xref: /linux/fs/nfs/client.c (revision f49f4ab95c301dbccad0efe85296d908b8ae7ad4)
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 <linux/slab.h>
39 #include <linux/idr.h>
40 #include <net/ipv6.h>
41 #include <linux/nfs_xdr.h>
42 #include <linux/sunrpc/bc_xprt.h>
43 #include <linux/nsproxy.h>
44 #include <linux/pid_namespace.h>
45 
46 
47 #include "nfs4_fs.h"
48 #include "callback.h"
49 #include "delegation.h"
50 #include "iostat.h"
51 #include "internal.h"
52 #include "fscache.h"
53 #include "pnfs.h"
54 #include "nfs.h"
55 #include "netns.h"
56 
57 #define NFSDBG_FACILITY		NFSDBG_CLIENT
58 
59 static DECLARE_WAIT_QUEUE_HEAD(nfs_client_active_wq);
60 static DEFINE_SPINLOCK(nfs_version_lock);
61 static DEFINE_MUTEX(nfs_version_mutex);
62 static LIST_HEAD(nfs_versions);
63 
64 /*
65  * RPC cruft for NFS
66  */
67 static const struct rpc_version *nfs_version[5] = {
68 	[2] = NULL,
69 	[3] = NULL,
70 	[4] = NULL,
71 };
72 
73 const struct rpc_program nfs_program = {
74 	.name			= "nfs",
75 	.number			= NFS_PROGRAM,
76 	.nrvers			= ARRAY_SIZE(nfs_version),
77 	.version		= nfs_version,
78 	.stats			= &nfs_rpcstat,
79 	.pipe_dir_name		= NFS_PIPE_DIRNAME,
80 };
81 
82 struct rpc_stat nfs_rpcstat = {
83 	.program		= &nfs_program
84 };
85 
86 static struct nfs_subversion *find_nfs_version(unsigned int version)
87 {
88 	struct nfs_subversion *nfs;
89 	spin_lock(&nfs_version_lock);
90 
91 	list_for_each_entry(nfs, &nfs_versions, list) {
92 		if (nfs->rpc_ops->version == version) {
93 			spin_unlock(&nfs_version_lock);
94 			return nfs;
95 		}
96 	}
97 
98 	spin_unlock(&nfs_version_lock);
99 	return ERR_PTR(-EPROTONOSUPPORT);
100 }
101 
102 struct nfs_subversion *get_nfs_version(unsigned int version)
103 {
104 	struct nfs_subversion *nfs = find_nfs_version(version);
105 
106 	if (IS_ERR(nfs)) {
107 		mutex_lock(&nfs_version_mutex);
108 		request_module("nfsv%d", version);
109 		nfs = find_nfs_version(version);
110 		mutex_unlock(&nfs_version_mutex);
111 	}
112 
113 	if (!IS_ERR(nfs))
114 		try_module_get(nfs->owner);
115 	return nfs;
116 }
117 
118 void put_nfs_version(struct nfs_subversion *nfs)
119 {
120 	module_put(nfs->owner);
121 }
122 
123 void register_nfs_version(struct nfs_subversion *nfs)
124 {
125 	spin_lock(&nfs_version_lock);
126 
127 	list_add(&nfs->list, &nfs_versions);
128 	nfs_version[nfs->rpc_ops->version] = nfs->rpc_vers;
129 
130 	spin_unlock(&nfs_version_lock);
131 }
132 EXPORT_SYMBOL_GPL(register_nfs_version);
133 
134 void unregister_nfs_version(struct nfs_subversion *nfs)
135 {
136 	spin_lock(&nfs_version_lock);
137 
138 	nfs_version[nfs->rpc_ops->version] = NULL;
139 	list_del(&nfs->list);
140 
141 	spin_unlock(&nfs_version_lock);
142 }
143 EXPORT_SYMBOL_GPL(unregister_nfs_version);
144 
145 /*
146  * Allocate a shared client record
147  *
148  * Since these are allocated/deallocated very rarely, we don't
149  * bother putting them in a slab cache...
150  */
151 struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init)
152 {
153 	struct nfs_client *clp;
154 	struct rpc_cred *cred;
155 	int err = -ENOMEM;
156 
157 	if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL)
158 		goto error_0;
159 
160 	clp->cl_nfs_mod = cl_init->nfs_mod;
161 	try_module_get(clp->cl_nfs_mod->owner);
162 
163 	clp->rpc_ops = clp->cl_nfs_mod->rpc_ops;
164 
165 	atomic_set(&clp->cl_count, 1);
166 	clp->cl_cons_state = NFS_CS_INITING;
167 
168 	memcpy(&clp->cl_addr, cl_init->addr, cl_init->addrlen);
169 	clp->cl_addrlen = cl_init->addrlen;
170 
171 	if (cl_init->hostname) {
172 		err = -ENOMEM;
173 		clp->cl_hostname = kstrdup(cl_init->hostname, GFP_KERNEL);
174 		if (!clp->cl_hostname)
175 			goto error_cleanup;
176 	}
177 
178 	INIT_LIST_HEAD(&clp->cl_superblocks);
179 	clp->cl_rpcclient = ERR_PTR(-EINVAL);
180 
181 	clp->cl_proto = cl_init->proto;
182 	clp->cl_net = get_net(cl_init->net);
183 
184 	cred = rpc_lookup_machine_cred("*");
185 	if (!IS_ERR(cred))
186 		clp->cl_machine_cred = cred;
187 	nfs_fscache_get_client_cookie(clp);
188 
189 	return clp;
190 
191 error_cleanup:
192 	put_nfs_version(clp->cl_nfs_mod);
193 	kfree(clp);
194 error_0:
195 	return ERR_PTR(err);
196 }
197 EXPORT_SYMBOL_GPL(nfs_alloc_client);
198 
199 #if IS_ENABLED(CONFIG_NFS_V4)
200 /* idr_remove_all is not needed as all id's are removed by nfs_put_client */
201 void nfs_cleanup_cb_ident_idr(struct net *net)
202 {
203 	struct nfs_net *nn = net_generic(net, nfs_net_id);
204 
205 	idr_destroy(&nn->cb_ident_idr);
206 }
207 
208 /* nfs_client_lock held */
209 static void nfs_cb_idr_remove_locked(struct nfs_client *clp)
210 {
211 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
212 
213 	if (clp->cl_cb_ident)
214 		idr_remove(&nn->cb_ident_idr, clp->cl_cb_ident);
215 }
216 
217 static void pnfs_init_server(struct nfs_server *server)
218 {
219 	rpc_init_wait_queue(&server->roc_rpcwaitq, "pNFS ROC");
220 }
221 
222 #else
223 void nfs_cleanup_cb_ident_idr(struct net *net)
224 {
225 }
226 
227 static void nfs_cb_idr_remove_locked(struct nfs_client *clp)
228 {
229 }
230 
231 static void pnfs_init_server(struct nfs_server *server)
232 {
233 }
234 
235 #endif /* CONFIG_NFS_V4 */
236 
237 /*
