xref: /openbmc/linux/fs/nfs/client.c (revision 79e790ff)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* client.c: NFS client sharing and management code
3  *
4  * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
5  * Written by David Howells (dhowells@redhat.com)
6  */
7 
8 
9 #include <linux/module.h>
10 #include <linux/init.h>
11 #include <linux/sched.h>
12 #include <linux/time.h>
13 #include <linux/kernel.h>
14 #include <linux/mm.h>
15 #include <linux/string.h>
16 #include <linux/stat.h>
17 #include <linux/errno.h>
18 #include <linux/unistd.h>
19 #include <linux/sunrpc/addr.h>
20 #include <linux/sunrpc/clnt.h>
21 #include <linux/sunrpc/stats.h>
22 #include <linux/sunrpc/metrics.h>
23 #include <linux/sunrpc/xprtsock.h>
24 #include <linux/sunrpc/xprtrdma.h>
25 #include <linux/nfs_fs.h>
26 #include <linux/nfs_mount.h>
27 #include <linux/nfs4_mount.h>
28 #include <linux/lockd/bind.h>
29 #include <linux/seq_file.h>
30 #include <linux/mount.h>
31 #include <linux/vfs.h>
32 #include <linux/inet.h>
33 #include <linux/in6.h>
34 #include <linux/slab.h>
35 #include <linux/idr.h>
36 #include <net/ipv6.h>
37 #include <linux/nfs_xdr.h>
38 #include <linux/sunrpc/bc_xprt.h>
39 #include <linux/nsproxy.h>
40 #include <linux/pid_namespace.h>
41 
42 
43 #include "nfs4_fs.h"
44 #include "callback.h"
45 #include "delegation.h"
46 #include "iostat.h"
47 #include "internal.h"
48 #include "fscache.h"
49 #include "pnfs.h"
50 #include "nfs.h"
51 #include "netns.h"
52 #include "sysfs.h"
53 #include "nfs42.h"
54 
55 #define NFSDBG_FACILITY		NFSDBG_CLIENT
56 
57 static DECLARE_WAIT_QUEUE_HEAD(nfs_client_active_wq);
58 static DEFINE_SPINLOCK(nfs_version_lock);
59 static DEFINE_MUTEX(nfs_version_mutex);
60 static LIST_HEAD(nfs_versions);
61 
62 /*
63  * RPC cruft for NFS
64  */
65 static const struct rpc_version *nfs_version[5] = {
66 	[2] = NULL,
67 	[3] = NULL,
68 	[4] = NULL,
69 };
70 
71 const struct rpc_program nfs_program = {
72 	.name			= "nfs",
73 	.number			= NFS_PROGRAM,
74 	.nrvers			= ARRAY_SIZE(nfs_version),
75 	.version		= nfs_version,
76 	.stats			= &nfs_rpcstat,
77 	.pipe_dir_name		= NFS_PIPE_DIRNAME,
78 };
79 
80 struct rpc_stat nfs_rpcstat = {
81 	.program		= &nfs_program
82 };
83 
84 static struct nfs_subversion *find_nfs_version(unsigned int version)
85 {
86 	struct nfs_subversion *nfs;
87 	spin_lock(&nfs_version_lock);
88 
89 	list_for_each_entry(nfs, &nfs_versions, list) {
90 		if (nfs->rpc_ops->version == version) {
91 			spin_unlock(&nfs_version_lock);
92 			return nfs;
93 		}
94 	}
95 
96 	spin_unlock(&nfs_version_lock);
97 	return ERR_PTR(-EPROTONOSUPPORT);
98 }
99 
100 struct nfs_subversion *get_nfs_version(unsigned int version)
101 {
102 	struct nfs_subversion *nfs = find_nfs_version(version);
103 
104 	if (IS_ERR(nfs)) {
105 		mutex_lock(&nfs_version_mutex);
106 		request_module("nfsv%d", version);
107 		nfs = find_nfs_version(version);
108 		mutex_unlock(&nfs_version_mutex);
109 	}
110 
111 	if (!IS_ERR(nfs) && !try_module_get(nfs->owner))
112 		return ERR_PTR(-EAGAIN);
113 	return nfs;
114 }
115 
116 void put_nfs_version(struct nfs_subversion *nfs)
117 {
118 	module_put(nfs->owner);
119 }
120 
121 void register_nfs_version(struct nfs_subversion *nfs)
122 {
123 	spin_lock(&nfs_version_lock);
124 
125 	list_add(&nfs->list, &nfs_versions);
126 	nfs_version[nfs->rpc_ops->version] = nfs->rpc_vers;
127 
128 	spin_unlock(&nfs_version_lock);
129 }
130 EXPORT_SYMBOL_GPL(register_nfs_version);
131 
132 void unregister_nfs_version(struct nfs_subversion *nfs)
133 {
134 	spin_lock(&nfs_version_lock);
135 
136 	nfs_version[nfs->rpc_ops->version] = NULL;
137 	list_del(&nfs->list);
138 
139 	spin_unlock(&nfs_version_lock);
140 }
141 EXPORT_SYMBOL_GPL(unregister_nfs_version);
142 
143 /*
144  * Allocate a shared client record
145  *
146  * Since these are allocated/deallocated very rarely, we don't
147  * bother putting them in a slab cache...
