xref: /openbmc/linux/fs/nfs/client.c (revision 5e012745)
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 
54 #define NFSDBG_FACILITY		NFSDBG_CLIENT
55 
56 static DECLARE_WAIT_QUEUE_HEAD(nfs_client_active_wq);
57 static DEFINE_SPINLOCK(nfs_version_lock);
58 static DEFINE_MUTEX(nfs_version_mutex);
59 static LIST_HEAD(nfs_versions);
60 
61 /*
62  * RPC cruft for NFS
63  */
64 static const struct rpc_version *nfs_version[5] = {
65 	[2] = NULL,
66 	[3] = NULL,
67 	[4] = NULL,
68 };
69 
70 const struct rpc_program nfs_program = {
71 	.name			= "nfs",
72 	.number			= NFS_PROGRAM,
73 	.nrvers			= ARRAY_SIZE(nfs_version),
74 	.version		= nfs_version,
75 	.stats			= &nfs_rpcstat,
76 	.pipe_dir_name		= NFS_PIPE_DIRNAME,
77 };
78 
79 struct rpc_stat nfs_rpcstat = {
80 	.program		= &nfs_program
81 };
82 
83 static 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 
99 struct 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 
115 void put_nfs_version(struct nfs_subversion *nfs)
116 {
117 	module_put(nfs->owner);
118 }
119 
120 void 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 }
129 EXPORT_SYMBOL_GPL(register_nfs_version);
130 
131 void 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 }
140 EXPORT_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  */
148 struct 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_nfs_mod = cl_init->nfs_mod;
157 	if (!try_module_get(clp->cl_nfs_mod->owner))
158 		goto error_dealloc;
159 
160 	clp->rpc_ops = clp->cl_nfs_mod->rpc_ops;
161 
162 	refcount_set(&clp->cl_count, 1);
163 	clp->cl_cons_state = NFS_CS_INITING;
164 
165 	memcpy(&clp->cl_addr, cl_init->addr, cl_init->addrlen);
166 	clp->cl_addrlen = cl_init->addrlen;
167 
168 	if (cl_init->hostname) {
169 		err = -ENOMEM;
170 		clp->cl_hostname = kstrdup(cl_init->hostname, GFP_KERNEL);
171 		if (!clp->cl_hostname)
172 			goto error_cleanup;
173 	}
174 
175 	INIT_LIST_HEAD(&clp->cl_superblocks);
176 	clp->cl_rpcclient = ERR_PTR(-EINVAL);
177 
178 	clp->cl_proto = cl_init->proto;
179 	clp->cl_nconnect = cl_init->nconnect;
180 	clp->cl_net = get_net(cl_init->net);
181 
182 	clp->cl_principal = "*";
183 	nfs_fscache_get_client_cookie(clp);
184 
185 	return clp;
186 
187 error_cleanup:
188 	put_nfs_version(clp->cl_nfs_mod);
189 error_dealloc:
190 	kfree(clp);
191 error_0:
192 	return ERR_PTR(err);
193 }
194 EXPORT_SYMBOL_GPL(nfs_alloc_client);
195 
196 #if IS_ENABLED(CONFIG_NFS_V4)
197 static void nfs_cleanup_cb_ident_idr(struct net *net)
198 {
199 	struct nfs_net *nn = net_generic(net, nfs_net_id);
200 
201 	idr_destroy(&nn->cb_ident_idr);
202 }
203 
204 /* nfs_client_lock held */
205 static void nfs_cb_idr_remove_locked(struct nfs_client *clp)
206 {
207 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
208 
209 	if (clp->cl_cb_ident)
210 		idr_remove(&nn->cb_ident_idr, clp->cl_cb_ident);
211 }
212 
213 static void pnfs_init_server(struct nfs_server *server)
214 {
215 	rpc_init_wait_queue(&server->roc_rpcwaitq, "pNFS ROC");
216 }
217 
218 #else
219 static void nfs_cleanup_cb_ident_idr(struct net *net)
220 {
221 }
222 
223 static void nfs_cb_idr_remove_locked(struct nfs_client *clp)
224 {
225 }
226 
227 static void pnfs_init_server(struct nfs_server *server)
228 {
229 }
230 
