xref: /linux/fs/nfs/client.c (revision 827634added7f38b7d724cab1dccdb2b004c13c3)
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/vfs.h>
35 #include <linux/inet.h>
36 #include <linux/in6.h>
37 #include <linux/slab.h>
38 #include <linux/idr.h>
39 #include <net/ipv6.h>
40 #include <linux/nfs_xdr.h>
41 #include <linux/sunrpc/bc_xprt.h>
42 #include <linux/nsproxy.h>
43 #include <linux/pid_namespace.h>
44 
45 
46 #include "nfs4_fs.h"
47 #include "callback.h"
48 #include "delegation.h"
49 #include "iostat.h"
50 #include "internal.h"
51 #include "fscache.h"
52 #include "pnfs.h"
53 #include "nfs.h"
54 #include "netns.h"
55 
56 #define NFSDBG_FACILITY		NFSDBG_CLIENT
57 
58 static DECLARE_WAIT_QUEUE_HEAD(nfs_client_active_wq);
59 static DEFINE_SPINLOCK(nfs_version_lock);
60 static DEFINE_MUTEX(nfs_version_mutex);
61 static LIST_HEAD(nfs_versions);
62 
63 /*
64  * RPC cruft for NFS
65  */
66 static const struct rpc_version *nfs_version[5] = {
67 	[2] = NULL,
68 	[3] = NULL,
69 	[4] = NULL,
70 };
71 
72 const struct rpc_program nfs_program = {
73 	.name			= "nfs",
74 	.number			= NFS_PROGRAM,
75 	.nrvers			= ARRAY_SIZE(nfs_version),
76 	.version		= nfs_version,
77 	.stats			= &nfs_rpcstat,
78 	.pipe_dir_name		= NFS_PIPE_DIRNAME,
79 };
80 
81 struct rpc_stat nfs_rpcstat = {
82 	.program		= &nfs_program
83 };
84 
85 static struct nfs_subversion *find_nfs_version(unsigned int version)
86 {
87 	struct nfs_subversion *nfs;
88 	spin_lock(&nfs_version_lock);
89 
90 	list_for_each_entry(nfs, &nfs_versions, list) {
91 		if (nfs->rpc_ops->version == version) {
92 			spin_unlock(&nfs_version_lock);
93 			return nfs;
94 		}
95 	}
96 
97 	spin_unlock(&nfs_version_lock);
98 	return ERR_PTR(-EPROTONOSUPPORT);
99 }
100 
101 struct nfs_subversion *get_nfs_version(unsigned int version)
102 {
103 	struct nfs_subversion *nfs = find_nfs_version(version);
104 
105 	if (IS_ERR(nfs)) {
106 		mutex_lock(&nfs_version_mutex);
107 		request_module("nfsv%d", version);
108 		nfs = find_nfs_version(version);
109 		mutex_unlock(&nfs_version_mutex);
110 	}
111 
112 	if (!IS_ERR(nfs) && !try_module_get(nfs->owner))
113 		return ERR_PTR(-EAGAIN);
114 	return nfs;
115 }
116 
117 void put_nfs_version(struct nfs_subversion *nfs)
118 {
119 	module_put(nfs->owner);
120 }
121 
122 void register_nfs_version(struct nfs_subversion *nfs)
123 {
124 	spin_lock(&nfs_version_lock);
125 
126 	list_add(&nfs->list, &nfs_versions);
127 	nfs_version[nfs->rpc_ops->version] = nfs->rpc_vers;
128 
129 	spin_unlock(&nfs_version_lock);
130 }
131 EXPORT_SYMBOL_GPL(register_nfs_version);
132 
133 void unregister_nfs_version(struct nfs_subversion *nfs)
134 {
135 	spin_lock(&nfs_version_lock);
136 
137 	nfs_version[nfs->rpc_ops->version] = NULL;
138 	list_del(&nfs->list);
139 
140 	spin_unlock(&nfs_version_lock);
141 }
142 EXPORT_SYMBOL_GPL(unregister_nfs_version);
143 
144 /*
145  * Allocate a shared client record
146  *
147  * Since these are allocated/deallocated very rarely, we don't
148  * bother putting them in a slab cache...
149  */
150 struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init)
151 {
152 	struct nfs_client *clp;
153 	struct rpc_cred *cred;
154 	int err = -ENOMEM;
155 
156 	if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL)
157 		goto error_0;
158 
159 	clp->cl_nfs_mod = cl_init->nfs_mod;
160 	if (!try_module_get(clp->cl_nfs_mod->owner))
161 		goto error_dealloc;
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 error_dealloc:
194 	kfree(clp);
195 error_0:
196 	return ERR_PTR(err);
197 }
198 EXPORT_SYMBOL_GPL(nfs_alloc_client);
199 
200 #if IS_ENABLED(CONFIG_NFS_V4)
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->cl_acceptor);
257 	kfree(clp);
258 
259 	dprintk("<-- nfs_free_client()\n");
260 }
261 EXPORT_SYMBOL_GPL(nfs_free_client);
262 
263 /*
264  * Release a reference to a shared client record
265  */
266 void nfs_put_client(struct nfs_client *clp)
267 {
268 	struct nfs_net *nn;
269 
270 	if (!clp)
271 		return;
272 
273 	dprintk("--> nfs_put_client({%d})\n", atomic_read(&clp->cl_count));
274 	nn = net_generic(clp->cl_net, nfs_net_id);
275 
276 	if (atomic_dec_and_lock(&clp->cl_count, &nn->nfs_client_lock)) {
277 		list_del(&clp->cl_share_link);
278 		nfs_cb_idr_remove_locked(clp);
279 		spin_unlock(&nn->nfs_client_lock);
280 
281 		WARN_ON_ONCE(!list_empty(&clp->cl_superblocks));
282 
283 		clp->rpc_ops->free_client(clp);
284 	}
285 }
286 EXPORT_SYMBOL_GPL(nfs_put_client);
287 
288 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
289 /*
290  * Test if two ip6 socket addresses refer to the same socket by
291  * comparing relevant fields. The padding bytes specifically, are not
292  * compared. sin6_flowinfo is not compared because it only affects QoS
293  * and sin6_scope_id is only compared if the address is "link local"
294  * because "link local" addresses need only be unique to a specific
295  * link. Conversely, ordinary unicast addresses might have different
296  * sin6_scope_id.
297  *
298  * The caller should ensure both socket addresses are AF_INET6.
