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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}
v5.4
   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
  64#define NFSDBG_FACILITY		NFSDBG_STATE
  65
  66#define OPENOWNER_POOL_SIZE	8
  67
  68const nfs4_stateid zero_stateid = {
  69	{ .data = { 0 } },
  70	.type = NFS4_SPECIAL_STATEID_TYPE,
  71};
  72const nfs4_stateid invalid_stateid = {
  73	{
  74		/* Funky initialiser keeps older gcc versions happy */
  75		.data = { 0xff, 0xff, 0xff, 0xff, 0 },
  76	},
  77	.type = NFS4_INVALID_STATEID_TYPE,
  78};
  79
  80const nfs4_stateid current_stateid = {
  81	{
  82		/* Funky initialiser keeps older gcc versions happy */
  83		.data = { 0x0, 0x0, 0x0, 0x1, 0 },
  84	},
  85	.type = NFS4_SPECIAL_STATEID_TYPE,
  86};
  87
  88static DEFINE_MUTEX(nfs_clid_init_mutex);
  89
  90static int nfs4_setup_state_renewal(struct nfs_client *clp)
  91{
  92	int status;
  93	struct nfs_fsinfo fsinfo;
  94	unsigned long now;
  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	now = jiffies;
 102	status = nfs4_proc_get_lease_time(clp, &fsinfo);
 103	if (status == 0) {
 104		nfs4_set_lease_period(clp, fsinfo.lease_time * HZ, now);
 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_simple_get(&server->openowner_id, 0, 0,
 501						gfp_flags);
 502	if (sp->so_seqid.owner_id < 0) {
 503		kfree(sp);
 504		return NULL;
 505	}
 506	sp->so_server = server;
 507	sp->so_cred = get_cred(cred);
 508	spin_lock_init(&sp->so_lock);
 509	INIT_LIST_HEAD(&sp->so_states);
 510	nfs4_init_seqid_counter(&sp->so_seqid);
 511	atomic_set(&sp->so_count, 1);
 512	INIT_LIST_HEAD(&sp->so_lru);
 513	seqcount_init(&sp->so_reclaim_seqcount);
 514	mutex_init(&sp->so_delegreturn_mutex);
 515	return sp;
 516}
 517
 518static void
 519nfs4_reset_state_owner(struct nfs4_state_owner *sp)
 520{
 521	/* This state_owner is no longer usable, but must
 522	 * remain in place so that state recovery can find it
 523	 * and the opens associated with it.
 524	 * It may also be used for new 'open' request to
 525	 * return a delegation to the server.
 526	 * So update the 'create_time' so that it looks like
 527	 * a new state_owner.  This will cause the server to
 528	 * request an OPEN_CONFIRM to start a new sequence.
 529	 */
 530	sp->so_seqid.create_time = ktime_get();
 531}
 532
 533static void nfs4_free_state_owner(struct nfs4_state_owner *sp)
 534{
 535	nfs4_destroy_seqid_counter(&sp->so_seqid);
 536	put_cred(sp->so_cred);
 537	ida_simple_remove(&sp->so_server->openowner_id, sp->so_seqid.owner_id);
 538	kfree(sp);
 539}
 540
 541static void nfs4_gc_state_owners(struct nfs_server *server)
 542{
 543	struct nfs_client *clp = server->nfs_client;
 544	struct nfs4_state_owner *sp, *tmp;
 545	unsigned long time_min, time_max;
 546	LIST_HEAD(doomed);
 547
 548	spin_lock(&clp->cl_lock);
 549	time_max = jiffies;
 550	time_min = (long)time_max - (long)clp->cl_lease_time;
 551	list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
 552		/* NB: LRU is sorted so that oldest is at the head */
 553		if (time_in_range(sp->so_expires, time_min, time_max))
 554			break;
 555		list_move(&sp->so_lru, &doomed);
 556		nfs4_remove_state_owner_locked(sp);
 557	}
 558	spin_unlock(&clp->cl_lock);
 559
 560	list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
 561		list_del(&sp->so_lru);
 562		nfs4_free_state_owner(sp);
 563	}
 564}
 565
 566/**
 567 * nfs4_get_state_owner - Look up a state owner given a credential
 568 * @server: nfs_server to search
 569 * @cred: RPC credential to match
 570 * @gfp_flags: allocation mode
 571 *
 572 * Returns a pointer to an instantiated nfs4_state_owner struct, or NULL.
 573 */
 574struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server,
 575					      const struct cred *cred,
 576					      gfp_t gfp_flags)
 577{
 578	struct nfs_client *clp = server->nfs_client;
 579	struct nfs4_state_owner *sp, *new;
 580
 581	spin_lock(&clp->cl_lock);
 582	sp = nfs4_find_state_owner_locked(server, cred);
 583	spin_unlock(&clp->cl_lock);
 584	if (sp != NULL)
 585		goto out;
 586	new = nfs4_alloc_state_owner(server, cred, gfp_flags);
 587	if (new == NULL)
 588		goto out;
 589	spin_lock(&clp->cl_lock);
 590	sp = nfs4_insert_state_owner_locked(new);
 591	spin_unlock(&clp->cl_lock);
 592	if (sp != new)
 593		nfs4_free_state_owner(new);
 594out:
 595	nfs4_gc_state_owners(server);
 596	return sp;
 597}
 598
 599/**
 600 * nfs4_put_state_owner - Release a nfs4_state_owner
 601 * @sp: state owner data to release
 602 *
 603 * Note that we keep released state owners on an LRU
 604 * list.
 605 * This caches valid state owners so that they can be
 606 * reused, to avoid the OPEN_CONFIRM on minor version 0.
 607 * It also pins the uniquifier of dropped state owners for
 608 * a while, to ensure that those state owner names are
 609 * never reused.
 610 */
 611void nfs4_put_state_owner(struct nfs4_state_owner *sp)
 612{
 613	struct nfs_server *server = sp->so_server;
 614	struct nfs_client *clp = server->nfs_client;
 615
 616	if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
 617		return;
 618
 619	sp->so_expires = jiffies;
 620	list_add_tail(&sp->so_lru, &server->state_owners_lru);
 621	spin_unlock(&clp->cl_lock);
 622}
 623
 624/**
 625 * nfs4_purge_state_owners - Release all cached state owners
 626 * @server: nfs_server with cached state owners to release
 627 * @head: resulting list of state owners
 628 *
 629 * Called at umount time.  Remaining state owners will be on
 630 * the LRU with ref count of zero.
 631 * Note that the state owners are not freed, but are added
 632 * to the list @head, which can later be used as an argument
 633 * to nfs4_free_state_owners.
 634 */
 635void nfs4_purge_state_owners(struct nfs_server *server, struct list_head *head)
 636{
 637	struct nfs_client *clp = server->nfs_client;
 638	struct nfs4_state_owner *sp, *tmp;
 639
 640	spin_lock(&clp->cl_lock);
 641	list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
 642		list_move(&sp->so_lru, head);
 643		nfs4_remove_state_owner_locked(sp);
 644	}
 645	spin_unlock(&clp->cl_lock);
 646}
 647
 648/**
 649 * nfs4_purge_state_owners - Release all cached state owners
 650 * @head: resulting list of state owners
 651 *
 652 * Frees a list of state owners that was generated by
 653 * nfs4_purge_state_owners
 654 */
 655void nfs4_free_state_owners(struct list_head *head)
 656{
 657	struct nfs4_state_owner *sp, *tmp;
 658
 659	list_for_each_entry_safe(sp, tmp, head, so_lru) {
 660		list_del(&sp->so_lru);
 661		nfs4_free_state_owner(sp);
 662	}
 663}
 664
 665static struct nfs4_state *
 666nfs4_alloc_open_state(void)
 667{
 668	struct nfs4_state *state;
 669
 670	state = kzalloc(sizeof(*state), GFP_NOFS);
 671	if (!state)
 672		return NULL;
 673	refcount_set(&state->count, 1);
 674	INIT_LIST_HEAD(&state->lock_states);
 675	spin_lock_init(&state->state_lock);
 676	seqlock_init(&state->seqlock);
 677	init_waitqueue_head(&state->waitq);
 678	return state;
 679}
 680
 681void
 682nfs4_state_set_mode_locked(struct nfs4_state *state, fmode_t fmode)
 683{
 684	if (state->state == fmode)
 685		return;
 686	/* NB! List reordering - see the reclaim code for why.  */
 687	if ((fmode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
 688		if (fmode & FMODE_WRITE)
 689			list_move(&state->open_states, &state->owner->so_states);
 690		else
 691			list_move_tail(&state->open_states, &state->owner->so_states);
 692	}
 693	state->state = fmode;
 694}
 695
 696static struct nfs4_state *
 697__nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
 698{
 699	struct nfs_inode *nfsi = NFS_I(inode);
 700	struct nfs4_state *state;
 701
 702	list_for_each_entry_rcu(state, &nfsi->open_states, inode_states) {
 703		if (state->owner != owner)
 704			continue;
 705		if (!nfs4_valid_open_stateid(state))
 706			continue;
 707		if (refcount_inc_not_zero(&state->count))
 708			return state;
 709	}
 710	return NULL;
 711}
 712
 713static void
 714nfs4_free_open_state(struct nfs4_state *state)
 715{
 716	kfree_rcu(state, rcu_head);
 717}
 718
 719struct nfs4_state *
 720nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
 721{
 722	struct nfs4_state *state, *new;
 723	struct nfs_inode *nfsi = NFS_I(inode);
 724
 725	rcu_read_lock();
 726	state = __nfs4_find_state_byowner(inode, owner);
 727	rcu_read_unlock();
 728	if (state)
 729		goto out;
 730	new = nfs4_alloc_open_state();
 731	spin_lock(&owner->so_lock);
 732	spin_lock(&inode->i_lock);
 733	state = __nfs4_find_state_byowner(inode, owner);
 734	if (state == NULL && new != NULL) {
 735		state = new;
 736		state->owner = owner;
 737		atomic_inc(&owner->so_count);
 738		list_add_rcu(&state->inode_states, &nfsi->open_states);
 739		ihold(inode);
 740		state->inode = inode;
 
