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v5.14.15
   1/*
   2 *  fs/nfs/nfs4state.c
   3 *
   4 *  Client-side XDR for NFSv4.
   5 *
   6 *  Copyright (c) 2002 The Regents of the University of Michigan.
   7 *  All rights reserved.
   8 *
   9 *  Kendrick Smith <kmsmith@umich.edu>
  10 *
  11 *  Redistribution and use in source and binary forms, with or without
  12 *  modification, are permitted provided that the following conditions
  13 *  are met:
  14 *
  15 *  1. Redistributions of source code must retain the above copyright
  16 *     notice, this list of conditions and the following disclaimer.
  17 *  2. Redistributions in binary form must reproduce the above copyright
  18 *     notice, this list of conditions and the following disclaimer in the
  19 *     documentation and/or other materials provided with the distribution.
  20 *  3. Neither the name of the University nor the names of its
  21 *     contributors may be used to endorse or promote products derived
  22 *     from this software without specific prior written permission.
  23 *
  24 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  25 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  26 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  27 *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  31 *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  32 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  33 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  34 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35 *
  36 * Implementation of the NFSv4 state model.  For the time being,
  37 * this is minimal, but will be made much more complex in a
  38 * subsequent patch.
  39 */
  40
  41#include <linux/kernel.h>
  42#include <linux/slab.h>
  43#include <linux/fs.h>
  44#include <linux/nfs_fs.h>
  45#include <linux/kthread.h>
  46#include <linux/module.h>
  47#include <linux/random.h>
  48#include <linux/ratelimit.h>
  49#include <linux/workqueue.h>
  50#include <linux/bitops.h>
  51#include <linux/jiffies.h>
 
  52
  53#include <linux/sunrpc/clnt.h>
  54
  55#include "nfs4_fs.h"
  56#include "callback.h"
  57#include "delegation.h"
  58#include "internal.h"
  59#include "nfs4idmap.h"
  60#include "nfs4session.h"
  61#include "pnfs.h"
  62#include "netns.h"
  63#include "nfs4trace.h"
  64
  65#define NFSDBG_FACILITY		NFSDBG_STATE
  66
  67#define OPENOWNER_POOL_SIZE	8
  68
  69const nfs4_stateid zero_stateid = {
  70	{ .data = { 0 } },
  71	.type = NFS4_SPECIAL_STATEID_TYPE,
  72};
  73const nfs4_stateid invalid_stateid = {
  74	{
  75		/* Funky initialiser keeps older gcc versions happy */
  76		.data = { 0xff, 0xff, 0xff, 0xff, 0 },
  77	},
  78	.type = NFS4_INVALID_STATEID_TYPE,
  79};
  80
  81const nfs4_stateid current_stateid = {
  82	{
  83		/* Funky initialiser keeps older gcc versions happy */
  84		.data = { 0x0, 0x0, 0x0, 0x1, 0 },
  85	},
  86	.type = NFS4_SPECIAL_STATEID_TYPE,
  87};
  88
  89static DEFINE_MUTEX(nfs_clid_init_mutex);
  90
  91static int nfs4_setup_state_renewal(struct nfs_client *clp)
  92{
  93	int status;
  94	struct nfs_fsinfo fsinfo;
  95
  96	if (!test_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state)) {
  97		nfs4_schedule_state_renewal(clp);
  98		return 0;
  99	}
 100
 101	status = nfs4_proc_get_lease_time(clp, &fsinfo);
 102	if (status == 0) {
 103		nfs4_set_lease_period(clp, fsinfo.lease_time * HZ);
 104		nfs4_schedule_state_renewal(clp);
 105	}
 106
 107	return status;
 108}
 109
 110int nfs4_init_clientid(struct nfs_client *clp, const struct cred *cred)
 111{
 112	struct nfs4_setclientid_res clid = {
 113		.clientid = clp->cl_clientid,
 114		.confirm = clp->cl_confirm,
 115	};
 116	unsigned short port;
 117	int status;
 118	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
 119
 120	if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
 121		goto do_confirm;
 122	port = nn->nfs_callback_tcpport;
 123	if (clp->cl_addr.ss_family == AF_INET6)
 124		port = nn->nfs_callback_tcpport6;
 125
 126	status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
 127	if (status != 0)
 128		goto out;
 129	clp->cl_clientid = clid.clientid;
 130	clp->cl_confirm = clid.confirm;
 131	set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 132do_confirm:
 133	status = nfs4_proc_setclientid_confirm(clp, &clid, cred);
 134	if (status != 0)
 135		goto out;
 136	clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 137	nfs4_setup_state_renewal(clp);
 138out:
 139	return status;
 140}
 141
 142/**
 143 * nfs40_discover_server_trunking - Detect server IP address trunking (mv0)
 144 *
 145 * @clp: nfs_client under test
 146 * @result: OUT: found nfs_client, or clp
 147 * @cred: credential to use for trunking test
 148 *
 149 * Returns zero, a negative errno, or a negative NFS4ERR status.
 150 * If zero is returned, an nfs_client pointer is planted in
 151 * "result".
 152 *
 153 * Note: The returned client may not yet be marked ready.
 154 */
 155int nfs40_discover_server_trunking(struct nfs_client *clp,
 156				   struct nfs_client **result,
 157				   const struct cred *cred)
 158{
 159	struct nfs4_setclientid_res clid = {
 160		.clientid = clp->cl_clientid,
 161		.confirm = clp->cl_confirm,
 162	};
 163	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
 164	unsigned short port;
 165	int status;
 166
 167	port = nn->nfs_callback_tcpport;
 168	if (clp->cl_addr.ss_family == AF_INET6)
 169		port = nn->nfs_callback_tcpport6;
 170
 171	status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
 172	if (status != 0)
 173		goto out;
 174	clp->cl_clientid = clid.clientid;
 175	clp->cl_confirm = clid.confirm;
 176
 177	status = nfs40_walk_client_list(clp, result, cred);
 178	if (status == 0) {
 179		/* Sustain the lease, even if it's empty.  If the clientid4
 180		 * goes stale it's of no use for trunking discovery. */
 181		nfs4_schedule_state_renewal(*result);
 182
 183		/* If the client state need to recover, do it. */
 184		if (clp->cl_state)
 185			nfs4_schedule_state_manager(clp);
 186	}
 187out:
 188	return status;
 189}
 190
 191const struct cred *nfs4_get_machine_cred(struct nfs_client *clp)
 192{
 193	return get_cred(rpc_machine_cred());
 194}
 195
 196static void nfs4_root_machine_cred(struct nfs_client *clp)
 197{
 198
 199	/* Force root creds instead of machine */
 200	clp->cl_principal = NULL;
 201	clp->cl_rpcclient->cl_principal = NULL;
 202}
 203
 204static const struct cred *
 205nfs4_get_renew_cred_server_locked(struct nfs_server *server)
 206{
 207	const struct cred *cred = NULL;
 208	struct nfs4_state_owner *sp;
 209	struct rb_node *pos;
 210
 211	for (pos = rb_first(&server->state_owners);
 212	     pos != NULL;
 213	     pos = rb_next(pos)) {
 214		sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
 215		if (list_empty(&sp->so_states))
 216			continue;
 217		cred = get_cred(sp->so_cred);
 218		break;
 219	}
 220	return cred;
 221}
 222
 223/**
 224 * nfs4_get_renew_cred - Acquire credential for a renew operation
 225 * @clp: client state handle
 226 *
 227 * Returns an rpc_cred with reference count bumped, or NULL.
 228 * Caller must hold clp->cl_lock.
 229 */
 230const struct cred *nfs4_get_renew_cred(struct nfs_client *clp)
 231{
 232	const struct cred *cred = NULL;
 233	struct nfs_server *server;
 234
 235	/* Use machine credentials if available */
 236	cred = nfs4_get_machine_cred(clp);
 237	if (cred != NULL)
 238		goto out;
 239
 240	spin_lock(&clp->cl_lock);
 241	rcu_read_lock();
 242	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 243		cred = nfs4_get_renew_cred_server_locked(server);
 244		if (cred != NULL)
 245			break;
 246	}
 247	rcu_read_unlock();
 248	spin_unlock(&clp->cl_lock);
 249
 250out:
 251	return cred;
 252}
 253
 254static void nfs4_end_drain_slot_table(struct nfs4_slot_table *tbl)
 255{
 256	if (test_and_clear_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state)) {
 257		spin_lock(&tbl->slot_tbl_lock);
 258		nfs41_wake_slot_table(tbl);
 259		spin_unlock(&tbl->slot_tbl_lock);
 260	}
 261}
 262
 263static void nfs4_end_drain_session(struct nfs_client *clp)
 264{
 265	struct nfs4_session *ses = clp->cl_session;
 266
 267	if (clp->cl_slot_tbl) {
 268		nfs4_end_drain_slot_table(clp->cl_slot_tbl);
 269		return;
 270	}
 271
 272	if (ses != NULL) {
 273		nfs4_end_drain_slot_table(&ses->bc_slot_table);
 274		nfs4_end_drain_slot_table(&ses->fc_slot_table);
 275	}
 276}
 277
 278static int nfs4_drain_slot_tbl(struct nfs4_slot_table *tbl)
 279{
 280	set_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
 281	spin_lock(&tbl->slot_tbl_lock);
 282	if (tbl->highest_used_slotid != NFS4_NO_SLOT) {
 283		reinit_completion(&tbl->complete);
 284		spin_unlock(&tbl->slot_tbl_lock);
 285		return wait_for_completion_interruptible(&tbl->complete);
 286	}
 287	spin_unlock(&tbl->slot_tbl_lock);
 288	return 0;
 289}
 290
 291static int nfs4_begin_drain_session(struct nfs_client *clp)
 292{
 293	struct nfs4_session *ses = clp->cl_session;
 294	int ret;
 295
 296	if (clp->cl_slot_tbl)
 297		return nfs4_drain_slot_tbl(clp->cl_slot_tbl);
 298
 299	/* back channel */
 300	ret = nfs4_drain_slot_tbl(&ses->bc_slot_table);
 301	if (ret)
 302		return ret;
 303	/* fore channel */
 304	return nfs4_drain_slot_tbl(&ses->fc_slot_table);
 305}
 306
 307#if defined(CONFIG_NFS_V4_1)
 308
 309static void nfs41_finish_session_reset(struct nfs_client *clp)
 310{
 311	clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 312	clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
 313	/* create_session negotiated new slot table */
 314	clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
 315	nfs4_setup_state_renewal(clp);
 316}
 317
 318int nfs41_init_clientid(struct nfs_client *clp, const struct cred *cred)
 319{
 320	int status;
 321
 322	if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
 323		goto do_confirm;
 324	status = nfs4_proc_exchange_id(clp, cred);
 325	if (status != 0)
 326		goto out;
 327	set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 328do_confirm:
 329	status = nfs4_proc_create_session(clp, cred);
 330	if (status != 0)
 331		goto out;
 332	nfs41_finish_session_reset(clp);
 333	nfs_mark_client_ready(clp, NFS_CS_READY);
 334out:
 335	return status;
 336}
 337
 338/**
 339 * nfs41_discover_server_trunking - Detect server IP address trunking (mv1)
 340 *
 341 * @clp: nfs_client under test
 342 * @result: OUT: found nfs_client, or clp
 343 * @cred: credential to use for trunking test
 344 *
 345 * Returns NFS4_OK, a negative errno, or a negative NFS4ERR status.
 346 * If NFS4_OK is returned, an nfs_client pointer is planted in
 347 * "result".
 348 *
 349 * Note: The returned client may not yet be marked ready.
 350 */
 351int nfs41_discover_server_trunking(struct nfs_client *clp,
 352				   struct nfs_client **result,
 353				   const struct cred *cred)
 354{
 355	int status;
 356
 357	status = nfs4_proc_exchange_id(clp, cred);
 358	if (status != NFS4_OK)
 359		return status;
 360
 361	status = nfs41_walk_client_list(clp, result, cred);
 362	if (status < 0)
 363		return status;
 364	if (clp != *result)
 365		return 0;
 366
 367	/*
 368	 * Purge state if the client id was established in a prior
 369	 * instance and the client id could not have arrived on the
 370	 * server via Transparent State Migration.
 371	 */
 372	if (clp->cl_exchange_flags & EXCHGID4_FLAG_CONFIRMED_R) {
 373		if (!test_bit(NFS_CS_TSM_POSSIBLE, &clp->cl_flags))
 374			set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
 375		else
 376			set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 377	}
 378	nfs4_schedule_state_manager(clp);
 379	status = nfs_wait_client_init_complete(clp);
 380	if (status < 0)
 381		nfs_put_client(clp);
 382	return status;
 383}
 384
 385#endif /* CONFIG_NFS_V4_1 */
 386
 387/**
 388 * nfs4_get_clid_cred - Acquire credential for a setclientid operation
 389 * @clp: client state handle
 390 *
 391 * Returns a cred with reference count bumped, or NULL.
 392 */
 393const struct cred *nfs4_get_clid_cred(struct nfs_client *clp)
 394{
 395	const struct cred *cred;
 396
 397	cred = nfs4_get_machine_cred(clp);
 398	return cred;
 399}
 400
 401static struct nfs4_state_owner *
 402nfs4_find_state_owner_locked(struct nfs_server *server, const struct cred *cred)
 403{
 404	struct rb_node **p = &server->state_owners.rb_node,
 405		       *parent = NULL;
 406	struct nfs4_state_owner *sp;
 407	int cmp;
 408
 409	while (*p != NULL) {
 410		parent = *p;
 411		sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
 412		cmp = cred_fscmp(cred, sp->so_cred);
 413
 414		if (cmp < 0)
 415			p = &parent->rb_left;
 416		else if (cmp > 0)
 417			p = &parent->rb_right;
 418		else {
 419			if (!list_empty(&sp->so_lru))
 420				list_del_init(&sp->so_lru);
 421			atomic_inc(&sp->so_count);
 422			return sp;
 423		}
 424	}
 425	return NULL;
 426}
 427
 428static struct nfs4_state_owner *
 429nfs4_insert_state_owner_locked(struct nfs4_state_owner *new)
 430{
 431	struct nfs_server *server = new->so_server;
 432	struct rb_node **p = &server->state_owners.rb_node,
 433		       *parent = NULL;
 434	struct nfs4_state_owner *sp;
 435	int cmp;
 436
 437	while (*p != NULL) {
 438		parent = *p;
 439		sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
 440		cmp = cred_fscmp(new->so_cred, sp->so_cred);
 441
 442		if (cmp < 0)
 443			p = &parent->rb_left;
 444		else if (cmp > 0)
 445			p = &parent->rb_right;
 446		else {
 447			if (!list_empty(&sp->so_lru))
 448				list_del_init(&sp->so_lru);
 449			atomic_inc(&sp->so_count);
 450			return sp;
 451		}
 452	}
 453	rb_link_node(&new->so_server_node, parent, p);
 454	rb_insert_color(&new->so_server_node, &server->state_owners);
 455	return new;
 456}
 457
 458static void
 459nfs4_remove_state_owner_locked(struct nfs4_state_owner *sp)
 460{
 461	struct nfs_server *server = sp->so_server;
 462
 463	if (!RB_EMPTY_NODE(&sp->so_server_node))
 464		rb_erase(&sp->so_server_node, &server->state_owners);
 465}
 466
 467static void
 468nfs4_init_seqid_counter(struct nfs_seqid_counter *sc)
 469{
 470	sc->create_time = ktime_get();
 471	sc->flags = 0;
 472	sc->counter = 0;
 473	spin_lock_init(&sc->lock);
 474	INIT_LIST_HEAD(&sc->list);
 475	rpc_init_wait_queue(&sc->wait, "Seqid_waitqueue");
 476}
 477
 478static void
 479nfs4_destroy_seqid_counter(struct nfs_seqid_counter *sc)
 480{
 481	rpc_destroy_wait_queue(&sc->wait);
 482}
 483
 484/*
 485 * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
 486 * create a new state_owner.
 487 *
 488 */
 489static struct nfs4_state_owner *
 490nfs4_alloc_state_owner(struct nfs_server *server,
 491		const struct cred *cred,
 492		gfp_t gfp_flags)
 493{
 494	struct nfs4_state_owner *sp;
 495
 496	sp = kzalloc(sizeof(*sp), gfp_flags);
 497	if (!sp)
 498		return NULL;
 499	sp->so_seqid.owner_id = ida_simple_get(&server->openowner_id, 0, 0,
 500						gfp_flags);
 501	if (sp->so_seqid.owner_id < 0) {
 502		kfree(sp);
 503		return NULL;
 504	}
 505	sp->so_server = server;
 506	sp->so_cred = get_cred(cred);
 507	spin_lock_init(&sp->so_lock);
 508	INIT_LIST_HEAD(&sp->so_states);
 509	nfs4_init_seqid_counter(&sp->so_seqid);
 510	atomic_set(&sp->so_count, 1);
 511	INIT_LIST_HEAD(&sp->so_lru);
 512	seqcount_spinlock_init(&sp->so_reclaim_seqcount, &sp->so_lock);
 513	mutex_init(&sp->so_delegreturn_mutex);
 514	return sp;
 515}
 516
 517static void
 518nfs4_reset_state_owner(struct nfs4_state_owner *sp)
 519{
 520	/* This state_owner is no longer usable, but must
 521	 * remain in place so that state recovery can find it
 522	 * and the opens associated with it.
 523	 * It may also be used for new 'open' request to
 524	 * return a delegation to the server.
 525	 * So update the 'create_time' so that it looks like
 526	 * a new state_owner.  This will cause the server to
 527	 * request an OPEN_CONFIRM to start a new sequence.
 528	 */
 529	sp->so_seqid.create_time = ktime_get();
 530}
 531
 532static void nfs4_free_state_owner(struct nfs4_state_owner *sp)
 533{
 534	nfs4_destroy_seqid_counter(&sp->so_seqid);
 535	put_cred(sp->so_cred);
 536	ida_simple_remove(&sp->so_server->openowner_id, sp->so_seqid.owner_id);
 537	kfree(sp);
 538}
 539
 540static void nfs4_gc_state_owners(struct nfs_server *server)
 541{
 542	struct nfs_client *clp = server->nfs_client;
 543	struct nfs4_state_owner *sp, *tmp;
 544	unsigned long time_min, time_max;
 545	LIST_HEAD(doomed);
 546
 547	spin_lock(&clp->cl_lock);
 548	time_max = jiffies;
 549	time_min = (long)time_max - (long)clp->cl_lease_time;
 550	list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
 551		/* NB: LRU is sorted so that oldest is at the head */
 552		if (time_in_range(sp->so_expires, time_min, time_max))
 553			break;
 554		list_move(&sp->so_lru, &doomed);
 555		nfs4_remove_state_owner_locked(sp);
 556	}
 557	spin_unlock(&clp->cl_lock);
 558
 559	list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
 560		list_del(&sp->so_lru);
 561		nfs4_free_state_owner(sp);
 562	}
 563}
 564
 565/**
 566 * nfs4_get_state_owner - Look up a state owner given a credential
 567 * @server: nfs_server to search
 568 * @cred: RPC credential to match
 569 * @gfp_flags: allocation mode
 570 *
 571 * Returns a pointer to an instantiated nfs4_state_owner struct, or NULL.
 572 */
 573struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server,
 574					      const struct cred *cred,
 575					      gfp_t gfp_flags)
 576{
 577	struct nfs_client *clp = server->nfs_client;
 578	struct nfs4_state_owner *sp, *new;
 579
 580	spin_lock(&clp->cl_lock);
 581	sp = nfs4_find_state_owner_locked(server, cred);
 582	spin_unlock(&clp->cl_lock);
 583	if (sp != NULL)
 584		goto out;
 585	new = nfs4_alloc_state_owner(server, cred, gfp_flags);
 586	if (new == NULL)
 587		goto out;
 588	spin_lock(&clp->cl_lock);
 589	sp = nfs4_insert_state_owner_locked(new);
 590	spin_unlock(&clp->cl_lock);
 591	if (sp != new)
 592		nfs4_free_state_owner(new);
 593out:
 594	nfs4_gc_state_owners(server);
 595	return sp;
 596}
 597
 598/**
 599 * nfs4_put_state_owner - Release a nfs4_state_owner
 600 * @sp: state owner data to release
 601 *
 602 * Note that we keep released state owners on an LRU
 603 * list.
 604 * This caches valid state owners so that they can be
 605 * reused, to avoid the OPEN_CONFIRM on minor version 0.
 606 * It also pins the uniquifier of dropped state owners for
 607 * a while, to ensure that those state owner names are
 608 * never reused.
 609 */
 610void nfs4_put_state_owner(struct nfs4_state_owner *sp)
 611{
 612	struct nfs_server *server = sp->so_server;
 613	struct nfs_client *clp = server->nfs_client;
 614
 615	if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
 616		return;
 617
 618	sp->so_expires = jiffies;
 619	list_add_tail(&sp->so_lru, &server->state_owners_lru);
 620	spin_unlock(&clp->cl_lock);
 621}
 622
 623/**
 624 * nfs4_purge_state_owners - Release all cached state owners
 625 * @server: nfs_server with cached state owners to release
 626 * @head: resulting list of state owners
 627 *
 628 * Called at umount time.  Remaining state owners will be on
 629 * the LRU with ref count of zero.
 630 * Note that the state owners are not freed, but are added
 631 * to the list @head, which can later be used as an argument
 632 * to nfs4_free_state_owners.
 633 */
 634void nfs4_purge_state_owners(struct nfs_server *server, struct list_head *head)
 635{
 636	struct nfs_client *clp = server->nfs_client;
 637	struct nfs4_state_owner *sp, *tmp;
 638
 639	spin_lock(&clp->cl_lock);
 640	list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
 641		list_move(&sp->so_lru, head);
 642		nfs4_remove_state_owner_locked(sp);
 643	}
 644	spin_unlock(&clp->cl_lock);
 645}
 646
 647/**
 648 * nfs4_free_state_owners - Release all cached state owners
 649 * @head: resulting list of state owners
 650 *
 651 * Frees a list of state owners that was generated by
 652 * nfs4_purge_state_owners
 653 */
 654void nfs4_free_state_owners(struct list_head *head)
 655{
 656	struct nfs4_state_owner *sp, *tmp;
 657
 658	list_for_each_entry_safe(sp, tmp, head, so_lru) {
 659		list_del(&sp->so_lru);
 660		nfs4_free_state_owner(sp);
 661	}
 662}
 663
 664static struct nfs4_state *
 665nfs4_alloc_open_state(void)
 666{
 667	struct nfs4_state *state;
 668
 669	state = kzalloc(sizeof(*state), GFP_NOFS);
 670	if (!state)
 671		return NULL;
 672	refcount_set(&state->count, 1);
 673	INIT_LIST_HEAD(&state->lock_states);
 674	spin_lock_init(&state->state_lock);
 675	seqlock_init(&state->seqlock);
 676	init_waitqueue_head(&state->waitq);
 677	return state;
 678}
 679
 680void
 681nfs4_state_set_mode_locked(struct nfs4_state *state, fmode_t fmode)
 682{
 683	if (state->state == fmode)
 684		return;
 685	/* NB! List reordering - see the reclaim code for why.  */
 686	if ((fmode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
 687		if (fmode & FMODE_WRITE)
 688			list_move(&state->open_states, &state->owner->so_states);
 689		else
 690			list_move_tail(&state->open_states, &state->owner->so_states);
 691	}
 692	state->state = fmode;
 693}
 694
 695static struct nfs4_state *
 696__nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
 697{
 698	struct nfs_inode *nfsi = NFS_I(inode);
 699	struct nfs4_state *state;
 700
 701	list_for_each_entry_rcu(state, &nfsi->open_states, inode_states) {
 702		if (state->owner != owner)
 703			continue;
 704		if (!nfs4_valid_open_stateid(state))
 705			continue;
 706		if (refcount_inc_not_zero(&state->count))
 707			return state;
 708	}
 709	return NULL;
 710}
 711
 712static void
 713nfs4_free_open_state(struct nfs4_state *state)
 714{
 715	kfree_rcu(state, rcu_head);
 716}
 717
 718struct nfs4_state *
 719nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
 720{
 721	struct nfs4_state *state, *new;
 722	struct nfs_inode *nfsi = NFS_I(inode);
 723
 724	rcu_read_lock();
 725	state = __nfs4_find_state_byowner(inode, owner);
 726	rcu_read_unlock();
 727	if (state)
 728		goto out;
 729	new = nfs4_alloc_open_state();
 730	spin_lock(&owner->so_lock);
 731	spin_lock(&inode->i_lock);
 732	state = __nfs4_find_state_byowner(inode, owner);
 733	if (state == NULL && new != NULL) {
 734		state = new;
 735		state->owner = owner;
 736		atomic_inc(&owner->so_count);
 737		ihold(inode);
 738		state->inode = inode;
 739		list_add_rcu(&state->inode_states, &nfsi->open_states);
 740		spin_unlock(&inode->i_lock);
 741		/* Note: The reclaim code dictates that we add stateless
 742		 * and read-only stateids to the end of the list */
 743		list_add_tail(&state->open_states, &owner->so_states);
 744		spin_unlock(&owner->so_lock);
 745	} else {
 746		spin_unlock(&inode->i_lock);
 747		spin_unlock(&owner->so_lock);
 748		if (new)
 749			nfs4_free_open_state(new);
 750	}
 751out:
 752	return state;
 753}
 754
 755void nfs4_put_open_state(struct nfs4_state *state)
 756{
 757	struct inode *inode = state->inode;
 758	struct nfs4_state_owner *owner = state->owner;
 759
 760	if (!refcount_dec_and_lock(&state->count, &owner->so_lock))
 761		return;
 762	spin_lock(&inode->i_lock);
 763	list_del_rcu(&state->inode_states);
 764	list_del(&state->open_states);
 765	spin_unlock(&inode->i_lock);
 766	spin_unlock(&owner->so_lock);
 767	nfs4_inode_return_delegation_on_close(inode);
 768	iput(inode);
 769	nfs4_free_open_state(state);
 770	nfs4_put_state_owner(owner);
 771}
 772
 773/*
 774 * Close the current file.
 775 */
 776static void __nfs4_close(struct nfs4_state *state,
 777		fmode_t fmode, gfp_t gfp_mask, int wait)
 778{
 779	struct nfs4_state_owner *owner = state->owner;
 780	int call_close = 0;
 781	fmode_t newstate;
 782
 783	atomic_inc(&owner->so_count);
 784	/* Protect against nfs4_find_state() */
 785	spin_lock(&owner->so_lock);
 786	switch (fmode & (FMODE_READ | FMODE_WRITE)) {
 787		case FMODE_READ:
 788			state->n_rdonly--;
 789			break;
 790		case FMODE_WRITE:
 791			state->n_wronly--;
 792			break;
 793		case FMODE_READ|FMODE_WRITE:
 794			state->n_rdwr--;
 795	}
 796	newstate = FMODE_READ|FMODE_WRITE;
 797	if (state->n_rdwr == 0) {
 798		if (state->n_rdonly == 0) {
 799			newstate &= ~FMODE_READ;
 800			call_close |= test_bit(NFS_O_RDONLY_STATE, &state->flags);
 801			call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
 802		}
 803		if (state->n_wronly == 0) {
 804			newstate &= ~FMODE_WRITE;
 805			call_close |= test_bit(NFS_O_WRONLY_STATE, &state->flags);
 806			call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
 807		}
 808		if (newstate == 0)
 809			clear_bit(NFS_DELEGATED_STATE, &state->flags);
 810	}
 811	nfs4_state_set_mode_locked(state, newstate);
 812	spin_unlock(&owner->so_lock);
 813
 814	if (!call_close) {
 815		nfs4_put_open_state(state);
 816		nfs4_put_state_owner(owner);
 817	} else
 818		nfs4_do_close(state, gfp_mask, wait);
 819}
 820
 821void nfs4_close_state(struct nfs4_state *state, fmode_t fmode)
 822{
 823	__nfs4_close(state, fmode, GFP_NOFS, 0);
 824}
 825
 826void nfs4_close_sync(struct nfs4_state *state, fmode_t fmode)
 827{
 828	__nfs4_close(state, fmode, GFP_KERNEL, 1);
 829}
 830
 831/*
 832 * Search the state->lock_states for an existing lock_owner
 833 * that is compatible with either of the given owners.
 834 * If the second is non-zero, then the first refers to a Posix-lock
 835 * owner (current->files) and the second refers to a flock/OFD
 836 * owner (struct file*).  In that case, prefer a match for the first
 837 * owner.
 838 * If both sorts of locks are held on the one file we cannot know
 839 * which stateid was intended to be used, so a "correct" choice cannot
 840 * be made.  Failing that, a "consistent" choice is preferable.  The
 841 * consistent choice we make is to prefer the first owner, that of a
 842 * Posix lock.
 843 */
 844static struct nfs4_lock_state *
 845__nfs4_find_lock_state(struct nfs4_state *state,
 846		       fl_owner_t fl_owner, fl_owner_t fl_owner2)
 847{
 848	struct nfs4_lock_state *pos, *ret = NULL;
 849	list_for_each_entry(pos, &state->lock_states, ls_locks) {
 850		if (pos->ls_owner == fl_owner) {
 851			ret = pos;
 852			break;
 853		}
 854		if (pos->ls_owner == fl_owner2)
 855			ret = pos;
 856	}
 857	if (ret)
 858		refcount_inc(&ret->ls_count);
 859	return ret;
 860}
 861
 862/*
 863 * Return a compatible lock_state. If no initialized lock_state structure
 864 * exists, return an uninitialized one.
 865 *
 866 */
 867static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 868{
 869	struct nfs4_lock_state *lsp;
 870	struct nfs_server *server = state->owner->so_server;
 871
 872	lsp = kzalloc(sizeof(*lsp), GFP_NOFS);
 873	if (lsp == NULL)
 874		return NULL;
 875	nfs4_init_seqid_counter(&lsp->ls_seqid);
 876	refcount_set(&lsp->ls_count, 1);
 877	lsp->ls_state = state;
 878	lsp->ls_owner = fl_owner;
 879	lsp->ls_seqid.owner_id = ida_simple_get(&server->lockowner_id, 0, 0, GFP_NOFS);
 880	if (lsp->ls_seqid.owner_id < 0)
 881		goto out_free;
 882	INIT_LIST_HEAD(&lsp->ls_locks);
 883	return lsp;
 884out_free:
 885	kfree(lsp);
 886	return NULL;
 887}
 888
 889void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp)
 890{
 891	ida_simple_remove(&server->lockowner_id, lsp->ls_seqid.owner_id);
 892	nfs4_destroy_seqid_counter(&lsp->ls_seqid);
 893	kfree(lsp);
 894}
 895
 896/*
 897 * Return a compatible lock_state. If no initialized lock_state structure
 898 * exists, return an uninitialized one.
 899 *
 900 */
 901static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
 902{
 903	struct nfs4_lock_state *lsp, *new = NULL;
 904	
 905	for(;;) {
 906		spin_lock(&state->state_lock);
 907		lsp = __nfs4_find_lock_state(state, owner, NULL);
 908		if (lsp != NULL)
 909			break;
 910		if (new != NULL) {
 911			list_add(&new->ls_locks, &state->lock_states);
 912			set_bit(LK_STATE_IN_USE, &state->flags);
 913			lsp = new;
 914			new = NULL;
 915			break;
 916		}
 917		spin_unlock(&state->state_lock);
 918		new = nfs4_alloc_lock_state(state, owner);
 919		if (new == NULL)
 920			return NULL;
 921	}
 922	spin_unlock(&state->state_lock);
 923	if (new != NULL)
 924		nfs4_free_lock_state(state->owner->so_server, new);
 925	return lsp;
 926}
 927
 928/*
 929 * Release reference to lock_state, and free it if we see that
 930 * it is no longer in use
 931 */
 932void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
 933{
 934	struct nfs_server *server;
 935	struct nfs4_state *state;
 936
 937	if (lsp == NULL)
 938		return;
 939	state = lsp->ls_state;
 940	if (!refcount_dec_and_lock(&lsp->ls_count, &state->state_lock))
 941		return;
 942	list_del(&lsp->ls_locks);
 943	if (list_empty(&state->lock_states))
 944		clear_bit(LK_STATE_IN_USE, &state->flags);
 945	spin_unlock(&state->state_lock);
 946	server = state->owner->so_server;
 947	if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) {
 948		struct nfs_client *clp = server->nfs_client;
 949
 950		clp->cl_mvops->free_lock_state(server, lsp);
 951	} else
 952		nfs4_free_lock_state(server, lsp);
 953}
 954
 955static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
 956{
 957	struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
 958
 959	dst->fl_u.nfs4_fl.owner = lsp;
 960	refcount_inc(&lsp->ls_count);
 961}
 962
 963static void nfs4_fl_release_lock(struct file_lock *fl)
 964{
 965	nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
 966}
 967
 968static const struct file_lock_operations nfs4_fl_lock_ops = {
 969	.fl_copy_lock = nfs4_fl_copy_lock,
 970	.fl_release_private = nfs4_fl_release_lock,
 971};
 972
 973int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
 974{
 975	struct nfs4_lock_state *lsp;
 976
 977	if (fl->fl_ops != NULL)
 978		return 0;
 979	lsp = nfs4_get_lock_state(state, fl->fl_owner);
 980	if (lsp == NULL)
 981		return -ENOMEM;
 982	fl->fl_u.nfs4_fl.owner = lsp;
 983	fl->fl_ops = &nfs4_fl_lock_ops;
 984	return 0;
 985}
 986
 987static int nfs4_copy_lock_stateid(nfs4_stateid *dst,
 988		struct nfs4_state *state,
 989		const struct nfs_lock_context *l_ctx)
 990{
 991	struct nfs4_lock_state *lsp;
 992	fl_owner_t fl_owner, fl_flock_owner;
 993	int ret = -ENOENT;
 994
 995	if (l_ctx == NULL)
 996		goto out;
 997
 998	if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
 999		goto out;
1000
1001	fl_owner = l_ctx->lockowner;
1002	fl_flock_owner = l_ctx->open_context->flock_owner;
1003
1004	spin_lock(&state->state_lock);
1005	lsp = __nfs4_find_lock_state(state, fl_owner, fl_flock_owner);
1006	if (lsp && test_bit(NFS_LOCK_LOST, &lsp->ls_flags))
1007		ret = -EIO;
1008	else if (lsp != NULL && test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) != 0) {
1009		nfs4_stateid_copy(dst, &lsp->ls_stateid);
1010		ret = 0;
1011	}
1012	spin_unlock(&state->state_lock);
1013	nfs4_put_lock_state(lsp);
1014out:
1015	return ret;
1016}
1017
1018bool nfs4_copy_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
1019{
1020	bool ret;
1021	const nfs4_stateid *src;
1022	int seq;
1023
1024	do {
1025		ret = false;
1026		src = &zero_stateid;
1027		seq = read_seqbegin(&state->seqlock);
1028		if (test_bit(NFS_OPEN_STATE, &state->flags)) {
1029			src = &state->open_stateid;
1030			ret = true;
1031		}
1032		nfs4_stateid_copy(dst, src);
1033	} while (read_seqretry(&state->seqlock, seq));
1034	return ret;
1035}
1036
1037/*
1038 * Byte-range lock aware utility to initialize the stateid of read/write
1039 * requests.
1040 */
1041int nfs4_select_rw_stateid(struct nfs4_state *state,
1042		fmode_t fmode, const struct nfs_lock_context *l_ctx,
1043		nfs4_stateid *dst, const struct cred **cred)
1044{
1045	int ret;
1046
1047	if (!nfs4_valid_open_stateid(state))
1048		return -EIO;
1049	if (cred != NULL)
1050		*cred = NULL;
1051	ret = nfs4_copy_lock_stateid(dst, state, l_ctx);
1052	if (ret == -EIO)
1053		/* A lost lock - don't even consider delegations */
1054		goto out;
1055	/* returns true if delegation stateid found and copied */
1056	if (nfs4_copy_delegation_stateid(state->inode, fmode, dst, cred)) {
1057		ret = 0;
1058		goto out;
1059	}
1060	if (ret != -ENOENT)
1061		/* nfs4_copy_delegation_stateid() didn't over-write
1062		 * dst, so it still has the lock stateid which we now
1063		 * choose to use.
1064		 */
1065		goto out;
1066	ret = nfs4_copy_open_stateid(dst, state) ? 0 : -EAGAIN;
1067out:
1068	if (nfs_server_capable(state->inode, NFS_CAP_STATEID_NFSV41))
1069		dst->seqid = 0;
1070	return ret;
1071}
1072
1073struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask)
1074{
1075	struct nfs_seqid *new;
1076
1077	new = kmalloc(sizeof(*new), gfp_mask);
1078	if (new == NULL)
1079		return ERR_PTR(-ENOMEM);
1080	new->sequence = counter;
1081	INIT_LIST_HEAD(&new->list);
1082	new->task = NULL;
1083	return new;
1084}
1085
1086void nfs_release_seqid(struct nfs_seqid *seqid)
1087{
1088	struct nfs_seqid_counter *sequence;
1089
1090	if (seqid == NULL || list_empty(&seqid->list))
1091		return;
1092	sequence = seqid->sequence;
1093	spin_lock(&sequence->lock);
1094	list_del_init(&seqid->list);
1095	if (!list_empty(&sequence->list)) {
1096		struct nfs_seqid *next;
1097
1098		next = list_first_entry(&sequence->list,
1099				struct nfs_seqid, list);
1100		rpc_wake_up_queued_task(&sequence->wait, next->task);
1101	}
1102	spin_unlock(&sequence->lock);
1103}
1104
1105void nfs_free_seqid(struct nfs_seqid *seqid)
1106{
1107	nfs_release_seqid(seqid);
1108	kfree(seqid);
1109}
1110
1111/*
1112 * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
1113 * failed with a seqid incrementing error -
1114 * see comments nfs4.h:seqid_mutating_error()
1115 */
1116static void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
1117{
1118	switch (status) {
1119		case 0:
1120			break;
1121		case -NFS4ERR_BAD_SEQID:
1122			if (seqid->sequence->flags & NFS_SEQID_CONFIRMED)
1123				return;
1124			pr_warn_ratelimited("NFS: v4 server returned a bad"
1125					" sequence-id error on an"
1126					" unconfirmed sequence %p!\n",
1127					seqid->sequence);
1128			return;
1129		case -NFS4ERR_STALE_CLIENTID:
1130		case -NFS4ERR_STALE_STATEID:
1131		case -NFS4ERR_BAD_STATEID:
1132		case -NFS4ERR_BADXDR:
1133		case -NFS4ERR_RESOURCE:
1134		case -NFS4ERR_NOFILEHANDLE:
1135		case -NFS4ERR_MOVED:
1136			/* Non-seqid mutating errors */
1137			return;
1138	}
1139	/*
1140	 * Note: no locking needed as we are guaranteed to be first
1141	 * on the sequence list
1142	 */
1143	seqid->sequence->counter++;
1144}
1145
1146void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
1147{
1148	struct nfs4_state_owner *sp;
1149
1150	if (seqid == NULL)
1151		return;
1152
1153	sp = container_of(seqid->sequence, struct nfs4_state_owner, so_seqid);
1154	if (status == -NFS4ERR_BAD_SEQID)
1155		nfs4_reset_state_owner(sp);
1156	if (!nfs4_has_session(sp->so_server->nfs_client))
1157		nfs_increment_seqid(status, seqid);
1158}
1159
1160/*
1161 * Increment the seqid if the LOCK/LOCKU succeeded, or
1162 * failed with a seqid incrementing error -
1163 * see comments nfs4.h:seqid_mutating_error()
1164 */
1165void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
1166{
1167	if (seqid != NULL)
1168		nfs_increment_seqid(status, seqid);
1169}
1170
1171int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
1172{
1173	struct nfs_seqid_counter *sequence;
1174	int status = 0;
1175
1176	if (seqid == NULL)
1177		goto out;
1178	sequence = seqid->sequence;
1179	spin_lock(&sequence->lock);
1180	seqid->task = task;
1181	if (list_empty(&seqid->list))
1182		list_add_tail(&seqid->list, &sequence->list);
1183	if (list_first_entry(&sequence->list, struct nfs_seqid, list) == seqid)
1184		goto unlock;
1185	rpc_sleep_on(&sequence->wait, task, NULL);
1186	status = -EAGAIN;
1187unlock:
1188	spin_unlock(&sequence->lock);
1189out:
1190	return status;
1191}
1192
1193static int nfs4_run_state_manager(void *);
1194
1195static void nfs4_clear_state_manager_bit(struct nfs_client *clp)
1196{
1197	smp_mb__before_atomic();
1198	clear_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state);
1199	smp_mb__after_atomic();
1200	wake_up_bit(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING);
1201	rpc_wake_up(&clp->cl_rpcwaitq);
1202}
1203
1204/*
1205 * Schedule the nfs_client asynchronous state management routine
1206 */
1207void nfs4_schedule_state_manager(struct nfs_client *clp)
1208{
1209	struct task_struct *task;
1210	char buf[INET6_ADDRSTRLEN + sizeof("-manager") + 1];
 
