xref: /linux/fs/nfs/client.c (revision 27ffaeb0ab160852c87e2dfa505594020e9a3a06)
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) && !try_module_get(nfs->owner))
114 		return ERR_PTR(-EAGAIN);
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 	if (!try_module_get(clp->cl_nfs_mod->owner))
162 		goto error_dealloc;
163 
164 	clp->rpc_ops = clp->cl_nfs_mod->rpc_ops;
165 
166 	atomic_set(&clp->cl_count, 1);
167 	clp->cl_cons_state = NFS_CS_INITING;
168 
169 	memcpy(&clp->cl_addr, cl_init->addr, cl_init->addrlen);
170 	clp->cl_addrlen = cl_init->addrlen;
171 
172 	if (cl_init->hostname) {
173 		err = -ENOMEM;
174 		clp->cl_hostname = kstrdup(cl_init->hostname, GFP_KERNEL);
175 		if (!clp->cl_hostname)
176 			goto error_cleanup;
177 	}
178 
179 	INIT_LIST_HEAD(&clp->cl_superblocks);
180 	clp->cl_rpcclient = ERR_PTR(-EINVAL);
181 
182 	clp->cl_proto = cl_init->proto;
183 	clp->cl_net = get_net(cl_init->net);
184 
185 	cred = rpc_lookup_machine_cred("*");
186 	if (!IS_ERR(cred))
187 		clp->cl_machine_cred = cred;
188 	nfs_fscache_get_client_cookie(clp);
189 
190 	return clp;
191 
192 error_cleanup:
193 	put_nfs_version(clp->cl_nfs_mod);
194 error_dealloc:
195 	kfree(clp);
196 error_0:
197 	return ERR_PTR(err);
198 }
199 EXPORT_SYMBOL_GPL(nfs_alloc_client);
200 
201 #if IS_ENABLED(CONFIG_NFS_V4)
202 void nfs_cleanup_cb_ident_idr(struct net *net)
203 {
204 	struct nfs_net *nn = net_generic(net, nfs_net_id);
205 
206 	idr_destroy(&nn->cb_ident_idr);
207 }
208 
209 /* nfs_client_lock held */
210 static void nfs_cb_idr_remove_locked(struct nfs_client *clp)
211 {
212 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
213 
214 	if (clp->cl_cb_ident)
215 		idr_remove(&nn->cb_ident_idr, clp->cl_cb_ident);
216 }
217 
218 static void pnfs_init_server(struct nfs_server *server)
219 {
220 	rpc_init_wait_queue(&server->roc_rpcwaitq, "pNFS ROC");
221 }
222 
223 #else
224 void nfs_cleanup_cb_ident_idr(struct net *net)
225 {
226 }
227 
228 static void nfs_cb_idr_remove_locked(struct nfs_client *clp)
229 {
230 }
231 
232 static void pnfs_init_server(struct nfs_server *server)
233 {
234 }
235 
236 #endif /* CONFIG_NFS_V4 */
237 
238 /*
239  * Destroy a shared client record
240  */
241 void nfs_free_client(struct nfs_client *clp)
242 {
243 	dprintk("--> nfs_free_client(%u)\n", clp->rpc_ops->version);
244 
245 	nfs_fscache_release_client_cookie(clp);
246 
247 	/* -EIO all pending I/O */
248 	if (!IS_ERR(clp->cl_rpcclient))
249 		rpc_shutdown_client(clp->cl_rpcclient);
250 
251 	if (clp->cl_machine_cred != NULL)
252 		put_rpccred(clp->cl_machine_cred);
253 
254 	put_net(clp->cl_net);
255 	put_nfs_version(clp->cl_nfs_mod);
256 	kfree(clp->cl_hostname);
257 	kfree(clp->cl_acceptor);
258 	kfree(clp);
259 
260 	dprintk("<-- nfs_free_client()\n");
261 }
262 EXPORT_SYMBOL_GPL(nfs_free_client);
263 
264 /*
265  * Release a reference to a shared client record
266  */
267 void nfs_put_client(struct nfs_client *clp)
268 {
269 	struct nfs_net *nn;
270 
271 	if (!clp)
272 		return;
273 
274 	dprintk("--> nfs_put_client({%d})\n", atomic_read(&clp->cl_count));
275 	nn = net_generic(clp->cl_net, nfs_net_id);
276 
277 	if (atomic_dec_and_lock(&clp->cl_count, &nn->nfs_client_lock)) {
278 		list_del(&clp->cl_share_link);
279 		nfs_cb_idr_remove_locked(clp);
280 		spin_unlock(&nn->nfs_client_lock);
281 
282 		WARN_ON_ONCE(!list_empty(&clp->cl_superblocks));
283 
284 		clp->rpc_ops->free_client(clp);
285 	}
286 }
287 EXPORT_SYMBOL_GPL(nfs_put_client);
288 
289 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
290 /*
291  * Test if two ip6 socket addresses refer to the same socket by
292  * comparing relevant fields. The padding bytes specifically, are not
293  * compared. sin6_flowinfo is not compared because it only affects QoS
294  * and sin6_scope_id is only compared if the address is "link local"
295  * because "link local" addresses need only be unique to a specific
296  * link. Conversely, ordinary unicast addresses might have different
297  * sin6_scope_id.
298  *
299  * The caller should ensure both socket addresses are AF_INET6.
300  */
301 static int nfs_sockaddr_match_ipaddr6(const struct sockaddr *sa1,
302 				      const struct sockaddr *sa2)
303 {
304 	const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sa1;
305 	const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sa2;
306 
307 	if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
308 		return 0;
309 	else if (ipv6_addr_type(&sin1->sin6_addr) & IPV6_ADDR_LINKLOCAL)
310 		return sin1->sin6_scope_id == sin2->sin6_scope_id;
311 
312 	return 1;
313 }
314 #else	/* !defined(CONFIG_IPV6) && !defined(CONFIG_IPV6_MODULE) */
315 static int nfs_sockaddr_match_ipaddr6(const struct sockaddr *sa1,
316 				      const struct sockaddr *sa2)
317 {
318 	return 0;
319 }
320 #endif
321 
322 /*
323  * Test if two ip4 socket addresses refer to the same socket, by
324  * comparing relevant fields. The padding bytes specifically, are
325  * not compared.
