xref: /openbmc/linux/fs/nfs/client.c (revision 9cdb81c7)
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 #include <asm/system.h>
47 
48 #include "nfs4_fs.h"
49 #include "callback.h"
50 #include "delegation.h"
51 #include "iostat.h"
52 #include "internal.h"
53 #include "fscache.h"
54 #include "pnfs.h"
55 #include "netns.h"
56 
57 #define NFSDBG_FACILITY		NFSDBG_CLIENT
58 
59 static DECLARE_WAIT_QUEUE_HEAD(nfs_client_active_wq);
60 #ifdef CONFIG_NFS_V4
61 
62 /*
63  * Get a unique NFSv4.0 callback identifier which will be used
64  * by the V4.0 callback service to lookup the nfs_client struct
65  */
66 static int nfs_get_cb_ident_idr(struct nfs_client *clp, int minorversion)
67 {
68 	int ret = 0;
69 	struct nfs_net *nn = net_generic(clp->net, nfs_net_id);
70 
71 	if (clp->rpc_ops->version != 4 || minorversion != 0)
72 		return ret;
73 retry:
74 	if (!idr_pre_get(&nn->cb_ident_idr, GFP_KERNEL))
75 		return -ENOMEM;
76 	spin_lock(&nn->nfs_client_lock);
77 	ret = idr_get_new(&nn->cb_ident_idr, clp, &clp->cl_cb_ident);
78 	spin_unlock(&nn->nfs_client_lock);
79 	if (ret == -EAGAIN)
80 		goto retry;
81 	return ret;
82 }
83 #endif /* CONFIG_NFS_V4 */
84 
85 /*
86  * Turn off NFSv4 uid/gid mapping when using AUTH_SYS
87  */
88 static bool nfs4_disable_idmapping = true;
89 
90 /*
91  * RPC cruft for NFS
92  */
93 static const struct rpc_version *nfs_version[5] = {
94 	[2]			= &nfs_version2,
95 #ifdef CONFIG_NFS_V3
96 	[3]			= &nfs_version3,
97 #endif
98 #ifdef CONFIG_NFS_V4
99 	[4]			= &nfs_version4,
100 #endif
101 };
102 
103 const struct rpc_program nfs_program = {
104 	.name			= "nfs",
105 	.number			= NFS_PROGRAM,
106 	.nrvers			= ARRAY_SIZE(nfs_version),
107 	.version		= nfs_version,
108 	.stats			= &nfs_rpcstat,
109 	.pipe_dir_name		= NFS_PIPE_DIRNAME,
110 };
111 
112 struct rpc_stat nfs_rpcstat = {
113 	.program		= &nfs_program
114 };
115 
116 
117 #ifdef CONFIG_NFS_V3_ACL
118 static struct rpc_stat		nfsacl_rpcstat = { &nfsacl_program };
119 static const struct rpc_version *nfsacl_version[] = {
120 	[3]			= &nfsacl_version3,
121 };
122 
123 const struct rpc_program nfsacl_program = {
124 	.name			= "nfsacl",
125 	.number			= NFS_ACL_PROGRAM,
126 	.nrvers			= ARRAY_SIZE(nfsacl_version),
127 	.version		= nfsacl_version,
128 	.stats			= &nfsacl_rpcstat,
129 };
130 #endif  /* CONFIG_NFS_V3_ACL */
131 
132 struct nfs_client_initdata {
133 	const char *hostname;
134 	const struct sockaddr *addr;
135 	size_t addrlen;
136 	const struct nfs_rpc_ops *rpc_ops;
137 	int proto;
138 	u32 minorversion;
139 	struct net *net;
140 };
141 
142 /*
143  * Allocate a shared client record
144  *
145  * Since these are allocated/deallocated very rarely, we don't
146  * bother putting them in a slab cache...
147  */
148 static struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init)
149 {
150 	struct nfs_client *clp;
151 	struct rpc_cred *cred;
152 	int err = -ENOMEM;
153 
154 	if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL)
155 		goto error_0;
156 
157 	clp->rpc_ops = cl_init->rpc_ops;
158 
159 	atomic_set(&clp->cl_count, 1);
160 	clp->cl_cons_state = NFS_CS_INITING;
161 
162 	memcpy(&clp->cl_addr, cl_init->addr, cl_init->addrlen);
163 	clp->cl_addrlen = cl_init->addrlen;
164 
165 	if (cl_init->hostname) {
166 		err = -ENOMEM;
167 		clp->cl_hostname = kstrdup(cl_init->hostname, GFP_KERNEL);
168 		if (!clp->cl_hostname)
169 			goto error_cleanup;
170 	}
171 
172 	INIT_LIST_HEAD(&clp->cl_superblocks);
173 	clp->cl_rpcclient = ERR_PTR(-EINVAL);
174 
175 	clp->cl_proto = cl_init->proto;
176 	clp->net = get_net(cl_init->net);
177 
178 #ifdef CONFIG_NFS_V4
179 	err = nfs_get_cb_ident_idr(clp, cl_init->minorversion);
180 	if (err)
181 		goto error_cleanup;
182 
183 	spin_lock_init(&clp->cl_lock);
184 	INIT_DELAYED_WORK(&clp->cl_renewd, nfs4_renew_state);
185 	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
186 	clp->cl_boot_time = CURRENT_TIME;
187 	clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
188 	clp->cl_minorversion = cl_init->minorversion;
189 	clp->cl_mvops = nfs_v4_minor_ops[cl_init->minorversion];
190 #endif
191 	cred = rpc_lookup_machine_cred("*");
192 	if (!IS_ERR(cred))
193 		clp->cl_machine_cred = cred;
194 	nfs_fscache_get_client_cookie(clp);
195 
196 	return clp;
197 
198 error_cleanup:
199 	kfree(clp);
200 error_0:
201 	return ERR_PTR(err);
202 }
203 
204 #ifdef CONFIG_NFS_V4
205 #ifdef CONFIG_NFS_V4_1
206 static void nfs4_shutdown_session(struct nfs_client *clp)
207 {
208 	if (nfs4_has_session(clp)) {
209 		nfs4_deviceid_purge_client(clp);
210 		nfs4_destroy_session(clp->cl_session);
211 	}
212 
213 }
214 #else /* CONFIG_NFS_V4_1 */
215 static void nfs4_shutdown_session(struct nfs_client *clp)
216 {
217 }
218 #endif /* CONFIG_NFS_V4_1 */
219 
220 /*
221  * Destroy the NFS4 callback service
222  */
223 static void nfs4_destroy_callback(struct nfs_client *clp)
224 {
225 	if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
226 		nfs_callback_down(clp->cl_mvops->minor_version);
227 }
228 
229 static void nfs4_shutdown_client(struct nfs_client *clp)
230 {
231 	if (__test_and_clear_bit(NFS_CS_RENEWD, &clp->cl_res_state))
232 		nfs4_kill_renewd(clp);
233 	nfs4_shutdown_session(clp);
234 	nfs4_destroy_callback(clp);
235 	if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state))
236 		nfs_idmap_delete(clp);
237 
238 	rpc_destroy_wait_queue(&clp->cl_rpcwaitq);
239 }
240 
241 /* idr_remove_all is not needed as all id's are removed by nfs_put_client */
242 void nfs_cleanup_cb_ident_idr(struct net *net)
243 {
244 	struct nfs_net *nn = net_generic(net, nfs_net_id);
245 
246 	idr_destroy(&nn->cb_ident_idr);
247 }
248 
249 /* nfs_client_lock held */
250 static void nfs_cb_idr_remove_locked(struct nfs_client *clp)
251 {
252 	struct nfs_net *nn = net_generic(clp->net, nfs_net_id);
253 
254 	if (clp->cl_cb_ident)
255 		idr_remove(&nn->cb_ident_idr, clp->cl_cb_ident);
256 }
257 
258 static void pnfs_init_server(struct nfs_server *server)
259 {
260 	rpc_init_wait_queue(&server->roc_rpcwaitq, "pNFS ROC");
261 }
262 
263 static void nfs4_destroy_server(struct nfs_server *server)
264 {
265 	nfs4_purge_state_owners(server);
266 }
267 
268 #else
269 static void nfs4_shutdown_client(struct nfs_client *clp)
270 {
271 }
272 
273 void nfs_cleanup_cb_ident_idr(struct net *net)
274 {
275 }
276 
277 static void nfs_cb_idr_remove_locked(struct nfs_client *clp)
278 {
279 }
280 
281 static void pnfs_init_server(struct nfs_server *server)
282 {
283 }
284 
285 #endif /* CONFIG_NFS_V4 */
286 
287 /*
288  * Destroy a shared client record
289  */
290 static void nfs_free_client(struct nfs_client *clp)
291 {
292 	dprintk("--> nfs_free_client(%u)\n", clp->rpc_ops->version);
293 
294 	nfs4_shutdown_client(clp);
295 
296 	nfs_fscache_release_client_cookie(clp);
297 
298 	/* -EIO all pending I/O */
299 	if (!IS_ERR(clp->cl_rpcclient))
300 		rpc_shutdown_client(clp->cl_rpcclient);
301 
302 	if (clp->cl_machine_cred != NULL)
303 		put_rpccred(clp->cl_machine_cred);
304 
305 	put_net(clp->net);
306 	kfree(clp->cl_hostname);
307 	kfree(clp->server_scope);
308 	kfree(clp->impl_id);
309 	kfree(clp);
310 
311 	dprintk("<-- nfs_free_client()\n");
312 }
313 
314 /*
315  * Release a reference to a shared client record
316  */
317 void nfs_put_client(struct nfs_client *clp)
318 {
319 	struct nfs_net *nn;
320 
321 	if (!clp)
322 		return;
323 
324 	dprintk("--> nfs_put_client({%d})\n", atomic_read(&clp->cl_count));
325 	nn = net_generic(clp->net, nfs_net_id);
326 
327 	if (atomic_dec_and_lock(&clp->cl_count, &nn->nfs_client_lock)) {
328 		list_del(&clp->cl_share_link);
329 		nfs_cb_idr_remove_locked(clp);
330 		spin_unlock(&nn->nfs_client_lock);
331 
332 		BUG_ON(!list_empty(&clp->cl_superblocks));
333 
334 		nfs_free_client(clp);
335 	}
336 }
337 EXPORT_SYMBOL_GPL(nfs_put_client);
338 
339 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
340 /*
341  * Test if two ip6 socket addresses refer to the same socket by
342  * comparing relevant fields. The padding bytes specifically, are not
343  * compared. sin6_flowinfo is not compared because it only affects QoS
344  * and sin6_scope_id is only compared if the address is "link local"
345  * because "link local" addresses need only be unique to a specific
346  * link. Conversely, ordinary unicast addresses might have different
347  * sin6_scope_id.
