xref: /linux/fs/nfs/client.c (revision 5bdef865eb358b6f3760e25e591ae115e9eeddef)
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 <net/ipv6.h>
39 #include <linux/nfs_xdr.h>
40 #include <linux/sunrpc/bc_xprt.h>
41 
42 #include <asm/system.h>
43 
44 #include "nfs4_fs.h"
45 #include "callback.h"
46 #include "delegation.h"
47 #include "iostat.h"
48 #include "internal.h"
49 #include "fscache.h"
50 
51 #define NFSDBG_FACILITY		NFSDBG_CLIENT
52 
53 static DEFINE_SPINLOCK(nfs_client_lock);
54 static LIST_HEAD(nfs_client_list);
55 static LIST_HEAD(nfs_volume_list);
56 static DECLARE_WAIT_QUEUE_HEAD(nfs_client_active_wq);
57 
58 /*
59  * RPC cruft for NFS
60  */
61 static struct rpc_version *nfs_version[5] = {
62 	[2]			= &nfs_version2,
63 #ifdef CONFIG_NFS_V3
64 	[3]			= &nfs_version3,
65 #endif
66 #ifdef CONFIG_NFS_V4
67 	[4]			= &nfs_version4,
68 #endif
69 };
70 
71 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",
78 };
79 
80 struct rpc_stat nfs_rpcstat = {
81 	.program		= &nfs_program
82 };
83 
84 
85 #ifdef CONFIG_NFS_V3_ACL
86 static struct rpc_stat		nfsacl_rpcstat = { &nfsacl_program };
87 static struct rpc_version *	nfsacl_version[] = {
88 	[3]			= &nfsacl_version3,
89 };
90 
91 struct rpc_program		nfsacl_program = {
92 	.name			= "nfsacl",
93 	.number			= NFS_ACL_PROGRAM,
94 	.nrvers			= ARRAY_SIZE(nfsacl_version),
95 	.version		= nfsacl_version,
96 	.stats			= &nfsacl_rpcstat,
97 };
98 #endif  /* CONFIG_NFS_V3_ACL */
99 
100 struct nfs_client_initdata {
101 	const char *hostname;
102 	const struct sockaddr *addr;
103 	size_t addrlen;
104 	const struct nfs_rpc_ops *rpc_ops;
105 	int proto;
106 	u32 minorversion;
107 };
108 
109 /*
110  * Allocate a shared client record
111  *
112  * Since these are allocated/deallocated very rarely, we don't
113  * bother putting them in a slab cache...
114  */
115 static struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init)
116 {
117 	struct nfs_client *clp;
118 	struct rpc_cred *cred;
119 	int err = -ENOMEM;
120 
121 	if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL)
122 		goto error_0;
123 
124 	clp->rpc_ops = cl_init->rpc_ops;
125 
126 	atomic_set(&clp->cl_count, 1);
127 	clp->cl_cons_state = NFS_CS_INITING;
128 
129 	memcpy(&clp->cl_addr, cl_init->addr, cl_init->addrlen);
130 	clp->cl_addrlen = cl_init->addrlen;
131 
132 	if (cl_init->hostname) {
133 		err = -ENOMEM;
134 		clp->cl_hostname = kstrdup(cl_init->hostname, GFP_KERNEL);
135 		if (!clp->cl_hostname)
136 			goto error_cleanup;
137 	}
138 
139 	INIT_LIST_HEAD(&clp->cl_superblocks);
140 	clp->cl_rpcclient = ERR_PTR(-EINVAL);
141 
142 	clp->cl_proto = cl_init->proto;
143 
144 #ifdef CONFIG_NFS_V4
145 	INIT_LIST_HEAD(&clp->cl_delegations);
146 	spin_lock_init(&clp->cl_lock);
147 	INIT_DELAYED_WORK(&clp->cl_renewd, nfs4_renew_state);
148 	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
149 	clp->cl_boot_time = CURRENT_TIME;
150 	clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
151 	clp->cl_minorversion = cl_init->minorversion;
152 #endif
153 	cred = rpc_lookup_machine_cred();
154 	if (!IS_ERR(cred))
155 		clp->cl_machine_cred = cred;
156 
157 	nfs_fscache_get_client_cookie(clp);
158 
159 	return clp;
160 
161 error_cleanup:
162 	kfree(clp);
163 error_0:
164 	return ERR_PTR(err);
165 }
166 
167 static void nfs4_shutdown_client(struct nfs_client *clp)
168 {
169 #ifdef CONFIG_NFS_V4
170 	if (__test_and_clear_bit(NFS_CS_RENEWD, &clp->cl_res_state))
171 		nfs4_kill_renewd(clp);
172 	BUG_ON(!RB_EMPTY_ROOT(&clp->cl_state_owners));
173 	if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state))
174 		nfs_idmap_delete(clp);
175 
176 	rpc_destroy_wait_queue(&clp->cl_rpcwaitq);
177 #endif
178 }
179 
180 /*
181  * Destroy the NFS4 callback service
182  */
183 static void nfs4_destroy_callback(struct nfs_client *clp)
184 {
185 #ifdef CONFIG_NFS_V4
186 	if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
187 		nfs_callback_down(clp->cl_minorversion);
188 #endif /* CONFIG_NFS_V4 */
189 }
190 
191 /*
192  * Clears/puts all minor version specific parts from an nfs_client struct
193  * reverting it to minorversion 0.
194  */
195 static void nfs4_clear_client_minor_version(struct nfs_client *clp)
196 {
197 #ifdef CONFIG_NFS_V4_1
198 	if (nfs4_has_session(clp)) {
199 		nfs4_destroy_session(clp->cl_session);
200 		clp->cl_session = NULL;
201 	}
202 
203 	clp->cl_call_sync = _nfs4_call_sync;
204 #endif /* CONFIG_NFS_V4_1 */
205 
206 	nfs4_destroy_callback(clp);
207 }
208 
209 /*
210  * Destroy a shared client record
211  */
212 static void nfs_free_client(struct nfs_client *clp)
213 {
214 	dprintk("--> nfs_free_client(%u)\n", clp->rpc_ops->version);
215 
216 	nfs4_clear_client_minor_version(clp);
217 	nfs4_shutdown_client(clp);
218 
219 	nfs_fscache_release_client_cookie(clp);
220 
221 	/* -EIO all pending I/O */
222 	if (!IS_ERR(clp->cl_rpcclient))
223 		rpc_shutdown_client(clp->cl_rpcclient);
224 
225 	if (clp->cl_machine_cred != NULL)
226 		put_rpccred(clp->cl_machine_cred);
227 
228 	kfree(clp->cl_hostname);
229 	kfree(clp);
230 
231 	dprintk("<-- nfs_free_client()\n");
232 }
233 
234 /*
235  * Release a reference to a shared client record
236  */
237 void nfs_put_client(struct nfs_client *clp)
238 {
239 	if (!clp)
240 		return;
241 
242 	dprintk("--> nfs_put_client({%d})\n", atomic_read(&clp->cl_count));
243 
244 	if (atomic_dec_and_lock(&clp->cl_count, &nfs_client_lock)) {
245 		list_del(&clp->cl_share_link);
246 		spin_unlock(&nfs_client_lock);
247 
248 		BUG_ON(!list_empty(&clp->cl_superblocks));
249 
250 		nfs_free_client(clp);
251 	}
252 }
253 
254 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
255 /*
256  * Test if two ip6 socket addresses refer to the same socket by
257  * comparing relevant fields. The padding bytes specifically, are not
258  * compared. sin6_flowinfo is not compared because it only affects QoS
259  * and sin6_scope_id is only compared if the address is "link local"
260  * because "link local" addresses need only be unique to a specific
261  * link. Conversely, ordinary unicast addresses might have different
262  * sin6_scope_id.
263  *
264  * The caller should ensure both socket addresses are AF_INET6.
