xref: /openbmc/linux/fs/nfs/client.c (revision a1e58bbd)
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/sunrpc/xprtsock.h>
27 #include <linux/sunrpc/xprtrdma.h>
28 #include <linux/nfs_fs.h>
29 #include <linux/nfs_mount.h>
30 #include <linux/nfs4_mount.h>
31 #include <linux/lockd/bind.h>
32 #include <linux/seq_file.h>
33 #include <linux/mount.h>
34 #include <linux/nfs_idmap.h>
35 #include <linux/vfs.h>
36 #include <linux/inet.h>
37 #include <linux/in6.h>
38 #include <net/ipv6.h>
39 #include <linux/nfs_xdr.h>
40 
41 #include <asm/system.h>
42 
43 #include "nfs4_fs.h"
44 #include "callback.h"
45 #include "delegation.h"
46 #include "iostat.h"
47 #include "internal.h"
48 
49 #define NFSDBG_FACILITY		NFSDBG_CLIENT
50 
51 static DEFINE_SPINLOCK(nfs_client_lock);
52 static LIST_HEAD(nfs_client_list);
53 static LIST_HEAD(nfs_volume_list);
54 static DECLARE_WAIT_QUEUE_HEAD(nfs_client_active_wq);
55 
56 /*
57  * RPC cruft for NFS
58  */
59 static struct rpc_version *nfs_version[5] = {
60 	[2]			= &nfs_version2,
61 #ifdef CONFIG_NFS_V3
62 	[3]			= &nfs_version3,
63 #endif
64 #ifdef CONFIG_NFS_V4
65 	[4]			= &nfs_version4,
66 #endif
67 };
68 
69 struct rpc_program nfs_program = {
70 	.name			= "nfs",
71 	.number			= NFS_PROGRAM,
72 	.nrvers			= ARRAY_SIZE(nfs_version),
73 	.version		= nfs_version,
74 	.stats			= &nfs_rpcstat,
75 	.pipe_dir_name		= "/nfs",
76 };
77 
78 struct rpc_stat nfs_rpcstat = {
79 	.program		= &nfs_program
80 };
81 
82 
83 #ifdef CONFIG_NFS_V3_ACL
84 static struct rpc_stat		nfsacl_rpcstat = { &nfsacl_program };
85 static struct rpc_version *	nfsacl_version[] = {
86 	[3]			= &nfsacl_version3,
87 };
88 
89 struct rpc_program		nfsacl_program = {
90 	.name			= "nfsacl",
91 	.number			= NFS_ACL_PROGRAM,
92 	.nrvers			= ARRAY_SIZE(nfsacl_version),
93 	.version		= nfsacl_version,
94 	.stats			= &nfsacl_rpcstat,
95 };
96 #endif  /* CONFIG_NFS_V3_ACL */
97 
98 struct nfs_client_initdata {
99 	const char *hostname;
100 	const struct sockaddr *addr;
101 	size_t addrlen;
102 	const struct nfs_rpc_ops *rpc_ops;
103 	int proto;
104 };
105 
106 /*
107  * Allocate a shared client record
108  *
109  * Since these are allocated/deallocated very rarely, we don't
110  * bother putting them in a slab cache...
111  */
112 static struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init)
113 {
114 	struct nfs_client *clp;
115 
116 	if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL)
117 		goto error_0;
118 
119 	clp->rpc_ops = cl_init->rpc_ops;
120 
121 	if (cl_init->rpc_ops->version == 4) {
122 		if (nfs_callback_up() < 0)
123 			goto error_2;
124 		__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
125 	}
126 
127 	atomic_set(&clp->cl_count, 1);
128 	clp->cl_cons_state = NFS_CS_INITING;
129 
130 	memcpy(&clp->cl_addr, cl_init->addr, cl_init->addrlen);
131 	clp->cl_addrlen = cl_init->addrlen;
132 
133 	if (cl_init->hostname) {
134 		clp->cl_hostname = kstrdup(cl_init->hostname, GFP_KERNEL);
135 		if (!clp->cl_hostname)
136 			goto error_3;
137 	}
138 
139 	INIT_LIST_HEAD(&clp->cl_superblocks);
140 	clp->cl_rpcclient = ERR_PTR(-EINVAL);
141 
142 	clp->cl_proto = cl_init->proto;
143 
144 #ifdef CONFIG_NFS_V4
145 	init_rwsem(&clp->cl_sem);
146 	INIT_LIST_HEAD(&clp->cl_delegations);
147 	spin_lock_init(&clp->cl_lock);
148 	INIT_DELAYED_WORK(&clp->cl_renewd, nfs4_renew_state);
149 	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
150 	clp->cl_boot_time = CURRENT_TIME;
151 	clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
152 #endif
153 
154 	return clp;
155 
156 error_3:
157 	if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
158 		nfs_callback_down();
159 error_2:
160 	kfree(clp);
161 error_0:
162 	return NULL;
163 }
164 
165 static void nfs4_shutdown_client(struct nfs_client *clp)
166 {
167 #ifdef CONFIG_NFS_V4
168 	if (__test_and_clear_bit(NFS_CS_RENEWD, &clp->cl_res_state))
169 		nfs4_kill_renewd(clp);
170 	BUG_ON(!RB_EMPTY_ROOT(&clp->cl_state_owners));
171 	if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state))
172 		nfs_idmap_delete(clp);
173 #endif
174 }
175 
176 /*
177  * Destroy a shared client record
178  */
179 static void nfs_free_client(struct nfs_client *clp)
180 {
181 	dprintk("--> nfs_free_client(%u)\n", clp->rpc_ops->version);
182 
183 	nfs4_shutdown_client(clp);
184 
185 	/* -EIO all pending I/O */
186 	if (!IS_ERR(clp->cl_rpcclient))
187 		rpc_shutdown_client(clp->cl_rpcclient);
188 
189 	if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
190 		nfs_callback_down();
191 
192 	kfree(clp->cl_hostname);
193 	kfree(clp);
194 
195 	dprintk("<-- nfs_free_client()\n");
196 }
197 
198 /*
199  * Release a reference to a shared client record
200  */
201 void nfs_put_client(struct nfs_client *clp)
202 {
203 	if (!clp)
204 		return;
205 
206 	dprintk("--> nfs_put_client({%d})\n", atomic_read(&clp->cl_count));
207 
208 	if (atomic_dec_and_lock(&clp->cl_count, &nfs_client_lock)) {
209 		list_del(&clp->cl_share_link);
210 		spin_unlock(&nfs_client_lock);
211 
212 		BUG_ON(!list_empty(&clp->cl_superblocks));
213 
214 		nfs_free_client(clp);
215 	}
216 }
217 
218 static int nfs_sockaddr_match_ipaddr4(const struct sockaddr_in *sa1,
219 				 const struct sockaddr_in *sa2)
220 {
221 	return sa1->sin_addr.s_addr == sa2->sin_addr.s_addr;
222 }
223 
224 static int nfs_sockaddr_match_ipaddr6(const struct sockaddr_in6 *sa1,
225 				 const struct sockaddr_in6 *sa2)
226 {
227 	return ipv6_addr_equal(&sa1->sin6_addr, &sa2->sin6_addr);