238  * Destroy a shared client record
239  */
240 void nfs_free_client(struct nfs_client *clp)
241 {
242 	dprintk("--> nfs_free_client(%u)\n", clp->rpc_ops->version);
243 
244 	nfs_fscache_release_client_cookie(clp);
245 
246 	/* -EIO all pending I/O */
247 	if (!IS_ERR(clp->cl_rpcclient))
248 		rpc_shutdown_client(clp->cl_rpcclient);
249 
250 	if (clp->cl_machine_cred != NULL)
251 		put_rpccred(clp->cl_machine_cred);
252 
253 	put_net(clp->cl_net);
254 	put_nfs_version(clp->cl_nfs_mod);
255 	kfree(clp->cl_hostname);
256 	kfree(clp);
257 
258 	dprintk("<-- nfs_free_client()\n");
259 }
260 EXPORT_SYMBOL_GPL(nfs_free_client);
261 
262 /*
263  * Release a reference to a shared client record
264  */
265 void nfs_put_client(struct nfs_client *clp)
266 {
267 	struct nfs_net *nn;
268 
269 	if (!clp)
270 		return;
271 
272 	dprintk("--> nfs_put_client({%d})\n", atomic_read(&clp->cl_count));
273 	nn = net_generic(clp->cl_net, nfs_net_id);
274 
275 	if (atomic_dec_and_lock(&clp->cl_count, &nn->nfs_client_lock)) {
276 		list_del(&clp->cl_share_link);
277 		nfs_cb_idr_remove_locked(clp);
278 		spin_unlock(&nn->nfs_client_lock);
279 
280 		BUG_ON(!list_empty(&clp->cl_superblocks));
281 
282 		clp->rpc_ops->free_client(clp);
283 	}
284 }
285 EXPORT_SYMBOL_GPL(nfs_put_client);
286 
287 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
288 /*
289  * Test if two ip6 socket addresses refer to the same socket by
290  * comparing relevant fields. The padding bytes specifically, are not
291  * compared. sin6_flowinfo is not compared because it only affects QoS
292  * and sin6_scope_id is only compared if the address is "link local"
293  * because "link local" addresses need only be unique to a specific
294  * link. Conversely, ordinary unicast addresses might have different
295  * sin6_scope_id.
296  *
297  * The caller should ensure both socket addresses are AF_INET6.
298  */
299 static int nfs_sockaddr_match_ipaddr6(const struct sockaddr *sa1,
300 				      const struct sockaddr *sa2)
301 {
302 	const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sa1;
303 	const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sa2;
304 
305 	if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
306 		return 0;
307 	else if (ipv6_addr_type(&sin1->sin6_addr) & IPV6_ADDR_LINKLOCAL)
308 		return sin1->sin6_scope_id == sin2->sin6_scope_id;
309 
310 	return 1;
311 }
312 #else	/* !defined(CONFIG_IPV6) && !defined(CONFIG_IPV6_MODULE) */
313 static int nfs_sockaddr_match_ipaddr6(const struct sockaddr *sa1,
314 				      const struct sockaddr *sa2)
315 {
316 	return 0;
317 }
318 #endif
319 
320 /*
321  * Test if two ip4 socket addresses refer to the same socket, by
322  * comparing relevant fields. The padding bytes specifically, are
323  * not compared.
324  *
325  * The caller should ensure both socket addresses are AF_INET.
326  */
327 static int nfs_sockaddr_match_ipaddr4(const struct sockaddr *sa1,
328 				      const struct sockaddr *sa2)
329 {
330 	const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sa1;
331 	const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sa2;
332 
333 	return sin1->sin_addr.s_addr == sin2->sin_addr.s_addr;
334 }
335 
336 static int nfs_sockaddr_cmp_ip6(const struct sockaddr *sa1,
337 				const struct sockaddr *sa2)
338 {
339 	const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sa1;
340 	const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sa2;
341 
342 	return nfs_sockaddr_match_ipaddr6(sa1, sa2) &&
343 		(sin1->sin6_port == sin2->sin6_port);
344 }
345 
346 static int nfs_sockaddr_cmp_ip4(const struct sockaddr *sa1,
347 				const struct sockaddr *sa2)
348 {
349 	const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sa1;
350 	const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sa2;
351 
352 	return nfs_sockaddr_match_ipaddr4(sa1, sa2) &&
353 		(sin1->sin_port == sin2->sin_port);
354 }
355 
356 #if defined(CONFIG_NFS_V4_1)
357 /*
358  * Test if two socket addresses represent the same actual socket,
359  * by comparing (only) relevant fields, excluding the port number.
360  */
361 int nfs_sockaddr_match_ipaddr(const struct sockaddr *sa1,
362 			      const struct sockaddr *sa2)
363 {
364 	if (sa1->sa_family != sa2->sa_family)
365 		return 0;
366 
367 	switch (sa1->sa_family) {
368 	case AF_INET:
369 		return nfs_sockaddr_match_ipaddr4(sa1, sa2);
370 	case AF_INET6:
371 		return nfs_sockaddr_match_ipaddr6(sa1, sa2);
372 	}
373 	return 0;
374 }
375 EXPORT_SYMBOL_GPL(nfs_sockaddr_match_ipaddr);
376 #endif /* CONFIG_NFS_V4_1 */
377 
378 /*
379  * Test if two socket addresses represent the same actual socket,
380  * by comparing (only) relevant fields, including the port number.
381  */
382 static int nfs_sockaddr_cmp(const struct sockaddr *sa1,
383 			    const struct sockaddr *sa2)
384 {
385 	if (sa1->sa_family != sa2->sa_family)
386 		return 0;
387 
388 	switch (sa1->sa_family) {
389 	case AF_INET:
390 		return nfs_sockaddr_cmp_ip4(sa1, sa2);
391 	case AF_INET6:
392 		return nfs_sockaddr_cmp_ip6(sa1, sa2);
393 	}
394 	return 0;
395 }
396 
397 /*
398  * Find an nfs_client on the list that matches the initialisation data
399  * that is supplied.
