xref: /linux/fs/nfs/client.c (revision 71ca97da9d027009d318d319cbacf54a72f666c1)
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 <linux/idr.h>
40 #include <net/ipv6.h>
41 #include <linux/nfs_xdr.h>
42 #include <linux/sunrpc/bc_xprt.h>
43 #include <linux/nsproxy.h>
44 #include <linux/pid_namespace.h>
45 
46 
47 #include "nfs4_fs.h"
48 #include "callback.h"
49 #include "delegation.h"
50 #include "iostat.h"
51 #include "internal.h"
52 #include "fscache.h"
53 #include "pnfs.h"
54 #include "netns.h"
55 
56 #define NFSDBG_FACILITY		NFSDBG_CLIENT
57 
58 static DECLARE_WAIT_QUEUE_HEAD(nfs_client_active_wq);
59 #ifdef CONFIG_NFS_V4
60 
61 /*
62  * Get a unique NFSv4.0 callback identifier which will be used
63  * by the V4.0 callback service to lookup the nfs_client struct
64  */
65 static int nfs_get_cb_ident_idr(struct nfs_client *clp, int minorversion)
66 {
67 	int ret = 0;
68 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
69 
70 	if (clp->rpc_ops->version != 4 || minorversion != 0)
71 		return ret;
72 retry:
73 	if (!idr_pre_get(&nn->cb_ident_idr, GFP_KERNEL))
74 		return -ENOMEM;
75 	spin_lock(&nn->nfs_client_lock);
76 	ret = idr_get_new(&nn->cb_ident_idr, clp, &clp->cl_cb_ident);
77 	spin_unlock(&nn->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 bool nfs4_disable_idmapping = true;
88 
89 /*
90  * RPC cruft for NFS
91  */
92 static const struct rpc_version *nfs_version[5] = {
93 #ifdef CONFIG_NFS_V2
94 	[2]			= &nfs_version2,
95 #endif
96 #ifdef CONFIG_NFS_V3
97 	[3]			= &nfs_version3,
98 #endif
99 #ifdef CONFIG_NFS_V4
100 	[4]			= &nfs_version4,
101 #endif
102 };
103 
104 const struct rpc_program nfs_program = {
105 	.name			= "nfs",
106 	.number			= NFS_PROGRAM,
107 	.nrvers			= ARRAY_SIZE(nfs_version),
108 	.version		= nfs_version,
109 	.stats			= &nfs_rpcstat,
110 	.pipe_dir_name		= NFS_PIPE_DIRNAME,
111 };
112 
113 struct rpc_stat nfs_rpcstat = {
114 	.program		= &nfs_program
115 };
116 
117 
118 #ifdef CONFIG_NFS_V3_ACL
119 static struct rpc_stat		nfsacl_rpcstat = { &nfsacl_program };
120 static const struct rpc_version *nfsacl_version[] = {
121 	[3]			= &nfsacl_version3,
122 };
123 
124 const struct rpc_program nfsacl_program = {
125 	.name			= "nfsacl",
126 	.number			= NFS_ACL_PROGRAM,
127 	.nrvers			= ARRAY_SIZE(nfsacl_version),
128 	.version		= nfsacl_version,
129 	.stats			= &nfsacl_rpcstat,
130 };
131 #endif  /* CONFIG_NFS_V3_ACL */
132 
133 struct nfs_client_initdata {
134 	unsigned long init_flags;
135 	const char *hostname;
136 	const struct sockaddr *addr;
137 	size_t addrlen;
138 	const struct nfs_rpc_ops *rpc_ops;
139 	int proto;
140 	u32 minorversion;
141 	struct net *net;
142 };
143 
144 /*
145  * Allocate a shared client record
146  *
147  * Since these are allocated/deallocated very rarely, we don't
148  * bother putting them in a slab cache...
149  */
150 static struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init)
151 {
152 	struct nfs_client *clp;
153 	struct rpc_cred *cred;
154 	int err = -ENOMEM;
155 
156 	if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL)
157 		goto error_0;
158 
159 	clp->rpc_ops = cl_init->rpc_ops;
160 
161 	atomic_set(&clp->cl_count, 1);
162 	clp->cl_cons_state = NFS_CS_INITING;
163 
164 	memcpy(&clp->cl_addr, cl_init->addr, cl_init->addrlen);
165 	clp->cl_addrlen = cl_init->addrlen;
166 
167 	if (cl_init->hostname) {
168 		err = -ENOMEM;
169 		clp->cl_hostname = kstrdup(cl_init->hostname, GFP_KERNEL);
170 		if (!clp->cl_hostname)
171 			goto error_cleanup;
172 	}
173 
174 	INIT_LIST_HEAD(&clp->cl_superblocks);
175 	clp->cl_rpcclient = ERR_PTR(-EINVAL);
176 
177 	clp->cl_proto = cl_init->proto;
178 	clp->cl_net = get_net(cl_init->net);
179 
180 #ifdef CONFIG_NFS_V4
181 	err = nfs_get_cb_ident_idr(clp, cl_init->minorversion);
182 	if (err)
183 		goto error_cleanup;
184 
185 	spin_lock_init(&clp->cl_lock);
186 	INIT_DELAYED_WORK(&clp->cl_renewd, nfs4_renew_state);
187 	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
188 	clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
189 	clp->cl_minorversion = cl_init->minorversion;
190 	clp->cl_mvops = nfs_v4_minor_ops[cl_init->minorversion];
191 #endif
192 	cred = rpc_lookup_machine_cred("*");
193 	if (!IS_ERR(cred))
194 		clp->cl_machine_cred = cred;
195 	nfs_fscache_get_client_cookie(clp);
196 
197 	return clp;
198 
199 error_cleanup:
200 	kfree(clp);
201 error_0:
202 	return ERR_PTR(err);
203 }
204 
205 #ifdef CONFIG_NFS_V4
206 #ifdef CONFIG_NFS_V4_1
207 static void nfs4_shutdown_session(struct nfs_client *clp)
208 {
209 	if (nfs4_has_session(clp)) {
210 		nfs4_deviceid_purge_client(clp);
211 		nfs4_destroy_session(clp->cl_session);
212 		nfs4_destroy_clientid(clp);
213 	}
214 
215 }
216 #else /* CONFIG_NFS_V4_1 */
217 static void nfs4_shutdown_session(struct nfs_client *clp)
218 {
219 }
220 #endif /* CONFIG_NFS_V4_1 */
221 
222 /*
223  * Destroy the NFS4 callback service
224  */
225 static void nfs4_destroy_callback(struct nfs_client *clp)
226 {
227 	if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
228 		nfs_callback_down(clp->cl_mvops->minor_version);
229 }
230 
231 static void nfs4_shutdown_client(struct nfs_client *clp)
232 {
233 	if (__test_and_clear_bit(NFS_CS_RENEWD, &clp->cl_res_state))
234 		nfs4_kill_renewd(clp);
235 	nfs4_shutdown_session(clp);
236 	nfs4_destroy_callback(clp);
237 	if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state))
238 		nfs_idmap_delete(clp);
239 
240 	rpc_destroy_wait_queue(&clp->cl_rpcwaitq);
241 	kfree(clp->cl_serverowner);
242 	kfree(clp->cl_serverscope);
243 	kfree(clp->cl_implid);
244 }
245 
246 /* idr_remove_all is not needed as all id's are removed by nfs_put_client */
247 void nfs_cleanup_cb_ident_idr(struct net *net)
248 {
249 	struct nfs_net *nn = net_generic(net, nfs_net_id);
250 
251 	idr_destroy(&nn->cb_ident_idr);
252 }
253 
254 /* nfs_client_lock held */
255 static void nfs_cb_idr_remove_locked(struct nfs_client *clp)
256 {
257 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
258 
259 	if (clp->cl_cb_ident)
260 		idr_remove(&nn->cb_ident_idr, clp->cl_cb_ident);
261 }
262 
263 static void pnfs_init_server(struct nfs_server *server)
264 {
265 	rpc_init_wait_queue(&server->roc_rpcwaitq, "pNFS ROC");
266 }
267 
268 static void nfs4_destroy_server(struct nfs_server *server)
269 {
270 	nfs4_purge_state_owners(server);
271 }
272 
273 #else
274 static void nfs4_shutdown_client(struct nfs_client *clp)
275 {
276 }
277 
278 void nfs_cleanup_cb_ident_idr(struct net *net)
279 {
280 }
281 
282 static void nfs_cb_idr_remove_locked(struct nfs_client *clp)
283 {
284 }
285 
286 static void pnfs_init_server(struct nfs_server *server)
287 {
288 }
289 
290 #endif /* CONFIG_NFS_V4 */
291 
292 /*
293  * Destroy a shared client record
294  */
295 static void nfs_free_client(struct nfs_client *clp)
296 {
297 	dprintk("--> nfs_free_client(%u)\n", clp->rpc_ops->version);
298 
299 	nfs4_shutdown_client(clp);
300 
301 	nfs_fscache_release_client_cookie(clp);
302 
303 	/* -EIO all pending I/O */
304 	if (!IS_ERR(clp->cl_rpcclient))
305 		rpc_shutdown_client(clp->cl_rpcclient);
306 
307 	if (clp->cl_machine_cred != NULL)
308 		put_rpccred(clp->cl_machine_cred);
309 
310 	put_net(clp->cl_net);
311 	kfree(clp->cl_hostname);
312 	kfree(clp);
313 
314 	dprintk("<-- nfs_free_client()\n");
315 }
316 
317 /*
318  * Release a reference to a shared client record
319  */
320 void nfs_put_client(struct nfs_client *clp)
321 {
322 	struct nfs_net *nn;
323 
324 	if (!clp)
325 		return;
326 
327 	dprintk("--> nfs_put_client({%d})\n", atomic_read(&clp->cl_count));
328 	nn = net_generic(clp->cl_net, nfs_net_id);
329 
330 	if (atomic_dec_and_lock(&clp->cl_count, &nn->nfs_client_lock)) {
331 		list_del(&clp->cl_share_link);
332 		nfs_cb_idr_remove_locked(clp);
333 		spin_unlock(&nn->nfs_client_lock);
334 
335 		BUG_ON(!list_empty(&clp->cl_superblocks));
336 
337 		nfs_free_client(clp);
338 	}
339 }
340 EXPORT_SYMBOL_GPL(nfs_put_client);
341 
342 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
343 /*
344  * Test if two ip6 socket addresses refer to the same socket by
345  * comparing relevant fields. The padding bytes specifically, are not
346  * compared. sin6_flowinfo is not compared because it only affects QoS
347  * and sin6_scope_id is only compared if the address is "link local"
348  * because "link local" addresses need only be unique to a specific
349  * link. Conversely, ordinary unicast addresses might have different
350  * sin6_scope_id.