326  *
327  * The caller should ensure both socket addresses are AF_INET.
328  */
329 static int nfs_sockaddr_match_ipaddr4(const struct sockaddr *sa1,
330 				      const struct sockaddr *sa2)
331 {
332 	const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sa1;
333 	const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sa2;
334 
335 	return sin1->sin_addr.s_addr == sin2->sin_addr.s_addr;
336 }
337 
338 static int nfs_sockaddr_cmp_ip6(const struct sockaddr *sa1,
339 				const struct sockaddr *sa2)
340 {
341 	const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sa1;
342 	const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sa2;
343 
344 	return nfs_sockaddr_match_ipaddr6(sa1, sa2) &&
345 		(sin1->sin6_port == sin2->sin6_port);
346 }
347 
348 static int nfs_sockaddr_cmp_ip4(const struct sockaddr *sa1,
349 				const struct sockaddr *sa2)
350 {
351 	const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sa1;
352 	const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sa2;
353 
354 	return nfs_sockaddr_match_ipaddr4(sa1, sa2) &&
355 		(sin1->sin_port == sin2->sin_port);
356 }
357 
358 #if defined(CONFIG_NFS_V4_1)
359 /*
360  * Test if two socket addresses represent the same actual socket,
361  * by comparing (only) relevant fields, excluding the port number.
362  */
363 int nfs_sockaddr_match_ipaddr(const struct sockaddr *sa1,
364 			      const struct sockaddr *sa2)
365 {
366 	if (sa1->sa_family != sa2->sa_family)
367 		return 0;
368 
369 	switch (sa1->sa_family) {
370 	case AF_INET:
371 		return nfs_sockaddr_match_ipaddr4(sa1, sa2);
372 	case AF_INET6:
373 		return nfs_sockaddr_match_ipaddr6(sa1, sa2);
374 	}
375 	return 0;
376 }
377 EXPORT_SYMBOL_GPL(nfs_sockaddr_match_ipaddr);
378 #endif /* CONFIG_NFS_V4_1 */
379 
380 /*
381  * Test if two socket addresses represent the same actual socket,
382  * by comparing (only) relevant fields, including the port number.
383  */
384 static int nfs_sockaddr_cmp(const struct sockaddr *sa1,
385 			    const struct sockaddr *sa2)
386 {
387 	if (sa1->sa_family != sa2->sa_family)
388 		return 0;
389 
390 	switch (sa1->sa_family) {
391 	case AF_INET:
392 		return nfs_sockaddr_cmp_ip4(sa1, sa2);
393 	case AF_INET6:
394 		return nfs_sockaddr_cmp_ip6(sa1, sa2);
395 	}
396 	return 0;
397 }
398 
399 /*
400  * Find an nfs_client on the list that matches the initialisation data
401  * that is supplied.
402  */
403 static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *data)
404 {
405 	struct nfs_client *clp;
406 	const struct sockaddr *sap = data->addr;
407 	struct nfs_net *nn = net_generic(data->net, nfs_net_id);
408 
409 	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
410 	        const struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
411 		/* Don't match clients that failed to initialise properly */
412 		if (clp->cl_cons_state < 0)
413 			continue;
414 
415 		/* Different NFS versions cannot share the same nfs_client */
416 		if (clp->rpc_ops != data->nfs_mod->rpc_ops)
417 			continue;
418 
419 		if (clp->cl_proto != data->proto)
420 			continue;
421 		/* Match nfsv4 minorversion */
422 		if (clp->cl_minorversion != data->minorversion)
423 			continue;
424 		/* Match the full socket address */
425 		if (!nfs_sockaddr_cmp(sap, clap))
426 			continue;
427 
428 		atomic_inc(&clp->cl_count);
429 		return clp;
430 	}
431 	return NULL;
432 }
433 
434 static bool nfs_client_init_is_complete(const struct nfs_client *clp)
435 {
436 	return clp->cl_cons_state != NFS_CS_INITING;
437 }
438 
439 int nfs_wait_client_init_complete(const struct nfs_client *clp)
440 {
441 	return wait_event_killable(nfs_client_active_wq,
442 			nfs_client_init_is_complete(clp));
443 }
444 EXPORT_SYMBOL_GPL(nfs_wait_client_init_complete);
445 
446 /*
447  * Found an existing client.  Make sure it's ready before returning.
448  */
449 static struct nfs_client *
450 nfs_found_client(const struct nfs_client_initdata *cl_init,
451 		 struct nfs_client *clp)
452 {
453 	int error;
454 
455 	error = nfs_wait_client_init_complete(clp);
456 	if (error < 0) {
457 		nfs_put_client(clp);
458 		return ERR_PTR(-ERESTARTSYS);
459 	}
460 
461 	if (clp->cl_cons_state < NFS_CS_READY) {
462 		error = clp->cl_cons_state;
463 		nfs_put_client(clp);
464 		return ERR_PTR(error);
465 	}
466 
467 	smp_rmb();
468 
469 	dprintk("<-- %s found nfs_client %p for %s\n",
470 		__func__, clp, cl_init->hostname ?: "");
471 	return clp;
472 }
473 
474 /*
475  * Look up a client by IP address and protocol version
476  * - creates a new record if one doesn't yet exist
477  */
478 struct nfs_client *
479 nfs_get_client(const struct nfs_client_initdata *cl_init,
480 	       const struct rpc_timeout *timeparms,
481 	       const char *ip_addr,
482 	       rpc_authflavor_t authflavour)
483 {
484 	struct nfs_client *clp, *new = NULL;
485 	struct nfs_net *nn = net_generic(cl_init->net, nfs_net_id);
