xref: /openbmc/linux/fs/nfs/client.c (revision 56b5b1c7)
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_flags = cl_init->init_flags;
181 	clp->cl_proto = cl_init->proto;
182 	clp->cl_nconnect = cl_init->nconnect;
183 	clp->cl_max_connect = cl_init->max_connect ? cl_init->max_connect : 1;
184 	clp->cl_net = get_net(cl_init->net);
185 
186 	clp->cl_principal = "*";
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 	/* -EIO all pending I/O */
241 	if (!IS_ERR(clp->cl_rpcclient))
242 		rpc_shutdown_client(clp->cl_rpcclient);
243 
244 	put_net(clp->cl_net);
245 	put_nfs_version(clp->cl_nfs_mod);
246 	kfree(clp->cl_hostname);
247 	kfree(clp->cl_acceptor);
248 	kfree(clp);
249 }
250 EXPORT_SYMBOL_GPL(nfs_free_client);
251 
252 /*
253  * Release a reference to a shared client record
254  */
255 void nfs_put_client(struct nfs_client *clp)
256 {
257 	struct nfs_net *nn;
258 
259 	if (!clp)
260 		return;
261 
262 	nn = net_generic(clp->cl_net, nfs_net_id);
263 
264 	if (refcount_dec_and_lock(&clp->cl_count, &nn->nfs_client_lock)) {
265 		list_del(&clp->cl_share_link);
266 		nfs_cb_idr_remove_locked(clp);
267 		spin_unlock(&nn->nfs_client_lock);
268 
269 		WARN_ON_ONCE(!list_empty(&clp->cl_superblocks));
270 
271 		clp->rpc_ops->free_client(clp);
272 	}
273 }
274 EXPORT_SYMBOL_GPL(nfs_put_client);
275 
276 /*
277  * Find an nfs_client on the list that matches the initialisation data
278  * that is supplied.
279  */
280 static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *data)
281 {
282 	struct nfs_client *clp;
283 	const struct sockaddr *sap = data->addr;
284 	struct nfs_net *nn = net_generic(data->net, nfs_net_id);
285 	int error;
286 
287 again:
288 	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
289 	        const struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
290 		/* Don't match clients that failed to initialise properly */
291 		if (clp->cl_cons_state < 0)
292 			continue;
293 
294 		/* If a client is still initializing then we need to wait */
295 		if (clp->cl_cons_state > NFS_CS_READY) {
296 			refcount_inc(&clp->cl_count);
297 			spin_unlock(&nn->nfs_client_lock);
298 			error = nfs_wait_client_init_complete(clp);
299 			nfs_put_client(clp);
300 			spin_lock(&nn->nfs_client_lock);
301 			if (error < 0)
302 				return ERR_PTR(error);
303 			goto again;
304 		}
305 
306 		/* Different NFS versions cannot share the same nfs_client */
307 		if (clp->rpc_ops != data->nfs_mod->rpc_ops)
308 			continue;
309 
310 		if (clp->cl_proto != data->proto)
311 			continue;
312 		/* Match nfsv4 minorversion */
313 		if (clp->cl_minorversion != data->minorversion)
314 			continue;
315 
316 		/* Match request for a dedicated DS */
317 		if (test_bit(NFS_CS_DS, &data->init_flags) !=
318 		    test_bit(NFS_CS_DS, &clp->cl_flags))
319 			continue;
320 
321 		/* Match the full socket address */
322 		if (!rpc_cmp_addr_port(sap, clap))
323 			/* Match all xprt_switch full socket addresses */
324 			if (IS_ERR(clp->cl_rpcclient) ||
325                             !rpc_clnt_xprt_switch_has_addr(clp->cl_rpcclient,
326 							   sap))
327 				continue;
328 
329 		refcount_inc(&clp->cl_count);
330 		return clp;
331 	}
332 	return NULL;
333 }
334 
335 /*
336  * Return true if @clp is done initializing, false if still working on it.
337  *
338  * Use nfs_client_init_status to check if it was successful.
339  */
340 bool nfs_client_init_is_complete(const struct nfs_client *clp)
341 {
342 	return clp->cl_cons_state <= NFS_CS_READY;
343 }
344 EXPORT_SYMBOL_GPL(nfs_client_init_is_complete);
345 
346 /*
347  * Return 0 if @clp was successfully initialized, -errno otherwise.
348  *
349  * This must be called *after* nfs_client_init_is_complete() returns true,
350  * otherwise it will pop WARN_ON_ONCE and return -EINVAL
351  */
352 int nfs_client_init_status(const struct nfs_client *clp)
353 {
354 	/* called without checking nfs_client_init_is_complete */
355 	if (clp->cl_cons_state > NFS_CS_READY) {
356 		WARN_ON_ONCE(1);
357 		return -EINVAL;
358 	}
359 	return clp->cl_cons_state;
360 }
361 EXPORT_SYMBOL_GPL(nfs_client_init_status);
362 
363 int nfs_wait_client_init_complete(const struct nfs_client *clp)
364 {
365 	return wait_event_killable(nfs_client_active_wq,
366 			nfs_client_init_is_complete(clp));
367 }
368 EXPORT_SYMBOL_GPL(nfs_wait_client_init_complete);
369 
370 /*
371  * Found an existing client.  Make sure it's ready before returning.
