xref: /linux/fs/nfs/nfs4client.c (revision 561add0da6d3d07c9bccb0832fb6ed5619167d26)
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 
235 	if (test_bit(NFS_CS_DS, &cl_init->init_flags))
236 		__set_bit(NFS_CS_DS, &clp->cl_flags);
237 	/*
238 	 * Set up the connection to the server before we add add to the
239 	 * global list.
240 	 */
241 	err = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_GSS_KRB5I);
242 	if (err == -EINVAL)
243 		err = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_UNIX);
244 	if (err < 0)
245 		goto error;
246 
247 	/* If no clientaddr= option was specified, find a usable cb address */
248 	if (ip_addr == NULL) {
249 		struct sockaddr_storage cb_addr;
250 		struct sockaddr *sap = (struct sockaddr *)&cb_addr;
251 
252 		err = rpc_localaddr(clp->cl_rpcclient, sap, sizeof(cb_addr));
253 		if (err < 0)
254 			goto error;
255 		err = rpc_ntop(sap, buf, sizeof(buf));
256 		if (err < 0)
257 			goto error;
258 		ip_addr = (const char *)buf;
259 	}
260 	strscpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr));
261 
262 	err = nfs_idmap_new(clp);
263 	if (err < 0) {
264 		dprintk("%s: failed to create idmapper. Error = %d\n",
265 			__func__, err);
266 		goto error;
267 	}
268 	__set_bit(NFS_CS_IDMAP, &clp->cl_res_state);
269 	return clp;
270 
271 error:
272 	nfs_free_client(clp);
273 	return ERR_PTR(err);
274 }
275 
276 /*
277  * Destroy the NFS4 callback service
278  */
279 static void nfs4_destroy_callback(struct nfs_client *clp)
280 {
281 	if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
282 		nfs_callback_down(clp->cl_mvops->minor_version, clp->cl_net);
283 }
284 
285 static void nfs4_shutdown_client(struct nfs_client *clp)
286 {
287 	if (__test_and_clear_bit(NFS_CS_RENEWD, &clp->cl_res_state))
288 		nfs4_kill_renewd(clp);
289 	clp->cl_mvops->shutdown_client(clp);
290 	nfs4_destroy_callback(clp);
291 	if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state))
292 		nfs_idmap_delete(clp);
293 
294 	rpc_destroy_wait_queue(&clp->cl_rpcwaitq);
295 	kfree(clp->cl_serverowner);
296 	kfree(clp->cl_serverscope);
297 	kfree(clp->cl_implid);
298 	kfree(clp->cl_owner_id);
299 }
300 
301 void nfs4_free_client(struct nfs_client *clp)
302 {
303 	nfs4_shutdown_client(clp);
304 	nfs_free_client(clp);
305 }
306 
307 /*
308  * Initialize the NFS4 callback service
309  */
310 static int nfs4_init_callback(struct nfs_client *clp)
311 {
312 	struct rpc_xprt *xprt;
313 	int error;
314 
315 	xprt = rcu_dereference_raw(clp->cl_rpcclient->cl_xprt);
316 
317 	if (nfs4_has_session(clp)) {
318 		error = xprt_setup_backchannel(xprt, NFS41_BC_MIN_CALLBACKS);
319 		if (error < 0)
320 			return error;
321 	}
322 
323 	error = nfs_callback_up(clp->cl_mvops->minor_version, xprt);
324 	if (error < 0) {
325 		dprintk("%s: failed to start callback. Error = %d\n",
326 			__func__, error);
327 		return error;
328 	}
329 	__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
330 
331 	return 0;
332 }
333 
334 /**
335  * nfs40_init_client - nfs_client initialization tasks for NFSv4.0
336  * @clp: nfs_client to initialize
337  *
338  * Returns zero on success, or a negative errno if some error occurred.
339  */
340 int nfs40_init_client(struct nfs_client *clp)
341 {
342 	struct nfs4_slot_table *tbl;
343 	int ret;
344 
345 	tbl = kzalloc(sizeof(*tbl), GFP_NOFS);
346 	if (tbl == NULL)
347 		return -ENOMEM;
348 
349 	ret = nfs4_setup_slot_table(tbl, NFS4_MAX_SLOT_TABLE,
350 					"NFSv4.0 transport Slot table");
351 	if (ret) {
352 		nfs4_shutdown_slot_table(tbl);
353 		kfree(tbl);
354 		return ret;
355 	}
356 
357 	clp->cl_slot_tbl = tbl;
358 	return 0;
359 }
360 
361 #if defined(CONFIG_NFS_V4_1)
362 
363 /**
364  * nfs41_init_client - nfs_client initialization tasks for NFSv4.1+
365  * @clp: nfs_client to initialize
366  *
367  * Returns zero on success, or a negative errno if some error occurred.
368  */
369 int nfs41_init_client(struct nfs_client *clp)
370 {
371 	struct nfs4_session *session = NULL;
372 
373 	/*
374 	 * Create the session and mark it expired.
375 	 * When a SEQUENCE operation encounters the expired session
376 	 * it will do session recovery to initialize it.
