xref: /linux/fs/nfs/nfs4client.c (revision fd639726bf15fca8ee1a00dce8e0096d0ad9bd18)
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_mount.h>
8 #include <linux/sunrpc/addr.h>
9 #include <linux/sunrpc/auth.h>
10 #include <linux/sunrpc/xprt.h>
11 #include <linux/sunrpc/bc_xprt.h>
12 #include <linux/sunrpc/rpc_pipe_fs.h>
13 #include "internal.h"
14 #include "callback.h"
15 #include "delegation.h"
16 #include "nfs4session.h"
17 #include "nfs4idmap.h"
18 #include "pnfs.h"
19 #include "netns.h"
20 
21 #define NFSDBG_FACILITY		NFSDBG_CLIENT
22 
23 /*
24  * Get a unique NFSv4.0 callback identifier which will be used
25  * by the V4.0 callback service to lookup the nfs_client struct
26  */
27 static int nfs_get_cb_ident_idr(struct nfs_client *clp, int minorversion)
28 {
29 	int ret = 0;
30 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
31 
32 	if (clp->rpc_ops->version != 4 || minorversion != 0)
33 		return ret;
34 	idr_preload(GFP_KERNEL);
35 	spin_lock(&nn->nfs_client_lock);
36 	ret = idr_alloc(&nn->cb_ident_idr, clp, 1, 0, GFP_NOWAIT);
37 	if (ret >= 0)
38 		clp->cl_cb_ident = ret;
39 	spin_unlock(&nn->nfs_client_lock);
40 	idr_preload_end();
41 	return ret < 0 ? ret : 0;
42 }
43 
44 #ifdef CONFIG_NFS_V4_1
45 /**
46  * Per auth flavor data server rpc clients
47  */
48 struct nfs4_ds_server {
49 	struct list_head	list;   /* ds_clp->cl_ds_clients */
50 	struct rpc_clnt		*rpc_clnt;
51 };
52 
53 /**
54  * Common lookup case for DS I/O
55  */
56 static struct nfs4_ds_server *
57 nfs4_find_ds_client(struct nfs_client *ds_clp, rpc_authflavor_t flavor)
58 {
59 	struct nfs4_ds_server *dss;
60 
61 	rcu_read_lock();
62 	list_for_each_entry_rcu(dss, &ds_clp->cl_ds_clients, list) {
63 		if (dss->rpc_clnt->cl_auth->au_flavor != flavor)
64 			continue;
65 		goto out;
66 	}
67 	dss = NULL;
68 out:
69 	rcu_read_unlock();
70 	return dss;
71 }
72 
73 static struct nfs4_ds_server *
74 nfs4_add_ds_client(struct nfs_client *ds_clp, rpc_authflavor_t flavor,
75 			   struct nfs4_ds_server *new)
76 {
77 	struct nfs4_ds_server *dss;
78 
79 	spin_lock(&ds_clp->cl_lock);
80 	list_for_each_entry(dss, &ds_clp->cl_ds_clients, list) {
81 		if (dss->rpc_clnt->cl_auth->au_flavor != flavor)
82 			continue;
83 		goto out;
84 	}
85 	if (new)
86 		list_add_rcu(&new->list, &ds_clp->cl_ds_clients);
87 	dss = new;
88 out:
89 	spin_unlock(&ds_clp->cl_lock); /* need some lock to protect list */
90 	return dss;
91 }
92 
93 static struct nfs4_ds_server *
94 nfs4_alloc_ds_server(struct nfs_client *ds_clp, rpc_authflavor_t flavor)
95 {
96 	struct nfs4_ds_server *dss;
97 
98 	dss = kmalloc(sizeof(*dss), GFP_NOFS);
99 	if (dss == NULL)
100 		return ERR_PTR(-ENOMEM);
101 
102 	dss->rpc_clnt = rpc_clone_client_set_auth(ds_clp->cl_rpcclient, flavor);
103 	if (IS_ERR(dss->rpc_clnt)) {
104 		int err = PTR_ERR(dss->rpc_clnt);
105 		kfree (dss);
106 		return ERR_PTR(err);
107 	}
108 	INIT_LIST_HEAD(&dss->list);
109 
110 	return dss;
111 }
112 
113 static void
114 nfs4_free_ds_server(struct nfs4_ds_server *dss)
115 {
116 	rpc_release_client(dss->rpc_clnt);
117 	kfree(dss);
118 }
119 
120 /**
121 * Find or create a DS rpc client with th MDS server rpc client auth flavor
122 * in the nfs_client cl_ds_clients list.