148  */
149 struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init)
150 {
151 	struct nfs_client *clp;
152 	int err = -ENOMEM;
153 
154 	if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL)
155 		goto error_0;
156 
157 	clp->cl_minorversion = cl_init->minorversion;
158 	clp->cl_nfs_mod = cl_init->nfs_mod;
159 	if (!try_module_get(clp->cl_nfs_mod->owner))
160 		goto error_dealloc;
161 
162 	clp->rpc_ops = clp->cl_nfs_mod->rpc_ops;
163 
164 	refcount_set(&clp->cl_count, 1);
165 	clp->cl_cons_state = NFS_CS_INITING;
166 
167 	memcpy(&clp->cl_addr, cl_init->addr, cl_init->addrlen);
168 	clp->cl_addrlen = cl_init->addrlen;
169 
170 	if (cl_init->hostname) {
171 		err = -ENOMEM;
172 		clp->cl_hostname = kstrdup(cl_init->hostname, GFP_KERNEL);
173 		if (!clp->cl_hostname)
174 			goto error_cleanup;
175 	}
176 
177 	INIT_LIST_HEAD(&clp->cl_superblocks);
178 	clp->cl_rpcclient = ERR_PTR(-EINVAL);
179 
180 	clp->cl_proto = cl_init->proto;
181 	clp->cl_nconnect = cl_init->nconnect;
182 	clp->cl_net = get_net(cl_init->net);
183 
184 	clp->cl_principal = "*";
185 	nfs_fscache_get_client_cookie(clp);
186 
187 	return clp;
188 
189 error_cleanup:
190 	put_nfs_version(clp->cl_nfs_mod);
191 error_dealloc:
192 	kfree(clp);
193 error_0:
194 	return ERR_PTR(err);
195 }
196 EXPORT_SYMBOL_GPL(nfs_alloc_client);
197 
198 #if IS_ENABLED(CONFIG_NFS_V4)
199 static void nfs_cleanup_cb_ident_idr(struct net *net)
200 {
201 	struct nfs_net *nn = net_generic(net, nfs_net_id);
202 
203 	idr_destroy(&nn->cb_ident_idr);
204 }
205 
206 /* nfs_client_lock held */
207 static void nfs_cb_idr_remove_locked(struct nfs_client *clp)
208 {
209 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
210 
211 	if (clp->cl_cb_ident)
212 		idr_remove(&nn->cb_ident_idr, clp->cl_cb_ident);
213 }
214 
215 static void pnfs_init_server(struct nfs_server *server)
216 {
217 	rpc_init_wait_queue(&server->roc_rpcwaitq, "pNFS ROC");
218 }
219 
220 #else
221 static void nfs_cleanup_cb_ident_idr(struct net *net)
222 {
223 }
224 
225 static void nfs_cb_idr_remove_locked(struct nfs_client *clp)
226 {
227 }
228 
229 static void pnfs_init_server(struct nfs_server *server)
230 {
231 }
232 
233 #endif /* CONFIG_NFS_V4 */
234 
235 /*
236  * Destroy a shared client record
237  */
238 void nfs_free_client(struct nfs_client *clp)
239 {
240 	nfs_fscache_release_client_cookie(clp);
241 
242 	/* -EIO all pending I/O */
243 	if (!IS_ERR(clp->cl_rpcclient))
244 		rpc_shutdown_client(clp->cl_rpcclient);
245 
246 	put_net(clp->cl_net);
247 	put_nfs_version(clp->cl_nfs_mod);
248 	kfree(clp->cl_hostname);
249 	kfree(clp->cl_acceptor);
250 	kfree(clp);
251 }
252 EXPORT_SYMBOL_GPL(nfs_free_client);
253 
254 /*
255  * Release a reference to a shared client record
256  */
257 void nfs_put_client(struct nfs_client *clp)
258 {
259 	struct nfs_net *nn;
260 
261 	if (!clp)
262 		return;
263 
264 	nn = net_generic(clp->cl_net, nfs_net_id);
265 
266 	if (refcount_dec_and_lock(&clp->cl_count, &nn->nfs_client_lock)) {
267 		list_del(&clp->cl_share_link);
268 		nfs_cb_idr_remove_locked(clp);
269 		spin_unlock(&nn->nfs_client_lock);
270 
271 		WARN_ON_ONCE(!list_empty(&clp->cl_superblocks));
272 
273 		clp->rpc_ops->free_client(clp);
274 	}
275 }
276 EXPORT_SYMBOL_GPL(nfs_put_client);
277 
278 /*
279  * Find an nfs_client on the list that matches the initialisation data
280  * that is supplied.
281  */
282 static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *data)
283 {
284 	struct nfs_client *clp;
285 	const struct sockaddr *sap = data->addr;
286 	struct nfs_net *nn = net_generic(data->net, nfs_net_id);
287 	int error;
288 
289 again:
290 	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
291 	        const struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
292 		/* Don't match clients that failed to initialise properly */
293 		if (clp->cl_cons_state < 0)
294 			continue;
295 
296 		/* If a client is still initializing then we need to wait */
297 		if (clp->cl_cons_state > NFS_CS_READY) {
298 			refcount_inc(&clp->cl_count);
299 			spin_unlock(&nn->nfs_client_lock);
300 			error = nfs_wait_client_init_complete(clp);
301 			nfs_put_client(clp);
302 			spin_lock(&nn->nfs_client_lock);
303 			if (error < 0)
304 				return ERR_PTR(error);
305 			goto again;
306 		}
307 
308 		/* Different NFS versions cannot share the same nfs_client */
309 		if (clp->rpc_ops != data->nfs_mod->rpc_ops)
310 			continue;
311 
312 		if (clp->cl_proto != data->proto)
313 			continue;
314 		/* Match nfsv4 minorversion */
315 		if (clp->cl_minorversion != data->minorversion)
316 			continue;
317 
318 		/* Match request for a dedicated DS */
319 		if (test_bit(NFS_CS_DS, &data->init_flags) !=
320 		    test_bit(NFS_CS_DS, &clp->cl_flags))
321 			continue;
322 
323 		/* Match the full socket address */
324 		if (!rpc_cmp_addr_port(sap, clap))
325 			/* Match all xprt_switch full socket addresses */
326 			if (IS_ERR(clp->cl_rpcclient) ||
327                             !rpc_clnt_xprt_switch_has_addr(clp->cl_rpcclient,
328 							   sap))
329 				continue;
330 
331 		refcount_inc(&clp->cl_count);
332 		return clp;
333 	}
334 	return NULL;
335 }
336 
337 /*
338  * Return true if @clp is done initializing, false if still working on it.
339  *
340  * Use nfs_client_init_status to check if it was successful.
341  */
342 bool nfs_client_init_is_complete(const struct nfs_client *clp)
343 {
344 	return clp->cl_cons_state <= NFS_CS_READY;
345 }
346 EXPORT_SYMBOL_GPL(nfs_client_init_is_complete);
347 
348 /*
349  * Return 0 if @clp was successfully initialized, -errno otherwise.
350  *
351  * This must be called *after* nfs_client_init_is_complete() returns true,
352  * otherwise it will pop WARN_ON_ONCE and return -EINVAL
353  */
354 int nfs_client_init_status(const struct nfs_client *clp)
355 {
356 	/* called without checking nfs_client_init_is_complete */
357 	if (clp->cl_cons_state > NFS_CS_READY) {
358 		WARN_ON_ONCE(1);
359 		return -EINVAL;
360 	}
361 	return clp->cl_cons_state;
362 }
363 EXPORT_SYMBOL_GPL(nfs_client_init_status);
364 
365 int nfs_wait_client_init_complete(const struct nfs_client *clp)
366 {
367 	return wait_event_killable(nfs_client_active_wq,
368 			nfs_client_init_is_complete(clp));
369 }
370 EXPORT_SYMBOL_GPL(nfs_wait_client_init_complete);
371 
372 /*
373  * Found an existing client.  Make sure it's ready before returning.
