET, NFS_PORT, 201 SVC_SOCK_DEFAULTS); 202 if (error < 0) 203 return error; 204 205 return 0; 206 } 207 208 static int nfsd_users = 0; 209 210 static int nfsd_startup_generic(int nrservs) 211 { 212 int ret; 213 214 if (nfsd_users++) 215 return 0; 216 217 /* 218 * Readahead param cache - will no-op if it already exists. 219 * (Note therefore results will be suboptimal if number of 220 * threads is modified after nfsd start.) 221 */ 222 ret = nfsd_racache_init(2*nrservs); 223 if (ret) 224 return ret; 225 ret = nfs4_state_start(); 226 if (ret) 227 goto out_racache; 228 return 0; 229 230 out_racache: 231 nfsd_racache_shutdown(); 232 return ret; 233 } 234 235 static void nfsd_shutdown_generic(void) 236 { 237 if (--nfsd_users) 238 return; 239 240 nfs4_state_shutdown(); 241 nfsd_racache_shutdown(); 242 } 243 244 static bool nfsd_needs_lockd(void) 245 { 246 #if defined(CONFIG_NFSD_V3) 247 return (nfsd_versions[2] != NULL) || (nfsd_versions[3] != NULL); 248 #else 249 return (nfsd_versions[2] != NULL); 250 #endif 251 } 252 253 static int nfsd_startup_net(int nrservs, struct net *net) 254 { 255 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 256 int ret; 257 258 if (nn->nfsd_net_up) 259 return 0; 260 261 ret = nfsd_startup_generic(nrservs); 262 if (ret) 263 return ret; 264 ret = nfsd_init_socks(net); 265 if (ret) 266 goto out_socks; 267 268 if (nfsd_needs_lockd() && !nn->lockd_up) { 269 ret = lockd_up(net); 270 if (ret) 271 goto out_socks; 272 nn->lockd_up = 1; 273 } 274 275 ret = nfs4_state_start_net(net); 276 if (ret) 277 goto out_lockd; 278 279 nn->nfsd_net_up = true; 280 return 0; 281 282 out_lockd: 283 if (nn->lockd_up) { 284 lockd_down(net); 285 nn->lockd_up = 0; 286 } 287 out_socks: 288 nfsd_shutdown_generic(); 289 return ret; 290 } 291 292 static void nfsd_shutdown_net(struct net *net) 293 { 294 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 295 296 nfs4_state_shutdown_net(net); 297 if (nn->lockd_up) { 298 lockd_down(net); 299 nn->lockd_up = 0; 300 } 301 nn->nfsd_net_up = false; 302 nfsd_shutdown_generic(); 303 } 304 305 static void nfsd_last_thread(struct svc_serv *serv, struct net *net) 306 { 307 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 308 309 /* 310 * write_ports can create the server without actually starting 311 * any threads--if we get shut down before any threads are 312 * started, then nfsd_last_thread will be run before any of this 313 * other initialization has been done. 314 */ 315 if (!nn->nfsd_net_up) 316 return; 317 nfsd_shutdown_net(net); 318 319 svc_rpcb_cleanup(serv, net); 320 321 printk(KERN_WARNING "nfsd: last server has exited, flushing export " 322 "cache\n"); 323 nfsd_export_flush(net); 324 } 325 326 void nfsd_reset_versions(void) 327 { 328 int found_one = 0; 329 int i; 330 331 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) { 332 if (nfsd_program.pg_vers[i]) 333 found_one = 1; 334 } 335 336 if (!found_one) { 337 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) 338 nfsd_program.pg_vers[i] = nfsd_version[i]; 339 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 340 for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) 341 nfsd_acl_program.pg_vers[i] = 342 nfsd_acl_version[i]; 343 #endif 344 } 345 } 346 347 /* 348 * Each session guarantees a negotiated per slot memory cache for replies 349 * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated 350 * NFSv4.1 server might want to use more memory for a DRC than a machine 351 * with mutiple services. 