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