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 	if (test_bit(NFS_CS_NETUNREACH_FATAL, &cl_init->init_flags))
237 		__set_bit(NFS_CS_NETUNREACH_FATAL, &clp->cl_flags);
238 	/*
239 	 * Set up the connection to the server before we add add to the
240 	 * global list.
241 	 */
242 	err = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_GSS_KRB5I);
243 	if (err == -EINVAL)
244 		err = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_UNIX);
245 	if (err < 0)
246 		goto error;
247 
248 	/* If no clientaddr= option was specified, find a usable cb address */
249 	if (ip_addr == NULL) {
250 		struct sockaddr_storage cb_addr;
251 		struct sockaddr *sap = (struct sockaddr *)&cb_addr;
252 
253 		err = rpc_localaddr(clp->cl_rpcclient, sap, sizeof(cb_addr));
254 		if (err < 0)
255 			goto error;
256 		err = rpc_ntop(sap, buf, sizeof(buf));
257 		if (err < 0)
258 			goto error;
259 		ip_addr = (const char *)buf;
260 	}
261 	strscpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr));
262 
263 	err = nfs_idmap_new(clp);
264 	if (err < 0) {
265 		dprintk("%s: failed to create idmapper. Error = %d\n",
266 			__func__, err);
267 		goto error;
268 	}
269 	__set_bit(NFS_CS_IDMAP, &clp->cl_res_state);
270 	return clp;
271 
272 error:
273 	nfs_free_client(clp);
274 	return ERR_PTR(err);
275 }
276 
277 /*
278  * Destroy the NFS4 callback service
279  */
280 static void nfs4_destroy_callback(struct nfs_client *clp)
281 {
282 	if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
283 		nfs_callback_down(clp->cl_mvops->minor_version, clp->cl_net);
284 }
285 
286 static void nfs4_shutdown_client(struct nfs_client *clp)
287 {
288 	if (__test_and_clear_bit(NFS_CS_RENEWD, &clp->cl_res_state))
289 		nfs4_kill_renewd(clp);
290 	clp->cl_mvops->shutdown_client(clp);
291 	nfs4_destroy_callback(clp);
292 	if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state))
293 		nfs_idmap_delete(clp);
294 
295 	rpc_destroy_wait_queue(&clp->cl_rpcwaitq);
296 	kfree(clp->cl_serverowner);
297 	kfree(clp->cl_serverscope);
298 	kfree(clp->cl_implid);
299 	kfree(clp->cl_owner_id);
300 }
301 
302 void nfs4_free_client(struct nfs_client *clp)
303 {
304 	nfs4_shutdown_client(clp);
305 	nfs_free_client(clp);
306 }
307 
308 /*
309  * Initialize the NFS4 callback service
310  */
311 static int nfs4_init_callback(struct nfs_client *clp)
312 {
313 	struct rpc_xprt *xprt;
314 	int error;
315 
316 	xprt = rcu_dereference_raw(clp->cl_rpcclient->cl_xprt);
317 
318 	if (nfs4_has_session(clp)) {
319 		error = xprt_setup_backchannel(xprt, NFS41_BC_MIN_CALLBACKS);
320 		if (error < 0)
321 			return error;
322 	}
323 
324 	error = nfs_callback_up(clp->cl_mvops->minor_version, xprt);
325 	if (error < 0) {
326 		dprintk("%s: failed to start callback. Error = %d\n",
327 			__func__, error);
328 		return error;
329 	}
330 	__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
331 
332 	return 0;
333 }
334 
335 /**
336  * nfs40_init_client - nfs_client initialization tasks for NFSv4.0
337  * @clp: nfs_client to initialize
338  *
339  * Returns zero on success, or a negative errno if some error occurred.
340  */
341 int nfs40_init_client(struct nfs_client *clp)
342 {
343 	struct nfs4_slot_table *tbl;
344 	int ret;
345 
346 	tbl = kzalloc(sizeof(*tbl), GFP_NOFS);
347 	if (tbl == NULL)
348 		return -ENOMEM;
349 
350 	ret = nfs4_setup_slot_table(tbl, NFS4_MAX_SLOT_TABLE,
351 					"NFSv4.0 transport Slot table");
352 	if (ret) {
353 		nfs4_shutdown_slot_table(tbl);
354 		kfree(tbl);
355 		return ret;
356 	}
357 
358 	clp->cl_slot_tbl = tbl;
359 	return 0;
360 }
361 
362 #if defined(CONFIG_NFS_V4_1)
363 
364 /**
365  * nfs41_init_client - nfs_client initialization tasks for NFSv4.1+
366  * @clp: nfs_client to initialize
367  *
368  * Returns zero on success, or a negative errno if some error occurred.
369  */
370 int nfs41_init_client(struct nfs_client *clp)
371 {
372 	struct nfs4_session *session = NULL;
373 
374 	/*
375 	 * Create the session and mark it expired.
376 	 * When a SEQUENCE operation encounters the expired session
377 	 * it will do session recovery to initialize it.
