xref: /linux/fs/nfs/client.c (revision 12871a0bd67dd4db4418e1daafcd46e9d329ef10)
1 /* client.c: NFS client sharing and management code
2  *
3  * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 
12 
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/sched.h>
16 #include <linux/time.h>
17 #include <linux/kernel.h>
18 #include <linux/mm.h>
19 #include <linux/string.h>
20 #include <linux/stat.h>
21 #include <linux/errno.h>
22 #include <linux/unistd.h>
23 #include <linux/sunrpc/clnt.h>
24 #include <linux/sunrpc/stats.h>
25 #include <linux/sunrpc/metrics.h>
26 #include <linux/sunrpc/xprtsock.h>
27 #include <linux/sunrpc/xprtrdma.h>
28 #include <linux/nfs_fs.h>
29 #include <linux/nfs_mount.h>
30 #include <linux/nfs4_mount.h>
31 #include <linux/lockd/bind.h>
32 #include <linux/seq_file.h>
33 #include <linux/mount.h>
34 #include <linux/nfs_idmap.h>
35 #include <linux/vfs.h>
36 #include <linux/inet.h>
37 #include <linux/in6.h>
38 #include <linux/slab.h>
39 #include <net/ipv6.h>
40 #include <linux/nfs_xdr.h>
41 #include <linux/sunrpc/bc_xprt.h>
42 
43 #include <asm/system.h>
44 
45 #include "nfs4_fs.h"
46 #include "callback.h"
47 #include "delegation.h"
48 #include "iostat.h"
49 #include "internal.h"
50 #include "fscache.h"
51 #include "pnfs.h"
52 
53 #define NFSDBG_FACILITY		NFSDBG_CLIENT
54 
55 static DEFINE_SPINLOCK(nfs_client_lock);
56 static LIST_HEAD(nfs_client_list);
57 static LIST_HEAD(nfs_volume_list);
58 static DECLARE_WAIT_QUEUE_HEAD(nfs_client_active_wq);
59 #ifdef CONFIG_NFS_V4
60 static DEFINE_IDR(cb_ident_idr); /* Protected by nfs_client_lock */
61 
62 /*
63  * Get a unique NFSv4.0 callback identifier which will be used
64  * by the V4.0 callback service to lookup the nfs_client struct
65  */
66 static int nfs_get_cb_ident_idr(struct nfs_client *clp, int minorversion)
67 {
68 	int ret = 0;
69 
70 	if (clp->rpc_ops->version != 4 || minorversion != 0)
71 		return ret;
72 retry:
73 	if (!idr_pre_get(&cb_ident_idr, GFP_KERNEL))
74 		return -ENOMEM;
75 	spin_lock(&nfs_client_lock);
76 	ret = idr_get_new(&cb_ident_idr, clp, &clp->cl_cb_ident);
77 	spin_unlock(&nfs_client_lock);
78 	if (ret == -EAGAIN)
79 		goto retry;
80 	return ret;
81 }
82 #endif /* CONFIG_NFS_V4 */
83 
84 /*
85  * Turn off NFSv4 uid/gid mapping when using AUTH_SYS
86  */
87 static int nfs4_disable_idmapping = 0;
88 
89 /*
90  * RPC cruft for NFS
91  */
92 static struct rpc_version *nfs_version[5] = {
93 	[2]			= &nfs_version2,
94 #ifdef CONFIG_NFS_V3
95 	[3]			= &nfs_version3,
96 #endif
97 #ifdef CONFIG_NFS_V4
98 	[4]			= &nfs_version4,
99 #endif
100 };
101 
102 struct rpc_program nfs_program = {
103 	.name			= "nfs",
104 	.number			= NFS_PROGRAM,
105 	.nrvers			= ARRAY_SIZE(nfs_version),
106 	.version		= nfs_version,
107 	.stats			= &nfs_rpcstat,
108 	.pipe_dir_name		= "/nfs",
109 };
110 
111 struct rpc_stat nfs_rpcstat = {
112 	.program		= &nfs_program
113 };
114 
115 
116 #ifdef CONFIG_NFS_V3_ACL
117 static struct rpc_stat		nfsacl_rpcstat = { &nfsacl_program };
118 static struct rpc_version *	nfsacl_version[] = {
119 	[3]			= &nfsacl_version3,
120 };
121 
122 struct rpc_program		nfsacl_program = {
123 	.name			= "nfsacl",
124 	.number			= NFS_ACL_PROGRAM,
125 	.nrvers			= ARRAY_SIZE(nfsacl_version),
126 	.version		= nfsacl_version,
127 	.stats			= &nfsacl_rpcstat,
128 };
129 #endif  /* CONFIG_NFS_V3_ACL */
130 
131 struct nfs_client_initdata {
132 	const char *hostname;
133 	const struct sockaddr *addr;
134 	size_t addrlen;
135 	const struct nfs_rpc_ops *rpc_ops;
136 	int proto;
137 	u32 minorversion;
138 };
139 
140 /*
141  * Allocate a shared client record
142  *
143  * Since these are allocated/deallocated very rarely, we don't
144  * bother putting them in a slab cache...
145  */
146 static struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init)
147 {
148 	struct nfs_client *clp;
149 	struct rpc_cred *cred;
150 	int err = -ENOMEM;
151 
152 	if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL)
153 		goto error_0;
154 
155 	clp->rpc_ops = cl_init->rpc_ops;
156 
157 	atomic_set(&clp->cl_count, 1);
158 	clp->cl_cons_state = NFS_CS_INITING;
159 
160 	memcpy(&clp->cl_addr, cl_init->addr, cl_init->addrlen);
161 	clp->cl_addrlen = cl_init->addrlen;
162 
163 	if (cl_init->hostname) {
164 		err = -ENOMEM;
165 		clp->cl_hostname = kstrdup(cl_init->hostname, GFP_KERNEL);
166 		if (!clp->cl_hostname)
167 			goto error_cleanup;
168 	}
169 
170 	INIT_LIST_HEAD(&clp->cl_superblocks);
171 	clp->cl_rpcclient = ERR_PTR(-EINVAL);
172 
173 	clp->cl_proto = cl_init->proto;
174 
175 #ifdef CONFIG_NFS_V4
176 	err = nfs_get_cb_ident_idr(clp, cl_init->minorversion);
177 	if (err)
178 		goto error_cleanup;
179 
180 	spin_lock_init(&clp->cl_lock);
181 	INIT_DELAYED_WORK(&clp->cl_renewd, nfs4_renew_state);
182 	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
183 	clp->cl_boot_time = CURRENT_TIME;
184 	clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
185 	clp->cl_minorversion = cl_init->minorversion;
186 	clp->cl_mvops = nfs_v4_minor_ops[cl_init->minorversion];
187 #endif
188 	cred = rpc_lookup_machine_cred();
189 	if (!IS_ERR(cred))
190 		clp->cl_machine_cred = cred;
191 #if defined(CONFIG_NFS_V4_1)
192 	INIT_LIST_HEAD(&clp->cl_layouts);
193 #endif
194 	nfs_fscache_get_client_cookie(clp);
195 
196 	return clp;
197 
198 error_cleanup:
199 	kfree(clp);
200 error_0:
201 	return ERR_PTR(err);
202 }
203 
204 #ifdef CONFIG_NFS_V4
205 #ifdef CONFIG_NFS_V4_1
206 static void nfs4_shutdown_session(struct nfs_client *clp)
207 {
208 	if (nfs4_has_session(clp))
209 		nfs4_destroy_session(clp->cl_session);
210 }
211 #else /* CONFIG_NFS_V4_1 */
212 static void nfs4_shutdown_session(struct nfs_client *clp)
213 {
214 }
215 #endif /* CONFIG_NFS_V4_1 */
216 
217 /*
218  * Destroy the NFS4 callback service
219  */
220 static void nfs4_destroy_callback(struct nfs_client *clp)
221 {
222 	if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
223 		nfs_callback_down(clp->cl_mvops->minor_version);
224 }
225 
226 static void nfs4_shutdown_client(struct nfs_client *clp)
227 {
228 	if (__test_and_clear_bit(NFS_CS_RENEWD, &clp->cl_res_state))
229 		nfs4_kill_renewd(clp);
230 	nfs4_shutdown_session(clp);
231 	nfs4_destroy_callback(clp);
232 	if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state))
233 		nfs_idmap_delete(clp);
234 
235 	rpc_destroy_wait_queue(&clp->cl_rpcwaitq);
236 }
237 
238 /* idr_remove_all is not needed as all id's are removed by nfs_put_client */
239 void nfs_cleanup_cb_ident_idr(void)
240 {
241 	idr_destroy(&cb_ident_idr);
242 }
243 
244 /* nfs_client_lock held */
245 static void nfs_cb_idr_remove_locked(struct nfs_client *clp)
246 {
247 	if (clp->cl_cb_ident)
248 		idr_remove(&cb_ident_idr, clp->cl_cb_ident);
249 }
250 
251 static void pnfs_init_server(struct nfs_server *server)
252 {
253 	rpc_init_wait_queue(&server->roc_rpcwaitq, "pNFS ROC");
254 }
255 
256 #else
257 static void nfs4_shutdown_client(struct nfs_client *clp)
258 {
259 }
260 
261 void nfs_cleanup_cb_ident_idr(void)
262 {
263 }
264 
265 static void nfs_cb_idr_remove_locked(struct nfs_client *clp)
266 {
267 }
268 
269 static void pnfs_init_server(struct nfs_server *server)
270 {
271 }
272 
273 #endif /* CONFIG_NFS_V4 */
274 
275 /*
276  * Destroy a shared client record
277  */
278 static void nfs_free_client(struct nfs_client *clp)
279 {
280 	dprintk("--> nfs_free_client(%u)\n", clp->rpc_ops->version);
281 
282 	nfs4_shutdown_client(clp);
283 
284 	nfs_fscache_release_client_cookie(clp);
285 
286 	/* -EIO all pending I/O */
287 	if (!IS_ERR(clp->cl_rpcclient))
288 		rpc_shutdown_client(clp->cl_rpcclient);
289 
290 	if (clp->cl_machine_cred != NULL)
291 		put_rpccred(clp->cl_machine_cred);
292 
293 	nfs4_deviceid_purge_client(clp);
294 
295 	kfree(clp->cl_hostname);
296 	kfree(clp);
297 
298 	dprintk("<-- nfs_free_client()\n");
299 }
300 
301 /*
302  * Release a reference to a shared client record
303  */
304 void nfs_put_client(struct nfs_client *clp)
305 {
306 	if (!clp)
307 		return;
308 
309 	dprintk("--> nfs_put_client({%d})\n", atomic_read(&clp->cl_count));
310 
311 	if (atomic_dec_and_lock(&clp->cl_count, &nfs_client_lock)) {
312 		list_del(&clp->cl_share_link);
313 		nfs_cb_idr_remove_locked(clp);
314 		spin_unlock(&nfs_client_lock);
315 
316 		BUG_ON(!list_empty(&clp->cl_superblocks));
317 
318 		nfs_free_client(clp);
319 	}
320 }
321 EXPORT_SYMBOL_GPL(nfs_put_client);
322 
323 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
324 /*
325  * Test if two ip6 socket addresses refer to the same socket by
326  * comparing relevant fields. The padding bytes specifically, are not
327  * compared. sin6_flowinfo is not compared because it only affects QoS
328  * and sin6_scope_id is only compared if the address is "link local"
329  * because "link local" addresses need only be unique to a specific
330  * link. Conversely, ordinary unicast addresses might have different
331  * sin6_scope_id.