377 	 */
378 	session = nfs4_alloc_session(clp);
379 	if (!session)
380 		return -ENOMEM;
381 
382 	clp->cl_session = session;
383 
384 	/*
385 	 * The create session reply races with the server back
386 	 * channel probe. Mark the client NFS_CS_SESSION_INITING
387 	 * so that the client back channel can find the
388 	 * nfs_client struct
389 	 */
390 	nfs_mark_client_ready(clp, NFS_CS_SESSION_INITING);
391 	return 0;
392 }
393 
394 #endif	/* CONFIG_NFS_V4_1 */
395 
396 /*
397  * Initialize the minor version specific parts of an NFS4 client record
398  */
399 static int nfs4_init_client_minor_version(struct nfs_client *clp)
400 {
401 	int ret;
402 
403 	ret = clp->cl_mvops->init_client(clp);
404 	if (ret)
405 		return ret;
406 	return nfs4_init_callback(clp);
407 }
408 
409 static void nfs4_add_trunk(struct nfs_client *clp, struct nfs_client *old)
410 {
411 	struct sockaddr_storage clp_addr, old_addr;
412 	struct sockaddr *clp_sap = (struct sockaddr *)&clp_addr;
413 	struct sockaddr *old_sap = (struct sockaddr *)&old_addr;
414 	size_t clp_salen;
415 	struct xprt_create xprt_args = {
416 		.ident = old->cl_proto,
417 		.net = old->cl_net,
418 		.servername = old->cl_hostname,
419 	};
420 
421 	if (clp->cl_proto != old->cl_proto)
422 		return;
423 	clp_salen = rpc_peeraddr(clp->cl_rpcclient, clp_sap, sizeof(clp_addr));
424 	rpc_peeraddr(old->cl_rpcclient, old_sap, sizeof(old_addr));
425 
426 	if (clp_addr.ss_family != old_addr.ss_family)
427 		return;
428 
429 	xprt_args.dstaddr = clp_sap;
430 	xprt_args.addrlen = clp_salen;
431 
432 	rpc_clnt_add_xprt(old->cl_rpcclient, &xprt_args,
433 			  rpc_clnt_test_and_add_xprt, NULL);
434 }
435 
436 /**
437  * nfs4_init_client - Initialise an NFS4 client record
438  *
439  * @clp: nfs_client to initialise
440  * @cl_init: pointer to nfs_client_initdata
441  *
442  * Returns pointer to an NFS client, or an ERR_PTR value.
443  */
444 struct nfs_client *nfs4_init_client(struct nfs_client *clp,
445 				    const struct nfs_client_initdata *cl_init)
446 {
447 	struct nfs_client *old;
448 	int error;
449 
450 	if (clp->cl_cons_state == NFS_CS_READY)
451 		/* the client is initialised already */
452 		return clp;
453 
454 	error = nfs4_init_client_minor_version(clp);
455 	if (error < 0)
456 		goto error;
457 
458 	error = nfs4_discover_server_trunking(clp, &old);
459 	if (error < 0)
460 		goto error;
461 
462 	if (clp != old) {
463 		clp->cl_preserve_clid = true;
464 		/*
465 		 * Mark the client as having failed initialization so other
466 		 * processes walking the nfs_client_list in nfs_match_client()
467 		 * won't try to use it.
468 		 */
469 		nfs_mark_client_ready(clp, -EPERM);
470 		if (old->cl_mvops->session_trunk)
471 			nfs4_add_trunk(clp, old);
472 	}
473 	clear_bit(NFS_CS_TSM_POSSIBLE, &clp->cl_flags);
474 	nfs_put_client(clp);
475 	return old;
476 
477 error:
478 	nfs_mark_client_ready(clp, error);
479 	nfs_put_client(clp);
480 	return ERR_PTR(error);
481 }
482 
483 /*
484  * SETCLIENTID just did a callback update with the callback ident in
485  * "drop," but server trunking discovery claims "drop" and "keep" are
486  * actually the same server.  Swap the callback IDs so that "keep"
487  * will continue to use the callback ident the server now knows about,
488  * and so that "keep"'s original callback ident is destroyed when
489  * "drop" is freed.
490  */
491 static void nfs4_swap_callback_idents(struct nfs_client *keep,
492 				      struct nfs_client *drop)
493 {
494 	struct nfs_net *nn = net_generic(keep->cl_net, nfs_net_id);
495 	unsigned int save = keep->cl_cb_ident;
496 
497 	if (keep->cl_cb_ident == drop->cl_cb_ident)
498 		return;
499 
500 	dprintk("%s: keeping callback ident %u and dropping ident %u\n",
501 		__func__, keep->cl_cb_ident, drop->cl_cb_ident);
502 
503 	spin_lock(&nn->nfs_client_lock);
504 
505 	idr_replace(&nn->cb_ident_idr, keep, drop->cl_cb_ident);
506 	keep->cl_cb_ident = drop->cl_cb_ident;
507 
508 	idr_replace(&nn->cb_ident_idr, drop, save);
509 	drop->cl_cb_ident = save;
510 
511 	spin_unlock(&nn->nfs_client_lock);
512 }
513 
514 static bool nfs4_match_client_owner_id(const struct nfs_client *clp1,
515 		const struct nfs_client *clp2)
516 {
517 	if (clp1->cl_owner_id == NULL || clp2->cl_owner_id == NULL)
518 		return true;
519 	return strcmp(clp1->cl_owner_id, clp2->cl_owner_id) == 0;
520 }
521 
522 static bool nfs4_same_verifier(nfs4_verifier *v1, nfs4_verifier *v2)
523 {
524 	return memcmp(v1->data, v2->data, sizeof(v1->data)) == 0;
525 }
526 
527 static int nfs4_match_client(struct nfs_client  *pos,  struct nfs_client *new,
528 			     struct nfs_client **prev, struct nfs_net *nn)
529 {
530 	int status;
531 
532 	if (pos->rpc_ops != new->rpc_ops)
533 		return 1;
534 
535 	if (pos->cl_minorversion != new->cl_minorversion)
536 		return 1;
537 
538 	/* If "pos" isn't marked ready, we can't trust the
539 	 * remaining fields in "pos", especially the client
540 	 * ID and serverowner fields.  Wait for CREATE_SESSION
541 	 * to finish. */
542 	if (pos->cl_cons_state > NFS_CS_READY) {
543 		refcount_inc(&pos->cl_count);
544 		spin_unlock(&nn->nfs_client_lock);
545 
546 		nfs_put_client(*prev);
547 		*prev = pos;
548 
549 		status = nfs_wait_client_init_complete(pos);
550 		spin_lock(&nn->nfs_client_lock);
551 
552 		if (status < 0)
553 			return status;
554 	}
555 
556 	if (pos->cl_cons_state != NFS_CS_READY)
557 		return 1;
558 
559 	if (pos->cl_clientid != new->cl_clientid)
560 		return 1;
561 
562 	/* NFSv4.1 always uses the uniform string, however someone
563 	 * might switch the uniquifier string on us.
