fs/nfs/nfs4state.c

   1 /*
   2  *  fs/nfs/nfs4state.c
   3  *
   4  *  Client-side XDR for NFSv4.
   5  *
   6  *  Copyright (c) 2002 The Regents of the University of Michigan.
   7  *  All rights reserved.
   8  *
   9  *  Kendrick Smith <kmsmith@umich.edu>
  10  *
  11  *  Redistribution and use in source and binary forms, with or without
  12  *  modification, are permitted provided that the following conditions
  13  *  are met:
  14  *
  15  *  1. Redistributions of source code must retain the above copyright
  16  *     notice, this list of conditions and the following disclaimer.
  17  *  2. Redistributions in binary form must reproduce the above copyright
  18  *     notice, this list of conditions and the following disclaimer in the
  19  *     documentation and/or other materials provided with the distribution.
  20  *  3. Neither the name of the University nor the names of its
  21  *     contributors may be used to endorse or promote products derived
  22  *     from this software without specific prior written permission.
  23  *
  24  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  25  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  26  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  27  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  31  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  32  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  33  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  34  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35  *
  36  * Implementation of the NFSv4 state model.  For the time being,
  37  * this is minimal, but will be made much more complex in a
  38  * subsequent patch.
  39  */
  40
  41 #include <linux/kernel.h>
  42 #include <linux/slab.h>
  43 #include <linux/fs.h>
  44 #include <linux/nfs_fs.h>
  45 #include <linux/kthread.h>
  46 #include <linux/module.h>
  47 #include <linux/random.h>
  48 #include <linux/ratelimit.h>
  49 #include <linux/workqueue.h>
  50 #include <linux/bitops.h>
  51 #include <linux/jiffies.h>
  52 #include <linux/sched/mm.h>
  53
  54 #include <linux/sunrpc/clnt.h>
  55
  56 #include "nfs4_fs.h"
  57 #include "callback.h"
  58 #include "delegation.h"
  59 #include "internal.h"
  60 #include "nfs4idmap.h"
  61 #include "nfs4session.h"
  62 #include "pnfs.h"
  63 #include "netns.h"
  64 #include "nfs4trace.h"
  65
  66 #define NFSDBG_FACILITY         NFSDBG_STATE
  67
  68 #define OPENOWNER_POOL_SIZE     8
  69
  70 static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp);
  71
  72 const nfs4_stateid zero_stateid = {
  73         { .data = { 0 } },
  74         .type = NFS4_SPECIAL_STATEID_TYPE,
  75 };
  76 const nfs4_stateid invalid_stateid = {
  77         {
  78                 /* Funky initialiser keeps older gcc versions happy */
  79                 .data = { 0xff, 0xff, 0xff, 0xff, 0 },
  80         },
  81         .type = NFS4_INVALID_STATEID_TYPE,
  82 };
  83
  84 const nfs4_stateid current_stateid = {
  85         {
  86                 /* Funky initialiser keeps older gcc versions happy */
  87                 .data = { 0x0, 0x0, 0x0, 0x1, 0 },
  88         },
  89         .type = NFS4_SPECIAL_STATEID_TYPE,
  90 };
  91
  92 static DEFINE_MUTEX(nfs_clid_init_mutex);
  93
  94 static int nfs4_setup_state_renewal(struct nfs_client *clp)
  95 {
  96         int status;
  97         struct nfs_fsinfo fsinfo;
  98
  99         if (!test_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state)) {
 100                 nfs4_schedule_state_renewal(clp);
 101                 return 0;
 102         }
 103
 104         status = nfs4_proc_get_lease_time(clp, &fsinfo);
 105         if (status == 0) {
 106                 nfs4_set_lease_period(clp, fsinfo.lease_time * HZ);
 107                 nfs4_schedule_state_renewal(clp);
 108         }
 109
 110         return status;
 111 }
 112
 113 int nfs4_init_clientid(struct nfs_client *clp, const struct cred *cred)
 114 {
 115         struct nfs4_setclientid_res clid = {
 116                 .clientid = clp->cl_clientid,
 117                 .confirm = clp->cl_confirm,
 118         };
 119         unsigned short port;
 120         int status;
 121         struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
 122
 123         if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
 124                 goto do_confirm;
 125         port = nn->nfs_callback_tcpport;
 126         if (clp->cl_addr.ss_family == AF_INET6)
 127                 port = nn->nfs_callback_tcpport6;
 128
 129         status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
 130         if (status != 0)
 131                 goto out;
 132         clp->cl_clientid = clid.clientid;
 133         clp->cl_confirm = clid.confirm;
 134         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 135 do_confirm:
 136         status = nfs4_proc_setclientid_confirm(clp, &clid, cred);
 137         if (status != 0)
 138                 goto out;
 139         clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 140         nfs4_setup_state_renewal(clp);
 141 out:
 142         return status;
 143 }
 144
 145 /**
 146  * nfs40_discover_server_trunking - Detect server IP address trunking (mv0)
 147  *
 148  * @clp: nfs_client under test
 149  * @result: OUT: found nfs_client, or clp
 150  * @cred: credential to use for trunking test
 151  *
 152  * Returns zero, a negative errno, or a negative NFS4ERR status.
 153  * If zero is returned, an nfs_client pointer is planted in
 154  * "result".
 155  *
 156  * Note: The returned client may not yet be marked ready.
 157  */
 158 int nfs40_discover_server_trunking(struct nfs_client *clp,
 159                                    struct nfs_client **result,
 160                                    const struct cred *cred)
 161 {
 162         struct nfs4_setclientid_res clid = {
 163                 .clientid = clp->cl_clientid,
 164                 .confirm = clp->cl_confirm,
 165         };
 166         struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
 167         unsigned short port;
 168         int status;
 169
 170         port = nn->nfs_callback_tcpport;
 171         if (clp->cl_addr.ss_family == AF_INET6)
 172                 port = nn->nfs_callback_tcpport6;
 173
 174         status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
 175         if (status != 0)
 176                 goto out;
 177         clp->cl_clientid = clid.clientid;
 178         clp->cl_confirm = clid.confirm;
 179
 180         status = nfs40_walk_client_list(clp, result, cred);
 181         if (status == 0) {
 182                 /* Sustain the lease, even if it's empty.  If the clientid4
 183                  * goes stale it's of no use for trunking discovery. */
 184                 nfs4_schedule_state_renewal(*result);
 185
 186                 /* If the client state need to recover, do it. */
 187                 if (clp->cl_state)
 188                         nfs4_schedule_state_manager(clp);
 189         }
 190 out:
 191         return status;
 192 }
 193
 194 const struct cred *nfs4_get_machine_cred(struct nfs_client *clp)
 195 {
 196         return get_cred(rpc_machine_cred());
 197 }
 198
 199 static void nfs4_root_machine_cred(struct nfs_client *clp)
 200 {
 201
 202         /* Force root creds instead of machine */
 203         clp->cl_principal = NULL;
 204         clp->cl_rpcclient->cl_principal = NULL;
 205 }
 206
 207 static const struct cred *
 208 nfs4_get_renew_cred_server_locked(struct nfs_server *server)
 209 {
 210         const struct cred *cred = NULL;
 211         struct nfs4_state_owner *sp;
 212         struct rb_node *pos;
 213
 214         for (pos = rb_first(&server->state_owners);
 215              pos != NULL;
 216              pos = rb_next(pos)) {
 217                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
 218                 if (list_empty(&sp->so_states))
 219                         continue;
 220                 cred = get_cred(sp->so_cred);
 221                 break;
 222         }
 223         return cred;
 224 }
 225
 226 /**
 227  * nfs4_get_renew_cred - Acquire credential for a renew operation
 228  * @clp: client state handle
 229  *
 230  * Returns an rpc_cred with reference count bumped, or NULL.
 231  * Caller must hold clp->cl_lock.
 232  */
 233 const struct cred *nfs4_get_renew_cred(struct nfs_client *clp)
 234 {
 235         const struct cred *cred = NULL;
 236         struct nfs_server *server;
 237
 238         /* Use machine credentials if available */
 239         cred = nfs4_get_machine_cred(clp);
 240         if (cred != NULL)
 241                 goto out;
 242
 243         spin_lock(&clp->cl_lock);
 244         rcu_read_lock();
 245         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 246                 cred = nfs4_get_renew_cred_server_locked(server);
 247                 if (cred != NULL)
 248                         break;
 249         }
 250         rcu_read_unlock();
 251         spin_unlock(&clp->cl_lock);
 252
 253 out:
 254         return cred;
 255 }
 256
 257 static void nfs4_end_drain_slot_table(struct nfs4_slot_table *tbl)
 258 {
 259         if (test_and_clear_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state)) {
 260                 spin_lock(&tbl->slot_tbl_lock);
 261                 nfs41_wake_slot_table(tbl);
 262                 spin_unlock(&tbl->slot_tbl_lock);
 263         }
 264 }
 265
 266 static void nfs4_end_drain_session(struct nfs_client *clp)
 267 {
 268         struct nfs4_session *ses = clp->cl_session;
 269
 270         if (clp->cl_slot_tbl) {
 271                 nfs4_end_drain_slot_table(clp->cl_slot_tbl);
 272                 return;
 273         }
 274
 275         if (ses != NULL) {
 276                 nfs4_end_drain_slot_table(&ses->bc_slot_table);
 277                 nfs4_end_drain_slot_table(&ses->fc_slot_table);
 278         }
 279 }
 280
 281 static int nfs4_drain_slot_tbl(struct nfs4_slot_table *tbl)
 282 {
 283         set_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
 284         spin_lock(&tbl->slot_tbl_lock);
 285         if (tbl->highest_used_slotid != NFS4_NO_SLOT) {
 286                 reinit_completion(&tbl->complete);
 287                 spin_unlock(&tbl->slot_tbl_lock);
 288                 return wait_for_completion_interruptible(&tbl->complete);
 289         }
 290         spin_unlock(&tbl->slot_tbl_lock);
 291         return 0;
 292 }
 293
 294 static int nfs4_begin_drain_session(struct nfs_client *clp)
 295 {
 296         struct nfs4_session *ses = clp->cl_session;
 297         int ret;
 298
 299         if (clp->cl_slot_tbl)
 300                 return nfs4_drain_slot_tbl(clp->cl_slot_tbl);
 301
 302         /* back channel */
 303         ret = nfs4_drain_slot_tbl(&ses->bc_slot_table);
 304         if (ret)
 305                 return ret;
 306         /* fore channel */
 307         return nfs4_drain_slot_tbl(&ses->fc_slot_table);
 308 }
 309
 310 #if defined(CONFIG_NFS_V4_1)
 311
 312 static void nfs41_finish_session_reset(struct nfs_client *clp)
 313 {
 314         clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 315         clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
 316         /* create_session negotiated new slot table */
 317         clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
 318         nfs4_setup_state_renewal(clp);
 319 }
 320
 321 int nfs41_init_clientid(struct nfs_client *clp, const struct cred *cred)
 322 {
 323         int status;
 324
 325         if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
 326                 goto do_confirm;
 327         status = nfs4_proc_exchange_id(clp, cred);
 328         if (status != 0)
 329                 goto out;
 330         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 331 do_confirm:
 332         status = nfs4_proc_create_session(clp, cred);
 333         if (status != 0)
 334                 goto out;
 335         if (!(clp->cl_exchange_flags & EXCHGID4_FLAG_CONFIRMED_R))
 336                 nfs4_state_start_reclaim_reboot(clp);
 337         nfs41_finish_session_reset(clp);
 338         nfs_mark_client_ready(clp, NFS_CS_READY);
 339 out:
 340         return status;
 341 }
 342
 343 /**
 344  * nfs41_discover_server_trunking - Detect server IP address trunking (mv1)
 345  *
 346  * @clp: nfs_client under test
 347  * @result: OUT: found nfs_client, or clp
 348  * @cred: credential to use for trunking test
 349  *
 350  * Returns NFS4_OK, a negative errno, or a negative NFS4ERR status.
 351  * If NFS4_OK is returned, an nfs_client pointer is planted in
 352  * "result".
 353  *
 354  * Note: The returned client may not yet be marked ready.
 355  */
 356 int nfs41_discover_server_trunking(struct nfs_client *clp,
 357                                    struct nfs_client **result,
 358                                    const struct cred *cred)
 359 {
 360         int status;
 361
 362         status = nfs4_proc_exchange_id(clp, cred);
 363         if (status != NFS4_OK)
 364                 return status;
 365
 366         status = nfs41_walk_client_list(clp, result, cred);
 367         if (status < 0)
 368                 return status;
 369         if (clp != *result)
 370                 return 0;
 371
 372         /*
 373          * Purge state if the client id was established in a prior
 374          * instance and the client id could not have arrived on the
 375          * server via Transparent State Migration.