228 }
229 
230 static int nfs_sockaddr_match_ipaddr(const struct sockaddr *sa1,
231 				 const struct sockaddr *sa2)
232 {
233 	switch (sa1->sa_family) {
234 	case AF_INET:
235 		return nfs_sockaddr_match_ipaddr4((const struct sockaddr_in *)sa1,
236 				(const struct sockaddr_in *)sa2);
237 	case AF_INET6:
238 		return nfs_sockaddr_match_ipaddr6((const struct sockaddr_in6 *)sa1,
239 				(const struct sockaddr_in6 *)sa2);
240 	}
241 	BUG();
242 }
243 
244 /*
245  * Find a client by IP address and protocol version
246  * - returns NULL if no such client
247  */
248 struct nfs_client *nfs_find_client(const struct sockaddr *addr, u32 nfsversion)
249 {
250 	struct nfs_client *clp;
251 
252 	spin_lock(&nfs_client_lock);
253 	list_for_each_entry(clp, &nfs_client_list, cl_share_link) {
254 		struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
255 
256 		/* Don't match clients that failed to initialise properly */
257 		if (clp->cl_cons_state != NFS_CS_READY)
258 			continue;
259 
260 		/* Different NFS versions cannot share the same nfs_client */
261 		if (clp->rpc_ops->version != nfsversion)
262 			continue;
263 
264 		if (addr->sa_family != clap->sa_family)
265 			continue;
266 		/* Match only the IP address, not the port number */
267 		if (!nfs_sockaddr_match_ipaddr(addr, clap))
268 			continue;
269 
270 		atomic_inc(&clp->cl_count);
271 		spin_unlock(&nfs_client_lock);
272 		return clp;
273 	}
274 	spin_unlock(&nfs_client_lock);
275 	return NULL;
276 }
277 
278 /*
279  * Find a client by IP address and protocol version
280  * - returns NULL if no such client
281  */
282 struct nfs_client *nfs_find_client_next(struct nfs_client *clp)
283 {
284 	struct sockaddr *sap = (struct sockaddr *)&clp->cl_addr;
285 	u32 nfsvers = clp->rpc_ops->version;
286 
287 	spin_lock(&nfs_client_lock);
288 	list_for_each_entry_continue(clp, &nfs_client_list, cl_share_link) {
289 		struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
290 
291 		/* Don't match clients that failed to initialise properly */
292 		if (clp->cl_cons_state != NFS_CS_READY)
293 			continue;
294 
295 		/* Different NFS versions cannot share the same nfs_client */
296 		if (clp->rpc_ops->version != nfsvers)
297 			continue;
298 
299 		if (sap->sa_family != clap->sa_family)
300 			continue;
301 		/* Match only the IP address, not the port number */
302 		if (!nfs_sockaddr_match_ipaddr(sap, clap))
303 			continue;
304 
305 		atomic_inc(&clp->cl_count);
306 		spin_unlock(&nfs_client_lock);
307 		return clp;
308 	}
309 	spin_unlock(&nfs_client_lock);
310 	return NULL;
311 }
312 
313 /*
314  * Find an nfs_client on the list that matches the initialisation data
315  * that is supplied.
316  */
317 static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *data)
318 {
319 	struct nfs_client *clp;
320 
321 	list_for_each_entry(clp, &nfs_client_list, cl_share_link) {
322 		/* Don't match clients that failed to initialise properly */
323 		if (clp->cl_cons_state < 0)
324 			continue;
325 
326 		/* Different NFS versions cannot share the same nfs_client */
327 		if (clp->rpc_ops != data->rpc_ops)
328 			continue;
329 
330 		if (clp->cl_proto != data->proto)
331 			continue;
332 
333 		/* Match the full socket address */
334 		if (memcmp(&clp->cl_addr, data->addr, sizeof(clp->cl_addr)) != 0)
335 			continue;
336 
337 		atomic_inc(&clp->cl_count);
338 		return clp;
339 	}
340 	return NULL;
341 }
342 
343 /*
344  * Look up a client by IP address and protocol version
345  * - creates a new record if one doesn't yet exist
346  */
347 static struct nfs_client *nfs_get_client(const struct nfs_client_initdata *cl_init)
348 {
349 	struct nfs_client *clp, *new = NULL;
350 	int error;
351 
352 	dprintk("--> nfs_get_client(%s,v%u)\n",
353 		cl_init->hostname ?: "", cl_init->rpc_ops->version);
354 
355 	/* see if the client already exists */
356 	do {
357 		spin_lock(&nfs_client_lock);
358 
359 		clp = nfs_match_client(cl_init);
360 		if (clp)
361 			goto found_client;
362 		if (new)
363 			goto install_client;
364 
365 		spin_unlock(&nfs_client_lock);
366 
367 		new = nfs_alloc_client(cl_init);
368 	} while (new);
369 
370 	return ERR_PTR(-ENOMEM);
371 
372 	/* install a new client and return with it unready */
373 install_client:
374 	clp = new;
375 	list_add(&clp->cl_share_link, &nfs_client_list);
376 	spin_unlock(&nfs_client_lock);
377 	dprintk("--> nfs_get_client() = %p [new]\n", clp);
378 	return clp;
379 
380 	/* found an existing client
381 	 * - make sure it's ready before returning
382 	 */
383 found_client:
384 	spin_unlock(&nfs_client_lock);
385 
386 	if (new)
387 		nfs_free_client(new);
388 
389 	error = wait_event_killable(nfs_client_active_wq,
390 				clp->cl_cons_state != NFS_CS_INITING);
391 	if (error < 0) {
392 		nfs_put_client(clp);
393 		return ERR_PTR(-ERESTARTSYS);
394 	}
395 
396 	if (clp->cl_cons_state < NFS_CS_READY) {
397 		error = clp->cl_cons_state;
398 		nfs_put_client(clp);
399 		return ERR_PTR(error);
400 	}
401 
402 	BUG_ON(clp->cl_cons_state != NFS_CS_READY);
403 
404 	dprintk("--> nfs_get_client() = %p [share]\n", clp);
405 	return clp;
406 }
407 
408 /*
409  * Mark a server as ready or failed
410  */
411 static void nfs_mark_client_ready(struct nfs_client *clp, int state)
412 {
413 	clp->cl_cons_state = state;
414 	wake_up_all(&nfs_client_active_wq);
415 }
416 
417 /*
418  * Initialise the timeout values for a connection
419  */
420 static void nfs_init_timeout_values(struct rpc_timeout *to, int proto,
