xref: /openbmc/linux/fs/nfs/nfs4client.c (revision c67ce71d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  */
6 #include <linux/module.h>
7 #include <linux/nfs_fs.h>
8 #include <linux/nfs_mount.h>
9 #include <linux/sunrpc/addr.h>
10 #include <linux/sunrpc/auth.h>
11 #include <linux/sunrpc/xprt.h>
12 #include <linux/sunrpc/bc_xprt.h>
13 #include <linux/sunrpc/rpc_pipe_fs.h>
14 #include "internal.h"
15 #include "callback.h"
16 #include "delegation.h"
17 #include "nfs4session.h"
18 #include "nfs4idmap.h"
19 #include "pnfs.h"
20 #include "netns.h"
21 #include "sysfs.h"
22 
23 #define NFSDBG_FACILITY		NFSDBG_CLIENT
24 
25 /*
26  * Get a unique NFSv4.0 callback identifier which will be used
27  * by the V4.0 callback service to lookup the nfs_client struct
28  */
29 static int nfs_get_cb_ident_idr(struct nfs_client *clp, int minorversion)
30 {
31 	int ret = 0;
32 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
33 
34 	if (clp->rpc_ops->version != 4 || minorversion != 0)
35 		return ret;
36 	idr_preload(GFP_KERNEL);
37 	spin_lock(&nn->nfs_client_lock);
38 	ret = idr_alloc(&nn->cb_ident_idr, clp, 1, 0, GFP_NOWAIT);
39 	if (ret >= 0)
40 		clp->cl_cb_ident = ret;
41 	spin_unlock(&nn->nfs_client_lock);
42 	idr_preload_end();
43 	return ret < 0 ? ret : 0;
44 }
45 
46 #ifdef CONFIG_NFS_V4_1
47 /*
48  * Per auth flavor data server rpc clients
49  */
50 struct nfs4_ds_server {
51 	struct list_head	list;   /* ds_clp->cl_ds_clients */
52 	struct rpc_clnt		*rpc_clnt;
53 };
54 
55 /**
56  * nfs4_find_ds_client - Common lookup case for DS I/O
57  * @ds_clp: pointer to the DS's nfs_client
58  * @flavor: rpc auth flavour to match
59  */
60 static struct nfs4_ds_server *
61 nfs4_find_ds_client(struct nfs_client *ds_clp, rpc_authflavor_t flavor)
62 {
63 	struct nfs4_ds_server *dss;
64 
65 	rcu_read_lock();
66 	list_for_each_entry_rcu(dss, &ds_clp->cl_ds_clients, list) {
67 		if (dss->rpc_clnt->cl_auth->au_flavor != flavor)
68 			continue;
69 		goto out;
70 	}
71 	dss = NULL;
72 out:
73 	rcu_read_unlock();
74 	return dss;
75 }
76 
77 static struct nfs4_ds_server *
78 nfs4_add_ds_client(struct nfs_client *ds_clp, rpc_authflavor_t flavor,
79 			   struct nfs4_ds_server *new)
80 {
81 	struct nfs4_ds_server *dss;
82 
83 	spin_lock(&ds_clp->cl_lock);
84 	list_for_each_entry(dss, &ds_clp->cl_ds_clients, list) {
85 		if (dss->rpc_clnt->cl_auth->au_flavor != flavor)
86 			continue;
87 		goto out;
88 	}
89 	if (new)
90 		list_add_rcu(&new->list, &ds_clp->cl_ds_clients);
91 	dss = new;
92 out:
93 	spin_unlock(&ds_clp->cl_lock); /* need some lock to protect list */
94 	return dss;
95 }
96 
97 static struct nfs4_ds_server *
98 nfs4_alloc_ds_server(struct nfs_client *ds_clp, rpc_authflavor_t flavor)
99 {
100 	struct nfs4_ds_server *dss;
101 
102 	dss = kmalloc(sizeof(*dss), GFP_NOFS);
103 	if (dss == NULL)
104 		return ERR_PTR(-ENOMEM);
105 
106 	dss->rpc_clnt = rpc_clone_client_set_auth(ds_clp->cl_rpcclient, flavor);
107 	if (IS_ERR(dss->rpc_clnt)) {
108 		int err = PTR_ERR(dss->rpc_clnt);
109 		kfree (dss);
110 		return ERR_PTR(err);
111 	}
112 	INIT_LIST_HEAD(&dss->list);
113 
114 	return dss;
115 }
116 
117 static void
118 nfs4_free_ds_server(struct nfs4_ds_server *dss)
119 {
120 	rpc_release_client(dss->rpc_clnt);
121 	kfree(dss);
122 }
123 
124 /**
125  * nfs4_find_or_create_ds_client - Find or create a DS rpc client
126  * @ds_clp: pointer to the DS's nfs_client
127  * @inode: pointer to the inode
128  *
129  * Find or create a DS rpc client with th MDS server rpc client auth flavor
130  * in the nfs_client cl_ds_clients list.