 376          */
 377         if (clp->cl_exchange_flags & EXCHGID4_FLAG_CONFIRMED_R) {
 378                 if (!test_bit(NFS_CS_TSM_POSSIBLE, &clp->cl_flags))
 379                         set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
 380                 else
 381                         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 382         }
 383         nfs4_schedule_state_manager(clp);
 384         status = nfs_wait_client_init_complete(clp);
 385         if (status < 0)
 386                 nfs_put_client(clp);
 387         return status;
 388 }
 389
 390 #endif /* CONFIG_NFS_V4_1 */
 391
 392 /**
 393  * nfs4_get_clid_cred - Acquire credential for a setclientid operation
 394  * @clp: client state handle
 395  *
 396  * Returns a cred with reference count bumped, or NULL.
 397  */
 398 const struct cred *nfs4_get_clid_cred(struct nfs_client *clp)
 399 {
 400         const struct cred *cred;
 401
 402         cred = nfs4_get_machine_cred(clp);
 403         return cred;
 404 }
 405
 406 static struct nfs4_state_owner *
 407 nfs4_find_state_owner_locked(struct nfs_server *server, const struct cred *cred)
 408 {
 409         struct rb_node **p = &server->state_owners.rb_node,
 410                        *parent = NULL;
 411         struct nfs4_state_owner *sp;
 412         int cmp;
 413
 414         while (*p != NULL) {
 415                 parent = *p;
 416                 sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
 417                 cmp = cred_fscmp(cred, sp->so_cred);
 418
 419                 if (cmp < 0)
 420                         p = &parent->rb_left;
 421                 else if (cmp > 0)
 422                         p = &parent->rb_right;
 423                 else {
 424                         if (!list_empty(&sp->so_lru))
 425                                 list_del_init(&sp->so_lru);
 426                         atomic_inc(&sp->so_count);
 427                         return sp;
 428                 }
 429         }
 430         return NULL;
 431 }
 432
 433 static struct nfs4_state_owner *
 434 nfs4_insert_state_owner_locked(struct nfs4_state_owner *new)
 435 {
 436         struct nfs_server *server = new->so_server;
 437         struct rb_node **p = &server->state_owners.rb_node,
 438                        *parent = NULL;
 439         struct nfs4_state_owner *sp;
 440         int cmp;
 441
 442         while (*p != NULL) {
 443                 parent = *p;
 444                 sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
 445                 cmp = cred_fscmp(new->so_cred, sp->so_cred);
 446
 447                 if (cmp < 0)
 448                         p = &parent->rb_left;
 449                 else if (cmp > 0)
 450                         p = &parent->rb_right;
 451                 else {
 452                         if (!list_empty(&sp->so_lru))
 453                                 list_del_init(&sp->so_lru);
 454                         atomic_inc(&sp->so_count);
 455                         return sp;
 456                 }
 457         }
 458         rb_link_node(&new->so_server_node, parent, p);
 459         rb_insert_color(&new->so_server_node, &server->state_owners);
 460         return new;
 461 }
 462
 463 static void
 464 nfs4_remove_state_owner_locked(struct nfs4_state_owner *sp)
 465 {
 466         struct nfs_server *server = sp->so_server;
 467
 468         if (!RB_EMPTY_NODE(&sp->so_server_node))
 469                 rb_erase(&sp->so_server_node, &server->state_owners);
 470 }
 471
 472 static void
 473 nfs4_init_seqid_counter(struct nfs_seqid_counter *sc)
 474 {
 475         sc->create_time = ktime_get();
 476         sc->flags = 0;
 477         sc->counter = 0;
 478         spin_lock_init(&sc->lock);
 479         INIT_LIST_HEAD(&sc->list);
 480         rpc_init_wait_queue(&sc->wait, "Seqid_waitqueue");
 481 }
 482
 483 static void
 484 nfs4_destroy_seqid_counter(struct nfs_seqid_counter *sc)
 485 {
 486         rpc_destroy_wait_queue(&sc->wait);
 487 }
 488
 489 /*
 490  * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
 491  * create a new state_owner.
 492  *
 493  */
 494 static struct nfs4_state_owner *
 495 nfs4_alloc_state_owner(struct nfs_server *server,
 496                 const struct cred *cred,
 497                 gfp_t gfp_flags)
 498 {
 499         struct nfs4_state_owner *sp;
 500
 501         sp = kzalloc(sizeof(*sp), gfp_flags);
 502         if (!sp)
 503                 return NULL;
 504         sp->so_seqid.owner_id = ida_alloc(&server->openowner_id, gfp_flags);
 505         if (sp->so_seqid.owner_id < 0) {
 506                 kfree(sp);
 507                 return NULL;
 508         }
 509         sp->so_server = server;
 510         sp->so_cred = get_cred(cred);
 511         spin_lock_init(&sp->so_lock);
 512         INIT_LIST_HEAD(&sp->so_states);
 513         nfs4_init_seqid_counter(&sp->so_seqid);
 514         atomic_set(&sp->so_count, 1);
 515         INIT_LIST_HEAD(&sp->so_lru);
 516         seqcount_spinlock_init(&sp->so_reclaim_seqcount, &sp->so_lock);
 517         mutex_init(&sp->so_delegreturn_mutex);
 518         return sp;
 519 }
 520
 521 static void
 522 nfs4_reset_state_owner(struct nfs4_state_owner *sp)
 523 {
 524         /* This state_owner is no longer usable, but must
 525          * remain in place so that state recovery can find it
 526          * and the opens associated with it.
 527          * It may also be used for new 'open' request to
 528          * return a delegation to the server.
 529          * So update the 'create_time' so that it looks like
 530          * a new state_owner.  This will cause the server to
 531          * request an OPEN_CONFIRM to start a new sequence.
 532          */
 533         sp->so_seqid.create_time = ktime_get();
 534 }
 535
 536 static void nfs4_free_state_owner(struct nfs4_state_owner *sp)
 537 {
 538         nfs4_destroy_seqid_counter(&sp->so_seqid);
 539         put_cred(sp->so_cred);
 540         ida_free(&sp->so_server->openowner_id, sp->so_seqid.owner_id);
 541         kfree(sp);
 542 }
 543
 544 static void nfs4_gc_state_owners(struct nfs_server *server)
 545 {
 546         struct nfs_client *clp = server->nfs_client;
 547         struct nfs4_state_owner *sp, *tmp;
 548         unsigned long time_min, time_max;
 549         LIST_HEAD(doomed);
 550
 551         spin_lock(&clp->cl_lock);
 552         time_max = jiffies;
 553         time_min = (long)time_max - (long)clp->cl_lease_time;
 554         list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
 555                 /* NB: LRU is sorted so that oldest is at the head */
 556                 if (time_in_range(sp->so_expires, time_min, time_max))
 557                         break;
 558                 list_move(&sp->so_lru, &doomed);
 559                 nfs4_remove_state_owner_locked(sp);
 560         }
 561         spin_unlock(&clp->cl_lock);
 562
 563         list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
 564                 list_del(&sp->so_lru);
 565                 nfs4_free_state_owner(sp);
 566         }
 567 }
 568
 569 /**
 570  * nfs4_get_state_owner - Look up a state owner given a credential
 571  * @server: nfs_server to search
 572  * @cred: RPC credential to match
 573  * @gfp_flags: allocation mode
 574  *
 575  * Returns a pointer to an instantiated nfs4_state_owner struct, or NULL.
 576  */
 577 struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server,
 578                                               const struct cred *cred,
 579                                               gfp_t gfp_flags)
 580 {
 581         struct nfs_client *clp = server->nfs_client;
 582         struct nfs4_state_owner *sp, *new;
 583
 584         spin_lock(&clp->cl_lock);
 585         sp = nfs4_find_state_owner_locked(server, cred);
 586         spin_unlock(&clp->cl_lock);
 587         if (sp != NULL)
 588                 goto out;
 589         new = nfs4_alloc_state_owner(server, cred, gfp_flags);
 590         if (new == NULL)
 591                 goto out;
 592         spin_lock(&clp->cl_lock);
 593         sp = nfs4_insert_state_owner_locked(new);
 594         spin_unlock(&clp->cl_lock);
 595         if (sp != new)
 596                 nfs4_free_state_owner(new);
 597 out:
 598         nfs4_gc_state_owners(server);
 599         return sp;
 600 }
 601
 602 /**
 603  * nfs4_put_state_owner - Release a nfs4_state_owner
 604  * @sp: state owner data to release
 605  *
 606  * Note that we keep released state owners on an LRU
 607  * list.
 608  * This caches valid state owners so that they can be
 609  * reused, to avoid the OPEN_CONFIRM on minor version 0.
 610  * It also pins the uniquifier of dropped state owners for
 611  * a while, to ensure that those state owner names are
 612  * never reused.
 613  */
 614 void nfs4_put_state_owner(struct nfs4_state_owner *sp)
 615 {
 616         struct nfs_server *server = sp->so_server;
 617         struct nfs_client *clp = server->nfs_client;
 618
 619         if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
 620                 return;
 621
 622         sp->so_expires = jiffies;
 623         list_add_tail(&sp->so_lru, &server->state_owners_lru);
 624         spin_unlock(&clp->cl_lock);
 625 }
 626
 627 /**
 628  * nfs4_purge_state_owners - Release all cached state owners
 629  * @server: nfs_server with cached state owners to release
 630  * @head: resulting list of state owners
 631  *
 632  * Called at umount time.  Remaining state owners will be on
 633  * the LRU with ref count of zero.
 634  * Note that the state owners are not freed, but are added
 635  * to the list @head, which can later be used as an argument
 636  * to nfs4_free_state_owners.
 637  */
 638 void nfs4_purge_state_owners(struct nfs_server *server, struct list_head *head)
 639 {
 640         struct nfs_client *clp = server->nfs_client;
 641         struct nfs4_state_owner *sp, *tmp;
 642
 643         spin_lock(&clp->cl_lock);
 644         list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
 645                 list_move(&sp->so_lru, head);
 646                 nfs4_remove_state_owner_locked(sp);
 647         }
 648         spin_unlock(&clp->cl_lock);
 649 }
 650
 651 /**
 652  * nfs4_free_state_owners - Release all cached state owners
 653  * @head: resulting list of state owners
 654  *
 655  * Frees a list of state owners that was generated by
 656  * nfs4_purge_state_owners
 657  */
 658 void nfs4_free_state_owners(struct list_head *head)
 659 {
 660         struct nfs4_state_owner *sp, *tmp;
 661
 662         list_for_each_entry_safe(sp, tmp, head, so_lru) {
 663                 list_del(&sp->so_lru);
 664                 nfs4_free_state_owner(sp);
 665         }
 666 }
 667
 668 static struct nfs4_state *
 669 nfs4_alloc_open_state(void)
 670 {
 671         struct nfs4_state *state;
 672
 673         state = kzalloc(sizeof(*state), GFP_KERNEL_ACCOUNT);
 674         if (!state)
 675                 return NULL;
 676         refcount_set(&state->count, 1);
 677         INIT_LIST_HEAD(&state->lock_states);
 678         spin_lock_init(&state->state_lock);
 679         seqlock_init(&state->seqlock);
 680         init_waitqueue_head(&state->waitq);
 681         return state;
 682 }
 683
 684 void
 685 nfs4_state_set_mode_locked(struct nfs4_state *state, fmode_t fmode)
 686 {
 687         if (state->state == fmode)
 688                 return;
 689         /* NB! List reordering - see the reclaim code for why.  */
 690         if ((fmode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
 691                 if (fmode & FMODE_WRITE)
 692                         list_move(&state->open_states, &state->owner->so_states);
 693                 else
 694                         list_move_tail(&state->open_states, &state->owner->so_states);
 695         }
 696         state->state = fmode;
 697 }
 698
 699 static struct nfs4_state *
 700 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
 701 {
 702         struct nfs_inode *nfsi = NFS_I(inode);
 703         struct nfs4_state *state;
 704
 705         list_for_each_entry_rcu(state, &nfsi->open_states, inode_states) {
 706                 if (state->owner != owner)
 707                         continue;
 708                 if (!nfs4_valid_open_stateid(state))
 709                         continue;
 710                 if (refcount_inc_not_zero(&state->count))
 711                         return state;
 712         }
 713         return NULL;
 714 }
 715
 716 static void
 717 nfs4_free_open_state(struct nfs4_state *state)
 718 {
 719         kfree_rcu(state, rcu_head);
 720 }
 721
 722 struct nfs4_state *
 723 nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
 724 {
 725         struct nfs4_state *state, *new;
 726         struct nfs_inode *nfsi = NFS_I(inode);
 727
 728         rcu_read_lock();
 729         state = __nfs4_find_state_byowner(inode, owner);
 730         rcu_read_unlock();
 731         if (state)
 732                 goto out;
 733         new = nfs4_alloc_open_state();
 734         spin_lock(&owner->so_lock);
 735         spin_lock(&inode->i_lock);
 736         state = __nfs4_find_state_byowner(inode, owner);
 737         if (state == NULL && new != NULL) {
 738                 state = new;
 739                 state->owner = owner;
 740                 atomic_inc(&owner->so_count);
 741                 ihold(inode);
 742                 state->inode = inode;
 743                 list_add_rcu(&state->inode_states, &nfsi->open_states);
 744                 spin_unlock(&inode->i_lock);
 745                 /* Note: The reclaim code dictates that we add stateless
 746                  * and read-only stateids to the end of the list */
 747                 list_add_tail(&state->open_states, &owner->so_states);
 748                 spin_unlock(&owner->so_lock);
 749         } else {
 750                 spin_unlock(&inode->i_lock);
 751                 spin_unlock(&owner->so_lock);
 752                 if (new)
 753                         nfs4_free_open_state(new);
 754         }
 755 out:
 756         return state;
 757 }
 758
 759 void nfs4_put_open_state(struct nfs4_state *state)
 760 {
 761         struct inode *inode = state->inode;
 762         struct nfs4_state_owner *owner = state->owner;
 763
 764         if (!refcount_dec_and_lock(&state->count, &owner->so_lock))
 765                 return;
 766         spin_lock(&inode->i_lock);
 767         list_del_rcu(&state->inode_states);
 768         list_del(&state->open_states);
 769         spin_unlock(&inode->i_lock);
 770         spin_unlock(&owner->so_lock);
 771         nfs4_inode_return_delegation_on_close(inode);
 772         iput(inode);
 773         nfs4_free_open_state(state);
 774         nfs4_put_state_owner(owner);
 775 }
 776
 777 /*
 778  * Close the current file.
