1 /* client.c: NFS client sharing and management code 2 * 3 * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells (dhowells@redhat.com) 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 */ 11 12 13 #include <linux/module.h> 14 #include <linux/init.h> 15 #include <linux/sched.h> 16 #include <linux/time.h> 17 #include <linux/kernel.h> 18 #include <linux/mm.h> 19 #include <linux/string.h> 20 #include <linux/stat.h> 21 #include <linux/errno.h> 22 #include <linux/unistd.h> 23 #include <linux/sunrpc/addr.h> 24 #include <linux/sunrpc/clnt.h> 25 #include <linux/sunrpc/stats.h> 26 #include <linux/sunrpc/metrics.h> 27 #include <linux/sunrpc/xprtsock.h> 28 #include <linux/sunrpc/xprtrdma.h> 29 #include <linux/nfs_fs.h> 30 #include <linux/nfs_mount.h> 31 #include <linux/nfs4_mount.h> 32 #include <linux/lockd/bind.h> 33 #include <linux/seq_file.h> 34 #include <linux/mount.h> 35 #include <linux/vfs.h> 36 #include <linux/inet.h> 37 #include <linux/in6.h> 38 #include <linux/slab.h> 39 #include <linux/idr.h> 40 #include <net/ipv6.h> 41 #include <linux/nfs_xdr.h> 42 #include <linux/sunrpc/bc_xprt.h> 43 #include <linux/nsproxy.h> 44 #include <linux/pid_namespace.h> 45 46 47 #include "nfs4_fs.h" 48 #include "callback.h" 49 #include "delegation.h" 50 #include "iostat.h" 51 #include "internal.h" 52 #include "fscache.h" 53 #include "pnfs.h" 54 #include "nfs.h" 55 #include "netns.h" 56 57 #define NFSDBG_FACILITY NFSDBG_CLIENT 58 59 static DECLARE_WAIT_QUEUE_HEAD(nfs_client_active_wq); 60 static DEFINE_SPINLOCK(nfs_version_lock); 61 static DEFINE_MUTEX(nfs_version_mutex); 62 static LIST_HEAD(nfs_versions); 63 64 /* 65 * RPC cruft for NFS 66 */ 67 static const struct rpc_version *nfs_version[5] = { 68 [2] = NULL, 69 [3] = NULL, 70 [4] = NULL, 71 }; 72 73 const struct rpc_program nfs_program = { 74 .name = "nfs", 75 .number = NFS_PROGRAM, 76 .nrvers = ARRAY_SIZE(nfs_version), 77 .version = nfs_version, 78 .stats = &nfs_rpcstat, 79 .pipe_dir_name = NFS_PIPE_DIRNAME, 80 }; 81 82 struct rpc_stat nfs_rpcstat = { 83 .program = &nfs_program 84 }; 85 86 static struct nfs_subversion *find_nfs_version(unsigned int version) 87 { 88 struct nfs_subversion *nfs; 89 spin_lock(&nfs_version_lock); 90 91 list_for_each_entry(nfs, &nfs_versions, list) { 92 if (nfs->rpc_ops->version == version) { 93 spin_unlock(&nfs_version_lock); 94 return nfs; 95 } 96 } 97 98 spin_unlock(&nfs_version_lock); 99 return ERR_PTR(-EPROTONOSUPPORT); 100 } 101 102 struct nfs_subversion *get_nfs_version(unsigned int version) 103 { 104 struct nfs_subversion *nfs = find_nfs_version(version); 105 106 if (IS_ERR(nfs)) { 107 mutex_lock(&nfs_version_mutex); 108 request_module("nfsv%d", version); 109 nfs = find_nfs_version(version); 110 mutex_unlock(&nfs_version_mutex); 111 } 112 113 if (!IS_ERR(nfs) && !try_module_get(nfs->owner)) 114 return ERR_PTR(-EAGAIN); 115 return nfs; 116 } 117 118 void put_nfs_version(struct nfs_subversion *nfs) 119 { 120 module_put(nfs->owner); 121 } 122 123 void register_nfs_version(struct nfs_subversion *nfs) 124 { 125 spin_lock(&nfs_version_lock); 126 127 list_add(&nfs->list, &nfs_versions); 128 nfs_version[nfs->rpc_ops->version] = nfs->rpc_vers; 129 130 spin_unlock(&nfs_version_lock); 131 } 132 EXPORT_SYMBOL_GPL(register_nfs_version); 133 134 void unregister_nfs_version(struct nfs_subversion *nfs) 135 { 136 spin_lock(&nfs_version_lock); 137 138 nfs_version[nfs->rpc_ops->version] = NULL; 139 list_del(&nfs->list); 140 141 spin_unlock(&nfs_version_lock); 142 } 143 EXPORT_SYMBOL_GPL(unregister_nfs_version); 144 145 /* 146 * Allocate a shared client record 147 * 148 * Since these are allocated/deallocated very rarely, we don't 149 * bother putting them in a slab cache... 150 */ 151 struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init) 152 { 153 struct nfs_client *clp; 154 struct rpc_cred *cred; 155 int err = -ENOMEM; 156 157 if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL) 158 goto error_0; 159 160 clp->cl_nfs_mod = cl_init->nfs_mod; 161 if (!try_module_get(clp->cl_nfs_mod->owner)) 162 goto error_dealloc; 163 164 clp->rpc_ops = clp->cl_nfs_mod->rpc_ops; 165 166 atomic_set(&clp->cl_count, 1); 167 clp->cl_cons_state = NFS_CS_INITING; 168 169 memcpy(&clp->cl_addr, cl_init->addr, cl_init->addrlen); 170 clp->cl_addrlen = cl_init->addrlen; 171 172 if (cl_init->hostname) { 173 err = -ENOMEM; 174 clp->cl_hostname = kstrdup(cl_init->hostname, GFP_KERNEL); 175 if (!clp->cl_hostname) 176 goto error_cleanup; 177 } 178 179 INIT_LIST_HEAD(&clp->cl_superblocks); 180 clp->cl_rpcclient = ERR_PTR(-EINVAL); 181 182 clp->cl_proto = cl_init->proto; 183 clp->cl_net = get_net(cl_init->net); 184 185 cred = rpc_lookup_machine_cred("*"); 186 if (!IS_ERR(cred)) 187 clp->cl_machine_cred = cred; 188 nfs_fscache_get_client_cookie(clp); 189 190 return clp; 191 192 error_cleanup: 193 put_nfs_version(clp->cl_nfs_mod); 