xref: /linux/fs/nfs/client.c (revision 8b4a40809e5330c9da5d20107d693d92d73b31dc)
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/clnt.h>
24 #include <linux/sunrpc/stats.h>
25 #include <linux/sunrpc/metrics.h>
26 #include <linux/nfs_fs.h>
27 #include <linux/nfs_mount.h>
28 #include <linux/nfs4_mount.h>
29 #include <linux/lockd/bind.h>
30 #include <linux/seq_file.h>
31 #include <linux/mount.h>
32 #include <linux/nfs_idmap.h>
33 #include <linux/vfs.h>
34 #include <linux/inet.h>
35 #include <linux/nfs_xdr.h>
36 
37 #include <asm/system.h>
38 
39 #include "nfs4_fs.h"
40 #include "callback.h"
41 #include "delegation.h"
42 #include "iostat.h"
43 #include "internal.h"
44 
45 #define NFSDBG_FACILITY		NFSDBG_CLIENT
46 
47 static DEFINE_SPINLOCK(nfs_client_lock);
48 static LIST_HEAD(nfs_client_list);
49 static LIST_HEAD(nfs_volume_list);
50 static DECLARE_WAIT_QUEUE_HEAD(nfs_client_active_wq);
51 
52 /*
53  * RPC cruft for NFS
54  */
55 static struct rpc_version *nfs_version[5] = {
56 	[2]			= &nfs_version2,
57 #ifdef CONFIG_NFS_V3
58 	[3]			= &nfs_version3,
59 #endif
60 #ifdef CONFIG_NFS_V4
61 	[4]			= &nfs_version4,
62 #endif
63 };
64 
65 struct rpc_program nfs_program = {
66 	.name			= "nfs",
67 	.number			= NFS_PROGRAM,
68 	.nrvers			= ARRAY_SIZE(nfs_version),
69 	.version		= nfs_version,
70 	.stats			= &nfs_rpcstat,
71 	.pipe_dir_name		= "/nfs",
72 };
73 
74 struct rpc_stat nfs_rpcstat = {
75 	.program		= &nfs_program
76 };
77 
78 
79 #ifdef CONFIG_NFS_V3_ACL
80 static struct rpc_stat		nfsacl_rpcstat = { &nfsacl_program };
81 static struct rpc_version *	nfsacl_version[] = {
82 	[3]			= &nfsacl_version3,
83 };
84 
85 struct rpc_program		nfsacl_program = {
86 	.name			= "nfsacl",
87 	.number			= NFS_ACL_PROGRAM,
88 	.nrvers			= ARRAY_SIZE(nfsacl_version),
89 	.version		= nfsacl_version,
90 	.stats			= &nfsacl_rpcstat,
91 };
92 #endif  /* CONFIG_NFS_V3_ACL */
93 
94 /*
95  * Allocate a shared client record
96  *
97  * Since these are allocated/deallocated very rarely, we don't
98  * bother putting them in a slab cache...
99  */
100 static struct nfs_client *nfs_alloc_client(const char *hostname,
101 					   const struct sockaddr_in *addr,
102 					   int nfsversion)
103 {
104 	struct nfs_client *clp;
105 
106 	if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL)
107 		goto error_0;
108 
109 	if (nfsversion == 4) {
110 		if (nfs_callback_up() < 0)
111 			goto error_2;
112 		__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
113 	}
114 
115 	atomic_set(&clp->cl_count, 1);
116 	clp->cl_cons_state = NFS_CS_INITING;
117 
118 	clp->cl_nfsversion = nfsversion;
119 	memcpy(&clp->cl_addr, addr, sizeof(clp->cl_addr));
120 
121 	if (hostname) {
122 		clp->cl_hostname = kstrdup(hostname, GFP_KERNEL);
123 		if (!clp->cl_hostname)
124 			goto error_3;
125 	}
126 
127 	INIT_LIST_HEAD(&clp->cl_superblocks);
128 	clp->cl_rpcclient = ERR_PTR(-EINVAL);
129 
130 #ifdef CONFIG_NFS_V4
131 	init_rwsem(&clp->cl_sem);
132 	INIT_LIST_HEAD(&clp->cl_delegations);
133 	spin_lock_init(&clp->cl_lock);
134 	INIT_DELAYED_WORK(&clp->cl_renewd, nfs4_renew_state);
135 	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
136 	clp->cl_boot_time = CURRENT_TIME;
137 	clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
138 #endif
139 
140 	return clp;
141 
142 error_3:
143 	if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
144 		nfs_callback_down();
145 error_2:
146 	kfree(clp);
147 error_0:
148 	return NULL;
149 }
150 
151 static void nfs4_shutdown_client(struct nfs_client *clp)
152 {
153 #ifdef CONFIG_NFS_V4
154 	if (__test_and_clear_bit(NFS_CS_RENEWD, &clp->cl_res_state))
155 		nfs4_kill_renewd(clp);
156 	BUG_ON(!RB_EMPTY_ROOT(&clp->cl_state_owners));
157 	if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state))
158 		nfs_idmap_delete(clp);
159 #endif
160 }
161 
162 /*
163  * Destroy a shared client record
164  */
165 static void nfs_free_client(struct nfs_client *clp)
166 {
167 	dprintk("--> nfs_free_client(%d)\n", clp->cl_nfsversion);
168 
169 	nfs4_shutdown_client(clp);
170 
171 	/* -EIO all pending I/O */
172 	if (!IS_ERR(clp->cl_rpcclient))
173 		rpc_shutdown_client(clp->cl_rpcclient);
174 
175 	if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
176 		nfs_callback_down();
177 
178 	kfree(clp->cl_hostname);
179 	kfree(clp);
180 
181 	dprintk("<-- nfs_free_client()\n");
182 }
183 
184 /*
185  * Release a reference to a shared client record
186  */
187 void nfs_put_client(struct nfs_client *clp)
188 {
189 	if (!clp)
190 		return;
191 
192 	dprintk("--> nfs_put_client({%d})\n", atomic_read(&clp->cl_count));
193 
194 	if (atomic_dec_and_lock(&clp->cl_count, &nfs_client_lock)) {
195 		list_del(&clp->cl_share_link);
196 		spin_unlock(&nfs_client_lock);
197 
198 		BUG_ON(!list_empty(&clp->cl_superblocks));
199 