231 #endif /* CONFIG_NFS_V4 */
232 
233 /*
234  * Destroy a shared client record
235  */
236 void nfs_free_client(struct nfs_client *clp)
237 {
238 	nfs_fscache_release_client_cookie(clp);
239 
240 	/* -EIO all pending I/O */
241 	if (!IS_ERR(clp->cl_rpcclient))
242 		rpc_shutdown_client(clp->cl_rpcclient);
243 
244 	put_net(clp->cl_net);
245 	put_nfs_version(clp->cl_nfs_mod);
246 	kfree(clp->cl_hostname);
247 	kfree(clp->cl_acceptor);
248 	kfree(clp);
249 }
250 EXPORT_SYMBOL_GPL(nfs_free_client);
251 
252 /*
253  * Release a reference to a shared client record
254  */
255 void nfs_put_client(struct nfs_client *clp)
256 {
257 	struct nfs_net *nn;
258 
259 	if (!clp)
260 		return;
261 
262 	nn = net_generic(clp->cl_net, nfs_net_id);
263 
264 	if (refcount_dec_and_lock(&clp->cl_count, &nn->nfs_client_lock)) {
265 		list_del(&clp->cl_share_link);
266 		nfs_cb_idr_remove_locked(clp);
267 		spin_unlock(&nn->nfs_client_lock);
268 
269 		WARN_ON_ONCE(!list_empty(&clp->cl_superblocks));
270 
271 		clp->rpc_ops->free_client(clp);
272 	}
273 }
274 EXPORT_SYMBOL_GPL(nfs_put_client);
275 
276 /*
277  * Find an nfs_client on the list that matches the initialisation data
278  * that is supplied.
279  */
280 static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *data)
281 {
282 	struct nfs_client *clp;
283 	const struct sockaddr *sap = data->addr;
284 	struct nfs_net *nn = net_generic(data->net, nfs_net_id);
285 	int error;
286 
287 again:
288 	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
289 	        const struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
290 		/* Don't match clients that failed to initialise properly */
291 		if (clp->cl_cons_state < 0)
292 			continue;
293 
294 		/* If a client is still initializing then we need to wait */
295 		if (clp->cl_cons_state > NFS_CS_READY) {
296 			refcount_inc(&clp->cl_count);
297 			spin_unlock(&nn->nfs_client_lock);
298 			error = nfs_wait_client_init_complete(clp);
299 			nfs_put_client(clp);
300 			spin_lock(&nn->nfs_client_lock);
301 			if (error < 0)
302 				return ERR_PTR(error);
303 			goto again;
304 		}
305 
306 		/* Different NFS versions cannot share the same nfs_client */
307 		if (clp->rpc_ops != data->nfs_mod->rpc_ops)
308 			continue;
309 
310 		if (clp->cl_proto != data->proto)
311 			continue;
312 		/* Match nfsv4 minorversion */
313 		if (clp->cl_minorversion != data->minorversion)
314 			continue;
315 		/* Match the full socket address */
316 		if (!rpc_cmp_addr_port(sap, clap))
317 			/* Match all xprt_switch full socket addresses */
318 			if (IS_ERR(clp->cl_rpcclient) ||
319                             !rpc_clnt_xprt_switch_has_addr(clp->cl_rpcclient,
320 							   sap))
321 				continue;
322 
323 		refcount_inc(&clp->cl_count);
324 		return clp;
325 	}
326 	return NULL;
327 }
328 
329 /*
330  * Return true if @clp is done initializing, false if still working on it.
331  *
332  * Use nfs_client_init_status to check if it was successful.
333  */
334 bool nfs_client_init_is_complete(const struct nfs_client *clp)
335 {
336 	return clp->cl_cons_state <= NFS_CS_READY;
337 }
338 EXPORT_SYMBOL_GPL(nfs_client_init_is_complete);
339 
340 /*
341  * Return 0 if @clp was successfully initialized, -errno otherwise.