332  *
333  * The caller should ensure both socket addresses are AF_INET6.
334  */
335 static int nfs_sockaddr_match_ipaddr6(const struct sockaddr *sa1,
336 				      const struct sockaddr *sa2)
337 {
338 	const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sa1;
339 	const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sa2;
340 
341 	if (ipv6_addr_scope(&sin1->sin6_addr) == IPV6_ADDR_SCOPE_LINKLOCAL &&
342 	    sin1->sin6_scope_id != sin2->sin6_scope_id)
343 		return 0;
344 
345 	return ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr);
346 }
347 #else	/* !defined(CONFIG_IPV6) && !defined(CONFIG_IPV6_MODULE) */
348 static int nfs_sockaddr_match_ipaddr6(const struct sockaddr *sa1,
349 				      const struct sockaddr *sa2)
350 {
351 	return 0;
352 }
353 #endif
354 
355 /*
356  * Test if two ip4 socket addresses refer to the same socket, by
357  * comparing relevant fields. The padding bytes specifically, are
358  * not compared.
359  *
360  * The caller should ensure both socket addresses are AF_INET.
361  */
362 static int nfs_sockaddr_match_ipaddr4(const struct sockaddr *sa1,
363 				      const struct sockaddr *sa2)
364 {
365 	const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sa1;
366 	const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sa2;
367 
368 	return sin1->sin_addr.s_addr == sin2->sin_addr.s_addr;
369 }
370 
371 static int nfs_sockaddr_cmp_ip6(const struct sockaddr *sa1,
372 				const struct sockaddr *sa2)
373 {
374 	const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sa1;
375 	const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sa2;
376 
377 	return nfs_sockaddr_match_ipaddr6(sa1, sa2) &&
378 		(sin1->sin6_port == sin2->sin6_port);
379 }
380 
381 static int nfs_sockaddr_cmp_ip4(const struct sockaddr *sa1,
382 				const struct sockaddr *sa2)
383 {
384 	const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sa1;
385 	const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sa2;
386 
387 	return nfs_sockaddr_match_ipaddr4(sa1, sa2) &&
388 		(sin1->sin_port == sin2->sin_port);
389 }
390 
391 /*
392  * Test if two socket addresses represent the same actual socket,
393  * by comparing (only) relevant fields, excluding the port number.
394  */
395 static int nfs_sockaddr_match_ipaddr(const struct sockaddr *sa1,
396 				     const struct sockaddr *sa2)
397 {
398 	if (sa1->sa_family != sa2->sa_family)
399 		return 0;
400 
401 	switch (sa1->sa_family) {
402 	case AF_INET:
403 		return nfs_sockaddr_match_ipaddr4(sa1, sa2);
404 	case AF_INET6:
405 		return nfs_sockaddr_match_ipaddr6(sa1, sa2);
406 	}
407 	return 0;
408 }
409 
410 /*
411  * Test if two socket addresses represent the same actual socket,
412  * by comparing (only) relevant fields, including the port number.
413  */
414 static int nfs_sockaddr_cmp(const struct sockaddr *sa1,
415 			    const struct sockaddr *sa2)
416 {
417 	if (sa1->sa_family != sa2->sa_family)
418 		return 0;
419 
420 	switch (sa1->sa_family) {
421 	case AF_INET:
422 		return nfs_sockaddr_cmp_ip4(sa1, sa2);
423 	case AF_INET6:
424 		return nfs_sockaddr_cmp_ip6(sa1, sa2);
425 	}
426 	return 0;
427 }
428 
429 /* Common match routine for v4.0 and v4.1 callback services */
430 bool
431 nfs4_cb_match_client(const struct sockaddr *addr, struct nfs_client *clp,
432 		     u32 minorversion)
433 {
434 	struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
435 
436 	/* Don't match clients that failed to initialise */
437 	if (!(clp->cl_cons_state == NFS_CS_READY ||
438 	    clp->cl_cons_state == NFS_CS_SESSION_INITING))
439 		return false;
440 
441 	/* Match the version and minorversion */
442 	if (clp->rpc_ops->version != 4 ||
443 	    clp->cl_minorversion != minorversion)
444 		return false;
445 
446 	/* Match only the IP address, not the port number */
447 	if (!nfs_sockaddr_match_ipaddr(addr, clap))
448 		return false;
449 
450 	return true;
451 }
452 
453 /*
454  * Find an nfs_client on the list that matches the initialisation data
455  * that is supplied.
456  */
457 static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *data)
458 {
459 	struct nfs_client *clp;
460 	const struct sockaddr *sap = data->addr;
461 
462 	list_for_each_entry(clp, &nfs_client_list, cl_share_link) {
463 	        const struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
464 		/* Don't match clients that failed to initialise properly */
465 		if (clp->cl_cons_state < 0)
466 			continue;
467 
468 		/* Different NFS versions cannot share the same nfs_client */
469 		if (clp->rpc_ops != data->rpc_ops)
470 			continue;
471 
472 		if (clp->cl_proto != data->proto)
473 			continue;
474 		/* Match nfsv4 minorversion */
475 		if (clp->cl_minorversion != data->minorversion)
476 			continue;
477 		/* Match the full socket address */
478 		if (!nfs_sockaddr_cmp(sap, clap))
479 			continue;
480 
481 		atomic_inc(&clp->cl_count);
482 		return clp;
483 	}
484 	return NULL;
485 }
486 
487 /*
488  * Look up a client by IP address and protocol version
489  * - creates a new record if one doesn't yet exist
490  */
491 static struct nfs_client *
492 nfs_get_client(const struct nfs_client_initdata *cl_init,
493 	       const struct rpc_timeout *timeparms,
494 	       const char *ip_addr,
495 	       rpc_authflavor_t authflavour,
496 	       int noresvport)
497 {
498 	struct nfs_client *clp, *new = NULL;
499 	int error;
500 
501 	dprintk("--> nfs_get_client(%s,v%u)\n",
502 		cl_init->hostname ?: "", cl_init->rpc_ops->version);
503 
504 	/* see if the client already exists */
505 	do {
506 		spin_lock(&nfs_client_lock);
507 
508 		clp = nfs_match_client(cl_init);
509 		if (clp)
510 			goto found_client;
511 		if (new)
512 			goto install_client;
513 
514 		spin_unlock(&nfs_client_lock);
515 
516 		new = nfs_alloc_client(cl_init);
517 	} while (!IS_ERR(new));
518 
519 	dprintk("--> nfs_get_client() = %ld [failed]\n", PTR_ERR(new));
520 	return new;
521 
522 	/* install a new client and return with it unready */
523 install_client:
524 	clp = new;
525 	list_add(&clp->cl_share_link, &nfs_client_list);
526 	spin_unlock(&nfs_client_lock);
527 
528 	error = cl_init->rpc_ops->init_client(clp, timeparms, ip_addr,
529 					      authflavour, noresvport);
530 	if (error < 0) {
531 		nfs_put_client(clp);
532 		return ERR_PTR(error);
533 	}
534 	dprintk("--> nfs_get_client() = %p [new]\n", clp);
535 	return clp;
536 
537 	/* found an existing client
538 	 * - make sure it's ready before returning
539 	 */
540 found_client:
541 	spin_unlock(&nfs_client_lock);
542 
543 	if (new)
544 		nfs_free_client(new);
545 
546 	error = wait_event_killable(nfs_client_active_wq,
547 				clp->cl_cons_state < NFS_CS_INITING);
548 	if (error < 0) {
549 		nfs_put_client(clp);
550 		return ERR_PTR(-ERESTARTSYS);
551 	}
552 
553 	if (clp->cl_cons_state < NFS_CS_READY) {
554 		error = clp->cl_cons_state;
555 		nfs_put_client(clp);
556 		return ERR_PTR(error);
557 	}
558 
559 	BUG_ON(clp->cl_cons_state != NFS_CS_READY);
560 
561 	dprintk("--> nfs_get_client() = %p [share]\n", clp);
562 	return clp;
563 }
564 
565 /*
566  * Mark a server as ready or failed
567  */
568 void nfs_mark_client_ready(struct nfs_client *clp, int state)
569 {
570 	clp->cl_cons_state = state;
571 	wake_up_all(&nfs_client_active_wq);
572 }
573 
574 /*
575  * With sessions, the client is not marked ready until after a
576  * successful EXCHANGE_ID and CREATE_SESSION.