123 */
124 struct rpc_clnt *
125 nfs4_find_or_create_ds_client(struct nfs_client *ds_clp, struct inode *inode)
126 {
127 	struct nfs4_ds_server *dss, *new;
128 	rpc_authflavor_t flavor = NFS_SERVER(inode)->client->cl_auth->au_flavor;
129 
130 	dss = nfs4_find_ds_client(ds_clp, flavor);
131 	if (dss != NULL)
132 		goto out;
133 	new = nfs4_alloc_ds_server(ds_clp, flavor);
134 	if (IS_ERR(new))
135 		return ERR_CAST(new);
136 	dss = nfs4_add_ds_client(ds_clp, flavor, new);
137 	if (dss != new)
138 		nfs4_free_ds_server(new);
139 out:
140 	return dss->rpc_clnt;
141 }
142 EXPORT_SYMBOL_GPL(nfs4_find_or_create_ds_client);
143 
144 static void
145 nfs4_shutdown_ds_clients(struct nfs_client *clp)
146 {
147 	struct nfs4_ds_server *dss;
148 	LIST_HEAD(shutdown_list);
149 
150 	while (!list_empty(&clp->cl_ds_clients)) {
151 		dss = list_entry(clp->cl_ds_clients.next,
152 					struct nfs4_ds_server, list);
153 		list_del(&dss->list);
154 		rpc_shutdown_client(dss->rpc_clnt);
155 		kfree (dss);
156 	}
157 }
158 
159 void nfs41_shutdown_client(struct nfs_client *clp)
160 {
161 	if (nfs4_has_session(clp)) {
162 		nfs4_shutdown_ds_clients(clp);
163 		nfs4_destroy_session(clp->cl_session);
164 		nfs4_destroy_clientid(clp);
165 	}
166 
167 }
168 #endif	/* CONFIG_NFS_V4_1 */
169 
170 void nfs40_shutdown_client(struct nfs_client *clp)
171 {
172 	if (clp->cl_slot_tbl) {
173 		nfs4_shutdown_slot_table(clp->cl_slot_tbl);
174 		kfree(clp->cl_slot_tbl);
175 	}
176 }
177 
178 struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *cl_init)
179 {
180 	int err;
181 	struct nfs_client *clp = nfs_alloc_client(cl_init);
182 	if (IS_ERR(clp))
183 		return clp;
184 
185 	err = nfs_get_cb_ident_idr(clp, cl_init->minorversion);
186 	if (err)
187 		goto error;
188 
189 	if (cl_init->minorversion > NFS4_MAX_MINOR_VERSION) {
190 		err = -EINVAL;
191 		goto error;
192 	}
193 
194 	spin_lock_init(&clp->cl_lock);
195 	INIT_DELAYED_WORK(&clp->cl_renewd, nfs4_renew_state);
196 	INIT_LIST_HEAD(&clp->cl_ds_clients);
197 	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
198 	clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
199 	clp->cl_minorversion = cl_init->minorversion;
200 	clp->cl_mvops = nfs_v4_minor_ops[cl_init->minorversion];
201 	clp->cl_mig_gen = 1;
202 #if IS_ENABLED(CONFIG_NFS_V4_1)
203 	init_waitqueue_head(&clp->cl_lock_waitq);
204 #endif
205 	return clp;
206 
207 error:
208 	nfs_free_client(clp);
209 	return ERR_PTR(err);
210 }
211 
212 /*
213  * Destroy the NFS4 callback service
214  */
215 static void nfs4_destroy_callback(struct nfs_client *clp)
216 {
217 	if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
218 		nfs_callback_down(clp->cl_mvops->minor_version, clp->cl_net);
219 }
220 
221 static void nfs4_shutdown_client(struct nfs_client *clp)
222 {
223 	if (__test_and_clear_bit(NFS_CS_RENEWD, &clp->cl_res_state))
224 		nfs4_kill_renewd(clp);
225 	clp->cl_mvops->shutdown_client(clp);
226 	nfs4_destroy_callback(clp);
227 	if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state))
228 		nfs_idmap_delete(clp);
229 
230 	rpc_destroy_wait_queue(&clp->cl_rpcwaitq);
231 	kfree(clp->cl_serverowner);
232 	kfree(clp->cl_serverscope);
233 	kfree(clp->cl_implid);
234 	kfree(clp->cl_owner_id);
235 }
236 
237 void nfs4_free_client(struct nfs_client *clp)
238 {
239 	nfs4_shutdown_client(clp);
240 	nfs_free_client(clp);
241 }
242 
243 /*
244  * Initialize the NFS4 callback service
245  */
246 static int nfs4_init_callback(struct nfs_client *clp)
247 {
248 	struct rpc_xprt *xprt;
249 	int error;
250 
251 	xprt = rcu_dereference_raw(clp->cl_rpcclient->cl_xprt);
252 
253 	if (nfs4_has_session(clp)) {
254 		error = xprt_setup_backchannel(xprt, NFS41_BC_MIN_CALLBACKS);
255 		if (error < 0)
256 			return error;
257 	}
258 
259 	error = nfs_callback_up(clp->cl_mvops->minor_version, xprt);
260 	if (error < 0) {
261 		dprintk("%s: failed to start callback. Error = %d\n",
262 			__func__, error);
263 		return error;
264 	}
265 	__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
266 
267 	return 0;
268 }
269 
270 /**
271  * nfs40_init_client - nfs_client initialization tasks for NFSv4.0
272  * @clp - nfs_client to initialize
273  *
274  * Returns zero on success, or a negative errno if some error occurred.
275  */
276 int nfs40_init_client(struct nfs_client *clp)
277 {
278 	struct nfs4_slot_table *tbl;
279 	int ret;
280 
281 	tbl = kzalloc(sizeof(*tbl), GFP_NOFS);
282 	if (tbl == NULL)
283 		return -ENOMEM;
284 
285 	ret = nfs4_setup_slot_table(tbl, NFS4_MAX_SLOT_TABLE,
286 					"NFSv4.0 transport Slot table");
287 	if (ret) {
288 		kfree(tbl);
289 		return ret;
290 	}
291 
292 	clp->cl_slot_tbl = tbl;
293 	return 0;
294 }
295 
296 #if defined(CONFIG_NFS_V4_1)
297 
298 /**
299  * nfs41_init_client - nfs_client initialization tasks for NFSv4.1+
300  * @clp - nfs_client to initialize
301  *
302  * Returns zero on success, or a negative errno if some error occurred.
303  */
304 int nfs41_init_client(struct nfs_client *clp)
305 {
306 	struct nfs4_session *session = NULL;
307 
308 	/*
309 	 * Create the session and mark it expired.
310 	 * When a SEQUENCE operation encounters the expired session
311 	 * it will do session recovery to initialize it.