378 	 */
379 	session = nfs4_alloc_session(clp);
380 	if (!session)
381 		return -ENOMEM;
382 
383 	clp->cl_session = session;
384 
385 	/*
386 	 * The create session reply races with the server back
387 	 * channel probe. Mark the client NFS_CS_SESSION_INITING
388 	 * so that the client back channel can find the
389 	 * nfs_client struct
390 	 */
391 	nfs_mark_client_ready(clp, NFS_CS_SESSION_INITING);
392 	return 0;
393 }
394 
395 #endif	/* CONFIG_NFS_V4_1 */
396 
397 /*
398  * Initialize the minor version specific parts of an NFS4 client record
399  */
400 static int nfs4_init_client_minor_version(struct nfs_client *clp)
401 {
402 	int ret;
403 
404 	ret = clp->cl_mvops->init_client(clp);
405 	if (ret)
406 		return ret;
407 	return nfs4_init_callback(clp);
408 }
409 
410 static void nfs4_add_trunk(struct nfs_client *clp, struct nfs_client *old)
411 {
412 	struct sockaddr_storage clp_addr, old_addr;
413 	struct sockaddr *clp_sap = (struct sockaddr *)&clp_addr;
414 	struct sockaddr *old_sap = (struct sockaddr *)&old_addr;
415 	size_t clp_salen;
416 	struct xprt_create xprt_args = {
417 		.ident = old->cl_proto,
418 		.net = old->cl_net,
419 		.servername = old->cl_hostname,
420 	};
421 	int max_connect = test_bit(NFS_CS_PNFS, &clp->cl_flags) ?
422 		clp->cl_max_connect : old->cl_max_connect;
423 
424 	if (clp->cl_proto != old->cl_proto)
425 		return;
426 	clp_salen = rpc_peeraddr(clp->cl_rpcclient, clp_sap, sizeof(clp_addr));
427 	rpc_peeraddr(old->cl_rpcclient, old_sap, sizeof(old_addr));
428 
429 	if (clp_addr.ss_family != old_addr.ss_family)
430 		return;
431 
432 	xprt_args.dstaddr = clp_sap;
433 	xprt_args.addrlen = clp_salen;
434 
435 	rpc_clnt_add_xprt(old->cl_rpcclient, &xprt_args,
436 			  rpc_clnt_test_and_add_xprt, &max_connect);
437 }
438 
439 /**
440  * nfs4_init_client - Initialise an NFS4 client record
441  *
442  * @clp: nfs_client to initialise
443  * @cl_init: pointer to nfs_client_initdata
444  *
445  * Returns pointer to an NFS client, or an ERR_PTR value.
446  */
447 struct nfs_client *nfs4_init_client(struct nfs_client *clp,
448 				    const struct nfs_client_initdata *cl_init)
449 {
450 	struct nfs_client *old;
451 	int error;
452 
453 	if (clp->cl_cons_state == NFS_CS_READY)
454 		/* the client is initialised already */
455 		return clp;
456 
457 	error = nfs4_init_client_minor_version(clp);
458 	if (error < 0)
459 		goto error;
460 
461 	error = nfs4_discover_server_trunking(clp, &old);
462 	if (error < 0)
463 		goto error;
464 
465 	if (clp != old) {
466 		clp->cl_preserve_clid = true;
467 		/*
468 		 * Mark the client as having failed initialization so other
469 		 * processes walking the nfs_client_list in nfs_match_client()
470 		 * won't try to use it.
471 		 */
472 		nfs_mark_client_ready(clp, -EPERM);
473 		if (old->cl_mvops->session_trunk)
474 			nfs4_add_trunk(clp, old);
475 	}
476 	clear_bit(NFS_CS_TSM_POSSIBLE, &clp->cl_flags);
477 	nfs_put_client(clp);
478 	return old;
479 
480 error:
481 	nfs_mark_client_ready(clp, error);
482 	nfs_put_client(clp);
483 	return ERR_PTR(error);
484 }
485 
486 /*
487  * SETCLIENTID just did a callback update with the callback ident in
488  * "drop," but server trunking discovery claims "drop" and "keep" are
489  * actually the same server.  Swap the callback IDs so that "keep"
490  * will continue to use the callback ident the server now knows about,
491  * and so that "keep"'s original callback ident is destroyed when
492  * "drop" is freed.
493  */
494 static void nfs4_swap_callback_idents(struct nfs_client *keep,
495 				      struct nfs_client *drop)
496 {
497 	struct nfs_net *nn = net_generic(keep->cl_net, nfs_net_id);
498 	unsigned int save = keep->cl_cb_ident;
499 
500 	if (keep->cl_cb_ident == drop->cl_cb_ident)
501 		return;
502 
503 	dprintk("%s: keeping callback ident %u and dropping ident %u\n",
504 		__func__, keep->cl_cb_ident, drop->cl_cb_ident);
505 
506 	spin_lock(&nn->nfs_client_lock);
507 
508 	idr_replace(&nn->cb_ident_idr, keep, drop->cl_cb_ident);
509 	keep->cl_cb_ident = drop->cl_cb_ident;
510 
511 	idr_replace(&nn->cb_ident_idr, drop, save);
512 	drop->cl_cb_ident = save;
513 
514 	spin_unlock(&nn->nfs_client_lock);
515 }
516 
517 static bool nfs4_match_client_owner_id(const struct nfs_client *clp1,
518 		const struct nfs_client *clp2)
519 {
520 	if (clp1->cl_owner_id == NULL || clp2->cl_owner_id == NULL)
521 		return true;
522 	return strcmp(clp1->cl_owner_id, clp2->cl_owner_id) == 0;
523 }
524 
525 static bool nfs4_same_verifier(nfs4_verifier *v1, nfs4_verifier *v2)
526 {
527 	return memcmp(v1->data, v2->data, sizeof(v1->data)) == 0;
528 }
529 
530 static int nfs4_match_client(struct nfs_client  *pos,  struct nfs_client *new,
531 			     struct nfs_client **prev, struct nfs_net *nn)
532 {
533 	int status;
534 
535 	if (pos->rpc_ops != new->rpc_ops)
536 		return 1;
537 
538 	if (pos->cl_minorversion != new->cl_minorversion)
539 		return 1;
540 
541 	/* If "pos" isn't marked ready, we can't trust the
542 	 * remaining fields in "pos", especially the client
543 	 * ID and serverowner fields.  Wait for CREATE_SESSION
544 	 * to finish. */
545 	if (pos->cl_cons_state > NFS_CS_READY) {
546 		refcount_inc(&pos->cl_count);
547 		spin_unlock(&nn->nfs_client_lock);
548 
549 		nfs_put_client(*prev);
550 		*prev = pos;
551 
552 		status = nfs_wait_client_init_complete(pos);
553 		spin_lock(&nn->nfs_client_lock);
554 
555 		if (status < 0)
556 			return status;
557 	}
558 
559 	if (pos->cl_cons_state != NFS_CS_READY)
560 		return 1;
561 
562 	if (pos->cl_clientid != new->cl_clientid)
563 		return 1;
564 
565 	/* NFSv4.1 always uses the uniform string, however someone
566 	 * might switch the uniquifier string on us.
