xref: /linux/fs/nfs/client.c (revision dfab99544c55378c1692c585e5e4df88dc7944c3)
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 	int err = -ENOMEM;
155 
156 	if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL)
157 		goto error_0;
158 
159 	clp->cl_nfs_mod = cl_init->nfs_mod;
160 	if (!try_module_get(clp->cl_nfs_mod->owner))
161 		goto error_dealloc;
162 
163 	clp->rpc_ops = clp->cl_nfs_mod->rpc_ops;
164 
165 	refcount_set(&clp->cl_count, 1);
166 	clp->cl_cons_state = NFS_CS_INITING;
167 
168 	memcpy(&clp->cl_addr, cl_init->addr, cl_init->addrlen);
169 	clp->cl_addrlen = cl_init->addrlen;
170 
171 	if (cl_init->hostname) {
172 		err = -ENOMEM;
173 		clp->cl_hostname = kstrdup(cl_init->hostname, GFP_KERNEL);
174 		if (!clp->cl_hostname)
175 			goto error_cleanup;
176 	}
177 
178 	INIT_LIST_HEAD(&clp->cl_superblocks);
179 	clp->cl_rpcclient = ERR_PTR(-EINVAL);
180 
181 	clp->cl_proto = cl_init->proto;
182 	clp->cl_net = get_net(cl_init->net);
183 
184 	clp->cl_principal = "*";
185 	nfs_fscache_get_client_cookie(clp);
186 
187 	return clp;
188 
189 error_cleanup:
190 	put_nfs_version(clp->cl_nfs_mod);
191 error_dealloc:
192 	kfree(clp);
193 error_0:
194 	return ERR_PTR(err);
195 }
196 EXPORT_SYMBOL_GPL(nfs_alloc_client);
197 
198 #if IS_ENABLED(CONFIG_NFS_V4)
199 void nfs_cleanup_cb_ident_idr(struct net *net)
200 {
201 	struct nfs_net *nn = net_generic(net, nfs_net_id);
202 
203 	idr_destroy(&nn->cb_ident_idr);
204 }
205 
206 /* nfs_client_lock held */
207 static void nfs_cb_idr_remove_locked(struct nfs_client *clp)
208 {
209 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
210 
211 	if (clp->cl_cb_ident)
212 		idr_remove(&nn->cb_ident_idr, clp->cl_cb_ident);
213 }
214 
215 static void pnfs_init_server(struct nfs_server *server)
216 {
217 	rpc_init_wait_queue(&server->roc_rpcwaitq, "pNFS ROC");
218 }
219 
220 #else
221 void nfs_cleanup_cb_ident_idr(struct net *net)
222 {
223 }
224 
225 static void nfs_cb_idr_remove_locked(struct nfs_client *clp)
226 {
227 }
228 
229 static void pnfs_init_server(struct nfs_server *server)
230 {
231 }
232 
233 #endif /* CONFIG_NFS_V4 */
234 
235 /*
236  * Destroy a shared client record
237  */
238 void nfs_free_client(struct nfs_client *clp)
239 {
240 	nfs_fscache_release_client_cookie(clp);
241 
242 	/* -EIO all pending I/O */
243 	if (!IS_ERR(clp->cl_rpcclient))
244 		rpc_shutdown_client(clp->cl_rpcclient);
245 
246 	put_net(clp->cl_net);
247 	put_nfs_version(clp->cl_nfs_mod);
248 	kfree(clp->cl_hostname);
249 	kfree(clp->cl_acceptor);
250 	kfree(clp);
251 }
252 EXPORT_SYMBOL_GPL(nfs_free_client);
253 
254 /*
255  * Release a reference to a shared client record
256  */
257 void nfs_put_client(struct nfs_client *clp)
258 {
259 	struct nfs_net *nn;
260 
261 	if (!clp)
262 		return;
263 
264 	nn = net_generic(clp->cl_net, nfs_net_id);
265 
266 	if (refcount_dec_and_lock(&clp->cl_count, &nn->nfs_client_lock)) {
267 		list_del(&clp->cl_share_link);
268 		nfs_cb_idr_remove_locked(clp);
269 		spin_unlock(&nn->nfs_client_lock);
270 
271 		WARN_ON_ONCE(!list_empty(&clp->cl_superblocks));
272 
273 		clp->rpc_ops->free_client(clp);
274 	}
275 }
276 EXPORT_SYMBOL_GPL(nfs_put_client);
277 
278 /*
279  * Find an nfs_client on the list that matches the initialisation data
280  * that is supplied.
281  */
282 static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *data)
283 {
284 	struct nfs_client *clp;
285 	const struct sockaddr *sap = data->addr;
286 	struct nfs_net *nn = net_generic(data->net, nfs_net_id);
287 	int error;
288 
289 again:
290 	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
291 	        const struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
292 		/* Don't match clients that failed to initialise properly */
293 		if (clp->cl_cons_state < 0)
294 			continue;
295 
296 		/* If a client is still initializing then we need to wait */
297 		if (clp->cl_cons_state > NFS_CS_READY) {
298 			refcount_inc(&clp->cl_count);
299 			spin_unlock(&nn->nfs_client_lock);
300 			error = nfs_wait_client_init_complete(clp);
301 			nfs_put_client(clp);
302 			spin_lock(&nn->nfs_client_lock);
303 			if (error < 0)
304 				return ERR_PTR(error);
305 			goto again;
306 		}
307 
308 		/* Different NFS versions cannot share the same nfs_client */
309 		if (clp->rpc_ops != data->nfs_mod->rpc_ops)
310 			continue;
311 
312 		if (clp->cl_proto != data->proto)
313 			continue;
314 		/* Match nfsv4 minorversion */
315 		if (clp->cl_minorversion != data->minorversion)
316 			continue;
317 		/* Match the full socket address */
318 		if (!rpc_cmp_addr_port(sap, clap))
319 			/* Match all xprt_switch full socket addresses */
320 			if (IS_ERR(clp->cl_rpcclient) ||
321                             !rpc_clnt_xprt_switch_has_addr(clp->cl_rpcclient,
322 							   sap))
323 				continue;
324 
325 		refcount_inc(&clp->cl_count);
326 		return clp;
327 	}
328 	return NULL;
329 }
330 
331 /*
332  * Return true if @clp is done initializing, false if still working on it.