312 	 */
313 	session = nfs4_alloc_session(clp);
314 	if (!session)
315 		return -ENOMEM;
316 
317 	clp->cl_session = session;
318 
319 	/*
320 	 * The create session reply races with the server back
321 	 * channel probe. Mark the client NFS_CS_SESSION_INITING
322 	 * so that the client back channel can find the
323 	 * nfs_client struct
324 	 */
325 	nfs_mark_client_ready(clp, NFS_CS_SESSION_INITING);
326 	return 0;
327 }
328 
329 #endif	/* CONFIG_NFS_V4_1 */
330 
331 /*
332  * Initialize the minor version specific parts of an NFS4 client record
333  */
334 static int nfs4_init_client_minor_version(struct nfs_client *clp)
335 {
336 	int ret;
337 
338 	ret = clp->cl_mvops->init_client(clp);
339 	if (ret)
340 		return ret;
341 	return nfs4_init_callback(clp);
342 }
343 
344 /**
345  * nfs4_init_client - Initialise an NFS4 client record
346  *
347  * @clp: nfs_client to initialise
348  * @timeparms: timeout parameters for underlying RPC transport
349  * @ip_addr: callback IP address in presentation format
350  * @authflavor: authentication flavor for underlying RPC transport
351  *
352  * Returns pointer to an NFS client, or an ERR_PTR value.
353  */
354 struct nfs_client *nfs4_init_client(struct nfs_client *clp,
355 				    const struct nfs_client_initdata *cl_init)
356 {
357 	char buf[INET6_ADDRSTRLEN + 1];
358 	const char *ip_addr = cl_init->ip_addr;
359 	struct nfs_client *old;
360 	int error;
361 
362 	if (clp->cl_cons_state == NFS_CS_READY)
363 		/* the client is initialised already */
364 		return clp;
365 
366 	/* Check NFS protocol revision and initialize RPC op vector */
367 	clp->rpc_ops = &nfs_v4_clientops;
368 
369 	if (clp->cl_minorversion != 0)
370 		__set_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags);
371 	__set_bit(NFS_CS_DISCRTRY, &clp->cl_flags);
372 	__set_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags);
373 
374 	error = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_GSS_KRB5I);
375 	if (error == -EINVAL)
376 		error = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_UNIX);
377 	if (error < 0)
378 		goto error;
379 
380 	/* If no clientaddr= option was specified, find a usable cb address */
381 	if (ip_addr == NULL) {
382 		struct sockaddr_storage cb_addr;
383 		struct sockaddr *sap = (struct sockaddr *)&cb_addr;
384 
385 		error = rpc_localaddr(clp->cl_rpcclient, sap, sizeof(cb_addr));
386 		if (error < 0)
387 			goto error;
388 		error = rpc_ntop(sap, buf, sizeof(buf));
389 		if (error < 0)
390 			goto error;
391 		ip_addr = (const char *)buf;
392 	}
393 	strlcpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr));
394 
395 	error = nfs_idmap_new(clp);
396 	if (error < 0) {
397 		dprintk("%s: failed to create idmapper. Error = %d\n",
398 			__func__, error);
399 		goto error;
400 	}
401 	__set_bit(NFS_CS_IDMAP, &clp->cl_res_state);
402 
403 	error = nfs4_init_client_minor_version(clp);
404 	if (error < 0)
405 		goto error;
406 
407 	if (!nfs4_has_session(clp))
408 		nfs_mark_client_ready(clp, NFS_CS_READY);
409 
410 	error = nfs4_discover_server_trunking(clp, &old);
411 	if (error < 0)
412 		goto error;
413 
414 	if (clp != old)
415 		clp->cl_preserve_clid = true;
416 	nfs_put_client(clp);
417 	clear_bit(NFS_CS_TSM_POSSIBLE, &clp->cl_flags);
418 	return old;
419 
420 error:
421 	nfs_mark_client_ready(clp, error);
422 	nfs_put_client(clp);
423 	return ERR_PTR(error);
424 }
425 
426 /*
427  * SETCLIENTID just did a callback update with the callback ident in
428  * "drop," but server trunking discovery claims "drop" and "keep" are
429  * actually the same server.  Swap the callback IDs so that "keep"
430  * will continue to use the callback ident the server now knows about,
431  * and so that "keep"'s original callback ident is destroyed when
432  * "drop" is freed.
