xref: /linux/fs/nfs/client.c (revision 9052e9c95d908d6c3d7570aadc8898e1d871c8bb)
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_max_connect = cl_init->max_connect ? cl_init->max_connect : 1;
183 	clp->cl_net = get_net(cl_init->net);
184 
185 	clp->cl_principal = "*";
186 	nfs_fscache_get_client_cookie(clp);
187 
188 	return clp;
189 
190 error_cleanup:
191 	put_nfs_version(clp->cl_nfs_mod);
192 error_dealloc:
193 	kfree(clp);
194 error_0:
195 	return ERR_PTR(err);
196 }
197 EXPORT_SYMBOL_GPL(nfs_alloc_client);
198 
199 #if IS_ENABLED(CONFIG_NFS_V4)
200 static void nfs_cleanup_cb_ident_idr(struct net *net)
201 {
202 	struct nfs_net *nn = net_generic(net, nfs_net_id);
203 
204 	idr_destroy(&nn->cb_ident_idr);
205 }
206 
207 /* nfs_client_lock held */
208 static void nfs_cb_idr_remove_locked(struct nfs_client *clp)
209 {
210 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
211 
212 	if (clp->cl_cb_ident)
213 		idr_remove(&nn->cb_ident_idr, clp->cl_cb_ident);
214 }
215 
216 static void pnfs_init_server(struct nfs_server *server)
217 {
218 	rpc_init_wait_queue(&server->roc_rpcwaitq, "pNFS ROC");
219 }
220 
221 #else
222 static void nfs_cleanup_cb_ident_idr(struct net *net)
223 {
224 }
225 
226 static void nfs_cb_idr_remove_locked(struct nfs_client *clp)
227 {
228 }
229 
230 static void pnfs_init_server(struct nfs_server *server)
231 {
232 }
233 
234 #endif /* CONFIG_NFS_V4 */
235 
236 /*
237  * Destroy a shared client record
238  */
239 void nfs_free_client(struct nfs_client *clp)
240 {
241 	nfs_fscache_release_client_cookie(clp);
242 
243 	/* -EIO all pending I/O */
244 	if (!IS_ERR(clp->cl_rpcclient))
245 		rpc_shutdown_client(clp->cl_rpcclient);
246 
247 	put_net(clp->cl_net);
248 	put_nfs_version(clp->cl_nfs_mod);
249 	kfree(clp->cl_hostname);
250 	kfree(clp->cl_acceptor);
251 	kfree(clp);
252 }
253 EXPORT_SYMBOL_GPL(nfs_free_client);
254 
255 /*
256  * Release a reference to a shared client record
257  */
258 void nfs_put_client(struct nfs_client *clp)
259 {
260 	struct nfs_net *nn;
261 
262 	if (!clp)
263 		return;
264 
265 	nn = net_generic(clp->cl_net, nfs_net_id);
266 
267 	if (refcount_dec_and_lock(&clp->cl_count, &nn->nfs_client_lock)) {
268 		list_del(&clp->cl_share_link);
269 		nfs_cb_idr_remove_locked(clp);
270 		spin_unlock(&nn->nfs_client_lock);
271 
272 		WARN_ON_ONCE(!list_empty(&clp->cl_superblocks));
273 
274 		clp->rpc_ops->free_client(clp);
275 	}
276 }
277 EXPORT_SYMBOL_GPL(nfs_put_client);
278 
279 /*
280  * Find an nfs_client on the list that matches the initialisation data
281  * that is supplied.
282  */
283 static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *data)
284 {
285 	struct nfs_client *clp;
286 	const struct sockaddr *sap = data->addr;
287 	struct nfs_net *nn = net_generic(data->net, nfs_net_id);
288 	int error;
289 
290 again:
291 	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
292 	        const struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
293 		/* Don't match clients that failed to initialise properly */
294 		if (clp->cl_cons_state < 0)
295 			continue;
296 
297 		/* If a client is still initializing then we need to wait */
298 		if (clp->cl_cons_state > NFS_CS_READY) {
299 			refcount_inc(&clp->cl_count);
300 			spin_unlock(&nn->nfs_client_lock);
301 			error = nfs_wait_client_init_complete(clp);
302 			nfs_put_client(clp);
303 			spin_lock(&nn->nfs_client_lock);
304 			if (error < 0)
305 				return ERR_PTR(error);
306 			goto again;
307 		}
308 
309 		/* Different NFS versions cannot share the same nfs_client */
310 		if (clp->rpc_ops != data->nfs_mod->rpc_ops)
311 			continue;
312 
313 		if (clp->cl_proto != data->proto)
314 			continue;
315 		/* Match nfsv4 minorversion */
316 		if (clp->cl_minorversion != data->minorversion)
317 			continue;
318 
319 		/* Match request for a dedicated DS */
320 		if (test_bit(NFS_CS_DS, &data->init_flags) !=
321 		    test_bit(NFS_CS_DS, &clp->cl_flags))
322 			continue;
323 
324 		/* Match the full socket address */
325 		if (!rpc_cmp_addr_port(sap, clap))
326 			/* Match all xprt_switch full socket addresses */
327 			if (IS_ERR(clp->cl_rpcclient) ||
328                             !rpc_clnt_xprt_switch_has_addr(clp->cl_rpcclient,
329 							   sap))
330 				continue;
331 
332 		refcount_inc(&clp->cl_count);
333 		return clp;
334 	}
335 	return NULL;
336 }
337 
338 /*
339  * Return true if @clp is done initializing, false if still working on it.
340  *
341  * Use nfs_client_init_status to check if it was successful.