265  */
266 static int nfs_sockaddr_match_ipaddr6(const struct sockaddr *sa1,
267 				      const struct sockaddr *sa2)
268 {
269 	const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sa1;
270 	const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sa2;
271 
272 	if (ipv6_addr_scope(&sin1->sin6_addr) == IPV6_ADDR_SCOPE_LINKLOCAL &&
273 	    sin1->sin6_scope_id != sin2->sin6_scope_id)
274 		return 0;
275 
276 	return ipv6_addr_equal(&sin1->sin6_addr, &sin1->sin6_addr);
277 }
278 #else	/* !defined(CONFIG_IPV6) && !defined(CONFIG_IPV6_MODULE) */
279 static int nfs_sockaddr_match_ipaddr6(const struct sockaddr *sa1,
280 				      const struct sockaddr *sa2)
281 {
282 	return 0;
283 }
284 #endif
285 
286 /*
287  * Test if two ip4 socket addresses refer to the same socket, by
288  * comparing relevant fields. The padding bytes specifically, are
289  * not compared.
290  *
291  * The caller should ensure both socket addresses are AF_INET.
292  */
293 static int nfs_sockaddr_match_ipaddr4(const struct sockaddr *sa1,
294 				      const struct sockaddr *sa2)
295 {
296 	const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sa1;
297 	const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sa2;
298 
299 	return sin1->sin_addr.s_addr == sin2->sin_addr.s_addr;
300 }
301 
302 static int nfs_sockaddr_cmp_ip6(const struct sockaddr *sa1,
303 				const struct sockaddr *sa2)
304 {
305 	const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sa1;
306 	const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sa2;
307 
308 	return nfs_sockaddr_match_ipaddr6(sa1, sa2) &&
309 		(sin1->sin6_port == sin2->sin6_port);
310 }
311 
312 static int nfs_sockaddr_cmp_ip4(const struct sockaddr *sa1,
313 				const struct sockaddr *sa2)
314 {
315 	const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sa1;
316 	const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sa2;
317 
318 	return nfs_sockaddr_match_ipaddr4(sa1, sa2) &&
319 		(sin1->sin_port == sin2->sin_port);
320 }
321 
322 /*
323  * Test if two socket addresses represent the same actual socket,
324  * by comparing (only) relevant fields, excluding the port number.
325  */
326 static int nfs_sockaddr_match_ipaddr(const struct sockaddr *sa1,
327 				     const struct sockaddr *sa2)
328 {
329 	if (sa1->sa_family != sa2->sa_family)
330 		return 0;
331 
332 	switch (sa1->sa_family) {
333 	case AF_INET:
334 		return nfs_sockaddr_match_ipaddr4(sa1, sa2);
335 	case AF_INET6:
336 		return nfs_sockaddr_match_ipaddr6(sa1, sa2);
337 	}
338 	return 0;
339 }
340 
341 /*
342  * Test if two socket addresses represent the same actual socket,
343  * by comparing (only) relevant fields, including the port number.
344  */
345 static int nfs_sockaddr_cmp(const struct sockaddr *sa1,
346 			    const struct sockaddr *sa2)
347 {
348 	if (sa1->sa_family != sa2->sa_family)
349 		return 0;
350 
351 	switch (sa1->sa_family) {
352 	case AF_INET:
353 		return nfs_sockaddr_cmp_ip4(sa1, sa2);
354 	case AF_INET6:
355 		return nfs_sockaddr_cmp_ip6(sa1, sa2);
356 	}
357 	return 0;
358 }
359 
360 /*
361  * Find a client by IP address and protocol version
362  * - returns NULL if no such client
363  */
364 struct nfs_client *nfs_find_client(const struct sockaddr *addr, u32 nfsversion)
365 {
366 	struct nfs_client *clp;
367 
368 	spin_lock(&nfs_client_lock);
369 	list_for_each_entry(clp, &nfs_client_list, cl_share_link) {
370 		struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
371 
372 		/* Don't match clients that failed to initialise properly */
373 		if (!(clp->cl_cons_state == NFS_CS_READY ||
374 		      clp->cl_cons_state == NFS_CS_SESSION_INITING))
375 			continue;
376 
377 		/* Different NFS versions cannot share the same nfs_client */
378 		if (clp->rpc_ops->version != nfsversion)
379 			continue;
380 
381 		/* Match only the IP address, not the port number */
382 		if (!nfs_sockaddr_match_ipaddr(addr, clap))
383 			continue;
384 
385 		atomic_inc(&clp->cl_count);
386 		spin_unlock(&nfs_client_lock);
387 		return clp;
388 	}
389 	spin_unlock(&nfs_client_lock);
390 	return NULL;
391 }
392 
393 /*
394  * Find a client by IP address and protocol version
395  * - returns NULL if no such client
396  */
397 struct nfs_client *nfs_find_client_next(struct nfs_client *clp)
398 {
399 	struct sockaddr *sap = (struct sockaddr *)&clp->cl_addr;
400 	u32 nfsvers = clp->rpc_ops->version;
401 
402 	spin_lock(&nfs_client_lock);
403 	list_for_each_entry_continue(clp, &nfs_client_list, cl_share_link) {
404 		struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
405 
406 		/* Don't match clients that failed to initialise properly */
407 		if (clp->cl_cons_state != NFS_CS_READY)
408 			continue;
409 
410 		/* Different NFS versions cannot share the same nfs_client */
411 		if (clp->rpc_ops->version != nfsvers)
412 			continue;
413 
414 		/* Match only the IP address, not the port number */
415 		if (!nfs_sockaddr_match_ipaddr(sap, clap))
416 			continue;
417 
418 		atomic_inc(&clp->cl_count);
419 		spin_unlock(&nfs_client_lock);
420 		return clp;
421 	}
422 	spin_unlock(&nfs_client_lock);
423 	return NULL;
424 }
425 
426 /*
427  * Find an nfs_client on the list that matches the initialisation data
428  * that is supplied.
429  */
430 static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *data)
431 {
432 	struct nfs_client *clp;
433 	const struct sockaddr *sap = data->addr;
434 
435 	list_for_each_entry(clp, &nfs_client_list, cl_share_link) {
436 	        const struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
437 		/* Don't match clients that failed to initialise properly */
438 		if (clp->cl_cons_state < 0)
439 			continue;
440 
441 		/* Different NFS versions cannot share the same nfs_client */
442 		if (clp->rpc_ops != data->rpc_ops)
443 			continue;
444 
445 		if (clp->cl_proto != data->proto)
446 			continue;
447 		/* Match nfsv4 minorversion */
448 		if (clp->cl_minorversion != data->minorversion)
449 			continue;
450 		/* Match the full socket address */
451 		if (!nfs_sockaddr_cmp(sap, clap))
452 			continue;
453 
454 		atomic_inc(&clp->cl_count);
455 		return clp;
456 	}
457 	return NULL;
458 }
459 
460 /*
461  * Look up a client by IP address and protocol version
462  * - creates a new record if one doesn't yet exist
463  */
464 static struct nfs_client *nfs_get_client(const struct nfs_client_initdata *cl_init)
465 {
466 	struct nfs_client *clp, *new = NULL;
467 	int error;
468 
469 	dprintk("--> nfs_get_client(%s,v%u)\n",
470 		cl_init->hostname ?: "", cl_init->rpc_ops->version);
471 
472 	/* see if the client already exists */
473 	do {
474 		spin_lock(&nfs_client_lock);
475 
476 		clp = nfs_match_client(cl_init);
477 		if (clp)
478 			goto found_client;
479 		if (new)
480 			goto install_client;
481 
482 		spin_unlock(&nfs_client_lock);
483 
484 		new = nfs_alloc_client(cl_init);
485 	} while (!IS_ERR(new));
486 
487 	dprintk("--> nfs_get_client() = %ld [failed]\n", PTR_ERR(new));
488 	return new;
489 
490 	/* install a new client and return with it unready */
491 install_client:
492 	clp = new;
493 	list_add(&clp->cl_share_link, &nfs_client_list);
494 	spin_unlock(&nfs_client_lock);
495 	dprintk("--> nfs_get_client() = %p [new]\n", clp);
496 	return clp;
497 
498 	/* found an existing client
499 	 * - make sure it's ready before returning
500 	 */
501 found_client:
502 	spin_unlock(&nfs_client_lock);
503 
504 	if (new)
505 		nfs_free_client(new);
506 
507 	error = wait_event_killable(nfs_client_active_wq,
508 				clp->cl_cons_state < NFS_CS_INITING);
509 	if (error < 0) {
510 		nfs_put_client(clp);
511 		return ERR_PTR(-ERESTARTSYS);
512 	}
513 
514 	if (clp->cl_cons_state < NFS_CS_READY) {
515 		error = clp->cl_cons_state;
516 		nfs_put_client(clp);
517 		return ERR_PTR(error);
518 	}
519 
520 	BUG_ON(clp->cl_cons_state != NFS_CS_READY);
521 
522 	dprintk("--> nfs_get_client() = %p [share]\n", clp);
523 	return clp;
524 }
525 
526 /*
527  * Mark a server as ready or failed
528  */
529 void nfs_mark_client_ready(struct nfs_client *clp, int state)
530 {
531 	clp->cl_cons_state = state;
532 	wake_up_all(&nfs_client_active_wq);
533 }
534 
535 /*
536  * With sessions, the client is not marked ready until after a
537  * successful EXCHANGE_ID and CREATE_SESSION.