333  *
334  * Use nfs_client_init_status to check if it was successful.
335  */
336 bool nfs_client_init_is_complete(const struct nfs_client *clp)
337 {
338 	return clp->cl_cons_state <= NFS_CS_READY;
339 }
340 EXPORT_SYMBOL_GPL(nfs_client_init_is_complete);
341 
342 /*
343  * Return 0 if @clp was successfully initialized, -errno otherwise.
344  *
345  * This must be called *after* nfs_client_init_is_complete() returns true,
346  * otherwise it will pop WARN_ON_ONCE and return -EINVAL
347  */
348 int nfs_client_init_status(const struct nfs_client *clp)
349 {
350 	/* called without checking nfs_client_init_is_complete */
351 	if (clp->cl_cons_state > NFS_CS_READY) {
352 		WARN_ON_ONCE(1);
353 		return -EINVAL;
354 	}
355 	return clp->cl_cons_state;
356 }
357 EXPORT_SYMBOL_GPL(nfs_client_init_status);
358 
359 int nfs_wait_client_init_complete(const struct nfs_client *clp)
360 {
361 	return wait_event_killable(nfs_client_active_wq,
362 			nfs_client_init_is_complete(clp));
363 }
364 EXPORT_SYMBOL_GPL(nfs_wait_client_init_complete);
365 
366 /*
367  * Found an existing client.  Make sure it's ready before returning.
368  */
369 static struct nfs_client *
370 nfs_found_client(const struct nfs_client_initdata *cl_init,
371 		 struct nfs_client *clp)
372 {
373 	int error;
374 
375 	error = nfs_wait_client_init_complete(clp);
376 	if (error < 0) {
377 		nfs_put_client(clp);
378 		return ERR_PTR(-ERESTARTSYS);
379 	}
380 
381 	if (clp->cl_cons_state < NFS_CS_READY) {
382 		error = clp->cl_cons_state;
383 		nfs_put_client(clp);
384 		return ERR_PTR(error);
385 	}
386 
387 	smp_rmb();
388 	return clp;
389 }
390 
391 /*
392  * Look up a client by IP address and protocol version
393  * - creates a new record if one doesn't yet exist
394  */
395 struct nfs_client *nfs_get_client(const struct nfs_client_initdata *cl_init)
396 {
397 	struct nfs_client *clp, *new = NULL;
398 	struct nfs_net *nn = net_generic(cl_init->net, nfs_net_id);
399 	const struct nfs_rpc_ops *rpc_ops = cl_init->nfs_mod->rpc_ops;
400 
401 	if (cl_init->hostname == NULL) {
402 		WARN_ON(1);
403 		return NULL;
404 	}
405 
406 	/* see if the client already exists */
407 	do {
408 		spin_lock(&nn->nfs_client_lock);
409 
410 		clp = nfs_match_client(cl_init);
411 		if (clp) {
412 			spin_unlock(&nn->nfs_client_lock);
413 			if (IS_ERR(clp))
414 				return clp;
415 			if (new)
416 				new->rpc_ops->free_client(new);
417 			return nfs_found_client(cl_init, clp);
418 		}
419 		if (new) {
420 			list_add_tail(&new->cl_share_link,
421 					&nn->nfs_client_list);
422 			spin_unlock(&nn->nfs_client_lock);
423 			new->cl_flags = cl_init->init_flags;
424 			return rpc_ops->init_client(new, cl_init);
425 		}
426 
427 		spin_unlock(&nn->nfs_client_lock);
428 
429 		new = rpc_ops->alloc_client(cl_init);
430 	} while (!IS_ERR(new));
431 
432 	return new;
433 }
434 EXPORT_SYMBOL_GPL(nfs_get_client);
435 
436 /*
437  * Mark a server as ready or failed
438  */
439 void nfs_mark_client_ready(struct nfs_client *clp, int state)
440 {
441 	smp_wmb();
442 	clp->cl_cons_state = state;
443 	wake_up_all(&nfs_client_active_wq);
444 }
445 EXPORT_SYMBOL_GPL(nfs_mark_client_ready);
446 
447 /*
448  * Initialise the timeout values for a connection
449  */
450 void nfs_init_timeout_values(struct rpc_timeout *to, int proto,
451 				    int timeo, int retrans)
452 {
453 	to->to_initval = timeo * HZ / 10;
454 	to->to_retries = retrans;
455 