564 	 */
565 	if (!nfs4_match_client_owner_id(pos, new))
566 		return 1;
567 
568 	return 0;
569 }
570 
571 /**
572  * nfs40_walk_client_list - Find server that recognizes a client ID
573  *
574  * @new: nfs_client with client ID to test
575  * @result: OUT: found nfs_client, or new
576  * @cred: credential to use for trunking test
577  *
578  * Returns zero, a negative errno, or a negative NFS4ERR status.
579  * If zero is returned, an nfs_client pointer is planted in "result."
580  *
581  * NB: nfs40_walk_client_list() relies on the new nfs_client being
582  *     the last nfs_client on the list.
583  */
584 int nfs40_walk_client_list(struct nfs_client *new,
585 			   struct nfs_client **result,
586 			   const struct cred *cred)
587 {
588 	struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
589 	struct nfs_client *pos, *prev = NULL;
590 	struct nfs4_setclientid_res clid = {
591 		.clientid	= new->cl_clientid,
592 		.confirm	= new->cl_confirm,
593 	};
594 	int status = -NFS4ERR_STALE_CLIENTID;
595 
596 	spin_lock(&nn->nfs_client_lock);
597 	list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
598 
599 		if (pos == new)
600 			goto found;
601 
602 		status = nfs4_match_client(pos, new, &prev, nn);
603 		if (status < 0)
604 			goto out_unlock;
605 		if (status != 0)
606 			continue;
607 		/*
608 		 * We just sent a new SETCLIENTID, which should have
609 		 * caused the server to return a new cl_confirm.  So if
610 		 * cl_confirm is the same, then this is a different
611 		 * server that just returned the same cl_confirm by
612 		 * coincidence:
613 		 */
614 		if ((new != pos) && nfs4_same_verifier(&pos->cl_confirm,
615 						       &new->cl_confirm))
616 			continue;
617 		/*
618 		 * But if the cl_confirm's are different, then the only
619 		 * way that a SETCLIENTID_CONFIRM to pos can succeed is
620 		 * if new and pos point to the same server:
621 		 */
622 found:
623 		refcount_inc(&pos->cl_count);
624 		spin_unlock(&nn->nfs_client_lock);
625 
626 		nfs_put_client(prev);
627 		prev = pos;
628 
629 		status = nfs4_proc_setclientid_confirm(pos, &clid, cred);
630 		switch (status) {
631 		case -NFS4ERR_STALE_CLIENTID:
632 			break;
633 		case 0:
634 			nfs4_swap_callback_idents(pos, new);
635 			pos->cl_confirm = new->cl_confirm;
636 			nfs_mark_client_ready(pos, NFS_CS_READY);
637 
638 			prev = NULL;
639 			*result = pos;
640 			goto out;
641 		case -ERESTARTSYS:
642 		case -ETIMEDOUT:
643 			/* The callback path may have been inadvertently
644 			 * changed. Schedule recovery!
645 			 */
646 			nfs4_schedule_path_down_recovery(pos);
647 			goto out;
648 		default:
649 			goto out;
650 		}
651 
652 		spin_lock(&nn->nfs_client_lock);
653 	}
654 out_unlock:
655 	spin_unlock(&nn->nfs_client_lock);
656 
657 	/* No match found. The server lost our clientid */
658 out:
659 	nfs_put_client(prev);
660 	return status;
661 }
662 
663 #ifdef CONFIG_NFS_V4_1
664 /*
665  * Returns true if the server major ids match
666  */
667 bool
668 nfs4_check_serverowner_major_id(struct nfs41_server_owner *o1,
669 				struct nfs41_server_owner *o2)
670 {
671 	if (o1->major_id_sz != o2->major_id_sz)
672 		return false;
673 	return memcmp(o1->major_id, o2->major_id, o1->major_id_sz) == 0;
674 }
675 
676 /*
677  * Returns true if the server scopes match
678  */
679 static bool
680 nfs4_check_server_scope(struct nfs41_server_scope *s1,
681 			struct nfs41_server_scope *s2)
682 {
683 	if (s1->server_scope_sz != s2->server_scope_sz)
684 		return false;
685 	return memcmp(s1->server_scope, s2->server_scope,
686 					s1->server_scope_sz) == 0;
687 }
688 
689 /**
690  * nfs4_detect_session_trunking - Checks for session trunking.