538  *
539  * Map errors cl_cons_state errors to EPROTONOSUPPORT to indicate
540  * other versions of NFS can be tried.
541  */
542 int nfs4_check_client_ready(struct nfs_client *clp)
543 {
544 	if (!nfs4_has_session(clp))
545 		return 0;
546 	if (clp->cl_cons_state < NFS_CS_READY)
547 		return -EPROTONOSUPPORT;
548 	return 0;
549 }
550 
551 /*
552  * Initialise the timeout values for a connection
553  */
554 static void nfs_init_timeout_values(struct rpc_timeout *to, int proto,
555 				    unsigned int timeo, unsigned int retrans)
556 {
557 	to->to_initval = timeo * HZ / 10;
558 	to->to_retries = retrans;
559 
560 	switch (proto) {
561 	case XPRT_TRANSPORT_TCP:
562 	case XPRT_TRANSPORT_RDMA:
563 		if (to->to_retries == 0)
564 			to->to_retries = NFS_DEF_TCP_RETRANS;
565 		if (to->to_initval == 0)
566 			to->to_initval = NFS_DEF_TCP_TIMEO * HZ / 10;
567 		if (to->to_initval > NFS_MAX_TCP_TIMEOUT)
568 			to->to_initval = NFS_MAX_TCP_TIMEOUT;
569 		to->to_increment = to->to_initval;
570 		to->to_maxval = to->to_initval + (to->to_increment * to->to_retries);
571 		if (to->to_maxval > NFS_MAX_TCP_TIMEOUT)
572 			to->to_maxval = NFS_MAX_TCP_TIMEOUT;
573 		if (to->to_maxval < to->to_initval)
574 			to->to_maxval = to->to_initval;
575 		to->to_exponential = 0;
576 		break;
577 	case XPRT_TRANSPORT_UDP:
578 		if (to->to_retries == 0)
579 			to->to_retries = NFS_DEF_UDP_RETRANS;
580 		if (!to->to_initval)
581 			to->to_initval = NFS_DEF_UDP_TIMEO * HZ / 10;
582 		if (to->to_initval > NFS_MAX_UDP_TIMEOUT)
583 			to->to_initval = NFS_MAX_UDP_TIMEOUT;
584 		to->to_maxval = NFS_MAX_UDP_TIMEOUT;
585 		to->to_exponential = 1;
586 		break;
587 	default:
588 		BUG();
589 	}
590 }
591 
592 /*
593  * Create an RPC client handle
594  */
595 static int nfs_create_rpc_client(struct nfs_client *clp,
596 				 const struct rpc_timeout *timeparms,
597 				 rpc_authflavor_t flavor,
598 				 int discrtry, int noresvport)
599 {
600 	struct rpc_clnt		*clnt = NULL;
601 	struct rpc_create_args args = {
602 		.protocol	= clp->cl_proto,
603 		.address	= (struct sockaddr *)&clp->cl_addr,
604 		.addrsize	= clp->cl_addrlen,
605 		.timeout	= timeparms,
606 		.servername	= clp->cl_hostname,
607 		.program	= &nfs_program,
608 		.version	= clp->rpc_ops->version,
609 		.authflavor	= flavor,
610 	};
611 
612 	if (discrtry)
613 		args.flags |= RPC_CLNT_CREATE_DISCRTRY;
614 	if (noresvport)
615 		args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
616 
617 	if (!IS_ERR(clp->cl_rpcclient))
618 		return 0;
619 
620 	clnt = rpc_create(&args);
621 	if (IS_ERR(clnt)) {
622 		dprintk("%s: cannot create RPC client. Error = %ld\n",
623 				__func__, PTR_ERR(clnt));
624 		return PTR_ERR(clnt);
625 	}
626 
627 	clp->cl_rpcclient = clnt;
628 	return 0;
629 }
630 
631 /*
632  * Version 2 or 3 client destruction
633  */
634 static void nfs_destroy_server(struct nfs_server *server)
635 {
636 	if (!(server->flags & NFS_MOUNT_NONLM))
637 		nlmclnt_done(server->nlm_host);
638 }
639 
640 /*
641  * Version 2 or 3 lockd setup
642  */
643 static int nfs_start_lockd(struct nfs_server *server)
644 {
645 	struct nlm_host *host;
646 	struct nfs_client *clp = server->nfs_client;
647 	struct nlmclnt_initdata nlm_init = {
648 		.hostname	= clp->cl_hostname,
649 		.address	= (struct sockaddr *)&clp->cl_addr,
650 		.addrlen	= clp->cl_addrlen,
651 		.protocol	= server->flags & NFS_MOUNT_TCP ?
652 						IPPROTO_TCP : IPPROTO_UDP,
653 		.nfs_version	= clp->rpc_ops->version,
654 		.noresvport	= server->flags & NFS_MOUNT_NORESVPORT ?