567 	 */
568 	if (!nfs4_match_client_owner_id(pos, new))
569 		return 1;
570 
571 	return 0;
572 }
573 
574 /**
575  * nfs40_walk_client_list - Find server that recognizes a client ID
576  *
577  * @new: nfs_client with client ID to test
578  * @result: OUT: found nfs_client, or new
579  * @cred: credential to use for trunking test
580  *
581  * Returns zero, a negative errno, or a negative NFS4ERR status.
582  * If zero is returned, an nfs_client pointer is planted in "result."
583  *
584  * NB: nfs40_walk_client_list() relies on the new nfs_client being
585  *     the last nfs_client on the list.
586  */
587 int nfs40_walk_client_list(struct nfs_client *new,
588 			   struct nfs_client **result,
589 			   const struct cred *cred)
590 {
591 	struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
592 	struct nfs_client *pos, *prev = NULL;
593 	struct nfs4_setclientid_res clid = {
594 		.clientid	= new->cl_clientid,
595 		.confirm	= new->cl_confirm,
596 	};
597 	int status = -NFS4ERR_STALE_CLIENTID;
598 
599 	spin_lock(&nn->nfs_client_lock);
600 	list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
601 
602 		if (pos == new)
603 			goto found;
604 
605 		status = nfs4_match_client(pos, new, &prev, nn);
606 		if (status < 0)
607 			goto out_unlock;
608 		if (status != 0)
609 			continue;
610 		/*
611 		 * We just sent a new SETCLIENTID, which should have
612 		 * caused the server to return a new cl_confirm.  So if
613 		 * cl_confirm is the same, then this is a different
614 		 * server that just returned the same cl_confirm by
615 		 * coincidence:
616 		 */
617 		if ((new != pos) && nfs4_same_verifier(&pos->cl_confirm,
618 						       &new->cl_confirm))
619 			continue;
620 		/*
621 		 * But if the cl_confirm's are different, then the only
622 		 * way that a SETCLIENTID_CONFIRM to pos can succeed is
623 		 * if new and pos point to the same server:
624 		 */
625 found:
626 		refcount_inc(&pos->cl_count);
627 		spin_unlock(&nn->nfs_client_lock);
628 
629 		nfs_put_client(prev);
630 		prev = pos;
631 
632 		status = nfs4_proc_setclientid_confirm(pos, &clid, cred);
633 		switch (status) {
634 		case -NFS4ERR_STALE_CLIENTID:
635 			break;
636 		case 0:
637 			nfs4_swap_callback_idents(pos, new);
638 			pos->cl_confirm = new->cl_confirm;
639 			nfs_mark_client_ready(pos, NFS_CS_READY);
640 
641 			prev = NULL;
642 			*result = pos;
643 			goto out;
644 		case -ERESTARTSYS:
645 		case -ETIMEDOUT:
646 			/* The callback path may have been inadvertently
647 			 * changed. Schedule recovery!
648 			 */
649 			nfs4_schedule_path_down_recovery(pos);
650 			goto out;
651 		default:
652 			goto out;
653 		}
654 
655 		spin_lock(&nn->nfs_client_lock);
656 	}
657 out_unlock:
658 	spin_unlock(&nn->nfs_client_lock);
659 
660 	/* No match found. The server lost our clientid */
661 out:
662 	nfs_put_client(prev);
663 	return status;
664 }
665 
666 #ifdef CONFIG_NFS_V4_1
667 /*
668  * Returns true if the server major ids match
669  */
670 bool
671 nfs4_check_serverowner_major_id(struct nfs41_server_owner *o1,
672 				struct nfs41_server_owner *o2)
673 {
674 	if (o1->major_id_sz != o2->major_id_sz)
675 		return false;
676 	return memcmp(o1->major_id, o2->major_id, o1->major_id_sz) == 0;
677 }
678 
679 /*
680  * Returns true if the server scopes match
681  */
682 static bool
683 nfs4_check_server_scope(struct nfs41_server_scope *s1,
684 			struct nfs41_server_scope *s2)
685 {
686 	if (s1->server_scope_sz != s2->server_scope_sz)
687 		return false;
688 	return memcmp(s1->server_scope, s2->server_scope,
689 					s1->server_scope_sz) == 0;
690 }
691 
692 /**
693  * nfs4_detect_session_trunking - Checks for session trunking.