194 error_dealloc: 195 kfree(clp); 196 error_0: 197 return ERR_PTR(err); 198 } 199 EXPORT_SYMBOL_GPL(nfs_alloc_client); 200 201 #if IS_ENABLED(CONFIG_NFS_V4) 202 void nfs_cleanup_cb_ident_idr(struct net *net) 203 { 204 struct nfs_net *nn = net_generic(net, nfs_net_id); 205 206 idr_destroy(&nn->cb_ident_idr); 207 } 208 209 /* nfs_client_lock held */ 210 static void nfs_cb_idr_remove_locked(struct nfs_client *clp) 211 { 212 struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id); 213 214 if (clp->cl_cb_ident) 215 idr_remove(&nn->cb_ident_idr, clp->cl_cb_ident); 216 } 217 218 static void pnfs_init_server(struct nfs_server *server) 219 { 220 rpc_init_wait_queue(&server->roc_rpcwaitq, "pNFS ROC"); 221 } 222 223 #else 224 void nfs_cleanup_cb_ident_idr(struct net *net) 225 { 226 } 227 228 static void nfs_cb_idr_remove_locked(struct nfs_client *clp) 229 { 230 } 231 232 static void pnfs_init_server(struct nfs_server *server) 233 { 234 } 235 236 #endif /* CONFIG_NFS_V4 */ 237 238 /* 239 * Destroy a shared client record 240 */ 241 void nfs_free_client(struct nfs_client *clp) 242 { 243 dprintk("--> nfs_free_client(%u)\n", clp->rpc_ops->version); 244 245 nfs_fscache_release_client_cookie(clp); 246 247 /* -EIO all pending I/O */ 248 if (!IS_ERR(clp->cl_rpcclient)) 249 rpc_shutdown_client(clp->cl_rpcclient); 250 251 if (clp->cl_machine_cred != NULL) 252 put_rpccred(clp->cl_machine_cred); 253 254 put_net(clp->cl_net); 255 put_nfs_version(clp->cl_nfs_mod); 256 kfree(clp->cl_hostname); 257 kfree(clp->cl_acceptor); 258 kfree(clp); 259 260 dprintk("<-- nfs_free_client()\n"); 261 } 262 EXPORT_SYMBOL_GPL(nfs_free_client); 263 264 /* 265 * Release a reference to a shared client record 266 */ 267 void nfs_put_client(struct nfs_client *clp) 268 { 269 struct nfs_net *nn; 270 271 if (!clp) 272 return; 273 274 dprintk("--> nfs_put_client({%d})\n", atomic_read(&clp->cl_count)); 275 nn = net_generic(clp->cl_net, nfs_net_id); 276 277 if (atomic_dec_and_lock(&clp->cl_count, &nn->nfs_client_lock)) { 278 list_del(&clp->cl_share_link); 279 nfs_cb_idr_remove_locked(clp); 280 spin_unlock(&nn->nfs_client_lock); 281 282 WARN_ON_ONCE(!list_empty(&clp->cl_superblocks)); 283 284 clp->rpc_ops->free_client(clp); 285 } 286 } 287 EXPORT_SYMBOL_GPL(nfs_put_client); 288 289 /* 290 * Find an nfs_client on the list that matches the initialisation data 291 * that is supplied. 292 */ 293 static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *data) 294 { 295 struct nfs_client *clp; 296 const struct sockaddr *sap = data->addr; 297 struct nfs_net *nn = net_generic(data->net, nfs_net_id); 298 299 list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) { 300 const struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr; 301 /* Don't match clients that failed to initialise properly */ 302 if (clp->cl_cons_state < 0) 303 continue; 304 305 /* Different NFS versions cannot share the same nfs_client */ 306 if (clp->rpc_ops != data->nfs_mod->rpc_ops) 307 continue; 308 309 if (clp->cl_proto != data->proto) 310 continue; 311 /* Match nfsv4 minorversion */ 312 if (clp->cl_minorversion != data->minorversion) 313 continue; 314 /* Match the full socket address */ 315 if (!rpc_cmp_addr_port(sap, clap)) 316 continue; 317 318 atomic_inc(&clp->cl_count); 319 return clp; 320 } 321 return NULL; 322 } 323 324 static bool nfs_client_init_is_complete(const struct nfs_client *clp) 325 { 326 return clp->cl_cons_state <= NFS_CS_READY; 327 } 328 329 int nfs_wait_client_init_complete(const struct nfs_client *clp) 330 { 331 return wait_event_killable(nfs_client_active_wq, 332 nfs_client_init_is_complete(clp)); 333 } 334 EXPORT_SYMBOL_GPL(nfs_wait_client_init_complete); 335 336 /* 337 * Found an existing client. Make sure it's ready before returning. 338 */ 339 static struct nfs_client * 340 nfs_found_client(const struct nfs_client_initdata *cl_init, 341 struct nfs_client *clp) 342 { 343 int error; 344 345 error = nfs_wait_client_init_complete(clp); 346 if (error < 0) { 347 nfs_put_client(clp); 348 return ERR_PTR(-ERESTARTSYS); 349 } 350 351 if (clp->cl_cons_state < NFS_CS_READY) { 352 error = clp->cl_cons_state; 353 nfs_put_client(clp); 354 return ERR_PTR(error); 355 } 356 357 smp_rmb(); 358 359 dprintk("<-- %s found nfs_client %p for %s\n", 360 __func__, clp, cl_init->hostname ?: ""); 361 return clp; 362 } 363 364 /* 365 * Look up a client by IP address and protocol version 366 * - creates a new record if one doesn't yet exist 367 */ 368 struct nfs_client * 369 nfs_get_client(const struct nfs_client_initdata *cl_init, 370 const struct rpc_timeout *timeparms, 371 const char *ip_addr, 372 rpc_authflavor_t authflavour) 373 { 374 struct nfs_client *clp, *new = NULL; 375 struct nfs_net *nn = net_generic(cl_init->net, nfs_net_id); 376 const struct nfs_rpc_ops *rpc_ops = cl_init->nfs_mod->rpc_ops; 377 378 if (cl_init->hostname == NULL) { 