372  */
373 static struct nfs_client *
374 nfs_found_client(const struct nfs_client_initdata *cl_init,
375 		 struct nfs_client *clp)
376 {
377 	int error;
378 
379 	error = nfs_wait_client_init_complete(clp);
380 	if (error < 0) {
381 		nfs_put_client(clp);
382 		return ERR_PTR(-ERESTARTSYS);
383 	}
384 
385 	if (clp->cl_cons_state < NFS_CS_READY) {
386 		error = clp->cl_cons_state;
387 		nfs_put_client(clp);
388 		return ERR_PTR(error);
389 	}
390 
391 	smp_rmb();
392 	return clp;
393 }
394 
395 /*
396  * Look up a client by IP address and protocol version
397  * - creates a new record if one doesn't yet exist
398  */
399 struct nfs_client *nfs_get_client(const struct nfs_client_initdata *cl_init)
400 {
401 	struct nfs_client *clp, *new = NULL;
402 	struct nfs_net *nn = net_generic(cl_init->net, nfs_net_id);
403 	const struct nfs_rpc_ops *rpc_ops = cl_init->nfs_mod->rpc_ops;
404 
405 	if (cl_init->hostname == NULL) {
406 		WARN_ON(1);
407 		return ERR_PTR(-EINVAL);
408 	}
409 
410 	/* see if the client already exists */
411 	do {
412 		spin_lock(&nn->nfs_client_lock);
413 
414 		clp = nfs_match_client(cl_init);
415 		if (clp) {
416 			spin_unlock(&nn->nfs_client_lock);
417 			if (new)
418 				new->rpc_ops->free_client(new);
419 			if (IS_ERR(clp))
420 				return clp;
421 			return nfs_found_client(cl_init, clp);
422 		}
423 		if (new) {
424 			list_add_tail(&new->cl_share_link,
425 					&nn->nfs_client_list);
426 			spin_unlock(&nn->nfs_client_lock);
427 			return rpc_ops->init_client(new, cl_init);
428 		}
429 
430 		spin_unlock(&nn->nfs_client_lock);
431 
432 		new = rpc_ops->alloc_client(cl_init);
433 	} while (!IS_ERR(new));
434 
435 	return new;
436 }
437 EXPORT_SYMBOL_GPL(nfs_get_client);
438 
439 /*
440  * Mark a server as ready or failed
441  */
442 void nfs_mark_client_ready(struct nfs_client *clp, int state)
443 {
444 	smp_wmb();
445 	clp->cl_cons_state = state;
446 	wake_up_all(&nfs_client_active_wq);
447 }
448 EXPORT_SYMBOL_GPL(nfs_mark_client_ready);
449 
450 /*
451  * Initialise the timeout values for a connection
452  */
453 void nfs_init_timeout_values(struct rpc_timeout *to, int proto,
454 				    int timeo, int retrans)
455 {
456 	to->to_initval = timeo * HZ / 10;
457 	to->to_retries = retrans;
458 
459 	switch (proto) {
460 	case XPRT_TRANSPORT_TCP:
461 	case XPRT_TRANSPORT_RDMA:
462 		if (retrans == NFS_UNSPEC_RETRANS)
463 			to->to_retries = NFS_DEF_TCP_RETRANS;
464 		if (timeo == NFS_UNSPEC_TIMEO || to->to_initval == 0)
465 			to->to_initval = NFS_DEF_TCP_TIMEO * HZ / 10;
466 		if (to->to_initval > NFS_MAX_TCP_TIMEOUT)
467 			to->to_initval = NFS_MAX_TCP_TIMEOUT;
468 		to->to_increment = to->to_initval;
469 		to->to_maxval = to->to_initval + (to->to_increment * to->to_retries);
470 		if (to->to_maxval > NFS_MAX_TCP_TIMEOUT)
471 			to->to_maxval = NFS_MAX_TCP_TIMEOUT;
472 		if (to->to_maxval < to->to_initval)
473 			to->to_maxval = to->to_initval;
474 		to->to_exponential = 0;
475 		break;
476 	case XPRT_TRANSPORT_UDP:
477 		if (retrans == NFS_UNSPEC_RETRANS)
478 			to->to_retries = NFS_DEF_UDP_RETRANS;
479 		if (timeo == NFS_UNSPEC_TIMEO || to->to_initval == 0)
480 			to->to_initval = NFS_DEF_UDP_TIMEO * HZ / 10;
481 		if (to->to_initval > NFS_MAX_UDP_TIMEOUT)
482 			to->to_initval = NFS_MAX_UDP_TIMEOUT;
483 		to->to_maxval = NFS_MAX_UDP_TIMEOUT;
484 		to->to_exponential = 1;
485 		break;
486 	default:
487 		BUG();
488 	}
489 }
490 EXPORT_SYMBOL_GPL(nfs_init_timeout_values);
491 
492 /*
493  * Create an RPC client handle
494  */
495 int nfs_create_rpc_client(struct nfs_client *clp,
496 			  const struct nfs_client_initdata *cl_init,
497 			  rpc_authflavor_t flavor)
498 {
499 	struct rpc_clnt		*clnt = NULL;
500 	struct rpc_create_args args = {
501 		.net		= clp->cl_net,
502 		.protocol	= clp->cl_proto,
503 		.nconnect	= clp->cl_nconnect,
504 		.address	= (struct sockaddr *)&clp->cl_addr,
505 		.addrsize	= clp->cl_addrlen,
506 		.timeout	= cl_init->timeparms,