374  */
375 static struct nfs_client *
376 nfs_found_client(const struct nfs_client_initdata *cl_init,
377 		 struct nfs_client *clp)
378 {
379 	int error;
380 
381 	error = nfs_wait_client_init_complete(clp);
382 	if (error < 0) {
383 		nfs_put_client(clp);
384 		return ERR_PTR(-ERESTARTSYS);
385 	}
386 
387 	if (clp->cl_cons_state < NFS_CS_READY) {
388 		error = clp->cl_cons_state;
389 		nfs_put_client(clp);
390 		return ERR_PTR(error);
391 	}
392 
393 	smp_rmb();
394 	return clp;
395 }
396 
397 /*
398  * Look up a client by IP address and protocol version
399  * - creates a new record if one doesn't yet exist
400  */
401 struct nfs_client *nfs_get_client(const struct nfs_client_initdata *cl_init)
402 {
403 	struct nfs_client *clp, *new = NULL;
404 	struct nfs_net *nn = net_generic(cl_init->net, nfs_net_id);
405 	const struct nfs_rpc_ops *rpc_ops = cl_init->nfs_mod->rpc_ops;
406 
407 	if (cl_init->hostname == NULL) {
408 		WARN_ON(1);
409 		return NULL;
410 	}
411 
412 	/* see if the client already exists */
413 	do {
414 		spin_lock(&nn->nfs_client_lock);
415 
416 		clp = nfs_match_client(cl_init);
417 		if (clp) {
418 			spin_unlock(&nn->nfs_client_lock);
419 			if (new)
420 				new->rpc_ops->free_client(new);
421 			if (IS_ERR(clp))
422 				return clp;
423 			return nfs_found_client(cl_init, clp);
424 		}
425 		if (new) {
426 			list_add_tail(&new->cl_share_link,
427 					&nn->nfs_client_list);
428 			spin_unlock(&nn->nfs_client_lock);
429 			new->cl_flags = cl_init->init_flags;
430 			return rpc_ops->init_client(new, cl_init);
431 		}
432 
433 		spin_unlock(&nn->nfs_client_lock);
434 
435 		new = rpc_ops->alloc_client(cl_init);
436 	} while (!IS_ERR(new));
437 
438 	return new;
439 }
440 EXPORT_SYMBOL_GPL(nfs_get_client);
441 
442 /*
443  * Mark a server as ready or failed
444  */
445 void nfs_mark_client_ready(struct nfs_client *clp, int state)
446 {
447 	smp_wmb();
448 	clp->cl_cons_state = state;
449 	wake_up_all(&nfs_client_active_wq);
450 }
451 EXPORT_SYMBOL_GPL(nfs_mark_client_ready);
452 
453 /*
454  * Initialise the timeout values for a connection
455  */
456 void nfs_init_timeout_values(struct rpc_timeout *to, int proto,
457 				    int timeo, int retrans)
458 {
459 	to->to_initval = timeo * HZ / 10;
460 	to->to_retries = retrans;
461 
462 	switch (proto) {
463 	case XPRT_TRANSPORT_TCP:
464 	case XPRT_TRANSPORT_RDMA:
465 		if (retrans == NFS_UNSPEC_RETRANS)
466 			to->to_retries = NFS_DEF_TCP_RETRANS;
467 		if (timeo == NFS_UNSPEC_TIMEO || to->to_initval == 0)
468 			to->to_initval = NFS_DEF_TCP_TIMEO * HZ / 10;
469 		if (to->to_initval > NFS_MAX_TCP_TIMEOUT)
470 			to->to_initval = NFS_MAX_TCP_TIMEOUT;
471 		to->to_increment = to->to_initval;
472 		to->to_maxval = to->to_initval + (to->to_increment * to->to_retries);
473 		if (to->to_maxval > NFS_MAX_TCP_TIMEOUT)
474 			to->to_maxval = NFS_MAX_TCP_TIMEOUT;
475 		if (to->to_maxval < to->to_initval)
476 			to->to_maxval = to->to_initval;
477 		to->to_exponential = 0;
478 		break;
479 	case XPRT_TRANSPORT_UDP:
480 		if (retrans == NFS_UNSPEC_RETRANS)
481 			to->to_retries = NFS_DEF_UDP_RETRANS;
482 		if (timeo == NFS_UNSPEC_TIMEO || to->to_initval == 0)
483 			to->to_initval = NFS_DEF_UDP_TIMEO * HZ / 10;
484 		if (to->to_initval > NFS_MAX_UDP_TIMEOUT)
485 			to->to_initval = NFS_MAX_UDP_TIMEOUT;
486 		to->to_maxval = NFS_MAX_UDP_TIMEOUT;
487 		to->to_exponential = 1;
488 		break;
489 	default:
490 		BUG();
491 	}
492 }
493 EXPORT_SYMBOL_GPL(nfs_init_timeout_values);
494 
495 /*
496  * Create an RPC client handle
497  */
498 int nfs_create_rpc_client(struct nfs_client *clp,
499 			  const struct nfs_client_initdata *cl_init,
500 			  rpc_authflavor_t flavor)
501 {
502 	struct rpc_clnt		*clnt = NULL;
503 	struct rpc_create_args args = {
504 		.net		= clp->cl_net,
505 		.protocol	= clp->cl_proto,
506 		.nconnect	= clp->cl_nconnect,
507 		.address	= (struct sockaddr *)&clp->cl_addr,
508 		.addrsize	= clp->cl_addrlen,
509 		.timeout	= cl_init->timeparms,
510 		.servername	= clp->cl_hostname,
511 		.nodename	= cl_init->nodename,
512 		.program	= &nfs_program,
513 		.version	= clp->rpc_ops->version,
514 		.authflavor	= flavor,
515 		.cred		= cl_init->cred,
516 	};
517 
518 	if (test_bit(NFS_CS_DISCRTRY, &clp->cl_flags))
519 		args.flags |= RPC_CLNT_CREATE_DISCRTRY;
520 	if (test_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags))
521 		args.flags |= RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT;
522 	if (test_bit(NFS_CS_NORESVPORT, &clp->cl_flags))
523 		args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
524 	if (test_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags))
525 		args.flags |= RPC_CLNT_CREATE_INFINITE_SLOTS;
526 	if (test_bit(NFS_CS_NOPING, &clp->cl_flags))
527 		args.flags |= RPC_CLNT_CREATE_NOPING;
528 	if (test_bit(NFS_CS_REUSEPORT, &clp->cl_flags))
529 		args.flags |= RPC_CLNT_CREATE_REUSEPORT;
530 
531 	if (!IS_ERR(clp->cl_rpcclient))
532 		return 0;
533 
534 	clnt = rpc_create(&args);
535 	if (IS_ERR(clnt)) {
536 		dprintk("%s: cannot create RPC client. Error = %ld\n",
537 				__func__, PTR_ERR(clnt));
538 		return PTR_ERR(clnt);
539 	}
540 
541 	clnt->cl_principal = clp->cl_principal;
542 	clp->cl_rpcclient = clnt;
543 	return 0;
544 }
545 EXPORT_SYMBOL_GPL(nfs_create_rpc_client);
546 
547 /*
548  * Version 2 or 3 client destruction
549  */
550 static void nfs_destroy_server(struct nfs_server *server)
551 {
552 	if (server->nlm_host)
553 		nlmclnt_done(server->nlm_host);
554 }
555 
556 /*
557  * Version 2 or 3 lockd setup
558  */
559 static int nfs_start_lockd(struct nfs_server *server)
560 {
561 	struct nlm_host *host;
562 	struct nfs_client *clp = server->nfs_client;
563 	struct nlmclnt_initdata nlm_init = {
564 		.hostname	= clp->cl_hostname,
565 		.address	= (struct sockaddr *)&clp->cl_addr,
566 		.addrlen	= clp->cl_addrlen,
567 		.nfs_version	= clp->rpc_ops->version,
568 		.noresvport	= server->flags & NFS_MOUNT_NORESVPORT ?
