xref: /kernel/linux/linux-5.10/fs/nfs/client.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-or-later
2/* client.c: NFS client sharing and management code
3 *
4 * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8
9#include <linux/module.h>
10#include <linux/init.h>
11#include <linux/sched.h>
12#include <linux/time.h>
13#include <linux/kernel.h>
14#include <linux/mm.h>
15#include <linux/string.h>
16#include <linux/stat.h>
17#include <linux/errno.h>
18#include <linux/unistd.h>
19#include <linux/sunrpc/addr.h>
20#include <linux/sunrpc/clnt.h>
21#include <linux/sunrpc/stats.h>
22#include <linux/sunrpc/metrics.h>
23#include <linux/sunrpc/xprtsock.h>
24#include <linux/sunrpc/xprtrdma.h>
25#include <linux/nfs_fs.h>
26#include <linux/nfs_mount.h>
27#include <linux/nfs4_mount.h>
28#include <linux/lockd/bind.h>
29#include <linux/seq_file.h>
30#include <linux/mount.h>
31#include <linux/vfs.h>
32#include <linux/inet.h>
33#include <linux/in6.h>
34#include <linux/slab.h>
35#include <linux/idr.h>
36#include <net/ipv6.h>
37#include <linux/nfs_xdr.h>
38#include <linux/sunrpc/bc_xprt.h>
39#include <linux/nsproxy.h>
40#include <linux/pid_namespace.h>
41
42
43#include "nfs4_fs.h"
44#include "callback.h"
45#include "delegation.h"
46#include "iostat.h"
47#include "internal.h"
48#include "fscache.h"
49#include "pnfs.h"
50#include "nfs.h"
51#include "netns.h"
52#include "sysfs.h"
53#include "nfs42.h"
54
55#define NFSDBG_FACILITY		NFSDBG_CLIENT
56
57static DECLARE_WAIT_QUEUE_HEAD(nfs_client_active_wq);
58static DEFINE_SPINLOCK(nfs_version_lock);
59static DEFINE_MUTEX(nfs_version_mutex);
60static LIST_HEAD(nfs_versions);
61
62/*
63 * RPC cruft for NFS
64 */
65static const struct rpc_version *nfs_version[5] = {
66	[2] = NULL,
67	[3] = NULL,
68	[4] = NULL,
69};
70
71const struct rpc_program nfs_program = {
72	.name			= "nfs",
73	.number			= NFS_PROGRAM,
74	.nrvers			= ARRAY_SIZE(nfs_version),
75	.version		= nfs_version,
76	.pipe_dir_name		= NFS_PIPE_DIRNAME,
77};
78
79struct rpc_stat nfs_rpcstat = {
80	.program		= &nfs_program
81};
82
83static struct nfs_subversion *find_nfs_version(unsigned int version)
84{
85	struct nfs_subversion *nfs;
86	spin_lock(&nfs_version_lock);
87
88	list_for_each_entry(nfs, &nfs_versions, list) {
89		if (nfs->rpc_ops->version == version) {
90			spin_unlock(&nfs_version_lock);
91			return nfs;
92		}
93	}
94
95	spin_unlock(&nfs_version_lock);
96	return ERR_PTR(-EPROTONOSUPPORT);
97}
98
99struct nfs_subversion *get_nfs_version(unsigned int version)
100{
101	struct nfs_subversion *nfs = find_nfs_version(version);
102
103	if (IS_ERR(nfs)) {
104		mutex_lock(&nfs_version_mutex);
105		request_module("nfsv%d", version);
106		nfs = find_nfs_version(version);
107		mutex_unlock(&nfs_version_mutex);
108	}
109
110	if (!IS_ERR(nfs) && !try_module_get(nfs->owner))
111		return ERR_PTR(-EAGAIN);
112	return nfs;
113}
114
115void put_nfs_version(struct nfs_subversion *nfs)
116{
117	module_put(nfs->owner);
118}
119
120void register_nfs_version(struct nfs_subversion *nfs)
121{
122	spin_lock(&nfs_version_lock);
123
124	list_add(&nfs->list, &nfs_versions);
125	nfs_version[nfs->rpc_ops->version] = nfs->rpc_vers;
126
127	spin_unlock(&nfs_version_lock);
128}
129EXPORT_SYMBOL_GPL(register_nfs_version);
130
131void unregister_nfs_version(struct nfs_subversion *nfs)
132{
133	spin_lock(&nfs_version_lock);
134
135	nfs_version[nfs->rpc_ops->version] = NULL;
136	list_del(&nfs->list);
137
138	spin_unlock(&nfs_version_lock);
139}
140EXPORT_SYMBOL_GPL(unregister_nfs_version);
141
142/*
143 * Allocate a shared client record
144 *
145 * Since these are allocated/deallocated very rarely, we don't
146 * bother putting them in a slab cache...