131  */
132 struct rpc_clnt *
133 nfs4_find_or_create_ds_client(struct nfs_client *ds_clp, struct inode *inode)
134 {
135 	struct nfs4_ds_server *dss, *new;
136 	rpc_authflavor_t flavor = NFS_SERVER(inode)->client->cl_auth->au_flavor;
137 
138 	dss = nfs4_find_ds_client(ds_clp, flavor);
139 	if (dss != NULL)
140 		goto out;
141 	new = nfs4_alloc_ds_server(ds_clp, flavor);
142 	if (IS_ERR(new))
143 		return ERR_CAST(new);
144 	dss = nfs4_add_ds_client(ds_clp, flavor, new);
145 	if (dss != new)
146 		nfs4_free_ds_server(new);
147 out:
148 	return dss->rpc_clnt;
149 }
150 EXPORT_SYMBOL_GPL(nfs4_find_or_create_ds_client);
151 
152 static void
153 nfs4_shutdown_ds_clients(struct nfs_client *clp)
154 {
155 	struct nfs4_ds_server *dss;
156 
157 	while (!list_empty(&clp->cl_ds_clients)) {
158 		dss = list_entry(clp->cl_ds_clients.next,
159 					struct nfs4_ds_server, list);
160 		list_del(&dss->list);
161 		rpc_shutdown_client(dss->rpc_clnt);
162 		kfree (dss);
163 	}
164 }
165 
166 static void
167 nfs4_cleanup_callback(struct nfs_client *clp)
168 {
169 	struct nfs4_copy_state *cp_state;
170 
171 	while (!list_empty(&clp->pending_cb_stateids)) {
172 		cp_state = list_entry(clp->pending_cb_stateids.next,
173 					struct nfs4_copy_state, copies);
174 		list_del(&cp_state->copies);
175 		kfree(cp_state);
176 	}
177 }
178 
179 void nfs41_shutdown_client(struct nfs_client *clp)
180 {
181 	if (nfs4_has_session(clp)) {
182 		nfs4_cleanup_callback(clp);
183 		nfs4_shutdown_ds_clients(clp);
184 		nfs4_destroy_session(clp->cl_session);
185 		nfs4_destroy_clientid(clp);
186 	}
187 
188 }
189 #endif	/* CONFIG_NFS_V4_1 */
190 
191 void nfs40_shutdown_client(struct nfs_client *clp)
192 {
193 	if (clp->cl_slot_tbl) {
194 		nfs4_shutdown_slot_table(clp->cl_slot_tbl);
195 		kfree(clp->cl_slot_tbl);
196 	}
197 }
198 
199 struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *cl_init)
200 {
201 	char buf[INET6_ADDRSTRLEN + 1];
202 	const char *ip_addr = cl_init->ip_addr;
203 	struct nfs_client *clp = nfs_alloc_client(cl_init);
204 	int err;
205 
206 	if (IS_ERR(clp))
207 		return clp;
208 
209 	err = nfs_get_cb_ident_idr(clp, cl_init->minorversion);
210 	if (err)
211 		goto error;
212 
213 	if (cl_init->minorversion > NFS4_MAX_MINOR_VERSION) {
214 		err = -EINVAL;
215 		goto error;
216 	}
217 
218 	spin_lock_init(&clp->cl_lock);
219 	INIT_DELAYED_WORK(&clp->cl_renewd, nfs4_renew_state);
220 	INIT_LIST_HEAD(&clp->cl_ds_clients);
221 	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
222 	clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
223 	clp->cl_mvops = nfs_v4_minor_ops[cl_init->minorversion];
224 	clp->cl_mig_gen = 1;
225 #if IS_ENABLED(CONFIG_NFS_V4_1)
226 	init_waitqueue_head(&clp->cl_lock_waitq);
227 #endif
228 	INIT_LIST_HEAD(&clp->pending_cb_stateids);
229 
230 	if (cl_init->minorversion != 0)
231 		__set_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags);
232 	__set_bit(NFS_CS_DISCRTRY, &clp->cl_flags);
233 	__set_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags);
234 	if (test_bit(NFS_CS_PNFS, &cl_init->init_flags))
235 		__set_bit(NFS_CS_PNFS, &clp->cl_flags);
236 	/*
237 	 * Set up the connection to the server before we add add to the
238 	 * global list.
239 	 */
240 	err = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_GSS_KRB5I);
241 	if (err == -EINVAL)
242 		err = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_UNIX);
243 	if (err < 0)
244 		goto error;
245 
246 	/* If no clientaddr= option was specified, find a usable cb address */
247 	if (ip_addr == NULL) {
248 		struct sockaddr_storage cb_addr;
249 		struct sockaddr *sap = (struct sockaddr *)&cb_addr;
250 
251 		err = rpc_localaddr(clp->cl_rpcclient, sap, sizeof(cb_addr));
252 		if (err < 0)
253 			goto error;
254 		err = rpc_ntop(sap, buf, sizeof(buf));
255 		if (err < 0)
256 			goto error;
257 		ip_addr = (const char *)buf;
258 	}
259 	strscpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr));
260 
261 	err = nfs_idmap_new(clp);
262 	if (err < 0) {
263 		dprintk("%s: failed to create idmapper. Error = %d\n",
264 			__func__, err);
265 		goto error;
266 	}
267 	__set_bit(NFS_CS_IDMAP, &clp->cl_res_state);
268 	return clp;
269 
270 error:
271 	nfs_free_client(clp);
272 	return ERR_PTR(err);
273 }
274 
275 /*
276  * Destroy the NFS4 callback service
277  */
278 static void nfs4_destroy_callback(struct nfs_client *clp)
279 {
280 	if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
281 		nfs_callback_down(clp->cl_mvops->minor_version, clp->cl_net);
282 }
283 
284 static void nfs4_shutdown_client(struct nfs_client *clp)
285 {
286 	if (__test_and_clear_bit(NFS_CS_RENEWD, &clp->cl_res_state))
287 		nfs4_kill_renewd(clp);
288 	clp->cl_mvops->shutdown_client(clp);
289 	nfs4_destroy_callback(clp);
290 	if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state))
291 		nfs_idmap_delete(clp);
292 
293 	rpc_destroy_wait_queue(&clp->cl_rpcwaitq);
294 	kfree(clp->cl_serverowner);
295 	kfree(clp->cl_serverscope);
296 	kfree(clp->cl_implid);
297 	kfree(clp->cl_owner_id);
298 }
299 
300 void nfs4_free_client(struct nfs_client *clp)
301 {
302 	nfs4_shutdown_client(clp);
303 	nfs_free_client(clp);
304 }
305 
306 /*
307  * Initialize the NFS4 callback service
308  */
309 static int nfs4_init_callback(struct nfs_client *clp)
310 {
311 	struct rpc_xprt *xprt;
312 	int error;
313 
314 	xprt = rcu_dereference_raw(clp->cl_rpcclient->cl_xprt);
315 
316 	if (nfs4_has_session(clp)) {
317 		error = xprt_setup_backchannel(xprt, NFS41_BC_MIN_CALLBACKS);
318 		if (error < 0)
319 			return error;
320 	}
321 
322 	error = nfs_callback_up(clp->cl_mvops->minor_version, xprt);
323 	if (error < 0) {
324 		dprintk("%s: failed to start callback. Error = %d\n",
325 			__func__, error);
326 		return error;
327 	}
328 	__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
329 
330 	return 0;
331 }
332 
333 /**
334  * nfs40_init_client - nfs_client initialization tasks for NFSv4.0
335  * @clp: nfs_client to initialize
336  *
337  * Returns zero on success, or a negative errno if some error occurred.
338  */
339 int nfs40_init_client(struct nfs_client *clp)
340 {
341 	struct nfs4_slot_table *tbl;
342 	int ret;
343 
344 	tbl = kzalloc(sizeof(*tbl), GFP_NOFS);
345 	if (tbl == NULL)
346 		return -ENOMEM;
347 
348 	ret = nfs4_setup_slot_table(tbl, NFS4_MAX_SLOT_TABLE,
349 					"NFSv4.0 transport Slot table");
350 	if (ret) {
351 		nfs4_shutdown_slot_table(tbl);
352 		kfree(tbl);
353 		return ret;
354 	}
355 
356 	clp->cl_slot_tbl = tbl;
357 	return 0;
358 }
359 
360 #if defined(CONFIG_NFS_V4_1)
361 
362 /**
363  * nfs41_init_client - nfs_client initialization tasks for NFSv4.1+
364  * @clp: nfs_client to initialize
365  *
366  * Returns zero on success, or a negative errno if some error occurred.