351  *
352  * The caller should ensure both socket addresses are AF_INET6.
353  */
354 static int nfs_sockaddr_match_ipaddr6(const struct sockaddr *sa1,
355 				      const struct sockaddr *sa2)
356 {
357 	const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sa1;
358 	const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sa2;
359 
360 	if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
361 		return 0;
362 	else if (ipv6_addr_type(&sin1->sin6_addr) & IPV6_ADDR_LINKLOCAL)
363 		return sin1->sin6_scope_id == sin2->sin6_scope_id;
364 
365 	return 1;
366 }
367 #else	/* !defined(CONFIG_IPV6) && !defined(CONFIG_IPV6_MODULE) */
368 static int nfs_sockaddr_match_ipaddr6(const struct sockaddr *sa1,
369 				      const struct sockaddr *sa2)
370 {
371 	return 0;
372 }
373 #endif
374 
375 /*
376  * Test if two ip4 socket addresses refer to the same socket, by
377  * comparing relevant fields. The padding bytes specifically, are
378  * not compared.
379  *
380  * The caller should ensure both socket addresses are AF_INET.
381  */
382 static int nfs_sockaddr_match_ipaddr4(const struct sockaddr *sa1,
383 				      const struct sockaddr *sa2)
384 {
385 	const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sa1;
386 	const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sa2;
387 
388 	return sin1->sin_addr.s_addr == sin2->sin_addr.s_addr;
389 }
390 
391 static int nfs_sockaddr_cmp_ip6(const struct sockaddr *sa1,
392 				const struct sockaddr *sa2)
393 {
394 	const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sa1;
395 	const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sa2;
396 
397 	return nfs_sockaddr_match_ipaddr6(sa1, sa2) &&
398 		(sin1->sin6_port == sin2->sin6_port);
399 }
400 
401 static int nfs_sockaddr_cmp_ip4(const struct sockaddr *sa1,
402 				const struct sockaddr *sa2)
403 {
404 	const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sa1;
405 	const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sa2;
406 
407 	return nfs_sockaddr_match_ipaddr4(sa1, sa2) &&
408 		(sin1->sin_port == sin2->sin_port);
409 }
410 
411 #if defined(CONFIG_NFS_V4_1)
412 /*
413  * Test if two socket addresses represent the same actual socket,
414  * by comparing (only) relevant fields, excluding the port number.
415  */
416 static int nfs_sockaddr_match_ipaddr(const struct sockaddr *sa1,
417 				     const struct sockaddr *sa2)
418 {
419 	if (sa1->sa_family != sa2->sa_family)
420 		return 0;
421 
422 	switch (sa1->sa_family) {
423 	case AF_INET:
424 		return nfs_sockaddr_match_ipaddr4(sa1, sa2);
425 	case AF_INET6:
426 		return nfs_sockaddr_match_ipaddr6(sa1, sa2);
427 	}
428 	return 0;
429 }
430 #endif /* CONFIG_NFS_V4_1 */
431 
432 /*
433  * Test if two socket addresses represent the same actual socket,
434  * by comparing (only) relevant fields, including the port number.
435  */
436 static int nfs_sockaddr_cmp(const struct sockaddr *sa1,
437 			    const struct sockaddr *sa2)
438 {
439 	if (sa1->sa_family != sa2->sa_family)
440 		return 0;
441 
442 	switch (sa1->sa_family) {
443 	case AF_INET:
444 		return nfs_sockaddr_cmp_ip4(sa1, sa2);
445 	case AF_INET6:
446 		return nfs_sockaddr_cmp_ip6(sa1, sa2);
447 	}
448 	return 0;
449 }
450 
451 #if defined(CONFIG_NFS_V4_1)
452 /* Common match routine for v4.0 and v4.1 callback services */
453 static bool nfs4_cb_match_client(const struct sockaddr *addr,
454 		struct nfs_client *clp, u32 minorversion)
455 {
456 	struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
457 
458 	/* Don't match clients that failed to initialise */
459 	if (!(clp->cl_cons_state == NFS_CS_READY ||
460 	    clp->cl_cons_state == NFS_CS_SESSION_INITING))
461 		return false;
462 
463 	smp_rmb();
464 
465 	/* Match the version and minorversion */
466 	if (clp->rpc_ops->version != 4 ||
467 	    clp->cl_minorversion != minorversion)
468 		return false;
469 
470 	/* Match only the IP address, not the port number */
471 	if (!nfs_sockaddr_match_ipaddr(addr, clap))
472 		return false;
473 
474 	return true;
475 }
476 #endif /* CONFIG_NFS_V4_1 */
477 
478 /*
479  * Find an nfs_client on the list that matches the initialisation data
480  * that is supplied.
481  */
482 static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *data)
483 {
484 	struct nfs_client *clp;
485 	const struct sockaddr *sap = data->addr;
486 	struct nfs_net *nn = net_generic(data->net, nfs_net_id);
487 
488 	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
489 	        const struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
490 		/* Don't match clients that failed to initialise properly */
491 		if (clp->cl_cons_state < 0)
492 			continue;
493 
494 		/* Different NFS versions cannot share the same nfs_client */
495 		if (clp->rpc_ops != data->rpc_ops)
496 			continue;
497 
498 		if (clp->cl_proto != data->proto)
499 			continue;
500 		/* Match nfsv4 minorversion */
501 		if (clp->cl_minorversion != data->minorversion)
502 			continue;
503 		/* Match the full socket address */
504 		if (!nfs_sockaddr_cmp(sap, clap))
505 			continue;
506 
507 		atomic_inc(&clp->cl_count);
508 		return clp;
509 	}
510 	return NULL;
511 }
512 
513 static bool nfs_client_init_is_complete(const struct nfs_client *clp)
514 {
515 	return clp->cl_cons_state != NFS_CS_INITING;
516 }
517 
518 int nfs_wait_client_init_complete(const struct nfs_client *clp)
519 {
520 	return wait_event_killable(nfs_client_active_wq,
521 			nfs_client_init_is_complete(clp));
522 }
523 
524 /*
525  * Found an existing client.  Make sure it's ready before returning.