456 	switch (proto) {
457 	case XPRT_TRANSPORT_TCP:
458 	case XPRT_TRANSPORT_RDMA:
459 		if (retrans == NFS_UNSPEC_RETRANS)
460 			to->to_retries = NFS_DEF_TCP_RETRANS;
461 		if (timeo == NFS_UNSPEC_TIMEO || to->to_initval == 0)
462 			to->to_initval = NFS_DEF_TCP_TIMEO * HZ / 10;
463 		if (to->to_initval > NFS_MAX_TCP_TIMEOUT)
464 			to->to_initval = NFS_MAX_TCP_TIMEOUT;
465 		to->to_increment = to->to_initval;
466 		to->to_maxval = to->to_initval + (to->to_increment * to->to_retries);
467 		if (to->to_maxval > NFS_MAX_TCP_TIMEOUT)
468 			to->to_maxval = NFS_MAX_TCP_TIMEOUT;
469 		if (to->to_maxval < to->to_initval)
470 			to->to_maxval = to->to_initval;
471 		to->to_exponential = 0;
472 		break;
473 	case XPRT_TRANSPORT_UDP:
474 		if (retrans == NFS_UNSPEC_RETRANS)
475 			to->to_retries = NFS_DEF_UDP_RETRANS;
476 		if (timeo == NFS_UNSPEC_TIMEO || to->to_initval == 0)
477 			to->to_initval = NFS_DEF_UDP_TIMEO * HZ / 10;
478 		if (to->to_initval > NFS_MAX_UDP_TIMEOUT)
479 			to->to_initval = NFS_MAX_UDP_TIMEOUT;
480 		to->to_maxval = NFS_MAX_UDP_TIMEOUT;
481 		to->to_exponential = 1;
482 		break;
483 	default:
484 		BUG();
485 	}
486 }
487 EXPORT_SYMBOL_GPL(nfs_init_timeout_values);
488 
489 /*
490  * Create an RPC client handle
491  */
492 int nfs_create_rpc_client(struct nfs_client *clp,
493 			  const struct nfs_client_initdata *cl_init,
494 			  rpc_authflavor_t flavor)
495 {
496 	struct rpc_clnt		*clnt = NULL;
497 	struct rpc_create_args args = {
498 		.net		= clp->cl_net,
499 		.protocol	= clp->cl_proto,
500 		.address	= (struct sockaddr *)&clp->cl_addr,
501 		.addrsize	= clp->cl_addrlen,
502 		.timeout	= cl_init->timeparms,
503 		.servername	= clp->cl_hostname,
504 		.nodename	= cl_init->nodename,
505 		.program	= &nfs_program,
506 		.version	= clp->rpc_ops->version,
507 		.authflavor	= flavor,
508 		.cred		= cl_init->cred,
509 	};
510 
511 	if (test_bit(NFS_CS_DISCRTRY, &clp->cl_flags))
512 		args.flags |= RPC_CLNT_CREATE_DISCRTRY;
513 	if (test_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags))
514 		args.flags |= RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT;
515 	if (test_bit(NFS_CS_NORESVPORT, &clp->cl_flags))
516 		args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
517 	if (test_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags))
518 		args.flags |= RPC_CLNT_CREATE_INFINITE_SLOTS;
519 
520 	if (!IS_ERR(clp->cl_rpcclient))
521 		return 0;
522 
523 	clnt = rpc_create(&args);
524 	if (IS_ERR(clnt)) {
525 		dprintk("%s: cannot create RPC client. Error = %ld\n",
526 				__func__, PTR_ERR(clnt));
527 		return PTR_ERR(clnt);
528 	}
529 
530 	clnt->cl_principal = clp->cl_principal;
531 	clp->cl_rpcclient = clnt;
532 	return 0;
533 }
534 EXPORT_SYMBOL_GPL(nfs_create_rpc_client);
535 
536 /*
537  * Version 2 or 3 client destruction
538  */
539 static void nfs_destroy_server(struct nfs_server *server)
540 {
541 	if (server->nlm_host)
542 		nlmclnt_done(server->nlm_host);
543 }
544 
545 /*
546  * Version 2 or 3 lockd setup
547  */
548 static int nfs_start_lockd(struct nfs_server *server)
549 {
550 	struct nlm_host *host;
551 	struct nfs_client *clp = server->nfs_client;
552 	struct nlmclnt_initdata nlm_init = {
553 		.hostname	= clp->cl_hostname,
554 		.address	= (struct sockaddr *)&clp->cl_addr,
555 		.addrlen	= clp->cl_addrlen,
556 		.nfs_version	= clp->rpc_ops->version,
557 		.noresvport	= server->flags & NFS_MOUNT_NORESVPORT ?