694  * @clp:    original mount nfs_client
695  * @res:    result structure from an exchange_id using the original mount
696  *          nfs_client with a new multi_addr transport
697  * @xprt:   pointer to the transport to add.
698  *
699  * Called after a successful EXCHANGE_ID on a multi-addr connection.
700  * Upon success, add the transport.
701  *
702  * Returns zero on success, otherwise -EINVAL
703  *
704  * Note: since the exchange_id for the new multi_addr transport uses the
705  * same nfs_client from the original mount, the cl_owner_id is reused,
706  * so eir_clientowner is the same.
707  */
708 int nfs4_detect_session_trunking(struct nfs_client *clp,
709 				 struct nfs41_exchange_id_res *res,
710 				 struct rpc_xprt *xprt)
711 {
712 	/* Check eir_clientid */
713 	if (clp->cl_clientid != res->clientid)
714 		goto out_err;
715 
716 	/* Check eir_server_owner so_major_id */
717 	if (!nfs4_check_serverowner_major_id(clp->cl_serverowner,
718 					     res->server_owner))
719 		goto out_err;
720 
721 	/* Check eir_server_owner so_minor_id */
722 	if (clp->cl_serverowner->minor_id != res->server_owner->minor_id)
723 		goto out_err;
724 
725 	/* Check eir_server_scope */
726 	if (!nfs4_check_server_scope(clp->cl_serverscope, res->server_scope))
727 		goto out_err;
728 
729 	pr_info("NFS:  %s: Session trunking succeeded for %s\n",
730 		clp->cl_hostname,
731 		xprt->address_strings[RPC_DISPLAY_ADDR]);
732 
733 	return 0;
734 out_err:
735 	pr_info("NFS:  %s: Session trunking failed for %s\n", clp->cl_hostname,
736 		xprt->address_strings[RPC_DISPLAY_ADDR]);
737 
738 	return -EINVAL;
739 }
740 
741 /**
742  * nfs41_walk_client_list - Find nfs_client that matches a client/server owner
743  *
744  * @new: nfs_client with client ID to test
745  * @result: OUT: found nfs_client, or new
746  * @cred: credential to use for trunking test
747  *
748  * Returns zero, a negative errno, or a negative NFS4ERR status.
749  * If zero is returned, an nfs_client pointer is planted in "result."
750  *
751  * NB: nfs41_walk_client_list() relies on the new nfs_client being
752  *     the last nfs_client on the list.
753  */
754 int nfs41_walk_client_list(struct nfs_client *new,
755 			   struct nfs_client **result,
756 			   const struct cred *cred)
757 {
758 	struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
759 	struct nfs_client *pos, *prev = NULL;
760 	int status = -NFS4ERR_STALE_CLIENTID;
761 
762 	spin_lock(&nn->nfs_client_lock);
763 	list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
764 
765 		if (pos == new)
766 			goto found;
767 
768 		status = nfs4_match_client(pos, new, &prev, nn);
769 		if (status < 0)
770 			goto out;
771 		if (status != 0)
772 			continue;
773 
774 		/*
775 		 * Note that session trunking is just a special subcase of
776 		 * client id trunking. In either case, we want to fall back
777 		 * to using the existing nfs_client.
778 		 */
779 		if (!nfs4_check_serverowner_major_id(pos->cl_serverowner,
780 						     new->cl_serverowner))
781 			continue;
782 
783 found:
784 		refcount_inc(&pos->cl_count);
785 		*result = pos;
786 		status = 0;
787 		break;
788 	}
789 
790 out:
791 	spin_unlock(&nn->nfs_client_lock);
792 	nfs_put_client(prev);
793 	return status;
794 }
795 #endif	/* CONFIG_NFS_V4_1 */
796 
797 static void nfs4_destroy_server(struct nfs_server *server)
798 {
799 	LIST_HEAD(freeme);
800 
801 	nfs_server_return_all_delegations(server);
802 	unset_pnfs_layoutdriver(server);
803 	nfs4_purge_state_owners(server, &freeme);
804 	nfs4_free_state_owners(&freeme);
805 }
806 
807 /*
808  * NFSv4.0 callback thread helper
809  *
810  * Find a client by callback identifier
811  */
812 struct nfs_client *
813 nfs4_find_client_ident(struct net *net, int cb_ident)
814 {
815 	struct nfs_client *clp;
816 	struct nfs_net *nn = net_generic(net, nfs_net_id);
817 
818 	spin_lock(&nn->nfs_client_lock);
819 	clp = idr_find(&nn->cb_ident_idr, cb_ident);
820 	if (clp)
821 		refcount_inc(&clp->cl_count);
822 	spin_unlock(&nn->nfs_client_lock);
823 	return clp;
824 }
825 
826 #if defined(CONFIG_NFS_V4_1)
827 /* Common match routine for v4.0 and v4.1 callback services */
828 static bool nfs4_cb_match_client(const struct sockaddr *addr,
829 		struct nfs_client *clp, u32 minorversion)
830 {
831 	struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
832 
833 	/* Don't match clients that failed to initialise */
