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 <[email protected]>
  10  *
  11  *  Redistribution and use in source and binary forms, with or without
  12  *  modification, are permitted provided that the following conditions
  13  *  are met:
  14  *
  15  *  1. Redistributions of source code must retain the above copyright
  16  *     notice, this list of conditions and the following disclaimer.
  17  *  2. Redistributions in binary form must reproduce the above copyright
  18  *     notice, this list of conditions and the following disclaimer in the
  19  *     documentation and/or other materials provided with the distribution.
  20  *  3. Neither the name of the University nor the names of its
  21  *     contributors may be used to endorse or promote products derived
  22  *     from this software without specific prior written permission.
  23  *
  24  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  25  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  26  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  27  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  31  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  32  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  33  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  34  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35  *
  36  * Implementation of the NFSv4 state model.  For the time being,
  37  * this is minimal, but will be made much more complex in a
  38  * subsequent patch.
  39  */
  40
  41 #include <linux/kernel.h>
  42 #include <linux/slab.h>
  43 #include <linux/fs.h>
  44 #include <linux/nfs_fs.h>
  45 #include <linux/kthread.h>
  46 #include <linux/module.h>
  47 #include <linux/random.h>
  48 #include <linux/ratelimit.h>
  49 #include <linux/workqueue.h>
  50 #include <linux/bitops.h>
  51 #include <linux/jiffies.h>
  52
  53 #include <linux/sunrpc/clnt.h>
  54
  55 #include "nfs4_fs.h"
  56 #include "callback.h"
  57 #include "delegation.h"
  58 #include "internal.h"
  59 #include "nfs4idmap.h"
  60 #include "nfs4session.h"
  61 #include "pnfs.h"
  62 #include "netns.h"
  63
  64 #define NFSDBG_FACILITY         NFSDBG_STATE
  65
  66 #define OPENOWNER_POOL_SIZE     8
  67
  68 const nfs4_stateid zero_stateid = {
  69         { .data = { 0 } },
  70         .type = NFS4_SPECIAL_STATEID_TYPE,
  71 };
  72 const nfs4_stateid invalid_stateid = {
  73         {
  74                 /* Funky initialiser keeps older gcc versions happy */
  75                 .data = { 0xff, 0xff, 0xff, 0xff, 0 },
  76         },
  77         .type = NFS4_INVALID_STATEID_TYPE,
  78 };
  79
  80 static DEFINE_MUTEX(nfs_clid_init_mutex);
  81
  82 int nfs4_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
  83 {
  84         struct nfs4_setclientid_res clid = {
  85                 .clientid = clp->cl_clientid,
  86                 .confirm = clp->cl_confirm,
  87         };
  88         unsigned short port;
  89         int status;
  90         struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
  91
  92         if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
  93                 goto do_confirm;
  94         port = nn->nfs_callback_tcpport;
  95         if (clp->cl_addr.ss_family == AF_INET6)
  96                 port = nn->nfs_callback_tcpport6;
  97
  98         status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
  99         if (status != 0)
 100                 goto out;
 101         clp->cl_clientid = clid.clientid;
 102         clp->cl_confirm = clid.confirm;
 103         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 104 do_confirm:
 105         status = nfs4_proc_setclientid_confirm(clp, &clid, cred);
 106         if (status != 0)
 107                 goto out;
 108         clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 109         nfs4_schedule_state_renewal(clp);
 110 out:
 111         return status;
 112 }
 113
 114 /**
 115  * nfs40_discover_server_trunking - Detect server IP address trunking (mv0)
 116  *
 117  * @clp: nfs_client under test
 118  * @result: OUT: found nfs_client, or clp
 119  * @cred: credential to use for trunking test
 120  *
 121  * Returns zero, a negative errno, or a negative NFS4ERR status.
 122  * If zero is returned, an nfs_client pointer is planted in
 123  * "result".
 124  *
 125  * Note: The returned client may not yet be marked ready.
 126  */
 127 int nfs40_discover_server_trunking(struct nfs_client *clp,
 128                                    struct nfs_client **result,
 129                                    struct rpc_cred *cred)
 130 {
 131         struct nfs4_setclientid_res clid = {
 132                 .clientid = clp->cl_clientid,
 133                 .confirm = clp->cl_confirm,
 134         };
 135         struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
 136         unsigned short port;
 137         int status;
 138
 139         port = nn->nfs_callback_tcpport;
 140         if (clp->cl_addr.ss_family == AF_INET6)
 141                 port = nn->nfs_callback_tcpport6;
 142
 143         status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
 144         if (status != 0)
 145                 goto out;
 146         clp->cl_clientid = clid.clientid;
 147         clp->cl_confirm = clid.confirm;
 148
 149         status = nfs40_walk_client_list(clp, result, cred);
 150         if (status == 0) {
 151                 /* Sustain the lease, even if it's empty.  If the clientid4
 152                  * goes stale it's of no use for trunking discovery. */
 153                 nfs4_schedule_state_renewal(*result);
 154         }
 155 out:
 156         return status;
 157 }
 158
 159 struct rpc_cred *nfs4_get_machine_cred_locked(struct nfs_client *clp)
 160 {
 161         struct rpc_cred *cred = NULL;
 162
 163         if (clp->cl_machine_cred != NULL)
 164                 cred = get_rpccred(clp->cl_machine_cred);
 165         return cred;
 166 }
 167
 168 static void nfs4_root_machine_cred(struct nfs_client *clp)
 169 {
 170         struct rpc_cred *cred, *new;
 171
 172         new = rpc_lookup_machine_cred(NULL);
 173         spin_lock(&clp->cl_lock);
 174         cred = clp->cl_machine_cred;
 175         clp->cl_machine_cred = new;
 176         spin_unlock(&clp->cl_lock);
 177         if (cred != NULL)
 178                 put_rpccred(cred);
 179 }
 180
 181 static struct rpc_cred *
 182 nfs4_get_renew_cred_server_locked(struct nfs_server *server)
 183 {
 184         struct rpc_cred *cred = NULL;
 185         struct nfs4_state_owner *sp;
 186         struct rb_node *pos;
 187
 188         for (pos = rb_first(&server->state_owners);
 189              pos != NULL;
 190              pos = rb_next(pos)) {
 191                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
 192                 if (list_empty(&sp->so_states))
 193                         continue;
 194                 cred = get_rpccred(sp->so_cred);
 195                 break;
 196         }
 197         return cred;
 198 }
 199
 200 /**
 201  * nfs4_get_renew_cred_locked - Acquire credential for a renew operation
 202  * @clp: client state handle
 203  *
 204  * Returns an rpc_cred with reference count bumped, or NULL.
 205  * Caller must hold clp->cl_lock.