200 		nfs_free_client(clp);
201 	}
202 }
203 
204 /*
205  * Find a client by address
206  * - caller must hold nfs_client_lock
207  */
208 static struct nfs_client *__nfs_find_client(const struct sockaddr_in *addr, int nfsversion, int match_port)
209 {
210 	struct nfs_client *clp;
211 
212 	list_for_each_entry(clp, &nfs_client_list, cl_share_link) {
213 		/* Don't match clients that failed to initialise properly */
214 		if (clp->cl_cons_state < 0)
215 			continue;
216 
217 		/* Different NFS versions cannot share the same nfs_client */
218 		if (clp->cl_nfsversion != nfsversion)
219 			continue;
220 
221 		if (memcmp(&clp->cl_addr.sin_addr, &addr->sin_addr,
222 			   sizeof(clp->cl_addr.sin_addr)) != 0)
223 			continue;
224 
225 		if (!match_port || clp->cl_addr.sin_port == addr->sin_port)
226 			goto found;
227 	}
228 
229 	return NULL;
230 
231 found:
232 	atomic_inc(&clp->cl_count);
233 	return clp;
234 }
235 
236 /*
237  * Find a client by IP address and protocol version
238  * - returns NULL if no such client
239  */
240 struct nfs_client *nfs_find_client(const struct sockaddr_in *addr, int nfsversion)
241 {
242 	struct nfs_client *clp;
243 
244 	spin_lock(&nfs_client_lock);
245 	clp = __nfs_find_client(addr, nfsversion, 0);
246 	spin_unlock(&nfs_client_lock);
247 	if (clp != NULL && clp->cl_cons_state != NFS_CS_READY) {
248 		nfs_put_client(clp);
249 		clp = NULL;
250 	}
251 	return clp;
252 }
253 
254 /*
255  * Look up a client by IP address and protocol version
256  * - creates a new record if one doesn't yet exist
257  */
258 static struct nfs_client *nfs_get_client(const char *hostname,
259 					 const struct sockaddr_in *addr,
260 					 int nfsversion)
261 {
262 	struct nfs_client *clp, *new = NULL;
263 	int error;
264 
265 	dprintk("--> nfs_get_client(%s,"NIPQUAD_FMT":%d,%d)\n",
266 		hostname ?: "", NIPQUAD(addr->sin_addr),
267 		addr->sin_port, nfsversion);
268 
269 	/* see if the client already exists */
270 	do {
271 		spin_lock(&nfs_client_lock);
272 
273 		clp = __nfs_find_client(addr, nfsversion, 1);
274 		if (clp)
275 			goto found_client;
276 		if (new)
277 			goto install_client;
278 
279 		spin_unlock(&nfs_client_lock);
280 
281 		new = nfs_alloc_client(hostname, addr, nfsversion);
282 	} while (new);
283 
284 	return ERR_PTR(-ENOMEM);
285 
286 	/* install a new client and return with it unready */
287 install_client:
288 	clp = new;
289 	list_add(&clp->cl_share_link, &nfs_client_list);
290 	spin_unlock(&nfs_client_lock);
291 	dprintk("--> nfs_get_client() = %p [new]\n", clp);
292 	return clp;
293 
294 	/* found an existing client
295 	 * - make sure it's ready before returning
296 	 */
297 found_client:
298 	spin_unlock(&nfs_client_lock);
299 
300 	if (new)
301 		nfs_free_client(new);
302 
303 	error = wait_event_interruptible(nfs_client_active_wq,
304 				clp->cl_cons_state != NFS_CS_INITING);
305 	if (error < 0) {
306 		nfs_put_client(clp);
307 		return ERR_PTR(-ERESTARTSYS);
308 	}
309 
310 	if (clp->cl_cons_state < NFS_CS_READY) {
311 		error = clp->cl_cons_state;
312 		nfs_put_client(clp);
313 		return ERR_PTR(error);
314 	}
315 
316 	BUG_ON(clp->cl_cons_state != NFS_CS_READY);
317 
318 	dprintk("--> nfs_get_client() = %p [share]\n", clp);
319 	return clp;
320 }
321 
322 /*
323  * Mark a server as ready or failed
324  */
325 static void nfs_mark_client_ready(struct nfs_client *clp, int state)
326 {
327 	clp->cl_cons_state = state;
328 	wake_up_all(&nfs_client_active_wq);
329 }
330 
331 /*
332  * Initialise the timeout values for a connection
333  */
334 static void nfs_init_timeout_values(struct rpc_timeout *to, int proto,
335 				    unsigned int timeo, unsigned int retrans)
336 {
337 	to->to_initval = timeo * HZ / 10;
338 	to->to_retries = retrans;
339 	if (!to->to_retries)
340 		to->to_retries = 2;
341 
342 	switch (proto) {
343 	case IPPROTO_TCP:
344 		if (!to->to_initval)
345 			to->to_initval = 60 * HZ;
346 		if (to->to_initval > NFS_MAX_TCP_TIMEOUT)
347 			to->to_initval = NFS_MAX_TCP_TIMEOUT;
348 		to->to_increment = to->to_initval;
349 		to->to_maxval = to->to_initval + (to->to_increment * to->to_retries);
350 		to->to_exponential = 0;
351 		break;
352 	case IPPROTO_UDP:
353 	default:
354 		if (!to->to_initval)
355 			to->to_initval = 11 * HZ / 10;
356 		if (to->to_initval > NFS_MAX_UDP_TIMEOUT)
357 			to->to_initval = NFS_MAX_UDP_TIMEOUT;
358 		to->to_maxval = NFS_MAX_UDP_TIMEOUT;
359 		to->to_exponential = 1;
360 		break;
361 	}
362 }
363 
364 /*
365  * Create an RPC client handle
366  */
367 static int nfs_create_rpc_client(struct nfs_client *clp, int proto,
368 						unsigned int timeo,
369 						unsigned int retrans,
370 						rpc_authflavor_t flavor,
371 						int flags)
372 {
373 	struct rpc_timeout	timeparms;
374 	struct rpc_clnt		*clnt = NULL;
375 	struct rpc_create_args args = {