379 WARN_ON(1); 380 return NULL; 381 } 382 383 dprintk("--> nfs_get_client(%s,v%u)\n", 384 cl_init->hostname, rpc_ops->version); 385 386 /* see if the client already exists */ 387 do { 388 spin_lock(&nn->nfs_client_lock); 389 390 clp = nfs_match_client(cl_init); 391 if (clp) { 392 spin_unlock(&nn->nfs_client_lock); 393 if (new) 394 new->rpc_ops->free_client(new); 395 return nfs_found_client(cl_init, clp); 396 } 397 if (new) { 398 list_add_tail(&new->cl_share_link, 399 &nn->nfs_client_list); 400 spin_unlock(&nn->nfs_client_lock); 401 new->cl_flags = cl_init->init_flags; 402 return rpc_ops->init_client(new, timeparms, ip_addr); 403 } 404 405 spin_unlock(&nn->nfs_client_lock); 406 407 new = rpc_ops->alloc_client(cl_init); 408 } while (!IS_ERR(new)); 409 410 dprintk("<-- nfs_get_client() Failed to find %s (%ld)\n", 411 cl_init->hostname, PTR_ERR(new)); 412 return new; 413 } 414 EXPORT_SYMBOL_GPL(nfs_get_client); 415 416 /* 417 * Mark a server as ready or failed 418 */ 419 void nfs_mark_client_ready(struct nfs_client *clp, int state) 420 { 421 smp_wmb(); 422 clp->cl_cons_state = state; 423 wake_up_all(&nfs_client_active_wq); 424 } 425 EXPORT_SYMBOL_GPL(nfs_mark_client_ready); 426 427 /* 428 * Initialise the timeout values for a connection 429 */ 430 void nfs_init_timeout_values(struct rpc_timeout *to, int proto, 431 unsigned int timeo, unsigned int retrans) 432 { 433 to->to_initval = timeo * HZ / 10; 434 to->to_retries = retrans; 435 436 switch (proto) { 437 case XPRT_TRANSPORT_TCP: 438 case XPRT_TRANSPORT_RDMA: 439 if (to->to_retries == 0) 440 to->to_retries = NFS_DEF_TCP_RETRANS; 441 if (to->to_initval == 0) 442 to->to_initval = NFS_DEF_TCP_TIMEO * HZ / 10; 443 if (to->to_initval > NFS_MAX_TCP_TIMEOUT) 444 to->to_initval = NFS_MAX_TCP_TIMEOUT; 445 to->to_increment = to->to_initval; 446 to->to_maxval = to->to_initval + (to->to_increment * to->to_retries); 447 if (to->to_maxval > NFS_MAX_TCP_TIMEOUT) 448 to->to_maxval = NFS_MAX_TCP_TIMEOUT; 449 if (to->to_maxval < to->to_initval) 450 to->to_maxval = to->to_initval; 451 to->to_exponential = 0; 452 break; 453 case XPRT_TRANSPORT_UDP: 454 if (to->to_retries == 0) 455 to->to_retries = NFS_DEF_UDP_RETRANS; 456 if (!to->to_initval) 457 to->to_initval = NFS_DEF_UDP_TIMEO * HZ / 10; 458 if (to->to_initval > NFS_MAX_UDP_TIMEOUT) 459 to->to_initval = NFS_MAX_UDP_TIMEOUT; 460 to->to_maxval = NFS_MAX_UDP_TIMEOUT; 461 to->to_exponential = 1; 462 break; 463 default: 464 BUG(); 465 } 466 } 467 EXPORT_SYMBOL_GPL(nfs_init_timeout_values); 468 469 /* 470 * Create an RPC client handle 471 */ 472 int nfs_create_rpc_client(struct nfs_client *clp, 473 const struct rpc_timeout *timeparms, 474 rpc_authflavor_t flavor) 475 { 476 struct rpc_clnt *clnt = NULL; 477 struct rpc_create_args args = { 478 .net = clp->cl_net, 479 .protocol = clp->cl_proto, 480 .address = (struct sockaddr *)&clp->cl_addr, 481 .addrsize = clp->cl_addrlen, 482 .timeout = timeparms, 483 .servername = clp->cl_hostname, 484 .program = &nfs_program, 485 .version = clp->rpc_ops->version, 486 .authflavor = flavor, 487 }; 488 489 if (test_bit(NFS_CS_DISCRTRY, &clp->cl_flags)) 490 args.flags |= RPC_CLNT_CREATE_DISCRTRY; 491 if (test_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags)) 492 args.flags |= RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT; 493 if (test_bit(NFS_CS_NORESVPORT, &clp->cl_flags)) 494 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT; 495 if (test_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags)) 496 args.flags |= RPC_CLNT_CREATE_INFINITE_SLOTS; 497 498 if (!IS_ERR(clp->cl_rpcclient)) 499 return 0; 500 501 clnt = rpc_create(&args); 502 if (IS_ERR(clnt)) { 503 dprintk("%s: cannot create RPC client. Error = %ld\n", 504 __func__, PTR_ERR(clnt)); 505 return PTR_ERR(clnt); 506 } 507 508 clp->cl_rpcclient = clnt; 509 return 0; 510 } 511 EXPORT_SYMBOL_GPL(nfs_create_rpc_client); 512 513 /* 514 * Version 2 or 3 client destruction 515 */ 516 static void nfs_destroy_server(struct nfs_server *server) 517 { 518 if (server->nlm_host) 519 nlmclnt_done(server->nlm_host); 520 } 521 522 /* 523 * Version 2 or 3 lockd setup 524 */ 525 static int nfs_start_lockd(struct nfs_server *server) 526 { 527 struct nlm_host *host; 528 struct nfs_client *clp = server->nfs_client; 529 struct nlmclnt_initdata nlm_init = { 530 .hostname = clp->cl_hostname, 531 .address = (struct sockaddr *)&clp->cl_addr, 532 .addrlen = clp->cl_addrlen, 533 .nfs_version = clp->rpc_ops->version, 534 .noresvport = server->flags & NFS_MOUNT_NORESVPORT ? 