348  *
349  * The caller should ensure both socket addresses are AF_INET6.
350  */
351 static int nfs_sockaddr_match_ipaddr6(const struct sockaddr *sa1,
352 				      const struct sockaddr *sa2)
353 {
354 	const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sa1;
355 	const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sa2;
356 
357 	if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
358 		return 0;
359 	else if (ipv6_addr_type(&sin1->sin6_addr) & IPV6_ADDR_LINKLOCAL)
360 		return sin1->sin6_scope_id == sin2->sin6_scope_id;
361 
362 	return 1;
363 }
364 #else	/* !defined(CONFIG_IPV6) && !defined(CONFIG_IPV6_MODULE) */
365 static int nfs_sockaddr_match_ipaddr6(const struct sockaddr *sa1,
366 				      const struct sockaddr *sa2)
367 {
368 	return 0;
369 }
370 #endif
371 
372 /*
373  * Test if two ip4 socket addresses refer to the same socket, by
374  * comparing relevant fields. The padding bytes specifically, are
375  * not compared.
376  *
377  * The caller should ensure both socket addresses are AF_INET.
378  */
379 static int nfs_sockaddr_match_ipaddr4(const struct sockaddr *sa1,
380 				      const struct sockaddr *sa2)
381 {
382 	const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sa1;
383 	const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sa2;
384 
385 	return sin1->sin_addr.s_addr == sin2->sin_addr.s_addr;
386 }
387 
388 static int nfs_sockaddr_cmp_ip6(const struct sockaddr *sa1,
389 				const struct sockaddr *sa2)
390 {
391 	const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sa1;
392 	const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sa2;
393 
394 	return nfs_sockaddr_match_ipaddr6(sa1, sa2) &&
395 		(sin1->sin6_port == sin2->sin6_port);
396 }
397 
398 static int nfs_sockaddr_cmp_ip4(const struct sockaddr *sa1,
399 				const struct sockaddr *sa2)
400 {
401 	const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sa1;
402 	const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sa2;
403 
404 	return nfs_sockaddr_match_ipaddr4(sa1, sa2) &&
405 		(sin1->sin_port == sin2->sin_port);
406 }
407 
408 #if defined(CONFIG_NFS_V4_1)
409 /*
410  * Test if two socket addresses represent the same actual socket,
411  * by comparing (only) relevant fields, excluding the port number.
412  */
413 static int nfs_sockaddr_match_ipaddr(const struct sockaddr *sa1,
414 				     const struct sockaddr *sa2)
415 {
416 	if (sa1->sa_family != sa2->sa_family)
417 		return 0;
418 
419 	switch (sa1->sa_family) {
420 	case AF_INET:
421 		return nfs_sockaddr_match_ipaddr4(sa1, sa2);
422 	case AF_INET6:
423 		return nfs_sockaddr_match_ipaddr6(sa1, sa2);
424 	}
425 	return 0;
426 }
427 #endif /* CONFIG_NFS_V4_1 */
428 
429 /*
430  * Test if two socket addresses represent the same actual socket,
431  * by comparing (only) relevant fields, including the port number.
432  */
433 static int nfs_sockaddr_cmp(const struct sockaddr *sa1,
434 			    const struct sockaddr *sa2)
435 {
436 	if (sa1->sa_family != sa2->sa_family)
437 		return 0;
438 
439 	switch (sa1->sa_family) {
440 	case AF_INET:
441 		return nfs_sockaddr_cmp_ip4(sa1, sa2);
442 	case AF_INET6:
443 		return nfs_sockaddr_cmp_ip6(sa1, sa2);
444 	}
445 	return 0;
446 }
447 
448 #if defined(CONFIG_NFS_V4_1)
449 /* Common match routine for v4.0 and v4.1 callback services */
450 static bool nfs4_cb_match_client(const struct sockaddr *addr,
451 		struct nfs_client *clp, u32 minorversion)
452 {
453 	struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
454 
455 	/* Don't match clients that failed to initialise */
456 	if (!(clp->cl_cons_state == NFS_CS_READY ||
457 	    clp->cl_cons_state == NFS_CS_SESSION_INITING))
458 		return false;
459 
460 	/* Match the version and minorversion */
461 	if (clp->rpc_ops->version != 4 ||
462 	    clp->cl_minorversion != minorversion)
463 		return false;
464 
465 	/* Match only the IP address, not the port number */
466 	if (!nfs_sockaddr_match_ipaddr(addr, clap))
467 		return false;
468 
469 	return true;
470 }
471 #endif /* CONFIG_NFS_V4_1 */
472 
473 /*
474  * Find an nfs_client on the list that matches the initialisation data
475  * that is supplied.
476  */
477 static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *data)
478 {
479 	struct nfs_client *clp;
480 	const struct sockaddr *sap = data->addr;
481 	struct nfs_net *nn = net_generic(data->net, nfs_net_id);
482 
483 	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
484 	        const struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
485 		/* Don't match clients that failed to initialise properly */
486 		if (clp->cl_cons_state < 0)
487 			continue;
488 
489 		/* Different NFS versions cannot share the same nfs_client */
490 		if (clp->rpc_ops != data->rpc_ops)
491 			continue;
492 
493 		if (clp->cl_proto != data->proto)
494 			continue;
495 		/* Match nfsv4 minorversion */
496 		if (clp->cl_minorversion != data->minorversion)
497 			continue;
498 		/* Match the full socket address */
499 		if (!nfs_sockaddr_cmp(sap, clap))
500 			continue;
501 
502 		atomic_inc(&clp->cl_count);
503 		return clp;
504 	}
505 	return NULL;
506 }
507 
508 /*
509  * Look up a client by IP address and protocol version
510  * - creates a new record if one doesn't yet exist
511  */
512 static struct nfs_client *
513 nfs_get_client(const struct nfs_client_initdata *cl_init,
514 	       const struct rpc_timeout *timeparms,
515 	       const char *ip_addr,
516 	       rpc_authflavor_t authflavour,
517 	       int noresvport)
518 {
519 	struct nfs_client *clp, *new = NULL;
520 	int error;
521 	struct nfs_net *nn = net_generic(cl_init->net, nfs_net_id);
522 
523 	dprintk("--> nfs_get_client(%s,v%u)\n",
524 		cl_init->hostname ?: "", cl_init->rpc_ops->version);
525 
526 	/* see if the client already exists */
527 	do {
528 		spin_lock(&nn->nfs_client_lock);
529 
530 		clp = nfs_match_client(cl_init);
531 		if (clp)
532 			goto found_client;
533 		if (new)
534 			goto install_client;
535 
536 		spin_unlock(&nn->nfs_client_lock);
537 
538 		new = nfs_alloc_client(cl_init);
539 	} while (!IS_ERR(new));
540 
541 	dprintk("--> nfs_get_client() = %ld [failed]\n", PTR_ERR(new));
542 	return new;
543 
544 	/* install a new client and return with it unready */
545 install_client:
546 	clp = new;
547 	list_add(&clp->cl_share_link, &nn->nfs_client_list);
548 	spin_unlock(&nn->nfs_client_lock);
549 
550 	error = cl_init->rpc_ops->init_client(clp, timeparms, ip_addr,
551 					      authflavour, noresvport);
552 	if (error < 0) {
553 		nfs_put_client(clp);
554 		return ERR_PTR(error);
555 	}
556 	dprintk("--> nfs_get_client() = %p [new]\n", clp);
557 	return clp;
558 
559 	/* found an existing client
560 	 * - make sure it's ready before returning
561 	 */
562 found_client:
563 	spin_unlock(&nn->nfs_client_lock);
564 
565 	if (new)
566 		nfs_free_client(new);
567 
568 	error = wait_event_killable(nfs_client_active_wq,
569 				clp->cl_cons_state < NFS_CS_INITING);
570 	if (error < 0) {
571 		nfs_put_client(clp);
572 		return ERR_PTR(-ERESTARTSYS);
573 	}
574 
575 	if (clp->cl_cons_state < NFS_CS_READY) {
576 		error = clp->cl_cons_state;
577 		nfs_put_client(clp);
578 		return ERR_PTR(error);
579 	}
580 
581 	BUG_ON(clp->cl_cons_state != NFS_CS_READY);
582 
583 	dprintk("--> nfs_get_client() = %p [share]\n", clp);
584 	return clp;
585 }
586 
587 /*
588  * Mark a server as ready or failed
589  */
590 void nfs_mark_client_ready(struct nfs_client *clp, int state)
591 {
592 	clp->cl_cons_state = state;
593 	wake_up_all(&nfs_client_active_wq);
594 }
595 
596 /*
597  * With sessions, the client is not marked ready until after a
598  * successful EXCHANGE_ID and CREATE_SESSION.