 741		spin_unlock(&inode->i_lock);
 742		/* Note: The reclaim code dictates that we add stateless
 743		 * and read-only stateids to the end of the list */
 744		list_add_tail(&state->open_states, &owner->so_states);
 745		spin_unlock(&owner->so_lock);
 746	} else {
 747		spin_unlock(&inode->i_lock);
 748		spin_unlock(&owner->so_lock);
 749		if (new)
 750			nfs4_free_open_state(new);
 751	}
 752out:
 753	return state;
 754}
 755
 756void nfs4_put_open_state(struct nfs4_state *state)
 757{
 758	struct inode *inode = state->inode;
 759	struct nfs4_state_owner *owner = state->owner;
 760
 761	if (!refcount_dec_and_lock(&state->count, &owner->so_lock))
 762		return;
 763	spin_lock(&inode->i_lock);
 764	list_del_rcu(&state->inode_states);
 765	list_del(&state->open_states);
 766	spin_unlock(&inode->i_lock);
 767	spin_unlock(&owner->so_lock);
 
 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		case -NFS4ERR_STALE_CLIENTID:
1129		case -NFS4ERR_STALE_STATEID:
1130		case -NFS4ERR_BAD_STATEID:
1131		case -NFS4ERR_BADXDR:
1132		case -NFS4ERR_RESOURCE:
1133		case -NFS4ERR_NOFILEHANDLE:
1134		case -NFS4ERR_MOVED:
1135			/* Non-seqid mutating errors */
1136			return;
1137	};
1138	/*
1139	 * Note: no locking needed as we are guaranteed to be first
1140	 * on the sequence list
1141	 */
1142	seqid->sequence->counter++;
1143}
1144
1145void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
1146{
1147	struct nfs4_state_owner *sp;
1148
1149	if (seqid == NULL)
1150		return;
1151
1152	sp = container_of(seqid->sequence, struct nfs4_state_owner, so_seqid);
1153	if (status == -NFS4ERR_BAD_SEQID)
1154		nfs4_reset_state_owner(sp);
1155	if (!nfs4_has_session(sp->so_server->nfs_client))
1156		nfs_increment_seqid(status, seqid);
1157}
1158
1159/*
1160 * Increment the seqid if the LOCK/LOCKU succeeded, or
1161 * failed with a seqid incrementing error -
1162 * see comments nfs4.h:seqid_mutating_error()
1163 */
1164void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
1165{
1166	if (seqid != NULL)
1167		nfs_increment_seqid(status, seqid);
1168}
1169
1170int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
1171{
1172	struct nfs_seqid_counter *sequence;
1173	int status = 0;
1174
1175	if (seqid == NULL)
1176		goto out;
1177	sequence = seqid->sequence;
1178	spin_lock(&sequence->lock);
1179	seqid->task = task;
1180	if (list_empty(&seqid->list))
1181		list_add_tail(&seqid->list, &sequence->list);
1182	if (list_first_entry(&sequence->list, struct nfs_seqid, list) == seqid)
1183		goto unlock;
1184	rpc_sleep_on(&sequence->wait, task, NULL);
1185	status = -EAGAIN;
1186unlock:
1187	spin_unlock(&sequence->lock);
1188out:
1189	return status;
1190}
1191
1192static int nfs4_run_state_manager(void *);
1193
1194static void nfs4_clear_state_manager_bit(struct nfs_client *clp)
1195{
1196	smp_mb__before_atomic();
1197	clear_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state);
1198	smp_mb__after_atomic();
1199	wake_up_bit(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING);
1200	rpc_wake_up(&clp->cl_rpcwaitq);
1201}
1202
1203/*
1204 * Schedule the nfs_client asynchronous state management routine
1205 */
1206void nfs4_schedule_state_manager(struct nfs_client *clp)
1207{
1208	struct task_struct *task;
1209	char buf[INET6_ADDRSTRLEN + sizeof("-manager") + 1];
1210
1211	set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
1212	if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
1213		return;
1214	__module_get(THIS_MODULE);
1215	refcount_inc(&clp->cl_count);
1216
1217	/* The rcu_read_lock() is not strictly necessary, as the state
1218	 * manager is the only thread that ever changes the rpc_xprt
1219	 * after it's initialized.  At this point, we're single threaded. */
1220	rcu_read_lock();
1221	snprintf(buf, sizeof(buf), "%s-manager",
1222			rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
1223	rcu_read_unlock();
1224	task = kthread_run(nfs4_run_state_manager, clp, "%s", buf);
1225	if (IS_ERR(task)) {
1226		printk(KERN_ERR "%s: kthread_run: %ld\n",
1227			__func__, PTR_ERR(task));
1228		nfs4_clear_state_manager_bit(clp);
1229		nfs_put_client(clp);
1230		module_put(THIS_MODULE);
1231	}
1232}
1233
1234/*
1235 * Schedule a lease recovery attempt
1236 */
1237void nfs4_schedule_lease_recovery(struct nfs_client *clp)
1238{
1239	if (!clp)
1240		return;
1241	if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1242		set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1243	dprintk("%s: scheduling lease recovery for server %s\n", __func__,
1244			clp->cl_hostname);
1245	nfs4_schedule_state_manager(clp);
1246}
1247EXPORT_SYMBOL_GPL(nfs4_schedule_lease_recovery);
1248
1249/**
1250 * nfs4_schedule_migration_recovery - trigger migration recovery
1251 *
1252 * @server: FSID that is migrating
1253 *
1254 * Returns zero if recovery has started, otherwise a negative NFS4ERR
1255 * value is returned.
1256 */
1257int nfs4_schedule_migration_recovery(const struct nfs_server *server)
1258{
1259	struct nfs_client *clp = server->nfs_client;
1260
1261	if (server->fh_expire_type != NFS4_FH_PERSISTENT) {
1262		pr_err("NFS: volatile file handles not supported (server %s)\n",
1263				clp->cl_hostname);
1264		return -NFS4ERR_IO;
1265	}
1266
1267	if (test_bit(NFS_MIG_FAILED, &server->mig_status))
1268		return -NFS4ERR_IO;
1269
1270	dprintk("%s: scheduling migration recovery for (%llx:%llx) on %s\n",
1271			__func__,
1272			(unsigned long long)server->fsid.major,
1273			(unsigned long long)server->fsid.minor,
1274			clp->cl_hostname);
1275
1276	set_bit(NFS_MIG_IN_TRANSITION,