147 */
148struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init)
149{
150	struct nfs_client *clp;
151	int err = -ENOMEM;
152
153	if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL)
154		goto error_0;
155
156	clp->cl_minorversion = cl_init->minorversion;
157	clp->cl_nfs_mod = cl_init->nfs_mod;
158	if (!try_module_get(clp->cl_nfs_mod->owner))
159		goto error_dealloc;
160
161	clp->rpc_ops = clp->cl_nfs_mod->rpc_ops;
162
163	refcount_set(&clp->cl_count, 1);
164	clp->cl_cons_state = NFS_CS_INITING;
165
166	memcpy(&clp->cl_addr, cl_init->addr, cl_init->addrlen);
167	clp->cl_addrlen = cl_init->addrlen;
168
169	if (cl_init->hostname) {
170		err = -ENOMEM;
171		clp->cl_hostname = kstrdup(cl_init->hostname, GFP_KERNEL);
172		if (!clp->cl_hostname)
173			goto error_cleanup;
174	}
175
176	INIT_LIST_HEAD(&clp->cl_superblocks);
177	clp->cl_rpcclient = ERR_PTR(-EINVAL);
178
179	clp->cl_flags = cl_init->init_flags;
180	clp->cl_proto = cl_init->proto;
181	clp->cl_nconnect = cl_init->nconnect;
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
189error_cleanup:
190	put_nfs_version(clp->cl_nfs_mod);
191error_dealloc:
192	kfree(clp);
193error_0:
194	return ERR_PTR(err);
195}
196EXPORT_SYMBOL_GPL(nfs_alloc_client);
197
198#if IS_ENABLED(CONFIG_NFS_V4)
199static 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 */
207static 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
215static void pnfs_init_server(struct nfs_server *server)
216{
217	rpc_init_wait_queue(&server->roc_rpcwaitq, "pNFS ROC");
218}
219
220#else
221static void nfs_cleanup_cb_ident_idr(struct net *net)
222{
223}
224
225static void nfs_cb_idr_remove_locked(struct nfs_client *clp)
226{
227}
228
229static 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 */
238void 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}
252EXPORT_SYMBOL_GPL(nfs_free_client);
253
254/*
255 * Release a reference to a shared client record
256 */
257void 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}
276EXPORT_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 */
282static 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
289again:
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
318		/* Match request for a dedicated DS */
319		if (test_bit(NFS_CS_DS, &data->init_flags) !=
320		    test_bit(NFS_CS_DS, &clp->cl_flags))
321			continue;
322
323		/* Match the full socket address */
324		if (!rpc_cmp_addr_port(sap, clap))
325			/* Match all xprt_switch full socket addresses */
326			if (IS_ERR(clp->cl_rpcclient) ||
327                            !rpc_clnt_xprt_switch_has_addr(clp->cl_rpcclient,
328							   sap))
329				continue;
330
331		refcount_inc(&clp->cl_count);
332		return clp;
333	}
334	return NULL;
335}
336
337/*
338 * Return true if @clp is done initializing, false if still working on it.
339 *
340 * Use nfs_client_init_status to check if it was successful.
341 */
342bool nfs_client_init_is_complete(const struct nfs_client *clp)
343{
344	return clp->cl_cons_state <= NFS_CS_READY;
345}
346EXPORT_SYMBOL_GPL(nfs_client_init_is_complete);
347
348/*
349 * Return 0 if @clp was successfully initialized, -errno otherwise.
350 *
351 * This must be called *after* nfs_client_init_is_complete() returns true,
352 * otherwise it will pop WARN_ON_ONCE and return -EINVAL
353 */
354int nfs_client_init_status(const struct nfs_client *clp)
355{
356	/* called without checking nfs_client_init_is_complete */
357	if (clp->cl_cons_state > NFS_CS_READY) {
358		WARN_ON_ONCE(1);
359		return -EINVAL;
360	}
361	return clp->cl_cons_state;
362}
363EXPORT_SYMBOL_GPL(nfs_client_init_status);
364
365int nfs_wait_client_init_complete(const struct nfs_client *clp)
366{
367	return wait_event_killable(nfs_client_active_wq,
368			nfs_client_init_is_complete(clp));
369}
370EXPORT_SYMBOL_GPL(nfs_wait_client_init_complete);
371
372/*
373 * Found an existing client.  Make sure it's ready before returning.
374 */
375static struct nfs_client *
376nfs_found_client(const struct nfs_client_initdata *cl_init,
377		 struct nfs_client *clp)
378{
379	int error;
380
381	error = nfs_wait_client_init_complete(clp);
382	if (error < 0) {
383		nfs_put_client(clp);
384		return ERR_PTR(-ERESTARTSYS);
385	}
386
387	if (clp->cl_cons_state < NFS_CS_READY) {
388		error = clp->cl_cons_state;
389		nfs_put_client(clp);
390		return ERR_PTR(error);
391	}
392
393	smp_rmb();
394	return clp;
395}
396
397/*
398 * Look up a client by IP address and protocol version
399 * - creates a new record if one doesn't yet exist
400 */
401struct nfs_client *nfs_get_client(const struct nfs_client_initdata *cl_init)
402{
403	struct nfs_client *clp, *new = NULL;
404	struct nfs_net *nn = net_generic(cl_init->net, nfs_net_id);
405	const struct nfs_rpc_ops *rpc_ops = cl_init->nfs_mod->rpc_ops;
406
407	if (cl_init->hostname == NULL) {
408		WARN_ON(1);
409		return ERR_PTR(-EINVAL);
410	}
411
412	/* see if the client already exists */