691  * @clp:    original mount nfs_client
692  * @res:    result structure from an exchange_id using the original mount
693  *          nfs_client with a new multi_addr transport
694  * @xprt:   pointer to the transport to add.
695  *
696  * Called after a successful EXCHANGE_ID on a multi-addr connection.
697  * Upon success, add the transport.
698  *
699  * Returns zero on success, otherwise -EINVAL
700  *
701  * Note: since the exchange_id for the new multi_addr transport uses the
702  * same nfs_client from the original mount, the cl_owner_id is reused,
703  * so eir_clientowner is the same.
704  */
705 int nfs4_detect_session_trunking(struct nfs_client *clp,
706 				 struct nfs41_exchange_id_res *res,
707 				 struct rpc_xprt *xprt)
708 {
709 	/* Check eir_clientid */
710 	if (clp->cl_clientid != res->clientid)
711 		goto out_err;
712 
713 	/* Check eir_server_owner so_major_id */
714 	if (!nfs4_check_serverowner_major_id(clp->cl_serverowner,
715 					     res->server_owner))
716 		goto out_err;
717 
718 	/* Check eir_server_owner so_minor_id */
719 	if (clp->cl_serverowner->minor_id != res->server_owner->minor_id)
720 		goto out_err;
721 
722 	/* Check eir_server_scope */
723 	if (!nfs4_check_server_scope(clp->cl_serverscope, res->server_scope))
724 		goto out_err;
725 
726 	pr_info("NFS:  %s: Session trunking succeeded for %s\n",
727 		clp->cl_hostname,
728 		xprt->address_strings[RPC_DISPLAY_ADDR]);
729 
730 	return 0;
731 out_err:
732 	pr_info("NFS:  %s: Session trunking failed for %s\n", clp->cl_hostname,
733 		xprt->address_strings[RPC_DISPLAY_ADDR]);
734 
735 	return -EINVAL;
736 }
737 
738 /**
739  * nfs41_walk_client_list - Find nfs_client that matches a client/server owner
740  *
741  * @new: nfs_client with client ID to test
742  * @result: OUT: found nfs_client, or new
743  * @cred: credential to use for trunking test
744  *
745  * Returns zero, a negative errno, or a negative NFS4ERR status.
746  * If zero is returned, an nfs_client pointer is planted in "result."
747  *
748  * NB: nfs41_walk_client_list() relies on the new nfs_client being
749  *     the last nfs_client on the list.
750  */
751 int nfs41_walk_client_list(struct nfs_client *new,
752 			   struct nfs_client **result,
753 			   const struct cred *cred)
754 {
755 	struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
756 	struct nfs_client *pos, *prev = NULL;
757 	int status = -NFS4ERR_STALE_CLIENTID;
758 
759 	spin_lock(&nn->nfs_client_lock);
760 	list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
761 
762 		if (pos == new)
763 			goto found;
764 
765 		status = nfs4_match_client(pos, new, &prev, nn);
766 		if (status < 0)
767 			goto out;
768 		if (status != 0)
769 			continue;
770 
771 		/*
772 		 * Note that session trunking is just a special subcase of
773 		 * client id trunking. In either case, we want to fall back
774 		 * to using the existing nfs_client.
775 		 */
776 		if (!nfs4_check_serverowner_major_id(pos->cl_serverowner,
777 						     new->cl_serverowner))
778 			continue;
779 
780 found:
781 		refcount_inc(&pos->cl_count);
782 		*result = pos;
783 		status = 0;
784 		break;
785 	}
786 
787 out:
788 	spin_unlock(&nn->nfs_client_lock);
789 	nfs_put_client(prev);
790 	return status;
791 }
792 #endif	/* CONFIG_NFS_V4_1 */
793 
794 static void nfs4_destroy_server(struct nfs_server *server)
795 {
796 	LIST_HEAD(freeme);
797 
798 	nfs_server_return_all_delegations(server);
799 	unset_pnfs_layoutdriver(server);
800 	nfs4_purge_state_owners(server, &freeme);
801 	nfs4_free_state_owners(&freeme);
802 }
803 
804 /*
805  * NFSv4.0 callback thread helper
806  *
807  * Find a client by callback identifier
808  */
809 struct nfs_client *
810 nfs4_find_client_ident(struct net *net, int cb_ident)
811 {
812 	struct nfs_client *clp;
813 	struct nfs_net *nn = net_generic(net, nfs_net_id);
814 
815 	spin_lock(&nn->nfs_client_lock);
816 	clp = idr_find(&nn->cb_ident_idr, cb_ident);
817 	if (clp)
818 		refcount_inc(&clp->cl_count);
819 	spin_unlock(&nn->nfs_client_lock);
820 	return clp;
821 }
822 
823 #if defined(CONFIG_NFS_V4_1)
824 /* Common match routine for v4.0 and v4.1 callback services */
825 static bool nfs4_cb_match_client(const struct sockaddr *addr,
826 		struct nfs_client *clp, u32 minorversion)
827 {