352 * 353 * Impose a hard limit on the number of pages for the DRC which varies 354 * according to the machines free pages. This is of course only a default. 355 * 356 * For now this is a #defined shift which could be under admin control 357 * in the future. 358 */ 359 static void set_max_drc(void) 360 { 361 #define NFSD_DRC_SIZE_SHIFT 10 362 nfsd_drc_max_mem = (nr_free_buffer_pages() 363 >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE; 364 nfsd_drc_mem_used = 0; 365 spin_lock_init(&nfsd_drc_lock); 366 dprintk("%s nfsd_drc_max_mem %lu \n", __func__, nfsd_drc_max_mem); 367 } 368 369 static int nfsd_get_default_max_blksize(void) 370 { 371 struct sysinfo i; 372 unsigned long long target; 373 unsigned long ret; 374 375 si_meminfo(&i); 376 target = (i.totalram - i.totalhigh) << PAGE_SHIFT; 377 /* 378 * Aim for 1/4096 of memory per thread This gives 1MB on 4Gig 379 * machines, but only uses 32K on 128M machines. Bottom out at 380 * 8K on 32M and smaller. Of course, this is only a default. 381 */ 382 target >>= 12; 383 384 ret = NFSSVC_MAXBLKSIZE; 385 while (ret > target && ret >= 8*1024*2) 386 ret /= 2; 387 return ret; 388 } 389 390 int nfsd_create_serv(struct net *net) 391 { 392 int error; 393 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 394 395 WARN_ON(!mutex_is_locked(&nfsd_mutex)); 396 if (nn->nfsd_serv) { 397 svc_get(nn->nfsd_serv); 398 return 0; 399 } 400 if (nfsd_max_blksize == 0) 401 nfsd_max_blksize = nfsd_get_default_max_blksize(); 402 nfsd_reset_versions(); 403 nn->nfsd_serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize, 404 nfsd_last_thread, nfsd, THIS_MODULE); 405 if (nn->nfsd_serv == NULL) 406 return -ENOMEM; 407 408 error = svc_bind(nn->nfsd_serv, net); 409 if (error < 0) { 410 svc_destroy(nn->nfsd_serv); 411 return error; 412 } 413 414 set_max_drc(); 415 do_gettimeofday(&nn->nfssvc_boot); /* record boot time */ 416 return 0; 417 } 418 419 int nfsd_nrpools(struct net *net) 420 { 421 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 422 423 if (nn->nfsd_serv == NULL) 424 return 0; 425 else 426 return nn->nfsd_serv->sv_nrpools; 427 } 428 429 int nfsd_get_nrthreads(int n, int *nthreads, struct net *net) 430 { 431 int i = 0; 432 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 433 434 if (nn->nfsd_serv != NULL) { 435 for (i = 0; i < nn->nfsd_serv->sv_nrpools && i < n; i++) 436 nthreads[i] = nn->nfsd_serv->sv_pools[i].sp_nrthreads; 437 } 438 439 return 0; 440 } 441 442 void nfsd_destroy(struct net *net) 443 { 444 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 445 int destroy = (nn->nfsd_serv->sv_nrthreads == 1); 446 447 if (destroy) 448 svc_shutdown_net(nn->nfsd_serv, net); 449 svc_destroy(nn->nfsd_serv); 450 if (destroy) 451 nn->nfsd_serv = NULL; 452 } 453 454 int nfsd_set_nrthreads(int n, int *nthreads, struct net *net) 455 { 456 int i = 0; 457 int tot = 0; 458 int err = 0; 459 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 460 461 WARN_ON(!mutex_is_locked(&nfsd_mutex)); 462 463 if (nn->nfsd_serv == NULL || n <= 0) 464 return 0; 465 466 if (n > nn->nfsd_serv->sv_nrpools) 467 n = nn->nfsd_serv->sv_nrpools; 468 469 /* enforce a global maximum number of threads */ 470 tot = 0; 471 for (i = 0; i < n; i++) { 472 if (nthreads[i] > NFSD_MAXSERVS) 473 nthreads[i] = NFSD_MAXSERVS; 474 tot += nthreads[i]; 475 } 476 if (tot > NFSD_MAXSERVS) { 477 /* total too large: scale down requested numbers */ 478 for (i = 0; i < n && tot > 0; i++) { 479 int new = nthreads[i] * NFSD_MAXSERVS / tot; 480 tot -= (nthreads[i] - new); 481 nthreads[i] = new; 482 } 483 for (i = 0; i < n && tot > 0; i++) { 484 nthreads[i]--; 485 tot--; 486 } 487 } 488 489 /* 490 * There must always be a thread in pool 0; the admin 491 * can't shut down NFS completely using pool_threads. 