507 		.servername	= clp->cl_hostname,
508 		.nodename	= cl_init->nodename,
509 		.program	= &nfs_program,
510 		.version	= clp->rpc_ops->version,
511 		.authflavor	= flavor,
512 		.cred		= cl_init->cred,
513 	};
514 
515 	if (test_bit(NFS_CS_DISCRTRY, &clp->cl_flags))
516 		args.flags |= RPC_CLNT_CREATE_DISCRTRY;
517 	if (test_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags))
518 		args.flags |= RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT;
519 	if (test_bit(NFS_CS_NORESVPORT, &clp->cl_flags))
520 		args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
521 	if (test_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags))
522 		args.flags |= RPC_CLNT_CREATE_INFINITE_SLOTS;
523 	if (test_bit(NFS_CS_NOPING, &clp->cl_flags))
524 		args.flags |= RPC_CLNT_CREATE_NOPING;
525 	if (test_bit(NFS_CS_REUSEPORT, &clp->cl_flags))
526 		args.flags |= RPC_CLNT_CREATE_REUSEPORT;
527 
528 	if (!IS_ERR(clp->cl_rpcclient))
529 		return 0;
530 
531 	clnt = rpc_create(&args);
532 	if (IS_ERR(clnt)) {
533 		dprintk("%s: cannot create RPC client. Error = %ld\n",
534 				__func__, PTR_ERR(clnt));
535 		return PTR_ERR(clnt);
536 	}
537 
538 	clnt->cl_principal = clp->cl_principal;
539 	clp->cl_rpcclient = clnt;
540 	clnt->cl_max_connect = clp->cl_max_connect;
541 	return 0;
542 }
543 EXPORT_SYMBOL_GPL(nfs_create_rpc_client);
544 
545 /*
546  * Version 2 or 3 client destruction
547  */
548 static void nfs_destroy_server(struct nfs_server *server)
549 {
550 	if (server->nlm_host)
551 		nlmclnt_done(server->nlm_host);
552 }
553 
554 /*
555  * Version 2 or 3 lockd setup
556  */
557 static int nfs_start_lockd(struct nfs_server *server)
558 {
559 	struct nlm_host *host;
560 	struct nfs_client *clp = server->nfs_client;
561 	struct nlmclnt_initdata nlm_init = {
562 		.hostname	= clp->cl_hostname,
563 		.address	= (struct sockaddr *)&clp->cl_addr,
564 		.addrlen	= clp->cl_addrlen,
565 		.nfs_version	= clp->rpc_ops->version,
566 		.noresvport	= server->flags & NFS_MOUNT_NORESVPORT ?
567 					1 : 0,
568 		.net		= clp->cl_net,
569 		.nlmclnt_ops 	= clp->cl_nfs_mod->rpc_ops->nlmclnt_ops,
570 		.cred		= server->cred,
571 	};
572 
573 	if (nlm_init.nfs_version > 3)
574 		return 0;
575 	if ((server->flags & NFS_MOUNT_LOCAL_FLOCK) &&
576 			(server->flags & NFS_MOUNT_LOCAL_FCNTL))
577 		return 0;
578 
579 	switch (clp->cl_proto) {
580 		default:
581 			nlm_init.protocol = IPPROTO_TCP;
582 			break;
583 #ifndef CONFIG_NFS_DISABLE_UDP_SUPPORT
584 		case XPRT_TRANSPORT_UDP:
585 			nlm_init.protocol = IPPROTO_UDP;
586 #endif
587 	}
588 
589 	host = nlmclnt_init(&nlm_init);
590 	if (IS_ERR(host))
591 		return PTR_ERR(host);
592 
593 	server->nlm_host = host;
594 	server->destroy = nfs_destroy_server;
595 	return 0;
596 }
597 
598 /*
599  * Create a general RPC client
600  */
601 int nfs_init_server_rpcclient(struct nfs_server *server,
602 		const struct rpc_timeout *timeo,
603 		rpc_authflavor_t pseudoflavour)
604 {
605 	struct nfs_client *clp = server->nfs_client;
606 
607 	server->client = rpc_clone_client_set_auth(clp->cl_rpcclient,
608 							pseudoflavour);
609 	if (IS_ERR(server->client)) {
610 		dprintk("%s: couldn't create rpc_client!\n", __func__);
611 		return PTR_ERR(server->client);
612 	}
613 
614 	memcpy(&server->client->cl_timeout_default,
615 			timeo,
616 			sizeof(server->client->cl_timeout_default));
617 	server->client->cl_timeout = &server->client->cl_timeout_default;
618 	server->client->cl_softrtry = 0;
619 	if (server->flags & NFS_MOUNT_SOFTERR)
620 		server->client->cl_softerr = 1;
621 	if (server->flags & NFS_MOUNT_SOFT)
622 		server->client->cl_softrtry = 1;
623 
624 	return 0;
625 }
626 EXPORT_SYMBOL_GPL(nfs_init_server_rpcclient);
627 
628 /**
629  * nfs_init_client - Initialise an NFS2 or NFS3 client
630  *
631  * @clp: nfs_client to initialise
632  * @cl_init: Initialisation parameters
633  *
634  * Returns pointer to an NFS client, or an ERR_PTR value.