 206  */
 207 struct rpc_cred *nfs4_get_renew_cred_locked(struct nfs_client *clp)
 208 {
 209         struct rpc_cred *cred = NULL;
 210         struct nfs_server *server;
 211
 212         /* Use machine credentials if available */
 213         cred = nfs4_get_machine_cred_locked(clp);
 214         if (cred != NULL)
 215                 goto out;
 216
 217         rcu_read_lock();
 218         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 219                 cred = nfs4_get_renew_cred_server_locked(server);
 220                 if (cred != NULL)
 221                         break;
 222         }
 223         rcu_read_unlock();
 224
 225 out:
 226         return cred;
 227 }
 228
 229 static void nfs4_end_drain_slot_table(struct nfs4_slot_table *tbl)
 230 {
 231         if (test_and_clear_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state)) {
 232                 spin_lock(&tbl->slot_tbl_lock);
 233                 nfs41_wake_slot_table(tbl);
 234                 spin_unlock(&tbl->slot_tbl_lock);
 235         }
 236 }
 237
 238 static void nfs4_end_drain_session(struct nfs_client *clp)
 239 {
 240         struct nfs4_session *ses = clp->cl_session;
 241
 242         if (clp->cl_slot_tbl) {
 243                 nfs4_end_drain_slot_table(clp->cl_slot_tbl);
 244                 return;
 245         }
 246
 247         if (ses != NULL) {
 248                 nfs4_end_drain_slot_table(&ses->bc_slot_table);
 249                 nfs4_end_drain_slot_table(&ses->fc_slot_table);
 250         }
 251 }
 252
 253 static int nfs4_drain_slot_tbl(struct nfs4_slot_table *tbl)
 254 {
 255         set_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
 256         spin_lock(&tbl->slot_tbl_lock);
 257         if (tbl->highest_used_slotid != NFS4_NO_SLOT) {
 258                 reinit_completion(&tbl->complete);
 259                 spin_unlock(&tbl->slot_tbl_lock);
 260                 return wait_for_completion_interruptible(&tbl->complete);
 261         }
 262         spin_unlock(&tbl->slot_tbl_lock);
 263         return 0;
 264 }
 265
 266 static int nfs4_begin_drain_session(struct nfs_client *clp)
 267 {
 268         struct nfs4_session *ses = clp->cl_session;
 269         int ret = 0;
 270
 271         if (clp->cl_slot_tbl)
 272                 return nfs4_drain_slot_tbl(clp->cl_slot_tbl);
 273
 274         /* back channel */
 275         ret = nfs4_drain_slot_tbl(&ses->bc_slot_table);
 276         if (ret)
 277                 return ret;
 278         /* fore channel */
 279         return nfs4_drain_slot_tbl(&ses->fc_slot_table);
 280 }
 281
 282 #if defined(CONFIG_NFS_V4_1)
 283
 284 static int nfs41_setup_state_renewal(struct nfs_client *clp)
 285 {
 286         int status;
 287         struct nfs_fsinfo fsinfo;
 288         unsigned long now;
 289
 290         if (!test_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state)) {
 291                 nfs4_schedule_state_renewal(clp);
 292                 return 0;
 293         }
 294
 295         now = jiffies;
 296         status = nfs4_proc_get_lease_time(clp, &fsinfo);
 297         if (status == 0) {
 298                 nfs4_set_lease_period(clp, fsinfo.lease_time * HZ, now);
 299                 nfs4_schedule_state_renewal(clp);
 300         }
 301
 302         return status;
 303 }
 304
 305 static void nfs41_finish_session_reset(struct nfs_client *clp)
 306 {
 307         clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 308         clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
 309         /* create_session negotiated new slot table */
 310         clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
 311         nfs41_setup_state_renewal(clp);
 312 }
 313
 314 int nfs41_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
 315 {
 316         int status;
 317
 318         if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
 319                 goto do_confirm;
 320         status = nfs4_proc_exchange_id(clp, cred);
 321         if (status != 0)
 322                 goto out;
 323         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 324 do_confirm:
 325         status = nfs4_proc_create_session(clp, cred);
 326         if (status != 0)
 327                 goto out;
 328         nfs41_finish_session_reset(clp);
 329         nfs_mark_client_ready(clp, NFS_CS_READY);
 330 out:
 331         return status;
 332 }
 333
 334 /**
 335  * nfs41_discover_server_trunking - Detect server IP address trunking (mv1)
 336  *
 337  * @clp: nfs_client under test
 338  * @result: OUT: found nfs_client, or clp
 339  * @cred: credential to use for trunking test
 340  *
 341  * Returns NFS4_OK, a negative errno, or a negative NFS4ERR status.
 342  * If NFS4_OK is returned, an nfs_client pointer is planted in
 343  * "result".
 344  *
 345  * Note: The returned client may not yet be marked ready.
 346  */
 347 int nfs41_discover_server_trunking(struct nfs_client *clp,
 348                                    struct nfs_client **result,
 349                                    struct rpc_cred *cred)
 350 {
 351         int status;
 352
 353         status = nfs4_proc_exchange_id(clp, cred);
 354         if (status != NFS4_OK)
 355                 return status;
 356
 357         status = nfs41_walk_client_list(clp, result, cred);
 358         if (status < 0)
 359                 return status;
 360         if (clp != *result)
 361                 return 0;
 362
 363         /*
 364          * Purge state if the client id was established in a prior
 365          * instance and the client id could not have arrived on the
 366          * server via Transparent State Migration.
 367          */
 368         if (clp->cl_exchange_flags & EXCHGID4_FLAG_CONFIRMED_R) {
 369                 if (!test_bit(NFS_CS_TSM_POSSIBLE, &clp->cl_flags))
 370                         set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
 371                 else
 372                         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 373         }
 374         nfs4_schedule_state_manager(clp);
 375         status = nfs_wait_client_init_complete(clp);
 376         if (status < 0)
 377                 nfs_put_client(clp);
 378         return status;
 379 }
 380
 381 #endif /* CONFIG_NFS_V4_1 */
 382
 383 /**
 384  * nfs4_get_clid_cred - Acquire credential for a setclientid operation
 385  * @clp: client state handle
 386  *
 387  * Returns an rpc_cred with reference count bumped, or NULL.
 388  */
 389 struct rpc_cred *nfs4_get_clid_cred(struct nfs_client *clp)
 390 {
 391         struct rpc_cred *cred;
 392
 393         spin_lock(&clp->cl_lock);
 394         cred = nfs4_get_machine_cred_locked(clp);
 395         spin_unlock(&clp->cl_lock);
 396         return cred;
 397 }
 398
 399 static struct nfs4_state_owner *
 400 nfs4_find_state_owner_locked(struct nfs_server *server, struct rpc_cred *cred)
 401 {
 402         struct rb_node **p = &server->state_owners.rb_node,
 403                        *parent = NULL;
 404         struct nfs4_state_owner *sp;
 405
 406         while (*p != NULL) {
 407                 parent = *p;
 408                 sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
 409
 410                 if (cred < sp->so_cred)
 411                         p = &parent->rb_left;
 412                 else if (cred > sp->so_cred)
 413                         p = &parent->rb_right;
 414                 else {
 415                         if (!list_empty(&sp->so_lru))
 416                                 list_del_init(&sp->so_lru);
 417                         atomic_inc(&sp->so_count);
 418                         return sp;
 419                 }
 420         }
 421         return NULL;
 422 }
 423
 424 static struct nfs4_state_owner *
 425 nfs4_insert_state_owner_locked(struct nfs4_state_owner *new)
 426 {
 427         struct nfs_server *server = new->so_server;
 428         struct rb_node **p = &server->state_owners.rb_node,
 429                        *parent = NULL;
 430         struct nfs4_state_owner *sp;
 431
 432         while (*p != NULL) {
 433                 parent = *p;
 434                 sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
 435
 436                 if (new->so_cred < sp->so_cred)
 437                         p = &parent->rb_left;
 438                 else if (new->so_cred > sp->so_cred)
 439                         p = &parent->rb_right;
 440                 else {
 441                         if (!list_empty(&sp->so_lru))
 442                                 list_del_init(&sp->so_lru);
 443                         atomic_inc(&sp->so_count);
 444                         return sp;
 445                 }
 446         }
 447         rb_link_node(&new->so_server_node, parent, p);
 448         rb_insert_color(&new->so_server_node, &server->state_owners);
 449         return new;
 450 }
 451
 452 static void
 453 nfs4_remove_state_owner_locked(struct nfs4_state_owner *sp)
 454 {
 455         struct nfs_server *server = sp->so_server;
 456
 457         if (!RB_EMPTY_NODE(&sp->so_server_node))
 458                 rb_erase(&sp->so_server_node, &server->state_owners);
 459 }
 460
 461 static void
 462 nfs4_init_seqid_counter(struct nfs_seqid_counter *sc)
 463 {
 464         sc->create_time = ktime_get();
 465         sc->flags = 0;
 466         sc->counter = 0;
 467         spin_lock_init(&sc->lock);
 468         INIT_LIST_HEAD(&sc->list);
 469         rpc_init_wait_queue(&sc->wait, "Seqid_waitqueue");
 470 }
 471
 472 static void
 473 nfs4_destroy_seqid_counter(struct nfs_seqid_counter *sc)
 474 {
 475         rpc_destroy_wait_queue(&sc->wait);
 476 }
 477
 478 /*
 479  * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
 480  * create a new state_owner.