433  */
434 static void nfs4_swap_callback_idents(struct nfs_client *keep,
435 				      struct nfs_client *drop)
436 {
437 	struct nfs_net *nn = net_generic(keep->cl_net, nfs_net_id);
438 	unsigned int save = keep->cl_cb_ident;
439 
440 	if (keep->cl_cb_ident == drop->cl_cb_ident)
441 		return;
442 
443 	dprintk("%s: keeping callback ident %u and dropping ident %u\n",
444 		__func__, keep->cl_cb_ident, drop->cl_cb_ident);
445 
446 	spin_lock(&nn->nfs_client_lock);
447 
448 	idr_replace(&nn->cb_ident_idr, keep, drop->cl_cb_ident);
449 	keep->cl_cb_ident = drop->cl_cb_ident;
450 
451 	idr_replace(&nn->cb_ident_idr, drop, save);
452 	drop->cl_cb_ident = save;
453 
454 	spin_unlock(&nn->nfs_client_lock);
455 }
456 
457 static bool nfs4_match_client_owner_id(const struct nfs_client *clp1,
458 		const struct nfs_client *clp2)
459 {
460 	if (clp1->cl_owner_id == NULL || clp2->cl_owner_id == NULL)
461 		return true;
462 	return strcmp(clp1->cl_owner_id, clp2->cl_owner_id) == 0;
463 }
464 
465 static bool nfs4_same_verifier(nfs4_verifier *v1, nfs4_verifier *v2)
466 {
467 	return memcmp(v1->data, v2->data, sizeof(v1->data)) == 0;
468 }
469 
470 static int nfs4_match_client(struct nfs_client  *pos,  struct nfs_client *new,
471 			     struct nfs_client **prev, struct nfs_net *nn)
472 {
473 	int status;
474 
475 	if (pos->rpc_ops != new->rpc_ops)
476 		return 1;
477 
478 	if (pos->cl_minorversion != new->cl_minorversion)
479 		return 1;
480 
481 	/* If "pos" isn't marked ready, we can't trust the
482 	 * remaining fields in "pos", especially the client
483 	 * ID and serverowner fields.  Wait for CREATE_SESSION
484 	 * to finish. */
485 	if (pos->cl_cons_state > NFS_CS_READY) {
486 		refcount_inc(&pos->cl_count);
487 		spin_unlock(&nn->nfs_client_lock);
488 
489 		nfs_put_client(*prev);
490 		*prev = pos;
491 
492 		status = nfs_wait_client_init_complete(pos);
493 		spin_lock(&nn->nfs_client_lock);
494 
495 		if (status < 0)
496 			return status;
497 	}
498 
499 	if (pos->cl_cons_state != NFS_CS_READY)
500 		return 1;
501 
502 	if (pos->cl_clientid != new->cl_clientid)
503 		return 1;
504 
505 	/* NFSv4.1 always uses the uniform string, however someone
506 	 * might switch the uniquifier string on us.
507 	 */
508 	if (!nfs4_match_client_owner_id(pos, new))
509 		return 1;
510 
511 	return 0;
512 }
513 
514 /**
515  * nfs40_walk_client_list - Find server that recognizes a client ID
516  *
517  * @new: nfs_client with client ID to test
518  * @result: OUT: found nfs_client, or new
519  * @cred: credential to use for trunking test
520  *
521  * Returns zero, a negative errno, or a negative NFS4ERR status.
522  * If zero is returned, an nfs_client pointer is planted in "result."
523  *
524  * NB: nfs40_walk_client_list() relies on the new nfs_client being
525  *     the last nfs_client on the list.
526  */
527 int nfs40_walk_client_list(struct nfs_client *new,
528 			   struct nfs_client **result,
529 			   struct rpc_cred *cred)
530 {
531 	struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
532 	struct nfs_client *pos, *prev = NULL;
533 	struct nfs4_setclientid_res clid = {
534 		.clientid	= new->cl_clientid,
535 		.confirm	= new->cl_confirm,
536 	};
537 	int status = -NFS4ERR_STALE_CLIENTID;
538 
539 	spin_lock(&nn->nfs_client_lock);
540 	list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
541 
542 		status = nfs4_match_client(pos, new, &prev, nn);
543 		if (status < 0)
544 			goto out_unlock;
545 		if (status != 0)
546 			continue;
547 		/*
548 		 * We just sent a new SETCLIENTID, which should have
549 		 * caused the server to return a new cl_confirm.  So if
550 		 * cl_confirm is the same, then this is a different
551 		 * server that just returned the same cl_confirm by
552 		 * coincidence:
553 		 */
554 		if ((new != pos) && nfs4_same_verifier(&pos->cl_confirm,
555 						       &new->cl_confirm))
556 			continue;
557 		/*
558 		 * But if the cl_confirm's are different, then the only
559 		 * way that a SETCLIENTID_CONFIRM to pos can succeed is
560 		 * if new and pos point to the same server:
561 		 */
562 		refcount_inc(&pos->cl_count);
563 		spin_unlock(&nn->nfs_client_lock);
564 
565 		nfs_put_client(prev);
566 		prev = pos;
567 
568 		status = nfs4_proc_setclientid_confirm(pos, &clid, cred);
569 		switch (status) {
570 		case -NFS4ERR_STALE_CLIENTID:
571 			break;
572 		case 0:
573 			nfs4_swap_callback_idents(pos, new);
574 			pos->cl_confirm = new->cl_confirm;
575 
576 			prev = NULL;
577 			*result = pos;
578 			goto out;
579 		case -ERESTARTSYS:
580 		case -ETIMEDOUT:
581 			/* The callback path may have been inadvertently
582 			 * changed. Schedule recovery!
583 			 */
584 			nfs4_schedule_path_down_recovery(pos);
585 		default:
586 			goto out;
587 		}
588 
589 		spin_lock(&nn->nfs_client_lock);
590 	}
591 out_unlock:
592 	spin_unlock(&nn->nfs_client_lock);
593 
594 	/* No match found. The server lost our clientid */
595 out:
596 	nfs_put_client(prev);
597 	return status;
598 }
599 
600 #ifdef CONFIG_NFS_V4_1
601 /*
602  * Returns true if the server major ids match
603  */
604 static bool
605 nfs4_check_serverowner_major_id(struct nfs41_server_owner *o1,
606 				struct nfs41_server_owner *o2)
607 {
608 	if (o1->major_id_sz != o2->major_id_sz)
609 		return false;
610 	return memcmp(o1->major_id, o2->major_id, o1->major_id_sz) == 0;
611 }
612 
613 /*
614  * Returns true if the server scopes match
615  */
616 static bool
617 nfs4_check_server_scope(struct nfs41_server_scope *s1,
618 			struct nfs41_server_scope *s2)
619 {
620 	if (s1->server_scope_sz != s2->server_scope_sz)
621 		return false;
622 	return memcmp(s1->server_scope, s2->server_scope,
623 					s1->server_scope_sz) == 0;
624 }
625 
626 /**
627  * nfs4_detect_session_trunking - Checks for session trunking.