492 */ 493 if (nthreads[0] == 0) 494 nthreads[0] = 1; 495 496 /* apply the new numbers */ 497 svc_get(nn->nfsd_serv); 498 for (i = 0; i < n; i++) { 499 err = svc_set_num_threads(nn->nfsd_serv, &nn->nfsd_serv->sv_pools[i], 500 nthreads[i]); 501 if (err) 502 break; 503 } 504 nfsd_destroy(net); 505 return err; 506 } 507 508 /* 509 * Adjust the number of threads and return the new number of threads. 510 * This is also the function that starts the server if necessary, if 511 * this is the first time nrservs is nonzero. 512 */ 513 int 514 nfsd_svc(int nrservs, struct net *net) 515 { 516 int error; 517 bool nfsd_up_before; 518 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 519 520 mutex_lock(&nfsd_mutex); 521 dprintk("nfsd: creating service\n"); 522 if (nrservs <= 0) 523 nrservs = 0; 524 if (nrservs > NFSD_MAXSERVS) 525 nrservs = NFSD_MAXSERVS; 526 error = 0; 527 if (nrservs == 0 && nn->nfsd_serv == NULL) 528 goto out; 529 530 error = nfsd_create_serv(net); 531 if (error) 532 goto out; 533 534 nfsd_up_before = nn->nfsd_net_up; 535 536 error = nfsd_startup_net(nrservs, net); 537 if (error) 538 goto out_destroy; 539 error = svc_set_num_threads(nn->nfsd_serv, NULL, nrservs); 540 if (error) 541 goto out_shutdown; 542 /* We are holding a reference to nn->nfsd_serv which 543 * we don't want to count in the return value, 544 * so subtract 1 545 */ 546 error = nn->nfsd_serv->sv_nrthreads - 1; 547 out_shutdown: 548 if (error < 0 && !nfsd_up_before) 549 nfsd_shutdown_net(net); 550 out_destroy: 551 nfsd_destroy(net); /* Release server */ 552 out: 553 mutex_unlock(&nfsd_mutex); 554 return error; 555 } 556 557 558 /* 559 * This is the NFS server kernel thread 560 */ 561 static int 562 nfsd(void *vrqstp) 563 { 564 struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp; 565 struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list); 566 struct net *net = perm_sock->xpt_net; 567 int err; 568 569 /* Lock module and set up kernel thread */ 570 mutex_lock(&nfsd_mutex); 571 572 /* At this point, the thread shares current->fs 573 * with the init process. We need to create files with a 574 * umask of 0 instead of init's umask. */ 575 if (unshare_fs_struct() < 0) { 576 printk("Unable to start nfsd thread: out of memory\n"); 577 goto out; 578 } 579 580 current->fs->umask = 0; 581 582 /* 583 * thread is spawned with all signals set to SIG_IGN, re-enable 584 * the ones that will bring down the thread 585 */ 586 allow_signal(SIGKILL); 587 allow_signal(SIGHUP); 588 allow_signal(SIGINT); 589 allow_signal(SIGQUIT); 590 591 nfsdstats.th_cnt++; 592 mutex_unlock(&nfsd_mutex); 593 594 set_freezable(); 595 596 /* 597 * The main request loop 598 */ 599 for (;;) { 600 /* 601 * Find a socket with data available and call its 602 * recvfrom routine. 