828 	struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
829 
830 	/* Don't match clients that failed to initialise */
831 	if (!(clp->cl_cons_state == NFS_CS_READY ||
832 	    clp->cl_cons_state == NFS_CS_SESSION_INITING))
833 		return false;
834 
835 	smp_rmb();
836 
837 	/* Match the version and minorversion */
838 	if (clp->rpc_ops->version != 4 ||
839 	    clp->cl_minorversion != minorversion)
840 		return false;
841 
842 	/* Match only the IP address, not the port number */
843 	return rpc_cmp_addr(addr, clap);
844 }
845 
846 /*
847  * NFSv4.1 callback thread helper
848  * For CB_COMPOUND calls, find a client by IP address, protocol version,
849  * minorversion, and sessionID
850  *
851  * Returns NULL if no such client
852  */
853 struct nfs_client *
854 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
855 			   struct nfs4_sessionid *sid, u32 minorversion)
856 {
857 	struct nfs_client *clp;
858 	struct nfs_net *nn = net_generic(net, nfs_net_id);
859 
860 	spin_lock(&nn->nfs_client_lock);
861 	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
862 		if (!nfs4_cb_match_client(addr, clp, minorversion))
863 			continue;
864 
865 		if (!nfs4_has_session(clp))
866 			continue;
867 
868 		/* Match sessionid*/
869 		if (memcmp(clp->cl_session->sess_id.data,
870 		    sid->data, NFS4_MAX_SESSIONID_LEN) != 0)
871 			continue;
872 
873 		refcount_inc(&clp->cl_count);
874 		spin_unlock(&nn->nfs_client_lock);
875 		return clp;
876 	}
877 	spin_unlock(&nn->nfs_client_lock);
878 	return NULL;
879 }
880 
881 #else /* CONFIG_NFS_V4_1 */
882 
883 struct nfs_client *
884 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
885 			   struct nfs4_sessionid *sid, u32 minorversion)
886 {
887 	return NULL;
888 }
889 #endif /* CONFIG_NFS_V4_1 */
890 
891 /*
892  * Set up an NFS4 client
893  */
894 static int nfs4_set_client(struct nfs_server *server,
895 		const char *hostname,
896 		const struct sockaddr_storage *addr,
897 		const size_t addrlen,
898 		const char *ip_addr,
899 		int proto, const struct rpc_timeout *timeparms,
900 		u32 minorversion, unsigned int nconnect,
901 		unsigned int max_connect,
902 		struct net *net,
903 		struct xprtsec_parms *xprtsec)
904 {
905 	struct nfs_client_initdata cl_init = {
906 		.hostname = hostname,
907 		.addr = addr,
908 		.addrlen = addrlen,
909 		.ip_addr = ip_addr,
910 		.nfs_mod = &nfs_v4,
911 		.proto = proto,
912 		.minorversion = minorversion,
913 		.net = net,
914 		.timeparms = timeparms,
915 		.cred = server->cred,
916 		.xprtsec = *xprtsec,
917 	};
918 	struct nfs_client *clp;
919 
920 	if (minorversion == 0)
921 		__set_bit(NFS_CS_REUSEPORT, &cl_init.init_flags);
922 	else
923 		cl_init.max_connect = max_connect;
924 	switch (proto) {
925 	case XPRT_TRANSPORT_TCP:
926 	case XPRT_TRANSPORT_TCP_TLS:
927 		cl_init.nconnect = nconnect;
928 	}
929 
930 	if (server->flags & NFS_MOUNT_NORESVPORT)
931 		__set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
932 	if (server->options & NFS_OPTION_MIGRATION)
933 		__set_bit(NFS_CS_MIGRATION, &cl_init.init_flags);
934 	if (test_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status))
935 		__set_bit(NFS_CS_TSM_POSSIBLE, &cl_init.init_flags);
936 	server->port = rpc_get_port((struct sockaddr *)addr);
937 
938 	/* Allocate or find a client reference we can use */
939 	clp = nfs_get_client(&cl_init);
940 	if (IS_ERR(clp))
941 		return PTR_ERR(clp);
942 
943 	if (server->nfs_client == clp) {
944 		nfs_put_client(clp);
945 		return -ELOOP;
946 	}
947 
948 	/*
949 	 * Query for the lease time on clientid setup or renewal
950 	 *
951 	 * Note that this will be set on nfs_clients that were created
952 	 * only for the DS role and did not set this bit, but now will
953 	 * serve a dual role.
954 	 */
955 	set_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state);
956 
957 	server->nfs_client = clp;
958 	nfs_sysfs_add_server(server);
959 	nfs_sysfs_link_rpc_client(server, clp->cl_rpcclient, "_state");
960 
961 	return 0;
962 }
963 
964 /*
965  * Set up a pNFS Data Server client.
966  *
967  * Return any existing nfs_client that matches server address,port,version
968  * and minorversion.
969  *
970  * For a new nfs_client, use a soft mount (default), a low retrans and a
971  * low timeout interval so that if a connection is lost, we retry through
972  * the MDS.