 
 
 
1211
1212	set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
1213	if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
 
1214		return;
 
 
1215	__module_get(THIS_MODULE);
1216	refcount_inc(&clp->cl_count);
1217
1218	/* The rcu_read_lock() is not strictly necessary, as the state
1219	 * manager is the only thread that ever changes the rpc_xprt
1220	 * after it's initialized.  At this point, we're single threaded. */
1221	rcu_read_lock();
1222	snprintf(buf, sizeof(buf), "%s-manager",
1223			rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
1224	rcu_read_unlock();
1225	task = kthread_run(nfs4_run_state_manager, clp, "%s", buf);
1226	if (IS_ERR(task)) {
1227		printk(KERN_ERR "%s: kthread_run: %ld\n",
1228			__func__, PTR_ERR(task));
 
 
1229		nfs4_clear_state_manager_bit(clp);
 
1230		nfs_put_client(clp);
1231		module_put(THIS_MODULE);
1232	}
1233}
1234
1235/*
1236 * Schedule a lease recovery attempt
1237 */
1238void nfs4_schedule_lease_recovery(struct nfs_client *clp)
1239{
1240	if (!clp)
1241		return;
1242	if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1243		set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1244	dprintk("%s: scheduling lease recovery for server %s\n", __func__,
1245			clp->cl_hostname);
1246	nfs4_schedule_state_manager(clp);
1247}
1248EXPORT_SYMBOL_GPL(nfs4_schedule_lease_recovery);
1249
1250/**
1251 * nfs4_schedule_migration_recovery - trigger migration recovery
1252 *
1253 * @server: FSID that is migrating
1254 *
1255 * Returns zero if recovery has started, otherwise a negative NFS4ERR
1256 * value is returned.
1257 */
1258int nfs4_schedule_migration_recovery(const struct nfs_server *server)
1259{
1260	struct nfs_client *clp = server->nfs_client;
1261
1262	if (server->fh_expire_type != NFS4_FH_PERSISTENT) {
1263		pr_err("NFS: volatile file handles not supported (server %s)\n",
1264				clp->cl_hostname);
1265		return -NFS4ERR_IO;
1266	}
1267
1268	if (test_bit(NFS_MIG_FAILED, &server->mig_status))
1269		return -NFS4ERR_IO;
1270
1271	dprintk("%s: scheduling migration recovery for (%llx:%llx) on %s\n",
1272			__func__,
1273			(unsigned long long)server->fsid.major,
1274			(unsigned long long)server->fsid.minor,
1275			clp->cl_hostname);
1276
1277	set_bit(NFS_MIG_IN_TRANSITION,
1278			&((struct nfs_server *)server)->mig_status);
1279	set_bit(NFS4CLNT_MOVED, &clp->cl_state);
1280
1281	nfs4_schedule_state_manager(clp);
1282	return 0;
1283}
1284EXPORT_SYMBOL_GPL(nfs4_schedule_migration_recovery);
1285
1286/**
1287 * nfs4_schedule_lease_moved_recovery - start lease-moved recovery
1288 *
1289 * @clp: server to check for moved leases
1290 *
1291 */
1292void nfs4_schedule_lease_moved_recovery(struct nfs_client *clp)
1293{
1294	dprintk("%s: scheduling lease-moved recovery for client ID %llx on %s\n",
1295		__func__, clp->cl_clientid, clp->cl_hostname);
1296
1297	set_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state);
1298	nfs4_schedule_state_manager(clp);
1299}
1300EXPORT_SYMBOL_GPL(nfs4_schedule_lease_moved_recovery);
1301
1302int nfs4_wait_clnt_recover(struct nfs_client *clp)
1303{
1304	int res;
1305
1306	might_sleep();
1307
1308	refcount_inc(&clp->cl_count);
1309	res = wait_on_bit_action(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING,
1310				 nfs_wait_bit_killable, TASK_KILLABLE);
 