 481  *
 482  */
 483 static struct nfs4_state_owner *
 484 nfs4_alloc_state_owner(struct nfs_server *server,
 485                 struct rpc_cred *cred,
 486                 gfp_t gfp_flags)
 487 {
 488         struct nfs4_state_owner *sp;
 489
 490         sp = kzalloc(sizeof(*sp), gfp_flags);
 491         if (!sp)
 492                 return NULL;
 493         sp->so_seqid.owner_id = ida_simple_get(&server->openowner_id, 0, 0,
 494                                                 gfp_flags);
 495         if (sp->so_seqid.owner_id < 0) {
 496                 kfree(sp);
 497                 return NULL;
 498         }
 499         sp->so_server = server;
 500         sp->so_cred = get_rpccred(cred);
 501         spin_lock_init(&sp->so_lock);
 502         INIT_LIST_HEAD(&sp->so_states);
 503         nfs4_init_seqid_counter(&sp->so_seqid);
 504         atomic_set(&sp->so_count, 1);
 505         INIT_LIST_HEAD(&sp->so_lru);
 506         seqcount_init(&sp->so_reclaim_seqcount);
 507         mutex_init(&sp->so_delegreturn_mutex);
 508         return sp;
 509 }
 510
 511 static void
 512 nfs4_reset_state_owner(struct nfs4_state_owner *sp)
 513 {
 514         /* This state_owner is no longer usable, but must
 515          * remain in place so that state recovery can find it
 516          * and the opens associated with it.
 517          * It may also be used for new 'open' request to
 518          * return a delegation to the server.
 519          * So update the 'create_time' so that it looks like
 520          * a new state_owner.  This will cause the server to
 521          * request an OPEN_CONFIRM to start a new sequence.
 522          */
 523         sp->so_seqid.create_time = ktime_get();
 524 }
 525
 526 static void nfs4_free_state_owner(struct nfs4_state_owner *sp)
 527 {
 528         nfs4_destroy_seqid_counter(&sp->so_seqid);
 529         put_rpccred(sp->so_cred);
 530         ida_simple_remove(&sp->so_server->openowner_id, sp->so_seqid.owner_id);
 531         kfree(sp);
 532 }
 533
 534 static void nfs4_gc_state_owners(struct nfs_server *server)
 535 {
 536         struct nfs_client *clp = server->nfs_client;
 537         struct nfs4_state_owner *sp, *tmp;
 538         unsigned long time_min, time_max;
 539         LIST_HEAD(doomed);
 540
 541         spin_lock(&clp->cl_lock);
 542         time_max = jiffies;
 543         time_min = (long)time_max - (long)clp->cl_lease_time;
 544         list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
 545                 /* NB: LRU is sorted so that oldest is at the head */
 546                 if (time_in_range(sp->so_expires, time_min, time_max))
 547                         break;
 548                 list_move(&sp->so_lru, &doomed);
 549                 nfs4_remove_state_owner_locked(sp);
 550         }
 551         spin_unlock(&clp->cl_lock);
 552
 553         list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
 554                 list_del(&sp->so_lru);
 555                 nfs4_free_state_owner(sp);
 556         }
 557 }
 558
 559 /**
 560  * nfs4_get_state_owner - Look up a state owner given a credential
 561  * @server: nfs_server to search
 562  * @cred: RPC credential to match
 563  *
 564  * Returns a pointer to an instantiated nfs4_state_owner struct, or NULL.
 565  */
 566 struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server,
 567                                               struct rpc_cred *cred,
 568                                               gfp_t gfp_flags)
 569 {
 570         struct nfs_client *clp = server->nfs_client;
 571         struct nfs4_state_owner *sp, *new;
 572
 573         spin_lock(&clp->cl_lock);
 574         sp = nfs4_find_state_owner_locked(server, cred);
 575         spin_unlock(&clp->cl_lock);
 576         if (sp != NULL)
 577                 goto out;
 578         new = nfs4_alloc_state_owner(server, cred, gfp_flags);
 579         if (new == NULL)
 580                 goto out;
 581         spin_lock(&clp->cl_lock);
 582         sp = nfs4_insert_state_owner_locked(new);
 583         spin_unlock(&clp->cl_lock);
 584         if (sp != new)
 585                 nfs4_free_state_owner(new);
 586 out:
 587         nfs4_gc_state_owners(server);
 588         return sp;
 589 }
 590
 591 /**
 592  * nfs4_put_state_owner - Release a nfs4_state_owner
 593  * @sp: state owner data to release
 594  *
 595  * Note that we keep released state owners on an LRU
 596  * list.
 597  * This caches valid state owners so that they can be
 598  * reused, to avoid the OPEN_CONFIRM on minor version 0.
 599  * It also pins the uniquifier of dropped state owners for
 600  * a while, to ensure that those state owner names are
 601  * never reused.
 602  */
 603 void nfs4_put_state_owner(struct nfs4_state_owner *sp)
 604 {
 605         struct nfs_server *server = sp->so_server;
 606         struct nfs_client *clp = server->nfs_client;
 607
 608         if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
 609                 return;
 610
 611         sp->so_expires = jiffies;
 612         list_add_tail(&sp->so_lru, &server->state_owners_lru);
 613         spin_unlock(&clp->cl_lock);
 614 }
 615
 616 /**
 617  * nfs4_purge_state_owners - Release all cached state owners
 618  * @server: nfs_server with cached state owners to release
 619  *
 620  * Called at umount time.  Remaining state owners will be on
 621  * the LRU with ref count of zero.