577  *
578  * Map errors cl_cons_state errors to EPROTONOSUPPORT to indicate
579  * other versions of NFS can be tried.
580  */
581 int nfs4_check_client_ready(struct nfs_client *clp)
582 {
583 	if (!nfs4_has_session(clp))
584 		return 0;
585 	if (clp->cl_cons_state < NFS_CS_READY)
586 		return -EPROTONOSUPPORT;
587 	return 0;
588 }
589 
590 /*
591  * Initialise the timeout values for a connection
592  */
593 static void nfs_init_timeout_values(struct rpc_timeout *to, int proto,
594 				    unsigned int timeo, unsigned int retrans)
595 {
596 	to->to_initval = timeo * HZ / 10;
597 	to->to_retries = retrans;
598 
599 	switch (proto) {
600 	case XPRT_TRANSPORT_TCP:
601 	case XPRT_TRANSPORT_RDMA:
602 		if (to->to_retries == 0)
603 			to->to_retries = NFS_DEF_TCP_RETRANS;
604 		if (to->to_initval == 0)
605 			to->to_initval = NFS_DEF_TCP_TIMEO * HZ / 10;
606 		if (to->to_initval > NFS_MAX_TCP_TIMEOUT)
607 			to->to_initval = NFS_MAX_TCP_TIMEOUT;
608 		to->to_increment = to->to_initval;
609 		to->to_maxval = to->to_initval + (to->to_increment * to->to_retries);
610 		if (to->to_maxval > NFS_MAX_TCP_TIMEOUT)
611 			to->to_maxval = NFS_MAX_TCP_TIMEOUT;
612 		if (to->to_maxval < to->to_initval)
613 			to->to_maxval = to->to_initval;
614 		to->to_exponential = 0;
615 		break;
616 	case XPRT_TRANSPORT_UDP:
617 		if (to->to_retries == 0)
618 			to->to_retries = NFS_DEF_UDP_RETRANS;
619 		if (!to->to_initval)
620 			to->to_initval = NFS_DEF_UDP_TIMEO * HZ / 10;
621 		if (to->to_initval > NFS_MAX_UDP_TIMEOUT)
622 			to->to_initval = NFS_MAX_UDP_TIMEOUT;
623 		to->to_maxval = NFS_MAX_UDP_TIMEOUT;
624 		to->to_exponential = 1;
625 		break;
626 	default:
627 		BUG();
628 	}
629 }
630 
631 /*
632  * Create an RPC client handle
633  */
634 static int nfs_create_rpc_client(struct nfs_client *clp,
635 				 const struct rpc_timeout *timeparms,
636 				 rpc_authflavor_t flavor,
637 				 int discrtry, int noresvport)
638 {
639 	struct rpc_clnt		*clnt = NULL;
640 	struct rpc_create_args args = {
641 		.net		= &init_net,
642 		.protocol	= clp->cl_proto,
643 		.address	= (struct sockaddr *)&clp->cl_addr,
644 		.addrsize	= clp->cl_addrlen,
645 		.timeout	= timeparms,
646 		.servername	= clp->cl_hostname,
647 		.program	= &nfs_program,
648 		.version	= clp->rpc_ops->version,
649 		.authflavor	= flavor,
650 	};
651 
652 	if (discrtry)
653 		args.flags |= RPC_CLNT_CREATE_DISCRTRY;
654 	if (noresvport)
655 		args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
656 
657 	if (!IS_ERR(clp->cl_rpcclient))
658 		return 0;
659 
660 	clnt = rpc_create(&args);
661 	if (IS_ERR(clnt)) {
662 		dprintk("%s: cannot create RPC client. Error = %ld\n",
663 				__func__, PTR_ERR(clnt));
664 		return PTR_ERR(clnt);
665 	}
666 
667 	clp->cl_rpcclient = clnt;
668 	return 0;
669 }
670 
671 /*
672  * Version 2 or 3 client destruction
673  */
674 static void nfs_destroy_server(struct nfs_server *server)
675 {
676 	if (!(server->flags & NFS_MOUNT_LOCAL_FLOCK) ||
677 			!(server->flags & NFS_MOUNT_LOCAL_FCNTL))
678 		nlmclnt_done(server->nlm_host);
679 }
680 
681 /*
682  * Version 2 or 3 lockd setup
683  */
684 static int nfs_start_lockd(struct nfs_server *server)
685 {
686 	struct nlm_host *host;
687 	struct nfs_client *clp = server->nfs_client;
688 	struct nlmclnt_initdata nlm_init = {
689 		.hostname	= clp->cl_hostname,
690 		.address	= (struct sockaddr *)&clp->cl_addr,
691 		.addrlen	= clp->cl_addrlen,
692 		.nfs_version	= clp->rpc_ops->version,
693 		.noresvport	= server->flags & NFS_MOUNT_NORESVPORT ?
694 					1 : 0,
695 	};
696 
697 	if (nlm_init.nfs_version > 3)
698 		return 0;
699 	if ((server->flags & NFS_MOUNT_LOCAL_FLOCK) &&
700 			(server->flags & NFS_MOUNT_LOCAL_FCNTL))
701 		return 0;
702 
703 	switch (clp->cl_proto) {
704 		default:
705 			nlm_init.protocol = IPPROTO_TCP;
706 			break;
707 		case XPRT_TRANSPORT_UDP:
708 			nlm_init.protocol = IPPROTO_UDP;
709 	}
710 
711 	host = nlmclnt_init(&nlm_init);
712 	if (IS_ERR(host))
713 		return PTR_ERR(host);
714 
715 	server->nlm_host = host;
716 	server->destroy = nfs_destroy_server;
717 	return 0;
718 }
719 
720 /*
721  * Initialise an NFSv3 ACL client connection
722  */
723 #ifdef CONFIG_NFS_V3_ACL
724 static void nfs_init_server_aclclient(struct nfs_server *server)
725 {
726 	if (server->nfs_client->rpc_ops->version != 3)
727 		goto out_noacl;
728 	if (server->flags & NFS_MOUNT_NOACL)
729 		goto out_noacl;
730 
731 	server->client_acl = rpc_bind_new_program(server->client, &nfsacl_program, 3);
732 	if (IS_ERR(server->client_acl))
733 		goto out_noacl;
734 
735 	/* No errors! Assume that Sun nfsacls are supported */
736 	server->caps |= NFS_CAP_ACLS;
737 	return;
738 
739 out_noacl:
740 	server->caps &= ~NFS_CAP_ACLS;
741 }
742 #else
743 static inline void nfs_init_server_aclclient(struct nfs_server *server)
744 {
745 	server->flags &= ~NFS_MOUNT_NOACL;
746 	server->caps &= ~NFS_CAP_ACLS;
747 }
748 #endif
749 
750 /*
751  * Create a general RPC client
752  */
753 static int nfs_init_server_rpcclient(struct nfs_server *server,
754 		const struct rpc_timeout *timeo,
755 		rpc_authflavor_t pseudoflavour)
756 {
757 	struct nfs_client *clp = server->nfs_client;
758 
759 	server->client = rpc_clone_client(clp->cl_rpcclient);
760 	if (IS_ERR(server->client)) {
761 		dprintk("%s: couldn't create rpc_client!\n", __func__);
762 		return PTR_ERR(server->client);
763 	}
764 
765 	memcpy(&server->client->cl_timeout_default,
766 			timeo,
767 			sizeof(server->client->cl_timeout_default));
768 	server->client->cl_timeout = &server->client->cl_timeout_default;
769 
770 	if (pseudoflavour != clp->cl_rpcclient->cl_auth->au_flavor) {
771 		struct rpc_auth *auth;
772 
773 		auth = rpcauth_create(pseudoflavour, server->client);
774 		if (IS_ERR(auth)) {
775 			dprintk("%s: couldn't create credcache!\n", __func__);
776 			return PTR_ERR(auth);
777 		}
778 	}
779 	server->client->cl_softrtry = 0;
780 	if (server->flags & NFS_MOUNT_SOFT)
781 		server->client->cl_softrtry = 1;
782 
783 	return 0;
784 }
785 
786 /*
787  * Initialise an NFS2 or NFS3 client
788  */
789 int nfs_init_client(struct nfs_client *clp, const struct rpc_timeout *timeparms,
790 		    const char *ip_addr, rpc_authflavor_t authflavour,
791 		    int noresvport)
792 {
793 	int error;
794 
795 	if (clp->cl_cons_state == NFS_CS_READY) {
796 		/* the client is already initialised */
797 		dprintk("<-- nfs_init_client() = 0 [already %p]\n", clp);
798 		return 0;
799 	}
800 
801 	/*
802 	 * Create a client RPC handle for doing FSSTAT with UNIX auth only
803 	 * - RFC 2623, sec 2.3.2
804 	 */
805 	error = nfs_create_rpc_client(clp, timeparms, RPC_AUTH_UNIX,
806 				      0, noresvport);
807 	if (error < 0)
808 		goto error;
809 	nfs_mark_client_ready(clp, NFS_CS_READY);
810 	return 0;
811 
812 error:
813 	nfs_mark_client_ready(clp, error);
814 	dprintk("<-- nfs_init_client() = xerror %d\n", error);
815 	return error;
816 }
817 
818 /*
819  * Create a version 2 or 3 client
820  */
821 static int nfs_init_server(struct nfs_server *server,
822 			   const struct nfs_parsed_mount_data *data)
823 {
824 	struct nfs_client_initdata cl_init = {
825 		.hostname = data->nfs_server.hostname,
826 		.addr = (const struct sockaddr *)&data->nfs_server.address,
827 		.addrlen = data->nfs_server.addrlen,
828 		.rpc_ops = &nfs_v2_clientops,