 779  */
 780 static void __nfs4_close(struct nfs4_state *state,
 781                 fmode_t fmode, gfp_t gfp_mask, int wait)
 782 {
 783         struct nfs4_state_owner *owner = state->owner;
 784         int call_close = 0;
 785         fmode_t newstate;
 786
 787         atomic_inc(&owner->so_count);
 788         /* Protect against nfs4_find_state() */
 789         spin_lock(&owner->so_lock);
 790         switch (fmode & (FMODE_READ | FMODE_WRITE)) {
 791                 case FMODE_READ:
 792                         state->n_rdonly--;
 793                         break;
 794                 case FMODE_WRITE:
 795                         state->n_wronly--;
 796                         break;
 797                 case FMODE_READ|FMODE_WRITE:
 798                         state->n_rdwr--;
 799         }
 800         newstate = FMODE_READ|FMODE_WRITE;
 801         if (state->n_rdwr == 0) {
 802                 if (state->n_rdonly == 0) {
 803                         newstate &= ~FMODE_READ;
 804                         call_close |= test_bit(NFS_O_RDONLY_STATE, &state->flags);
 805                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
 806                 }
 807                 if (state->n_wronly == 0) {
 808                         newstate &= ~FMODE_WRITE;
 809                         call_close |= test_bit(NFS_O_WRONLY_STATE, &state->flags);
 810                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
 811                 }
 812                 if (newstate == 0)
 813                         clear_bit(NFS_DELEGATED_STATE, &state->flags);
 814         }
 815         nfs4_state_set_mode_locked(state, newstate);
 816         spin_unlock(&owner->so_lock);
 817
 818         if (!call_close) {
 819                 nfs4_put_open_state(state);
 820                 nfs4_put_state_owner(owner);
 821         } else
 822                 nfs4_do_close(state, gfp_mask, wait);
 823 }
 824
 825 void nfs4_close_state(struct nfs4_state *state, fmode_t fmode)
 826 {
 827         __nfs4_close(state, fmode, GFP_KERNEL, 0);
 828 }
 829
 830 void nfs4_close_sync(struct nfs4_state *state, fmode_t fmode)
 831 {
 832         __nfs4_close(state, fmode, GFP_KERNEL, 1);
 833 }
 834
 835 /*
 836  * Search the state->lock_states for an existing lock_owner
 837  * that is compatible with either of the given owners.
 838  * If the second is non-zero, then the first refers to a Posix-lock
 839  * owner (current->files) and the second refers to a flock/OFD
 840  * owner (struct file*).  In that case, prefer a match for the first
 841  * owner.
 842  * If both sorts of locks are held on the one file we cannot know
 843  * which stateid was intended to be used, so a "correct" choice cannot
 844  * be made.  Failing that, a "consistent" choice is preferable.  The
 845  * consistent choice we make is to prefer the first owner, that of a
 846  * Posix lock.
 847  */
 848 static struct nfs4_lock_state *
 849 __nfs4_find_lock_state(struct nfs4_state *state,
 850                        fl_owner_t fl_owner, fl_owner_t fl_owner2)
 851 {
 852         struct nfs4_lock_state *pos, *ret = NULL;
 853         list_for_each_entry(pos, &state->lock_states, ls_locks) {
 854                 if (pos->ls_owner == fl_owner) {
 855                         ret = pos;
 856                         break;
 857                 }
 858                 if (pos->ls_owner == fl_owner2)
 859                         ret = pos;
 860         }
 861         if (ret)
 862                 refcount_inc(&ret->ls_count);
 863         return ret;
 864 }
 865
 866 /*
 867  * Return a compatible lock_state. If no initialized lock_state structure
 868  * exists, return an uninitialized one.
 869  *
 870  */
 871 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 872 {
 873         struct nfs4_lock_state *lsp;
 874         struct nfs_server *server = state->owner->so_server;
 875
 876         lsp = kzalloc(sizeof(*lsp), GFP_KERNEL_ACCOUNT);
 877         if (lsp == NULL)
 878                 return NULL;
 879         nfs4_init_seqid_counter(&lsp->ls_seqid);
 880         refcount_set(&lsp->ls_count, 1);
 881         lsp->ls_state = state;
 882         lsp->ls_owner = fl_owner;
 883         lsp->ls_seqid.owner_id = ida_alloc(&server->lockowner_id, GFP_KERNEL_ACCOUNT);
 884         if (lsp->ls_seqid.owner_id < 0)
 885                 goto out_free;
 886         INIT_LIST_HEAD(&lsp->ls_locks);
 887         return lsp;
 888 out_free:
 889         kfree(lsp);
 890         return NULL;
 891 }
 892
 893 void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp)
 894 {
 895         ida_free(&server->lockowner_id, lsp->ls_seqid.owner_id);
 896         nfs4_destroy_seqid_counter(&lsp->ls_seqid);
 897         kfree(lsp);
 898 }
 899
 900 /*
 901  * Return a compatible lock_state. If no initialized lock_state structure
 902  * exists, return an uninitialized one.
 903  *
 904  */
 905 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
 906 {
 907         struct nfs4_lock_state *lsp, *new = NULL;
 908
 909         for(;;) {
 910                 spin_lock(&state->state_lock);
 911                 lsp = __nfs4_find_lock_state(state, owner, NULL);
 912                 if (lsp != NULL)
 913                         break;
 914                 if (new != NULL) {
 915                         list_add(&new->ls_locks, &state->lock_states);
 916                         set_bit(LK_STATE_IN_USE, &state->flags);
 917                         lsp = new;
 918                         new = NULL;
 919                         break;
 920                 }
 921                 spin_unlock(&state->state_lock);
 922                 new = nfs4_alloc_lock_state(state, owner);
 923                 if (new == NULL)
 924                         return NULL;
 925         }
 926         spin_unlock(&state->state_lock);
 927         if (new != NULL)
 928                 nfs4_free_lock_state(state->owner->so_server, new);
 929         return lsp;
 930 }
 931
 932 /*
 933  * Release reference to lock_state, and free it if we see that
 934  * it is no longer in use
 935  */
 936 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
 937 {
 938         struct nfs_server *server;
 939         struct nfs4_state *state;
 940
 941         if (lsp == NULL)
 942                 return;
 943         state = lsp->ls_state;
 944         if (!refcount_dec_and_lock(&lsp->ls_count, &state->state_lock))
 945                 return;
 946         list_del(&lsp->ls_locks);
 947         if (list_empty(&state->lock_states))
 948                 clear_bit(LK_STATE_IN_USE, &state->flags);
 949         spin_unlock(&state->state_lock);
 950         server = state->owner->so_server;
 951         if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) {
 952                 struct nfs_client *clp = server->nfs_client;
 953
 954                 clp->cl_mvops->free_lock_state(server, lsp);
 955         } else
 956                 nfs4_free_lock_state(server, lsp);
 957 }
 958
 959 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
 960 {
 961         struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
 962
 963         dst->fl_u.nfs4_fl.owner = lsp;
 964         refcount_inc(&lsp->ls_count);
 965 }
 966
 967 static void nfs4_fl_release_lock(struct file_lock *fl)
 968 {
 969         nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
 970 }
 971
 972 static const struct file_lock_operations nfs4_fl_lock_ops = {
 973         .fl_copy_lock = nfs4_fl_copy_lock,
 974         .fl_release_private = nfs4_fl_release_lock,
 975 };
 976
 977 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
 978 {
 979         struct nfs4_lock_state *lsp;
 980
 981         if (fl->fl_ops != NULL)
 982                 return 0;
 983         lsp = nfs4_get_lock_state(state, fl->fl_owner);
 984         if (lsp == NULL)
 985                 return -ENOMEM;
 986         fl->fl_u.nfs4_fl.owner = lsp;
 987         fl->fl_ops = &nfs4_fl_lock_ops;
 988         return 0;
 989 }
 990
 991 static int nfs4_copy_lock_stateid(nfs4_stateid *dst,
 992                 struct nfs4_state *state,
 993                 const struct nfs_lock_context *l_ctx)
 994 {
 995         struct nfs4_lock_state *lsp;
 996         fl_owner_t fl_owner, fl_flock_owner;
 997         int ret = -ENOENT;
 998
 999         if (l_ctx == NULL)
1000                 goto out;
1001
1002         if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
1003                 goto out;
1004
1005         fl_owner = l_ctx->lockowner;
1006         fl_flock_owner = l_ctx->open_context->flock_owner;
1007
1008         spin_lock(&state->state_lock);
1009         lsp = __nfs4_find_lock_state(state, fl_owner, fl_flock_owner);
1010         if (lsp && test_bit(NFS_LOCK_LOST, &lsp->ls_flags))
1011                 ret = -EIO;
1012         else if (lsp != NULL && test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) != 0) {
1013                 nfs4_stateid_copy(dst, &lsp->ls_stateid);
1014                 ret = 0;
1015         }
1016         spin_unlock(&state->state_lock);
1017         nfs4_put_lock_state(lsp);
1018 out:
1019         return ret;
1020 }
1021
1022 bool nfs4_copy_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
1023 {
1024         bool ret;
1025         const nfs4_stateid *src;
1026         int seq;
1027
1028         do {
1029                 ret = false;
1030                 src = &zero_stateid;
1031                 seq = read_seqbegin(&state->seqlock);
1032                 if (test_bit(NFS_OPEN_STATE, &state->flags)) {
1033                         src = &state->open_stateid;
1034                         ret = true;
1035                 }
1036                 nfs4_stateid_copy(dst, src);
1037         } while (read_seqretry(&state->seqlock, seq));
1038         return ret;
1039 }
1040
1041 /*
1042  * Byte-range lock aware utility to initialize the stateid of read/write
1043  * requests.
1044  */
1045 int nfs4_select_rw_stateid(struct nfs4_state *state,
1046                 fmode_t fmode, const struct nfs_lock_context *l_ctx,
1047                 nfs4_stateid *dst, const struct cred **cred)
1048 {
1049         int ret;
1050
1051         if (!nfs4_valid_open_stateid(state))
1052                 return -EIO;
1053         if (cred != NULL)
1054                 *cred = NULL;
1055         ret = nfs4_copy_lock_stateid(dst, state, l_ctx);
1056         if (ret == -EIO)
1057                 /* A lost lock - don't even consider delegations */
1058                 goto out;
1059         /* returns true if delegation stateid found and copied */
1060         if (nfs4_copy_delegation_stateid(state->inode, fmode, dst, cred)) {
1061                 ret = 0;
1062                 goto out;
1063         }
1064         if (ret != -ENOENT)
1065                 /* nfs4_copy_delegation_stateid() didn't over-write
1066                  * dst, so it still has the lock stateid which we now
1067                  * choose to use.