1311	if (res)
1312		goto out;
1313	if (clp->cl_cons_state < 0)
1314		res = clp->cl_cons_state;
1315out:
1316	nfs_put_client(clp);
1317	return res;
1318}
1319
1320int nfs4_client_recover_expired_lease(struct nfs_client *clp)
1321{
1322	unsigned int loop;
1323	int ret;
1324
1325	for (loop = NFS4_MAX_LOOP_ON_RECOVER; loop != 0; loop--) {
1326		ret = nfs4_wait_clnt_recover(clp);
1327		if (ret != 0)
1328			break;
1329		if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) &&
1330		    !test_bit(NFS4CLNT_CHECK_LEASE,&clp->cl_state))
1331			break;
1332		nfs4_schedule_state_manager(clp);
1333		ret = -EIO;
1334	}
1335	return ret;
1336}
1337
1338/*
1339 * nfs40_handle_cb_pathdown - return all delegations after NFS4ERR_CB_PATH_DOWN
1340 * @clp: client to process
1341 *
1342 * Set the NFS4CLNT_LEASE_EXPIRED state in order to force a
1343 * resend of the SETCLIENTID and hence re-establish the
1344 * callback channel. Then return all existing delegations.
1345 */
1346static void nfs40_handle_cb_pathdown(struct nfs_client *clp)
1347{
1348	set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1349	nfs_expire_all_delegations(clp);
1350	dprintk("%s: handling CB_PATHDOWN recovery for server %s\n", __func__,
1351			clp->cl_hostname);
1352}
1353
1354void nfs4_schedule_path_down_recovery(struct nfs_client *clp)
1355{
1356	nfs40_handle_cb_pathdown(clp);
1357	nfs4_schedule_state_manager(clp);
1358}
1359
1360static int nfs4_state_mark_reclaim_reboot(struct nfs_client *clp, struct nfs4_state *state)
1361{
1362
1363	if (!nfs4_valid_open_stateid(state))
1364		return 0;
1365	set_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1366	/* Don't recover state that expired before the reboot */
1367	if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags)) {
1368		clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1369		return 0;
1370	}
1371	set_bit(NFS_OWNER_RECLAIM_REBOOT, &state->owner->so_flags);
1372	set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1373	return 1;
1374}
1375
1376int nfs4_state_mark_reclaim_nograce(struct nfs_client *clp, struct nfs4_state *state)
1377{
1378	if (!nfs4_valid_open_stateid(state))
1379		return 0;
1380	set_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1381	clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1382	set_bit(NFS_OWNER_RECLAIM_NOGRACE, &state->owner->so_flags);
1383	set_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
1384	return 1;
1385}
1386
1387int nfs4_schedule_stateid_recovery(const struct nfs_server *server, struct nfs4_state *state)
1388{
1389	struct nfs_client *clp = server->nfs_client;
1390
1391	if (!nfs4_state_mark_reclaim_nograce(clp, state))
1392		return -EBADF;
1393	nfs_inode_find_delegation_state_and_recover(state->inode,
1394			&state->stateid);
1395	dprintk("%s: scheduling stateid recovery for server %s\n", __func__,
1396			clp->cl_hostname);
1397	nfs4_schedule_state_manager(clp);
1398	return 0;
1399}
1400EXPORT_SYMBOL_GPL(nfs4_schedule_stateid_recovery);
1401
1402static struct nfs4_lock_state *
1403nfs_state_find_lock_state_by_stateid(struct nfs4_state *state,
1404		const nfs4_stateid *stateid)
1405{
1406	struct nfs4_lock_state *pos;
1407
1408	list_for_each_entry(pos, &state->lock_states, ls_locks) {
1409		if (!test_bit(NFS_LOCK_INITIALIZED, &pos->ls_flags))
1410			continue;
1411		if (nfs4_stateid_match_or_older(&pos->ls_stateid, stateid))
1412			return pos;
1413	}
1414	return NULL;
1415}
1416
1417static bool nfs_state_lock_state_matches_stateid(struct nfs4_state *state,
1418		const nfs4_stateid *stateid)
1419{
1420	bool found = false;
1421
1422	if (test_bit(LK_STATE_IN_USE, &state->flags)) {
1423		spin_lock(&state->state_lock);
1424		if (nfs_state_find_lock_state_by_stateid(state, stateid))
1425			found = true;
1426		spin_unlock(&state->state_lock);
1427	}
1428	return found;
1429}
1430
1431void nfs_inode_find_state_and_recover(struct inode *inode,
1432		const nfs4_stateid *stateid)
1433{
1434	struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
1435	struct nfs_inode *nfsi = NFS_I(inode);
1436	struct nfs_open_context *ctx;
1437	struct nfs4_state *state;
1438	bool found = false;
1439
1440	rcu_read_lock();
1441	list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1442		state = ctx->state;
1443		if (state == NULL)
1444			continue;
1445		if (nfs4_stateid_match_or_older(&state->stateid, stateid) &&
1446		    nfs4_state_mark_reclaim_nograce(clp, state)) {
1447			found = true;
1448			continue;
1449		}
1450		if (test_bit(NFS_OPEN_STATE, &state->flags) &&
1451		    nfs4_stateid_match_or_older(&state->open_stateid, stateid) &&
1452		    nfs4_state_mark_reclaim_nograce(clp, state)) {
1453			found = true;
1454			continue;
1455		}
1456		if (nfs_state_lock_state_matches_stateid(state, stateid) &&
1457		    nfs4_state_mark_reclaim_nograce(clp, state))
1458			found = true;
1459	}
1460	rcu_read_unlock();
1461
1462	nfs_inode_find_delegation_state_and_recover(inode, stateid);
1463	if (found)
1464		nfs4_schedule_state_manager(clp);
1465}
1466
1467static void nfs4_state_mark_open_context_bad(struct nfs4_state *state, int err)
1468{
1469	struct inode *inode = state->inode;
1470	struct nfs_inode *nfsi = NFS_I(inode);
1471	struct nfs_open_context *ctx;
1472
1473	rcu_read_lock();
1474	list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1475		if (ctx->state != state)
1476			continue;
1477		set_bit(NFS_CONTEXT_BAD, &ctx->flags);
1478		pr_warn("NFSv4: state recovery failed for open file %pd2, "
1479				"error = %d\n", ctx->dentry, err);
1480	}
1481	rcu_read_unlock();
1482}
1483
1484static void nfs4_state_mark_recovery_failed(struct nfs4_state *state, int error)
1485{
1486	set_bit(NFS_STATE_RECOVERY_FAILED, &state->flags);
1487	nfs4_state_mark_open_context_bad(state, error);
1488}
1489
1490
1491static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_recovery_ops *ops)
1492{
1493	struct inode *inode = state->inode;
1494	struct nfs_inode *nfsi = NFS_I(inode);
1495	struct file_lock *fl;
1496	struct nfs4_lock_state *lsp;
1497	int status = 0;
1498	struct file_lock_context *flctx = inode->i_flctx;
1499	struct list_head *list;
1500
1501	if (flctx == NULL)
1502		return 0;
1503
1504	list = &flctx->flc_posix;
1505
1506	/* Guard against delegation returns and new lock/unlock calls */
1507	down_write(&nfsi->rwsem);
1508	spin_lock(&flctx->flc_lock);
1509restart:
1510	list_for_each_entry(fl, list, fl_list) {
1511		if (nfs_file_open_context(fl->fl_file)->state != state)
1512			continue;
1513		spin_unlock(&flctx->flc_lock);
1514		status = ops->recover_lock(state, fl);
1515		switch (status) {
1516		case 0:
1517			break;
1518		case -ETIMEDOUT:
1519		case -ESTALE:
1520		case -NFS4ERR_ADMIN_REVOKED:
1521		case -NFS4ERR_STALE_STATEID:
1522		case -NFS4ERR_BAD_STATEID:
1523		case -NFS4ERR_EXPIRED:
1524		case -NFS4ERR_NO_GRACE:
1525		case -NFS4ERR_STALE_CLIENTID:
1526		case -NFS4ERR_BADSESSION:
1527		case -NFS4ERR_BADSLOT:
1528		case -NFS4ERR_BAD_HIGH_SLOT:
1529		case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1530			goto out;
1531		default:
1532			pr_err("NFS: %s: unhandled error %d\n",
1533					__func__, status);
1534			fallthrough;
1535		case -ENOMEM:
1536		case -NFS4ERR_DENIED:
1537		case -NFS4ERR_RECLAIM_BAD:
1538		case -NFS4ERR_RECLAIM_CONFLICT:
1539			lsp = fl->fl_u.nfs4_fl.owner;
1540			if (lsp)
1541				set_bit(NFS_LOCK_LOST, &lsp->ls_flags);
1542			status = 0;
1543		}
1544		spin_lock(&flctx->flc_lock);
1545	}
1546	if (list == &flctx->flc_posix) {
1547		list = &flctx->flc_flock;
1548		goto restart;
1549	}
1550	spin_unlock(&flctx->flc_lock);
1551out:
1552	up_write(&nfsi->rwsem);
1553	return status;
1554}
1555
1556#ifdef CONFIG_NFS_V4_2
1557static void nfs42_complete_copies(struct nfs4_state_owner *sp, struct nfs4_state *state)
1558{
1559	struct nfs4_copy_state *copy;
1560
1561	if (!test_bit(NFS_CLNT_DST_SSC_COPY_STATE, &state->flags) &&
1562		!test_bit(NFS_CLNT_SRC_SSC_COPY_STATE, &state->flags))
1563		return;
1564
1565	spin_lock(&sp->so_server->nfs_client->cl_lock);
1566	list_for_each_entry(copy, &sp->so_server->ss_copies, copies) {
1567		if ((test_bit(NFS_CLNT_DST_SSC_COPY_STATE, &state->flags) &&
1568				!nfs4_stateid_match_other(&state->stateid,
1569				&copy->parent_dst_state->stateid)))
1570				continue;
1571		copy->flags = 1;
1572		if (test_and_clear_bit(NFS_CLNT_DST_SSC_COPY_STATE,
1573				&state->flags)) {
1574			clear_bit(NFS_CLNT_SRC_SSC_COPY_STATE, &state->flags);
1575			complete(&copy->completion);
1576		}
1577	}
1578	list_for_each_entry(copy, &sp->so_server->ss_copies, src_copies) {
1579		if ((test_bit(NFS_CLNT_SRC_SSC_COPY_STATE, &state->flags) &&
1580				!nfs4_stateid_match_other(&state->stateid,
1581				&copy->parent_src_state->stateid)))
1582				continue;
1583		copy->flags = 1;
1584		if (test_and_clear_bit(NFS_CLNT_DST_SSC_COPY_STATE,
1585				&state->flags))
1586			complete(&copy->completion);
1587	}
1588	spin_unlock(&sp->so_server->nfs_client->cl_lock);
1589}
1590#else /* !CONFIG_NFS_V4_2 */
1591static inline void nfs42_complete_copies(struct nfs4_state_owner *sp,
1592					 struct nfs4_state *state)
1593{
1594}
1595#endif /* CONFIG_NFS_V4_2 */
1596
1597static int __nfs4_reclaim_open_state(struct nfs4_state_owner *sp, struct nfs4_state *state,
1598				     const struct nfs4_state_recovery_ops *ops)
 
1599{
1600	struct nfs4_lock_state *lock;
1601	int status;
1602
1603	status = ops->recover_open(sp, state);
1604	if (status < 0)
1605		return status;
1606
1607	status = nfs4_reclaim_locks(state, ops);
1608	if (status < 0)
1609		return status;
1610
1611	if (!test_bit(NFS_DELEGATED_STATE, &state->flags)) {
1612		spin_lock(&state->state_lock);
1613		list_for_each_entry(lock, &state->lock_states, ls_locks) {
1614			trace_nfs4_state_lock_reclaim(state, lock);
1615			if (!test_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags))
1616				pr_warn_ratelimited("NFS: %s: Lock reclaim failed!\n", __func__);
 
1617		}
1618		spin_unlock(&state->state_lock);
1619	}
1620
1621	nfs42_complete_copies(sp, state);
1622	clear_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1623	return status;
1624}
1625
1626static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs4_state_recovery_ops *ops)
 
 
1627{
1628	struct nfs4_state *state;
1629	unsigned int loop = 0;
1630	int status = 0;
1631#ifdef CONFIG_NFS_V4_2
1632	bool found_ssc_copy_state = false;
1633#endif /* CONFIG_NFS_V4_2 */
1634
1635	/* Note: we rely on the sp->so_states list being ordered 
1636	 * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
1637	 * states first.
1638	 * This is needed to ensure that the server won't give us any
1639	 * read delegations that we have to return if, say, we are
1640	 * recovering after a network partition or a reboot from a
1641	 * server that doesn't support a grace period.
1642	 */
1643	spin_lock(&sp->so_lock);
1644	raw_write_seqcount_begin(&sp->so_reclaim_seqcount);
1645restart:
1646	list_for_each_entry(state, &sp->so_states, open_states) {
1647		if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
1648			continue;
1649		if (!nfs4_valid_open_stateid(state))
1650			continue;
1651		if (state->state == 0)
1652			continue;
1653#ifdef CONFIG_NFS_V4_2
1654		if (test_bit(NFS_SRV_SSC_COPY_STATE, &state->flags)) {
1655			nfs4_state_mark_recovery_failed(state, -EIO);
1656			found_ssc_copy_state = true;
1657			continue;
1658		}
1659#endif /* CONFIG_NFS_V4_2 */
1660		refcount_inc(&state->count);
1661		spin_unlock(&sp->so_lock);
1662		status = __nfs4_reclaim_open_state(sp, state, ops);
1663
1664		switch (status) {
1665		default:
1666			if (status >= 0) {
1667				loop = 0;
1668				break;
1669			}
1670			printk(KERN_ERR "NFS: %s: unhandled error %d\n", __func__, status);
1671			fallthrough;
1672		case -ENOENT:
1673		case -ENOMEM:
1674		case -EACCES:
1675		case -EROFS:
1676		case -EIO:
1677		case -ESTALE:
1678			/* Open state on this file cannot be recovered */
1679			nfs4_state_mark_recovery_failed(state, status);
1680			break;
1681		case -EAGAIN:
1682			ssleep(1);
1683			if (loop++ < 10) {
1684				set_bit(ops->state_flag_bit, &state->flags);
1685				break;
1686			}
1687			fallthrough;
1688		case -NFS4ERR_ADMIN_REVOKED:
1689		case -NFS4ERR_STALE_STATEID:
1690		case -NFS4ERR_OLD_STATEID:
1691		case -NFS4ERR_BAD_STATEID:
1692		case -NFS4ERR_RECLAIM_BAD:
1693		case -NFS4ERR_RECLAIM_CONFLICT:
1694			nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1695			break;
1696		case -NFS4ERR_EXPIRED:
1697		case -NFS4ERR_NO_GRACE:
1698			nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1699			fallthrough;
1700		case -NFS4ERR_STALE_CLIENTID:
1701		case -NFS4ERR_BADSESSION:
1702		case -NFS4ERR_BADSLOT:
1703		case -NFS4ERR_BAD_HIGH_SLOT:
1704		case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1705		case -ETIMEDOUT:
1706			goto out_err;
1707		}
1708		nfs4_put_open_state(state);
1709		spin_lock(&sp->so_lock);
1710		goto restart;
1711	}
1712	raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1713	spin_unlock(&sp->so_lock);
1714#ifdef CONFIG_NFS_V4_2
1715	if (found_ssc_copy_state)
1716		return -EIO;
1717#endif /* CONFIG_NFS_V4_2 */
1718	return 0;
1719out_err:
1720	nfs4_put_open_state(state);
1721	spin_lock(&sp->so_lock);
1722	raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1723	spin_unlock(&sp->so_lock);
1724	return status;
1725}
1726
1727static void nfs4_clear_open_state(struct nfs4_state *state)
1728{
1729	struct nfs4_lock_state *lock;
1730
1731	clear_bit(NFS_DELEGATED_STATE, &state->flags);
1732	clear_bit(NFS_O_RDONLY_STATE, &state->flags);
1733	clear_bit(NFS_O_WRONLY_STATE, &state->flags);
1734	clear_bit(NFS_O_RDWR_STATE, &state->flags);
1735	spin_lock(&state->state_lock);
1736	list_for_each_entry(lock, &state->lock_states, ls_locks) {
1737		lock->ls_seqid.flags = 0;
1738		clear_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags);
1739	}
1740	spin_unlock(&state->state_lock);
1741}
1742
1743static void nfs4_reset_seqids(struct nfs_server *server,
1744	int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1745{
1746	struct nfs_client *clp = server->nfs_client;
1747	struct nfs4_state_owner *sp;
1748	struct rb_node *pos;
1749	struct nfs4_state *state;
1750
1751	spin_lock(&clp->cl_lock);
1752	for (pos = rb_first(&server->state_owners);
1753	     pos != NULL;
1754	     pos = rb_next(pos)) {
1755		sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1756		sp->so_seqid.flags = 0;
1757		spin_lock(&sp->so_lock);
1758		list_for_each_entry(state, &sp->so_states, open_states) {
1759			if (mark_reclaim(clp, state))
1760				nfs4_clear_open_state(state);
1761		}
1762		spin_unlock(&sp->so_lock);
1763	}
1764	spin_unlock(&clp->cl_lock);
1765}
1766
1767static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp,
1768	int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1769{
1770	struct nfs_server *server;
1771
1772	rcu_read_lock();
1773	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1774		nfs4_reset_seqids(server, mark_reclaim);
1775	rcu_read_unlock();
1776}
1777
1778static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp)
1779{
 
1780	/* Mark all delegations for reclaim */
1781	nfs_delegation_mark_reclaim(clp);
1782	nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_reboot);
1783}
1784
1785static int nfs4_reclaim_complete(struct nfs_client *clp,
1786				 const struct nfs4_state_recovery_ops *ops,
1787				 const struct cred *cred)
1788{
1789	/* Notify the server we're done reclaiming our state */
1790	if (ops->reclaim_complete)
1791		return ops->reclaim_complete(clp, cred);
1792	return 0;
1793}
1794
1795static void nfs4_clear_reclaim_server(struct nfs_server *server)
1796{
1797	struct nfs_client *clp = server->nfs_client;
1798	struct nfs4_state_owner *sp;
1799	struct rb_node *pos;
1800	struct nfs4_state *state;
1801
1802	spin_lock(&clp->cl_lock);
1803	for (pos = rb_first(&server->state_owners);
1804	     pos != NULL;
1805	     pos = rb_next(pos)) {
1806		sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1807		spin_lock(&sp->so_lock);
1808		list_for_each_entry(state, &sp->so_states, open_states) {
1809			if (!test_and_clear_bit(NFS_STATE_RECLAIM_REBOOT,
1810						&state->flags))
1811				continue;
1812			nfs4_state_mark_reclaim_nograce(clp, state);
1813		}
1814		spin_unlock(&sp->so_lock);
1815	}
1816	spin_unlock(&clp->cl_lock);
1817}
1818
1819static int nfs4_state_clear_reclaim_reboot(struct nfs_client *clp)
1820{
1821	struct nfs_server *server;
1822
1823	if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
1824		return 0;
1825
1826	rcu_read_lock();
1827	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1828		nfs4_clear_reclaim_server(server);
1829	rcu_read_unlock();
1830
1831	nfs_delegation_reap_unclaimed(clp);
1832	return 1;
1833}
1834
1835static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
1836{
1837	const struct nfs4_state_recovery_ops *ops;
1838	const struct cred *cred;
1839	int err;
1840
1841	if (!nfs4_state_clear_reclaim_reboot(clp))
1842		return;
1843	ops = clp->cl_mvops->reboot_recovery_ops;
1844	cred = nfs4_get_clid_cred(clp);
1845	err = nfs4_reclaim_complete(clp, ops, cred);
1846	put_cred(cred);
1847	if (err == -NFS4ERR_CONN_NOT_BOUND_TO_SESSION)
1848		set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1849}
1850
1851static void nfs4_state_start_reclaim_nograce(struct nfs_client *clp)
1852{
1853	nfs_mark_test_expired_all_delegations(clp);
1854	nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
1855}
1856
1857static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
1858{
1859	switch (error) {
1860	case 0:
1861		break;
1862	case -NFS4ERR_CB_PATH_DOWN:
1863		nfs40_handle_cb_pathdown(clp);
1864		break;
1865	case -NFS4ERR_NO_GRACE:
1866		nfs4_state_end_reclaim_reboot(clp);
1867		break;
1868	case -NFS4ERR_STALE_CLIENTID:
1869		set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1870		nfs4_state_start_reclaim_reboot(clp);
1871		break;
1872	case -NFS4ERR_EXPIRED:
1873		set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1874		nfs4_state_start_reclaim_nograce(clp);
1875		break;
1876	case -NFS4ERR_BADSESSION:
1877	case -NFS4ERR_BADSLOT:
1878	case -NFS4ERR_BAD_HIGH_SLOT:
1879	case -NFS4ERR_DEADSESSION:
1880	case -NFS4ERR_SEQ_FALSE_RETRY:
1881	case -NFS4ERR_SEQ_MISORDERED:
1882		set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
1883		/* Zero session reset errors */
1884		break;
1885	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1886		set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
1887		break;
1888	default:
1889		dprintk("%s: failed to handle error %d for server %s\n",
1890				__func__, error, clp->cl_hostname);
1891		return error;
1892	}
1893	dprintk("%s: handled error %d for server %s\n", __func__, error,
1894			clp->cl_hostname);
1895	return 0;
1896}
1897
1898static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recovery_ops *ops)
1899{
1900	struct nfs4_state_owner *sp;
1901	struct nfs_server *server;
1902	struct rb_node *pos;
1903	LIST_HEAD(freeme);
1904	int status = 0;
 
1905
1906restart:
1907	rcu_read_lock();
1908	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1909		nfs4_purge_state_owners(server, &freeme);
1910		spin_lock(&clp->cl_lock);
1911		for (pos = rb_first(&server->state_owners);
1912		     pos != NULL;
1913		     pos = rb_next(pos)) {
1914			sp = rb_entry(pos,
1915				struct nfs4_state_owner, so_server_node);
1916			if (!test_and_clear_bit(ops->owner_flag_bit,
1917							&sp->so_flags))
1918				continue;
1919			if (!atomic_inc_not_zero(&sp->so_count))
1920				continue;
1921			spin_unlock(&clp->cl_lock);
1922			rcu_read_unlock();
1923
1924			status = nfs4_reclaim_open_state(sp, ops);
1925			if (status < 0) {
 
 
 
1926				set_bit(ops->owner_flag_bit, &sp->so_flags);
1927				nfs4_put_state_owner(sp);
1928				status = nfs4_recovery_handle_error(clp, status);
1929				return (status != 0) ? status : -EAGAIN;
1930			}
1931
1932			nfs4_put_state_owner(sp);
1933			goto restart;
1934		}
1935		spin_unlock(&clp->cl_lock);
1936	}
1937	rcu_read_unlock();
1938	nfs4_free_state_owners(&freeme);
 
 
 
1939	return 0;
1940}
1941
1942static int nfs4_check_lease(struct nfs_client *clp)
1943{
1944	const struct cred *cred;
1945	const struct nfs4_state_maintenance_ops *ops =
1946		clp->cl_mvops->state_renewal_ops;
1947	int status;
1948
1949	/* Is the client already known to have an expired lease? */
1950	if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1951		return 0;
1952	cred = ops->get_state_renewal_cred(clp);
1953	if (cred == NULL) {
1954		cred = nfs4_get_clid_cred(clp);
1955		status = -ENOKEY;
1956		if (cred == NULL)
1957			goto out;
1958	}
1959	status = ops->renew_lease(clp, cred);
1960	put_cred(cred);
1961	if (status == -ETIMEDOUT) {
1962		set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1963		return 0;
1964	}
1965out:
1966	return nfs4_recovery_handle_error(clp, status);
1967}
1968
1969/* Set NFS4CLNT_LEASE_EXPIRED and reclaim reboot state for all v4.0 errors
1970 * and for recoverable errors on EXCHANGE_ID for v4.1
1971 */
1972static int nfs4_handle_reclaim_lease_error(struct nfs_client *clp, int status)
1973{
1974	switch (status) {
1975	case -NFS4ERR_SEQ_MISORDERED:
1976		if (test_and_set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state))
1977			return -ESERVERFAULT;
1978		/* Lease confirmation error: retry after purging the lease */
1979		ssleep(1);
1980		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1981		break;
1982	case -NFS4ERR_STALE_CLIENTID:
1983		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1984		nfs4_state_start_reclaim_reboot(clp);
1985		break;
1986	case -NFS4ERR_CLID_INUSE:
1987		pr_err("NFS: Server %s reports our clientid is in use\n",
1988			clp->cl_hostname);
1989		nfs_mark_client_ready(clp, -EPERM);
1990		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1991		return -EPERM;
1992	case -EACCES:
1993	case -NFS4ERR_DELAY:
1994	case -EAGAIN:
1995		ssleep(1);
1996		break;
1997
1998	case -NFS4ERR_MINOR_VERS_MISMATCH:
1999		if (clp->cl_cons_state == NFS_CS_SESSION_INITING)
2000			nfs_mark_client_ready(clp, -EPROTONOSUPPORT);
2001		dprintk("%s: exit with error %d for server %s\n",
2002				__func__, -EPROTONOSUPPORT, clp->cl_hostname);
2003		return -EPROTONOSUPPORT;
 
 
 