 622  */
 623 void nfs4_purge_state_owners(struct nfs_server *server)
 624 {
 625         struct nfs_client *clp = server->nfs_client;
 626         struct nfs4_state_owner *sp, *tmp;
 627         LIST_HEAD(doomed);
 628
 629         spin_lock(&clp->cl_lock);
 630         list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
 631                 list_move(&sp->so_lru, &doomed);
 632                 nfs4_remove_state_owner_locked(sp);
 633         }
 634         spin_unlock(&clp->cl_lock);
 635
 636         list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
 637                 list_del(&sp->so_lru);
 638                 nfs4_free_state_owner(sp);
 639         }
 640 }
 641
 642 static struct nfs4_state *
 643 nfs4_alloc_open_state(void)
 644 {
 645         struct nfs4_state *state;
 646
 647         state = kzalloc(sizeof(*state), GFP_NOFS);
 648         if (!state)
 649                 return NULL;
 650         atomic_set(&state->count, 1);
 651         INIT_LIST_HEAD(&state->lock_states);
 652         spin_lock_init(&state->state_lock);
 653         seqlock_init(&state->seqlock);
 654         init_waitqueue_head(&state->waitq);
 655         return state;
 656 }
 657
 658 void
 659 nfs4_state_set_mode_locked(struct nfs4_state *state, fmode_t fmode)
 660 {
 661         if (state->state == fmode)
 662                 return;
 663         /* NB! List reordering - see the reclaim code for why.  */
 664         if ((fmode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
 665                 if (fmode & FMODE_WRITE)
 666                         list_move(&state->open_states, &state->owner->so_states);
 667                 else
 668                         list_move_tail(&state->open_states, &state->owner->so_states);
 669         }
 670         state->state = fmode;
 671 }
 672
 673 static struct nfs4_state *
 674 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
 675 {
 676         struct nfs_inode *nfsi = NFS_I(inode);
 677         struct nfs4_state *state;
 678
 679         list_for_each_entry(state, &nfsi->open_states, inode_states) {
 680                 if (state->owner != owner)
 681                         continue;
 682                 if (!nfs4_valid_open_stateid(state))
 683                         continue;
 684                 if (atomic_inc_not_zero(&state->count))
 685                         return state;
 686         }
 687         return NULL;
 688 }
 689
 690 static void
 691 nfs4_free_open_state(struct nfs4_state *state)
 692 {
 693         kfree(state);
 694 }
 695
 696 struct nfs4_state *
 697 nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
 698 {
 699         struct nfs4_state *state, *new;
 700         struct nfs_inode *nfsi = NFS_I(inode);
 701
 702         spin_lock(&inode->i_lock);
 703         state = __nfs4_find_state_byowner(inode, owner);
 704         spin_unlock(&inode->i_lock);
 705         if (state)
 706                 goto out;
 707         new = nfs4_alloc_open_state();
 708         spin_lock(&owner->so_lock);
 709         spin_lock(&inode->i_lock);
 710         state = __nfs4_find_state_byowner(inode, owner);
 711         if (state == NULL && new != NULL) {
 712                 state = new;
 713                 state->owner = owner;
 714                 atomic_inc(&owner->so_count);
 715                 list_add(&state->inode_states, &nfsi->open_states);
 716                 ihold(inode);
 717                 state->inode = inode;
 718                 spin_unlock(&inode->i_lock);
 719                 /* Note: The reclaim code dictates that we add stateless
 720                  * and read-only stateids to the end of the list */
 721                 list_add_tail(&state->open_states, &owner->so_states);
 722                 spin_unlock(&owner->so_lock);
 723         } else {
 724                 spin_unlock(&inode->i_lock);
 725                 spin_unlock(&owner->so_lock);
 726                 if (new)
 727                         nfs4_free_open_state(new);
 728         }
 729 out:
 730         return state;
 731 }
 732
 733 void nfs4_put_open_state(struct nfs4_state *state)
 734 {
 735         struct inode *inode = state->inode;
 736         struct nfs4_state_owner *owner = state->owner;
 737
 738         if (!atomic_dec_and_lock(&state->count, &owner->so_lock))
 739                 return;
 740         spin_lock(&inode->i_lock);
 741         list_del(&state->inode_states);
 742         list_del(&state->open_states);
 743         spin_unlock(&inode->i_lock);
 744         spin_unlock(&owner->so_lock);
 745         iput(inode);
 746         nfs4_free_open_state(state);
 747         nfs4_put_state_owner(owner);
 748 }
 749
 750 /*
 751  * Close the current file.
 752  */
 753 static void __nfs4_close(struct nfs4_state *state,
 754                 fmode_t fmode, gfp_t gfp_mask, int wait)
 755 {
 756         struct nfs4_state_owner *owner = state->owner;
 757         int call_close = 0;
 758         fmode_t newstate;
 759
 760         atomic_inc(&owner->so_count);
 761         /* Protect against nfs4_find_state() */
 762         spin_lock(&owner->so_lock);
 763         switch (fmode & (FMODE_READ | FMODE_WRITE)) {
 764                 case FMODE_READ:
 765                         state->n_rdonly--;
 766                         break;
 767                 case FMODE_WRITE:
 768                         state->n_wronly--;
 769                         break;
 770                 case FMODE_READ|FMODE_WRITE:
 771                         state->n_rdwr--;
 772         }
 773         newstate = FMODE_READ|FMODE_WRITE;
 774         if (state->n_rdwr == 0) {
 775                 if (state->n_rdonly == 0) {
 776                         newstate &= ~FMODE_READ;
 777                         call_close |= test_bit(NFS_O_RDONLY_STATE, &state->flags);
 778                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
 779                 }
 780                 if (state->n_wronly == 0) {
 781                         newstate &= ~FMODE_WRITE;
 782                         call_close |= test_bit(NFS_O_WRONLY_STATE, &state->flags);
 783                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
 784                 }
 785                 if (newstate == 0)
 786                         clear_bit(NFS_DELEGATED_STATE, &state->flags);
 787         }
 788         nfs4_state_set_mode_locked(state, newstate);
 789         spin_unlock(&owner->so_lock);
 790
 791         if (!call_close) {
 792                 nfs4_put_open_state(state);
 793                 nfs4_put_state_owner(owner);
 794         } else
 795                 nfs4_do_close(state, gfp_mask, wait);
 796 }
 797
 798 void nfs4_close_state(struct nfs4_state *state, fmode_t fmode)
 799 {
 800         __nfs4_close(state, fmode, GFP_NOFS, 0);
 801 }
 802
 803 void nfs4_close_sync(struct nfs4_state *state, fmode_t fmode)
 804 {
 805         __nfs4_close(state, fmode, GFP_KERNEL, 1);
 806 }
 807
 808 /*
 809  * Search the state->lock_states for an existing lock_owner
 810  * that is compatible with either of the given owners.
 811  * If the second is non-zero, then the first refers to a Posix-lock
 812  * owner (current->files) and the second refers to a flock/OFD
 813  * owner (struct file*).  In that case, prefer a match for the first
 814  * owner.
 815  * If both sorts of locks are held on the one file we cannot know
 816  * which stateid was intended to be used, so a "correct" choice cannot
 817  * be made.  Failing that, a "consistent" choice is preferable.  The
 818  * consistent choice we make is to prefer the first owner, that of a
 819  * Posix lock.
 820  */
 821 static struct nfs4_lock_state *
 822 __nfs4_find_lock_state(struct nfs4_state *state,
 823                        fl_owner_t fl_owner, fl_owner_t fl_owner2)
 824 {
 825         struct nfs4_lock_state *pos, *ret = NULL;
 826         list_for_each_entry(pos, &state->lock_states, ls_locks) {
 827                 if (pos->ls_owner == fl_owner) {
 828                         ret = pos;
 829                         break;
 830                 }
 831                 if (pos->ls_owner == fl_owner2)
 832                         ret = pos;
 833         }
 834         if (ret)
 835                 refcount_inc(&ret->ls_count);
 836         return ret;
 837 }
 838
 839 /*
 840  * Return a compatible lock_state. If no initialized lock_state structure
 841  * exists, return an uninitialized one.
 842  *
 843  */
 844 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 845 {
 846         struct nfs4_lock_state *lsp;
 847         struct nfs_server *server = state->owner->so_server;
 848
 849         lsp = kzalloc(sizeof(*lsp), GFP_NOFS);
 850         if (lsp == NULL)
 851                 return NULL;
 852         nfs4_init_seqid_counter(&lsp->ls_seqid);
 853         refcount_set(&lsp->ls_count, 1);
 854         lsp->ls_state = state;
 855         lsp->ls_owner = fl_owner;
 856         lsp->ls_seqid.owner_id = ida_simple_get(&server->lockowner_id, 0, 0, GFP_NOFS);
 857         if (lsp->ls_seqid.owner_id < 0)
 858                 goto out_free;
 859         INIT_LIST_HEAD(&lsp->ls_locks);
 860         return lsp;
 861 out_free:
 862         kfree(lsp);
 863         return NULL;
 864 }
 865
 866 void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp)
 867 {
 868         ida_simple_remove(&server->lockowner_id, lsp->ls_seqid.owner_id);
 869         nfs4_destroy_seqid_counter(&lsp->ls_seqid);
 870         kfree(lsp);
 871 }
 872
 873 /*
 874  * Return a compatible lock_state. If no initialized lock_state structure
 875  * exists, return an uninitialized one.