1068                  */
1069                 goto out;
1070         ret = nfs4_copy_open_stateid(dst, state) ? 0 : -EAGAIN;
1071 out:
1072         if (nfs_server_capable(state->inode, NFS_CAP_STATEID_NFSV41))
1073                 dst->seqid = 0;
1074         return ret;
1075 }
1076
1077 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask)
1078 {
1079         struct nfs_seqid *new;
1080
1081         new = kmalloc(sizeof(*new), gfp_mask);
1082         if (new == NULL)
1083                 return ERR_PTR(-ENOMEM);
1084         new->sequence = counter;
1085         INIT_LIST_HEAD(&new->list);
1086         new->task = NULL;
1087         return new;
1088 }
1089
1090 void nfs_release_seqid(struct nfs_seqid *seqid)
1091 {
1092         struct nfs_seqid_counter *sequence;
1093
1094         if (seqid == NULL || list_empty(&seqid->list))
1095                 return;
1096         sequence = seqid->sequence;
1097         spin_lock(&sequence->lock);
1098         list_del_init(&seqid->list);
1099         if (!list_empty(&sequence->list)) {
1100                 struct nfs_seqid *next;
1101
1102                 next = list_first_entry(&sequence->list,
1103                                 struct nfs_seqid, list);
1104                 rpc_wake_up_queued_task(&sequence->wait, next->task);
1105         }
1106         spin_unlock(&sequence->lock);
1107 }
1108
1109 void nfs_free_seqid(struct nfs_seqid *seqid)
1110 {
1111         nfs_release_seqid(seqid);
1112         kfree(seqid);
1113 }
1114
1115 /*
1116  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
1117  * failed with a seqid incrementing error -
1118  * see comments nfs4.h:seqid_mutating_error()
1119  */
1120 static void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
1121 {
1122         switch (status) {
1123                 case 0:
1124                         break;
1125                 case -NFS4ERR_BAD_SEQID:
1126                         if (seqid->sequence->flags & NFS_SEQID_CONFIRMED)
1127                                 return;
1128                         pr_warn_ratelimited("NFS: v4 server returned a bad"
1129                                         " sequence-id error on an"
1130                                         " unconfirmed sequence %p!\n",
1131                                         seqid->sequence);
1132                         return;
1133                 case -NFS4ERR_STALE_CLIENTID:
1134                 case -NFS4ERR_STALE_STATEID:
1135                 case -NFS4ERR_BAD_STATEID:
1136                 case -NFS4ERR_BADXDR:
1137                 case -NFS4ERR_RESOURCE:
1138                 case -NFS4ERR_NOFILEHANDLE:
1139                 case -NFS4ERR_MOVED:
1140                         /* Non-seqid mutating errors */
1141                         return;
1142         }
1143         /*
1144          * Note: no locking needed as we are guaranteed to be first
1145          * on the sequence list
1146          */
1147         seqid->sequence->counter++;
1148 }
1149
1150 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
1151 {
1152         struct nfs4_state_owner *sp;
1153
1154         if (seqid == NULL)
1155                 return;
1156
1157         sp = container_of(seqid->sequence, struct nfs4_state_owner, so_seqid);
1158         if (status == -NFS4ERR_BAD_SEQID)
1159                 nfs4_reset_state_owner(sp);
1160         if (!nfs4_has_session(sp->so_server->nfs_client))
1161                 nfs_increment_seqid(status, seqid);
1162 }
1163
1164 /*
1165  * Increment the seqid if the LOCK/LOCKU succeeded, or
1166  * failed with a seqid incrementing error -
1167  * see comments nfs4.h:seqid_mutating_error()
1168  */
1169 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
1170 {
1171         if (seqid != NULL)
1172                 nfs_increment_seqid(status, seqid);
1173 }
1174
1175 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
1176 {
1177         struct nfs_seqid_counter *sequence;
1178         int status = 0;
1179
1180         if (seqid == NULL)
1181                 goto out;
1182         sequence = seqid->sequence;
1183         spin_lock(&sequence->lock);
1184         seqid->task = task;
1185         if (list_empty(&seqid->list))
1186                 list_add_tail(&seqid->list, &sequence->list);
1187         if (list_first_entry(&sequence->list, struct nfs_seqid, list) == seqid)
1188                 goto unlock;
1189         rpc_sleep_on(&sequence->wait, task, NULL);
1190         status = -EAGAIN;
1191 unlock:
1192         spin_unlock(&sequence->lock);
1193 out:
1194         return status;
1195 }
1196
1197 static int nfs4_run_state_manager(void *);
1198
1199 static void nfs4_clear_state_manager_bit(struct nfs_client *clp)
1200 {
1201         clear_and_wake_up_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state);
1202         rpc_wake_up(&clp->cl_rpcwaitq);
1203 }
1204
1205 /*
1206  * Schedule the nfs_client asynchronous state management routine
1207  */
1208 void nfs4_schedule_state_manager(struct nfs_client *clp)
1209 {
1210         struct task_struct *task;
1211         char buf[INET6_ADDRSTRLEN + sizeof("-manager") + 1];
1212         struct rpc_clnt *clnt = clp->cl_rpcclient;
1213         bool swapon = false;
1214
1215         if (clnt->cl_shutdown)
1216                 return;
1217
1218         set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
1219
1220         if (atomic_read(&clnt->cl_swapper)) {
1221                 swapon = !test_and_set_bit(NFS4CLNT_MANAGER_AVAILABLE,
1222                                            &clp->cl_state);
1223                 if (!swapon) {
1224                         wake_up_var(&clp->cl_state);
1225                         return;
1226                 }
1227         }
1228
1229         if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
1230                 return;
1231
1232         __module_get(THIS_MODULE);
1233         refcount_inc(&clp->cl_count);
1234
1235         /* The rcu_read_lock() is not strictly necessary, as the state
1236          * manager is the only thread that ever changes the rpc_xprt
1237          * after it's initialized.  At this point, we're single threaded. */
1238         rcu_read_lock();
1239         snprintf(buf, sizeof(buf), "%s-manager",
1240                         rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
1241         rcu_read_unlock();
1242         task = kthread_run(nfs4_run_state_manager, clp, "%s", buf);
1243         if (IS_ERR(task)) {
1244                 printk(KERN_ERR "%s: kthread_run: %ld\n",
1245                         __func__, PTR_ERR(task));
1246                 if (!nfs_client_init_is_complete(clp))
1247                         nfs_mark_client_ready(clp, PTR_ERR(task));
1248                 if (swapon)
1249                         clear_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state);
1250                 nfs4_clear_state_manager_bit(clp);
1251                 nfs_put_client(clp);
1252                 module_put(THIS_MODULE);
1253         }
1254 }
1255
1256 /*
1257  * Schedule a lease recovery attempt
1258  */
1259 void nfs4_schedule_lease_recovery(struct nfs_client *clp)
1260 {
1261         if (!clp)
1262                 return;
1263         if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1264                 set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1265         dprintk("%s: scheduling lease recovery for server %s\n", __func__,
1266                         clp->cl_hostname);
1267         nfs4_schedule_state_manager(clp);
1268 }
1269 EXPORT_SYMBOL_GPL(nfs4_schedule_lease_recovery);
1270
1271 /**
1272  * nfs4_schedule_migration_recovery - trigger migration recovery
1273  *
1274  * @server: FSID that is migrating
1275  *
1276  * Returns zero if recovery has started, otherwise a negative NFS4ERR
1277  * value is returned.
1278  */
1279 int nfs4_schedule_migration_recovery(const struct nfs_server *server)
1280 {
1281         struct nfs_client *clp = server->nfs_client;
1282
1283         if (server->fh_expire_type != NFS4_FH_PERSISTENT) {
1284                 pr_err("NFS: volatile file handles not supported (server %s)\n",
1285                                 clp->cl_hostname);
1286                 return -NFS4ERR_IO;
1287         }
1288
1289         if (test_bit(NFS_MIG_FAILED, &server->mig_status))
1290                 return -NFS4ERR_IO;
1291
1292         dprintk("%s: scheduling migration recovery for (%llx:%llx) on %s\n",
1293                         __func__,
1294                         (unsigned long long)server->fsid.major,
1295                         (unsigned long long)server->fsid.minor,
1296                         clp->cl_hostname);
1297
1298         set_bit(NFS_MIG_IN_TRANSITION,
1299                         &((struct nfs_server *)server)->mig_status);
1300         set_bit(NFS4CLNT_MOVED, &clp->cl_state);
1301
1302         nfs4_schedule_state_manager(clp);
1303         return 0;
1304 }
1305 EXPORT_SYMBOL_GPL(nfs4_schedule_migration_recovery);
1306
1307 /**
1308  * nfs4_schedule_lease_moved_recovery - start lease-moved recovery
1309  *
1310  * @clp: server to check for moved leases
1311  *
1312  */
1313 void nfs4_schedule_lease_moved_recovery(struct nfs_client *clp)
1314 {
1315         dprintk("%s: scheduling lease-moved recovery for client ID %llx on %s\n",
1316                 __func__, clp->cl_clientid, clp->cl_hostname);
1317
1318         set_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state);
1319         nfs4_schedule_state_manager(clp);
1320 }
1321 EXPORT_SYMBOL_GPL(nfs4_schedule_lease_moved_recovery);
1322
1323 int nfs4_wait_clnt_recover(struct nfs_client *clp)
1324 {
1325         int res;
1326
1327         might_sleep();
1328
1329         refcount_inc(&clp->cl_count);
1330         res = wait_on_bit_action(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING,
1331                                  nfs_wait_bit_killable,
1332                                  TASK_KILLABLE|TASK_FREEZABLE_UNSAFE);
1333         if (res)
1334                 goto out;
1335         if (clp->cl_cons_state < 0)
1336                 res = clp->cl_cons_state;
1337 out:
1338         nfs_put_client(clp);
1339         return res;
1340 }
1341
1342 int nfs4_client_recover_expired_lease(struct nfs_client *clp)
1343 {
1344         unsigned int loop;
1345         int ret;
1346
1347         for (loop = NFS4_MAX_LOOP_ON_RECOVER; loop != 0; loop--) {
1348                 ret = nfs4_wait_clnt_recover(clp);
1349                 if (ret != 0)
1350                         break;
1351                 if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) &&
1352                     !test_bit(NFS4CLNT_CHECK_LEASE,&clp->cl_state))
1353                         break;
1354                 nfs4_schedule_state_manager(clp);
1355                 ret = -EIO;
1356         }
1357         return ret;
1358 }
1359
1360 /*
1361  * nfs40_handle_cb_pathdown - return all delegations after NFS4ERR_CB_PATH_DOWN
1362  * @clp: client to process
1363  *
1364  * Set the NFS4CLNT_LEASE_EXPIRED state in order to force a
1365  * resend of the SETCLIENTID and hence re-establish the
1366  * callback channel. Then return all existing delegations.