628  *
629  * Called after a successful EXCHANGE_ID on a multi-addr connection.
630  * Upon success, add the transport.
631  *
632  * @clp:    original mount nfs_client
633  * @res:    result structure from an exchange_id using the original mount
634  *          nfs_client with a new multi_addr transport
635  *
636  * Returns zero on success, otherwise -EINVAL
637  *
638  * Note: since the exchange_id for the new multi_addr transport uses the
639  * same nfs_client from the original mount, the cl_owner_id is reused,
640  * so eir_clientowner is the same.
641  */
642 int nfs4_detect_session_trunking(struct nfs_client *clp,
643 				 struct nfs41_exchange_id_res *res,
644 				 struct rpc_xprt *xprt)
645 {
646 	/* Check eir_clientid */
647 	if (clp->cl_clientid != res->clientid)
648 		goto out_err;
649 
650 	/* Check eir_server_owner so_major_id */
651 	if (!nfs4_check_serverowner_major_id(clp->cl_serverowner,
652 					     res->server_owner))
653 		goto out_err;
654 
655 	/* Check eir_server_owner so_minor_id */
656 	if (clp->cl_serverowner->minor_id != res->server_owner->minor_id)
657 		goto out_err;
658 
659 	/* Check eir_server_scope */
660 	if (!nfs4_check_server_scope(clp->cl_serverscope, res->server_scope))
661 		goto out_err;
662 
663 	pr_info("NFS:  %s: Session trunking succeeded for %s\n",
664 		clp->cl_hostname,
665 		xprt->address_strings[RPC_DISPLAY_ADDR]);
666 
667 	return 0;
668 out_err:
669 	pr_info("NFS:  %s: Session trunking failed for %s\n", clp->cl_hostname,
670 		xprt->address_strings[RPC_DISPLAY_ADDR]);
671 
672 	return -EINVAL;
673 }
674 
675 /**
676  * nfs41_walk_client_list - Find nfs_client that matches a client/server owner
677  *
678  * @new: nfs_client with client ID to test
679  * @result: OUT: found nfs_client, or new
680  * @cred: credential to use for trunking test
681  *
682  * Returns zero, a negative errno, or a negative NFS4ERR status.
683  * If zero is returned, an nfs_client pointer is planted in "result."
684  *
685  * NB: nfs41_walk_client_list() relies on the new nfs_client being
686  *     the last nfs_client on the list.
687  */
688 int nfs41_walk_client_list(struct nfs_client *new,
689 			   struct nfs_client **result,
690 			   struct rpc_cred *cred)
691 {
692 	struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
693 	struct nfs_client *pos, *prev = NULL;
694 	int status = -NFS4ERR_STALE_CLIENTID;
695 
696 	spin_lock(&nn->nfs_client_lock);
697 	list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
698 
699 		if (pos == new)
700 			goto found;
701 
702 		status = nfs4_match_client(pos, new, &prev, nn);
703 		if (status < 0)
704 			goto out;
705 		if (status != 0)
706 			continue;
707 
708 		/*
709 		 * Note that session trunking is just a special subcase of
710 		 * client id trunking. In either case, we want to fall back
711 		 * to using the existing nfs_client.
712 		 */
713 		if (!nfs4_check_serverowner_major_id(pos->cl_serverowner,
714 						     new->cl_serverowner))
715 			continue;
716 
717 found:
718 		refcount_inc(&pos->cl_count);
719 		*result = pos;
720 		status = 0;
721 		break;
722 	}
723 
724 out:
725 	spin_unlock(&nn->nfs_client_lock);
726 	nfs_put_client(prev);
727 	return status;
728 }
729 #endif	/* CONFIG_NFS_V4_1 */
730 
731 static void nfs4_destroy_server(struct nfs_server *server)
732 {
733 	nfs_server_return_all_delegations(server);
734 	unset_pnfs_layoutdriver(server);
735 	nfs4_purge_state_owners(server);
736 }
737 
738 /*
739  * NFSv4.0 callback thread helper
740  *
741  * Find a client by callback identifier
742  */
743 struct nfs_client *
744 nfs4_find_client_ident(struct net *net, int cb_ident)
745 {
746 	struct nfs_client *clp;
747 	struct nfs_net *nn = net_generic(net, nfs_net_id);
748 
749 	spin_lock(&nn->nfs_client_lock);
750 	clp = idr_find(&nn->cb_ident_idr, cb_ident);
751 	if (clp)
752 		refcount_inc(&clp->cl_count);
753 	spin_unlock(&nn->nfs_client_lock);
754 	return clp;
755 }
756 
757 #if defined(CONFIG_NFS_V4_1)
758 /* Common match routine for v4.0 and v4.1 callback services */
759 static bool nfs4_cb_match_client(const struct sockaddr *addr,
760 		struct nfs_client *clp, u32 minorversion)
761 {
762 	struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
763 
764 	/* Don't match clients that failed to initialise */
765 	if (!(clp->cl_cons_state == NFS_CS_READY ||
766 	    clp->cl_cons_state == NFS_CS_SESSION_INITING))
767 		return false;
768 
769 	smp_rmb();
770 
771 	/* Match the version and minorversion */
772 	if (clp->rpc_ops->version != 4 ||
773 	    clp->cl_minorversion != minorversion)
774 		return false;
775 
776 	/* Match only the IP address, not the port number */
777 	return rpc_cmp_addr(addr, clap);