 
2004	case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
2005				 * in nfs4_exchange_id */
2006	default:
2007		dprintk("%s: exit with error %d for server %s\n", __func__,
2008				status, clp->cl_hostname);
2009		return status;
2010	}
2011	set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2012	dprintk("%s: handled error %d for server %s\n", __func__, status,
2013			clp->cl_hostname);
2014	return 0;
2015}
2016
2017static int nfs4_establish_lease(struct nfs_client *clp)
2018{
2019	const struct cred *cred;
2020	const struct nfs4_state_recovery_ops *ops =
2021		clp->cl_mvops->reboot_recovery_ops;
2022	int status;
2023
2024	status = nfs4_begin_drain_session(clp);
2025	if (status != 0)
2026		return status;
2027	cred = nfs4_get_clid_cred(clp);
2028	if (cred == NULL)
2029		return -ENOENT;
2030	status = ops->establish_clid(clp, cred);
2031	put_cred(cred);
2032	if (status != 0)
2033		return status;
2034	pnfs_destroy_all_layouts(clp);
2035	return 0;
2036}
2037
2038/*
2039 * Returns zero or a negative errno.  NFS4ERR values are converted
2040 * to local errno values.
2041 */
2042static int nfs4_reclaim_lease(struct nfs_client *clp)
2043{
2044	int status;
2045
2046	status = nfs4_establish_lease(clp);
2047	if (status < 0)
2048		return nfs4_handle_reclaim_lease_error(clp, status);
2049	if (test_and_clear_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH, &clp->cl_state))
2050		nfs4_state_start_reclaim_nograce(clp);
2051	if (!test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
2052		set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
2053	clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2054	clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2055	return 0;
2056}
2057
2058static int nfs4_purge_lease(struct nfs_client *clp)
2059{
2060	int status;
2061
2062	status = nfs4_establish_lease(clp);
2063	if (status < 0)
2064		return nfs4_handle_reclaim_lease_error(clp, status);
2065	clear_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2066	set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2067	nfs4_state_start_reclaim_nograce(clp);
2068	return 0;
2069}
2070
2071/*
2072 * Try remote migration of one FSID from a source server to a
2073 * destination server.  The source server provides a list of
2074 * potential destinations.
2075 *
2076 * Returns zero or a negative NFS4ERR status code.
2077 */
2078static int nfs4_try_migration(struct nfs_server *server, const struct cred *cred)
2079{
2080	struct nfs_client *clp = server->nfs_client;
2081	struct nfs4_fs_locations *locations = NULL;
2082	struct inode *inode;
2083	struct page *page;
2084	int status, result;
2085
2086	dprintk("--> %s: FSID %llx:%llx on \"%s\"\n", __func__,
2087			(unsigned long long)server->fsid.major,
2088			(unsigned long long)server->fsid.minor,
2089			clp->cl_hostname);
2090
2091	result = 0;
2092	page = alloc_page(GFP_KERNEL);
2093	locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
2094	if (page == NULL || locations == NULL) {
2095		dprintk("<-- %s: no memory\n", __func__);
2096		goto out;
2097	}
 
 
 
 
 
2098
2099	inode = d_inode(server->super->s_root);
2100	result = nfs4_proc_get_locations(inode, locations, page, cred);
 
2101	if (result) {
2102		dprintk("<-- %s: failed to retrieve fs_locations: %d\n",
2103			__func__, result);
2104		goto out;
2105	}
2106
2107	result = -NFS4ERR_NXIO;
2108	if (!(locations->fattr.valid & NFS_ATTR_FATTR_V4_LOCATIONS)) {
 
 
 
2109		dprintk("<-- %s: No fs_locations data, migration skipped\n",
2110			__func__);
2111		goto out;
2112	}
2113
2114	status = nfs4_begin_drain_session(clp);
2115	if (status != 0) {
2116		result = status;
2117		goto out;
2118	}
2119
2120	status = nfs4_replace_transport(server, locations);
2121	if (status != 0) {
2122		dprintk("<-- %s: failed to replace transport: %d\n",
2123			__func__, status);
2124		goto out;
2125	}
2126
2127	result = 0;
2128	dprintk("<-- %s: migration succeeded\n", __func__);
2129
2130out:
2131	if (page != NULL)
2132		__free_page(page);
 
 
2133	kfree(locations);
2134	if (result) {
2135		pr_err("NFS: migration recovery failed (server %s)\n",
2136				clp->cl_hostname);
2137		set_bit(NFS_MIG_FAILED, &server->mig_status);
2138	}
2139	return result;
2140}
2141
2142/*
2143 * Returns zero or a negative NFS4ERR status code.
2144 */
2145static int nfs4_handle_migration(struct nfs_client *clp)
2146{
2147	const struct nfs4_state_maintenance_ops *ops =
2148				clp->cl_mvops->state_renewal_ops;
2149	struct nfs_server *server;
2150	const struct cred *cred;
2151
2152	dprintk("%s: migration reported on \"%s\"\n", __func__,
2153			clp->cl_hostname);
2154
2155	cred = ops->get_state_renewal_cred(clp);
2156	if (cred == NULL)
2157		return -NFS4ERR_NOENT;
2158
2159	clp->cl_mig_gen++;
2160restart:
2161	rcu_read_lock();
2162	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2163		int status;
2164
2165		if (server->mig_gen == clp->cl_mig_gen)
2166			continue;
2167		server->mig_gen = clp->cl_mig_gen;
2168
2169		if (!test_and_clear_bit(NFS_MIG_IN_TRANSITION,
2170						&server->mig_status))
2171			continue;
2172
2173		rcu_read_unlock();
2174		status = nfs4_try_migration(server, cred);
2175		if (status < 0) {
2176			put_cred(cred);
2177			return status;
2178		}
2179		goto restart;
2180	}
2181	rcu_read_unlock();
2182	put_cred(cred);
2183	return 0;
2184}
2185
2186/*
2187 * Test each nfs_server on the clp's cl_superblocks list to see
2188 * if it's moved to another server.  Stop when the server no longer
2189 * returns NFS4ERR_LEASE_MOVED.
2190 */
2191static int nfs4_handle_lease_moved(struct nfs_client *clp)
2192{
2193	const struct nfs4_state_maintenance_ops *ops =
2194				clp->cl_mvops->state_renewal_ops;
2195	struct nfs_server *server;
2196	const struct cred *cred;
2197
2198	dprintk("%s: lease moved reported on \"%s\"\n", __func__,
2199			clp->cl_hostname);
2200
2201	cred = ops->get_state_renewal_cred(clp);
2202	if (cred == NULL)
2203		return -NFS4ERR_NOENT;
2204
2205	clp->cl_mig_gen++;
2206restart:
2207	rcu_read_lock();
2208	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2209		struct inode *inode;
2210		int status;
2211
2212		if (server->mig_gen == clp->cl_mig_gen)
2213			continue;
2214		server->mig_gen = clp->cl_mig_gen;
2215
2216		rcu_read_unlock();
2217
2218		inode = d_inode(server->super->s_root);
2219		status = nfs4_proc_fsid_present(inode, cred);
2220		if (status != -NFS4ERR_MOVED)
2221			goto restart;	/* wasn't this one */
2222		if (nfs4_try_migration(server, cred) == -NFS4ERR_LEASE_MOVED)
2223			goto restart;	/* there are more */
2224		goto out;
2225	}
2226	rcu_read_unlock();
2227
2228out:
2229	put_cred(cred);
2230	return 0;
2231}
2232
2233/**
2234 * nfs4_discover_server_trunking - Detect server IP address trunking
2235 *
2236 * @clp: nfs_client under test
2237 * @result: OUT: found nfs_client, or clp
2238 *
2239 * Returns zero or a negative errno.  If zero is returned,
2240 * an nfs_client pointer is planted in "result".
2241 *
2242 * Note: since we are invoked in process context, and
2243 * not from inside the state manager, we cannot use
2244 * nfs4_handle_reclaim_lease_error().
2245 */
2246int nfs4_discover_server_trunking(struct nfs_client *clp,
2247				  struct nfs_client **result)
2248{
2249	const struct nfs4_state_recovery_ops *ops =
2250				clp->cl_mvops->reboot_recovery_ops;
2251	struct rpc_clnt *clnt;
2252	const struct cred *cred;
2253	int i, status;
2254
2255	dprintk("NFS: %s: testing '%s'\n", __func__, clp->cl_hostname);
2256
2257	clnt = clp->cl_rpcclient;
2258	i = 0;
2259
2260	mutex_lock(&nfs_clid_init_mutex);
2261again:
2262	status  = -ENOENT;
2263	cred = nfs4_get_clid_cred(clp);
2264	if (cred == NULL)
2265		goto out_unlock;
2266
2267	status = ops->detect_trunking(clp, result, cred);
2268	put_cred(cred);
2269	switch (status) {
2270	case 0:
2271	case -EINTR:
2272	case -ERESTARTSYS:
2273		break;
2274	case -ETIMEDOUT:
2275		if (clnt->cl_softrtry)
2276			break;
2277		fallthrough;
2278	case -NFS4ERR_DELAY:
2279	case -EAGAIN:
2280		ssleep(1);
2281		fallthrough;
2282	case -NFS4ERR_STALE_CLIENTID:
2283		dprintk("NFS: %s after status %d, retrying\n",
2284			__func__, status);
2285		goto again;
2286	case -EACCES:
2287		if (i++ == 0) {
2288			nfs4_root_machine_cred(clp);
2289			goto again;
2290		}
2291		if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX)
2292			break;
2293		fallthrough;
2294	case -NFS4ERR_CLID_INUSE:
2295	case -NFS4ERR_WRONGSEC:
2296		/* No point in retrying if we already used RPC_AUTH_UNIX */
2297		if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX) {
2298			status = -EPERM;
2299			break;
2300		}
2301		clnt = rpc_clone_client_set_auth(clnt, RPC_AUTH_UNIX);
2302		if (IS_ERR(clnt)) {
2303			status = PTR_ERR(clnt);
2304			break;
2305		}
2306		/* Note: this is safe because we haven't yet marked the
2307		 * client as ready, so we are the only user of
2308		 * clp->cl_rpcclient
2309		 */
2310		clnt = xchg(&clp->cl_rpcclient, clnt);
2311		rpc_shutdown_client(clnt);
2312		clnt = clp->cl_rpcclient;
2313		goto again;
2314
2315	case -NFS4ERR_MINOR_VERS_MISMATCH:
2316		status = -EPROTONOSUPPORT;
2317		break;
2318
2319	case -EKEYEXPIRED:
2320	case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
2321				 * in nfs4_exchange_id */
2322		status = -EKEYEXPIRED;
2323		break;
2324	default:
2325		pr_warn("NFS: %s unhandled error %d. Exiting with error EIO\n",
2326				__func__, status);
2327		status = -EIO;
2328	}
2329
2330out_unlock:
2331	mutex_unlock(&nfs_clid_init_mutex);
2332	dprintk("NFS: %s: status = %d\n", __func__, status);
2333	return status;
2334}
2335
2336#ifdef CONFIG_NFS_V4_1
2337void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
2338{
2339	struct nfs_client *clp = session->clp;
2340
2341	switch (err) {
2342	default:
2343		set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2344		break;
2345	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
2346		set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2347	}
2348	nfs4_schedule_state_manager(clp);
2349}
2350EXPORT_SYMBOL_GPL(nfs4_schedule_session_recovery);
2351
2352void nfs41_notify_server(struct nfs_client *clp)
2353{
2354	/* Use CHECK_LEASE to ping the server with a SEQUENCE */
2355	set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2356	nfs4_schedule_state_manager(clp);
2357}
2358
2359static void nfs4_reset_all_state(struct nfs_client *clp)
2360{
2361	if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2362		set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2363		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2364		nfs4_state_start_reclaim_nograce(clp);
2365		dprintk("%s: scheduling reset of all state for server %s!\n",
2366				__func__, clp->cl_hostname);
2367		nfs4_schedule_state_manager(clp);
2368	}
2369}
2370
2371static void nfs41_handle_server_reboot(struct nfs_client *clp)
2372{
2373	if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2374		nfs4_state_start_reclaim_reboot(clp);
2375		dprintk("%s: server %s rebooted!\n", __func__,
2376				clp->cl_hostname);
2377		nfs4_schedule_state_manager(clp);
2378	}
2379}
2380
2381static void nfs41_handle_all_state_revoked(struct nfs_client *clp)
2382{
2383	nfs4_reset_all_state(clp);
2384	dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2385}
2386
2387static void nfs41_handle_some_state_revoked(struct nfs_client *clp)
2388{
2389	nfs4_state_start_reclaim_nograce(clp);
2390	nfs4_schedule_state_manager(clp);
2391
2392	dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2393}
2394
2395static void nfs41_handle_recallable_state_revoked(struct nfs_client *clp)
2396{
2397	/* FIXME: For now, we destroy all layouts. */
2398	pnfs_destroy_all_layouts(clp);
2399	nfs_test_expired_all_delegations(clp);
2400	dprintk("%s: Recallable state revoked on server %s!\n", __func__,
2401			clp->cl_hostname);
2402}
2403
2404static void nfs41_handle_backchannel_fault(struct nfs_client *clp)
2405{
2406	set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2407	nfs4_schedule_state_manager(clp);
2408
2409	dprintk("%s: server %s declared a backchannel fault\n", __func__,
2410			clp->cl_hostname);
2411}
2412
2413static void nfs41_handle_cb_path_down(struct nfs_client *clp)
2414{
2415	if (test_and_set_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2416		&clp->cl_state) == 0)
2417		nfs4_schedule_state_manager(clp);
2418}
2419
2420void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags,
2421		bool recovery)
2422{
2423	if (!flags)
2424		return;
2425
2426	dprintk("%s: \"%s\" (client ID %llx) flags=0x%08x\n",
2427		__func__, clp->cl_hostname, clp->cl_clientid, flags);
2428	/*
2429	 * If we're called from the state manager thread, then assume we're
2430	 * already handling the RECLAIM_NEEDED and/or STATE_REVOKED.
2431	 * Those flags are expected to remain set until we're done
2432	 * recovering (see RFC5661, section 18.46.3).
2433	 */
2434	if (recovery)
2435		goto out_recovery;
2436
2437	if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED)
2438		nfs41_handle_server_reboot(clp);
2439	if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED))
2440		nfs41_handle_all_state_revoked(clp);
2441	if (flags & (SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED |
2442			    SEQ4_STATUS_ADMIN_STATE_REVOKED))
2443		nfs41_handle_some_state_revoked(clp);
2444	if (flags & SEQ4_STATUS_LEASE_MOVED)
2445		nfs4_schedule_lease_moved_recovery(clp);
2446	if (flags & SEQ4_STATUS_RECALLABLE_STATE_REVOKED)
2447		nfs41_handle_recallable_state_revoked(clp);
2448out_recovery:
2449	if (flags & SEQ4_STATUS_BACKCHANNEL_FAULT)
2450		nfs41_handle_backchannel_fault(clp);
2451	else if (flags & (SEQ4_STATUS_CB_PATH_DOWN |
2452				SEQ4_STATUS_CB_PATH_DOWN_SESSION))
2453		nfs41_handle_cb_path_down(clp);
2454}
2455
2456static int nfs4_reset_session(struct nfs_client *clp)
2457{
2458	const struct cred *cred;
2459	int status;
2460
2461	if (!nfs4_has_session(clp))
2462		return 0;
2463	status = nfs4_begin_drain_session(clp);
2464	if (status != 0)
2465		return status;
2466	cred = nfs4_get_clid_cred(clp);
2467	status = nfs4_proc_destroy_session(clp->cl_session, cred);
2468	switch (status) {
2469	case 0:
2470	case -NFS4ERR_BADSESSION:
2471	case -NFS4ERR_DEADSESSION:
2472		break;
2473	case -NFS4ERR_BACK_CHAN_BUSY:
2474	case -NFS4ERR_DELAY:
2475		set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2476		status = 0;
2477		ssleep(1);
2478		goto out;
2479	default:
2480		status = nfs4_recovery_handle_error(clp, status);
2481		goto out;
2482	}
2483
2484	memset(clp->cl_session->sess_id.data, 0, NFS4_MAX_SESSIONID_LEN);
2485	status = nfs4_proc_create_session(clp, cred);
2486	if (status) {
2487		dprintk("%s: session reset failed with status %d for server %s!\n",
2488			__func__, status, clp->cl_hostname);
2489		status = nfs4_handle_reclaim_lease_error(clp, status);
2490		goto out;
2491	}
2492	nfs41_finish_session_reset(clp);
2493	dprintk("%s: session reset was successful for server %s!\n",
2494			__func__, clp->cl_hostname);
2495out:
2496	put_cred(cred);
2497	return status;
2498}
2499
2500static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2501{
2502	const struct cred *cred;
2503	int ret;
2504
2505	if (!nfs4_has_session(clp))
2506		return 0;
2507	ret = nfs4_begin_drain_session(clp);
2508	if (ret != 0)
2509		return ret;
2510	cred = nfs4_get_clid_cred(clp);
2511	ret = nfs4_proc_bind_conn_to_session(clp, cred);
2512	put_cred(cred);
2513	clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2514	switch (ret) {
2515	case 0:
2516		dprintk("%s: bind_conn_to_session was successful for server %s!\n",
2517			__func__, clp->cl_hostname);
2518		break;
2519	case -NFS4ERR_DELAY:
2520		ssleep(1);
2521		set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2522		break;
2523	default:
2524		return nfs4_recovery_handle_error(clp, ret);
2525	}
2526	return 0;
2527}
2528
2529static void nfs4_layoutreturn_any_run(struct nfs_client *clp)
2530{
2531	int iomode = 0;
2532
2533	if (test_and_clear_bit(NFS4CLNT_RECALL_ANY_LAYOUT_READ, &clp->cl_state))
2534		iomode += IOMODE_READ;
2535	if (test_and_clear_bit(NFS4CLNT_RECALL_ANY_LAYOUT_RW, &clp->cl_state))
2536		iomode += IOMODE_RW;
2537	/* Note: IOMODE_READ + IOMODE_RW == IOMODE_ANY */
2538	if (iomode) {
2539		pnfs_layout_return_unused_byclid(clp, iomode);
2540		set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2541	}
2542}
2543#else /* CONFIG_NFS_V4_1 */
2544static int nfs4_reset_session(struct nfs_client *clp) { return 0; }
2545
2546static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2547{
2548	return 0;
2549}
2550
2551static void nfs4_layoutreturn_any_run(struct nfs_client *clp)
2552{
2553}
2554#endif /* CONFIG_NFS_V4_1 */
2555
2556static void nfs4_state_manager(struct nfs_client *clp)
2557{
 
2558	int status = 0;
2559	const char *section = "", *section_sep = "";
2560
 
 
 
 
 
 
 
2561	/* Ensure exclusive access to NFSv4 state */
2562	do {
2563		trace_nfs4_state_mgr(clp);
2564		clear_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2565		if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
2566			section = "purge state";
2567			status = nfs4_purge_lease(clp);
2568			if (status < 0)
2569				goto out_error;
2570			continue;
2571		}
2572
2573		if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
2574			section = "lease expired";
2575			/* We're going to have to re-establish a clientid */
2576			status = nfs4_reclaim_lease(clp);
2577			if (status < 0)
2578				goto out_error;
2579			continue;
2580		}
2581
2582		/* Initialize or reset the session */
2583		if (test_and_clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state)) {
2584			section = "reset session";
2585			status = nfs4_reset_session(clp);
2586			if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
2587				continue;
2588			if (status < 0)
2589				goto out_error;
2590		}
2591
2592		/* Send BIND_CONN_TO_SESSION */
2593		if (test_and_clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2594				&clp->cl_state)) {
2595			section = "bind conn to session";
2596			status = nfs4_bind_conn_to_session(clp);
2597			if (status < 0)
2598				goto out_error;
2599			continue;
2600		}
2601
2602		if (test_and_clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state)) {
2603			section = "check lease";
2604			status = nfs4_check_lease(clp);
2605			if (status < 0)
2606				goto out_error;
2607			continue;
2608		}
2609
2610		if (test_and_clear_bit(NFS4CLNT_MOVED, &clp->cl_state)) {
2611			section = "migration";
2612			status = nfs4_handle_migration(clp);
2613			if (status < 0)
2614				goto out_error;
2615		}
2616
2617		if (test_and_clear_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state)) {
2618			section = "lease moved";
2619			status = nfs4_handle_lease_moved(clp);
2620			if (status < 0)
2621				goto out_error;
2622		}
2623
2624		/* First recover reboot state... */
2625		if (test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {
2626			section = "reclaim reboot";
2627			status = nfs4_do_reclaim(clp,
2628				clp->cl_mvops->reboot_recovery_ops);
2629			if (status == -EAGAIN)
2630				continue;
2631			if (status < 0)
2632				goto out_error;
2633			nfs4_state_end_reclaim_reboot(clp);
 
2634		}
2635
2636		/* Detect expired delegations... */
2637		if (test_and_clear_bit(NFS4CLNT_DELEGATION_EXPIRED, &clp->cl_state)) {
2638			section = "detect expired delegations";
2639			nfs_reap_expired_delegations(clp);
2640			continue;
2641		}
2642
2643		/* Now recover expired state... */
2644		if (test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state)) {
2645			section = "reclaim nograce";
2646			status = nfs4_do_reclaim(clp,
2647				clp->cl_mvops->nograce_recovery_ops);
2648			if (status == -EAGAIN)
2649				continue;
2650			if (status < 0)
2651				goto out_error;
2652			clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
2653		}
2654
 
2655		nfs4_end_drain_session(clp);
2656		nfs4_clear_state_manager_bit(clp);
2657
2658		if (!test_and_set_bit(NFS4CLNT_RECALL_RUNNING, &clp->cl_state)) {
2659			if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
2660				nfs_client_return_marked_delegations(clp);
2661				set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2662			}
2663			nfs4_layoutreturn_any_run(clp);
2664			clear_bit(NFS4CLNT_RECALL_RUNNING, &clp->cl_state);
2665		}
2666
2667		/* Did we race with an attempt to give us more work? */
2668		if (!test_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state))
2669			return;
2670		if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
2671			return;
2672	} while (refcount_read(&clp->cl_count) > 1 && !signalled());
2673	goto out_drain;
2674
2675out_error:
2676	if (strlen(section))
2677		section_sep = ": ";
2678	trace_nfs4_state_mgr_failed(clp, section, status);
2679	pr_warn_ratelimited("NFS: state manager%s%s failed on NFSv4 server %s"
2680			" with error %d\n", section_sep, section,
2681			clp->cl_hostname, -status);
2682	ssleep(1);
2683out_drain:
 
2684	nfs4_end_drain_session(clp);
2685	nfs4_clear_state_manager_bit(clp);
2686}
2687
2688static int nfs4_run_state_manager(void *ptr)
2689{
2690	struct nfs_client *clp = ptr;
 
 
 
 
2691
2692	allow_signal(SIGKILL);
 