400  */
401 static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *data)
402 {
403 	struct nfs_client *clp;
404 	const struct sockaddr *sap = data->addr;
405 	struct nfs_net *nn = net_generic(data->net, nfs_net_id);
406 
407 	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
408 	        const struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
409 		/* Don't match clients that failed to initialise properly */
410 		if (clp->cl_cons_state < 0)
411 			continue;
412 
413 		/* Different NFS versions cannot share the same nfs_client */
414 		if (clp->rpc_ops != data->nfs_mod->rpc_ops)
415 			continue;
416 
417 		if (clp->cl_proto != data->proto)
418 			continue;
419 		/* Match nfsv4 minorversion */
420 		if (clp->cl_minorversion != data->minorversion)
421 			continue;
422 		/* Match the full socket address */
423 		if (!nfs_sockaddr_cmp(sap, clap))
424 			continue;
425 
426 		atomic_inc(&clp->cl_count);
427 		return clp;
428 	}
429 	return NULL;
430 }
431 
432 static bool nfs_client_init_is_complete(const struct nfs_client *clp)
433 {
434 	return clp->cl_cons_state != NFS_CS_INITING;
435 }
436 
437 int nfs_wait_client_init_complete(const struct nfs_client *clp)
438 {
439 	return wait_event_killable(nfs_client_active_wq,
440 			nfs_client_init_is_complete(clp));
441 }
442 EXPORT_SYMBOL_GPL(nfs_wait_client_init_complete);
443 
444 /*
445  * Found an existing client.  Make sure it's ready before returning.
446  */
447 static struct nfs_client *
448 nfs_found_client(const struct nfs_client_initdata *cl_init,
449 		 struct nfs_client *clp)
450 {
451 	int error;
452 
453 	error = nfs_wait_client_init_complete(clp);
454 	if (error < 0) {
455 		nfs_put_client(clp);
456 		return ERR_PTR(-ERESTARTSYS);
457 	}
458 
459 	if (clp->cl_cons_state < NFS_CS_READY) {
460 		error = clp->cl_cons_state;
461 		nfs_put_client(clp);
462 		return ERR_PTR(error);
463 	}
464 
465 	smp_rmb();
466 
467 	dprintk("<-- %s found nfs_client %p for %s\n",
468 		__func__, clp, cl_init->hostname ?: "");
469 	return clp;
470 }
471 
472 /*
473  * Look up a client by IP address and protocol version
474  * - creates a new record if one doesn't yet exist
475  */
476 struct nfs_client *
477 nfs_get_client(const struct nfs_client_initdata *cl_init,
478 	       const struct rpc_timeout *timeparms,
479 	       const char *ip_addr,
480 	       rpc_authflavor_t authflavour)
481 {
482 	struct nfs_client *clp, *new = NULL;
483 	struct nfs_net *nn = net_generic(cl_init->net, nfs_net_id);
484 	const struct nfs_rpc_ops *rpc_ops = cl_init->nfs_mod->rpc_ops;
485 
486 	dprintk("--> nfs_get_client(%s,v%u)\n",
487 		cl_init->hostname ?: "", rpc_ops->version);
488 
489 	/* see if the client already exists */
490 	do {
491 		spin_lock(&nn->nfs_client_lock);
492 
493 		clp = nfs_match_client(cl_init);
494 		if (clp) {
495 			spin_unlock(&nn->nfs_client_lock);
496 			if (new)
497 				new->rpc_ops->free_client(new);
498 			return nfs_found_client(cl_init, clp);
499 		}
500 		if (new) {
501 			list_add_tail(&new->cl_share_link,
502 					&nn->nfs_client_list);
503 			spin_unlock(&nn->nfs_client_lock);
504 			new->cl_flags = cl_init->init_flags;
505 			return rpc_ops->init_client(new, timeparms, ip_addr,
506 						    authflavour);
507 		}
508 
509 		spin_unlock(&nn->nfs_client_lock);
510 
511 		new = rpc_ops->alloc_client(cl_init);
512 	} while (!IS_ERR(new));
513 
514 	dprintk("<-- nfs_get_client() Failed to find %s (%ld)\n",
515 		cl_init->hostname ?: "", PTR_ERR(new));
516 	return new;
517 }
518 EXPORT_SYMBOL_GPL(nfs_get_client);
519 
520 /*
521  * Mark a server as ready or failed
522  */
523 void nfs_mark_client_ready(struct nfs_client *clp, int state)
524 {
525 	smp_wmb();
526 	clp->cl_cons_state = state;
527 	wake_up_all(&nfs_client_active_wq);
528 }
529 EXPORT_SYMBOL_GPL(nfs_mark_client_ready);
530 
531 /*
532  * Initialise the timeout values for a connection
533  */
534 void nfs_init_timeout_values(struct rpc_timeout *to, int proto,
535 				    unsigned int timeo, unsigned int retrans)
536 {
537 	to->to_initval = timeo * HZ / 10;
538 	to->to_retries = retrans;
539 
540 	switch (proto) {
541 	case XPRT_TRANSPORT_TCP:
542 	case XPRT_TRANSPORT_RDMA:
543 		if (to->to_retries == 0)
544 			to->to_retries = NFS_DEF_TCP_RETRANS;
545 		if (to->to_initval == 0)
546 			to->to_initval = NFS_DEF_TCP_TIMEO * HZ / 10;
547 		if (to->to_initval > NFS_MAX_TCP_TIMEOUT)
548 			to->to_initval = NFS_MAX_TCP_TIMEOUT;
549 		to->to_increment = to->to_initval;
550 		to->to_maxval = to->to_initval + (to->to_increment * to->to_retries);
551 		if (to->to_maxval > NFS_MAX_TCP_TIMEOUT)
552 			to->to_maxval = NFS_MAX_TCP_TIMEOUT;
553 		if (to->to_maxval < to->to_initval)
554 			to->to_maxval = to->to_initval;
555 		to->to_exponential = 0;
556 		break;
557 	case XPRT_TRANSPORT_UDP:
558 		if (to->to_retries == 0)
559 			to->to_retries = NFS_DEF_UDP_RETRANS;
560 		if (!to->to_initval)
561 			to->to_initval = NFS_DEF_UDP_TIMEO * HZ / 10;
562 		if (to->to_initval > NFS_MAX_UDP_TIMEOUT)
563 			to->to_initval = NFS_MAX_UDP_TIMEOUT;
564 		to->to_maxval = NFS_MAX_UDP_TIMEOUT;
565 		to->to_exponential = 1;
566 		break;
567 	default:
568 		BUG();
569 	}
570 }
571 EXPORT_SYMBOL_GPL(nfs_init_timeout_values);
572 
573 /*
574  * Create an RPC client handle
575  */
576 int nfs_create_rpc_client(struct nfs_client *clp,
577 			  const struct rpc_timeout *timeparms,
578 			  rpc_authflavor_t flavor)
579 {
580 	struct rpc_clnt		*clnt = NULL;
581 	struct rpc_create_args args = {
582 		.net		= clp->cl_net,
583 		.protocol	= clp->cl_proto,
584 		.address	= (struct sockaddr *)&clp->cl_addr,
585 		.addrsize	= clp->cl_addrlen,
586 		.timeout	= timeparms,
587 		.servername	= clp->cl_hostname,
588 		.program	= &nfs_program,
589 		.version	= clp->rpc_ops->version,
590 		.authflavor	= flavor,
591 	};
592 
593 	if (test_bit(NFS_CS_DISCRTRY, &clp->cl_flags))
594 		args.flags |= RPC_CLNT_CREATE_DISCRTRY;
595 	if (test_bit(NFS_CS_NORESVPORT, &clp->cl_flags))
596 		args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
597 
598 	if (!IS_ERR(clp->cl_rpcclient))
599 		return 0;
600 
601 	clnt = rpc_create(&args);
602 	if (IS_ERR(clnt)) {
603 		dprintk("%s: cannot create RPC client. Error = %ld\n",
604 				__func__, PTR_ERR(clnt));
605 		return PTR_ERR(clnt);
606 	}
607 
608 	clp->cl_rpcclient = clnt;
609 	return 0;
610 }
611 EXPORT_SYMBOL_GPL(nfs_create_rpc_client);
612 
613 /*
614  * Version 2 or 3 client destruction
615  */
616 static void nfs_destroy_server(struct nfs_server *server)
617 {
618 	if (!(server->flags & NFS_MOUNT_LOCAL_FLOCK) ||
619 			!(server->flags & NFS_MOUNT_LOCAL_FCNTL))
620 		nlmclnt_done(server->nlm_host);
621 }
622 
623 /*
624  * Version 2 or 3 lockd setup
625  */
626 static int nfs_start_lockd(struct nfs_server *server)
627 {
628 	struct nlm_host *host;
629 	struct nfs_client *clp = server->nfs_client;
630 	struct nlmclnt_initdata nlm_init = {
631 		.hostname	= clp->cl_hostname,
632 		.address	= (struct sockaddr *)&clp->cl_addr,
633 		.addrlen	= clp->cl_addrlen,
634 		.nfs_version	= clp->rpc_ops->version,
635 		.noresvport	= server->flags & NFS_MOUNT_NORESVPORT ?