558 					1 : 0,
559 		.net		= clp->cl_net,
560 		.nlmclnt_ops 	= clp->cl_nfs_mod->rpc_ops->nlmclnt_ops,
561 		.cred		= current_cred(),
562 	};
563 
564 	if (nlm_init.nfs_version > 3)
565 		return 0;
566 	if ((server->flags & NFS_MOUNT_LOCAL_FLOCK) &&
567 			(server->flags & NFS_MOUNT_LOCAL_FCNTL))
568 		return 0;
569 
570 	switch (clp->cl_proto) {
571 		default:
572 			nlm_init.protocol = IPPROTO_TCP;
573 			break;
574 		case XPRT_TRANSPORT_UDP:
575 			nlm_init.protocol = IPPROTO_UDP;
576 	}
577 
578 	host = nlmclnt_init(&nlm_init);
579 	if (IS_ERR(host))
580 		return PTR_ERR(host);
581 
582 	server->nlm_host = host;
583 	server->destroy = nfs_destroy_server;
584 	return 0;
585 }
586 
587 /*
588  * Create a general RPC client
589  */
590 int nfs_init_server_rpcclient(struct nfs_server *server,
591 		const struct rpc_timeout *timeo,
592 		rpc_authflavor_t pseudoflavour)
593 {
594 	struct nfs_client *clp = server->nfs_client;
595 
596 	server->client = rpc_clone_client_set_auth(clp->cl_rpcclient,
597 							pseudoflavour);
598 	if (IS_ERR(server->client)) {
599 		dprintk("%s: couldn't create rpc_client!\n", __func__);
600 		return PTR_ERR(server->client);
601 	}
602 
603 	memcpy(&server->client->cl_timeout_default,
604 			timeo,
605 			sizeof(server->client->cl_timeout_default));
606 	server->client->cl_timeout = &server->client->cl_timeout_default;
607 	server->client->cl_softrtry = 0;
608 	if (server->flags & NFS_MOUNT_SOFTERR)
609 		server->client->cl_softerr = 1;
610 	if (server->flags & NFS_MOUNT_SOFT)
611 		server->client->cl_softrtry = 1;
612 
613 	return 0;
614 }
615 EXPORT_SYMBOL_GPL(nfs_init_server_rpcclient);
616 
617 /**
618  * nfs_init_client - Initialise an NFS2 or NFS3 client
619  *
620  * @clp: nfs_client to initialise
621  * @cl_init: Initialisation parameters
622  *
623  * Returns pointer to an NFS client, or an ERR_PTR value.
624  */
625 struct nfs_client *nfs_init_client(struct nfs_client *clp,
626 				   const struct nfs_client_initdata *cl_init)
627 {
628 	int error;
629 
630 	/* the client is already initialised */
631 	if (clp->cl_cons_state == NFS_CS_READY)
632 		return clp;
633 
634 	/*
635 	 * Create a client RPC handle for doing FSSTAT with UNIX auth only
636 	 * - RFC 2623, sec 2.3.2
637 	 */
638 	error = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_UNIX);
639 	nfs_mark_client_ready(clp, error == 0 ? NFS_CS_READY : error);
640 	if (error < 0) {
641 		nfs_put_client(clp);
642 		clp = ERR_PTR(error);
643 	}
644 	return clp;
645 }
646 EXPORT_SYMBOL_GPL(nfs_init_client);
647 
648 /*
649  * Create a version 2 or 3 client
650  */
651 static int nfs_init_server(struct nfs_server *server,
652 			   const struct nfs_parsed_mount_data *data,
653 			   struct nfs_subversion *nfs_mod)
654 {
655 	struct rpc_timeout timeparms;
656 	struct nfs_client_initdata cl_init = {
657 		.hostname = data->nfs_server.hostname,
658 		.addr = (const struct sockaddr *)&data->nfs_server.address,
659 		.addrlen = data->nfs_server.addrlen,
660 		.nfs_mod = nfs_mod,
661 		.proto = data->nfs_server.protocol,
662 		.net = data->net,
663 		.timeparms = &timeparms,
664 		.cred = server->cred,
665 	};
666 	struct nfs_client *clp;
667 	int error;
668 
669 	nfs_init_timeout_values(&timeparms, data->nfs_server.protocol,
670 			data->timeo, data->retrans);
671 	if (data->flags & NFS_MOUNT_NORESVPORT)
672 		set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
673 
674 	/* Allocate or find a client reference we can use */
675 	clp = nfs_get_client(&cl_init);
676 	if (IS_ERR(clp))
677 		return PTR_ERR(clp);
678 
679 	server->nfs_client = clp;
680 
681 	/* Initialise the client representation from the mount data */
682 	server->flags = data->flags;
683 	server->options = data->options;
684 	server->caps |= NFS_CAP_HARDLINKS|NFS_CAP_SYMLINKS|NFS_CAP_FILEID|
685 		NFS_CAP_MODE|NFS_CAP_NLINK|NFS_CAP_OWNER|NFS_CAP_OWNER_GROUP|
686 		NFS_CAP_ATIME|NFS_CAP_CTIME|NFS_CAP_MTIME;
687 
688 	if (data->rsize)
689 		server->rsize = nfs_block_size(data->rsize, NULL);
690 	if (data->wsize)
691 		server->wsize = nfs_block_size(data->wsize, NULL);
692 
693 	server->acregmin = data->acregmin * HZ;
694 	server->acregmax = data->acregmax * HZ;
695 	server->acdirmin = data->acdirmin * HZ;
696 	server->acdirmax = data->acdirmax * HZ;
697 
698 	/* Start lockd here, before we might error out */
699 	error = nfs_start_lockd(server);
700 	if (error < 0)
701 		goto error;
702 
703 	server->port = data->nfs_server.port;
704 	server->auth_info = data->auth_info;
705 
706 	error = nfs_init_server_rpcclient(server, &timeparms,