299  */
300 static int nfs_sockaddr_match_ipaddr6(const struct sockaddr *sa1,
301 				      const struct sockaddr *sa2)
302 {
303 	const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sa1;
304 	const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sa2;
305 
306 	if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
307 		return 0;
308 	else if (ipv6_addr_type(&sin1->sin6_addr) & IPV6_ADDR_LINKLOCAL)
309 		return sin1->sin6_scope_id == sin2->sin6_scope_id;
310 
311 	return 1;
312 }
313 #else	/* !defined(CONFIG_IPV6) && !defined(CONFIG_IPV6_MODULE) */
314 static int nfs_sockaddr_match_ipaddr6(const struct sockaddr *sa1,
315 				      const struct sockaddr *sa2)
316 {
317 	return 0;
318 }
319 #endif
320 
321 /*
322  * Test if two ip4 socket addresses refer to the same socket, by
323  * comparing relevant fields. The padding bytes specifically, are
324  * not compared.
325  *
326  * The caller should ensure both socket addresses are AF_INET.
327  */
328 static int nfs_sockaddr_match_ipaddr4(const struct sockaddr *sa1,
329 				      const struct sockaddr *sa2)
330 {
331 	const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sa1;
332 	const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sa2;
333 
334 	return sin1->sin_addr.s_addr == sin2->sin_addr.s_addr;
335 }
336 
337 static int nfs_sockaddr_cmp_ip6(const struct sockaddr *sa1,
338 				const struct sockaddr *sa2)
339 {
340 	const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sa1;
341 	const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sa2;
342 
343 	return nfs_sockaddr_match_ipaddr6(sa1, sa2) &&
344 		(sin1->sin6_port == sin2->sin6_port);
345 }
346 
347 static int nfs_sockaddr_cmp_ip4(const struct sockaddr *sa1,
348 				const struct sockaddr *sa2)
349 {
350 	const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sa1;
351 	const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sa2;
352 
353 	return nfs_sockaddr_match_ipaddr4(sa1, sa2) &&
354 		(sin1->sin_port == sin2->sin_port);
355 }
356 
357 #if defined(CONFIG_NFS_V4_1)
358 /*
359  * Test if two socket addresses represent the same actual socket,
360  * by comparing (only) relevant fields, excluding the port number.
361  */
362 int nfs_sockaddr_match_ipaddr(const struct sockaddr *sa1,
363 			      const struct sockaddr *sa2)
364 {
365 	if (sa1->sa_family != sa2->sa_family)
366 		return 0;
367 
368 	switch (sa1->sa_family) {
369 	case AF_INET:
370 		return nfs_sockaddr_match_ipaddr4(sa1, sa2);
371 	case AF_INET6:
372 		return nfs_sockaddr_match_ipaddr6(sa1, sa2);
373 	}
374 	return 0;
375 }
376 EXPORT_SYMBOL_GPL(nfs_sockaddr_match_ipaddr);
377 #endif /* CONFIG_NFS_V4_1 */
378 
379 /*
380  * Test if two socket addresses represent the same actual socket,
381  * by comparing (only) relevant fields, including the port number.
382  */
383 static int nfs_sockaddr_cmp(const struct sockaddr *sa1,
384 			    const struct sockaddr *sa2)
385 {
386 	if (sa1->sa_family != sa2->sa_family)
387 		return 0;
388 
389 	switch (sa1->sa_family) {
390 	case AF_INET:
391 		return nfs_sockaddr_cmp_ip4(sa1, sa2);
392 	case AF_INET6:
393 		return nfs_sockaddr_cmp_ip6(sa1, sa2);
394 	}
395 	return 0;
396 }
397 
398 /*
399  * Find an nfs_client on the list that matches the initialisation data
400  * that is supplied.
401  */
402 static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *data)
403 {
404 	struct nfs_client *clp;
405 	const struct sockaddr *sap = data->addr;
406 	struct nfs_net *nn = net_generic(data->net, nfs_net_id);
407 
408 	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
409 	        const struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
410 		/* Don't match clients that failed to initialise properly */
411 		if (clp->cl_cons_state < 0)
412 			continue;
413 
414 		/* Different NFS versions cannot share the same nfs_client */
415 		if (clp->rpc_ops != data->nfs_mod->rpc_ops)
416 			continue;
417 
418 		if (clp->cl_proto != data->proto)
419 			continue;
420 		/* Match nfsv4 minorversion */
421 		if (clp->cl_minorversion != data->minorversion)
422 			continue;
423 		/* Match the full socket address */
424 		if (!nfs_sockaddr_cmp(sap, clap))
425 			continue;
426 
427 		atomic_inc(&clp->cl_count);
428 		return clp;
429 	}
430 	return NULL;
431 }
432 
433 static bool nfs_client_init_is_complete(const struct nfs_client *clp)
434 {
435 	return clp->cl_cons_state <= NFS_CS_READY;
436 }
437 
438 int nfs_wait_client_init_complete(const struct nfs_client *clp)
439 {
440 	return wait_event_killable(nfs_client_active_wq,
441 			nfs_client_init_is_complete(clp));
442 }
443 EXPORT_SYMBOL_GPL(nfs_wait_client_init_complete);
444 
445 /*
446  * Found an existing client.  Make sure it's ready before returning.