636 					1 : 0,
637 		.net		= clp->cl_net,
638 	};
639 
640 	if (nlm_init.nfs_version > 3)
641 		return 0;
642 	if ((server->flags & NFS_MOUNT_LOCAL_FLOCK) &&
643 			(server->flags & NFS_MOUNT_LOCAL_FCNTL))
644 		return 0;
645 
646 	switch (clp->cl_proto) {
647 		default:
648 			nlm_init.protocol = IPPROTO_TCP;
649 			break;
650 		case XPRT_TRANSPORT_UDP:
651 			nlm_init.protocol = IPPROTO_UDP;
652 	}
653 
654 	host = nlmclnt_init(&nlm_init);
655 	if (IS_ERR(host))
656 		return PTR_ERR(host);
657 
658 	server->nlm_host = host;
659 	server->destroy = nfs_destroy_server;
660 	return 0;
661 }
662 
663 /*
664  * Create a general RPC client
665  */
666 int nfs_init_server_rpcclient(struct nfs_server *server,
667 		const struct rpc_timeout *timeo,
668 		rpc_authflavor_t pseudoflavour)
669 {
670 	struct nfs_client *clp = server->nfs_client;
671 
672 	server->client = rpc_clone_client_set_auth(clp->cl_rpcclient,
673 							pseudoflavour);
674 	if (IS_ERR(server->client)) {
675 		dprintk("%s: couldn't create rpc_client!\n", __func__);
676 		return PTR_ERR(server->client);
677 	}
678 
679 	memcpy(&server->client->cl_timeout_default,
680 			timeo,
681 			sizeof(server->client->cl_timeout_default));
682 	server->client->cl_timeout = &server->client->cl_timeout_default;
683 	server->client->cl_softrtry = 0;
684 	if (server->flags & NFS_MOUNT_SOFT)
685 		server->client->cl_softrtry = 1;
686 
687 	return 0;
688 }
689 EXPORT_SYMBOL_GPL(nfs_init_server_rpcclient);
690 
691 /**
692  * nfs_init_client - Initialise an NFS2 or NFS3 client
693  *
694  * @clp: nfs_client to initialise
695  * @timeparms: timeout parameters for underlying RPC transport
696  * @ip_addr: IP presentation address (not used)
697  * @authflavor: authentication flavor for underlying RPC transport
698  *
699  * Returns pointer to an NFS client, or an ERR_PTR value.
700  */
701 struct nfs_client *nfs_init_client(struct nfs_client *clp,
702 		    const struct rpc_timeout *timeparms,
703 		    const char *ip_addr, rpc_authflavor_t authflavour)
704 {
705 	int error;
706 
707 	if (clp->cl_cons_state == NFS_CS_READY) {
708 		/* the client is already initialised */
709 		dprintk("<-- nfs_init_client() = 0 [already %p]\n", clp);
710 		return clp;
711 	}
712 
713 	/*
714 	 * Create a client RPC handle for doing FSSTAT with UNIX auth only
715 	 * - RFC 2623, sec 2.3.2
716 	 */
717 	error = nfs_create_rpc_client(clp, timeparms, RPC_AUTH_UNIX);
718 	if (error < 0)
719 		goto error;
720 	nfs_mark_client_ready(clp, NFS_CS_READY);
721 	return clp;
722 
723 error:
724 	nfs_mark_client_ready(clp, error);
725 	nfs_put_client(clp);
726 	dprintk("<-- nfs_init_client() = xerror %d\n", error);
727 	return ERR_PTR(error);
728 }
729 EXPORT_SYMBOL_GPL(nfs_init_client);
730 
731 /*
732  * Create a version 2 or 3 client
733  */
734 static int nfs_init_server(struct nfs_server *server,
735 			   const struct nfs_parsed_mount_data *data,
736 			   struct nfs_subversion *nfs_mod)
737 {
738 	struct nfs_client_initdata cl_init = {
739 		.hostname = data->nfs_server.hostname,
740 		.addr = (const struct sockaddr *)&data->nfs_server.address,
741 		.addrlen = data->nfs_server.addrlen,
742 		.nfs_mod = nfs_mod,
743 		.proto = data->nfs_server.protocol,
744 		.net = data->net,
745 	};
746 	struct rpc_timeout timeparms;
747 	struct nfs_client *clp;
748 	int error;
749 
750 	dprintk("--> nfs_init_server()\n");
751 
752 	nfs_init_timeout_values(&timeparms, data->nfs_server.protocol,
753 			data->timeo, data->retrans);
754 	if (data->flags & NFS_MOUNT_NORESVPORT)
755 		set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
756 	if (server->options & NFS_OPTION_MIGRATION)
757 		set_bit(NFS_CS_MIGRATION, &cl_init.init_flags);
758 
759 	/* Allocate or find a client reference we can use */
760 	clp = nfs_get_client(&cl_init, &timeparms, NULL, RPC_AUTH_UNIX);
761 	if (IS_ERR(clp)) {
762 		dprintk("<-- nfs_init_server() = error %ld\n", PTR_ERR(clp));
763 		return PTR_ERR(clp);
764 	}
765 
766 	server->nfs_client = clp;
767 
768 	/* Initialise the client representation from the mount data */
769 	server->flags = data->flags;
770 	server->options = data->options;
771 	server->caps |= NFS_CAP_HARDLINKS|NFS_CAP_SYMLINKS|NFS_CAP_FILEID|
772 		NFS_CAP_MODE|NFS_CAP_NLINK|NFS_CAP_OWNER|NFS_CAP_OWNER_GROUP|
773 		NFS_CAP_ATIME|NFS_CAP_CTIME|NFS_CAP_MTIME|NFS_CAP_CHANGE_ATTR;
774 
775 	if (data->rsize)
776 		server->rsize = nfs_block_size(data->rsize, NULL);
777 	if (data->wsize)
778 		server->wsize = nfs_block_size(data->wsize, NULL);
779 
780 	server->acregmin = data->acregmin * HZ;
781 	server->acregmax = data->acregmax * HZ;
782 	server->acdirmin = data->acdirmin * HZ;
783 	server->acdirmax = data->acdirmax * HZ;
784 
785 	/* Start lockd here, before we might error out */
786 	error = nfs_start_lockd(server);
787 	if (error < 0)
788 		goto error;
789 
790 	server->port = data->nfs_server.port;
791 
792 	error = nfs_init_server_rpcclient(server, &timeparms, data->auth_flavors[0]);
793 	if (error < 0)
794 		goto error;
795 
796 	/* Preserve the values of mount_server-related mount options */