655 					1 : 0,
656 	};
657 
658 	if (nlm_init.nfs_version > 3)
659 		return 0;
660 	if (server->flags & NFS_MOUNT_NONLM)
661 		return 0;
662 
663 	host = nlmclnt_init(&nlm_init);
664 	if (IS_ERR(host))
665 		return PTR_ERR(host);
666 
667 	server->nlm_host = host;
668 	server->destroy = nfs_destroy_server;
669 	return 0;
670 }
671 
672 /*
673  * Initialise an NFSv3 ACL client connection
674  */
675 #ifdef CONFIG_NFS_V3_ACL
676 static void nfs_init_server_aclclient(struct nfs_server *server)
677 {
678 	if (server->nfs_client->rpc_ops->version != 3)
679 		goto out_noacl;
680 	if (server->flags & NFS_MOUNT_NOACL)
681 		goto out_noacl;
682 
683 	server->client_acl = rpc_bind_new_program(server->client, &nfsacl_program, 3);
684 	if (IS_ERR(server->client_acl))
685 		goto out_noacl;
686 
687 	/* No errors! Assume that Sun nfsacls are supported */
688 	server->caps |= NFS_CAP_ACLS;
689 	return;
690 
691 out_noacl:
692 	server->caps &= ~NFS_CAP_ACLS;
693 }
694 #else
695 static inline void nfs_init_server_aclclient(struct nfs_server *server)
696 {
697 	server->flags &= ~NFS_MOUNT_NOACL;
698 	server->caps &= ~NFS_CAP_ACLS;
699 }
700 #endif
701 
702 /*
703  * Create a general RPC client
704  */
705 static int nfs_init_server_rpcclient(struct nfs_server *server,
706 		const struct rpc_timeout *timeo,
707 		rpc_authflavor_t pseudoflavour)
708 {
709 	struct nfs_client *clp = server->nfs_client;
710 
711 	server->client = rpc_clone_client(clp->cl_rpcclient);
712 	if (IS_ERR(server->client)) {
713 		dprintk("%s: couldn't create rpc_client!\n", __func__);
714 		return PTR_ERR(server->client);
715 	}
716 
717 	memcpy(&server->client->cl_timeout_default,
718 			timeo,
719 			sizeof(server->client->cl_timeout_default));
720 	server->client->cl_timeout = &server->client->cl_timeout_default;
721 
722 	if (pseudoflavour != clp->cl_rpcclient->cl_auth->au_flavor) {
723 		struct rpc_auth *auth;
724 
725 		auth = rpcauth_create(pseudoflavour, server->client);
726 		if (IS_ERR(auth)) {
727 			dprintk("%s: couldn't create credcache!\n", __func__);
728 			return PTR_ERR(auth);
729 		}
730 	}
731 	server->client->cl_softrtry = 0;
732 	if (server->flags & NFS_MOUNT_SOFT)
733 		server->client->cl_softrtry = 1;
734 
735 	return 0;
736 }
737 
738 /*
739  * Initialise an NFS2 or NFS3 client
740  */
741 static int nfs_init_client(struct nfs_client *clp,
742 			   const struct rpc_timeout *timeparms,
743 			   const struct nfs_parsed_mount_data *data)
744 {
745 	int error;
746 
747 	if (clp->cl_cons_state == NFS_CS_READY) {
748 		/* the client is already initialised */
749 		dprintk("<-- nfs_init_client() = 0 [already %p]\n", clp);
750 		return 0;
751 	}
752 
753 	/*
754 	 * Create a client RPC handle for doing FSSTAT with UNIX auth only
755 	 * - RFC 2623, sec 2.3.2
756 	 */
757 	error = nfs_create_rpc_client(clp, timeparms, RPC_AUTH_UNIX,
758 				      0, data->flags & NFS_MOUNT_NORESVPORT);
759 	if (error < 0)
760 		goto error;
761 	nfs_mark_client_ready(clp, NFS_CS_READY);
762 	return 0;
763 
764 error:
765 	nfs_mark_client_ready(clp, error);
766 	dprintk("<-- nfs_init_client() = xerror %d\n", error);
767 	return error;
768 }
769 
770 /*
771  * Create a version 2 or 3 client
772  */
773 static int nfs_init_server(struct nfs_server *server,
774 			   const struct nfs_parsed_mount_data *data)
775 {
776 	struct nfs_client_initdata cl_init = {
777 		.hostname = data->nfs_server.hostname,
778 		.addr = (const struct sockaddr *)&data->nfs_server.address,
779 		.addrlen = data->nfs_server.addrlen,
780 		.rpc_ops = &nfs_v2_clientops,
781 		.proto = data->nfs_server.protocol,
782 	};
783 	struct rpc_timeout timeparms;
784 	struct nfs_client *clp;
785 	int error;
786 
787 	dprintk("--> nfs_init_server()\n");
788 
789 #ifdef CONFIG_NFS_V3
790 	if (data->flags & NFS_MOUNT_VER3)
791 		cl_init.rpc_ops = &nfs_v3_clientops;
792 #endif
793 
794 	/* Allocate or find a client reference we can use */
795 	clp = nfs_get_client(&cl_init);
796 	if (IS_ERR(clp)) {
797 		dprintk("<-- nfs_init_server() = error %ld\n", PTR_ERR(clp));
798 		return PTR_ERR(clp);
799 	}
800 
801 	nfs_init_timeout_values(&timeparms, data->nfs_server.protocol,
802 			data->timeo, data->retrans);
803 	error = nfs_init_client(clp, &timeparms, data);
804 	if (error < 0)
805 		goto error;
806 
807 	server->nfs_client = clp;
808 
809 	/* Initialise the client representation from the mount data */
810 	server->flags = data->flags;
811 	server->options = data->options;
812 
813 	if (data->rsize)
814 		server->rsize = nfs_block_size(data->rsize, NULL);
815 	if (data->wsize)
816 		server->wsize = nfs_block_size(data->wsize, NULL);
817 
818 	server->acregmin = data->acregmin * HZ;
819 	server->acregmax = data->acregmax * HZ;
820 	server->acdirmin = data->acdirmin * HZ;
821 	server->acdirmax = data->acdirmax * HZ;
822 
823 	/* Start lockd here, before we might error out */
824 	error = nfs_start_lockd(server);
825 	if (error < 0)
826 		goto error;
827 
828 	server->port = data->nfs_server.port;
829 
830 	error = nfs_init_server_rpcclient(server, &timeparms, data->auth_flavors[0]);
831 	if (error < 0)
832 		goto error;
833 
834 	/* Preserve the values of mount_server-related mount options */
835 	if (data->mount_server.addrlen) {
836 		memcpy(&server->mountd_address, &data->mount_server.address,
837 			data->mount_server.addrlen);
838 		server->mountd_addrlen = data->mount_server.addrlen;
839 	}
840 	server->mountd_version = data->mount_server.version;
841 	server->mountd_port = data->mount_server.port;
842 	server->mountd_protocol = data->mount_server.protocol;
843 
844 	server->namelen  = data->namlen;
845 	/* Create a client RPC handle for the NFSv3 ACL management interface */
846 	nfs_init_server_aclclient(server);
847 	dprintk("<-- nfs_init_server() = 0 [new %p]\n", clp);
848 	return 0;
849 
850 error:
851 	server->nfs_client = NULL;
852 	nfs_put_client(clp);
853 	dprintk("<-- nfs_init_server() = xerror %d\n", error);
854 	return error;
855 }
856 
857 /*
858  * Load up the server record from information gained in an fsinfo record
859  */
860 static void nfs_server_set_fsinfo(struct nfs_server *server, struct nfs_fsinfo *fsinfo)
861 {
862 	unsigned long max_rpc_payload;
863 
864 	/* Work out a lot of parameters */
865 	if (server->rsize == 0)
866 		server->rsize = nfs_block_size(fsinfo->rtpref, NULL);
867 	if (server->wsize == 0)
868 		server->wsize = nfs_block_size(fsinfo->wtpref, NULL);
869 
870 	if (fsinfo->rtmax >= 512 && server->rsize > fsinfo->rtmax)
871 		server->rsize = nfs_block_size(fsinfo->rtmax, NULL);
872 	if (fsinfo->wtmax >= 512 && server->wsize > fsinfo->wtmax)
873 		server->wsize = nfs_block_size(fsinfo->wtmax, NULL);
874 
875 	max_rpc_payload = nfs_block_size(rpc_max_payload(server->client), NULL);
876 	if (server->rsize > max_rpc_payload)
877 		server->rsize = max_rpc_payload;
878 	if (server->rsize > NFS_MAX_FILE_IO_SIZE)
879 		server->rsize = NFS_MAX_FILE_IO_SIZE;
880 	server->rpages = (server->rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
881 
882 	server->backing_dev_info.ra_pages = server->rpages * NFS_MAX_READAHEAD;
883 
884 	if (server->wsize > max_rpc_payload)
885 		server->wsize = max_rpc_payload;
886 	if (server->wsize > NFS_MAX_FILE_IO_SIZE)