486 	const struct nfs_rpc_ops *rpc_ops = cl_init->nfs_mod->rpc_ops;
487 
488 	if (cl_init->hostname == NULL) {
489 		WARN_ON(1);
490 		return NULL;
491 	}
492 
493 	dprintk("--> nfs_get_client(%s,v%u)\n",
494 		cl_init->hostname, rpc_ops->version);
495 
496 	/* see if the client already exists */
497 	do {
498 		spin_lock(&nn->nfs_client_lock);
499 
500 		clp = nfs_match_client(cl_init);
501 		if (clp) {
502 			spin_unlock(&nn->nfs_client_lock);
503 			if (new)
504 				new->rpc_ops->free_client(new);
505 			return nfs_found_client(cl_init, clp);
506 		}
507 		if (new) {
508 			list_add_tail(&new->cl_share_link,
509 					&nn->nfs_client_list);
510 			spin_unlock(&nn->nfs_client_lock);
511 			new->cl_flags = cl_init->init_flags;
512 			return rpc_ops->init_client(new, timeparms, ip_addr);
513 		}
514 
515 		spin_unlock(&nn->nfs_client_lock);
516 
517 		new = rpc_ops->alloc_client(cl_init);
518 	} while (!IS_ERR(new));
519 
520 	dprintk("<-- nfs_get_client() Failed to find %s (%ld)\n",
521 		cl_init->hostname, PTR_ERR(new));
522 	return new;
523 }
524 EXPORT_SYMBOL_GPL(nfs_get_client);
525 
526 /*
527  * Mark a server as ready or failed
528  */
529 void nfs_mark_client_ready(struct nfs_client *clp, int state)
530 {
531 	smp_wmb();
532 	clp->cl_cons_state = state;
533 	wake_up_all(&nfs_client_active_wq);
534 }
535 EXPORT_SYMBOL_GPL(nfs_mark_client_ready);
536 
537 /*
538  * Initialise the timeout values for a connection
539  */
540 void nfs_init_timeout_values(struct rpc_timeout *to, int proto,
541 				    unsigned int timeo, unsigned int retrans)
542 {
543 	to->to_initval = timeo * HZ / 10;
544 	to->to_retries = retrans;
545 
546 	switch (proto) {
547 	case XPRT_TRANSPORT_TCP:
548 	case XPRT_TRANSPORT_RDMA:
549 		if (to->to_retries == 0)
550 			to->to_retries = NFS_DEF_TCP_RETRANS;
551 		if (to->to_initval == 0)
552 			to->to_initval = NFS_DEF_TCP_TIMEO * HZ / 10;
553 		if (to->to_initval > NFS_MAX_TCP_TIMEOUT)
554 			to->to_initval = NFS_MAX_TCP_TIMEOUT;
555 		to->to_increment = to->to_initval;
556 		to->to_maxval = to->to_initval + (to->to_increment * to->to_retries);
557 		if (to->to_maxval > NFS_MAX_TCP_TIMEOUT)
558 			to->to_maxval = NFS_MAX_TCP_TIMEOUT;
559 		if (to->to_maxval < to->to_initval)
560 			to->to_maxval = to->to_initval;
561 		to->to_exponential = 0;
562 		break;
563 	case XPRT_TRANSPORT_UDP:
564 		if (to->to_retries == 0)
565 			to->to_retries = NFS_DEF_UDP_RETRANS;
566 		if (!to->to_initval)
567 			to->to_initval = NFS_DEF_UDP_TIMEO * HZ / 10;
568 		if (to->to_initval > NFS_MAX_UDP_TIMEOUT)
569 			to->to_initval = NFS_MAX_UDP_TIMEOUT;
570 		to->to_maxval = NFS_MAX_UDP_TIMEOUT;
571 		to->to_exponential = 1;
572 		break;
573 	default:
574 		BUG();
575 	}
576 }
577 EXPORT_SYMBOL_GPL(nfs_init_timeout_values);
578 
579 /*
580  * Create an RPC client handle
581  */
582 int nfs_create_rpc_client(struct nfs_client *clp,
583 			  const struct rpc_timeout *timeparms,
584 			  rpc_authflavor_t flavor)
585 {
586 	struct rpc_clnt		*clnt = NULL;
587 	struct rpc_create_args args = {
588 		.net		= clp->cl_net,
589 		.protocol	= clp->cl_proto,
590 		.address	= (struct sockaddr *)&clp->cl_addr,
591 		.addrsize	= clp->cl_addrlen,
592 		.timeout	= timeparms,
593 		.servername	= clp->cl_hostname,
594 		.program	= &nfs_program,
595 		.version	= clp->rpc_ops->version,
596 		.authflavor	= flavor,
597 	};
598 
599 	if (test_bit(NFS_CS_DISCRTRY, &clp->cl_flags))
600 		args.flags |= RPC_CLNT_CREATE_DISCRTRY;
601 	if (test_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags))
602 		args.flags |= RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT;
603 	if (test_bit(NFS_CS_NORESVPORT, &clp->cl_flags))
604 		args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
605 	if (test_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags))
606 		args.flags |= RPC_CLNT_CREATE_INFINITE_SLOTS;
607 
608 	if (!IS_ERR(clp->cl_rpcclient))
609 		return 0;
610 
611 	clnt = rpc_create(&args);
612 	if (IS_ERR(clnt)) {
613 		dprintk("%s: cannot create RPC client. Error = %ld\n",
614 				__func__, PTR_ERR(clnt));
615 		return PTR_ERR(clnt);
616 	}
617 
618 	clp->cl_rpcclient = clnt;
619 	return 0;
620 }
621 EXPORT_SYMBOL_GPL(nfs_create_rpc_client);
622 
623 /*
624  * Version 2 or 3 client destruction
625  */
626 static void nfs_destroy_server(struct nfs_server *server)
627 {
628 	if (server->nlm_host)
629 		nlmclnt_done(server->nlm_host);
630 }
631 
632 /*
633  * Version 2 or 3 lockd setup
634  */
635 static int nfs_start_lockd(struct nfs_server *server)
636 {
637 	struct nlm_host *host;
638 	struct nfs_client *clp = server->nfs_client;
639 	struct nlmclnt_initdata nlm_init = {
640 		.hostname	= clp->cl_hostname,
641 		.address	= (struct sockaddr *)&clp->cl_addr,
642 		.addrlen	= clp->cl_addrlen,
643 		.nfs_version	= clp->rpc_ops->version,
644 		.noresvport	= server->flags & NFS_MOUNT_NORESVPORT ?