599  *
600  * Map errors cl_cons_state errors to EPROTONOSUPPORT to indicate
601  * other versions of NFS can be tried.
602  */
603 int nfs4_check_client_ready(struct nfs_client *clp)
604 {
605 	if (!nfs4_has_session(clp))
606 		return 0;
607 	if (clp->cl_cons_state < NFS_CS_READY)
608 		return -EPROTONOSUPPORT;
609 	return 0;
610 }
611 
612 /*
613  * Initialise the timeout values for a connection
614  */
615 static void nfs_init_timeout_values(struct rpc_timeout *to, int proto,
616 				    unsigned int timeo, unsigned int retrans)
617 {
618 	to->to_initval = timeo * HZ / 10;
619 	to->to_retries = retrans;
620 
621 	switch (proto) {
622 	case XPRT_TRANSPORT_TCP:
623 	case XPRT_TRANSPORT_RDMA:
624 		if (to->to_retries == 0)
625 			to->to_retries = NFS_DEF_TCP_RETRANS;
626 		if (to->to_initval == 0)
627 			to->to_initval = NFS_DEF_TCP_TIMEO * HZ / 10;
628 		if (to->to_initval > NFS_MAX_TCP_TIMEOUT)
629 			to->to_initval = NFS_MAX_TCP_TIMEOUT;
630 		to->to_increment = to->to_initval;
631 		to->to_maxval = to->to_initval + (to->to_increment * to->to_retries);
632 		if (to->to_maxval > NFS_MAX_TCP_TIMEOUT)
633 			to->to_maxval = NFS_MAX_TCP_TIMEOUT;
634 		if (to->to_maxval < to->to_initval)
635 			to->to_maxval = to->to_initval;
636 		to->to_exponential = 0;
637 		break;
638 	case XPRT_TRANSPORT_UDP:
639 		if (to->to_retries == 0)
640 			to->to_retries = NFS_DEF_UDP_RETRANS;
641 		if (!to->to_initval)
642 			to->to_initval = NFS_DEF_UDP_TIMEO * HZ / 10;
643 		if (to->to_initval > NFS_MAX_UDP_TIMEOUT)
644 			to->to_initval = NFS_MAX_UDP_TIMEOUT;
645 		to->to_maxval = NFS_MAX_UDP_TIMEOUT;
646 		to->to_exponential = 1;
647 		break;
648 	default:
649 		BUG();
650 	}
651 }
652 
653 /*
654  * Create an RPC client handle
655  */
656 static int nfs_create_rpc_client(struct nfs_client *clp,
657 				 const struct rpc_timeout *timeparms,
658 				 rpc_authflavor_t flavor,
659 				 int discrtry, int noresvport)
660 {
661 	struct rpc_clnt		*clnt = NULL;
662 	struct rpc_create_args args = {
663 		.net		= clp->net,
664 		.protocol	= clp->cl_proto,
665 		.address	= (struct sockaddr *)&clp->cl_addr,
666 		.addrsize	= clp->cl_addrlen,
667 		.timeout	= timeparms,
668 		.servername	= clp->cl_hostname,
669 		.program	= &nfs_program,
670 		.version	= clp->rpc_ops->version,
671 		.authflavor	= flavor,
672 	};
673 
674 	if (discrtry)
675 		args.flags |= RPC_CLNT_CREATE_DISCRTRY;
676 	if (noresvport)
677 		args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
678 
679 	if (!IS_ERR(clp->cl_rpcclient))
680 		return 0;
681 
682 	clnt = rpc_create(&args);
683 	if (IS_ERR(clnt)) {
684 		dprintk("%s: cannot create RPC client. Error = %ld\n",
685 				__func__, PTR_ERR(clnt));
686 		return PTR_ERR(clnt);
687 	}
688 
689 	clp->cl_rpcclient = clnt;
690 	return 0;
691 }
692 
693 /*
694  * Version 2 or 3 client destruction
695  */
696 static void nfs_destroy_server(struct nfs_server *server)
697 {
698 	if (!(server->flags & NFS_MOUNT_LOCAL_FLOCK) ||
699 			!(server->flags & NFS_MOUNT_LOCAL_FCNTL))
700 		nlmclnt_done(server->nlm_host);
701 }
702 
703 /*
704  * Version 2 or 3 lockd setup
705  */
706 static int nfs_start_lockd(struct nfs_server *server)
707 {
708 	struct nlm_host *host;
709 	struct nfs_client *clp = server->nfs_client;
710 	struct nlmclnt_initdata nlm_init = {
711 		.hostname	= clp->cl_hostname,
712 		.address	= (struct sockaddr *)&clp->cl_addr,
713 		.addrlen	= clp->cl_addrlen,
714 		.nfs_version	= clp->rpc_ops->version,
715 		.noresvport	= server->flags & NFS_MOUNT_NORESVPORT ?
716 					1 : 0,
717 		.net		= clp->net,
718 	};
719 
720 	if (nlm_init.nfs_version > 3)
721 		return 0;
722 	if ((server->flags & NFS_MOUNT_LOCAL_FLOCK) &&
723 			(server->flags & NFS_MOUNT_LOCAL_FCNTL))
724 		return 0;
725 
726 	switch (clp->cl_proto) {
727 		default:
728 			nlm_init.protocol = IPPROTO_TCP;
729 			break;
730 		case XPRT_TRANSPORT_UDP:
731 			nlm_init.protocol = IPPROTO_UDP;
732 	}
733 
734 	host = nlmclnt_init(&nlm_init);
735 	if (IS_ERR(host))
736 		return PTR_ERR(host);
737 
738 	server->nlm_host = host;
739 	server->destroy = nfs_destroy_server;
740 	return 0;
741 }
742 
743 /*
744  * Initialise an NFSv3 ACL client connection
745  */
746 #ifdef CONFIG_NFS_V3_ACL
747 static void nfs_init_server_aclclient(struct nfs_server *server)
748 {
749 	if (server->nfs_client->rpc_ops->version != 3)
750 		goto out_noacl;
751 	if (server->flags & NFS_MOUNT_NOACL)
752 		goto out_noacl;
753 
754 	server->client_acl = rpc_bind_new_program(server->client, &nfsacl_program, 3);
755 	if (IS_ERR(server->client_acl))
756 		goto out_noacl;
757 
758 	/* No errors! Assume that Sun nfsacls are supported */
759 	server->caps |= NFS_CAP_ACLS;
760 	return;
761 
762 out_noacl:
763 	server->caps &= ~NFS_CAP_ACLS;
764 }
765 #else
766 static inline void nfs_init_server_aclclient(struct nfs_server *server)
767 {
768 	server->flags &= ~NFS_MOUNT_NOACL;
769 	server->caps &= ~NFS_CAP_ACLS;
770 }
771 #endif
772 
773 /*
774  * Create a general RPC client
775  */
776 static int nfs_init_server_rpcclient(struct nfs_server *server,
777 		const struct rpc_timeout *timeo,
778 		rpc_authflavor_t pseudoflavour)
779 {
780 	struct nfs_client *clp = server->nfs_client;
781 
782 	server->client = rpc_clone_client(clp->cl_rpcclient);
783 	if (IS_ERR(server->client)) {
784 		dprintk("%s: couldn't create rpc_client!\n", __func__);
785 		return PTR_ERR(server->client);
786 	}
787 
788 	memcpy(&server->client->cl_timeout_default,
789 			timeo,
790 			sizeof(server->client->cl_timeout_default));
791 	server->client->cl_timeout = &server->client->cl_timeout_default;
792 
793 	if (pseudoflavour != clp->cl_rpcclient->cl_auth->au_flavor) {
794 		struct rpc_auth *auth;
795 
796 		auth = rpcauth_create(pseudoflavour, server->client);
797 		if (IS_ERR(auth)) {
798 			dprintk("%s: couldn't create credcache!\n", __func__);
799 			return PTR_ERR(auth);
800 		}
801 	}
802 	server->client->cl_softrtry = 0;
803 	if (server->flags & NFS_MOUNT_SOFT)
804 		server->client->cl_softrtry = 1;
805 
806 	return 0;
807 }
808 
809 /*
810  * Initialise an NFS2 or NFS3 client
811  */
812 int nfs_init_client(struct nfs_client *clp, const struct rpc_timeout *timeparms,
813 		    const char *ip_addr, rpc_authflavor_t authflavour,
814 		    int noresvport)
815 {
816 	int error;
817 
818 	if (clp->cl_cons_state == NFS_CS_READY) {
819 		/* the client is already initialised */
820 		dprintk("<-- nfs_init_client() = 0 [already %p]\n", clp);
821 		return 0;
822 	}
823 
824 	/*
825 	 * Create a client RPC handle for doing FSSTAT with UNIX auth only
826 	 * - RFC 2623, sec 2.3.2
827 	 */
828 	error = nfs_create_rpc_client(clp, timeparms, RPC_AUTH_UNIX,
829 				      0, noresvport);
830 	if (error < 0)
831 		goto error;
832 	nfs_mark_client_ready(clp, NFS_CS_READY);
833 	return 0;
834 
835 error:
836 	nfs_mark_client_ready(clp, error);
837 	dprintk("<-- nfs_init_client() = xerror %d\n", error);
838 	return error;
839 }
840 
841 /*
842  * Create a version 2 or 3 client
843  */
844 static int nfs_init_server(struct nfs_server *server,
845 			   const struct nfs_parsed_mount_data *data)
846 {
847 	struct nfs_client_initdata cl_init = {
848 		.hostname = data->nfs_server.hostname,
849 		.addr = (const struct sockaddr *)&data->nfs_server.address,
850 		.addrlen = data->nfs_server.addrlen,
851 		.rpc_ops = &nfs_v2_clientops,
852 		.proto = data->nfs_server.protocol,