797 	if (data->mount_server.addrlen) {
798 		memcpy(&server->mountd_address, &data->mount_server.address,
799 			data->mount_server.addrlen);
800 		server->mountd_addrlen = data->mount_server.addrlen;
801 	}
802 	server->mountd_version = data->mount_server.version;
803 	server->mountd_port = data->mount_server.port;
804 	server->mountd_protocol = data->mount_server.protocol;
805 
806 	server->namelen  = data->namlen;
807 	dprintk("<-- nfs_init_server() = 0 [new %p]\n", clp);
808 	return 0;
809 
810 error:
811 	server->nfs_client = NULL;
812 	nfs_put_client(clp);
813 	dprintk("<-- nfs_init_server() = xerror %d\n", error);
814 	return error;
815 }
816 
817 /*
818  * Load up the server record from information gained in an fsinfo record
819  */
820 static void nfs_server_set_fsinfo(struct nfs_server *server,
821 				  struct nfs_fh *mntfh,
822 				  struct nfs_fsinfo *fsinfo)
823 {
824 	unsigned long max_rpc_payload;
825 
826 	/* Work out a lot of parameters */
827 	if (server->rsize == 0)
828 		server->rsize = nfs_block_size(fsinfo->rtpref, NULL);
829 	if (server->wsize == 0)
830 		server->wsize = nfs_block_size(fsinfo->wtpref, NULL);
831 
832 	if (fsinfo->rtmax >= 512 && server->rsize > fsinfo->rtmax)
833 		server->rsize = nfs_block_size(fsinfo->rtmax, NULL);
834 	if (fsinfo->wtmax >= 512 && server->wsize > fsinfo->wtmax)
835 		server->wsize = nfs_block_size(fsinfo->wtmax, NULL);
836 
837 	max_rpc_payload = nfs_block_size(rpc_max_payload(server->client), NULL);
838 	if (server->rsize > max_rpc_payload)
839 		server->rsize = max_rpc_payload;
840 	if (server->rsize > NFS_MAX_FILE_IO_SIZE)
841 		server->rsize = NFS_MAX_FILE_IO_SIZE;
842 	server->rpages = (server->rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
843 
844 	server->backing_dev_info.name = "nfs";
845 	server->backing_dev_info.ra_pages = server->rpages * NFS_MAX_READAHEAD;
846 
847 	if (server->wsize > max_rpc_payload)
848 		server->wsize = max_rpc_payload;
849 	if (server->wsize > NFS_MAX_FILE_IO_SIZE)
850 		server->wsize = NFS_MAX_FILE_IO_SIZE;
851 	server->wpages = (server->wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
852 
853 	server->wtmult = nfs_block_bits(fsinfo->wtmult, NULL);
854 
855 	server->dtsize = nfs_block_size(fsinfo->dtpref, NULL);
856 	if (server->dtsize > PAGE_CACHE_SIZE * NFS_MAX_READDIR_PAGES)
857 		server->dtsize = PAGE_CACHE_SIZE * NFS_MAX_READDIR_PAGES;
858 	if (server->dtsize > server->rsize)
859 		server->dtsize = server->rsize;
860 
861 	if (server->flags & NFS_MOUNT_NOAC) {
862 		server->acregmin = server->acregmax = 0;
863 		server->acdirmin = server->acdirmax = 0;
864 	}
865 
866 	server->maxfilesize = fsinfo->maxfilesize;
867 
868 	server->time_delta = fsinfo->time_delta;
869 
870 	/* We're airborne Set socket buffersize */
871 	rpc_setbufsize(server->client, server->wsize + 100, server->rsize + 100);
872 }
873 
874 /*
875  * Probe filesystem information, including the FSID on v2/v3
876  */
877 int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *mntfh, struct nfs_fattr *fattr)
878 {
879 	struct nfs_fsinfo fsinfo;
880 	struct nfs_client *clp = server->nfs_client;
881 	int error;
882 
883 	dprintk("--> nfs_probe_fsinfo()\n");
884 
885 	if (clp->rpc_ops->set_capabilities != NULL) {
886 		error = clp->rpc_ops->set_capabilities(server, mntfh);
887 		if (error < 0)
888 			goto out_error;
889 	}
890 
891 	fsinfo.fattr = fattr;
892 	fsinfo.layouttype = 0;
893 	error = clp->rpc_ops->fsinfo(server, mntfh, &fsinfo);
894 	if (error < 0)
895 		goto out_error;
896 
897 	nfs_server_set_fsinfo(server, mntfh, &fsinfo);
898 
899 	/* Get some general file system info */
900 	if (server->namelen == 0) {
901 		struct nfs_pathconf pathinfo;
902 
903 		pathinfo.fattr = fattr;
904 		nfs_fattr_init(fattr);
905 
906 		if (clp->rpc_ops->pathconf(server, mntfh, &pathinfo) >= 0)
907 			server->namelen = pathinfo.max_namelen;
908 	}
909 
910 	dprintk("<-- nfs_probe_fsinfo() = 0\n");
911 	return 0;
912 
913 out_error:
914 	dprintk("nfs_probe_fsinfo: error = %d\n", -error);
915 	return error;
916 }
917 EXPORT_SYMBOL_GPL(nfs_probe_fsinfo);
918 
919 /*
920  * Copy useful information when duplicating a server record
921  */
922 void nfs_server_copy_userdata(struct nfs_server *target, struct nfs_server *source)
923 {
924 	target->flags = source->flags;
925 	target->rsize = source->rsize;
926 	target->wsize = source->wsize;
927 	target->acregmin = source->acregmin;
928 	target->acregmax = source->acregmax;
929 	target->acdirmin = source->acdirmin;
930 	target->acdirmax = source->acdirmax;
931 	target->caps = source->caps;
932 	target->options = source->options;
933 }
934 EXPORT_SYMBOL_GPL(nfs_server_copy_userdata);
935 
936 void nfs_server_insert_lists(struct nfs_server *server)
937 {
938 	struct nfs_client *clp = server->nfs_client;
939 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
940 
941 	spin_lock(&nn->nfs_client_lock);
942 	list_add_tail_rcu(&server->client_link, &clp->cl_superblocks);
943 	list_add_tail(&server->master_link, &nn->nfs_volume_list);
944 	clear_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