367  */
368 int nfs41_init_client(struct nfs_client *clp)
369 {
370 	struct nfs4_session *session = NULL;
371 
372 	/*
373 	 * Create the session and mark it expired.
374 	 * When a SEQUENCE operation encounters the expired session
375 	 * it will do session recovery to initialize it.
376 	 */
377 	session = nfs4_alloc_session(clp);
378 	if (!session)
379 		return -ENOMEM;
380 
381 	clp->cl_session = session;
382 
383 	/*
384 	 * The create session reply races with the server back
385 	 * channel probe. Mark the client NFS_CS_SESSION_INITING
386 	 * so that the client back channel can find the
387 	 * nfs_client struct
388 	 */
389 	nfs_mark_client_ready(clp, NFS_CS_SESSION_INITING);
390 	return 0;
391 }
392 
393 #endif	/* CONFIG_NFS_V4_1 */
394 
395 /*
396  * Initialize the minor version specific parts of an NFS4 client record
397  */
398 static int nfs4_init_client_minor_version(struct nfs_client *clp)
399 {
400 	int ret;
401 
402 	ret = clp->cl_mvops->init_client(clp);
403 	if (ret)
404 		return ret;
405 	return nfs4_init_callback(clp);
406 }
407 
408 static void nfs4_add_trunk(struct nfs_client *clp, struct nfs_client *old)
409 {
410 	struct sockaddr_storage clp_addr, old_addr;
411 	struct sockaddr *clp_sap = (struct sockaddr *)&clp_addr;
412 	struct sockaddr *old_sap = (struct sockaddr *)&old_addr;
413 	size_t clp_salen;
414 	struct xprt_create xprt_args = {
415 		.ident = old->cl_proto,
416 		.net = old->cl_net,
417 		.servername = old->cl_hostname,
418 	};
419 	int max_connect = test_bit(NFS_CS_PNFS, &clp->cl_flags) ?
420 		clp->cl_max_connect : old->cl_max_connect;
421 
422 	if (clp->cl_proto != old->cl_proto)
423 		return;
424 	clp_salen = rpc_peeraddr(clp->cl_rpcclient, clp_sap, sizeof(clp_addr));
425 	rpc_peeraddr(old->cl_rpcclient, old_sap, sizeof(old_addr));
426 
427 	if (clp_addr.ss_family != old_addr.ss_family)
428 		return;
429 
430 	xprt_args.dstaddr = clp_sap;
431 	xprt_args.addrlen = clp_salen;
432 
433 	rpc_clnt_add_xprt(old->cl_rpcclient, &xprt_args,
434 			  rpc_clnt_test_and_add_xprt, &max_connect);
435 }
436 
437 /**
438  * nfs4_init_client - Initialise an NFS4 client record
439  *
440  * @clp: nfs_client to initialise
441  * @cl_init: pointer to nfs_client_initdata
442  *
443  * Returns pointer to an NFS client, or an ERR_PTR value.
444  */
445 struct nfs_client *nfs4_init_client(struct nfs_client *clp,
446 				    const struct nfs_client_initdata *cl_init)
447 {
448 	struct nfs_client *old;
449 	int error;
450 
451 	if (clp->cl_cons_state == NFS_CS_READY)
452 		/* the client is initialised already */
453 		return clp;
454 
455 	error = nfs4_init_client_minor_version(clp);
456 	if (error < 0)
457 		goto error;
458 
459 	error = nfs4_discover_server_trunking(clp, &old);
460 	if (error < 0)
461 		goto error;
462 
463 	if (clp != old) {
464 		clp->cl_preserve_clid = true;
465 		/*
466 		 * Mark the client as having failed initialization so other
467 		 * processes walking the nfs_client_list in nfs_match_client()
468 		 * won't try to use it.
469 		 */
470 		nfs_mark_client_ready(clp, -EPERM);
471 		if (old->cl_mvops->session_trunk)
472 			nfs4_add_trunk(clp, old);
473 	}
474 	clear_bit(NFS_CS_TSM_POSSIBLE, &clp->cl_flags);
475 	nfs_put_client(clp);
476 	return old;
477 
478 error:
479 	nfs_mark_client_ready(clp, error);
480 	nfs_put_client(clp);
481 	return ERR_PTR(error);
482 }
483 
484 /*
485  * SETCLIENTID just did a callback update with the callback ident in
486  * "drop," but server trunking discovery claims "drop" and "keep" are
487  * actually the same server.  Swap the callback IDs so that "keep"
488  * will continue to use the callback ident the server now knows about,
489  * and so that "keep"'s original callback ident is destroyed when
490  * "drop" is freed.
491  */
492 static void nfs4_swap_callback_idents(struct nfs_client *keep,
493 				      struct nfs_client *drop)
494 {
495 	struct nfs_net *nn = net_generic(keep->cl_net, nfs_net_id);
496 	unsigned int save = keep->cl_cb_ident;
497 
498 	if (keep->cl_cb_ident == drop->cl_cb_ident)
499 		return;
500 
501 	dprintk("%s: keeping callback ident %u and dropping ident %u\n",
502 		__func__, keep->cl_cb_ident, drop->cl_cb_ident);
503 
504 	spin_lock(&nn->nfs_client_lock);
505 
506 	idr_replace(&nn->cb_ident_idr, keep, drop->cl_cb_ident);
507 	keep->cl_cb_ident = drop->cl_cb_ident;
508 
509 	idr_replace(&nn->cb_ident_idr, drop, save);
510 	drop->cl_cb_ident = save;
511 
512 	spin_unlock(&nn->nfs_client_lock);
513 }
514 
515 static bool nfs4_match_client_owner_id(const struct nfs_client *clp1,
516 		const struct nfs_client *clp2)
517 {
518 	if (clp1->cl_owner_id == NULL || clp2->cl_owner_id == NULL)
519 		return true;
520 	return strcmp(clp1->cl_owner_id, clp2->cl_owner_id) == 0;
521 }
522 
523 static bool nfs4_same_verifier(nfs4_verifier *v1, nfs4_verifier *v2)
524 {
525 	return memcmp(v1->data, v2->data, sizeof(v1->data)) == 0;
526 }
527 
528 static int nfs4_match_client(struct nfs_client  *pos,  struct nfs_client *new,
529 			     struct nfs_client **prev, struct nfs_net *nn)
530 {
531 	int status;
532 
533 	if (pos->rpc_ops != new->rpc_ops)
534 		return 1;
535 
536 	if (pos->cl_minorversion != new->cl_minorversion)
537 		return 1;
538 
539 	/* If "pos" isn't marked ready, we can't trust the
540 	 * remaining fields in "pos", especially the client
541 	 * ID and serverowner fields.  Wait for CREATE_SESSION
542 	 * to finish. */
543 	if (pos->cl_cons_state > NFS_CS_READY) {
544 		refcount_inc(&pos->cl_count);
545 		spin_unlock(&nn->nfs_client_lock);
546 
547 		nfs_put_client(*prev);
548 		*prev = pos;
549 
550 		status = nfs_wait_client_init_complete(pos);
551 		spin_lock(&nn->nfs_client_lock);
552 
553 		if (status < 0)
554 			return status;
555 	}
556 
557 	if (pos->cl_cons_state != NFS_CS_READY)
558 		return 1;
559 
560 	if (pos->cl_clientid != new->cl_clientid)
561 		return 1;
562 
563 	/* NFSv4.1 always uses the uniform string, however someone
564 	 * might switch the uniquifier string on us.