707 					  data->selected_flavor);
708 	if (error < 0)
709 		goto error;
710 
711 	/* Preserve the values of mount_server-related mount options */
712 	if (data->mount_server.addrlen) {
713 		memcpy(&server->mountd_address, &data->mount_server.address,
714 			data->mount_server.addrlen);
715 		server->mountd_addrlen = data->mount_server.addrlen;
716 	}
717 	server->mountd_version = data->mount_server.version;
718 	server->mountd_port = data->mount_server.port;
719 	server->mountd_protocol = data->mount_server.protocol;
720 
721 	server->namelen  = data->namlen;
722 	return 0;
723 
724 error:
725 	server->nfs_client = NULL;
726 	nfs_put_client(clp);
727 	return error;
728 }
729 
730 /*
731  * Load up the server record from information gained in an fsinfo record
732  */
733 static void nfs_server_set_fsinfo(struct nfs_server *server,
734 				  struct nfs_fsinfo *fsinfo)
735 {
736 	unsigned long max_rpc_payload;
737 
738 	/* Work out a lot of parameters */
739 	if (server->rsize == 0)
740 		server->rsize = nfs_block_size(fsinfo->rtpref, NULL);
741 	if (server->wsize == 0)
742 		server->wsize = nfs_block_size(fsinfo->wtpref, NULL);
743 
744 	if (fsinfo->rtmax >= 512 && server->rsize > fsinfo->rtmax)
745 		server->rsize = nfs_block_size(fsinfo->rtmax, NULL);
746 	if (fsinfo->wtmax >= 512 && server->wsize > fsinfo->wtmax)
747 		server->wsize = nfs_block_size(fsinfo->wtmax, NULL);
748 
749 	max_rpc_payload = nfs_block_size(rpc_max_payload(server->client), NULL);
750 	if (server->rsize > max_rpc_payload)
751 		server->rsize = max_rpc_payload;
752 	if (server->rsize > NFS_MAX_FILE_IO_SIZE)
753 		server->rsize = NFS_MAX_FILE_IO_SIZE;
754 	server->rpages = (server->rsize + PAGE_SIZE - 1) >> PAGE_SHIFT;
755 
756 	if (server->wsize > max_rpc_payload)
757 		server->wsize = max_rpc_payload;
758 	if (server->wsize > NFS_MAX_FILE_IO_SIZE)
759 		server->wsize = NFS_MAX_FILE_IO_SIZE;
760 	server->wpages = (server->wsize + PAGE_SIZE - 1) >> PAGE_SHIFT;
761 
762 	server->wtmult = nfs_block_bits(fsinfo->wtmult, NULL);
763 
764 	server->dtsize = nfs_block_size(fsinfo->dtpref, NULL);
765 	if (server->dtsize > PAGE_SIZE * NFS_MAX_READDIR_PAGES)
766 		server->dtsize = PAGE_SIZE * NFS_MAX_READDIR_PAGES;
767 	if (server->dtsize > server->rsize)
768 		server->dtsize = server->rsize;
769 
770 	if (server->flags & NFS_MOUNT_NOAC) {
771 		server->acregmin = server->acregmax = 0;
772 		server->acdirmin = server->acdirmax = 0;
773 	}
774 
775 	server->maxfilesize = fsinfo->maxfilesize;
776 
777 	server->time_delta = fsinfo->time_delta;
778 
779 	server->clone_blksize = fsinfo->clone_blksize;
780 	/* We're airborne Set socket buffersize */
781 	rpc_setbufsize(server->client, server->wsize + 100, server->rsize + 100);
782 }
783 
784 /*
785  * Probe filesystem information, including the FSID on v2/v3
786  */
787 int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *mntfh, struct nfs_fattr *fattr)
788 {
789 	struct nfs_fsinfo fsinfo;
790 	struct nfs_client *clp = server->nfs_client;
791 	int error;
792 
793 	if (clp->rpc_ops->set_capabilities != NULL) {
794 		error = clp->rpc_ops->set_capabilities(server, mntfh);
795 		if (error < 0)
796 			return error;
797 	}
798 
799 	fsinfo.fattr = fattr;
800 	fsinfo.nlayouttypes = 0;
801 	memset(fsinfo.layouttype, 0, sizeof(fsinfo.layouttype));
802 	error = clp->rpc_ops->fsinfo(server, mntfh, &fsinfo);
803 	if (error < 0)
804 		return error;
805 
806 	nfs_server_set_fsinfo(server, &fsinfo);
807 
808 	/* Get some general file system info */
809 	if (server->namelen == 0) {
810 		struct nfs_pathconf pathinfo;
811 
812 		pathinfo.fattr = fattr;
813 		nfs_fattr_init(fattr);
814 
815 		if (clp->rpc_ops->pathconf(server, mntfh, &pathinfo) >= 0)
816 			server->namelen = pathinfo.max_namelen;
817 	}
818 
819 	return 0;
820 }
821 EXPORT_SYMBOL_GPL(nfs_probe_fsinfo);
822 
823 /*
824  * Copy useful information when duplicating a server record
825  */
826 void nfs_server_copy_userdata(struct nfs_server *target, struct nfs_server *source)
827 {
828 	target->flags = source->flags;
829 	target->rsize = source->rsize;
830 	target->wsize = source->wsize;
831 	target->acregmin = source->acregmin;
832 	target->acregmax = source->acregmax;
833 	target->acdirmin = source->acdirmin;
834 	target->acdirmax = source->acdirmax;
835 	target->caps = source->caps;
836 	target->options = source->options;
837 	target->auth_info = source->auth_info;
838 	target->port = source->port;
839 }
840 EXPORT_SYMBOL_GPL(nfs_server_copy_userdata);
841 
842 void nfs_server_insert_lists(struct nfs_server *server)
843 {