829 		.proto = data->nfs_server.protocol,
830 	};
831 	struct rpc_timeout timeparms;
832 	struct nfs_client *clp;
833 	int error;
834 
835 	dprintk("--> nfs_init_server()\n");
836 
837 #ifdef CONFIG_NFS_V3
838 	if (data->version == 3)
839 		cl_init.rpc_ops = &nfs_v3_clientops;
840 #endif
841 
842 	nfs_init_timeout_values(&timeparms, data->nfs_server.protocol,
843 			data->timeo, data->retrans);
844 
845 	/* Allocate or find a client reference we can use */
846 	clp = nfs_get_client(&cl_init, &timeparms, NULL, RPC_AUTH_UNIX,
847 			     data->flags & NFS_MOUNT_NORESVPORT);
848 	if (IS_ERR(clp)) {
849 		dprintk("<-- nfs_init_server() = error %ld\n", PTR_ERR(clp));
850 		return PTR_ERR(clp);
851 	}
852 
853 	server->nfs_client = clp;
854 
855 	/* Initialise the client representation from the mount data */
856 	server->flags = data->flags;
857 	server->options = data->options;
858 	server->caps |= NFS_CAP_HARDLINKS|NFS_CAP_SYMLINKS|NFS_CAP_FILEID|
859 		NFS_CAP_MODE|NFS_CAP_NLINK|NFS_CAP_OWNER|NFS_CAP_OWNER_GROUP|
860 		NFS_CAP_ATIME|NFS_CAP_CTIME|NFS_CAP_MTIME;
861 
862 	if (data->rsize)
863 		server->rsize = nfs_block_size(data->rsize, NULL);
864 	if (data->wsize)
865 		server->wsize = nfs_block_size(data->wsize, NULL);
866 
867 	server->acregmin = data->acregmin * HZ;
868 	server->acregmax = data->acregmax * HZ;
869 	server->acdirmin = data->acdirmin * HZ;
870 	server->acdirmax = data->acdirmax * HZ;
871 
872 	/* Start lockd here, before we might error out */
873 	error = nfs_start_lockd(server);
874 	if (error < 0)
875 		goto error;
876 
877 	server->port = data->nfs_server.port;
878 
879 	error = nfs_init_server_rpcclient(server, &timeparms, data->auth_flavors[0]);
880 	if (error < 0)
881 		goto error;
882 
883 	/* Preserve the values of mount_server-related mount options */
884 	if (data->mount_server.addrlen) {
885 		memcpy(&server->mountd_address, &data->mount_server.address,
886 			data->mount_server.addrlen);
887 		server->mountd_addrlen = data->mount_server.addrlen;
888 	}
889 	server->mountd_version = data->mount_server.version;
890 	server->mountd_port = data->mount_server.port;
891 	server->mountd_protocol = data->mount_server.protocol;
892 
893 	server->namelen  = data->namlen;
894 	/* Create a client RPC handle for the NFSv3 ACL management interface */
895 	nfs_init_server_aclclient(server);
896 	dprintk("<-- nfs_init_server() = 0 [new %p]\n", clp);
897 	return 0;
898 
899 error:
900 	server->nfs_client = NULL;
901 	nfs_put_client(clp);
902 	dprintk("<-- nfs_init_server() = xerror %d\n", error);
903 	return error;
904 }
905 
906 /*
907  * Load up the server record from information gained in an fsinfo record
908  */
909 static void nfs_server_set_fsinfo(struct nfs_server *server, struct nfs_fsinfo *fsinfo)
910 {
911 	unsigned long max_rpc_payload;
912 
913 	/* Work out a lot of parameters */
914 	if (server->rsize == 0)
915 		server->rsize = nfs_block_size(fsinfo->rtpref, NULL);
916 	if (server->wsize == 0)
917 		server->wsize = nfs_block_size(fsinfo->wtpref, NULL);
918 
919 	if (fsinfo->rtmax >= 512 && server->rsize > fsinfo->rtmax)
920 		server->rsize = nfs_block_size(fsinfo->rtmax, NULL);
921 	if (fsinfo->wtmax >= 512 && server->wsize > fsinfo->wtmax)
922 		server->wsize = nfs_block_size(fsinfo->wtmax, NULL);
923 
924 	max_rpc_payload = nfs_block_size(rpc_max_payload(server->client), NULL);
925 	if (server->rsize > max_rpc_payload)
926 		server->rsize = max_rpc_payload;
927 	if (server->rsize > NFS_MAX_FILE_IO_SIZE)
928 		server->rsize = NFS_MAX_FILE_IO_SIZE;
929 	server->rpages = (server->rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
930 
931 	server->backing_dev_info.name = "nfs";
932 	server->backing_dev_info.ra_pages = server->rpages * NFS_MAX_READAHEAD;
933 
934 	if (server->wsize > max_rpc_payload)
935 		server->wsize = max_rpc_payload;
936 	if (server->wsize > NFS_MAX_FILE_IO_SIZE)
937 		server->wsize = NFS_MAX_FILE_IO_SIZE;
938 	server->wpages = (server->wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
939 	set_pnfs_layoutdriver(server, fsinfo->layouttype);
940 
941 	server->wtmult = nfs_block_bits(fsinfo->wtmult, NULL);
942 
943 	server->dtsize = nfs_block_size(fsinfo->dtpref, NULL);
944 	if (server->dtsize > PAGE_CACHE_SIZE * NFS_MAX_READDIR_PAGES)
945 		server->dtsize = PAGE_CACHE_SIZE * NFS_MAX_READDIR_PAGES;
946 	if (server->dtsize > server->rsize)
947 		server->dtsize = server->rsize;
948 
949 	if (server->flags & NFS_MOUNT_NOAC) {
950 		server->acregmin = server->acregmax = 0;
951 		server->acdirmin = server->acdirmax = 0;
952 	}
953 
954 	server->maxfilesize = fsinfo->maxfilesize;
955 
956 	server->time_delta = fsinfo->time_delta;
957 
958 	/* We're airborne Set socket buffersize */
959 	rpc_setbufsize(server->client, server->wsize + 100, server->rsize + 100);
960 }
961 
962 /*
963  * Probe filesystem information, including the FSID on v2/v3
964  */
965 static int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *mntfh, struct nfs_fattr *fattr)
966 {
967 	struct nfs_fsinfo fsinfo;
968 	struct nfs_client *clp = server->nfs_client;
969 	int error;
970 
971 	dprintk("--> nfs_probe_fsinfo()\n");
972 
973 	if (clp->rpc_ops->set_capabilities != NULL) {
974 		error = clp->rpc_ops->set_capabilities(server, mntfh);
975 		if (error < 0)
976 			goto out_error;
977 	}
978 
979 	fsinfo.fattr = fattr;
980 	fsinfo.layouttype = 0;
981 	error = clp->rpc_ops->fsinfo(server, mntfh, &fsinfo);
982 	if (error < 0)
983 		goto out_error;
984 
985 	nfs_server_set_fsinfo(server, &fsinfo);
986 
987 	/* Get some general file system info */
988 	if (server->namelen == 0) {
989 		struct nfs_pathconf pathinfo;
990 
991 		pathinfo.fattr = fattr;
992 		nfs_fattr_init(fattr);
993 
994 		if (clp->rpc_ops->pathconf(server, mntfh, &pathinfo) >= 0)
995 			server->namelen = pathinfo.max_namelen;
996 	}
997 
998 	dprintk("<-- nfs_probe_fsinfo() = 0\n");
999 	return 0;
1000 
1001 out_error:
1002 	dprintk("nfs_probe_fsinfo: error = %d\n", -error);
1003 	return error;
1004 }
1005 
1006 /*
1007  * Copy useful information when duplicating a server record
1008  */
1009 static void nfs_server_copy_userdata(struct nfs_server *target, struct nfs_server *source)
1010 {
1011 	target->flags = source->flags;
1012 	target->rsize = source->rsize;
1013 	target->wsize = source->wsize;
1014 	target->acregmin = source->acregmin;
1015 	target->acregmax = source->acregmax;
1016 	target->acdirmin = source->acdirmin;
1017 	target->acdirmax = source->acdirmax;
1018 	target->caps = source->caps;
1019 	target->options = source->options;
1020 }
1021 
1022 static void nfs_server_insert_lists(struct nfs_server *server)
1023 {
1024 	struct nfs_client *clp = server->nfs_client;
1025 
1026 	spin_lock(&nfs_client_lock);
1027 	list_add_tail_rcu(&server->client_link, &clp->cl_superblocks);
1028 	list_add_tail(&server->master_link, &nfs_volume_list);
1029 	clear_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
1030 	spin_unlock(&nfs_client_lock);
1031 
1032 }
1033 
1034 static void nfs_server_remove_lists(struct nfs_server *server)
1035 {
1036 	struct nfs_client *clp = server->nfs_client;
1037 
1038 	spin_lock(&nfs_client_lock);
1039 	list_del_rcu(&server->client_link);
1040 	if (clp && list_empty(&clp->cl_superblocks))
1041 		set_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
1042 	list_del(&server->master_link);
