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 int nfsd_startup_net(int nrservs, struct net *net) 245 { 246 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 247 int ret; 248 249 if (nn->nfsd_net_up) 250 return 0; 251 252 ret = nfsd_startup_generic(nrservs); 253 if (ret) 254 return ret; 255 ret = nfsd_init_socks(net); 256 if (ret) 257 goto out_socks; 258 ret = lockd_up(net); 259 if (ret) 260 goto out_socks; 261 ret = nfs4_state_start_net(net); 262 if (ret) 263 goto out_lockd; 264 265 nn->nfsd_net_up = true; 266 return 0; 267 268 out_lockd: 269 lockd_down(net); 270 out_socks: 271 nfsd_shutdown_generic(); 272 return ret; 273 } 274 275 static void nfsd_shutdown_net(struct net *net) 276 { 277 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 278 279 nfs4_state_shutdown_net(net); 280 lockd_down(net); 281 nn->nfsd_net_up = false; 282 nfsd_shutdown_generic(); 283 } 284 285 static void nfsd_last_thread(struct svc_serv *serv, struct net *net) 286 { 287 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 288 289 /* 290 * write_ports can create the server without actually starting 291 * any threads--if we get shut down before any threads are 292 * started, then nfsd_last_thread will be run before any of this 293 * other initialization has been done. 294 */ 295 if (!nn->nfsd_net_up) 296 return; 297 nfsd_shutdown_net(net); 298 299 svc_rpcb_cleanup(serv, net); 300 301 printk(KERN_WARNING "nfsd: last server has exited, flushing export " 302 "cache\n"); 303 nfsd_export_flush(net); 304 } 305 306 void nfsd_reset_versions(void) 307 { 308 int found_one = 0; 309 int i; 310 311 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) { 312 if (nfsd_program.pg_vers[i]) 313 found_one = 1; 314 } 315 316 if (!found_one) { 317 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) 318 nfsd_program.pg_vers[i] = nfsd_version[i]; 319 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 320 for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) 321 nfsd_acl_program.pg_vers[i] = 322 nfsd_acl_version[i]; 323 #endif 324 } 325 } 326 327 /* 328 * Each session guarantees a negotiated per slot memory cache for replies 329 * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated 330 * NFSv4.1 server might want to use more memory for a DRC than a machine 331 * with mutiple services. 332 * 333 * Impose a hard limit on the number of pages for the DRC which varies 334 * according to the machines free pages. This is of course only a default. 335 * 336 * For now this is a #defined shift which could be under admin control 337 * in the future. 338 */ 339 static void set_max_drc(void) 340 { 341 #define NFSD_DRC_SIZE_SHIFT 10 342 nfsd_drc_max_mem = (nr_free_buffer_pages() 343 >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE; 344 nfsd_drc_mem_used = 0; 345 spin_lock_init(&nfsd_drc_lock); 346 dprintk("%s nfsd_drc_max_mem %lu \n", __func__, nfsd_drc_max_mem); 347 } 348 349 static int nfsd_get_default_max_blksize(void) 350 { 351 struct sysinfo i; 352 unsigned long long target; 353 unsigned long ret; 354 355 si_meminfo(&i); 356 target = (i.totalram - i.totalhigh) << PAGE_SHIFT; 357 /* 358 * Aim for 1/4096 of memory per thread This gives 1MB on 4Gig 359 * machines, but only uses 32K on 128M machines. Bottom out at 360 * 8K on 32M and smaller. Of course, this is only a default. 