526  */
527 static struct nfs_client *
528 nfs_found_client(const struct nfs_client_initdata *cl_init,
529 		 struct nfs_client *clp)
530 {
531 	int error;
532 
533 	error = nfs_wait_client_init_complete(clp);
534 	if (error < 0) {
535 		nfs_put_client(clp);
536 		return ERR_PTR(-ERESTARTSYS);
537 	}
538 
539 	if (clp->cl_cons_state < NFS_CS_READY) {
540 		error = clp->cl_cons_state;
541 		nfs_put_client(clp);
542 		return ERR_PTR(error);
543 	}
544 
545 	smp_rmb();
546 
547 	BUG_ON(clp->cl_cons_state != NFS_CS_READY);
548 
549 	dprintk("<-- %s found nfs_client %p for %s\n",
550 		__func__, clp, cl_init->hostname ?: "");
551 	return clp;
552 }
553 
554 /*
555  * Look up a client by IP address and protocol version
556  * - creates a new record if one doesn't yet exist
557  */
558 static struct nfs_client *
559 nfs_get_client(const struct nfs_client_initdata *cl_init,
560 	       const struct rpc_timeout *timeparms,
561 	       const char *ip_addr,
562 	       rpc_authflavor_t authflavour)
563 {
564 	struct nfs_client *clp, *new = NULL;
565 	struct nfs_net *nn = net_generic(cl_init->net, nfs_net_id);
566 
567 	dprintk("--> nfs_get_client(%s,v%u)\n",
568 		cl_init->hostname ?: "", cl_init->rpc_ops->version);
569 
570 	/* see if the client already exists */
571 	do {
572 		spin_lock(&nn->nfs_client_lock);
573 
574 		clp = nfs_match_client(cl_init);
575 		if (clp) {
576 			spin_unlock(&nn->nfs_client_lock);
577 			if (new)
578 				nfs_free_client(new);
579 			return nfs_found_client(cl_init, clp);
580 		}
581 		if (new) {
582 			list_add(&new->cl_share_link, &nn->nfs_client_list);
583 			spin_unlock(&nn->nfs_client_lock);
584 			new->cl_flags = cl_init->init_flags;
585 			return cl_init->rpc_ops->init_client(new,
586 						timeparms, ip_addr,
587 						authflavour);
588 		}
589 
590 		spin_unlock(&nn->nfs_client_lock);
591 
592 		new = nfs_alloc_client(cl_init);
593 	} while (!IS_ERR(new));
594 
595 	dprintk("<-- nfs_get_client() Failed to find %s (%ld)\n",
596 		cl_init->hostname ?: "", PTR_ERR(new));
597 	return new;
598 }
599 
600 /*
601  * Mark a server as ready or failed
602  */
603 void nfs_mark_client_ready(struct nfs_client *clp, int state)
604 {
605 	smp_wmb();
606 	clp->cl_cons_state = state;
607 	wake_up_all(&nfs_client_active_wq);
608 }
609 
610 /*
611  * Initialise the timeout values for a connection
612  */
613 static void nfs_init_timeout_values(struct rpc_timeout *to, int proto,
614 				    unsigned int timeo, unsigned int retrans)
615 {
616 	to->to_initval = timeo * HZ / 10;
617 	to->to_retries = retrans;
618 
619 	switch (proto) {
620 	case XPRT_TRANSPORT_TCP:
621 	case XPRT_TRANSPORT_RDMA:
622 		if (to->to_retries == 0)
623 			to->to_retries = NFS_DEF_TCP_RETRANS;
624 		if (to->to_initval == 0)
625 			to->to_initval = NFS_DEF_TCP_TIMEO * HZ / 10;
626 		if (to->to_initval > NFS_MAX_TCP_TIMEOUT)
627 			to->to_initval = NFS_MAX_TCP_TIMEOUT;
628 		to->to_increment = to->to_initval;
629 		to->to_maxval = to->to_initval + (to->to_increment * to->to_retries);
630 		if (to->to_maxval > NFS_MAX_TCP_TIMEOUT)
631 			to->to_maxval = NFS_MAX_TCP_TIMEOUT;
632 		if (to->to_maxval < to->to_initval)
633 			to->to_maxval = to->to_initval;
634 		to->to_exponential = 0;
635 		break;
636 	case XPRT_TRANSPORT_UDP:
637 		if (to->to_retries == 0)
638 			to->to_retries = NFS_DEF_UDP_RETRANS;
639 		if (!to->to_initval)
640 			to->to_initval = NFS_DEF_UDP_TIMEO * HZ / 10;
641 		if (to->to_initval > NFS_MAX_UDP_TIMEOUT)
642 			to->to_initval = NFS_MAX_UDP_TIMEOUT;
643 		to->to_maxval = NFS_MAX_UDP_TIMEOUT;
644 		to->to_exponential = 1;
645 		break;
646 	default:
647 		BUG();
648 	}
649 }
650 
651 /*
652  * Create an RPC client handle
653  */
654 static int nfs_create_rpc_client(struct nfs_client *clp,
655 				 const struct rpc_timeout *timeparms,
656 				 rpc_authflavor_t flavor)
657 {
658 	struct rpc_clnt		*clnt = NULL;
659 	struct rpc_create_args args = {
660 		.net		= clp->cl_net,
661 		.protocol	= clp->cl_proto,
662 		.address	= (struct sockaddr *)&clp->cl_addr,
663 		.addrsize	= clp->cl_addrlen,
664 		.timeout	= timeparms,
665 		.servername	= clp->cl_hostname,
666 		.program	= &nfs_program,
667 		.version	= clp->rpc_ops->version,
668 		.authflavor	= flavor,
669 	};
670 
671 	if (test_bit(NFS_CS_DISCRTRY, &clp->cl_flags))
672 		args.flags |= RPC_CLNT_CREATE_DISCRTRY;
673 	if (test_bit(NFS_CS_NORESVPORT, &clp->cl_flags))
674 		args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
675 
676 	if (!IS_ERR(clp->cl_rpcclient))
677 		return 0;
678 
679 	clnt = rpc_create(&args);
680 	if (IS_ERR(clnt)) {
681 		dprintk("%s: cannot create RPC client. Error = %ld\n",
682 				__func__, PTR_ERR(clnt));
683 		return PTR_ERR(clnt);
684 	}
685 
686 	clp->cl_rpcclient = clnt;
687 	return 0;
688 }
689 
690 /*
691  * Version 2 or 3 client destruction
692  */
693 static void nfs_destroy_server(struct nfs_server *server)
694 {
695 	if (!(server->flags & NFS_MOUNT_LOCAL_FLOCK) ||
696 			!(server->flags & NFS_MOUNT_LOCAL_FCNTL))
697 		nlmclnt_done(server->nlm_host);
698 }
699 
700 /*
701  * Version 2 or 3 lockd setup
702  */
703 static int nfs_start_lockd(struct nfs_server *server)
704 {
705 	struct nlm_host *host;
706 	struct nfs_client *clp = server->nfs_client;
707 	struct nlmclnt_initdata nlm_init = {
708 		.hostname	= clp->cl_hostname,
709 		.address	= (struct sockaddr *)&clp->cl_addr,
710 		.addrlen	= clp->cl_addrlen,
711 		.nfs_version	= clp->rpc_ops->version,
712 		.noresvport	= server->flags & NFS_MOUNT_NORESVPORT ?
713 					1 : 0,
714 		.net		= clp->cl_net,
715 	};
716 
717 	if (nlm_init.nfs_version > 3)
718 		return 0;
719 	if ((server->flags & NFS_MOUNT_LOCAL_FLOCK) &&
720 			(server->flags & NFS_MOUNT_LOCAL_FCNTL))
721 		return 0;
722 
723 	switch (clp->cl_proto) {
724 		default:
725 			nlm_init.protocol = IPPROTO_TCP;
726 			break;
727 		case XPRT_TRANSPORT_UDP:
728 			nlm_init.protocol = IPPROTO_UDP;
729 	}
730 
731 	host = nlmclnt_init(&nlm_init);
732 	if (IS_ERR(host))
733 		return PTR_ERR(host);
734 
735 	server->nlm_host = host;
736 	server->destroy = nfs_destroy_server;
737 	return 0;
738 }
739 
740 /*
741  * Initialise an NFSv3 ACL client connection
742  */
743 #ifdef CONFIG_NFS_V3_ACL
744 static void nfs_init_server_aclclient(struct nfs_server *server)
745 {
746 	if (server->nfs_client->rpc_ops->version != 3)
747 		goto out_noacl;
748 	if (server->flags & NFS_MOUNT_NOACL)
749 		goto out_noacl;
750 
751 	server->client_acl = rpc_bind_new_program(server->client, &nfsacl_program, 3);
752 	if (IS_ERR(server->client_acl))
753 		goto out_noacl;
754 
755 	/* No errors! Assume that Sun nfsacls are supported */
756 	server->caps |= NFS_CAP_ACLS;
757 	return;
758 
759 out_noacl:
760 	server->caps &= ~NFS_CAP_ACLS;
761 }
762 #else
763 static inline void nfs_init_server_aclclient(struct nfs_server *server)
764 {
765 	server->flags &= ~NFS_MOUNT_NOACL;
766 	server->caps &= ~NFS_CAP_ACLS;
767 }
768 #endif
769 
770 /*
771  * Create a general RPC client
772  */
773 static int nfs_init_server_rpcclient(struct nfs_server *server,
774 		const struct rpc_timeout *timeo,
775 		rpc_authflavor_t pseudoflavour)
776 {
777 	struct nfs_client *clp = server->nfs_client;
778 
779 	server->client = rpc_clone_client(clp->cl_rpcclient);
780 	if (IS_ERR(server->client)) {
781 		dprintk("%s: couldn't create rpc_client!\n", __func__);
782 		return PTR_ERR(server->client);
783 	}
784 
785 	memcpy(&server->client->cl_timeout_default,
786 			timeo,
787 			sizeof(server->client->cl_timeout_default));
788 	server->client->cl_timeout = &server->client->cl_timeout_default;
789 
790 	if (pseudoflavour != clp->cl_rpcclient->cl_auth->au_flavor) {
791 		struct rpc_auth *auth;
792 
793 		auth = rpcauth_create(pseudoflavour, server->client);
794 		if (IS_ERR(auth)) {
795 			dprintk("%s: couldn't create credcache!\n", __func__);
796 			return PTR_ERR(auth);
797 		}
798 	}
799 	server->client->cl_softrtry = 0;
800 	if (server->flags & NFS_MOUNT_SOFT)
801 		server->client->cl_softrtry = 1;
802 
803 	return 0;
804 }
805 
806 /**
807  * nfs_init_client - Initialise an NFS2 or NFS3 client
808  *
809  * @clp: nfs_client to initialise
810  * @timeparms: timeout parameters for underlying RPC transport
811  * @ip_addr: IP presentation address (not used)
812  * @authflavor: authentication flavor for underlying RPC transport
813  *
814  * Returns pointer to an NFS client, or an ERR_PTR value.