1043 	spin_unlock(&nfs_client_lock);
1044 
1045 	synchronize_rcu();
1046 }
1047 
1048 /*
1049  * Allocate and initialise a server record
1050  */
1051 static struct nfs_server *nfs_alloc_server(void)
1052 {
1053 	struct nfs_server *server;
1054 
1055 	server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
1056 	if (!server)
1057 		return NULL;
1058 
1059 	server->client = server->client_acl = ERR_PTR(-EINVAL);
1060 
1061 	/* Zero out the NFS state stuff */
1062 	INIT_LIST_HEAD(&server->client_link);
1063 	INIT_LIST_HEAD(&server->master_link);
1064 	INIT_LIST_HEAD(&server->delegations);
1065 
1066 	atomic_set(&server->active, 0);
1067 
1068 	server->io_stats = nfs_alloc_iostats();
1069 	if (!server->io_stats) {
1070 		kfree(server);
1071 		return NULL;
1072 	}
1073 
1074 	if (bdi_init(&server->backing_dev_info)) {
1075 		nfs_free_iostats(server->io_stats);
1076 		kfree(server);
1077 		return NULL;
1078 	}
1079 
1080 	pnfs_init_server(server);
1081 
1082 	return server;
1083 }
1084 
1085 /*
1086  * Free up a server record
1087  */
1088 void nfs_free_server(struct nfs_server *server)
1089 {
1090 	dprintk("--> nfs_free_server()\n");
1091 
1092 	nfs_server_remove_lists(server);
1093 	unset_pnfs_layoutdriver(server);
1094 
1095 	if (server->destroy != NULL)
1096 		server->destroy(server);
1097 
1098 	if (!IS_ERR(server->client_acl))
1099 		rpc_shutdown_client(server->client_acl);
1100 	if (!IS_ERR(server->client))
1101 		rpc_shutdown_client(server->client);
1102 
1103 	nfs_put_client(server->nfs_client);
1104 
1105 	nfs_free_iostats(server->io_stats);
1106 	bdi_destroy(&server->backing_dev_info);
1107 	kfree(server);
1108 	nfs_release_automount_timer();
1109 	dprintk("<-- nfs_free_server()\n");
1110 }
1111 
1112 /*
1113  * Create a version 2 or 3 volume record
1114  * - keyed on server and FSID
1115  */
1116 struct nfs_server *nfs_create_server(const struct nfs_parsed_mount_data *data,
1117 				     struct nfs_fh *mntfh)
1118 {
1119 	struct nfs_server *server;
1120 	struct nfs_fattr *fattr;
1121 	int error;
1122 
1123 	server = nfs_alloc_server();
1124 	if (!server)
1125 		return ERR_PTR(-ENOMEM);
1126 
1127 	error = -ENOMEM;
1128 	fattr = nfs_alloc_fattr();
1129 	if (fattr == NULL)
1130 		goto error;
1131 
1132 	/* Get a client representation */
1133 	error = nfs_init_server(server, data);
1134 	if (error < 0)
1135 		goto error;
1136 
1137 	BUG_ON(!server->nfs_client);
1138 	BUG_ON(!server->nfs_client->rpc_ops);
1139 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
1140 
1141 	/* Probe the root fh to retrieve its FSID */
1142 	error = nfs_probe_fsinfo(server, mntfh, fattr);
1143 	if (error < 0)
1144 		goto error;
1145 	if (server->nfs_client->rpc_ops->version == 3) {
1146 		if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN)
1147 			server->namelen = NFS3_MAXNAMLEN;
1148 		if (!(data->flags & NFS_MOUNT_NORDIRPLUS))
1149 			server->caps |= NFS_CAP_READDIRPLUS;
1150 	} else {
1151 		if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN)
1152 			server->namelen = NFS2_MAXNAMLEN;
1153 	}
1154 
1155 	if (!(fattr->valid & NFS_ATTR_FATTR)) {
1156 		error = server->nfs_client->rpc_ops->getattr(server, mntfh, fattr);
1157 		if (error < 0) {
1158 			dprintk("nfs_create_server: getattr error = %d\n", -error);
1159 			goto error;
1160 		}
1161 	}
1162 	memcpy(&server->fsid, &fattr->fsid, sizeof(server->fsid));
1163 
1164 	dprintk("Server FSID: %llx:%llx\n",
1165 		(unsigned long long) server->fsid.major,
1166 		(unsigned long long) server->fsid.minor);
1167 
1168 	nfs_server_insert_lists(server);
1169 	server->mount_time = jiffies;
1170 	nfs_free_fattr(fattr);
1171 	return server;
1172 
1173 error:
1174 	nfs_free_fattr(fattr);
1175 	nfs_free_server(server);
1176 	return ERR_PTR(error);
1177 }
1178 
1179 #ifdef CONFIG_NFS_V4
1180 /*
1181  * NFSv4.0 callback thread helper
1182  *
1183  * Find a client by IP address, protocol version, and minorversion
1184  *
1185  * Called from the pg_authenticate method. The callback identifier
1186  * is not used as it has not been decoded.
1187  *
1188  * Returns NULL if no such client
1189  */
1190 struct nfs_client *
1191 nfs4_find_client_no_ident(const struct sockaddr *addr)
1192 {
1193 	struct nfs_client *clp;
1194 
1195 	spin_lock(&nfs_client_lock);
1196 	list_for_each_entry(clp, &nfs_client_list, cl_share_link) {
1197 		if (nfs4_cb_match_client(addr, clp, 0) == false)
1198 			continue;
1199 		atomic_inc(&clp->cl_count);
1200 		spin_unlock(&nfs_client_lock);
1201 		return clp;
1202 	}
1203 	spin_unlock(&nfs_client_lock);
1204 	return NULL;
1205 }
1206 
1207 /*
1208  * NFSv4.0 callback thread helper
1209  *
1210  * Find a client by callback identifier
1211  */
1212 struct nfs_client *
1213 nfs4_find_client_ident(int cb_ident)
1214 {
1215 	struct nfs_client *clp;
1216 
1217 	spin_lock(&nfs_client_lock);
1218 	clp = idr_find(&cb_ident_idr, cb_ident);
1219 	if (clp)
1220 		atomic_inc(&clp->cl_count);
1221 	spin_unlock(&nfs_client_lock);
1222 	return clp;
1223 }
1224 
1225 #if defined(CONFIG_NFS_V4_1)
1226 /*
1227  * NFSv4.1 callback thread helper
1228  * For CB_COMPOUND calls, find a client by IP address, protocol version,
1229  * minorversion, and sessionID
1230  *
1231  * Returns NULL if no such client
1232  */
1233 struct nfs_client *
1234 nfs4_find_client_sessionid(const struct sockaddr *addr,
1235 			   struct nfs4_sessionid *sid)
1236 {
1237 	struct nfs_client *clp;
1238 
1239 	spin_lock(&nfs_client_lock);
1240 	list_for_each_entry(clp, &nfs_client_list, cl_share_link) {
1241 		if (nfs4_cb_match_client(addr, clp, 1) == false)
1242 			continue;
1243 
1244 		if (!nfs4_has_session(clp))
1245 			continue;
1246 
1247 		/* Match sessionid*/
1248 		if (memcmp(clp->cl_session->sess_id.data,
1249 		    sid->data, NFS4_MAX_SESSIONID_LEN) != 0)
1250 			continue;
1251 
1252 		atomic_inc(&clp->cl_count);
1253 		spin_unlock(&nfs_client_lock);
1254 		return clp;
1255 	}
1256 	spin_unlock(&nfs_client_lock);
1257 	return NULL;
1258 }
1259 
1260 #else /* CONFIG_NFS_V4_1 */
1261 
1262 struct nfs_client *
1263 nfs4_find_client_sessionid(const struct sockaddr *addr,
1264 			   struct nfs4_sessionid *sid)
1265 {
1266 	return NULL;
1267 }
1268 #endif /* CONFIG_NFS_V4_1 */
1269 
1270 /*
1271  * Initialize the NFS4 callback service
1272  */
1273 static int nfs4_init_callback(struct nfs_client *clp)
1274 {
1275 	int error;
1276 
1277 	if (clp->rpc_ops->version == 4) {
1278 		if (nfs4_has_session(clp)) {
1279 			error = xprt_setup_backchannel(
1280 						clp->cl_rpcclient->cl_xprt,
1281 						NFS41_BC_MIN_CALLBACKS);
1282 			if (error < 0)
1283 				return error;
1284 		}
1285 
1286 		error = nfs_callback_up(clp->cl_mvops->minor_version,
1287 					clp->cl_rpcclient->cl_xprt);
1288 		if (error < 0) {
1289 			dprintk("%s: failed to start callback. Error = %d\n",
1290 				__func__, error);
1291 			return error;
1292 		}
1293 		__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
1294 	}
1295 	return 0;
1296 }
1297 
1298 /*
1299  * Initialize the minor version specific parts of an NFS4 client record
1300  */
1301 static int nfs4_init_client_minor_version(struct nfs_client *clp)
1302 {
1303 #if defined(CONFIG_NFS_V4_1)
1304 	if (clp->cl_mvops->minor_version) {
1305 		struct nfs4_session *session = NULL;
1306 		/*
1307 		 * Create the session and mark it expired.
