xref: /openbmc/linux/fs/nfs/nfs4client.c (revision 05bcf503)
1 /*
2  * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
3  * Written by David Howells (dhowells@redhat.com)
4  */
5 #include <linux/module.h>
6 #include <linux/nfs_fs.h>
7 #include <linux/nfs_idmap.h>
8 #include <linux/nfs_mount.h>
9 #include <linux/sunrpc/auth.h>
10 #include <linux/sunrpc/xprt.h>
11 #include <linux/sunrpc/bc_xprt.h>
12 #include "internal.h"
13 #include "callback.h"
14 #include "delegation.h"
15 #include "pnfs.h"
16 #include "netns.h"
17 
18 #define NFSDBG_FACILITY		NFSDBG_CLIENT
19 
20 /*
21  * Get a unique NFSv4.0 callback identifier which will be used
22  * by the V4.0 callback service to lookup the nfs_client struct
23  */
24 static int nfs_get_cb_ident_idr(struct nfs_client *clp, int minorversion)
25 {
26 	int ret = 0;
27 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
28 
29 	if (clp->rpc_ops->version != 4 || minorversion != 0)
30 		return ret;
31 retry:
32 	if (!idr_pre_get(&nn->cb_ident_idr, GFP_KERNEL))
33 		return -ENOMEM;
34 	spin_lock(&nn->nfs_client_lock);
35 	ret = idr_get_new(&nn->cb_ident_idr, clp, &clp->cl_cb_ident);
36 	spin_unlock(&nn->nfs_client_lock);
37 	if (ret == -EAGAIN)
38 		goto retry;
39 	return ret;
40 }
41 
42 #ifdef CONFIG_NFS_V4_1
43 static void nfs4_shutdown_session(struct nfs_client *clp)
44 {
45 	if (nfs4_has_session(clp)) {
46 		nfs4_destroy_session(clp->cl_session);
47 		nfs4_destroy_clientid(clp);
48 	}
49 
50 }
51 #else /* CONFIG_NFS_V4_1 */
52 static void nfs4_shutdown_session(struct nfs_client *clp)
53 {
54 }
55 #endif /* CONFIG_NFS_V4_1 */
56 
57 struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *cl_init)
58 {
59 	int err;
60 	struct nfs_client *clp = nfs_alloc_client(cl_init);
61 	if (IS_ERR(clp))
62 		return clp;
63 
64 	err = nfs_get_cb_ident_idr(clp, cl_init->minorversion);
65 	if (err)
66 		goto error;
67 
68 	spin_lock_init(&clp->cl_lock);
69 	INIT_DELAYED_WORK(&clp->cl_renewd, nfs4_renew_state);
70 	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
71 	clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
72 	clp->cl_minorversion = cl_init->minorversion;
73 	clp->cl_mvops = nfs_v4_minor_ops[cl_init->minorversion];
74 	return clp;
75 
76 error:
77 	nfs_free_client(clp);
78 	return ERR_PTR(err);
79 }
80 
81 /*
82  * Destroy the NFS4 callback service
83  */
84 static void nfs4_destroy_callback(struct nfs_client *clp)
85 {
86 	if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
87 		nfs_callback_down(clp->cl_mvops->minor_version, clp->cl_net);
88 }
89 
90 static void nfs4_shutdown_client(struct nfs_client *clp)
91 {
92 	if (__test_and_clear_bit(NFS_CS_RENEWD, &clp->cl_res_state))
93 		nfs4_kill_renewd(clp);
94 	nfs4_shutdown_session(clp);
95 	nfs4_destroy_callback(clp);
96 	if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state))
97 		nfs_idmap_delete(clp);
98 
99 	rpc_destroy_wait_queue(&clp->cl_rpcwaitq);
100 	kfree(clp->cl_serverowner);
101 	kfree(clp->cl_serverscope);
102 	kfree(clp->cl_implid);
103 }
104 
105 void nfs4_free_client(struct nfs_client *clp)
106 {
107 	nfs4_shutdown_client(clp);
108 	nfs_free_client(clp);
109 }
110 
111 /*
112  * Initialize the NFS4 callback service
113  */
114 static int nfs4_init_callback(struct nfs_client *clp)
115 {
116 	int error;
117 
118 	if (clp->rpc_ops->version == 4) {
119 		struct rpc_xprt *xprt;
120 
121 		xprt = rcu_dereference_raw(clp->cl_rpcclient->cl_xprt);
122 
123 		if (nfs4_has_session(clp)) {
124 			error = xprt_setup_backchannel(xprt,
125 						NFS41_BC_MIN_CALLBACKS);
126 			if (error < 0)
127 				return error;
128 		}
129 
130 		error = nfs_callback_up(clp->cl_mvops->minor_version, xprt);
131 		if (error < 0) {
132 			dprintk("%s: failed to start callback. Error = %d\n",
133 				__func__, error);
134 			return error;
135 		}
136 		__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
137 	}
138 	return 0;
139 }
140 
141 /*
142  * Initialize the minor version specific parts of an NFS4 client record
143  */
144 static int nfs4_init_client_minor_version(struct nfs_client *clp)
145 {
146 #if defined(CONFIG_NFS_V4_1)
147 	if (clp->cl_mvops->minor_version) {
148 		struct nfs4_session *session = NULL;
149 		/*
150 		 * Create the session and mark it expired.