342  *
343  * This must be called *after* nfs_client_init_is_complete() returns true,
344  * otherwise it will pop WARN_ON_ONCE and return -EINVAL
345  */
346 int nfs_client_init_status(const struct nfs_client *clp)
347 {
348 	/* called without checking nfs_client_init_is_complete */
349 	if (clp->cl_cons_state > NFS_CS_READY) {
350 		WARN_ON_ONCE(1);
351 		return -EINVAL;
352 	}
353 	return clp->cl_cons_state;
354 }
355 EXPORT_SYMBOL_GPL(nfs_client_init_status);
356 
357 int nfs_wait_client_init_complete(const struct nfs_client *clp)
358 {
359 	return wait_event_killable(nfs_client_active_wq,
360 			nfs_client_init_is_complete(clp));
361 }
362 EXPORT_SYMBOL_GPL(nfs_wait_client_init_complete);
363 
364 /*
365  * Found an existing client.  Make sure it's ready before returning.
366  */
367 static struct nfs_client *
368 nfs_found_client(const struct nfs_client_initdata *cl_init,
369 		 struct nfs_client *clp)
370 {
371 	int error;
372 
373 	error = nfs_wait_client_init_complete(clp);
374 	if (error < 0) {
375 		nfs_put_client(clp);
376 		return ERR_PTR(-ERESTARTSYS);
377 	}
378 
379 	if (clp->cl_cons_state < NFS_CS_READY) {
380 		error = clp->cl_cons_state;
381 		nfs_put_client(clp);
382 		return ERR_PTR(error);
383 	}
384 
385 	smp_rmb();
386 	return clp;
387 }
388 
389 /*
390  * Look up a client by IP address and protocol version
391  * - creates a new record if one doesn't yet exist
392  */
393 struct nfs_client *nfs_get_client(const struct nfs_client_initdata *cl_init)
394 {
395 	struct nfs_client *clp, *new = NULL;
396 	struct nfs_net *nn = net_generic(cl_init->net, nfs_net_id);
397 	const struct nfs_rpc_ops *rpc_ops = cl_init->nfs_mod->rpc_ops;
398 
399 	if (cl_init->hostname == NULL) {
400 		WARN_ON(1);
401 		return NULL;
402 	}
403 
404 	/* see if the client already exists */
405 	do {
406 		spin_lock(&nn->nfs_client_lock);
407 
408 		clp = nfs_match_client(cl_init);
409 		if (clp) {
410 			spin_unlock(&nn->nfs_client_lock);
411 			if (new)
412 				new->rpc_ops->free_client(new);
413 			if (IS_ERR(clp))
414 				return clp;
415 			return nfs_found_client(cl_init, clp);
416 		}
417 		if (new) {
418 			list_add_tail(&new->cl_share_link,
419 					&nn->nfs_client_list);
420 			spin_unlock(&nn->nfs_client_lock);
421 			new->cl_flags = cl_init->init_flags;
422 			return rpc_ops->init_client(new, cl_init);
423 		}
424 
425 		spin_unlock(&nn->nfs_client_lock);
426 
427 		new = rpc_ops->alloc_client(cl_init);
428 	} while (!IS_ERR(new));
429 
430 	return new;
431 }
432 EXPORT_SYMBOL_GPL(nfs_get_client);
433 
434 /*
435  * Mark a server as ready or failed
436  */
437 void nfs_mark_client_ready(struct nfs_client *clp, int state)
438 {
439 	smp_wmb();
440 	clp->cl_cons_state = state;
441 	wake_up_all(&nfs_client_active_wq);
442 }
443 EXPORT_SYMBOL_GPL(nfs_mark_client_ready);
444 
445 /*
446  * Initialise the timeout values for a connection
447  */
448 void nfs_init_timeout_values(struct rpc_timeout *to, int proto,
449 				    int timeo, int retrans)
450 {
451 	to->to_initval = timeo * HZ / 10;
452 	to->to_retries = retrans;
453 
454 	switch (proto) {
455 	case XPRT_TRANSPORT_TCP:
456 	case XPRT_TRANSPORT_RDMA:
457 		if (retrans == NFS_UNSPEC_RETRANS)
458 			to->to_retries = NFS_DEF_TCP_RETRANS;