778 }
779 
780 /*
781  * NFSv4.1 callback thread helper
782  * For CB_COMPOUND calls, find a client by IP address, protocol version,
783  * minorversion, and sessionID
784  *
785  * Returns NULL if no such client
786  */
787 struct nfs_client *
788 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
789 			   struct nfs4_sessionid *sid, u32 minorversion)
790 {
791 	struct nfs_client *clp;
792 	struct nfs_net *nn = net_generic(net, nfs_net_id);
793 
794 	spin_lock(&nn->nfs_client_lock);
795 	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
796 		if (!nfs4_cb_match_client(addr, clp, minorversion))
797 			continue;
798 
799 		if (!nfs4_has_session(clp))
800 			continue;
801 
802 		/* Match sessionid*/
803 		if (memcmp(clp->cl_session->sess_id.data,
804 		    sid->data, NFS4_MAX_SESSIONID_LEN) != 0)
805 			continue;
806 
807 		refcount_inc(&clp->cl_count);
808 		spin_unlock(&nn->nfs_client_lock);
809 		return clp;
810 	}
811 	spin_unlock(&nn->nfs_client_lock);
812 	return NULL;
813 }
814 
815 #else /* CONFIG_NFS_V4_1 */
816 
817 struct nfs_client *
818 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
819 			   struct nfs4_sessionid *sid, u32 minorversion)
820 {
821 	return NULL;
822 }
823 #endif /* CONFIG_NFS_V4_1 */
824 
825 /*
826  * Set up an NFS4 client
827  */
828 static int nfs4_set_client(struct nfs_server *server,
829 		const char *hostname,
830 		const struct sockaddr *addr,
831 		const size_t addrlen,
832 		const char *ip_addr,
833 		int proto, const struct rpc_timeout *timeparms,
834 		u32 minorversion, struct net *net)
835 {
836 	struct nfs_client_initdata cl_init = {
837 		.hostname = hostname,
838 		.addr = addr,
839 		.addrlen = addrlen,
840 		.ip_addr = ip_addr,
841 		.nfs_mod = &nfs_v4,
842 		.proto = proto,
843 		.minorversion = minorversion,
844 		.net = net,
845 		.timeparms = timeparms,
846 	};
847 	struct nfs_client *clp;
848 
849 	if (server->flags & NFS_MOUNT_NORESVPORT)
850 		set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
851 	if (server->options & NFS_OPTION_MIGRATION)
852 		set_bit(NFS_CS_MIGRATION, &cl_init.init_flags);
853 	if (test_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status))
854 		set_bit(NFS_CS_TSM_POSSIBLE, &cl_init.init_flags);
855 
856 	/* Allocate or find a client reference we can use */
857 	clp = nfs_get_client(&cl_init);
858 	if (IS_ERR(clp))
859 		return PTR_ERR(clp);
860 
861 	if (server->nfs_client == clp)
862 		return -ELOOP;
863 
864 	/*
865 	 * Query for the lease time on clientid setup or renewal
866 	 *
867 	 * Note that this will be set on nfs_clients that were created
868 	 * only for the DS role and did not set this bit, but now will
869 	 * serve a dual role.
870 	 */
871 	set_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state);
872 
873 	server->nfs_client = clp;
874 	return 0;
875 }
876 
877 /*
878  * Set up a pNFS Data Server client.
879  *
880  * Return any existing nfs_client that matches server address,port,version
881  * and minorversion.
882  *
883  * For a new nfs_client, use a soft mount (default), a low retrans and a
884  * low timeout interval so that if a connection is lost, we retry through
885  * the MDS.
886  */
887 struct nfs_client *nfs4_set_ds_client(struct nfs_server *mds_srv,
888 		const struct sockaddr *ds_addr, int ds_addrlen,
889 		int ds_proto, unsigned int ds_timeo, unsigned int ds_retrans,
890 		u32 minor_version)
891 {
892 	struct rpc_timeout ds_timeout;
893 	struct nfs_client *mds_clp = mds_srv->nfs_client;
894 	struct nfs_client_initdata cl_init = {
895 		.addr = ds_addr,
896 		.addrlen = ds_addrlen,
897 		.nodename = mds_clp->cl_rpcclient->cl_nodename,
898 		.ip_addr = mds_clp->cl_ipaddr,
899 		.nfs_mod = &nfs_v4,
900 		.proto = ds_proto,
901 		.minorversion = minor_version,
902 		.net = mds_clp->cl_net,
903 		.timeparms = &ds_timeout,
904 	};
905 	char buf[INET6_ADDRSTRLEN + 1];
906 
907 	if (rpc_ntop(ds_addr, buf, sizeof(buf)) <= 0)
908 		return ERR_PTR(-EINVAL);
909 	cl_init.hostname = buf;
910 
911 	if (mds_srv->flags & NFS_MOUNT_NORESVPORT)
912 		__set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
913 
914 	/*
915 	 * Set an authflavor equual to the MDS value. Use the MDS nfs_client
916 	 * cl_ipaddr so as to use the same EXCHANGE_ID co_ownerid as the MDS
917 	 * (section 13.1 RFC 5661).
918 	 */
919 	nfs_init_timeout_values(&ds_timeout, ds_proto, ds_timeo, ds_retrans);
920 	return nfs_get_client(&cl_init);
921 }
922 EXPORT_SYMBOL_GPL(nfs4_set_ds_client);
923 
924 /*
925  * Session has been established, and the client marked ready.
926  * Set the mount rsize and wsize with negotiated fore channel
927  * attributes which will be bound checked in nfs_server_set_fsinfo.