342  */
343 bool nfs_client_init_is_complete(const struct nfs_client *clp)
344 {
345 	return clp->cl_cons_state <= NFS_CS_READY;
346 }
347 EXPORT_SYMBOL_GPL(nfs_client_init_is_complete);
348 
349 /*
350  * Return 0 if @clp was successfully initialized, -errno otherwise.
351  *
352  * This must be called *after* nfs_client_init_is_complete() returns true,
353  * otherwise it will pop WARN_ON_ONCE and return -EINVAL
354  */
355 int nfs_client_init_status(const struct nfs_client *clp)
356 {
357 	/* called without checking nfs_client_init_is_complete */
358 	if (clp->cl_cons_state > NFS_CS_READY) {
359 		WARN_ON_ONCE(1);
360 		return -EINVAL;
361 	}
362 	return clp->cl_cons_state;
363 }
364 EXPORT_SYMBOL_GPL(nfs_client_init_status);
365 
366 int nfs_wait_client_init_complete(const struct nfs_client *clp)
367 {
368 	return wait_event_killable(nfs_client_active_wq,
369 			nfs_client_init_is_complete(clp));
370 }
371 EXPORT_SYMBOL_GPL(nfs_wait_client_init_complete);
372 
373 /*
374  * Found an existing client.  Make sure it's ready before returning.
375  */
376 static struct nfs_client *
377 nfs_found_client(const struct nfs_client_initdata *cl_init,
378 		 struct nfs_client *clp)
379 {
380 	int error;
381 
382 	error = nfs_wait_client_init_complete(clp);
383 	if (error < 0) {
384 		nfs_put_client(clp);
385 		return ERR_PTR(-ERESTARTSYS);
386 	}
387 
388 	if (clp->cl_cons_state < NFS_CS_READY) {
389 		error = clp->cl_cons_state;
390 		nfs_put_client(clp);
391 		return ERR_PTR(error);
392 	}
393 
394 	smp_rmb();
395 	return clp;
396 }
397 
398 /*
399  * Look up a client by IP address and protocol version
400  * - creates a new record if one doesn't yet exist
401  */
402 struct nfs_client *nfs_get_client(const struct nfs_client_initdata *cl_init)
403 {
404 	struct nfs_client *clp, *new = NULL;
405 	struct nfs_net *nn = net_generic(cl_init->net, nfs_net_id);
406 	const struct nfs_rpc_ops *rpc_ops = cl_init->nfs_mod->rpc_ops;
407 
408 	if (cl_init->hostname == NULL) {
409 		WARN_ON(1);
410 		return ERR_PTR(-EINVAL);
411 	}
412 
413 	/* see if the client already exists */
414 	do {
415 		spin_lock(&nn->nfs_client_lock);
416 
417 		clp = nfs_match_client(cl_init);
418 		if (clp) {
419 			spin_unlock(&nn->nfs_client_lock);
420 			if (new)
421 				new->rpc_ops->free_client(new);
422 			if (IS_ERR(clp))
423 				return clp;
424 			return nfs_found_client(cl_init, clp);
425 		}
426 		if (new) {
427 			list_add_tail(&new->cl_share_link,
428 					&nn->nfs_client_list);
429 			spin_unlock(&nn->nfs_client_lock);
430 			new->cl_flags = cl_init->init_flags;
431 			return rpc_ops->init_client(new, cl_init);
432 		}
433 
434 		spin_unlock(&nn->nfs_client_lock);
435 
436 		new = rpc_ops->alloc_client(cl_init);
437 	} while (!IS_ERR(new));
438 
439 	return new;
440 }
441 EXPORT_SYMBOL_GPL(nfs_get_client);
442 
443 /*
444  * Mark a server as ready or failed
445  */
446 void nfs_mark_client_ready(struct nfs_client *clp, int state)
447 {
448 	smp_wmb();
449 	clp->cl_cons_state = state;
450 	wake_up_all(&nfs_client_active_wq);
451 }
452 EXPORT_SYMBOL_GPL(nfs_mark_client_ready);
453 
454 /*
455  * Initialise the timeout values for a connection
456  */
457 void nfs_init_timeout_values(struct rpc_timeout *to, int proto,
458 				    int timeo, int retrans)
459 {
460 	to->to_initval = timeo * HZ / 10;
461 	to->to_retries = retrans;
462 
463 	switch (proto) {
464 	case XPRT_TRANSPORT_TCP:
465 	case XPRT_TRANSPORT_RDMA:
466 		if (retrans == NFS_UNSPEC_RETRANS)
467 			to->to_retries = NFS_DEF_TCP_RETRANS;
468 		if (timeo == NFS_UNSPEC_TIMEO || to->to_initval == 0)
469 			to->to_initval = NFS_DEF_TCP_TIMEO * HZ / 10;
470 		if (to->to_initval > NFS_MAX_TCP_TIMEOUT)
471 			to->to_initval = NFS_MAX_TCP_TIMEOUT;
472 		to->to_increment = to->to_initval;
473 		to->to_maxval = to->to_initval + (to->to_increment * to->to_retries);
474 		if (to->to_maxval > NFS_MAX_TCP_TIMEOUT)
475 			to->to_maxval = NFS_MAX_TCP_TIMEOUT;
476 		if (to->to_maxval < to->to_initval)
477 			to->to_maxval = to->to_initval;
478 		to->to_exponential = 0;
479 		break;
480 	case XPRT_TRANSPORT_UDP:
481 		if (retrans == NFS_UNSPEC_RETRANS)
482 			to->to_retries = NFS_DEF_UDP_RETRANS;
483 		if (timeo == NFS_UNSPEC_TIMEO || to->to_initval == 0)
484 			to->to_initval = NFS_DEF_UDP_TIMEO * HZ / 10;
485 		if (to->to_initval > NFS_MAX_UDP_TIMEOUT)
486 			to->to_initval = NFS_MAX_UDP_TIMEOUT;
487 		to->to_maxval = NFS_MAX_UDP_TIMEOUT;
488 		to->to_exponential = 1;
489 		break;
490 	default:
491 		BUG();
492 	}
493 }
494 EXPORT_SYMBOL_GPL(nfs_init_timeout_values);
495 
496 /*
497  * Create an RPC client handle
498  */
499 int nfs_create_rpc_client(struct nfs_client *clp,
500 			  const struct nfs_client_initdata *cl_init,
501 			  rpc_authflavor_t flavor)
502 {
503 	struct rpc_clnt		*clnt = NULL;
504 	struct rpc_create_args args = {
505 		.net		= clp->cl_net,
506 		.protocol	= clp->cl_proto,
507 		.nconnect	= clp->cl_nconnect,
508 		.address	= (struct sockaddr *)&clp->cl_addr,
509 		.addrsize	= clp->cl_addrlen,
510 		.timeout	= cl_init->timeparms,
511 		.servername	= clp->cl_hostname,
512 		.nodename	= cl_init->nodename,
513 		.program	= &nfs_program,
514 		.version	= clp->rpc_ops->version,
515 		.authflavor	= flavor,
516 		.cred		= cl_init->cred,
517 	};
518 
519 	if (test_bit(NFS_CS_DISCRTRY, &clp->cl_flags))
520 		args.flags |= RPC_CLNT_CREATE_DISCRTRY;
521 	if (test_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags))
522 		args.flags |= RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT;
523 	if (test_bit(NFS_CS_NORESVPORT, &clp->cl_flags))
524 		args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
525 	if (test_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags))
526 		args.flags |= RPC_CLNT_CREATE_INFINITE_SLOTS;
527 	if (test_bit(NFS_CS_NOPING, &clp->cl_flags))
528 		args.flags |= RPC_CLNT_CREATE_NOPING;
529 	if (test_bit(NFS_CS_REUSEPORT, &clp->cl_flags))
530 		args.flags |= RPC_CLNT_CREATE_REUSEPORT;
531 
532 	if (!IS_ERR(clp->cl_rpcclient))
533 		return 0;
534 
535 	clnt = rpc_create(&args);
536 	if (IS_ERR(clnt)) {
537 		dprintk("%s: cannot create RPC client. Error = %ld\n",
538 				__func__, PTR_ERR(clnt));
539 		return PTR_ERR(clnt);
540 	}
541 
542 	clnt->cl_principal = clp->cl_principal;
543 	clp->cl_rpcclient = clnt;
544 	clnt->cl_max_connect = clp->cl_max_connect;
545 	return 0;
546 }
547 EXPORT_SYMBOL_GPL(nfs_create_rpc_client);
548 
549 /*
550  * Version 2 or 3 client destruction
551  */
552 static void nfs_destroy_server(struct nfs_server *server)
553 {
554 	if (server->nlm_host)
555 		nlmclnt_done(server->nlm_host);
556 }
557 
558 /*
559  * Version 2 or 3 lockd setup
560  */
561 static int nfs_start_lockd(struct nfs_server *server)
562 {
563 	struct nlm_host *host;
564 	struct nfs_client *clp = server->nfs_client;
565 	struct nlmclnt_initdata nlm_init = {
566 		.hostname	= clp->cl_hostname,
567 		.address	= (struct sockaddr *)&clp->cl_addr,
568 		.addrlen	= clp->cl_addrlen,
569 		.nfs_version	= clp->rpc_ops->version,
570 		.noresvport	= server->flags & NFS_MOUNT_NORESVPORT ?
571 					1 : 0,
572 		.net		= clp->cl_net,
573 		.nlmclnt_ops 	= clp->cl_nfs_mod->rpc_ops->nlmclnt_ops,
574 		.cred		= server->cred,
575 	};
576 
577 	if (nlm_init.nfs_version > 3)
578 		return 0;
579 	if ((server->flags & NFS_MOUNT_LOCAL_FLOCK) &&
580 			(server->flags & NFS_MOUNT_LOCAL_FCNTL))
581 		return 0;
582 
583 	switch (clp->cl_proto) {
584 		default:
585 			nlm_init.protocol = IPPROTO_TCP;
586 			break;
587 #ifndef CONFIG_NFS_DISABLE_UDP_SUPPORT
588 		case XPRT_TRANSPORT_UDP:
589 			nlm_init.protocol = IPPROTO_UDP;
590 #endif
591 	}
592 
593 	host = nlmclnt_init(&nlm_init);
594 	if (IS_ERR(host))
595 		return PTR_ERR(host);
596 
597 	server->nlm_host = host;
598 	server->destroy = nfs_destroy_server;
599 	return 0;
600 }
601 
602 /*
603  * Create a general RPC client
604  */
605 int nfs_init_server_rpcclient(struct nfs_server *server,
606 		const struct rpc_timeout *timeo,
607 		rpc_authflavor_t pseudoflavour)
608 {
609 	struct nfs_client *clp = server->nfs_client;
610 
611 	server->client = rpc_clone_client_set_auth(clp->cl_rpcclient,
612 							pseudoflavour);
613 	if (IS_ERR(server->client)) {
614 		dprintk("%s: couldn't create rpc_client!\n", __func__);
615 		return PTR_ERR(server->client);
616 	}
617 
618 	memcpy(&server->client->cl_timeout_default,
619 			timeo,
620 			sizeof(server->client->cl_timeout_default));
621 	server->client->cl_timeout = &server->client->cl_timeout_default;
622 	server->client->cl_softrtry = 0;
623 	if (server->flags & NFS_MOUNT_SOFTERR)
624 		server->client->cl_softerr = 1;
625 	if (server->flags & NFS_MOUNT_SOFT)
626 		server->client->cl_softrtry = 1;
627 
628 	return 0;
629 }
630 EXPORT_SYMBOL_GPL(nfs_init_server_rpcclient);
631 
632 /**
633  * nfs_init_client - Initialise an NFS2 or NFS3 client
634  *
635  * @clp: nfs_client to initialise
636  * @cl_init: Initialisation parameters
637  *
638  * Returns pointer to an NFS client, or an ERR_PTR value.