844 	struct nfs_client *clp = server->nfs_client;
845 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
846 
847 	spin_lock(&nn->nfs_client_lock);
848 	list_add_tail_rcu(&server->client_link, &clp->cl_superblocks);
849 	list_add_tail(&server->master_link, &nn->nfs_volume_list);
850 	clear_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
851 	spin_unlock(&nn->nfs_client_lock);
852 
853 }
854 EXPORT_SYMBOL_GPL(nfs_server_insert_lists);
855 
856 void nfs_server_remove_lists(struct nfs_server *server)
857 {
858 	struct nfs_client *clp = server->nfs_client;
859 	struct nfs_net *nn;
860 
861 	if (clp == NULL)
862 		return;
863 	nn = net_generic(clp->cl_net, nfs_net_id);
864 	spin_lock(&nn->nfs_client_lock);
865 	list_del_rcu(&server->client_link);
866 	if (list_empty(&clp->cl_superblocks))
867 		set_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
868 	list_del(&server->master_link);
869 	spin_unlock(&nn->nfs_client_lock);
870 
871 	synchronize_rcu();
872 }
873 EXPORT_SYMBOL_GPL(nfs_server_remove_lists);
874 
875 /*
876  * Allocate and initialise a server record
877  */
878 struct nfs_server *nfs_alloc_server(void)
879 {
880 	struct nfs_server *server;
881 
882 	server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
883 	if (!server)
884 		return NULL;
885 
886 	server->client = server->client_acl = ERR_PTR(-EINVAL);
887 
888 	/* Zero out the NFS state stuff */
889 	INIT_LIST_HEAD(&server->client_link);
890 	INIT_LIST_HEAD(&server->master_link);
891 	INIT_LIST_HEAD(&server->delegations);
892 	INIT_LIST_HEAD(&server->layouts);
893 	INIT_LIST_HEAD(&server->state_owners_lru);
894 	INIT_LIST_HEAD(&server->ss_copies);
895 
896 	atomic_set(&server->active, 0);
897 
898 	server->io_stats = nfs_alloc_iostats();
899 	if (!server->io_stats) {
900 		kfree(server);
901 		return NULL;
902 	}
903 
904 	ida_init(&server->openowner_id);
905 	ida_init(&server->lockowner_id);
906 	pnfs_init_server(server);
907 	rpc_init_wait_queue(&server->uoc_rpcwaitq, "NFS UOC");
908 
909 	return server;
910 }
911 EXPORT_SYMBOL_GPL(nfs_alloc_server);
912 
913 /*
914  * Free up a server record
915  */
916 void nfs_free_server(struct nfs_server *server)
917 {
918 	nfs_server_remove_lists(server);
919 
920 	if (server->destroy != NULL)
921 		server->destroy(server);
922 
923 	if (!IS_ERR(server->client_acl))
924 		rpc_shutdown_client(server->client_acl);
925 	if (!IS_ERR(server->client))
926 		rpc_shutdown_client(server->client);
927 
928 	nfs_put_client(server->nfs_client);
929 
930 	ida_destroy(&server->lockowner_id);
931 	ida_destroy(&server->openowner_id);
932 	nfs_free_iostats(server->io_stats);
933 	put_cred(server->cred);
934 	kfree(server);
935 	nfs_release_automount_timer();
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 	server->cred = get_cred(current_cred());
955 
956 	error = -ENOMEM;
957 	fattr = nfs_alloc_fattr();
958 	if (fattr == NULL)
959 		goto error;
960 
961 	/* Get a client representation */
962 	error = nfs_init_server(server, mount_info->parsed, nfs_mod);
963 	if (error < 0)
964 		goto error;
965 
966 	/* Probe the root fh to retrieve its FSID */
967 	error = nfs_probe_fsinfo(server, mount_info->mntfh, fattr);
968 	if (error < 0)
969 		goto error;
970 	if (server->nfs_client->rpc_ops->version == 3) {
971 		if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN)
972 			server->namelen = NFS3_MAXNAMLEN;
973 		if (!(mount_info->parsed->flags & NFS_MOUNT_NORDIRPLUS))
974 			server->caps |= NFS_CAP_READDIRPLUS;
975 	} else {
976 		if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN)
977 			server->namelen = NFS2_MAXNAMLEN;
978 	}
979 
980 	if (!(fattr->valid & NFS_ATTR_FATTR)) {
981 		error = nfs_mod->rpc_ops->getattr(server, mount_info->mntfh,
982 				fattr, NULL, NULL);
983 		if (error < 0) {
984 			dprintk("nfs_create_server: getattr error = %d\n", -error);
985 			goto error;
986 		}
987 	}
988 	memcpy(&server->fsid, &fattr->fsid, sizeof(server->fsid));
989 
990 	dprintk("Server FSID: %llx:%llx\n",
991 		(unsigned long long) server->fsid.major,
992 		(unsigned long long) server->fsid.minor);
993 
994 	nfs_server_insert_lists(server);
995 	server->mount_time = jiffies;
996 	nfs_free_fattr(fattr);
997 	return server;
998 
999 error:
1000 	nfs_free_fattr(fattr);
1001 	nfs_free_server(server);
1002 	return ERR_PTR(error);
1003 }
1004 EXPORT_SYMBOL_GPL(nfs_create_server);
1005 
1006 /*
1007  * Clone an NFS2, NFS3 or NFS4 server record
1008  */
1009 struct nfs_server *nfs_clone_server(struct nfs_server *source,
1010 				    struct nfs_fh *fh,
1011 				    struct nfs_fattr *fattr,