565 	 */
566 	if (!nfs4_match_client_owner_id(pos, new))
567 		return 1;
568 
569 	return 0;
570 }
571 
572 /**
573  * nfs40_walk_client_list - Find server that recognizes a client ID
574  *
575  * @new: nfs_client with client ID to test
576  * @result: OUT: found nfs_client, or new
577  * @cred: credential to use for trunking test
578  *
579  * Returns zero, a negative errno, or a negative NFS4ERR status.
580  * If zero is returned, an nfs_client pointer is planted in "result."
581  *
582  * NB: nfs40_walk_client_list() relies on the new nfs_client being
583  *     the last nfs_client on the list.
584  */
585 int nfs40_walk_client_list(struct nfs_client *new,
586 			   struct nfs_client **result,
587 			   const struct cred *cred)
588 {
589 	struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
590 	struct nfs_client *pos, *prev = NULL;
591 	struct nfs4_setclientid_res clid = {
592 		.clientid	= new->cl_clientid,
593 		.confirm	= new->cl_confirm,
594 	};
595 	int status = -NFS4ERR_STALE_CLIENTID;
596 
597 	spin_lock(&nn->nfs_client_lock);
598 	list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
599 
600 		if (pos == new)
601 			goto found;
602 
603 		status = nfs4_match_client(pos, new, &prev, nn);
604 		if (status < 0)
605 			goto out_unlock;
606 		if (status != 0)
607 			continue;
608 		/*
609 		 * We just sent a new SETCLIENTID, which should have
610 		 * caused the server to return a new cl_confirm.  So if
611 		 * cl_confirm is the same, then this is a different
612 		 * server that just returned the same cl_confirm by
613 		 * coincidence:
614 		 */
615 		if ((new != pos) && nfs4_same_verifier(&pos->cl_confirm,
616 						       &new->cl_confirm))
617 			continue;
618 		/*
619 		 * But if the cl_confirm's are different, then the only
620 		 * way that a SETCLIENTID_CONFIRM to pos can succeed is
621 		 * if new and pos point to the same server:
622 		 */
623 found:
624 		refcount_inc(&pos->cl_count);
625 		spin_unlock(&nn->nfs_client_lock);
626 
627 		nfs_put_client(prev);
628 		prev = pos;
629 
630 		status = nfs4_proc_setclientid_confirm(pos, &clid, cred);
631 		switch (status) {
632 		case -NFS4ERR_STALE_CLIENTID:
633 			break;
634 		case 0:
635 			nfs4_swap_callback_idents(pos, new);
636 			pos->cl_confirm = new->cl_confirm;
637 			nfs_mark_client_ready(pos, NFS_CS_READY);
638 
639 			prev = NULL;
640 			*result = pos;
641 			goto out;
642 		case -ERESTARTSYS:
643 		case -ETIMEDOUT:
644 			/* The callback path may have been inadvertently
645 			 * changed. Schedule recovery!
646 			 */
647 			nfs4_schedule_path_down_recovery(pos);
648 			goto out;
649 		default:
650 			goto out;
651 		}
652 
653 		spin_lock(&nn->nfs_client_lock);
654 	}
655 out_unlock:
656 	spin_unlock(&nn->nfs_client_lock);
657 
658 	/* No match found. The server lost our clientid */
659 out:
660 	nfs_put_client(prev);
661 	return status;
662 }
663 
664 #ifdef CONFIG_NFS_V4_1
665 /*
666  * Returns true if the server major ids match
667  */
668 bool
669 nfs4_check_serverowner_major_id(struct nfs41_server_owner *o1,
670 				struct nfs41_server_owner *o2)
671 {
672 	if (o1->major_id_sz != o2->major_id_sz)
673 		return false;
674 	return memcmp(o1->major_id, o2->major_id, o1->major_id_sz) == 0;
675 }
676 
677 /*
678  * Returns true if the server scopes match
679  */
680 static bool
681 nfs4_check_server_scope(struct nfs41_server_scope *s1,
682 			struct nfs41_server_scope *s2)
683 {
684 	if (s1->server_scope_sz != s2->server_scope_sz)
685 		return false;
686 	return memcmp(s1->server_scope, s2->server_scope,
687 					s1->server_scope_sz) == 0;
688 }
689 
690 /**
691  * nfs4_detect_session_trunking - Checks for session trunking.
692  * @clp:    original mount nfs_client
693  * @res:    result structure from an exchange_id using the original mount
694  *          nfs_client with a new multi_addr transport
695  * @xprt:   pointer to the transport to add.
696  *
697  * Called after a successful EXCHANGE_ID on a multi-addr connection.
698  * Upon success, add the transport.
699  *
700  * Returns zero on success, otherwise -EINVAL
701  *
702  * Note: since the exchange_id for the new multi_addr transport uses the
703  * same nfs_client from the original mount, the cl_owner_id is reused,
704  * so eir_clientowner is the same.