815  */
816 struct nfs_client *nfs_init_client(struct nfs_client *clp,
817 		    const struct rpc_timeout *timeparms,
818 		    const char *ip_addr, rpc_authflavor_t authflavour)
819 {
820 	int error;
821 
822 	if (clp->cl_cons_state == NFS_CS_READY) {
823 		/* the client is already initialised */
824 		dprintk("<-- nfs_init_client() = 0 [already %p]\n", clp);
825 		return clp;
826 	}
827 
828 	/*
829 	 * Create a client RPC handle for doing FSSTAT with UNIX auth only
830 	 * - RFC 2623, sec 2.3.2
831 	 */
832 	error = nfs_create_rpc_client(clp, timeparms, RPC_AUTH_UNIX);
833 	if (error < 0)
834 		goto error;
835 	nfs_mark_client_ready(clp, NFS_CS_READY);
836 	return clp;
837 
838 error:
839 	nfs_mark_client_ready(clp, error);
840 	nfs_put_client(clp);
841 	dprintk("<-- nfs_init_client() = xerror %d\n", error);
842 	return ERR_PTR(error);
843 }
844 
845 /*
846  * Create a version 2 or 3 client
847  */
848 static int nfs_init_server(struct nfs_server *server,
849 			   const struct nfs_parsed_mount_data *data)
850 {
851 	struct nfs_client_initdata cl_init = {
852 		.hostname = data->nfs_server.hostname,
853 		.addr = (const struct sockaddr *)&data->nfs_server.address,
854 		.addrlen = data->nfs_server.addrlen,
855 		.rpc_ops = NULL,
856 		.proto = data->nfs_server.protocol,
857 		.net = data->net,
858 	};
859 	struct rpc_timeout timeparms;
860 	struct nfs_client *clp;
861 	int error;
862 
863 	dprintk("--> nfs_init_server()\n");
864 
865 	switch (data->version) {
866 #ifdef CONFIG_NFS_V2
867 	case 2:
868 		cl_init.rpc_ops = &nfs_v2_clientops;
869 		break;
870 #endif
871 #ifdef CONFIG_NFS_V3
872 	case 3:
873 		cl_init.rpc_ops = &nfs_v3_clientops;
874 		break;
875 #endif
876 	default:
877 		return -EPROTONOSUPPORT;
878 	}
879 
880 	nfs_init_timeout_values(&timeparms, data->nfs_server.protocol,
881 			data->timeo, data->retrans);
882 	if (data->flags & NFS_MOUNT_NORESVPORT)
883 		set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
884 
885 	/* Allocate or find a client reference we can use */
886 	clp = nfs_get_client(&cl_init, &timeparms, NULL, RPC_AUTH_UNIX);
887 	if (IS_ERR(clp)) {
888 		dprintk("<-- nfs_init_server() = error %ld\n", PTR_ERR(clp));
889 		return PTR_ERR(clp);
890 	}
891 
892 	server->nfs_client = clp;
893 
894 	/* Initialise the client representation from the mount data */
895 	server->flags = data->flags;
896 	server->options = data->options;
897 	server->caps |= NFS_CAP_HARDLINKS|NFS_CAP_SYMLINKS|NFS_CAP_FILEID|
898 		NFS_CAP_MODE|NFS_CAP_NLINK|NFS_CAP_OWNER|NFS_CAP_OWNER_GROUP|
899 		NFS_CAP_ATIME|NFS_CAP_CTIME|NFS_CAP_MTIME|NFS_CAP_CHANGE_ATTR;
900 
901 	if (data->rsize)
902 		server->rsize = nfs_block_size(data->rsize, NULL);
903 	if (data->wsize)
904 		server->wsize = nfs_block_size(data->wsize, NULL);
905 
906 	server->acregmin = data->acregmin * HZ;
907 	server->acregmax = data->acregmax * HZ;
908 	server->acdirmin = data->acdirmin * HZ;
909 	server->acdirmax = data->acdirmax * HZ;
910 
911 	/* Start lockd here, before we might error out */
912 	error = nfs_start_lockd(server);
913 	if (error < 0)
914 		goto error;
915 
916 	server->port = data->nfs_server.port;
917 
918 	error = nfs_init_server_rpcclient(server, &timeparms, data->auth_flavors[0]);
919 	if (error < 0)
920 		goto error;
921 
922 	/* Preserve the values of mount_server-related mount options */
923 	if (data->mount_server.addrlen) {
924 		memcpy(&server->mountd_address, &data->mount_server.address,
925 			data->mount_server.addrlen);
926 		server->mountd_addrlen = data->mount_server.addrlen;
927 	}
928 	server->mountd_version = data->mount_server.version;
929 	server->mountd_port = data->mount_server.port;
930 	server->mountd_protocol = data->mount_server.protocol;
931 
932 	server->namelen  = data->namlen;
933 	/* Create a client RPC handle for the NFSv3 ACL management interface */
934 	nfs_init_server_aclclient(server);
935 	dprintk("<-- nfs_init_server() = 0 [new %p]\n", clp);
936 	return 0;
937 
938 error:
939 	server->nfs_client = NULL;
940 	nfs_put_client(clp);
941 	dprintk("<-- nfs_init_server() = xerror %d\n", error);
942 	return error;
943 }
944 
945 /*
946  * Load up the server record from information gained in an fsinfo record
947  */
948 static void nfs_server_set_fsinfo(struct nfs_server *server,
949 				  struct nfs_fh *mntfh,
950 				  struct nfs_fsinfo *fsinfo)
951 {
952 	unsigned long max_rpc_payload;
953 
954 	/* Work out a lot of parameters */
955 	if (server->rsize == 0)
956 		server->rsize = nfs_block_size(fsinfo->rtpref, NULL);
957 	if (server->wsize == 0)
958 		server->wsize = nfs_block_size(fsinfo->wtpref, NULL);
959 
960 	if (fsinfo->rtmax >= 512 && server->rsize > fsinfo->rtmax)
961 		server->rsize = nfs_block_size(fsinfo->rtmax, NULL);
962 	if (fsinfo->wtmax >= 512 && server->wsize > fsinfo->wtmax)
963 		server->wsize = nfs_block_size(fsinfo->wtmax, NULL);
964 
965 	max_rpc_payload = nfs_block_size(rpc_max_payload(server->client), NULL);
966 	if (server->rsize > max_rpc_payload)
967 		server->rsize = max_rpc_payload;
968 	if (server->rsize > NFS_MAX_FILE_IO_SIZE)
969 		server->rsize = NFS_MAX_FILE_IO_SIZE;
970 	server->rpages = (server->rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
971 
972 	server->backing_dev_info.name = "nfs";
973 	server->backing_dev_info.ra_pages = server->rpages * NFS_MAX_READAHEAD;
974 
975 	if (server->wsize > max_rpc_payload)
976 		server->wsize = max_rpc_payload;
977 	if (server->wsize > NFS_MAX_FILE_IO_SIZE)
978 		server->wsize = NFS_MAX_FILE_IO_SIZE;
979 	server->wpages = (server->wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
980 	server->pnfs_blksize = fsinfo->blksize;
981 	set_pnfs_layoutdriver(server, mntfh, fsinfo->layouttype);
982 
983 	server->wtmult = nfs_block_bits(fsinfo->wtmult, NULL);
984 
985 	server->dtsize = nfs_block_size(fsinfo->dtpref, NULL);
986 	if (server->dtsize > PAGE_CACHE_SIZE * NFS_MAX_READDIR_PAGES)
987 		server->dtsize = PAGE_CACHE_SIZE * NFS_MAX_READDIR_PAGES;
988 	if (server->dtsize > server->rsize)
989 		server->dtsize = server->rsize;
990 
991 	if (server->flags & NFS_MOUNT_NOAC) {
992 		server->acregmin = server->acregmax = 0;
993 		server->acdirmin = server->acdirmax = 0;
994 	}
995 
996 	server->maxfilesize = fsinfo->maxfilesize;
997 
998 	server->time_delta = fsinfo->time_delta;
999 
1000 	/* We're airborne Set socket buffersize */
1001 	rpc_setbufsize(server->client, server->wsize + 100, server->rsize + 100);
1002 }
1003 
1004 /*
1005  * Probe filesystem information, including the FSID on v2/v3
1006  */
1007 static int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *mntfh, struct nfs_fattr *fattr)
1008 {
1009 	struct nfs_fsinfo fsinfo;
1010 	struct nfs_client *clp = server->nfs_client;
1011 	int error;
1012 
1013 	dprintk("--> nfs_probe_fsinfo()\n");
1014 
1015 	if (clp->rpc_ops->set_capabilities != NULL) {
1016 		error = clp->rpc_ops->set_capabilities(server, mntfh);
1017 		if (error < 0)
1018 			goto out_error;
1019 	}
1020 
1021 	fsinfo.fattr = fattr;
1022 	fsinfo.layouttype = 0;
1023 	error = clp->rpc_ops->fsinfo(server, mntfh, &fsinfo);
1024 	if (error < 0)
1025 		goto out_error;
1026 
1027 	nfs_server_set_fsinfo(server, mntfh, &fsinfo);
1028 
1029 	/* Get some general file system info */
1030 	if (server->namelen == 0) {
1031 		struct nfs_pathconf pathinfo;
1032 
1033 		pathinfo.fattr = fattr;
1034 		nfs_fattr_init(fattr);
1035 
1036 		if (clp->rpc_ops->pathconf(server, mntfh, &pathinfo) >= 0)
1037 			server->namelen = pathinfo.max_namelen;
1038 	}
1039 
1040 	dprintk("<-- nfs_probe_fsinfo() = 0\n");
1041 	return 0;
1042 
1043 out_error:
1044 	dprintk("nfs_probe_fsinfo: error = %d\n", -error);
1045 	return error;
1046 }
1047 
1048 /*
1049  * Copy useful information when duplicating a server record
1050  */
1051 static void nfs_server_copy_userdata(struct nfs_server *target, struct nfs_server *source)
1052 {
1053 	target->flags = source->flags;
1054 	target->rsize = source->rsize;
1055 	target->wsize = source->wsize;
1056 	target->acregmin = source->acregmin;
1057 	target->acregmax = source->acregmax;
1058 	target->acdirmin = source->acdirmin;
1059 	target->acdirmax = source->acdirmax;