535 1 : 0, 536 .net = clp->cl_net, 537 }; 538 539 if (nlm_init.nfs_version > 3) 540 return 0; 541 if ((server->flags & NFS_MOUNT_LOCAL_FLOCK) && 542 (server->flags & NFS_MOUNT_LOCAL_FCNTL)) 543 return 0; 544 545 switch (clp->cl_proto) { 546 default: 547 nlm_init.protocol = IPPROTO_TCP; 548 break; 549 case XPRT_TRANSPORT_UDP: 550 nlm_init.protocol = IPPROTO_UDP; 551 } 552 553 host = nlmclnt_init(&nlm_init); 554 if (IS_ERR(host)) 555 return PTR_ERR(host); 556 557 server->nlm_host = host; 558 server->destroy = nfs_destroy_server; 559 return 0; 560 } 561 562 /* 563 * Create a general RPC client 564 */ 565 int nfs_init_server_rpcclient(struct nfs_server *server, 566 const struct rpc_timeout *timeo, 567 rpc_authflavor_t pseudoflavour) 568 { 569 struct nfs_client *clp = server->nfs_client; 570 571 server->client = rpc_clone_client_set_auth(clp->cl_rpcclient, 572 pseudoflavour); 573 if (IS_ERR(server->client)) { 574 dprintk("%s: couldn't create rpc_client!\n", __func__); 575 return PTR_ERR(server->client); 576 } 577 578 memcpy(&server->client->cl_timeout_default, 579 timeo, 580 sizeof(server->client->cl_timeout_default)); 581 server->client->cl_timeout = &server->client->cl_timeout_default; 582 server->client->cl_softrtry = 0; 583 if (server->flags & NFS_MOUNT_SOFT) 584 server->client->cl_softrtry = 1; 585 586 return 0; 587 } 588 EXPORT_SYMBOL_GPL(nfs_init_server_rpcclient); 589 590 /** 591 * nfs_init_client - Initialise an NFS2 or NFS3 client 592 * 593 * @clp: nfs_client to initialise 594 * @timeparms: timeout parameters for underlying RPC transport 595 * @ip_addr: IP presentation address (not used) 596 * 597 * Returns pointer to an NFS client, or an ERR_PTR value. 598 */ 599 struct nfs_client *nfs_init_client(struct nfs_client *clp, 600 const struct rpc_timeout *timeparms, 601 const char *ip_addr) 602 { 603 int error; 604 605 if (clp->cl_cons_state == NFS_CS_READY) { 606 /* the client is already initialised */ 607 dprintk("<-- nfs_init_client() = 0 [already %p]\n", clp); 608 return clp; 609 } 610 611 /* 612 * Create a client RPC handle for doing FSSTAT with UNIX auth only 613 * - RFC 2623, sec 2.3.2 614 */ 615 error = nfs_create_rpc_client(clp, timeparms, RPC_AUTH_UNIX); 616 if (error < 0) 617 goto error; 618 nfs_mark_client_ready(clp, NFS_CS_READY); 619 return clp; 620 621 error: 622 nfs_mark_client_ready(clp, error); 623 nfs_put_client(clp); 624 dprintk("<-- nfs_init_client() = xerror %d\n", error); 625 return ERR_PTR(error); 626 } 627 EXPORT_SYMBOL_GPL(nfs_init_client); 628 629 /* 630 * Create a version 2 or 3 client 631 */ 632 static int nfs_init_server(struct nfs_server *server, 633 const struct nfs_parsed_mount_data *data, 634 struct nfs_subversion *nfs_mod) 635 { 636 struct nfs_client_initdata cl_init = { 637 .hostname = data->nfs_server.hostname, 638 .addr = (const struct sockaddr *)&data->nfs_server.address, 639 .addrlen = data->nfs_server.addrlen, 640 .nfs_mod = nfs_mod, 641 .proto = data->nfs_server.protocol, 642 .net = data->net, 643 }; 644 struct rpc_timeout timeparms; 645 struct nfs_client *clp; 646 int error; 647 648 dprintk("--> nfs_init_server()\n"); 649 650 nfs_init_timeout_values(&timeparms, data->nfs_server.protocol, 651 data->timeo, data->retrans); 652 if (data->flags & NFS_MOUNT_NORESVPORT) 653 set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags); 654 655 /* Allocate or find a client reference we can use */ 656 clp = nfs_get_client(&cl_init, &timeparms, NULL, RPC_AUTH_UNIX); 657 if (IS_ERR(clp)) { 658 dprintk("<-- nfs_init_server() = error %ld\n", PTR_ERR(clp)); 659 return PTR_ERR(clp); 660 } 661 662 server->nfs_client = clp; 663 664 /* Initialise the client representation from the mount data */ 665 server->flags = data->flags; 666 server->options = data->options; 667 server->caps |= NFS_CAP_HARDLINKS|NFS_CAP_SYMLINKS|NFS_CAP_FILEID| 668 NFS_CAP_MODE|NFS_CAP_NLINK|NFS_CAP_OWNER|NFS_CAP_OWNER_GROUP| 669 NFS_CAP_ATIME|NFS_CAP_CTIME|NFS_CAP_MTIME; 670 671 if (data->rsize) 672 server->rsize = nfs_block_size(data->rsize, NULL); 673 if (data->wsize) 674 server->wsize = nfs_block_size(data->wsize, NULL); 675 676 server->acregmin = data->acregmin * HZ; 677 server->acregmax = data->acregmax * HZ; 678 server->acdirmin = data->acdirmin * HZ; 679 server->acdirmax = data->acdirmax * HZ; 680 681 /* Start lockd here, before we might error out */ 682 error = nfs_start_lockd(server); 683 if (error < 0) 684 goto error; 685 686 server->port = data->nfs_server.port; 687 server->auth_info = data->auth_info; 688 689 error = nfs_init_server_rpcclient(server, &timeparms, 690 data->selected_flavor); 691 if (error < 0) 692 goto error; 693 694 /* Preserve the values of mount_server-related mount options */ 695 if (data->mount_server.addrlen) { 696 memcpy(&server->mountd_address, &data->mount_server.address, 697 data->mount_server.addrlen); 698 server->mountd_addrlen = data->mount_server.addrlen; 699 } 700 server->mountd_version = data->mount_server.version; 701 server->mountd_port = data->mount_server.port; 702 server->mountd_protocol = data->mount_server.protocol; 703 704 server->namelen = data->namlen; 705 dprintk("<-- nfs_init_server() = 0 [new %p]\n", clp); 706 return 0; 707 708 error: 709 