1308 		 * When a SEQUENCE operation encounters the expired session
1309 		 * it will do session recovery to initialize it.
1310 		 */
1311 		session = nfs4_alloc_session(clp);
1312 		if (!session)
1313 			return -ENOMEM;
1314 
1315 		clp->cl_session = session;
1316 		/*
1317 		 * The create session reply races with the server back
1318 		 * channel probe. Mark the client NFS_CS_SESSION_INITING
1319 		 * so that the client back channel can find the
1320 		 * nfs_client struct
1321 		 */
1322 		clp->cl_cons_state = NFS_CS_SESSION_INITING;
1323 	}
1324 #endif /* CONFIG_NFS_V4_1 */
1325 
1326 	return nfs4_init_callback(clp);
1327 }
1328 
1329 /*
1330  * Initialise an NFS4 client record
1331  */
1332 int nfs4_init_client(struct nfs_client *clp,
1333 		     const struct rpc_timeout *timeparms,
1334 		     const char *ip_addr,
1335 		     rpc_authflavor_t authflavour,
1336 		     int noresvport)
1337 {
1338 	int error;
1339 
1340 	if (clp->cl_cons_state == NFS_CS_READY) {
1341 		/* the client is initialised already */
1342 		dprintk("<-- nfs4_init_client() = 0 [already %p]\n", clp);
1343 		return 0;
1344 	}
1345 
1346 	/* Check NFS protocol revision and initialize RPC op vector */
1347 	clp->rpc_ops = &nfs_v4_clientops;
1348 
1349 	error = nfs_create_rpc_client(clp, timeparms, authflavour,
1350 				      1, noresvport);
1351 	if (error < 0)
1352 		goto error;
1353 	strlcpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr));
1354 
1355 	error = nfs_idmap_new(clp);
1356 	if (error < 0) {
1357 		dprintk("%s: failed to create idmapper. Error = %d\n",
1358 			__func__, error);
1359 		goto error;
1360 	}
1361 	__set_bit(NFS_CS_IDMAP, &clp->cl_res_state);
1362 
1363 	error = nfs4_init_client_minor_version(clp);
1364 	if (error < 0)
1365 		goto error;
1366 
1367 	if (!nfs4_has_session(clp))
1368 		nfs_mark_client_ready(clp, NFS_CS_READY);
1369 	return 0;
1370 
1371 error:
1372 	nfs_mark_client_ready(clp, error);
1373 	dprintk("<-- nfs4_init_client() = xerror %d\n", error);
1374 	return error;
1375 }
1376 
1377 /*
1378  * Set up an NFS4 client
1379  */
1380 static int nfs4_set_client(struct nfs_server *server,
1381 		const char *hostname,
1382 		const struct sockaddr *addr,
1383 		const size_t addrlen,
1384 		const char *ip_addr,
1385 		rpc_authflavor_t authflavour,
1386 		int proto, const struct rpc_timeout *timeparms,
1387 		u32 minorversion)
1388 {
1389 	struct nfs_client_initdata cl_init = {
1390 		.hostname = hostname,
1391 		.addr = addr,
1392 		.addrlen = addrlen,
1393 		.rpc_ops = &nfs_v4_clientops,
1394 		.proto = proto,
1395 		.minorversion = minorversion,
1396 	};
1397 	struct nfs_client *clp;
1398 	int error;
1399 
1400 	dprintk("--> nfs4_set_client()\n");
1401 
1402 	/* Allocate or find a client reference we can use */
1403 	clp = nfs_get_client(&cl_init, timeparms, ip_addr, authflavour,
1404 			     server->flags & NFS_MOUNT_NORESVPORT);
1405 	if (IS_ERR(clp)) {
1406 		error = PTR_ERR(clp);
1407 		goto error;
1408 	}
1409 
1410 	/*
1411 	 * Query for the lease time on clientid setup or renewal
1412 	 *
1413 	 * Note that this will be set on nfs_clients that were created
1414 	 * only for the DS role and did not set this bit, but now will
1415 	 * serve a dual role.
1416 	 */
1417 	set_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state);
1418 
1419 	server->nfs_client = clp;
1420 	dprintk("<-- nfs4_set_client() = 0 [new %p]\n", clp);
1421 	return 0;
1422 error:
1423 	dprintk("<-- nfs4_set_client() = xerror %d\n", error);
1424 	return error;
1425 }
1426 
1427 /*
1428  * Set up a pNFS Data Server client.
1429  *
1430  * Return any existing nfs_client that matches server address,port,version
1431  * and minorversion.
1432  *
1433  * For a new nfs_client, use a soft mount (default), a low retrans and a
1434  * low timeout interval so that if a connection is lost, we retry through
1435  * the MDS.
1436  */
1437 struct nfs_client *nfs4_set_ds_client(struct nfs_client* mds_clp,
1438 		const struct sockaddr *ds_addr,
1439 		int ds_addrlen, int ds_proto)
1440 {
1441 	struct nfs_client_initdata cl_init = {
1442 		.addr = ds_addr,
1443 		.addrlen = ds_addrlen,
1444 		.rpc_ops = &nfs_v4_clientops,
1445 		.proto = ds_proto,
1446 		.minorversion = mds_clp->cl_minorversion,
1447 	};
1448 	struct rpc_timeout ds_timeout = {
1449 		.to_initval = 15 * HZ,
1450 		.to_maxval = 15 * HZ,
1451 		.to_retries = 1,
1452 		.to_exponential = 1,
1453 	};
1454 	struct nfs_client *clp;
1455 
1456 	/*
1457 	 * Set an authflavor equual to the MDS value. Use the MDS nfs_client
1458 	 * cl_ipaddr so as to use the same EXCHANGE_ID co_ownerid as the MDS
1459 	 * (section 13.1 RFC 5661).
1460 	 */
1461 	clp = nfs_get_client(&cl_init, &ds_timeout, mds_clp->cl_ipaddr,
1462 			     mds_clp->cl_rpcclient->cl_auth->au_flavor, 0);
1463 
1464 	dprintk("<-- %s %p\n", __func__, clp);
1465 	return clp;
1466 }
1467 EXPORT_SYMBOL(nfs4_set_ds_client);
1468 
1469 /*
1470  * Session has been established, and the client marked ready.
1471  * Set the mount rsize and wsize with negotiated fore channel
1472  * attributes which will be bound checked in nfs_server_set_fsinfo.