421 				    unsigned int timeo, unsigned int retrans)
422 {
423 	to->to_initval = timeo * HZ / 10;
424 	to->to_retries = retrans;
425 	if (!to->to_retries)
426 		to->to_retries = 2;
427 
428 	switch (proto) {
429 	case XPRT_TRANSPORT_TCP:
430 	case XPRT_TRANSPORT_RDMA:
431 		if (to->to_initval == 0)
432 			to->to_initval = 60 * HZ;
433 		if (to->to_initval > NFS_MAX_TCP_TIMEOUT)
434 			to->to_initval = NFS_MAX_TCP_TIMEOUT;
435 		to->to_increment = to->to_initval;
436 		to->to_maxval = to->to_initval + (to->to_increment * to->to_retries);
437 		if (to->to_maxval > NFS_MAX_TCP_TIMEOUT)
438 			to->to_maxval = NFS_MAX_TCP_TIMEOUT;
439 		if (to->to_maxval < to->to_initval)
440 			to->to_maxval = to->to_initval;
441 		to->to_exponential = 0;
442 		break;
443 	case XPRT_TRANSPORT_UDP:
444 	default:
445 		if (!to->to_initval)
446 			to->to_initval = 11 * HZ / 10;
447 		if (to->to_initval > NFS_MAX_UDP_TIMEOUT)
448 			to->to_initval = NFS_MAX_UDP_TIMEOUT;
449 		to->to_maxval = NFS_MAX_UDP_TIMEOUT;
450 		to->to_exponential = 1;
451 		break;
452 	}
453 }
454 
455 /*
456  * Create an RPC client handle
457  */
458 static int nfs_create_rpc_client(struct nfs_client *clp,
459 				 const struct rpc_timeout *timeparms,
460 				 rpc_authflavor_t flavor,
461 				 int flags)
462 {
463 	struct rpc_clnt		*clnt = NULL;
464 	struct rpc_create_args args = {
465 		.protocol	= clp->cl_proto,
466 		.address	= (struct sockaddr *)&clp->cl_addr,
467 		.addrsize	= clp->cl_addrlen,
468 		.timeout	= timeparms,
469 		.servername	= clp->cl_hostname,
470 		.program	= &nfs_program,
471 		.version	= clp->rpc_ops->version,
472 		.authflavor	= flavor,
473 		.flags		= flags,
474 	};
475 
476 	if (!IS_ERR(clp->cl_rpcclient))
477 		return 0;
478 
479 	clnt = rpc_create(&args);
480 	if (IS_ERR(clnt)) {
481 		dprintk("%s: cannot create RPC client. Error = %ld\n",
482 				__FUNCTION__, PTR_ERR(clnt));
483 		return PTR_ERR(clnt);
484 	}
485 
486 	clp->cl_rpcclient = clnt;
487 	return 0;
488 }
489 
490 /*
491  * Version 2 or 3 client destruction
492  */
493 static void nfs_destroy_server(struct nfs_server *server)
494 {
495 	if (!(server->flags & NFS_MOUNT_NONLM))
496 		nlmclnt_done(server->nlm_host);
497 }
498 
499 /*
500  * Version 2 or 3 lockd setup
501  */
502 static int nfs_start_lockd(struct nfs_server *server)
503 {
504 	struct nlm_host *host;
505 	struct nfs_client *clp = server->nfs_client;
506 	struct nlmclnt_initdata nlm_init = {
507 		.hostname	= clp->cl_hostname,
508 		.address	= (struct sockaddr *)&clp->cl_addr,
509 		.addrlen	= clp->cl_addrlen,
510 		.protocol	= server->flags & NFS_MOUNT_TCP ?
511 						IPPROTO_TCP : IPPROTO_UDP,
512 		.nfs_version	= clp->rpc_ops->version,
513 	};
514 
515 	if (nlm_init.nfs_version > 3)
516 		return 0;
517 	if (server->flags & NFS_MOUNT_NONLM)
518 		return 0;
519 
520 	host = nlmclnt_init(&nlm_init);
521 	if (IS_ERR(host))
522 		return PTR_ERR(host);
523 
524 	server->nlm_host = host;
525 	server->destroy = nfs_destroy_server;
526 	return 0;
527 }
528 
529 /*
530  * Initialise an NFSv3 ACL client connection
531  */
532 #ifdef CONFIG_NFS_V3_ACL
533 static void nfs_init_server_aclclient(struct nfs_server *server)
534 {
535 	if (server->nfs_client->rpc_ops->version != 3)
536 		goto out_noacl;
537 	if (server->flags & NFS_MOUNT_NOACL)
538 		goto out_noacl;
539 
540 	server->client_acl = rpc_bind_new_program(server->client, &nfsacl_program, 3);
541 	if (IS_ERR(server->client_acl))
542 		goto out_noacl;
543 
544 	/* No errors! Assume that Sun nfsacls are supported */
545 	server->caps |= NFS_CAP_ACLS;
546 	return;
547 
548 out_noacl:
549 	server->caps &= ~NFS_CAP_ACLS;
550 }
551 #else
552 static inline void nfs_init_server_aclclient(struct nfs_server *server)
553 {
554 	server->flags &= ~NFS_MOUNT_NOACL;
555 	server->caps &= ~NFS_CAP_ACLS;
556 }
557 #endif
558 
559 /*
560  * Create a general RPC client
561  */
562 static int nfs_init_server_rpcclient(struct nfs_server *server,
563 		const struct rpc_timeout *timeo,
564 		rpc_authflavor_t pseudoflavour)
565 {
566 	struct nfs_client *clp = server->nfs_client;
567 
568 	server->client = rpc_clone_client(clp->cl_rpcclient);
569 	if (IS_ERR(server->client)) {
570 		dprintk("%s: couldn't create rpc_client!\n", __FUNCTION__);
571 		return PTR_ERR(server->client);
572 	}
573 
574 	memcpy(&server->client->cl_timeout_default,
575 			timeo,
576 			sizeof(server->client->cl_timeout_default));
577 	server->client->cl_timeout = &server->client->cl_timeout_default;
578 
579 	if (pseudoflavour != clp->cl_rpcclient->cl_auth->au_flavor) {
580 		struct rpc_auth *auth;
581 
582 		auth = rpcauth_create(pseudoflavour, server->client);
583 		if (IS_ERR(auth)) {
584 			dprintk("%s: couldn't create credcache!\n", __FUNCTION__);
585 			return PTR_ERR(auth);
586 		}
587 	}
588 	server->client->cl_softrtry = 0;
589 	if (server->flags & NFS_MOUNT_SOFT)
590 		server->client->cl_softrtry = 1;
591 
592 	return 0;
593 }
594 
595 /*
596  * Initialise an NFS2 or NFS3 client
597  */
598 static int nfs_init_client(struct nfs_client *clp,
599 			   const struct rpc_timeout *timeparms,
600 			   const struct nfs_parsed_mount_data *data)
601 {
602 	int error;
603 
604 	if (clp->cl_cons_state == NFS_CS_READY) {
605 		/* the client is already initialised */
606 		dprintk("<-- nfs_init_client() = 0 [already %p]\n", clp);
607 		return 0;
608 	}
609 
610 	/*
611 	 * Create a client RPC handle for doing FSSTAT with UNIX auth only