server->nfs_client = NULL; 710 nfs_put_client(clp); 711 dprintk("<-- nfs_init_server() = xerror %d\n", error); 712 return error; 713 } 714 715 /* 716 * Load up the server record from information gained in an fsinfo record 717 */ 718 static void nfs_server_set_fsinfo(struct nfs_server *server, 719 struct nfs_fsinfo *fsinfo) 720 { 721 unsigned long max_rpc_payload; 722 723 /* Work out a lot of parameters */ 724 if (server->rsize == 0) 725 server->rsize = nfs_block_size(fsinfo->rtpref, NULL); 726 if (server->wsize == 0) 727 server->wsize = nfs_block_size(fsinfo->wtpref, NULL); 728 729 if (fsinfo->rtmax >= 512 && server->rsize > fsinfo->rtmax) 730 server->rsize = nfs_block_size(fsinfo->rtmax, NULL); 731 if (fsinfo->wtmax >= 512 && server->wsize > fsinfo->wtmax) 732 server->wsize = nfs_block_size(fsinfo->wtmax, NULL); 733 734 max_rpc_payload = nfs_block_size(rpc_max_payload(server->client), NULL); 735 if (server->rsize > max_rpc_payload) 736 server->rsize = max_rpc_payload; 737 if (server->rsize > NFS_MAX_FILE_IO_SIZE) 738 server->rsize = NFS_MAX_FILE_IO_SIZE; 739 server->rpages = (server->rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; 740 741 server->backing_dev_info.name = "nfs"; 742 server->backing_dev_info.ra_pages = server->rpages * NFS_MAX_READAHEAD; 743 744 if (server->wsize > max_rpc_payload) 745 server->wsize = max_rpc_payload; 746 if (server->wsize > NFS_MAX_FILE_IO_SIZE) 747 server->wsize = NFS_MAX_FILE_IO_SIZE; 748 server->wpages = (server->wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; 749 750 server->wtmult = nfs_block_bits(fsinfo->wtmult, NULL); 751 752 server->dtsize = nfs_block_size(fsinfo->dtpref, NULL); 753 if (server->dtsize > PAGE_CACHE_SIZE * NFS_MAX_READDIR_PAGES) 754 server->dtsize = PAGE_CACHE_SIZE * NFS_MAX_READDIR_PAGES; 755 if (server->dtsize > server->rsize) 756 server->dtsize = server->rsize; 757 758 if (server->flags & NFS_MOUNT_NOAC) { 759 server->acregmin = server->acregmax = 0; 760 server->acdirmin = server->acdirmax = 0; 761 } 762 763 server->maxfilesize = fsinfo->maxfilesize; 764 765 server->time_delta = fsinfo->time_delta; 766 767 server->clone_blksize = fsinfo->clone_blksize; 768 /* We're airborne Set socket buffersize */ 769 rpc_setbufsize(server->client, server->wsize + 100, server->rsize + 100); 770 } 771 772 /* 773 * Probe filesystem information, including the FSID on v2/v3 774 */ 775 int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *mntfh, struct nfs_fattr *fattr) 776 { 777 struct nfs_fsinfo fsinfo; 778 struct nfs_client *clp = server->nfs_client; 779 int error; 780 781 dprintk("--> nfs_probe_fsinfo()\n"); 782 783 if (clp->rpc_ops->set_capabilities != NULL) { 784 error = clp->rpc_ops->set_capabilities(server, mntfh); 785 if (error < 0) 786 goto out_error; 787 } 788 789 fsinfo.fattr = fattr; 790 fsinfo.layouttype = 0; 791 error = clp->rpc_ops->fsinfo(server, mntfh, &fsinfo); 792 if (error < 0) 793 goto out_error; 794 795 nfs_server_set_fsinfo(server, &fsinfo); 796 797 /* Get some general file system info */ 798 if (server->namelen == 0) { 799 struct nfs_pathconf pathinfo; 800 801 pathinfo.fattr = fattr; 802 nfs_fattr_init(fattr); 803 804 if (clp->rpc_ops->pathconf(server, mntfh, &pathinfo) >= 0) 805 server->namelen = pathinfo.max_namelen; 806 } 807 808 dprintk("<-- nfs_probe_fsinfo() = 0\n"); 809 return 0; 810 811 out_error: 812 dprintk("nfs_probe_fsinfo: error = %d\n", -error); 813 return error; 814 } 815 EXPORT_SYMBOL_GPL(nfs_probe_fsinfo); 816 817 /* 818 * Copy useful information when duplicating a server record 819 */ 820 void nfs_server_copy_userdata(struct nfs_server *target, struct nfs_server *source) 821 { 822 target->flags = source->flags; 823 target->rsize = source->rsize; 824 target->wsize = source->wsize; 825 target->acregmin = source->acregmin; 826 target->acregmax = source->acregmax; 827 target->acdirmin = source->acdirmin; 828 target->acdirmax = source->acdirmax; 829 target->caps = source->caps; 830 target->options = source->options; 831 target->auth_info = source->auth_info; 832 } 833 EXPORT_SYMBOL_GPL(nfs_server_copy_userdata); 834 835 void nfs_server_insert_lists(struct nfs_server *server) 836 { 837 struct nfs_client *clp = server->nfs_client; 838 struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id); 839 840 spin_lock(&nn->nfs_client_lock); 841 list_add_tail_rcu(&server->client_link, &clp->cl_superblocks); 842 list_add_tail(&server->master_link, &nn->nfs_volume_list); 843 clear_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state); 844 spin_unlock(&nn->nfs_client_lock); 845 846 } 847 EXPORT_SYMBOL_GPL(nfs_server_insert_lists); 848 849 void nfs_server_remove_lists(struct nfs_server *server) 850 { 851 struct nfs_client *clp = server->nfs_client; 852 struct nfs_net *nn; 853 854 if (clp == NULL) 855 return; 856 nn = net_generic(clp->cl_net, nfs_net_id); 857 spin_lock(&nn->nfs_client_lock); 