 876  *
 877  */
 878 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
 879 {
 880         struct nfs4_lock_state *lsp, *new = NULL;
 881
 882         for(;;) {
 883                 spin_lock(&state->state_lock);
 884                 lsp = __nfs4_find_lock_state(state, owner, NULL);
 885                 if (lsp != NULL)
 886                         break;
 887                 if (new != NULL) {
 888                         list_add(&new->ls_locks, &state->lock_states);
 889                         set_bit(LK_STATE_IN_USE, &state->flags);
 890                         lsp = new;
 891                         new = NULL;
 892                         break;
 893                 }
 894                 spin_unlock(&state->state_lock);
 895                 new = nfs4_alloc_lock_state(state, owner);
 896                 if (new == NULL)
 897                         return NULL;
 898         }
 899         spin_unlock(&state->state_lock);
 900         if (new != NULL)
 901                 nfs4_free_lock_state(state->owner->so_server, new);
 902         return lsp;
 903 }
 904
 905 /*
 906  * Release reference to lock_state, and free it if we see that
 907  * it is no longer in use
 908  */
 909 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
 910 {
 911         struct nfs_server *server;
 912         struct nfs4_state *state;
 913
 914         if (lsp == NULL)
 915                 return;
 916         state = lsp->ls_state;
 917         if (!refcount_dec_and_lock(&lsp->ls_count, &state->state_lock))
 918                 return;
 919         list_del(&lsp->ls_locks);
 920         if (list_empty(&state->lock_states))
 921                 clear_bit(LK_STATE_IN_USE, &state->flags);
 922         spin_unlock(&state->state_lock);
 923         server = state->owner->so_server;
 924         if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) {
 925                 struct nfs_client *clp = server->nfs_client;
 926
 927                 clp->cl_mvops->free_lock_state(server, lsp);
 928         } else
 929                 nfs4_free_lock_state(server, lsp);
 930 }
 931
 932 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
 933 {
 934         struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
 935
 936         dst->fl_u.nfs4_fl.owner = lsp;
 937         refcount_inc(&lsp->ls_count);
 938 }
 939
 940 static void nfs4_fl_release_lock(struct file_lock *fl)
 941 {
 942         nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
 943 }
 944
 945 static const struct file_lock_operations nfs4_fl_lock_ops = {
 946         .fl_copy_lock = nfs4_fl_copy_lock,
 947         .fl_release_private = nfs4_fl_release_lock,
 948 };
 949
 950 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
 951 {
 952         struct nfs4_lock_state *lsp;
 953
 954         if (fl->fl_ops != NULL)
 955                 return 0;
 956         lsp = nfs4_get_lock_state(state, fl->fl_owner);
 957         if (lsp == NULL)
 958                 return -ENOMEM;
 959         fl->fl_u.nfs4_fl.owner = lsp;
 960         fl->fl_ops = &nfs4_fl_lock_ops;
 961         return 0;
 962 }
 963
 964 static int nfs4_copy_lock_stateid(nfs4_stateid *dst,
 965                 struct nfs4_state *state,
 966                 const struct nfs_lock_context *l_ctx)
 967 {
 968         struct nfs4_lock_state *lsp;
 969         fl_owner_t fl_owner, fl_flock_owner;
 970         int ret = -ENOENT;
 971
 972         if (l_ctx == NULL)
 973                 goto out;
 974
 975         if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
 976                 goto out;
 977
 978         fl_owner = l_ctx->lockowner;
 979         fl_flock_owner = l_ctx->open_context->flock_owner;
 980
 981         spin_lock(&state->state_lock);
 982         lsp = __nfs4_find_lock_state(state, fl_owner, fl_flock_owner);
 983         if (lsp && test_bit(NFS_LOCK_LOST, &lsp->ls_flags))
 984                 ret = -EIO;
 985         else if (lsp != NULL && test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) != 0) {
 986                 nfs4_stateid_copy(dst, &lsp->ls_stateid);
 987                 ret = 0;
 988         }
 989         spin_unlock(&state->state_lock);
 990         nfs4_put_lock_state(lsp);
 991 out:
 992         return ret;
 993 }
 994
 995 bool nfs4_refresh_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
 996 {
 997         bool ret;
 998         int seq;
 999
1000         do {
1001                 ret = false;
1002                 seq = read_seqbegin(&state->seqlock);
1003                 if (nfs4_state_match_open_stateid_other(state, dst)) {
1004                         dst->seqid = state->open_stateid.seqid;
1005                         ret = true;
1006                 }
1007         } while (read_seqretry(&state->seqlock, seq));
1008         return ret;
1009 }
1010
1011 bool nfs4_copy_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
1012 {
1013         bool ret;
1014         const nfs4_stateid *src;
1015         int seq;
1016
1017         do {
1018                 ret = false;
1019                 src = &zero_stateid;
1020                 seq = read_seqbegin(&state->seqlock);
1021                 if (test_bit(NFS_OPEN_STATE, &state->flags)) {
1022                         src = &state->open_stateid;
1023                         ret = true;
1024                 }
1025                 nfs4_stateid_copy(dst, src);
1026         } while (read_seqretry(&state->seqlock, seq));
1027         return ret;
1028 }
1029
1030 /*
1031  * Byte-range lock aware utility to initialize the stateid of read/write
1032  * requests.
1033  */
1034 int nfs4_select_rw_stateid(struct nfs4_state *state,
1035                 fmode_t fmode, const struct nfs_lock_context *l_ctx,
1036                 nfs4_stateid *dst, struct rpc_cred **cred)
1037 {
1038         int ret;
1039
1040         if (!nfs4_valid_open_stateid(state))
1041                 return -EIO;
1042         if (cred != NULL)
1043                 *cred = NULL;
1044         ret = nfs4_copy_lock_stateid(dst, state, l_ctx);
1045         if (ret == -EIO)
1046                 /* A lost lock - don't even consider delegations */
1047                 goto out;
1048         /* returns true if delegation stateid found and copied */
1049         if (nfs4_copy_delegation_stateid(state->inode, fmode, dst, cred)) {
1050                 ret = 0;
1051                 goto out;
1052         }
1053         if (ret != -ENOENT)
1054                 /* nfs4_copy_delegation_stateid() didn't over-write
1055                  * dst, so it still has the lock stateid which we now
1056                  * choose to use.