945 	spin_unlock(&nn->nfs_client_lock);
946 
947 }
948 EXPORT_SYMBOL_GPL(nfs_server_insert_lists);
949 
950 static void nfs_server_remove_lists(struct nfs_server *server)
951 {
952 	struct nfs_client *clp = server->nfs_client;
953 	struct nfs_net *nn;
954 
955 	if (clp == NULL)
956 		return;
957 	nn = net_generic(clp->cl_net, nfs_net_id);
958 	spin_lock(&nn->nfs_client_lock);
959 	list_del_rcu(&server->client_link);
960 	if (list_empty(&clp->cl_superblocks))
961 		set_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
962 	list_del(&server->master_link);
963 	spin_unlock(&nn->nfs_client_lock);
964 
965 	synchronize_rcu();
966 }
967 
968 /*
969  * Allocate and initialise a server record
970  */
971 struct nfs_server *nfs_alloc_server(void)
972 {
973 	struct nfs_server *server;
974 
975 	server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
976 	if (!server)
977 		return NULL;
978 
979 	server->client = server->client_acl = ERR_PTR(-EINVAL);
980 
981 	/* Zero out the NFS state stuff */
982 	INIT_LIST_HEAD(&server->client_link);
983 	INIT_LIST_HEAD(&server->master_link);
984 	INIT_LIST_HEAD(&server->delegations);
985 	INIT_LIST_HEAD(&server->layouts);
986 	INIT_LIST_HEAD(&server->state_owners_lru);
987 
988 	atomic_set(&server->active, 0);
989 
990 	server->io_stats = nfs_alloc_iostats();
991 	if (!server->io_stats) {
992 		kfree(server);
993 		return NULL;
994 	}
995 
996 	if (bdi_init(&server->backing_dev_info)) {
997 		nfs_free_iostats(server->io_stats);
998 		kfree(server);
999 		return NULL;
1000 	}
1001 
1002 	ida_init(&server->openowner_id);
1003 	ida_init(&server->lockowner_id);
1004 	pnfs_init_server(server);
1005 
1006 	return server;
1007 }
1008 EXPORT_SYMBOL_GPL(nfs_alloc_server);
1009 
1010 /*
1011  * Free up a server record
1012  */
1013 void nfs_free_server(struct nfs_server *server)
1014 {
1015 	dprintk("--> nfs_free_server()\n");
1016 
1017 	nfs_server_remove_lists(server);
1018 
1019 	if (server->destroy != NULL)
1020 		server->destroy(server);
1021 
1022 	if (!IS_ERR(server->client_acl))
1023 		rpc_shutdown_client(server->client_acl);
1024 	if (!IS_ERR(server->client))
1025 		rpc_shutdown_client(server->client);
1026 
1027 	nfs_put_client(server->nfs_client);
1028 
1029 	ida_destroy(&server->lockowner_id);
1030 	ida_destroy(&server->openowner_id);
1031 	nfs_free_iostats(server->io_stats);
1032 	bdi_destroy(&server->backing_dev_info);
1033 	kfree(server);
1034 	nfs_release_automount_timer();
1035 	dprintk("<-- nfs_free_server()\n");
1036 }
1037 EXPORT_SYMBOL_GPL(nfs_free_server);
1038 
1039 /*
1040  * Create a version 2 or 3 volume record
1041  * - keyed on server and FSID
1042  */
1043 struct nfs_server *nfs_create_server(struct nfs_mount_info *mount_info,
1044 				     struct nfs_subversion *nfs_mod)
1045 {
1046 	struct nfs_server *server;
1047 	struct nfs_fattr *fattr;
1048 	int error;
1049 
1050 	server = nfs_alloc_server();
1051 	if (!server)
1052 		return ERR_PTR(-ENOMEM);
1053 
1054 	error = -ENOMEM;
1055 	fattr = nfs_alloc_fattr();
1056 	if (fattr == NULL)
1057 		goto error;
1058 
1059 	/* Get a client representation */
1060 	error = nfs_init_server(server, mount_info->parsed, nfs_mod);
1061 	if (error < 0)
1062 		goto error;
1063 
1064 	BUG_ON(!server->nfs_client);
1065 	BUG_ON(!server->nfs_client->rpc_ops);
1066 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
1067 
1068 	/* Probe the root fh to retrieve its FSID */
1069 	error = nfs_probe_fsinfo(server, mount_info->mntfh, fattr);
1070 	if (error < 0)
1071 		goto error;
1072 	if (server->nfs_client->rpc_ops->version == 3) {
1073 		if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN)
1074 			server->namelen = NFS3_MAXNAMLEN;
1075 		if (!(mount_info->parsed->flags & NFS_MOUNT_NORDIRPLUS))
1076 			server->caps |= NFS_CAP_READDIRPLUS;
1077 	} else {
1078 		if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN)
1079 			server->namelen = NFS2_MAXNAMLEN;
1080 	}
1081 
1082 	if (!(fattr->valid & NFS_ATTR_FATTR)) {
1083 		error = nfs_mod->rpc_ops->getattr(server, mount_info->mntfh, fattr);
1084 		if (error < 0) {
1085 			dprintk("nfs_create_server: getattr error = %d\n", -error);
1086 			goto error;
1087 		}
1088 	}
1089 	memcpy(&server->fsid, &fattr->fsid, sizeof(server->fsid));
1090 
1091 	dprintk("Server FSID: %llx:%llx\n",
1092 		(unsigned long long) server->fsid.major,
1093 		(unsigned long long) server->fsid.minor);
1094 
1095 	nfs_server_insert_lists(server);
1096 	server->mount_time = jiffies;
1097 	nfs_free_fattr(fattr);
1098 	return server;
1099 
1100 error:
1101 	nfs_free_fattr(fattr);
1102 	nfs_free_server(server);
1103 	return ERR_PTR(error);
1104 }
1105 EXPORT_SYMBOL_GPL(nfs_create_server);
1106 
1107 /*
1108  * Clone an NFS2, NFS3 or NFS4 server record
1109  */
1110 struct nfs_server *nfs_clone_server(struct nfs_server *source,
1111 				    struct nfs_fh *fh,
1112 				    struct nfs_fattr *fattr,
1113 				    rpc_authflavor_t flavor)
1114 {
1115 	struct nfs_server *server;
1116 	struct nfs_fattr *fattr_fsinfo;
1117 	int error;
1118 
1119 	dprintk("--> nfs_clone_server(,%llx:%llx,)\n",