853 		.net = data->net,
854 	};
855 	struct rpc_timeout timeparms;
856 	struct nfs_client *clp;
857 	int error;
858 
859 	dprintk("--> nfs_init_server()\n");
860 
861 #ifdef CONFIG_NFS_V3
862 	if (data->version == 3)
863 		cl_init.rpc_ops = &nfs_v3_clientops;
864 #endif
865 
866 	nfs_init_timeout_values(&timeparms, data->nfs_server.protocol,
867 			data->timeo, data->retrans);
868 
869 	/* Allocate or find a client reference we can use */
870 	clp = nfs_get_client(&cl_init, &timeparms, NULL, RPC_AUTH_UNIX,
871 			     data->flags & NFS_MOUNT_NORESVPORT);
872 	if (IS_ERR(clp)) {
873 		dprintk("<-- nfs_init_server() = error %ld\n", PTR_ERR(clp));
874 		return PTR_ERR(clp);
875 	}
876 
877 	server->nfs_client = clp;
878 
879 	/* Initialise the client representation from the mount data */
880 	server->flags = data->flags;
881 	server->options = data->options;
882 	server->caps |= NFS_CAP_HARDLINKS|NFS_CAP_SYMLINKS|NFS_CAP_FILEID|
883 		NFS_CAP_MODE|NFS_CAP_NLINK|NFS_CAP_OWNER|NFS_CAP_OWNER_GROUP|
884 		NFS_CAP_ATIME|NFS_CAP_CTIME|NFS_CAP_MTIME;
885 
886 	if (data->rsize)
887 		server->rsize = nfs_block_size(data->rsize, NULL);
888 	if (data->wsize)
889 		server->wsize = nfs_block_size(data->wsize, NULL);
890 
891 	server->acregmin = data->acregmin * HZ;
892 	server->acregmax = data->acregmax * HZ;
893 	server->acdirmin = data->acdirmin * HZ;
894 	server->acdirmax = data->acdirmax * HZ;
895 
896 	/* Start lockd here, before we might error out */
897 	error = nfs_start_lockd(server);
898 	if (error < 0)
899 		goto error;
900 
901 	server->port = data->nfs_server.port;
902 
903 	error = nfs_init_server_rpcclient(server, &timeparms, data->auth_flavors[0]);
904 	if (error < 0)
905 		goto error;
906 
907 	/* Preserve the values of mount_server-related mount options */
908 	if (data->mount_server.addrlen) {
909 		memcpy(&server->mountd_address, &data->mount_server.address,
910 			data->mount_server.addrlen);
911 		server->mountd_addrlen = data->mount_server.addrlen;
912 	}
913 	server->mountd_version = data->mount_server.version;
914 	server->mountd_port = data->mount_server.port;
915 	server->mountd_protocol = data->mount_server.protocol;
916 
917 	server->namelen  = data->namlen;
918 	/* Create a client RPC handle for the NFSv3 ACL management interface */
919 	nfs_init_server_aclclient(server);
920 	dprintk("<-- nfs_init_server() = 0 [new %p]\n", clp);
921 	return 0;
922 
923 error:
924 	server->nfs_client = NULL;
925 	nfs_put_client(clp);
926 	dprintk("<-- nfs_init_server() = xerror %d\n", error);
927 	return error;
928 }
929 
930 /*
931  * Load up the server record from information gained in an fsinfo record
932  */
933 static void nfs_server_set_fsinfo(struct nfs_server *server,
934 				  struct nfs_fh *mntfh,
935 				  struct nfs_fsinfo *fsinfo)
936 {
937 	unsigned long max_rpc_payload;
938 
939 	/* Work out a lot of parameters */
940 	if (server->rsize == 0)
941 		server->rsize = nfs_block_size(fsinfo->rtpref, NULL);
942 	if (server->wsize == 0)
943 		server->wsize = nfs_block_size(fsinfo->wtpref, NULL);
944 
945 	if (fsinfo->rtmax >= 512 && server->rsize > fsinfo->rtmax)
946 		server->rsize = nfs_block_size(fsinfo->rtmax, NULL);
947 	if (fsinfo->wtmax >= 512 && server->wsize > fsinfo->wtmax)
948 		server->wsize = nfs_block_size(fsinfo->wtmax, NULL);
949 
950 	max_rpc_payload = nfs_block_size(rpc_max_payload(server->client), NULL);
951 	if (server->rsize > max_rpc_payload)
952 		server->rsize = max_rpc_payload;
953 	if (server->rsize > NFS_MAX_FILE_IO_SIZE)
954 		server->rsize = NFS_MAX_FILE_IO_SIZE;
955 	server->rpages = (server->rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
956 
957 	server->backing_dev_info.name = "nfs";
958 	server->backing_dev_info.ra_pages = server->rpages * NFS_MAX_READAHEAD;
959 
960 	if (server->wsize > max_rpc_payload)
961 		server->wsize = max_rpc_payload;
962 	if (server->wsize > NFS_MAX_FILE_IO_SIZE)
963 		server->wsize = NFS_MAX_FILE_IO_SIZE;
964 	server->wpages = (server->wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
965 	server->pnfs_blksize = fsinfo->blksize;
966 	set_pnfs_layoutdriver(server, mntfh, fsinfo->layouttype);
967 
968 	server->wtmult = nfs_block_bits(fsinfo->wtmult, NULL);
969 
970 	server->dtsize = nfs_block_size(fsinfo->dtpref, NULL);
971 	if (server->dtsize > PAGE_CACHE_SIZE * NFS_MAX_READDIR_PAGES)
972 		server->dtsize = PAGE_CACHE_SIZE * NFS_MAX_READDIR_PAGES;
973 	if (server->dtsize > server->rsize)
974 		server->dtsize = server->rsize;
975 
976 	if (server->flags & NFS_MOUNT_NOAC) {
977 		server->acregmin = server->acregmax = 0;
978 		server->acdirmin = server->acdirmax = 0;
979 	}
980 
981 	server->maxfilesize = fsinfo->maxfilesize;
982 
983 	server->time_delta = fsinfo->time_delta;
984 
985 	/* We're airborne Set socket buffersize */
986 	rpc_setbufsize(server->client, server->wsize + 100, server->rsize + 100);
987 }
988 
989 /*
990  * Probe filesystem information, including the FSID on v2/v3
991  */
992 static int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *mntfh, struct nfs_fattr *fattr)
993 {
994 	struct nfs_fsinfo fsinfo;
995 	struct nfs_client *clp = server->nfs_client;
996 	int error;
997 
998 	dprintk("--> nfs_probe_fsinfo()\n");
999 
1000 	if (clp->rpc_ops->set_capabilities != NULL) {
1001 		error = clp->rpc_ops->set_capabilities(server, mntfh);
1002 		if (error < 0)
1003 			goto out_error;
1004 	}
1005 
1006 	fsinfo.fattr = fattr;
1007 	fsinfo.layouttype = 0;
1008 	error = clp->rpc_ops->fsinfo(server, mntfh, &fsinfo);
1009 	if (error < 0)
1010 		goto out_error;
1011 
1012 	nfs_server_set_fsinfo(server, mntfh, &fsinfo);
1013 
1014 	/* Get some general file system info */
1015 	if (server->namelen == 0) {
1016 		struct nfs_pathconf pathinfo;
1017 
1018 		pathinfo.fattr = fattr;
1019 		nfs_fattr_init(fattr);
1020 
1021 		if (clp->rpc_ops->pathconf(server, mntfh, &pathinfo) >= 0)
1022 			server->namelen = pathinfo.max_namelen;
1023 	}
1024 
1025 	dprintk("<-- nfs_probe_fsinfo() = 0\n");
1026 	return 0;
1027 
1028 out_error:
1029 	dprintk("nfs_probe_fsinfo: error = %d\n", -error);
1030 	return error;
1031 }
1032 
1033 /*
1034  * Copy useful information when duplicating a server record
1035  */
1036 static void nfs_server_copy_userdata(struct nfs_server *target, struct nfs_server *source)
1037 {
1038 	target->flags = source->flags;
1039 	target->rsize = source->rsize;
1040 	target->wsize = source->wsize;
1041 	target->acregmin = source->acregmin;
1042 	target->acregmax = source->acregmax;
1043 	target->acdirmin = source->acdirmin;
1044 	target->acdirmax = source->acdirmax;
1045 	target->caps = source->caps;
1046 	target->options = source->options;
1047 }
1048 
1049 static void nfs_server_insert_lists(struct nfs_server *server)
1050 {
1051 	struct nfs_client *clp = server->nfs_client;
1052 	struct nfs_net *nn = net_generic(clp->net, nfs_net_id);
1053 
1054 	spin_lock(&nn->nfs_client_lock);
1055 	list_add_tail_rcu(&server->client_link, &clp->cl_superblocks);
1056 	list_add_tail(&server->master_link, &nn->nfs_volume_list);
1057 	clear_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
1058 	spin_unlock(&nn->nfs_client_lock);
1059 
1060 }
1061 
1062 static void nfs_server_remove_lists(struct nfs_server *server)
1063 {
1064 	struct nfs_client *clp = server->nfs_client;
1065 	struct nfs_net *nn;
1066 
1067 	if (clp == NULL)
1068 		return;