887 		server->wsize = NFS_MAX_FILE_IO_SIZE;
888 	server->wpages = (server->wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
889 	server->wtmult = nfs_block_bits(fsinfo->wtmult, NULL);
890 
891 	server->dtsize = nfs_block_size(fsinfo->dtpref, NULL);
892 	if (server->dtsize > PAGE_CACHE_SIZE)
893 		server->dtsize = PAGE_CACHE_SIZE;
894 	if (server->dtsize > server->rsize)
895 		server->dtsize = server->rsize;
896 
897 	if (server->flags & NFS_MOUNT_NOAC) {
898 		server->acregmin = server->acregmax = 0;
899 		server->acdirmin = server->acdirmax = 0;
900 	}
901 
902 	server->maxfilesize = fsinfo->maxfilesize;
903 
904 	/* We're airborne Set socket buffersize */
905 	rpc_setbufsize(server->client, server->wsize + 100, server->rsize + 100);
906 }
907 
908 /*
909  * Probe filesystem information, including the FSID on v2/v3
910  */
911 static int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *mntfh, struct nfs_fattr *fattr)
912 {
913 	struct nfs_fsinfo fsinfo;
914 	struct nfs_client *clp = server->nfs_client;
915 	int error;
916 
917 	dprintk("--> nfs_probe_fsinfo()\n");
918 
919 	if (clp->rpc_ops->set_capabilities != NULL) {
920 		error = clp->rpc_ops->set_capabilities(server, mntfh);
921 		if (error < 0)
922 			goto out_error;
923 	}
924 
925 	fsinfo.fattr = fattr;
926 	nfs_fattr_init(fattr);
927 	error = clp->rpc_ops->fsinfo(server, mntfh, &fsinfo);
928 	if (error < 0)
929 		goto out_error;
930 
931 	nfs_server_set_fsinfo(server, &fsinfo);
932 	error = bdi_init(&server->backing_dev_info);
933 	if (error)
934 		goto out_error;
935 
936 
937 	/* Get some general file system info */
938 	if (server->namelen == 0) {
939 		struct nfs_pathconf pathinfo;
940 
941 		pathinfo.fattr = fattr;
942 		nfs_fattr_init(fattr);
943 
944 		if (clp->rpc_ops->pathconf(server, mntfh, &pathinfo) >= 0)
945 			server->namelen = pathinfo.max_namelen;
946 	}
947 
948 	dprintk("<-- nfs_probe_fsinfo() = 0\n");
949 	return 0;
950 
951 out_error:
952 	dprintk("nfs_probe_fsinfo: error = %d\n", -error);
953 	return error;
954 }
955 
956 /*
957  * Copy useful information when duplicating a server record
958  */
959 static void nfs_server_copy_userdata(struct nfs_server *target, struct nfs_server *source)
960 {
961 	target->flags = source->flags;
962 	target->acregmin = source->acregmin;
963 	target->acregmax = source->acregmax;
964 	target->acdirmin = source->acdirmin;
965 	target->acdirmax = source->acdirmax;
966 	target->caps = source->caps;
967 }
968 
969 /*
970  * Allocate and initialise a server record
971  */
972 static struct nfs_server *nfs_alloc_server(void)
973 {
974 	struct nfs_server *server;
975 
976 	server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
977 	if (!server)
978 		return NULL;
979 
980 	server->client = server->client_acl = ERR_PTR(-EINVAL);
981 
982 	/* Zero out the NFS state stuff */
983 	INIT_LIST_HEAD(&server->client_link);
984 	INIT_LIST_HEAD(&server->master_link);
985 
986 	atomic_set(&server->active, 0);
987 
988 	server->io_stats = nfs_alloc_iostats();
989 	if (!server->io_stats) {
990 		kfree(server);
991 		return NULL;
992 	}
993 
994 	return server;
995 }
996 
997 /*
998  * Free up a server record
999  */
1000 void nfs_free_server(struct nfs_server *server)
1001 {
1002 	dprintk("--> nfs_free_server()\n");
1003 
1004 	spin_lock(&nfs_client_lock);
1005 	list_del(&server->client_link);
1006 	list_del(&server->master_link);
1007 	spin_unlock(&nfs_client_lock);
1008 
1009 	if (server->destroy != NULL)
1010 		server->destroy(server);
1011 
1012 	if (!IS_ERR(server->client_acl))
1013 		rpc_shutdown_client(server->client_acl);
1014 	if (!IS_ERR(server->client))
1015 		rpc_shutdown_client(server->client);
1016 
1017 	nfs_put_client(server->nfs_client);
1018 
1019 	nfs_free_iostats(server->io_stats);
1020 	bdi_destroy(&server->backing_dev_info);
1021 	kfree(server);
1022 	nfs_release_automount_timer();
1023 	dprintk("<-- nfs_free_server()\n");
1024 }
1025 
1026 /*
1027  * Create a version 2 or 3 volume record
1028  * - keyed on server and FSID
1029  */
1030 struct nfs_server *nfs_create_server(const struct nfs_parsed_mount_data *data,
1031 				     struct nfs_fh *mntfh)
1032 {
1033 	struct nfs_server *server;
1034 	struct nfs_fattr fattr;
1035 	int error;
1036 
1037 	server = nfs_alloc_server();
1038 	if (!server)
1039 		return ERR_PTR(-ENOMEM);
1040 
1041 	/* Get a client representation */
1042 	error = nfs_init_server(server, data);
1043 	if (error < 0)
1044 		goto error;
1045 
1046 	BUG_ON(!server->nfs_client);
1047 	BUG_ON(!server->nfs_client->rpc_ops);
1048 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
1049 
1050 	/* Probe the root fh to retrieve its FSID */
1051 	error = nfs_probe_fsinfo(server, mntfh, &fattr);
1052 	if (error < 0)
1053 		goto error;
1054 	if (server->nfs_client->rpc_ops->version == 3) {
1055 		if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN)
1056 			server->namelen = NFS3_MAXNAMLEN;
1057 		if (!(data->flags & NFS_MOUNT_NORDIRPLUS))
1058 			server->caps |= NFS_CAP_READDIRPLUS;
1059 	} else {
1060 		if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN)
1061 			server->namelen = NFS2_MAXNAMLEN;
1062 	}
1063 
1064 	if (!(fattr.valid & NFS_ATTR_FATTR)) {
1065 		error = server->nfs_client->rpc_ops->getattr(server, mntfh, &fattr);
1066 		if (error < 0) {
1067 			dprintk("nfs_create_server: getattr error = %d\n", -error);
1068 			goto error;
1069 		}
1070 	}
1071 	memcpy(&server->fsid, &fattr.fsid, sizeof(server->fsid));
1072 
1073 	dprintk("Server FSID: %llx:%llx\n",
1074 		(unsigned long long) server->fsid.major,
1075 		(unsigned long long) server->fsid.minor);
1076 
1077 	BUG_ON(!server->nfs_client);
1078 	BUG_ON(!server->nfs_client->rpc_ops);
1079 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
1080 
1081 	spin_lock(&nfs_client_lock);
1082 	list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);
1083 	list_add_tail(&server->master_link, &nfs_volume_list);
1084 	spin_unlock(&nfs_client_lock);
1085 
1086 	server->mount_time = jiffies;
1087 	return server;
1088 
1089 error:
1090 	nfs_free_server(server);
1091 	return ERR_PTR(error);
1092 }
1093 
1094 #ifdef CONFIG_NFS_V4
1095 /*
1096  * Initialize the NFS4 callback service
1097  */
1098 static int nfs4_init_callback(struct nfs_client *clp)
1099 {
1100 	int error;
1101 
1102 	if (clp->rpc_ops->version == 4) {
1103 		if (nfs4_has_session(clp)) {
1104 			error = xprt_setup_backchannel(
1105 						clp->cl_rpcclient->cl_xprt,
1106 						NFS41_BC_MIN_CALLBACKS);
1107 			if (error < 0)
1108 				return error;
1109 		}
1110 
1111 		error = nfs_callback_up(clp->cl_minorversion,
1112 					clp->cl_rpcclient->cl_xprt);
1113 		if (error < 0) {
1114 			dprintk("%s: failed to start callback. Error = %d\n",
1115 				__func__, error);
1116 			return error;
1117 		}
1118 		__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
1119 	}
1120 	return 0;
1121 }
1122 
1123 /*
1124  * Initialize the minor version specific parts of an NFS4 client record
1125  */
1126 static int nfs4_init_client_minor_version(struct nfs_client *clp)
1127 {
1128 	clp->cl_call_sync = _nfs4_call_sync;
1129 
1130 #if defined(CONFIG_NFS_V4_1)
1131 	if (clp->cl_minorversion) {
1132 		struct nfs4_session *session = NULL;
1133 		/*
1134 		 * Create the session and mark it expired.