 
2693	nfs4_state_manager(clp);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2694	nfs_put_client(clp);
2695	module_put_and_exit(0);
2696	return 0;
2697}
v6.2
   1/*
   2 *  fs/nfs/nfs4state.c
   3 *
   4 *  Client-side XDR for NFSv4.
   5 *
   6 *  Copyright (c) 2002 The Regents of the University of Michigan.
   7 *  All rights reserved.
   8 *
   9 *  Kendrick Smith <kmsmith@umich.edu>
  10 *
  11 *  Redistribution and use in source and binary forms, with or without
  12 *  modification, are permitted provided that the following conditions
  13 *  are met:
  14 *
  15 *  1. Redistributions of source code must retain the above copyright
  16 *     notice, this list of conditions and the following disclaimer.
  17 *  2. Redistributions in binary form must reproduce the above copyright
  18 *     notice, this list of conditions and the following disclaimer in the
  19 *     documentation and/or other materials provided with the distribution.
  20 *  3. Neither the name of the University nor the names of its
  21 *     contributors may be used to endorse or promote products derived
  22 *     from this software without specific prior written permission.
  23 *
  24 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  25 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  26 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  27 *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  31 *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  32 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  33 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  34 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35 *
  36 * Implementation of the NFSv4 state model.  For the time being,
  37 * this is minimal, but will be made much more complex in a
  38 * subsequent patch.
  39 */
  40
  41#include <linux/kernel.h>
  42#include <linux/slab.h>
  43#include <linux/fs.h>
  44#include <linux/nfs_fs.h>
  45#include <linux/kthread.h>
  46#include <linux/module.h>
  47#include <linux/random.h>
  48#include <linux/ratelimit.h>
  49#include <linux/workqueue.h>
  50#include <linux/bitops.h>
  51#include <linux/jiffies.h>
  52#include <linux/sched/mm.h>
  53
  54#include <linux/sunrpc/clnt.h>
  55
  56#include "nfs4_fs.h"
  57#include "callback.h"
  58#include "delegation.h"
  59#include "internal.h"
  60#include "nfs4idmap.h"
  61#include "nfs4session.h"
  62#include "pnfs.h"
  63#include "netns.h"
  64#include "nfs4trace.h"
  65
  66#define NFSDBG_FACILITY		NFSDBG_STATE
  67
  68#define OPENOWNER_POOL_SIZE	8
  69
  70const nfs4_stateid zero_stateid = {
  71	{ .data = { 0 } },
  72	.type = NFS4_SPECIAL_STATEID_TYPE,
  73};
  74const nfs4_stateid invalid_stateid = {
  75	{
  76		/* Funky initialiser keeps older gcc versions happy */
  77		.data = { 0xff, 0xff, 0xff, 0xff, 0 },
  78	},
  79	.type = NFS4_INVALID_STATEID_TYPE,
  80};
  81
  82const nfs4_stateid current_stateid = {
  83	{
  84		/* Funky initialiser keeps older gcc versions happy */
  85		.data = { 0x0, 0x0, 0x0, 0x1, 0 },
  86	},
  87	.type = NFS4_SPECIAL_STATEID_TYPE,
  88};
  89
  90static DEFINE_MUTEX(nfs_clid_init_mutex);
  91
  92static int nfs4_setup_state_renewal(struct nfs_client *clp)
  93{
  94	int status;
  95	struct nfs_fsinfo fsinfo;
  96
  97	if (!test_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state)) {
  98		nfs4_schedule_state_renewal(clp);
  99		return 0;
 100	}
 101
 102	status = nfs4_proc_get_lease_time(clp, &fsinfo);
 103	if (status == 0) {
 104		nfs4_set_lease_period(clp, fsinfo.lease_time * HZ);
 105		nfs4_schedule_state_renewal(clp);
 106	}
 107
 108	return status;
 109}
 110
 111int nfs4_init_clientid(struct nfs_client *clp, const struct cred *cred)
 112{
 113	struct nfs4_setclientid_res clid = {
 114		.clientid = clp->cl_clientid,
 115		.confirm = clp->cl_confirm,
 116	};
 117	unsigned short port;
 118	int status;
 119	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
 120
 121	if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
 122		goto do_confirm;
 123	port = nn->nfs_callback_tcpport;
 124	if (clp->cl_addr.ss_family == AF_INET6)
 125		port = nn->nfs_callback_tcpport6;
 126
 127	status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
 128	if (status != 0)
 129		goto out;
 130	clp->cl_clientid = clid.clientid;
 131	clp->cl_confirm = clid.confirm;
 132	set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 133do_confirm:
 134	status = nfs4_proc_setclientid_confirm(clp, &clid, cred);
 135	if (status != 0)
 136		goto out;
 137	clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 138	nfs4_setup_state_renewal(clp);
 139out:
 140	return status;
 141}
 142
 143/**
 144 * nfs40_discover_server_trunking - Detect server IP address trunking (mv0)
 145 *
 146 * @clp: nfs_client under test
 147 * @result: OUT: found nfs_client, or clp
 148 * @cred: credential to use for trunking test
 149 *
 150 * Returns zero, a negative errno, or a negative NFS4ERR status.
 151 * If zero is returned, an nfs_client pointer is planted in
 152 * "result".
 153 *
 154 * Note: The returned client may not yet be marked ready.
 155 */
 156int nfs40_discover_server_trunking(struct nfs_client *clp,
 157				   struct nfs_client **result,
 158				   const struct cred *cred)
 159{
 160	struct nfs4_setclientid_res clid = {
 161		.clientid = clp->cl_clientid,
 162		.confirm = clp->cl_confirm,
 163	};
 164	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
 165	unsigned short port;
 166	int status;
 167
 168	port = nn->nfs_callback_tcpport;
 169	if (clp->cl_addr.ss_family == AF_INET6)
 170		port = nn->nfs_callback_tcpport6;
 171
 172	status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
 173	if (status != 0)
 174		goto out;
 175	clp->cl_clientid = clid.clientid;
 176	clp->cl_confirm = clid.confirm;
 177
 178	status = nfs40_walk_client_list(clp, result, cred);
 179	if (status == 0) {
 180		/* Sustain the lease, even if it's empty.  If the clientid4
 181		 * goes stale it's of no use for trunking discovery. */
 182		nfs4_schedule_state_renewal(*result);
 183
 184		/* If the client state need to recover, do it. */
 185		if (clp->cl_state)
 186			nfs4_schedule_state_manager(clp);
 187	}
 188out:
 189	return status;
 190}
 191
 192const struct cred *nfs4_get_machine_cred(struct nfs_client *clp)
 193{
 194	return get_cred(rpc_machine_cred());
 195}
 196
 197static void nfs4_root_machine_cred(struct nfs_client *clp)
 198{
 199
 200	/* Force root creds instead of machine */
 201	clp->cl_principal = NULL;
 202	clp->cl_rpcclient->cl_principal = NULL;
 203}
 204
 205static const struct cred *
 206nfs4_get_renew_cred_server_locked(struct nfs_server *server)
 207{
 208	const struct cred *cred = NULL;
 209	struct nfs4_state_owner *sp;
 210	struct rb_node *pos;
 211
 212	for (pos = rb_first(&server->state_owners);
 213	     pos != NULL;
 214	     pos = rb_next(pos)) {
 215		sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
 216		if (list_empty(&sp->so_states))
 217			continue;
 218		cred = get_cred(sp->so_cred);
 219		break;
 220	}
 221	return cred;
 222}
 223
 224/**
 225 * nfs4_get_renew_cred - Acquire credential for a renew operation
 226 * @clp: client state handle
 227 *
 228 * Returns an rpc_cred with reference count bumped, or NULL.
 229 * Caller must hold clp->cl_lock.
 230 */
 231const struct cred *nfs4_get_renew_cred(struct nfs_client *clp)
 232{
 233	const struct cred *cred = NULL;
 234	struct nfs_server *server;
 235
 236	/* Use machine credentials if available */
 237	cred = nfs4_get_machine_cred(clp);
 238	if (cred != NULL)
 239		goto out;
 240
 241	spin_lock(&clp->cl_lock);
 242	rcu_read_lock();
 243	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 244		cred = nfs4_get_renew_cred_server_locked(server);
 245		if (cred != NULL)
 246			break;
 247	}
 248	rcu_read_unlock();
 249	spin_unlock(&clp->cl_lock);
 250
 251out:
 252	return cred;
 253}
 254
 255static void nfs4_end_drain_slot_table(struct nfs4_slot_table *tbl)
 256{
 257	if (test_and_clear_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state)) {
 258		spin_lock(&tbl->slot_tbl_lock);
 259		nfs41_wake_slot_table(tbl);
 260		spin_unlock(&tbl->slot_tbl_lock);
 261	}
 262}
 263
 264static void nfs4_end_drain_session(struct nfs_client *clp)
 265{
 266	struct nfs4_session *ses = clp->cl_session;
 267
 268	if (clp->cl_slot_tbl) {
 269		nfs4_end_drain_slot_table(clp->cl_slot_tbl);
 270		return;
 271	}
 272
 273	if (ses != NULL) {
 274		nfs4_end_drain_slot_table(&ses->bc_slot_table);
 275		nfs4_end_drain_slot_table(&ses->fc_slot_table);
 276	}
 277}
 278
 279static int nfs4_drain_slot_tbl(struct nfs4_slot_table *tbl)
 280{
 281	set_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
 282	spin_lock(&tbl->slot_tbl_lock);
 283	if (tbl->highest_used_slotid != NFS4_NO_SLOT) {
 284		reinit_completion(&tbl->complete);
 285		spin_unlock(&tbl->slot_tbl_lock);
 286		return wait_for_completion_interruptible(&tbl->complete);
 287	}
 288	spin_unlock(&tbl->slot_tbl_lock);
 289	return 0;
 290}
 291
 292static int nfs4_begin_drain_session(struct nfs_client *clp)
 293{
 294	struct nfs4_session *ses = clp->cl_session;
 295	int ret;
 296
 297	if (clp->cl_slot_tbl)
 298		return nfs4_drain_slot_tbl(clp->cl_slot_tbl);
 299
 300	/* back channel */
 301	ret = nfs4_drain_slot_tbl(&ses->bc_slot_table);
 302	if (ret)
 303		return ret;
 304	/* fore channel */
 305	return nfs4_drain_slot_tbl(&ses->fc_slot_table);
 306}
 307
 308#if defined(CONFIG_NFS_V4_1)
 309
 310static void nfs41_finish_session_reset(struct nfs_client *clp)
 311{
 312	clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 313	clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
 314	/* create_session negotiated new slot table */
 315	clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
 316	nfs4_setup_state_renewal(clp);
 317}
 318
 319int nfs41_init_clientid(struct nfs_client *clp, const struct cred *cred)
 320{
 321	int status;
 322
 323	if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
 324		goto do_confirm;
 325	status = nfs4_proc_exchange_id(clp, cred);
 326	if (status != 0)
 327		goto out;
 328	set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 329do_confirm:
 330	status = nfs4_proc_create_session(clp, cred);
 331	if (status != 0)
 332		goto out;
 333	nfs41_finish_session_reset(clp);
 334	nfs_mark_client_ready(clp, NFS_CS_READY);
 335out:
 336	return status;
 337}
 338
 339/**
 340 * nfs41_discover_server_trunking - Detect server IP address trunking (mv1)
 341 *
 342 * @clp: nfs_client under test
 343 * @result: OUT: found nfs_client, or clp
 344 * @cred: credential to use for trunking test
 345 *
 346 * Returns NFS4_OK, a negative errno, or a negative NFS4ERR status.
 347 * If NFS4_OK is returned, an nfs_client pointer is planted in
 348 * "result".
 349 *
 350 * Note: The returned client may not yet be marked ready.
 351 */
 352int nfs41_discover_server_trunking(struct nfs_client *clp,
 353				   struct nfs_client **result,
 354				   const struct cred *cred)
 355{
 356	int status;
 357
 358	status = nfs4_proc_exchange_id(clp, cred);
 359	if (status != NFS4_OK)
 360		return status;
 361
 362	status = nfs41_walk_client_list(clp, result, cred);
 363	if (status < 0)
 364		return status;
 365	if (clp != *result)
 366		return 0;
 367
 368	/*
 369	 * Purge state if the client id was established in a prior
 370	 * instance and the client id could not have arrived on the
 371	 * server via Transparent State Migration.
 372	 */
 373	if (clp->cl_exchange_flags & EXCHGID4_FLAG_CONFIRMED_R) {
 374		if (!test_bit(NFS_CS_TSM_POSSIBLE, &clp->cl_flags))
 375			set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
 376		else
 377			set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 378	}
 379	nfs4_schedule_state_manager(clp);
 380	status = nfs_wait_client_init_complete(clp);
 381	if (status < 0)
 382		nfs_put_client(clp);
 383	return status;
 384}
 385
 386#endif /* CONFIG_NFS_V4_1 */
 387
 388/**
 389 * nfs4_get_clid_cred - Acquire credential for a setclientid operation
 390 * @clp: client state handle
 391 *
 392 * Returns a cred with reference count bumped, or NULL.
 393 */
 394const struct cred *nfs4_get_clid_cred(struct nfs_client *clp)
 395{
 396	const struct cred *cred;
 397
 398	cred = nfs4_get_machine_cred(clp);
 399	return cred;
 400}
 401
 402static struct nfs4_state_owner *
 403nfs4_find_state_owner_locked(struct nfs_server *server, const struct cred *cred)
 404{
 405	struct rb_node **p = &server->state_owners.rb_node,
 406		       *parent = NULL;
 407	struct nfs4_state_owner *sp;
 408	int cmp;
 409
 410	while (*p != NULL) {
 411		parent = *p;
 412		sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
 413		cmp = cred_fscmp(cred, sp->so_cred);
 414
 415		if (cmp < 0)
 416			p = &parent->rb_left;
 417		else if (cmp > 0)
 418			p = &parent->rb_right;
 419		else {
 420			if (!list_empty(&sp->so_lru))
 421				list_del_init(&sp->so_lru);
 422			atomic_inc(&sp->so_count);
 423			return sp;
 424		}
 425	}
 426	return NULL;
 427}
 428
 429static struct nfs4_state_owner *
 430nfs4_insert_state_owner_locked(struct nfs4_state_owner *new)
 431{
 432	struct nfs_server *server = new->so_server;
 433	struct rb_node **p = &server->state_owners.rb_node,
 434		       *parent = NULL;
 435	struct nfs4_state_owner *sp;
 436	int cmp;
 437
 438	while (*p != NULL) {
 439		parent = *p;
 440		sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
 441		cmp = cred_fscmp(new->so_cred, sp->so_cred);
 442
 443		if (cmp < 0)
 444			p = &parent->rb_left;
 445		else if (cmp > 0)
 446			p = &parent->rb_right;
 447		else {
 448			if (!list_empty(&sp->so_lru))
 449				list_del_init(&sp->so_lru);
 450			atomic_inc(&sp->so_count);
 451			return sp;
 452		}
 453	}
 454	rb_link_node(&new->so_server_node, parent, p);
 455	rb_insert_color(&new->so_server_node, &server->state_owners);
 456	return new;
 457}
 458
 459static void
 460nfs4_remove_state_owner_locked(struct nfs4_state_owner *sp)
 461{
 462	struct nfs_server *server = sp->so_server;
 463
 464	if (!RB_EMPTY_NODE(&sp->so_server_node))
 465		rb_erase(&sp->so_server_node, &server->state_owners);
 466}
 467
 468static void
 469nfs4_init_seqid_counter(struct nfs_seqid_counter *sc)
 470{
 471	sc->create_time = ktime_get();
 472	sc->flags = 0;
 473	sc->counter = 0;
 474	spin_lock_init(&sc->lock);
 475	INIT_LIST_HEAD(&sc->list);
 476	rpc_init_wait_queue(&sc->wait, "Seqid_waitqueue");
 477}
 478
 479static void
 480nfs4_destroy_seqid_counter(struct nfs_seqid_counter *sc)
 481{
 482	rpc_destroy_wait_queue(&sc->wait);
 483}
 484
 485/*
 486 * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
 487 * create a new state_owner.
 488 *
 489 */
 490static struct nfs4_state_owner *
 491nfs4_alloc_state_owner(struct nfs_server *server,
 492		const struct cred *cred,
 493		gfp_t gfp_flags)
 494{
 495	struct nfs4_state_owner *sp;
 496
 497	sp = kzalloc(sizeof(*sp), gfp_flags);
 498	if (!sp)
 499		return NULL;
 500	sp->so_seqid.owner_id = ida_alloc(&server->openowner_id, gfp_flags);
 