1069 	nn = net_generic(clp->net, nfs_net_id);
1070 	spin_lock(&nn->nfs_client_lock);
1071 	list_del_rcu(&server->client_link);
1072 	if (list_empty(&clp->cl_superblocks))
1073 		set_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
1074 	list_del(&server->master_link);
1075 	spin_unlock(&nn->nfs_client_lock);
1076 
1077 	synchronize_rcu();
1078 }
1079 
1080 /*
1081  * Allocate and initialise a server record
1082  */
1083 static struct nfs_server *nfs_alloc_server(void)
1084 {
1085 	struct nfs_server *server;
1086 
1087 	server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
1088 	if (!server)
1089 		return NULL;
1090 
1091 	server->client = server->client_acl = ERR_PTR(-EINVAL);
1092 
1093 	/* Zero out the NFS state stuff */
1094 	INIT_LIST_HEAD(&server->client_link);
1095 	INIT_LIST_HEAD(&server->master_link);
1096 	INIT_LIST_HEAD(&server->delegations);
1097 	INIT_LIST_HEAD(&server->layouts);
1098 	INIT_LIST_HEAD(&server->state_owners_lru);
1099 
1100 	atomic_set(&server->active, 0);
1101 
1102 	server->io_stats = nfs_alloc_iostats();
1103 	if (!server->io_stats) {
1104 		kfree(server);
1105 		return NULL;
1106 	}
1107 
1108 	if (bdi_init(&server->backing_dev_info)) {
1109 		nfs_free_iostats(server->io_stats);
1110 		kfree(server);
1111 		return NULL;
1112 	}
1113 
1114 	ida_init(&server->openowner_id);
1115 	ida_init(&server->lockowner_id);
1116 	pnfs_init_server(server);
1117 
1118 	return server;
1119 }
1120 
1121 /*
1122  * Free up a server record
1123  */
1124 void nfs_free_server(struct nfs_server *server)
1125 {
1126 	dprintk("--> nfs_free_server()\n");
1127 
1128 	nfs_server_remove_lists(server);
1129 	unset_pnfs_layoutdriver(server);
1130 
1131 	if (server->destroy != NULL)
1132 		server->destroy(server);
1133 
1134 	if (!IS_ERR(server->client_acl))
1135 		rpc_shutdown_client(server->client_acl);
1136 	if (!IS_ERR(server->client))
1137 		rpc_shutdown_client(server->client);
1138 
1139 	nfs_put_client(server->nfs_client);
1140 
1141 	ida_destroy(&server->lockowner_id);
1142 	ida_destroy(&server->openowner_id);
1143 	nfs_free_iostats(server->io_stats);
1144 	bdi_destroy(&server->backing_dev_info);
1145 	kfree(server);
1146 	nfs_release_automount_timer();
1147 	dprintk("<-- nfs_free_server()\n");
1148 }
1149 
1150 /*
1151  * Create a version 2 or 3 volume record
1152  * - keyed on server and FSID
1153  */
1154 struct nfs_server *nfs_create_server(const struct nfs_parsed_mount_data *data,
1155 				     struct nfs_fh *mntfh)
1156 {
1157 	struct nfs_server *server;
1158 	struct nfs_fattr *fattr;
1159 	int error;
1160 
1161 	server = nfs_alloc_server();
1162 	if (!server)
1163 		return ERR_PTR(-ENOMEM);
1164 
1165 	error = -ENOMEM;
1166 	fattr = nfs_alloc_fattr();
1167 	if (fattr == NULL)
1168 		goto error;
1169 
1170 	/* Get a client representation */
1171 	error = nfs_init_server(server, data);
1172 	if (error < 0)
1173 		goto error;
1174 
1175 	BUG_ON(!server->nfs_client);
1176 	BUG_ON(!server->nfs_client->rpc_ops);
1177 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
1178 
1179 	/* Probe the root fh to retrieve its FSID */
1180 	error = nfs_probe_fsinfo(server, mntfh, fattr);
1181 	if (error < 0)
1182 		goto error;
1183 	if (server->nfs_client->rpc_ops->version == 3) {
1184 		if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN)
1185 			server->namelen = NFS3_MAXNAMLEN;
1186 		if (!(data->flags & NFS_MOUNT_NORDIRPLUS))
1187 			server->caps |= NFS_CAP_READDIRPLUS;
1188 	} else {
1189 		if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN)
1190 			server->namelen = NFS2_MAXNAMLEN;
1191 	}
1192 
1193 	if (!(fattr->valid & NFS_ATTR_FATTR)) {
1194 		error = server->nfs_client->rpc_ops->getattr(server, mntfh, fattr);
1195 		if (error < 0) {
1196 			dprintk("nfs_create_server: getattr error = %d\n", -error);
1197 			goto error;
1198 		}
1199 	}
1200 	memcpy(&server->fsid, &fattr->fsid, sizeof(server->fsid));
1201 
1202 	dprintk("Server FSID: %llx:%llx\n",
1203 		(unsigned long long) server->fsid.major,
1204 		(unsigned long long) server->fsid.minor);
1205 
1206 	nfs_server_insert_lists(server);
1207 	server->mount_time = jiffies;
1208 	nfs_free_fattr(fattr);
1209 	return server;
1210 
1211 error:
1212 	nfs_free_fattr(fattr);
1213 	nfs_free_server(server);
1214 	return ERR_PTR(error);
1215 }
1216 
1217 #ifdef CONFIG_NFS_V4
1218 /*
1219  * NFSv4.0 callback thread helper
1220  *
1221  * Find a client by callback identifier
1222  */
1223 struct nfs_client *
1224 nfs4_find_client_ident(struct net *net, int cb_ident)
1225 {
1226 	struct nfs_client *clp;
1227 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1228 
1229 	spin_lock(&nn->nfs_client_lock);
1230 	clp = idr_find(&nn->cb_ident_idr, cb_ident);
1231 	if (clp)
1232 		atomic_inc(&clp->cl_count);
1233 	spin_unlock(&nn->nfs_client_lock);
1234 	return clp;
1235 }
1236 
1237 #if defined(CONFIG_NFS_V4_1)
1238 /*
1239  * NFSv4.1 callback thread helper
1240  * For CB_COMPOUND calls, find a client by IP address, protocol version,
1241  * minorversion, and sessionID
1242  *
1243  * Returns NULL if no such client
1244  */
1245 struct nfs_client *
1246 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
1247 			   struct nfs4_sessionid *sid)
1248 {
1249 	struct nfs_client *clp;
1250 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1251 
1252 	spin_lock(&nn->nfs_client_lock);
1253 	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
1254 		if (nfs4_cb_match_client(addr, clp, 1) == false)
1255 			continue;
1256 
1257 		if (!nfs4_has_session(clp))
1258 			continue;
1259 
1260 		/* Match sessionid*/
1261 		if (memcmp(clp->cl_session->sess_id.data,
1262 		    sid->data, NFS4_MAX_SESSIONID_LEN) != 0)
1263 			continue;
1264 
1265 		atomic_inc(&clp->cl_count);
1266 		spin_unlock(&nn->nfs_client_lock);
1267 		return clp;
1268 	}
1269 	spin_unlock(&nn->nfs_client_lock);
1270 	return NULL;
1271 }
1272 
1273 #else /* CONFIG_NFS_V4_1 */
1274 
1275 struct nfs_client *
1276 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
1277 			   struct nfs4_sessionid *sid)
1278 {
1279 	return NULL;
1280 }
1281 #endif /* CONFIG_NFS_V4_1 */
1282 
1283 /*
1284  * Initialize the NFS4 callback service
1285  */
1286 static int nfs4_init_callback(struct nfs_client *clp)
1287 {
1288 	int error;
1289 
1290 	if (clp->rpc_ops->version == 4) {
1291 		struct rpc_xprt *xprt;
1292 
1293 		xprt = rcu_dereference_raw(clp->cl_rpcclient->cl_xprt);
1294 
1295 		if (nfs4_has_session(clp)) {
1296 			error = xprt_setup_backchannel(xprt,
1297 						NFS41_BC_MIN_CALLBACKS);
1298 			if (error < 0)
1299 				return error;
1300 		}
1301 
1302 		error = nfs_callback_up(clp->cl_mvops->minor_version, xprt);
1303 		if (error < 0) {
1304 			dprintk("%s: failed to start callback. Error = %d\n",
1305 				__func__, error);
1306 			return error;
1307 		}
1308 		__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
1309 	}
1310 	return 0;
1311 }
1312 
1313 /*
1314  * Initialize the minor version specific parts of an NFS4 client record
1315  */
1316 static int nfs4_init_client_minor_version(struct nfs_client *clp)
1317 {
1318 #if defined(CONFIG_NFS_V4_1)
1319 	if (clp->cl_mvops->minor_version) {
1320 		struct nfs4_session *session = NULL;
1321 		/*
1322 		 * Create the session and mark it expired.
1323 		 * When a SEQUENCE operation encounters the expired session
1324 		 * it will do session recovery to initialize it.