1012 				    rpc_authflavor_t flavor)
1013 {
1014 	struct nfs_server *server;
1015 	struct nfs_fattr *fattr_fsinfo;
1016 	int error;
1017 
1018 	server = nfs_alloc_server();
1019 	if (!server)
1020 		return ERR_PTR(-ENOMEM);
1021 
1022 	server->cred = get_cred(source->cred);
1023 
1024 	error = -ENOMEM;
1025 	fattr_fsinfo = nfs_alloc_fattr();
1026 	if (fattr_fsinfo == NULL)
1027 		goto out_free_server;
1028 
1029 	/* Copy data from the source */
1030 	server->nfs_client = source->nfs_client;
1031 	server->destroy = source->destroy;
1032 	refcount_inc(&server->nfs_client->cl_count);
1033 	nfs_server_copy_userdata(server, source);
1034 
1035 	server->fsid = fattr->fsid;
1036 
1037 	error = nfs_init_server_rpcclient(server,
1038 			source->client->cl_timeout,
1039 			flavor);
1040 	if (error < 0)
1041 		goto out_free_server;
1042 
1043 	/* probe the filesystem info for this server filesystem */
1044 	error = nfs_probe_fsinfo(server, fh, fattr_fsinfo);
1045 	if (error < 0)
1046 		goto out_free_server;
1047 
1048 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1049 		server->namelen = NFS4_MAXNAMLEN;
1050 
1051 	error = nfs_start_lockd(server);
1052 	if (error < 0)
1053 		goto out_free_server;
1054 
1055 	nfs_server_insert_lists(server);
1056 	server->mount_time = jiffies;
1057 
1058 	nfs_free_fattr(fattr_fsinfo);
1059 	return server;
1060 
1061 out_free_server:
1062 	nfs_free_fattr(fattr_fsinfo);
1063 	nfs_free_server(server);
1064 	return ERR_PTR(error);
1065 }
1066 EXPORT_SYMBOL_GPL(nfs_clone_server);
1067 
1068 void nfs_clients_init(struct net *net)
1069 {
1070 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1071 
1072 	INIT_LIST_HEAD(&nn->nfs_client_list);
1073 	INIT_LIST_HEAD(&nn->nfs_volume_list);
1074 #if IS_ENABLED(CONFIG_NFS_V4)
1075 	idr_init(&nn->cb_ident_idr);
1076 #endif
1077 	spin_lock_init(&nn->nfs_client_lock);
1078 	nn->boot_time = ktime_get_real();
1079 }
1080 
1081 #ifdef CONFIG_PROC_FS
1082 static void *nfs_server_list_start(struct seq_file *p, loff_t *pos);
1083 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos);
1084 static void nfs_server_list_stop(struct seq_file *p, void *v);
1085 static int nfs_server_list_show(struct seq_file *m, void *v);
1086 
1087 static const struct seq_operations nfs_server_list_ops = {
1088 	.start	= nfs_server_list_start,
1089 	.next	= nfs_server_list_next,
1090 	.stop	= nfs_server_list_stop,
1091 	.show	= nfs_server_list_show,
1092 };
1093 
1094 static void *nfs_volume_list_start(struct seq_file *p, loff_t *pos);
1095 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos);
1096 static void nfs_volume_list_stop(struct seq_file *p, void *v);
1097 static int nfs_volume_list_show(struct seq_file *m, void *v);
1098 
1099 static const struct seq_operations nfs_volume_list_ops = {
1100 	.start	= nfs_volume_list_start,
1101 	.next	= nfs_volume_list_next,
1102 	.stop	= nfs_volume_list_stop,
1103 	.show	= nfs_volume_list_show,
1104 };
1105 
1106 /*
1107  * set up the iterator to start reading from the server list and return the first item
1108  */
1109 static void *nfs_server_list_start(struct seq_file *m, loff_t *_pos)
1110 				__acquires(&nn->nfs_client_lock)
1111 {
1112 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1113 
1114 	/* lock the list against modification */
1115 	spin_lock(&nn->nfs_client_lock);
1116 	return seq_list_start_head(&nn->nfs_client_list, *_pos);
1117 }
1118 
1119 /*
1120  * move to next server
1121  */
1122 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos)
1123 {
1124 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1125 
1126 	return seq_list_next(v, &nn->nfs_client_list, pos);
1127 }
1128 
1129 /*
1130  * clean up after reading from the transports list
1131  */
1132 static void nfs_server_list_stop(struct seq_file *p, void *v)
1133 				__releases(&nn->nfs_client_lock)
1134 {
1135 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1136 
1137 	spin_unlock(&nn->nfs_client_lock);
1138 }
1139 
1140 /*
1141  * display a header line followed by a load of call lines
1142  */
1143 static int nfs_server_list_show(struct seq_file *m, void *v)
1144 {
1145 	struct nfs_client *clp;
1146 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1147 
1148 	/* display header on line 1 */
1149 	if (v == &nn->nfs_client_list) {
1150 		seq_puts(m, "NV SERVER   PORT USE HOSTNAME\n");
1151 		return 0;
1152 	}
1153 
1154 	/* display one transport per line on subsequent lines */
1155 	clp = list_entry(v, struct nfs_client, cl_share_link);
1156 
1157 	/* Check if the client is initialized */
1158 	if (clp->cl_cons_state != NFS_CS_READY)