413	do {
414		spin_lock(&nn->nfs_client_lock);
415
416		clp = nfs_match_client(cl_init);
417		if (clp) {
418			spin_unlock(&nn->nfs_client_lock);
419			if (new)
420				new->rpc_ops->free_client(new);
421			if (IS_ERR(clp))
422				return clp;
423			return nfs_found_client(cl_init, clp);
424		}
425		if (new) {
426			list_add_tail(&new->cl_share_link,
427					&nn->nfs_client_list);
428			spin_unlock(&nn->nfs_client_lock);
429			return rpc_ops->init_client(new, cl_init);
430		}
431
432		spin_unlock(&nn->nfs_client_lock);
433
434		new = rpc_ops->alloc_client(cl_init);
435	} while (!IS_ERR(new));
436
437	return new;
438}
439EXPORT_SYMBOL_GPL(nfs_get_client);
440
441/*
442 * Mark a server as ready or failed
443 */
444void nfs_mark_client_ready(struct nfs_client *clp, int state)
445{
446	smp_wmb();
447	clp->cl_cons_state = state;
448	wake_up_all(&nfs_client_active_wq);
449}
450EXPORT_SYMBOL_GPL(nfs_mark_client_ready);
451
452/*
453 * Initialise the timeout values for a connection
454 */
455void nfs_init_timeout_values(struct rpc_timeout *to, int proto,
456				    int timeo, int retrans)
457{
458	to->to_initval = timeo * HZ / 10;
459	to->to_retries = retrans;
460
461	switch (proto) {
462	case XPRT_TRANSPORT_TCP:
463	case XPRT_TRANSPORT_RDMA:
464		if (retrans == NFS_UNSPEC_RETRANS)
465			to->to_retries = NFS_DEF_TCP_RETRANS;
466		if (timeo == NFS_UNSPEC_TIMEO || to->to_initval == 0)
467			to->to_initval = NFS_DEF_TCP_TIMEO * HZ / 10;
468		if (to->to_initval > NFS_MAX_TCP_TIMEOUT)
469			to->to_initval = NFS_MAX_TCP_TIMEOUT;
470		to->to_increment = to->to_initval;
471		to->to_maxval = to->to_initval + (to->to_increment * to->to_retries);
472		if (to->to_maxval > NFS_MAX_TCP_TIMEOUT)
473			to->to_maxval = NFS_MAX_TCP_TIMEOUT;
474		if (to->to_maxval < to->to_initval)
475			to->to_maxval = to->to_initval;
476		to->to_exponential = 0;
477		break;
478#ifndef CONFIG_NFS_DISABLE_UDP_SUPPORT
479	case XPRT_TRANSPORT_UDP:
480		if (retrans == NFS_UNSPEC_RETRANS)
481			to->to_retries = NFS_DEF_UDP_RETRANS;
482		if (timeo == NFS_UNSPEC_TIMEO || to->to_initval == 0)
483			to->to_initval = NFS_DEF_UDP_TIMEO * HZ / 10;
484		if (to->to_initval > NFS_MAX_UDP_TIMEOUT)
485			to->to_initval = NFS_MAX_UDP_TIMEOUT;
486		to->to_maxval = NFS_MAX_UDP_TIMEOUT;
487		to->to_exponential = 1;
488		break;
489#endif
490	default:
491		BUG();
492	}
493}
494EXPORT_SYMBOL_GPL(nfs_init_timeout_values);
495
496/*
497 * Create an RPC client handle
498 */
499int nfs_create_rpc_client(struct nfs_client *clp,
500			  const struct nfs_client_initdata *cl_init,
501			  rpc_authflavor_t flavor)
502{
503	struct nfs_net		*nn = net_generic(clp->cl_net, nfs_net_id);
504	struct rpc_clnt		*clnt = NULL;
505	struct rpc_create_args args = {
506		.net		= clp->cl_net,
507		.protocol	= clp->cl_proto,
508		.nconnect	= clp->cl_nconnect,
509		.address	= (struct sockaddr *)&clp->cl_addr,
510		.addrsize	= clp->cl_addrlen,
511		.timeout	= cl_init->timeparms,
512		.servername	= clp->cl_hostname,
513		.nodename	= cl_init->nodename,
514		.program	= &nfs_program,
515		.stats		= &nn->rpcstats,
516		.version	= clp->rpc_ops->version,
517		.authflavor	= flavor,
518		.cred		= cl_init->cred,
519	};
520
521	if (test_bit(NFS_CS_DISCRTRY, &clp->cl_flags))
522		args.flags |= RPC_CLNT_CREATE_DISCRTRY;
523	if (test_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags))
524		args.flags |= RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT;
525	if (test_bit(NFS_CS_NORESVPORT, &clp->cl_flags))
526		args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
527	if (test_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags))
528		args.flags |= RPC_CLNT_CREATE_INFINITE_SLOTS;
529	if (test_bit(NFS_CS_NOPING, &clp->cl_flags))
530		args.flags |= RPC_CLNT_CREATE_NOPING;
531	if (test_bit(NFS_CS_REUSEPORT, &clp->cl_flags))
532		args.flags |= RPC_CLNT_CREATE_REUSEPORT;
533
534	if (!IS_ERR(clp->cl_rpcclient))
535		return 0;
536
537	clnt = rpc_create(&args);
538	if (IS_ERR(clnt)) {
539		dprintk("%s: cannot create RPC client. Error = %ld\n",
540				__func__, PTR_ERR(clnt));
541		return PTR_ERR(clnt);
542	}
543
544	clnt->cl_principal = clp->cl_principal;
545	clp->cl_rpcclient = clnt;
546	return 0;
547}
548EXPORT_SYMBOL_GPL(nfs_create_rpc_client);
549
550/*
551 * Version 2 or 3 client destruction
552 */
553static void nfs_destroy_server(struct nfs_server *server)
554{
555	if (server->nlm_host)
556		nlmclnt_done(server->nlm_host);
557}
558
559/*
560 * Version 2 or 3 lockd setup
561 */
562static int nfs_start_lockd(struct nfs_server *server)
563{
564	struct nlm_host *host;
565	struct nfs_client *clp = server->nfs_client;
566	struct nlmclnt_initdata nlm_init = {
567		.hostname	= clp->cl_hostname,
568		.address	= (struct sockaddr *)&clp->cl_addr,
569		.addrlen	= clp->cl_addrlen,
570		.nfs_version	= clp->rpc_ops->version,
571		.noresvport	= server->flags & NFS_MOUNT_NORESVPORT ?