361 */ 362 target >>= 12; 363 364 ret = NFSSVC_MAXBLKSIZE; 365 while (ret > target && ret >= 8*1024*2) 366 ret /= 2; 367 return ret; 368 } 369 370 int nfsd_create_serv(struct net *net) 371 { 372 int error; 373 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 374 375 WARN_ON(!mutex_is_locked(&nfsd_mutex)); 376 if (nn->nfsd_serv) { 377 svc_get(nn->nfsd_serv); 378 return 0; 379 } 380 if (nfsd_max_blksize == 0) 381 nfsd_max_blksize = nfsd_get_default_max_blksize(); 382 nfsd_reset_versions(); 383 nn->nfsd_serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize, 384 nfsd_last_thread, nfsd, THIS_MODULE); 385 if (nn->nfsd_serv == NULL) 386 return -ENOMEM; 387 388 error = svc_bind(nn->nfsd_serv, net); 389 if (error < 0) { 390 svc_destroy(nn->nfsd_serv); 391 return error; 392 } 393 394 set_max_drc(); 395 do_gettimeofday(&nn->nfssvc_boot); /* record boot time */ 396 return 0; 397 } 398 399 int nfsd_nrpools(struct net *net) 400 { 401 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 402 403 if (nn->nfsd_serv == NULL) 404 return 0; 405 else 406 return nn->nfsd_serv->sv_nrpools; 407 } 408 409 int nfsd_get_nrthreads(int n, int *nthreads, struct net *net) 410 { 411 int i = 0; 412 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 413 414 if (nn->nfsd_serv != NULL) { 415 for (i = 0; i < nn->nfsd_serv->sv_nrpools && i < n; i++) 416 nthreads[i] = nn->nfsd_serv->sv_pools[i].sp_nrthreads; 417 } 418 419 return 0; 420 } 421 422 void nfsd_destroy(struct net *net) 423 { 424 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 425 int destroy = (nn->nfsd_serv->sv_nrthreads == 1); 426 427 if (destroy) 428 svc_shutdown_net(nn->nfsd_serv, net); 429 svc_destroy(nn->nfsd_serv); 430 if (destroy) 431 nn->nfsd_serv = NULL; 432 } 433 434 int nfsd_set_nrthreads(int n, int *nthreads, struct net *net) 435 { 436 int i = 0; 437 int tot = 0; 438 int err = 0; 439 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 440 441 WARN_ON(!mutex_is_locked(&nfsd_mutex)); 442 443 if (nn->nfsd_serv == NULL || n <= 0) 444 return 0; 445 446 if (n > nn->nfsd_serv->sv_nrpools) 447 n = nn->nfsd_serv->sv_nrpools; 448 449 /* enforce a global maximum number of threads */ 450 tot = 0; 451 for (i = 0; i < n; i++) { 452 if (nthreads[i] > NFSD_MAXSERVS) 453 nthreads[i] = NFSD_MAXSERVS; 454 tot += nthreads[i]; 455 } 456 if (tot > NFSD_MAXSERVS) { 457 /* total too large: scale down requested numbers */ 458 for (i = 0; i < n && tot > 0; i++) { 459 int new = nthreads[i] * NFSD_MAXSERVS / tot; 460 tot -= (nthreads[i] - new); 461 nthreads[i] = new; 462 } 463 for (i = 0; i < n && tot > 0; i++) { 464 nthreads[i]--; 465 tot--; 466 } 467 } 468 469 /* 470 * There must always be a thread in pool 0; the admin 471 * can't shut down NFS completely using pool_threads. 472 */ 473 if (nthreads[0] == 0) 474 nthreads[0] = 1; 475 476 /* apply the new numbers */ 477 svc_get(nn->nfsd_serv); 478 for (i = 0; i < n; i++) { 479 err = svc_set_num_threads(nn->nfsd_serv, &nn->nfsd_serv->sv_pools[i], 480 nthreads[i]); 481 if (err) 482 break; 483 } 484 nfsd_destroy(net); 485 return err; 486 } 487 488 /* 489 * Adjust the number of threads and return the new number of threads. 