1060 	target->caps = source->caps;
1061 	target->options = source->options;
1062 }
1063 
1064 static void nfs_server_insert_lists(struct nfs_server *server)
1065 {
1066 	struct nfs_client *clp = server->nfs_client;
1067 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
1068 
1069 	spin_lock(&nn->nfs_client_lock);
1070 	list_add_tail_rcu(&server->client_link, &clp->cl_superblocks);
1071 	list_add_tail(&server->master_link, &nn->nfs_volume_list);
1072 	clear_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
1073 	spin_unlock(&nn->nfs_client_lock);
1074 
1075 }
1076 
1077 static void nfs_server_remove_lists(struct nfs_server *server)
1078 {
1079 	struct nfs_client *clp = server->nfs_client;
1080 	struct nfs_net *nn;
1081 
1082 	if (clp == NULL)
1083 		return;
1084 	nn = net_generic(clp->cl_net, nfs_net_id);
1085 	spin_lock(&nn->nfs_client_lock);
1086 	list_del_rcu(&server->client_link);
1087 	if (list_empty(&clp->cl_superblocks))
1088 		set_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
1089 	list_del(&server->master_link);
1090 	spin_unlock(&nn->nfs_client_lock);
1091 
1092 	synchronize_rcu();
1093 }
1094 
1095 /*
1096  * Allocate and initialise a server record
1097  */
1098 static struct nfs_server *nfs_alloc_server(void)
1099 {
1100 	struct nfs_server *server;
1101 
1102 	server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
1103 	if (!server)
1104 		return NULL;
1105 
1106 	server->client = server->client_acl = ERR_PTR(-EINVAL);
1107 
1108 	/* Zero out the NFS state stuff */
1109 	INIT_LIST_HEAD(&server->client_link);
1110 	INIT_LIST_HEAD(&server->master_link);
1111 	INIT_LIST_HEAD(&server->delegations);
1112 	INIT_LIST_HEAD(&server->layouts);
1113 	INIT_LIST_HEAD(&server->state_owners_lru);
1114 
1115 	atomic_set(&server->active, 0);
1116 
1117 	server->io_stats = nfs_alloc_iostats();
1118 	if (!server->io_stats) {
1119 		kfree(server);
1120 		return NULL;
1121 	}
1122 
1123 	if (bdi_init(&server->backing_dev_info)) {
1124 		nfs_free_iostats(server->io_stats);
1125 		kfree(server);
1126 		return NULL;
1127 	}
1128 
1129 	ida_init(&server->openowner_id);
1130 	ida_init(&server->lockowner_id);
1131 	pnfs_init_server(server);
1132 
1133 	return server;
1134 }
1135 
1136 /*
1137  * Free up a server record
1138  */
1139 void nfs_free_server(struct nfs_server *server)
1140 {
1141 	dprintk("--> nfs_free_server()\n");
1142 
1143 	nfs_server_remove_lists(server);
1144 	unset_pnfs_layoutdriver(server);
1145 
1146 	if (server->destroy != NULL)
1147 		server->destroy(server);
1148 
1149 	if (!IS_ERR(server->client_acl))
1150 		rpc_shutdown_client(server->client_acl);
1151 	if (!IS_ERR(server->client))
1152 		rpc_shutdown_client(server->client);
1153 
1154 	nfs_put_client(server->nfs_client);
1155 
1156 	ida_destroy(&server->lockowner_id);
1157 	ida_destroy(&server->openowner_id);
1158 	nfs_free_iostats(server->io_stats);
1159 	bdi_destroy(&server->backing_dev_info);
1160 	kfree(server);
1161 	nfs_release_automount_timer();
1162 	dprintk("<-- nfs_free_server()\n");
1163 }
1164 
1165 /*
1166  * Create a version 2 or 3 volume record
1167  * - keyed on server and FSID
1168  */
1169 struct nfs_server *nfs_create_server(const struct nfs_parsed_mount_data *data,
1170 				     struct nfs_fh *mntfh)
1171 {
1172 	struct nfs_server *server;
1173 	struct nfs_fattr *fattr;
1174 	int error;
1175 
1176 	server = nfs_alloc_server();
1177 	if (!server)
1178 		return ERR_PTR(-ENOMEM);
1179 
1180 	error = -ENOMEM;
1181 	fattr = nfs_alloc_fattr();
1182 	if (fattr == NULL)
1183 		goto error;
1184 
1185 	/* Get a client representation */
1186 	error = nfs_init_server(server, data);
1187 	if (error < 0)
1188 		goto error;
1189 
1190 	BUG_ON(!server->nfs_client);
1191 	BUG_ON(!server->nfs_client->rpc_ops);
1192 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
1193 
1194 	/* Probe the root fh to retrieve its FSID */
1195 	error = nfs_probe_fsinfo(server, mntfh, fattr);
1196 	if (error < 0)
1197 		goto error;
1198 	if (server->nfs_client->rpc_ops->version == 3) {
1199 		if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN)
1200 			server->namelen = NFS3_MAXNAMLEN;
1201 		if (!(data->flags & NFS_MOUNT_NORDIRPLUS))
1202 			server->caps |= NFS_CAP_READDIRPLUS;
1203 	} else {
1204 		if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN)
1205 			server->namelen = NFS2_MAXNAMLEN;
1206 	}
1207 
1208 	if (!(fattr->valid & NFS_ATTR_FATTR)) {
1209 		error = server->nfs_client->rpc_ops->getattr(server, mntfh, fattr);
1210 		if (error < 0) {
1211 			dprintk("nfs_create_server: getattr error = %d\n", -error);
1212 			goto error;
1213 		}
1214 	}
1215 	memcpy(&server->fsid, &fattr->fsid, sizeof(server->fsid));
1216 
1217 	dprintk("Server FSID: %llx:%llx\n",
1218 		(unsigned long long) server->fsid.major,
1219 		(unsigned long long) server->fsid.minor);
1220 
1221 	nfs_server_insert_lists(server);
1222 	server->mount_time = jiffies;
1223 	nfs_free_fattr(fattr);
1224 	return server;
1225 
1226 error:
1227 	nfs_free_fattr(fattr);
1228 	nfs_free_server(server);
1229 	return ERR_PTR(error);
1230 }
1231 
1232 #ifdef CONFIG_NFS_V4
1233 /*
1234  * NFSv4.0 callback thread helper
1235  *
1236  * Find a client by callback identifier
1237  */
1238 struct nfs_client *
1239 nfs4_find_client_ident(struct net *net, int cb_ident)
1240 {
1241 	struct nfs_client *clp;
1242 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1243 
1244 	spin_lock(&nn->nfs_client_lock);
1245 	clp = idr_find(&nn->cb_ident_idr, cb_ident);
1246 	if (clp)
1247 		atomic_inc(&clp->cl_count);
1248 	spin_unlock(&nn->nfs_client_lock);
1249 	return clp;
1250 }
1251 
1252 #if defined(CONFIG_NFS_V4_1)
1253 /*
1254  * NFSv4.1 callback thread helper
1255  * For CB_COMPOUND calls, find a client by IP address, protocol version,
1256  * minorversion, and sessionID
1257  *
1258  * Returns NULL if no such client
1259  */
1260 struct nfs_client *
1261 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
1262 			   struct nfs4_sessionid *sid)
1263 {
1264 	struct nfs_client *clp;
1265 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1266 
1267 	spin_lock(&nn->nfs_client_lock);
1268 	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
1269 		if (nfs4_cb_match_client(addr, clp, 1) == false)
1270 			continue;
1271 
1272 		if (!nfs4_has_session(clp))
1273 			continue;
1274 
1275 		/* Match sessionid*/
1276 		if (memcmp(clp->cl_session->sess_id.data,
1277 		    sid->data, NFS4_MAX_SESSIONID_LEN) != 0)
1278 			continue;
1279 
1280 		atomic_inc(&clp->cl_count);
1281 		spin_unlock(&nn->nfs_client_lock);
1282 		return clp;
1283 	}
1284 	spin_unlock(&nn->nfs_client_lock);
1285 	return NULL;
1286 }
1287 
1288 #else /* CONFIG_NFS_V4_1 */
1289 
1290 struct nfs_client *
1291 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
1292 			   struct nfs4_sessionid *sid)
1293 {
1294 	return NULL;
1295 }
1296 #endif /* CONFIG_NFS_V4_1 */
1297 
1298 /*
1299  * Initialize the NFS4 callback service
1300  */
1301 static int nfs4_init_callback(struct nfs_client *clp)
1302 {
1303 	int error;
1304 
1305 	if (clp->rpc_ops->version == 4) {
1306 		struct rpc_xprt *xprt;
1307 
1308 		xprt = rcu_dereference_raw(clp->cl_rpcclient->cl_xprt);
1309 
1310 		if (nfs4_has_session(clp)) {
1311 			error = xprt_setup_backchannel(xprt,
1312 						NFS41_BC_MIN_CALLBACKS);
1313 			if (error < 0)
1314 				return error;
1315 		}
1316 
1317 		error = nfs_callback_up(clp->cl_mvops->minor_version, xprt);
1318 		if (error < 0) {
1319 			dprintk("%s: failed to start callback. Error = %d\n",
1320 				__func__, error);
1321 			return error;
1322 		}
1323 		__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
1324 	}
1325 	return 0;
1326 }
1327 
1328 /*
1329  * Initialize the minor version specific parts of an NFS4 client record
1330  */
1331 static int nfs4_init_client_minor_version(struct nfs_client *clp)
1332 {
1333 #if defined(CONFIG_NFS_V4_1)
1334 	if (clp->cl_mvops->minor_version) {
1335 		struct nfs4_session *session = NULL;
1336 		/*
1337 		 * Create the session and mark it expired.
1338 		 * When a SEQUENCE operation encounters the expired session
1339 		 * it will do session recovery to initialize it.