639  */
640 struct nfs_client *nfs_init_client(struct nfs_client *clp,
641 				   const struct nfs_client_initdata *cl_init)
642 {
643 	int error;
644 
645 	/* the client is already initialised */
646 	if (clp->cl_cons_state == NFS_CS_READY)
647 		return clp;
648 
649 	/*
650 	 * Create a client RPC handle for doing FSSTAT with UNIX auth only
651 	 * - RFC 2623, sec 2.3.2
652 	 */
653 	error = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_UNIX);
654 	nfs_mark_client_ready(clp, error == 0 ? NFS_CS_READY : error);
655 	if (error < 0) {
656 		nfs_put_client(clp);
657 		clp = ERR_PTR(error);
658 	}
659 	return clp;
660 }
661 EXPORT_SYMBOL_GPL(nfs_init_client);
662 
663 /*
664  * Create a version 2 or 3 client
665  */
666 static int nfs_init_server(struct nfs_server *server,
667 			   const struct fs_context *fc)
668 {
669 	const struct nfs_fs_context *ctx = nfs_fc2context(fc);
670 	struct rpc_timeout timeparms;
671 	struct nfs_client_initdata cl_init = {
672 		.hostname = ctx->nfs_server.hostname,
673 		.addr = (const struct sockaddr *)&ctx->nfs_server.address,
674 		.addrlen = ctx->nfs_server.addrlen,
675 		.nfs_mod = ctx->nfs_mod,
676 		.proto = ctx->nfs_server.protocol,
677 		.net = fc->net_ns,
678 		.timeparms = &timeparms,
679 		.cred = server->cred,
680 		.nconnect = ctx->nfs_server.nconnect,
681 		.init_flags = (1UL << NFS_CS_REUSEPORT),
682 	};
683 	struct nfs_client *clp;
684 	int error;
685 
686 	nfs_init_timeout_values(&timeparms, ctx->nfs_server.protocol,
687 				ctx->timeo, ctx->retrans);
688 	if (ctx->flags & NFS_MOUNT_NORESVPORT)
689 		set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
690 
691 	/* Allocate or find a client reference we can use */
692 	clp = nfs_get_client(&cl_init);
693 	if (IS_ERR(clp))
694 		return PTR_ERR(clp);
695 
696 	server->nfs_client = clp;
697 
698 	/* Initialise the client representation from the mount data */
699 	server->flags = ctx->flags;
700 	server->options = ctx->options;
701 	server->caps |= NFS_CAP_HARDLINKS | NFS_CAP_SYMLINKS;
702 
703 	switch (clp->rpc_ops->version) {
704 	case 2:
705 		server->fattr_valid = NFS_ATTR_FATTR_V2;
706 		break;
707 	case 3:
708 		server->fattr_valid = NFS_ATTR_FATTR_V3;
709 		break;
710 	default:
711 		server->fattr_valid = NFS_ATTR_FATTR_V4;
712 	}
713 
714 	if (ctx->rsize)
715 		server->rsize = nfs_block_size(ctx->rsize, NULL);
716 	if (ctx->wsize)
717 		server->wsize = nfs_block_size(ctx->wsize, NULL);
718 
719 	server->acregmin = ctx->acregmin * HZ;
720 	server->acregmax = ctx->acregmax * HZ;
721 	server->acdirmin = ctx->acdirmin * HZ;
722 	server->acdirmax = ctx->acdirmax * HZ;
723 
724 	/* Start lockd here, before we might error out */
725 	error = nfs_start_lockd(server);
726 	if (error < 0)
727 		goto error;
728 
729 	server->port = ctx->nfs_server.port;
730 	server->auth_info = ctx->auth_info;
731 
732 	error = nfs_init_server_rpcclient(server, &timeparms,
733 					  ctx->selected_flavor);
734 	if (error < 0)
735 		goto error;
736 
737 	/* Preserve the values of mount_server-related mount options */
738 	if (ctx->mount_server.addrlen) {
739 		memcpy(&server->mountd_address, &ctx->mount_server.address,
740 			ctx->mount_server.addrlen);
741 		server->mountd_addrlen = ctx->mount_server.addrlen;
742 	}
743 	server->mountd_version = ctx->mount_server.version;
744 	server->mountd_port = ctx->mount_server.port;
745 	server->mountd_protocol = ctx->mount_server.protocol;
746 
747 	server->namelen  = ctx->namlen;
748 	return 0;
749 
750 error:
751 	server->nfs_client = NULL;
752 	nfs_put_client(clp);
753 	return error;
754 }
755 
756 /*
757  * Load up the server record from information gained in an fsinfo record
758  */
759 static void nfs_server_set_fsinfo(struct nfs_server *server,
760 				  struct nfs_fsinfo *fsinfo)
761 {
762 	unsigned long max_rpc_payload, raw_max_rpc_payload;
763 
764 	/* Work out a lot of parameters */
765 	if (server->rsize == 0)
766 		server->rsize = nfs_block_size(fsinfo->rtpref, NULL);
767 	if (server->wsize == 0)
768 		server->wsize = nfs_block_size(fsinfo->wtpref, NULL);
769 
770 	if (fsinfo->rtmax >= 512 && server->rsize > fsinfo->rtmax)
771 		server->rsize = nfs_block_size(fsinfo->rtmax, NULL);
772 	if (fsinfo->wtmax >= 512 && server->wsize > fsinfo->wtmax)
773 		server->wsize = nfs_block_size(fsinfo->wtmax, NULL);
774 
775 	raw_max_rpc_payload = rpc_max_payload(server->client);
776 	max_rpc_payload = nfs_block_size(raw_max_rpc_payload, NULL);
777 
778 	if (server->rsize > max_rpc_payload)
779 		server->rsize = max_rpc_payload;