447  */
448 static struct nfs_client *
449 nfs_found_client(const struct nfs_client_initdata *cl_init,
450 		 struct nfs_client *clp)
451 {
452 	int error;
453 
454 	error = nfs_wait_client_init_complete(clp);
455 	if (error < 0) {
456 		nfs_put_client(clp);
457 		return ERR_PTR(-ERESTARTSYS);
458 	}
459 
460 	if (clp->cl_cons_state < NFS_CS_READY) {
461 		error = clp->cl_cons_state;
462 		nfs_put_client(clp);
463 		return ERR_PTR(error);
464 	}
465 
466 	smp_rmb();
467 
468 	dprintk("<-- %s found nfs_client %p for %s\n",
469 		__func__, clp, cl_init->hostname ?: "");
470 	return clp;
471 }
472 
473 /*
474  * Look up a client by IP address and protocol version
475  * - creates a new record if one doesn't yet exist
476  */
477 struct nfs_client *
478 nfs_get_client(const struct nfs_client_initdata *cl_init,
479 	       const struct rpc_timeout *timeparms,
480 	       const char *ip_addr,
481 	       rpc_authflavor_t authflavour)
482 {
483 	struct nfs_client *clp, *new = NULL;
484 	struct nfs_net *nn = net_generic(cl_init->net, nfs_net_id);
485 	const struct nfs_rpc_ops *rpc_ops = cl_init->nfs_mod->rpc_ops;
486 
487 	if (cl_init->hostname == NULL) {
488 		WARN_ON(1);
489 		return NULL;
490 	}
491 
492 	dprintk("--> nfs_get_client(%s,v%u)\n",
493 		cl_init->hostname, rpc_ops->version);
494 
495 	/* see if the client already exists */
496 	do {
497 		spin_lock(&nn->nfs_client_lock);
498 
499 		clp = nfs_match_client(cl_init);
500 		if (clp) {
501 			spin_unlock(&nn->nfs_client_lock);
502 			if (new)
503 				new->rpc_ops->free_client(new);
504 			return nfs_found_client(cl_init, clp);
505 		}
506 		if (new) {
507 			list_add_tail(&new->cl_share_link,
508 					&nn->nfs_client_list);
509 			spin_unlock(&nn->nfs_client_lock);
510 			new->cl_flags = cl_init->init_flags;
511 			return rpc_ops->init_client(new, timeparms, ip_addr);
512 		}
513 
514 		spin_unlock(&nn->nfs_client_lock);
515 
516 		new = rpc_ops->alloc_client(cl_init);
517 	} while (!IS_ERR(new));
518 
519 	dprintk("<-- nfs_get_client() Failed to find %s (%ld)\n",
520 		cl_init->hostname, PTR_ERR(new));
521 	return new;
522 }
523 EXPORT_SYMBOL_GPL(nfs_get_client);
524 
525 /*
526  * Mark a server as ready or failed
527  */
528 void nfs_mark_client_ready(struct nfs_client *clp, int state)
529 {
530 	smp_wmb();
531 	clp->cl_cons_state = state;
532 	wake_up_all(&nfs_client_active_wq);
533 }
534 EXPORT_SYMBOL_GPL(nfs_mark_client_ready);
535 
536 /*
537  * Initialise the timeout values for a connection
538  */
539 void nfs_init_timeout_values(struct rpc_timeout *to, int proto,
540 				    unsigned int timeo, unsigned int retrans)
541 {
542 	to->to_initval = timeo * HZ / 10;
543 	to->to_retries = retrans;
544 
545 	switch (proto) {
546 	case XPRT_TRANSPORT_TCP:
547 	case XPRT_TRANSPORT_RDMA:
548 		if (to->to_retries == 0)
549 			to->to_retries = NFS_DEF_TCP_RETRANS;
550 		if (to->to_initval == 0)
551 			to->to_initval = NFS_DEF_TCP_TIMEO * HZ / 10;
552 		if (to->to_initval > NFS_MAX_TCP_TIMEOUT)
553 			to->to_initval = NFS_MAX_TCP_TIMEOUT;
554 		to->to_increment = to->to_initval;
555 		to->to_maxval = to->to_initval + (to->to_increment * to->to_retries);
556 		if (to->to_maxval > NFS_MAX_TCP_TIMEOUT)
557 			to->to_maxval = NFS_MAX_TCP_TIMEOUT;
558 		if (to->to_maxval < to->to_initval)
559 			to->to_maxval = to->to_initval;
560 		to->to_exponential = 0;
561 		break;
562 	case XPRT_TRANSPORT_UDP:
563 		if (to->to_retries == 0)
564 			to->to_retries = NFS_DEF_UDP_RETRANS;
565 		if (!to->to_initval)
566 			to->to_initval = NFS_DEF_UDP_TIMEO * HZ / 10;
567 		if (to->to_initval > NFS_MAX_UDP_TIMEOUT)
568 			to->to_initval = NFS_MAX_UDP_TIMEOUT;
569 		to->to_maxval = NFS_MAX_UDP_TIMEOUT;
570 		to->to_exponential = 1;
571 		break;
572 	default:
573 		BUG();
574 	}
575 }
576 EXPORT_SYMBOL_GPL(nfs_init_timeout_values);
577 
578 /*
579  * Create an RPC client handle
580  */
581 int nfs_create_rpc_client(struct nfs_client *clp,
582 			  const struct rpc_timeout *timeparms,
583 			  rpc_authflavor_t flavor)
584 {
585 	struct rpc_clnt		*clnt = NULL;
586 	struct rpc_create_args args = {
587 		.net		= clp->cl_net,
588 		.protocol	= clp->cl_proto,
589 		.address	= (struct sockaddr *)&clp->cl_addr,
590 		.addrsize	= clp->cl_addrlen,
591 		.timeout	= timeparms,
592 		.servername	= clp->cl_hostname,
593 		.program	= &nfs_program,
594 		.version	= clp->rpc_ops->version,
595 		.authflavor	= flavor,
596 	};
597 
598 	if (test_bit(NFS_CS_DISCRTRY, &clp->cl_flags))
599 		args.flags |= RPC_CLNT_CREATE_DISCRTRY;
600 	if (test_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags))
601 		args.flags |= RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT;
602 	if (test_bit(NFS_CS_NORESVPORT, &clp->cl_flags))
603 		args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
604 	if (test_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags))
605 		args.flags |= RPC_CLNT_CREATE_INFINITE_SLOTS;
606 
607 	if (!IS_ERR(clp->cl_rpcclient))
608 		return 0;
609 
610 	clnt = rpc_create(&args);
611 	if (IS_ERR(clnt)) {
612 		dprintk("%s: cannot create RPC client. Error = %ld\n",
613 				__func__, PTR_ERR(clnt));
614 		return PTR_ERR(clnt);
615 	}
616 
617 	clp->cl_rpcclient = clnt;
618 	return 0;
619 }
620 EXPORT_SYMBOL_GPL(nfs_create_rpc_client);
621 
622 /*
623  * Version 2 or 3 client destruction
624  */
625 static void nfs_destroy_server(struct nfs_server *server)
626 {
627 	if (server->nlm_host)
628 		nlmclnt_done(server->nlm_host);
629 }
630 
631 /*
632  * Version 2 or 3 lockd setup
633  */
634 static int nfs_start_lockd(struct nfs_server *server)
635 {
636 	struct nlm_host *host;
637 	struct nfs_client *clp = server->nfs_client;
638 	struct nlmclnt_initdata nlm_init = {
639 		.hostname	= clp->cl_hostname,
640 		.address	= (struct sockaddr *)&clp->cl_addr,
641 		.addrlen	= clp->cl_addrlen,
642 		.nfs_version	= clp->rpc_ops->version,
643 		.noresvport	= server->flags & NFS_MOUNT_NORESVPORT ?