1135 		 * When a SEQUENCE operation encounters the expired session
1136 		 * it will do session recovery to initialize it.
1137 		 */
1138 		session = nfs4_alloc_session(clp);
1139 		if (!session)
1140 			return -ENOMEM;
1141 
1142 		clp->cl_session = session;
1143 		clp->cl_call_sync = _nfs4_call_sync_session;
1144 	}
1145 #endif /* CONFIG_NFS_V4_1 */
1146 
1147 	return nfs4_init_callback(clp);
1148 }
1149 
1150 /*
1151  * Initialise an NFS4 client record
1152  */
1153 static int nfs4_init_client(struct nfs_client *clp,
1154 		const struct rpc_timeout *timeparms,
1155 		const char *ip_addr,
1156 		rpc_authflavor_t authflavour,
1157 		int flags)
1158 {
1159 	int error;
1160 
1161 	if (clp->cl_cons_state == NFS_CS_READY) {
1162 		/* the client is initialised already */
1163 		dprintk("<-- nfs4_init_client() = 0 [already %p]\n", clp);
1164 		return 0;
1165 	}
1166 
1167 	/* Check NFS protocol revision and initialize RPC op vector */
1168 	clp->rpc_ops = &nfs_v4_clientops;
1169 
1170 	error = nfs_create_rpc_client(clp, timeparms, authflavour,
1171 				      1, flags & NFS_MOUNT_NORESVPORT);
1172 	if (error < 0)
1173 		goto error;
1174 	memcpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr));
1175 
1176 	error = nfs_idmap_new(clp);
1177 	if (error < 0) {
1178 		dprintk("%s: failed to create idmapper. Error = %d\n",
1179 			__func__, error);
1180 		goto error;
1181 	}
1182 	__set_bit(NFS_CS_IDMAP, &clp->cl_res_state);
1183 
1184 	error = nfs4_init_client_minor_version(clp);
1185 	if (error < 0)
1186 		goto error;
1187 
1188 	if (!nfs4_has_session(clp))
1189 		nfs_mark_client_ready(clp, NFS_CS_READY);
1190 	return 0;
1191 
1192 error:
1193 	nfs_mark_client_ready(clp, error);
1194 	dprintk("<-- nfs4_init_client() = xerror %d\n", error);
1195 	return error;
1196 }
1197 
1198 /*
1199  * Set up an NFS4 client
1200  */
1201 static int nfs4_set_client(struct nfs_server *server,
1202 		const char *hostname,
1203 		const struct sockaddr *addr,
1204 		const size_t addrlen,
1205 		const char *ip_addr,
1206 		rpc_authflavor_t authflavour,
1207 		int proto, const struct rpc_timeout *timeparms,
1208 		u32 minorversion)
1209 {
1210 	struct nfs_client_initdata cl_init = {
1211 		.hostname = hostname,
1212 		.addr = addr,
1213 		.addrlen = addrlen,
1214 		.rpc_ops = &nfs_v4_clientops,
1215 		.proto = proto,
1216 		.minorversion = minorversion,
1217 	};
1218 	struct nfs_client *clp;
1219 	int error;
1220 
1221 	dprintk("--> nfs4_set_client()\n");
1222 
1223 	/* Allocate or find a client reference we can use */
1224 	clp = nfs_get_client(&cl_init);
1225 	if (IS_ERR(clp)) {
1226 		error = PTR_ERR(clp);
1227 		goto error;
1228 	}
1229 	error = nfs4_init_client(clp, timeparms, ip_addr, authflavour,
1230 					server->flags);
1231 	if (error < 0)
1232 		goto error_put;
1233 
1234 	server->nfs_client = clp;
1235 	dprintk("<-- nfs4_set_client() = 0 [new %p]\n", clp);
1236 	return 0;
1237 
1238 error_put:
1239 	nfs_put_client(clp);
1240 error:
1241 	dprintk("<-- nfs4_set_client() = xerror %d\n", error);
1242 	return error;
1243 }
1244 
1245 
1246 /*
1247  * Session has been established, and the client marked ready.
1248  * Set the mount rsize and wsize with negotiated fore channel
1249  * attributes which will be bound checked in nfs_server_set_fsinfo.
1250  */
1251 static void nfs4_session_set_rwsize(struct nfs_server *server)
1252 {
1253 #ifdef CONFIG_NFS_V4_1
1254 	if (!nfs4_has_session(server->nfs_client))
1255 		return;
1256 	server->rsize = server->nfs_client->cl_session->fc_attrs.max_resp_sz;
1257 	server->wsize = server->nfs_client->cl_session->fc_attrs.max_rqst_sz;
1258 #endif /* CONFIG_NFS_V4_1 */
1259 }
1260 
1261 /*
1262  * Create a version 4 volume record
1263  */
1264 static int nfs4_init_server(struct nfs_server *server,
1265 		const struct nfs_parsed_mount_data *data)
1266 {
1267 	struct rpc_timeout timeparms;
1268 	int error;
1269 
1270 	dprintk("--> nfs4_init_server()\n");
1271 
1272 	nfs_init_timeout_values(&timeparms, data->nfs_server.protocol,
1273 			data->timeo, data->retrans);
1274 
1275 	/* Initialise the client representation from the mount data */
1276 	server->flags = data->flags;
1277 	server->caps |= NFS_CAP_ATOMIC_OPEN;
1278 	server->options = data->options;
1279 
1280 	/* Get a client record */
1281 	error = nfs4_set_client(server,
1282 			data->nfs_server.hostname,
1283 			(const struct sockaddr *)&data->nfs_server.address,
1284 			data->nfs_server.addrlen,
1285 			data->client_address,
1286 			data->auth_flavors[0],
1287 			data->nfs_server.protocol,
1288 			&timeparms,
1289 			data->minorversion);
1290 	if (error < 0)
1291 		goto error;
1292 
1293 	if (data->rsize)
1294 		server->rsize = nfs_block_size(data->rsize, NULL);
1295 	if (data->wsize)
1296 		server->wsize = nfs_block_size(data->wsize, NULL);
1297 
1298 	server->acregmin = data->acregmin * HZ;
1299 	server->acregmax = data->acregmax * HZ;
1300 	server->acdirmin = data->acdirmin * HZ;
1301 	server->acdirmax = data->acdirmax * HZ;
1302 
1303 	server->port = data->nfs_server.port;
1304 
1305 	error = nfs_init_server_rpcclient(server, &timeparms, data->auth_flavors[0]);
1306 
1307 error:
1308 	/* Done */
1309 	dprintk("<-- nfs4_init_server() = %d\n", error);
1310 	return error;
1311 }
1312 
1313 /*
1314  * Create a version 4 volume record
1315  * - keyed on server and FSID
1316  */
1317 struct nfs_server *nfs4_create_server(const struct nfs_parsed_mount_data *data,
1318 				      struct nfs_fh *mntfh)
1319 {
1320 	struct nfs_fattr fattr;
1321 	struct nfs_server *server;
1322 	int error;
1323 
1324 	dprintk("--> nfs4_create_server()\n");
1325 
1326 	server = nfs_alloc_server();
1327 	if (!server)
1328 		return ERR_PTR(-ENOMEM);
1329 
1330 	/* set up the general RPC client */
1331 	error = nfs4_init_server(server, data);
1332 	if (error < 0)
1333 		goto error;
1334 
1335 	BUG_ON(!server->nfs_client);
1336 	BUG_ON(!server->nfs_client->rpc_ops);
1337 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
1338 
1339 	error = nfs4_init_session(server);
1340 	if (error < 0)
1341 		goto error;
1342 
1343 	/* Probe the root fh to retrieve its FSID */
1344 	error = nfs4_path_walk(server, mntfh, data->nfs_server.export_path);
1345 	if (error < 0)
1346 		goto error;
1347 
1348 	dprintk("Server FSID: %llx:%llx\n",
1349 		(unsigned long long) server->fsid.major,