490 * This is also the function that starts the server if necessary, if 491 * this is the first time nrservs is nonzero. 492 */ 493 int 494 nfsd_svc(int nrservs, struct net *net) 495 { 496 int error; 497 bool nfsd_up_before; 498 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 499 500 mutex_lock(&nfsd_mutex); 501 dprintk("nfsd: creating service\n"); 502 if (nrservs <= 0) 503 nrservs = 0; 504 if (nrservs > NFSD_MAXSERVS) 505 nrservs = NFSD_MAXSERVS; 506 error = 0; 507 if (nrservs == 0 && nn->nfsd_serv == NULL) 508 goto out; 509 510 error = nfsd_create_serv(net); 511 if (error) 512 goto out; 513 514 nfsd_up_before = nn->nfsd_net_up; 515 516 error = nfsd_startup_net(nrservs, net); 517 if (error) 518 goto out_destroy; 519 error = svc_set_num_threads(nn->nfsd_serv, NULL, nrservs); 520 if (error) 521 goto out_shutdown; 522 /* We are holding a reference to nn->nfsd_serv which 523 * we don't want to count in the return value, 524 * so subtract 1 525 */ 526 error = nn->nfsd_serv->sv_nrthreads - 1; 527 out_shutdown: 528 if (error < 0 && !nfsd_up_before) 529 nfsd_shutdown_net(net); 530 out_destroy: 531 nfsd_destroy(net); /* Release server */ 532 out: 533 mutex_unlock(&nfsd_mutex); 534 return error; 535 } 536 537 538 /* 539 * This is the NFS server kernel thread 540 */ 541 static int 542 nfsd(void *vrqstp) 543 { 544 struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp; 545 struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list); 546 struct net *net = perm_sock->xpt_net; 547 int err; 548 549 /* Lock module and set up kernel thread */ 550 mutex_lock(&nfsd_mutex); 551 552 /* At this point, the thread shares current->fs 553 * with the init process. We need to create files with a 554 * umask of 0 instead of init's umask. */ 555 if (unshare_fs_struct() < 0) { 556 printk("Unable to start nfsd thread: out of memory\n"); 557 goto out; 558 } 559 560 current->fs->umask = 0; 561 562 /* 563 * thread is spawned with all signals set to SIG_IGN, re-enable 564 * the ones that will bring down the thread 565 */ 566 allow_signal(SIGKILL); 567 allow_signal(SIGHUP); 568 allow_signal(SIGINT); 569 allow_signal(SIGQUIT); 570 571 nfsdstats.th_cnt++; 572 mutex_unlock(&nfsd_mutex); 573 574 /* 575 * We want less throttling in balance_dirty_pages() so that nfs to 576 * localhost doesn't cause nfsd to lock up due to all the client's 577 * dirty pages. 578 */ 579 current->flags |= PF_LESS_THROTTLE; 580 set_freezable(); 581 582 /* 583 * The main request loop 584 */ 585 for (;;) { 586 /* 587 * Find a socket with data available and call its 588 * recvfrom routine. 589 */ 590 while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN) 591 ; 592 if (err == -EINTR) 593 break; 594 validate_process_creds(); 595 svc_process(rqstp); 596 validate_process_creds(); 597 } 598 599 /* Clear signals before calling svc_exit_thread() */ 600 flush_signals(current); 601 602 mutex_lock(&nfsd_mutex); 603 nfsdstats.th_cnt --; 604 605 out: 606 rqstp->rq_server = NULL; 607 608 /* Release the thread */ 609 svc_exit_thread(rqstp); 610 611 nfsd_destroy(net); 612 613 /* Release module */ 614 mutex_unlock(&nfsd_mutex); 615 module_put_and_exit(0); 616 return 0; 617 } 618 619 static __be32 