645 					1 : 0,
646 		.net		= clp->cl_net,
647 	};
648 
649 	if (nlm_init.nfs_version > 3)
650 		return 0;
651 	if ((server->flags & NFS_MOUNT_LOCAL_FLOCK) &&
652 			(server->flags & NFS_MOUNT_LOCAL_FCNTL))
653 		return 0;
654 
655 	switch (clp->cl_proto) {
656 		default:
657 			nlm_init.protocol = IPPROTO_TCP;
658 			break;
659 		case XPRT_TRANSPORT_UDP:
660 			nlm_init.protocol = IPPROTO_UDP;
661 	}
662 
663 	host = nlmclnt_init(&nlm_init);
664 	if (IS_ERR(host))
665 		return PTR_ERR(host);
666 
667 	server->nlm_host = host;
668 	server->destroy = nfs_destroy_server;
669 	return 0;
670 }
671 
672 /*
673  * Create a general RPC client
674  */
675 int nfs_init_server_rpcclient(struct nfs_server *server,
676 		const struct rpc_timeout *timeo,
677 		rpc_authflavor_t pseudoflavour)
678 {
679 	struct nfs_client *clp = server->nfs_client;
680 
681 	server->client = rpc_clone_client_set_auth(clp->cl_rpcclient,
682 							pseudoflavour);
683 	if (IS_ERR(server->client)) {
684 		dprintk("%s: couldn't create rpc_client!\n", __func__);
685 		return PTR_ERR(server->client);
686 	}
687 
688 	memcpy(&server->client->cl_timeout_default,
689 			timeo,
690 			sizeof(server->client->cl_timeout_default));
691 	server->client->cl_timeout = &server->client->cl_timeout_default;
692 	server->client->cl_softrtry = 0;
693 	if (server->flags & NFS_MOUNT_SOFT)
694 		server->client->cl_softrtry = 1;
695 
696 	return 0;
697 }
698 EXPORT_SYMBOL_GPL(nfs_init_server_rpcclient);
699 
700 /**
701  * nfs_init_client - Initialise an NFS2 or NFS3 client
702  *
703  * @clp: nfs_client to initialise
704  * @timeparms: timeout parameters for underlying RPC transport
705  * @ip_addr: IP presentation address (not used)
706  *
707  * Returns pointer to an NFS client, or an ERR_PTR value.
708  */
709 struct nfs_client *nfs_init_client(struct nfs_client *clp,
710 		    const struct rpc_timeout *timeparms,
711 		    const char *ip_addr)
712 {
713 	int error;
714 
715 	if (clp->cl_cons_state == NFS_CS_READY) {
716 		/* the client is already initialised */
717 		dprintk("<-- nfs_init_client() = 0 [already %p]\n", clp);
718 		return clp;
719 	}
720 
721 	/*
722 	 * Create a client RPC handle for doing FSSTAT with UNIX auth only
723 	 * - RFC 2623, sec 2.3.2
724 	 */
725 	error = nfs_create_rpc_client(clp, timeparms, RPC_AUTH_UNIX);
726 	if (error < 0)
727 		goto error;
728 	nfs_mark_client_ready(clp, NFS_CS_READY);
729 	return clp;
730 
731 error:
732 	nfs_mark_client_ready(clp, error);
733 	nfs_put_client(clp);
734 	dprintk("<-- nfs_init_client() = xerror %d\n", error);
735 	return ERR_PTR(error);
736 }
737 EXPORT_SYMBOL_GPL(nfs_init_client);
738 
739 /*
740  * Create a version 2 or 3 client
741  */
742 static int nfs_init_server(struct nfs_server *server,
743 			   const struct nfs_parsed_mount_data *data,
744 			   struct nfs_subversion *nfs_mod)
745 {
746 	struct nfs_client_initdata cl_init = {
747 		.hostname = data->nfs_server.hostname,
748 		.addr = (const struct sockaddr *)&data->nfs_server.address,
749 		.addrlen = data->nfs_server.addrlen,
750 		.nfs_mod = nfs_mod,
751 		.proto = data->nfs_server.protocol,
752 		.net = data->net,
753 	};
754 	struct rpc_timeout timeparms;
755 	struct nfs_client *clp;
756 	int error;
757 
758 	dprintk("--> nfs_init_server()\n");
759 
760 	nfs_init_timeout_values(&timeparms, data->nfs_server.protocol,
761 			data->timeo, data->retrans);
762 	if (data->flags & NFS_MOUNT_NORESVPORT)
763 		set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
764 
765 	/* Allocate or find a client reference we can use */
766 	clp = nfs_get_client(&cl_init, &timeparms, NULL, RPC_AUTH_UNIX);
767 	if (IS_ERR(clp)) {
768 		dprintk("<-- nfs_init_server() = error %ld\n", PTR_ERR(clp));
769 		return PTR_ERR(clp);
770 	}
771 
772 	server->nfs_client = clp;
773 
774 	/* Initialise the client representation from the mount data */
775 	server->flags = data->flags;
776 	server->options = data->options;
777 	server->caps |= NFS_CAP_HARDLINKS|NFS_CAP_SYMLINKS|NFS_CAP_FILEID|
778 		NFS_CAP_MODE|NFS_CAP_NLINK|NFS_CAP_OWNER|NFS_CAP_OWNER_GROUP|
779 		NFS_CAP_ATIME|NFS_CAP_CTIME|NFS_CAP_MTIME|NFS_CAP_CHANGE_ATTR;
780 
781 	if (data->rsize)
782 		server->rsize = nfs_block_size(data->rsize, NULL);
783 	if (data->wsize)
784 		server->wsize = nfs_block_size(data->wsize, NULL);
785 
786 	server->acregmin = data->acregmin * HZ;
787 	server->acregmax = data->acregmax * HZ;
788 	server->acdirmin = data->acdirmin * HZ;
789 	server->acdirmax = data->acdirmax * HZ;
790 
791 	/* Start lockd here, before we might error out */
792 	error = nfs_start_lockd(server);
793 	if (error < 0)
794 		goto error;
795 
796 	server->port = data->nfs_server.port;
797 	server->auth_info = data->auth_info;
798 
799 	error = nfs_init_server_rpcclient(server, &timeparms,
800 					  data->selected_flavor);
801 	if (error < 0)
802 		goto error;
803 
804 	/* Preserve the values of mount_server-related mount options */
805 	if (data->mount_server.addrlen) {
806 		memcpy(&server->mountd_address, &data->mount_server.address,
807 			data->mount_server.addrlen);
808 		server->mountd_addrlen = data->mount_server.addrlen;
809 	}