612 	 * - RFC 2623, sec 2.3.2
613 	 */
614 	error = nfs_create_rpc_client(clp, timeparms, RPC_AUTH_UNIX, 0);
615 	if (error < 0)
616 		goto error;
617 	nfs_mark_client_ready(clp, NFS_CS_READY);
618 	return 0;
619 
620 error:
621 	nfs_mark_client_ready(clp, error);
622 	dprintk("<-- nfs_init_client() = xerror %d\n", error);
623 	return error;
624 }
625 
626 /*
627  * Create a version 2 or 3 client
628  */
629 static int nfs_init_server(struct nfs_server *server,
630 			   const struct nfs_parsed_mount_data *data)
631 {
632 	struct nfs_client_initdata cl_init = {
633 		.hostname = data->nfs_server.hostname,
634 		.addr = (const struct sockaddr *)&data->nfs_server.address,
635 		.addrlen = data->nfs_server.addrlen,
636 		.rpc_ops = &nfs_v2_clientops,
637 		.proto = data->nfs_server.protocol,
638 	};
639 	struct rpc_timeout timeparms;
640 	struct nfs_client *clp;
641 	int error;
642 
643 	dprintk("--> nfs_init_server()\n");
644 
645 #ifdef CONFIG_NFS_V3
646 	if (data->flags & NFS_MOUNT_VER3)
647 		cl_init.rpc_ops = &nfs_v3_clientops;
648 #endif
649 
650 	/* Allocate or find a client reference we can use */
651 	clp = nfs_get_client(&cl_init);
652 	if (IS_ERR(clp)) {
653 		dprintk("<-- nfs_init_server() = error %ld\n", PTR_ERR(clp));
654 		return PTR_ERR(clp);
655 	}
656 
657 	nfs_init_timeout_values(&timeparms, data->nfs_server.protocol,
658 			data->timeo, data->retrans);
659 	error = nfs_init_client(clp, &timeparms, data);
660 	if (error < 0)
661 		goto error;
662 
663 	server->nfs_client = clp;
664 
665 	/* Initialise the client representation from the mount data */
666 	server->flags = data->flags & NFS_MOUNT_FLAGMASK;
667 
668 	if (data->rsize)
669 		server->rsize = nfs_block_size(data->rsize, NULL);
670 	if (data->wsize)
671 		server->wsize = nfs_block_size(data->wsize, NULL);
672 
673 	server->acregmin = data->acregmin * HZ;
674 	server->acregmax = data->acregmax * HZ;
675 	server->acdirmin = data->acdirmin * HZ;
676 	server->acdirmax = data->acdirmax * HZ;
677 
678 	/* Start lockd here, before we might error out */
679 	error = nfs_start_lockd(server);
680 	if (error < 0)
681 		goto error;
682 
683 	error = nfs_init_server_rpcclient(server, &timeparms, data->auth_flavors[0]);
684 	if (error < 0)
685 		goto error;
686 
687 	server->namelen  = data->namlen;
688 	/* Create a client RPC handle for the NFSv3 ACL management interface */
689 	nfs_init_server_aclclient(server);
690 	dprintk("<-- nfs_init_server() = 0 [new %p]\n", clp);
691 	return 0;
692 
693 error:
694 	server->nfs_client = NULL;
695 	nfs_put_client(clp);
696 	dprintk("<-- nfs_init_server() = xerror %d\n", error);
697 	return error;
698 }
699 
700 /*
701  * Load up the server record from information gained in an fsinfo record
702  */
703 static void nfs_server_set_fsinfo(struct nfs_server *server, struct nfs_fsinfo *fsinfo)
704 {
705 	unsigned long max_rpc_payload;
706 
707 	/* Work out a lot of parameters */
708 	if (server->rsize == 0)
709 		server->rsize = nfs_block_size(fsinfo->rtpref, NULL);
710 	if (server->wsize == 0)
711 		server->wsize = nfs_block_size(fsinfo->wtpref, NULL);
712 
713 	if (fsinfo->rtmax >= 512 && server->rsize > fsinfo->rtmax)
714 		server->rsize = nfs_block_size(fsinfo->rtmax, NULL);
715 	if (fsinfo->wtmax >= 512 && server->wsize > fsinfo->wtmax)
716 		server->wsize = nfs_block_size(fsinfo->wtmax, NULL);
717 
718 	max_rpc_payload = nfs_block_size(rpc_max_payload(server->client), NULL);
719 	if (server->rsize > max_rpc_payload)
720 		server->rsize = max_rpc_payload;
721 	if (server->rsize > NFS_MAX_FILE_IO_SIZE)
722 		server->rsize = NFS_MAX_FILE_IO_SIZE;
723 	server->rpages = (server->rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
724 
725 	server->backing_dev_info.ra_pages = server->rpages * NFS_MAX_READAHEAD;
726 
727 	if (server->wsize > max_rpc_payload)
728 		server->wsize = max_rpc_payload;
729 	if (server->wsize > NFS_MAX_FILE_IO_SIZE)
730 		server->wsize = NFS_MAX_FILE_IO_SIZE;
731 	server->wpages = (server->wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
732 	server->wtmult = nfs_block_bits(fsinfo->wtmult, NULL);
733 
734 	server->dtsize = nfs_block_size(fsinfo->dtpref, NULL);
735 	if (server->dtsize > PAGE_CACHE_SIZE)
736 		server->dtsize = PAGE_CACHE_SIZE;
737 	if (server->dtsize > server->rsize)
738 		server->dtsize = server->rsize;
739 
740 	if (server->flags & NFS_MOUNT_NOAC) {
741 		server->acregmin = server->acregmax = 0;
742 		server->acdirmin = server->acdirmax = 0;
743 	}
744 
745 	server->maxfilesize = fsinfo->maxfilesize;
746 
747 	/* We're airborne Set socket buffersize */
748 	rpc_setbufsize(server->client, server->wsize + 100, server->rsize + 100);
749 }
750 
751 /*
752  * Probe filesystem information, including the FSID on v2/v3
753  */
754 static int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *mntfh, struct nfs_fattr *fattr)
755 {
756 	struct nfs_fsinfo fsinfo;
757 	struct nfs_client *clp = server->nfs_client;
758 	int error;
759 
760 	dprintk("--> nfs_probe_fsinfo()\n");
761 
762 	if (clp->rpc_ops->set_capabilities != NULL) {
763 		error = clp->rpc_ops->set_capabilities(server, mntfh);
764 		if (error < 0)
765 			goto out_error;
766 	}
767 
768 	fsinfo.fattr = fattr;
769 	nfs_fattr_init(fattr);
770 	error = clp->rpc_ops->fsinfo(server, mntfh, &fsinfo);
771 	if (error < 0)
772 		goto out_error;
773 
774 	nfs_server_set_fsinfo(server, &fsinfo);
775 	error = bdi_init(&server->backing_dev_info);
776 	if (error)