1277			&((struct nfs_server *)server)->mig_status);
1278	set_bit(NFS4CLNT_MOVED, &clp->cl_state);
1279
1280	nfs4_schedule_state_manager(clp);
1281	return 0;
1282}
1283EXPORT_SYMBOL_GPL(nfs4_schedule_migration_recovery);
1284
1285/**
1286 * nfs4_schedule_lease_moved_recovery - start lease-moved recovery
1287 *
1288 * @clp: server to check for moved leases
1289 *
1290 */
1291void nfs4_schedule_lease_moved_recovery(struct nfs_client *clp)
1292{
1293	dprintk("%s: scheduling lease-moved recovery for client ID %llx on %s\n",
1294		__func__, clp->cl_clientid, clp->cl_hostname);
1295
1296	set_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state);
1297	nfs4_schedule_state_manager(clp);
1298}
1299EXPORT_SYMBOL_GPL(nfs4_schedule_lease_moved_recovery);
1300
1301int nfs4_wait_clnt_recover(struct nfs_client *clp)
1302{
1303	int res;
1304
1305	might_sleep();
1306
1307	refcount_inc(&clp->cl_count);
1308	res = wait_on_bit_action(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING,
1309				 nfs_wait_bit_killable, TASK_KILLABLE);
1310	if (res)
1311		goto out;
1312	if (clp->cl_cons_state < 0)
1313		res = clp->cl_cons_state;
1314out:
1315	nfs_put_client(clp);
1316	return res;
1317}
1318
1319int nfs4_client_recover_expired_lease(struct nfs_client *clp)
1320{
1321	unsigned int loop;
1322	int ret;
1323
1324	for (loop = NFS4_MAX_LOOP_ON_RECOVER; loop != 0; loop--) {
1325		ret = nfs4_wait_clnt_recover(clp);
1326		if (ret != 0)
1327			break;
1328		if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) &&
1329		    !test_bit(NFS4CLNT_CHECK_LEASE,&clp->cl_state))
1330			break;
1331		nfs4_schedule_state_manager(clp);
1332		ret = -EIO;
1333	}
1334	return ret;
1335}
1336
1337/*
1338 * nfs40_handle_cb_pathdown - return all delegations after NFS4ERR_CB_PATH_DOWN
1339 * @clp: client to process
1340 *
1341 * Set the NFS4CLNT_LEASE_EXPIRED state in order to force a
1342 * resend of the SETCLIENTID and hence re-establish the
1343 * callback channel. Then return all existing delegations.
1344 */
1345static void nfs40_handle_cb_pathdown(struct nfs_client *clp)
1346{
1347	set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1348	nfs_expire_all_delegations(clp);
1349	dprintk("%s: handling CB_PATHDOWN recovery for server %s\n", __func__,
1350			clp->cl_hostname);
1351}
1352
1353void nfs4_schedule_path_down_recovery(struct nfs_client *clp)
1354{
1355	nfs40_handle_cb_pathdown(clp);
1356	nfs4_schedule_state_manager(clp);
1357}
1358
1359static int nfs4_state_mark_reclaim_reboot(struct nfs_client *clp, struct nfs4_state *state)
1360{
1361
1362	if (!nfs4_valid_open_stateid(state))
1363		return 0;
1364	set_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1365	/* Don't recover state that expired before the reboot */
1366	if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags)) {
1367		clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1368		return 0;
1369	}
1370	set_bit(NFS_OWNER_RECLAIM_REBOOT, &state->owner->so_flags);
1371	set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1372	return 1;
1373}
1374
1375int nfs4_state_mark_reclaim_nograce(struct nfs_client *clp, struct nfs4_state *state)
1376{
1377	if (!nfs4_valid_open_stateid(state))
1378		return 0;
1379	set_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1380	clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1381	set_bit(NFS_OWNER_RECLAIM_NOGRACE, &state->owner->so_flags);
1382	set_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
1383	return 1;
1384}
1385
1386int nfs4_schedule_stateid_recovery(const struct nfs_server *server, struct nfs4_state *state)
1387{
1388	struct nfs_client *clp = server->nfs_client;
1389
1390	if (!nfs4_state_mark_reclaim_nograce(clp, state))
1391		return -EBADF;
1392	nfs_inode_find_delegation_state_and_recover(state->inode,
1393			&state->stateid);
1394	dprintk("%s: scheduling stateid recovery for server %s\n", __func__,
1395			clp->cl_hostname);
1396	nfs4_schedule_state_manager(clp);
1397	return 0;
1398}
1399EXPORT_SYMBOL_GPL(nfs4_schedule_stateid_recovery);
1400
1401static struct nfs4_lock_state *
1402nfs_state_find_lock_state_by_stateid(struct nfs4_state *state,
1403		const nfs4_stateid *stateid)
1404{
1405	struct nfs4_lock_state *pos;
1406
1407	list_for_each_entry(pos, &state->lock_states, ls_locks) {
1408		if (!test_bit(NFS_LOCK_INITIALIZED, &pos->ls_flags))
1409			continue;
1410		if (nfs4_stateid_match_other(&pos->ls_stateid, stateid))
1411			return pos;
1412	}
1413	return NULL;
1414}
1415
1416static bool nfs_state_lock_state_matches_stateid(struct nfs4_state *state,
1417		const nfs4_stateid *stateid)
1418{
1419	bool found = false;
1420
1421	if (test_bit(LK_STATE_IN_USE, &state->flags)) {
1422		spin_lock(&state->state_lock);
1423		if (nfs_state_find_lock_state_by_stateid(state, stateid))
1424			found = true;
1425		spin_unlock(&state->state_lock);
1426	}
1427	return found;
1428}
1429
1430void nfs_inode_find_state_and_recover(struct inode *inode,
1431		const nfs4_stateid *stateid)
1432{
1433	struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
1434	struct nfs_inode *nfsi = NFS_I(inode);
1435	struct nfs_open_context *ctx;
1436	struct nfs4_state *state;
1437	bool found = false;
1438
1439	rcu_read_lock();
1440	list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1441		state = ctx->state;
1442		if (state == NULL)
1443			continue;
1444		if (nfs4_stateid_match_other(&state->stateid, stateid) &&
1445		    nfs4_state_mark_reclaim_nograce(clp, state)) {
1446			found = true;
1447			continue;
1448		}
1449		if (nfs4_stateid_match_other(&state->open_stateid, stateid) &&
 