780 	if (server->rsize > NFS_MAX_FILE_IO_SIZE)
781 		server->rsize = NFS_MAX_FILE_IO_SIZE;
782 	server->rpages = (server->rsize + PAGE_SIZE - 1) >> PAGE_SHIFT;
783 
784 	if (server->wsize > max_rpc_payload)
785 		server->wsize = max_rpc_payload;
786 	if (server->wsize > NFS_MAX_FILE_IO_SIZE)
787 		server->wsize = NFS_MAX_FILE_IO_SIZE;
788 	server->wpages = (server->wsize + PAGE_SIZE - 1) >> PAGE_SHIFT;
789 
790 	server->wtmult = nfs_block_bits(fsinfo->wtmult, NULL);
791 
792 	server->dtsize = nfs_block_size(fsinfo->dtpref, NULL);
793 	if (server->dtsize > NFS_MAX_FILE_IO_SIZE)
794 		server->dtsize = NFS_MAX_FILE_IO_SIZE;
795 	if (server->dtsize > server->rsize)
796 		server->dtsize = server->rsize;
797 
798 	if (server->flags & NFS_MOUNT_NOAC) {
799 		server->acregmin = server->acregmax = 0;
800 		server->acdirmin = server->acdirmax = 0;
801 	}
802 
803 	server->maxfilesize = fsinfo->maxfilesize;
804 
805 	server->time_delta = fsinfo->time_delta;
806 	server->change_attr_type = fsinfo->change_attr_type;
807 
808 	server->clone_blksize = fsinfo->clone_blksize;
809 	/* We're airborne Set socket buffersize */
810 	rpc_setbufsize(server->client, server->wsize + 100, server->rsize + 100);
811 
812 #ifdef CONFIG_NFS_V4_2
813 	/*
814 	 * Defaults until limited by the session parameters.
815 	 */
816 	server->gxasize = min_t(unsigned int, raw_max_rpc_payload,
817 				XATTR_SIZE_MAX);
818 	server->sxasize = min_t(unsigned int, raw_max_rpc_payload,
819 				XATTR_SIZE_MAX);
820 	server->lxasize = min_t(unsigned int, raw_max_rpc_payload,
821 				nfs42_listxattr_xdrsize(XATTR_LIST_MAX));
822 
823 	if (fsinfo->xattr_support)
824 		server->caps |= NFS_CAP_XATTR;
825 #endif
826 }
827 
828 /*
829  * Probe filesystem information, including the FSID on v2/v3
830  */
831 int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *mntfh, struct nfs_fattr *fattr)
832 {
833 	struct nfs_fsinfo fsinfo;
834 	struct nfs_client *clp = server->nfs_client;
835 	int error;
836 
837 	if (clp->rpc_ops->set_capabilities != NULL) {
838 		error = clp->rpc_ops->set_capabilities(server, mntfh);
839 		if (error < 0)
840 			return error;
841 	}
842 
843 	fsinfo.fattr = fattr;
844 	fsinfo.nlayouttypes = 0;
845 	memset(fsinfo.layouttype, 0, sizeof(fsinfo.layouttype));
846 	error = clp->rpc_ops->fsinfo(server, mntfh, &fsinfo);
847 	if (error < 0)
848 		return error;
849 
850 	nfs_server_set_fsinfo(server, &fsinfo);
851 
852 	/* Get some general file system info */
853 	if (server->namelen == 0) {
854 		struct nfs_pathconf pathinfo;
855 
856 		pathinfo.fattr = fattr;
857 		nfs_fattr_init(fattr);
858 
859 		if (clp->rpc_ops->pathconf(server, mntfh, &pathinfo) >= 0)
860 			server->namelen = pathinfo.max_namelen;
861 	}
862 
863 	return 0;
864 }
865 EXPORT_SYMBOL_GPL(nfs_probe_fsinfo);
866 
867 /*
868  * Copy useful information when duplicating a server record
869  */
870 void nfs_server_copy_userdata(struct nfs_server *target, struct nfs_server *source)
871 {
872 	target->flags = source->flags;
873 	target->rsize = source->rsize;
874 	target->wsize = source->wsize;
875 	target->acregmin = source->acregmin;
876 	target->acregmax = source->acregmax;
877 	target->acdirmin = source->acdirmin;
878 	target->acdirmax = source->acdirmax;
879 	target->caps = source->caps;
880 	target->options = source->options;
881 	target->auth_info = source->auth_info;
882 	target->port = source->port;
883 }
884 EXPORT_SYMBOL_GPL(nfs_server_copy_userdata);
885 
886 void nfs_server_insert_lists(struct nfs_server *server)
887 {
888 	struct nfs_client *clp = server->nfs_client;
889 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
890 
891 	spin_lock(&nn->nfs_client_lock);
892 	list_add_tail_rcu(&server->client_link, &clp->cl_superblocks);
893 	list_add_tail(&server->master_link, &nn->nfs_volume_list);
894 	clear_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
895 	spin_unlock(&nn->nfs_client_lock);
896 
897 }
898 EXPORT_SYMBOL_GPL(nfs_server_insert_lists);
899 
900 void nfs_server_remove_lists(struct nfs_server *server)
901 {
902 	struct nfs_client *clp = server->nfs_client;
903 	struct nfs_net *nn;
904 
905 	if (clp == NULL)
906 		return;
907 	nn = net_generic(clp->cl_net, nfs_net_id);
908 	spin_lock(&nn->nfs_client_lock);
909 	list_del_rcu(&server->client_link);
910 	if (list_empty(&clp->cl_superblocks))
911 		set_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
912 	list_del(&server->master_link);
913 	spin_unlock(&nn->nfs_client_lock);
914 
915 	synchronize_rcu();
916 }