834 	if (!(clp->cl_cons_state == NFS_CS_READY ||
835 	    clp->cl_cons_state == NFS_CS_SESSION_INITING))
836 		return false;
837 
838 	smp_rmb();
839 
840 	/* Match the version and minorversion */
841 	if (clp->rpc_ops->version != 4 ||
842 	    clp->cl_minorversion != minorversion)
843 		return false;
844 
845 	/* Match only the IP address, not the port number */
846 	return rpc_cmp_addr(addr, clap);
847 }
848 
849 /*
850  * NFSv4.1 callback thread helper
851  * For CB_COMPOUND calls, find a client by IP address, protocol version,
852  * minorversion, and sessionID
853  *
854  * Returns NULL if no such client
855  */
856 struct nfs_client *
857 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
858 			   struct nfs4_sessionid *sid, u32 minorversion)
859 {
860 	struct nfs_client *clp;
861 	struct nfs_net *nn = net_generic(net, nfs_net_id);
862 
863 	spin_lock(&nn->nfs_client_lock);
864 	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
865 		if (!nfs4_cb_match_client(addr, clp, minorversion))
866 			continue;
867 
868 		if (!nfs4_has_session(clp))
869 			continue;
870 
871 		/* Match sessionid*/
872 		if (memcmp(clp->cl_session->sess_id.data,
873 		    sid->data, NFS4_MAX_SESSIONID_LEN) != 0)
874 			continue;
875 
876 		refcount_inc(&clp->cl_count);
877 		spin_unlock(&nn->nfs_client_lock);
878 		return clp;
879 	}
880 	spin_unlock(&nn->nfs_client_lock);
881 	return NULL;
882 }
883 
884 #else /* CONFIG_NFS_V4_1 */
885 
886 struct nfs_client *
887 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
888 			   struct nfs4_sessionid *sid, u32 minorversion)
889 {
890 	return NULL;
891 }
892 #endif /* CONFIG_NFS_V4_1 */
893 
894 /*
895  * Set up an NFS4 client
896  */
897 static int nfs4_set_client(struct nfs_server *server,
898 		const char *hostname,
899 		const struct sockaddr_storage *addr,
900 		const size_t addrlen,
901 		const char *ip_addr,
902 		int proto, const struct rpc_timeout *timeparms,
903 		u32 minorversion, unsigned int nconnect,
904 		unsigned int max_connect,
905 		struct net *net,
906 		struct xprtsec_parms *xprtsec)
907 {
908 	struct nfs_client_initdata cl_init = {
909 		.hostname = hostname,
910 		.addr = addr,
911 		.addrlen = addrlen,
912 		.ip_addr = ip_addr,
913 		.nfs_mod = &nfs_v4,
914 		.proto = proto,
915 		.minorversion = minorversion,
916 		.net = net,
917 		.timeparms = timeparms,
918 		.cred = server->cred,
919 		.xprtsec = *xprtsec,
920 	};
921 	struct nfs_client *clp;
922 
923 	if (minorversion == 0)
924 		__set_bit(NFS_CS_REUSEPORT, &cl_init.init_flags);
925 	else
926 		cl_init.max_connect = max_connect;
927 	switch (proto) {
928 	case XPRT_TRANSPORT_RDMA:
929 	case XPRT_TRANSPORT_TCP:
930 	case XPRT_TRANSPORT_TCP_TLS:
931 		cl_init.nconnect = nconnect;
932 	}
933 
934 	if (server->flags & NFS_MOUNT_NORESVPORT)
935 		__set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
936 	if (server->options & NFS_OPTION_MIGRATION)
937 		__set_bit(NFS_CS_MIGRATION, &cl_init.init_flags);
938 	if (test_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status))
939 		__set_bit(NFS_CS_TSM_POSSIBLE, &cl_init.init_flags);
940 	server->port = rpc_get_port((struct sockaddr *)addr);
941 
942 	if (server->flags & NFS_MOUNT_NETUNREACH_FATAL)
943 		__set_bit(NFS_CS_NETUNREACH_FATAL, &cl_init.init_flags);
944 
945 	/* Allocate or find a client reference we can use */
946 	clp = nfs_get_client(&cl_init);
947 	if (IS_ERR(clp))
948 		return PTR_ERR(clp);
949 
950 	if (server->nfs_client == clp) {
951 		nfs_put_client(clp);
952 		return -ELOOP;
953 	}
954 
955 	/*
956 	 * Query for the lease time on clientid setup or renewal
957 	 *
958 	 * Note that this will be set on nfs_clients that were created
959 	 * only for the DS role and did not set this bit, but now will
960 	 * serve a dual role.
961 	 */
962 	set_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state);
963 
964 	server->nfs_client = clp;
965 	nfs_sysfs_add_server(server);
966 	nfs_sysfs_link_rpc_client(server, clp->cl_rpcclient, "_state");
967 
968 	return 0;
969 }
970 
971 /*
972  * Set up a pNFS Data Server client.
973  *
974  * Return any existing nfs_client that matches server address,port,version
975  * and minorversion.
976  *
977  * For a new nfs_client, use a soft mount (default), a low retrans and a
978  * low timeout interval so that if a connection is lost, we retry through
979  * the MDS.