1450		    nfs4_state_mark_reclaim_nograce(clp, state)) {
1451			found = true;
1452			continue;
1453		}
1454		if (nfs_state_lock_state_matches_stateid(state, stateid) &&
1455		    nfs4_state_mark_reclaim_nograce(clp, state))
1456			found = true;
1457	}
1458	rcu_read_unlock();
1459
1460	nfs_inode_find_delegation_state_and_recover(inode, stateid);
1461	if (found)
1462		nfs4_schedule_state_manager(clp);
1463}
1464
1465static void nfs4_state_mark_open_context_bad(struct nfs4_state *state, int err)
1466{
1467	struct inode *inode = state->inode;
1468	struct nfs_inode *nfsi = NFS_I(inode);
1469	struct nfs_open_context *ctx;
1470
1471	rcu_read_lock();
1472	list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1473		if (ctx->state != state)
1474			continue;
1475		set_bit(NFS_CONTEXT_BAD, &ctx->flags);
1476		pr_warn("NFSv4: state recovery failed for open file %pd2, "
1477				"error = %d\n", ctx->dentry, err);
1478	}
1479	rcu_read_unlock();
1480}
1481
1482static void nfs4_state_mark_recovery_failed(struct nfs4_state *state, int error)
1483{
1484	set_bit(NFS_STATE_RECOVERY_FAILED, &state->flags);
1485	nfs4_state_mark_open_context_bad(state, error);
1486}
1487
1488
1489static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_recovery_ops *ops)
1490{
1491	struct inode *inode = state->inode;
1492	struct nfs_inode *nfsi = NFS_I(inode);
1493	struct file_lock *fl;
1494	struct nfs4_lock_state *lsp;
1495	int status = 0;
1496	struct file_lock_context *flctx = inode->i_flctx;
1497	struct list_head *list;
1498
1499	if (flctx == NULL)
1500		return 0;
1501
1502	list = &flctx->flc_posix;
1503
1504	/* Guard against delegation returns and new lock/unlock calls */
1505	down_write(&nfsi->rwsem);
1506	spin_lock(&flctx->flc_lock);
1507restart:
1508	list_for_each_entry(fl, list, fl_list) {
1509		if (nfs_file_open_context(fl->fl_file)->state != state)
1510			continue;
1511		spin_unlock(&flctx->flc_lock);
1512		status = ops->recover_lock(state, fl);
1513		switch (status) {
1514		case 0:
1515			break;
1516		case -ETIMEDOUT:
1517		case -ESTALE:
1518		case -NFS4ERR_ADMIN_REVOKED:
1519		case -NFS4ERR_STALE_STATEID:
1520		case -NFS4ERR_BAD_STATEID:
1521		case -NFS4ERR_EXPIRED:
1522		case -NFS4ERR_NO_GRACE:
1523		case -NFS4ERR_STALE_CLIENTID:
1524		case -NFS4ERR_BADSESSION:
1525		case -NFS4ERR_BADSLOT:
1526		case -NFS4ERR_BAD_HIGH_SLOT:
1527		case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1528			goto out;
1529		default:
1530			pr_err("NFS: %s: unhandled error %d\n",
1531					__func__, status);
1532			/* Fall through */
1533		case -ENOMEM:
1534		case -NFS4ERR_DENIED:
1535		case -NFS4ERR_RECLAIM_BAD:
1536		case -NFS4ERR_RECLAIM_CONFLICT:
1537			lsp = fl->fl_u.nfs4_fl.owner;
1538			if (lsp)
1539				set_bit(NFS_LOCK_LOST, &lsp->ls_flags);
1540			status = 0;
1541		}
1542		spin_lock(&flctx->flc_lock);
1543	}
1544	if (list == &flctx->flc_posix) {
1545		list = &flctx->flc_flock;
1546		goto restart;
1547	}
1548	spin_unlock(&flctx->flc_lock);
1549out:
1550	up_write(&nfsi->rwsem);
1551	return status;
1552}
1553
1554#ifdef CONFIG_NFS_V4_2
1555static void nfs42_complete_copies(struct nfs4_state_owner *sp, struct nfs4_state *state)
1556{
1557	struct nfs4_copy_state *copy;
1558
1559	if (!test_bit(NFS_CLNT_DST_SSC_COPY_STATE, &state->flags))
 
1560		return;
1561
1562	spin_lock(&sp->so_server->nfs_client->cl_lock);
1563	list_for_each_entry(copy, &sp->so_server->ss_copies, copies) {
1564		if (!nfs4_stateid_match_other(&state->stateid, &copy->parent_state->stateid))
1565			continue;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1566		copy->flags = 1;
1567		complete(&copy->completion);
1568		break;
 
1569	}
1570	spin_unlock(&sp->so_server->nfs_client->cl_lock);
1571}
1572#else /* !CONFIG_NFS_V4_2 */
1573static inline void nfs42_complete_copies(struct nfs4_state_owner *sp,
1574					 struct nfs4_state *state)
1575{
1576}
1577#endif /* CONFIG_NFS_V4_2 */
1578
1579static int __nfs4_reclaim_open_state(struct nfs4_state_owner *sp, struct nfs4_state *state,
1580				     const struct nfs4_state_recovery_ops *ops)
1581{
1582	struct nfs4_lock_state *lock;
1583	int status;
1584
1585	status = ops->recover_open(sp, state);
1586	if (status < 0)
1587		return status;
1588
1589	status = nfs4_reclaim_locks(state, ops);
1590	if (status < 0)
1591		return status;
1592
1593	if (!test_bit(NFS_DELEGATED_STATE, &state->flags)) {
1594		spin_lock(&state->state_lock);
1595		list_for_each_entry(lock, &state->lock_states, ls_locks) {
 
1596			if (!test_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags))
1597				pr_warn_ratelimited("NFS: %s: Lock reclaim failed!\n", __func__);
1598		}
1599		spin_unlock(&state->state_lock);
1600	}
1601
1602	nfs42_complete_copies(sp, state);
1603	clear_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1604	return status;
1605}
1606
1607static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs4_state_recovery_ops *ops)
1608{
1609	struct nfs4_state *state;
1610	unsigned int loop = 0;
1611	int status = 0;
 
 
 
1612
1613	/* Note: we rely on the sp->so_states list being ordered 
1614	 * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
1615	 * states first.
1616	 * This is needed to ensure that the server won't give us any
1617	 * read delegations that we have to return if, say, we are
1618	 * recovering after a network partition or a reboot from a
1619	 * server that doesn't support a grace period.
1620	 */
1621	spin_lock(&sp->so_lock);
1622	raw_write_seqcount_begin(&sp->so_reclaim_seqcount);
1623restart:
1624	list_for_each_entry(state, &sp->so_states, open_states) {
1625		if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
1626			continue;
1627		if (!nfs4_valid_open_stateid(state))
1628			continue;
1629		if (state->state == 0)
1630			continue;
 
 
 
 
 
 
 
1631		refcount_inc(&state->count);
1632		spin_unlock(&sp->so_lock);
1633		status = __nfs4_reclaim_open_state(sp, state, ops);
1634
1635		switch (status) {
1636		default:
1637			if (status >= 0) {
1638				loop = 0;
1639				break;
1640			}
1641			printk(KERN_ERR "NFS: %s: unhandled error %d\n", __func__, status);
1642			/* Fall through */
1643		case -ENOENT:
1644		case -ENOMEM:
1645		case -EACCES:
1646		case -EROFS:
1647		case -EIO:
1648		case -ESTALE:
1649			/* Open state on this file cannot be recovered */
1650			nfs4_state_mark_recovery_failed(state, status);
1651			break;
1652		case -EAGAIN:
1653			ssleep(1);
1654			if (loop++ < 10) {
1655				set_bit(ops->state_flag_bit, &state->flags);
1656				break;
1657			}
1658			/* Fall through */
1659		case -NFS4ERR_ADMIN_REVOKED:
1660		case -NFS4ERR_STALE_STATEID:
1661		case -NFS4ERR_OLD_STATEID:
1662		case -NFS4ERR_BAD_STATEID:
1663		case -NFS4ERR_RECLAIM_BAD:
1664		case -NFS4ERR_RECLAIM_CONFLICT:
1665			nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1666			break;
1667		case -NFS4ERR_EXPIRED:
1668		case -NFS4ERR_NO_GRACE:
1669			nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1670			/* Fall through */
1671		case -NFS4ERR_STALE_CLIENTID:
1672		case -NFS4ERR_BADSESSION:
1673		case -NFS4ERR_BADSLOT:
1674		case -NFS4ERR_BAD_HIGH_SLOT:
1675		case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1676		case -ETIMEDOUT:
1677			goto out_err;
1678		}
1679		nfs4_put_open_state(state);
1680		spin_lock(&sp->so_lock);
1681		goto restart;
1682	}
1683	raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1684	spin_unlock(&sp->so_lock);
 
 
 