151 		 * When a SEQUENCE operation encounters the expired session
152 		 * it will do session recovery to initialize it.
153 		 */
154 		session = nfs4_alloc_session(clp);
155 		if (!session)
156 			return -ENOMEM;
157 
158 		clp->cl_session = session;
159 		/*
160 		 * The create session reply races with the server back
161 		 * channel probe. Mark the client NFS_CS_SESSION_INITING
162 		 * so that the client back channel can find the
163 		 * nfs_client struct
164 		 */
165 		nfs_mark_client_ready(clp, NFS_CS_SESSION_INITING);
166 	}
167 #endif /* CONFIG_NFS_V4_1 */
168 
169 	return nfs4_init_callback(clp);
170 }
171 
172 /**
173  * nfs4_init_client - Initialise an NFS4 client record
174  *
175  * @clp: nfs_client to initialise
176  * @timeparms: timeout parameters for underlying RPC transport
177  * @ip_addr: callback IP address in presentation format
178  * @authflavor: authentication flavor for underlying RPC transport
179  *
180  * Returns pointer to an NFS client, or an ERR_PTR value.
181  */
182 struct nfs_client *nfs4_init_client(struct nfs_client *clp,
183 				    const struct rpc_timeout *timeparms,
184 				    const char *ip_addr,
185 				    rpc_authflavor_t authflavour)
186 {
187 	char buf[INET6_ADDRSTRLEN + 1];
188 	struct nfs_client *old;
189 	int error;
190 
191 	if (clp->cl_cons_state == NFS_CS_READY) {
192 		/* the client is initialised already */
193 		dprintk("<-- nfs4_init_client() = 0 [already %p]\n", clp);
194 		return clp;
195 	}
196 
197 	/* Check NFS protocol revision and initialize RPC op vector */
198 	clp->rpc_ops = &nfs_v4_clientops;
199 
200 	__set_bit(NFS_CS_DISCRTRY, &clp->cl_flags);
201 	error = nfs_create_rpc_client(clp, timeparms, authflavour);
202 	if (error < 0)
203 		goto error;
204 
205 	/* If no clientaddr= option was specified, find a usable cb address */
206 	if (ip_addr == NULL) {
207 		struct sockaddr_storage cb_addr;
208 		struct sockaddr *sap = (struct sockaddr *)&cb_addr;
209 
210 		error = rpc_localaddr(clp->cl_rpcclient, sap, sizeof(cb_addr));
211 		if (error < 0)
212 			goto error;
213 		error = rpc_ntop(sap, buf, sizeof(buf));
214 		if (error < 0)
215 			goto error;
216 		ip_addr = (const char *)buf;
217 	}
218 	strlcpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr));
219 
220 	error = nfs_idmap_new(clp);
221 	if (error < 0) {
222 		dprintk("%s: failed to create idmapper. Error = %d\n",
223 			__func__, error);
224 		goto error;
225 	}
226 	__set_bit(NFS_CS_IDMAP, &clp->cl_res_state);
227 
228 	error = nfs4_init_client_minor_version(clp);
229 	if (error < 0)
230 		goto error;
231 
232 	if (!nfs4_has_session(clp))
233 		nfs_mark_client_ready(clp, NFS_CS_READY);
234 
235 	error = nfs4_discover_server_trunking(clp, &old);
236 	if (error < 0)
237 		goto error;
238 	if (clp != old) {
239 		clp->cl_preserve_clid = true;
240 		nfs_put_client(clp);
241 		clp = old;
242 		atomic_inc(&clp->cl_count);
243 	}
244 
245 	return clp;
246 
247 error:
248 	nfs_mark_client_ready(clp, error);
249 	nfs_put_client(clp);
250 	dprintk("<-- nfs4_init_client() = xerror %d\n", error);
251 	return ERR_PTR(error);
252 }
253 
254 /*
255  * SETCLIENTID just did a callback update with the callback ident in
256  * "drop," but server trunking discovery claims "drop" and "keep" are
257  * actually the same server.  Swap the callback IDs so that "keep"
258  * will continue to use the callback ident the server now knows about,
259  * and so that "keep"'s original callback ident is destroyed when
260  * "drop" is freed.