376 		.protocol	= proto,
377 		.address	= (struct sockaddr *)&clp->cl_addr,
378 		.addrsize	= sizeof(clp->cl_addr),
379 		.timeout	= &timeparms,
380 		.servername	= clp->cl_hostname,
381 		.program	= &nfs_program,
382 		.version	= clp->rpc_ops->version,
383 		.authflavor	= flavor,
384 		.flags		= flags,
385 	};
386 
387 	if (!IS_ERR(clp->cl_rpcclient))
388 		return 0;
389 
390 	nfs_init_timeout_values(&timeparms, proto, timeo, retrans);
391 	clp->retrans_timeo = timeparms.to_initval;
392 	clp->retrans_count = timeparms.to_retries;
393 
394 	clnt = rpc_create(&args);
395 	if (IS_ERR(clnt)) {
396 		dprintk("%s: cannot create RPC client. Error = %ld\n",
397 				__FUNCTION__, PTR_ERR(clnt));
398 		return PTR_ERR(clnt);
399 	}
400 
401 	clp->cl_rpcclient = clnt;
402 	return 0;
403 }
404 
405 /*
406  * Version 2 or 3 client destruction
407  */
408 static void nfs_destroy_server(struct nfs_server *server)
409 {
410 	if (!IS_ERR(server->client_acl))
411 		rpc_shutdown_client(server->client_acl);
412 
413 	if (!(server->flags & NFS_MOUNT_NONLM))
414 		lockd_down();	/* release rpc.lockd */
415 }
416 
417 /*
418  * Version 2 or 3 lockd setup
419  */
420 static int nfs_start_lockd(struct nfs_server *server)
421 {
422 	int error = 0;
423 
424 	if (server->nfs_client->cl_nfsversion > 3)
425 		goto out;
426 	if (server->flags & NFS_MOUNT_NONLM)
427 		goto out;
428 	error = lockd_up((server->flags & NFS_MOUNT_TCP) ?
429 			IPPROTO_TCP : IPPROTO_UDP);
430 	if (error < 0)
431 		server->flags |= NFS_MOUNT_NONLM;
432 	else
433 		server->destroy = nfs_destroy_server;
434 out:
435 	return error;
436 }
437 
438 /*
439  * Initialise an NFSv3 ACL client connection
440  */
441 #ifdef CONFIG_NFS_V3_ACL
442 static void nfs_init_server_aclclient(struct nfs_server *server)
443 {
444 	if (server->nfs_client->cl_nfsversion != 3)
445 		goto out_noacl;
446 	if (server->flags & NFS_MOUNT_NOACL)
447 		goto out_noacl;
448 
449 	server->client_acl = rpc_bind_new_program(server->client, &nfsacl_program, 3);
450 	if (IS_ERR(server->client_acl))
451 		goto out_noacl;
452 
453 	/* No errors! Assume that Sun nfsacls are supported */
454 	server->caps |= NFS_CAP_ACLS;
455 	return;
456 
457 out_noacl:
458 	server->caps &= ~NFS_CAP_ACLS;
459 }
460 #else
461 static inline void nfs_init_server_aclclient(struct nfs_server *server)
462 {
463 	server->flags &= ~NFS_MOUNT_NOACL;
464 	server->caps &= ~NFS_CAP_ACLS;
465 }
466 #endif
467 
468 /*
469  * Create a general RPC client
470  */
471 static int nfs_init_server_rpcclient(struct nfs_server *server, rpc_authflavor_t pseudoflavour)
472 {
473 	struct nfs_client *clp = server->nfs_client;
474 
475 	server->client = rpc_clone_client(clp->cl_rpcclient);
476 	if (IS_ERR(server->client)) {
477 		dprintk("%s: couldn't create rpc_client!\n", __FUNCTION__);
478 		return PTR_ERR(server->client);
479 	}
480 
481 	if (pseudoflavour != clp->cl_rpcclient->cl_auth->au_flavor) {
482 		struct rpc_auth *auth;
483 
484 		auth = rpcauth_create(pseudoflavour, server->client);
485 		if (IS_ERR(auth)) {
486 			dprintk("%s: couldn't create credcache!\n", __FUNCTION__);
487 			return PTR_ERR(auth);
488 		}
489 	}
490 	server->client->cl_softrtry = 0;
491 	if (server->flags & NFS_MOUNT_SOFT)
492 		server->client->cl_softrtry = 1;
493 
494 	server->client->cl_intr = 0;
495 	if (server->flags & NFS4_MOUNT_INTR)
496 		server->client->cl_intr = 1;
497 
498 	return 0;
499 }
500 
501 /*
502  * Initialise an NFS2 or NFS3 client
503  */
504 static int nfs_init_client(struct nfs_client *clp, const struct nfs_mount_data *data)
505 {
506 	int proto = (data->flags & NFS_MOUNT_TCP) ? IPPROTO_TCP : IPPROTO_UDP;
507 	int error;
508 
509 	if (clp->cl_cons_state == NFS_CS_READY) {
510 		/* the client is already initialised */
511 		dprintk("<-- nfs_init_client() = 0 [already %p]\n", clp);
512 		return 0;
513 	}
514 
515 	/* Check NFS protocol revision and initialize RPC op vector */
516 	clp->rpc_ops = &nfs_v2_clientops;
517 #ifdef CONFIG_NFS_V3
518 	if (clp->cl_nfsversion == 3)
519 		clp->rpc_ops = &nfs_v3_clientops;
520 #endif
521 	/*
522 	 * Create a client RPC handle for doing FSSTAT with UNIX auth only
523 	 * - RFC 2623, sec 2.3.2
524 	 */
525 	error = nfs_create_rpc_client(clp, proto, data->timeo, data->retrans,
526 					RPC_AUTH_UNIX, 0);
527 	if (error < 0)
528 		goto error;
529 	nfs_mark_client_ready(clp, NFS_CS_READY);
530 	return 0;
531 
532 error:
533 	nfs_mark_client_ready(clp, error);
534 	dprintk("<-- nfs_init_client() = xerror %d\n", error);
535 	return error;
536 }
537 
538 /*
539  * Create a version 2 or 3 client
540  */
541 static int nfs_init_server(struct nfs_server *server, const struct nfs_mount_data *data)
542 {
543 	struct nfs_client *clp;
544 	int error, nfsvers = 2;
545 
546 	dprintk("--> nfs_init_server()\n");
547 