705  */
706 int nfs4_detect_session_trunking(struct nfs_client *clp,
707 				 struct nfs41_exchange_id_res *res,
708 				 struct rpc_xprt *xprt)
709 {
710 	/* Check eir_clientid */
711 	if (clp->cl_clientid != res->clientid)
712 		goto out_err;
713 
714 	/* Check eir_server_owner so_major_id */
715 	if (!nfs4_check_serverowner_major_id(clp->cl_serverowner,
716 					     res->server_owner))
717 		goto out_err;
718 
719 	/* Check eir_server_owner so_minor_id */
720 	if (clp->cl_serverowner->minor_id != res->server_owner->minor_id)
721 		goto out_err;
722 
723 	/* Check eir_server_scope */
724 	if (!nfs4_check_server_scope(clp->cl_serverscope, res->server_scope))
725 		goto out_err;
726 
727 	pr_info("NFS:  %s: Session trunking succeeded for %s\n",
728 		clp->cl_hostname,
729 		xprt->address_strings[RPC_DISPLAY_ADDR]);
730 
731 	return 0;
732 out_err:
733 	pr_info("NFS:  %s: Session trunking failed for %s\n", clp->cl_hostname,
734 		xprt->address_strings[RPC_DISPLAY_ADDR]);
735 
736 	return -EINVAL;
737 }
738 
739 /**
740  * nfs41_walk_client_list - Find nfs_client that matches a client/server owner
741  *
742  * @new: nfs_client with client ID to test
743  * @result: OUT: found nfs_client, or new
744  * @cred: credential to use for trunking test
745  *
746  * Returns zero, a negative errno, or a negative NFS4ERR status.
747  * If zero is returned, an nfs_client pointer is planted in "result."
748  *
749  * NB: nfs41_walk_client_list() relies on the new nfs_client being
750  *     the last nfs_client on the list.
751  */
752 int nfs41_walk_client_list(struct nfs_client *new,
753 			   struct nfs_client **result,
754 			   const struct cred *cred)
755 {
756 	struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
757 	struct nfs_client *pos, *prev = NULL;
758 	int status = -NFS4ERR_STALE_CLIENTID;
759 
760 	spin_lock(&nn->nfs_client_lock);
761 	list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
762 
763 		if (pos == new)
764 			goto found;
765 
766 		status = nfs4_match_client(pos, new, &prev, nn);
767 		if (status < 0)
768 			goto out;
769 		if (status != 0)
770 			continue;
771 
772 		/*
773 		 * Note that session trunking is just a special subcase of
774 		 * client id trunking. In either case, we want to fall back
775 		 * to using the existing nfs_client.
776 		 */
777 		if (!nfs4_check_serverowner_major_id(pos->cl_serverowner,
778 						     new->cl_serverowner))
779 			continue;
780 
781 found:
782 		refcount_inc(&pos->cl_count);
783 		*result = pos;
784 		status = 0;
785 		break;
786 	}
787 
788 out:
789 	spin_unlock(&nn->nfs_client_lock);
790 	nfs_put_client(prev);
791 	return status;
792 }
793 #endif	/* CONFIG_NFS_V4_1 */
794 
795 static void nfs4_destroy_server(struct nfs_server *server)
796 {
797 	LIST_HEAD(freeme);
798 
799 	nfs_server_return_all_delegations(server);
800 	unset_pnfs_layoutdriver(server);
801 	nfs4_purge_state_owners(server, &freeme);
802 	nfs4_free_state_owners(&freeme);
803 }
804 
805 /*
806  * NFSv4.0 callback thread helper
807  *
808  * Find a client by callback identifier
809  */
810 struct nfs_client *
811 nfs4_find_client_ident(struct net *net, int cb_ident)
812 {
813 	struct nfs_client *clp;
814 	struct nfs_net *nn = net_generic(net, nfs_net_id);
815 
816 	spin_lock(&nn->nfs_client_lock);
817 	clp = idr_find(&nn->cb_ident_idr, cb_ident);
818 	if (clp)
819 		refcount_inc(&clp->cl_count);
820 	spin_unlock(&nn->nfs_client_lock);
821 	return clp;
822 }
823 
824 #if defined(CONFIG_NFS_V4_1)
825 /* Common match routine for v4.0 and v4.1 callback services */
826 static bool nfs4_cb_match_client(const struct sockaddr *addr,
827 		struct nfs_client *clp, u32 minorversion)
828 {
829 	struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
830 
831 	/* Don't match clients that failed to initialise */
832 	if (!(clp->cl_cons_state == NFS_CS_READY ||
833 	    clp->cl_cons_state == NFS_CS_SESSION_INITING))
834 		return false;
835 
836 	smp_rmb();
837 
838 	/* Match the version and minorversion */
839 	if (clp->rpc_ops->version != 4 ||
840 	    clp->cl_minorversion != minorversion)
841 		return false;
842 
843 	/* Match only the IP address, not the port number */
844 	return rpc_cmp_addr(addr, clap);
845 }
846 
847 /*
848  * NFSv4.1 callback thread helper
849  * For CB_COMPOUND calls, find a client by IP address, protocol version,
850  * minorversion, and sessionID
851  *
852  * Returns NULL if no such client
853  */
854 struct nfs_client *
855 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
856 			   struct nfs4_sessionid *sid, u32 minorversion)
857 {
858 	struct nfs_client *clp;
859 	struct nfs_net *nn = net_generic(net, nfs_net_id);
860 
861 	spin_lock(&nn->nfs_client_lock);
862 	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
863 		if (!nfs4_cb_match_client(addr, clp, minorversion))
864 			continue;
865 
866 		if (!nfs4_has_session(clp))
867 			continue;
868 
869 		/* Match sessionid*/
870 		if (memcmp(clp->cl_session->sess_id.data,
871 		    sid->data, NFS4_MAX_SESSIONID_LEN) != 0)
872 			continue;
873 
874 		refcount_inc(&clp->cl_count);
875 		spin_unlock(&nn->nfs_client_lock);
876 		return clp;
877 	}
878 	spin_unlock(&nn->nfs_client_lock);
879 	return NULL;
880 }
881 
882 #else /* CONFIG_NFS_V4_1 */
883 
884 struct nfs_client *
885 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
886 			   struct nfs4_sessionid *sid, u32 minorversion)
887 {