777 		goto out_error;
778 
779 
780 	/* Get some general file system info */
781 	if (server->namelen == 0) {
782 		struct nfs_pathconf pathinfo;
783 
784 		pathinfo.fattr = fattr;
785 		nfs_fattr_init(fattr);
786 
787 		if (clp->rpc_ops->pathconf(server, mntfh, &pathinfo) >= 0)
788 			server->namelen = pathinfo.max_namelen;
789 	}
790 
791 	dprintk("<-- nfs_probe_fsinfo() = 0\n");
792 	return 0;
793 
794 out_error:
795 	dprintk("nfs_probe_fsinfo: error = %d\n", -error);
796 	return error;
797 }
798 
799 /*
800  * Copy useful information when duplicating a server record
801  */
802 static void nfs_server_copy_userdata(struct nfs_server *target, struct nfs_server *source)
803 {
804 	target->flags = source->flags;
805 	target->acregmin = source->acregmin;
806 	target->acregmax = source->acregmax;
807 	target->acdirmin = source->acdirmin;
808 	target->acdirmax = source->acdirmax;
809 	target->caps = source->caps;
810 }
811 
812 /*
813  * Allocate and initialise a server record
814  */
815 static struct nfs_server *nfs_alloc_server(void)
816 {
817 	struct nfs_server *server;
818 
819 	server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
820 	if (!server)
821 		return NULL;
822 
823 	server->client = server->client_acl = ERR_PTR(-EINVAL);
824 
825 	/* Zero out the NFS state stuff */
826 	INIT_LIST_HEAD(&server->client_link);
827 	INIT_LIST_HEAD(&server->master_link);
828 
829 	init_waitqueue_head(&server->active_wq);
830 	atomic_set(&server->active, 0);
831 
832 	server->io_stats = nfs_alloc_iostats();
833 	if (!server->io_stats) {
834 		kfree(server);
835 		return NULL;
836 	}
837 
838 	return server;
839 }
840 
841 /*
842  * Free up a server record
843  */
844 void nfs_free_server(struct nfs_server *server)
845 {
846 	dprintk("--> nfs_free_server()\n");
847 
848 	spin_lock(&nfs_client_lock);
849 	list_del(&server->client_link);
850 	list_del(&server->master_link);
851 	spin_unlock(&nfs_client_lock);
852 
853 	if (server->destroy != NULL)
854 		server->destroy(server);
855 
856 	if (!IS_ERR(server->client_acl))
857 		rpc_shutdown_client(server->client_acl);
858 	if (!IS_ERR(server->client))
859 		rpc_shutdown_client(server->client);
860 
861 	nfs_put_client(server->nfs_client);
862 
863 	nfs_free_iostats(server->io_stats);
864 	bdi_destroy(&server->backing_dev_info);
865 	kfree(server);
866 	nfs_release_automount_timer();
867 	dprintk("<-- nfs_free_server()\n");
868 }
869 
870 /*
871  * Create a version 2 or 3 volume record
872  * - keyed on server and FSID
873  */
874 struct nfs_server *nfs_create_server(const struct nfs_parsed_mount_data *data,
875 				     struct nfs_fh *mntfh)
876 {
877 	struct nfs_server *server;
878 	struct nfs_fattr fattr;
879 	int error;
880 
881 	server = nfs_alloc_server();
882 	if (!server)
883 		return ERR_PTR(-ENOMEM);
884 
885 	/* Get a client representation */
886 	error = nfs_init_server(server, data);
887 	if (error < 0)
888 		goto error;
889 
890 	BUG_ON(!server->nfs_client);
891 	BUG_ON(!server->nfs_client->rpc_ops);
892 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
893 
894 	/* Probe the root fh to retrieve its FSID */
895 	error = nfs_probe_fsinfo(server, mntfh, &fattr);
896 	if (error < 0)
897 		goto error;
898 	if (server->nfs_client->rpc_ops->version == 3) {
899 		if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN)
900 			server->namelen = NFS3_MAXNAMLEN;
901 		if (!(data->flags & NFS_MOUNT_NORDIRPLUS))
902 			server->caps |= NFS_CAP_READDIRPLUS;
903 	} else {
904 		if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN)
905 			server->namelen = NFS2_MAXNAMLEN;
906 	}
907 
908 	if (!(fattr.valid & NFS_ATTR_FATTR)) {
909 		error = server->nfs_client->rpc_ops->getattr(server, mntfh, &fattr);
910 		if (error < 0) {
911 			dprintk("nfs_create_server: getattr error = %d\n", -error);
912 			goto error;
913 		}
914 	}
915 	memcpy(&server->fsid, &fattr.fsid, sizeof(server->fsid));
916 
917 	dprintk("Server FSID: %llx:%llx\n",
918 		(unsigned long long) server->fsid.major,
919 		(unsigned long long) server->fsid.minor);
920 
921 	BUG_ON(!server->nfs_client);
922 	BUG_ON(!server->nfs_client->rpc_ops);
923 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
924 
925 	spin_lock(&nfs_client_lock);
926 	list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);
927 	list_add_tail(&server->master_link, &nfs_volume_list);
928 	spin_unlock(&nfs_client_lock);
929 
930 	server->mount_time = jiffies;
931 	return server;
932 
933 error:
934 	nfs_free_server(server);
935 	return ERR_PTR(error);
936 }
937 
938 #ifdef CONFIG_NFS_V4
939 /*
940  * Initialise an NFS4 client record
941  */
942 static int nfs4_init_client(struct nfs_client *clp,
943 		const struct rpc_timeout *timeparms,
944 		const char *ip_addr,
945 		rpc_authflavor_t authflavour)
946 {
947 	int error;
948 
949 	if (clp->cl_cons_state == NFS_CS_READY) {
950 		/* the client is initialised already */
951 		dprintk("<-- nfs4_init_client() = 0 [already %p]\n", clp);
952 		return 0;
953 	}
954 
955 	/* Check NFS protocol revision and initialize RPC op vector */
956 	clp->rpc_ops = &nfs_v4_clientops;
957 
958 	error = nfs_create_rpc_client(clp, timeparms, authflavour,
959 					RPC_CLNT_CREATE_DISCRTRY);
960 	if (error < 0)
961 		goto error;
962 	memcpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr));
963 
964 	error = nfs_idmap_new(clp);
965 	if (error < 0) {
966 		dprintk("%s: failed to create idmapper. Error = %d\n",
967 			__FUNCTION__, error);
968 		goto error;