1057                  */
1058                 goto out;
1059         nfs4_copy_open_stateid(dst, state);
1060         ret = 0;
1061 out:
1062         if (nfs_server_capable(state->inode, NFS_CAP_STATEID_NFSV41))
1063                 dst->seqid = 0;
1064         return ret;
1065 }
1066
1067 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask)
1068 {
1069         struct nfs_seqid *new;
1070
1071         new = kmalloc(sizeof(*new), gfp_mask);
1072         if (new == NULL)
1073                 return ERR_PTR(-ENOMEM);
1074         new->sequence = counter;
1075         INIT_LIST_HEAD(&new->list);
1076         new->task = NULL;
1077         return new;
1078 }
1079
1080 void nfs_release_seqid(struct nfs_seqid *seqid)
1081 {
1082         struct nfs_seqid_counter *sequence;
1083
1084         if (seqid == NULL || list_empty(&seqid->list))
1085                 return;
1086         sequence = seqid->sequence;
1087         spin_lock(&sequence->lock);
1088         list_del_init(&seqid->list);
1089         if (!list_empty(&sequence->list)) {
1090                 struct nfs_seqid *next;
1091
1092                 next = list_first_entry(&sequence->list,
1093                                 struct nfs_seqid, list);
1094                 rpc_wake_up_queued_task(&sequence->wait, next->task);
1095         }
1096         spin_unlock(&sequence->lock);
1097 }
1098
1099 void nfs_free_seqid(struct nfs_seqid *seqid)
1100 {
1101         nfs_release_seqid(seqid);
1102         kfree(seqid);
1103 }
1104
1105 /*
1106  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
1107  * failed with a seqid incrementing error -
1108  * see comments nfs4.h:seqid_mutating_error()
1109  */
1110 static void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
1111 {
1112         switch (status) {
1113                 case 0:
1114                         break;
1115                 case -NFS4ERR_BAD_SEQID:
1116                         if (seqid->sequence->flags & NFS_SEQID_CONFIRMED)
1117                                 return;
1118                         pr_warn_ratelimited("NFS: v4 server returned a bad"
1119                                         " sequence-id error on an"
1120                                         " unconfirmed sequence %p!\n",
1121                                         seqid->sequence);
1122                 case -NFS4ERR_STALE_CLIENTID:
1123                 case -NFS4ERR_STALE_STATEID:
1124                 case -NFS4ERR_BAD_STATEID:
1125                 case -NFS4ERR_BADXDR:
1126                 case -NFS4ERR_RESOURCE:
1127                 case -NFS4ERR_NOFILEHANDLE:
1128                 case -NFS4ERR_MOVED:
1129                         /* Non-seqid mutating errors */
1130                         return;
1131         };
1132         /*
1133          * Note: no locking needed as we are guaranteed to be first
1134          * on the sequence list
1135          */
1136         seqid->sequence->counter++;
1137 }
1138
1139 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
1140 {
1141         struct nfs4_state_owner *sp;
1142
1143         if (seqid == NULL)
1144                 return;
1145
1146         sp = container_of(seqid->sequence, struct nfs4_state_owner, so_seqid);
1147         if (status == -NFS4ERR_BAD_SEQID)
1148                 nfs4_reset_state_owner(sp);
1149         if (!nfs4_has_session(sp->so_server->nfs_client))
1150                 nfs_increment_seqid(status, seqid);
1151 }
1152
1153 /*
1154  * Increment the seqid if the LOCK/LOCKU succeeded, or
1155  * failed with a seqid incrementing error -
1156  * see comments nfs4.h:seqid_mutating_error()
1157  */
1158 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
1159 {
1160         if (seqid != NULL)
1161                 nfs_increment_seqid(status, seqid);
1162 }
1163
1164 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
1165 {
1166         struct nfs_seqid_counter *sequence;
1167         int status = 0;
1168
1169         if (seqid == NULL)
1170                 goto out;
1171         sequence = seqid->sequence;
1172         spin_lock(&sequence->lock);
1173         seqid->task = task;
1174         if (list_empty(&seqid->list))
1175                 list_add_tail(&seqid->list, &sequence->list);
1176         if (list_first_entry(&sequence->list, struct nfs_seqid, list) == seqid)
1177                 goto unlock;
1178         rpc_sleep_on(&sequence->wait, task, NULL);
1179         status = -EAGAIN;
1180 unlock:
1181         spin_unlock(&sequence->lock);
1182 out:
1183         return status;
1184 }
1185
1186 static int nfs4_run_state_manager(void *);
1187
1188 static void nfs4_clear_state_manager_bit(struct nfs_client *clp)
1189 {
1190         smp_mb__before_atomic();
1191         clear_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state);
1192         smp_mb__after_atomic();
1193         wake_up_bit(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING);
1194         rpc_wake_up(&clp->cl_rpcwaitq);
1195 }
1196
1197 /*
1198  * Schedule the nfs_client asynchronous state management routine
1199  */
1200 void nfs4_schedule_state_manager(struct nfs_client *clp)
1201 {
1202         struct task_struct *task;
1203         char buf[INET6_ADDRSTRLEN + sizeof("-manager") + 1];
1204
1205         if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
1206                 return;
1207         __module_get(THIS_MODULE);
1208         refcount_inc(&clp->cl_count);
1209
1210         /* The rcu_read_lock() is not strictly necessary, as the state
1211          * manager is the only thread that ever changes the rpc_xprt
1212          * after it's initialized.  At this point, we're single threaded. */
1213         rcu_read_lock();
1214         snprintf(buf, sizeof(buf), "%s-manager",
1215                         rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
1216         rcu_read_unlock();
1217         task = kthread_run(nfs4_run_state_manager, clp, "%s", buf);
1218         if (IS_ERR(task)) {
1219                 printk(KERN_ERR "%s: kthread_run: %ld\n",
1220                         __func__, PTR_ERR(task));
1221                 nfs4_clear_state_manager_bit(clp);
1222                 nfs_put_client(clp);
1223                 module_put(THIS_MODULE);
1224         }
1225 }
1226
1227 /*
1228  * Schedule a lease recovery attempt
1229  */
1230 void nfs4_schedule_lease_recovery(struct nfs_client *clp)
1231 {
1232         if (!clp)
1233                 return;
1234         if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1235                 set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1236         dprintk("%s: scheduling lease recovery for server %s\n", __func__,
1237                         clp->cl_hostname);
1238         nfs4_schedule_state_manager(clp);
1239 }
1240 EXPORT_SYMBOL_GPL(nfs4_schedule_lease_recovery);
1241
1242 /**
1243  * nfs4_schedule_migration_recovery - trigger migration recovery
1244  *
1245  * @server: FSID that is migrating
1246  *
1247  * Returns zero if recovery has started, otherwise a negative NFS4ERR
1248  * value is returned.
1249  */
1250 int nfs4_schedule_migration_recovery(const struct nfs_server *server)
1251 {
1252         struct nfs_client *clp = server->nfs_client;
1253
1254         if (server->fh_expire_type != NFS4_FH_PERSISTENT) {
1255                 pr_err("NFS: volatile file handles not supported (server %s)\n",
1256                                 clp->cl_hostname);
1257                 return -NFS4ERR_IO;
1258         }
1259
1260         if (test_bit(NFS_MIG_FAILED, &server->mig_status))
1261                 return -NFS4ERR_IO;
1262
1263         dprintk("%s: scheduling migration recovery for (%llx:%llx) on %s\n",
1264                         __func__,
1265                         (unsigned long long)server->fsid.major,
1266                         (unsigned long long)server->fsid.minor,
1267                         clp->cl_hostname);
1268
1269         set_bit(NFS_MIG_IN_TRANSITION,
1270                         &((struct nfs_server *)server)->mig_status);
1271         set_bit(NFS4CLNT_MOVED, &clp->cl_state);
1272
1273         nfs4_schedule_state_manager(clp);
1274         return 0;
1275 }
1276 EXPORT_SYMBOL_GPL(nfs4_schedule_migration_recovery);
1277
1278 /**
1279  * nfs4_schedule_lease_moved_recovery - start lease-moved recovery
1280  *
1281  * @clp: server to check for moved leases
1282  *
1283  */
1284 void nfs4_schedule_lease_moved_recovery(struct nfs_client *clp)
1285 {
1286         dprintk("%s: scheduling lease-moved recovery for client ID %llx on %s\n",
1287                 __func__, clp->cl_clientid, clp->cl_hostname);
1288
1289         set_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state);
1290         nfs4_schedule_state_manager(clp);
1291 }
1292 EXPORT_SYMBOL_GPL(nfs4_schedule_lease_moved_recovery);
1293
1294 int nfs4_wait_clnt_recover(struct nfs_client *clp)
1295 {
1296         int res;
1297
1298         might_sleep();
1299
1300         refcount_inc(&clp->cl_count);
1301         res = wait_on_bit_action(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING,
1302                                  nfs_wait_bit_killable, TASK_KILLABLE);
1303         if (res)
1304                 goto out;
1305         if (clp->cl_cons_state < 0)
1306                 res = clp->cl_cons_state;
1307 out:
1308         nfs_put_client(clp);
1309         return res;
1310 }
1311
1312 int nfs4_client_recover_expired_lease(struct nfs_client *clp)
1313 {
1314         unsigned int loop;
1315         int ret;
1316
1317         for (loop = NFS4_MAX_LOOP_ON_RECOVER; loop != 0; loop--) {
1318                 ret = nfs4_wait_clnt_recover(clp);
1319                 if (ret != 0)
1320                         break;
1321                 if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) &&
1322                     !test_bit(NFS4CLNT_CHECK_LEASE,&clp->cl_state))
1323                         break;
1324                 nfs4_schedule_state_manager(clp);
1325                 ret = -EIO;
1326         }
1327         return ret;
1328 }
1329
1330 /*
1331  * nfs40_handle_cb_pathdown - return all delegations after NFS4ERR_CB_PATH_DOWN
1332  * @clp: client to process
1333  *
1334  * Set the NFS4CLNT_LEASE_EXPIRED state in order to force a
1335  * resend of the SETCLIENTID and hence re-establish the
1336  * callback channel. Then return all existing delegations.