917 EXPORT_SYMBOL_GPL(nfs_server_remove_lists);
918 
919 /*
920  * Allocate and initialise a server record
921  */
922 struct nfs_server *nfs_alloc_server(void)
923 {
924 	struct nfs_server *server;
925 
926 	server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
927 	if (!server)
928 		return NULL;
929 
930 	server->client = server->client_acl = ERR_PTR(-EINVAL);
931 
932 	/* Zero out the NFS state stuff */
933 	INIT_LIST_HEAD(&server->client_link);
934 	INIT_LIST_HEAD(&server->master_link);
935 	INIT_LIST_HEAD(&server->delegations);
936 	INIT_LIST_HEAD(&server->layouts);
937 	INIT_LIST_HEAD(&server->state_owners_lru);
938 	INIT_LIST_HEAD(&server->ss_copies);
939 
940 	atomic_set(&server->active, 0);
941 
942 	server->io_stats = nfs_alloc_iostats();
943 	if (!server->io_stats) {
944 		kfree(server);
945 		return NULL;
946 	}
947 
948 	server->change_attr_type = NFS4_CHANGE_TYPE_IS_UNDEFINED;
949 
950 	ida_init(&server->openowner_id);
951 	ida_init(&server->lockowner_id);
952 	pnfs_init_server(server);
953 	rpc_init_wait_queue(&server->uoc_rpcwaitq, "NFS UOC");
954 
955 	return server;
956 }
957 EXPORT_SYMBOL_GPL(nfs_alloc_server);
958 
959 /*
960  * Free up a server record
961  */
962 void nfs_free_server(struct nfs_server *server)
963 {
964 	nfs_server_remove_lists(server);
965 
966 	if (server->destroy != NULL)
967 		server->destroy(server);
968 
969 	if (!IS_ERR(server->client_acl))
970 		rpc_shutdown_client(server->client_acl);
971 	if (!IS_ERR(server->client))
972 		rpc_shutdown_client(server->client);
973 
974 	nfs_put_client(server->nfs_client);
975 
976 	ida_destroy(&server->lockowner_id);
977 	ida_destroy(&server->openowner_id);
978 	nfs_free_iostats(server->io_stats);
979 	put_cred(server->cred);
980 	kfree(server);
981 	nfs_release_automount_timer();
982 }
983 EXPORT_SYMBOL_GPL(nfs_free_server);
984 
985 /*
986  * Create a version 2 or 3 volume record
987  * - keyed on server and FSID
988  */
989 struct nfs_server *nfs_create_server(struct fs_context *fc)
990 {
991 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
992 	struct nfs_server *server;
993 	struct nfs_fattr *fattr;
994 	int error;
995 
996 	server = nfs_alloc_server();
997 	if (!server)
998 		return ERR_PTR(-ENOMEM);
999 
1000 	server->cred = get_cred(fc->cred);
1001 
1002 	error = -ENOMEM;
1003 	fattr = nfs_alloc_fattr();
1004 	if (fattr == NULL)
1005 		goto error;
1006 
1007 	/* Get a client representation */
1008 	error = nfs_init_server(server, fc);
1009 	if (error < 0)
1010 		goto error;
1011 
1012 	/* Probe the root fh to retrieve its FSID */
1013 	error = nfs_probe_fsinfo(server, ctx->mntfh, fattr);
1014 	if (error < 0)
1015 		goto error;
1016 	if (server->nfs_client->rpc_ops->version == 3) {
1017 		if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN)
1018 			server->namelen = NFS3_MAXNAMLEN;
1019 		if (!(ctx->flags & NFS_MOUNT_NORDIRPLUS))
1020 			server->caps |= NFS_CAP_READDIRPLUS;
1021 	} else {
1022 		if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN)
1023 			server->namelen = NFS2_MAXNAMLEN;
1024 	}
1025 
1026 	if (!(fattr->valid & NFS_ATTR_FATTR)) {
1027 		error = ctx->nfs_mod->rpc_ops->getattr(server, ctx->mntfh,
1028 						       fattr, NULL, NULL);
1029 		if (error < 0) {
1030 			dprintk("nfs_create_server: getattr error = %d\n", -error);
1031 			goto error;
1032 		}
1033 	}
1034 	memcpy(&server->fsid, &fattr->fsid, sizeof(server->fsid));
1035 
1036 	dprintk("Server FSID: %llx:%llx\n",
1037 		(unsigned long long) server->fsid.major,
1038 		(unsigned long long) server->fsid.minor);
1039 
1040 	nfs_server_insert_lists(server);
1041 	server->mount_time = jiffies;
1042 	nfs_free_fattr(fattr);
1043 	return server;
1044 
1045 error:
1046 	nfs_free_fattr(fattr);
1047 	nfs_free_server(server);
1048 	return ERR_PTR(error);
1049 }
1050 EXPORT_SYMBOL_GPL(nfs_create_server);
1051 
1052 /*
1053  * Clone an NFS2, NFS3 or NFS4 server record
1054  */
1055 struct nfs_server *nfs_clone_server(struct nfs_server *source,
1056 				    struct nfs_fh *fh,
1057 				    struct nfs_fattr *fattr,
1058 				    rpc_authflavor_t flavor)
1059 {
1060 	struct nfs_server *server;
1061 	struct nfs_fattr *fattr_fsinfo;
1062 	int error;
1063 
1064 	server = nfs_alloc_server();
1065 	if (!server)
1066 		return ERR_PTR(-ENOMEM);
1067 
1068 	server->cred = get_cred(source->cred);
1069 
1070 	error = -ENOMEM;
1071 	fattr_fsinfo = nfs_alloc_fattr();
1072 	if (fattr_fsinfo == NULL)
1073 		goto out_free_server;
1074 
1075 	/* Copy data from the source */
1076 	server->nfs_client = source->nfs_client;