969 	}
970 	__set_bit(NFS_CS_IDMAP, &clp->cl_res_state);
971 
972 	nfs_mark_client_ready(clp, NFS_CS_READY);
973 	return 0;
974 
975 error:
976 	nfs_mark_client_ready(clp, error);
977 	dprintk("<-- nfs4_init_client() = xerror %d\n", error);
978 	return error;
979 }
980 
981 /*
982  * Set up an NFS4 client
983  */
984 static int nfs4_set_client(struct nfs_server *server,
985 		const char *hostname,
986 		const struct sockaddr *addr,
987 		const size_t addrlen,
988 		const char *ip_addr,
989 		rpc_authflavor_t authflavour,
990 		int proto, const struct rpc_timeout *timeparms)
991 {
992 	struct nfs_client_initdata cl_init = {
993 		.hostname = hostname,
994 		.addr = addr,
995 		.addrlen = addrlen,
996 		.rpc_ops = &nfs_v4_clientops,
997 		.proto = proto,
998 	};
999 	struct nfs_client *clp;
1000 	int error;
1001 
1002 	dprintk("--> nfs4_set_client()\n");
1003 
1004 	/* Allocate or find a client reference we can use */
1005 	clp = nfs_get_client(&cl_init);
1006 	if (IS_ERR(clp)) {
1007 		error = PTR_ERR(clp);
1008 		goto error;
1009 	}
1010 	error = nfs4_init_client(clp, timeparms, ip_addr, authflavour);
1011 	if (error < 0)
1012 		goto error_put;
1013 
1014 	server->nfs_client = clp;
1015 	dprintk("<-- nfs4_set_client() = 0 [new %p]\n", clp);
1016 	return 0;
1017 
1018 error_put:
1019 	nfs_put_client(clp);
1020 error:
1021 	dprintk("<-- nfs4_set_client() = xerror %d\n", error);
1022 	return error;
1023 }
1024 
1025 /*
1026  * Create a version 4 volume record
1027  */
1028 static int nfs4_init_server(struct nfs_server *server,
1029 		const struct nfs_parsed_mount_data *data)
1030 {
1031 	struct rpc_timeout timeparms;
1032 	int error;
1033 
1034 	dprintk("--> nfs4_init_server()\n");
1035 
1036 	nfs_init_timeout_values(&timeparms, data->nfs_server.protocol,
1037 			data->timeo, data->retrans);
1038 
1039 	/* Get a client record */
1040 	error = nfs4_set_client(server,
1041 			data->nfs_server.hostname,
1042 			(const struct sockaddr *)&data->nfs_server.address,
1043 			data->nfs_server.addrlen,
1044 			data->client_address,
1045 			data->auth_flavors[0],
1046 			data->nfs_server.protocol,
1047 			&timeparms);
1048 	if (error < 0)
1049 		goto error;
1050 
1051 	/* Initialise the client representation from the mount data */
1052 	server->flags = data->flags & NFS_MOUNT_FLAGMASK;
1053 	server->caps |= NFS_CAP_ATOMIC_OPEN;
1054 
1055 	if (data->rsize)
1056 		server->rsize = nfs_block_size(data->rsize, NULL);
1057 	if (data->wsize)
1058 		server->wsize = nfs_block_size(data->wsize, NULL);
1059 
1060 	server->acregmin = data->acregmin * HZ;
1061 	server->acregmax = data->acregmax * HZ;
1062 	server->acdirmin = data->acdirmin * HZ;
1063 	server->acdirmax = data->acdirmax * HZ;
1064 
1065 	error = nfs_init_server_rpcclient(server, &timeparms, data->auth_flavors[0]);
1066 
1067 error:
1068 	/* Done */
1069 	dprintk("<-- nfs4_init_server() = %d\n", error);
1070 	return error;
1071 }
1072 
1073 /*
1074  * Create a version 4 volume record
1075  * - keyed on server and FSID
1076  */
1077 struct nfs_server *nfs4_create_server(const struct nfs_parsed_mount_data *data,
1078 				      struct nfs_fh *mntfh)
1079 {
1080 	struct nfs_fattr fattr;
1081 	struct nfs_server *server;
1082 	int error;
1083 
1084 	dprintk("--> nfs4_create_server()\n");
1085 
1086 	server = nfs_alloc_server();
1087 	if (!server)
1088 		return ERR_PTR(-ENOMEM);
1089 
1090 	/* set up the general RPC client */
1091 	error = nfs4_init_server(server, data);
1092 	if (error < 0)
1093 		goto error;
1094 
1095 	BUG_ON(!server->nfs_client);
1096 	BUG_ON(!server->nfs_client->rpc_ops);
1097 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
1098 
1099 	/* Probe the root fh to retrieve its FSID */
1100 	error = nfs4_path_walk(server, mntfh, data->nfs_server.export_path);
1101 	if (error < 0)
1102 		goto error;
1103 
1104 	dprintk("Server FSID: %llx:%llx\n",
1105 		(unsigned long long) server->fsid.major,
1106 		(unsigned long long) server->fsid.minor);
1107 	dprintk("Mount FH: %d\n", mntfh->size);
1108 
1109 	error = nfs_probe_fsinfo(server, mntfh, &fattr);
1110 	if (error < 0)
1111 		goto error;
1112 
1113 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1114 		server->namelen = NFS4_MAXNAMLEN;
1115 
1116 	BUG_ON(!server->nfs_client);
1117 	BUG_ON(!server->nfs_client->rpc_ops);
1118 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
1119 
1120 	spin_lock(&nfs_client_lock);
1121 	list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);
1122 	list_add_tail(&server->master_link, &nfs_volume_list);
1123 	spin_unlock(&nfs_client_lock);
1124 
1125 	server->mount_time = jiffies;
1126 	dprintk("<-- nfs4_create_server() = %p\n", server);
1127 	return server;
1128 
1129 error:
1130 	nfs_free_server(server);
1131 	dprintk("<-- nfs4_create_server() = error %d\n", error);
1132 	return ERR_PTR(error);
1133 }
1134 
1135 /*
1136  * Create an NFS4 referral server record
1137  */
1138 struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data,
1139 					       struct nfs_fh *mntfh)
1140 {
1141 	struct nfs_client *parent_client;
1142 	struct nfs_server *server, *parent_server;
1143 	struct nfs_fattr fattr;
1144 	int error;
1145 
1146 	dprintk("--> nfs4_create_referral_server()\n");
1147 
1148 	server = nfs_alloc_server();
1149 	if (!server)
1150 		return ERR_PTR(-ENOMEM);
1151 
1152 	parent_server = NFS_SB(data->sb);
1153 	parent_client = parent_server->nfs_client;
1154 
1155 	/* Get a client representation.