261  */
262 static void nfs4_swap_callback_idents(struct nfs_client *keep,
263 				      struct nfs_client *drop)
264 {
265 	struct nfs_net *nn = net_generic(keep->cl_net, nfs_net_id);
266 	unsigned int save = keep->cl_cb_ident;
267 
268 	if (keep->cl_cb_ident == drop->cl_cb_ident)
269 		return;
270 
271 	dprintk("%s: keeping callback ident %u and dropping ident %u\n",
272 		__func__, keep->cl_cb_ident, drop->cl_cb_ident);
273 
274 	spin_lock(&nn->nfs_client_lock);
275 
276 	idr_replace(&nn->cb_ident_idr, keep, drop->cl_cb_ident);
277 	keep->cl_cb_ident = drop->cl_cb_ident;
278 
279 	idr_replace(&nn->cb_ident_idr, drop, save);
280 	drop->cl_cb_ident = save;
281 
282 	spin_unlock(&nn->nfs_client_lock);
283 }
284 
285 /**
286  * nfs40_walk_client_list - Find server that recognizes a client ID
287  *
288  * @new: nfs_client with client ID to test
289  * @result: OUT: found nfs_client, or new
290  * @cred: credential to use for trunking test
291  *
292  * Returns zero, a negative errno, or a negative NFS4ERR status.
293  * If zero is returned, an nfs_client pointer is planted in "result."
294  *
295  * NB: nfs40_walk_client_list() relies on the new nfs_client being
296  *     the last nfs_client on the list.
297  */
298 int nfs40_walk_client_list(struct nfs_client *new,
299 			   struct nfs_client **result,
300 			   struct rpc_cred *cred)
301 {
302 	struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
303 	struct nfs_client *pos, *n, *prev = NULL;
304 	struct nfs4_setclientid_res clid = {
305 		.clientid	= new->cl_clientid,
306 		.confirm	= new->cl_confirm,
307 	};
308 	int status;
309 
310 	spin_lock(&nn->nfs_client_lock);
311 	list_for_each_entry_safe(pos, n, &nn->nfs_client_list, cl_share_link) {
312 		/* If "pos" isn't marked ready, we can't trust the
313 		 * remaining fields in "pos" */
314 		if (pos->cl_cons_state < NFS_CS_READY)
315 			continue;
316 
317 		if (pos->rpc_ops != new->rpc_ops)
318 			continue;
319 
320 		if (pos->cl_proto != new->cl_proto)
321 			continue;
322 
323 		if (pos->cl_minorversion != new->cl_minorversion)
324 			continue;
325 
326 		if (pos->cl_clientid != new->cl_clientid)
327 			continue;
328 
329 		atomic_inc(&pos->cl_count);
330 		spin_unlock(&nn->nfs_client_lock);
331 
332 		if (prev)
333 			nfs_put_client(prev);
334 
335 		status = nfs4_proc_setclientid_confirm(pos, &clid, cred);
336 		if (status == 0) {
337 			nfs4_swap_callback_idents(pos, new);
338 
339 			nfs_put_client(pos);
340 			*result = pos;
341 			dprintk("NFS: <-- %s using nfs_client = %p ({%d})\n",
342 				__func__, pos, atomic_read(&pos->cl_count));
343 			return 0;
344 		}
345 		if (status != -NFS4ERR_STALE_CLIENTID) {
346 			nfs_put_client(pos);
347 			dprintk("NFS: <-- %s status = %d, no result\n",
348 				__func__, status);
349 			return status;
350 		}
351 
352 		spin_lock(&nn->nfs_client_lock);
353 		prev = pos;
354 	}
355 
356 	/*
357 	 * No matching nfs_client found.  This should be impossible,
358 	 * because the new nfs_client has already been added to
359 	 * nfs_client_list by nfs_get_client().