1120 		(unsigned long long) fattr->fsid.major,
1121 		(unsigned long long) fattr->fsid.minor);
1122 
1123 	server = nfs_alloc_server();
1124 	if (!server)
1125 		return ERR_PTR(-ENOMEM);
1126 
1127 	error = -ENOMEM;
1128 	fattr_fsinfo = nfs_alloc_fattr();
1129 	if (fattr_fsinfo == NULL)
1130 		goto out_free_server;
1131 
1132 	/* Copy data from the source */
1133 	server->nfs_client = source->nfs_client;
1134 	server->destroy = source->destroy;
1135 	atomic_inc(&server->nfs_client->cl_count);
1136 	nfs_server_copy_userdata(server, source);
1137 
1138 	server->fsid = fattr->fsid;
1139 
1140 	error = nfs_init_server_rpcclient(server,
1141 			source->client->cl_timeout,
1142 			flavor);
1143 	if (error < 0)
1144 		goto out_free_server;
1145 
1146 	/* probe the filesystem info for this server filesystem */
1147 	error = nfs_probe_fsinfo(server, fh, fattr_fsinfo);
1148 	if (error < 0)
1149 		goto out_free_server;
1150 
1151 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1152 		server->namelen = NFS4_MAXNAMLEN;
1153 
1154 	dprintk("Cloned FSID: %llx:%llx\n",
1155 		(unsigned long long) server->fsid.major,
1156 		(unsigned long long) server->fsid.minor);
1157 
1158 	error = nfs_start_lockd(server);
1159 	if (error < 0)
1160 		goto out_free_server;
1161 
1162 	nfs_server_insert_lists(server);
1163 	server->mount_time = jiffies;
1164 
1165 	nfs_free_fattr(fattr_fsinfo);
1166 	dprintk("<-- nfs_clone_server() = %p\n", server);
1167 	return server;
1168 
1169 out_free_server:
1170 	nfs_free_fattr(fattr_fsinfo);
1171 	nfs_free_server(server);
1172 	dprintk("<-- nfs_clone_server() = error %d\n", error);
1173 	return ERR_PTR(error);
1174 }
1175 EXPORT_SYMBOL_GPL(nfs_clone_server);
1176 
1177 void nfs_clients_init(struct net *net)
1178 {
1179 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1180 
1181 	INIT_LIST_HEAD(&nn->nfs_client_list);
1182 	INIT_LIST_HEAD(&nn->nfs_volume_list);
1183 #if IS_ENABLED(CONFIG_NFS_V4)
1184 	idr_init(&nn->cb_ident_idr);
1185 #endif
1186 	spin_lock_init(&nn->nfs_client_lock);
1187 	nn->boot_time = CURRENT_TIME;
1188 }
1189 
1190 #ifdef CONFIG_PROC_FS
1191 static struct proc_dir_entry *proc_fs_nfs;
1192 
1193 static int nfs_server_list_open(struct inode *inode, struct file *file);
1194 static void *nfs_server_list_start(struct seq_file *p, loff_t *pos);
1195 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos);
1196 static void nfs_server_list_stop(struct seq_file *p, void *v);
1197 static int nfs_server_list_show(struct seq_file *m, void *v);
1198 
1199 static const struct seq_operations nfs_server_list_ops = {
1200 	.start	= nfs_server_list_start,
1201 	.next	= nfs_server_list_next,
1202 	.stop	= nfs_server_list_stop,
1203 	.show	= nfs_server_list_show,
1204 };
1205 
1206 static const struct file_operations nfs_server_list_fops = {
1207 	.open		= nfs_server_list_open,
1208 	.read		= seq_read,
1209 	.llseek		= seq_lseek,
1210 	.release	= seq_release,
1211 	.owner		= THIS_MODULE,
1212 };
1213 
1214 static int nfs_volume_list_open(struct inode *inode, struct file *file);
1215 static void *nfs_volume_list_start(struct seq_file *p, loff_t *pos);
1216 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos);
1217 static void nfs_volume_list_stop(struct seq_file *p, void *v);
1218 static int nfs_volume_list_show(struct seq_file *m, void *v);
1219 
1220 static const struct seq_operations nfs_volume_list_ops = {
1221 	.start	= nfs_volume_list_start,
1222 	.next	= nfs_volume_list_next,
1223 	.stop	= nfs_volume_list_stop,
1224 	.show	= nfs_volume_list_show,
1225 };
1226 
1227 static const struct file_operations nfs_volume_list_fops = {
1228 	.open		= nfs_volume_list_open,
1229 	.read		= seq_read,
1230 	.llseek		= seq_lseek,
1231 	.release	= seq_release,
1232 	.owner		= THIS_MODULE,
1233 };
1234 
1235 /*
1236  * open "/proc/fs/nfsfs/servers" which provides a summary of servers with which
1237  * we're dealing
1238  */
1239 static int nfs_server_list_open(struct inode *inode, struct file *file)
1240 {
1241 	struct seq_file *m;
1242 	int ret;
1243 	struct pid_namespace *pid_ns = file->f_dentry->d_sb->s_fs_info;
1244 	struct net *net = pid_ns->child_reaper->nsproxy->net_ns;
1245 
1246 	ret = seq_open(file, &nfs_server_list_ops);
1247 	if (ret < 0)
1248 		return ret;
1249 
1250 	m = file->private_data;
1251 	m->private = net;
1252 
1253 	return 0;
1254 }
1255 
1256 /*
1257  * set up the iterator to start reading from the server list and return the first item
1258  */
1259 static void *nfs_server_list_start(struct seq_file *m, loff_t *_pos)
1260 {
1261 	struct nfs_net *nn = net_generic(m->private, nfs_net_id);
1262 
1263 	/* lock the list against modification */
1264 	spin_lock(&nn->nfs_client_lock);
1265 	return seq_list_start_head(&nn->nfs_client_list, *_pos);
1266 }
1267 
1268 /*
1269  * move to next server
1270  */
1271 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos)
1272 {
1273 	struct nfs_net *nn = net_generic(p->private, nfs_net_id);
1274 
1275 	return seq_list_next(v, &nn->nfs_client_list, pos);
1276 }
1277 
1278 /*