810 	server->mountd_version = data->mount_server.version;
811 	server->mountd_port = data->mount_server.port;
812 	server->mountd_protocol = data->mount_server.protocol;
813 
814 	server->namelen  = data->namlen;
815 	dprintk("<-- nfs_init_server() = 0 [new %p]\n", clp);
816 	return 0;
817 
818 error:
819 	server->nfs_client = NULL;
820 	nfs_put_client(clp);
821 	dprintk("<-- nfs_init_server() = xerror %d\n", error);
822 	return error;
823 }
824 
825 /*
826  * Load up the server record from information gained in an fsinfo record
827  */
828 static void nfs_server_set_fsinfo(struct nfs_server *server,
829 				  struct nfs_fh *mntfh,
830 				  struct nfs_fsinfo *fsinfo)
831 {
832 	unsigned long max_rpc_payload;
833 
834 	/* Work out a lot of parameters */
835 	if (server->rsize == 0)
836 		server->rsize = nfs_block_size(fsinfo->rtpref, NULL);
837 	if (server->wsize == 0)
838 		server->wsize = nfs_block_size(fsinfo->wtpref, NULL);
839 
840 	if (fsinfo->rtmax >= 512 && server->rsize > fsinfo->rtmax)
841 		server->rsize = nfs_block_size(fsinfo->rtmax, NULL);
842 	if (fsinfo->wtmax >= 512 && server->wsize > fsinfo->wtmax)
843 		server->wsize = nfs_block_size(fsinfo->wtmax, NULL);
844 
845 	max_rpc_payload = nfs_block_size(rpc_max_payload(server->client), NULL);
846 	if (server->rsize > max_rpc_payload)
847 		server->rsize = max_rpc_payload;
848 	if (server->rsize > NFS_MAX_FILE_IO_SIZE)
849 		server->rsize = NFS_MAX_FILE_IO_SIZE;
850 	server->rpages = (server->rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
851 
852 	server->backing_dev_info.name = "nfs";
853 	server->backing_dev_info.ra_pages = server->rpages * NFS_MAX_READAHEAD;
854 
855 	if (server->wsize > max_rpc_payload)
856 		server->wsize = max_rpc_payload;
857 	if (server->wsize > NFS_MAX_FILE_IO_SIZE)
858 		server->wsize = NFS_MAX_FILE_IO_SIZE;
859 	server->wpages = (server->wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
860 
861 	server->wtmult = nfs_block_bits(fsinfo->wtmult, NULL);
862 
863 	server->dtsize = nfs_block_size(fsinfo->dtpref, NULL);
864 	if (server->dtsize > PAGE_CACHE_SIZE * NFS_MAX_READDIR_PAGES)
865 		server->dtsize = PAGE_CACHE_SIZE * NFS_MAX_READDIR_PAGES;
866 	if (server->dtsize > server->rsize)
867 		server->dtsize = server->rsize;
868 
869 	if (server->flags & NFS_MOUNT_NOAC) {
870 		server->acregmin = server->acregmax = 0;
871 		server->acdirmin = server->acdirmax = 0;
872 	}
873 
874 	server->maxfilesize = fsinfo->maxfilesize;
875 
876 	server->time_delta = fsinfo->time_delta;
877 
878 	/* We're airborne Set socket buffersize */
879 	rpc_setbufsize(server->client, server->wsize + 100, server->rsize + 100);
880 }
881 
882 /*
883  * Probe filesystem information, including the FSID on v2/v3
884  */
885 int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *mntfh, struct nfs_fattr *fattr)
886 {
887 	struct nfs_fsinfo fsinfo;
888 	struct nfs_client *clp = server->nfs_client;
889 	int error;
890 
891 	dprintk("--> nfs_probe_fsinfo()\n");
892 
893 	if (clp->rpc_ops->set_capabilities != NULL) {
894 		error = clp->rpc_ops->set_capabilities(server, mntfh);
895 		if (error < 0)
896 			goto out_error;
897 	}
898 
899 	fsinfo.fattr = fattr;
900 	fsinfo.layouttype = 0;
901 	error = clp->rpc_ops->fsinfo(server, mntfh, &fsinfo);
902 	if (error < 0)
903 		goto out_error;
904 
905 	nfs_server_set_fsinfo(server, mntfh, &fsinfo);
906 
907 	/* Get some general file system info */
908 	if (server->namelen == 0) {
909 		struct nfs_pathconf pathinfo;
910 
911 		pathinfo.fattr = fattr;
912 		nfs_fattr_init(fattr);
913 
914 		if (clp->rpc_ops->pathconf(server, mntfh, &pathinfo) >= 0)
915 			server->namelen = pathinfo.max_namelen;
916 	}
917 
918 	dprintk("<-- nfs_probe_fsinfo() = 0\n");
919 	return 0;
920 
921 out_error:
922 	dprintk("nfs_probe_fsinfo: error = %d\n", -error);
923 	return error;
924 }
925 EXPORT_SYMBOL_GPL(nfs_probe_fsinfo);
926 
927 /*
928  * Copy useful information when duplicating a server record
929  */
930 void nfs_server_copy_userdata(struct nfs_server *target, struct nfs_server *source)
931 {
932 	target->flags = source->flags;
933 	target->rsize = source->rsize;
934 	target->wsize = source->wsize;
935 	target->acregmin = source->acregmin;
936 	target->acregmax = source->acregmax;
937 	target->acdirmin = source->acdirmin;
938 	target->acdirmax = source->acdirmax;
939 	target->caps = source->caps;
940 	target->options = source->options;
941 	target->auth_info = source->auth_info;
942 }
943 EXPORT_SYMBOL_GPL(nfs_server_copy_userdata);
944 
945 void nfs_server_insert_lists(struct nfs_server *server)
946 {
947 	struct nfs_client *clp = server->nfs_client;
948 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
949 
950 	spin_lock(&nn->nfs_client_lock);
951 	list_add_tail_rcu(&server->client_link, &clp->cl_superblocks);
952 	list_add_tail(&server->master_link, &nn->nfs_volume_list);
953 	clear_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
954 	spin_unlock(&nn->nfs_client_lock);
955 
956 }
957 EXPORT_SYMBOL_GPL(nfs_server_insert_lists);
958 
959 void nfs_server_remove_lists(struct nfs_server *server)
960 {
961 	struct nfs_client *clp = server->nfs_client;