973  */
974 struct nfs_client *nfs4_set_ds_client(struct nfs_server *mds_srv,
975 		const struct sockaddr_storage *ds_addr, int ds_addrlen,
976 		int ds_proto, unsigned int ds_timeo, unsigned int ds_retrans,
977 		u32 minor_version)
978 {
979 	struct rpc_timeout ds_timeout;
980 	struct nfs_client *mds_clp = mds_srv->nfs_client;
981 	struct nfs_client_initdata cl_init = {
982 		.addr = ds_addr,
983 		.addrlen = ds_addrlen,
984 		.nodename = mds_clp->cl_rpcclient->cl_nodename,
985 		.ip_addr = mds_clp->cl_ipaddr,
986 		.nfs_mod = &nfs_v4,
987 		.proto = ds_proto,
988 		.minorversion = minor_version,
989 		.net = mds_clp->cl_net,
990 		.timeparms = &ds_timeout,
991 		.cred = mds_srv->cred,
992 		.xprtsec = mds_srv->nfs_client->cl_xprtsec,
993 	};
994 	char buf[INET6_ADDRSTRLEN + 1];
995 
996 	if (rpc_ntop((struct sockaddr *)ds_addr, buf, sizeof(buf)) <= 0)
997 		return ERR_PTR(-EINVAL);
998 	cl_init.hostname = buf;
999 
1000 	switch (ds_proto) {
1001 	case XPRT_TRANSPORT_TCP:
1002 	case XPRT_TRANSPORT_TCP_TLS:
1003 		if (mds_clp->cl_nconnect > 1) {
1004 			cl_init.nconnect = mds_clp->cl_nconnect;
1005 			cl_init.max_connect = NFS_MAX_TRANSPORTS;
1006 		}
1007 	}
1008 
1009 	if (mds_srv->flags & NFS_MOUNT_NORESVPORT)
1010 		__set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
1011 
1012 	__set_bit(NFS_CS_DS, &cl_init.init_flags);
1013 	/*
1014 	 * Set an authflavor equual to the MDS value. Use the MDS nfs_client
1015 	 * cl_ipaddr so as to use the same EXCHANGE_ID co_ownerid as the MDS
1016 	 * (section 13.1 RFC 5661).
1017 	 */
1018 	nfs_init_timeout_values(&ds_timeout, ds_proto, ds_timeo, ds_retrans);
1019 	return nfs_get_client(&cl_init);
1020 }
1021 EXPORT_SYMBOL_GPL(nfs4_set_ds_client);
1022 
1023 /*
1024  * Session has been established, and the client marked ready.
1025  * Limit the mount rsize, wsize and dtsize using negotiated fore
1026  * channel attributes.
1027  */
1028 static void nfs4_session_limit_rwsize(struct nfs_server *server)
1029 {
1030 #ifdef CONFIG_NFS_V4_1
1031 	struct nfs4_session *sess;
1032 	u32 server_resp_sz;
1033 	u32 server_rqst_sz;
1034 
1035 	if (!nfs4_has_session(server->nfs_client))
1036 		return;
1037 	sess = server->nfs_client->cl_session;
1038 	server_resp_sz = sess->fc_attrs.max_resp_sz - nfs41_maxread_overhead;
1039 	server_rqst_sz = sess->fc_attrs.max_rqst_sz - nfs41_maxwrite_overhead;
1040 
1041 	if (server->dtsize > server_resp_sz)
1042 		server->dtsize = server_resp_sz;
1043 	if (server->rsize > server_resp_sz)
1044 		server->rsize = server_resp_sz;
1045 	if (server->wsize > server_rqst_sz)
1046 		server->wsize = server_rqst_sz;
1047 #endif /* CONFIG_NFS_V4_1 */
1048 }
1049 
1050 /*
1051  * Limit xattr sizes using the channel attributes.
1052  */
1053 static void nfs4_session_limit_xasize(struct nfs_server *server)
1054 {
1055 #ifdef CONFIG_NFS_V4_2
1056 	struct nfs4_session *sess;
1057 	u32 server_gxa_sz;
1058 	u32 server_sxa_sz;
1059 	u32 server_lxa_sz;
1060 
1061 	if (!nfs4_has_session(server->nfs_client))
1062 		return;
1063 
1064 	sess = server->nfs_client->cl_session;
1065 
1066 	server_gxa_sz = sess->fc_attrs.max_resp_sz - nfs42_maxgetxattr_overhead;
1067 	server_sxa_sz = sess->fc_attrs.max_rqst_sz - nfs42_maxsetxattr_overhead;
1068 	server_lxa_sz = sess->fc_attrs.max_resp_sz -
1069 	    nfs42_maxlistxattrs_overhead;
1070 
1071 	if (server->gxasize > server_gxa_sz)
1072 		server->gxasize = server_gxa_sz;
1073 	if (server->sxasize > server_sxa_sz)
1074 		server->sxasize = server_sxa_sz;
1075 	if (server->lxasize > server_lxa_sz)
1076 		server->lxasize = server_lxa_sz;
1077 #endif
1078 }
1079 
1080 void nfs4_server_set_init_caps(struct nfs_server *server)
1081 {
1082 	/* Set the basic capabilities */
1083 	server->caps |= server->nfs_client->cl_mvops->init_caps;
1084 	if (server->flags & NFS_MOUNT_NORDIRPLUS)
1085 			server->caps &= ~NFS_CAP_READDIRPLUS;
1086 	if (server->nfs_client->cl_proto == XPRT_TRANSPORT_RDMA)
1087 		server->caps &= ~NFS_CAP_READ_PLUS;
1088 
1089 	/*
1090 	 * Don't use NFS uid/gid mapping if we're using AUTH_SYS or lower
1091 	 * authentication.