360 	 *
361 	 * Don't BUG(), since the caller is holding a mutex.
362 	 */
363 	if (prev)
364 		nfs_put_client(prev);
365 	spin_unlock(&nn->nfs_client_lock);
366 	pr_err("NFS: %s Error: no matching nfs_client found\n", __func__);
367 	return -NFS4ERR_STALE_CLIENTID;
368 }
369 
370 #ifdef CONFIG_NFS_V4_1
371 /*
372  * Returns true if the client IDs match
373  */
374 static bool nfs4_match_clientids(struct nfs_client *a, struct nfs_client *b)
375 {
376 	if (a->cl_clientid != b->cl_clientid) {
377 		dprintk("NFS: --> %s client ID %llx does not match %llx\n",
378 			__func__, a->cl_clientid, b->cl_clientid);
379 		return false;
380 	}
381 	dprintk("NFS: --> %s client ID %llx matches %llx\n",
382 		__func__, a->cl_clientid, b->cl_clientid);
383 	return true;
384 }
385 
386 /*
387  * Returns true if the server owners match
388  */
389 static bool
390 nfs4_match_serverowners(struct nfs_client *a, struct nfs_client *b)
391 {
392 	struct nfs41_server_owner *o1 = a->cl_serverowner;
393 	struct nfs41_server_owner *o2 = b->cl_serverowner;
394 
395 	if (o1->minor_id != o2->minor_id) {
396 		dprintk("NFS: --> %s server owner minor IDs do not match\n",
397 			__func__);
398 		return false;
399 	}
400 
401 	if (o1->major_id_sz != o2->major_id_sz)
402 		goto out_major_mismatch;
403 	if (memcmp(o1->major_id, o2->major_id, o1->major_id_sz) != 0)
404 		goto out_major_mismatch;
405 
406 	dprintk("NFS: --> %s server owners match\n", __func__);
407 	return true;
408 
409 out_major_mismatch:
410 	dprintk("NFS: --> %s server owner major IDs do not match\n",
411 		__func__);
412 	return false;
413 }
414 
415 /**
416  * nfs41_walk_client_list - Find nfs_client that matches a client/server owner
417  *
418  * @new: nfs_client with client ID to test
419  * @result: OUT: found nfs_client, or new
420  * @cred: credential to use for trunking test
421  *
422  * Returns zero, a negative errno, or a negative NFS4ERR status.
423  * If zero is returned, an nfs_client pointer is planted in "result."
424  *
425  * NB: nfs41_walk_client_list() relies on the new nfs_client being
426  *     the last nfs_client on the list.