548 #ifdef CONFIG_NFS_V3
549 	if (data->flags & NFS_MOUNT_VER3)
550 		nfsvers = 3;
551 #endif
552 
553 	/* Allocate or find a client reference we can use */
554 	clp = nfs_get_client(data->hostname, &data->addr, nfsvers);
555 	if (IS_ERR(clp)) {
556 		dprintk("<-- nfs_init_server() = error %ld\n", PTR_ERR(clp));
557 		return PTR_ERR(clp);
558 	}
559 
560 	error = nfs_init_client(clp, data);
561 	if (error < 0)
562 		goto error;
563 
564 	server->nfs_client = clp;
565 
566 	/* Initialise the client representation from the mount data */
567 	server->flags = data->flags & NFS_MOUNT_FLAGMASK;
568 
569 	if (data->rsize)
570 		server->rsize = nfs_block_size(data->rsize, NULL);
571 	if (data->wsize)
572 		server->wsize = nfs_block_size(data->wsize, NULL);
573 
574 	server->acregmin = data->acregmin * HZ;
575 	server->acregmax = data->acregmax * HZ;
576 	server->acdirmin = data->acdirmin * HZ;
577 	server->acdirmax = data->acdirmax * HZ;
578 
579 	/* Start lockd here, before we might error out */
580 	error = nfs_start_lockd(server);
581 	if (error < 0)
582 		goto error;
583 
584 	error = nfs_init_server_rpcclient(server, data->pseudoflavor);
585 	if (error < 0)
586 		goto error;
587 
588 	server->namelen  = data->namlen;
589 	/* Create a client RPC handle for the NFSv3 ACL management interface */
590 	nfs_init_server_aclclient(server);
591 	if (clp->cl_nfsversion == 3) {
592 		if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN)
593 			server->namelen = NFS3_MAXNAMLEN;
594 		if (!(data->flags & NFS_MOUNT_NORDIRPLUS))
595 			server->caps |= NFS_CAP_READDIRPLUS;
596 	} else {
597 		if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN)
598 			server->namelen = NFS2_MAXNAMLEN;
599 	}
600 
601 	dprintk("<-- nfs_init_server() = 0 [new %p]\n", clp);
602 	return 0;
603 
604 error:
605 	server->nfs_client = NULL;
606 	nfs_put_client(clp);
607 	dprintk("<-- nfs_init_server() = xerror %d\n", error);
608 	return error;
609 }
610 
611 /*
612  * Load up the server record from information gained in an fsinfo record
613  */
614 static void nfs_server_set_fsinfo(struct nfs_server *server, struct nfs_fsinfo *fsinfo)
615 {
616 	unsigned long max_rpc_payload;
617 
618 	/* Work out a lot of parameters */
619 	if (server->rsize == 0)
620 		server->rsize = nfs_block_size(fsinfo->rtpref, NULL);
621 	if (server->wsize == 0)
622 		server->wsize = nfs_block_size(fsinfo->wtpref, NULL);
623 
624 	if (fsinfo->rtmax >= 512 && server->rsize > fsinfo->rtmax)
625 		server->rsize = nfs_block_size(fsinfo->rtmax, NULL);
626 	if (fsinfo->wtmax >= 512 && server->wsize > fsinfo->wtmax)
627 		server->wsize = nfs_block_size(fsinfo->wtmax, NULL);
628 
629 	max_rpc_payload = nfs_block_size(rpc_max_payload(server->client), NULL);
630 	if (server->rsize > max_rpc_payload)
631 		server->rsize = max_rpc_payload;
632 	if (server->rsize > NFS_MAX_FILE_IO_SIZE)
633 		server->rsize = NFS_MAX_FILE_IO_SIZE;
634 	server->rpages = (server->rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
635 	server->backing_dev_info.ra_pages = server->rpages * NFS_MAX_READAHEAD;
636 
637 	if (server->wsize > max_rpc_payload)
638 		server->wsize = max_rpc_payload;
639 	if (server->wsize > NFS_MAX_FILE_IO_SIZE)
640 		server->wsize = NFS_MAX_FILE_IO_SIZE;
641 	server->wpages = (server->wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
642 	server->wtmult = nfs_block_bits(fsinfo->wtmult, NULL);
643 
644 	server->dtsize = nfs_block_size(fsinfo->dtpref, NULL);
645 	if (server->dtsize > PAGE_CACHE_SIZE)
646 		server->dtsize = PAGE_CACHE_SIZE;
647 	if (server->dtsize > server->rsize)
648 		server->dtsize = server->rsize;
649 
650 	if (server->flags & NFS_MOUNT_NOAC) {
651 		server->acregmin = server->acregmax = 0;
652 		server->acdirmin = server->acdirmax = 0;
653 	}
654 
655 	server->maxfilesize = fsinfo->maxfilesize;
656 
657 	/* We're airborne Set socket buffersize */
658 	rpc_setbufsize(server->client, server->wsize + 100, server->rsize + 100);
659 }
660 
661 /*
662  * Probe filesystem information, including the FSID on v2/v3
663  */
664 static int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *mntfh, struct nfs_fattr *fattr)
665 {
666 	struct nfs_fsinfo fsinfo;
667 	struct nfs_client *clp = server->nfs_client;
668 	int error;
669 
670 	dprintk("--> nfs_probe_fsinfo()\n");
671 
672 	if (clp->rpc_ops->set_capabilities != NULL) {
673 		error = clp->rpc_ops->set_capabilities(server, mntfh);
674 		if (error < 0)
675 			goto out_error;
676 	}
677 
678 	fsinfo.fattr = fattr;
679 	nfs_fattr_init(fattr);
680 	error = clp->rpc_ops->fsinfo(server, mntfh, &fsinfo);
681 	if (error < 0)
682 		goto out_error;
683 
684 	nfs_server_set_fsinfo(server, &fsinfo);
685 
686 	/* Get some general file system info */
687 	if (server->namelen == 0) {
688 		struct nfs_pathconf pathinfo;
689 