1340 		 */
1341 		session = nfs4_alloc_session(clp);
1342 		if (!session)
1343 			return -ENOMEM;
1344 
1345 		clp->cl_session = session;
1346 		/*
1347 		 * The create session reply races with the server back
1348 		 * channel probe. Mark the client NFS_CS_SESSION_INITING
1349 		 * so that the client back channel can find the
1350 		 * nfs_client struct
1351 		 */
1352 		nfs_mark_client_ready(clp, NFS_CS_SESSION_INITING);
1353 	}
1354 #endif /* CONFIG_NFS_V4_1 */
1355 
1356 	return nfs4_init_callback(clp);
1357 }
1358 
1359 /**
1360  * nfs4_init_client - Initialise an NFS4 client record
1361  *
1362  * @clp: nfs_client to initialise
1363  * @timeparms: timeout parameters for underlying RPC transport
1364  * @ip_addr: callback IP address in presentation format
1365  * @authflavor: authentication flavor for underlying RPC transport
1366  *
1367  * Returns pointer to an NFS client, or an ERR_PTR value.
1368  */
1369 struct nfs_client *nfs4_init_client(struct nfs_client *clp,
1370 				    const struct rpc_timeout *timeparms,
1371 				    const char *ip_addr,
1372 				    rpc_authflavor_t authflavour)
1373 {
1374 	char buf[INET6_ADDRSTRLEN + 1];
1375 	int error;
1376 
1377 	if (clp->cl_cons_state == NFS_CS_READY) {
1378 		/* the client is initialised already */
1379 		dprintk("<-- nfs4_init_client() = 0 [already %p]\n", clp);
1380 		return clp;
1381 	}
1382 
1383 	/* Check NFS protocol revision and initialize RPC op vector */
1384 	clp->rpc_ops = &nfs_v4_clientops;
1385 
1386 	__set_bit(NFS_CS_DISCRTRY, &clp->cl_flags);
1387 	error = nfs_create_rpc_client(clp, timeparms, authflavour);
1388 	if (error < 0)
1389 		goto error;
1390 
1391 	/* If no clientaddr= option was specified, find a usable cb address */
1392 	if (ip_addr == NULL) {
1393 		struct sockaddr_storage cb_addr;
1394 		struct sockaddr *sap = (struct sockaddr *)&cb_addr;
1395 
1396 		error = rpc_localaddr(clp->cl_rpcclient, sap, sizeof(cb_addr));
1397 		if (error < 0)
1398 			goto error;
1399 		error = rpc_ntop(sap, buf, sizeof(buf));
1400 		if (error < 0)
1401 			goto error;
1402 		ip_addr = (const char *)buf;
1403 	}
1404 	strlcpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr));
1405 
1406 	error = nfs_idmap_new(clp);
1407 	if (error < 0) {
1408 		dprintk("%s: failed to create idmapper. Error = %d\n",
1409 			__func__, error);
1410 		goto error;
1411 	}
1412 	__set_bit(NFS_CS_IDMAP, &clp->cl_res_state);
1413 
1414 	error = nfs4_init_client_minor_version(clp);
1415 	if (error < 0)
1416 		goto error;
1417 
1418 	if (!nfs4_has_session(clp))
1419 		nfs_mark_client_ready(clp, NFS_CS_READY);
1420 	return clp;
1421 
1422 error:
1423 	nfs_mark_client_ready(clp, error);
1424 	nfs_put_client(clp);
1425 	dprintk("<-- nfs4_init_client() = xerror %d\n", error);
1426 	return ERR_PTR(error);
1427 }
1428 
1429 /*
1430  * Set up an NFS4 client
1431  */
1432 static int nfs4_set_client(struct nfs_server *server,
1433 		const char *hostname,
1434 		const struct sockaddr *addr,
1435 		const size_t addrlen,
1436 		const char *ip_addr,
1437 		rpc_authflavor_t authflavour,
1438 		int proto, const struct rpc_timeout *timeparms,
1439 		u32 minorversion, struct net *net)
1440 {
1441 	struct nfs_client_initdata cl_init = {
1442 		.hostname = hostname,
1443 		.addr = addr,
1444 		.addrlen = addrlen,
1445 		.rpc_ops = &nfs_v4_clientops,
1446 		.proto = proto,
1447 		.minorversion = minorversion,
1448 		.net = net,
1449 	};
1450 	struct nfs_client *clp;
1451 	int error;
1452 
1453 	dprintk("--> nfs4_set_client()\n");
1454 
1455 	if (server->flags & NFS_MOUNT_NORESVPORT)
1456 		set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
1457 
1458 	/* Allocate or find a client reference we can use */
1459 	clp = nfs_get_client(&cl_init, timeparms, ip_addr, authflavour);
1460 	if (IS_ERR(clp)) {
1461 		error = PTR_ERR(clp);
1462 		goto error;
1463 	}
1464 
1465 	/*
1466 	 * Query for the lease time on clientid setup or renewal
1467 	 *
1468 	 * Note that this will be set on nfs_clients that were created
1469 	 * only for the DS role and did not set this bit, but now will
1470 	 * serve a dual role.
1471 	 */
1472 	set_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state);
1473 
1474 	server->nfs_client = clp;
1475 	dprintk("<-- nfs4_set_client() = 0 [new %p]\n", clp);
1476 	return 0;
1477 error:
1478 	dprintk("<-- nfs4_set_client() = xerror %d\n", error);
1479 	return error;
1480 }
1481 
1482 /*
1483  * Set up a pNFS Data Server client.
1484  *
1485  * Return any existing nfs_client that matches server address,port,version
1486  * and minorversion.
1487  *
1488  * For a new nfs_client, use a soft mount (default), a low retrans and a
1489  * low timeout interval so that if a connection is lost, we retry through
1490  * the MDS.
1491  */
1492 struct nfs_client *nfs4_set_ds_client(struct nfs_client* mds_clp,
1493 		const struct sockaddr *ds_addr, int ds_addrlen,
1494 		int ds_proto, unsigned int ds_timeo, unsigned int ds_retrans)
1495 {
1496 	struct nfs_client_initdata cl_init = {
1497 		.addr = ds_addr,
1498 		.addrlen = ds_addrlen,
1499 		.rpc_ops = &nfs_v4_clientops,
1500 		.proto = ds_proto,
1501 		.minorversion = mds_clp->cl_minorversion,
1502 		.net = mds_clp->cl_net,
1503 	};
1504 	struct rpc_timeout ds_timeout;
1505 	struct nfs_client *clp;
1506 
1507 	/*
1508 	 * Set an authflavor equual to the MDS value. Use the MDS nfs_client
1509 	 * cl_ipaddr so as to use the same EXCHANGE_ID co_ownerid as the MDS
1510 	 * (section 13.1 RFC 5661).
1511 	 */
1512 	nfs_init_timeout_values(&ds_timeout, ds_proto, ds_timeo, ds_retrans);
1513 	clp = nfs_get_client(&cl_init, &ds_timeout, mds_clp->cl_ipaddr,
1514 			     mds_clp->cl_rpcclient->cl_auth->au_flavor);
1515 
1516 	dprintk("<-- %s %p\n", __func__, clp);
1517 	return clp;
1518 }
1519 EXPORT_SYMBOL_GPL(nfs4_set_ds_client);
1520 
1521 /*
1522  * Session has been established, and the client marked ready.
1523  * Set the mount rsize and wsize with negotiated fore channel
1524  * attributes which will be bound checked in nfs_server_set_fsinfo.
1525  */
1526 static void nfs4_session_set_rwsize(struct nfs_server *server)
1527 {
1528 #ifdef CONFIG_NFS_V4_1
1529 	struct nfs4_session *sess;
1530 	u32 server_resp_sz;
1531 	u32 server_rqst_sz;
1532 
1533 	if (!nfs4_has_session(server->nfs_client))
1534 		return;
1535 	sess = server->nfs_client->cl_session;
1536 	server_resp_sz = sess->fc_attrs.max_resp_sz - nfs41_maxread_overhead;
1537 	server_rqst_sz = sess->fc_attrs.max_rqst_sz - nfs41_maxwrite_overhead;
1538 
1539 	if (server->rsize > server_resp_sz)
1540 		server->rsize = server_resp_sz;
1541 	if (server->wsize > server_rqst_sz)
1542 		server->wsize = server_rqst_sz;
1543 #endif /* CONFIG_NFS_V4_1 */
1544 }
1545 
1546 static int nfs4_server_common_setup(struct nfs_server *server,
1547 		struct nfs_fh *mntfh)
1548 {
1549 	struct nfs_fattr *fattr;
1550 	int error;
1551 
1552 	BUG_ON(!server->nfs_client);
1553 	BUG_ON(!server->nfs_client->rpc_ops);
1554 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
1555 
1556 	/* data servers support only a subset of NFSv4.1 */
1557 	if (is_ds_only_client(server->nfs_client))
1558 		return -EPROTONOSUPPORT;
1559 
1560 	fattr = nfs_alloc_fattr();
1561 	if (fattr == NULL)
1562 		return -ENOMEM;
1563 
1564 	/* We must ensure the session is initialised first */
1565 	error = nfs4_init_session(server);
1566 	if (error < 0)
1567 		goto out;
1568 
1569 	/* Probe the root fh to retrieve its FSID and filehandle */
1570 	error = nfs4_get_rootfh(server, mntfh);
1571 	if (error < 0)
1572 		goto out;
1573 
1574 	dprintk("Server FSID: %llx:%llx\n",
1575 			(unsigned long long) server->fsid.major,
1576 			(unsigned long long) server->fsid.minor);
1577 	dprintk("Mount FH: %d\n", mntfh->size);
1578 
1579 	nfs4_session_set_rwsize(server);
1580 
1581 	error = nfs_probe_fsinfo(server, mntfh, fattr);
1582 	if (error < 0)
1583 		goto out;
1584 
1585 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1586 		server->namelen = NFS4_MAXNAMLEN;
1587 
1588 	nfs_server_insert_lists(server);
1589 	server->mount_time = jiffies;
1590 	server->destroy = nfs4_destroy_server;
1591 out:
1592 	nfs_free_fattr(fattr);
1593 	return error;
1594 }
1595 
1596 /*
1597  * Create a version 4 volume record
1598  */
1599 static int nfs4_init_server(struct nfs_server *server,
1600 		const struct nfs_parsed_mount_data *data)
1601 {
1602 	struct rpc_timeout timeparms;
1603 	int error;
1604 
1605 	dprintk("--> nfs4_init_server()\n");
1606 
1607 	nfs_init_timeout_values(&timeparms, data->nfs_server.protocol,
1608 			data->timeo, data->retrans);
1609 
1610 	/* Initialise the client representation from the mount data */
1611 	server->flags = data->flags;
1612 	server->caps |= NFS_CAP_ATOMIC_OPEN|NFS_CAP_CHANGE_ATTR|NFS_CAP_POSIX_LOCK;
1613 	if (!(data->flags & NFS_MOUNT_NORDIRPLUS))
1614 			server->caps |= NFS_CAP_READDIRPLUS;
1615 	server->options = data->options;
1616 
1617 	/* Get a client record */
1618 	error = nfs4_set_client(server,
1619 			data->nfs_server.hostname,
1620 			(const struct sockaddr *)&data->nfs_server.address,
1621 			data->nfs_server.addrlen,
1622 			data->client_address,
1623 			data->auth_flavors[0],
1624 			data->nfs_server.protocol,
1625 			&timeparms,
1626 			data->minorversion,
1627 			data->net);
1628 	if (error < 0)
1629 		goto error;
1630 
1631 	/*
1632 	 * Don't use NFS uid/gid mapping if we're using AUTH_SYS or lower
1633 	 * authentication.