635  */
636 struct nfs_client *nfs_init_client(struct nfs_client *clp,
637 				   const struct nfs_client_initdata *cl_init)
638 {
639 	int error;
640 
641 	/* the client is already initialised */
642 	if (clp->cl_cons_state == NFS_CS_READY)
643 		return clp;
644 
645 	/*
646 	 * Create a client RPC handle for doing FSSTAT with UNIX auth only
647 	 * - RFC 2623, sec 2.3.2
648 	 */
649 	error = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_UNIX);
650 	nfs_mark_client_ready(clp, error == 0 ? NFS_CS_READY : error);
651 	if (error < 0) {
652 		nfs_put_client(clp);
653 		clp = ERR_PTR(error);
654 	}
655 	return clp;
656 }
657 EXPORT_SYMBOL_GPL(nfs_init_client);
658 
659 /*
660  * Create a version 2 or 3 client
661  */
662 static int nfs_init_server(struct nfs_server *server,
663 			   const struct fs_context *fc)
664 {
665 	const struct nfs_fs_context *ctx = nfs_fc2context(fc);
666 	struct rpc_timeout timeparms;
667 	struct nfs_client_initdata cl_init = {
668 		.hostname = ctx->nfs_server.hostname,
669 		.addr = (const struct sockaddr *)&ctx->nfs_server.address,
670 		.addrlen = ctx->nfs_server.addrlen,
671 		.nfs_mod = ctx->nfs_mod,
672 		.proto = ctx->nfs_server.protocol,
673 		.net = fc->net_ns,
674 		.timeparms = &timeparms,
675 		.cred = server->cred,
676 		.nconnect = ctx->nfs_server.nconnect,
677 		.init_flags = (1UL << NFS_CS_REUSEPORT),
678 	};
679 	struct nfs_client *clp;
680 	int error;
681 
682 	nfs_init_timeout_values(&timeparms, ctx->nfs_server.protocol,
683 				ctx->timeo, ctx->retrans);
684 	if (ctx->flags & NFS_MOUNT_NORESVPORT)
685 		set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
686 
687 	/* Allocate or find a client reference we can use */
688 	clp = nfs_get_client(&cl_init);
689 	if (IS_ERR(clp))
690 		return PTR_ERR(clp);
691 
692 	server->nfs_client = clp;
693 
694 	/* Initialise the client representation from the mount data */
695 	server->flags = ctx->flags;
696 	server->options = ctx->options;
697 	server->caps |= NFS_CAP_HARDLINKS | NFS_CAP_SYMLINKS;
698 
699 	switch (clp->rpc_ops->version) {
700 	case 2:
701 		server->fattr_valid = NFS_ATTR_FATTR_V2;
702 		break;
703 	case 3:
704 		server->fattr_valid = NFS_ATTR_FATTR_V3;
705 		break;
706 	default:
707 		server->fattr_valid = NFS_ATTR_FATTR_V4;
708 	}
709 
710 	if (ctx->rsize)
711 		server->rsize = nfs_block_size(ctx->rsize, NULL);
712 	if (ctx->wsize)
713 		server->wsize = nfs_block_size(ctx->wsize, NULL);
714 
715 	server->acregmin = ctx->acregmin * HZ;
716 	server->acregmax = ctx->acregmax * HZ;
717 	server->acdirmin = ctx->acdirmin * HZ;
718 	server->acdirmax = ctx->acdirmax * HZ;
719 
720 	/* Start lockd here, before we might error out */
721 	error = nfs_start_lockd(server);
722 	if (error < 0)
723 		goto error;
724 
725 	server->port = ctx->nfs_server.port;
726 	server->auth_info = ctx->auth_info;
727 
728 	error = nfs_init_server_rpcclient(server, &timeparms,
729 					  ctx->selected_flavor);
730 	if (error < 0)
731 		goto error;
732 
733 	/* Preserve the values of mount_server-related mount options */
734 	if (ctx->mount_server.addrlen) {
735 		memcpy(&server->mountd_address, &ctx->mount_server.address,
736 			ctx->mount_server.addrlen);
737 		server->mountd_addrlen = ctx->mount_server.addrlen;
738 	}
739 	server->mountd_version = ctx->mount_server.version;
740 	server->mountd_port = ctx->mount_server.port;
741 	server->mountd_protocol = ctx->mount_server.protocol;
742 
743 	server->namelen  = ctx->namlen;
744 	return 0;
745 
746 error:
747 	server->nfs_client = NULL;
748 	nfs_put_client(clp);
749 	return error;
750 }
751 
752 /*
753  * Load up the server record from information gained in an fsinfo record
754  */
755 static void nfs_server_set_fsinfo(struct nfs_server *server,
756 				  struct nfs_fsinfo *fsinfo)
757 {
758 	unsigned long max_rpc_payload, raw_max_rpc_payload;
759 
760 	/* Work out a lot of parameters */
761 	if (server->rsize == 0)
762 		server->rsize = nfs_block_size(fsinfo->rtpref, NULL);
763 	if (server->wsize == 0)
764 		server->wsize = nfs_block_size(fsinfo->wtpref, NULL);
765 
766 	if (fsinfo->rtmax >= 512 && server->rsize > fsinfo->rtmax)
767 		server->rsize = nfs_block_size(fsinfo->rtmax, NULL);
768 	if (fsinfo->wtmax >= 512 && server->wsize > fsinfo->wtmax)
769 		server->wsize = nfs_block_size(fsinfo->wtmax, NULL);
770 
771 	raw_max_rpc_payload = rpc_max_payload(server->client);
772 	max_rpc_payload = nfs_block_size(raw_max_rpc_payload, NULL);
773 
774 	if (server->rsize > max_rpc_payload)
775 		server->rsize = max_rpc_payload;
776 	if (server->rsize > NFS_MAX_FILE_IO_SIZE)
777 		server->rsize = NFS_MAX_FILE_IO_SIZE;
778 	server->rpages = (server->rsize + PAGE_SIZE - 1) >> PAGE_SHIFT;
779 
780 	if (server->wsize > max_rpc_payload)
781 		server->wsize = max_rpc_payload;
782 	if (server->wsize > NFS_MAX_FILE_IO_SIZE)
783 		server->wsize = NFS_MAX_FILE_IO_SIZE;
784 	server->wpages = (server->wsize + PAGE_SIZE - 1) >> PAGE_SHIFT;
785 
786 	server->wtmult = nfs_block_bits(fsinfo->wtmult, NULL);
787 
788 	server->dtsize = nfs_block_size(fsinfo->dtpref, NULL);
789 	if (server->dtsize > NFS_MAX_FILE_IO_SIZE)
790 		server->dtsize = NFS_MAX_FILE_IO_SIZE;
791 	if (server->dtsize > server->rsize)
792 		server->dtsize = server->rsize;
793 
794 	if (server->flags & NFS_MOUNT_NOAC) {
795 		server->acregmin = server->acregmax = 0;
796 		server->acdirmin = server->acdirmax = 0;
797 	}
798 
799 	server->maxfilesize = fsinfo->maxfilesize;
800 
801 	server->time_delta = fsinfo->time_delta;
802 	server->change_attr_type = fsinfo->change_attr_type;
803 
804 	server->clone_blksize = fsinfo->clone_blksize;
805 	/* We're airborne Set socket buffersize */
806 	rpc_setbufsize(server->client, server->wsize + 100, server->rsize + 100);
807 
808 #ifdef CONFIG_NFS_V4_2
809 	/*
810 	 * Defaults until limited by the session parameters.