690 		pathinfo.fattr = fattr;
691 		nfs_fattr_init(fattr);
692 
693 		if (clp->rpc_ops->pathconf(server, mntfh, &pathinfo) >= 0)
694 			server->namelen = pathinfo.max_namelen;
695 	}
696 
697 	dprintk("<-- nfs_probe_fsinfo() = 0\n");
698 	return 0;
699 
700 out_error:
701 	dprintk("nfs_probe_fsinfo: error = %d\n", -error);
702 	return error;
703 }
704 
705 /*
706  * Copy useful information when duplicating a server record
707  */
708 static void nfs_server_copy_userdata(struct nfs_server *target, struct nfs_server *source)
709 {
710 	target->flags = source->flags;
711 	target->acregmin = source->acregmin;
712 	target->acregmax = source->acregmax;
713 	target->acdirmin = source->acdirmin;
714 	target->acdirmax = source->acdirmax;
715 	target->caps = source->caps;
716 }
717 
718 /*
719  * Allocate and initialise a server record
720  */
721 static struct nfs_server *nfs_alloc_server(void)
722 {
723 	struct nfs_server *server;
724 
725 	server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
726 	if (!server)
727 		return NULL;
728 
729 	server->client = server->client_acl = ERR_PTR(-EINVAL);
730 
731 	/* Zero out the NFS state stuff */
732 	INIT_LIST_HEAD(&server->client_link);
733 	INIT_LIST_HEAD(&server->master_link);
734 
735 	server->io_stats = nfs_alloc_iostats();
736 	if (!server->io_stats) {
737 		kfree(server);
738 		return NULL;
739 	}
740 
741 	return server;
742 }
743 
744 /*
745  * Free up a server record
746  */
747 void nfs_free_server(struct nfs_server *server)
748 {
749 	dprintk("--> nfs_free_server()\n");
750 
751 	spin_lock(&nfs_client_lock);
752 	list_del(&server->client_link);
753 	list_del(&server->master_link);
754 	spin_unlock(&nfs_client_lock);
755 
756 	if (server->destroy != NULL)
757 		server->destroy(server);
758 	if (!IS_ERR(server->client))
759 		rpc_shutdown_client(server->client);
760 
761 	nfs_put_client(server->nfs_client);
762 
763 	nfs_free_iostats(server->io_stats);
764 	kfree(server);
765 	nfs_release_automount_timer();
766 	dprintk("<-- nfs_free_server()\n");
767 }
768 
769 /*
770  * Create a version 2 or 3 volume record
771  * - keyed on server and FSID
772  */
773 struct nfs_server *nfs_create_server(const struct nfs_mount_data *data,
774 				     struct nfs_fh *mntfh)
775 {
776 	struct nfs_server *server;
777 	struct nfs_fattr fattr;
778 	int error;
779 
780 	server = nfs_alloc_server();
781 	if (!server)
782 		return ERR_PTR(-ENOMEM);
783 
784 	/* Get a client representation */
785 	error = nfs_init_server(server, data);
786 	if (error < 0)
787 		goto error;
788 
789 	BUG_ON(!server->nfs_client);
790 	BUG_ON(!server->nfs_client->rpc_ops);
791 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
792 
793 	/* Probe the root fh to retrieve its FSID */
794 	error = nfs_probe_fsinfo(server, mntfh, &fattr);
795 	if (error < 0)
796 		goto error;
797 	if (!(fattr.valid & NFS_ATTR_FATTR)) {
798 		error = server->nfs_client->rpc_ops->getattr(server, mntfh, &fattr);
799 		if (error < 0) {
800 			dprintk("nfs_create_server: getattr error = %d\n", -error);
801 			goto error;
802 		}
803 	}
804 	memcpy(&server->fsid, &fattr.fsid, sizeof(server->fsid));
805 
806 	dprintk("Server FSID: %llx:%llx\n",
807 		(unsigned long long) server->fsid.major,
808 		(unsigned long long) server->fsid.minor);
809 
810 	BUG_ON(!server->nfs_client);
811 	BUG_ON(!server->nfs_client->rpc_ops);
812 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
813 
814 	spin_lock(&nfs_client_lock);
815 	list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);
816 	list_add_tail(&server->master_link, &nfs_volume_list);
817 	spin_unlock(&nfs_client_lock);
818 
819 	server->mount_time = jiffies;
820 	return server;
821 
822 error:
823 	nfs_free_server(server);
824 	return ERR_PTR(error);
825 }
826 
827 #ifdef CONFIG_NFS_V4
828 /*
829  * Initialise an NFS4 client record
830  */
831 static int nfs4_init_client(struct nfs_client *clp,
832 		int proto, int timeo, int retrans,
833 		const char *ip_addr,
834 		rpc_authflavor_t authflavour)
835 {
836 	int error;
837 
838 	if (clp->cl_cons_state == NFS_CS_READY) {
839 		/* the client is initialised already */
840 		dprintk("<-- nfs4_init_client() = 0 [already %p]\n", clp);
841 		return 0;
842 	}
843 
844 	/* Check NFS protocol revision and initialize RPC op vector */
845 	clp->rpc_ops = &nfs_v4_clientops;
846 
847 	error = nfs_create_rpc_client(clp, proto, timeo, retrans, authflavour,
848 					RPC_CLNT_CREATE_DISCRTRY);
849 	if (error < 0)
850 		goto error;
851 	memcpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr));
852 
853 	error = nfs_idmap_new(clp);
854 	if (error < 0) {
855 		dprintk("%s: failed to create idmapper. Error = %d\n",
856 			__FUNCTION__, error);
857 		goto error;
858 	}
859 	__set_bit(NFS_CS_IDMAP, &clp->cl_res_state);
860 
861 	nfs_mark_client_ready(clp, NFS_CS_READY);