1077 	server->destroy = source->destroy;
1078 	refcount_inc(&server->nfs_client->cl_count);
1079 	nfs_server_copy_userdata(server, source);
1080 
1081 	server->fsid = fattr->fsid;
1082 
1083 	error = nfs_init_server_rpcclient(server,
1084 			source->client->cl_timeout,
1085 			flavor);
1086 	if (error < 0)
1087 		goto out_free_server;
1088 
1089 	/* probe the filesystem info for this server filesystem */
1090 	error = nfs_probe_fsinfo(server, fh, fattr_fsinfo);
1091 	if (error < 0)
1092 		goto out_free_server;
1093 
1094 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1095 		server->namelen = NFS4_MAXNAMLEN;
1096 
1097 	error = nfs_start_lockd(server);
1098 	if (error < 0)
1099 		goto out_free_server;
1100 
1101 	nfs_server_insert_lists(server);
1102 	server->mount_time = jiffies;
1103 
1104 	nfs_free_fattr(fattr_fsinfo);
1105 	return server;
1106 
1107 out_free_server:
1108 	nfs_free_fattr(fattr_fsinfo);
1109 	nfs_free_server(server);
1110 	return ERR_PTR(error);
1111 }
1112 EXPORT_SYMBOL_GPL(nfs_clone_server);
1113 
1114 void nfs_clients_init(struct net *net)
1115 {
1116 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1117 
1118 	INIT_LIST_HEAD(&nn->nfs_client_list);
1119 	INIT_LIST_HEAD(&nn->nfs_volume_list);
1120 #if IS_ENABLED(CONFIG_NFS_V4)
1121 	idr_init(&nn->cb_ident_idr);
1122 #endif
1123 	spin_lock_init(&nn->nfs_client_lock);
1124 	nn->boot_time = ktime_get_real();
1125 
1126 	nfs_netns_sysfs_setup(nn, net);
1127 }
1128 
1129 void nfs_clients_exit(struct net *net)
1130 {
1131 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1132 
1133 	nfs_netns_sysfs_destroy(nn);
1134 	nfs_cleanup_cb_ident_idr(net);
1135 	WARN_ON_ONCE(!list_empty(&nn->nfs_client_list));
1136 	WARN_ON_ONCE(!list_empty(&nn->nfs_volume_list));
1137 }
1138 
1139 #ifdef CONFIG_PROC_FS
1140 static void *nfs_server_list_start(struct seq_file *p, loff_t *pos);
1141 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos);
1142 static void nfs_server_list_stop(struct seq_file *p, void *v);
1143 static int nfs_server_list_show(struct seq_file *m, void *v);
1144 
1145 static const struct seq_operations nfs_server_list_ops = {
1146 	.start	= nfs_server_list_start,
1147 	.next	= nfs_server_list_next,
1148 	.stop	= nfs_server_list_stop,
1149 	.show	= nfs_server_list_show,
1150 };
1151 
1152 static void *nfs_volume_list_start(struct seq_file *p, loff_t *pos);
1153 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos);
1154 static void nfs_volume_list_stop(struct seq_file *p, void *v);
1155 static int nfs_volume_list_show(struct seq_file *m, void *v);
1156 
1157 static const struct seq_operations nfs_volume_list_ops = {
1158 	.start	= nfs_volume_list_start,
1159 	.next	= nfs_volume_list_next,
1160 	.stop	= nfs_volume_list_stop,
1161 	.show	= nfs_volume_list_show,
1162 };
1163 
1164 /*
1165  * set up the iterator to start reading from the server list and return the first item
1166  */
1167 static void *nfs_server_list_start(struct seq_file *m, loff_t *_pos)
1168 				__acquires(&nn->nfs_client_lock)
1169 {
1170 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1171 
1172 	/* lock the list against modification */
1173 	spin_lock(&nn->nfs_client_lock);
1174 	return seq_list_start_head(&nn->nfs_client_list, *_pos);
1175 }
1176 
1177 /*
1178  * move to next server
1179  */
1180 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos)
1181 {
1182 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1183 
1184 	return seq_list_next(v, &nn->nfs_client_list, pos);
1185 }
1186 
1187 /*
1188  * clean up after reading from the transports list
1189  */
1190 static void nfs_server_list_stop(struct seq_file *p, void *v)
1191 				__releases(&nn->nfs_client_lock)
1192 {
1193 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1194 
1195 	spin_unlock(&nn->nfs_client_lock);
1196 }
1197 
1198 /*
1199  * display a header line followed by a load of call lines
1200  */
1201 static int nfs_server_list_show(struct seq_file *m, void *v)
1202 {
1203 	struct nfs_client *clp;
1204 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1205 
1206 	/* display header on line 1 */
1207 	if (v == &nn->nfs_client_list) {
1208 		seq_puts(m, "NV SERVER   PORT USE HOSTNAME\n");
1209 		return 0;
1210 	}
1211 
1212 	/* display one transport per line on subsequent lines */
1213 	clp = list_entry(v, struct nfs_client, cl_share_link);
1214 
1215 	/* Check if the client is initialized */
1216 	if (clp->cl_cons_state != NFS_CS_READY)
1217 		return 0;
1218 
1219 	rcu_read_lock();