811 	 */
812 	server->gxasize = min_t(unsigned int, raw_max_rpc_payload,
813 				XATTR_SIZE_MAX);
814 	server->sxasize = min_t(unsigned int, raw_max_rpc_payload,
815 				XATTR_SIZE_MAX);
816 	server->lxasize = min_t(unsigned int, raw_max_rpc_payload,
817 				nfs42_listxattr_xdrsize(XATTR_LIST_MAX));
818 
819 	if (fsinfo->xattr_support)
820 		server->caps |= NFS_CAP_XATTR;
821 #endif
822 }
823 
824 /*
825  * Probe filesystem information, including the FSID on v2/v3
826  */
827 static int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *mntfh, struct nfs_fattr *fattr)
828 {
829 	struct nfs_fsinfo fsinfo;
830 	struct nfs_client *clp = server->nfs_client;
831 	int error;
832 
833 	if (clp->rpc_ops->set_capabilities != NULL) {
834 		error = clp->rpc_ops->set_capabilities(server, mntfh);
835 		if (error < 0)
836 			return error;
837 	}
838 
839 	fsinfo.fattr = fattr;
840 	fsinfo.nlayouttypes = 0;
841 	memset(fsinfo.layouttype, 0, sizeof(fsinfo.layouttype));
842 	error = clp->rpc_ops->fsinfo(server, mntfh, &fsinfo);
843 	if (error < 0)
844 		return error;
845 
846 	nfs_server_set_fsinfo(server, &fsinfo);
847 
848 	/* Get some general file system info */
849 	if (server->namelen == 0) {
850 		struct nfs_pathconf pathinfo;
851 
852 		pathinfo.fattr = fattr;
853 		nfs_fattr_init(fattr);
854 
855 		if (clp->rpc_ops->pathconf(server, mntfh, &pathinfo) >= 0)
856 			server->namelen = pathinfo.max_namelen;
857 	}
858 
859 	if (clp->rpc_ops->discover_trunking != NULL &&
860 			(server->caps & NFS_CAP_FS_LOCATIONS)) {
861 		error = clp->rpc_ops->discover_trunking(server, mntfh);
862 		if (error < 0)
863 			return error;
864 	}
865 
866 	return 0;
867 }
868 
869 /*
870  * Grab the destination's particulars, including lease expiry time.
871  *
872  * Returns zero if probe succeeded and retrieved FSID matches the FSID
873  * we have cached.
874  */
875 int nfs_probe_server(struct nfs_server *server, struct nfs_fh *mntfh)
876 {
877 	struct nfs_fattr *fattr;
878 	int error;
879 
880 	fattr = nfs_alloc_fattr();
881 	if (fattr == NULL)
882 		return -ENOMEM;
883 
884 	/* Sanity: the probe won't work if the destination server
885 	 * does not recognize the migrated FH. */
886 	error = nfs_probe_fsinfo(server, mntfh, fattr);
887 
888 	nfs_free_fattr(fattr);
889 	return error;
890 }
891 EXPORT_SYMBOL_GPL(nfs_probe_server);
892 
893 /*
894  * Copy useful information when duplicating a server record
895  */
896 void nfs_server_copy_userdata(struct nfs_server *target, struct nfs_server *source)
897 {
898 	target->flags = source->flags;
899 	target->rsize = source->rsize;
900 	target->wsize = source->wsize;
901 	target->acregmin = source->acregmin;
902 	target->acregmax = source->acregmax;
903 	target->acdirmin = source->acdirmin;
904 	target->acdirmax = source->acdirmax;
905 	target->caps = source->caps;
906 	target->options = source->options;
907 	target->auth_info = source->auth_info;
908 	target->port = source->port;
909 }
910 EXPORT_SYMBOL_GPL(nfs_server_copy_userdata);
911 
912 void nfs_server_insert_lists(struct nfs_server *server)
913 {
914 	struct nfs_client *clp = server->nfs_client;
915 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
916 
917 	spin_lock(&nn->nfs_client_lock);
918 	list_add_tail_rcu(&server->client_link, &clp->cl_superblocks);
919 	list_add_tail(&server->master_link, &nn->nfs_volume_list);
920 	clear_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
921 	spin_unlock(&nn->nfs_client_lock);
922 
923 }
924 EXPORT_SYMBOL_GPL(nfs_server_insert_lists);
925 
926 void nfs_server_remove_lists(struct nfs_server *server)
927 {
928 	struct nfs_client *clp = server->nfs_client;
929 	struct nfs_net *nn;
930 
931 	if (clp == NULL)
932 		return;
933 	nn = net_generic(clp->cl_net, nfs_net_id);
934 	spin_lock(&nn->nfs_client_lock);
935 	list_del_rcu(&server->client_link);
936 	if (list_empty(&clp->cl_superblocks))
937 		set_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
938 	list_del(&server->master_link);
939 	spin_unlock(&nn->nfs_client_lock);
940 
941 	synchronize_rcu();
942 }
943 EXPORT_SYMBOL_GPL(nfs_server_remove_lists);
944 
945 /*
946  * Allocate and initialise a server record
947  */
948 struct nfs_server *nfs_alloc_server(void)
949 {
950 	struct nfs_server *server;
951 
952 	server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
953 	if (!server)