569 					1 : 0,
570 		.net		= clp->cl_net,
571 		.nlmclnt_ops 	= clp->cl_nfs_mod->rpc_ops->nlmclnt_ops,
572 		.cred		= server->cred,
573 	};
574 
575 	if (nlm_init.nfs_version > 3)
576 		return 0;
577 	if ((server->flags & NFS_MOUNT_LOCAL_FLOCK) &&
578 			(server->flags & NFS_MOUNT_LOCAL_FCNTL))
579 		return 0;
580 
581 	switch (clp->cl_proto) {
582 		default:
583 			nlm_init.protocol = IPPROTO_TCP;
584 			break;
585 #ifndef CONFIG_NFS_DISABLE_UDP_SUPPORT
586 		case XPRT_TRANSPORT_UDP:
587 			nlm_init.protocol = IPPROTO_UDP;
588 #endif
589 	}
590 
591 	host = nlmclnt_init(&nlm_init);
592 	if (IS_ERR(host))
593 		return PTR_ERR(host);
594 
595 	server->nlm_host = host;
596 	server->destroy = nfs_destroy_server;
597 	return 0;
598 }
599 
600 /*
601  * Create a general RPC client
602  */
603 int nfs_init_server_rpcclient(struct nfs_server *server,
604 		const struct rpc_timeout *timeo,
605 		rpc_authflavor_t pseudoflavour)
606 {
607 	struct nfs_client *clp = server->nfs_client;
608 
609 	server->client = rpc_clone_client_set_auth(clp->cl_rpcclient,
610 							pseudoflavour);
611 	if (IS_ERR(server->client)) {
612 		dprintk("%s: couldn't create rpc_client!\n", __func__);
613 		return PTR_ERR(server->client);
614 	}
615 
616 	memcpy(&server->client->cl_timeout_default,
617 			timeo,
618 			sizeof(server->client->cl_timeout_default));
619 	server->client->cl_timeout = &server->client->cl_timeout_default;
620 	server->client->cl_softrtry = 0;
621 	if (server->flags & NFS_MOUNT_SOFTERR)
622 		server->client->cl_softerr = 1;
623 	if (server->flags & NFS_MOUNT_SOFT)
624 		server->client->cl_softrtry = 1;
625 
626 	return 0;
627 }
628 EXPORT_SYMBOL_GPL(nfs_init_server_rpcclient);
629 
630 /**
631  * nfs_init_client - Initialise an NFS2 or NFS3 client
632  *
633  * @clp: nfs_client to initialise
634  * @cl_init: Initialisation parameters
635  *
636  * Returns pointer to an NFS client, or an ERR_PTR value.
637  */
638 struct nfs_client *nfs_init_client(struct nfs_client *clp,
639 				   const struct nfs_client_initdata *cl_init)
640 {
641 	int error;
642 
643 	/* the client is already initialised */
644 	if (clp->cl_cons_state == NFS_CS_READY)
645 		return clp;
646 
647 	/*
648 	 * Create a client RPC handle for doing FSSTAT with UNIX auth only
649 	 * - RFC 2623, sec 2.3.2
650 	 */
651 	error = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_UNIX);
652 	nfs_mark_client_ready(clp, error == 0 ? NFS_CS_READY : error);
653 	if (error < 0) {
654 		nfs_put_client(clp);
655 		clp = ERR_PTR(error);
656 	}
657 	return clp;
658 }
659 EXPORT_SYMBOL_GPL(nfs_init_client);
660 
661 /*
662  * Create a version 2 or 3 client
663  */
664 static int nfs_init_server(struct nfs_server *server,
665 			   const struct fs_context *fc)
666 {
667 	const struct nfs_fs_context *ctx = nfs_fc2context(fc);
668 	struct rpc_timeout timeparms;
669 	struct nfs_client_initdata cl_init = {
670 		.hostname = ctx->nfs_server.hostname,
671 		.addr = (const struct sockaddr *)&ctx->nfs_server.address,
672 		.addrlen = ctx->nfs_server.addrlen,
673 		.nfs_mod = ctx->nfs_mod,
674 		.proto = ctx->nfs_server.protocol,
675 		.net = fc->net_ns,
676 		.timeparms = &timeparms,
677 		.cred = server->cred,
678 		.nconnect = ctx->nfs_server.nconnect,
679 		.init_flags = (1UL << NFS_CS_REUSEPORT),
680 	};
681 	struct nfs_client *clp;
682 	int error;
683 
684 	nfs_init_timeout_values(&timeparms, ctx->nfs_server.protocol,
685 				ctx->timeo, ctx->retrans);
686 	if (ctx->flags & NFS_MOUNT_NORESVPORT)
687 		set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
688 
689 	/* Allocate or find a client reference we can use */
690 	clp = nfs_get_client(&cl_init);
691 	if (IS_ERR(clp))
692 		return PTR_ERR(clp);
693 
694 	server->nfs_client = clp;
695 
696 	/* Initialise the client representation from the mount data */
697 	server->flags = ctx->flags;
698 	server->options = ctx->options;