 
1685	return 0;
1686out_err:
1687	nfs4_put_open_state(state);
1688	spin_lock(&sp->so_lock);
1689	raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1690	spin_unlock(&sp->so_lock);
1691	return status;
1692}
1693
1694static void nfs4_clear_open_state(struct nfs4_state *state)
1695{
1696	struct nfs4_lock_state *lock;
1697
1698	clear_bit(NFS_DELEGATED_STATE, &state->flags);
1699	clear_bit(NFS_O_RDONLY_STATE, &state->flags);
1700	clear_bit(NFS_O_WRONLY_STATE, &state->flags);
1701	clear_bit(NFS_O_RDWR_STATE, &state->flags);
1702	spin_lock(&state->state_lock);
1703	list_for_each_entry(lock, &state->lock_states, ls_locks) {
1704		lock->ls_seqid.flags = 0;
1705		clear_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags);
1706	}
1707	spin_unlock(&state->state_lock);
1708}
1709
1710static void nfs4_reset_seqids(struct nfs_server *server,
1711	int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1712{
1713	struct nfs_client *clp = server->nfs_client;
1714	struct nfs4_state_owner *sp;
1715	struct rb_node *pos;
1716	struct nfs4_state *state;
1717
1718	spin_lock(&clp->cl_lock);
1719	for (pos = rb_first(&server->state_owners);
1720	     pos != NULL;
1721	     pos = rb_next(pos)) {
1722		sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1723		sp->so_seqid.flags = 0;
1724		spin_lock(&sp->so_lock);
1725		list_for_each_entry(state, &sp->so_states, open_states) {
1726			if (mark_reclaim(clp, state))
1727				nfs4_clear_open_state(state);
1728		}
1729		spin_unlock(&sp->so_lock);
1730	}
1731	spin_unlock(&clp->cl_lock);
1732}
1733
1734static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp,
1735	int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1736{
1737	struct nfs_server *server;
1738
1739	rcu_read_lock();
1740	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1741		nfs4_reset_seqids(server, mark_reclaim);
1742	rcu_read_unlock();
1743}
1744
1745static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp)
1746{
1747	/* Mark all delegations for reclaim */
1748	nfs_delegation_mark_reclaim(clp);
1749	nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_reboot);
1750}
1751
1752static int nfs4_reclaim_complete(struct nfs_client *clp,
1753				 const struct nfs4_state_recovery_ops *ops,
1754				 const struct cred *cred)
1755{
1756	/* Notify the server we're done reclaiming our state */
1757	if (ops->reclaim_complete)
1758		return ops->reclaim_complete(clp, cred);
1759	return 0;
1760}
1761
1762static void nfs4_clear_reclaim_server(struct nfs_server *server)
1763{
1764	struct nfs_client *clp = server->nfs_client;
1765	struct nfs4_state_owner *sp;
1766	struct rb_node *pos;
1767	struct nfs4_state *state;
1768
1769	spin_lock(&clp->cl_lock);
1770	for (pos = rb_first(&server->state_owners);
1771	     pos != NULL;
1772	     pos = rb_next(pos)) {
1773		sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1774		spin_lock(&sp->so_lock);
1775		list_for_each_entry(state, &sp->so_states, open_states) {
1776			if (!test_and_clear_bit(NFS_STATE_RECLAIM_REBOOT,
1777						&state->flags))
1778				continue;
1779			nfs4_state_mark_reclaim_nograce(clp, state);
1780		}
1781		spin_unlock(&sp->so_lock);
1782	}
1783	spin_unlock(&clp->cl_lock);
1784}
1785
1786static int nfs4_state_clear_reclaim_reboot(struct nfs_client *clp)
1787{
1788	struct nfs_server *server;
1789
1790	if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
1791		return 0;
1792
1793	rcu_read_lock();
1794	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1795		nfs4_clear_reclaim_server(server);
1796	rcu_read_unlock();
1797
1798	nfs_delegation_reap_unclaimed(clp);
1799	return 1;
1800}
1801
1802static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
1803{
1804	const struct nfs4_state_recovery_ops *ops;
1805	const struct cred *cred;
1806	int err;
1807
1808	if (!nfs4_state_clear_reclaim_reboot(clp))
1809		return;
1810	ops = clp->cl_mvops->reboot_recovery_ops;
1811	cred = nfs4_get_clid_cred(clp);
1812	err = nfs4_reclaim_complete(clp, ops, cred);
1813	put_cred(cred);
1814	if (err == -NFS4ERR_CONN_NOT_BOUND_TO_SESSION)
1815		set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1816}
1817
1818static void nfs4_state_start_reclaim_nograce(struct nfs_client *clp)
1819{
1820	nfs_mark_test_expired_all_delegations(clp);
1821	nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
1822}
1823
1824static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
1825{
1826	switch (error) {
1827	case 0:
1828		break;
1829	case -NFS4ERR_CB_PATH_DOWN:
1830		nfs40_handle_cb_pathdown(clp);
1831		break;
1832	case -NFS4ERR_NO_GRACE:
1833		nfs4_state_end_reclaim_reboot(clp);
1834		break;
1835	case -NFS4ERR_STALE_CLIENTID:
1836		set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1837		nfs4_state_start_reclaim_reboot(clp);
1838		break;
1839	case -NFS4ERR_EXPIRED:
1840		set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1841		nfs4_state_start_reclaim_nograce(clp);
1842		break;
1843	case -NFS4ERR_BADSESSION:
1844	case -NFS4ERR_BADSLOT:
1845	case -NFS4ERR_BAD_HIGH_SLOT:
1846	case -NFS4ERR_DEADSESSION:
1847	case -NFS4ERR_SEQ_FALSE_RETRY:
1848	case -NFS4ERR_SEQ_MISORDERED:
1849		set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
1850		/* Zero session reset errors */
1851		break;
1852	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1853		set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
1854		break;
1855	default:
1856		dprintk("%s: failed to handle error %d for server %s\n",
1857				__func__, error, clp->cl_hostname);
1858		return error;
1859	}
1860	dprintk("%s: handled error %d for server %s\n", __func__, error,
1861			clp->cl_hostname);
1862	return 0;
1863}
1864
1865static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recovery_ops *ops)
1866{
1867	struct nfs4_state_owner *sp;
1868	struct nfs_server *server;
1869	struct rb_node *pos;
1870	LIST_HEAD(freeme);
1871	int status = 0;
1872
1873restart:
1874	rcu_read_lock();
1875	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1876		nfs4_purge_state_owners(server, &freeme);
1877		spin_lock(&clp->cl_lock);
1878		for (pos = rb_first(&server->state_owners);
1879		     pos != NULL;
1880		     pos = rb_next(pos)) {
1881			sp = rb_entry(pos,
1882				struct nfs4_state_owner, so_server_node);
1883			if (!test_and_clear_bit(ops->owner_flag_bit,
1884							&sp->so_flags))
1885				continue;
1886			if (!atomic_inc_not_zero(&sp->so_count))
1887				continue;
1888			spin_unlock(&clp->cl_lock);
1889			rcu_read_unlock();
1890
1891			status = nfs4_reclaim_open_state(sp, ops);
1892			if (status < 0) {
1893				set_bit(ops->owner_flag_bit, &sp->so_flags);
1894				nfs4_put_state_owner(sp);
1895				status = nfs4_recovery_handle_error(clp, status);
1896				return (status != 0) ? status : -EAGAIN;
1897			}
1898
1899			nfs4_put_state_owner(sp);
1900			goto restart;
1901		}
1902		spin_unlock(&clp->cl_lock);
1903	}
1904	rcu_read_unlock();
1905	nfs4_free_state_owners(&freeme);
1906	return 0;
1907}
1908
1909static int nfs4_check_lease(struct nfs_client *clp)
1910{
1911	const struct cred *cred;
1912	const struct nfs4_state_maintenance_ops *ops =
1913		clp->cl_mvops->state_renewal_ops;
1914	int status;
1915
1916	/* Is the client already known to have an expired lease? */
1917	if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1918		return 0;
1919	cred = ops->get_state_renewal_cred(clp);
1920	if (cred == NULL) {
1921		cred = nfs4_get_clid_cred(clp);
1922		status = -ENOKEY;
1923		if (cred == NULL)
1924			goto out;
1925	}
1926	status = ops->renew_lease(clp, cred);
1927	put_cred(cred);
1928	if (status == -ETIMEDOUT) {
1929		set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1930		return 0;
1931	}
1932out:
1933	return nfs4_recovery_handle_error(clp, status);
1934}
1935
1936/* Set NFS4CLNT_LEASE_EXPIRED and reclaim reboot state for all v4.0 errors
1937 * and for recoverable errors on EXCHANGE_ID for v4.1
1938 */
1939static int nfs4_handle_reclaim_lease_error(struct nfs_client *clp, int status)
1940{
1941	switch (status) {
1942	case -NFS4ERR_SEQ_MISORDERED:
1943		if (test_and_set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state))
1944			return -ESERVERFAULT;
1945		/* Lease confirmation error: retry after purging the lease */
1946		ssleep(1);
1947		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1948		break;
1949	case -NFS4ERR_STALE_CLIENTID:
1950		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1951		nfs4_state_start_reclaim_reboot(clp);