1350 		(unsigned long long) server->fsid.minor);
1351 	dprintk("Mount FH: %d\n", mntfh->size);
1352 
1353 	nfs4_session_set_rwsize(server);
1354 
1355 	error = nfs_probe_fsinfo(server, mntfh, &fattr);
1356 	if (error < 0)
1357 		goto error;
1358 
1359 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1360 		server->namelen = NFS4_MAXNAMLEN;
1361 
1362 	BUG_ON(!server->nfs_client);
1363 	BUG_ON(!server->nfs_client->rpc_ops);
1364 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
1365 
1366 	spin_lock(&nfs_client_lock);
1367 	list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);
1368 	list_add_tail(&server->master_link, &nfs_volume_list);
1369 	spin_unlock(&nfs_client_lock);
1370 
1371 	server->mount_time = jiffies;
1372 	dprintk("<-- nfs4_create_server() = %p\n", server);
1373 	return server;
1374 
1375 error:
1376 	nfs_free_server(server);
1377 	dprintk("<-- nfs4_create_server() = error %d\n", error);
1378 	return ERR_PTR(error);
1379 }
1380 
1381 /*
1382  * Create an NFS4 referral server record
1383  */
1384 struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data,
1385 					       struct nfs_fh *mntfh)
1386 {
1387 	struct nfs_client *parent_client;
1388 	struct nfs_server *server, *parent_server;
1389 	struct nfs_fattr fattr;
1390 	int error;
1391 
1392 	dprintk("--> nfs4_create_referral_server()\n");
1393 
1394 	server = nfs_alloc_server();
1395 	if (!server)
1396 		return ERR_PTR(-ENOMEM);
1397 
1398 	parent_server = NFS_SB(data->sb);
1399 	parent_client = parent_server->nfs_client;
1400 
1401 	/* Initialise the client representation from the parent server */
1402 	nfs_server_copy_userdata(server, parent_server);
1403 	server->caps |= NFS_CAP_ATOMIC_OPEN;
1404 
1405 	/* Get a client representation.
1406 	 * Note: NFSv4 always uses TCP, */
1407 	error = nfs4_set_client(server, data->hostname,
1408 				data->addr,
1409 				data->addrlen,
1410 				parent_client->cl_ipaddr,
1411 				data->authflavor,
1412 				parent_server->client->cl_xprt->prot,
1413 				parent_server->client->cl_timeout,
1414 				parent_client->cl_minorversion);
1415 	if (error < 0)
1416 		goto error;
1417 
1418 	error = nfs_init_server_rpcclient(server, parent_server->client->cl_timeout, data->authflavor);
1419 	if (error < 0)
1420 		goto error;
1421 
1422 	BUG_ON(!server->nfs_client);
1423 	BUG_ON(!server->nfs_client->rpc_ops);
1424 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
1425 
1426 	/* Probe the root fh to retrieve its FSID and filehandle */
1427 	error = nfs4_path_walk(server, mntfh, data->mnt_path);
1428 	if (error < 0)
1429 		goto error;
1430 
1431 	/* probe the filesystem info for this server filesystem */
1432 	error = nfs_probe_fsinfo(server, mntfh, &fattr);
1433 	if (error < 0)
1434 		goto error;
1435 
1436 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1437 		server->namelen = NFS4_MAXNAMLEN;
1438 
1439 	dprintk("Referral FSID: %llx:%llx\n",
1440 		(unsigned long long) server->fsid.major,
1441 		(unsigned long long) server->fsid.minor);
1442 
1443 	spin_lock(&nfs_client_lock);
1444 	list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);
1445 	list_add_tail(&server->master_link, &nfs_volume_list);
1446 	spin_unlock(&nfs_client_lock);
1447 
1448 	server->mount_time = jiffies;
1449 
1450 	dprintk("<-- nfs_create_referral_server() = %p\n", server);
1451 	return server;
1452 
1453 error:
1454 	nfs_free_server(server);
1455 	dprintk("<-- nfs4_create_referral_server() = error %d\n", error);
1456 	return ERR_PTR(error);
1457 }
1458 
1459 #endif /* CONFIG_NFS_V4 */
1460 
1461 /*
1462  * Clone an NFS2, NFS3 or NFS4 server record
1463  */
1464 struct nfs_server *nfs_clone_server(struct nfs_server *source,
1465 				    struct nfs_fh *fh,
1466 				    struct nfs_fattr *fattr)
1467 {
1468 	struct nfs_server *server;
1469 	struct nfs_fattr fattr_fsinfo;
1470 	int error;
1471 
1472 	dprintk("--> nfs_clone_server(,%llx:%llx,)\n",
1473 		(unsigned long long) fattr->fsid.major,
1474 		(unsigned long long) fattr->fsid.minor);
1475 
1476 	server = nfs_alloc_server();
1477 	if (!server)
1478 		return ERR_PTR(-ENOMEM);
1479 
1480 	/* Copy data from the source */
1481 	server->nfs_client = source->nfs_client;
1482 	atomic_inc(&server->nfs_client->cl_count);
1483 	nfs_server_copy_userdata(server, source);
1484 
1485 	server->fsid = fattr->fsid;
1486 
1487 	error = nfs_init_server_rpcclient(server,
1488 			source->client->cl_timeout,
1489 			source->client->cl_auth->au_flavor);
1490 	if (error < 0)
1491 		goto out_free_server;
1492 	if (!IS_ERR(source->client_acl))
1493 		nfs_init_server_aclclient(server);
1494 
1495 	/* probe the filesystem info for this server filesystem */
1496 	error = nfs_probe_fsinfo(server, fh, &fattr_fsinfo);
1497 	if (error < 0)
1498 		goto out_free_server;
1499 
1500 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1501 		server->namelen = NFS4_MAXNAMLEN;
1502 
1503 	dprintk("Cloned FSID: %llx:%llx\n",
1504 		(unsigned long long) server->fsid.major,
1505 		(unsigned long long) server->fsid.minor);
1506 
1507 	error = nfs_start_lockd(server);
1508 	if (error < 0)
1509 		goto out_free_server;
1510 
1511 	spin_lock(&nfs_client_lock);
1512 	list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);
1513 	list_add_tail(&server->master_link, &nfs_volume_list);
1514 	spin_unlock(&nfs_client_lock);
1515 
1516 	server->mount_time = jiffies;
1517 
1518 	dprintk("<-- nfs_clone_server() = %p\n", server);
1519 	return server;
1520 
1521 out_free_server:
1522 	nfs_free_server(server);
1523 	dprintk("<-- nfs_clone_server() = error %d\n", error);
1524 	return ERR_PTR(error);
1525 }
1526 
1527 #ifdef CONFIG_PROC_FS
1528 static struct proc_dir_entry *proc_fs_nfs;
1529 
1530 static int nfs_server_list_open(struct inode *inode, struct file *file);
1531 static void *nfs_server_list_start(struct seq_file *p, loff_t *pos);
1532 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos);
1533 static void nfs_server_list_stop(struct seq_file *p, void *v);
1534 static int nfs_server_list_show(struct seq_file *m, void *v);
1535 
1536 static struct seq_operations nfs_server_list_ops = {
1537 	.start	= nfs_server_list_start,
1538 	.next	= nfs_server_list_next,
1539 	.stop	= nfs_server_list_stop,
1540 	.show	= nfs_server_list_show,
1541 };
1542 
1543 static const struct file_operations nfs_server_list_fops = {