459 		if (timeo == NFS_UNSPEC_TIMEO || to->to_initval == 0)
460 			to->to_initval = NFS_DEF_TCP_TIMEO * HZ / 10;
461 		if (to->to_initval > NFS_MAX_TCP_TIMEOUT)
462 			to->to_initval = NFS_MAX_TCP_TIMEOUT;
463 		to->to_increment = to->to_initval;
464 		to->to_maxval = to->to_initval + (to->to_increment * to->to_retries);
465 		if (to->to_maxval > NFS_MAX_TCP_TIMEOUT)
466 			to->to_maxval = NFS_MAX_TCP_TIMEOUT;
467 		if (to->to_maxval < to->to_initval)
468 			to->to_maxval = to->to_initval;
469 		to->to_exponential = 0;
470 		break;
471 	case XPRT_TRANSPORT_UDP:
472 		if (retrans == NFS_UNSPEC_RETRANS)
473 			to->to_retries = NFS_DEF_UDP_RETRANS;
474 		if (timeo == NFS_UNSPEC_TIMEO || to->to_initval == 0)
475 			to->to_initval = NFS_DEF_UDP_TIMEO * HZ / 10;
476 		if (to->to_initval > NFS_MAX_UDP_TIMEOUT)
477 			to->to_initval = NFS_MAX_UDP_TIMEOUT;
478 		to->to_maxval = NFS_MAX_UDP_TIMEOUT;
479 		to->to_exponential = 1;
480 		break;
481 	default:
482 		BUG();
483 	}
484 }
485 EXPORT_SYMBOL_GPL(nfs_init_timeout_values);
486 
487 /*
488  * Create an RPC client handle
489  */
490 int nfs_create_rpc_client(struct nfs_client *clp,
491 			  const struct nfs_client_initdata *cl_init,
492 			  rpc_authflavor_t flavor)
493 {
494 	struct rpc_clnt		*clnt = NULL;
495 	struct rpc_create_args args = {
496 		.net		= clp->cl_net,
497 		.protocol	= clp->cl_proto,
498 		.nconnect	= clp->cl_nconnect,
499 		.address	= (struct sockaddr *)&clp->cl_addr,
500 		.addrsize	= clp->cl_addrlen,
501 		.timeout	= cl_init->timeparms,
502 		.servername	= clp->cl_hostname,
503 		.nodename	= cl_init->nodename,
504 		.program	= &nfs_program,
505 		.version	= clp->rpc_ops->version,
506 		.authflavor	= flavor,
507 		.cred		= cl_init->cred,
508 	};
509 
510 	if (test_bit(NFS_CS_DISCRTRY, &clp->cl_flags))
511 		args.flags |= RPC_CLNT_CREATE_DISCRTRY;
512 	if (test_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags))
513 		args.flags |= RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT;
514 	if (test_bit(NFS_CS_NORESVPORT, &clp->cl_flags))
515 		args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
516 	if (test_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags))
517 		args.flags |= RPC_CLNT_CREATE_INFINITE_SLOTS;
518 
519 	if (!IS_ERR(clp->cl_rpcclient))
520 		return 0;
521 
522 	clnt = rpc_create(&args);
523 	if (IS_ERR(clnt)) {
524 		dprintk("%s: cannot create RPC client. Error = %ld\n",
525 				__func__, PTR_ERR(clnt));
526 		return PTR_ERR(clnt);
527 	}
528 
529 	clnt->cl_principal = clp->cl_principal;
530 	clp->cl_rpcclient = clnt;
531 	return 0;
532 }
533 EXPORT_SYMBOL_GPL(nfs_create_rpc_client);
534 
535 /*
536  * Version 2 or 3 client destruction
537  */
538 static void nfs_destroy_server(struct nfs_server *server)
539 {
540 	if (server->nlm_host)
541 		nlmclnt_done(server->nlm_host);
542 }
543 
544 /*
545  * Version 2 or 3 lockd setup
546  */
547 static int nfs_start_lockd(struct nfs_server *server)
548 {
549 	struct nlm_host *host;
550 	struct nfs_client *clp = server->nfs_client;
551 	struct nlmclnt_initdata nlm_init = {
552 		.hostname	= clp->cl_hostname,
553 		.address	= (struct sockaddr *)&clp->cl_addr,
554 		.addrlen	= clp->cl_addrlen,
555 		.nfs_version	= clp->rpc_ops->version,
556 		.noresvport	= server->flags & NFS_MOUNT_NORESVPORT ?