map_new_errors(u32 vers, __be32 nfserr) 620 { 621 if (nfserr == nfserr_jukebox && vers == 2) 622 return nfserr_dropit; 623 if (nfserr == nfserr_wrongsec && vers < 4) 624 return nfserr_acces; 625 return nfserr; 626 } 627 628 int 629 nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp) 630 { 631 struct svc_procedure *proc; 632 kxdrproc_t xdr; 633 __be32 nfserr; 634 __be32 *nfserrp; 635 636 dprintk("nfsd_dispatch: vers %d proc %d\n", 637 rqstp->rq_vers, rqstp->rq_proc); 638 proc = rqstp->rq_procinfo; 639 640 /* 641 * Give the xdr decoder a chance to change this if it wants 642 * (necessary in the NFSv4.0 compound case) 643 */ 644 rqstp->rq_cachetype = proc->pc_cachetype; 645 /* Decode arguments */ 646 xdr = proc->pc_decode; 647 if (xdr && !xdr(rqstp, (__be32*)rqstp->rq_arg.head[0].iov_base, 648 rqstp->rq_argp)) { 649 dprintk("nfsd: failed to decode arguments!\n"); 650 *statp = rpc_garbage_args; 651 return 1; 652 } 653 654 /* Check whether we have this call in the cache. */ 655 switch (nfsd_cache_lookup(rqstp)) { 656 case RC_DROPIT: 657 return 0; 658 case RC_REPLY: 659 return 1; 660 case RC_DOIT:; 661 /* do it */ 662 } 663 664 /* need to grab the location to store the status, as 665 * nfsv4 does some encoding while processing 666 */ 667 nfserrp = rqstp->rq_res.head[0].iov_base 668 + rqstp->rq_res.head[0].iov_len; 669 rqstp->rq_res.head[0].iov_len += sizeof(__be32); 670 671 /* Now call the procedure handler, and encode NFS status. */ 672 nfserr = proc->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp); 673 nfserr = map_new_errors(rqstp->rq_vers, nfserr); 674 if (nfserr == nfserr_dropit || rqstp->rq_dropme) { 675 dprintk("nfsd: Dropping request; may be revisited later\n"); 676 nfsd_cache_update(rqstp, RC_NOCACHE, NULL); 677 return 0; 678 } 679 680 if (rqstp->rq_proc != 0) 681 *nfserrp++ = nfserr; 682 683 /* Encode result. 684 * For NFSv2, additional info is never returned in case of an error. 685 */ 686 if (!(nfserr && rqstp->rq_vers == 2)) { 687 xdr = proc->pc_encode; 688 if (xdr && !xdr(rqstp, nfserrp, 689 rqstp->rq_resp)) { 690 /* Failed to encode result. Release cache entry */ 691 dprintk("nfsd: failed to encode result!\n"); 692 nfsd_cache_update(rqstp, RC_NOCACHE, NULL); 693 *statp = rpc_system_err; 694 return 1; 695 } 696 } 697 698 /* Store reply in cache. */ 699 nfsd_cache_update(rqstp, rqstp->rq_cachetype, statp + 1); 700 return 1; 701 } 702 703 int nfsd_pool_stats_open(struct inode *inode, struct file *file) 704 { 705 int ret; 706 struct nfsd_net *nn = net_generic(inode->i_sb->s_fs_info, nfsd_net_id); 707 708 mutex_lock(&nfsd_mutex); 709 if (nn->nfsd_serv == NULL) { 710 mutex_unlock(&nfsd_mutex); 711 return -ENODEV; 712 } 713 /* bump up the psudo refcount while traversing */ 714 svc_get(nn->nfsd_serv); 715 ret = svc_pool_stats_open(nn->nfsd_serv, file); 716 mutex_unlock(&nfsd_mutex); 717 return ret; 718 } 719 720 int nfsd_pool_stats_release(struct inode *inode, struct file *file) 721 { 722 int ret = seq_release(inode, file); 723 struct net *net = inode->i_sb->s_fs_info; 724 725 mutex_lock(&nfsd_mutex); 726 /* this function really, really should have been called svc_put() */ 727 nfsd_destroy(net); 728 mutex_unlock(&nfsd_mutex); 729 return ret; 730 } 731