1367  */
1368 static void nfs40_handle_cb_pathdown(struct nfs_client *clp)
1369 {
1370         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1371         nfs_expire_all_delegations(clp);
1372         dprintk("%s: handling CB_PATHDOWN recovery for server %s\n", __func__,
1373                         clp->cl_hostname);
1374 }
1375
1376 void nfs4_schedule_path_down_recovery(struct nfs_client *clp)
1377 {
1378         nfs40_handle_cb_pathdown(clp);
1379         nfs4_schedule_state_manager(clp);
1380 }
1381
1382 static int nfs4_state_mark_reclaim_reboot(struct nfs_client *clp, struct nfs4_state *state)
1383 {
1384
1385         if (!nfs4_valid_open_stateid(state))
1386                 return 0;
1387         set_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1388         /* Don't recover state that expired before the reboot */
1389         if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags)) {
1390                 clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1391                 return 0;
1392         }
1393         set_bit(NFS_OWNER_RECLAIM_REBOOT, &state->owner->so_flags);
1394         set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1395         return 1;
1396 }
1397
1398 int nfs4_state_mark_reclaim_nograce(struct nfs_client *clp, struct nfs4_state *state)
1399 {
1400         if (!nfs4_valid_open_stateid(state))
1401                 return 0;
1402         set_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1403         clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1404         set_bit(NFS_OWNER_RECLAIM_NOGRACE, &state->owner->so_flags);
1405         set_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
1406         return 1;
1407 }
1408
1409 int nfs4_schedule_stateid_recovery(const struct nfs_server *server, struct nfs4_state *state)
1410 {
1411         struct nfs_client *clp = server->nfs_client;
1412
1413         if (!nfs4_state_mark_reclaim_nograce(clp, state))
1414                 return -EBADF;
1415         nfs_inode_find_delegation_state_and_recover(state->inode,
1416                         &state->stateid);
1417         dprintk("%s: scheduling stateid recovery for server %s\n", __func__,
1418                         clp->cl_hostname);
1419         nfs4_schedule_state_manager(clp);
1420         return 0;
1421 }
1422 EXPORT_SYMBOL_GPL(nfs4_schedule_stateid_recovery);
1423
1424 static struct nfs4_lock_state *
1425 nfs_state_find_lock_state_by_stateid(struct nfs4_state *state,
1426                 const nfs4_stateid *stateid)
1427 {
1428         struct nfs4_lock_state *pos;
1429
1430         list_for_each_entry(pos, &state->lock_states, ls_locks) {
1431                 if (!test_bit(NFS_LOCK_INITIALIZED, &pos->ls_flags))
1432                         continue;
1433                 if (nfs4_stateid_match_or_older(&pos->ls_stateid, stateid))
1434                         return pos;
1435         }
1436         return NULL;
1437 }
1438
1439 static bool nfs_state_lock_state_matches_stateid(struct nfs4_state *state,
1440                 const nfs4_stateid *stateid)
1441 {
1442         bool found = false;
1443
1444         if (test_bit(LK_STATE_IN_USE, &state->flags)) {
1445                 spin_lock(&state->state_lock);
1446                 if (nfs_state_find_lock_state_by_stateid(state, stateid))
1447                         found = true;
1448                 spin_unlock(&state->state_lock);
1449         }
1450         return found;
1451 }
1452
1453 void nfs_inode_find_state_and_recover(struct inode *inode,
1454                 const nfs4_stateid *stateid)
1455 {
1456         struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
1457         struct nfs_inode *nfsi = NFS_I(inode);
1458         struct nfs_open_context *ctx;
1459         struct nfs4_state *state;
1460         bool found = false;
1461
1462         rcu_read_lock();
1463         list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1464                 state = ctx->state;
1465                 if (state == NULL)
1466                         continue;
1467                 if (nfs4_stateid_match_or_older(&state->stateid, stateid) &&
1468                     nfs4_state_mark_reclaim_nograce(clp, state)) {
1469                         found = true;
1470                         continue;
1471                 }
1472                 if (test_bit(NFS_OPEN_STATE, &state->flags) &&
1473                     nfs4_stateid_match_or_older(&state->open_stateid, stateid) &&
1474                     nfs4_state_mark_reclaim_nograce(clp, state)) {
1475                         found = true;
1476                         continue;
1477                 }
1478                 if (nfs_state_lock_state_matches_stateid(state, stateid) &&
1479                     nfs4_state_mark_reclaim_nograce(clp, state))
1480                         found = true;
1481         }
1482         rcu_read_unlock();
1483
1484         nfs_inode_find_delegation_state_and_recover(inode, stateid);
1485         if (found)
1486                 nfs4_schedule_state_manager(clp);
1487 }
1488
1489 static void nfs4_state_mark_open_context_bad(struct nfs4_state *state, int err)
1490 {
1491         struct inode *inode = state->inode;
1492         struct nfs_inode *nfsi = NFS_I(inode);
1493         struct nfs_open_context *ctx;
1494
1495         rcu_read_lock();
1496         list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1497                 if (ctx->state != state)
1498                         continue;
1499                 set_bit(NFS_CONTEXT_BAD, &ctx->flags);
1500                 pr_warn("NFSv4: state recovery failed for open file %pd2, "
1501                                 "error = %d\n", ctx->dentry, err);
1502         }
1503         rcu_read_unlock();
1504 }
1505
1506 static void nfs4_state_mark_recovery_failed(struct nfs4_state *state, int error)
1507 {
1508         set_bit(NFS_STATE_RECOVERY_FAILED, &state->flags);
1509         nfs4_state_mark_open_context_bad(state, error);
1510 }
1511
1512
1513 static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_recovery_ops *ops)
1514 {
1515         struct inode *inode = state->inode;
1516         struct nfs_inode *nfsi = NFS_I(inode);
1517         struct file_lock *fl;
1518         struct nfs4_lock_state *lsp;
1519         int status = 0;
1520         struct file_lock_context *flctx = locks_inode_context(inode);
1521         struct list_head *list;
1522
1523         if (flctx == NULL)
1524                 return 0;
1525
1526         list = &flctx->flc_posix;
1527
1528         /* Guard against delegation returns and new lock/unlock calls */
1529         down_write(&nfsi->rwsem);
1530         spin_lock(&flctx->flc_lock);
1531 restart:
1532         list_for_each_entry(fl, list, fl_list) {
1533                 if (nfs_file_open_context(fl->fl_file)->state != state)
1534                         continue;
1535                 spin_unlock(&flctx->flc_lock);
1536                 status = ops->recover_lock(state, fl);
1537                 switch (status) {
1538                 case 0:
1539                         break;
1540                 case -ETIMEDOUT:
1541                 case -ESTALE:
1542                 case -NFS4ERR_ADMIN_REVOKED:
1543                 case -NFS4ERR_STALE_STATEID:
1544                 case -NFS4ERR_BAD_STATEID:
1545                 case -NFS4ERR_EXPIRED:
1546                 case -NFS4ERR_NO_GRACE:
1547                 case -NFS4ERR_STALE_CLIENTID:
1548                 case -NFS4ERR_BADSESSION:
1549                 case -NFS4ERR_BADSLOT:
1550                 case -NFS4ERR_BAD_HIGH_SLOT:
1551                 case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1552                         goto out;
1553                 default:
1554                         pr_err("NFS: %s: unhandled error %d\n",
1555                                         __func__, status);
1556                         fallthrough;
1557                 case -ENOMEM:
1558                 case -NFS4ERR_DENIED:
1559                 case -NFS4ERR_RECLAIM_BAD:
1560                 case -NFS4ERR_RECLAIM_CONFLICT:
1561                         lsp = fl->fl_u.nfs4_fl.owner;
1562                         if (lsp)
1563                                 set_bit(NFS_LOCK_LOST, &lsp->ls_flags);
1564                         status = 0;
1565                 }
1566                 spin_lock(&flctx->flc_lock);
1567         }
1568         if (list == &flctx->flc_posix) {
1569                 list = &flctx->flc_flock;
1570                 goto restart;
1571         }
1572         spin_unlock(&flctx->flc_lock);
1573 out:
1574         up_write(&nfsi->rwsem);
1575         return status;
1576 }
1577
1578 #ifdef CONFIG_NFS_V4_2
1579 static void nfs42_complete_copies(struct nfs4_state_owner *sp, struct nfs4_state *state)
1580 {
1581         struct nfs4_copy_state *copy;
1582
1583         if (!test_bit(NFS_CLNT_DST_SSC_COPY_STATE, &state->flags) &&
1584                 !test_bit(NFS_CLNT_SRC_SSC_COPY_STATE, &state->flags))
1585                 return;
1586
1587         spin_lock(&sp->so_server->nfs_client->cl_lock);
1588         list_for_each_entry(copy, &sp->so_server->ss_copies, copies) {
1589                 if ((test_bit(NFS_CLNT_DST_SSC_COPY_STATE, &state->flags) &&
1590                                 !nfs4_stateid_match_other(&state->stateid,
1591                                 &copy->parent_dst_state->stateid)))
1592                                 continue;
1593                 copy->flags = 1;
1594                 if (test_and_clear_bit(NFS_CLNT_DST_SSC_COPY_STATE,
1595                                 &state->flags)) {
1596                         clear_bit(NFS_CLNT_SRC_SSC_COPY_STATE, &state->flags);
1597                         complete(&copy->completion);
1598                 }
1599         }
1600         list_for_each_entry(copy, &sp->so_server->ss_copies, src_copies) {
1601                 if ((test_bit(NFS_CLNT_SRC_SSC_COPY_STATE, &state->flags) &&
1602                                 !nfs4_stateid_match_other(&state->stateid,
1603                                 &copy->parent_src_state->stateid)))
1604                                 continue;
1605                 copy->flags = 1;
1606                 if (test_and_clear_bit(NFS_CLNT_DST_SSC_COPY_STATE,
1607                                 &state->flags))
1608                         complete(&copy->completion);
1609         }
1610         spin_unlock(&sp->so_server->nfs_client->cl_lock);
1611 }
1612 #else /* !CONFIG_NFS_V4_2 */
1613 static inline void nfs42_complete_copies(struct nfs4_state_owner *sp,
1614                                          struct nfs4_state *state)
1615 {
1616 }
1617 #endif /* CONFIG_NFS_V4_2 */
1618
1619 static int __nfs4_reclaim_open_state(struct nfs4_state_owner *sp, struct nfs4_state *state,
1620                                      const struct nfs4_state_recovery_ops *ops,
1621                                      int *lost_locks)
1622 {
1623         struct nfs4_lock_state *lock;
1624         int status;
1625
1626         status = ops->recover_open(sp, state);
1627         if (status < 0)
1628                 return status;
1629
1630         status = nfs4_reclaim_locks(state, ops);
1631         if (status < 0)
1632                 return status;
1633
1634         if (!test_bit(NFS_DELEGATED_STATE, &state->flags)) {
1635                 spin_lock(&state->state_lock);
1636                 list_for_each_entry(lock, &state->lock_states, ls_locks) {
1637                         trace_nfs4_state_lock_reclaim(state, lock);
1638                         if (!test_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags) &&
1639                             !test_bit(NFS_LOCK_UNLOCKING, &lock->ls_flags))
1640                                 *lost_locks += 1;
1641                 }
1642                 spin_unlock(&state->state_lock);
1643         }
1644
1645         nfs42_complete_copies(sp, state);
1646         clear_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1647         return status;
1648 }
1649
1650 static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp,
1651                                    const struct nfs4_state_recovery_ops *ops,
1652                                    int *lost_locks)
1653 {
1654         struct nfs4_state *state;
1655         unsigned int loop = 0;
1656         int status = 0;
1657 #ifdef CONFIG_NFS_V4_2
1658         bool found_ssc_copy_state = false;
1659 #endif /* CONFIG_NFS_V4_2 */
1660
1661         /* Note: we rely on the sp->so_states list being ordered
1662          * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
1663          * states first.
1664          * This is needed to ensure that the server won't give us any
1665          * read delegations that we have to return if, say, we are
1666          * recovering after a network partition or a reboot from a
1667          * server that doesn't support a grace period.