572					1 : 0,
573		.net		= clp->cl_net,
574		.nlmclnt_ops 	= clp->cl_nfs_mod->rpc_ops->nlmclnt_ops,
575		.cred		= server->cred,
576	};
577
578	if (nlm_init.nfs_version > 3)
579		return 0;
580	if ((server->flags & NFS_MOUNT_LOCAL_FLOCK) &&
581			(server->flags & NFS_MOUNT_LOCAL_FCNTL))
582		return 0;
583
584	switch (clp->cl_proto) {
585		default:
586			nlm_init.protocol = IPPROTO_TCP;
587			break;
588#ifndef CONFIG_NFS_DISABLE_UDP_SUPPORT
589		case XPRT_TRANSPORT_UDP:
590			nlm_init.protocol = IPPROTO_UDP;
591#endif
592	}
593
594	host = nlmclnt_init(&nlm_init);
595	if (IS_ERR(host))
596		return PTR_ERR(host);
597
598	server->nlm_host = host;
599	server->destroy = nfs_destroy_server;
600	return 0;
601}
602
603/*
604 * Create a general RPC client
605 */
606int nfs_init_server_rpcclient(struct nfs_server *server,
607		const struct rpc_timeout *timeo,
608		rpc_authflavor_t pseudoflavour)
609{
610	struct nfs_client *clp = server->nfs_client;
611
612	server->client = rpc_clone_client_set_auth(clp->cl_rpcclient,
613							pseudoflavour);
614	if (IS_ERR(server->client)) {
615		dprintk("%s: couldn't create rpc_client!\n", __func__);
616		return PTR_ERR(server->client);
617	}
618
619	memcpy(&server->client->cl_timeout_default,
620			timeo,
621			sizeof(server->client->cl_timeout_default));
622	server->client->cl_timeout = &server->client->cl_timeout_default;
623	server->client->cl_softrtry = 0;
624	if (server->flags & NFS_MOUNT_SOFTERR)
625		server->client->cl_softerr = 1;
626	if (server->flags & NFS_MOUNT_SOFT)
627		server->client->cl_softrtry = 1;
628
629	return 0;
630}
631EXPORT_SYMBOL_GPL(nfs_init_server_rpcclient);
632
633/**
634 * nfs_init_client - Initialise an NFS2 or NFS3 client
635 *
636 * @clp: nfs_client to initialise
637 * @cl_init: Initialisation parameters
638 *
639 * Returns pointer to an NFS client, or an ERR_PTR value.
640 */
641struct nfs_client *nfs_init_client(struct nfs_client *clp,
642				   const struct nfs_client_initdata *cl_init)
643{
644	int error;
645
646	/* the client is already initialised */
647	if (clp->cl_cons_state == NFS_CS_READY)
648		return clp;
649
650	/*
651	 * Create a client RPC handle for doing FSSTAT with UNIX auth only
652	 * - RFC 2623, sec 2.3.2
653	 */
654	error = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_UNIX);
655	nfs_mark_client_ready(clp, error == 0 ? NFS_CS_READY : error);
656	if (error < 0) {
657		nfs_put_client(clp);
658		clp = ERR_PTR(error);
659	}
660	return clp;
661}
662EXPORT_SYMBOL_GPL(nfs_init_client);
663
664/*
665 * Create a version 2 or 3 client
666 */
667static int nfs_init_server(struct nfs_server *server,
668			   const struct fs_context *fc)
669{
670	const struct nfs_fs_context *ctx = nfs_fc2context(fc);
671	struct rpc_timeout timeparms;
672	struct nfs_client_initdata cl_init = {
673		.hostname = ctx->nfs_server.hostname,
674		.addr = (const struct sockaddr *)&ctx->nfs_server.address,
675		.addrlen = ctx->nfs_server.addrlen,
676		.nfs_mod = ctx->nfs_mod,
677		.proto = ctx->nfs_server.protocol,
678		.net = fc->net_ns,
679		.timeparms = &timeparms,
680		.cred = server->cred,
681		.nconnect = ctx->nfs_server.nconnect,
682		.init_flags = (1UL << NFS_CS_REUSEPORT),
683	};
684	struct nfs_client *clp;
685	int error;
686
687	nfs_init_timeout_values(&timeparms, ctx->nfs_server.protocol,
688				ctx->timeo, ctx->retrans);
689	if (ctx->flags & NFS_MOUNT_NORESVPORT)
690		set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
691
692	/* Allocate or find a client reference we can use */
693	clp = nfs_get_client(&cl_init);
694	if (IS_ERR(clp))
695		return PTR_ERR(clp);
696
697	server->nfs_client = clp;
698
699	/* Initialise the client representation from the mount data */
700	server->flags = ctx->flags;
701	server->options = ctx->options;
702	server->caps |= NFS_CAP_HARDLINKS|NFS_CAP_SYMLINKS|NFS_CAP_FILEID|
703		NFS_CAP_MODE|NFS_CAP_NLINK|NFS_CAP_OWNER|NFS_CAP_OWNER_GROUP|
704		NFS_CAP_ATIME|NFS_CAP_CTIME|NFS_CAP_MTIME;
705
706	if (ctx->rsize)
707		server->rsize = nfs_block_size(ctx->rsize, NULL);
708	if (ctx->wsize)
709		server->wsize = nfs_block_size(ctx->wsize, NULL);
710
711	server->acregmin = ctx->acregmin * HZ;
712	server->acregmax = ctx->acregmax * HZ;
713	server->acdirmin = ctx->acdirmin * HZ;
714	server->acdirmax = ctx->acdirmax * HZ;
715
716	/* Start lockd here, before we might error out */
717	error = nfs_start_lockd(server);
718	if (error < 0)
719		goto error;
720
721	server->port = ctx->nfs_server.port;
722	server->auth_info = ctx->auth_info;
723
724	error = nfs_init_server_rpcclient(server, &timeparms,
725					  ctx->selected_flavor);
726	if (error < 0)
727		goto error;
728
729	/* Preserve the values of mount_server-related mount options */
730	if (ctx->mount_server.addrlen) {