1279  * clean up after reading from the transports list
1280  */
1281 static void nfs_server_list_stop(struct seq_file *p, void *v)
1282 {
1283 	struct nfs_net *nn = net_generic(p->private, nfs_net_id);
1284 
1285 	spin_unlock(&nn->nfs_client_lock);
1286 }
1287 
1288 /*
1289  * display a header line followed by a load of call lines
1290  */
1291 static int nfs_server_list_show(struct seq_file *m, void *v)
1292 {
1293 	struct nfs_client *clp;
1294 	struct nfs_net *nn = net_generic(m->private, nfs_net_id);
1295 
1296 	/* display header on line 1 */
1297 	if (v == &nn->nfs_client_list) {
1298 		seq_puts(m, "NV SERVER   PORT USE HOSTNAME\n");
1299 		return 0;
1300 	}
1301 
1302 	/* display one transport per line on subsequent lines */
1303 	clp = list_entry(v, struct nfs_client, cl_share_link);
1304 
1305 	/* Check if the client is initialized */
1306 	if (clp->cl_cons_state != NFS_CS_READY)
1307 		return 0;
1308 
1309 	rcu_read_lock();
1310 	seq_printf(m, "v%u %s %s %3d %s\n",
1311 		   clp->rpc_ops->version,
1312 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1313 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1314 		   atomic_read(&clp->cl_count),
1315 		   clp->cl_hostname);
1316 	rcu_read_unlock();
1317 
1318 	return 0;
1319 }
1320 
1321 /*
1322  * open "/proc/fs/nfsfs/volumes" which provides a summary of extant volumes
1323  */
1324 static int nfs_volume_list_open(struct inode *inode, struct file *file)
1325 {
1326 	struct seq_file *m;
1327 	int ret;
1328 	struct pid_namespace *pid_ns = file->f_dentry->d_sb->s_fs_info;
1329 	struct net *net = pid_ns->child_reaper->nsproxy->net_ns;
1330 
1331 	ret = seq_open(file, &nfs_volume_list_ops);
1332 	if (ret < 0)
1333 		return ret;
1334 
1335 	m = file->private_data;
1336 	m->private = net;
1337 
1338 	return 0;
1339 }
1340 
1341 /*
1342  * set up the iterator to start reading from the volume list and return the first item
1343  */
1344 static void *nfs_volume_list_start(struct seq_file *m, loff_t *_pos)
1345 {
1346 	struct nfs_net *nn = net_generic(m->private, nfs_net_id);
1347 
1348 	/* lock the list against modification */
1349 	spin_lock(&nn->nfs_client_lock);
1350 	return seq_list_start_head(&nn->nfs_volume_list, *_pos);
1351 }
1352 
1353 /*
1354  * move to next volume
1355  */
1356 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos)
1357 {
1358 	struct nfs_net *nn = net_generic(p->private, nfs_net_id);
1359 
1360 	return seq_list_next(v, &nn->nfs_volume_list, pos);
1361 }
1362 
1363 /*
1364  * clean up after reading from the transports list
1365  */
1366 static void nfs_volume_list_stop(struct seq_file *p, void *v)
1367 {
1368 	struct nfs_net *nn = net_generic(p->private, nfs_net_id);
1369 
1370 	spin_unlock(&nn->nfs_client_lock);
1371 }
1372 
1373 /*
1374  * display a header line followed by a load of call lines
1375  */
1376 static int nfs_volume_list_show(struct seq_file *m, void *v)
1377 {
1378 	struct nfs_server *server;
1379 	struct nfs_client *clp;
1380 	char dev[8], fsid[17];
1381 	struct nfs_net *nn = net_generic(m->private, nfs_net_id);
1382 
1383 	/* display header on line 1 */
1384 	if (v == &nn->nfs_volume_list) {
1385 		seq_puts(m, "NV SERVER   PORT DEV     FSID              FSC\n");
1386 		return 0;
1387 	}
1388 	/* display one transport per line on subsequent lines */
1389 	server = list_entry(v, struct nfs_server, master_link);
1390 	clp = server->nfs_client;
1391 
1392 	snprintf(dev, 8, "%u:%u",
1393 		 MAJOR(server->s_dev), MINOR(server->s_dev));
1394 
1395 	snprintf(fsid, 17, "%llx:%llx",
1396 		 (unsigned long long) server->fsid.major,
1397 		 (unsigned long long) server->fsid.minor);
1398 
1399 	rcu_read_lock();
1400 	seq_printf(m, "v%u %s %s %-7s %-17s %s\n",
1401 		   clp->rpc_ops->version,
1402 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1403 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1404 		   dev,
1405 		   fsid,
1406 		   nfs_server_fscache_state(server));
1407 	rcu_read_unlock();
1408 
1409 	return 0;
1410 }
1411 
1412 /*
1413  * initialise the /proc/fs/nfsfs/ directory
1414  */
1415 int __init nfs_fs_proc_init(void)
1416 {
1417 	struct proc_dir_entry *p;
1418 
1419 	proc_fs_nfs = proc_mkdir("fs/nfsfs", NULL);
1420 	if (!proc_fs_nfs)
1421 		goto error_0;
1422 
1423 	/* a file of servers with which we're dealing */
1424 	p = proc_create("servers", S_IFREG|S_IRUGO,
1425 			proc_fs_nfs, &nfs_server_list_fops);
1426 	if (!p)
1427 		goto error_1;
1428 
1429 	/* a file of volumes that we have mounted */
1430 	p = proc_create("volumes", S_IFREG|S_IRUGO,
1431 			proc_fs_nfs, &nfs_volume_list_fops);
1432 	if (!p)
1433 		goto error_2;
1434 	return 0;
1435 
1436 error_2:
1437 	remove_proc_entry("servers", proc_fs_nfs);
1438 error_1:
1439 	remove_proc_entry("fs/nfsfs", NULL);
1440 error_0:
1441 	return -ENOMEM;
1442 }
1443 
1444 /*
1445  * clean up the /proc/fs/nfsfs/ directory
1446  */
1447 void nfs_fs_proc_exit(void)
1448 {
1449 	remove_proc_entry("volumes", proc_fs_nfs);
1450 	remove_proc_entry("servers", proc_fs_nfs);
1451 	remove_proc_entry("fs/nfsfs", NULL);
1452 }
1453 
1454 #endif /* CONFIG_PROC_FS */
1455