980  */
981 struct nfs_client *nfs4_set_ds_client(struct nfs_server *mds_srv,
982 		const struct sockaddr_storage *ds_addr, int ds_addrlen,
983 		int ds_proto, unsigned int ds_timeo, unsigned int ds_retrans,
984 		u32 minor_version)
985 {
986 	struct rpc_timeout ds_timeout;
987 	struct nfs_client *mds_clp = mds_srv->nfs_client;
988 	struct nfs_client_initdata cl_init = {
989 		.addr = ds_addr,
990 		.addrlen = ds_addrlen,
991 		.nodename = mds_clp->cl_rpcclient->cl_nodename,
992 		.ip_addr = mds_clp->cl_ipaddr,
993 		.nfs_mod = &nfs_v4,
994 		.proto = ds_proto,
995 		.minorversion = minor_version,
996 		.net = mds_clp->cl_net,
997 		.timeparms = &ds_timeout,
998 		.cred = mds_srv->cred,
999 		.xprtsec = mds_srv->nfs_client->cl_xprtsec,
1000 	};
1001 	char buf[INET6_ADDRSTRLEN + 1];
1002 
1003 	if (rpc_ntop((struct sockaddr *)ds_addr, buf, sizeof(buf)) <= 0)
1004 		return ERR_PTR(-EINVAL);
1005 	cl_init.hostname = buf;
1006 
1007 	switch (ds_proto) {
1008 	case XPRT_TRANSPORT_RDMA:
1009 	case XPRT_TRANSPORT_TCP:
1010 	case XPRT_TRANSPORT_TCP_TLS:
1011 		if (mds_clp->cl_nconnect > 1) {
1012 			cl_init.nconnect = mds_clp->cl_nconnect;
1013 			cl_init.max_connect = NFS_MAX_TRANSPORTS;
1014 		}
1015 	}
1016 
1017 	if (mds_srv->flags & NFS_MOUNT_NORESVPORT)
1018 		__set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
1019 	if (test_bit(NFS_CS_NETUNREACH_FATAL, &mds_clp->cl_flags))
1020 		__set_bit(NFS_CS_NETUNREACH_FATAL, &cl_init.init_flags);
1021 
1022 	__set_bit(NFS_CS_PNFS, &cl_init.init_flags);
1023 	cl_init.max_connect = NFS_MAX_TRANSPORTS;
1024 	/*
1025 	 * Set an authflavor equual to the MDS value. Use the MDS nfs_client
1026 	 * cl_ipaddr so as to use the same EXCHANGE_ID co_ownerid as the MDS
1027 	 * (section 13.1 RFC 5661).
1028 	 */
1029 	nfs_init_timeout_values(&ds_timeout, ds_proto, ds_timeo, ds_retrans);
1030 	return nfs_get_client(&cl_init);
1031 }
1032 EXPORT_SYMBOL_GPL(nfs4_set_ds_client);
1033 
1034 /*
1035  * Session has been established, and the client marked ready.
1036  * Limit the mount rsize, wsize and dtsize using negotiated fore
1037  * channel attributes.
1038  */
1039 static void nfs4_session_limit_rwsize(struct nfs_server *server)
1040 {
1041 #ifdef CONFIG_NFS_V4_1
1042 	struct nfs4_session *sess;
1043 	u32 server_resp_sz;
1044 	u32 server_rqst_sz;
1045 
1046 	if (!nfs4_has_session(server->nfs_client))
1047 		return;
1048 	sess = server->nfs_client->cl_session;
1049 	server_resp_sz = sess->fc_attrs.max_resp_sz - nfs41_maxread_overhead;
1050 	server_rqst_sz = sess->fc_attrs.max_rqst_sz - nfs41_maxwrite_overhead;
1051 
1052 	if (server->dtsize > server_resp_sz)
1053 		server->dtsize = server_resp_sz;
1054 	if (server->rsize > server_resp_sz)
1055 		server->rsize = server_resp_sz;
1056 	if (server->wsize > server_rqst_sz)
1057 		server->wsize = server_rqst_sz;
1058 #endif /* CONFIG_NFS_V4_1 */
1059 }
1060 
1061 /*
1062  * Limit xattr sizes using the channel attributes.
1063  */
1064 static void nfs4_session_limit_xasize(struct nfs_server *server)
1065 {
1066 #ifdef CONFIG_NFS_V4_2
1067 	struct nfs4_session *sess;
1068 	u32 server_gxa_sz;
1069 	u32 server_sxa_sz;
1070 	u32 server_lxa_sz;
1071 
1072 	if (!nfs4_has_session(server->nfs_client))
1073 		return;
1074 
1075 	sess = server->nfs_client->cl_session;
1076 
1077 	server_gxa_sz = sess->fc_attrs.max_resp_sz - nfs42_maxgetxattr_overhead;
1078 	server_sxa_sz = sess->fc_attrs.max_rqst_sz - nfs42_maxsetxattr_overhead;
1079 	server_lxa_sz = sess->fc_attrs.max_resp_sz -
1080 	    nfs42_maxlistxattrs_overhead;
1081 
1082 	if (server->gxasize > server_gxa_sz)
1083 		server->gxasize = server_gxa_sz;
1084 	if (server->sxasize > server_sxa_sz)
1085 		server->sxasize = server_sxa_sz;
1086 	if (server->lxasize > server_lxa_sz)
1087 		server->lxasize = server_lxa_sz;
1088 #endif
1089 }
1090 
1091 void nfs4_server_set_init_caps(struct nfs_server *server)
1092 {
1093 	/* Set the basic capabilities */
1094 	server->caps |= server->nfs_client->cl_mvops->init_caps;
1095 	if (server->flags & NFS_MOUNT_NORDIRPLUS)
1096 			server->caps &= ~NFS_CAP_READDIRPLUS;
1097 	if (server->nfs_client->cl_proto == XPRT_TRANSPORT_RDMA)
1098 		server->caps &= ~NFS_CAP_READ_PLUS;
1099 
1100 	/*
1101 	 * Don't use NFS uid/gid mapping if we're using AUTH_SYS or lower
1102 	 * authentication.