1668          */
1669         spin_lock(&sp->so_lock);
1670         raw_write_seqcount_begin(&sp->so_reclaim_seqcount);
1671 restart:
1672         list_for_each_entry(state, &sp->so_states, open_states) {
1673                 if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
1674                         continue;
1675                 if (!nfs4_valid_open_stateid(state))
1676                         continue;
1677                 if (state->state == 0)
1678                         continue;
1679 #ifdef CONFIG_NFS_V4_2
1680                 if (test_bit(NFS_SRV_SSC_COPY_STATE, &state->flags)) {
1681                         nfs4_state_mark_recovery_failed(state, -EIO);
1682                         found_ssc_copy_state = true;
1683                         continue;
1684                 }
1685 #endif /* CONFIG_NFS_V4_2 */
1686                 refcount_inc(&state->count);
1687                 spin_unlock(&sp->so_lock);
1688                 status = __nfs4_reclaim_open_state(sp, state, ops, lost_locks);
1689
1690                 switch (status) {
1691                 default:
1692                         if (status >= 0) {
1693                                 loop = 0;
1694                                 break;
1695                         }
1696                         printk(KERN_ERR "NFS: %s: unhandled error %d\n", __func__, status);
1697                         fallthrough;
1698                 case -ENOENT:
1699                 case -ENOMEM:
1700                 case -EACCES:
1701                 case -EROFS:
1702                 case -EIO:
1703                 case -ESTALE:
1704                         /* Open state on this file cannot be recovered */
1705                         nfs4_state_mark_recovery_failed(state, status);
1706                         break;
1707                 case -EAGAIN:
1708                         ssleep(1);
1709                         if (loop++ < 10) {
1710                                 set_bit(ops->state_flag_bit, &state->flags);
1711                                 break;
1712                         }
1713                         fallthrough;
1714                 case -NFS4ERR_ADMIN_REVOKED:
1715                 case -NFS4ERR_STALE_STATEID:
1716                 case -NFS4ERR_OLD_STATEID:
1717                 case -NFS4ERR_BAD_STATEID:
1718                 case -NFS4ERR_RECLAIM_BAD:
1719                 case -NFS4ERR_RECLAIM_CONFLICT:
1720                         nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1721                         break;
1722                 case -NFS4ERR_EXPIRED:
1723                 case -NFS4ERR_NO_GRACE:
1724                         nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1725                         fallthrough;
1726                 case -NFS4ERR_STALE_CLIENTID:
1727                 case -NFS4ERR_BADSESSION:
1728                 case -NFS4ERR_BADSLOT:
1729                 case -NFS4ERR_BAD_HIGH_SLOT:
1730                 case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1731                 case -ETIMEDOUT:
1732                         goto out_err;
1733                 }
1734                 nfs4_put_open_state(state);
1735                 spin_lock(&sp->so_lock);
1736                 goto restart;
1737         }
1738         raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1739         spin_unlock(&sp->so_lock);
1740 #ifdef CONFIG_NFS_V4_2
1741         if (found_ssc_copy_state)
1742                 return -EIO;
1743 #endif /* CONFIG_NFS_V4_2 */
1744         return 0;
1745 out_err:
1746         nfs4_put_open_state(state);
1747         spin_lock(&sp->so_lock);
1748         raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1749         spin_unlock(&sp->so_lock);
1750         return status;
1751 }
1752
1753 static void nfs4_clear_open_state(struct nfs4_state *state)
1754 {
1755         struct nfs4_lock_state *lock;
1756
1757         clear_bit(NFS_DELEGATED_STATE, &state->flags);
1758         clear_bit(NFS_O_RDONLY_STATE, &state->flags);
1759         clear_bit(NFS_O_WRONLY_STATE, &state->flags);
1760         clear_bit(NFS_O_RDWR_STATE, &state->flags);
1761         spin_lock(&state->state_lock);
1762         list_for_each_entry(lock, &state->lock_states, ls_locks) {
1763                 lock->ls_seqid.flags = 0;
1764                 clear_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags);
1765         }
1766         spin_unlock(&state->state_lock);
1767 }
1768
1769 static void nfs4_reset_seqids(struct nfs_server *server,
1770         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1771 {
1772         struct nfs_client *clp = server->nfs_client;
1773         struct nfs4_state_owner *sp;
1774         struct rb_node *pos;
1775         struct nfs4_state *state;
1776
1777         spin_lock(&clp->cl_lock);
1778         for (pos = rb_first(&server->state_owners);
1779              pos != NULL;
1780              pos = rb_next(pos)) {
1781                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1782                 sp->so_seqid.flags = 0;
1783                 spin_lock(&sp->so_lock);
1784                 list_for_each_entry(state, &sp->so_states, open_states) {
1785                         if (mark_reclaim(clp, state))
1786                                 nfs4_clear_open_state(state);
1787                 }
1788                 spin_unlock(&sp->so_lock);
1789         }
1790         spin_unlock(&clp->cl_lock);
1791 }
1792
1793 static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp,
1794         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1795 {
1796         struct nfs_server *server;
1797
1798         rcu_read_lock();
1799         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1800                 nfs4_reset_seqids(server, mark_reclaim);
1801         rcu_read_unlock();
1802 }
1803
1804 static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp)
1805 {
1806         set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1807         /* Mark all delegations for reclaim */
1808         nfs_delegation_mark_reclaim(clp);
1809         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_reboot);
1810 }
1811
1812 static int nfs4_reclaim_complete(struct nfs_client *clp,
1813                                  const struct nfs4_state_recovery_ops *ops,
1814                                  const struct cred *cred)
1815 {
1816         /* Notify the server we're done reclaiming our state */
1817         if (ops->reclaim_complete)
1818                 return ops->reclaim_complete(clp, cred);
1819         return 0;
1820 }
1821
1822 static void nfs4_clear_reclaim_server(struct nfs_server *server)
1823 {
1824         struct nfs_client *clp = server->nfs_client;
1825         struct nfs4_state_owner *sp;
1826         struct rb_node *pos;
1827         struct nfs4_state *state;
1828
1829         spin_lock(&clp->cl_lock);
1830         for (pos = rb_first(&server->state_owners);
1831              pos != NULL;
1832              pos = rb_next(pos)) {
1833                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1834                 spin_lock(&sp->so_lock);
1835                 list_for_each_entry(state, &sp->so_states, open_states) {
1836                         if (!test_and_clear_bit(NFS_STATE_RECLAIM_REBOOT,
1837                                                 &state->flags))
1838                                 continue;
1839                         nfs4_state_mark_reclaim_nograce(clp, state);
1840                 }
1841                 spin_unlock(&sp->so_lock);
1842         }
1843         spin_unlock(&clp->cl_lock);
1844 }
1845
1846 static int nfs4_state_clear_reclaim_reboot(struct nfs_client *clp)
1847 {
1848         struct nfs_server *server;
1849
1850         if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
1851                 return 0;
1852
1853         rcu_read_lock();
1854         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1855                 nfs4_clear_reclaim_server(server);
1856         rcu_read_unlock();
1857
1858         nfs_delegation_reap_unclaimed(clp);
1859         return 1;
1860 }
1861
1862 static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
1863 {
1864         const struct nfs4_state_recovery_ops *ops;
1865         const struct cred *cred;
1866         int err;
1867
1868         if (!nfs4_state_clear_reclaim_reboot(clp))
1869                 return;
1870         ops = clp->cl_mvops->reboot_recovery_ops;
1871         cred = nfs4_get_clid_cred(clp);
1872         err = nfs4_reclaim_complete(clp, ops, cred);
1873         put_cred(cred);
1874         if (err == -NFS4ERR_CONN_NOT_BOUND_TO_SESSION)
1875                 set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1876 }
1877
1878 static void nfs4_state_start_reclaim_nograce(struct nfs_client *clp)
1879 {
1880         nfs_mark_test_expired_all_delegations(clp);
1881         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
1882 }
1883
1884 static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
1885 {
1886         switch (error) {
1887         case 0:
1888                 break;
1889         case -NFS4ERR_CB_PATH_DOWN:
1890                 nfs40_handle_cb_pathdown(clp);
1891                 break;
1892         case -NFS4ERR_NO_GRACE:
1893                 nfs4_state_end_reclaim_reboot(clp);
1894                 break;
1895         case -NFS4ERR_STALE_CLIENTID:
1896                 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1897                 nfs4_state_start_reclaim_reboot(clp);
1898                 break;
1899         case -NFS4ERR_EXPIRED:
1900                 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1901                 nfs4_state_start_reclaim_nograce(clp);
1902                 break;
1903         case -NFS4ERR_BADSESSION:
1904         case -NFS4ERR_BADSLOT:
1905         case -NFS4ERR_BAD_HIGH_SLOT:
1906         case -NFS4ERR_DEADSESSION:
1907         case -NFS4ERR_SEQ_FALSE_RETRY:
1908         case -NFS4ERR_SEQ_MISORDERED:
1909                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
1910                 /* Zero session reset errors */
1911                 break;
1912         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1913                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
1914                 break;
1915         default:
1916                 dprintk("%s: failed to handle error %d for server %s\n",
1917                                 __func__, error, clp->cl_hostname);
1918                 return error;
1919         }
1920         dprintk("%s: handled error %d for server %s\n", __func__, error,
1921                         clp->cl_hostname);
1922         return 0;
1923 }
1924
1925 static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recovery_ops *ops)
1926 {
1927         struct nfs4_state_owner *sp;
1928         struct nfs_server *server;
1929         struct rb_node *pos;
1930         LIST_HEAD(freeme);
1931         int status = 0;
1932         int lost_locks = 0;
1933
1934 restart:
1935         rcu_read_lock();
1936         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1937                 nfs4_purge_state_owners(server, &freeme);
1938                 spin_lock(&clp->cl_lock);
1939                 for (pos = rb_first(&server->state_owners);
1940                      pos != NULL;
1941                      pos = rb_next(pos)) {
1942                         sp = rb_entry(pos,
1943                                 struct nfs4_state_owner, so_server_node);
1944                         if (!test_and_clear_bit(ops->owner_flag_bit,
1945                                                         &sp->so_flags))
1946                                 continue;
1947                         if (!atomic_inc_not_zero(&sp->so_count))
1948                                 continue;
1949                         spin_unlock(&clp->cl_lock);
1950                         rcu_read_unlock();
1951
1952                         status = nfs4_reclaim_open_state(sp, ops, &lost_locks);
1953                         if (status < 0) {
1954                                 if (lost_locks)
1955                                         pr_warn("NFS: %s: lost %d locks\n",
1956                                                 clp->cl_hostname, lost_locks);
1957                                 set_bit(ops->owner_flag_bit, &sp->so_flags);
1958                                 nfs4_put_state_owner(sp);
1959                                 status = nfs4_recovery_handle_error(clp, status);
1960                                 return (status != 0) ? status : -EAGAIN;
1961                         }
1962
1963                         nfs4_put_state_owner(sp);
1964                         goto restart;
1965                 }
1966                 spin_unlock(&clp->cl_lock);
1967         }
1968         rcu_read_unlock();
1969         nfs4_free_state_owners(&freeme);
1970         if (lost_locks)
1971                 pr_warn("NFS: %s: lost %d locks\n",
1972                         clp->cl_hostname, lost_locks);
1973         return 0;
1974 }
1975
1976 static int nfs4_check_lease(struct nfs_client *clp)
1977 {
1978         const struct cred *cred;
1979         const struct nfs4_state_maintenance_ops *ops =
1980                 clp->cl_mvops->state_renewal_ops;
1981         int status;
1982
1983         /* Is the client already known to have an expired lease? */
1984         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1985                 return 0;
1986         cred = ops->get_state_renewal_cred(clp);
1987         if (cred == NULL) {
1988                 cred = nfs4_get_clid_cred(clp);
1989                 status = -ENOKEY;
1990                 if (cred == NULL)
1991                         goto out;
1992         }
1993         status = ops->renew_lease(clp, cred);
1994         put_cred(cred);
1995         if (status == -ETIMEDOUT) {
1996                 set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1997                 return 0;
1998         }
1999 out:
2000         return nfs4_recovery_handle_error(clp, status);
2001 }
2002
2003 /* Set NFS4CLNT_LEASE_EXPIRED and reclaim reboot state for all v4.0 errors
2004  * and for recoverable errors on EXCHANGE_ID for v4.1
2005  */
2006 static int nfs4_handle_reclaim_lease_error(struct nfs_client *clp, int status)
2007 {
2008         switch (status) {
2009         case -NFS4ERR_SEQ_MISORDERED:
2010                 if (test_and_set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state))
2011                         return -ESERVERFAULT;
2012                 /* Lease confirmation error: retry after purging the lease */
2013                 ssleep(1);
2014                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2015                 break;
2016         case -NFS4ERR_STALE_CLIENTID:
2017                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2018                 nfs4_state_start_reclaim_reboot(clp);
2019                 break;
2020         case -NFS4ERR_CLID_INUSE:
2021                 pr_err("NFS: Server %s reports our clientid is in use\n",
2022                         clp->cl_hostname);
2023                 nfs_mark_client_ready(clp, -EPERM);
2024                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2025                 return -EPERM;
2026         case -EACCES:
2027         case -NFS4ERR_DELAY:
2028         case -EAGAIN:
2029                 ssleep(1);
2030                 break;
2031
2032         case -NFS4ERR_MINOR_VERS_MISMATCH:
2033                 if (clp->cl_cons_state == NFS_CS_SESSION_INITING)
2034                         nfs_mark_client_ready(clp, -EPROTONOSUPPORT);
2035                 dprintk("%s: exit with error %d for server %s\n",
2036                                 __func__, -EPROTONOSUPPORT, clp->cl_hostname);
2037                 return -EPROTONOSUPPORT;
2038         case -ENOSPC:
2039                 if (clp->cl_cons_state == NFS_CS_SESSION_INITING)
2040                         nfs_mark_client_ready(clp, -EIO);
2041                 return -EIO;
2042         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
2043                                  * in nfs4_exchange_id */
2044         default:
2045                 dprintk("%s: exit with error %d for server %s\n", __func__,
2046                                 status, clp->cl_hostname);
2047                 return status;
2048         }
2049         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2050         dprintk("%s: handled error %d for server %s\n", __func__, status,
2051                         clp->cl_hostname);
2052         return 0;
2053 }
2054
2055 static int nfs4_establish_lease(struct nfs_client *clp)
2056 {
2057         const struct cred *cred;
2058         const struct nfs4_state_recovery_ops *ops =
2059                 clp->cl_mvops->reboot_recovery_ops;
2060         int status;
2061
2062         status = nfs4_begin_drain_session(clp);
2063         if (status != 0)
2064                 return status;
2065         cred = nfs4_get_clid_cred(clp);
2066         if (cred == NULL)
2067                 return -ENOENT;
2068         status = ops->establish_clid(clp, cred);
2069         put_cred(cred);
2070         if (status != 0)
2071                 return status;
2072         pnfs_destroy_all_layouts(clp);
2073         return 0;
2074 }
2075
2076 /*
2077  * Returns zero or a negative errno.  NFS4ERR values are converted
2078  * to local errno values.