862 	return 0;
863 
864 error:
865 	nfs_mark_client_ready(clp, error);
866 	dprintk("<-- nfs4_init_client() = xerror %d\n", error);
867 	return error;
868 }
869 
870 /*
871  * Set up an NFS4 client
872  */
873 static int nfs4_set_client(struct nfs_server *server,
874 		const char *hostname, const struct sockaddr_in *addr,
875 		const char *ip_addr,
876 		rpc_authflavor_t authflavour,
877 		int proto, int timeo, int retrans)
878 {
879 	struct nfs_client *clp;
880 	int error;
881 
882 	dprintk("--> nfs4_set_client()\n");
883 
884 	/* Allocate or find a client reference we can use */
885 	clp = nfs_get_client(hostname, addr, 4);
886 	if (IS_ERR(clp)) {
887 		error = PTR_ERR(clp);
888 		goto error;
889 	}
890 	error = nfs4_init_client(clp, proto, timeo, retrans, ip_addr, authflavour);
891 	if (error < 0)
892 		goto error_put;
893 
894 	server->nfs_client = clp;
895 	dprintk("<-- nfs4_set_client() = 0 [new %p]\n", clp);
896 	return 0;
897 
898 error_put:
899 	nfs_put_client(clp);
900 error:
901 	dprintk("<-- nfs4_set_client() = xerror %d\n", error);
902 	return error;
903 }
904 
905 /*
906  * Create a version 4 volume record
907  */
908 static int nfs4_init_server(struct nfs_server *server,
909 		const struct nfs4_mount_data *data, rpc_authflavor_t authflavour)
910 {
911 	int error;
912 
913 	dprintk("--> nfs4_init_server()\n");
914 
915 	/* Initialise the client representation from the mount data */
916 	server->flags = data->flags & NFS_MOUNT_FLAGMASK;
917 	server->caps |= NFS_CAP_ATOMIC_OPEN;
918 
919 	if (data->rsize)
920 		server->rsize = nfs_block_size(data->rsize, NULL);
921 	if (data->wsize)
922 		server->wsize = nfs_block_size(data->wsize, NULL);
923 
924 	server->acregmin = data->acregmin * HZ;
925 	server->acregmax = data->acregmax * HZ;
926 	server->acdirmin = data->acdirmin * HZ;
927 	server->acdirmax = data->acdirmax * HZ;
928 
929 	error = nfs_init_server_rpcclient(server, authflavour);
930 
931 	/* Done */
932 	dprintk("<-- nfs4_init_server() = %d\n", error);
933 	return error;
934 }
935 
936 /*
937  * Create a version 4 volume record
938  * - keyed on server and FSID
939  */
940 struct nfs_server *nfs4_create_server(const struct nfs4_mount_data *data,
941 				      const char *hostname,
942 				      const struct sockaddr_in *addr,
943 				      const char *mntpath,
944 				      const char *ip_addr,
945 				      rpc_authflavor_t authflavour,
946 				      struct nfs_fh *mntfh)
947 {
948 	struct nfs_fattr fattr;
949 	struct nfs_server *server;
950 	int error;
951 
952 	dprintk("--> nfs4_create_server()\n");
953 
954 	server = nfs_alloc_server();
955 	if (!server)
956 		return ERR_PTR(-ENOMEM);
957 
958 	/* Get a client record */
959 	error = nfs4_set_client(server, hostname, addr, ip_addr, authflavour,
960 			data->proto, data->timeo, data->retrans);
961 	if (error < 0)
962 		goto error;
963 
964 	/* set up the general RPC client */
965 	error = nfs4_init_server(server, data, authflavour);
966 	if (error < 0)
967 		goto error;
968 
969 	BUG_ON(!server->nfs_client);
970 	BUG_ON(!server->nfs_client->rpc_ops);
971 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
972 
973 	/* Probe the root fh to retrieve its FSID */
974 	error = nfs4_path_walk(server, mntfh, mntpath);
975 	if (error < 0)
976 		goto error;
977 
978 	dprintk("Server FSID: %llx:%llx\n",
979 		(unsigned long long) server->fsid.major,
980 		(unsigned long long) server->fsid.minor);
981 	dprintk("Mount FH: %d\n", mntfh->size);
982 
983 	error = nfs_probe_fsinfo(server, mntfh, &fattr);
984 	if (error < 0)
985 		goto error;
986 
987 	BUG_ON(!server->nfs_client);
988 	BUG_ON(!server->nfs_client->rpc_ops);
989 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
990 
991 	spin_lock(&nfs_client_lock);
992 	list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);
993 	list_add_tail(&server->master_link, &nfs_volume_list);
994 	spin_unlock(&nfs_client_lock);
995 
996 	server->mount_time = jiffies;
997 	dprintk("<-- nfs4_create_server() = %p\n", server);
998 	return server;
999 
1000 error:
1001 	nfs_free_server(server);
1002 	dprintk("<-- nfs4_create_server() = error %d\n", error);
1003 	return ERR_PTR(error);
1004 }
1005 
1006 /*
1007  * Create an NFS4 referral server record
1008  */
1009 struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data,
1010 					       struct nfs_fh *mntfh)
1011 {
1012 	struct nfs_client *parent_client;
1013 	struct nfs_server *server, *parent_server;
1014 	struct nfs_fattr fattr;
1015 	int error;
1016 
1017 	dprintk("--> nfs4_create_referral_server()\n");
1018 
1019 	server = nfs_alloc_server();
1020 	if (!server)
1021 		return ERR_PTR(-ENOMEM);
1022 
1023 	parent_server = NFS_SB(data->sb);
1024 	parent_client = parent_server->nfs_client;
1025 
1026 	/* Get a client representation.