699 	server->caps |= NFS_CAP_HARDLINKS | NFS_CAP_SYMLINKS;
700 
701 	switch (clp->rpc_ops->version) {
702 	case 2:
703 		server->fattr_valid = NFS_ATTR_FATTR_V2;
704 		break;
705 	case 3:
706 		server->fattr_valid = NFS_ATTR_FATTR_V3;
707 		break;
708 	default:
709 		server->fattr_valid = NFS_ATTR_FATTR_V4;
710 	}
711 
712 	if (ctx->rsize)
713 		server->rsize = nfs_block_size(ctx->rsize, NULL);
714 	if (ctx->wsize)
715 		server->wsize = nfs_block_size(ctx->wsize, NULL);
716 
717 	server->acregmin = ctx->acregmin * HZ;
718 	server->acregmax = ctx->acregmax * HZ;
719 	server->acdirmin = ctx->acdirmin * HZ;
720 	server->acdirmax = ctx->acdirmax * HZ;
721 
722 	/* Start lockd here, before we might error out */
723 	error = nfs_start_lockd(server);
724 	if (error < 0)
725 		goto error;
726 
727 	server->port = ctx->nfs_server.port;
728 	server->auth_info = ctx->auth_info;
729 
730 	error = nfs_init_server_rpcclient(server, &timeparms,
731 					  ctx->selected_flavor);
732 	if (error < 0)
733 		goto error;
734 
735 	/* Preserve the values of mount_server-related mount options */
736 	if (ctx->mount_server.addrlen) {
737 		memcpy(&server->mountd_address, &ctx->mount_server.address,
738 			ctx->mount_server.addrlen);
739 		server->mountd_addrlen = ctx->mount_server.addrlen;
740 	}
741 	server->mountd_version = ctx->mount_server.version;
742 	server->mountd_port = ctx->mount_server.port;
743 	server->mountd_protocol = ctx->mount_server.protocol;
744 
745 	server->namelen  = ctx->namlen;
746 	return 0;
747 
748 error:
749 	server->nfs_client = NULL;
750 	nfs_put_client(clp);
751 	return error;
752 }
753 
754 /*
755  * Load up the server record from information gained in an fsinfo record
756  */
757 static void nfs_server_set_fsinfo(struct nfs_server *server,
758 				  struct nfs_fsinfo *fsinfo)
759 {
760 	unsigned long max_rpc_payload, raw_max_rpc_payload;
761 
762 	/* Work out a lot of parameters */
763 	if (server->rsize == 0)
764 		server->rsize = nfs_block_size(fsinfo->rtpref, NULL);
765 	if (server->wsize == 0)
766 		server->wsize = nfs_block_size(fsinfo->wtpref, NULL);
767 
768 	if (fsinfo->rtmax >= 512 && server->rsize > fsinfo->rtmax)
769 		server->rsize = nfs_block_size(fsinfo->rtmax, NULL);
770 	if (fsinfo->wtmax >= 512 && server->wsize > fsinfo->wtmax)
771 		server->wsize = nfs_block_size(fsinfo->wtmax, NULL);
772 
773 	raw_max_rpc_payload = rpc_max_payload(server->client);
774 	max_rpc_payload = nfs_block_size(raw_max_rpc_payload, NULL);
775 
776 	if (server->rsize > max_rpc_payload)
777 		server->rsize = max_rpc_payload;
778 	if (server->rsize > NFS_MAX_FILE_IO_SIZE)
779 		server->rsize = NFS_MAX_FILE_IO_SIZE;
780 	server->rpages = (server->rsize + PAGE_SIZE - 1) >> PAGE_SHIFT;
781 
782 	if (server->wsize > max_rpc_payload)
783 		server->wsize = max_rpc_payload;
784 	if (server->wsize > NFS_MAX_FILE_IO_SIZE)
785 		server->wsize = NFS_MAX_FILE_IO_SIZE;
786 	server->wpages = (server->wsize + PAGE_SIZE - 1) >> PAGE_SHIFT;
787 
788 	server->wtmult = nfs_block_bits(fsinfo->wtmult, NULL);
789 
790 	server->dtsize = nfs_block_size(fsinfo->dtpref, NULL);
791 	if (server->dtsize > NFS_MAX_FILE_IO_SIZE)
792 		server->dtsize = NFS_MAX_FILE_IO_SIZE;
793 	if (server->dtsize > server->rsize)
794 		server->dtsize = server->rsize;
795 
796 	if (server->flags & NFS_MOUNT_NOAC) {
797 		server->acregmin = server->acregmax = 0;
798 		server->acdirmin = server->acdirmax = 0;
799 	}
800 
801 	server->maxfilesize = fsinfo->maxfilesize;
802 
803 	server->time_delta = fsinfo->time_delta;
804 	server->change_attr_type = fsinfo->change_attr_type;
805 
806 	server->clone_blksize = fsinfo->clone_blksize;
807 	/* We're airborne Set socket buffersize */
808 	rpc_setbufsize(server->client, server->wsize + 100, server->rsize + 100);
809 
810 #ifdef CONFIG_NFS_V4_2
811 	/*
812 	 * Defaults until limited by the session parameters.