962 	struct nfs_net *nn;
963 
964 	if (clp == NULL)
965 		return;
966 	nn = net_generic(clp->cl_net, nfs_net_id);
967 	spin_lock(&nn->nfs_client_lock);
968 	list_del_rcu(&server->client_link);
969 	if (list_empty(&clp->cl_superblocks))
970 		set_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
971 	list_del(&server->master_link);
972 	spin_unlock(&nn->nfs_client_lock);
973 
974 	synchronize_rcu();
975 }
976 EXPORT_SYMBOL_GPL(nfs_server_remove_lists);
977 
978 /*
979  * Allocate and initialise a server record
980  */
981 struct nfs_server *nfs_alloc_server(void)
982 {
983 	struct nfs_server *server;
984 
985 	server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
986 	if (!server)
987 		return NULL;
988 
989 	server->client = server->client_acl = ERR_PTR(-EINVAL);
990 
991 	/* Zero out the NFS state stuff */
992 	INIT_LIST_HEAD(&server->client_link);
993 	INIT_LIST_HEAD(&server->master_link);
994 	INIT_LIST_HEAD(&server->delegations);
995 	INIT_LIST_HEAD(&server->layouts);
996 	INIT_LIST_HEAD(&server->state_owners_lru);
997 
998 	atomic_set(&server->active, 0);
999 
1000 	server->io_stats = nfs_alloc_iostats();
1001 	if (!server->io_stats) {
1002 		kfree(server);
1003 		return NULL;
1004 	}
1005 
1006 	if (bdi_init(&server->backing_dev_info)) {
1007 		nfs_free_iostats(server->io_stats);
1008 		kfree(server);
1009 		return NULL;
1010 	}
1011 
1012 	ida_init(&server->openowner_id);
1013 	ida_init(&server->lockowner_id);
1014 	pnfs_init_server(server);
1015 
1016 	return server;
1017 }
1018 EXPORT_SYMBOL_GPL(nfs_alloc_server);
1019 
1020 /*
1021  * Free up a server record
1022  */
1023 void nfs_free_server(struct nfs_server *server)
1024 {
1025 	dprintk("--> nfs_free_server()\n");
1026 
1027 	nfs_server_remove_lists(server);
1028 
1029 	if (server->destroy != NULL)
1030 		server->destroy(server);
1031 
1032 	if (!IS_ERR(server->client_acl))
1033 		rpc_shutdown_client(server->client_acl);
1034 	if (!IS_ERR(server->client))
1035 		rpc_shutdown_client(server->client);
1036 
1037 	nfs_put_client(server->nfs_client);
1038 
1039 	ida_destroy(&server->lockowner_id);
1040 	ida_destroy(&server->openowner_id);
1041 	nfs_free_iostats(server->io_stats);
1042 	bdi_destroy(&server->backing_dev_info);
1043 	kfree(server);
1044 	nfs_release_automount_timer();
1045 	dprintk("<-- nfs_free_server()\n");
1046 }
1047 EXPORT_SYMBOL_GPL(nfs_free_server);
1048 
1049 /*
1050  * Create a version 2 or 3 volume record
1051  * - keyed on server and FSID
1052  */
1053 struct nfs_server *nfs_create_server(struct nfs_mount_info *mount_info,
1054 				     struct nfs_subversion *nfs_mod)
1055 {
1056 	struct nfs_server *server;
1057 	struct nfs_fattr *fattr;
1058 	int error;
1059 
1060 	server = nfs_alloc_server();
1061 	if (!server)
1062 		return ERR_PTR(-ENOMEM);
1063 
1064 	error = -ENOMEM;
1065 	fattr = nfs_alloc_fattr();
1066 	if (fattr == NULL)
1067 		goto error;
1068 
1069 	/* Get a client representation */
1070 	error = nfs_init_server(server, mount_info->parsed, nfs_mod);
1071 	if (error < 0)
1072 		goto error;
1073 
1074 	/* Probe the root fh to retrieve its FSID */
1075 	error = nfs_probe_fsinfo(server, mount_info->mntfh, fattr);
1076 	if (error < 0)
1077 		goto error;
1078 	if (server->nfs_client->rpc_ops->version == 3) {
1079 		if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN)
1080 			server->namelen = NFS3_MAXNAMLEN;
1081 		if (!(mount_info->parsed->flags & NFS_MOUNT_NORDIRPLUS))
1082 			server->caps |= NFS_CAP_READDIRPLUS;
1083 	} else {
1084 		if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN)
1085 			server->namelen = NFS2_MAXNAMLEN;
1086 	}
1087 
1088 	if (!(fattr->valid & NFS_ATTR_FATTR)) {
1089 		error = nfs_mod->rpc_ops->getattr(server, mount_info->mntfh, fattr, NULL);
1090 		if (error < 0) {
1091 			dprintk("nfs_create_server: getattr error = %d\n", -error);
1092 			goto error;
1093 		}
1094 	}
1095 	memcpy(&server->fsid, &fattr->fsid, sizeof(server->fsid));
1096 
1097 	dprintk("Server FSID: %llx:%llx\n",
1098 		(unsigned long long) server->fsid.major,
1099 		(unsigned long long) server->fsid.minor);
1100 
1101 	nfs_server_insert_lists(server);
1102 	server->mount_time = jiffies;
1103 	nfs_free_fattr(fattr);
1104 	return server;
1105 
1106 error:
1107 	nfs_free_fattr(fattr);
1108 	nfs_free_server(server);
1109 	return ERR_PTR(error);
1110 }
1111 EXPORT_SYMBOL_GPL(nfs_create_server);
1112 
1113 /*
1114  * Clone an NFS2, NFS3 or NFS4 server record
1115  */
1116 struct nfs_server *nfs_clone_server(struct nfs_server *source,
1117 				    struct nfs_fh *fh,
1118 				    struct nfs_fattr *fattr,
1119 				    rpc_authflavor_t flavor)
1120 {
1121 	struct nfs_server *server;
1122 	struct nfs_fattr *fattr_fsinfo;
1123 	int error;
1124 
1125 	dprintk("--> nfs_clone_server(,%llx:%llx,)\n",
1126 		(unsigned long long) fattr->fsid.major,
1127 		(unsigned long long) fattr->fsid.minor);
1128 
1129 	server = nfs_alloc_server();
1130 	if (!server)
1131 		return ERR_PTR(-ENOMEM);
1132 
1133 	error = -ENOMEM;
1134 	fattr_fsinfo = nfs_alloc_fattr();
1135 	if (fattr_fsinfo == NULL)
1136 		goto out_free_server;
1137 
1138 	/* Copy data from the source */