1156 	 * Note: NFSv4 always uses TCP, */
1157 	error = nfs4_set_client(server, data->hostname,
1158 				data->addr,
1159 				data->addrlen,
1160 				parent_client->cl_ipaddr,
1161 				data->authflavor,
1162 				parent_server->client->cl_xprt->prot,
1163 				parent_server->client->cl_timeout);
1164 	if (error < 0)
1165 		goto error;
1166 
1167 	/* Initialise the client representation from the parent server */
1168 	nfs_server_copy_userdata(server, parent_server);
1169 	server->caps |= NFS_CAP_ATOMIC_OPEN;
1170 
1171 	error = nfs_init_server_rpcclient(server, parent_server->client->cl_timeout, data->authflavor);
1172 	if (error < 0)
1173 		goto error;
1174 
1175 	BUG_ON(!server->nfs_client);
1176 	BUG_ON(!server->nfs_client->rpc_ops);
1177 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
1178 
1179 	/* Probe the root fh to retrieve its FSID and filehandle */
1180 	error = nfs4_path_walk(server, mntfh, data->mnt_path);
1181 	if (error < 0)
1182 		goto error;
1183 
1184 	/* probe the filesystem info for this server filesystem */
1185 	error = nfs_probe_fsinfo(server, mntfh, &fattr);
1186 	if (error < 0)
1187 		goto error;
1188 
1189 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1190 		server->namelen = NFS4_MAXNAMLEN;
1191 
1192 	dprintk("Referral FSID: %llx:%llx\n",
1193 		(unsigned long long) server->fsid.major,
1194 		(unsigned long long) server->fsid.minor);
1195 
1196 	spin_lock(&nfs_client_lock);
1197 	list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);
1198 	list_add_tail(&server->master_link, &nfs_volume_list);
1199 	spin_unlock(&nfs_client_lock);
1200 
1201 	server->mount_time = jiffies;
1202 
1203 	dprintk("<-- nfs_create_referral_server() = %p\n", server);
1204 	return server;
1205 
1206 error:
1207 	nfs_free_server(server);
1208 	dprintk("<-- nfs4_create_referral_server() = error %d\n", error);
1209 	return ERR_PTR(error);
1210 }
1211 
1212 #endif /* CONFIG_NFS_V4 */
1213 
1214 /*
1215  * Clone an NFS2, NFS3 or NFS4 server record
1216  */
1217 struct nfs_server *nfs_clone_server(struct nfs_server *source,
1218 				    struct nfs_fh *fh,
1219 				    struct nfs_fattr *fattr)
1220 {
1221 	struct nfs_server *server;
1222 	struct nfs_fattr fattr_fsinfo;
1223 	int error;
1224 
1225 	dprintk("--> nfs_clone_server(,%llx:%llx,)\n",
1226 		(unsigned long long) fattr->fsid.major,
1227 		(unsigned long long) fattr->fsid.minor);
1228 
1229 	server = nfs_alloc_server();
1230 	if (!server)
1231 		return ERR_PTR(-ENOMEM);
1232 
1233 	/* Copy data from the source */
1234 	server->nfs_client = source->nfs_client;
1235 	atomic_inc(&server->nfs_client->cl_count);
1236 	nfs_server_copy_userdata(server, source);
1237 
1238 	server->fsid = fattr->fsid;
1239 
1240 	error = nfs_init_server_rpcclient(server,
1241 			source->client->cl_timeout,
1242 			source->client->cl_auth->au_flavor);
1243 	if (error < 0)
1244 		goto out_free_server;
1245 	if (!IS_ERR(source->client_acl))
1246 		nfs_init_server_aclclient(server);
1247 
1248 	/* probe the filesystem info for this server filesystem */
1249 	error = nfs_probe_fsinfo(server, fh, &fattr_fsinfo);
1250 	if (error < 0)
1251 		goto out_free_server;
1252 
1253 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1254 		server->namelen = NFS4_MAXNAMLEN;
1255 
1256 	dprintk("Cloned FSID: %llx:%llx\n",
1257 		(unsigned long long) server->fsid.major,
1258 		(unsigned long long) server->fsid.minor);
1259 
1260 	error = nfs_start_lockd(server);
1261 	if (error < 0)
1262 		goto out_free_server;
1263 
1264 	spin_lock(&nfs_client_lock);
1265 	list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);
1266 	list_add_tail(&server->master_link, &nfs_volume_list);
1267 	spin_unlock(&nfs_client_lock);
1268 
1269 	server->mount_time = jiffies;
1270 
1271 	dprintk("<-- nfs_clone_server() = %p\n", server);
1272 	return server;
1273 
1274 out_free_server:
1275 	nfs_free_server(server);
1276 	dprintk("<-- nfs_clone_server() = error %d\n", error);
1277 	return ERR_PTR(error);
1278 }
1279 
1280 #ifdef CONFIG_PROC_FS
1281 static struct proc_dir_entry *proc_fs_nfs;
1282 
1283 static int nfs_server_list_open(struct inode *inode, struct file *file);
1284 static void *nfs_server_list_start(struct seq_file *p, loff_t *pos);
1285 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos);
1286 static void nfs_server_list_stop(struct seq_file *p, void *v);
1287 static int nfs_server_list_show(struct seq_file *m, void *v);
1288 
1289 static struct seq_operations nfs_server_list_ops = {
1290 	.start	= nfs_server_list_start,
1291 	.next	= nfs_server_list_next,
1292 	.stop	= nfs_server_list_stop,
1293 	.show	= nfs_server_list_show,
1294 };
1295 
1296 static const struct file_operations nfs_server_list_fops = {
1297 	.open		= nfs_server_list_open,
1298 	.read		= seq_read,
1299 	.llseek		= seq_lseek,
1300 	.release	= seq_release,
1301 };
1302 
1303 static int nfs_volume_list_open(struct inode *inode, struct file *file);
1304 static void *nfs_volume_list_start(struct seq_file *p, loff_t *pos);
1305 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos);
1306 static void nfs_volume_list_stop(struct seq_file *p, void *v);
1307 static int nfs_volume_list_show(struct seq_file *m, void *v);
1308 
1309 static struct seq_operations nfs_volume_list_ops = {
1310 	.start	= nfs_volume_list_start,
1311 	.next	= nfs_volume_list_next,
1312 	.stop	= nfs_volume_list_stop,
1313 	.show	= nfs_volume_list_show,
1314 };
1315 
1316 static const struct file_operations nfs_volume_list_fops = {
1317 	.open		= nfs_volume_list_open,