813 	 */
814 	server->gxasize = min_t(unsigned int, raw_max_rpc_payload,
815 				XATTR_SIZE_MAX);
816 	server->sxasize = min_t(unsigned int, raw_max_rpc_payload,
817 				XATTR_SIZE_MAX);
818 	server->lxasize = min_t(unsigned int, raw_max_rpc_payload,
819 				nfs42_listxattr_xdrsize(XATTR_LIST_MAX));
820 
821 	if (fsinfo->xattr_support)
822 		server->caps |= NFS_CAP_XATTR;
823 #endif
824 }
825 
826 /*
827  * Probe filesystem information, including the FSID on v2/v3
828  */
829 int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *mntfh, struct nfs_fattr *fattr)
830 {
831 	struct nfs_fsinfo fsinfo;
832 	struct nfs_client *clp = server->nfs_client;
833 	int error;
834 
835 	if (clp->rpc_ops->set_capabilities != NULL) {
836 		error = clp->rpc_ops->set_capabilities(server, mntfh);
837 		if (error < 0)
838 			return error;
839 	}
840 
841 	fsinfo.fattr = fattr;
842 	fsinfo.nlayouttypes = 0;
843 	memset(fsinfo.layouttype, 0, sizeof(fsinfo.layouttype));
844 	error = clp->rpc_ops->fsinfo(server, mntfh, &fsinfo);
845 	if (error < 0)
846 		return error;
847 
848 	nfs_server_set_fsinfo(server, &fsinfo);
849 
850 	/* Get some general file system info */
851 	if (server->namelen == 0) {
852 		struct nfs_pathconf pathinfo;
853 
854 		pathinfo.fattr = fattr;
855 		nfs_fattr_init(fattr);
856 
857 		if (clp->rpc_ops->pathconf(server, mntfh, &pathinfo) >= 0)
858 			server->namelen = pathinfo.max_namelen;
859 	}
860 
861 	return 0;
862 }
863 EXPORT_SYMBOL_GPL(nfs_probe_fsinfo);
864 
865 /*
866  * Copy useful information when duplicating a server record
867  */
868 void nfs_server_copy_userdata(struct nfs_server *target, struct nfs_server *source)
869 {
870 	target->flags = source->flags;
871 	target->rsize = source->rsize;
872 	target->wsize = source->wsize;
873 	target->acregmin = source->acregmin;
874 	target->acregmax = source->acregmax;
875 	target->acdirmin = source->acdirmin;
876 	target->acdirmax = source->acdirmax;
877 	target->caps = source->caps;
878 	target->options = source->options;
879 	target->auth_info = source->auth_info;
880 	target->port = source->port;
881 }
882 EXPORT_SYMBOL_GPL(nfs_server_copy_userdata);
883 
884 void nfs_server_insert_lists(struct nfs_server *server)
885 {
886 	struct nfs_client *clp = server->nfs_client;
887 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
888 
889 	spin_lock(&nn->nfs_client_lock);
890 	list_add_tail_rcu(&server->client_link, &clp->cl_superblocks);
891 	list_add_tail(&server->master_link, &nn->nfs_volume_list);
892 	clear_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
893 	spin_unlock(&nn->nfs_client_lock);
894 
895 }
896 EXPORT_SYMBOL_GPL(nfs_server_insert_lists);
897 
898 void nfs_server_remove_lists(struct nfs_server *server)
899 {
900 	struct nfs_client *clp = server->nfs_client;
901 	struct nfs_net *nn;
902 
903 	if (clp == NULL)
904 		return;
905 	nn = net_generic(clp->cl_net, nfs_net_id);
906 	spin_lock(&nn->nfs_client_lock);
907 	list_del_rcu(&server->client_link);
908 	if (list_empty(&clp->cl_superblocks))
909 		set_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
910 	list_del(&server->master_link);
911 	spin_unlock(&nn->nfs_client_lock);
912 
913 	synchronize_rcu();
914 }
915 EXPORT_SYMBOL_GPL(nfs_server_remove_lists);
916 
917 /*
918  * Allocate and initialise a server record
919  */
920 struct nfs_server *nfs_alloc_server(void)
921 {
922 	struct nfs_server *server;
923 
924 	server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
925 	if (!server)
926 		return NULL;
927 
928 	server->client = server->client_acl = ERR_PTR(-EINVAL);
929 
930 	/* Zero out the NFS state stuff */
931 	INIT_LIST_HEAD(&server->client_link);
932 	INIT_LIST_HEAD(&server->master_link);
933 	INIT_LIST_HEAD(&server->delegations);
934 	INIT_LIST_HEAD(&server->layouts);
935 	INIT_LIST_HEAD(&server->state_owners_lru);
936 	INIT_LIST_HEAD(&server->ss_copies);
937 
938 	atomic_set(&server->active, 0);
939 
940 	server->io_stats = nfs_alloc_iostats();
941 	if (!server->io_stats) {
942 		kfree(server);
943 		return NULL;
944 	}
945 
946 	server->change_attr_type = NFS4_CHANGE_TYPE_IS_UNDEFINED;
947 
948 	ida_init(&server->openowner_id);
949 	ida_init(&server->lockowner_id);
950 	pnfs_init_server(server);
951 	rpc_init_wait_queue(&server->uoc_rpcwaitq, "NFS UOC");
952 
953 	return server;
954 }
955 EXPORT_SYMBOL_GPL(nfs_alloc_server);
956 
957 /*
958  * Free up a server record
959  */
960 void nfs_free_server(struct nfs_server *server)
961 {
962 	nfs_server_remove_lists(server);
963 
964 	if (server->destroy != NULL)
965 		server->destroy(server);
966 
967 	if (!IS_ERR(server->client_acl))
968 		rpc_shutdown_client(server->client_acl);
969 	if (!IS_ERR(server->client))
970 		rpc_shutdown_client(server->client);
971 
972 	nfs_put_client(server->nfs_client);
973 
974 	ida_destroy(&server->lockowner_id);
975 	ida_destroy(&server->openowner_id);
976 	nfs_free_iostats(server->io_stats);
977 	put_cred(server->cred);
978 	kfree(server);
979 	nfs_release_automount_timer();
980 }
981 EXPORT_SYMBOL_GPL(nfs_free_server);
982 
983 /*
984  * Create a version 2 or 3 volume record
985  * - keyed on server and FSID
986  */
987 struct nfs_server *nfs_create_server(struct fs_context *fc)
988 {
989 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
990 	struct nfs_server *server;
991 	struct nfs_fattr *fattr;
992 	int error;
993 
994 	server = nfs_alloc_server();
995 	if (!server)
996 		return ERR_PTR(-ENOMEM);
997 
998 	server->cred = get_cred(fc->cred);
999 
1000 	error = -ENOMEM;
1001 	fattr = nfs_alloc_fattr();
1002 	if (fattr == NULL)
1003 		goto error;
1004 