1103 	 */
1104 	if (nfs4_disable_idmapping &&
1105 			server->client->cl_auth->au_flavor == RPC_AUTH_UNIX)
1106 		server->caps |= NFS_CAP_UIDGID_NOMAP;
1107 }
1108 
1109 static int nfs4_server_common_setup(struct nfs_server *server,
1110 		struct nfs_fh *mntfh, bool auth_probe)
1111 {
1112 	int error;
1113 
1114 	/* data servers support only a subset of NFSv4.1 */
1115 	if (is_ds_only_client(server->nfs_client))
1116 		return -EPROTONOSUPPORT;
1117 
1118 	/* We must ensure the session is initialised first */
1119 	error = nfs4_init_session(server->nfs_client);
1120 	if (error < 0)
1121 		goto out;
1122 
1123 	nfs4_server_set_init_caps(server);
1124 
1125 	/* Probe the root fh to retrieve its FSID and filehandle */
1126 	error = nfs4_get_rootfh(server, mntfh, auth_probe);
1127 	if (error < 0)
1128 		goto out;
1129 
1130 	dprintk("Server FSID: %llx:%llx\n",
1131 			(unsigned long long) server->fsid.major,
1132 			(unsigned long long) server->fsid.minor);
1133 	nfs_display_fhandle(mntfh, "Pseudo-fs root FH");
1134 
1135 	error = nfs_probe_server(server, mntfh);
1136 	if (error < 0)
1137 		goto out;
1138 
1139 	nfs4_session_limit_rwsize(server);
1140 	nfs4_session_limit_xasize(server);
1141 
1142 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1143 		server->namelen = NFS4_MAXNAMLEN;
1144 
1145 	nfs_server_insert_lists(server);
1146 	server->mount_time = jiffies;
1147 	server->destroy = nfs4_destroy_server;
1148 out:
1149 	return error;
1150 }
1151 
1152 /*
1153  * Create a version 4 volume record
1154  */
1155 static int nfs4_init_server(struct nfs_server *server, struct fs_context *fc)
1156 {
1157 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1158 	struct rpc_timeout timeparms;
1159 	int error;
1160 
1161 	nfs_init_timeout_values(&timeparms, ctx->nfs_server.protocol,
1162 				ctx->timeo, ctx->retrans);
1163 
1164 	/* Initialise the client representation from the mount data */
1165 	server->flags = ctx->flags;
1166 	server->options = ctx->options;
1167 	server->auth_info = ctx->auth_info;
1168 
1169 	/* Use the first specified auth flavor. If this flavor isn't
1170 	 * allowed by the server, use the SECINFO path to try the
1171 	 * other specified flavors */
1172 	if (ctx->auth_info.flavor_len >= 1)
1173 		ctx->selected_flavor = ctx->auth_info.flavors[0];
1174 	else
1175 		ctx->selected_flavor = RPC_AUTH_UNIX;
1176 
1177 	/* Get a client record */
1178 	error = nfs4_set_client(server,
1179 				ctx->nfs_server.hostname,
1180 				&ctx->nfs_server._address,
1181 				ctx->nfs_server.addrlen,
1182 				ctx->client_address,
1183 				ctx->nfs_server.protocol,
1184 				&timeparms,
1185 				ctx->minorversion,
1186 				ctx->nfs_server.nconnect,
1187 				ctx->nfs_server.max_connect,
1188 				fc->net_ns,
1189 				&ctx->xprtsec);
1190 	if (error < 0)
1191 		return error;
1192 
1193 	if (ctx->rsize)
1194 		server->rsize = nfs_io_size(ctx->rsize, server->nfs_client->cl_proto);
1195 	if (ctx->wsize)
1196 		server->wsize = nfs_io_size(ctx->wsize, server->nfs_client->cl_proto);
1197 
1198 	server->acregmin = ctx->acregmin * HZ;
1199 	server->acregmax = ctx->acregmax * HZ;
1200 	server->acdirmin = ctx->acdirmin * HZ;
1201 	server->acdirmax = ctx->acdirmax * HZ;
1202 	server->port     = ctx->nfs_server.port;
1203 
1204 	return nfs_init_server_rpcclient(server, &timeparms,
1205 					 ctx->selected_flavor);
1206 }
1207 
1208 /*
1209  * Create a version 4 volume record
1210  * - keyed on server and FSID
1211  */
1212 struct nfs_server *nfs4_create_server(struct fs_context *fc)
1213 {
1214 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1215 	struct nfs_server *server;
1216 	bool auth_probe;
1217 	int error;
1218 
1219 	server = nfs_alloc_server();
1220 	if (!server)
1221 		return ERR_PTR(-ENOMEM);
1222 
1223 	server->cred = get_cred(fc->cred);
1224 
1225 	auth_probe = ctx->auth_info.flavor_len < 1;
1226 
1227 	/* set up the general RPC client */
1228 	error = nfs4_init_server(server, fc);
1229 	if (error < 0)
1230 		goto error;
1231 
1232 	error = nfs4_server_common_setup(server, ctx->mntfh, auth_probe);
1233 	if (error < 0)
1234 		goto error;
1235 
1236 	return server;
1237 
1238 error:
1239 	nfs_free_server(server);
1240 	return ERR_PTR(error);
1241 }
1242 
1243 /*
1244  * Create an NFS4 referral server record
1245  */
1246 struct nfs_server *nfs4_create_referral_server(struct fs_context *fc)
1247 {
1248 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1249 	struct nfs_client *parent_client;
1250 	struct nfs_server *server, *parent_server;
1251 	int proto, error;
1252 	bool auth_probe;
1253 
1254 	server = nfs_alloc_server();
1255 	if (!server)
1256 		return ERR_PTR(-ENOMEM);
1257 