1159 		return 0;
1160 
1161 	rcu_read_lock();
1162 	seq_printf(m, "v%u %s %s %3d %s\n",
1163 		   clp->rpc_ops->version,
1164 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1165 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1166 		   refcount_read(&clp->cl_count),
1167 		   clp->cl_hostname);
1168 	rcu_read_unlock();
1169 
1170 	return 0;
1171 }
1172 
1173 /*
1174  * set up the iterator to start reading from the volume list and return the first item
1175  */
1176 static void *nfs_volume_list_start(struct seq_file *m, loff_t *_pos)
1177 				__acquires(&nn->nfs_client_lock)
1178 {
1179 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1180 
1181 	/* lock the list against modification */
1182 	spin_lock(&nn->nfs_client_lock);
1183 	return seq_list_start_head(&nn->nfs_volume_list, *_pos);
1184 }
1185 
1186 /*
1187  * move to next volume
1188  */
1189 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos)
1190 {
1191 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1192 
1193 	return seq_list_next(v, &nn->nfs_volume_list, pos);
1194 }
1195 
1196 /*
1197  * clean up after reading from the transports list
1198  */
1199 static void nfs_volume_list_stop(struct seq_file *p, void *v)
1200 				__releases(&nn->nfs_client_lock)
1201 {
1202 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1203 
1204 	spin_unlock(&nn->nfs_client_lock);
1205 }
1206 
1207 /*
1208  * display a header line followed by a load of call lines
1209  */
1210 static int nfs_volume_list_show(struct seq_file *m, void *v)
1211 {
1212 	struct nfs_server *server;
1213 	struct nfs_client *clp;
1214 	char dev[13];	// 8 for 2^24, 1 for ':', 3 for 2^8, 1 for '\0'
1215 	char fsid[34];	// 2 * 16 for %llx, 1 for ':', 1 for '\0'
1216 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1217 
1218 	/* display header on line 1 */
1219 	if (v == &nn->nfs_volume_list) {
1220 		seq_puts(m, "NV SERVER   PORT DEV          FSID"
1221 			    "                              FSC\n");
1222 		return 0;
1223 	}
1224 	/* display one transport per line on subsequent lines */
1225 	server = list_entry(v, struct nfs_server, master_link);
1226 	clp = server->nfs_client;
1227 
1228 	snprintf(dev, sizeof(dev), "%u:%u",
1229 		 MAJOR(server->s_dev), MINOR(server->s_dev));
1230 
1231 	snprintf(fsid, sizeof(fsid), "%llx:%llx",
1232 		 (unsigned long long) server->fsid.major,
1233 		 (unsigned long long) server->fsid.minor);
1234 
1235 	rcu_read_lock();
1236 	seq_printf(m, "v%u %s %s %-12s %-33s %s\n",
1237 		   clp->rpc_ops->version,
1238 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1239 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1240 		   dev,
1241 		   fsid,
1242 		   nfs_server_fscache_state(server));
1243 	rcu_read_unlock();
1244 
1245 	return 0;
1246 }
1247 
1248 int nfs_fs_proc_net_init(struct net *net)
1249 {
1250 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1251 	struct proc_dir_entry *p;
1252 
1253 	nn->proc_nfsfs = proc_net_mkdir(net, "nfsfs", net->proc_net);
1254 	if (!nn->proc_nfsfs)
1255 		goto error_0;
1256 
1257 	/* a file of servers with which we're dealing */
1258 	p = proc_create_net("servers", S_IFREG|S_IRUGO, nn->proc_nfsfs,
1259 			&nfs_server_list_ops, sizeof(struct seq_net_private));
1260 	if (!p)
1261 		goto error_1;
1262 
1263 	/* a file of volumes that we have mounted */
1264 	p = proc_create_net("volumes", S_IFREG|S_IRUGO, nn->proc_nfsfs,
1265 			&nfs_volume_list_ops, sizeof(struct seq_net_private));
1266 	if (!p)
1267 		goto error_1;
1268 	return 0;
1269 
1270 error_1:
1271 	remove_proc_subtree("nfsfs", net->proc_net);
1272 error_0:
1273 	return -ENOMEM;
1274 }
1275 
1276 void nfs_fs_proc_net_exit(struct net *net)
1277 {
1278 	remove_proc_subtree("nfsfs", net->proc_net);
1279 }
1280 
1281 /*
1282  * initialise the /proc/fs/nfsfs/ directory
1283  */
1284 int __init nfs_fs_proc_init(void)
1285 {
1286 	if (!proc_mkdir("fs/nfsfs", NULL))
1287 		goto error_0;
1288 
1289 	/* a file of servers with which we're dealing */
1290 	if (!proc_symlink("fs/nfsfs/servers", NULL, "../../net/nfsfs/servers"))
1291 		goto error_1;
1292 
1293 	/* a file of volumes that we have mounted */
1294 	if (!proc_symlink("fs/nfsfs/volumes", NULL, "../../net/nfsfs/volumes"))
1295 		goto error_1;
1296 
1297 	return 0;
1298 error_1:
1299 	remove_proc_subtree("fs/nfsfs", NULL);
1300 error_0:
1301 	return -ENOMEM;
1302 }
1303 
1304 /*
1305  * clean up the /proc/fs/nfsfs/ directory
1306  */
1307 void nfs_fs_proc_exit(void)
1308 {
1309 	remove_proc_subtree("fs/nfsfs", NULL);
1310 }
1311 
1312 #endif /* CONFIG_PROC_FS */
1313