557 					1 : 0,
558 		.net		= clp->cl_net,
559 		.nlmclnt_ops 	= clp->cl_nfs_mod->rpc_ops->nlmclnt_ops,
560 		.cred		= current_cred(),
561 	};
562 
563 	if (nlm_init.nfs_version > 3)
564 		return 0;
565 	if ((server->flags & NFS_MOUNT_LOCAL_FLOCK) &&
566 			(server->flags & NFS_MOUNT_LOCAL_FCNTL))
567 		return 0;
568 
569 	switch (clp->cl_proto) {
570 		default:
571 			nlm_init.protocol = IPPROTO_TCP;
572 			break;
573 		case XPRT_TRANSPORT_UDP:
574 			nlm_init.protocol = IPPROTO_UDP;
575 	}
576 
577 	host = nlmclnt_init(&nlm_init);
578 	if (IS_ERR(host))
579 		return PTR_ERR(host);
580 
581 	server->nlm_host = host;
582 	server->destroy = nfs_destroy_server;
583 	return 0;
584 }
585 
586 /*
587  * Create a general RPC client
588  */
589 int nfs_init_server_rpcclient(struct nfs_server *server,
590 		const struct rpc_timeout *timeo,
591 		rpc_authflavor_t pseudoflavour)
592 {
593 	struct nfs_client *clp = server->nfs_client;
594 
595 	server->client = rpc_clone_client_set_auth(clp->cl_rpcclient,
596 							pseudoflavour);
597 	if (IS_ERR(server->client)) {
598 		dprintk("%s: couldn't create rpc_client!\n", __func__);
599 		return PTR_ERR(server->client);
600 	}
601 
602 	memcpy(&server->client->cl_timeout_default,
603 			timeo,
604 			sizeof(server->client->cl_timeout_default));
605 	server->client->cl_timeout = &server->client->cl_timeout_default;
606 	server->client->cl_softrtry = 0;
607 	if (server->flags & NFS_MOUNT_SOFTERR)
608 		server->client->cl_softerr = 1;
609 	if (server->flags & NFS_MOUNT_SOFT)
610 		server->client->cl_softrtry = 1;
611 
612 	return 0;
613 }
614 EXPORT_SYMBOL_GPL(nfs_init_server_rpcclient);
615 
616 /**
617  * nfs_init_client - Initialise an NFS2 or NFS3 client
618  *
619  * @clp: nfs_client to initialise
620  * @cl_init: Initialisation parameters
621  *
622  * Returns pointer to an NFS client, or an ERR_PTR value.
623  */
624 struct nfs_client *nfs_init_client(struct nfs_client *clp,
625 				   const struct nfs_client_initdata *cl_init)
626 {
627 	int error;
628 
629 	/* the client is already initialised */
630 	if (clp->cl_cons_state == NFS_CS_READY)
631 		return clp;
632 
633 	/*
634 	 * Create a client RPC handle for doing FSSTAT with UNIX auth only
635 	 * - RFC 2623, sec 2.3.2
636 	 */
637 	error = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_UNIX);
638 	nfs_mark_client_ready(clp, error == 0 ? NFS_CS_READY : error);
639 	if (error < 0) {
640 		nfs_put_client(clp);
641 		clp = ERR_PTR(error);
642 	}
643 	return clp;
644 }
645 EXPORT_SYMBOL_GPL(nfs_init_client);
646 
647 /*
648  * Create a version 2 or 3 client
649  */
650 static int nfs_init_server(struct nfs_server *server,
651 			   const struct nfs_parsed_mount_data *data,
652 			   struct nfs_subversion *nfs_mod)
653 {
654 	struct rpc_timeout timeparms;
655 	struct nfs_client_initdata cl_init = {
656 		.hostname = data->nfs_server.hostname,
657 		.addr = (const struct sockaddr *)&data->nfs_server.address,
658 		.addrlen = data->nfs_server.addrlen,
659 		.nfs_mod = nfs_mod,
660 		.proto = data->nfs_server.protocol,
661 		.net = data->net,
662 		.timeparms = &timeparms,
663 		.cred = server->cred,
664 		.nconnect = data->nfs_server.nconnect,
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 	nfs_netns_sysfs_setup(nn, net);
1081 }
1082 
1083 void nfs_clients_exit(struct net *net)
1084 {
1085 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1086 
1087 	nfs_netns_sysfs_destroy(nn);
1088 	nfs_cleanup_cb_ident_idr(net);
1089 	WARN_ON_ONCE(!list_empty(&nn->nfs_client_list));
1090 	WARN_ON_ONCE(!list_empty(&nn->nfs_volume_list));
1091 }
1092 
1093 #ifdef CONFIG_PROC_FS