928  */
929 static void nfs4_session_set_rwsize(struct nfs_server *server)
930 {
931 #ifdef CONFIG_NFS_V4_1
932 	struct nfs4_session *sess;
933 	u32 server_resp_sz;
934 	u32 server_rqst_sz;
935 
936 	if (!nfs4_has_session(server->nfs_client))
937 		return;
938 	sess = server->nfs_client->cl_session;
939 	server_resp_sz = sess->fc_attrs.max_resp_sz - nfs41_maxread_overhead;
940 	server_rqst_sz = sess->fc_attrs.max_rqst_sz - nfs41_maxwrite_overhead;
941 
942 	if (!server->rsize || server->rsize > server_resp_sz)
943 		server->rsize = server_resp_sz;
944 	if (!server->wsize || server->wsize > server_rqst_sz)
945 		server->wsize = server_rqst_sz;
946 #endif /* CONFIG_NFS_V4_1 */
947 }
948 
949 static int nfs4_server_common_setup(struct nfs_server *server,
950 		struct nfs_fh *mntfh, bool auth_probe)
951 {
952 	struct nfs_fattr *fattr;
953 	int error;
954 
955 	/* data servers support only a subset of NFSv4.1 */
956 	if (is_ds_only_client(server->nfs_client))
957 		return -EPROTONOSUPPORT;
958 
959 	fattr = nfs_alloc_fattr();
960 	if (fattr == NULL)
961 		return -ENOMEM;
962 
963 	/* We must ensure the session is initialised first */
964 	error = nfs4_init_session(server->nfs_client);
965 	if (error < 0)
966 		goto out;
967 
968 	/* Set the basic capabilities */
969 	server->caps |= server->nfs_client->cl_mvops->init_caps;
970 	if (server->flags & NFS_MOUNT_NORDIRPLUS)
971 			server->caps &= ~NFS_CAP_READDIRPLUS;
972 	/*
973 	 * Don't use NFS uid/gid mapping if we're using AUTH_SYS or lower
974 	 * authentication.
975 	 */
976 	if (nfs4_disable_idmapping &&
977 			server->client->cl_auth->au_flavor == RPC_AUTH_UNIX)
978 		server->caps |= NFS_CAP_UIDGID_NOMAP;
979 
980 
981 	/* Probe the root fh to retrieve its FSID and filehandle */
982 	error = nfs4_get_rootfh(server, mntfh, auth_probe);
983 	if (error < 0)
984 		goto out;
985 
986 	dprintk("Server FSID: %llx:%llx\n",
987 			(unsigned long long) server->fsid.major,
988 			(unsigned long long) server->fsid.minor);
989 	nfs_display_fhandle(mntfh, "Pseudo-fs root FH");
990 
991 	nfs4_session_set_rwsize(server);
992 
993 	error = nfs_probe_fsinfo(server, mntfh, fattr);
994 	if (error < 0)
995 		goto out;
996 
997 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
998 		server->namelen = NFS4_MAXNAMLEN;
999 
1000 	nfs_server_insert_lists(server);
1001 	server->mount_time = jiffies;
1002 	server->destroy = nfs4_destroy_server;
1003 out:
1004 	nfs_free_fattr(fattr);
1005 	return error;
1006 }
1007 
1008 /*
1009  * Create a version 4 volume record
1010  */
1011 static int nfs4_init_server(struct nfs_server *server,
1012 		struct nfs_parsed_mount_data *data)
1013 {
1014 	struct rpc_timeout timeparms;
1015 	int error;
1016 
1017 	nfs_init_timeout_values(&timeparms, data->nfs_server.protocol,
1018 			data->timeo, data->retrans);
1019 
1020 	/* Initialise the client representation from the mount data */
1021 	server->flags = data->flags;
1022 	server->options = data->options;
1023 	server->auth_info = data->auth_info;
1024 
1025 	/* Use the first specified auth flavor. If this flavor isn't
1026 	 * allowed by the server, use the SECINFO path to try the
1027 	 * other specified flavors */
1028 	if (data->auth_info.flavor_len >= 1)
1029 		data->selected_flavor = data->auth_info.flavors[0];
1030 	else
1031 		data->selected_flavor = RPC_AUTH_UNIX;
1032 
1033 	/* Get a client record */
1034 	error = nfs4_set_client(server,
1035 			data->nfs_server.hostname,
1036 			(const struct sockaddr *)&data->nfs_server.address,
1037 			data->nfs_server.addrlen,
1038 			data->client_address,
1039 			data->nfs_server.protocol,
1040 			&timeparms,
1041 			data->minorversion,
1042 			data->net);
1043 	if (error < 0)
1044 		return error;
1045 
1046 	if (data->rsize)
1047 		server->rsize = nfs_block_size(data->rsize, NULL);
1048 	if (data->wsize)
1049 		server->wsize = nfs_block_size(data->wsize, NULL);
1050 
1051 	server->acregmin = data->acregmin * HZ;
1052 	server->acregmax = data->acregmax * HZ;
1053 	server->acdirmin = data->acdirmin * HZ;
1054 	server->acdirmax = data->acdirmax * HZ;
1055 	server->port     = data->nfs_server.port;
1056 
1057 	return nfs_init_server_rpcclient(server, &timeparms,
1058 					 data->selected_flavor);
1059 }
1060 
1061 /*
1062  * Create a version 4 volume record
1063  * - keyed on server and FSID
1064  */
1065 /*struct nfs_server *nfs4_create_server(const struct nfs_parsed_mount_data *data,
1066 				      struct nfs_fh *mntfh)*/
1067 struct nfs_server *nfs4_create_server(struct nfs_mount_info *mount_info,
1068 				      struct nfs_subversion *nfs_mod)
1069 {
1070 	struct nfs_server *server;
1071 	bool auth_probe;
1072 	int error;
1073 
1074 	server = nfs_alloc_server();
1075 	if (!server)
1076 		return ERR_PTR(-ENOMEM);
1077 
1078 	auth_probe = mount_info->parsed->auth_info.flavor_len < 1;
1079 
1080 	/* set up the general RPC client */
1081 	error = nfs4_init_server(server, mount_info->parsed);
1082 	if (error < 0)
1083 		goto error;
1084 
1085 	error = nfs4_server_common_setup(server, mount_info->mntfh, auth_probe);
1086 	if (error < 0)
1087 		goto error;
1088 
1089 	return server;
1090 
1091 error:
1092 	nfs_free_server(server);
1093 	return ERR_PTR(error);
1094 }
1095 
1096 /*
1097  * Create an NFS4 referral server record
1098  */
1099 struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data,
1100 					       struct nfs_fh *mntfh)
1101 {
1102 	struct nfs_client *parent_client;
1103 	struct nfs_server *server, *parent_server;
1104 	bool auth_probe;
1105 	int error;
1106 
1107 	server = nfs_alloc_server();
1108 	if (!server)
1109 		return ERR_PTR(-ENOMEM);
1110 
1111 	parent_server = NFS_SB(data->sb);
1112 	parent_client = parent_server->nfs_client;
1113 
1114 	/* Initialise the client representation from the parent server */
1115 	nfs_server_copy_userdata(server, parent_server);
1116 
1117 	/* Get a client representation.