 501	if (sp->so_seqid.owner_id < 0) {
 502		kfree(sp);
 503		return NULL;
 504	}
 505	sp->so_server = server;
 506	sp->so_cred = get_cred(cred);
 507	spin_lock_init(&sp->so_lock);
 508	INIT_LIST_HEAD(&sp->so_states);
 509	nfs4_init_seqid_counter(&sp->so_seqid);
 510	atomic_set(&sp->so_count, 1);
 511	INIT_LIST_HEAD(&sp->so_lru);
 512	seqcount_spinlock_init(&sp->so_reclaim_seqcount, &sp->so_lock);
 513	mutex_init(&sp->so_delegreturn_mutex);
 514	return sp;
 515}
 516
 517static void
 518nfs4_reset_state_owner(struct nfs4_state_owner *sp)
 519{
 520	/* This state_owner is no longer usable, but must
 521	 * remain in place so that state recovery can find it
 522	 * and the opens associated with it.
 523	 * It may also be used for new 'open' request to
 524	 * return a delegation to the server.
 525	 * So update the 'create_time' so that it looks like
 526	 * a new state_owner.  This will cause the server to
 527	 * request an OPEN_CONFIRM to start a new sequence.
 528	 */
 529	sp->so_seqid.create_time = ktime_get();
 530}
 531
 532static void nfs4_free_state_owner(struct nfs4_state_owner *sp)
 533{
 534	nfs4_destroy_seqid_counter(&sp->so_seqid);
 535	put_cred(sp->so_cred);
 536	ida_free(&sp->so_server->openowner_id, sp->so_seqid.owner_id);
 537	kfree(sp);
 538}
 539
 540static void nfs4_gc_state_owners(struct nfs_server *server)
 541{
 542	struct nfs_client *clp = server->nfs_client;
 543	struct nfs4_state_owner *sp, *tmp;
 544	unsigned long time_min, time_max;
 545	LIST_HEAD(doomed);
 546
 547	spin_lock(&clp->cl_lock);
 548	time_max = jiffies;
 549	time_min = (long)time_max - (long)clp->cl_lease_time;
 550	list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
 551		/* NB: LRU is sorted so that oldest is at the head */
 552		if (time_in_range(sp->so_expires, time_min, time_max))
 553			break;
 554		list_move(&sp->so_lru, &doomed);
 555		nfs4_remove_state_owner_locked(sp);
 556	}
 557	spin_unlock(&clp->cl_lock);
 558
 559	list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
 560		list_del(&sp->so_lru);
 561		nfs4_free_state_owner(sp);
 562	}
 563}
 564
 565/**
 566 * nfs4_get_state_owner - Look up a state owner given a credential
 567 * @server: nfs_server to search
 568 * @cred: RPC credential to match
 569 * @gfp_flags: allocation mode
 570 *
 571 * Returns a pointer to an instantiated nfs4_state_owner struct, or NULL.
 572 */
 573struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server,
 574					      const struct cred *cred,
 575					      gfp_t gfp_flags)
 576{
 577	struct nfs_client *clp = server->nfs_client;
 578	struct nfs4_state_owner *sp, *new;
 579
 580	spin_lock(&clp->cl_lock);
 581	sp = nfs4_find_state_owner_locked(server, cred);
 582	spin_unlock(&clp->cl_lock);
 583	if (sp != NULL)
 584		goto out;
 585	new = nfs4_alloc_state_owner(server, cred, gfp_flags);
 586	if (new == NULL)
 587		goto out;
 588	spin_lock(&clp->cl_lock);
 589	sp = nfs4_insert_state_owner_locked(new);
 590	spin_unlock(&clp->cl_lock);
 591	if (sp != new)
 592		nfs4_free_state_owner(new);
 593out:
 594	nfs4_gc_state_owners(server);
 595	return sp;
 596}
 597
 598/**
 599 * nfs4_put_state_owner - Release a nfs4_state_owner
 600 * @sp: state owner data to release
 601 *
 602 * Note that we keep released state owners on an LRU
 603 * list.
 604 * This caches valid state owners so that they can be
 605 * reused, to avoid the OPEN_CONFIRM on minor version 0.
 606 * It also pins the uniquifier of dropped state owners for
 607 * a while, to ensure that those state owner names are
 608 * never reused.
 609 */
 610void nfs4_put_state_owner(struct nfs4_state_owner *sp)
 611{
 612	struct nfs_server *server = sp->so_server;
 613	struct nfs_client *clp = server->nfs_client;
 614
 615	if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
 616		return;
 617
 618	sp->so_expires = jiffies;
 619	list_add_tail(&sp->so_lru, &server->state_owners_lru);
 620	spin_unlock(&clp->cl_lock);
 621}
 622
 623/**
 624 * nfs4_purge_state_owners - Release all cached state owners
 625 * @server: nfs_server with cached state owners to release
 626 * @head: resulting list of state owners
 627 *
 628 * Called at umount time.  Remaining state owners will be on
 629 * the LRU with ref count of zero.
 630 * Note that the state owners are not freed, but are added
 631 * to the list @head, which can later be used as an argument
 632 * to nfs4_free_state_owners.
 633 */
 634void nfs4_purge_state_owners(struct nfs_server *server, struct list_head *head)
 635{
 636	struct nfs_client *clp = server->nfs_client;
 637	struct nfs4_state_owner *sp, *tmp;
 638
 639	spin_lock(&clp->cl_lock);
 640	list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
 641		list_move(&sp->so_lru, head);
 642		nfs4_remove_state_owner_locked(sp);
 643	}
 644	spin_unlock(&clp->cl_lock);
 645}
 646
 647/**
 648 * nfs4_free_state_owners - Release all cached state owners
 649 * @head: resulting list of state owners
 650 *
 651 * Frees a list of state owners that was generated by
 652 * nfs4_purge_state_owners
 653 */
 654void nfs4_free_state_owners(struct list_head *head)
 655{
 656	struct nfs4_state_owner *sp, *tmp;
 657
 658	list_for_each_entry_safe(sp, tmp, head, so_lru) {
 659		list_del(&sp->so_lru);
 660		nfs4_free_state_owner(sp);
 661	}
 662}
 663
 664static struct nfs4_state *
 665nfs4_alloc_open_state(void)
 666{
 667	struct nfs4_state *state;
 668
 669	state = kzalloc(sizeof(*state), GFP_KERNEL_ACCOUNT);
 670	if (!state)
 671		return NULL;
 672	refcount_set(&state->count, 1);
 673	INIT_LIST_HEAD(&state->lock_states);
 674	spin_lock_init(&state->state_lock);
 675	seqlock_init(&state->seqlock);
 676	init_waitqueue_head(&state->waitq);
 677	return state;
 678}
 679
 680void
 681nfs4_state_set_mode_locked(struct nfs4_state *state, fmode_t fmode)
 682{
 683	if (state->state == fmode)
 684		return;
 685	/* NB! List reordering - see the reclaim code for why.  */
 686	if ((fmode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
 687		if (fmode & FMODE_WRITE)
 688			list_move(&state->open_states, &state->owner->so_states);
 689		else
 690			list_move_tail(&state->open_states, &state->owner->so_states);
 691	}
 692	state->state = fmode;
 693}
 694
 695static struct nfs4_state *
 696__nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
 697{
 698	struct nfs_inode *nfsi = NFS_I(inode);
 699	struct nfs4_state *state;
 700
 701	list_for_each_entry_rcu(state, &nfsi->open_states, inode_states) {
 702		if (state->owner != owner)
 703			continue;
 704		if (!nfs4_valid_open_stateid(state))
 705			continue;
 706		if (refcount_inc_not_zero(&state->count))
 707			return state;
 708	}
 709	return NULL;
 710}
 711
 712static void
 713nfs4_free_open_state(struct nfs4_state *state)
 714{
 715	kfree_rcu(state, rcu_head);
 716}
 717
 718struct nfs4_state *
 719nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
 720{
 721	struct nfs4_state *state, *new;
 722	struct nfs_inode *nfsi = NFS_I(inode);
 723
 724	rcu_read_lock();
 725	state = __nfs4_find_state_byowner(inode, owner);
 726	rcu_read_unlock();
 727	if (state)
 728		goto out;
 729	new = nfs4_alloc_open_state();
 730	spin_lock(&owner->so_lock);
 731	spin_lock(&inode->i_lock);
 732	state = __nfs4_find_state_byowner(inode, owner);
 733	if (state == NULL && new != NULL) {
 734		state = new;
 735		state->owner = owner;
 736		atomic_inc(&owner->so_count);
 737		ihold(inode);
 738		state->inode = inode;
 739		list_add_rcu(&state->inode_states, &nfsi->open_states);
 740		spin_unlock(&inode->i_lock);
 741		/* Note: The reclaim code dictates that we add stateless
 742		 * and read-only stateids to the end of the list */
 743		list_add_tail(&state->open_states, &owner->so_states);
 744		spin_unlock(&owner->so_lock);
 745	} else {
 746		spin_unlock(&inode->i_lock);
 747		spin_unlock(&owner->so_lock);
 748		if (new)
 749			nfs4_free_open_state(new);
 750	}
 751out:
 752	return state;
 753}
 754
 755void nfs4_put_open_state(struct nfs4_state *state)
 756{
 757	struct inode *inode = state->inode;
 758	struct nfs4_state_owner *owner = state->owner;
 759
 760	if (!refcount_dec_and_lock(&state->count, &owner->so_lock))
 761		return;
 762	spin_lock(&inode->i_lock);
 763	list_del_rcu(&state->inode_states);
 764	list_del(&state->open_states);
 765	spin_unlock(&inode->i_lock);
 766	spin_unlock(&owner->so_lock);
 767	nfs4_inode_return_delegation_on_close(inode);
 768	iput(inode);
 769	nfs4_free_open_state(state);
 770	nfs4_put_state_owner(owner);
 771}
 772
 773/*
 774 * Close the current file.
 775 */
 776static void __nfs4_close(struct nfs4_state *state,
 777		fmode_t fmode, gfp_t gfp_mask, int wait)
 778{
 779	struct nfs4_state_owner *owner = state->owner;
 780	int call_close = 0;
 781	fmode_t newstate;
 782
 783	atomic_inc(&owner->so_count);
 784	/* Protect against nfs4_find_state() */
 785	spin_lock(&owner->so_lock);
 786	switch (fmode & (FMODE_READ | FMODE_WRITE)) {
 787		case FMODE_READ:
 788			state->n_rdonly--;
 789			break;
 790		case FMODE_WRITE:
 791			state->n_wronly--;
 792			break;
 793		case FMODE_READ|FMODE_WRITE:
 794			state->n_rdwr--;
 795	}
 796	newstate = FMODE_READ|FMODE_WRITE;
 797	if (state->n_rdwr == 0) {
 798		if (state->n_rdonly == 0) {
 799			newstate &= ~FMODE_READ;
 800			call_close |= test_bit(NFS_O_RDONLY_STATE, &state->flags);
 801			call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
 802		}
 803		if (state->n_wronly == 0) {
 804			newstate &= ~FMODE_WRITE;
 805			call_close |= test_bit(NFS_O_WRONLY_STATE, &state->flags);
 806			call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
 807		}
 808		if (newstate == 0)
 809			clear_bit(NFS_DELEGATED_STATE, &state->flags);
 810	}
 811	nfs4_state_set_mode_locked(state, newstate);
 812	spin_unlock(&owner->so_lock);
 813
 814	if (!call_close) {
 815		nfs4_put_open_state(state);
 816		nfs4_put_state_owner(owner);
 817	} else
 818		nfs4_do_close(state, gfp_mask, wait);
 819}
 820
 821void nfs4_close_state(struct nfs4_state *state, fmode_t fmode)
 822{
 823	__nfs4_close(state, fmode, GFP_KERNEL, 0);
 824}
 825
 826void nfs4_close_sync(struct nfs4_state *state, fmode_t fmode)
 827{
 828	__nfs4_close(state, fmode, GFP_KERNEL, 1);
 829}
 830
 831/*
 832 * Search the state->lock_states for an existing lock_owner
 833 * that is compatible with either of the given owners.
 834 * If the second is non-zero, then the first refers to a Posix-lock
 835 * owner (current->files) and the second refers to a flock/OFD
 836 * owner (struct file*).  In that case, prefer a match for the first
 837 * owner.
 838 * If both sorts of locks are held on the one file we cannot know
 839 * which stateid was intended to be used, so a "correct" choice cannot
 840 * be made.  Failing that, a "consistent" choice is preferable.  The
 841 * consistent choice we make is to prefer the first owner, that of a
 842 * Posix lock.
 843 */
 844static struct nfs4_lock_state *
 845__nfs4_find_lock_state(struct nfs4_state *state,
 846		       fl_owner_t fl_owner, fl_owner_t fl_owner2)
 847{
 848	struct nfs4_lock_state *pos, *ret = NULL;
 849	list_for_each_entry(pos, &state->lock_states, ls_locks) {
 850		if (pos->ls_owner == fl_owner) {
 851			ret = pos;
 852			break;
 853		}
 854		if (pos->ls_owner == fl_owner2)
 855			ret = pos;
 856	}
 857	if (ret)
 858		refcount_inc(&ret->ls_count);
 859	return ret;
 860}
 861
 862/*
 863 * Return a compatible lock_state. If no initialized lock_state structure
 864 * exists, return an uninitialized one.
 865 *
 866 */
 867static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 868{
 869	struct nfs4_lock_state *lsp;
 870	struct nfs_server *server = state->owner->so_server;
 871
 872	lsp = kzalloc(sizeof(*lsp), GFP_KERNEL_ACCOUNT);
 873	if (lsp == NULL)
 874		return NULL;
 875	nfs4_init_seqid_counter(&lsp->ls_seqid);
 876	refcount_set(&lsp->ls_count, 1);
 877	lsp->ls_state = state;
 878	lsp->ls_owner = fl_owner;
 879	lsp->ls_seqid.owner_id = ida_alloc(&server->lockowner_id, GFP_KERNEL_ACCOUNT);
 880	if (lsp->ls_seqid.owner_id < 0)
 881		goto out_free;
 882	INIT_LIST_HEAD(&lsp->ls_locks);
 883	return lsp;
 884out_free:
 885	kfree(lsp);
 886	return NULL;
 887}
 888
 889void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp)
 890{
 891	ida_free(&server->lockowner_id, lsp->ls_seqid.owner_id);
 892	nfs4_destroy_seqid_counter(&lsp->ls_seqid);
 893	kfree(lsp);
 894}
 895
 896/*
 897 * Return a compatible lock_state. If no initialized lock_state structure
 898 * exists, return an uninitialized one.
 899 *
 900 */
 901static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
 902{
 903	struct nfs4_lock_state *lsp, *new = NULL;
 904	
 905	for(;;) {
 906		spin_lock(&state->state_lock);
 907		lsp = __nfs4_find_lock_state(state, owner, NULL);
 908		if (lsp != NULL)
 909			break;
 910		if (new != NULL) {
 911			list_add(&new->ls_locks, &state->lock_states);
 912			set_bit(LK_STATE_IN_USE, &state->flags);
 913			lsp = new;
 914			new = NULL;
 915			break;
 916		}
 917		spin_unlock(&state->state_lock);
 918		new = nfs4_alloc_lock_state(state, owner);
 919		if (new == NULL)
 920			return NULL;
 921	}
 922	spin_unlock(&state->state_lock);
 923	if (new != NULL)
 924		nfs4_free_lock_state(state->owner->so_server, new);
 925	return lsp;
 926}
 927
 928/*
 929 * Release reference to lock_state, and free it if we see that
 930 * it is no longer in use
 931 */
 932void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
 933{
 934	struct nfs_server *server;
 935	struct nfs4_state *state;
 936
 937	if (lsp == NULL)
 938		return;
 939	state = lsp->ls_state;
 940	if (!refcount_dec_and_lock(&lsp->ls_count, &state->state_lock))
 941		return;
 942	list_del(&lsp->ls_locks);
 943	if (list_empty(&state->lock_states))
 944		clear_bit(LK_STATE_IN_USE, &state->flags);
 945	spin_unlock(&state->state_lock);
 946	server = state->owner->so_server;
 947	if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) {
 948		struct nfs_client *clp = server->nfs_client;
 949
 950		clp->cl_mvops->free_lock_state(server, lsp);
 951	} else
 952		nfs4_free_lock_state(server, lsp);
 953}
 954
 955static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
 956{
 957	struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
 958
 959	dst->fl_u.nfs4_fl.owner = lsp;
 960	refcount_inc(&lsp->ls_count);
 961}
 962
 963static void nfs4_fl_release_lock(struct file_lock *fl)
 964{
 965	nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
 966}
 967
 968static const struct file_lock_operations nfs4_fl_lock_ops = {
 969	.fl_copy_lock = nfs4_fl_copy_lock,
 970	.fl_release_private = nfs4_fl_release_lock,
 971};
 972
 973int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
 974{
 975	struct nfs4_lock_state *lsp;
 976
 977	if (fl->fl_ops != NULL)
 978		return 0;
 979	lsp = nfs4_get_lock_state(state, fl->fl_owner);
 980	if (lsp == NULL)
 981		return -ENOMEM;
 982	fl->fl_u.nfs4_fl.owner = lsp;
 983	fl->fl_ops = &nfs4_fl_lock_ops;
 984	return 0;
 985}
 986
 987static int nfs4_copy_lock_stateid(nfs4_stateid *dst,
 988		struct nfs4_state *state,
 989		const struct nfs_lock_context *l_ctx)
 990{
 991	struct nfs4_lock_state *lsp;
 992	fl_owner_t fl_owner, fl_flock_owner;
 993	int ret = -ENOENT;
 994
 995	if (l_ctx == NULL)
 996		goto out;
 997
 998	if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
 999		goto out;
1000
1001	fl_owner = l_ctx->lockowner;
1002	fl_flock_owner = l_ctx->open_context->flock_owner;
1003
1004	spin_lock(&state->state_lock);
1005	lsp = __nfs4_find_lock_state(state, fl_owner, fl_flock_owner);
1006	if (lsp && test_bit(NFS_LOCK_LOST, &lsp->ls_flags))
1007		ret = -EIO;
1008	else if (lsp != NULL && test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) != 0) {
1009		nfs4_stateid_copy(dst, &lsp->ls_stateid);
1010		ret = 0;
1011	}
1012	spin_unlock(&state->state_lock);
1013	nfs4_put_lock_state(lsp);
1014out:
1015	return ret;
1016}
1017
1018bool nfs4_copy_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
1019{
1020	bool ret;
1021	const nfs4_stateid *src;
1022	int seq;
1023
1024	do {
1025		ret = false;
1026		src = &zero_stateid;
1027		seq = read_seqbegin(&state->seqlock);
1028		if (test_bit(NFS_OPEN_STATE, &state->flags)) {
1029			src = &state->open_stateid;
1030			ret = true;
1031		}
1032		nfs4_stateid_copy(dst, src);
1033	} while (read_seqretry(&state->seqlock, seq));
1034	return ret;
1035}
1036
1037/*
1038 * Byte-range lock aware utility to initialize the stateid of read/write
1039 * requests.
1040 */
1041int nfs4_select_rw_stateid(struct nfs4_state *state,
1042		fmode_t fmode, const struct nfs_lock_context *l_ctx,
1043		nfs4_stateid *dst, const struct cred **cred)
1044{
1045	int ret;
1046
1047	if (!nfs4_valid_open_stateid(state))
1048		return -EIO;
1049	if (cred != NULL)
1050		*cred = NULL;
1051	ret = nfs4_copy_lock_stateid(dst, state, l_ctx);
1052	if (ret == -EIO)
1053		/* A lost lock - don't even consider delegations */
1054		goto out;
1055	/* returns true if delegation stateid found and copied */
1056	if (nfs4_copy_delegation_stateid(state->inode, fmode, dst, cred)) {
1057		ret = 0;
1058		goto out;
1059	}
1060	if (ret != -ENOENT)
1061		/* nfs4_copy_delegation_stateid() didn't over-write
1062		 * dst, so it still has the lock stateid which we now
1063		 * choose to use.
1064		 */
1065		goto out;
1066	ret = nfs4_copy_open_stateid(dst, state) ? 0 : -EAGAIN;
1067out:
1068	if (nfs_server_capable(state->inode, NFS_CAP_STATEID_NFSV41))
1069		dst->seqid = 0;
1070	return ret;
1071}
1072
1073struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask)
1074{
1075	struct nfs_seqid *new;
1076
1077	new = kmalloc(sizeof(*new), gfp_mask);
1078	if (new == NULL)
1079		return ERR_PTR(-ENOMEM);
1080	new->sequence = counter;
1081	INIT_LIST_HEAD(&new->list);
1082	new->task = NULL;
1083	return new;
1084}
1085
1086void nfs_release_seqid(struct nfs_seqid *seqid)
1087{
1088	struct nfs_seqid_counter *sequence;
1089
1090	if (seqid == NULL || list_empty(&seqid->list))
1091		return;
1092	sequence = seqid->sequence;
1093	spin_lock(&sequence->lock);
1094	list_del_init(&seqid->list);
1095	if (!list_empty(&sequence->list)) {
1096		struct nfs_seqid *next;
1097
1098		next = list_first_entry(&sequence->list,
1099				struct nfs_seqid, list);
1100		rpc_wake_up_queued_task(&sequence->wait, next->task);
1101	}
1102	spin_unlock(&sequence->lock);
1103}
1104
1105void nfs_free_seqid(struct nfs_seqid *seqid)
1106{
1107	nfs_release_seqid(seqid);
1108	kfree(seqid);
1109}
1110
1111/*
1112 * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
1113 * failed with a seqid incrementing error -
1114 * see comments nfs4.h:seqid_mutating_error()
1115 */
1116static void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
1117{
1118	switch (status) {
1119		case 0:
1120			break;
1121		case -NFS4ERR_BAD_SEQID:
1122			if (seqid->sequence->flags & NFS_SEQID_CONFIRMED)
1123				return;
1124			pr_warn_ratelimited("NFS: v4 server returned a bad"
1125					" sequence-id error on an"
1126					" unconfirmed sequence %p!\n",
1127					seqid->sequence);
1128			return;
1129		case -NFS4ERR_STALE_CLIENTID:
1130		case -NFS4ERR_STALE_STATEID:
1131		case -NFS4ERR_BAD_STATEID:
1132		case -NFS4ERR_BADXDR:
1133		case -NFS4ERR_RESOURCE:
1134		case -NFS4ERR_NOFILEHANDLE:
1135		case -NFS4ERR_MOVED:
1136			/* Non-seqid mutating errors */
1137			return;
1138	}
1139	/*
1140	 * Note: no locking needed as we are guaranteed to be first
1141	 * on the sequence list
1142	 */
1143	seqid->sequence->counter++;
1144}
1145
1146void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
1147{
1148	struct nfs4_state_owner *sp;
1149
1150	if (seqid == NULL)
1151		return;
1152
1153	sp = container_of(seqid->sequence, struct nfs4_state_owner, so_seqid);
1154	if (status == -NFS4ERR_BAD_SEQID)
1155		nfs4_reset_state_owner(sp);
1156	if (!nfs4_has_session(sp->so_server->nfs_client))
1157		nfs_increment_seqid(status, seqid);
1158}
1159
1160/*
1161 * Increment the seqid if the LOCK/LOCKU succeeded, or
1162 * failed with a seqid incrementing error -
1163 * see comments nfs4.h:seqid_mutating_error()
1164 */
1165void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
1166{
1167	if (seqid != NULL)
1168		nfs_increment_seqid(status, seqid);
1169}
1170
1171int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
1172{
1173	struct nfs_seqid_counter *sequence;
1174	int status = 0;
1175
1176	if (seqid == NULL)
1177		goto out;
1178	sequence = seqid->sequence;
1179	spin_lock(&sequence->lock);
1180	seqid->task = task;
1181	if (list_empty(&seqid->list))
1182		list_add_tail(&seqid->list, &sequence->list);
1183	if (list_first_entry(&sequence->list, struct nfs_seqid, list) == seqid)
1184		goto unlock;
1185	rpc_sleep_on(&sequence->wait, task, NULL);
1186	status = -EAGAIN;
1187unlock:
1188	spin_unlock(&sequence->lock);
1189out:
1190	return status;
1191}
1192
1193static int nfs4_run_state_manager(void *);
1194
1195static void nfs4_clear_state_manager_bit(struct nfs_client *clp)
1196{
1197	clear_and_wake_up_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state);
 
 
 