1005 	/* Get a client representation */
1006 	error = nfs_init_server(server, fc);
1007 	if (error < 0)
1008 		goto error;
1009 
1010 	/* Probe the root fh to retrieve its FSID */
1011 	error = nfs_probe_fsinfo(server, ctx->mntfh, fattr);
1012 	if (error < 0)
1013 		goto error;
1014 	if (server->nfs_client->rpc_ops->version == 3) {
1015 		if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN)
1016 			server->namelen = NFS3_MAXNAMLEN;
1017 		if (!(ctx->flags & NFS_MOUNT_NORDIRPLUS))
1018 			server->caps |= NFS_CAP_READDIRPLUS;
1019 	} else {
1020 		if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN)
1021 			server->namelen = NFS2_MAXNAMLEN;
1022 	}
1023 
1024 	if (!(fattr->valid & NFS_ATTR_FATTR)) {
1025 		error = ctx->nfs_mod->rpc_ops->getattr(server, ctx->mntfh,
1026 						       fattr, NULL, NULL);
1027 		if (error < 0) {
1028 			dprintk("nfs_create_server: getattr error = %d\n", -error);
1029 			goto error;
1030 		}
1031 	}
1032 	memcpy(&server->fsid, &fattr->fsid, sizeof(server->fsid));
1033 
1034 	dprintk("Server FSID: %llx:%llx\n",
1035 		(unsigned long long) server->fsid.major,
1036 		(unsigned long long) server->fsid.minor);
1037 
1038 	nfs_server_insert_lists(server);
1039 	server->mount_time = jiffies;
1040 	nfs_free_fattr(fattr);
1041 	return server;
1042 
1043 error:
1044 	nfs_free_fattr(fattr);
1045 	nfs_free_server(server);
1046 	return ERR_PTR(error);
1047 }
1048 EXPORT_SYMBOL_GPL(nfs_create_server);
1049 
1050 /*
1051  * Clone an NFS2, NFS3 or NFS4 server record
1052  */
1053 struct nfs_server *nfs_clone_server(struct nfs_server *source,
1054 				    struct nfs_fh *fh,
1055 				    struct nfs_fattr *fattr,
1056 				    rpc_authflavor_t flavor)
1057 {
1058 	struct nfs_server *server;
1059 	struct nfs_fattr *fattr_fsinfo;
1060 	int error;
1061 
1062 	server = nfs_alloc_server();
1063 	if (!server)
1064 		return ERR_PTR(-ENOMEM);
1065 
1066 	server->cred = get_cred(source->cred);
1067 
1068 	error = -ENOMEM;
1069 	fattr_fsinfo = nfs_alloc_fattr();
1070 	if (fattr_fsinfo == NULL)
1071 		goto out_free_server;
1072 
1073 	/* Copy data from the source */
1074 	server->nfs_client = source->nfs_client;
1075 	server->destroy = source->destroy;
1076 	refcount_inc(&server->nfs_client->cl_count);
1077 	nfs_server_copy_userdata(server, source);
1078 
1079 	server->fsid = fattr->fsid;
1080 
1081 	error = nfs_init_server_rpcclient(server,
1082 			source->client->cl_timeout,
1083 			flavor);
1084 	if (error < 0)
1085 		goto out_free_server;
1086 
1087 	/* probe the filesystem info for this server filesystem */
1088 	error = nfs_probe_fsinfo(server, fh, fattr_fsinfo);
1089 	if (error < 0)
1090 		goto out_free_server;
1091 
1092 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1093 		server->namelen = NFS4_MAXNAMLEN;
1094 
1095 	error = nfs_start_lockd(server);
1096 	if (error < 0)
1097 		goto out_free_server;
1098 
1099 	nfs_server_insert_lists(server);
1100 	server->mount_time = jiffies;
1101 
1102 	nfs_free_fattr(fattr_fsinfo);
1103 	return server;
1104 
1105 out_free_server:
1106 	nfs_free_fattr(fattr_fsinfo);
1107 	nfs_free_server(server);
1108 	return ERR_PTR(error);
1109 }
1110 EXPORT_SYMBOL_GPL(nfs_clone_server);
1111 
1112 void nfs_clients_init(struct net *net)
1113 {
1114 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1115 
1116 	INIT_LIST_HEAD(&nn->nfs_client_list);
1117 	INIT_LIST_HEAD(&nn->nfs_volume_list);
1118 #if IS_ENABLED(CONFIG_NFS_V4)
1119 	idr_init(&nn->cb_ident_idr);
1120 #endif
1121 	spin_lock_init(&nn->nfs_client_lock);
1122 	nn->boot_time = ktime_get_real();
1123 
1124 	nfs_netns_sysfs_setup(nn, net);
1125 }
1126 
1127 void nfs_clients_exit(struct net *net)
1128 {
1129 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1130 
1131 	nfs_netns_sysfs_destroy(nn);
1132 	nfs_cleanup_cb_ident_idr(net);
1133 	WARN_ON_ONCE(!list_empty(&nn->nfs_client_list));
1134 	WARN_ON_ONCE(!list_empty(&nn->nfs_volume_list));
1135 }
1136 
1137 #ifdef CONFIG_PROC_FS
1138 static void *nfs_server_list_start(struct seq_file *p, loff_t *pos);
1139 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos);
1140 static void nfs_server_list_stop(struct seq_file *p, void *v);
1141 static int nfs_server_list_show(struct seq_file *m, void *v);
1142 
1143 static const struct seq_operations nfs_server_list_ops = {
1144 	.start	= nfs_server_list_start,
1145 	.next	= nfs_server_list_next,
1146 	.stop	= nfs_server_list_stop,
1147 	.show	= nfs_server_list_show,
1148 };
1149 
1150 static void *nfs_volume_list_start(struct seq_file *p, loff_t *pos);
1151 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos);
1152 static void nfs_volume_list_stop(struct seq_file *p, void *v);
1153 static int nfs_volume_list_show(struct seq_file *m, void *v);
1154 
1155 static const struct seq_operations nfs_volume_list_ops = {
1156 	.start	= nfs_volume_list_start,
1157 	.next	= nfs_volume_list_next,
1158 	.stop	= nfs_volume_list_stop,
1159 	.show	= nfs_volume_list_show,
1160 };
1161 
1162 /*
1163  * set up the iterator to start reading from the server list and return the first item
1164  */
1165 static void *nfs_server_list_start(struct seq_file *m, loff_t *_pos)
1166 				__acquires(&nn->nfs_client_lock)
1167 {
1168 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1169 
1170 	/* lock the list against modification */
1171 	spin_lock(&nn->nfs_client_lock);
1172 	return seq_list_start_head(&nn->nfs_client_list, *_pos);
1173 }
1174 
1175 /*
1176  * move to next server
1177  */
1178 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos)
1179 {
1180 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1181 