1094 static void *nfs_server_list_start(struct seq_file *p, loff_t *pos);
1095 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos);
1096 static void nfs_server_list_stop(struct seq_file *p, void *v);
1097 static int nfs_server_list_show(struct seq_file *m, void *v);
1098 
1099 static const struct seq_operations nfs_server_list_ops = {
1100 	.start	= nfs_server_list_start,
1101 	.next	= nfs_server_list_next,
1102 	.stop	= nfs_server_list_stop,
1103 	.show	= nfs_server_list_show,
1104 };
1105 
1106 static void *nfs_volume_list_start(struct seq_file *p, loff_t *pos);
1107 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos);
1108 static void nfs_volume_list_stop(struct seq_file *p, void *v);
1109 static int nfs_volume_list_show(struct seq_file *m, void *v);
1110 
1111 static const struct seq_operations nfs_volume_list_ops = {
1112 	.start	= nfs_volume_list_start,
1113 	.next	= nfs_volume_list_next,
1114 	.stop	= nfs_volume_list_stop,
1115 	.show	= nfs_volume_list_show,
1116 };
1117 
1118 /*
1119  * set up the iterator to start reading from the server list and return the first item
1120  */
1121 static void *nfs_server_list_start(struct seq_file *m, loff_t *_pos)
1122 				__acquires(&nn->nfs_client_lock)
1123 {
1124 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1125 
1126 	/* lock the list against modification */
1127 	spin_lock(&nn->nfs_client_lock);
1128 	return seq_list_start_head(&nn->nfs_client_list, *_pos);
1129 }
1130 
1131 /*
1132  * move to next server
1133  */
1134 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos)
1135 {
1136 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1137 
1138 	return seq_list_next(v, &nn->nfs_client_list, pos);
1139 }
1140 
1141 /*
1142  * clean up after reading from the transports list
1143  */
1144 static void nfs_server_list_stop(struct seq_file *p, void *v)
1145 				__releases(&nn->nfs_client_lock)
1146 {
1147 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1148 
1149 	spin_unlock(&nn->nfs_client_lock);
1150 }
1151 
1152 /*
1153  * display a header line followed by a load of call lines
1154  */
1155 static int nfs_server_list_show(struct seq_file *m, void *v)
1156 {
1157 	struct nfs_client *clp;
1158 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1159 
1160 	/* display header on line 1 */
1161 	if (v == &nn->nfs_client_list) {
1162 		seq_puts(m, "NV SERVER   PORT USE HOSTNAME\n");
1163 		return 0;
1164 	}
1165 
1166 	/* display one transport per line on subsequent lines */
1167 	clp = list_entry(v, struct nfs_client, cl_share_link);
1168 
1169 	/* Check if the client is initialized */
1170 	if (clp->cl_cons_state != NFS_CS_READY)
1171 		return 0;
1172 
1173 	rcu_read_lock();
1174 	seq_printf(m, "v%u %s %s %3d %s\n",
1175 		   clp->rpc_ops->version,
1176 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1177 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1178 		   refcount_read(&clp->cl_count),
1179 		   clp->cl_hostname);
1180 	rcu_read_unlock();
1181 
1182 	return 0;
1183 }
1184 
1185 /*
1186  * set up the iterator to start reading from the volume list and return the first item
1187  */
1188 static void *nfs_volume_list_start(struct seq_file *m, loff_t *_pos)
1189 				__acquires(&nn->nfs_client_lock)
1190 {
1191 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1192 
1193 	/* lock the list against modification */
1194 	spin_lock(&nn->nfs_client_lock);
1195 	return seq_list_start_head(&nn->nfs_volume_list, *_pos);
1196 }
1197 
1198 /*
1199  * move to next volume
1200  */
1201 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos)
1202 {