1952		break;
1953	case -NFS4ERR_CLID_INUSE:
1954		pr_err("NFS: Server %s reports our clientid is in use\n",
1955			clp->cl_hostname);
1956		nfs_mark_client_ready(clp, -EPERM);
1957		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1958		return -EPERM;
1959	case -EACCES:
1960	case -NFS4ERR_DELAY:
1961	case -EAGAIN:
1962		ssleep(1);
1963		break;
1964
1965	case -NFS4ERR_MINOR_VERS_MISMATCH:
1966		if (clp->cl_cons_state == NFS_CS_SESSION_INITING)
1967			nfs_mark_client_ready(clp, -EPROTONOSUPPORT);
1968		dprintk("%s: exit with error %d for server %s\n",
1969				__func__, -EPROTONOSUPPORT, clp->cl_hostname);
1970		return -EPROTONOSUPPORT;
1971	case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
1972				 * in nfs4_exchange_id */
1973	default:
1974		dprintk("%s: exit with error %d for server %s\n", __func__,
1975				status, clp->cl_hostname);
1976		return status;
1977	}
1978	set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1979	dprintk("%s: handled error %d for server %s\n", __func__, status,
1980			clp->cl_hostname);
1981	return 0;
1982}
1983
1984static int nfs4_establish_lease(struct nfs_client *clp)
1985{
1986	const struct cred *cred;
1987	const struct nfs4_state_recovery_ops *ops =
1988		clp->cl_mvops->reboot_recovery_ops;
1989	int status;
1990
1991	status = nfs4_begin_drain_session(clp);
1992	if (status != 0)
1993		return status;
1994	cred = nfs4_get_clid_cred(clp);
1995	if (cred == NULL)
1996		return -ENOENT;
1997	status = ops->establish_clid(clp, cred);
1998	put_cred(cred);
1999	if (status != 0)
2000		return status;
2001	pnfs_destroy_all_layouts(clp);
2002	return 0;
2003}
2004
2005/*
2006 * Returns zero or a negative errno.  NFS4ERR values are converted
2007 * to local errno values.
2008 */
2009static int nfs4_reclaim_lease(struct nfs_client *clp)
2010{
2011	int status;
2012
2013	status = nfs4_establish_lease(clp);
2014	if (status < 0)
2015		return nfs4_handle_reclaim_lease_error(clp, status);
2016	if (test_and_clear_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH, &clp->cl_state))
2017		nfs4_state_start_reclaim_nograce(clp);
2018	if (!test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
2019		set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
2020	clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2021	clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2022	return 0;
2023}
2024
2025static int nfs4_purge_lease(struct nfs_client *clp)
2026{
2027	int status;
2028
2029	status = nfs4_establish_lease(clp);
2030	if (status < 0)
2031		return nfs4_handle_reclaim_lease_error(clp, status);
2032	clear_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2033	set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2034	nfs4_state_start_reclaim_nograce(clp);
2035	return 0;
2036}
2037
2038/*
2039 * Try remote migration of one FSID from a source server to a
2040 * destination server.  The source server provides a list of
2041 * potential destinations.
2042 *
2043 * Returns zero or a negative NFS4ERR status code.
2044 */
2045static int nfs4_try_migration(struct nfs_server *server, const struct cred *cred)
2046{
2047	struct nfs_client *clp = server->nfs_client;
2048	struct nfs4_fs_locations *locations = NULL;
2049	struct inode *inode;
2050	struct page *page;
2051	int status, result;
2052
2053	dprintk("--> %s: FSID %llx:%llx on \"%s\"\n", __func__,
2054			(unsigned long long)server->fsid.major,
2055			(unsigned long long)server->fsid.minor,
2056			clp->cl_hostname);
2057
2058	result = 0;
2059	page = alloc_page(GFP_KERNEL);
2060	locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
2061	if (page == NULL || locations == NULL) {
2062		dprintk("<-- %s: no memory\n", __func__);
2063		goto out;
2064	}
2065
2066	inode = d_inode(server->super->s_root);
2067	result = nfs4_proc_get_locations(inode, locations, page, cred);
2068	if (result) {
2069		dprintk("<-- %s: failed to retrieve fs_locations: %d\n",
2070			__func__, result);
2071		goto out;
2072	}
2073
2074	result = -NFS4ERR_NXIO;
2075	if (!(locations->fattr.valid & NFS_ATTR_FATTR_V4_LOCATIONS)) {
2076		dprintk("<-- %s: No fs_locations data, migration skipped\n",
2077			__func__);
2078		goto out;
2079	}
2080
2081	status = nfs4_begin_drain_session(clp);
2082	if (status != 0) {
2083		result = status;
2084		goto out;
2085	}
2086
2087	status = nfs4_replace_transport(server, locations);
2088	if (status != 0) {
2089		dprintk("<-- %s: failed to replace transport: %d\n",
2090			__func__, status);
2091		goto out;
2092	}
2093
2094	result = 0;
2095	dprintk("<-- %s: migration succeeded\n", __func__);
2096
2097out:
2098	if (page != NULL)
2099		__free_page(page);
2100	kfree(locations);
2101	if (result) {
2102		pr_err("NFS: migration recovery failed (server %s)\n",
2103				clp->cl_hostname);
2104		set_bit(NFS_MIG_FAILED, &server->mig_status);
2105	}
2106	return result;
2107}
2108
2109/*
2110 * Returns zero or a negative NFS4ERR status code.
2111 */
2112static int nfs4_handle_migration(struct nfs_client *clp)
2113{
2114	const struct nfs4_state_maintenance_ops *ops =
2115				clp->cl_mvops->state_renewal_ops;
2116	struct nfs_server *server;
2117	const struct cred *cred;
2118
2119	dprintk("%s: migration reported on \"%s\"\n", __func__,
2120			clp->cl_hostname);
2121
2122	cred = ops->get_state_renewal_cred(clp);
2123	if (cred == NULL)
2124		return -NFS4ERR_NOENT;
2125
2126	clp->cl_mig_gen++;
2127restart:
2128	rcu_read_lock();
2129	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2130		int status;
2131
2132		if (server->mig_gen == clp->cl_mig_gen)
2133			continue;
2134		server->mig_gen = clp->cl_mig_gen;
2135
2136		if (!test_and_clear_bit(NFS_MIG_IN_TRANSITION,
2137						&server->mig_status))
2138			continue;
2139
2140		rcu_read_unlock();
2141		status = nfs4_try_migration(server, cred);
2142		if (status < 0) {
2143			put_cred(cred);
2144			return status;
2145		}
2146		goto restart;
2147	}
2148	rcu_read_unlock();
2149	put_cred(cred);
2150	return 0;
2151}
2152
2153/*
2154 * Test each nfs_server on the clp's cl_superblocks list to see
2155 * if it's moved to another server.  Stop when the server no longer
2156 * returns NFS4ERR_LEASE_MOVED.
2157 */
2158static int nfs4_handle_lease_moved(struct nfs_client *clp)
2159{
2160	const struct nfs4_state_maintenance_ops *ops =
2161				clp->cl_mvops->state_renewal_ops;
2162	struct nfs_server *server;
2163	const struct cred *cred;
2164
2165	dprintk("%s: lease moved reported on \"%s\"\n", __func__,
2166			clp->cl_hostname);
2167
2168	cred = ops->get_state_renewal_cred(clp);
2169	if (cred == NULL)
2170		return -NFS4ERR_NOENT;
2171
2172	clp->cl_mig_gen++;
2173restart:
2174	rcu_read_lock();
2175	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2176		struct inode *inode;
2177		int status;
2178
2179		if (server->mig_gen == clp->cl_mig_gen)
2180			continue;
2181		server->mig_gen = clp->cl_mig_gen;
2182
2183		rcu_read_unlock();
2184
2185		inode = d_inode(server->super->s_root);
2186		status = nfs4_proc_fsid_present(inode, cred);
2187		if (status != -NFS4ERR_MOVED)
2188			goto restart;	/* wasn't this one */
2189		if (nfs4_try_migration(server, cred) == -NFS4ERR_LEASE_MOVED)
2190			goto restart;	/* there are more */
2191		goto out;
2192	}
2193	rcu_read_unlock();
2194
2195out:
2196	put_cred(cred);
2197	return 0;
2198}
2199
2200/**
2201 * nfs4_discover_server_trunking - Detect server IP address trunking
2202 *
2203 * @clp: nfs_client under test
2204 * @result: OUT: found nfs_client, or clp
2205 *
2206 * Returns zero or a negative errno.  If zero is returned,
2207 * an nfs_client pointer is planted in "result".
2208 *
2209 * Note: since we are invoked in process context, and
2210 * not from inside the state manager, we cannot use
2211 * nfs4_handle_reclaim_lease_error().
2212 */
2213int nfs4_discover_server_trunking(struct nfs_client *clp,
2214				  struct nfs_client **result)
2215{
2216	const struct nfs4_state_recovery_ops *ops =
2217				clp->cl_mvops->reboot_recovery_ops;
2218	struct rpc_clnt *clnt;
2219	const struct cred *cred;
2220	int i, status;
2221
2222	dprintk("NFS: %s: testing '%s'\n", __func__, clp->cl_hostname);
2223
2224	clnt = clp->cl_rpcclient;
2225	i = 0;
2226
2227	mutex_lock(&nfs_clid_init_mutex);
2228again:
2229	status  = -ENOENT;
2230	cred = nfs4_get_clid_cred(clp);
2231	if (cred == NULL)
2232		goto out_unlock;
2233