2079  */
2080 static int nfs4_reclaim_lease(struct nfs_client *clp)
2081 {
2082         int status;
2083
2084         status = nfs4_establish_lease(clp);
2085         if (status < 0)
2086                 return nfs4_handle_reclaim_lease_error(clp, status);
2087         if (test_and_clear_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH, &clp->cl_state))
2088                 nfs4_state_start_reclaim_nograce(clp);
2089         if (!test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
2090                 set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
2091         clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2092         clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2093         return 0;
2094 }
2095
2096 static int nfs4_purge_lease(struct nfs_client *clp)
2097 {
2098         int status;
2099
2100         status = nfs4_establish_lease(clp);
2101         if (status < 0)
2102                 return nfs4_handle_reclaim_lease_error(clp, status);
2103         clear_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2104         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2105         nfs4_state_start_reclaim_nograce(clp);
2106         return 0;
2107 }
2108
2109 /*
2110  * Try remote migration of one FSID from a source server to a
2111  * destination server.  The source server provides a list of
2112  * potential destinations.
2113  *
2114  * Returns zero or a negative NFS4ERR status code.
2115  */
2116 static int nfs4_try_migration(struct nfs_server *server, const struct cred *cred)
2117 {
2118         struct nfs_client *clp = server->nfs_client;
2119         struct nfs4_fs_locations *locations = NULL;
2120         struct inode *inode;
2121         struct page *page;
2122         int status, result;
2123
2124         dprintk("--> %s: FSID %llx:%llx on \"%s\"\n", __func__,
2125                         (unsigned long long)server->fsid.major,
2126                         (unsigned long long)server->fsid.minor,
2127                         clp->cl_hostname);
2128
2129         result = 0;
2130         page = alloc_page(GFP_KERNEL);
2131         locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
2132         if (page == NULL || locations == NULL) {
2133                 dprintk("<-- %s: no memory\n", __func__);
2134                 goto out;
2135         }
2136         locations->fattr = nfs_alloc_fattr();
2137         if (locations->fattr == NULL) {
2138                 dprintk("<-- %s: no memory\n", __func__);
2139                 goto out;
2140         }
2141
2142         inode = d_inode(server->super->s_root);
2143         result = nfs4_proc_get_locations(server, NFS_FH(inode), locations,
2144                                          page, cred);
2145         if (result) {
2146                 dprintk("<-- %s: failed to retrieve fs_locations: %d\n",
2147                         __func__, result);
2148                 goto out;
2149         }
2150
2151         result = -NFS4ERR_NXIO;
2152         if (!locations->nlocations)
2153                 goto out;
2154
2155         if (!(locations->fattr->valid & NFS_ATTR_FATTR_V4_LOCATIONS)) {
2156                 dprintk("<-- %s: No fs_locations data, migration skipped\n",
2157                         __func__);
2158                 goto out;
2159         }
2160
2161         status = nfs4_begin_drain_session(clp);
2162         if (status != 0) {
2163                 result = status;
2164                 goto out;
2165         }
2166
2167         status = nfs4_replace_transport(server, locations);
2168         if (status != 0) {
2169                 dprintk("<-- %s: failed to replace transport: %d\n",
2170                         __func__, status);
2171                 goto out;
2172         }
2173
2174         result = 0;
2175         dprintk("<-- %s: migration succeeded\n", __func__);
2176
2177 out:
2178         if (page != NULL)
2179                 __free_page(page);
2180         if (locations != NULL)
2181                 kfree(locations->fattr);
2182         kfree(locations);
2183         if (result) {
2184                 pr_err("NFS: migration recovery failed (server %s)\n",
2185                                 clp->cl_hostname);
2186                 set_bit(NFS_MIG_FAILED, &server->mig_status);
2187         }
2188         return result;
2189 }
2190
2191 /*
2192  * Returns zero or a negative NFS4ERR status code.
2193  */
2194 static int nfs4_handle_migration(struct nfs_client *clp)
2195 {
2196         const struct nfs4_state_maintenance_ops *ops =
2197                                 clp->cl_mvops->state_renewal_ops;
2198         struct nfs_server *server;
2199         const struct cred *cred;
2200
2201         dprintk("%s: migration reported on \"%s\"\n", __func__,
2202                         clp->cl_hostname);
2203
2204         cred = ops->get_state_renewal_cred(clp);
2205         if (cred == NULL)
2206                 return -NFS4ERR_NOENT;
2207
2208         clp->cl_mig_gen++;
2209 restart:
2210         rcu_read_lock();
2211         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2212                 int status;
2213
2214                 if (server->mig_gen == clp->cl_mig_gen)
2215                         continue;
2216                 server->mig_gen = clp->cl_mig_gen;
2217
2218                 if (!test_and_clear_bit(NFS_MIG_IN_TRANSITION,
2219                                                 &server->mig_status))
2220                         continue;
2221
2222                 rcu_read_unlock();
2223                 status = nfs4_try_migration(server, cred);
2224                 if (status < 0) {
2225                         put_cred(cred);
2226                         return status;
2227                 }
2228                 goto restart;
2229         }
2230         rcu_read_unlock();
2231         put_cred(cred);
2232         return 0;
2233 }
2234
2235 /*
2236  * Test each nfs_server on the clp's cl_superblocks list to see
2237  * if it's moved to another server.  Stop when the server no longer
2238  * returns NFS4ERR_LEASE_MOVED.
2239  */
2240 static int nfs4_handle_lease_moved(struct nfs_client *clp)
2241 {
2242         const struct nfs4_state_maintenance_ops *ops =
2243                                 clp->cl_mvops->state_renewal_ops;
2244         struct nfs_server *server;
2245         const struct cred *cred;
2246
2247         dprintk("%s: lease moved reported on \"%s\"\n", __func__,
2248                         clp->cl_hostname);
2249
2250         cred = ops->get_state_renewal_cred(clp);
2251         if (cred == NULL)
2252                 return -NFS4ERR_NOENT;
2253
2254         clp->cl_mig_gen++;
2255 restart:
2256         rcu_read_lock();
2257         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2258                 struct inode *inode;
2259                 int status;
2260
2261                 if (server->mig_gen == clp->cl_mig_gen)
2262                         continue;
2263                 server->mig_gen = clp->cl_mig_gen;
2264
2265                 rcu_read_unlock();
2266
2267                 inode = d_inode(server->super->s_root);
2268                 status = nfs4_proc_fsid_present(inode, cred);
2269                 if (status != -NFS4ERR_MOVED)
2270                         goto restart;   /* wasn't this one */
2271                 if (nfs4_try_migration(server, cred) == -NFS4ERR_LEASE_MOVED)
2272                         goto restart;   /* there are more */
2273                 goto out;
2274         }
2275         rcu_read_unlock();
2276
2277 out:
2278         put_cred(cred);
2279         return 0;
2280 }
2281
2282 /**
2283  * nfs4_discover_server_trunking - Detect server IP address trunking
2284  *
2285  * @clp: nfs_client under test
2286  * @result: OUT: found nfs_client, or clp
2287  *
2288  * Returns zero or a negative errno.  If zero is returned,
2289  * an nfs_client pointer is planted in "result".
2290  *
2291  * Note: since we are invoked in process context, and
2292  * not from inside the state manager, we cannot use
2293  * nfs4_handle_reclaim_lease_error().
2294  */
2295 int nfs4_discover_server_trunking(struct nfs_client *clp,
2296                                   struct nfs_client **result)
2297 {
2298         const struct nfs4_state_recovery_ops *ops =
2299                                 clp->cl_mvops->reboot_recovery_ops;
2300         struct rpc_clnt *clnt;
2301         const struct cred *cred;
2302         int i, status;
2303
2304         dprintk("NFS: %s: testing '%s'\n", __func__, clp->cl_hostname);
2305
2306         clnt = clp->cl_rpcclient;
2307         i = 0;
2308
2309         mutex_lock(&nfs_clid_init_mutex);
2310 again:
2311         status  = -ENOENT;
2312         cred = nfs4_get_clid_cred(clp);
2313         if (cred == NULL)
2314                 goto out_unlock;
2315
2316         status = ops->detect_trunking(clp, result, cred);
2317         put_cred(cred);
2318         switch (status) {
2319         case 0:
2320         case -EINTR:
2321         case -ERESTARTSYS:
2322                 break;
2323         case -ETIMEDOUT:
2324                 if (clnt->cl_softrtry)
2325                         break;
2326                 fallthrough;
2327         case -NFS4ERR_DELAY:
2328         case -EAGAIN:
2329                 ssleep(1);
2330                 fallthrough;
2331         case -NFS4ERR_STALE_CLIENTID:
2332                 dprintk("NFS: %s after status %d, retrying\n",
2333                         __func__, status);
2334                 goto again;
2335         case -EACCES:
2336                 if (i++ == 0) {
2337                         nfs4_root_machine_cred(clp);
2338                         goto again;
2339                 }
2340                 if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX)
2341                         break;
2342                 fallthrough;
2343         case -NFS4ERR_CLID_INUSE:
2344         case -NFS4ERR_WRONGSEC:
2345                 /* No point in retrying if we already used RPC_AUTH_UNIX */
2346                 if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX) {
2347                         status = -EPERM;
2348                         break;
2349                 }
2350                 clnt = rpc_clone_client_set_auth(clnt, RPC_AUTH_UNIX);
2351                 if (IS_ERR(clnt)) {
2352                         status = PTR_ERR(clnt);
2353                         break;
2354                 }
2355                 /* Note: this is safe because we haven't yet marked the
2356                  * client as ready, so we are the only user of
2357                  * clp->cl_rpcclient
2358                  */
2359                 clnt = xchg(&clp->cl_rpcclient, clnt);
2360                 rpc_shutdown_client(clnt);
2361                 clnt = clp->cl_rpcclient;
2362                 goto again;
2363
2364         case -NFS4ERR_MINOR_VERS_MISMATCH:
2365                 status = -EPROTONOSUPPORT;
2366                 break;
2367
2368         case -EKEYEXPIRED:
2369         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
2370                                  * in nfs4_exchange_id */
2371                 status = -EKEYEXPIRED;
2372                 break;
2373         default:
2374                 pr_warn("NFS: %s unhandled error %d. Exiting with error EIO\n",
2375                                 __func__, status);
2376                 status = -EIO;
2377         }
2378
2379 out_unlock:
2380         mutex_unlock(&nfs_clid_init_mutex);
2381         dprintk("NFS: %s: status = %d\n", __func__, status);
2382         return status;
2383 }
2384
2385 #ifdef CONFIG_NFS_V4_1
2386 void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
2387 {
2388         struct nfs_client *clp = session->clp;
2389
2390         switch (err) {
2391         default:
2392                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2393                 break;
2394         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
2395                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2396         }
2397         nfs4_schedule_state_manager(clp);
2398 }
2399 EXPORT_SYMBOL_GPL(nfs4_schedule_session_recovery);
2400
2401 void nfs41_notify_server(struct nfs_client *clp)
2402 {
2403         /* Use CHECK_LEASE to ping the server with a SEQUENCE */
2404         set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2405         nfs4_schedule_state_manager(clp);
2406 }
2407
2408 static void nfs4_reset_all_state(struct nfs_client *clp)
2409 {
2410         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2411                 set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2412                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2413                 nfs4_state_start_reclaim_nograce(clp);
2414                 dprintk("%s: scheduling reset of all state for server %s!\n",
2415                                 __func__, clp->cl_hostname);
2416                 nfs4_schedule_state_manager(clp);
2417         }
2418 }
2419
2420 static void nfs41_handle_server_reboot(struct nfs_client *clp)
2421 {
2422         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2423                 nfs4_state_start_reclaim_reboot(clp);
2424                 dprintk("%s: server %s rebooted!\n", __func__,
2425                                 clp->cl_hostname);
2426                 nfs4_schedule_state_manager(clp);
2427         }
2428 }
2429
2430 static void nfs41_handle_all_state_revoked(struct nfs_client *clp)
2431 {
2432         nfs4_reset_all_state(clp);
2433         dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2434 }
2435
2436 static void nfs41_handle_some_state_revoked(struct nfs_client *clp)
2437 {
2438         nfs4_state_start_reclaim_nograce(clp);
2439         nfs4_schedule_state_manager(clp);
2440
2441         dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2442 }
2443
2444 static void nfs41_handle_recallable_state_revoked(struct nfs_client *clp)
2445 {
2446         /* FIXME: For now, we destroy all layouts. */
2447         pnfs_destroy_all_layouts(clp);
2448         nfs_test_expired_all_delegations(clp);
2449         dprintk("%s: Recallable state revoked on server %s!\n", __func__,
2450                         clp->cl_hostname);
2451 }
2452
2453 static void nfs41_handle_backchannel_fault(struct nfs_client *clp)
2454 {
2455         set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2456         nfs4_schedule_state_manager(clp);
2457
2458         dprintk("%s: server %s declared a backchannel fault\n", __func__,
2459                         clp->cl_hostname);
2460 }
2461
2462 static void nfs41_handle_cb_path_down(struct nfs_client *clp)
2463 {
2464         if (test_and_set_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2465                 &clp->cl_state) == 0)
2466                 nfs4_schedule_state_manager(clp);
2467 }
2468
2469 void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags,
2470                 bool recovery)
2471 {
2472         if (!flags)
2473                 return;
2474
2475         dprintk("%s: \"%s\" (client ID %llx) flags=0x%08x\n",
2476                 __func__, clp->cl_hostname, clp->cl_clientid, flags);
2477         /*
2478          * If we're called from the state manager thread, then assume we're
2479          * already handling the RECLAIM_NEEDED and/or STATE_REVOKED.