731		memcpy(&server->mountd_address, &ctx->mount_server.address,
732			ctx->mount_server.addrlen);
733		server->mountd_addrlen = ctx->mount_server.addrlen;
734	}
735	server->mountd_version = ctx->mount_server.version;
736	server->mountd_port = ctx->mount_server.port;
737	server->mountd_protocol = ctx->mount_server.protocol;
738
739	server->namelen  = ctx->namlen;
740	return 0;
741
742error:
743	server->nfs_client = NULL;
744	nfs_put_client(clp);
745	return error;
746}
747
748/*
749 * Load up the server record from information gained in an fsinfo record
750 */
751static void nfs_server_set_fsinfo(struct nfs_server *server,
752				  struct nfs_fsinfo *fsinfo)
753{
754	unsigned long max_rpc_payload, raw_max_rpc_payload;
755
756	/* Work out a lot of parameters */
757	if (server->rsize == 0)
758		server->rsize = nfs_block_size(fsinfo->rtpref, NULL);
759	if (server->wsize == 0)
760		server->wsize = nfs_block_size(fsinfo->wtpref, NULL);
761
762	if (fsinfo->rtmax >= 512 && server->rsize > fsinfo->rtmax)
763		server->rsize = nfs_block_size(fsinfo->rtmax, NULL);
764	if (fsinfo->wtmax >= 512 && server->wsize > fsinfo->wtmax)
765		server->wsize = nfs_block_size(fsinfo->wtmax, NULL);
766
767	raw_max_rpc_payload = rpc_max_payload(server->client);
768	max_rpc_payload = nfs_block_size(raw_max_rpc_payload, NULL);
769
770	if (server->rsize > max_rpc_payload)
771		server->rsize = max_rpc_payload;
772	if (server->rsize > NFS_MAX_FILE_IO_SIZE)
773		server->rsize = NFS_MAX_FILE_IO_SIZE;
774	server->rpages = (server->rsize + PAGE_SIZE - 1) >> PAGE_SHIFT;
775
776	if (server->wsize > max_rpc_payload)
777		server->wsize = max_rpc_payload;
778	if (server->wsize > NFS_MAX_FILE_IO_SIZE)
779		server->wsize = NFS_MAX_FILE_IO_SIZE;
780	server->wpages = (server->wsize + PAGE_SIZE - 1) >> PAGE_SHIFT;
781
782	server->wtmult = nfs_block_bits(fsinfo->wtmult, NULL);
783
784	server->dtsize = nfs_block_size(fsinfo->dtpref, NULL);
785	if (server->dtsize > PAGE_SIZE * NFS_MAX_READDIR_PAGES)
786		server->dtsize = PAGE_SIZE * NFS_MAX_READDIR_PAGES;
787	if (server->dtsize > server->rsize)
788		server->dtsize = server->rsize;
789
790	if (server->flags & NFS_MOUNT_NOAC) {
791		server->acregmin = server->acregmax = 0;
792		server->acdirmin = server->acdirmax = 0;
793	}
794
795	server->maxfilesize = fsinfo->maxfilesize;
796
797	server->time_delta = fsinfo->time_delta;
798
799	server->clone_blksize = fsinfo->clone_blksize;
800	/* We're airborne Set socket buffersize */
801	rpc_setbufsize(server->client, server->wsize + 100, server->rsize + 100);
802
803#ifdef CONFIG_NFS_V4_2
804	/*
805	 * Defaults until limited by the session parameters.
806	 */
807	server->gxasize = min_t(unsigned int, raw_max_rpc_payload,
808				XATTR_SIZE_MAX);
809	server->sxasize = min_t(unsigned int, raw_max_rpc_payload,
810				XATTR_SIZE_MAX);
811	server->lxasize = min_t(unsigned int, raw_max_rpc_payload,
812				nfs42_listxattr_xdrsize(XATTR_LIST_MAX));
813
814	if (fsinfo->xattr_support)
815		server->caps |= NFS_CAP_XATTR;
816#endif
817}
818
819/*
820 * Probe filesystem information, including the FSID on v2/v3
821 */
822int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *mntfh, struct nfs_fattr *fattr)
823{
824	struct nfs_fsinfo fsinfo;
825	struct nfs_client *clp = server->nfs_client;
826	int error;
827
828	if (clp->rpc_ops->set_capabilities != NULL) {
829		error = clp->rpc_ops->set_capabilities(server, mntfh);
830		if (error < 0)
831			return error;
832	}
833
834	fsinfo.fattr = fattr;
835	fsinfo.nlayouttypes = 0;
836	memset(fsinfo.layouttype, 0, sizeof(fsinfo.layouttype));
837	error = clp->rpc_ops->fsinfo(server, mntfh, &fsinfo);
838	if (error < 0)
839		return error;
840
841	nfs_server_set_fsinfo(server, &fsinfo);
842
843	/* Get some general file system info */
844	if (server->namelen == 0) {
845		struct nfs_pathconf pathinfo;
846
847		pathinfo.fattr = fattr;
848		nfs_fattr_init(fattr);
849
850		if (clp->rpc_ops->pathconf(server, mntfh, &pathinfo) >= 0)
851			server->namelen = pathinfo.max_namelen;
852	}
853
854	return 0;
855}
856EXPORT_SYMBOL_GPL(nfs_probe_fsinfo);
857
858/*
859 * Copy useful information when duplicating a server record
860 */
861void nfs_server_copy_userdata(struct nfs_server *target, struct nfs_server *source)
862{
863	target->flags = source->flags;
864	target->rsize = source->rsize;
865	target->wsize = source->wsize;
866	target->acregmin = source->acregmin;
867	target->acregmax = source->acregmax;
868	target->acdirmin = source->acdirmin;
869	target->acdirmax = source->acdirmax;
870	target->caps = source->caps;
871	target->options = source->options;
872	target->auth_info = source->auth_info;
873	target->port = source->port;
874}
875EXPORT_SYMBOL_GPL(nfs_server_copy_userdata);
876
