xref: /linux/fs/nfs/client.c (revision 63027b34189a6f4a788c536be6495e93d75fb4c3)
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