1139 	server->nfs_client = source->nfs_client;
1140 	server->destroy = source->destroy;
1141 	atomic_inc(&server->nfs_client->cl_count);
1142 	nfs_server_copy_userdata(server, source);
1143 
1144 	server->fsid = fattr->fsid;
1145 
1146 	error = nfs_init_server_rpcclient(server,
1147 			source->client->cl_timeout,
1148 			flavor);
1149 	if (error < 0)
1150 		goto out_free_server;
1151 
1152 	/* probe the filesystem info for this server filesystem */
1153 	error = nfs_probe_fsinfo(server, fh, fattr_fsinfo);
1154 	if (error < 0)
1155 		goto out_free_server;
1156 
1157 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1158 		server->namelen = NFS4_MAXNAMLEN;
1159 
1160 	dprintk("Cloned FSID: %llx:%llx\n",
1161 		(unsigned long long) server->fsid.major,
1162 		(unsigned long long) server->fsid.minor);
1163 
1164 	error = nfs_start_lockd(server);
1165 	if (error < 0)
1166 		goto out_free_server;
1167 
1168 	nfs_server_insert_lists(server);
1169 	server->mount_time = jiffies;
1170 
1171 	nfs_free_fattr(fattr_fsinfo);
1172 	dprintk("<-- nfs_clone_server() = %p\n", server);
1173 	return server;
1174 
1175 out_free_server:
1176 	nfs_free_fattr(fattr_fsinfo);
1177 	nfs_free_server(server);
1178 	dprintk("<-- nfs_clone_server() = error %d\n", error);
1179 	return ERR_PTR(error);
1180 }
1181 EXPORT_SYMBOL_GPL(nfs_clone_server);
1182 
1183 void nfs_clients_init(struct net *net)
1184 {
1185 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1186 
1187 	INIT_LIST_HEAD(&nn->nfs_client_list);
1188 	INIT_LIST_HEAD(&nn->nfs_volume_list);
1189 #if IS_ENABLED(CONFIG_NFS_V4)
1190 	idr_init(&nn->cb_ident_idr);
1191 #endif
1192 	spin_lock_init(&nn->nfs_client_lock);
1193 	nn->boot_time = CURRENT_TIME;
1194 }
1195 
1196 #ifdef CONFIG_PROC_FS
1197 static struct proc_dir_entry *proc_fs_nfs;
1198 
1199 static int nfs_server_list_open(struct inode *inode, struct file *file);
1200 static void *nfs_server_list_start(struct seq_file *p, loff_t *pos);
1201 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos);
1202 static void nfs_server_list_stop(struct seq_file *p, void *v);
1203 static int nfs_server_list_show(struct seq_file *m, void *v);
1204 
1205 static const struct seq_operations nfs_server_list_ops = {
1206 	.start	= nfs_server_list_start,
1207 	.next	= nfs_server_list_next,
1208 	.stop	= nfs_server_list_stop,
1209 	.show	= nfs_server_list_show,
1210 };
1211 
1212 static const struct file_operations nfs_server_list_fops = {
1213 	.open		= nfs_server_list_open,
1214 	.read		= seq_read,
1215 	.llseek		= seq_lseek,
1216 	.release	= seq_release_net,
1217 	.owner		= THIS_MODULE,
1218 };
1219 
1220 static int nfs_volume_list_open(struct inode *inode, struct file *file);
1221 static void *nfs_volume_list_start(struct seq_file *p, loff_t *pos);
1222 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos);
1223 static void nfs_volume_list_stop(struct seq_file *p, void *v);
1224 static int nfs_volume_list_show(struct seq_file *m, void *v);
1225 
1226 static const struct seq_operations nfs_volume_list_ops = {
1227 	.start	= nfs_volume_list_start,
1228 	.next	= nfs_volume_list_next,
1229 	.stop	= nfs_volume_list_stop,
1230 	.show	= nfs_volume_list_show,
1231 };
1232 
1233 static const struct file_operations nfs_volume_list_fops = {
1234 	.open		= nfs_volume_list_open,
1235 	.read		= seq_read,
1236 	.llseek		= seq_lseek,
1237 	.release	= seq_release_net,
1238 	.owner		= THIS_MODULE,
1239 };
1240 
1241 /*
1242  * open "/proc/fs/nfsfs/servers" which provides a summary of servers with which
1243  * we're dealing
1244  */
1245 static int nfs_server_list_open(struct inode *inode, struct file *file)
1246 {
1247 	return seq_open_net(inode, file, &nfs_server_list_ops,
1248 			   sizeof(struct seq_net_private));
1249 }
1250 
1251 /*
1252  * set up the iterator to start reading from the server list and return the first item
1253  */
1254 static void *nfs_server_list_start(struct seq_file *m, loff_t *_pos)
1255 				__acquires(&nn->nfs_client_lock)
1256 {
1257 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1258 
1259 	/* lock the list against modification */
1260 	spin_lock(&nn->nfs_client_lock);
1261 	return seq_list_start_head(&nn->nfs_client_list, *_pos);
1262 }
1263 
1264 /*
1265  * move to next server
1266  */
1267 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos)
1268 {
1269 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1270 
1271 	return seq_list_next(v, &nn->nfs_client_list, pos);
1272 }
1273 
1274 /*
1275  * clean up after reading from the transports list
1276  */
1277 static void nfs_server_list_stop(struct seq_file *p, void *v)
1278 				__releases(&nn->nfs_client_lock)
1279 {
1280 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1281 
1282 	spin_unlock(&nn->nfs_client_lock);
1283 }
1284 
1285 /*
1286  * display a header line followed by a load of call lines
1287  */
1288 static int nfs_server_list_show(struct seq_file *m, void *v)
1289 {
1290 	struct nfs_client *clp;
1291 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1292 
1293 	/* display header on line 1 */
1294 	if (v == &nn->nfs_client_list) {
1295 		seq_puts(m, "NV SERVER   PORT USE HOSTNAME\n");