877void nfs_server_insert_lists(struct nfs_server *server)
878{
879	struct nfs_client *clp = server->nfs_client;
880	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
881
882	spin_lock(&nn->nfs_client_lock);
883	list_add_tail_rcu(&server->client_link, &clp->cl_superblocks);
884	list_add_tail(&server->master_link, &nn->nfs_volume_list);
885	clear_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
886	spin_unlock(&nn->nfs_client_lock);
887
888}
889EXPORT_SYMBOL_GPL(nfs_server_insert_lists);
890
891void nfs_server_remove_lists(struct nfs_server *server)
892{
893	struct nfs_client *clp = server->nfs_client;
894	struct nfs_net *nn;
895
896	if (clp == NULL)
897		return;
898	nn = net_generic(clp->cl_net, nfs_net_id);
899	spin_lock(&nn->nfs_client_lock);
900	list_del_rcu(&server->client_link);
901	if (list_empty(&clp->cl_superblocks))
902		set_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
903	list_del(&server->master_link);
904	spin_unlock(&nn->nfs_client_lock);
905
906	synchronize_rcu();
907}
908EXPORT_SYMBOL_GPL(nfs_server_remove_lists);
909
910/*
911 * Allocate and initialise a server record
912 */
913struct nfs_server *nfs_alloc_server(void)
914{
915	struct nfs_server *server;
916
917	server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
918	if (!server)
919		return NULL;
920
921	server->client = server->client_acl = ERR_PTR(-EINVAL);
922
923	/* Zero out the NFS state stuff */
924	INIT_LIST_HEAD(&server->client_link);
925	INIT_LIST_HEAD(&server->master_link);
926	INIT_LIST_HEAD(&server->delegations);
927	INIT_LIST_HEAD(&server->layouts);
928	INIT_LIST_HEAD(&server->state_owners_lru);
929	INIT_LIST_HEAD(&server->ss_copies);
930
931	atomic_set(&server->active, 0);
932
933	server->io_stats = nfs_alloc_iostats();
934	if (!server->io_stats) {
935		kfree(server);
936		return NULL;
937	}
938
939	ida_init(&server->openowner_id);
940	ida_init(&server->lockowner_id);
941	pnfs_init_server(server);
942	rpc_init_wait_queue(&server->uoc_rpcwaitq, "NFS UOC");
943
944	return server;
945}
946EXPORT_SYMBOL_GPL(nfs_alloc_server);
947
948/*
949 * Free up a server record
950 */
951void nfs_free_server(struct nfs_server *server)
952{
953	nfs_server_remove_lists(server);
954
955	if (server->destroy != NULL)
956		server->destroy(server);
957
958	if (!IS_ERR(server->client_acl))
959		rpc_shutdown_client(server->client_acl);
960	if (!IS_ERR(server->client))
961		rpc_shutdown_client(server->client);
962
963	nfs_put_client(server->nfs_client);
964
965	ida_destroy(&server->lockowner_id);
966	ida_destroy(&server->openowner_id);
967	nfs_free_iostats(server->io_stats);
968	put_cred(server->cred);
969	kfree(server);
970	nfs_release_automount_timer();
971}
972EXPORT_SYMBOL_GPL(nfs_free_server);
973
974/*
975 * Create a version 2 or 3 volume record
976 * - keyed on server and FSID
977 */
978struct nfs_server *nfs_create_server(struct fs_context *fc)
979{
980	struct nfs_fs_context *ctx = nfs_fc2context(fc);
981	struct nfs_server *server;
982	struct nfs_fattr *fattr;
983	int error;
984
985	server = nfs_alloc_server();
986	if (!server)
987		return ERR_PTR(-ENOMEM);
988
989	server->cred = get_cred(fc->cred);
990
991	error = -ENOMEM;
992	fattr = nfs_alloc_fattr();
993	if (fattr == NULL)
994		goto error;
995
996	/* Get a client representation */
997	error = nfs_init_server(server, fc);
998	if (error < 0)
999		goto error;
1000
1001	/* Probe the root fh to retrieve its FSID */
1002	error = nfs_probe_fsinfo(server, ctx->mntfh, fattr);
1003	if (error < 0)
1004		goto error;
1005	if (server->nfs_client->rpc_ops->version == 3) {
1006		if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN)
1007			server->namelen = NFS3_MAXNAMLEN;
1008		if (!(ctx->flags & NFS_MOUNT_NORDIRPLUS))
1009			server->caps |= NFS_CAP_READDIRPLUS;
1010	} else {
1011		if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN)
1012			server->namelen = NFS2_MAXNAMLEN;
1013	}
1014
1015	if (!(fattr->valid & NFS_ATTR_FATTR)) {
1016		error = ctx->nfs_mod->rpc_ops->getattr(server, ctx->mntfh,
1017						       fattr, NULL, NULL);
1018		if (error < 0) {
1019			dprintk("nfs_create_server: getattr error = %d\n", -error);
1020			goto error;
1021		}
1022	}
1023	memcpy(&server->fsid, &fattr->fsid, sizeof(server->fsid));
1024
1025	dprintk("Server FSID: %llx:%llx\n",
1026		(unsigned long long) server->fsid.major,
1027		(unsigned long long) server->fsid.minor);
1028
1029	nfs_server_insert_lists(server);
1030	server->mount_time = jiffies;
1031	nfs_free_fattr(fattr);
1032	return server;
1033
1034error:
1035	nfs_free_fattr(fattr);
1036	nfs_free_server(server);
1037	return ERR_PTR(error);
1038}
1039EXPORT_SYMBOL_GPL(nfs_create_server);
1040
1041/*
1042 * Clone an NFS2, NFS3 or NFS4 server record
1043 */