954 		return NULL;
955 
956 	server->client = server->client_acl = ERR_PTR(-EINVAL);
957 
958 	/* Zero out the NFS state stuff */
959 	INIT_LIST_HEAD(&server->client_link);
960 	INIT_LIST_HEAD(&server->master_link);
961 	INIT_LIST_HEAD(&server->delegations);
962 	INIT_LIST_HEAD(&server->layouts);
963 	INIT_LIST_HEAD(&server->state_owners_lru);
964 	INIT_LIST_HEAD(&server->ss_copies);
965 
966 	atomic_set(&server->active, 0);
967 
968 	server->io_stats = nfs_alloc_iostats();
969 	if (!server->io_stats) {
970 		kfree(server);
971 		return NULL;
972 	}
973 
974 	server->change_attr_type = NFS4_CHANGE_TYPE_IS_UNDEFINED;
975 
976 	ida_init(&server->openowner_id);
977 	ida_init(&server->lockowner_id);
978 	pnfs_init_server(server);
979 	rpc_init_wait_queue(&server->uoc_rpcwaitq, "NFS UOC");
980 
981 	return server;
982 }
983 EXPORT_SYMBOL_GPL(nfs_alloc_server);
984 
985 /*
986  * Free up a server record
987  */
988 void nfs_free_server(struct nfs_server *server)
989 {
990 	nfs_server_remove_lists(server);
991 
992 	if (server->destroy != NULL)
993 		server->destroy(server);
994 
995 	if (!IS_ERR(server->client_acl))
996 		rpc_shutdown_client(server->client_acl);
997 	if (!IS_ERR(server->client))
998 		rpc_shutdown_client(server->client);
999 
1000 	nfs_put_client(server->nfs_client);
1001 
1002 	ida_destroy(&server->lockowner_id);
1003 	ida_destroy(&server->openowner_id);
1004 	nfs_free_iostats(server->io_stats);
1005 	put_cred(server->cred);
1006 	kfree(server);
1007 	nfs_release_automount_timer();
1008 }
1009 EXPORT_SYMBOL_GPL(nfs_free_server);
1010 
1011 /*
1012  * Create a version 2 or 3 volume record
1013  * - keyed on server and FSID
1014  */
1015 struct nfs_server *nfs_create_server(struct fs_context *fc)
1016 {
1017 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1018 	struct nfs_server *server;
1019 	struct nfs_fattr *fattr;
1020 	int error;
1021 
1022 	server = nfs_alloc_server();
1023 	if (!server)
1024 		return ERR_PTR(-ENOMEM);
1025 
1026 	server->cred = get_cred(fc->cred);
1027 
1028 	error = -ENOMEM;
1029 	fattr = nfs_alloc_fattr();
1030 	if (fattr == NULL)
1031 		goto error;
1032 
1033 	/* Get a client representation */
1034 	error = nfs_init_server(server, fc);
1035 	if (error < 0)
1036 		goto error;
1037 
1038 	/* Probe the root fh to retrieve its FSID */
1039 	error = nfs_probe_fsinfo(server, ctx->mntfh, fattr);
1040 	if (error < 0)
1041 		goto error;
1042 	if (server->nfs_client->rpc_ops->version == 3) {
1043 		if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN)
1044 			server->namelen = NFS3_MAXNAMLEN;
1045 		if (!(ctx->flags & NFS_MOUNT_NORDIRPLUS))
1046 			server->caps |= NFS_CAP_READDIRPLUS;
1047 	} else {
1048 		if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN)
1049 			server->namelen = NFS2_MAXNAMLEN;
1050 	}
1051 
1052 	if (!(fattr->valid & NFS_ATTR_FATTR)) {
1053 		error = ctx->nfs_mod->rpc_ops->getattr(server, ctx->mntfh,
1054 						       fattr, NULL);
1055 		if (error < 0) {
1056 			dprintk("nfs_create_server: getattr error = %d\n", -error);
1057 			goto error;
1058 		}
1059 	}
1060 	memcpy(&server->fsid, &fattr->fsid, sizeof(server->fsid));
1061 
1062 	dprintk("Server FSID: %llx:%llx\n",
1063 		(unsigned long long) server->fsid.major,
1064 		(unsigned long long) server->fsid.minor);
1065 
1066 	nfs_server_insert_lists(server);
1067 	server->mount_time = jiffies;
1068 	nfs_free_fattr(fattr);
1069 	return server;
1070 
1071 error:
1072 	nfs_free_fattr(fattr);
1073 	nfs_free_server(server);
1074 	return ERR_PTR(error);
1075 }
1076 EXPORT_SYMBOL_GPL(nfs_create_server);
1077 
1078 /*
1079  * Clone an NFS2, NFS3 or NFS4 server record
1080  */
1081 struct nfs_server *nfs_clone_server(struct nfs_server *source,
1082 				    struct nfs_fh *fh,
1083 				    struct nfs_fattr *fattr,
1084 				    rpc_authflavor_t flavor)
1085 {
1086 	struct nfs_server *server;
1087 	int error;
1088 
1089 	server = nfs_alloc_server();
1090 	if (!server)
1091 		return ERR_PTR(-ENOMEM);
1092 
1093 	server->cred = get_cred(source->cred);
1094 
1095 	/* Copy data from the source */
1096 	server->nfs_client = source->nfs_client;
1097 	server->destroy = source->destroy;
1098 	refcount_inc(&server->nfs_client->cl_count);
1099 	nfs_server_copy_userdata(server, source);
1100 
1101 	server->fsid = fattr->fsid;
1102 
1103 	error = nfs_init_server_rpcclient(server,