1092 	 */
1093 	if (nfs4_disable_idmapping &&
1094 			server->client->cl_auth->au_flavor == RPC_AUTH_UNIX)
1095 		server->caps |= NFS_CAP_UIDGID_NOMAP;
1096 }
1097 
1098 static int nfs4_server_common_setup(struct nfs_server *server,
1099 		struct nfs_fh *mntfh, bool auth_probe)
1100 {
1101 	int error;
1102 
1103 	/* data servers support only a subset of NFSv4.1 */
1104 	if (is_ds_only_client(server->nfs_client))
1105 		return -EPROTONOSUPPORT;
1106 
1107 	/* We must ensure the session is initialised first */
1108 	error = nfs4_init_session(server->nfs_client);
1109 	if (error < 0)
1110 		goto out;
1111 
1112 	nfs4_server_set_init_caps(server);
1113 
1114 	/* Probe the root fh to retrieve its FSID and filehandle */
1115 	error = nfs4_get_rootfh(server, mntfh, auth_probe);
1116 	if (error < 0)
1117 		goto out;
1118 
1119 	dprintk("Server FSID: %llx:%llx\n",
1120 			(unsigned long long) server->fsid.major,
1121 			(unsigned long long) server->fsid.minor);
1122 	nfs_display_fhandle(mntfh, "Pseudo-fs root FH");
1123 
1124 	error = nfs_probe_server(server, mntfh);
1125 	if (error < 0)
1126 		goto out;
1127 
1128 	nfs4_session_limit_rwsize(server);
1129 	nfs4_session_limit_xasize(server);
1130 
1131 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1132 		server->namelen = NFS4_MAXNAMLEN;
1133 
1134 	nfs_server_insert_lists(server);
1135 	server->mount_time = jiffies;
1136 	server->destroy = nfs4_destroy_server;
1137 out:
1138 	return error;
1139 }
1140 
1141 /*
1142  * Create a version 4 volume record
1143  */
1144 static int nfs4_init_server(struct nfs_server *server, struct fs_context *fc)
1145 {
1146 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1147 	struct rpc_timeout timeparms;
1148 	int error;
1149 
1150 	nfs_init_timeout_values(&timeparms, ctx->nfs_server.protocol,
1151 				ctx->timeo, ctx->retrans);
1152 
1153 	/* Initialise the client representation from the mount data */
1154 	server->flags = ctx->flags;
1155 	server->options = ctx->options;
1156 	server->auth_info = ctx->auth_info;
1157 
1158 	/* Use the first specified auth flavor. If this flavor isn't
1159 	 * allowed by the server, use the SECINFO path to try the
1160 	 * other specified flavors */
1161 	if (ctx->auth_info.flavor_len >= 1)
1162 		ctx->selected_flavor = ctx->auth_info.flavors[0];
1163 	else
1164 		ctx->selected_flavor = RPC_AUTH_UNIX;
1165 
1166 	/* Get a client record */
1167 	error = nfs4_set_client(server,
1168 				ctx->nfs_server.hostname,
1169 				&ctx->nfs_server._address,
1170 				ctx->nfs_server.addrlen,
1171 				ctx->client_address,
1172 				ctx->nfs_server.protocol,
1173 				&timeparms,
1174 				ctx->minorversion,
1175 				ctx->nfs_server.nconnect,
1176 				ctx->nfs_server.max_connect,
1177 				fc->net_ns,
1178 				&ctx->xprtsec);
1179 	if (error < 0)
1180 		return error;
1181 
1182 	if (ctx->rsize)
1183 		server->rsize = nfs_io_size(ctx->rsize, server->nfs_client->cl_proto);
1184 	if (ctx->wsize)
1185 		server->wsize = nfs_io_size(ctx->wsize, server->nfs_client->cl_proto);
1186 
1187 	server->acregmin = ctx->acregmin * HZ;
1188 	server->acregmax = ctx->acregmax * HZ;
1189 	server->acdirmin = ctx->acdirmin * HZ;
1190 	server->acdirmax = ctx->acdirmax * HZ;
1191 	server->port     = ctx->nfs_server.port;
1192 
1193 	return nfs_init_server_rpcclient(server, &timeparms,
1194 					 ctx->selected_flavor);
1195 }
1196 
1197 /*
1198  * Create a version 4 volume record
1199  * - keyed on server and FSID
1200  */
1201 struct nfs_server *nfs4_create_server(struct fs_context *fc)
1202 {
1203 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1204 	struct nfs_server *server;
1205 	bool auth_probe;
1206 	int error;
1207 
1208 	server = nfs_alloc_server();
1209 	if (!server)
1210 		return ERR_PTR(-ENOMEM);
1211 
1212 	server->cred = get_cred(fc->cred);
1213 
1214 	auth_probe = ctx->auth_info.flavor_len < 1;
1215 
1216 	/* set up the general RPC client */
1217 	error = nfs4_init_server(server, fc);
1218 	if (error < 0)
1219 		goto error;
1220 
1221 	error = nfs4_server_common_setup(server, ctx->mntfh, auth_probe);
1222 	if (error < 0)
1223 		goto error;
1224 
1225 	return server;
1226 
1227 error:
1228 	nfs_free_server(server);
1229 	return ERR_PTR(error);
1230 }
1231 
1232 /*
1233  * Create an NFS4 referral server record
1234  */
1235 struct nfs_server *nfs4_create_referral_server(struct fs_context *fc)
1236 {
1237 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1238 	struct nfs_client *parent_client;
1239 	struct nfs_server *server, *parent_server;
1240 	int proto, error;
1241 	bool auth_probe;
1242 
1243 	server = nfs_alloc_server();
1244 	if (!server)
1245 		return ERR_PTR(-ENOMEM);
1246 