1182 	return seq_list_next(v, &nn->nfs_client_list, pos);
1183 }
1184 
1185 /*
1186  * clean up after reading from the transports list
1187  */
1188 static void nfs_server_list_stop(struct seq_file *p, void *v)
1189 				__releases(&nn->nfs_client_lock)
1190 {
1191 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1192 
1193 	spin_unlock(&nn->nfs_client_lock);
1194 }
1195 
1196 /*
1197  * display a header line followed by a load of call lines
1198  */
1199 static int nfs_server_list_show(struct seq_file *m, void *v)
1200 {
1201 	struct nfs_client *clp;
1202 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1203 
1204 	/* display header on line 1 */
1205 	if (v == &nn->nfs_client_list) {
1206 		seq_puts(m, "NV SERVER   PORT USE HOSTNAME\n");
1207 		return 0;
1208 	}
1209 
1210 	/* display one transport per line on subsequent lines */
1211 	clp = list_entry(v, struct nfs_client, cl_share_link);
1212 
1213 	/* Check if the client is initialized */
1214 	if (clp->cl_cons_state != NFS_CS_READY)
1215 		return 0;
1216 
1217 	rcu_read_lock();
1218 	seq_printf(m, "v%u %s %s %3d %s\n",
1219 		   clp->rpc_ops->version,
1220 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1221 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1222 		   refcount_read(&clp->cl_count),
1223 		   clp->cl_hostname);
1224 	rcu_read_unlock();
1225 
1226 	return 0;
1227 }
1228 
1229 /*
1230  * set up the iterator to start reading from the volume list and return the first item
1231  */
1232 static void *nfs_volume_list_start(struct seq_file *m, loff_t *_pos)
1233 				__acquires(&nn->nfs_client_lock)
1234 {
1235 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1236 
1237 	/* lock the list against modification */
1238 	spin_lock(&nn->nfs_client_lock);
1239 	return seq_list_start_head(&nn->nfs_volume_list, *_pos);
1240 }
1241 
1242 /*
1243  * move to next volume
1244  */
1245 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos)
1246 {
1247 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1248 
1249 	return seq_list_next(v, &nn->nfs_volume_list, pos);
1250 }
1251 
1252 /*
1253  * clean up after reading from the transports list
1254  */
1255 static void nfs_volume_list_stop(struct seq_file *p, void *v)
1256 				__releases(&nn->nfs_client_lock)
1257 {
1258 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1259 
1260 	spin_unlock(&nn->nfs_client_lock);
1261 }
1262 
1263 /*
1264  * display a header line followed by a load of call lines
1265  */
1266 static int nfs_volume_list_show(struct seq_file *m, void *v)
1267 {
1268 	struct nfs_server *server;
1269 	struct nfs_client *clp;
1270 	char dev[13];	// 8 for 2^24, 1 for ':', 3 for 2^8, 1 for '\0'
1271 	char fsid[34];	// 2 * 16 for %llx, 1 for ':', 1 for '\0'
1272 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1273 
1274 	/* display header on line 1 */
1275 	if (v == &nn->nfs_volume_list) {
1276 		seq_puts(m, "NV SERVER   PORT DEV          FSID"
1277 			    "                              FSC\n");
1278 		return 0;
1279 	}
1280 	/* display one transport per line on subsequent lines */
1281 	server = list_entry(v, struct nfs_server, master_link);
1282 	clp = server->nfs_client;
1283 
1284 	snprintf(dev, sizeof(dev), "%u:%u",
1285 		 MAJOR(server->s_dev), MINOR(server->s_dev));
1286 
1287 	snprintf(fsid, sizeof(fsid), "%llx:%llx",
1288 		 (unsigned long long) server->fsid.major,
1289 		 (unsigned long long) server->fsid.minor);
1290 
1291 	rcu_read_lock();
1292 	seq_printf(m, "v%u %s %s %-12s %-33s %s\n",
1293 		   clp->rpc_ops->version,
1294 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1295 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1296 		   dev,
1297 		   fsid,
1298 		   nfs_server_fscache_state(server));
1299 	rcu_read_unlock();
1300 
1301 	return 0;
1302 }
1303 
1304 int nfs_fs_proc_net_init(struct net *net)
1305 {
1306 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1307 	struct proc_dir_entry *p;
1308 
1309 	nn->proc_nfsfs = proc_net_mkdir(net, "nfsfs", net->proc_net);
1310 	if (!nn->proc_nfsfs)
1311 		goto error_0;
1312 
1313 	/* a file of servers with which we're dealing */
1314 	p = proc_create_net("servers", S_IFREG|S_IRUGO, nn->proc_nfsfs,
1315 			&nfs_server_list_ops, sizeof(struct seq_net_private));
1316 	if (!p)
1317 		goto error_1;
1318 
1319 	/* a file of volumes that we have mounted */
1320 	p = proc_create_net("volumes", S_IFREG|S_IRUGO, nn->proc_nfsfs,
1321 			&nfs_volume_list_ops, sizeof(struct seq_net_private));
1322 	if (!p)
1323 		goto error_1;
1324 	return 0;
1325 
1326 error_1:
1327 	remove_proc_subtree("nfsfs", net->proc_net);
1328 error_0:
1329 	return -ENOMEM;
1330 }
1331 
1332 void nfs_fs_proc_net_exit(struct net *net)
1333 {
1334 	remove_proc_subtree("nfsfs", net->proc_net);
1335 }
1336 
1337 /*
1338  * initialise the /proc/fs/nfsfs/ directory
1339  */
1340 int __init nfs_fs_proc_init(void)
1341 {
1342 	if (!proc_mkdir("fs/nfsfs", NULL))
1343 		goto error_0;
1344 
1345 	/* a file of servers with which we're dealing */
1346 	if (!proc_symlink("fs/nfsfs/servers", NULL, "../../net/nfsfs/servers"))
1347 		goto error_1;
1348 
1349 	/* a file of volumes that we have mounted */
1350 	if (!proc_symlink("fs/nfsfs/volumes", NULL, "../../net/nfsfs/volumes"))
1351 		goto error_1;
1352 
1353 	return 0;
1354 error_1:
1355 	remove_proc_subtree("fs/nfsfs", NULL);
1356 error_0:
1357 	return -ENOMEM;
1358 }
1359 
1360 /*
1361  * clean up the /proc/fs/nfsfs/ directory
1362  */
1363 void nfs_fs_proc_exit(void)
1364 {
1365 	remove_proc_subtree("fs/nfsfs", NULL);
1366 }
1367 
1368 #endif /* CONFIG_PROC_FS */
1369