888 	return NULL;
889 }
890 #endif /* CONFIG_NFS_V4_1 */
891 
892 /*
893  * Set up an NFS4 client
894  */
895 static int nfs4_set_client(struct nfs_server *server,
896 		const char *hostname,
897 		const struct sockaddr_storage *addr,
898 		const size_t addrlen,
899 		const char *ip_addr,
900 		int proto, const struct rpc_timeout *timeparms,
901 		u32 minorversion, unsigned int nconnect,
902 		unsigned int max_connect,
903 		struct net *net,
904 		struct xprtsec_parms *xprtsec)
905 {
906 	struct nfs_client_initdata cl_init = {
907 		.hostname = hostname,
908 		.addr = addr,
909 		.addrlen = addrlen,
910 		.ip_addr = ip_addr,
911 		.nfs_mod = &nfs_v4,
912 		.proto = proto,
913 		.minorversion = minorversion,
914 		.net = net,
915 		.timeparms = timeparms,
916 		.cred = server->cred,
917 		.xprtsec = *xprtsec,
918 	};
919 	struct nfs_client *clp;
920 
921 	if (minorversion == 0)
922 		__set_bit(NFS_CS_REUSEPORT, &cl_init.init_flags);
923 	else
924 		cl_init.max_connect = max_connect;
925 	switch (proto) {
926 	case XPRT_TRANSPORT_TCP:
927 	case XPRT_TRANSPORT_TCP_TLS:
928 		cl_init.nconnect = nconnect;
929 	}
930 
931 	if (server->flags & NFS_MOUNT_NORESVPORT)
932 		__set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
933 	if (server->options & NFS_OPTION_MIGRATION)
934 		__set_bit(NFS_CS_MIGRATION, &cl_init.init_flags);
935 	if (test_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status))
936 		__set_bit(NFS_CS_TSM_POSSIBLE, &cl_init.init_flags);
937 	server->port = rpc_get_port((struct sockaddr *)addr);
938 
939 	/* Allocate or find a client reference we can use */
940 	clp = nfs_get_client(&cl_init);
941 	if (IS_ERR(clp))
942 		return PTR_ERR(clp);
943 
944 	if (server->nfs_client == clp) {
945 		nfs_put_client(clp);
946 		return -ELOOP;
947 	}
948 
949 	/*
950 	 * Query for the lease time on clientid setup or renewal
951 	 *
952 	 * Note that this will be set on nfs_clients that were created
953 	 * only for the DS role and did not set this bit, but now will
954 	 * serve a dual role.
955 	 */
956 	set_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state);
957 
958 	server->nfs_client = clp;
959 	nfs_sysfs_add_server(server);
960 	nfs_sysfs_link_rpc_client(server, clp->cl_rpcclient, "_state");
961 
962 	return 0;
963 }
964 
965 /*
966  * Set up a pNFS Data Server client.
967  *
968  * Return any existing nfs_client that matches server address,port,version
969  * and minorversion.
970  *
971  * For a new nfs_client, use a soft mount (default), a low retrans and a
972  * low timeout interval so that if a connection is lost, we retry through
973  * the MDS.
974  */
975 struct nfs_client *nfs4_set_ds_client(struct nfs_server *mds_srv,
976 		const struct sockaddr_storage *ds_addr, int ds_addrlen,
977 		int ds_proto, unsigned int ds_timeo, unsigned int ds_retrans,
978 		u32 minor_version)
979 {
980 	struct rpc_timeout ds_timeout;
981 	struct nfs_client *mds_clp = mds_srv->nfs_client;
982 	struct nfs_client_initdata cl_init = {
983 		.addr = ds_addr,
984 		.addrlen = ds_addrlen,
985 		.nodename = mds_clp->cl_rpcclient->cl_nodename,
986 		.ip_addr = mds_clp->cl_ipaddr,
987 		.nfs_mod = &nfs_v4,
988 		.proto = ds_proto,
989 		.minorversion = minor_version,
990 		.net = mds_clp->cl_net,
991 		.timeparms = &ds_timeout,
992 		.cred = mds_srv->cred,
993 		.xprtsec = mds_srv->nfs_client->cl_xprtsec,
994 	};
995 	char buf[INET6_ADDRSTRLEN + 1];
996 
997 	if (rpc_ntop((struct sockaddr *)ds_addr, buf, sizeof(buf)) <= 0)
998 		return ERR_PTR(-EINVAL);
999 	cl_init.hostname = buf;
1000 
1001 	switch (ds_proto) {
1002 	case XPRT_TRANSPORT_TCP:
1003 	case XPRT_TRANSPORT_TCP_TLS:
1004 		if (mds_clp->cl_nconnect > 1) {
1005 			cl_init.nconnect = mds_clp->cl_nconnect;
1006 			cl_init.max_connect = NFS_MAX_TRANSPORTS;
1007 		}
1008 	}
1009 
1010 	if (mds_srv->flags & NFS_MOUNT_NORESVPORT)
1011 		__set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
1012 
1013 	__set_bit(NFS_CS_PNFS, &cl_init.init_flags);
1014 	cl_init.max_connect = NFS_MAX_TRANSPORTS;
1015 	/*
1016 	 * Set an authflavor equual to the MDS value. Use the MDS nfs_client
1017 	 * cl_ipaddr so as to use the same EXCHANGE_ID co_ownerid as the MDS
1018 	 * (section 13.1 RFC 5661).
1019 	 */
1020 	nfs_init_timeout_values(&ds_timeout, ds_proto, ds_timeo, ds_retrans);
1021 	return nfs_get_client(&cl_init);
1022 }
1023 EXPORT_SYMBOL_GPL(nfs4_set_ds_client);
1024 
1025 /*
1026  * Session has been established, and the client marked ready.
1027  * Limit the mount rsize, wsize and dtsize using negotiated fore
1028  * channel attributes.
1029  */
1030 static void nfs4_session_limit_rwsize(struct nfs_server *server)
1031 {
1032 #ifdef CONFIG_NFS_V4_1
1033 	struct nfs4_session *sess;
1034 	u32 server_resp_sz;
1035 	u32 server_rqst_sz;
1036 
1037 	if (!nfs4_has_session(server->nfs_client))
1038 		return;
1039 	sess = server->nfs_client->cl_session;
1040 	server_resp_sz = sess->fc_attrs.max_resp_sz - nfs41_maxread_overhead;
1041 	server_rqst_sz = sess->fc_attrs.max_rqst_sz - nfs41_maxwrite_overhead;
1042 
1043 	if (server->dtsize > server_resp_sz)
1044 		server->dtsize = server_resp_sz;
1045 	if (server->rsize > server_resp_sz)
1046 		server->rsize = server_resp_sz;
1047 	if (server->wsize > server_rqst_sz)
1048 		server->wsize = server_rqst_sz;
1049 #endif /* CONFIG_NFS_V4_1 */
1050 }
1051 
1052 /*
1053  * Limit xattr sizes using the channel attributes.