427  */
428 int nfs41_walk_client_list(struct nfs_client *new,
429 			   struct nfs_client **result,
430 			   struct rpc_cred *cred)
431 {
432 	struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
433 	struct nfs_client *pos, *n, *prev = NULL;
434 	int error;
435 
436 	spin_lock(&nn->nfs_client_lock);
437 	list_for_each_entry_safe(pos, n, &nn->nfs_client_list, cl_share_link) {
438 		/* If "pos" isn't marked ready, we can't trust the
439 		 * remaining fields in "pos", especially the client
440 		 * ID and serverowner fields.  Wait for CREATE_SESSION
441 		 * to finish. */
442 		if (pos->cl_cons_state < NFS_CS_READY) {
443 			atomic_inc(&pos->cl_count);
444 			spin_unlock(&nn->nfs_client_lock);
445 
446 			if (prev)
447 				nfs_put_client(prev);
448 			prev = pos;
449 
450 			error = nfs_wait_client_init_complete(pos);
451 			if (error < 0) {
452 				nfs_put_client(pos);
453 				spin_lock(&nn->nfs_client_lock);
454 				continue;
455 			}
456 
457 			spin_lock(&nn->nfs_client_lock);
458 		}
459 
460 		if (pos->rpc_ops != new->rpc_ops)
461 			continue;
462 
463 		if (pos->cl_proto != new->cl_proto)
464 			continue;
465 
466 		if (pos->cl_minorversion != new->cl_minorversion)
467 			continue;
468 
469 		if (!nfs4_match_clientids(pos, new))
470 			continue;
471 
472 		if (!nfs4_match_serverowners(pos, new))
473 			continue;
474 
475 		spin_unlock(&nn->nfs_client_lock);
476 		dprintk("NFS: <-- %s using nfs_client = %p ({%d})\n",
477 			__func__, pos, atomic_read(&pos->cl_count));
478 
479 		*result = pos;
480 		return 0;
481 	}
482 
483 	/*
484 	 * No matching nfs_client found.  This should be impossible,
485 	 * because the new nfs_client has already been added to
486 	 * nfs_client_list by nfs_get_client().
487 	 *
488 	 * Don't BUG(), since the caller is holding a mutex.
489 	 */
490 	spin_unlock(&nn->nfs_client_lock);
491 	pr_err("NFS: %s Error: no matching nfs_client found\n", __func__);
492 	return -NFS4ERR_STALE_CLIENTID;
493 }
494 #endif	/* CONFIG_NFS_V4_1 */
495 
496 static void nfs4_destroy_server(struct nfs_server *server)
497 {
498 	nfs_server_return_all_delegations(server);
499 	unset_pnfs_layoutdriver(server);
500 	nfs4_purge_state_owners(server);
501 }
502 
503 /*
504  * NFSv4.0 callback thread helper
505  *
506  * Find a client by callback identifier
507  */
508 struct nfs_client *
509 nfs4_find_client_ident(struct net *net, int cb_ident)
510 {
511 	struct nfs_client *clp;
512 	struct nfs_net *nn = net_generic(net, nfs_net_id);
513 
514 	spin_lock(&nn->nfs_client_lock);
515 	clp = idr_find(&nn->cb_ident_idr, cb_ident);
516 	if (clp)
517 		atomic_inc(&clp->cl_count);
518 	spin_unlock(&nn->nfs_client_lock);
519 	return clp;
520 }
521 
522 #if defined(CONFIG_NFS_V4_1)
523 /* Common match routine for v4.0 and v4.1 callback services */
524 static bool nfs4_cb_match_client(const struct sockaddr *addr,
525 		struct nfs_client *clp, u32 minorversion)
526 {
527 	struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
528 
529 	/* Don't match clients that failed to initialise */
530 	if (!(clp->cl_cons_state == NFS_CS_READY ||
531 	    clp->cl_cons_state == NFS_CS_SESSION_INITING))
532 		return false;
533 
534 	smp_rmb();
535 
536 	/* Match the version and minorversion */
537 	if (clp->rpc_ops->version != 4 ||
538 	    clp->cl_minorversion != minorversion)
539 		return false;
540 
541 	/* Match only the IP address, not the port number */
542 	if (!nfs_sockaddr_match_ipaddr(addr, clap))
543 		return false;
544 
545 	return true;
546 }
547 
548 /*
549  * NFSv4.1 callback thread helper
550  * For CB_COMPOUND calls, find a client by IP address, protocol version,
551  * minorversion, and sessionID
552  *
553  * Returns NULL if no such client
554  */
555 struct nfs_client *
556 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
557 			   struct nfs4_sessionid *sid)