1337  */
1338 static void nfs40_handle_cb_pathdown(struct nfs_client *clp)
1339 {
1340         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1341         nfs_expire_all_delegations(clp);
1342         dprintk("%s: handling CB_PATHDOWN recovery for server %s\n", __func__,
1343                         clp->cl_hostname);
1344 }
1345
1346 void nfs4_schedule_path_down_recovery(struct nfs_client *clp)
1347 {
1348         nfs40_handle_cb_pathdown(clp);
1349         nfs4_schedule_state_manager(clp);
1350 }
1351
1352 static int nfs4_state_mark_reclaim_reboot(struct nfs_client *clp, struct nfs4_state *state)
1353 {
1354
1355         if (!nfs4_valid_open_stateid(state))
1356                 return 0;
1357         set_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1358         /* Don't recover state that expired before the reboot */
1359         if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags)) {
1360                 clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1361                 return 0;
1362         }
1363         set_bit(NFS_OWNER_RECLAIM_REBOOT, &state->owner->so_flags);
1364         set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1365         return 1;
1366 }
1367
1368 int nfs4_state_mark_reclaim_nograce(struct nfs_client *clp, struct nfs4_state *state)
1369 {
1370         if (!nfs4_valid_open_stateid(state))
1371                 return 0;
1372         set_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1373         clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1374         set_bit(NFS_OWNER_RECLAIM_NOGRACE, &state->owner->so_flags);
1375         set_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
1376         return 1;
1377 }
1378
1379 int nfs4_schedule_stateid_recovery(const struct nfs_server *server, struct nfs4_state *state)
1380 {
1381         struct nfs_client *clp = server->nfs_client;
1382
1383         if (!nfs4_state_mark_reclaim_nograce(clp, state))
1384                 return -EBADF;
1385         dprintk("%s: scheduling stateid recovery for server %s\n", __func__,
1386                         clp->cl_hostname);
1387         nfs4_schedule_state_manager(clp);
1388         return 0;
1389 }
1390 EXPORT_SYMBOL_GPL(nfs4_schedule_stateid_recovery);
1391
1392 static struct nfs4_lock_state *
1393 nfs_state_find_lock_state_by_stateid(struct nfs4_state *state,
1394                 const nfs4_stateid *stateid)
1395 {
1396         struct nfs4_lock_state *pos;
1397
1398         list_for_each_entry(pos, &state->lock_states, ls_locks) {
1399                 if (!test_bit(NFS_LOCK_INITIALIZED, &pos->ls_flags))
1400                         continue;
1401                 if (nfs4_stateid_match_other(&pos->ls_stateid, stateid))
1402                         return pos;
1403         }
1404         return NULL;
1405 }
1406
1407 static bool nfs_state_lock_state_matches_stateid(struct nfs4_state *state,
1408                 const nfs4_stateid *stateid)
1409 {
1410         bool found = false;
1411
1412         if (test_bit(LK_STATE_IN_USE, &state->flags)) {
1413                 spin_lock(&state->state_lock);
1414                 if (nfs_state_find_lock_state_by_stateid(state, stateid))
1415                         found = true;
1416                 spin_unlock(&state->state_lock);
1417         }
1418         return found;
1419 }
1420
1421 void nfs_inode_find_state_and_recover(struct inode *inode,
1422                 const nfs4_stateid *stateid)
1423 {
1424         struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
1425         struct nfs_inode *nfsi = NFS_I(inode);
1426         struct nfs_open_context *ctx;
1427         struct nfs4_state *state;
1428         bool found = false;
1429
1430         spin_lock(&inode->i_lock);
1431         list_for_each_entry(ctx, &nfsi->open_files, list) {
1432                 state = ctx->state;
1433                 if (state == NULL)
1434                         continue;
1435                 if (nfs4_stateid_match_other(&state->stateid, stateid) &&
1436                     nfs4_state_mark_reclaim_nograce(clp, state)) {
1437                         found = true;
1438                         continue;
1439                 }
1440                 if (nfs4_stateid_match_other(&state->open_stateid, stateid) &&
1441                     nfs4_state_mark_reclaim_nograce(clp, state)) {
1442                         found = true;
1443                         continue;
1444                 }
1445                 if (nfs_state_lock_state_matches_stateid(state, stateid) &&
1446                     nfs4_state_mark_reclaim_nograce(clp, state))
1447                         found = true;
1448         }
1449         spin_unlock(&inode->i_lock);
1450
1451         nfs_inode_find_delegation_state_and_recover(inode, stateid);
1452         if (found)
1453                 nfs4_schedule_state_manager(clp);
1454 }
1455
1456 static void nfs4_state_mark_open_context_bad(struct nfs4_state *state)
1457 {
1458         struct inode *inode = state->inode;
1459         struct nfs_inode *nfsi = NFS_I(inode);
1460         struct nfs_open_context *ctx;
1461
1462         spin_lock(&inode->i_lock);
1463         list_for_each_entry(ctx, &nfsi->open_files, list) {
1464                 if (ctx->state != state)
1465                         continue;
1466                 set_bit(NFS_CONTEXT_BAD, &ctx->flags);
1467         }
1468         spin_unlock(&inode->i_lock);
1469 }
1470
1471 static void nfs4_state_mark_recovery_failed(struct nfs4_state *state, int error)
1472 {
1473         set_bit(NFS_STATE_RECOVERY_FAILED, &state->flags);
1474         nfs4_state_mark_open_context_bad(state);
1475 }
1476
1477
1478 static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_recovery_ops *ops)
1479 {
1480         struct inode *inode = state->inode;
1481         struct nfs_inode *nfsi = NFS_I(inode);
1482         struct file_lock *fl;
1483         struct nfs4_lock_state *lsp;
1484         int status = 0;
1485         struct file_lock_context *flctx = inode->i_flctx;
1486         struct list_head *list;
1487
1488         if (flctx == NULL)
1489                 return 0;
1490
1491         list = &flctx->flc_posix;
1492
1493         /* Guard against delegation returns and new lock/unlock calls */
1494         down_write(&nfsi->rwsem);
1495         spin_lock(&flctx->flc_lock);
1496 restart:
1497         list_for_each_entry(fl, list, fl_list) {
1498                 if (nfs_file_open_context(fl->fl_file)->state != state)
1499                         continue;
1500                 spin_unlock(&flctx->flc_lock);
1501                 status = ops->recover_lock(state, fl);
1502                 switch (status) {
1503                 case 0:
1504                         break;
1505                 case -ESTALE:
1506                 case -NFS4ERR_ADMIN_REVOKED:
1507                 case -NFS4ERR_STALE_STATEID:
1508                 case -NFS4ERR_BAD_STATEID:
1509                 case -NFS4ERR_EXPIRED:
1510                 case -NFS4ERR_NO_GRACE:
1511                 case -NFS4ERR_STALE_CLIENTID:
1512                 case -NFS4ERR_BADSESSION:
1513                 case -NFS4ERR_BADSLOT:
1514                 case -NFS4ERR_BAD_HIGH_SLOT:
1515                 case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1516                         goto out;
1517                 default:
1518                         pr_err("NFS: %s: unhandled error %d\n",
1519                                         __func__, status);
1520                 case -ENOMEM:
1521                 case -NFS4ERR_DENIED:
1522                 case -NFS4ERR_RECLAIM_BAD:
1523                 case -NFS4ERR_RECLAIM_CONFLICT:
1524                         lsp = fl->fl_u.nfs4_fl.owner;
1525                         if (lsp)
1526                                 set_bit(NFS_LOCK_LOST, &lsp->ls_flags);
1527                         status = 0;
1528                 }
1529                 spin_lock(&flctx->flc_lock);
1530         }
1531         if (list == &flctx->flc_posix) {
1532                 list = &flctx->flc_flock;
1533                 goto restart;
1534         }
1535         spin_unlock(&flctx->flc_lock);
1536 out:
1537         up_write(&nfsi->rwsem);
1538         return status;
1539 }
1540
1541 static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs4_state_recovery_ops *ops)
1542 {
1543         struct nfs4_state *state;
1544         struct nfs4_lock_state *lock;
1545         int status = 0;
1546
1547         /* Note: we rely on the sp->so_states list being ordered
1548          * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
1549          * states first.