858 list_del_rcu(&server->client_link); 859 if (list_empty(&clp->cl_superblocks)) 860 set_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state); 861 list_del(&server->master_link); 862 spin_unlock(&nn->nfs_client_lock); 863 864 synchronize_rcu(); 865 } 866 EXPORT_SYMBOL_GPL(nfs_server_remove_lists); 867 868 /* 869 * Allocate and initialise a server record 870 */ 871 struct nfs_server *nfs_alloc_server(void) 872 { 873 struct nfs_server *server; 874 875 server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL); 876 if (!server) 877 return NULL; 878 879 server->client = server->client_acl = ERR_PTR(-EINVAL); 880 881 /* Zero out the NFS state stuff */ 882 INIT_LIST_HEAD(&server->client_link); 883 INIT_LIST_HEAD(&server->master_link); 884 INIT_LIST_HEAD(&server->delegations); 885 INIT_LIST_HEAD(&server->layouts); 886 INIT_LIST_HEAD(&server->state_owners_lru); 887 888 atomic_set(&server->active, 0); 889 890 server->io_stats = nfs_alloc_iostats(); 891 if (!server->io_stats) { 892 kfree(server); 893 return NULL; 894 } 895 896 if (bdi_init(&server->backing_dev_info)) { 897 nfs_free_iostats(server->io_stats); 898 kfree(server); 899 return NULL; 900 } 901 902 ida_init(&server->openowner_id); 903 ida_init(&server->lockowner_id); 904 pnfs_init_server(server); 905 906 return server; 907 } 908 EXPORT_SYMBOL_GPL(nfs_alloc_server); 909 910 /* 911 * Free up a server record 912 */ 913 void nfs_free_server(struct nfs_server *server) 914 { 915 dprintk("--> nfs_free_server()\n"); 916 917 nfs_server_remove_lists(server); 918 919 if (server->destroy != NULL) 920 server->destroy(server); 921 922 if (!IS_ERR(server->client_acl)) 923 rpc_shutdown_client(server->client_acl); 924 if (!IS_ERR(server->client)) 925 rpc_shutdown_client(server->client); 926 927 nfs_put_client(server->nfs_client); 928 929 ida_destroy(&server->lockowner_id); 930 ida_destroy(&server->openowner_id); 931 nfs_free_iostats(server->io_stats); 932 bdi_destroy(&server->backing_dev_info); 933 kfree(server); 934 nfs_release_automount_timer(); 935 dprintk("<-- nfs_free_server()\n"); 936 } 937 EXPORT_SYMBOL_GPL(nfs_free_server); 938 939 /* 940 * Create a version 2 or 3 volume record 941 * - keyed on server and FSID 942 */ 943 struct nfs_server *nfs_create_server(struct nfs_mount_info *mount_info, 944 struct nfs_subversion *nfs_mod) 945 { 946 struct nfs_server *server; 947 struct nfs_fattr *fattr; 948 int error; 949 950 server = nfs_alloc_server(); 951 if (!server) 952 return ERR_PTR(-ENOMEM); 953 954 error = -ENOMEM; 955 fattr = nfs_alloc_fattr(); 956 if (fattr == NULL) 957 goto error; 958 959 /* Get a client representation */ 960 error = nfs_init_server(server, mount_info->parsed, nfs_mod); 961 if (error < 0) 962 goto error; 963 964 /* Probe the root fh to retrieve its FSID */ 965 error = nfs_probe_fsinfo(server, mount_info->mntfh, fattr); 966 if (error < 0) 967 goto error; 968 if (server->nfs_client->rpc_ops->version == 3) { 969 if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN) 970 server->namelen = NFS3_MAXNAMLEN; 971 if (!(mount_info->parsed->flags & NFS_MOUNT_NORDIRPLUS)) 972 server->caps |= NFS_CAP_READDIRPLUS; 973 } else { 974 if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN) 975 server->namelen = NFS2_MAXNAMLEN; 976 } 977 978 if (!(fattr->valid & NFS_ATTR_FATTR)) { 979 error = nfs_mod->rpc_ops->getattr(server, mount_info->mntfh, fattr, NULL); 980 if (error < 0) { 981 dprintk("nfs_create_server: getattr error = %d\n", -error); 982 goto error; 983 } 984 } 985 memcpy(&server->fsid, &fattr->fsid, sizeof(server->fsid)); 986 987 dprintk("Server FSID: %llx:%llx\n", 988 (unsigned long long) server->fsid.major, 989 (unsigned long long) server->fsid.minor); 990 991 nfs_server_insert_lists(server); 992 server->mount_time = jiffies; 993 nfs_free_fattr(fattr); 994 return server; 995 996 error: 997 nfs_free_fattr(fattr); 998 nfs_free_server(server); 999 return ERR_PTR(error); 1000 } 1001 EXPORT_SYMBOL_GPL(nfs_create_server); 1002 1003 /* 1004 * Clone an NFS2, NFS3 or NFS4 server record 1005 */ 1006 struct nfs_server *nfs_clone_server(struct nfs_server *source, 1007 struct nfs_fh *fh, 1008 struct nfs_fattr *fattr, 1009 rpc_authflavor_t flavor) 1010 { 1011 struct nfs_server *server; 1012 struct nfs_fattr *fattr_fsinfo; 1013 int error; 1014 1015 dprintk("--> nfs_clone_server(,%llx:%llx,)\n", 1016 (unsigned long long) fattr->fsid.major, 1017 (unsigned long long) fattr->fsid.minor); 1018 1019 server = nfs_alloc_server(); 1020 if (!server) 1021 return ERR_PTR(-ENOMEM); 1022 1023 error = -ENOMEM; 1024 fattr_fsinfo = nfs_alloc_fattr(); 1025 if (fattr_fsinfo == NULL) 1026 goto out_free_server; 1027 1028 /* Copy data from the source */ 1029 server->nfs_client = source->nfs_client; 1030 server->destroy = source->destroy; 1031 atomic_inc(&server->nfs_client->cl_count); 1032 nfs_server_copy_userdata(server, source); 