558 {
559 	struct nfs_client *clp;
560 	struct nfs_net *nn = net_generic(net, nfs_net_id);
561 
562 	spin_lock(&nn->nfs_client_lock);
563 	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
564 		if (nfs4_cb_match_client(addr, clp, 1) == false)
565 			continue;
566 
567 		if (!nfs4_has_session(clp))
568 			continue;
569 
570 		/* Match sessionid*/
571 		if (memcmp(clp->cl_session->sess_id.data,
572 		    sid->data, NFS4_MAX_SESSIONID_LEN) != 0)
573 			continue;
574 
575 		atomic_inc(&clp->cl_count);
576 		spin_unlock(&nn->nfs_client_lock);
577 		return clp;
578 	}
579 	spin_unlock(&nn->nfs_client_lock);
580 	return NULL;
581 }
582 
583 #else /* CONFIG_NFS_V4_1 */
584 
585 struct nfs_client *
586 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
587 			   struct nfs4_sessionid *sid)
588 {
589 	return NULL;
590 }
591 #endif /* CONFIG_NFS_V4_1 */
592 
593 /*
594  * Set up an NFS4 client
595  */
596 static int nfs4_set_client(struct nfs_server *server,
597 		const char *hostname,
598 		const struct sockaddr *addr,
599 		const size_t addrlen,
600 		const char *ip_addr,
601 		rpc_authflavor_t authflavour,
602 		int proto, const struct rpc_timeout *timeparms,
603 		u32 minorversion, struct net *net)
604 {
605 	struct nfs_client_initdata cl_init = {
606 		.hostname = hostname,
607 		.addr = addr,
608 		.addrlen = addrlen,
609 		.nfs_mod = &nfs_v4,
610 		.proto = proto,
611 		.minorversion = minorversion,
612 		.net = net,
613 	};
614 	struct nfs_client *clp;
615 	int error;
616 
617 	dprintk("--> nfs4_set_client()\n");
618 
619 	if (server->flags & NFS_MOUNT_NORESVPORT)
620 		set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
621 
622 	/* Allocate or find a client reference we can use */
623 	clp = nfs_get_client(&cl_init, timeparms, ip_addr, authflavour);
624 	if (IS_ERR(clp)) {
625 		error = PTR_ERR(clp);
626 		goto error;
627 	}
628 
629 	/*
630 	 * Query for the lease time on clientid setup or renewal
631 	 *
632 	 * Note that this will be set on nfs_clients that were created
633 	 * only for the DS role and did not set this bit, but now will
634 	 * serve a dual role.
635 	 */
636 	set_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state);
637 
638 	server->nfs_client = clp;
639 	dprintk("<-- nfs4_set_client() = 0 [new %p]\n", clp);
640 	return 0;
641 error:
642 	dprintk("<-- nfs4_set_client() = xerror %d\n", error);
643 	return error;
644 }
645 
646 /*
647  * Set up a pNFS Data Server client.
648  *
649  * Return any existing nfs_client that matches server address,port,version
650  * and minorversion.
651  *
652  * For a new nfs_client, use a soft mount (default), a low retrans and a
653  * low timeout interval so that if a connection is lost, we retry through
654  * the MDS.
655  */
656 struct nfs_client *nfs4_set_ds_client(struct nfs_client* mds_clp,
657 		const struct sockaddr *ds_addr, int ds_addrlen,
658 		int ds_proto, unsigned int ds_timeo, unsigned int ds_retrans)
659 {
660 	struct nfs_client_initdata cl_init = {
661 		.addr = ds_addr,
662 		.addrlen = ds_addrlen,
663 		.nfs_mod = &nfs_v4,
664 		.proto = ds_proto,
665 		.minorversion = mds_clp->cl_minorversion,
666 		.net = mds_clp->cl_net,
667 	};
668 	struct rpc_timeout ds_timeout;
669 	struct nfs_client *clp;
670 
671 	/*
672 	 * Set an authflavor equual to the MDS value. Use the MDS nfs_client
673 	 * cl_ipaddr so as to use the same EXCHANGE_ID co_ownerid as the MDS
674 	 * (section 13.1 RFC 5661).
675 	 */
676 	nfs_init_timeout_values(&ds_timeout, ds_proto, ds_timeo, ds_retrans);
677 	clp = nfs_get_client(&cl_init, &ds_timeout, mds_clp->cl_ipaddr,
678 			     mds_clp->cl_rpcclient->cl_auth->au_flavor);
679 
680 	dprintk("<-- %s %p\n", __func__, clp);
681 	return clp;
682 }
683 EXPORT_SYMBOL_GPL(nfs4_set_ds_client);
684 
685 /*
686  * Session has been established, and the client marked ready.