1054  */
1055 static void nfs4_session_limit_xasize(struct nfs_server *server)
1056 {
1057 #ifdef CONFIG_NFS_V4_2
1058 	struct nfs4_session *sess;
1059 	u32 server_gxa_sz;
1060 	u32 server_sxa_sz;
1061 	u32 server_lxa_sz;
1062 
1063 	if (!nfs4_has_session(server->nfs_client))
1064 		return;
1065 
1066 	sess = server->nfs_client->cl_session;
1067 
1068 	server_gxa_sz = sess->fc_attrs.max_resp_sz - nfs42_maxgetxattr_overhead;
1069 	server_sxa_sz = sess->fc_attrs.max_rqst_sz - nfs42_maxsetxattr_overhead;
1070 	server_lxa_sz = sess->fc_attrs.max_resp_sz -
1071 	    nfs42_maxlistxattrs_overhead;
1072 
1073 	if (server->gxasize > server_gxa_sz)
1074 		server->gxasize = server_gxa_sz;
1075 	if (server->sxasize > server_sxa_sz)
1076 		server->sxasize = server_sxa_sz;
1077 	if (server->lxasize > server_lxa_sz)
1078 		server->lxasize = server_lxa_sz;
1079 #endif
1080 }
1081 
1082 void nfs4_server_set_init_caps(struct nfs_server *server)
1083 {
1084 	/* Set the basic capabilities */
1085 	server->caps |= server->nfs_client->cl_mvops->init_caps;
1086 	if (server->flags & NFS_MOUNT_NORDIRPLUS)
1087 			server->caps &= ~NFS_CAP_READDIRPLUS;
1088 	if (server->nfs_client->cl_proto == XPRT_TRANSPORT_RDMA)
1089 		server->caps &= ~NFS_CAP_READ_PLUS;
1090 
1091 	/*
1092 	 * Don't use NFS uid/gid mapping if we're using AUTH_SYS or lower
1093 	 * authentication.
1094 	 */
1095 	if (nfs4_disable_idmapping &&
1096 			server->client->cl_auth->au_flavor == RPC_AUTH_UNIX)
1097 		server->caps |= NFS_CAP_UIDGID_NOMAP;
1098 }
1099 
1100 static int nfs4_server_common_setup(struct nfs_server *server,
1101 		struct nfs_fh *mntfh, bool auth_probe)
1102 {
1103 	int error;
1104 
1105 	/* data servers support only a subset of NFSv4.1 */
1106 	if (is_ds_only_client(server->nfs_client))
1107 		return -EPROTONOSUPPORT;
1108 
1109 	/* We must ensure the session is initialised first */
1110 	error = nfs4_init_session(server->nfs_client);
1111 	if (error < 0)
1112 		goto out;
1113 
1114 	nfs4_server_set_init_caps(server);
1115 
1116 	/* Probe the root fh to retrieve its FSID and filehandle */
1117 	error = nfs4_get_rootfh(server, mntfh, auth_probe);
1118 	if (error < 0)
1119 		goto out;
1120 
1121 	dprintk("Server FSID: %llx:%llx\n",
1122 			(unsigned long long) server->fsid.major,
1123 			(unsigned long long) server->fsid.minor);
1124 	nfs_display_fhandle(mntfh, "Pseudo-fs root FH");
1125 
1126 	error = nfs_probe_server(server, mntfh);
1127 	if (error < 0)
1128 		goto out;
1129 
1130 	nfs4_session_limit_rwsize(server);
1131 	nfs4_session_limit_xasize(server);
1132 
1133 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1134 		server->namelen = NFS4_MAXNAMLEN;
1135 
1136 	nfs_server_insert_lists(server);
1137 	server->mount_time = jiffies;
1138 	server->destroy = nfs4_destroy_server;
1139 out:
1140 	return error;
1141 }
1142 
1143 /*
1144  * Create a version 4 volume record
1145  */
1146 static int nfs4_init_server(struct nfs_server *server, struct fs_context *fc)
1147 {
1148 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1149 	struct rpc_timeout timeparms;
1150 	int error;
1151 
1152 	nfs_init_timeout_values(&timeparms, ctx->nfs_server.protocol,
1153 				ctx->timeo, ctx->retrans);
1154 
1155 	/* Initialise the client representation from the mount data */
1156 	server->flags = ctx->flags;
1157 	server->options = ctx->options;
1158 	server->auth_info = ctx->auth_info;
1159 
1160 	/* Use the first specified auth flavor. If this flavor isn't
1161 	 * allowed by the server, use the SECINFO path to try the
1162 	 * other specified flavors */
1163 	if (ctx->auth_info.flavor_len >= 1)
1164 		ctx->selected_flavor = ctx->auth_info.flavors[0];
1165 	else
1166 		ctx->selected_flavor = RPC_AUTH_UNIX;
1167 
1168 	/* Get a client record */
1169 	error = nfs4_set_client(server,
1170 				ctx->nfs_server.hostname,
1171 				&ctx->nfs_server._address,
1172 				ctx->nfs_server.addrlen,
1173 				ctx->client_address,
1174 				ctx->nfs_server.protocol,
1175 				&timeparms,
1176 				ctx->minorversion,
1177 				ctx->nfs_server.nconnect,
1178 				ctx->nfs_server.max_connect,
1179 				fc->net_ns,
1180 				&ctx->xprtsec);
1181 	if (error < 0)
1182 		return error;
1183 
1184 	if (ctx->rsize)
1185 		server->rsize = nfs_io_size(ctx->rsize, server->nfs_client->cl_proto);
1186 	if (ctx->wsize)
1187 		server->wsize = nfs_io_size(ctx->wsize, server->nfs_client->cl_proto);
1188 
1189 	server->acregmin = ctx->acregmin * HZ;
1190 	server->acregmax = ctx->acregmax * HZ;
1191 	server->acdirmin = ctx->acdirmin * HZ;
1192 	server->acdirmax = ctx->acdirmax * HZ;
1193 	server->port     = ctx->nfs_server.port;
1194 
1195 	return nfs_init_server_rpcclient(server, &timeparms,
1196 					 ctx->selected_flavor);
1197 }
1198 
1199 /*
1200  * Create a version 4 volume record
1201  * - keyed on server and FSID
1202  */
1203 struct nfs_server *nfs4_create_server(struct fs_context *fc)
1204 {
1205 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1206 	struct nfs_server *server;
1207 	bool auth_probe;
1208 	int error;
1209 
1210 	server = nfs_alloc_server();
1211 	if (!server)
1212 		return ERR_PTR(-ENOMEM);
1213 
1214 	server->cred = get_cred(fc->cred);
1215 
1216 	auth_probe = ctx->auth_info.flavor_len < 1;
1217 
1218 	/* set up the general RPC client */
1219 	error = nfs4_init_server(server, fc);
1220 	if (error < 0)
1221 		goto error;
1222 