1634 	 */
1635 	if (nfs4_disable_idmapping && data->auth_flavors[0] == RPC_AUTH_UNIX)
1636 		server->caps |= NFS_CAP_UIDGID_NOMAP;
1637 
1638 	if (data->rsize)
1639 		server->rsize = nfs_block_size(data->rsize, NULL);
1640 	if (data->wsize)
1641 		server->wsize = nfs_block_size(data->wsize, NULL);
1642 
1643 	server->acregmin = data->acregmin * HZ;
1644 	server->acregmax = data->acregmax * HZ;
1645 	server->acdirmin = data->acdirmin * HZ;
1646 	server->acdirmax = data->acdirmax * HZ;
1647 
1648 	server->port = data->nfs_server.port;
1649 
1650 	error = nfs_init_server_rpcclient(server, &timeparms, data->auth_flavors[0]);
1651 
1652 error:
1653 	/* Done */
1654 	dprintk("<-- nfs4_init_server() = %d\n", error);
1655 	return error;
1656 }
1657 
1658 /*
1659  * Create a version 4 volume record
1660  * - keyed on server and FSID
1661  */
1662 struct nfs_server *nfs4_create_server(const struct nfs_parsed_mount_data *data,
1663 				      struct nfs_fh *mntfh)
1664 {
1665 	struct nfs_server *server;
1666 	int error;
1667 
1668 	dprintk("--> nfs4_create_server()\n");
1669 
1670 	server = nfs_alloc_server();
1671 	if (!server)
1672 		return ERR_PTR(-ENOMEM);
1673 
1674 	/* set up the general RPC client */
1675 	error = nfs4_init_server(server, data);
1676 	if (error < 0)
1677 		goto error;
1678 
1679 	error = nfs4_server_common_setup(server, mntfh);
1680 	if (error < 0)
1681 		goto error;
1682 
1683 	dprintk("<-- nfs4_create_server() = %p\n", server);
1684 	return server;
1685 
1686 error:
1687 	nfs_free_server(server);
1688 	dprintk("<-- nfs4_create_server() = error %d\n", error);
1689 	return ERR_PTR(error);
1690 }
1691 
1692 /*
1693  * Create an NFS4 referral server record
1694  */
1695 struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data,
1696 					       struct nfs_fh *mntfh)
1697 {
1698 	struct nfs_client *parent_client;
1699 	struct nfs_server *server, *parent_server;
1700 	int error;
1701 
1702 	dprintk("--> nfs4_create_referral_server()\n");
1703 
1704 	server = nfs_alloc_server();
1705 	if (!server)
1706 		return ERR_PTR(-ENOMEM);
1707 
1708 	parent_server = NFS_SB(data->sb);
1709 	parent_client = parent_server->nfs_client;
1710 
1711 	/* Initialise the client representation from the parent server */
1712 	nfs_server_copy_userdata(server, parent_server);
1713 	server->caps |= NFS_CAP_ATOMIC_OPEN|NFS_CAP_CHANGE_ATTR;
1714 
1715 	/* Get a client representation.
1716 	 * Note: NFSv4 always uses TCP, */
1717 	error = nfs4_set_client(server, data->hostname,
1718 				data->addr,
1719 				data->addrlen,
1720 				parent_client->cl_ipaddr,
1721 				data->authflavor,
1722 				rpc_protocol(parent_server->client),
1723 				parent_server->client->cl_timeout,
1724 				parent_client->cl_mvops->minor_version,
1725 				parent_client->cl_net);
1726 	if (error < 0)
1727 		goto error;
1728 
1729 	error = nfs_init_server_rpcclient(server, parent_server->client->cl_timeout, data->authflavor);
1730 	if (error < 0)
1731 		goto error;
1732 
1733 	error = nfs4_server_common_setup(server, mntfh);
1734 	if (error < 0)
1735 		goto error;
1736 
1737 	dprintk("<-- nfs_create_referral_server() = %p\n", server);
1738 	return server;
1739 
1740 error:
1741 	nfs_free_server(server);
1742 	dprintk("<-- nfs4_create_referral_server() = error %d\n", error);
1743 	return ERR_PTR(error);
1744 }
1745 
1746 #endif /* CONFIG_NFS_V4 */
1747 
1748 /*
1749  * Clone an NFS2, NFS3 or NFS4 server record
1750  */
1751 struct nfs_server *nfs_clone_server(struct nfs_server *source,
1752 				    struct nfs_fh *fh,
1753 				    struct nfs_fattr *fattr,
1754 				    rpc_authflavor_t flavor)
1755 {
1756 	struct nfs_server *server;
1757 	struct nfs_fattr *fattr_fsinfo;
1758 	int error;
1759 
1760 	dprintk("--> nfs_clone_server(,%llx:%llx,)\n",
1761 		(unsigned long long) fattr->fsid.major,
1762 		(unsigned long long) fattr->fsid.minor);
1763 
1764 	server = nfs_alloc_server();
1765 	if (!server)
1766 		return ERR_PTR(-ENOMEM);
1767 
1768 	error = -ENOMEM;
1769 	fattr_fsinfo = nfs_alloc_fattr();
1770 	if (fattr_fsinfo == NULL)
1771 		goto out_free_server;
1772 
1773 	/* Copy data from the source */
1774 	server->nfs_client = source->nfs_client;
1775 	server->destroy = source->destroy;
1776 	atomic_inc(&server->nfs_client->cl_count);
1777 	nfs_server_copy_userdata(server, source);
1778 
1779 	server->fsid = fattr->fsid;
1780 
1781 	error = nfs_init_server_rpcclient(server,
1782 			source->client->cl_timeout,
1783 			flavor);
1784 	if (error < 0)
1785 		goto out_free_server;
1786 	if (!IS_ERR(source->client_acl))
1787 		nfs_init_server_aclclient(server);
1788 
1789 	/* probe the filesystem info for this server filesystem */
1790 	error = nfs_probe_fsinfo(server, fh, fattr_fsinfo);
1791 	if (error < 0)
1792 		goto out_free_server;
1793 
1794 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1795 		server->namelen = NFS4_MAXNAMLEN;
1796 
1797 	dprintk("Cloned FSID: %llx:%llx\n",
1798 		(unsigned long long) server->fsid.major,
1799 		(unsigned long long) server->fsid.minor);
1800 
1801 	error = nfs_start_lockd(server);
1802 	if (error < 0)
1803 		goto out_free_server;
1804 
1805 	nfs_server_insert_lists(server);
1806 	server->mount_time = jiffies;
1807 
1808 	nfs_free_fattr(fattr_fsinfo);
1809 	dprintk("<-- nfs_clone_server() = %p\n", server);
1810 	return server;
1811 
1812 out_free_server:
1813 	nfs_free_fattr(fattr_fsinfo);
1814 	nfs_free_server(server);
1815 	dprintk("<-- nfs_clone_server() = error %d\n", error);
1816 	return ERR_PTR(error);
1817 }
1818 
1819 void nfs_clients_init(struct net *net)
1820 {
1821 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1822 
1823 	INIT_LIST_HEAD(&nn->nfs_client_list);
1824 	INIT_LIST_HEAD(&nn->nfs_volume_list);
1825 #ifdef CONFIG_NFS_V4
1826 	idr_init(&nn->cb_ident_idr);
1827 #endif
1828 	spin_lock_init(&nn->nfs_client_lock);
1829 	nn->boot_time = CURRENT_TIME;
1830 }
1831 
1832 #ifdef CONFIG_PROC_FS
1833 static struct proc_dir_entry *proc_fs_nfs;
1834 
1835 static int nfs_server_list_open(struct inode *inode, struct file *file);
1836 static void *nfs_server_list_start(struct seq_file *p, loff_t *pos);
1837 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos);
1838 static void nfs_server_list_stop(struct seq_file *p, void *v);
1839 static int nfs_server_list_show(struct seq_file *m, void *v);
1840 
1841 static const struct seq_operations nfs_server_list_ops = {
1842 	.start	= nfs_server_list_start,
1843 	.next	= nfs_server_list_next,
1844 	.stop	= nfs_server_list_stop,
1845 	.show	= nfs_server_list_show,
1846 };
1847 
1848 static const struct file_operations nfs_server_list_fops = {
1849 	.open		= nfs_server_list_open,
1850 	.read		= seq_read,
1851 	.llseek		= seq_lseek,
1852 	.release	= seq_release,
1853 	.owner		= THIS_MODULE,
1854 };
1855 
1856 static int nfs_volume_list_open(struct inode *inode, struct file *file);
1857 static void *nfs_volume_list_start(struct seq_file *p, loff_t *pos);
1858 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos);
1859 static void nfs_volume_list_stop(struct seq_file *p, void *v);