687  * Set the mount rsize and wsize with negotiated fore channel
688  * attributes which will be bound checked in nfs_server_set_fsinfo.
689  */
690 static void nfs4_session_set_rwsize(struct nfs_server *server)
691 {
692 #ifdef CONFIG_NFS_V4_1
693 	struct nfs4_session *sess;
694 	u32 server_resp_sz;
695 	u32 server_rqst_sz;
696 
697 	if (!nfs4_has_session(server->nfs_client))
698 		return;
699 	sess = server->nfs_client->cl_session;
700 	server_resp_sz = sess->fc_attrs.max_resp_sz - nfs41_maxread_overhead;
701 	server_rqst_sz = sess->fc_attrs.max_rqst_sz - nfs41_maxwrite_overhead;
702 
703 	if (server->rsize > server_resp_sz)
704 		server->rsize = server_resp_sz;
705 	if (server->wsize > server_rqst_sz)
706 		server->wsize = server_rqst_sz;
707 #endif /* CONFIG_NFS_V4_1 */
708 }
709 
710 static int nfs4_server_common_setup(struct nfs_server *server,
711 		struct nfs_fh *mntfh)
712 {
713 	struct nfs_fattr *fattr;
714 	int error;
715 
716 	BUG_ON(!server->nfs_client);
717 	BUG_ON(!server->nfs_client->rpc_ops);
718 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
719 
720 	/* data servers support only a subset of NFSv4.1 */
721 	if (is_ds_only_client(server->nfs_client))
722 		return -EPROTONOSUPPORT;
723 
724 	fattr = nfs_alloc_fattr();
725 	if (fattr == NULL)
726 		return -ENOMEM;
727 
728 	/* We must ensure the session is initialised first */
729 	error = nfs4_init_session(server);
730 	if (error < 0)
731 		goto out;
732 
733 	/* Probe the root fh to retrieve its FSID and filehandle */
734 	error = nfs4_get_rootfh(server, mntfh);
735 	if (error < 0)
736 		goto out;
737 
738 	dprintk("Server FSID: %llx:%llx\n",
739 			(unsigned long long) server->fsid.major,
740 			(unsigned long long) server->fsid.minor);
741 	dprintk("Mount FH: %d\n", mntfh->size);
742 
743 	nfs4_session_set_rwsize(server);
744 
745 	error = nfs_probe_fsinfo(server, mntfh, fattr);
746 	if (error < 0)
747 		goto out;
748 
749 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
750 		server->namelen = NFS4_MAXNAMLEN;
751 
752 	nfs_server_insert_lists(server);
753 	server->mount_time = jiffies;
754 	server->destroy = nfs4_destroy_server;
755 out:
756 	nfs_free_fattr(fattr);
757 	return error;
758 }
759 
760 /*
761  * Create a version 4 volume record
762  */
763 static int nfs4_init_server(struct nfs_server *server,
764 		const struct nfs_parsed_mount_data *data)
765 {
766 	struct rpc_timeout timeparms;
767 	int error;
768 
769 	dprintk("--> nfs4_init_server()\n");
770 
771 	nfs_init_timeout_values(&timeparms, data->nfs_server.protocol,
772 			data->timeo, data->retrans);
773 
774 	/* Initialise the client representation from the mount data */
775 	server->flags = data->flags;
776 	server->caps |= NFS_CAP_ATOMIC_OPEN|NFS_CAP_CHANGE_ATTR|NFS_CAP_POSIX_LOCK;
777 	if (!(data->flags & NFS_MOUNT_NORDIRPLUS))
778 			server->caps |= NFS_CAP_READDIRPLUS;
779 	server->options = data->options;
780 
781 	/* Get a client record */
782 	error = nfs4_set_client(server,
783 			data->nfs_server.hostname,
784 			(const struct sockaddr *)&data->nfs_server.address,
785 			data->nfs_server.addrlen,
786 			data->client_address,
787 			data->auth_flavors[0],
788 			data->nfs_server.protocol,
789 			&timeparms,
790 			data->minorversion,
791 			data->net);
792 	if (error < 0)
793 		goto error;
794 
795 	/*
796 	 * Don't use NFS uid/gid mapping if we're using AUTH_SYS or lower
797 	 * authentication.