1044struct nfs_server *nfs_clone_server(struct nfs_server *source,
1045				    struct nfs_fh *fh,
1046				    struct nfs_fattr *fattr,
1047				    rpc_authflavor_t flavor)
1048{
1049	struct nfs_server *server;
1050	struct nfs_fattr *fattr_fsinfo;
1051	int error;
1052
1053	server = nfs_alloc_server();
1054	if (!server)
1055		return ERR_PTR(-ENOMEM);
1056
1057	server->cred = get_cred(source->cred);
1058
1059	error = -ENOMEM;
1060	fattr_fsinfo = nfs_alloc_fattr();
1061	if (fattr_fsinfo == NULL)
1062		goto out_free_server;
1063
1064	/* Copy data from the source */
1065	server->nfs_client = source->nfs_client;
1066	server->destroy = source->destroy;
1067	refcount_inc(&server->nfs_client->cl_count);
1068	nfs_server_copy_userdata(server, source);
1069
1070	server->fsid = fattr->fsid;
1071
1072	error = nfs_init_server_rpcclient(server,
1073			source->client->cl_timeout,
1074			flavor);
1075	if (error < 0)
1076		goto out_free_server;
1077
1078	/* probe the filesystem info for this server filesystem */
1079	error = nfs_probe_fsinfo(server, fh, fattr_fsinfo);
1080	if (error < 0)
1081		goto out_free_server;
1082
1083	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1084		server->namelen = NFS4_MAXNAMLEN;
1085
1086	error = nfs_start_lockd(server);
1087	if (error < 0)
1088		goto out_free_server;
1089
1090	nfs_server_insert_lists(server);
1091	server->mount_time = jiffies;
1092
1093	nfs_free_fattr(fattr_fsinfo);
1094	return server;
1095
1096out_free_server:
1097	nfs_free_fattr(fattr_fsinfo);
1098	nfs_free_server(server);
1099	return ERR_PTR(error);
1100}
1101EXPORT_SYMBOL_GPL(nfs_clone_server);
1102
1103void nfs_clients_init(struct net *net)
1104{
1105	struct nfs_net *nn = net_generic(net, nfs_net_id);
1106
1107	INIT_LIST_HEAD(&nn->nfs_client_list);
1108	INIT_LIST_HEAD(&nn->nfs_volume_list);
1109#if IS_ENABLED(CONFIG_NFS_V4)
1110	idr_init(&nn->cb_ident_idr);
1111#endif
1112	spin_lock_init(&nn->nfs_client_lock);
1113	nn->boot_time = ktime_get_real();
1114	memset(&nn->rpcstats, 0, sizeof(nn->rpcstats));
1115	nn->rpcstats.program = &nfs_program;
1116
1117	nfs_netns_sysfs_setup(nn, net);
1118}
1119
1120void nfs_clients_exit(struct net *net)
1121{
1122	struct nfs_net *nn = net_generic(net, nfs_net_id);
1123
1124	nfs_netns_sysfs_destroy(nn);
1125	nfs_cleanup_cb_ident_idr(net);
1126	WARN_ON_ONCE(!list_empty(&nn->nfs_client_list));
1127	WARN_ON_ONCE(!list_empty(&nn->nfs_volume_list));
1128}
1129
1130#ifdef CONFIG_PROC_FS
1131static void *nfs_server_list_start(struct seq_file *p, loff_t *pos);
1132static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos);
1133static void nfs_server_list_stop(struct seq_file *p, void *v);
1134static int nfs_server_list_show(struct seq_file *m, void *v);
1135
1136static const struct seq_operations nfs_server_list_ops = {
1137	.start	= nfs_server_list_start,
1138	.next	= nfs_server_list_next,
1139	.stop	= nfs_server_list_stop,
1140	.show	= nfs_server_list_show,
1141};
1142
1143static void *nfs_volume_list_start(struct seq_file *p, loff_t *pos);
1144static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos);
1145static void nfs_volume_list_stop(struct seq_file *p, void *v);
1146static int nfs_volume_list_show(struct seq_file *m, void *v);
1147
1148static const struct seq_operations nfs_volume_list_ops = {
1149	.start	= nfs_volume_list_start,
1150	.next	= nfs_volume_list_next,
1151	.stop	= nfs_volume_list_stop,
1152	.show	= nfs_volume_list_show,
1153};
1154
1155/*
1156 * set up the iterator to start reading from the server list and return the first item
1157 */
1158static void *nfs_server_list_start(struct seq_file *m, loff_t *_pos)
1159				__acquires(&nn->nfs_client_lock)
1160{
1161	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1162
1163	/* lock the list against modification */
1164	spin_lock(&nn->nfs_client_lock);
1165	return seq_list_start_head(&nn->nfs_client_list, *_pos);
1166}
1167
1168/*
1169 * move to next server
1170 */
1171static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos)
1172{
1173	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1174
1175	return seq_list_next(v, &nn->nfs_client_list, pos);
1176}
1177
1178/*
1179 * clean up after reading from the transports list
1180 */
1181static void nfs_server_list_stop(struct seq_file *p, void *v)
1182				__releases(&nn->nfs_client_lock)
1183{
1184	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1185
1186	spin_unlock(&nn->nfs_client_lock);
1187}
1188
1189/*
1190 * display a header line followed by a load of call lines
1191 */
1192static int nfs_server_list_show(struct seq_file *m, void *v)
1193{
1194	struct nfs_client *clp;
1195	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1196
1197	/* display header on line 1 */
1198	if (v == &nn->nfs_client_list) {