603 */ 604 while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN) 605 ; 606 if (err == -EINTR) 607 break; 608 validate_process_creds(); 609 svc_process(rqstp); 610 validate_process_creds(); 611 } 612 613 /* Clear signals before calling svc_exit_thread() */ 614 flush_signals(current); 615 616 mutex_lock(&nfsd_mutex); 617 nfsdstats.th_cnt --; 618 619 out: 620 rqstp->rq_server = NULL; 621 622 /* Release the thread */ 623 svc_exit_thread(rqstp); 624 625 nfsd_destroy(net); 626 627 /* Release module */ 628 mutex_unlock(&nfsd_mutex); 629 module_put_and_exit(0); 630 return 0; 631 } 632 633 static __be32 map_new_errors(u32 vers, __be32 nfserr) 634 { 635 if (nfserr == nfserr_jukebox && vers == 2) 636 return nfserr_dropit; 637 if (nfserr == nfserr_wrongsec && vers < 4) 638 return nfserr_acces; 639 return nfserr; 640 } 641 642 int 643 nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp) 644 { 645 struct svc_procedure *proc; 646 kxdrproc_t xdr; 647 __be32 nfserr; 648 __be32 *nfserrp; 649 650 dprintk("nfsd_dispatch: vers %d proc %d\n", 651 rqstp->rq_vers, rqstp->rq_proc); 652 proc = rqstp->rq_procinfo; 653 654 /* 655 * Give the xdr decoder a chance to change this if it wants 656 * (necessary in the NFSv4.0 compound case) 657 */ 658 rqstp->rq_cachetype = proc->pc_cachetype; 659 /* Decode arguments */ 660 xdr = proc->pc_decode; 661 if (xdr && !xdr(rqstp, (__be32*)rqstp->rq_arg.head[0].iov_base, 662 rqstp->rq_argp)) { 663 dprintk("nfsd: failed to decode arguments!\n"); 664 *statp = rpc_garbage_args; 665 return 1; 666 } 667 668 /* Check whether we have this call in the cache. */ 669 switch (nfsd_cache_lookup(rqstp)) { 670 case RC_DROPIT: 671 return 0; 672 case RC_REPLY: 673 return 1; 674 case RC_DOIT:; 675 /* do it */ 676 } 677 678 /* need to grab the location to store the status, as 679 * nfsv4 does some encoding while processing 680 */ 681 nfserrp = rqstp->rq_res.head[0].iov_base 682 + rqstp->rq_res.head[0].iov_len; 683 rqstp->rq_res.head[0].iov_len += sizeof(__be32); 684 685 /* Now call the procedure handler, and encode NFS status. */ 686 nfserr = proc->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp); 687 nfserr = map_new_errors(rqstp->rq_vers, nfserr); 688 if (nfserr == nfserr_dropit || rqstp->rq_dropme) { 689 dprintk("nfsd: Dropping request; may be revisited later\n"); 690 nfsd_cache_update(rqstp, RC_NOCACHE, NULL); 691 return 0; 692 } 693 694 if (rqstp->rq_proc != 0) 695 *nfserrp++ = nfserr; 696 697 /* Encode result. 698 * For NFSv2, additional info is never returned in case of an error. 699 */ 700 if (!(nfserr && rqstp->rq_vers == 2)) { 701 xdr = proc->pc_encode; 702 if (xdr && !xdr(rqstp, nfserrp, 703 rqstp->rq_resp)) { 704 /* Failed to encode result. Release cache entry */ 705 dprintk("nfsd: failed to encode result!\n"); 706 nfsd_cache_update(rqstp, RC_NOCACHE, NULL); 707 *statp = rpc_system_err; 708 return 1; 709 } 710 } 711 712 /* Store reply in cache. */ 713 nfsd_cache_update(rqstp, rqstp->rq_cachetype, statp + 1); 714 return 1; 715 } 716 717 int nfsd_pool_stats_open(struct inode *inode, struct file *file) 718 { 719 int ret; 720 struct nfsd_net *nn = net_generic(inode->i_sb->s_fs_info, nfsd_net_id); 721 722 mutex_lock(&nfsd_mutex); 723 if (nn->nfsd_serv == NULL) { 724 mutex_unlock(&nfsd_mutex); 725 return -ENODEV; 726 } 727 /* bump up the psudo refcount while traversing */ 728 svc_get(nn->nfsd_serv); 729 ret = svc_pool_stats_open(nn->nfsd_serv, file); 730 mutex_unlock(&nfsd_mutex); 731 return ret; 732 } 733 734 int nfsd_pool_stats_release(struct inode *inode, struct file *file) 735 { 736 int ret = seq_release(inode, file); 737 struct net *net = inode->i_sb->s_fs_info; 738 739 mutex_lock(&nfsd_mutex); 740 /* this function really, really should have been called svc_put() */ 741 nfsd_destroy(net); 742 mutex_unlock(&nfsd_mutex); 743 return ret; 744 } 745