644 					1 : 0,
645 		.net		= clp->cl_net,
646 	};
647 
648 	if (nlm_init.nfs_version > 3)
649 		return 0;
650 	if ((server->flags & NFS_MOUNT_LOCAL_FLOCK) &&
651 			(server->flags & NFS_MOUNT_LOCAL_FCNTL))
652 		return 0;
653 
654 	switch (clp->cl_proto) {
655 		default:
656 			nlm_init.protocol = IPPROTO_TCP;
657 			break;
658 		case XPRT_TRANSPORT_UDP:
659 			nlm_init.protocol = IPPROTO_UDP;
660 	}
661 
662 	host = nlmclnt_init(&nlm_init);
663 	if (IS_ERR(host))
664 		return PTR_ERR(host);
665 
666 	server->nlm_host = host;
667 	server->destroy = nfs_destroy_server;
668 	return 0;
669 }
670 
671 /*
672  * Create a general RPC client
673  */
674 int nfs_init_server_rpcclient(struct nfs_server *server,
675 		const struct rpc_timeout *timeo,
676 		rpc_authflavor_t pseudoflavour)
677 {
678 	struct nfs_client *clp = server->nfs_client;
679 
680 	server->client = rpc_clone_client_set_auth(clp->cl_rpcclient,
681 							pseudoflavour);
682 	if (IS_ERR(server->client)) {
683 		dprintk("%s: couldn't create rpc_client!\n", __func__);
684 		return PTR_ERR(server->client);
685 	}
686 
687 	memcpy(&server->client->cl_timeout_default,
688 			timeo,
689 			sizeof(server->client->cl_timeout_default));
690 	server->client->cl_timeout = &server->client->cl_timeout_default;
691 	server->client->cl_softrtry = 0;
692 	if (server->flags & NFS_MOUNT_SOFT)
693 		server->client->cl_softrtry = 1;
694 
695 	return 0;
696 }
697 EXPORT_SYMBOL_GPL(nfs_init_server_rpcclient);
698 
699 /**
700  * nfs_init_client - Initialise an NFS2 or NFS3 client
701  *
702  * @clp: nfs_client to initialise
703  * @timeparms: timeout parameters for underlying RPC transport
704  * @ip_addr: IP presentation address (not used)
705  *
706  * Returns pointer to an NFS client, or an ERR_PTR value.
707  */
708 struct nfs_client *nfs_init_client(struct nfs_client *clp,
709 		    const struct rpc_timeout *timeparms,
710 		    const char *ip_addr)
711 {
712 	int error;
713 
714 	if (clp->cl_cons_state == NFS_CS_READY) {
715 		/* the client is already initialised */
716 		dprintk("<-- nfs_init_client() = 0 [already %p]\n", clp);
717 		return clp;
718 	}
719 
720 	/*
721 	 * Create a client RPC handle for doing FSSTAT with UNIX auth only
722 	 * - RFC 2623, sec 2.3.2
723 	 */
724 	error = nfs_create_rpc_client(clp, timeparms, RPC_AUTH_UNIX);
725 	if (error < 0)
726 		goto error;
727 	nfs_mark_client_ready(clp, NFS_CS_READY);
728 	return clp;
729 
730 error:
731 	nfs_mark_client_ready(clp, error);
732 	nfs_put_client(clp);
733 	dprintk("<-- nfs_init_client() = xerror %d\n", error);
734 	return ERR_PTR(error);
735 }
736 EXPORT_SYMBOL_GPL(nfs_init_client);
737 
738 /*
739  * Create a version 2 or 3 client
740  */
741 static int nfs_init_server(struct nfs_server *server,
742 			   const struct nfs_parsed_mount_data *data,
743 			   struct nfs_subversion *nfs_mod)
744 {
745 	struct nfs_client_initdata cl_init = {
746 		.hostname = data->nfs_server.hostname,
747 		.addr = (const struct sockaddr *)&data->nfs_server.address,
748 		.addrlen = data->nfs_server.addrlen,
749 		.nfs_mod = nfs_mod,
750 		.proto = data->nfs_server.protocol,
751 		.net = data->net,
752 	};
753 	struct rpc_timeout timeparms;
754 	struct nfs_client *clp;
755 	int error;
756 
757 	dprintk("--> nfs_init_server()\n");
758 
759 	nfs_init_timeout_values(&timeparms, data->nfs_server.protocol,
760 			data->timeo, data->retrans);
761 	if (data->flags & NFS_MOUNT_NORESVPORT)
762 		set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
763 
764 	/* Allocate or find a client reference we can use */
765 	clp = nfs_get_client(&cl_init, &timeparms, NULL, RPC_AUTH_UNIX);
766 	if (IS_ERR(clp)) {
767 		dprintk("<-- nfs_init_server() = error %ld\n", PTR_ERR(clp));
768 		return PTR_ERR(clp);
769 	}
770 
771 	server->nfs_client = clp;
772 
773 	/* Initialise the client representation from the mount data */
774 	server->flags = data->flags;
775 	server->options = data->options;
776 	server->caps |= NFS_CAP_HARDLINKS|NFS_CAP_SYMLINKS|NFS_CAP_FILEID|
777 		NFS_CAP_MODE|NFS_CAP_NLINK|NFS_CAP_OWNER|NFS_CAP_OWNER_GROUP|
778 		NFS_CAP_ATIME|NFS_CAP_CTIME|NFS_CAP_MTIME|NFS_CAP_CHANGE_ATTR;
779 
780 	if (data->rsize)
781 		server->rsize = nfs_block_size(data->rsize, NULL);
782 	if (data->wsize)
783 		server->wsize = nfs_block_size(data->wsize, NULL);
784 
785 	server->acregmin = data->acregmin * HZ;
786 	server->acregmax = data->acregmax * HZ;
787 	server->acdirmin = data->acdirmin * HZ;
788 	server->acdirmax = data->acdirmax * HZ;
789 
790 	/* Start lockd here, before we might error out */
791 	error = nfs_start_lockd(server);
792 	if (error < 0)
793 		goto error;
794 
795 	server->port = data->nfs_server.port;
796 	server->auth_info = data->auth_info;
797 
798 	error = nfs_init_server_rpcclient(server, &timeparms,
799 					  data->selected_flavor);
800 	if (error < 0)
801 		goto error;
802 
803 	/* Preserve the values of mount_server-related mount options */
804 	if (data->mount_server.addrlen) {
805 		memcpy(&server->mountd_address, &data->mount_server.address,
806 			data->mount_server.addrlen);
807 		server->mountd_addrlen = data->mount_server.addrlen;
808 	}