1118 	 * Note: NFSv4 always uses TCP, */
1119 	error = nfs4_set_client(server, data->hostname,
1120 				data->addr,
1121 				data->addrlen,
1122 				parent_client->cl_ipaddr,
1123 				rpc_protocol(parent_server->client),
1124 				parent_server->client->cl_timeout,
1125 				parent_client->cl_mvops->minor_version,
1126 				parent_client->cl_net);
1127 	if (error < 0)
1128 		goto error;
1129 
1130 	error = nfs_init_server_rpcclient(server, parent_server->client->cl_timeout, data->authflavor);
1131 	if (error < 0)
1132 		goto error;
1133 
1134 	auth_probe = parent_server->auth_info.flavor_len < 1;
1135 
1136 	error = nfs4_server_common_setup(server, mntfh, auth_probe);
1137 	if (error < 0)
1138 		goto error;
1139 
1140 	return server;
1141 
1142 error:
1143 	nfs_free_server(server);
1144 	return ERR_PTR(error);
1145 }
1146 
1147 /*
1148  * Grab the destination's particulars, including lease expiry time.
1149  *
1150  * Returns zero if probe succeeded and retrieved FSID matches the FSID
1151  * we have cached.
1152  */
1153 static int nfs_probe_destination(struct nfs_server *server)
1154 {
1155 	struct inode *inode = d_inode(server->super->s_root);
1156 	struct nfs_fattr *fattr;
1157 	int error;
1158 
1159 	fattr = nfs_alloc_fattr();
1160 	if (fattr == NULL)
1161 		return -ENOMEM;
1162 
1163 	/* Sanity: the probe won't work if the destination server
1164 	 * does not recognize the migrated FH. */
1165 	error = nfs_probe_fsinfo(server, NFS_FH(inode), fattr);
1166 
1167 	nfs_free_fattr(fattr);
1168 	return error;
1169 }
1170 
1171 /**
1172  * nfs4_update_server - Move an nfs_server to a different nfs_client
1173  *
1174  * @server: represents FSID to be moved
1175  * @hostname: new end-point's hostname
1176  * @sap: new end-point's socket address
1177  * @salen: size of "sap"
1178  * @net: net namespace
1179  *
1180  * The nfs_server must be quiescent before this function is invoked.
1181  * Either its session is drained (NFSv4.1+), or its transport is
1182  * plugged and drained (NFSv4.0).
1183  *
1184  * Returns zero on success, or a negative errno value.
1185  */
1186 int nfs4_update_server(struct nfs_server *server, const char *hostname,
1187 		       struct sockaddr *sap, size_t salen, struct net *net)
1188 {
1189 	struct nfs_client *clp = server->nfs_client;
1190 	struct rpc_clnt *clnt = server->client;
1191 	struct xprt_create xargs = {
1192 		.ident		= clp->cl_proto,
1193 		.net		= net,
1194 		.dstaddr	= sap,
1195 		.addrlen	= salen,
1196 		.servername	= hostname,
1197 	};
1198 	char buf[INET6_ADDRSTRLEN + 1];
1199 	struct sockaddr_storage address;
1200 	struct sockaddr *localaddr = (struct sockaddr *)&address;
1201 	int error;
1202 
1203 	error = rpc_switch_client_transport(clnt, &xargs, clnt->cl_timeout);
1204 	if (error != 0)
1205 		return error;
1206 
1207 	error = rpc_localaddr(clnt, localaddr, sizeof(address));
1208 	if (error != 0)
1209 		return error;
1210 
1211 	if (rpc_ntop(localaddr, buf, sizeof(buf)) == 0)
1212 		return -EAFNOSUPPORT;
1213 
1214 	nfs_server_remove_lists(server);
1215 	set_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status);
1216 	error = nfs4_set_client(server, hostname, sap, salen, buf,
1217 				clp->cl_proto, clnt->cl_timeout,
1218 				clp->cl_minorversion, net);
1219 	clear_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status);
1220 	nfs_put_client(clp);
1221 	if (error != 0) {
1222 		nfs_server_insert_lists(server);
1223 		return error;
1224 	}
1225 
1226 	if (server->nfs_client->cl_hostname == NULL)
1227 		server->nfs_client->cl_hostname = kstrdup(hostname, GFP_KERNEL);
1228 	nfs_server_insert_lists(server);
1229 
1230 	return nfs_probe_destination(server);
1231 }
1232