1027 	 * Note: NFSv4 always uses TCP, */
1028 	error = nfs4_set_client(server, data->hostname, data->addr,
1029 			parent_client->cl_ipaddr,
1030 			data->authflavor,
1031 			parent_server->client->cl_xprt->prot,
1032 			parent_client->retrans_timeo,
1033 			parent_client->retrans_count);
1034 	if (error < 0)
1035 		goto error;
1036 
1037 	/* Initialise the client representation from the parent server */
1038 	nfs_server_copy_userdata(server, parent_server);
1039 	server->caps |= NFS_CAP_ATOMIC_OPEN;
1040 
1041 	error = nfs_init_server_rpcclient(server, data->authflavor);
1042 	if (error < 0)
1043 		goto error;
1044 
1045 	BUG_ON(!server->nfs_client);
1046 	BUG_ON(!server->nfs_client->rpc_ops);
1047 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
1048 
1049 	/* Probe the root fh to retrieve its FSID and filehandle */
1050 	error = nfs4_path_walk(server, mntfh, data->mnt_path);
1051 	if (error < 0)
1052 		goto error;
1053 
1054 	/* probe the filesystem info for this server filesystem */
1055 	error = nfs_probe_fsinfo(server, mntfh, &fattr);
1056 	if (error < 0)
1057 		goto error;
1058 
1059 	dprintk("Referral FSID: %llx:%llx\n",
1060 		(unsigned long long) server->fsid.major,
1061 		(unsigned long long) server->fsid.minor);
1062 
1063 	spin_lock(&nfs_client_lock);
1064 	list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);
1065 	list_add_tail(&server->master_link, &nfs_volume_list);
1066 	spin_unlock(&nfs_client_lock);
1067 
1068 	server->mount_time = jiffies;
1069 
1070 	dprintk("<-- nfs_create_referral_server() = %p\n", server);
1071 	return server;
1072 
1073 error:
1074 	nfs_free_server(server);
1075 	dprintk("<-- nfs4_create_referral_server() = error %d\n", error);
1076 	return ERR_PTR(error);
1077 }
1078 
1079 #endif /* CONFIG_NFS_V4 */
1080 
1081 /*
1082  * Clone an NFS2, NFS3 or NFS4 server record
1083  */
1084 struct nfs_server *nfs_clone_server(struct nfs_server *source,
1085 				    struct nfs_fh *fh,
1086 				    struct nfs_fattr *fattr)
1087 {
1088 	struct nfs_server *server;
1089 	struct nfs_fattr fattr_fsinfo;
1090 	int error;
1091 
1092 	dprintk("--> nfs_clone_server(,%llx:%llx,)\n",
1093 		(unsigned long long) fattr->fsid.major,
1094 		(unsigned long long) fattr->fsid.minor);
1095 
1096 	server = nfs_alloc_server();
1097 	if (!server)
1098 		return ERR_PTR(-ENOMEM);
1099 
1100 	/* Copy data from the source */
1101 	server->nfs_client = source->nfs_client;
1102 	atomic_inc(&server->nfs_client->cl_count);
1103 	nfs_server_copy_userdata(server, source);
1104 
1105 	server->fsid = fattr->fsid;
1106 
1107 	error = nfs_init_server_rpcclient(server, source->client->cl_auth->au_flavor);
1108 	if (error < 0)
1109 		goto out_free_server;
1110 	if (!IS_ERR(source->client_acl))
1111 		nfs_init_server_aclclient(server);
1112 
1113 	/* probe the filesystem info for this server filesystem */
1114 	error = nfs_probe_fsinfo(server, fh, &fattr_fsinfo);
1115 	if (error < 0)
1116 		goto out_free_server;
1117 
1118 	dprintk("Cloned FSID: %llx:%llx\n",
1119 		(unsigned long long) server->fsid.major,
1120 		(unsigned long long) server->fsid.minor);
1121 
1122 	error = nfs_start_lockd(server);
1123 	if (error < 0)
1124 		goto out_free_server;
1125 
1126 	spin_lock(&nfs_client_lock);
1127 	list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);
1128 	list_add_tail(&server->master_link, &nfs_volume_list);
1129 	spin_unlock(&nfs_client_lock);
1130 
1131 	server->mount_time = jiffies;
1132 
1133 	dprintk("<-- nfs_clone_server() = %p\n", server);
1134 	return server;
1135 
1136 out_free_server:
1137 	nfs_free_server(server);
1138 	dprintk("<-- nfs_clone_server() = error %d\n", error);
1139 	return ERR_PTR(error);
1140 }
1141 
1142 #ifdef CONFIG_PROC_FS
1143 static struct proc_dir_entry *proc_fs_nfs;
1144 
1145 static int nfs_server_list_open(struct inode *inode, struct file *file);
1146 static void *nfs_server_list_start(struct seq_file *p, loff_t *pos);
1147 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos);
1148 static void nfs_server_list_stop(struct seq_file *p, void *v);
1149 static int nfs_server_list_show(struct seq_file *m, void *v);
1150 
1151 static struct seq_operations nfs_server_list_ops = {
1152 	.start	= nfs_server_list_start,
1153 	.next	= nfs_server_list_next,
1154 	.stop	= nfs_server_list_stop,
1155 	.show	= nfs_server_list_show,
1156 };
1157 
1158 static const struct file_operations nfs_server_list_fops = {
1159 	.open		= nfs_server_list_open,
1160 	.read		= seq_read,
1161 	.llseek		= seq_lseek,
1162 	.release	= seq_release,
1163 };
1164 
1165 static int nfs_volume_list_open(struct inode *inode, struct file *file);
1166 static void *nfs_volume_list_start(struct seq_file *p, loff_t *pos);
1167 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos);
1168 static void nfs_volume_list_stop(struct seq_file *p, void *v);
1169 static int nfs_volume_list_show(struct seq_file *m, void *v);
1170 
1171 static struct seq_operations nfs_volume_list_ops = {
1172 	.start	= nfs_volume_list_start,
1173 	.next	= nfs_volume_list_next,
1174 	.stop	= nfs_volume_list_stop,
1175 	.show	= nfs_volume_list_show,
1176 };
1177 
1178 static const struct file_operations nfs_volume_list_fops = {
1179 	.open		= nfs_volume_list_open,
1180 	.read		= seq_read,
1181 	.llseek		= seq_lseek,
1182 	.release	= seq_release,
1183 };
1184 
1185 /*