1247 	parent_server = NFS_SB(ctx->clone_data.sb);
1248 	parent_client = parent_server->nfs_client;
1249 
1250 	server->cred = get_cred(parent_server->cred);
1251 
1252 	/* Initialise the client representation from the parent server */
1253 	nfs_server_copy_userdata(server, parent_server);
1254 
1255 	/* Get a client representation */
1256 #if IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA)
1257 	rpc_set_port(&ctx->nfs_server.address, NFS_RDMA_PORT);
1258 	error = nfs4_set_client(server,
1259 				ctx->nfs_server.hostname,
1260 				&ctx->nfs_server._address,
1261 				ctx->nfs_server.addrlen,
1262 				parent_client->cl_ipaddr,
1263 				XPRT_TRANSPORT_RDMA,
1264 				parent_server->client->cl_timeout,
1265 				parent_client->cl_mvops->minor_version,
1266 				parent_client->cl_nconnect,
1267 				parent_client->cl_max_connect,
1268 				parent_client->cl_net,
1269 				&parent_client->cl_xprtsec);
1270 	if (!error)
1271 		goto init_server;
1272 #endif	/* IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA) */
1273 
1274 	proto = XPRT_TRANSPORT_TCP;
1275 	if (parent_client->cl_xprtsec.policy != RPC_XPRTSEC_NONE)
1276 		proto = XPRT_TRANSPORT_TCP_TLS;
1277 	rpc_set_port(&ctx->nfs_server.address, NFS_PORT);
1278 	error = nfs4_set_client(server,
1279 				ctx->nfs_server.hostname,
1280 				&ctx->nfs_server._address,
1281 				ctx->nfs_server.addrlen,
1282 				parent_client->cl_ipaddr,
1283 				proto,
1284 				parent_server->client->cl_timeout,
1285 				parent_client->cl_mvops->minor_version,
1286 				parent_client->cl_nconnect,
1287 				parent_client->cl_max_connect,
1288 				parent_client->cl_net,
1289 				&parent_client->cl_xprtsec);
1290 	if (error < 0)
1291 		goto error;
1292 
1293 #if IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA)
1294 init_server:
1295 #endif
1296 	error = nfs_init_server_rpcclient(server, parent_server->client->cl_timeout,
1297 					  ctx->selected_flavor);
1298 	if (error < 0)
1299 		goto error;
1300 
1301 	auth_probe = parent_server->auth_info.flavor_len < 1;
1302 
1303 	error = nfs4_server_common_setup(server, ctx->mntfh, auth_probe);
1304 	if (error < 0)
1305 		goto error;
1306 
1307 	return server;
1308 
1309 error:
1310 	nfs_free_server(server);
1311 	return ERR_PTR(error);
1312 }
1313 
1314 /**
1315  * nfs4_update_server - Move an nfs_server to a different nfs_client
1316  *
1317  * @server: represents FSID to be moved
1318  * @hostname: new end-point's hostname
1319  * @sap: new end-point's socket address
1320  * @salen: size of "sap"
1321  * @net: net namespace
1322  *
1323  * The nfs_server must be quiescent before this function is invoked.
1324  * Either its session is drained (NFSv4.1+), or its transport is
1325  * plugged and drained (NFSv4.0).
1326  *
1327  * Returns zero on success, or a negative errno value.
1328  */
1329 int nfs4_update_server(struct nfs_server *server, const char *hostname,
1330 		       struct sockaddr_storage *sap, size_t salen, struct net *net)
1331 {
1332 	struct nfs_client *clp = server->nfs_client;
1333 	struct rpc_clnt *clnt = server->client;
1334 	struct xprt_create xargs = {
1335 		.ident		= clp->cl_proto,
1336 		.net		= net,
1337 		.dstaddr	= (struct sockaddr *)sap,
1338 		.addrlen	= salen,
1339 		.servername	= hostname,
1340 		/* cel: bleh. We might need to pass TLS parameters here */
1341 	};
1342 	char buf[INET6_ADDRSTRLEN + 1];
1343 	struct sockaddr_storage address;
1344 	struct sockaddr *localaddr = (struct sockaddr *)&address;
1345 	int error;
1346 
1347 	error = rpc_switch_client_transport(clnt, &xargs, clnt->cl_timeout);
1348 	if (error != 0)
1349 		return error;
1350 
1351 	error = rpc_localaddr(clnt, localaddr, sizeof(address));
1352 	if (error != 0)
1353 		return error;
1354 
1355 	if (rpc_ntop(localaddr, buf, sizeof(buf)) == 0)
1356 		return -EAFNOSUPPORT;
1357 
1358 	nfs_server_remove_lists(server);
1359 	set_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status);
1360 	error = nfs4_set_client(server, hostname, sap, salen, buf,
1361 				clp->cl_proto, clnt->cl_timeout,
1362 				clp->cl_minorversion,
1363 				clp->cl_nconnect, clp->cl_max_connect,
1364 				net, &clp->cl_xprtsec);
1365 	clear_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status);
1366 	if (error != 0) {
1367 		nfs_server_insert_lists(server);
1368 		return error;
1369 	}
1370 	nfs_put_client(clp);
1371 
1372 	if (server->nfs_client->cl_hostname == NULL) {
1373 		server->nfs_client->cl_hostname = kstrdup(hostname, GFP_KERNEL);
1374 		if (server->nfs_client->cl_hostname == NULL)
1375 			return -ENOMEM;
1376 	}
1377 	nfs_server_insert_lists(server);
1378 
1379 	return nfs_probe_server(server, NFS_FH(d_inode(server->super->s_root)));
1380 }
1381