1473  */
1474 static void nfs4_session_set_rwsize(struct nfs_server *server)
1475 {
1476 #ifdef CONFIG_NFS_V4_1
1477 	struct nfs4_session *sess;
1478 	u32 server_resp_sz;
1479 	u32 server_rqst_sz;
1480 
1481 	if (!nfs4_has_session(server->nfs_client))
1482 		return;
1483 	sess = server->nfs_client->cl_session;
1484 	server_resp_sz = sess->fc_attrs.max_resp_sz - nfs41_maxread_overhead;
1485 	server_rqst_sz = sess->fc_attrs.max_rqst_sz - nfs41_maxwrite_overhead;
1486 
1487 	if (server->rsize > server_resp_sz)
1488 		server->rsize = server_resp_sz;
1489 	if (server->wsize > server_rqst_sz)
1490 		server->wsize = server_rqst_sz;
1491 #endif /* CONFIG_NFS_V4_1 */
1492 }
1493 
1494 static int nfs4_server_common_setup(struct nfs_server *server,
1495 		struct nfs_fh *mntfh)
1496 {
1497 	struct nfs_fattr *fattr;
1498 	int error;
1499 
1500 	BUG_ON(!server->nfs_client);
1501 	BUG_ON(!server->nfs_client->rpc_ops);
1502 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
1503 
1504 	/* data servers support only a subset of NFSv4.1 */
1505 	if (is_ds_only_client(server->nfs_client))
1506 		return -EPROTONOSUPPORT;
1507 
1508 	fattr = nfs_alloc_fattr();
1509 	if (fattr == NULL)
1510 		return -ENOMEM;
1511 
1512 	/* We must ensure the session is initialised first */
1513 	error = nfs4_init_session(server);
1514 	if (error < 0)
1515 		goto out;
1516 
1517 	/* Probe the root fh to retrieve its FSID and filehandle */
1518 	error = nfs4_get_rootfh(server, mntfh);
1519 	if (error < 0)
1520 		goto out;
1521 
1522 	dprintk("Server FSID: %llx:%llx\n",
1523 			(unsigned long long) server->fsid.major,
1524 			(unsigned long long) server->fsid.minor);
1525 	dprintk("Mount FH: %d\n", mntfh->size);
1526 
1527 	nfs4_session_set_rwsize(server);
1528 
1529 	error = nfs_probe_fsinfo(server, mntfh, fattr);
1530 	if (error < 0)
1531 		goto out;
1532 
1533 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1534 		server->namelen = NFS4_MAXNAMLEN;
1535 
1536 	nfs_server_insert_lists(server);
1537 	server->mount_time = jiffies;
1538 out:
1539 	nfs_free_fattr(fattr);
1540 	return error;
1541 }
1542 
1543 /*
1544  * Create a version 4 volume record
1545  */
1546 static int nfs4_init_server(struct nfs_server *server,
1547 		const struct nfs_parsed_mount_data *data)
1548 {
1549 	struct rpc_timeout timeparms;
1550 	int error;
1551 
1552 	dprintk("--> nfs4_init_server()\n");
1553 
1554 	nfs_init_timeout_values(&timeparms, data->nfs_server.protocol,
1555 			data->timeo, data->retrans);
1556 
1557 	/* Initialise the client representation from the mount data */
1558 	server->flags = data->flags;
1559 	server->caps |= NFS_CAP_ATOMIC_OPEN|NFS_CAP_CHANGE_ATTR|NFS_CAP_POSIX_LOCK;
1560 	if (!(data->flags & NFS_MOUNT_NORDIRPLUS))
1561 			server->caps |= NFS_CAP_READDIRPLUS;
1562 	server->options = data->options;
1563 
1564 	/* Get a client record */
1565 	error = nfs4_set_client(server,
1566 			data->nfs_server.hostname,
1567 			(const struct sockaddr *)&data->nfs_server.address,
1568 			data->nfs_server.addrlen,
1569 			data->client_address,
1570 			data->auth_flavors[0],
1571 			data->nfs_server.protocol,
1572 			&timeparms,
1573 			data->minorversion);
1574 	if (error < 0)
1575 		goto error;
1576 
1577 	/*
1578 	 * Don't use NFS uid/gid mapping if we're using AUTH_SYS or lower
1579 	 * authentication.
1580 	 */
1581 	if (nfs4_disable_idmapping && data->auth_flavors[0] == RPC_AUTH_UNIX)
1582 		server->caps |= NFS_CAP_UIDGID_NOMAP;
1583 
1584 	if (data->rsize)
1585 		server->rsize = nfs_block_size(data->rsize, NULL);
1586 	if (data->wsize)
1587 		server->wsize = nfs_block_size(data->wsize, NULL);
1588 
1589 	server->acregmin = data->acregmin * HZ;
1590 	server->acregmax = data->acregmax * HZ;
1591 	server->acdirmin = data->acdirmin * HZ;
1592 	server->acdirmax = data->acdirmax * HZ;
1593 
1594 	server->port = data->nfs_server.port;
1595 
1596 	error = nfs_init_server_rpcclient(server, &timeparms, data->auth_flavors[0]);
1597 
1598 error:
1599 	/* Done */
1600 	dprintk("<-- nfs4_init_server() = %d\n", error);
1601 	return error;
1602 }
1603 
1604 /*
1605  * Create a version 4 volume record
1606  * - keyed on server and FSID
1607  */
1608 struct nfs_server *nfs4_create_server(const struct nfs_parsed_mount_data *data,
1609 				      struct nfs_fh *mntfh)
1610 {
1611 	struct nfs_server *server;
1612 	int error;
1613 
1614 	dprintk("--> nfs4_create_server()\n");
1615 
1616 	server = nfs_alloc_server();
1617 	if (!server)
1618 		return ERR_PTR(-ENOMEM);
1619 
1620 	/* set up the general RPC client */
1621 	error = nfs4_init_server(server, data);
1622 	if (error < 0)
1623 		goto error;
1624 
1625 	error = nfs4_server_common_setup(server, mntfh);
1626 	if (error < 0)
1627 		goto error;
1628 
1629 	dprintk("<-- nfs4_create_server() = %p\n", server);
1630 	return server;
1631 
1632 error:
1633 	nfs_free_server(server);
1634 	dprintk("<-- nfs4_create_server() = error %d\n", error);
1635 	return ERR_PTR(error);
1636 }
1637 
1638 /*
1639  * Create an NFS4 referral server record
1640  */
1641 struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data,
1642 					       struct nfs_fh *mntfh)
1643 {
1644 	struct nfs_client *parent_client;
1645 	struct nfs_server *server, *parent_server;
1646 	int error;
1647 
1648 	dprintk("--> nfs4_create_referral_server()\n");
1649 
1650 	server = nfs_alloc_server();
1651 	if (!server)
1652 		return ERR_PTR(-ENOMEM);
1653 
1654 	parent_server = NFS_SB(data->sb);
1655 	parent_client = parent_server->nfs_client;
1656 
1657 	/* Initialise the client representation from the parent server */
1658 	nfs_server_copy_userdata(server, parent_server);
1659 	server->caps |= NFS_CAP_ATOMIC_OPEN|NFS_CAP_CHANGE_ATTR;
1660 
1661 	/* Get a client representation.
1662 	 * Note: NFSv4 always uses TCP, */
1663 	error = nfs4_set_client(server, data->hostname,
1664 				data->addr,
1665 				data->addrlen,
1666 				parent_client->cl_ipaddr,
1667 				data->authflavor,
1668 				parent_server->client->cl_xprt->prot,
1669 				parent_server->client->cl_timeout,
1670 				parent_client->cl_mvops->minor_version);
1671 	if (error < 0)
1672 		goto error;
1673 
1674 	error = nfs_init_server_rpcclient(server, parent_server->client->cl_timeout, data->authflavor);
1675 	if (error < 0)
1676 		goto error;
1677 
1678 	error = nfs4_server_common_setup(server, mntfh);
1679 	if (error < 0)
1680 		goto error;
1681 
1682 	dprintk("<-- nfs_create_referral_server() = %p\n", server);
1683 	return server;
1684 
1685 error:
1686 	nfs_free_server(server);
1687 	dprintk("<-- nfs4_create_referral_server() = error %d\n", error);
1688 	return ERR_PTR(error);
1689 }
1690 
1691 #endif /* CONFIG_NFS_V4 */
1692 
1693 /*
1694  * Clone an NFS2, NFS3 or NFS4 server record
1695  */
1696 struct nfs_server *nfs_clone_server(struct nfs_server *source,
1697 				    struct nfs_fh *fh,
1698 				    struct nfs_fattr *fattr)
1699 {
1700 	struct nfs_server *server;
1701 	struct nfs_fattr *fattr_fsinfo;
1702 	int error;
1703 
1704 	dprintk("--> nfs_clone_server(,%llx:%llx,)\n",
1705 		(unsigned long long) fattr->fsid.major,
1706 		(unsigned long long) fattr->fsid.minor);
1707 
1708 	server = nfs_alloc_server();
1709 	if (!server)
1710 		return ERR_PTR(-ENOMEM);
1711 
1712 	error = -ENOMEM;
1713 	fattr_fsinfo = nfs_alloc_fattr();
1714 	if (fattr_fsinfo == NULL)
1715 		goto out_free_server;
1716 
1717 	/* Copy data from the source */
1718 	server->nfs_client = source->nfs_client;
1719 	atomic_inc(&server->nfs_client->cl_count);
1720 	nfs_server_copy_userdata(server, source);
1721 
1722 	server->fsid = fattr->fsid;
1723 
1724 	error = nfs_init_server_rpcclient(server,
1725 			source->client->cl_timeout,
1726 			source->client->cl_auth->au_flavor);
1727 	if (error < 0)
1728 		goto out_free_server;
1729 	if (!IS_ERR(source->client_acl))
1730 		nfs_init_server_aclclient(server);
1731 
1732 	/* probe the filesystem info for this server filesystem */
1733 	error = nfs_probe_fsinfo(server, fh, fattr_fsinfo);
1734 	if (error < 0)