809 	server->mountd_version = data->mount_server.version;
810 	server->mountd_port = data->mount_server.port;
811 	server->mountd_protocol = data->mount_server.protocol;
812 
813 	server->namelen  = data->namlen;
814 	dprintk("<-- nfs_init_server() = 0 [new %p]\n", clp);
815 	return 0;
816 
817 error:
818 	server->nfs_client = NULL;
819 	nfs_put_client(clp);
820 	dprintk("<-- nfs_init_server() = xerror %d\n", error);
821 	return error;
822 }
823 
824 /*
825  * Load up the server record from information gained in an fsinfo record
826  */
827 static void nfs_server_set_fsinfo(struct nfs_server *server,
828 				  struct nfs_fh *mntfh,
829 				  struct nfs_fsinfo *fsinfo)
830 {
831 	unsigned long max_rpc_payload;
832 
833 	/* Work out a lot of parameters */
834 	if (server->rsize == 0)
835 		server->rsize = nfs_block_size(fsinfo->rtpref, NULL);
836 	if (server->wsize == 0)
837 		server->wsize = nfs_block_size(fsinfo->wtpref, NULL);
838 
839 	if (fsinfo->rtmax >= 512 && server->rsize > fsinfo->rtmax)
840 		server->rsize = nfs_block_size(fsinfo->rtmax, NULL);
841 	if (fsinfo->wtmax >= 512 && server->wsize > fsinfo->wtmax)
842 		server->wsize = nfs_block_size(fsinfo->wtmax, NULL);
843 
844 	max_rpc_payload = nfs_block_size(rpc_max_payload(server->client), NULL);
845 	if (server->rsize > max_rpc_payload)
846 		server->rsize = max_rpc_payload;
847 	if (server->rsize > NFS_MAX_FILE_IO_SIZE)
848 		server->rsize = NFS_MAX_FILE_IO_SIZE;
849 	server->rpages = (server->rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
850 
851 	server->backing_dev_info.name = "nfs";
852 	server->backing_dev_info.ra_pages = server->rpages * NFS_MAX_READAHEAD;
853 
854 	if (server->wsize > max_rpc_payload)
855 		server->wsize = max_rpc_payload;
856 	if (server->wsize > NFS_MAX_FILE_IO_SIZE)
857 		server->wsize = NFS_MAX_FILE_IO_SIZE;
858 	server->wpages = (server->wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
859 
860 	server->wtmult = nfs_block_bits(fsinfo->wtmult, NULL);
861 
862 	server->dtsize = nfs_block_size(fsinfo->dtpref, NULL);
863 	if (server->dtsize > PAGE_CACHE_SIZE * NFS_MAX_READDIR_PAGES)
864 		server->dtsize = PAGE_CACHE_SIZE * NFS_MAX_READDIR_PAGES;
865 	if (server->dtsize > server->rsize)
866 		server->dtsize = server->rsize;
867 
868 	if (server->flags & NFS_MOUNT_NOAC) {
869 		server->acregmin = server->acregmax = 0;
870 		server->acdirmin = server->acdirmax = 0;
871 	}
872 
873 	server->maxfilesize = fsinfo->maxfilesize;
874 
875 	server->time_delta = fsinfo->time_delta;
876 
877 	/* We're airborne Set socket buffersize */
878 	rpc_setbufsize(server->client, server->wsize + 100, server->rsize + 100);
879 }
880 
881 /*
882  * Probe filesystem information, including the FSID on v2/v3
883  */
884 int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *mntfh, struct nfs_fattr *fattr)
885 {
886 	struct nfs_fsinfo fsinfo;
887 	struct nfs_client *clp = server->nfs_client;
888 	int error;
889 
890 	dprintk("--> nfs_probe_fsinfo()\n");
891 
892 	if (clp->rpc_ops->set_capabilities != NULL) {
893 		error = clp->rpc_ops->set_capabilities(server, mntfh);
894 		if (error < 0)
895 			goto out_error;
896 	}
897 
898 	fsinfo.fattr = fattr;
899 	fsinfo.layouttype = 0;
900 	error = clp->rpc_ops->fsinfo(server, mntfh, &fsinfo);
901 	if (error < 0)
902 		goto out_error;
903 
904 	nfs_server_set_fsinfo(server, mntfh, &fsinfo);
905 
906 	/* Get some general file system info */
907 	if (server->namelen == 0) {
908 		struct nfs_pathconf pathinfo;
909 
910 		pathinfo.fattr = fattr;
911 		nfs_fattr_init(fattr);
912 
913 		if (clp->rpc_ops->pathconf(server, mntfh, &pathinfo) >= 0)
914 			server->namelen = pathinfo.max_namelen;
915 	}
916 
917 	dprintk("<-- nfs_probe_fsinfo() = 0\n");
918 	return 0;
919 
920 out_error:
921 	dprintk("nfs_probe_fsinfo: error = %d\n", -error);
922 	return error;
923 }
924 EXPORT_SYMBOL_GPL(nfs_probe_fsinfo);
925 
926 /*
927  * Copy useful information when duplicating a server record
928  */
929 void nfs_server_copy_userdata(struct nfs_server *target, struct nfs_server *source)
930 {
931 	target->flags = source->flags;
932 	target->rsize = source->rsize;
933 	target->wsize = source->wsize;
934 	target->acregmin = source->acregmin;
935 	target->acregmax = source->acregmax;
936 	target->acdirmin = source->acdirmin;
937 	target->acdirmax = source->acdirmax;
938 	target->caps = source->caps;
939 	target->options = source->options;
940 	target->auth_info = source->auth_info;
941 }
942 EXPORT_SYMBOL_GPL(nfs_server_copy_userdata);
943 
944 void nfs_server_insert_lists(struct nfs_server *server)
945 {
946 	struct nfs_client *clp = server->nfs_client;
947 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
948 
949 	spin_lock(&nn->nfs_client_lock);
950 	list_add_tail_rcu(&server->client_link, &clp->cl_superblocks);
951 	list_add_tail(&server->master_link, &nn->nfs_volume_list);
952 	clear_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
953 	spin_unlock(&nn->nfs_client_lock);
954 
955 }
956 EXPORT_SYMBOL_GPL(nfs_server_insert_lists);
957 
958 void nfs_server_remove_lists(struct nfs_server *server)
959 {
960 	struct nfs_client *clp = server->nfs_client;