1258 	parent_server = NFS_SB(ctx->clone_data.sb);
1259 	parent_client = parent_server->nfs_client;
1260 
1261 	server->cred = get_cred(parent_server->cred);
1262 
1263 	/* Initialise the client representation from the parent server */
1264 	nfs_server_copy_userdata(server, parent_server);
1265 
1266 	/* Get a client representation */
1267 #if IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA)
1268 	rpc_set_port(&ctx->nfs_server.address, NFS_RDMA_PORT);
1269 	error = nfs4_set_client(server,
1270 				ctx->nfs_server.hostname,
1271 				&ctx->nfs_server._address,
1272 				ctx->nfs_server.addrlen,
1273 				parent_client->cl_ipaddr,
1274 				XPRT_TRANSPORT_RDMA,
1275 				parent_server->client->cl_timeout,
1276 				parent_client->cl_mvops->minor_version,
1277 				parent_client->cl_nconnect,
1278 				parent_client->cl_max_connect,
1279 				parent_client->cl_net,
1280 				&parent_client->cl_xprtsec);
1281 	if (!error)
1282 		goto init_server;
1283 #endif	/* IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA) */
1284 
1285 	proto = XPRT_TRANSPORT_TCP;
1286 	if (parent_client->cl_xprtsec.policy != RPC_XPRTSEC_NONE)
1287 		proto = XPRT_TRANSPORT_TCP_TLS;
1288 	rpc_set_port(&ctx->nfs_server.address, NFS_PORT);
1289 	error = nfs4_set_client(server,
1290 				ctx->nfs_server.hostname,
1291 				&ctx->nfs_server._address,
1292 				ctx->nfs_server.addrlen,
1293 				parent_client->cl_ipaddr,
1294 				proto,
1295 				parent_server->client->cl_timeout,
1296 				parent_client->cl_mvops->minor_version,
1297 				parent_client->cl_nconnect,
1298 				parent_client->cl_max_connect,
1299 				parent_client->cl_net,
1300 				&parent_client->cl_xprtsec);
1301 	if (error < 0)
1302 		goto error;
1303 
1304 #if IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA)
1305 init_server:
1306 #endif
1307 	error = nfs_init_server_rpcclient(server, parent_server->client->cl_timeout,
1308 					  ctx->selected_flavor);
1309 	if (error < 0)
1310 		goto error;
1311 
1312 	auth_probe = parent_server->auth_info.flavor_len < 1;
1313 
1314 	error = nfs4_server_common_setup(server, ctx->mntfh, auth_probe);
1315 	if (error < 0)
1316 		goto error;
1317 
1318 	return server;
1319 
1320 error:
1321 	nfs_free_server(server);
1322 	return ERR_PTR(error);
1323 }
1324 
1325 /**
1326  * nfs4_update_server - Move an nfs_server to a different nfs_client
1327  *
1328  * @server: represents FSID to be moved
1329  * @hostname: new end-point's hostname
1330  * @sap: new end-point's socket address
1331  * @salen: size of "sap"
1332  * @net: net namespace
1333  *
1334  * The nfs_server must be quiescent before this function is invoked.
1335  * Either its session is drained (NFSv4.1+), or its transport is
1336  * plugged and drained (NFSv4.0).
1337  *
1338  * Returns zero on success, or a negative errno value.
1339  */
1340 int nfs4_update_server(struct nfs_server *server, const char *hostname,
1341 		       struct sockaddr_storage *sap, size_t salen, struct net *net)
1342 {
1343 	struct nfs_client *clp = server->nfs_client;
1344 	struct rpc_clnt *clnt = server->client;
1345 	struct xprt_create xargs = {
1346 		.ident		= clp->cl_proto,
1347 		.net		= net,
1348 		.dstaddr	= (struct sockaddr *)sap,
1349 		.addrlen	= salen,
1350 		.servername	= hostname,
1351 		/* cel: bleh. We might need to pass TLS parameters here */
1352 	};
1353 	char buf[INET6_ADDRSTRLEN + 1];
1354 	struct sockaddr_storage address;
1355 	struct sockaddr *localaddr = (struct sockaddr *)&address;
1356 	int error;
1357 
1358 	error = rpc_switch_client_transport(clnt, &xargs, clnt->cl_timeout);
1359 	if (error != 0)
1360 		return error;
1361 
1362 	error = rpc_localaddr(clnt, localaddr, sizeof(address));
1363 	if (error != 0)
1364 		return error;
1365 
1366 	if (rpc_ntop(localaddr, buf, sizeof(buf)) == 0)
1367 		return -EAFNOSUPPORT;
1368 
1369 	nfs_server_remove_lists(server);
1370 	set_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status);
1371 	error = nfs4_set_client(server, hostname, sap, salen, buf,
1372 				clp->cl_proto, clnt->cl_timeout,
1373 				clp->cl_minorversion,
1374 				clp->cl_nconnect, clp->cl_max_connect,
1375 				net, &clp->cl_xprtsec);
1376 	clear_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status);
1377 	if (error != 0) {
1378 		nfs_server_insert_lists(server);
1379 		return error;
1380 	}
1381 	nfs_put_client(clp);
1382 
1383 	if (server->nfs_client->cl_hostname == NULL) {
1384 		server->nfs_client->cl_hostname = kstrdup(hostname, GFP_KERNEL);
1385 		if (server->nfs_client->cl_hostname == NULL)
1386 			return -ENOMEM;
1387 	}
1388 	nfs_server_insert_lists(server);
1389 
1390 	return nfs_probe_server(server, NFS_FH(d_inode(server->super->s_root)));
1391 }
1392