1318 	.read		= seq_read,
1319 	.llseek		= seq_lseek,
1320 	.release	= seq_release,
1321 };
1322 
1323 /*
1324  * open "/proc/fs/nfsfs/servers" which provides a summary of servers with which
1325  * we're dealing
1326  */
1327 static int nfs_server_list_open(struct inode *inode, struct file *file)
1328 {
1329 	struct seq_file *m;
1330 	int ret;
1331 
1332 	ret = seq_open(file, &nfs_server_list_ops);
1333 	if (ret < 0)
1334 		return ret;
1335 
1336 	m = file->private_data;
1337 	m->private = PDE(inode)->data;
1338 
1339 	return 0;
1340 }
1341 
1342 /*
1343  * set up the iterator to start reading from the server list and return the first item
1344  */
1345 static void *nfs_server_list_start(struct seq_file *m, loff_t *_pos)
1346 {
1347 	/* lock the list against modification */
1348 	spin_lock(&nfs_client_lock);
1349 	return seq_list_start_head(&nfs_client_list, *_pos);
1350 }
1351 
1352 /*
1353  * move to next server
1354  */
1355 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos)
1356 {
1357 	return seq_list_next(v, &nfs_client_list, pos);
1358 }
1359 
1360 /*
1361  * clean up after reading from the transports list
1362  */
1363 static void nfs_server_list_stop(struct seq_file *p, void *v)
1364 {
1365 	spin_unlock(&nfs_client_lock);
1366 }
1367 
1368 /*
1369  * display a header line followed by a load of call lines
1370  */
1371 static int nfs_server_list_show(struct seq_file *m, void *v)
1372 {
1373 	struct nfs_client *clp;
1374 
1375 	/* display header on line 1 */
1376 	if (v == &nfs_client_list) {
1377 		seq_puts(m, "NV SERVER   PORT USE HOSTNAME\n");
1378 		return 0;
1379 	}
1380 
1381 	/* display one transport per line on subsequent lines */
1382 	clp = list_entry(v, struct nfs_client, cl_share_link);
1383 
1384 	seq_printf(m, "v%u %s %s %3d %s\n",
1385 		   clp->rpc_ops->version,
1386 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1387 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1388 		   atomic_read(&clp->cl_count),
1389 		   clp->cl_hostname);
1390 
1391 	return 0;
1392 }
1393 
1394 /*
1395  * open "/proc/fs/nfsfs/volumes" which provides a summary of extant volumes
1396  */
1397 static int nfs_volume_list_open(struct inode *inode, struct file *file)
1398 {
1399 	struct seq_file *m;
1400 	int ret;
1401 
1402 	ret = seq_open(file, &nfs_volume_list_ops);
1403 	if (ret < 0)
1404 		return ret;
1405 
1406 	m = file->private_data;
1407 	m->private = PDE(inode)->data;
1408 
1409 	return 0;
1410 }
1411 
1412 /*
1413  * set up the iterator to start reading from the volume list and return the first item
1414  */
1415 static void *nfs_volume_list_start(struct seq_file *m, loff_t *_pos)
1416 {
1417 	/* lock the list against modification */
1418 	spin_lock(&nfs_client_lock);
1419 	return seq_list_start_head(&nfs_volume_list, *_pos);
1420 }
1421 
1422 /*
1423  * move to next volume
1424  */
1425 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos)
1426 {
1427 	return seq_list_next(v, &nfs_volume_list, pos);
1428 }
1429 
1430 /*
1431  * clean up after reading from the transports list
1432  */
1433 static void nfs_volume_list_stop(struct seq_file *p, void *v)
1434 {
1435 	spin_unlock(&nfs_client_lock);
1436 }
1437 
1438 /*
1439  * display a header line followed by a load of call lines
1440  */
1441 static int nfs_volume_list_show(struct seq_file *m, void *v)
1442 {
1443 	struct nfs_server *server;
1444 	struct nfs_client *clp;
1445 	char dev[8], fsid[17];
1446 
1447 	/* display header on line 1 */
1448 	if (v == &nfs_volume_list) {
1449 		seq_puts(m, "NV SERVER   PORT DEV     FSID\n");
1450 		return 0;
1451 	}
1452 	/* display one transport per line on subsequent lines */
1453 	server = list_entry(v, struct nfs_server, master_link);
1454 	clp = server->nfs_client;
1455 
1456 	snprintf(dev, 8, "%u:%u",
1457 		 MAJOR(server->s_dev), MINOR(server->s_dev));
1458 
1459 	snprintf(fsid, 17, "%llx:%llx",
1460 		 (unsigned long long) server->fsid.major,
1461 		 (unsigned long long) server->fsid.minor);
1462 
1463 	seq_printf(m, "v%u %s %s %-7s %-17s\n",
1464 		   clp->rpc_ops->version,
1465 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1466 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1467 		   dev,
1468 		   fsid);
1469 
1470 	return 0;
1471 }
1472 
1473 /*
1474  * initialise the /proc/fs/nfsfs/ directory
1475  */
1476 int __init nfs_fs_proc_init(void)
1477 {
1478 	struct proc_dir_entry *p;
1479 
1480 	proc_fs_nfs = proc_mkdir("nfsfs", proc_root_fs);
1481 	if (!proc_fs_nfs)
1482 		goto error_0;
1483 
1484 	proc_fs_nfs->owner = THIS_MODULE;
1485 
1486 	/* a file of servers with which we're dealing */
1487 	p = create_proc_entry("servers", S_IFREG|S_IRUGO, proc_fs_nfs);
1488 	if (!p)
1489 		goto error_1;
1490 
1491 	p->proc_fops = &nfs_server_list_fops;
1492 	p->owner = THIS_MODULE;
1493 
1494 	/* a file of volumes that we have mounted */
1495 	p = create_proc_entry("volumes", S_IFREG|S_IRUGO, proc_fs_nfs);
1496 	if (!p)
1497 		goto error_2;
1498 
1499 	p->proc_fops = &nfs_volume_list_fops;
1500 	p->owner = THIS_MODULE;
1501 	return 0;
1502 
1503 error_2:
1504 	remove_proc_entry("servers", proc_fs_nfs);
1505 error_1:
1506 	remove_proc_entry("nfsfs", proc_root_fs);
1507 error_0:
1508 	return -ENOMEM;
1509 }
1510 
1511 /*
1512  * clean up the /proc/fs/nfsfs/ directory
1513  */
1514 void nfs_fs_proc_exit(void)
1515 {
1516 	remove_proc_entry("volumes", proc_fs_nfs);
1517 	remove_proc_entry("servers", proc_fs_nfs);
1518 	remove_proc_entry("nfsfs", proc_root_fs);
1519 }
1520 
1521 #endif /* CONFIG_PROC_FS */
1522