1203 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1204 
1205 	return seq_list_next(v, &nn->nfs_volume_list, pos);
1206 }
1207 
1208 /*
1209  * clean up after reading from the transports list
1210  */
1211 static void nfs_volume_list_stop(struct seq_file *p, void *v)
1212 				__releases(&nn->nfs_client_lock)
1213 {
1214 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1215 
1216 	spin_unlock(&nn->nfs_client_lock);
1217 }
1218 
1219 /*
1220  * display a header line followed by a load of call lines
1221  */
1222 static int nfs_volume_list_show(struct seq_file *m, void *v)
1223 {
1224 	struct nfs_server *server;
1225 	struct nfs_client *clp;
1226 	char dev[13];	// 8 for 2^24, 1 for ':', 3 for 2^8, 1 for '\0'
1227 	char fsid[34];	// 2 * 16 for %llx, 1 for ':', 1 for '\0'
1228 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1229 
1230 	/* display header on line 1 */
1231 	if (v == &nn->nfs_volume_list) {
1232 		seq_puts(m, "NV SERVER   PORT DEV          FSID"
1233 			    "                              FSC\n");
1234 		return 0;
1235 	}
1236 	/* display one transport per line on subsequent lines */
1237 	server = list_entry(v, struct nfs_server, master_link);
1238 	clp = server->nfs_client;
1239 
1240 	snprintf(dev, sizeof(dev), "%u:%u",
1241 		 MAJOR(server->s_dev), MINOR(server->s_dev));
1242 
1243 	snprintf(fsid, sizeof(fsid), "%llx:%llx",
1244 		 (unsigned long long) server->fsid.major,
1245 		 (unsigned long long) server->fsid.minor);
1246 
1247 	rcu_read_lock();
1248 	seq_printf(m, "v%u %s %s %-12s %-33s %s\n",
1249 		   clp->rpc_ops->version,
1250 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1251 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1252 		   dev,
1253 		   fsid,
1254 		   nfs_server_fscache_state(server));
1255 	rcu_read_unlock();
1256 
1257 	return 0;
1258 }
1259 
1260 int nfs_fs_proc_net_init(struct net *net)
1261 {
1262 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1263 	struct proc_dir_entry *p;
1264 
1265 	nn->proc_nfsfs = proc_net_mkdir(net, "nfsfs", net->proc_net);
1266 	if (!nn->proc_nfsfs)
1267 		goto error_0;
1268 
1269 	/* a file of servers with which we're dealing */
1270 	p = proc_create_net("servers", S_IFREG|S_IRUGO, nn->proc_nfsfs,
1271 			&nfs_server_list_ops, sizeof(struct seq_net_private));
1272 	if (!p)
1273 		goto error_1;
1274 
1275 	/* a file of volumes that we have mounted */
1276 	p = proc_create_net("volumes", S_IFREG|S_IRUGO, nn->proc_nfsfs,
1277 			&nfs_volume_list_ops, sizeof(struct seq_net_private));
1278 	if (!p)
1279 		goto error_1;
1280 	return 0;
1281 
1282 error_1:
1283 	remove_proc_subtree("nfsfs", net->proc_net);
1284 error_0:
1285 	return -ENOMEM;
1286 }
1287 
1288 void nfs_fs_proc_net_exit(struct net *net)
1289 {
1290 	remove_proc_subtree("nfsfs", net->proc_net);
1291 }
1292 
1293 /*
1294  * initialise the /proc/fs/nfsfs/ directory
1295  */
1296 int __init nfs_fs_proc_init(void)
1297 {
1298 	if (!proc_mkdir("fs/nfsfs", NULL))
1299 		goto error_0;
1300 
1301 	/* a file of servers with which we're dealing */
1302 	if (!proc_symlink("fs/nfsfs/servers", NULL, "../../net/nfsfs/servers"))
1303 		goto error_1;
1304 
1305 	/* a file of volumes that we have mounted */
1306 	if (!proc_symlink("fs/nfsfs/volumes", NULL, "../../net/nfsfs/volumes"))
1307 		goto error_1;
1308 
1309 	return 0;
1310 error_1:
1311 	remove_proc_subtree("fs/nfsfs", NULL);
1312 error_0:
1313 	return -ENOMEM;
1314 }
1315 
1316 /*
1317  * clean up the /proc/fs/nfsfs/ directory
1318  */
1319 void nfs_fs_proc_exit(void)
1320 {
1321 	remove_proc_subtree("fs/nfsfs", NULL);
1322 }
1323 
1324 #endif /* CONFIG_PROC_FS */
1325