798 	 */
799 	if (nfs4_disable_idmapping && data->auth_flavors[0] == RPC_AUTH_UNIX)
800 		server->caps |= NFS_CAP_UIDGID_NOMAP;
801 
802 	if (data->rsize)
803 		server->rsize = nfs_block_size(data->rsize, NULL);
804 	if (data->wsize)
805 		server->wsize = nfs_block_size(data->wsize, NULL);
806 
807 	server->acregmin = data->acregmin * HZ;
808 	server->acregmax = data->acregmax * HZ;
809 	server->acdirmin = data->acdirmin * HZ;
810 	server->acdirmax = data->acdirmax * HZ;
811 
812 	server->port = data->nfs_server.port;
813 
814 	error = nfs_init_server_rpcclient(server, &timeparms, data->auth_flavors[0]);
815 
816 error:
817 	/* Done */
818 	dprintk("<-- nfs4_init_server() = %d\n", error);
819 	return error;
820 }
821 
822 /*
823  * Create a version 4 volume record
824  * - keyed on server and FSID
825  */
826 /*struct nfs_server *nfs4_create_server(const struct nfs_parsed_mount_data *data,
827 				      struct nfs_fh *mntfh)*/
828 struct nfs_server *nfs4_create_server(struct nfs_mount_info *mount_info,
829 				      struct nfs_subversion *nfs_mod)
830 {
831 	struct nfs_server *server;
832 	int error;
833 
834 	dprintk("--> nfs4_create_server()\n");
835 
836 	server = nfs_alloc_server();
837 	if (!server)
838 		return ERR_PTR(-ENOMEM);
839 
840 	/* set up the general RPC client */
841 	error = nfs4_init_server(server, mount_info->parsed);
842 	if (error < 0)
843 		goto error;
844 
845 	error = nfs4_server_common_setup(server, mount_info->mntfh);
846 	if (error < 0)
847 		goto error;
848 
849 	dprintk("<-- nfs4_create_server() = %p\n", server);
850 	return server;
851 
852 error:
853 	nfs_free_server(server);
854 	dprintk("<-- nfs4_create_server() = error %d\n", error);
855 	return ERR_PTR(error);
856 }
857 
858 /*
859  * Create an NFS4 referral server record
860  */
861 struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data,
862 					       struct nfs_fh *mntfh)
863 {
864 	struct nfs_client *parent_client;
865 	struct nfs_server *server, *parent_server;
866 	int error;
867 
868 	dprintk("--> nfs4_create_referral_server()\n");
869 
870 	server = nfs_alloc_server();
871 	if (!server)
872 		return ERR_PTR(-ENOMEM);
873 
874 	parent_server = NFS_SB(data->sb);
875 	parent_client = parent_server->nfs_client;
876 
877 	/* Initialise the client representation from the parent server */
878 	nfs_server_copy_userdata(server, parent_server);
879 	server->caps |= NFS_CAP_ATOMIC_OPEN|NFS_CAP_CHANGE_ATTR;
880 
881 	/* Get a client representation.
882 	 * Note: NFSv4 always uses TCP, */
883 	error = nfs4_set_client(server, data->hostname,
884 				data->addr,
885 				data->addrlen,
886 				parent_client->cl_ipaddr,
887 				data->authflavor,
888 				rpc_protocol(parent_server->client),
889 				parent_server->client->cl_timeout,
890 				parent_client->cl_mvops->minor_version,
891 				parent_client->cl_net);
892 	if (error < 0)
893 		goto error;
894 
895 	error = nfs_init_server_rpcclient(server, parent_server->client->cl_timeout, data->authflavor);
896 	if (error < 0)
897 		goto error;
898 
899 	error = nfs4_server_common_setup(server, mntfh);
900 	if (error < 0)
901 		goto error;
902 
903 	dprintk("<-- nfs_create_referral_server() = %p\n", server);
904 	return server;
905 
906 error:
907 	nfs_free_server(server);
908 	dprintk("<-- nfs4_create_referral_server() = error %d\n", error);
909 	return ERR_PTR(error);
910 }
911