2234	status = ops->detect_trunking(clp, result, cred);
2235	put_cred(cred);
2236	switch (status) {
2237	case 0:
2238	case -EINTR:
2239	case -ERESTARTSYS:
2240		break;
2241	case -ETIMEDOUT:
2242		if (clnt->cl_softrtry)
2243			break;
2244		/* Fall through */
2245	case -NFS4ERR_DELAY:
2246	case -EAGAIN:
2247		ssleep(1);
2248		/* Fall through */
2249	case -NFS4ERR_STALE_CLIENTID:
2250		dprintk("NFS: %s after status %d, retrying\n",
2251			__func__, status);
2252		goto again;
2253	case -EACCES:
2254		if (i++ == 0) {
2255			nfs4_root_machine_cred(clp);
2256			goto again;
2257		}
2258		if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX)
2259			break;
2260		/* Fall through */
2261	case -NFS4ERR_CLID_INUSE:
2262	case -NFS4ERR_WRONGSEC:
2263		/* No point in retrying if we already used RPC_AUTH_UNIX */
2264		if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX) {
2265			status = -EPERM;
2266			break;
2267		}
2268		clnt = rpc_clone_client_set_auth(clnt, RPC_AUTH_UNIX);
2269		if (IS_ERR(clnt)) {
2270			status = PTR_ERR(clnt);
2271			break;
2272		}
2273		/* Note: this is safe because we haven't yet marked the
2274		 * client as ready, so we are the only user of
2275		 * clp->cl_rpcclient
2276		 */
2277		clnt = xchg(&clp->cl_rpcclient, clnt);
2278		rpc_shutdown_client(clnt);
2279		clnt = clp->cl_rpcclient;
2280		goto again;
2281
2282	case -NFS4ERR_MINOR_VERS_MISMATCH:
2283		status = -EPROTONOSUPPORT;
2284		break;
2285
2286	case -EKEYEXPIRED:
2287	case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
2288				 * in nfs4_exchange_id */
2289		status = -EKEYEXPIRED;
2290		break;
2291	default:
2292		pr_warn("NFS: %s unhandled error %d. Exiting with error EIO\n",
2293				__func__, status);
2294		status = -EIO;
2295	}
2296
2297out_unlock:
2298	mutex_unlock(&nfs_clid_init_mutex);
2299	dprintk("NFS: %s: status = %d\n", __func__, status);
2300	return status;
2301}
2302
2303#ifdef CONFIG_NFS_V4_1
2304void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
2305{
2306	struct nfs_client *clp = session->clp;
2307
2308	switch (err) {
2309	default:
2310		set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2311		break;
2312	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
2313		set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2314	}
2315	nfs4_schedule_state_manager(clp);
2316}
2317EXPORT_SYMBOL_GPL(nfs4_schedule_session_recovery);
2318
2319void nfs41_notify_server(struct nfs_client *clp)
2320{
2321	/* Use CHECK_LEASE to ping the server with a SEQUENCE */
2322	set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2323	nfs4_schedule_state_manager(clp);
2324}
2325
2326static void nfs4_reset_all_state(struct nfs_client *clp)
2327{
2328	if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2329		set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2330		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2331		nfs4_state_start_reclaim_nograce(clp);
2332		dprintk("%s: scheduling reset of all state for server %s!\n",
2333				__func__, clp->cl_hostname);
2334		nfs4_schedule_state_manager(clp);
2335	}
2336}
2337
2338static void nfs41_handle_server_reboot(struct nfs_client *clp)
2339{
2340	if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2341		nfs4_state_start_reclaim_reboot(clp);
2342		dprintk("%s: server %s rebooted!\n", __func__,
2343				clp->cl_hostname);
2344		nfs4_schedule_state_manager(clp);
2345	}
2346}
2347
2348static void nfs41_handle_all_state_revoked(struct nfs_client *clp)
2349{
2350	nfs4_reset_all_state(clp);
2351	dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2352}
2353
2354static void nfs41_handle_some_state_revoked(struct nfs_client *clp)
2355{
2356	nfs4_state_start_reclaim_nograce(clp);
2357	nfs4_schedule_state_manager(clp);
2358
2359	dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2360}
2361
2362static void nfs41_handle_recallable_state_revoked(struct nfs_client *clp)
2363{
2364	/* FIXME: For now, we destroy all layouts. */
2365	pnfs_destroy_all_layouts(clp);
2366	nfs_test_expired_all_delegations(clp);
2367	dprintk("%s: Recallable state revoked on server %s!\n", __func__,
2368			clp->cl_hostname);
2369}
2370
2371static void nfs41_handle_backchannel_fault(struct nfs_client *clp)
2372{
2373	set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2374	nfs4_schedule_state_manager(clp);
2375
2376	dprintk("%s: server %s declared a backchannel fault\n", __func__,
2377			clp->cl_hostname);
2378}
2379
2380static void nfs41_handle_cb_path_down(struct nfs_client *clp)
2381{
2382	if (test_and_set_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2383		&clp->cl_state) == 0)
2384		nfs4_schedule_state_manager(clp);
2385}
2386
2387void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags,
2388		bool recovery)
2389{
2390	if (!flags)
2391		return;
2392
2393	dprintk("%s: \"%s\" (client ID %llx) flags=0x%08x\n",
2394		__func__, clp->cl_hostname, clp->cl_clientid, flags);
2395	/*
2396	 * If we're called from the state manager thread, then assume we're
2397	 * already handling the RECLAIM_NEEDED and/or STATE_REVOKED.
2398	 * Those flags are expected to remain set until we're done
2399	 * recovering (see RFC5661, section 18.46.3).
2400	 */
2401	if (recovery)
2402		goto out_recovery;
2403
2404	if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED)
2405		nfs41_handle_server_reboot(clp);
2406	if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED))
2407		nfs41_handle_all_state_revoked(clp);
2408	if (flags & (SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED |
2409			    SEQ4_STATUS_ADMIN_STATE_REVOKED))
2410		nfs41_handle_some_state_revoked(clp);
2411	if (flags & SEQ4_STATUS_LEASE_MOVED)
2412		nfs4_schedule_lease_moved_recovery(clp);
2413	if (flags & SEQ4_STATUS_RECALLABLE_STATE_REVOKED)
2414		nfs41_handle_recallable_state_revoked(clp);
2415out_recovery:
2416	if (flags & SEQ4_STATUS_BACKCHANNEL_FAULT)
2417		nfs41_handle_backchannel_fault(clp);
2418	else if (flags & (SEQ4_STATUS_CB_PATH_DOWN |
2419				SEQ4_STATUS_CB_PATH_DOWN_SESSION))
2420		nfs41_handle_cb_path_down(clp);
2421}
2422
2423static int nfs4_reset_session(struct nfs_client *clp)
2424{
2425	const struct cred *cred;
2426	int status;
2427
2428	if (!nfs4_has_session(clp))
2429		return 0;
2430	status = nfs4_begin_drain_session(clp);
2431	if (status != 0)
2432		return status;
2433	cred = nfs4_get_clid_cred(clp);
2434	status = nfs4_proc_destroy_session(clp->cl_session, cred);
2435	switch (status) {
2436	case 0:
2437	case -NFS4ERR_BADSESSION:
2438	case -NFS4ERR_DEADSESSION:
2439		break;
2440	case -NFS4ERR_BACK_CHAN_BUSY:
2441	case -NFS4ERR_DELAY:
2442		set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2443		status = 0;
2444		ssleep(1);
2445		goto out;
2446	default:
2447		status = nfs4_recovery_handle_error(clp, status);
2448		goto out;
2449	}
2450
2451	memset(clp->cl_session->sess_id.data, 0, NFS4_MAX_SESSIONID_LEN);
2452	status = nfs4_proc_create_session(clp, cred);
2453	if (status) {
2454		dprintk("%s: session reset failed with status %d for server %s!\n",
2455			__func__, status, clp->cl_hostname);
2456		status = nfs4_handle_reclaim_lease_error(clp, status);
2457		goto out;
2458	}
2459	nfs41_finish_session_reset(clp);
2460	dprintk("%s: session reset was successful for server %s!\n",
2461			__func__, clp->cl_hostname);
2462out:
2463	put_cred(cred);
2464	return status;
2465}
2466
2467static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2468{
2469	const struct cred *cred;
2470	int ret;
2471
2472	if (!nfs4_has_session(clp))
2473		return 0;
2474	ret = nfs4_begin_drain_session(clp);
2475	if (ret != 0)
2476		return ret;
2477	cred = nfs4_get_clid_cred(clp);
2478	ret = nfs4_proc_bind_conn_to_session(clp, cred);
2479	put_cred(cred);
2480	clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2481	switch (ret) {
2482	case 0:
2483		dprintk("%s: bind_conn_to_session was successful for server %s!\n",
2484			__func__, clp->cl_hostname);
2485		break;
2486	case -NFS4ERR_DELAY:
2487		ssleep(1);
2488		set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2489		break;
2490	default:
2491		return nfs4_recovery_handle_error(clp, ret);
2492	}
2493	return 0;
2494}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2495#else /* CONFIG_NFS_V4_1 */
2496static int nfs4_reset_session(struct nfs_client *clp) { return 0; }
2497
2498static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2499{
2500	return 0;
2501}
 