1296 		return 0;
1297 	}
1298 
1299 	/* display one transport per line on subsequent lines */
1300 	clp = list_entry(v, struct nfs_client, cl_share_link);
1301 
1302 	/* Check if the client is initialized */
1303 	if (clp->cl_cons_state != NFS_CS_READY)
1304 		return 0;
1305 
1306 	rcu_read_lock();
1307 	seq_printf(m, "v%u %s %s %3d %s\n",
1308 		   clp->rpc_ops->version,
1309 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1310 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1311 		   atomic_read(&clp->cl_count),
1312 		   clp->cl_hostname);
1313 	rcu_read_unlock();
1314 
1315 	return 0;
1316 }
1317 
1318 /*
1319  * open "/proc/fs/nfsfs/volumes" which provides a summary of extant volumes
1320  */
1321 static int nfs_volume_list_open(struct inode *inode, struct file *file)
1322 {
1323 	return seq_open_net(inode, file, &nfs_volume_list_ops,
1324 			   sizeof(struct seq_net_private));
1325 }
1326 
1327 /*
1328  * set up the iterator to start reading from the volume list and return the first item
1329  */
1330 static void *nfs_volume_list_start(struct seq_file *m, loff_t *_pos)
1331 				__acquires(&nn->nfs_client_lock)
1332 {
1333 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1334 
1335 	/* lock the list against modification */
1336 	spin_lock(&nn->nfs_client_lock);
1337 	return seq_list_start_head(&nn->nfs_volume_list, *_pos);
1338 }
1339 
1340 /*
1341  * move to next volume
1342  */
1343 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos)
1344 {
1345 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1346 
1347 	return seq_list_next(v, &nn->nfs_volume_list, pos);
1348 }
1349 
1350 /*
1351  * clean up after reading from the transports list
1352  */
1353 static void nfs_volume_list_stop(struct seq_file *p, void *v)
1354 				__releases(&nn->nfs_client_lock)
1355 {
1356 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1357 
1358 	spin_unlock(&nn->nfs_client_lock);
1359 }
1360 
1361 /*
1362  * display a header line followed by a load of call lines
1363  */
1364 static int nfs_volume_list_show(struct seq_file *m, void *v)
1365 {
1366 	struct nfs_server *server;
1367 	struct nfs_client *clp;
1368 	char dev[8], fsid[17];
1369 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1370 
1371 	/* display header on line 1 */
1372 	if (v == &nn->nfs_volume_list) {
1373 		seq_puts(m, "NV SERVER   PORT DEV     FSID              FSC\n");
1374 		return 0;
1375 	}
1376 	/* display one transport per line on subsequent lines */
1377 	server = list_entry(v, struct nfs_server, master_link);
1378 	clp = server->nfs_client;
1379 
1380 	snprintf(dev, 8, "%u:%u",
1381 		 MAJOR(server->s_dev), MINOR(server->s_dev));
1382 
1383 	snprintf(fsid, 17, "%llx:%llx",
1384 		 (unsigned long long) server->fsid.major,
1385 		 (unsigned long long) server->fsid.minor);
1386 
1387 	rcu_read_lock();
1388 	seq_printf(m, "v%u %s %s %-7s %-17s %s\n",
1389 		   clp->rpc_ops->version,
1390 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1391 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1392 		   dev,
1393 		   fsid,
1394 		   nfs_server_fscache_state(server));
1395 	rcu_read_unlock();
1396 
1397 	return 0;
1398 }
1399 
1400 int nfs_fs_proc_net_init(struct net *net)
1401 {
1402 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1403 	struct proc_dir_entry *p;
1404 
1405 	nn->proc_nfsfs = proc_net_mkdir(net, "nfsfs", net->proc_net);
1406 	if (!nn->proc_nfsfs)
1407 		goto error_0;
1408 
1409 	/* a file of servers with which we're dealing */
1410 	p = proc_create("servers", S_IFREG|S_IRUGO,
1411 			nn->proc_nfsfs, &nfs_server_list_fops);
1412 	if (!p)
1413 		goto error_1;
1414 
1415 	/* a file of volumes that we have mounted */
1416 	p = proc_create("volumes", S_IFREG|S_IRUGO,
1417 			nn->proc_nfsfs, &nfs_volume_list_fops);
1418 	if (!p)
1419 		goto error_1;
1420 	return 0;
1421 
1422 error_1:
1423 	remove_proc_subtree("nfsfs", net->proc_net);
1424 error_0:
1425 	return -ENOMEM;
1426 }
1427 
1428 void nfs_fs_proc_net_exit(struct net *net)
1429 {
1430 	remove_proc_subtree("nfsfs", net->proc_net);
1431 }
1432 
1433 /*
1434  * initialise the /proc/fs/nfsfs/ directory
1435  */
1436 int __init nfs_fs_proc_init(void)
1437 {
1438 	struct proc_dir_entry *p;
1439 
1440 	proc_fs_nfs = proc_mkdir("fs/nfsfs", NULL);
1441 	if (!proc_fs_nfs)
1442 		goto error_0;
1443 
1444 	/* a file of servers with which we're dealing */
1445 	p = proc_symlink("servers", proc_fs_nfs, "../../net/nfsfs/servers");
1446 	if (!p)
1447 		goto error_1;
1448 
1449 	/* a file of volumes that we have mounted */
1450 	p = proc_symlink("volumes", proc_fs_nfs, "../../net/nfsfs/volumes");
1451 	if (!p)
1452 		goto error_2;
1453 	return 0;
1454 
1455 error_2:
1456 	remove_proc_entry("servers", proc_fs_nfs);
1457 error_1:
1458 	remove_proc_entry("fs/nfsfs", NULL);
1459 error_0:
1460 	return -ENOMEM;
1461 }
1462 
1463 /*
1464  * clean up the /proc/fs/nfsfs/ directory
1465  */
1466 void nfs_fs_proc_exit(void)
1467 {
1468 	remove_proc_entry("volumes", proc_fs_nfs);
1469 	remove_proc_entry("servers", proc_fs_nfs);
1470 	remove_proc_entry("fs/nfsfs", NULL);
1471 }
1472 
1473 #endif /* CONFIG_PROC_FS */
1474