1223 	error = nfs4_server_common_setup(server, ctx->mntfh, auth_probe);
1224 	if (error < 0)
1225 		goto error;
1226 
1227 	return server;
1228 
1229 error:
1230 	nfs_free_server(server);
1231 	return ERR_PTR(error);
1232 }
1233 
1234 /*
1235  * Create an NFS4 referral server record
1236  */
1237 struct nfs_server *nfs4_create_referral_server(struct fs_context *fc)
1238 {
1239 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1240 	struct nfs_client *parent_client;
1241 	struct nfs_server *server, *parent_server;
1242 	int proto, error;
1243 	bool auth_probe;
1244 
1245 	server = nfs_alloc_server();
1246 	if (!server)
1247 		return ERR_PTR(-ENOMEM);
1248 
1249 	parent_server = NFS_SB(ctx->clone_data.sb);
1250 	parent_client = parent_server->nfs_client;
1251 
1252 	server->cred = get_cred(parent_server->cred);
1253 
1254 	/* Initialise the client representation from the parent server */
1255 	nfs_server_copy_userdata(server, parent_server);
1256 
1257 	/* Get a client representation */
1258 #if IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA)
1259 	rpc_set_port(&ctx->nfs_server.address, NFS_RDMA_PORT);
1260 	error = nfs4_set_client(server,
1261 				ctx->nfs_server.hostname,
1262 				&ctx->nfs_server._address,
1263 				ctx->nfs_server.addrlen,
1264 				parent_client->cl_ipaddr,
1265 				XPRT_TRANSPORT_RDMA,
1266 				parent_server->client->cl_timeout,
1267 				parent_client->cl_mvops->minor_version,
1268 				parent_client->cl_nconnect,
1269 				parent_client->cl_max_connect,
1270 				parent_client->cl_net,
1271 				&parent_client->cl_xprtsec);
1272 	if (!error)
1273 		goto init_server;
1274 #endif	/* IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA) */
1275 
1276 	proto = XPRT_TRANSPORT_TCP;
1277 	if (parent_client->cl_xprtsec.policy != RPC_XPRTSEC_NONE)
1278 		proto = XPRT_TRANSPORT_TCP_TLS;
1279 	rpc_set_port(&ctx->nfs_server.address, NFS_PORT);
1280 	error = nfs4_set_client(server,
1281 				ctx->nfs_server.hostname,
1282 				&ctx->nfs_server._address,
1283 				ctx->nfs_server.addrlen,
1284 				parent_client->cl_ipaddr,
1285 				proto,
1286 				parent_server->client->cl_timeout,
1287 				parent_client->cl_mvops->minor_version,
1288 				parent_client->cl_nconnect,
1289 				parent_client->cl_max_connect,
1290 				parent_client->cl_net,
1291 				&parent_client->cl_xprtsec);
1292 	if (error < 0)
1293 		goto error;
1294 
1295 #if IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA)
1296 init_server:
1297 #endif
1298 	error = nfs_init_server_rpcclient(server, parent_server->client->cl_timeout,
1299 					  ctx->selected_flavor);
1300 	if (error < 0)
1301 		goto error;
1302 
1303 	auth_probe = parent_server->auth_info.flavor_len < 1;
1304 
1305 	error = nfs4_server_common_setup(server, ctx->mntfh, auth_probe);
1306 	if (error < 0)
1307 		goto error;
1308 
1309 	return server;
1310 
1311 error:
1312 	nfs_free_server(server);
1313 	return ERR_PTR(error);
1314 }
1315 
1316 /**
1317  * nfs4_update_server - Move an nfs_server to a different nfs_client
1318  *
1319  * @server: represents FSID to be moved
1320  * @hostname: new end-point's hostname
1321  * @sap: new end-point's socket address
1322  * @salen: size of "sap"
1323  * @net: net namespace
1324  *
1325  * The nfs_server must be quiescent before this function is invoked.
1326  * Either its session is drained (NFSv4.1+), or its transport is
1327  * plugged and drained (NFSv4.0).
1328  *
1329  * Returns zero on success, or a negative errno value.
1330  */
1331 int nfs4_update_server(struct nfs_server *server, const char *hostname,
1332 		       struct sockaddr_storage *sap, size_t salen, struct net *net)
1333 {
1334 	struct nfs_client *clp = server->nfs_client;
1335 	struct rpc_clnt *clnt = server->client;
1336 	struct xprt_create xargs = {
1337 		.ident		= clp->cl_proto,
1338 		.net		= net,
1339 		.dstaddr	= (struct sockaddr *)sap,
1340 		.addrlen	= salen,
1341 		.servername	= hostname,
1342 		/* cel: bleh. We might need to pass TLS parameters here */
1343 	};
1344 	char buf[INET6_ADDRSTRLEN + 1];
1345 	struct sockaddr_storage address;
1346 	struct sockaddr *localaddr = (struct sockaddr *)&address;
1347 	int error;
1348 
1349 	error = rpc_switch_client_transport(clnt, &xargs, clnt->cl_timeout);
1350 	if (error != 0)
1351 		return error;
1352 
1353 	error = rpc_localaddr(clnt, localaddr, sizeof(address));
1354 	if (error != 0)
1355 		return error;
1356 
1357 	if (rpc_ntop(localaddr, buf, sizeof(buf)) == 0)
1358 		return -EAFNOSUPPORT;
1359 
1360 	nfs_server_remove_lists(server);
1361 	set_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status);
1362 	error = nfs4_set_client(server, hostname, sap, salen, buf,
1363 				clp->cl_proto, clnt->cl_timeout,
1364 				clp->cl_minorversion,
1365 				clp->cl_nconnect, clp->cl_max_connect,
1366 				net, &clp->cl_xprtsec);
1367 	clear_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status);
1368 	if (error != 0) {
1369 		nfs_server_insert_lists(server);
1370 		return error;
1371 	}
1372 	nfs_put_client(clp);
1373 
1374 	if (server->nfs_client->cl_hostname == NULL) {
1375 		server->nfs_client->cl_hostname = kstrdup(hostname, GFP_KERNEL);
1376 		if (server->nfs_client->cl_hostname == NULL)
1377 			return -ENOMEM;
1378 	}
1379 	nfs_server_insert_lists(server);
1380 
1381 	return nfs_probe_server(server, NFS_FH(d_inode(server->super->s_root)));
1382 }
1383