1033 1034 server->fsid = fattr->fsid; 1035 1036 error = nfs_init_server_rpcclient(server, 1037 source->client->cl_timeout, 1038 flavor); 1039 if (error < 0) 1040 goto out_free_server; 1041 1042 /* probe the filesystem info for this server filesystem */ 1043 error = nfs_probe_fsinfo(server, fh, fattr_fsinfo); 1044 if (error < 0) 1045 goto out_free_server; 1046 1047 if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN) 1048 server->namelen = NFS4_MAXNAMLEN; 1049 1050 dprintk("Cloned FSID: %llx:%llx\n", 1051 (unsigned long long) server->fsid.major, 1052 (unsigned long long) server->fsid.minor); 1053 1054 error = nfs_start_lockd(server); 1055 if (error < 0) 1056 goto out_free_server; 1057 1058 nfs_server_insert_lists(server); 1059 server->mount_time = jiffies; 1060 1061 nfs_free_fattr(fattr_fsinfo); 1062 dprintk("<-- nfs_clone_server() = %p\n", server); 1063 return server; 1064 1065 out_free_server: 1066 nfs_free_fattr(fattr_fsinfo); 1067 nfs_free_server(server); 1068 dprintk("<-- nfs_clone_server() = error %d\n", error); 1069 return ERR_PTR(error); 1070 } 1071 EXPORT_SYMBOL_GPL(nfs_clone_server); 1072 1073 void nfs_clients_init(struct net *net) 1074 { 1075 struct nfs_net *nn = net_generic(net, nfs_net_id); 1076 1077 INIT_LIST_HEAD(&nn->nfs_client_list); 1078 INIT_LIST_HEAD(&nn->nfs_volume_list); 1079 #if IS_ENABLED(CONFIG_NFS_V4) 1080 idr_init(&nn->cb_ident_idr); 1081 #endif 1082 spin_lock_init(&nn->nfs_client_lock); 1083 nn->boot_time = CURRENT_TIME; 1084 } 1085 1086 #ifdef CONFIG_PROC_FS 1087 static int nfs_server_list_open(struct inode *inode, struct file *file); 1088 static void *nfs_server_list_start(struct seq_file *p, loff_t *pos); 1089 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos); 1090 static void nfs_server_list_stop(struct seq_file *p, void *v); 1091 static int nfs_server_list_show(struct seq_file *m, void *v); 1092 1093 static const struct seq_operations nfs_server_list_ops = { 1094 .start = nfs_server_list_start, 1095 .next = nfs_server_list_next, 1096 .stop = nfs_server_list_stop, 1097 .show = nfs_server_list_show, 1098 }; 1099 1100 static const struct file_operations nfs_server_list_fops = { 1101 .open = nfs_server_list_open, 1102 .read = seq_read, 1103 .llseek = seq_lseek, 1104 .release = seq_release_net, 1105 .owner = THIS_MODULE, 1106 }; 1107 1108 static int nfs_volume_list_open(struct inode *inode, struct file *file); 1109 static void *nfs_volume_list_start(struct seq_file *p, loff_t *pos); 1110 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos); 1111 static void nfs_volume_list_stop(struct seq_file *p, void *v); 1112 static int nfs_volume_list_show(struct seq_file *m, void *v); 1113 1114 static const struct seq_operations nfs_volume_list_ops = { 1115 .start = nfs_volume_list_start, 1116 .next = nfs_volume_list_next, 1117 .stop = nfs_volume_list_stop, 1118 .show = nfs_volume_list_show, 1119 }; 1120 1121 static const struct file_operations nfs_volume_list_fops = { 1122 .open = nfs_volume_list_open, 1123 .read = seq_read, 1124 .llseek = seq_lseek, 1125 .release = seq_release_net, 1126 .owner = THIS_MODULE, 1127 }; 1128 1129 /* 1130 * open "/proc/fs/nfsfs/servers" which provides a summary of servers with which 1131 * we're dealing 1132 */ 1133 static int nfs_server_list_open(struct inode *inode, struct file *file) 1134 { 1135 return seq_open_net(inode, file, &nfs_server_list_ops, 1136 sizeof(struct seq_net_private)); 1137 } 1138 1139 /* 1140 * set up the iterator to start reading from the server list and return the first item 1141 */ 1142 static void *nfs_server_list_start(struct seq_file *m, loff_t *_pos) 1143 __acquires(&nn->nfs_client_lock) 1144 { 1145 struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id); 1146 1147 /* lock the list against modification */ 1148 spin_lock(&nn->nfs_client_lock); 1149 return seq_list_start_head(&nn->nfs_client_list, *_pos); 1150 } 1151 1152 /* 1153 * move to next server 1154 */ 1155 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos) 1156 { 1157 struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id); 1158 1159 return seq_list_next(v, &nn->nfs_client_list, pos); 1160 } 1161 1162 /* 1163 * clean up after reading from the transports list 1164 */ 1165 static void nfs_server_list_stop(struct seq_file *p, void *v) 1166 __releases(&nn->nfs_client_lock) 1167 { 1168 struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id); 1169 1170 spin_unlock(&nn->nfs_client_lock); 1171 } 1172 1173 /* 1174 * display a header line followed by a load of call lines 1175 */ 1176 static int nfs_server_list_show(struct seq_file *m, void *v) 1177 { 1178 struct nfs_client *clp; 1179 struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id); 1180 1181 /* display header on line 1 */ 1182 if (v == &nn->nfs_client_list) { 1183 seq_puts(m, "NV SERVER PORT USE HOSTNAME\n"); 1184 return 0; 1185 } 1186 