1325 		 */
1326 		session = nfs4_alloc_session(clp);
1327 		if (!session)
1328 			return -ENOMEM;
1329 
1330 		clp->cl_session = session;
1331 		/*
1332 		 * The create session reply races with the server back
1333 		 * channel probe. Mark the client NFS_CS_SESSION_INITING
1334 		 * so that the client back channel can find the
1335 		 * nfs_client struct
1336 		 */
1337 		clp->cl_cons_state = NFS_CS_SESSION_INITING;
1338 	}
1339 #endif /* CONFIG_NFS_V4_1 */
1340 
1341 	return nfs4_init_callback(clp);
1342 }
1343 
1344 /*
1345  * Initialise an NFS4 client record
1346  */
1347 int nfs4_init_client(struct nfs_client *clp,
1348 		     const struct rpc_timeout *timeparms,
1349 		     const char *ip_addr,
1350 		     rpc_authflavor_t authflavour,
1351 		     int noresvport)
1352 {
1353 	char buf[INET6_ADDRSTRLEN + 1];
1354 	int error;
1355 
1356 	if (clp->cl_cons_state == NFS_CS_READY) {
1357 		/* the client is initialised already */
1358 		dprintk("<-- nfs4_init_client() = 0 [already %p]\n", clp);
1359 		return 0;
1360 	}
1361 
1362 	/* Check NFS protocol revision and initialize RPC op vector */
1363 	clp->rpc_ops = &nfs_v4_clientops;
1364 
1365 	error = nfs_create_rpc_client(clp, timeparms, authflavour,
1366 				      1, noresvport);
1367 	if (error < 0)
1368 		goto error;
1369 
1370 	/* If no clientaddr= option was specified, find a usable cb address */
1371 	if (ip_addr == NULL) {
1372 		struct sockaddr_storage cb_addr;
1373 		struct sockaddr *sap = (struct sockaddr *)&cb_addr;
1374 
1375 		error = rpc_localaddr(clp->cl_rpcclient, sap, sizeof(cb_addr));
1376 		if (error < 0)
1377 			goto error;
1378 		error = rpc_ntop(sap, buf, sizeof(buf));
1379 		if (error < 0)
1380 			goto error;
1381 		ip_addr = (const char *)buf;
1382 	}
1383 	strlcpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr));
1384 
1385 	error = nfs_idmap_new(clp);
1386 	if (error < 0) {
1387 		dprintk("%s: failed to create idmapper. Error = %d\n",
1388 			__func__, error);
1389 		goto error;
1390 	}
1391 	__set_bit(NFS_CS_IDMAP, &clp->cl_res_state);
1392 
1393 	error = nfs4_init_client_minor_version(clp);
1394 	if (error < 0)
1395 		goto error;
1396 
1397 	if (!nfs4_has_session(clp))
1398 		nfs_mark_client_ready(clp, NFS_CS_READY);
1399 	return 0;
1400 
1401 error:
1402 	nfs_mark_client_ready(clp, error);
1403 	dprintk("<-- nfs4_init_client() = xerror %d\n", error);
1404 	return error;
1405 }
1406 
1407 /*
1408  * Set up an NFS4 client
1409  */
1410 static int nfs4_set_client(struct nfs_server *server,
1411 		const char *hostname,
1412 		const struct sockaddr *addr,
1413 		const size_t addrlen,
1414 		const char *ip_addr,
1415 		rpc_authflavor_t authflavour,
1416 		int proto, const struct rpc_timeout *timeparms,
1417 		u32 minorversion, struct net *net)
1418 {
1419 	struct nfs_client_initdata cl_init = {
1420 		.hostname = hostname,
1421 		.addr = addr,
1422 		.addrlen = addrlen,
1423 		.rpc_ops = &nfs_v4_clientops,
1424 		.proto = proto,
1425 		.minorversion = minorversion,
1426 		.net = net,
1427 	};
1428 	struct nfs_client *clp;
1429 	int error;
1430 
1431 	dprintk("--> nfs4_set_client()\n");
1432 
1433 	/* Allocate or find a client reference we can use */
1434 	clp = nfs_get_client(&cl_init, timeparms, ip_addr, authflavour,
1435 			     server->flags & NFS_MOUNT_NORESVPORT);
1436 	if (IS_ERR(clp)) {
1437 		error = PTR_ERR(clp);
1438 		goto error;
1439 	}
1440 
1441 	/*
1442 	 * Query for the lease time on clientid setup or renewal
1443 	 *
1444 	 * Note that this will be set on nfs_clients that were created
1445 	 * only for the DS role and did not set this bit, but now will
1446 	 * serve a dual role.
1447 	 */
1448 	set_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state);
1449 
1450 	server->nfs_client = clp;
1451 	dprintk("<-- nfs4_set_client() = 0 [new %p]\n", clp);
1452 	return 0;
1453 error:
1454 	dprintk("<-- nfs4_set_client() = xerror %d\n", error);
1455 	return error;
1456 }
1457 
1458 /*
1459  * Set up a pNFS Data Server client.
1460  *
1461  * Return any existing nfs_client that matches server address,port,version
1462  * and minorversion.
1463  *
1464  * For a new nfs_client, use a soft mount (default), a low retrans and a
1465  * low timeout interval so that if a connection is lost, we retry through
1466  * the MDS.
1467  */
1468 struct nfs_client *nfs4_set_ds_client(struct nfs_client* mds_clp,
1469 		const struct sockaddr *ds_addr,
1470 		int ds_addrlen, int ds_proto)
1471 {
1472 	struct nfs_client_initdata cl_init = {
1473 		.addr = ds_addr,
1474 		.addrlen = ds_addrlen,
1475 		.rpc_ops = &nfs_v4_clientops,
1476 		.proto = ds_proto,
1477 		.minorversion = mds_clp->cl_minorversion,
1478 		.net = mds_clp->net,
1479 	};
1480 	struct rpc_timeout ds_timeout = {
1481 		.to_initval = 15 * HZ,
1482 		.to_maxval = 15 * HZ,
1483 		.to_retries = 1,
1484 		.to_exponential = 1,
1485 	};
1486 	struct nfs_client *clp;
1487 
1488 	/*
1489 	 * Set an authflavor equual to the MDS value. Use the MDS nfs_client
1490 	 * cl_ipaddr so as to use the same EXCHANGE_ID co_ownerid as the MDS
1491 	 * (section 13.1 RFC 5661).
1492 	 */
1493 	clp = nfs_get_client(&cl_init, &ds_timeout, mds_clp->cl_ipaddr,
1494 			     mds_clp->cl_rpcclient->cl_auth->au_flavor, 0);
1495 
1496 	dprintk("<-- %s %p\n", __func__, clp);
1497 	return clp;
1498 }
1499 EXPORT_SYMBOL_GPL(nfs4_set_ds_client);
1500 
1501 /*
1502  * Session has been established, and the client marked ready.
1503  * Set the mount rsize and wsize with negotiated fore channel
1504  * attributes which will be bound checked in nfs_server_set_fsinfo.
1505  */
1506 static void nfs4_session_set_rwsize(struct nfs_server *server)
1507 {
1508 #ifdef CONFIG_NFS_V4_1
1509 	struct nfs4_session *sess;
1510 	u32 server_resp_sz;
1511 	u32 server_rqst_sz;
1512 
1513 	if (!nfs4_has_session(server->nfs_client))
1514 		return;
1515 	sess = server->nfs_client->cl_session;
1516 	server_resp_sz = sess->fc_attrs.max_resp_sz - nfs41_maxread_overhead;
1517 	server_rqst_sz = sess->fc_attrs.max_rqst_sz - nfs41_maxwrite_overhead;
1518 
1519 	if (server->rsize > server_resp_sz)
1520 		server->rsize = server_resp_sz;
1521 	if (server->wsize > server_rqst_sz)
1522 		server->wsize = server_rqst_sz;
1523 #endif /* CONFIG_NFS_V4_1 */
1524 }
1525 
1526 static int nfs4_server_common_setup(struct nfs_server *server,
1527 		struct nfs_fh *mntfh)
1528 {
1529 	struct nfs_fattr *fattr;
1530 	int error;
1531 
1532 	BUG_ON(!server->nfs_client);
1533 	BUG_ON(!server->nfs_client->rpc_ops);
1534 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
1535 
1536 	/* data servers support only a subset of NFSv4.1 */
1537 	if (is_ds_only_client(server->nfs_client))
1538 		return -EPROTONOSUPPORT;
1539 
1540 	fattr = nfs_alloc_fattr();
1541 	if (fattr == NULL)
1542 		return -ENOMEM;
1543 
1544 	/* We must ensure the session is initialised first */
1545 	error = nfs4_init_session(server);
1546 	if (error < 0)
1547 		goto out;
1548 
1549 	/* Probe the root fh to retrieve its FSID and filehandle */
1550 	error = nfs4_get_rootfh(server, mntfh);
1551 	if (error < 0)
1552 		goto out;
1553 
1554 	dprintk("Server FSID: %llx:%llx\n",
1555 			(unsigned long long) server->fsid.major,
1556 			(unsigned long long) server->fsid.minor);
1557 	dprintk("Mount FH: %d\n", mntfh->size);
1558 
1559 	nfs4_session_set_rwsize(server);
1560 
1561 	error = nfs_probe_fsinfo(server, mntfh, fattr);
1562 	if (error < 0)
1563 		goto out;
1564 
1565 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1566 		server->namelen = NFS4_MAXNAMLEN;
1567 
1568 	nfs_server_insert_lists(server);
1569 	server->mount_time = jiffies;
1570 	server->destroy = nfs4_destroy_server;
1571 out:
1572 	nfs_free_fattr(fattr);
1573 	return error;
1574 }
1575 
1576 /*
1577  * Create a version 4 volume record
1578  */
1579 static int nfs4_init_server(struct nfs_server *server,
1580 		const struct nfs_parsed_mount_data *data)
1581 {
1582 	struct rpc_timeout timeparms;
1583 	int error;
1584 
1585 	dprintk("--> nfs4_init_server()\n");
1586 
1587 	nfs_init_timeout_values(&timeparms, data->nfs_server.protocol,
1588 			data->timeo, data->retrans);
1589 
1590 	/* Initialise the client representation from the mount data */
1591 	server->flags = data->flags;
1592 	server->caps |= NFS_CAP_ATOMIC_OPEN|NFS_CAP_CHANGE_ATTR|NFS_CAP_POSIX_LOCK;
1593 	if (!(data->flags & NFS_MOUNT_NORDIRPLUS))
1594 			server->caps |= NFS_CAP_READDIRPLUS;
1595 	server->options = data->options;
1596 
1597 	/* Get a client record */
1598 	error = nfs4_set_client(server,
1599 			data->nfs_server.hostname,
1600 			(const struct sockaddr *)&data->nfs_server.address,
1601 			data->nfs_server.addrlen,
1602 			data->client_address,
1603 			data->auth_flavors[0],
1604 			data->nfs_server.protocol,
1605 			&timeparms,
1606 			data->minorversion,
1607 			data->net);
1608 	if (error < 0)
1609 		goto error;
1610 
1611 	/*
1612 	 * Don't use NFS uid/gid mapping if we're using AUTH_SYS or lower
1613 	 * authentication.