1186  * open "/proc/fs/nfsfs/servers" which provides a summary of servers with which
1187  * we're dealing
1188  */
1189 static int nfs_server_list_open(struct inode *inode, struct file *file)
1190 {
1191 	struct seq_file *m;
1192 	int ret;
1193 
1194 	ret = seq_open(file, &nfs_server_list_ops);
1195 	if (ret < 0)
1196 		return ret;
1197 
1198 	m = file->private_data;
1199 	m->private = PDE(inode)->data;
1200 
1201 	return 0;
1202 }
1203 
1204 /*
1205  * set up the iterator to start reading from the server list and return the first item
1206  */
1207 static void *nfs_server_list_start(struct seq_file *m, loff_t *_pos)
1208 {
1209 	/* lock the list against modification */
1210 	spin_lock(&nfs_client_lock);
1211 	return seq_list_start_head(&nfs_client_list, *_pos);
1212 }
1213 
1214 /*
1215  * move to next server
1216  */
1217 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos)
1218 {
1219 	return seq_list_next(v, &nfs_client_list, pos);
1220 }
1221 
1222 /*
1223  * clean up after reading from the transports list
1224  */
1225 static void nfs_server_list_stop(struct seq_file *p, void *v)
1226 {
1227 	spin_unlock(&nfs_client_lock);
1228 }
1229 
1230 /*
1231  * display a header line followed by a load of call lines
1232  */
1233 static int nfs_server_list_show(struct seq_file *m, void *v)
1234 {
1235 	struct nfs_client *clp;
1236 
1237 	/* display header on line 1 */
1238 	if (v == &nfs_client_list) {
1239 		seq_puts(m, "NV SERVER   PORT USE HOSTNAME\n");
1240 		return 0;
1241 	}
1242 
1243 	/* display one transport per line on subsequent lines */
1244 	clp = list_entry(v, struct nfs_client, cl_share_link);
1245 
1246 	seq_printf(m, "v%d %02x%02x%02x%02x %4hx %3d %s\n",
1247 		   clp->cl_nfsversion,
1248 		   NIPQUAD(clp->cl_addr.sin_addr),
1249 		   ntohs(clp->cl_addr.sin_port),
1250 		   atomic_read(&clp->cl_count),
1251 		   clp->cl_hostname);
1252 
1253 	return 0;
1254 }
1255 
1256 /*
1257  * open "/proc/fs/nfsfs/volumes" which provides a summary of extant volumes
1258  */
1259 static int nfs_volume_list_open(struct inode *inode, struct file *file)
1260 {
1261 	struct seq_file *m;
1262 	int ret;
1263 
1264 	ret = seq_open(file, &nfs_volume_list_ops);
1265 	if (ret < 0)
1266 		return ret;
1267 
1268 	m = file->private_data;
1269 	m->private = PDE(inode)->data;
1270 
1271 	return 0;
1272 }
1273 
1274 /*
1275  * set up the iterator to start reading from the volume list and return the first item
1276  */
1277 static void *nfs_volume_list_start(struct seq_file *m, loff_t *_pos)
1278 {
1279 	/* lock the list against modification */
1280 	spin_lock(&nfs_client_lock);
1281 	return seq_list_start_head(&nfs_volume_list, *_pos);
1282 }
1283 
1284 /*
1285  * move to next volume
1286  */
1287 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos)
1288 {
1289 	return seq_list_next(v, &nfs_volume_list, pos);
1290 }
1291 
1292 /*
1293  * clean up after reading from the transports list
1294  */
1295 static void nfs_volume_list_stop(struct seq_file *p, void *v)
1296 {
1297 	spin_unlock(&nfs_client_lock);
1298 }
1299 
1300 /*
1301  * display a header line followed by a load of call lines
1302  */
1303 static int nfs_volume_list_show(struct seq_file *m, void *v)
1304 {
1305 	struct nfs_server *server;
1306 	struct nfs_client *clp;
1307 	char dev[8], fsid[17];
1308 
1309 	/* display header on line 1 */
1310 	if (v == &nfs_volume_list) {
1311 		seq_puts(m, "NV SERVER   PORT DEV     FSID\n");
1312 		return 0;
1313 	}
1314 	/* display one transport per line on subsequent lines */
1315 	server = list_entry(v, struct nfs_server, master_link);
1316 	clp = server->nfs_client;
1317 
1318 	snprintf(dev, 8, "%u:%u",
1319 		 MAJOR(server->s_dev), MINOR(server->s_dev));
1320 
1321 	snprintf(fsid, 17, "%llx:%llx",
1322 		 (unsigned long long) server->fsid.major,
1323 		 (unsigned long long) server->fsid.minor);
1324 
1325 	seq_printf(m, "v%d %02x%02x%02x%02x %4hx %-7s %-17s\n",
1326 		   clp->cl_nfsversion,
1327 		   NIPQUAD(clp->cl_addr.sin_addr),
1328 		   ntohs(clp->cl_addr.sin_port),
1329 		   dev,
1330 		   fsid);
1331 
1332 	return 0;
1333 }
1334 
1335 /*
1336  * initialise the /proc/fs/nfsfs/ directory
1337  */
1338 int __init nfs_fs_proc_init(void)
1339 {
1340 	struct proc_dir_entry *p;
1341 
1342 	proc_fs_nfs = proc_mkdir("nfsfs", proc_root_fs);
1343 	if (!proc_fs_nfs)
1344 		goto error_0;
1345 
1346 	proc_fs_nfs->owner = THIS_MODULE;
1347 
1348 	/* a file of servers with which we're dealing */
1349 	p = create_proc_entry("servers", S_IFREG|S_IRUGO, proc_fs_nfs);
1350 	if (!p)
1351 		goto error_1;
1352 
1353 	p->proc_fops = &nfs_server_list_fops;
1354 	p->owner = THIS_MODULE;
1355 
1356 	/* a file of volumes that we have mounted */
1357 	p = create_proc_entry("volumes", S_IFREG|S_IRUGO, proc_fs_nfs);
1358 	if (!p)
1359 		goto error_2;
1360 
1361 	p->proc_fops = &nfs_volume_list_fops;
1362 	p->owner = THIS_MODULE;
1363 	return 0;
1364 
1365 error_2:
1366 	remove_proc_entry("servers", proc_fs_nfs);
1367 error_1:
1368 	remove_proc_entry("nfsfs", proc_root_fs);
1369 error_0:
1370 	return -ENOMEM;
1371 }
1372 
1373 /*
1374  * clean up the /proc/fs/nfsfs/ directory
1375  */
1376 void nfs_fs_proc_exit(void)
1377 {
1378 	remove_proc_entry("volumes", proc_fs_nfs);
1379 	remove_proc_entry("servers", proc_fs_nfs);
1380 	remove_proc_entry("nfsfs", proc_root_fs);
1381 }
1382 
1383 #endif /* CONFIG_PROC_FS */
1384