1187 /* display one transport per line on subsequent lines */ 1188 clp = list_entry(v, struct nfs_client, cl_share_link); 1189 1190 /* Check if the client is initialized */ 1191 if (clp->cl_cons_state != NFS_CS_READY) 1192 return 0; 1193 1194 rcu_read_lock(); 1195 seq_printf(m, "v%u %s %s %3d %s\n", 1196 clp->rpc_ops->version, 1197 rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR), 1198 rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT), 1199 atomic_read(&clp->cl_count), 1200 clp->cl_hostname); 1201 rcu_read_unlock(); 1202 1203 return 0; 1204 } 1205 1206 /* 1207 * open "/proc/fs/nfsfs/volumes" which provides a summary of extant volumes 1208 */ 1209 static int nfs_volume_list_open(struct inode *inode, struct file *file) 1210 { 1211 return seq_open_net(inode, file, &nfs_volume_list_ops, 1212 sizeof(struct seq_net_private)); 1213 } 1214 1215 /* 1216 * set up the iterator to start reading from the volume list and return the first item 1217 */ 1218 static void *nfs_volume_list_start(struct seq_file *m, loff_t *_pos) 1219 __acquires(&nn->nfs_client_lock) 1220 { 1221 struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id); 1222 1223 /* lock the list against modification */ 1224 spin_lock(&nn->nfs_client_lock); 1225 return seq_list_start_head(&nn->nfs_volume_list, *_pos); 1226 } 1227 1228 /* 1229 * move to next volume 1230 */ 1231 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos) 1232 { 1233 struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id); 1234 1235 return seq_list_next(v, &nn->nfs_volume_list, pos); 1236 } 1237 1238 /* 1239 * clean up after reading from the transports list 1240 */ 1241 static void nfs_volume_list_stop(struct seq_file *p, void *v) 1242 __releases(&nn->nfs_client_lock) 1243 { 1244 struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id); 1245 1246 spin_unlock(&nn->nfs_client_lock); 1247 } 1248 1249 /* 1250 * display a header line followed by a load of call lines 1251 */ 1252 static int nfs_volume_list_show(struct seq_file *m, void *v) 1253 { 1254 struct nfs_server *server; 1255 struct nfs_client *clp; 1256 char dev[13]; // 8 for 2^24, 1 for ':', 3 for 2^8, 1 for '\0' 1257 char fsid[34]; // 2 * 16 for %llx, 1 for ':', 1 for '\0' 1258 struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id); 1259 1260 /* display header on line 1 */ 1261 if (v == &nn->nfs_volume_list) { 1262 seq_puts(m, "NV SERVER PORT DEV FSID" 1263 " FSC\n"); 1264 return 0; 1265 } 1266 /* display one transport per line on subsequent lines */ 1267 server = list_entry(v, struct nfs_server, master_link); 1268 clp = server->nfs_client; 1269 1270 snprintf(dev, sizeof(dev), "%u:%u", 1271 MAJOR(server->s_dev), MINOR(server->s_dev)); 1272 1273 snprintf(fsid, sizeof(fsid), "%llx:%llx", 1274 (unsigned long long) server->fsid.major, 1275 (unsigned long long) server->fsid.minor); 1276 1277 rcu_read_lock(); 1278 seq_printf(m, "v%u %s %s %-12s %-33s %s\n", 1279 clp->rpc_ops->version, 1280 rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR), 1281 rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT), 1282 dev, 1283 fsid, 1284 nfs_server_fscache_state(server)); 1285 rcu_read_unlock(); 1286 1287 return 0; 1288 } 1289 1290 int nfs_fs_proc_net_init(struct net *net) 1291 { 1292 struct nfs_net *nn = net_generic(net, nfs_net_id); 1293 struct proc_dir_entry *p; 1294 1295 nn->proc_nfsfs = proc_net_mkdir(net, "nfsfs", net->proc_net); 1296 if (!nn->proc_nfsfs) 1297 goto error_0; 1298 1299 /* a file of servers with which we're dealing */ 1300 p = proc_create("servers", S_IFREG|S_IRUGO, 1301 nn->proc_nfsfs, &nfs_server_list_fops); 1302 if (!p) 1303 goto error_1; 1304 1305 /* a file of volumes that we have mounted */ 1306 p = proc_create("volumes", S_IFREG|S_IRUGO, 1307 nn->proc_nfsfs, &nfs_volume_list_fops); 1308 if (!p) 1309 goto error_1; 1310 return 0; 1311 1312 error_1: 1313 remove_proc_subtree("nfsfs", net->proc_net); 1314 error_0: 1315 return -ENOMEM; 1316 } 1317 1318 void nfs_fs_proc_net_exit(struct net *net) 1319 { 1320 remove_proc_subtree("nfsfs", net->proc_net); 1321 } 1322 1323 /* 1324 * initialise the /proc/fs/nfsfs/ directory 1325 */ 1326 int __init nfs_fs_proc_init(void) 1327 { 1328 if (!proc_mkdir("fs/nfsfs", NULL)) 1329 goto error_0; 1330 1331 /* a file of servers with which we're dealing */ 1332 if (!proc_symlink("fs/nfsfs/servers", NULL, "../../net/nfsfs/servers")) 1333 goto error_1; 1334 1335 /* a file of volumes that we have mounted */ 1336 if (!proc_symlink("fs/nfsfs/volumes", NULL, "../../net/nfsfs/volumes")) 1337 goto error_1; 1338 1339 return 0; 1340 error_1: 1341 remove_proc_subtree("fs/nfsfs", NULL); 1342 error_0: 1343 return -ENOMEM; 1344 } 1345 1346 /* 1347 * clean up the /proc/fs/nfsfs/ directory 1348 */ 1349 void nfs_fs_proc_exit(void) 1350 { 1351 remove_proc_subtree("fs/nfsfs", NULL); 1352 } 1353 1354 #endif /* CONFIG_PROC_FS */ 1355