1614 	 */
1615 	if (nfs4_disable_idmapping && data->auth_flavors[0] == RPC_AUTH_UNIX)
1616 		server->caps |= NFS_CAP_UIDGID_NOMAP;
1617 
1618 	if (data->rsize)
1619 		server->rsize = nfs_block_size(data->rsize, NULL);
1620 	if (data->wsize)
1621 		server->wsize = nfs_block_size(data->wsize, NULL);
1622 
1623 	server->acregmin = data->acregmin * HZ;
1624 	server->acregmax = data->acregmax * HZ;
1625 	server->acdirmin = data->acdirmin * HZ;
1626 	server->acdirmax = data->acdirmax * HZ;
1627 
1628 	server->port = data->nfs_server.port;
1629 
1630 	error = nfs_init_server_rpcclient(server, &timeparms, data->auth_flavors[0]);
1631 
1632 error:
1633 	/* Done */
1634 	dprintk("<-- nfs4_init_server() = %d\n", error);
1635 	return error;
1636 }
1637 
1638 /*
1639  * Create a version 4 volume record
1640  * - keyed on server and FSID
1641  */
1642 struct nfs_server *nfs4_create_server(const struct nfs_parsed_mount_data *data,
1643 				      struct nfs_fh *mntfh)
1644 {
1645 	struct nfs_server *server;
1646 	int error;
1647 
1648 	dprintk("--> nfs4_create_server()\n");
1649 
1650 	server = nfs_alloc_server();
1651 	if (!server)
1652 		return ERR_PTR(-ENOMEM);
1653 
1654 	/* set up the general RPC client */
1655 	error = nfs4_init_server(server, data);
1656 	if (error < 0)
1657 		goto error;
1658 
1659 	error = nfs4_server_common_setup(server, mntfh);
1660 	if (error < 0)
1661 		goto error;
1662 
1663 	dprintk("<-- nfs4_create_server() = %p\n", server);
1664 	return server;
1665 
1666 error:
1667 	nfs_free_server(server);
1668 	dprintk("<-- nfs4_create_server() = error %d\n", error);
1669 	return ERR_PTR(error);
1670 }
1671 
1672 /*
1673  * Create an NFS4 referral server record
1674  */
1675 struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data,
1676 					       struct nfs_fh *mntfh)
1677 {
1678 	struct nfs_client *parent_client;
1679 	struct nfs_server *server, *parent_server;
1680 	int error;
1681 
1682 	dprintk("--> nfs4_create_referral_server()\n");
1683 
1684 	server = nfs_alloc_server();
1685 	if (!server)
1686 		return ERR_PTR(-ENOMEM);
1687 
1688 	parent_server = NFS_SB(data->sb);
1689 	parent_client = parent_server->nfs_client;
1690 
1691 	/* Initialise the client representation from the parent server */
1692 	nfs_server_copy_userdata(server, parent_server);
1693 	server->caps |= NFS_CAP_ATOMIC_OPEN|NFS_CAP_CHANGE_ATTR;
1694 
1695 	/* Get a client representation.
1696 	 * Note: NFSv4 always uses TCP, */
1697 	error = nfs4_set_client(server, data->hostname,
1698 				data->addr,
1699 				data->addrlen,
1700 				parent_client->cl_ipaddr,
1701 				data->authflavor,
1702 				rpc_protocol(parent_server->client),
1703 				parent_server->client->cl_timeout,
1704 				parent_client->cl_mvops->minor_version,
1705 				parent_client->net);
1706 	if (error < 0)
1707 		goto error;
1708 
1709 	error = nfs_init_server_rpcclient(server, parent_server->client->cl_timeout, data->authflavor);
1710 	if (error < 0)
1711 		goto error;
1712 
1713 	error = nfs4_server_common_setup(server, mntfh);
1714 	if (error < 0)
1715 		goto error;
1716 
1717 	dprintk("<-- nfs_create_referral_server() = %p\n", server);
1718 	return server;
1719 
1720 error:
1721 	nfs_free_server(server);
1722 	dprintk("<-- nfs4_create_referral_server() = error %d\n", error);
1723 	return ERR_PTR(error);
1724 }
1725 
1726 #endif /* CONFIG_NFS_V4 */
1727 
1728 /*
1729  * Clone an NFS2, NFS3 or NFS4 server record
1730  */
1731 struct nfs_server *nfs_clone_server(struct nfs_server *source,
1732 				    struct nfs_fh *fh,
1733 				    struct nfs_fattr *fattr)
1734 {
1735 	struct nfs_server *server;
1736 	struct nfs_fattr *fattr_fsinfo;
1737 	int error;
1738 
1739 	dprintk("--> nfs_clone_server(,%llx:%llx,)\n",
1740 		(unsigned long long) fattr->fsid.major,
1741 		(unsigned long long) fattr->fsid.minor);
1742 
1743 	server = nfs_alloc_server();
1744 	if (!server)
1745 		return ERR_PTR(-ENOMEM);
1746 
1747 	error = -ENOMEM;
1748 	fattr_fsinfo = nfs_alloc_fattr();
1749 	if (fattr_fsinfo == NULL)
1750 		goto out_free_server;
1751 
1752 	/* Copy data from the source */
1753 	server->nfs_client = source->nfs_client;
1754 	server->destroy = source->destroy;
1755 	atomic_inc(&server->nfs_client->cl_count);
1756 	nfs_server_copy_userdata(server, source);
1757 
1758 	server->fsid = fattr->fsid;
1759 
1760 	error = nfs_init_server_rpcclient(server,
1761 			source->client->cl_timeout,
1762 			source->client->cl_auth->au_flavor);
1763 	if (error < 0)
1764 		goto out_free_server;
1765 	if (!IS_ERR(source->client_acl))
1766 		nfs_init_server_aclclient(server);
1767 
1768 	/* probe the filesystem info for this server filesystem */
1769 	error = nfs_probe_fsinfo(server, fh, fattr_fsinfo);
1770 	if (error < 0)
1771 		goto out_free_server;
1772 
1773 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1774 		server->namelen = NFS4_MAXNAMLEN;
1775 
1776 	dprintk("Cloned FSID: %llx:%llx\n",
1777 		(unsigned long long) server->fsid.major,
1778 		(unsigned long long) server->fsid.minor);
1779 
1780 	error = nfs_start_lockd(server);
1781 	if (error < 0)
1782 		goto out_free_server;
1783 
1784 	nfs_server_insert_lists(server);
1785 	server->mount_time = jiffies;
1786 
1787 	nfs_free_fattr(fattr_fsinfo);
1788 	dprintk("<-- nfs_clone_server() = %p\n", server);
1789 	return server;
1790 
1791 out_free_server:
1792 	nfs_free_fattr(fattr_fsinfo);
1793 	nfs_free_server(server);
1794 	dprintk("<-- nfs_clone_server() = error %d\n", error);
1795 	return ERR_PTR(error);
1796 }
1797 
1798 void nfs_clients_init(struct net *net)
1799 {
1800 	struct nfs_net *nn = net_generic(net, nfs_net_id);
1801 
1802 	INIT_LIST_HEAD(&nn->nfs_client_list);
1803 	INIT_LIST_HEAD(&nn->nfs_volume_list);
1804 #ifdef CONFIG_NFS_V4
1805 	idr_init(&nn->cb_ident_idr);
1806 #endif
1807 	spin_lock_init(&nn->nfs_client_lock);
1808 }
1809 
1810 #ifdef CONFIG_PROC_FS
1811 static struct proc_dir_entry *proc_fs_nfs;
1812 
1813 static int nfs_server_list_open(struct inode *inode, struct file *file);
1814 static void *nfs_server_list_start(struct seq_file *p, loff_t *pos);
1815 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos);
1816 static void nfs_server_list_stop(struct seq_file *p, void *v);
1817 static int nfs_server_list_show(struct seq_file *m, void *v);
1818 
1819 static const struct seq_operations nfs_server_list_ops = {
1820 	.start	= nfs_server_list_start,
1821 	.next	= nfs_server_list_next,
1822 	.stop	= nfs_server_list_stop,
1823 	.show	= nfs_server_list_show,
1824 };
1825 
1826 static const struct file_operations nfs_server_list_fops = {
1827 	.open		= nfs_server_list_open,
1828 	.read		= seq_read,
1829 	.llseek		= seq_lseek,
1830 	.release	= seq_release,
1831 	.owner		= THIS_MODULE,
1832 };
1833 
1834 static int nfs_volume_list_open(struct inode *inode, struct file *file);
1835 static void *nfs_volume_list_start(struct seq_file *p, loff_t *pos);
1836 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos);
1837 static void nfs_volume_list_stop(struct seq_file *p, void *v);