961 	struct nfs_net *nn;
962 
963 	if (clp == NULL)
964 		return;
965 	nn = net_generic(clp->cl_net, nfs_net_id);
966 	spin_lock(&nn->nfs_client_lock);
967 	list_del_rcu(&server->client_link);
968 	if (list_empty(&clp->cl_superblocks))
969 		set_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
970 	list_del(&server->master_link);
971 	spin_unlock(&nn->nfs_client_lock);
972 
973 	synchronize_rcu();
974 }
975 EXPORT_SYMBOL_GPL(nfs_server_remove_lists);
976 
977 /*
978  * Allocate and initialise a server record
979  */
980 struct nfs_server *nfs_alloc_server(void)
981 {
982 	struct nfs_server *server;
983 
984 	server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
985 	if (!server)
986 		return NULL;
987 
988 	server->client = server->client_acl = ERR_PTR(-EINVAL);
989 
990 	/* Zero out the NFS state stuff */
991 	INIT_LIST_HEAD(&server->client_link);
992 	INIT_LIST_HEAD(&server->master_link);
993 	INIT_LIST_HEAD(&server->delegations);
994 	INIT_LIST_HEAD(&server->layouts);
995 	INIT_LIST_HEAD(&server->state_owners_lru);
996 
997 	atomic_set(&server->active, 0);
998 
999 	server->io_stats = nfs_alloc_iostats();
1000 	if (!server->io_stats) {
1001 		kfree(server);
1002 		return NULL;
1003 	}
1004 
1005 	if (bdi_init(&server->backing_dev_info)) {
1006 		nfs_free_iostats(server->io_stats);
1007 		kfree(server);
1008 		return NULL;
1009 	}
1010 
1011 	ida_init(&server->openowner_id);
1012 	ida_init(&server->lockowner_id);
1013 	pnfs_init_server(server);
1014 
1015 	return server;
1016 }
1017 EXPORT_SYMBOL_GPL(nfs_alloc_server);
1018 
1019 /*
1020  * Free up a server record
1021  */
1022 void nfs_free_server(struct nfs_server *server)
1023 {
1024 	dprintk("--> nfs_free_server()\n");
1025 
1026 	nfs_server_remove_lists(server);
1027 
1028 	if (server->destroy != NULL)
1029 		server->destroy(server);
1030 
1031 	if (!IS_ERR(server->client_acl))
1032 		rpc_shutdown_client(server->client_acl);
1033 	if (!IS_ERR(server->client))
1034 		rpc_shutdown_client(server->client);
1035 
1036 	nfs_put_client(server->nfs_client);
1037 
1038 	ida_destroy(&server->lockowner_id);
1039 	ida_destroy(&server->openowner_id);
1040 	nfs_free_iostats(server->io_stats);
1041 	bdi_destroy(&server->backing_dev_info);
1042 	kfree(server);
1043 	nfs_release_automount_timer();
1044 	dprintk("<-- nfs_free_server()\n");
1045 }
1046 EXPORT_SYMBOL_GPL(nfs_free_server);
1047 
1048 /*
1049  * Create a version 2 or 3 volume record
1050  * - keyed on server and FSID
1051  */
1052 struct nfs_server *nfs_create_server(struct nfs_mount_info *mount_info,
1053 				     struct nfs_subversion *nfs_mod)
1054 {
1055 	struct nfs_server *server;
1056 	struct nfs_fattr *fattr;
1057 	int error;
1058 
1059 	server = nfs_alloc_server();
1060 	if (!server)
1061 		return ERR_PTR(-ENOMEM);
1062 
1063 	error = -ENOMEM;
1064 	fattr = nfs_alloc_fattr();
1065 	if (fattr == NULL)
1066 		goto error;
1067 
1068 	/* Get a client representation */
1069 	error = nfs_init_server(server, mount_info->parsed, nfs_mod);
1070 	if (error < 0)
1071 		goto error;
1072 
1073 	/* Probe the root fh to retrieve its FSID */
1074 	error = nfs_probe_fsinfo(server, mount_info->mntfh, fattr);
1075 	if (error < 0)
1076 		goto error;
1077 	if (server->nfs_client->rpc_ops->version == 3) {
1078 		if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN)
1079 			server->namelen = NFS3_MAXNAMLEN;
1080 		if (!(mount_info->parsed->flags & NFS_MOUNT_NORDIRPLUS))
1081 			server->caps |= NFS_CAP_READDIRPLUS;
1082 	} else {
1083 		if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN)
1084 			server->namelen = NFS2_MAXNAMLEN;
1085 	}
1086 
1087 	if (!(fattr->valid & NFS_ATTR_FATTR)) {
1088 		error = nfs_mod->rpc_ops->getattr(server, mount_info->mntfh, fattr, NULL);
1089 		if (error < 0) {
1090 			dprintk("nfs_create_server: getattr error = %d\n", -error);
1091 			goto error;
1092 		}
1093 	}
1094 	memcpy(&server->fsid, &fattr->fsid, sizeof(server->fsid));
1095 
1096 	dprintk("Server FSID: %llx:%llx\n",
1097 		(unsigned long long) server->fsid.major,
1098 		(unsigned long long) server->fsid.minor);
1099 
1100 	nfs_server_insert_lists(server);
1101 	server->mount_time = jiffies;
1102 	nfs_free_fattr(fattr);
1103 	return server;
1104 
1105 error:
1106 	nfs_free_fattr(fattr);
1107 	nfs_free_server(server);
1108 	return ERR_PTR(error);
1109 }
1110 EXPORT_SYMBOL_GPL(nfs_create_server);
1111 
1112 /*
1113  * Clone an NFS2, NFS3 or NFS4 server record
1114  */
1115 struct nfs_server *nfs_clone_server(struct nfs_server *source,
1116 				    struct nfs_fh *fh,
1117 				    struct nfs_fattr *fattr,
1118 				    rpc_authflavor_t flavor)
1119 {
1120 	struct nfs_server *server;
1121 	struct nfs_fattr *fattr_fsinfo;
1122 	int error;
1123 
1124 	dprintk("--> nfs_clone_server(,%llx:%llx,)\n",
1125 		(unsigned long long) fattr->fsid.major,
1126 		(unsigned long long) fattr->fsid.minor);
1127 
1128 	server = nfs_alloc_server();
1129 	if (!server)
1130 		return ERR_PTR(-ENOMEM);
1131 
1132 	error = -ENOMEM;
1133 	fattr_fsinfo = nfs_alloc_fattr();
1134 	if (fattr_fsinfo == NULL)
1135 		goto out_free_server;
1136 
1137 	/* Copy data from the source */