 
 
 
2502#endif /* CONFIG_NFS_V4_1 */
2503
2504static void nfs4_state_manager(struct nfs_client *clp)
2505{
2506	int status = 0;
2507	const char *section = "", *section_sep = "";
2508
2509	/* Ensure exclusive access to NFSv4 state */
2510	do {
 
2511		clear_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2512		if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
2513			section = "purge state";
2514			status = nfs4_purge_lease(clp);
2515			if (status < 0)
2516				goto out_error;
2517			continue;
2518		}
2519
2520		if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
2521			section = "lease expired";
2522			/* We're going to have to re-establish a clientid */
2523			status = nfs4_reclaim_lease(clp);
2524			if (status < 0)
2525				goto out_error;
2526			continue;
2527		}
2528
2529		/* Initialize or reset the session */
2530		if (test_and_clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state)) {
2531			section = "reset session";
2532			status = nfs4_reset_session(clp);
2533			if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
2534				continue;
2535			if (status < 0)
2536				goto out_error;
2537		}
2538
2539		/* Send BIND_CONN_TO_SESSION */
2540		if (test_and_clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2541				&clp->cl_state)) {
2542			section = "bind conn to session";
2543			status = nfs4_bind_conn_to_session(clp);
2544			if (status < 0)
2545				goto out_error;
2546			continue;
2547		}
2548
2549		if (test_and_clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state)) {
2550			section = "check lease";
2551			status = nfs4_check_lease(clp);
2552			if (status < 0)
2553				goto out_error;
2554			continue;
2555		}
2556
2557		if (test_and_clear_bit(NFS4CLNT_MOVED, &clp->cl_state)) {
2558			section = "migration";
2559			status = nfs4_handle_migration(clp);
2560			if (status < 0)
2561				goto out_error;
2562		}
2563
2564		if (test_and_clear_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state)) {
2565			section = "lease moved";
2566			status = nfs4_handle_lease_moved(clp);
2567			if (status < 0)
2568				goto out_error;
2569		}
2570
2571		/* First recover reboot state... */
2572		if (test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {
2573			section = "reclaim reboot";
2574			status = nfs4_do_reclaim(clp,
2575				clp->cl_mvops->reboot_recovery_ops);
2576			if (status == -EAGAIN)
2577				continue;
2578			if (status < 0)
2579				goto out_error;
2580			nfs4_state_end_reclaim_reboot(clp);
2581		}
2582
2583		/* Detect expired delegations... */
2584		if (test_and_clear_bit(NFS4CLNT_DELEGATION_EXPIRED, &clp->cl_state)) {
2585			section = "detect expired delegations";
2586			nfs_reap_expired_delegations(clp);
2587			continue;
2588		}
2589
2590		/* Now recover expired state... */
2591		if (test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state)) {
2592			section = "reclaim nograce";
2593			status = nfs4_do_reclaim(clp,
2594				clp->cl_mvops->nograce_recovery_ops);
2595			if (status == -EAGAIN)
2596				continue;
2597			if (status < 0)
2598				goto out_error;
2599			clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
2600		}
2601
2602		nfs4_end_drain_session(clp);
2603		nfs4_clear_state_manager_bit(clp);
2604
2605		if (!test_and_set_bit(NFS4CLNT_DELEGRETURN_RUNNING, &clp->cl_state)) {
2606			if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
2607				nfs_client_return_marked_delegations(clp);
2608				set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2609			}
2610			clear_bit(NFS4CLNT_DELEGRETURN_RUNNING, &clp->cl_state);
 
2611		}
2612
2613		/* Did we race with an attempt to give us more work? */
2614		if (!test_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state))
2615			return;
2616		if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
2617			return;
2618	} while (refcount_read(&clp->cl_count) > 1 && !signalled());
2619	goto out_drain;
2620
2621out_error:
2622	if (strlen(section))
2623		section_sep = ": ";
 
2624	pr_warn_ratelimited("NFS: state manager%s%s failed on NFSv4 server %s"
2625			" with error %d\n", section_sep, section,
2626			clp->cl_hostname, -status);
2627	ssleep(1);
2628out_drain:
2629	nfs4_end_drain_session(clp);
2630	nfs4_clear_state_manager_bit(clp);
2631}
2632
2633static int nfs4_run_state_manager(void *ptr)
2634{
2635	struct nfs_client *clp = ptr;
2636
2637	allow_signal(SIGKILL);
2638	nfs4_state_manager(clp);
2639	nfs_put_client(clp);
2640	module_put_and_exit(0);
2641	return 0;
2642}
2643
2644/*
2645 * Local variables:
2646 *  c-basic-offset: 8
2647 * End:
2648 */