1838 static int nfs_volume_list_show(struct seq_file *m, void *v);
1839 
1840 static const struct seq_operations nfs_volume_list_ops = {
1841 	.start	= nfs_volume_list_start,
1842 	.next	= nfs_volume_list_next,
1843 	.stop	= nfs_volume_list_stop,
1844 	.show	= nfs_volume_list_show,
1845 };
1846 
1847 static const struct file_operations nfs_volume_list_fops = {
1848 	.open		= nfs_volume_list_open,
1849 	.read		= seq_read,
1850 	.llseek		= seq_lseek,
1851 	.release	= seq_release,
1852 	.owner		= THIS_MODULE,
1853 };
1854 
1855 /*
1856  * open "/proc/fs/nfsfs/servers" which provides a summary of servers with which
1857  * we're dealing
1858  */
1859 static int nfs_server_list_open(struct inode *inode, struct file *file)
1860 {
1861 	struct seq_file *m;
1862 	int ret;
1863 	struct pid_namespace *pid_ns = file->f_dentry->d_sb->s_fs_info;
1864 	struct net *net = pid_ns->child_reaper->nsproxy->net_ns;
1865 
1866 	ret = seq_open(file, &nfs_server_list_ops);
1867 	if (ret < 0)
1868 		return ret;
1869 
1870 	m = file->private_data;
1871 	m->private = net;
1872 
1873 	return 0;
1874 }
1875 
1876 /*
1877  * set up the iterator to start reading from the server list and return the first item
1878  */
1879 static void *nfs_server_list_start(struct seq_file *m, loff_t *_pos)
1880 {
1881 	struct nfs_net *nn = net_generic(m->private, nfs_net_id);
1882 
1883 	/* lock the list against modification */
1884 	spin_lock(&nn->nfs_client_lock);
1885 	return seq_list_start_head(&nn->nfs_client_list, *_pos);
1886 }
1887 
1888 /*
1889  * move to next server
1890  */
1891 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos)
1892 {
1893 	struct nfs_net *nn = net_generic(p->private, nfs_net_id);
1894 
1895 	return seq_list_next(v, &nn->nfs_client_list, pos);
1896 }
1897 
1898 /*
1899  * clean up after reading from the transports list
1900  */
1901 static void nfs_server_list_stop(struct seq_file *p, void *v)
1902 {
1903 	struct nfs_net *nn = net_generic(p->private, nfs_net_id);
1904 
1905 	spin_unlock(&nn->nfs_client_lock);
1906 }
1907 
1908 /*
1909  * display a header line followed by a load of call lines
1910  */
1911 static int nfs_server_list_show(struct seq_file *m, void *v)
1912 {
1913 	struct nfs_client *clp;
1914 	struct nfs_net *nn = net_generic(m->private, nfs_net_id);
1915 
1916 	/* display header on line 1 */
1917 	if (v == &nn->nfs_client_list) {
1918 		seq_puts(m, "NV SERVER   PORT USE HOSTNAME\n");
1919 		return 0;
1920 	}
1921 
1922 	/* display one transport per line on subsequent lines */
1923 	clp = list_entry(v, struct nfs_client, cl_share_link);
1924 
1925 	/* Check if the client is initialized */
1926 	if (clp->cl_cons_state != NFS_CS_READY)
1927 		return 0;
1928 
1929 	rcu_read_lock();
1930 	seq_printf(m, "v%u %s %s %3d %s\n",
1931 		   clp->rpc_ops->version,
1932 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
1933 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
1934 		   atomic_read(&clp->cl_count),
1935 		   clp->cl_hostname);
1936 	rcu_read_unlock();
1937 
1938 	return 0;
1939 }
1940 
1941 /*
1942  * open "/proc/fs/nfsfs/volumes" which provides a summary of extant volumes
1943  */
1944 static int nfs_volume_list_open(struct inode *inode, struct file *file)
1945 {
1946 	struct seq_file *m;
1947 	int ret;
1948 	struct pid_namespace *pid_ns = file->f_dentry->d_sb->s_fs_info;
1949 	struct net *net = pid_ns->child_reaper->nsproxy->net_ns;
1950 
1951 	ret = seq_open(file, &nfs_volume_list_ops);
1952 	if (ret < 0)
1953 		return ret;
1954 
1955 	m = file->private_data;
1956 	m->private = net;
1957 
1958 	return 0;
1959 }
1960 
1961 /*
1962  * set up the iterator to start reading from the volume list and return the first item
1963  */
1964 static void *nfs_volume_list_start(struct seq_file *m, loff_t *_pos)
1965 {
1966 	struct nfs_net *nn = net_generic(m->private, nfs_net_id);
1967 
1968 	/* lock the list against modification */
1969 	spin_lock(&nn->nfs_client_lock);
1970 	return seq_list_start_head(&nn->nfs_volume_list, *_pos);
1971 }
1972 
1973 /*
1974  * move to next volume
1975  */
1976 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos)
1977 {
1978 	struct nfs_net *nn = net_generic(p->private, nfs_net_id);
1979 
1980 	return seq_list_next(v, &nn->nfs_volume_list, pos);
1981 }
1982 
1983 /*
1984  * clean up after reading from the transports list
1985  */
1986 static void nfs_volume_list_stop(struct seq_file *p, void *v)
1987 {
1988 	struct nfs_net *nn = net_generic(p->private, nfs_net_id);
1989 
1990 	spin_unlock(&nn->nfs_client_lock);
1991 }
1992 
1993 /*
1994  * display a header line followed by a load of call lines
1995  */
1996 static int nfs_volume_list_show(struct seq_file *m, void *v)
1997 {
1998 	struct nfs_server *server;
1999 	struct nfs_client *clp;
2000 	char dev[8], fsid[17];
2001 	struct nfs_net *nn = net_generic(m->private, nfs_net_id);
2002 
2003 	/* display header on line 1 */
2004 	if (v == &nn->nfs_volume_list) {
2005 		seq_puts(m, "NV SERVER   PORT DEV     FSID              FSC\n");
2006 		return 0;
2007 	}
2008 	/* display one transport per line on subsequent lines */
2009 	server = list_entry(v, struct nfs_server, master_link);
2010 	clp = server->nfs_client;
2011 
2012 	snprintf(dev, 8, "%u:%u",
2013 		 MAJOR(server->s_dev), MINOR(server->s_dev));
2014 
2015 	snprintf(fsid, 17, "%llx:%llx",
2016 		 (unsigned long long) server->fsid.major,
2017 		 (unsigned long long) server->fsid.minor);
2018 
2019 	rcu_read_lock();
2020 	seq_printf(m, "v%u %s %s %-7s %-17s %s\n",
2021 		   clp->rpc_ops->version,
2022 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
2023 		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
2024 		   dev,
2025 		   fsid,
2026 		   nfs_server_fscache_state(server));
2027 	rcu_read_unlock();
2028 
2029 	return 0;
2030 }
2031 
2032 /*
2033  * initialise the /proc/fs/nfsfs/ directory
2034  */
2035 int __init nfs_fs_proc_init(void)
2036 {
2037 	struct proc_dir_entry *p;
2038 
2039 	proc_fs_nfs = proc_mkdir("fs/nfsfs", NULL);
2040 	if (!proc_fs_nfs)
2041 		goto error_0;
2042 
2043 	/* a file of servers with which we're dealing */
2044 	p = proc_create("servers", S_IFREG|S_IRUGO,
2045 			proc_fs_nfs, &nfs_server_list_fops);
2046 	if (!p)
2047 		goto error_1;
2048 
2049 	/* a file of volumes that we have mounted */
2050 	p = proc_create("volumes", S_IFREG|S_IRUGO,
2051 			proc_fs_nfs, &nfs_volume_list_fops);
2052 	if (!p)
2053 		goto error_2;
2054 	return 0;
2055 
2056 error_2:
2057 	remove_proc_entry("servers", proc_fs_nfs);
2058 error_1:
2059 	remove_proc_entry("fs/nfsfs", NULL);
2060 error_0:
2061 	return -ENOMEM;
2062 }
2063 
2064 /*
2065  * clean up the /proc/fs/nfsfs/ directory
2066  */
2067 void nfs_fs_proc_exit(void)
2068 {
2069 	remove_proc_entry("volumes", proc_fs_nfs);
2070 	remove_proc_entry("servers", proc_fs_nfs);
2071 	remove_proc_entry("fs/nfsfs", NULL);
2072 }
2073 
2074 #endif /* CONFIG_PROC_FS */
2075 
2076 module_param(nfs4_disable_idmapping, bool, 0644);
2077 MODULE_PARM_DESC(nfs4_disable_idmapping,
2078 		"Turn off NFSv4 idmapping when using 'sec=sys'");
2079