1198	rpc_wake_up(&clp->cl_rpcwaitq);
1199}
1200
1201/*
1202 * Schedule the nfs_client asynchronous state management routine
1203 */
1204void nfs4_schedule_state_manager(struct nfs_client *clp)
1205{
1206	struct task_struct *task;
1207	char buf[INET6_ADDRSTRLEN + sizeof("-manager") + 1];
1208	struct rpc_clnt *cl = clp->cl_rpcclient;
1209
1210	while (cl != cl->cl_parent)
1211		cl = cl->cl_parent;
1212
1213	set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
1214	if (test_and_set_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state) != 0) {
1215		wake_up_var(&clp->cl_state);
1216		return;
1217	}
1218	set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state);
1219	__module_get(THIS_MODULE);
1220	refcount_inc(&clp->cl_count);
1221
1222	/* The rcu_read_lock() is not strictly necessary, as the state
1223	 * manager is the only thread that ever changes the rpc_xprt
1224	 * after it's initialized.  At this point, we're single threaded. */
1225	rcu_read_lock();
1226	snprintf(buf, sizeof(buf), "%s-manager",
1227			rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
1228	rcu_read_unlock();
1229	task = kthread_run(nfs4_run_state_manager, clp, "%s", buf);
1230	if (IS_ERR(task)) {
1231		printk(KERN_ERR "%s: kthread_run: %ld\n",
1232			__func__, PTR_ERR(task));
1233		if (!nfs_client_init_is_complete(clp))
1234			nfs_mark_client_ready(clp, PTR_ERR(task));
1235		nfs4_clear_state_manager_bit(clp);
1236		clear_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state);
1237		nfs_put_client(clp);
1238		module_put(THIS_MODULE);
1239	}
1240}
1241
1242/*
1243 * Schedule a lease recovery attempt
1244 */
1245void nfs4_schedule_lease_recovery(struct nfs_client *clp)
1246{
1247	if (!clp)
1248		return;
1249	if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1250		set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1251	dprintk("%s: scheduling lease recovery for server %s\n", __func__,
1252			clp->cl_hostname);
1253	nfs4_schedule_state_manager(clp);
1254}
1255EXPORT_SYMBOL_GPL(nfs4_schedule_lease_recovery);
1256
1257/**
1258 * nfs4_schedule_migration_recovery - trigger migration recovery
1259 *
1260 * @server: FSID that is migrating
1261 *
1262 * Returns zero if recovery has started, otherwise a negative NFS4ERR
1263 * value is returned.
1264 */
1265int nfs4_schedule_migration_recovery(const struct nfs_server *server)
1266{
1267	struct nfs_client *clp = server->nfs_client;
1268
1269	if (server->fh_expire_type != NFS4_FH_PERSISTENT) {
1270		pr_err("NFS: volatile file handles not supported (server %s)\n",
1271				clp->cl_hostname);
1272		return -NFS4ERR_IO;
1273	}
1274
1275	if (test_bit(NFS_MIG_FAILED, &server->mig_status))
1276		return -NFS4ERR_IO;
1277
1278	dprintk("%s: scheduling migration recovery for (%llx:%llx) on %s\n",
1279			__func__,
1280			(unsigned long long)server->fsid.major,
1281			(unsigned long long)server->fsid.minor,
1282			clp->cl_hostname);
1283
1284	set_bit(NFS_MIG_IN_TRANSITION,
1285			&((struct nfs_server *)server)->mig_status);
1286	set_bit(NFS4CLNT_MOVED, &clp->cl_state);
1287
1288	nfs4_schedule_state_manager(clp);
1289	return 0;
1290}
1291EXPORT_SYMBOL_GPL(nfs4_schedule_migration_recovery);
1292
1293/**
1294 * nfs4_schedule_lease_moved_recovery - start lease-moved recovery
1295 *
1296 * @clp: server to check for moved leases
1297 *
1298 */
1299void nfs4_schedule_lease_moved_recovery(struct nfs_client *clp)
1300{
1301	dprintk("%s: scheduling lease-moved recovery for client ID %llx on %s\n",
1302		__func__, clp->cl_clientid, clp->cl_hostname);
1303
1304	set_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state);
1305	nfs4_schedule_state_manager(clp);
1306}
1307EXPORT_SYMBOL_GPL(nfs4_schedule_lease_moved_recovery);
1308
1309int nfs4_wait_clnt_recover(struct nfs_client *clp)
1310{
1311	int res;
1312
1313	might_sleep();
1314
1315	refcount_inc(&clp->cl_count);
1316	res = wait_on_bit_action(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING,
1317				 nfs_wait_bit_killable,
1318				 TASK_KILLABLE|TASK_FREEZABLE_UNSAFE);
1319	if (res)
1320		goto out;
1321	if (clp->cl_cons_state < 0)
1322		res = clp->cl_cons_state;
1323out:
1324	nfs_put_client(clp);
1325	return res;
1326}
1327
1328int nfs4_client_recover_expired_lease(struct nfs_client *clp)
1329{
1330	unsigned int loop;
1331	int ret;
1332
1333	for (loop = NFS4_MAX_LOOP_ON_RECOVER; loop != 0; loop--) {
1334		ret = nfs4_wait_clnt_recover(clp);
1335		if (ret != 0)
1336			break;
1337		if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) &&
1338		    !test_bit(NFS4CLNT_CHECK_LEASE,&clp->cl_state))
1339			break;
1340		nfs4_schedule_state_manager(clp);
1341		ret = -EIO;
1342	}
1343	return ret;
1344}
1345
1346/*
1347 * nfs40_handle_cb_pathdown - return all delegations after NFS4ERR_CB_PATH_DOWN
1348 * @clp: client to process
1349 *
1350 * Set the NFS4CLNT_LEASE_EXPIRED state in order to force a
1351 * resend of the SETCLIENTID and hence re-establish the
1352 * callback channel. Then return all existing delegations.
1353 */
1354static void nfs40_handle_cb_pathdown(struct nfs_client *clp)
1355{
1356	set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1357	nfs_expire_all_delegations(clp);
1358	dprintk("%s: handling CB_PATHDOWN recovery for server %s\n", __func__,
1359			clp->cl_hostname);
1360}
1361
1362void nfs4_schedule_path_down_recovery(struct nfs_client *clp)
1363{
1364	nfs40_handle_cb_pathdown(clp);
1365	nfs4_schedule_state_manager(clp);
1366}
1367
1368static int nfs4_state_mark_reclaim_reboot(struct nfs_client *clp, struct nfs4_state *state)
1369{
1370
1371	if (!nfs4_valid_open_stateid(state))
1372		return 0;
1373	set_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1374	/* Don't recover state that expired before the reboot */
1375	if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags)) {
1376		clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1377		return 0;
1378	}
1379	set_bit(NFS_OWNER_RECLAIM_REBOOT, &state->owner->so_flags);
1380	set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1381	return 1;
1382}
1383
1384int nfs4_state_mark_reclaim_nograce(struct nfs_client *clp, struct nfs4_state *state)
1385{
1386	if (!nfs4_valid_open_stateid(state))
1387		return 0;
1388	set_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1389	clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1390	set_bit(NFS_OWNER_RECLAIM_NOGRACE, &state->owner->so_flags);
1391	set_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
1392	return 1;
1393}
1394
1395int nfs4_schedule_stateid_recovery(const struct nfs_server *server, struct nfs4_state *state)
1396{
1397	struct nfs_client *clp = server->nfs_client;
1398
1399	if (!nfs4_state_mark_reclaim_nograce(clp, state))
1400		return -EBADF;
1401	nfs_inode_find_delegation_state_and_recover(state->inode,
1402			&state->stateid);
1403	dprintk("%s: scheduling stateid recovery for server %s\n", __func__,
1404			clp->cl_hostname);
1405	nfs4_schedule_state_manager(clp);
1406	return 0;
1407}
1408EXPORT_SYMBOL_GPL(nfs4_schedule_stateid_recovery);
1409
1410static struct nfs4_lock_state *
1411nfs_state_find_lock_state_by_stateid(struct nfs4_state *state,
1412		const nfs4_stateid *stateid)
1413{
1414	struct nfs4_lock_state *pos;
1415
1416	list_for_each_entry(pos, &state->lock_states, ls_locks) {
1417		if (!test_bit(NFS_LOCK_INITIALIZED, &pos->ls_flags))
1418			continue;
1419		if (nfs4_stateid_match_or_older(&pos->ls_stateid, stateid))
1420			return pos;
1421	}
1422	return NULL;
1423}
1424
1425static bool nfs_state_lock_state_matches_stateid(struct nfs4_state *state,
1426		const nfs4_stateid *stateid)
1427{
1428	bool found = false;
1429
1430	if (test_bit(LK_STATE_IN_USE, &state->flags)) {
1431		spin_lock(&state->state_lock);
1432		if (nfs_state_find_lock_state_by_stateid(state, stateid))
1433			found = true;
1434		spin_unlock(&state->state_lock);
1435	}
1436	return found;
1437}
1438
1439void nfs_inode_find_state_and_recover(struct inode *inode,
1440		const nfs4_stateid *stateid)
1441{
1442	struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
1443	struct nfs_inode *nfsi = NFS_I(inode);
1444	struct nfs_open_context *ctx;
1445	struct nfs4_state *state;
1446	bool found = false;
1447
1448	rcu_read_lock();
1449	list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1450		state = ctx->state;
1451		if (state == NULL)
1452			continue;
1453		if (nfs4_stateid_match_or_older(&state->stateid, stateid) &&
1454		    nfs4_state_mark_reclaim_nograce(clp, state)) {
1455			found = true;
1456			continue;
1457		}
1458		if (test_bit(NFS_OPEN_STATE, &state->flags) &&
1459		    nfs4_stateid_match_or_older(&state->open_stateid, stateid) &&
1460		    nfs4_state_mark_reclaim_nograce(clp, state)) {
1461			found = true;
1462			continue;
1463		}
1464		if (nfs_state_lock_state_matches_stateid(state, stateid) &&
1465		    nfs4_state_mark_reclaim_nograce(clp, state))
1466			found = true;
1467	}
1468	rcu_read_unlock();
1469
1470	nfs_inode_find_delegation_state_and_recover(inode, stateid);
1471	if (found)
1472		nfs4_schedule_state_manager(clp);
1473}
1474
1475static void nfs4_state_mark_open_context_bad(struct nfs4_state *state, int err)
1476{
1477	struct inode *inode = state->inode;
1478	struct nfs_inode *nfsi = NFS_I(inode);
1479	struct nfs_open_context *ctx;
1480
1481	rcu_read_lock();
1482	list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1483		if (ctx->state != state)
1484			continue;
1485		set_bit(NFS_CONTEXT_BAD, &ctx->flags);
1486		pr_warn("NFSv4: state recovery failed for open file %pd2, "
1487				"error = %d\n", ctx->dentry, err);
1488	}
1489	rcu_read_unlock();
1490}
1491
1492static void nfs4_state_mark_recovery_failed(struct nfs4_state *state, int error)
1493{
1494	set_bit(NFS_STATE_RECOVERY_FAILED, &state->flags);
1495	nfs4_state_mark_open_context_bad(state, error);
1496}
1497
1498
1499static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_recovery_ops *ops)
1500{
1501	struct inode *inode = state->inode;
1502	struct nfs_inode *nfsi = NFS_I(inode);
1503	struct file_lock *fl;
1504	struct nfs4_lock_state *lsp;
1505	int status = 0;
1506	struct file_lock_context *flctx = locks_inode_context(inode);
1507	struct list_head *list;
1508
1509	if (flctx == NULL)
1510		return 0;
1511
1512	list = &flctx->flc_posix;
1513
1514	/* Guard against delegation returns and new lock/unlock calls */
1515	down_write(&nfsi->rwsem);
1516	spin_lock(&flctx->flc_lock);
1517restart:
1518	list_for_each_entry(fl, list, fl_list) {
1519		if (nfs_file_open_context(fl->fl_file)->state != state)
1520			continue;
1521		spin_unlock(&flctx->flc_lock);
1522		status = ops->recover_lock(state, fl);
1523		switch (status) {
1524		case 0:
1525			break;
1526		case -ETIMEDOUT:
1527		case -ESTALE:
1528		case -NFS4ERR_ADMIN_REVOKED:
1529		case -NFS4ERR_STALE_STATEID:
1530		case -NFS4ERR_BAD_STATEID:
1531		case -NFS4ERR_EXPIRED:
1532		case -NFS4ERR_NO_GRACE:
1533		case -NFS4ERR_STALE_CLIENTID:
1534		case -NFS4ERR_BADSESSION:
1535		case -NFS4ERR_BADSLOT:
1536		case -NFS4ERR_BAD_HIGH_SLOT:
1537		case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1538			goto out;
1539		default:
1540			pr_err("NFS: %s: unhandled error %d\n",
1541					__func__, status);
1542			fallthrough;
1543		case -ENOMEM:
1544		case -NFS4ERR_DENIED:
1545		case -NFS4ERR_RECLAIM_BAD:
1546		case -NFS4ERR_RECLAIM_CONFLICT:
1547			lsp = fl->fl_u.nfs4_fl.owner;
1548			if (lsp)
1549				set_bit(NFS_LOCK_LOST, &lsp->ls_flags);
1550			status = 0;
1551		}
1552		spin_lock(&flctx->flc_lock);
1553	}
1554	if (list == &flctx->flc_posix) {
1555		list = &flctx->flc_flock;
1556		goto restart;
1557	}
1558	spin_unlock(&flctx->flc_lock);
1559out:
1560	up_write(&nfsi->rwsem);
1561	return status;
1562}
1563
1564#ifdef CONFIG_NFS_V4_2
1565static void nfs42_complete_copies(struct nfs4_state_owner *sp, struct nfs4_state *state)
1566{
1567	struct nfs4_copy_state *copy;
1568
1569	if (!test_bit(NFS_CLNT_DST_SSC_COPY_STATE, &state->flags) &&
1570		!test_bit(NFS_CLNT_SRC_SSC_COPY_STATE, &state->flags))
1571		return;
1572
1573	spin_lock(&sp->so_server->nfs_client->cl_lock);
1574	list_for_each_entry(copy, &sp->so_server->ss_copies, copies) {
1575		if ((test_bit(NFS_CLNT_DST_SSC_COPY_STATE, &state->flags) &&
1576				!nfs4_stateid_match_other(&state->stateid,
1577				&copy->parent_dst_state->stateid)))
1578				continue;
1579		copy->flags = 1;
1580		if (test_and_clear_bit(NFS_CLNT_DST_SSC_COPY_STATE,
1581				&state->flags)) {
1582			clear_bit(NFS_CLNT_SRC_SSC_COPY_STATE, &state->flags);
1583			complete(&copy->completion);
1584		}
1585	}
1586	list_for_each_entry(copy, &sp->so_server->ss_copies, src_copies) {
1587		if ((test_bit(NFS_CLNT_SRC_SSC_COPY_STATE, &state->flags) &&
1588				!nfs4_stateid_match_other(&state->stateid,
1589				&copy->parent_src_state->stateid)))
1590				continue;
1591		copy->flags = 1;
1592		if (test_and_clear_bit(NFS_CLNT_DST_SSC_COPY_STATE,
1593				&state->flags))
1594			complete(&copy->completion);
1595	}
1596	spin_unlock(&sp->so_server->nfs_client->cl_lock);
1597}
1598#else /* !CONFIG_NFS_V4_2 */
1599static inline void nfs42_complete_copies(struct nfs4_state_owner *sp,
1600					 struct nfs4_state *state)
1601{
1602}
1603#endif /* CONFIG_NFS_V4_2 */
1604
1605static int __nfs4_reclaim_open_state(struct nfs4_state_owner *sp, struct nfs4_state *state,
1606				     const struct nfs4_state_recovery_ops *ops,
1607				     int *lost_locks)
1608{
1609	struct nfs4_lock_state *lock;
1610	int status;
1611
1612	status = ops->recover_open(sp, state);
1613	if (status < 0)
1614		return status;
1615
1616	status = nfs4_reclaim_locks(state, ops);
1617	if (status < 0)
1618		return status;
1619
1620	if (!test_bit(NFS_DELEGATED_STATE, &state->flags)) {
1621		spin_lock(&state->state_lock);
1622		list_for_each_entry(lock, &state->lock_states, ls_locks) {
1623			trace_nfs4_state_lock_reclaim(state, lock);
1624			if (!test_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags) &&
1625			    !test_bit(NFS_LOCK_UNLOCKING, &lock->ls_flags))
1626				*lost_locks += 1;
1627		}
1628		spin_unlock(&state->state_lock);
1629	}
1630
1631	nfs42_complete_copies(sp, state);
1632	clear_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1633	return status;
1634}
1635
1636static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp,
1637				   const struct nfs4_state_recovery_ops *ops,
1638				   int *lost_locks)
1639{
1640	struct nfs4_state *state;
1641	unsigned int loop = 0;
1642	int status = 0;
1643#ifdef CONFIG_NFS_V4_2
1644	bool found_ssc_copy_state = false;
1645#endif /* CONFIG_NFS_V4_2 */
1646
1647	/* Note: we rely on the sp->so_states list being ordered 
1648	 * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
1649	 * states first.
1650	 * This is needed to ensure that the server won't give us any
1651	 * read delegations that we have to return if, say, we are
1652	 * recovering after a network partition or a reboot from a
1653	 * server that doesn't support a grace period.
1654	 */
1655	spin_lock(&sp->so_lock);
1656	raw_write_seqcount_begin(&sp->so_reclaim_seqcount);
1657restart:
1658	list_for_each_entry(state, &sp->so_states, open_states) {
1659		if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
1660			continue;
1661		if (!nfs4_valid_open_stateid(state))
1662			continue;
1663		if (state->state == 0)
1664			continue;
1665#ifdef CONFIG_NFS_V4_2
1666		if (test_bit(NFS_SRV_SSC_COPY_STATE, &state->flags)) {
1667			nfs4_state_mark_recovery_failed(state, -EIO);
1668			found_ssc_copy_state = true;
1669			continue;
1670		}
1671#endif /* CONFIG_NFS_V4_2 */
1672		refcount_inc(&state->count);
1673		spin_unlock(&sp->so_lock);
1674		status = __nfs4_reclaim_open_state(sp, state, ops, lost_locks);
1675
1676		switch (status) {
1677		default:
1678			if (status >= 0) {
1679				loop = 0;
1680				break;
1681			}
1682			printk(KERN_ERR "NFS: %s: unhandled error %d\n", __func__, status);
1683			fallthrough;
1684		case -ENOENT:
1685		case -ENOMEM:
1686		case -EACCES:
1687		case -EROFS:
1688		case -EIO:
1689		case -ESTALE:
1690			/* Open state on this file cannot be recovered */
1691			nfs4_state_mark_recovery_failed(state, status);
1692			break;
1693		case -EAGAIN:
1694			ssleep(1);
1695			if (loop++ < 10) {
1696				set_bit(ops->state_flag_bit, &state->flags);
1697				break;
1698			}
1699			fallthrough;
1700		case -NFS4ERR_ADMIN_REVOKED:
1701		case -NFS4ERR_STALE_STATEID:
1702		case -NFS4ERR_OLD_STATEID:
1703		case -NFS4ERR_BAD_STATEID:
1704		case -NFS4ERR_RECLAIM_BAD:
1705		case -NFS4ERR_RECLAIM_CONFLICT:
1706			nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1707			break;
1708		case -NFS4ERR_EXPIRED:
1709		case -NFS4ERR_NO_GRACE:
1710			nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1711			fallthrough;
1712		case -NFS4ERR_STALE_CLIENTID:
1713		case -NFS4ERR_BADSESSION:
1714		case -NFS4ERR_BADSLOT:
1715		case -NFS4ERR_BAD_HIGH_SLOT:
1716		case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1717		case -ETIMEDOUT:
1718			goto out_err;
1719		}
1720		nfs4_put_open_state(state);
1721		spin_lock(&sp->so_lock);
1722		goto restart;
1723	}
1724	raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1725	spin_unlock(&sp->so_lock);
1726#ifdef CONFIG_NFS_V4_2
1727	if (found_ssc_copy_state)
1728		return -EIO;
1729#endif /* CONFIG_NFS_V4_2 */
1730	return 0;
1731out_err:
1732	nfs4_put_open_state(state);
1733	spin_lock(&sp->so_lock);
1734	raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1735	spin_unlock(&sp->so_lock);
1736	return status;
1737}
1738
1739static void nfs4_clear_open_state(struct nfs4_state *state)
1740{
1741	struct nfs4_lock_state *lock;
1742
1743	clear_bit(NFS_DELEGATED_STATE, &state->flags);
1744	clear_bit(NFS_O_RDONLY_STATE, &state->flags);
1745	clear_bit(NFS_O_WRONLY_STATE, &state->flags);
1746	clear_bit(NFS_O_RDWR_STATE, &state->flags);
1747	spin_lock(&state->state_lock);
1748	list_for_each_entry(lock, &state->lock_states, ls_locks) {
1749		lock->ls_seqid.flags = 0;
1750		clear_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags);
1751	}
1752	spin_unlock(&state->state_lock);
1753}
1754
1755static void nfs4_reset_seqids(struct nfs_server *server,
1756	int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1757{
1758	struct nfs_client *clp = server->nfs_client;
1759	struct nfs4_state_owner *sp;
1760	struct rb_node *pos;
1761	struct nfs4_state *state;
1762
1763	spin_lock(&clp->cl_lock);
1764	for (pos = rb_first(&server->state_owners);
1765	     pos != NULL;
1766	     pos = rb_next(pos)) {
1767		sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1768		sp->so_seqid.flags = 0;
1769		spin_lock(&sp->so_lock);
1770		list_for_each_entry(state, &sp->so_states, open_states) {
1771			if (mark_reclaim(clp, state))
1772				nfs4_clear_open_state(state);
1773		}
1774		spin_unlock(&sp->so_lock);
1775	}
1776	spin_unlock(&clp->cl_lock);
1777}
1778
1779static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp,
1780	int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1781{
1782	struct nfs_server *server;
1783
1784	rcu_read_lock();
1785	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1786		nfs4_reset_seqids(server, mark_reclaim);
1787	rcu_read_unlock();
1788}
1789
1790static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp)
1791{
1792	set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1793	/* Mark all delegations for reclaim */
1794	nfs_delegation_mark_reclaim(clp);
1795	nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_reboot);
1796}
1797
1798static int nfs4_reclaim_complete(struct nfs_client *clp,
1799				 const struct nfs4_state_recovery_ops *ops,
1800				 const struct cred *cred)
1801{
1802	/* Notify the server we're done reclaiming our state */
1803	if (ops->reclaim_complete)
1804		return ops->reclaim_complete(clp, cred);
1805	return 0;
1806}
1807
1808static void nfs4_clear_reclaim_server(struct nfs_server *server)
1809{
1810	struct nfs_client *clp = server->nfs_client;
1811	struct nfs4_state_owner *sp;
1812	struct rb_node *pos;
1813	struct nfs4_state *state;
1814
1815	spin_lock(&clp->cl_lock);
1816	for (pos = rb_first(&server->state_owners);
1817	     pos != NULL;
1818	     pos = rb_next(pos)) {
1819		sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1820		spin_lock(&sp->so_lock);
1821		list_for_each_entry(state, &sp->so_states, open_states) {
1822			if (!test_and_clear_bit(NFS_STATE_RECLAIM_REBOOT,
1823						&state->flags))
1824				continue;
1825			nfs4_state_mark_reclaim_nograce(clp, state);
1826		}
1827		spin_unlock(&sp->so_lock);
1828	}
1829	spin_unlock(&clp->cl_lock);
1830}
1831
1832static int nfs4_state_clear_reclaim_reboot(struct nfs_client *clp)
1833{
1834	struct nfs_server *server;
1835
1836	if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
1837		return 0;
1838
1839	rcu_read_lock();
1840	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1841		nfs4_clear_reclaim_server(server);
1842	rcu_read_unlock();
1843
1844	nfs_delegation_reap_unclaimed(clp);
1845	return 1;
1846}
1847
1848static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
1849{
1850	const struct nfs4_state_recovery_ops *ops;
1851	const struct cred *cred;
1852	int err;
1853
1854	if (!nfs4_state_clear_reclaim_reboot(clp))
1855		return;
1856	ops = clp->cl_mvops->reboot_recovery_ops;
1857	cred = nfs4_get_clid_cred(clp);
1858	err = nfs4_reclaim_complete(clp, ops, cred);
1859	put_cred(cred);
1860	if (err == -NFS4ERR_CONN_NOT_BOUND_TO_SESSION)
1861		set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1862}
1863
1864static void nfs4_state_start_reclaim_nograce(struct nfs_client *clp)
1865{
1866	nfs_mark_test_expired_all_delegations(clp);
1867	nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
1868}
1869
1870static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
1871{
1872	switch (error) {
1873	case 0:
1874		break;
1875	case -NFS4ERR_CB_PATH_DOWN:
1876		nfs40_handle_cb_pathdown(clp);
1877		break;
1878	case -NFS4ERR_NO_GRACE:
1879		nfs4_state_end_reclaim_reboot(clp);
1880		break;
1881	case -NFS4ERR_STALE_CLIENTID:
1882		set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1883		nfs4_state_start_reclaim_reboot(clp);
1884		break;
1885	case -NFS4ERR_EXPIRED:
1886		set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1887		nfs4_state_start_reclaim_nograce(clp);
1888		break;
1889	case -NFS4ERR_BADSESSION:
1890	case -NFS4ERR_BADSLOT:
1891	case -NFS4ERR_BAD_HIGH_SLOT:
1892	case -NFS4ERR_DEADSESSION:
1893	case -NFS4ERR_SEQ_FALSE_RETRY:
1894	case -NFS4ERR_SEQ_MISORDERED:
1895		set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
1896		/* Zero session reset errors */
1897		break;
1898	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1899		set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
1900		break;
1901	default:
1902		dprintk("%s: failed to handle error %d for server %s\n",
1903				__func__, error, clp->cl_hostname);
1904		return error;
1905	}
1906	dprintk("%s: handled error %d for server %s\n", __func__, error,
1907			clp->cl_hostname);
1908	return 0;
1909}
1910
1911static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recovery_ops *ops)
1912{
1913	struct nfs4_state_owner *sp;
1914	struct nfs_server *server;
1915	struct rb_node *pos;
1916	LIST_HEAD(freeme);
1917	int status = 0;
1918	int lost_locks = 0;
1919
1920restart:
1921	rcu_read_lock();
1922	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1923		nfs4_purge_state_owners(server, &freeme);
1924		spin_lock(&clp->cl_lock);
1925		for (pos = rb_first(&server->state_owners);
1926		     pos != NULL;
1927		     pos = rb_next(pos)) {
1928			sp = rb_entry(pos,
1929				struct nfs4_state_owner, so_server_node);
1930			if (!test_and_clear_bit(ops->owner_flag_bit,
1931							&sp->so_flags))
1932				continue;
1933			if (!atomic_inc_not_zero(&sp->so_count))
1934				continue;
1935			spin_unlock(&clp->cl_lock);
1936			rcu_read_unlock();
1937
1938			status = nfs4_reclaim_open_state(sp, ops, &lost_locks);
1939			if (status < 0) {
1940				if (lost_locks)
1941					pr_warn("NFS: %s: lost %d locks\n",
1942						clp->cl_hostname, lost_locks);
1943				set_bit(ops->owner_flag_bit, &sp->so_flags);
1944				nfs4_put_state_owner(sp);
1945				status = nfs4_recovery_handle_error(clp, status);
1946				return (status != 0) ? status : -EAGAIN;
1947			}
1948
1949			nfs4_put_state_owner(sp);
1950			goto restart;
1951		}
1952		spin_unlock(&clp->cl_lock);
1953	}
1954	rcu_read_unlock();
1955	nfs4_free_state_owners(&freeme);
1956	if (lost_locks)
1957		pr_warn("NFS: %s: lost %d locks\n",
1958			clp->cl_hostname, lost_locks);
1959	return 0;
1960}
1961
1962static int nfs4_check_lease(struct nfs_client *clp)
1963{
1964	const struct cred *cred;
1965	const struct nfs4_state_maintenance_ops *ops =
1966		clp->cl_mvops->state_renewal_ops;
1967	int status;
1968
1969	/* Is the client already known to have an expired lease? */
1970	if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1971		return 0;
1972	cred = ops->get_state_renewal_cred(clp);
1973	if (cred == NULL) {
1974		cred = nfs4_get_clid_cred(clp);
1975		status = -ENOKEY;
1976		if (cred == NULL)
1977			goto out;
1978	}
1979	status = ops->renew_lease(clp, cred);
1980	put_cred(cred);
1981	if (status == -ETIMEDOUT) {
1982		set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1983		return 0;
1984	}
1985out:
1986	return nfs4_recovery_handle_error(clp, status);
1987}
1988
1989/* Set NFS4CLNT_LEASE_EXPIRED and reclaim reboot state for all v4.0 errors
1990 * and for recoverable errors on EXCHANGE_ID for v4.1
1991 */
1992static int nfs4_handle_reclaim_lease_error(struct nfs_client *clp, int status)
1993{
1994	switch (status) {
1995	case -NFS4ERR_SEQ_MISORDERED:
1996		if (test_and_set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state))
1997			return -ESERVERFAULT;
1998		/* Lease confirmation error: retry after purging the lease */
1999		ssleep(1);
2000		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2001		break;
2002	case -NFS4ERR_STALE_CLIENTID:
2003		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2004		nfs4_state_start_reclaim_reboot(clp);
2005		break;
2006	case -NFS4ERR_CLID_INUSE:
2007		pr_err("NFS: Server %s reports our clientid is in use\n",
2008			clp->cl_hostname);
2009		nfs_mark_client_ready(clp, -EPERM);
2010		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2011		return -EPERM;
2012	case -EACCES:
2013	case -NFS4ERR_DELAY:
2014	case -EAGAIN:
2015		ssleep(1);
2016		break;
2017
2018	case -NFS4ERR_MINOR_VERS_MISMATCH:
2019		if (clp->cl_cons_state == NFS_CS_SESSION_INITING)
2020			nfs_mark_client_ready(clp, -EPROTONOSUPPORT);
2021		dprintk("%s: exit with error %d for server %s\n",
2022				__func__, -EPROTONOSUPPORT, clp->cl_hostname);
2023		return -EPROTONOSUPPORT;
2024	case -ENOSPC:
2025		if (clp->cl_cons_state == NFS_CS_SESSION_INITING)
2026			nfs_mark_client_ready(clp, -EIO);
2027		return -EIO;
2028	case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
2029				 * in nfs4_exchange_id */
2030	default:
2031		dprintk("%s: exit with error %d for server %s\n", __func__,
2032				status, clp->cl_hostname);
2033		return status;
2034	}
2035	set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2036	dprintk("%s: handled error %d for server %s\n", __func__, status,
2037			clp->cl_hostname);
2038	return 0;
2039}
2040
2041static int nfs4_establish_lease(struct nfs_client *clp)
2042{
2043	const struct cred *cred;
2044	const struct nfs4_state_recovery_ops *ops =
2045		clp->cl_mvops->reboot_recovery_ops;
2046	int status;
2047
2048	status = nfs4_begin_drain_session(clp);
2049	if (status != 0)
2050		return status;
2051	cred = nfs4_get_clid_cred(clp);
2052	if (cred == NULL)
2053		return -ENOENT;
2054	status = ops->establish_clid(clp, cred);
2055	put_cred(cred);
2056	if (status != 0)
2057		return status;
2058	pnfs_destroy_all_layouts(clp);
2059	return 0;
2060}
2061
2062/*
2063 * Returns zero or a negative errno.  NFS4ERR values are converted
2064 * to local errno values.
2065 */
2066static int nfs4_reclaim_lease(struct nfs_client *clp)
2067{
2068	int status;
2069
2070	status = nfs4_establish_lease(clp);
2071	if (status < 0)
2072		return nfs4_handle_reclaim_lease_error(clp, status);
2073	if (test_and_clear_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH, &clp->cl_state))
2074		nfs4_state_start_reclaim_nograce(clp);
2075	if (!test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
2076		set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
2077	clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2078	clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2079	return 0;
2080}
2081
2082static int nfs4_purge_lease(struct nfs_client *clp)
2083{
2084	int status;
2085
2086	status = nfs4_establish_lease(clp);
2087	if (status < 0)
2088		return nfs4_handle_reclaim_lease_error(clp, status);
2089	clear_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2090	set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2091	nfs4_state_start_reclaim_nograce(clp);
2092	return 0;
2093}
2094
2095/*
2096 * Try remote migration of one FSID from a source server to a
2097 * destination server.  The source server provides a list of
2098 * potential destinations.
2099 *
2100 * Returns zero or a negative NFS4ERR status code.
2101 */
2102static int nfs4_try_migration(struct nfs_server *server, const struct cred *cred)
2103{
2104	struct nfs_client *clp = server->nfs_client;
2105	struct nfs4_fs_locations *locations = NULL;
2106	struct inode *inode;
2107	struct page *page;
2108	int status, result;
2109
2110	dprintk("--> %s: FSID %llx:%llx on \"%s\"\n", __func__,
2111			(unsigned long long)server->fsid.major,
2112			(unsigned long long)server->fsid.minor,
2113			clp->cl_hostname);
2114
2115	result = 0;
2116	page = alloc_page(GFP_KERNEL);
2117	locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
2118	if (page == NULL || locations == NULL) {
2119		dprintk("<-- %s: no memory\n", __func__);
2120		goto out;
2121	}
2122	locations->fattr = nfs_alloc_fattr();
2123	if (locations->fattr == NULL) {
2124		dprintk("<-- %s: no memory\n", __func__);
2125		goto out;
2126	}
2127
2128	inode = d_inode(server->super->s_root);
2129	result = nfs4_proc_get_locations(server, NFS_FH(inode), locations,
2130					 page, cred);
2131	if (result) {
2132		dprintk("<-- %s: failed to retrieve fs_locations: %d\n",
2133			__func__, result);
2134		goto out;
2135	}
2136
2137	result = -NFS4ERR_NXIO;
2138	if (!locations->nlocations)
2139		goto out;
2140
2141	if (!(locations->fattr->valid & NFS_ATTR_FATTR_V4_LOCATIONS)) {
2142		dprintk("<-- %s: No fs_locations data, migration skipped\n",
2143			__func__);
2144		goto out;
2145	}
2146
2147	status = nfs4_begin_drain_session(clp);
2148	if (status != 0) {
2149		result = status;
2150		goto out;
2151	}
2152
2153	status = nfs4_replace_transport(server, locations);
2154	if (status != 0) {
2155		dprintk("<-- %s: failed to replace transport: %d\n",
2156			__func__, status);
2157		goto out;
2158	}
2159
2160	result = 0;
2161	dprintk("<-- %s: migration succeeded\n", __func__);
2162
2163out:
2164	if (page != NULL)
2165		__free_page(page);
2166	if (locations != NULL)
2167		kfree(locations->fattr);
2168	kfree(locations);
2169	if (result) {
2170		pr_err("NFS: migration recovery failed (server %s)\n",
2171				clp->cl_hostname);
2172		set_bit(NFS_MIG_FAILED, &server->mig_status);
2173	}
2174	return result;
2175}
2176
2177/*
2178 * Returns zero or a negative NFS4ERR status code.
2179 */
2180static int nfs4_handle_migration(struct nfs_client *clp)
2181{
2182	const struct nfs4_state_maintenance_ops *ops =
2183				clp->cl_mvops->state_renewal_ops;
2184	struct nfs_server *server;
2185	const struct cred *cred;
2186
2187	dprintk("%s: migration reported on \"%s\"\n", __func__,
2188			clp->cl_hostname);
2189
2190	cred = ops->get_state_renewal_cred(clp);
2191	if (cred == NULL)
2192		return -NFS4ERR_NOENT;
2193
2194	clp->cl_mig_gen++;
2195restart:
2196	rcu_read_lock();
2197	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2198		int status;
2199
2200		if (server->mig_gen == clp->cl_mig_gen)
2201			continue;
2202		server->mig_gen = clp->cl_mig_gen;
2203
2204		if (!test_and_clear_bit(NFS_MIG_IN_TRANSITION,
2205						&server->mig_status))
2206			continue;
2207
2208		rcu_read_unlock();
2209		status = nfs4_try_migration(server, cred);
2210		if (status < 0) {
2211			put_cred(cred);
2212			return status;
2213		}
2214		goto restart;
2215	}
2216	rcu_read_unlock();
2217	put_cred(cred);
2218	return 0;
2219}
2220
2221/*
2222 * Test each nfs_server on the clp's cl_superblocks list to see
2223 * if it's moved to another server.  Stop when the server no longer
2224 * returns NFS4ERR_LEASE_MOVED.
2225 */
2226static int nfs4_handle_lease_moved(struct nfs_client *clp)
2227{
2228	const struct nfs4_state_maintenance_ops *ops =
2229				clp->cl_mvops->state_renewal_ops;
2230	struct nfs_server *server;
2231	const struct cred *cred;
2232
2233	dprintk("%s: lease moved reported on \"%s\"\n", __func__,
2234			clp->cl_hostname);
2235
2236	cred = ops->get_state_renewal_cred(clp);
2237	if (cred == NULL)
2238		return -NFS4ERR_NOENT;
2239
2240	clp->cl_mig_gen++;
2241restart:
2242	rcu_read_lock();
2243	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2244		struct inode *inode;
2245		int status;
2246
2247		if (server->mig_gen == clp->cl_mig_gen)
2248			continue;
2249		server->mig_gen = clp->cl_mig_gen;
2250
2251		rcu_read_unlock();
2252
2253		inode = d_inode(server->super->s_root);
2254		status = nfs4_proc_fsid_present(inode, cred);
2255		if (status != -NFS4ERR_MOVED)
2256			goto restart;	/* wasn't this one */
2257		if (nfs4_try_migration(server, cred) == -NFS4ERR_LEASE_MOVED)
2258			goto restart;	/* there are more */
2259		goto out;
2260	}
2261	rcu_read_unlock();
2262
2263out:
2264	put_cred(cred);
2265	return 0;
2266}
2267
2268/**
2269 * nfs4_discover_server_trunking - Detect server IP address trunking
2270 *
2271 * @clp: nfs_client under test
2272 * @result: OUT: found nfs_client, or clp
2273 *
2274 * Returns zero or a negative errno.  If zero is returned,
2275 * an nfs_client pointer is planted in "result".
2276 *
2277 * Note: since we are invoked in process context, and
2278 * not from inside the state manager, we cannot use
2279 * nfs4_handle_reclaim_lease_error().
2280 */
2281int nfs4_discover_server_trunking(struct nfs_client *clp,
2282				  struct nfs_client **result)
2283{
2284	const struct nfs4_state_recovery_ops *ops =
2285				clp->cl_mvops->reboot_recovery_ops;
2286	struct rpc_clnt *clnt;
2287	const struct cred *cred;
2288	int i, status;
2289
2290	dprintk("NFS: %s: testing '%s'\n", __func__, clp->cl_hostname);
2291
2292	clnt = clp->cl_rpcclient;
2293	i = 0;
2294
2295	mutex_lock(&nfs_clid_init_mutex);
2296again:
2297	status  = -ENOENT;
2298	cred = nfs4_get_clid_cred(clp);
2299	if (cred == NULL)
2300		goto out_unlock;
2301
2302	status = ops->detect_trunking(clp, result, cred);
2303	put_cred(cred);
2304	switch (status) {
2305	case 0:
2306	case -EINTR:
2307	case -ERESTARTSYS:
2308		break;
2309	case -ETIMEDOUT:
2310		if (clnt->cl_softrtry)
2311			break;
2312		fallthrough;
2313	case -NFS4ERR_DELAY:
2314	case -EAGAIN:
2315		ssleep(1);
2316		fallthrough;
2317	case -NFS4ERR_STALE_CLIENTID:
2318		dprintk("NFS: %s after status %d, retrying\n",
2319			__func__, status);
2320		goto again;
2321	case -EACCES:
2322		if (i++ == 0) {
2323			nfs4_root_machine_cred(clp);
2324			goto again;
2325		}
2326		if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX)
2327			break;
2328		fallthrough;
2329	case -NFS4ERR_CLID_INUSE:
2330	case -NFS4ERR_WRONGSEC:
2331		/* No point in retrying if we already used RPC_AUTH_UNIX */
2332		if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX) {
2333			status = -EPERM;
2334			break;
2335		}
2336		clnt = rpc_clone_client_set_auth(clnt, RPC_AUTH_UNIX);
2337		if (IS_ERR(clnt)) {
2338			status = PTR_ERR(clnt);
2339			break;
2340		}
2341		/* Note: this is safe because we haven't yet marked the
2342		 * client as ready, so we are the only user of
2343		 * clp->cl_rpcclient
2344		 */
2345		clnt = xchg(&clp->cl_rpcclient, clnt);
2346		rpc_shutdown_client(clnt);
2347		clnt = clp->cl_rpcclient;
2348		goto again;
2349
2350	case -NFS4ERR_MINOR_VERS_MISMATCH:
2351		status = -EPROTONOSUPPORT;
2352		break;
2353
2354	case -EKEYEXPIRED:
2355	case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
2356				 * in nfs4_exchange_id */
2357		status = -EKEYEXPIRED;
2358		break;
2359	default:
2360		pr_warn("NFS: %s unhandled error %d. Exiting with error EIO\n",
2361				__func__, status);
2362		status = -EIO;
2363	}
2364
2365out_unlock:
2366	mutex_unlock(&nfs_clid_init_mutex);
2367	dprintk("NFS: %s: status = %d\n", __func__, status);
2368	return status;
2369}
2370
2371#ifdef CONFIG_NFS_V4_1
2372void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
2373{
2374	struct nfs_client *clp = session->clp;
2375
2376	switch (err) {
2377	default:
2378		set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2379		break;
2380	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
2381		set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2382	}
2383	nfs4_schedule_state_manager(clp);
2384}
2385EXPORT_SYMBOL_GPL(nfs4_schedule_session_recovery);
2386
2387void nfs41_notify_server(struct nfs_client *clp)
2388{
2389	/* Use CHECK_LEASE to ping the server with a SEQUENCE */
2390	set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2391	nfs4_schedule_state_manager(clp);
2392}
2393
2394static void nfs4_reset_all_state(struct nfs_client *clp)
2395{
2396	if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2397		set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2398		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2399		nfs4_state_start_reclaim_nograce(clp);
2400		dprintk("%s: scheduling reset of all state for server %s!\n",
2401				__func__, clp->cl_hostname);
2402		nfs4_schedule_state_manager(clp);
2403	}
2404}
2405
2406static void nfs41_handle_server_reboot(struct nfs_client *clp)
2407{
2408	if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2409		nfs4_state_start_reclaim_reboot(clp);
2410		dprintk("%s: server %s rebooted!\n", __func__,
2411				clp->cl_hostname);
2412		nfs4_schedule_state_manager(clp);
2413	}
2414}
2415
2416static void nfs41_handle_all_state_revoked(struct nfs_client *clp)
2417{
2418	nfs4_reset_all_state(clp);
2419	dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2420}
2421
2422static void nfs41_handle_some_state_revoked(struct nfs_client *clp)
2423{
2424	nfs4_state_start_reclaim_nograce(clp);
2425	nfs4_schedule_state_manager(clp);
2426
2427	dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2428}
2429
2430static void nfs41_handle_recallable_state_revoked(struct nfs_client *clp)
2431{
2432	/* FIXME: For now, we destroy all layouts. */
2433	pnfs_destroy_all_layouts(clp);
2434	nfs_test_expired_all_delegations(clp);
2435	dprintk("%s: Recallable state revoked on server %s!\n", __func__,
2436			clp->cl_hostname);
2437}
2438
2439static void nfs41_handle_backchannel_fault(struct nfs_client *clp)
2440{
2441	set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2442	nfs4_schedule_state_manager(clp);
2443
2444	dprintk("%s: server %s declared a backchannel fault\n", __func__,
2445			clp->cl_hostname);
2446}
2447
2448static void nfs41_handle_cb_path_down(struct nfs_client *clp)
2449{
2450	if (test_and_set_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2451		&clp->cl_state) == 0)
2452		nfs4_schedule_state_manager(clp);
2453}
2454
2455void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags,
2456		bool recovery)
2457{
2458	if (!flags)
2459		return;
2460
2461	dprintk("%s: \"%s\" (client ID %llx) flags=0x%08x\n",
2462		__func__, clp->cl_hostname, clp->cl_clientid, flags);
2463	/*
2464	 * If we're called from the state manager thread, then assume we're
2465	 * already handling the RECLAIM_NEEDED and/or STATE_REVOKED.
2466	 * Those flags are expected to remain set until we're done
2467	 * recovering (see RFC5661, section 18.46.3).
2468	 */
2469	if (recovery)
2470		goto out_recovery;
2471
2472	if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED)
2473		nfs41_handle_server_reboot(clp);
2474	if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED))
2475		nfs41_handle_all_state_revoked(clp);
2476	if (flags & (SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED |
2477			    SEQ4_STATUS_ADMIN_STATE_REVOKED))
2478		nfs41_handle_some_state_revoked(clp);
2479	if (flags & SEQ4_STATUS_LEASE_MOVED)
2480		nfs4_schedule_lease_moved_recovery(clp);
2481	if (flags & SEQ4_STATUS_RECALLABLE_STATE_REVOKED)
2482		nfs41_handle_recallable_state_revoked(clp);
2483out_recovery:
2484	if (flags & SEQ4_STATUS_BACKCHANNEL_FAULT)
2485		nfs41_handle_backchannel_fault(clp);
2486	else if (flags & (SEQ4_STATUS_CB_PATH_DOWN |
2487				SEQ4_STATUS_CB_PATH_DOWN_SESSION))
2488		nfs41_handle_cb_path_down(clp);
2489}
2490
2491static int nfs4_reset_session(struct nfs_client *clp)
2492{
2493	const struct cred *cred;
2494	int status;
2495
2496	if (!nfs4_has_session(clp))
2497		return 0;
2498	status = nfs4_begin_drain_session(clp);
2499	if (status != 0)
2500		return status;
2501	cred = nfs4_get_clid_cred(clp);
2502	status = nfs4_proc_destroy_session(clp->cl_session, cred);
2503	switch (status) {
2504	case 0:
2505	case -NFS4ERR_BADSESSION:
2506	case -NFS4ERR_DEADSESSION:
2507		break;
2508	case -NFS4ERR_BACK_CHAN_BUSY:
2509	case -NFS4ERR_DELAY:
2510		set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2511		status = 0;
2512		ssleep(1);
2513		goto out;
2514	default:
2515		status = nfs4_recovery_handle_error(clp, status);
2516		goto out;
2517	}
2518
2519	memset(clp->cl_session->sess_id.data, 0, NFS4_MAX_SESSIONID_LEN);
2520	status = nfs4_proc_create_session(clp, cred);
2521	if (status) {
2522		dprintk("%s: session reset failed with status %d for server %s!\n",
2523			__func__, status, clp->cl_hostname);
2524		status = nfs4_handle_reclaim_lease_error(clp, status);
2525		goto out;
2526	}
2527	nfs41_finish_session_reset(clp);
2528	dprintk("%s: session reset was successful for server %s!\n",
2529			__func__, clp->cl_hostname);
2530out:
2531	put_cred(cred);
2532	return status;
2533}
2534
2535static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2536{
2537	const struct cred *cred;
2538	int ret;
2539
2540	if (!nfs4_has_session(clp))
2541		return 0;
2542	ret = nfs4_begin_drain_session(clp);
2543	if (ret != 0)
2544		return ret;
2545	cred = nfs4_get_clid_cred(clp);
2546	ret = nfs4_proc_bind_conn_to_session(clp, cred);
2547	put_cred(cred);
2548	clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2549	switch (ret) {
2550	case 0:
2551		dprintk("%s: bind_conn_to_session was successful for server %s!\n",
2552			__func__, clp->cl_hostname);
2553		break;
2554	case -NFS4ERR_DELAY:
2555		ssleep(1);
2556		set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2557		break;
2558	default:
2559		return nfs4_recovery_handle_error(clp, ret);
2560	}
2561	return 0;
2562}
2563
2564static void nfs4_layoutreturn_any_run(struct nfs_client *clp)
2565{
2566	int iomode = 0;
2567
2568	if (test_and_clear_bit(NFS4CLNT_RECALL_ANY_LAYOUT_READ, &clp->cl_state))
2569		iomode += IOMODE_READ;
2570	if (test_and_clear_bit(NFS4CLNT_RECALL_ANY_LAYOUT_RW, &clp->cl_state))
2571		iomode += IOMODE_RW;
2572	/* Note: IOMODE_READ + IOMODE_RW == IOMODE_ANY */
2573	if (iomode) {
2574		pnfs_layout_return_unused_byclid(clp, iomode);
2575		set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2576	}
2577}
2578#else /* CONFIG_NFS_V4_1 */
2579static int nfs4_reset_session(struct nfs_client *clp) { return 0; }
2580
2581static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2582{
2583	return 0;
2584}
2585
2586static void nfs4_layoutreturn_any_run(struct nfs_client *clp)
2587{
2588}
2589#endif /* CONFIG_NFS_V4_1 */
2590
2591static void nfs4_state_manager(struct nfs_client *clp)
2592{
2593	unsigned int memflags;
2594	int status = 0;
2595	const char *section = "", *section_sep = "";
2596
2597	/*
2598	 * State recovery can deadlock if the direct reclaim code tries
2599	 * start NFS writeback. So ensure memory allocations are all
2600	 * GFP_NOFS.
2601	 */
2602	memflags = memalloc_nofs_save();
2603
2604	/* Ensure exclusive access to NFSv4 state */
2605	do {
2606		trace_nfs4_state_mgr(clp);
2607		clear_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2608		if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
2609			section = "purge state";
2610			status = nfs4_purge_lease(clp);
2611			if (status < 0)
2612				goto out_error;
2613			continue;
2614		}
2615
2616		if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
2617			section = "lease expired";
2618			/* We're going to have to re-establish a clientid */
2619			status = nfs4_reclaim_lease(clp);
2620			if (status < 0)
2621				goto out_error;
2622			continue;
2623		}
2624
2625		/* Initialize or reset the session */
2626		if (test_and_clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state)) {
2627			section = "reset session";
2628			status = nfs4_reset_session(clp);
2629			if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
2630				continue;
2631			if (status < 0)
2632				goto out_error;
2633		}
2634
2635		/* Send BIND_CONN_TO_SESSION */
2636		if (test_and_clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2637				&clp->cl_state)) {
2638			section = "bind conn to session";
2639			status = nfs4_bind_conn_to_session(clp);
2640			if (status < 0)
2641				goto out_error;
2642			continue;
2643		}
2644
2645		if (test_and_clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state)) {
2646			section = "check lease";
2647			status = nfs4_check_lease(clp);
2648			if (status < 0)
2649				goto out_error;
2650			continue;
2651		}
2652
2653		if (test_and_clear_bit(NFS4CLNT_MOVED, &clp->cl_state)) {
2654			section = "migration";
2655			status = nfs4_handle_migration(clp);
2656			if (status < 0)
2657				goto out_error;
2658		}
2659
2660		if (test_and_clear_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state)) {
2661			section = "lease moved";
2662			status = nfs4_handle_lease_moved(clp);
2663			if (status < 0)
2664				goto out_error;
2665		}
2666
2667		/* First recover reboot state... */
2668		if (test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {
2669			section = "reclaim reboot";
2670			status = nfs4_do_reclaim(clp,
2671				clp->cl_mvops->reboot_recovery_ops);
2672			if (status == -EAGAIN)
2673				continue;
2674			if (status < 0)
2675				goto out_error;
2676			nfs4_state_end_reclaim_reboot(clp);
2677			continue;
2678		}
2679
2680		/* Detect expired delegations... */
2681		if (test_and_clear_bit(NFS4CLNT_DELEGATION_EXPIRED, &clp->cl_state)) {
2682			section = "detect expired delegations";
2683			nfs_reap_expired_delegations(clp);
2684			continue;
2685		}
2686
2687		/* Now recover expired state... */
2688		if (test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state)) {
2689			section = "reclaim nograce";
2690			status = nfs4_do_reclaim(clp,
2691				clp->cl_mvops->nograce_recovery_ops);
2692			if (status == -EAGAIN)
2693				continue;
2694			if (status < 0)
2695				goto out_error;
2696			clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
2697		}
2698
2699		memalloc_nofs_restore(memflags);
2700		nfs4_end_drain_session(clp);
2701		nfs4_clear_state_manager_bit(clp);
2702
2703		if (!test_and_set_bit(NFS4CLNT_RECALL_RUNNING, &clp->cl_state)) {
2704			if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
2705				nfs_client_return_marked_delegations(clp);
2706				set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2707			}
2708			nfs4_layoutreturn_any_run(clp);
2709			clear_bit(NFS4CLNT_RECALL_RUNNING, &clp->cl_state);
2710		}
2711
2712		return;
2713
 