1138 	server->nfs_client = source->nfs_client;
1139 	server->destroy = source->destroy;
1140 	atomic_inc(&server->nfs_client->cl_count);
1141 	nfs_server_copy_userdata(server, source);
1142 
1143 	server->fsid = fattr->fsid;
1144 
1145 	error = nfs_init_server_rpcclient(server,
1146 			source->client->cl_timeout,
1147 			flavor);
1148 	if (error < 0)
1149 		goto out_free_server;
1150 
1151 	/* probe the filesystem info for this server filesystem */
1152 	error = nfs_probe_fsinfo(server, fh, fattr_fsinfo);
1153 	if (error < 0)
1154 		goto out_free_server;
1155 
1156 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1157 		server->namelen = NFS4_MAXNAMLEN;
1158 
1159 	dprintk("Cloned FSID: %llx:%llx\n",
1160 		(unsigned long long) server->fsid.major,
1161 		(unsigned long long) server->fsid.minor);
1162 
1163 	error = nfs_start_lockd(server);
1164 	if (error < 0)
1165 		goto out_free_server;
1166 
1167 	nfs_server_insert_lists(server);
1168 	server->mount_time = jiffies;
1169 
1170 	nfs_free_fattr(fattr_fsinfo);
1171 	dprintk("<-- nfs_clone_server() = %p\n", server);
1172 	return server;
1173 
1174 out_free_server:
1175 	nfs_free_fattr(fattr_fsinfo);
1176 	nfs_free_server(server);
1177 	dprintk("<-- nfs_clone_server() = error %d\n", error);
1178 	return ERR_PTR(error);
1179 }
1180 EXPORT_SYMBOL_GPL(nfs_clone_server);
1181 
1182 void nfs_clients_init(struct net *net)
1183 {
1184 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1185 
1186 	INIT_LIST_HEAD(&nn->nfs_client_list);
1187 	INIT_LIST_HEAD(&nn->nfs_volume_list);
1188 #if IS_ENABLED(CONFIG_NFS_V4)
1189 	idr_init(&nn->cb_ident_idr);
1190 #endif
1191 	spin_lock_init(&nn->nfs_client_lock);
1192 	nn->boot_time = CURRENT_TIME;
1193 }
1194 
1195 #ifdef CONFIG_PROC_FS
1196 static struct proc_dir_entry *proc_fs_nfs;
1197 
1198 static int nfs_server_list_open(struct inode *inode, struct file *file);
1199 static void *nfs_server_list_start(struct seq_file *p, loff_t *pos);
1200 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos);
1201 static void nfs_server_list_stop(struct seq_file *p, void *v);
1202 static int nfs_server_list_show(struct seq_file *m, void *v);
1203 
1204 static const struct seq_operations nfs_server_list_ops = {
1205 	.start	= nfs_server_list_start,
1206 	.next	= nfs_server_list_next,
1207 	.stop	= nfs_server_list_stop,
1208 	.show	= nfs_server_list_show,
1209 };
1210 
1211 static const struct file_operations nfs_server_list_fops = {
1212 	.open		= nfs_server_list_open,
1213 	.read		= seq_read,
1214 	.llseek		= seq_lseek,
1215 	.release	= seq_release_net,
1216 	.owner		= THIS_MODULE,
1217 };
1218 
1219 static int nfs_volume_list_open(struct inode *inode, struct file *file);
1220 static void *nfs_volume_list_start(struct seq_file *p, loff_t *pos);
1221 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos);
1222 static void nfs_volume_list_stop(struct seq_file *p, void *v);
1223 static int nfs_volume_list_show(struct seq_file *m, void *v);
1224 
1225 static const struct seq_operations nfs_volume_list_ops = {
1226 	.start	= nfs_volume_list_start,
1227 	.next	= nfs_volume_list_next,
1228 	.stop	= nfs_volume_list_stop,
1229 	.show	= nfs_volume_list_show,
1230 };
1231 
1232 static const struct file_operations nfs_volume_list_fops = {
1233 	.open		= nfs_volume_list_open,
1234 	.read		= seq_read,
1235 	.llseek		= seq_lseek,
1236 	.release	= seq_release_net,
1237 	.owner		= THIS_MODULE,
1238 };
1239 
1240 /*
1241  * open "/proc/fs/nfsfs/servers" which provides a summary of servers with which
1242  * we're dealing
1243  */
1244 static int nfs_server_list_open(struct inode *inode, struct file *file)
1245 {
1246 	return seq_open_net(inode, file, &nfs_server_list_ops,
1247 			   sizeof(struct seq_net_private));
1248 }
1249 
1250 /*
1251  * set up the iterator to start reading from the server list and return the first item
1252  */
1253 static void *nfs_server_list_start(struct seq_file *m, loff_t *_pos)
1254 				__acquires(&nn->nfs_client_lock)
1255 {
1256 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1257 
1258 	/* lock the list against modification */
1259 	spin_lock(&nn->nfs_client_lock);
1260 	return seq_list_start_head(&nn->nfs_client_list, *_pos);
1261 }
1262 
1263 /*
1264  * move to next server
1265  */
1266 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos)
1267 {
1268 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1269 
1270 	return seq_list_next(v, &nn->nfs_client_list, pos);
1271 }
1272 
1273 /*
1274  * clean up after reading from the transports list
1275  */
1276 static void nfs_server_list_stop(struct seq_file *p, void *v)
1277 				__releases(&nn->nfs_client_lock)
1278 {
1279 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1280 
1281 	spin_unlock(&nn->nfs_client_lock);
1282 }
1283 
1284 /*
1285  * display a header line followed by a load of call lines
1286  */
1287 static int nfs_server_list_show(struct seq_file *m, void *v)
1288 {
1289 	struct nfs_client *clp;
1290 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1291 
1292 	/* display header on line 1 */
1293 	if (v == &nn->nfs_client_list) {
1294 		seq_puts(m, "NV SERVER   PORT USE HOSTNAME\n");