1220 	seq_printf(m, "v%u %s %s %3d %s\n",
1221 		   clp->rpc_ops->version,
1222 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1223 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1224 		   refcount_read(&clp->cl_count),
1225 		   clp->cl_hostname);
1226 	rcu_read_unlock();
1227 
1228 	return 0;
1229 }
1230 
1231 /*
1232  * set up the iterator to start reading from the volume list and return the first item
1233  */
1234 static void *nfs_volume_list_start(struct seq_file *m, loff_t *_pos)
1235 				__acquires(&nn->nfs_client_lock)
1236 {
1237 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1238 
1239 	/* lock the list against modification */
1240 	spin_lock(&nn->nfs_client_lock);
1241 	return seq_list_start_head(&nn->nfs_volume_list, *_pos);
1242 }
1243 
1244 /*
1245  * move to next volume
1246  */
1247 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos)
1248 {
1249 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1250 
1251 	return seq_list_next(v, &nn->nfs_volume_list, pos);
1252 }
1253 
1254 /*
1255  * clean up after reading from the transports list
1256  */
1257 static void nfs_volume_list_stop(struct seq_file *p, void *v)
1258 				__releases(&nn->nfs_client_lock)
1259 {
1260 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1261 
1262 	spin_unlock(&nn->nfs_client_lock);
1263 }
1264 
1265 /*
1266  * display a header line followed by a load of call lines
1267  */
1268 static int nfs_volume_list_show(struct seq_file *m, void *v)
1269 {
1270 	struct nfs_server *server;
1271 	struct nfs_client *clp;
1272 	char dev[13];	// 8 for 2^24, 1 for ':', 3 for 2^8, 1 for '\0'
1273 	char fsid[34];	// 2 * 16 for %llx, 1 for ':', 1 for '\0'
1274 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1275 
1276 	/* display header on line 1 */
1277 	if (v == &nn->nfs_volume_list) {
1278 		seq_puts(m, "NV SERVER   PORT DEV          FSID"
1279 			    "                              FSC\n");
1280 		return 0;
1281 	}
1282 	/* display one transport per line on subsequent lines */
1283 	server = list_entry(v, struct nfs_server, master_link);
1284 	clp = server->nfs_client;
1285 
1286 	snprintf(dev, sizeof(dev), "%u:%u",
1287 		 MAJOR(server->s_dev), MINOR(server->s_dev));
1288 
1289 	snprintf(fsid, sizeof(fsid), "%llx:%llx",
1290 		 (unsigned long long) server->fsid.major,
1291 		 (unsigned long long) server->fsid.minor);
1292 
1293 	rcu_read_lock();
1294 	seq_printf(m, "v%u %s %s %-12s %-33s %s\n",
1295 		   clp->rpc_ops->version,
1296 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1297 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1298 		   dev,
1299 		   fsid,
1300 		   nfs_server_fscache_state(server));
1301 	rcu_read_unlock();
1302 
1303 	return 0;
1304 }
1305 
1306 int nfs_fs_proc_net_init(struct net *net)
1307 {
1308 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1309 	struct proc_dir_entry *p;
1310 
1311 	nn->proc_nfsfs = proc_net_mkdir(net, "nfsfs", net->proc_net);
1312 	if (!nn->proc_nfsfs)
1313 		goto error_0;
1314 
1315 	/* a file of servers with which we're dealing */
1316 	p = proc_create_net("servers", S_IFREG|S_IRUGO, nn->proc_nfsfs,
1317 			&nfs_server_list_ops, sizeof(struct seq_net_private));
1318 	if (!p)
1319 		goto error_1;
1320 
1321 	/* a file of volumes that we have mounted */
1322 	p = proc_create_net("volumes", S_IFREG|S_IRUGO, nn->proc_nfsfs,
1323 			&nfs_volume_list_ops, sizeof(struct seq_net_private));
1324 	if (!p)
1325 		goto error_1;
1326 	return 0;
1327 
1328 error_1:
1329 	remove_proc_subtree("nfsfs", net->proc_net);
1330 error_0:
1331 	return -ENOMEM;
1332 }
1333 
1334 void nfs_fs_proc_net_exit(struct net *net)
1335 {
1336 	remove_proc_subtree("nfsfs", net->proc_net);
1337 }
1338 
1339 /*
1340  * initialise the /proc/fs/nfsfs/ directory
1341  */
1342 int __init nfs_fs_proc_init(void)
1343 {
1344 	if (!proc_mkdir("fs/nfsfs", NULL))
1345 		goto error_0;
1346 
1347 	/* a file of servers with which we're dealing */
1348 	if (!proc_symlink("fs/nfsfs/servers", NULL, "../../net/nfsfs/servers"))
1349 		goto error_1;
1350 
1351 	/* a file of volumes that we have mounted */
1352 	if (!proc_symlink("fs/nfsfs/volumes", NULL, "../../net/nfsfs/volumes"))
1353 		goto error_1;
1354 
1355 	return 0;
1356 error_1:
1357 	remove_proc_subtree("fs/nfsfs", NULL);
1358 error_0:
1359 	return -ENOMEM;
1360 }
1361 
1362 /*
1363  * clean up the /proc/fs/nfsfs/ directory
1364  */
1365 void nfs_fs_proc_exit(void)
1366 {
1367 	remove_proc_subtree("fs/nfsfs", NULL);
1368 }
1369 
1370 #endif /* CONFIG_PROC_FS */
1371