1104 			source->client->cl_timeout,
1105 			flavor);
1106 	if (error < 0)
1107 		goto out_free_server;
1108 
1109 	/* probe the filesystem info for this server filesystem */
1110 	error = nfs_probe_server(server, fh);
1111 	if (error < 0)
1112 		goto out_free_server;
1113 
1114 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1115 		server->namelen = NFS4_MAXNAMLEN;
1116 
1117 	error = nfs_start_lockd(server);
1118 	if (error < 0)
1119 		goto out_free_server;
1120 
1121 	nfs_server_insert_lists(server);
1122 	server->mount_time = jiffies;
1123 
1124 	return server;
1125 
1126 out_free_server:
1127 	nfs_free_server(server);
1128 	return ERR_PTR(error);
1129 }
1130 EXPORT_SYMBOL_GPL(nfs_clone_server);
1131 
1132 void nfs_clients_init(struct net *net)
1133 {
1134 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1135 
1136 	INIT_LIST_HEAD(&nn->nfs_client_list);
1137 	INIT_LIST_HEAD(&nn->nfs_volume_list);
1138 #if IS_ENABLED(CONFIG_NFS_V4)
1139 	idr_init(&nn->cb_ident_idr);
1140 #endif
1141 	spin_lock_init(&nn->nfs_client_lock);
1142 	nn->boot_time = ktime_get_real();
1143 
1144 	nfs_netns_sysfs_setup(nn, net);
1145 }
1146 
1147 void nfs_clients_exit(struct net *net)
1148 {
1149 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1150 
1151 	nfs_netns_sysfs_destroy(nn);
1152 	nfs_cleanup_cb_ident_idr(net);
1153 	WARN_ON_ONCE(!list_empty(&nn->nfs_client_list));
1154 	WARN_ON_ONCE(!list_empty(&nn->nfs_volume_list));
1155 }
1156 
1157 #ifdef CONFIG_PROC_FS
1158 static void *nfs_server_list_start(struct seq_file *p, loff_t *pos);
1159 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos);
1160 static void nfs_server_list_stop(struct seq_file *p, void *v);
1161 static int nfs_server_list_show(struct seq_file *m, void *v);
1162 
1163 static const struct seq_operations nfs_server_list_ops = {
1164 	.start	= nfs_server_list_start,
1165 	.next	= nfs_server_list_next,
1166 	.stop	= nfs_server_list_stop,
1167 	.show	= nfs_server_list_show,
1168 };
1169 
1170 static void *nfs_volume_list_start(struct seq_file *p, loff_t *pos);
1171 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos);
1172 static void nfs_volume_list_stop(struct seq_file *p, void *v);
1173 static int nfs_volume_list_show(struct seq_file *m, void *v);
1174 
1175 static const struct seq_operations nfs_volume_list_ops = {
1176 	.start	= nfs_volume_list_start,
1177 	.next	= nfs_volume_list_next,
1178 	.stop	= nfs_volume_list_stop,
1179 	.show	= nfs_volume_list_show,
1180 };
1181 
1182 /*
1183  * set up the iterator to start reading from the server list and return the first item
1184  */
1185 static void *nfs_server_list_start(struct seq_file *m, loff_t *_pos)
1186 				__acquires(&nn->nfs_client_lock)
1187 {
1188 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1189 
1190 	/* lock the list against modification */
1191 	spin_lock(&nn->nfs_client_lock);
1192 	return seq_list_start_head(&nn->nfs_client_list, *_pos);
1193 }
1194 
1195 /*
1196  * move to next server
1197  */
1198 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos)
1199 {
1200 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1201 
1202 	return seq_list_next(v, &nn->nfs_client_list, pos);
1203 }
1204 
1205 /*
1206  * clean up after reading from the transports list
1207  */
1208 static void nfs_server_list_stop(struct seq_file *p, void *v)
1209 				__releases(&nn->nfs_client_lock)
1210 {
1211 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1212 
1213 	spin_unlock(&nn->nfs_client_lock);
1214 }
1215 
1216 /*
1217  * display a header line followed by a load of call lines
1218  */
1219 static int nfs_server_list_show(struct seq_file *m, void *v)
1220 {
1221 	struct nfs_client *clp;
1222 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1223 
1224 	/* display header on line 1 */
1225 	if (v == &nn->nfs_client_list) {
1226 		seq_puts(m, "NV SERVER   PORT USE HOSTNAME\n");
1227 		return 0;
1228 	}
1229 
1230 	/* display one transport per line on subsequent lines */
1231 	clp = list_entry(v, struct nfs_client, cl_share_link);
1232 
1233 	/* Check if the client is initialized */
1234 	if (clp->cl_cons_state != NFS_CS_READY)
1235 		return 0;
1236 
1237 	rcu_read_lock();
1238 	seq_printf(m, "v%u %s %s %3d %s\n",
1239 		   clp->rpc_ops->version,
1240 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1241 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1242 		   refcount_read(&clp->cl_count),