1295 		return 0;
1296 	}
1297 
1298 	/* display one transport per line on subsequent lines */
1299 	clp = list_entry(v, struct nfs_client, cl_share_link);
1300 
1301 	/* Check if the client is initialized */
1302 	if (clp->cl_cons_state != NFS_CS_READY)
1303 		return 0;
1304 
1305 	rcu_read_lock();
1306 	seq_printf(m, "v%u %s %s %3d %s\n",
1307 		   clp->rpc_ops->version,
1308 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1309 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1310 		   atomic_read(&clp->cl_count),
1311 		   clp->cl_hostname);
1312 	rcu_read_unlock();
1313 
1314 	return 0;
1315 }
1316 
1317 /*
1318  * open "/proc/fs/nfsfs/volumes" which provides a summary of extant volumes
1319  */
1320 static int nfs_volume_list_open(struct inode *inode, struct file *file)
1321 {
1322 	return seq_open_net(inode, file, &nfs_volume_list_ops,
1323 			   sizeof(struct seq_net_private));
1324 }
1325 
1326 /*
1327  * set up the iterator to start reading from the volume list and return the first item
1328  */
1329 static void *nfs_volume_list_start(struct seq_file *m, loff_t *_pos)
1330 				__acquires(&nn->nfs_client_lock)
1331 {
1332 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1333 
1334 	/* lock the list against modification */
1335 	spin_lock(&nn->nfs_client_lock);
1336 	return seq_list_start_head(&nn->nfs_volume_list, *_pos);
1337 }
1338 
1339 /*
1340  * move to next volume
1341  */
1342 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos)
1343 {
1344 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1345 
1346 	return seq_list_next(v, &nn->nfs_volume_list, pos);
1347 }
1348 
1349 /*
1350  * clean up after reading from the transports list
1351  */
1352 static void nfs_volume_list_stop(struct seq_file *p, void *v)
1353 				__releases(&nn->nfs_client_lock)
1354 {
1355 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1356 
1357 	spin_unlock(&nn->nfs_client_lock);
1358 }
1359 
1360 /*
1361  * display a header line followed by a load of call lines
1362  */
1363 static int nfs_volume_list_show(struct seq_file *m, void *v)
1364 {
1365 	struct nfs_server *server;
1366 	struct nfs_client *clp;
1367 	char dev[8], fsid[17];
1368 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1369 
1370 	/* display header on line 1 */
1371 	if (v == &nn->nfs_volume_list) {
1372 		seq_puts(m, "NV SERVER   PORT DEV     FSID              FSC\n");
1373 		return 0;
1374 	}
1375 	/* display one transport per line on subsequent lines */
1376 	server = list_entry(v, struct nfs_server, master_link);
1377 	clp = server->nfs_client;
1378 
1379 	snprintf(dev, 8, "%u:%u",
1380 		 MAJOR(server->s_dev), MINOR(server->s_dev));
1381 
1382 	snprintf(fsid, 17, "%llx:%llx",
1383 		 (unsigned long long) server->fsid.major,
1384 		 (unsigned long long) server->fsid.minor);
1385 
1386 	rcu_read_lock();
1387 	seq_printf(m, "v%u %s %s %-7s %-17s %s\n",
1388 		   clp->rpc_ops->version,
1389 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1390 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1391 		   dev,
1392 		   fsid,
1393 		   nfs_server_fscache_state(server));
1394 	rcu_read_unlock();
1395 
1396 	return 0;
1397 }
1398 
1399 int nfs_fs_proc_net_init(struct net *net)
1400 {
1401 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1402 	struct proc_dir_entry *p;
1403 
1404 	nn->proc_nfsfs = proc_net_mkdir(net, "nfsfs", net->proc_net);
1405 	if (!nn->proc_nfsfs)
1406 		goto error_0;
1407 
1408 	/* a file of servers with which we're dealing */
1409 	p = proc_create("servers", S_IFREG|S_IRUGO,
1410 			nn->proc_nfsfs, &nfs_server_list_fops);
1411 	if (!p)
1412 		goto error_1;
1413 
1414 	/* a file of volumes that we have mounted */
1415 	p = proc_create("volumes", S_IFREG|S_IRUGO,
1416 			nn->proc_nfsfs, &nfs_volume_list_fops);
1417 	if (!p)
1418 		goto error_1;
1419 	return 0;
1420 
1421 error_1:
1422 	remove_proc_subtree("nfsfs", net->proc_net);
1423 error_0:
1424 	return -ENOMEM;
1425 }
1426 
1427 void nfs_fs_proc_net_exit(struct net *net)
1428 {
1429 	remove_proc_subtree("nfsfs", net->proc_net);
1430 }
1431 
1432 /*
1433  * initialise the /proc/fs/nfsfs/ directory
1434  */
1435 int __init nfs_fs_proc_init(void)
1436 {
1437 	struct proc_dir_entry *p;
1438 
1439 	proc_fs_nfs = proc_mkdir("fs/nfsfs", NULL);
1440 	if (!proc_fs_nfs)
1441 		goto error_0;
1442 
1443 	/* a file of servers with which we're dealing */
1444 	p = proc_symlink("servers", proc_fs_nfs, "../../net/nfsfs/servers");
1445 	if (!p)
1446 		goto error_1;
1447 
1448 	/* a file of volumes that we have mounted */
1449 	p = proc_symlink("volumes", proc_fs_nfs, "../../net/nfsfs/volumes");
1450 	if (!p)
1451 		goto error_2;
1452 	return 0;
1453 
1454 error_2:
1455 	remove_proc_entry("servers", proc_fs_nfs);
1456 error_1:
1457 	remove_proc_entry("fs/nfsfs", NULL);
1458 error_0:
1459 	return -ENOMEM;
1460 }
1461 
1462 /*
1463  * clean up the /proc/fs/nfsfs/ directory
1464  */
1465 void nfs_fs_proc_exit(void)
1466 {
1467 	remove_proc_entry("volumes", proc_fs_nfs);
1468 	remove_proc_entry("servers", proc_fs_nfs);
1469 	remove_proc_entry("fs/nfsfs", NULL);
1470 }
1471 
1472 #endif /* CONFIG_PROC_FS */
1473