1199		seq_puts(m, "NV SERVER   PORT USE HOSTNAME\n");
1200		return 0;
1201	}
1202
1203	/* display one transport per line on subsequent lines */
1204	clp = list_entry(v, struct nfs_client, cl_share_link);
1205
1206	/* Check if the client is initialized */
1207	if (clp->cl_cons_state != NFS_CS_READY)
1208		return 0;
1209
1210	rcu_read_lock();
1211	seq_printf(m, "v%u %s %s %3d %s\n",
1212		   clp->rpc_ops->version,
1213		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1214		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1215		   refcount_read(&clp->cl_count),
1216		   clp->cl_hostname);
1217	rcu_read_unlock();
1218
1219	return 0;
1220}
1221
1222/*
1223 * set up the iterator to start reading from the volume list and return the first item
1224 */
1225static void *nfs_volume_list_start(struct seq_file *m, loff_t *_pos)
1226				__acquires(&nn->nfs_client_lock)
1227{
1228	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1229
1230	/* lock the list against modification */
1231	spin_lock(&nn->nfs_client_lock);
1232	return seq_list_start_head(&nn->nfs_volume_list, *_pos);
1233}
1234
1235/*
1236 * move to next volume
1237 */
1238static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos)
1239{
1240	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1241
1242	return seq_list_next(v, &nn->nfs_volume_list, pos);
1243}
1244
1245/*
1246 * clean up after reading from the transports list
1247 */
1248static void nfs_volume_list_stop(struct seq_file *p, void *v)
1249				__releases(&nn->nfs_client_lock)
1250{
1251	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1252
1253	spin_unlock(&nn->nfs_client_lock);
1254}
1255
1256/*
1257 * display a header line followed by a load of call lines
1258 */
1259static int nfs_volume_list_show(struct seq_file *m, void *v)
1260{
1261	struct nfs_server *server;
1262	struct nfs_client *clp;
1263	char dev[13];	// 8 for 2^24, 1 for ':', 3 for 2^8, 1 for '\0'
1264	char fsid[34];	// 2 * 16 for %llx, 1 for ':', 1 for '\0'
1265	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1266
1267	/* display header on line 1 */
1268	if (v == &nn->nfs_volume_list) {
1269		seq_puts(m, "NV SERVER   PORT DEV          FSID"
1270			    "                              FSC\n");
1271		return 0;
1272	}
1273	/* display one transport per line on subsequent lines */
1274	server = list_entry(v, struct nfs_server, master_link);
1275	clp = server->nfs_client;
1276
1277	snprintf(dev, sizeof(dev), "%u:%u",
1278		 MAJOR(server->s_dev), MINOR(server->s_dev));
1279
1280	snprintf(fsid, sizeof(fsid), "%llx:%llx",
1281		 (unsigned long long) server->fsid.major,
1282		 (unsigned long long) server->fsid.minor);
1283
1284	rcu_read_lock();
1285	seq_printf(m, "v%u %s %s %-12s %-33s %s\n",
1286		   clp->rpc_ops->version,
1287		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1288		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1289		   dev,
1290		   fsid,
1291		   nfs_server_fscache_state(server));
1292	rcu_read_unlock();
1293
1294	return 0;
1295}
1296
1297int nfs_fs_proc_net_init(struct net *net)
1298{
1299	struct nfs_net *nn = net_generic(net, nfs_net_id);
1300	struct proc_dir_entry *p;
1301
1302	nn->proc_nfsfs = proc_net_mkdir(net, "nfsfs", net->proc_net);
1303	if (!nn->proc_nfsfs)
1304		goto error_0;
1305
1306	/* a file of servers with which we're dealing */
1307	p = proc_create_net("servers", S_IFREG|S_IRUGO, nn->proc_nfsfs,
1308			&nfs_server_list_ops, sizeof(struct seq_net_private));
1309	if (!p)
1310		goto error_1;
1311
1312	/* a file of volumes that we have mounted */
1313	p = proc_create_net("volumes", S_IFREG|S_IRUGO, nn->proc_nfsfs,
1314			&nfs_volume_list_ops, sizeof(struct seq_net_private));
1315	if (!p)
1316		goto error_1;
1317	return 0;
1318
1319error_1:
1320	remove_proc_subtree("nfsfs", net->proc_net);
1321error_0:
1322	return -ENOMEM;
1323}
1324
1325void nfs_fs_proc_net_exit(struct net *net)
1326{
1327	remove_proc_subtree("nfsfs", net->proc_net);
1328}
1329
1330/*
1331 * initialise the /proc/fs/nfsfs/ directory
1332 */
1333int __init nfs_fs_proc_init(void)
1334{
1335	if (!proc_mkdir("fs/nfsfs", NULL))
1336		goto error_0;
1337
1338	/* a file of servers with which we're dealing */
1339	if (!proc_symlink("fs/nfsfs/servers", NULL, "../../net/nfsfs/servers"))
1340		goto error_1;
1341
1342	/* a file of volumes that we have mounted */
1343	if (!proc_symlink("fs/nfsfs/volumes", NULL, "../../net/nfsfs/volumes"))
1344		goto error_1;
1345
1346	return 0;
1347error_1:
1348	remove_proc_subtree("fs/nfsfs", NULL);
1349error_0:
1350	return -ENOMEM;
1351}
1352
1353/*
1354 * clean up the /proc/fs/nfsfs/ directory
1355 */
1356void nfs_fs_proc_exit(void)
1357{
1358	remove_proc_subtree("fs/nfsfs", NULL);
1359}
1360
1361#endif /* CONFIG_PROC_FS */
1362