1735 		goto out_free_server;
1736 
1737 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1738 		server->namelen = NFS4_MAXNAMLEN;
1739 
1740 	dprintk("Cloned FSID: %llx:%llx\n",
1741 		(unsigned long long) server->fsid.major,
1742 		(unsigned long long) server->fsid.minor);
1743 
1744 	error = nfs_start_lockd(server);
1745 	if (error < 0)
1746 		goto out_free_server;
1747 
1748 	nfs_server_insert_lists(server);
1749 	server->mount_time = jiffies;
1750 
1751 	nfs_free_fattr(fattr_fsinfo);
1752 	dprintk("<-- nfs_clone_server() = %p\n", server);
1753 	return server;
1754 
1755 out_free_server:
1756 	nfs_free_fattr(fattr_fsinfo);
1757 	nfs_free_server(server);
1758 	dprintk("<-- nfs_clone_server() = error %d\n", error);
1759 	return ERR_PTR(error);
1760 }
1761 
1762 #ifdef CONFIG_PROC_FS
1763 static struct proc_dir_entry *proc_fs_nfs;
1764 
1765 static int nfs_server_list_open(struct inode *inode, struct file *file);
1766 static void *nfs_server_list_start(struct seq_file *p, loff_t *pos);
1767 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos);
1768 static void nfs_server_list_stop(struct seq_file *p, void *v);
1769 static int nfs_server_list_show(struct seq_file *m, void *v);
1770 
1771 static const struct seq_operations nfs_server_list_ops = {
1772 	.start	= nfs_server_list_start,
1773 	.next	= nfs_server_list_next,
1774 	.stop	= nfs_server_list_stop,
1775 	.show	= nfs_server_list_show,
1776 };
1777 
1778 static const struct file_operations nfs_server_list_fops = {
1779 	.open		= nfs_server_list_open,
1780 	.read		= seq_read,
1781 	.llseek		= seq_lseek,
1782 	.release	= seq_release,
1783 	.owner		= THIS_MODULE,
1784 };
1785 
1786 static int nfs_volume_list_open(struct inode *inode, struct file *file);
1787 static void *nfs_volume_list_start(struct seq_file *p, loff_t *pos);
1788 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos);
1789 static void nfs_volume_list_stop(struct seq_file *p, void *v);
1790 static int nfs_volume_list_show(struct seq_file *m, void *v);
1791 
1792 static const struct seq_operations nfs_volume_list_ops = {
1793 	.start	= nfs_volume_list_start,
1794 	.next	= nfs_volume_list_next,
1795 	.stop	= nfs_volume_list_stop,
1796 	.show	= nfs_volume_list_show,
1797 };
1798 
1799 static const struct file_operations nfs_volume_list_fops = {
1800 	.open		= nfs_volume_list_open,
1801 	.read		= seq_read,
1802 	.llseek		= seq_lseek,
1803 	.release	= seq_release,
1804 	.owner		= THIS_MODULE,
1805 };
1806 
1807 /*
1808  * open "/proc/fs/nfsfs/servers" which provides a summary of servers with which
1809  * we're dealing
1810  */
1811 static int nfs_server_list_open(struct inode *inode, struct file *file)
1812 {
1813 	struct seq_file *m;
1814 	int ret;
1815 
1816 	ret = seq_open(file, &nfs_server_list_ops);
1817 	if (ret < 0)
1818 		return ret;
1819 
1820 	m = file->private_data;
1821 	m->private = PDE(inode)->data;
1822 
1823 	return 0;
1824 }
1825 
1826 /*
1827  * set up the iterator to start reading from the server list and return the first item
1828  */
1829 static void *nfs_server_list_start(struct seq_file *m, loff_t *_pos)
1830 {
1831 	/* lock the list against modification */
1832 	spin_lock(&nfs_client_lock);
1833 	return seq_list_start_head(&nfs_client_list, *_pos);
1834 }
1835 
1836 /*
1837  * move to next server
1838  */
1839 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos)
1840 {
1841 	return seq_list_next(v, &nfs_client_list, pos);
1842 }
1843 
1844 /*
1845  * clean up after reading from the transports list
1846  */
1847 static void nfs_server_list_stop(struct seq_file *p, void *v)
1848 {
1849 	spin_unlock(&nfs_client_lock);
1850 }
1851 
1852 /*
1853  * display a header line followed by a load of call lines
1854  */
1855 static int nfs_server_list_show(struct seq_file *m, void *v)
1856 {
1857 	struct nfs_client *clp;
1858 
1859 	/* display header on line 1 */
1860 	if (v == &nfs_client_list) {
1861 		seq_puts(m, "NV SERVER   PORT USE HOSTNAME\n");
1862 		return 0;
1863 	}
1864 
1865 	/* display one transport per line on subsequent lines */
1866 	clp = list_entry(v, struct nfs_client, cl_share_link);
1867 
1868 	seq_printf(m, "v%u %s %s %3d %s\n",
1869 		   clp->rpc_ops->version,
1870 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1871 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1872 		   atomic_read(&clp->cl_count),
1873 		   clp->cl_hostname);
1874 
1875 	return 0;
1876 }
1877 
1878 /*
1879  * open "/proc/fs/nfsfs/volumes" which provides a summary of extant volumes
1880  */
1881 static int nfs_volume_list_open(struct inode *inode, struct file *file)
1882 {
1883 	struct seq_file *m;
1884 	int ret;
1885 
1886 	ret = seq_open(file, &nfs_volume_list_ops);
1887 	if (ret < 0)
1888 		return ret;
1889 
1890 	m = file->private_data;
1891 	m->private = PDE(inode)->data;
1892 
1893 	return 0;
1894 }
1895 
1896 /*
1897  * set up the iterator to start reading from the volume list and return the first item
1898  */
1899 static void *nfs_volume_list_start(struct seq_file *m, loff_t *_pos)
1900 {
1901 	/* lock the list against modification */
1902 	spin_lock(&nfs_client_lock);
1903 	return seq_list_start_head(&nfs_volume_list, *_pos);
1904 }
1905 
1906 /*
1907  * move to next volume
1908  */
1909 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos)
1910 {
1911 	return seq_list_next(v, &nfs_volume_list, pos);
1912 }
1913 
1914 /*
1915  * clean up after reading from the transports list
1916  */
1917 static void nfs_volume_list_stop(struct seq_file *p, void *v)
1918 {
1919 	spin_unlock(&nfs_client_lock);
1920 }
1921 
1922 /*
1923  * display a header line followed by a load of call lines
1924  */
1925 static int nfs_volume_list_show(struct seq_file *m, void *v)
1926 {
1927 	struct nfs_server *server;
1928 	struct nfs_client *clp;
1929 	char dev[8], fsid[17];
1930 
1931 	/* display header on line 1 */
1932 	if (v == &nfs_volume_list) {
1933 		seq_puts(m, "NV SERVER   PORT DEV     FSID              FSC\n");
1934 		return 0;
1935 	}
1936 	/* display one transport per line on subsequent lines */
1937 	server = list_entry(v, struct nfs_server, master_link);
1938 	clp = server->nfs_client;
1939 
1940 	snprintf(dev, 8, "%u:%u",
1941 		 MAJOR(server->s_dev), MINOR(server->s_dev));
1942 
1943 	snprintf(fsid, 17, "%llx:%llx",
1944 		 (unsigned long long) server->fsid.major,
1945 		 (unsigned long long) server->fsid.minor);
1946 
1947 	seq_printf(m, "v%u %s %s %-7s %-17s %s\n",
1948 		   clp->rpc_ops->version,
1949 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1950 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1951 		   dev,
1952 		   fsid,
1953 		   nfs_server_fscache_state(server));
1954 
1955 	return 0;
1956 }
1957 
1958 /*
1959  * initialise the /proc/fs/nfsfs/ directory
1960  */
1961 int __init nfs_fs_proc_init(void)
1962 {
1963 	struct proc_dir_entry *p;
1964 
1965 	proc_fs_nfs = proc_mkdir("fs/nfsfs", NULL);
1966 	if (!proc_fs_nfs)
1967 		goto error_0;
1968 
1969 	/* a file of servers with which we're dealing */
1970 	p = proc_create("servers", S_IFREG|S_IRUGO,
1971 			proc_fs_nfs, &nfs_server_list_fops);
1972 	if (!p)
1973 		goto error_1;
1974 
1975 	/* a file of volumes that we have mounted */
1976 	p = proc_create("volumes", S_IFREG|S_IRUGO,
1977 			proc_fs_nfs, &nfs_volume_list_fops);
1978 	if (!p)
1979 		goto error_2;
1980 	return 0;
1981 
1982 error_2:
1983 	remove_proc_entry("servers", proc_fs_nfs);
1984 error_1:
1985 	remove_proc_entry("fs/nfsfs", NULL);
1986 error_0:
1987 	return -ENOMEM;
1988 }
1989 
1990 /*
1991  * clean up the /proc/fs/nfsfs/ directory
1992  */
1993 void nfs_fs_proc_exit(void)
1994 {
1995 	remove_proc_entry("volumes", proc_fs_nfs);
1996 	remove_proc_entry("servers", proc_fs_nfs);
1997 	remove_proc_entry("fs/nfsfs", NULL);
1998 }
1999 
2000 #endif /* CONFIG_PROC_FS */
2001 
2002 module_param(nfs4_disable_idmapping, bool, 0644);
2003 MODULE_PARM_DESC(nfs4_disable_idmapping,
2004 		"Turn off NFSv4 idmapping when using 'sec=sys'");
2005