2480          * Those flags are expected to remain set until we're done
2481          * recovering (see RFC5661, section 18.46.3).
2482          */
2483         if (recovery)
2484                 goto out_recovery;
2485
2486         if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED)
2487                 nfs41_handle_server_reboot(clp);
2488         if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED))
2489                 nfs41_handle_all_state_revoked(clp);
2490         if (flags & (SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED |
2491                             SEQ4_STATUS_ADMIN_STATE_REVOKED))
2492                 nfs41_handle_some_state_revoked(clp);
2493         if (flags & SEQ4_STATUS_LEASE_MOVED)
2494                 nfs4_schedule_lease_moved_recovery(clp);
2495         if (flags & SEQ4_STATUS_RECALLABLE_STATE_REVOKED)
2496                 nfs41_handle_recallable_state_revoked(clp);
2497 out_recovery:
2498         if (flags & SEQ4_STATUS_BACKCHANNEL_FAULT)
2499                 nfs41_handle_backchannel_fault(clp);
2500         else if (flags & (SEQ4_STATUS_CB_PATH_DOWN |
2501                                 SEQ4_STATUS_CB_PATH_DOWN_SESSION))
2502                 nfs41_handle_cb_path_down(clp);
2503 }
2504
2505 static int nfs4_reset_session(struct nfs_client *clp)
2506 {
2507         const struct cred *cred;
2508         int status;
2509
2510         if (!nfs4_has_session(clp))
2511                 return 0;
2512         status = nfs4_begin_drain_session(clp);
2513         if (status != 0)
2514                 return status;
2515         cred = nfs4_get_clid_cred(clp);
2516         status = nfs4_proc_destroy_session(clp->cl_session, cred);
2517         switch (status) {
2518         case 0:
2519         case -NFS4ERR_BADSESSION:
2520         case -NFS4ERR_DEADSESSION:
2521                 break;
2522         case -NFS4ERR_BACK_CHAN_BUSY:
2523         case -NFS4ERR_DELAY:
2524                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2525                 status = 0;
2526                 ssleep(1);
2527                 goto out;
2528         default:
2529                 status = nfs4_recovery_handle_error(clp, status);
2530                 goto out;
2531         }
2532
2533         memset(clp->cl_session->sess_id.data, 0, NFS4_MAX_SESSIONID_LEN);
2534         status = nfs4_proc_create_session(clp, cred);
2535         if (status) {
2536                 dprintk("%s: session reset failed with status %d for server %s!\n",
2537                         __func__, status, clp->cl_hostname);
2538                 status = nfs4_handle_reclaim_lease_error(clp, status);
2539                 goto out;
2540         }
2541         nfs41_finish_session_reset(clp);
2542         dprintk("%s: session reset was successful for server %s!\n",
2543                         __func__, clp->cl_hostname);
2544 out:
2545         put_cred(cred);
2546         return status;
2547 }
2548
2549 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2550 {
2551         const struct cred *cred;
2552         int ret;
2553
2554         if (!nfs4_has_session(clp))
2555                 return 0;
2556         ret = nfs4_begin_drain_session(clp);
2557         if (ret != 0)
2558                 return ret;
2559         cred = nfs4_get_clid_cred(clp);
2560         ret = nfs4_proc_bind_conn_to_session(clp, cred);
2561         put_cred(cred);
2562         clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2563         switch (ret) {
2564         case 0:
2565                 dprintk("%s: bind_conn_to_session was successful for server %s!\n",
2566                         __func__, clp->cl_hostname);
2567                 break;
2568         case -NFS4ERR_DELAY:
2569                 ssleep(1);
2570                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2571                 break;
2572         default:
2573                 return nfs4_recovery_handle_error(clp, ret);
2574         }
2575         return 0;
2576 }
2577
2578 static void nfs4_layoutreturn_any_run(struct nfs_client *clp)
2579 {
2580         int iomode = 0;
2581
2582         if (test_and_clear_bit(NFS4CLNT_RECALL_ANY_LAYOUT_READ, &clp->cl_state))
2583                 iomode += IOMODE_READ;
2584         if (test_and_clear_bit(NFS4CLNT_RECALL_ANY_LAYOUT_RW, &clp->cl_state))
2585                 iomode += IOMODE_RW;
2586         /* Note: IOMODE_READ + IOMODE_RW == IOMODE_ANY */
2587         if (iomode) {
2588                 pnfs_layout_return_unused_byclid(clp, iomode);
2589                 set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2590         }
2591 }
2592 #else /* CONFIG_NFS_V4_1 */
2593 static int nfs4_reset_session(struct nfs_client *clp) { return 0; }
2594
2595 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2596 {
2597         return 0;
2598 }
2599
2600 static void nfs4_layoutreturn_any_run(struct nfs_client *clp)
2601 {
2602 }
2603 #endif /* CONFIG_NFS_V4_1 */
2604
2605 static void nfs4_state_manager(struct nfs_client *clp)
2606 {
2607         unsigned int memflags;
2608         int status = 0;
2609         const char *section = "", *section_sep = "";
2610
2611         /*
2612          * State recovery can deadlock if the direct reclaim code tries
2613          * start NFS writeback. So ensure memory allocations are all
2614          * GFP_NOFS.
2615          */
2616         memflags = memalloc_nofs_save();
2617
2618         /* Ensure exclusive access to NFSv4 state */
2619         do {
2620                 trace_nfs4_state_mgr(clp);
2621                 clear_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2622                 if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
2623                         section = "purge state";
2624                         status = nfs4_purge_lease(clp);
2625                         if (status < 0)
2626                                 goto out_error;
2627                         continue;
2628                 }
2629
2630                 if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
2631                         section = "lease expired";
2632                         /* We're going to have to re-establish a clientid */
2633                         status = nfs4_reclaim_lease(clp);
2634                         if (status < 0)
2635                                 goto out_error;
2636                         continue;
2637                 }
2638
2639                 /* Initialize or reset the session */
2640                 if (test_and_clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state)) {
2641                         section = "reset session";
2642                         status = nfs4_reset_session(clp);
2643                         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
2644                                 continue;
2645                         if (status < 0)
2646                                 goto out_error;
2647                 }
2648
2649                 /* Send BIND_CONN_TO_SESSION */
2650                 if (test_and_clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2651                                 &clp->cl_state)) {
2652                         section = "bind conn to session";
2653                         status = nfs4_bind_conn_to_session(clp);
2654                         if (status < 0)
2655                                 goto out_error;
2656                         continue;
2657                 }
2658
2659                 if (test_and_clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state)) {
2660                         section = "check lease";
2661                         status = nfs4_check_lease(clp);
2662                         if (status < 0)
2663                                 goto out_error;
2664                         continue;
2665                 }
2666
2667                 if (test_and_clear_bit(NFS4CLNT_MOVED, &clp->cl_state)) {
2668                         section = "migration";
2669                         status = nfs4_handle_migration(clp);
2670                         if (status < 0)
2671                                 goto out_error;
2672                 }
2673
2674                 if (test_and_clear_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state)) {
2675                         section = "lease moved";
2676                         status = nfs4_handle_lease_moved(clp);
2677                         if (status < 0)
2678                                 goto out_error;
2679                 }
2680
2681                 /* First recover reboot state... */
2682                 if (test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {
2683                         section = "reclaim reboot";
2684                         status = nfs4_do_reclaim(clp,
2685                                 clp->cl_mvops->reboot_recovery_ops);
2686                         if (status == -EAGAIN)
2687                                 continue;
2688                         if (status < 0)
2689                                 goto out_error;
2690                         nfs4_state_end_reclaim_reboot(clp);
2691                         continue;
2692                 }
2693
2694                 /* Detect expired delegations... */
2695                 if (test_and_clear_bit(NFS4CLNT_DELEGATION_EXPIRED, &clp->cl_state)) {
2696                         section = "detect expired delegations";
2697                         nfs_reap_expired_delegations(clp);
2698                         continue;
2699                 }
2700
2701                 /* Now recover expired state... */
2702                 if (test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state)) {
2703                         section = "reclaim nograce";
2704                         status = nfs4_do_reclaim(clp,
2705                                 clp->cl_mvops->nograce_recovery_ops);
2706                         if (status == -EAGAIN)
2707                                 continue;
2708                         if (status < 0)
2709                                 goto out_error;
2710                         clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
2711                 }
2712
2713                 memalloc_nofs_restore(memflags);
2714                 nfs4_end_drain_session(clp);
2715                 nfs4_clear_state_manager_bit(clp);
2716
2717                 if (test_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state) &&
2718                     !test_and_set_bit(NFS4CLNT_MANAGER_RUNNING,
2719                                       &clp->cl_state)) {
2720                         memflags = memalloc_nofs_save();
2721                         continue;
2722                 }
2723
2724                 if (!test_and_set_bit(NFS4CLNT_RECALL_RUNNING, &clp->cl_state)) {
2725                         if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
2726                                 nfs_client_return_marked_delegations(clp);
2727                                 set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2728                         }
2729                         nfs4_layoutreturn_any_run(clp);
2730                         clear_bit(NFS4CLNT_RECALL_RUNNING, &clp->cl_state);
2731                 }
2732
2733                 return;
2734
2735         } while (refcount_read(&clp->cl_count) > 1 && !signalled());
2736         goto out_drain;
2737
2738 out_error:
2739         if (strlen(section))
2740                 section_sep = ": ";
2741         trace_nfs4_state_mgr_failed(clp, section, status);
2742         pr_warn_ratelimited("NFS: state manager%s%s failed on NFSv4 server %s"
2743                         " with error %d\n", section_sep, section,
2744                         clp->cl_hostname, -status);
2745         ssleep(1);
2746 out_drain:
2747         memalloc_nofs_restore(memflags);
2748         nfs4_end_drain_session(clp);
2749         nfs4_clear_state_manager_bit(clp);
2750 }
2751
2752 static int nfs4_run_state_manager(void *ptr)
2753 {
2754         struct nfs_client *clp = ptr;
2755         struct rpc_clnt *cl = clp->cl_rpcclient;
2756
2757         while (cl != cl->cl_parent)
2758                 cl = cl->cl_parent;
2759
2760         allow_signal(SIGKILL);
2761 again:
2762         nfs4_state_manager(clp);
2763
2764         if (test_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state) &&
2765             !test_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state)) {
2766                 wait_var_event_interruptible(&clp->cl_state,
2767                                              test_bit(NFS4CLNT_RUN_MANAGER,
2768                                                       &clp->cl_state));
2769                 if (!atomic_read(&cl->cl_swapper))
2770                         clear_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state);
2771                 if (refcount_read(&clp->cl_count) > 1 && !signalled() &&
2772                     !test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state))
2773                         goto again;
2774                 /* Either no longer a swapper, or were signalled */
2775                 clear_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state);
2776         }
2777
2778         if (refcount_read(&clp->cl_count) > 1 && !signalled() &&
2779             test_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state) &&
2780             !test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state))
2781                 goto again;
2782
2783         nfs_put_client(clp);
2784         module_put_and_kthread_exit(0);
2785         return 0;
2786 }