1243 		   clp->cl_hostname);
1244 	rcu_read_unlock();
1245 
1246 	return 0;
1247 }
1248 
1249 /*
1250  * set up the iterator to start reading from the volume list and return the first item
1251  */
1252 static void *nfs_volume_list_start(struct seq_file *m, loff_t *_pos)
1253 				__acquires(&nn->nfs_client_lock)
1254 {
1255 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1256 
1257 	/* lock the list against modification */
1258 	spin_lock(&nn->nfs_client_lock);
1259 	return seq_list_start_head(&nn->nfs_volume_list, *_pos);
1260 }
1261 
1262 /*
1263  * move to next volume
1264  */
1265 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos)
1266 {
1267 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1268 
1269 	return seq_list_next(v, &nn->nfs_volume_list, pos);
1270 }
1271 
1272 /*
1273  * clean up after reading from the transports list
1274  */
1275 static void nfs_volume_list_stop(struct seq_file *p, void *v)
1276 				__releases(&nn->nfs_client_lock)
1277 {
1278 	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
1279 
1280 	spin_unlock(&nn->nfs_client_lock);
1281 }
1282 
1283 /*
1284  * display a header line followed by a load of call lines
1285  */
1286 static int nfs_volume_list_show(struct seq_file *m, void *v)
1287 {
1288 	struct nfs_server *server;
1289 	struct nfs_client *clp;
1290 	char dev[13];	// 8 for 2^24, 1 for ':', 3 for 2^8, 1 for '\0'
1291 	char fsid[34];	// 2 * 16 for %llx, 1 for ':', 1 for '\0'
1292 	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
1293 
1294 	/* display header on line 1 */
1295 	if (v == &nn->nfs_volume_list) {
1296 		seq_puts(m, "NV SERVER   PORT DEV          FSID"
1297 			    "                              FSC\n");
1298 		return 0;
1299 	}
1300 	/* display one transport per line on subsequent lines */
1301 	server = list_entry(v, struct nfs_server, master_link);
1302 	clp = server->nfs_client;
1303 
1304 	snprintf(dev, sizeof(dev), "%u:%u",
1305 		 MAJOR(server->s_dev), MINOR(server->s_dev));
1306 
1307 	snprintf(fsid, sizeof(fsid), "%llx:%llx",
1308 		 (unsigned long long) server->fsid.major,
1309 		 (unsigned long long) server->fsid.minor);
1310 
1311 	rcu_read_lock();
1312 	seq_printf(m, "v%u %s %s %-12s %-33s %s\n",
1313 		   clp->rpc_ops->version,
1314 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1315 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1316 		   dev,
1317 		   fsid,
1318 		   nfs_server_fscache_state(server));
1319 	rcu_read_unlock();
1320 
1321 	return 0;
1322 }
1323 
1324 int nfs_fs_proc_net_init(struct net *net)
1325 {
1326 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1327 	struct proc_dir_entry *p;
1328 
1329 	nn->proc_nfsfs = proc_net_mkdir(net, "nfsfs", net->proc_net);
1330 	if (!nn->proc_nfsfs)
1331 		goto error_0;
1332 
1333 	/* a file of servers with which we're dealing */
1334 	p = proc_create_net("servers", S_IFREG|S_IRUGO, nn->proc_nfsfs,
1335 			&nfs_server_list_ops, sizeof(struct seq_net_private));
1336 	if (!p)
1337 		goto error_1;
1338 
1339 	/* a file of volumes that we have mounted */
1340 	p = proc_create_net("volumes", S_IFREG|S_IRUGO, nn->proc_nfsfs,
1341 			&nfs_volume_list_ops, sizeof(struct seq_net_private));
1342 	if (!p)
1343 		goto error_1;
1344 	return 0;
1345 
1346 error_1:
1347 	remove_proc_subtree("nfsfs", net->proc_net);
1348 error_0:
1349 	return -ENOMEM;
1350 }
1351 
1352 void nfs_fs_proc_net_exit(struct net *net)
1353 {
1354 	remove_proc_subtree("nfsfs", net->proc_net);
1355 }
1356 
1357 /*
1358  * initialise the /proc/fs/nfsfs/ directory
1359  */
1360 int __init nfs_fs_proc_init(void)
1361 {
1362 	if (!proc_mkdir("fs/nfsfs", NULL))
1363 		goto error_0;
1364 
1365 	/* a file of servers with which we're dealing */
1366 	if (!proc_symlink("fs/nfsfs/servers", NULL, "../../net/nfsfs/servers"))
1367 		goto error_1;
1368 
1369 	/* a file of volumes that we have mounted */
1370 	if (!proc_symlink("fs/nfsfs/volumes", NULL, "../../net/nfsfs/volumes"))
1371 		goto error_1;
1372 
1373 	return 0;
1374 error_1:
1375 	remove_proc_subtree("fs/nfsfs", NULL);
1376 error_0:
1377 	return -ENOMEM;
1378 }
1379 
1380 /*
1381  * clean up the /proc/fs/nfsfs/ directory
1382  */
1383 void nfs_fs_proc_exit(void)
1384 {
1385 	remove_proc_subtree("fs/nfsfs", NULL);
1386 }
1387 
1388 #endif /* CONFIG_PROC_FS */
1389