1860 static int nfs_volume_list_show(struct seq_file *m, void *v);
1861 
1862 static const struct seq_operations nfs_volume_list_ops = {
1863 	.start	= nfs_volume_list_start,
1864 	.next	= nfs_volume_list_next,
1865 	.stop	= nfs_volume_list_stop,
1866 	.show	= nfs_volume_list_show,
1867 };
1868 
1869 static const struct file_operations nfs_volume_list_fops = {
1870 	.open		= nfs_volume_list_open,
1871 	.read		= seq_read,
1872 	.llseek		= seq_lseek,
1873 	.release	= seq_release,
1874 	.owner		= THIS_MODULE,
1875 };
1876 
1877 /*
1878  * open "/proc/fs/nfsfs/servers" which provides a summary of servers with which
1879  * we're dealing
1880  */
1881 static int nfs_server_list_open(struct inode *inode, struct file *file)
1882 {
1883 	struct seq_file *m;
1884 	int ret;
1885 	struct pid_namespace *pid_ns = file->f_dentry->d_sb->s_fs_info;
1886 	struct net *net = pid_ns->child_reaper->nsproxy->net_ns;
1887 
1888 	ret = seq_open(file, &nfs_server_list_ops);
1889 	if (ret < 0)
1890 		return ret;
1891 
1892 	m = file->private_data;
1893 	m->private = net;
1894 
1895 	return 0;
1896 }
1897 
1898 /*
1899  * set up the iterator to start reading from the server list and return the first item
1900  */
1901 static void *nfs_server_list_start(struct seq_file *m, loff_t *_pos)
1902 {
1903 	struct nfs_net *nn = net_generic(m->private, nfs_net_id);
1904 
1905 	/* lock the list against modification */
1906 	spin_lock(&nn->nfs_client_lock);
1907 	return seq_list_start_head(&nn->nfs_client_list, *_pos);
1908 }
1909 
1910 /*
1911  * move to next server
1912  */
1913 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos)
1914 {
1915 	struct nfs_net *nn = net_generic(p->private, nfs_net_id);
1916 
1917 	return seq_list_next(v, &nn->nfs_client_list, pos);
1918 }
1919 
1920 /*
1921  * clean up after reading from the transports list
1922  */
1923 static void nfs_server_list_stop(struct seq_file *p, void *v)
1924 {
1925 	struct nfs_net *nn = net_generic(p->private, nfs_net_id);
1926 
1927 	spin_unlock(&nn->nfs_client_lock);
1928 }
1929 
1930 /*
1931  * display a header line followed by a load of call lines
1932  */
1933 static int nfs_server_list_show(struct seq_file *m, void *v)
1934 {
1935 	struct nfs_client *clp;
1936 	struct nfs_net *nn = net_generic(m->private, nfs_net_id);
1937 
1938 	/* display header on line 1 */
1939 	if (v == &nn->nfs_client_list) {
1940 		seq_puts(m, "NV SERVER   PORT USE HOSTNAME\n");
1941 		return 0;
1942 	}
1943 
1944 	/* display one transport per line on subsequent lines */
1945 	clp = list_entry(v, struct nfs_client, cl_share_link);
1946 
1947 	/* Check if the client is initialized */
1948 	if (clp->cl_cons_state != NFS_CS_READY)
1949 		return 0;
1950 
1951 	rcu_read_lock();
1952 	seq_printf(m, "v%u %s %s %3d %s\n",
1953 		   clp->rpc_ops->version,
1954 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1955 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1956 		   atomic_read(&clp->cl_count),
1957 		   clp->cl_hostname);
1958 	rcu_read_unlock();
1959 
1960 	return 0;
1961 }
1962 
1963 /*
1964  * open "/proc/fs/nfsfs/volumes" which provides a summary of extant volumes
1965  */
1966 static int nfs_volume_list_open(struct inode *inode, struct file *file)
1967 {
1968 	struct seq_file *m;
1969 	int ret;
1970 	struct pid_namespace *pid_ns = file->f_dentry->d_sb->s_fs_info;
1971 	struct net *net = pid_ns->child_reaper->nsproxy->net_ns;
1972 
1973 	ret = seq_open(file, &nfs_volume_list_ops);
1974 	if (ret < 0)
1975 		return ret;
1976 
1977 	m = file->private_data;
1978 	m->private = net;
1979 
1980 	return 0;
1981 }
1982 
1983 /*
1984  * set up the iterator to start reading from the volume list and return the first item
1985  */
1986 static void *nfs_volume_list_start(struct seq_file *m, loff_t *_pos)
1987 {
1988 	struct nfs_net *nn = net_generic(m->private, nfs_net_id);
1989 
1990 	/* lock the list against modification */
1991 	spin_lock(&nn->nfs_client_lock);
1992 	return seq_list_start_head(&nn->nfs_volume_list, *_pos);
1993 }
1994 
1995 /*
1996  * move to next volume
1997  */
1998 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos)
1999 {
2000 	struct nfs_net *nn = net_generic(p->private, nfs_net_id);
2001 
2002 	return seq_list_next(v, &nn->nfs_volume_list, pos);
2003 }
2004 
2005 /*
2006  * clean up after reading from the transports list
2007  */
2008 static void nfs_volume_list_stop(struct seq_file *p, void *v)
2009 {
2010 	struct nfs_net *nn = net_generic(p->private, nfs_net_id);
2011 
2012 	spin_unlock(&nn->nfs_client_lock);
2013 }
2014 
2015 /*
2016  * display a header line followed by a load of call lines
2017  */
2018 static int nfs_volume_list_show(struct seq_file *m, void *v)
2019 {
2020 	struct nfs_server *server;
2021 	struct nfs_client *clp;
2022 	char dev[8], fsid[17];
2023 	struct nfs_net *nn = net_generic(m->private, nfs_net_id);
2024 
2025 	/* display header on line 1 */
2026 	if (v == &nn->nfs_volume_list) {
2027 		seq_puts(m, "NV SERVER   PORT DEV     FSID              FSC\n");
2028 		return 0;
2029 	}
2030 	/* display one transport per line on subsequent lines */
2031 	server = list_entry(v, struct nfs_server, master_link);
2032 	clp = server->nfs_client;
2033 
2034 	snprintf(dev, 8, "%u:%u",
2035 		 MAJOR(server->s_dev), MINOR(server->s_dev));
2036 
2037 	snprintf(fsid, 17, "%llx:%llx",
2038 		 (unsigned long long) server->fsid.major,
2039 		 (unsigned long long) server->fsid.minor);
2040 
2041 	rcu_read_lock();
2042 	seq_printf(m, "v%u %s %s %-7s %-17s %s\n",
2043 		   clp->rpc_ops->version,
2044 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
2045 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
2046 		   dev,
2047 		   fsid,
2048 		   nfs_server_fscache_state(server));
2049 	rcu_read_unlock();
2050 
2051 	return 0;
2052 }
2053 
2054 /*
2055  * initialise the /proc/fs/nfsfs/ directory
2056  */
2057 int __init nfs_fs_proc_init(void)
2058 {
2059 	struct proc_dir_entry *p;
2060 
2061 	proc_fs_nfs = proc_mkdir("fs/nfsfs", NULL);
2062 	if (!proc_fs_nfs)
2063 		goto error_0;
2064 
2065 	/* a file of servers with which we're dealing */
2066 	p = proc_create("servers", S_IFREG|S_IRUGO,
2067 			proc_fs_nfs, &nfs_server_list_fops);
2068 	if (!p)
2069 		goto error_1;
2070 
2071 	/* a file of volumes that we have mounted */
2072 	p = proc_create("volumes", S_IFREG|S_IRUGO,
2073 			proc_fs_nfs, &nfs_volume_list_fops);
2074 	if (!p)
2075 		goto error_2;
2076 	return 0;
2077 
2078 error_2:
2079 	remove_proc_entry("servers", proc_fs_nfs);
2080 error_1:
2081 	remove_proc_entry("fs/nfsfs", NULL);
2082 error_0:
2083 	return -ENOMEM;
2084 }
2085 
2086 /*
2087  * clean up the /proc/fs/nfsfs/ directory
2088  */
2089 void nfs_fs_proc_exit(void)
2090 {
2091 	remove_proc_entry("volumes", proc_fs_nfs);
2092 	remove_proc_entry("servers", proc_fs_nfs);
2093 	remove_proc_entry("fs/nfsfs", NULL);
2094 }
2095 
2096 #endif /* CONFIG_PROC_FS */
2097 
2098 module_param(nfs4_disable_idmapping, bool, 0644);
2099 MODULE_PARM_DESC(nfs4_disable_idmapping,
2100 		"Turn off NFSv4 idmapping when using 'sec=sys'");
2101