1544 	.open		= nfs_server_list_open,
1545 	.read		= seq_read,
1546 	.llseek		= seq_lseek,
1547 	.release	= seq_release,
1548 	.owner		= THIS_MODULE,
1549 };
1550 
1551 static int nfs_volume_list_open(struct inode *inode, struct file *file);
1552 static void *nfs_volume_list_start(struct seq_file *p, loff_t *pos);
1553 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos);
1554 static void nfs_volume_list_stop(struct seq_file *p, void *v);
1555 static int nfs_volume_list_show(struct seq_file *m, void *v);
1556 
1557 static struct seq_operations nfs_volume_list_ops = {
1558 	.start	= nfs_volume_list_start,
1559 	.next	= nfs_volume_list_next,
1560 	.stop	= nfs_volume_list_stop,
1561 	.show	= nfs_volume_list_show,
1562 };
1563 
1564 static const struct file_operations nfs_volume_list_fops = {
1565 	.open		= nfs_volume_list_open,
1566 	.read		= seq_read,
1567 	.llseek		= seq_lseek,
1568 	.release	= seq_release,
1569 	.owner		= THIS_MODULE,
1570 };
1571 
1572 /*
1573  * open "/proc/fs/nfsfs/servers" which provides a summary of servers with which
1574  * we're dealing
1575  */
1576 static int nfs_server_list_open(struct inode *inode, struct file *file)
1577 {
1578 	struct seq_file *m;
1579 	int ret;
1580 
1581 	ret = seq_open(file, &nfs_server_list_ops);
1582 	if (ret < 0)
1583 		return ret;
1584 
1585 	m = file->private_data;
1586 	m->private = PDE(inode)->data;
1587 
1588 	return 0;
1589 }
1590 
1591 /*
1592  * set up the iterator to start reading from the server list and return the first item
1593  */
1594 static void *nfs_server_list_start(struct seq_file *m, loff_t *_pos)
1595 {
1596 	/* lock the list against modification */
1597 	spin_lock(&nfs_client_lock);
1598 	return seq_list_start_head(&nfs_client_list, *_pos);
1599 }
1600 
1601 /*
1602  * move to next server
1603  */
1604 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos)
1605 {
1606 	return seq_list_next(v, &nfs_client_list, pos);
1607 }
1608 
1609 /*
1610  * clean up after reading from the transports list
1611  */
1612 static void nfs_server_list_stop(struct seq_file *p, void *v)
1613 {
1614 	spin_unlock(&nfs_client_lock);
1615 }
1616 
1617 /*
1618  * display a header line followed by a load of call lines
1619  */
1620 static int nfs_server_list_show(struct seq_file *m, void *v)
1621 {
1622 	struct nfs_client *clp;
1623 
1624 	/* display header on line 1 */
1625 	if (v == &nfs_client_list) {
1626 		seq_puts(m, "NV SERVER   PORT USE HOSTNAME\n");
1627 		return 0;
1628 	}
1629 
1630 	/* display one transport per line on subsequent lines */
1631 	clp = list_entry(v, struct nfs_client, cl_share_link);
1632 
1633 	seq_printf(m, "v%u %s %s %3d %s\n",
1634 		   clp->rpc_ops->version,
1635 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1636 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1637 		   atomic_read(&clp->cl_count),
1638 		   clp->cl_hostname);
1639 
1640 	return 0;
1641 }
1642 
1643 /*
1644  * open "/proc/fs/nfsfs/volumes" which provides a summary of extant volumes
1645  */
1646 static int nfs_volume_list_open(struct inode *inode, struct file *file)
1647 {
1648 	struct seq_file *m;
1649 	int ret;
1650 
1651 	ret = seq_open(file, &nfs_volume_list_ops);
1652 	if (ret < 0)
1653 		return ret;
1654 
1655 	m = file->private_data;
1656 	m->private = PDE(inode)->data;
1657 
1658 	return 0;
1659 }
1660 
1661 /*
1662  * set up the iterator to start reading from the volume list and return the first item
1663  */
1664 static void *nfs_volume_list_start(struct seq_file *m, loff_t *_pos)
1665 {
1666 	/* lock the list against modification */
1667 	spin_lock(&nfs_client_lock);
1668 	return seq_list_start_head(&nfs_volume_list, *_pos);
1669 }
1670 
1671 /*
1672  * move to next volume
1673  */
1674 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos)
1675 {
1676 	return seq_list_next(v, &nfs_volume_list, pos);
1677 }
1678 
1679 /*
1680  * clean up after reading from the transports list
1681  */
1682 static void nfs_volume_list_stop(struct seq_file *p, void *v)
1683 {
1684 	spin_unlock(&nfs_client_lock);
1685 }
1686 
1687 /*
1688  * display a header line followed by a load of call lines
1689  */
1690 static int nfs_volume_list_show(struct seq_file *m, void *v)
1691 {
1692 	struct nfs_server *server;
1693 	struct nfs_client *clp;
1694 	char dev[8], fsid[17];
1695 
1696 	/* display header on line 1 */
1697 	if (v == &nfs_volume_list) {
1698 		seq_puts(m, "NV SERVER   PORT DEV     FSID              FSC\n");
1699 		return 0;
1700 	}
1701 	/* display one transport per line on subsequent lines */
1702 	server = list_entry(v, struct nfs_server, master_link);
1703 	clp = server->nfs_client;
1704 
1705 	snprintf(dev, 8, "%u:%u",
1706 		 MAJOR(server->s_dev), MINOR(server->s_dev));
1707 
1708 	snprintf(fsid, 17, "%llx:%llx",
1709 		 (unsigned long long) server->fsid.major,
1710 		 (unsigned long long) server->fsid.minor);
1711 
1712 	seq_printf(m, "v%u %s %s %-7s %-17s %s\n",
1713 		   clp->rpc_ops->version,
1714 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1715 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1716 		   dev,
1717 		   fsid,
1718 		   nfs_server_fscache_state(server));
1719 
1720 	return 0;
1721 }
1722 
1723 /*
1724  * initialise the /proc/fs/nfsfs/ directory
1725  */
1726 int __init nfs_fs_proc_init(void)
1727 {
1728 	struct proc_dir_entry *p;
1729 
1730 	proc_fs_nfs = proc_mkdir("fs/nfsfs", NULL);
1731 	if (!proc_fs_nfs)
1732 		goto error_0;
1733 
1734 	/* a file of servers with which we're dealing */
1735 	p = proc_create("servers", S_IFREG|S_IRUGO,
1736 			proc_fs_nfs, &nfs_server_list_fops);
1737 	if (!p)
1738 		goto error_1;
1739 
1740 	/* a file of volumes that we have mounted */
1741 	p = proc_create("volumes", S_IFREG|S_IRUGO,
1742 			proc_fs_nfs, &nfs_volume_list_fops);
1743 	if (!p)
1744 		goto error_2;
1745 	return 0;
1746 
1747 error_2:
1748 	remove_proc_entry("servers", proc_fs_nfs);
1749 error_1:
1750 	remove_proc_entry("fs/nfsfs", NULL);
1751 error_0:
1752 	return -ENOMEM;
1753 }
1754 
1755 /*
1756  * clean up the /proc/fs/nfsfs/ directory
1757  */
1758 void nfs_fs_proc_exit(void)
1759 {
1760 	remove_proc_entry("volumes", proc_fs_nfs);
1761 	remove_proc_entry("servers", proc_fs_nfs);
1762 	remove_proc_entry("fs/nfsfs", NULL);
1763 }
1764 
1765 #endif /* CONFIG_PROC_FS */
1766