 
 
2714	} while (refcount_read(&clp->cl_count) > 1 && !signalled());
2715	goto out_drain;
2716
2717out_error:
2718	if (strlen(section))
2719		section_sep = ": ";
2720	trace_nfs4_state_mgr_failed(clp, section, status);
2721	pr_warn_ratelimited("NFS: state manager%s%s failed on NFSv4 server %s"
2722			" with error %d\n", section_sep, section,
2723			clp->cl_hostname, -status);
2724	ssleep(1);
2725out_drain:
2726	memalloc_nofs_restore(memflags);
2727	nfs4_end_drain_session(clp);
2728	nfs4_clear_state_manager_bit(clp);
2729}
2730
2731static int nfs4_run_state_manager(void *ptr)
2732{
2733	struct nfs_client *clp = ptr;
2734	struct rpc_clnt *cl = clp->cl_rpcclient;
2735
2736	while (cl != cl->cl_parent)
2737		cl = cl->cl_parent;
2738
2739	allow_signal(SIGKILL);
2740again:
2741	set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state);
2742	nfs4_state_manager(clp);
2743	if (atomic_read(&cl->cl_swapper)) {
2744		wait_var_event_interruptible(&clp->cl_state,
2745					     test_bit(NFS4CLNT_RUN_MANAGER,
2746						      &clp->cl_state));
2747		if (atomic_read(&cl->cl_swapper) &&
2748		    test_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state))
2749			goto again;
2750		/* Either no longer a swapper, or were signalled */
2751	}
2752	clear_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state);
2753
2754	if (refcount_read(&clp->cl_count) > 1 && !signalled() &&
2755	    test_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state) &&
2756	    !test_and_set_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state))
2757		goto again;
2758
2759	nfs_put_client(clp);
2760	module_put_and_kthread_exit(0);
2761	return 0;
2762}