1550          * This is needed to ensure that the server won't give us any
1551          * read delegations that we have to return if, say, we are
1552          * recovering after a network partition or a reboot from a
1553          * server that doesn't support a grace period.
1554          */
1555         spin_lock(&sp->so_lock);
1556         raw_write_seqcount_begin(&sp->so_reclaim_seqcount);
1557 restart:
1558         list_for_each_entry(state, &sp->so_states, open_states) {
1559                 if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
1560                         continue;
1561                 if (!nfs4_valid_open_stateid(state))
1562                         continue;
1563                 if (state->state == 0)
1564                         continue;
1565                 atomic_inc(&state->count);
1566                 spin_unlock(&sp->so_lock);
1567                 status = ops->recover_open(sp, state);
1568                 if (status >= 0) {
1569                         status = nfs4_reclaim_locks(state, ops);
1570                         if (status >= 0) {
1571                                 if (!test_bit(NFS_DELEGATED_STATE, &state->flags)) {
1572                                         spin_lock(&state->state_lock);
1573                                         list_for_each_entry(lock, &state->lock_states, ls_locks) {
1574                                                 if (!test_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags))
1575                                                         pr_warn_ratelimited("NFS: "
1576                                                                             "%s: Lock reclaim "
1577                                                                             "failed!\n", __func__);
1578                                         }
1579                                         spin_unlock(&state->state_lock);
1580                                 }
1581                                 clear_bit(NFS_STATE_RECLAIM_NOGRACE,
1582                                         &state->flags);
1583                                 nfs4_put_open_state(state);
1584                                 spin_lock(&sp->so_lock);
1585                                 goto restart;
1586                         }
1587                 }
1588                 switch (status) {
1589                         default:
1590                                 printk(KERN_ERR "NFS: %s: unhandled error %d\n",
1591                                         __func__, status);
1592                         case -ENOENT:
1593                         case -ENOMEM:
1594                         case -EACCES:
1595                         case -EROFS:
1596                         case -EIO:
1597                         case -ESTALE:
1598                                 /* Open state on this file cannot be recovered */
1599                                 nfs4_state_mark_recovery_failed(state, status);
1600                                 break;
1601                         case -EAGAIN:
1602                                 ssleep(1);
1603                         case -NFS4ERR_ADMIN_REVOKED:
1604                         case -NFS4ERR_STALE_STATEID:
1605                         case -NFS4ERR_OLD_STATEID:
1606                         case -NFS4ERR_BAD_STATEID:
1607                         case -NFS4ERR_RECLAIM_BAD:
1608                         case -NFS4ERR_RECLAIM_CONFLICT:
1609                                 nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1610                                 break;
1611                         case -NFS4ERR_EXPIRED:
1612                         case -NFS4ERR_NO_GRACE:
1613                                 nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1614                         case -NFS4ERR_STALE_CLIENTID:
1615                         case -NFS4ERR_BADSESSION:
1616                         case -NFS4ERR_BADSLOT:
1617                         case -NFS4ERR_BAD_HIGH_SLOT:
1618                         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1619                                 goto out_err;
1620                 }
1621                 nfs4_put_open_state(state);
1622                 spin_lock(&sp->so_lock);
1623                 goto restart;
1624         }
1625         raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1626         spin_unlock(&sp->so_lock);
1627         return 0;
1628 out_err:
1629         nfs4_put_open_state(state);
1630         spin_lock(&sp->so_lock);
1631         raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1632         spin_unlock(&sp->so_lock);
1633         return status;
1634 }
1635
1636 static void nfs4_clear_open_state(struct nfs4_state *state)
1637 {
1638         struct nfs4_lock_state *lock;
1639
1640         clear_bit(NFS_DELEGATED_STATE, &state->flags);
1641         clear_bit(NFS_O_RDONLY_STATE, &state->flags);
1642         clear_bit(NFS_O_WRONLY_STATE, &state->flags);
1643         clear_bit(NFS_O_RDWR_STATE, &state->flags);
1644         spin_lock(&state->state_lock);
1645         list_for_each_entry(lock, &state->lock_states, ls_locks) {
1646                 lock->ls_seqid.flags = 0;
1647                 clear_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags);
1648         }
1649         spin_unlock(&state->state_lock);
1650 }
1651
1652 static void nfs4_reset_seqids(struct nfs_server *server,
1653         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1654 {
1655         struct nfs_client *clp = server->nfs_client;
1656         struct nfs4_state_owner *sp;
1657         struct rb_node *pos;
1658         struct nfs4_state *state;
1659
1660         spin_lock(&clp->cl_lock);
1661         for (pos = rb_first(&server->state_owners);
1662              pos != NULL;
1663              pos = rb_next(pos)) {
1664                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1665                 sp->so_seqid.flags = 0;
1666                 spin_lock(&sp->so_lock);
1667                 list_for_each_entry(state, &sp->so_states, open_states) {
1668                         if (mark_reclaim(clp, state))
1669                                 nfs4_clear_open_state(state);
1670                 }
1671                 spin_unlock(&sp->so_lock);
1672         }
1673         spin_unlock(&clp->cl_lock);
1674 }
1675
1676 static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp,
1677         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1678 {
1679         struct nfs_server *server;
1680
1681         rcu_read_lock();
1682         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1683                 nfs4_reset_seqids(server, mark_reclaim);
1684         rcu_read_unlock();
1685 }
1686
1687 static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp)
1688 {
1689         /* Mark all delegations for reclaim */
1690         nfs_delegation_mark_reclaim(clp);
1691         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_reboot);
1692 }
1693
1694 static int nfs4_reclaim_complete(struct nfs_client *clp,
1695                                  const struct nfs4_state_recovery_ops *ops,
1696                                  struct rpc_cred *cred)
1697 {
1698         /* Notify the server we're done reclaiming our state */
1699         if (ops->reclaim_complete)
1700                 return ops->reclaim_complete(clp, cred);
1701         return 0;
1702 }
1703
1704 static void nfs4_clear_reclaim_server(struct nfs_server *server)
1705 {
1706         struct nfs_client *clp = server->nfs_client;
1707         struct nfs4_state_owner *sp;
1708         struct rb_node *pos;
1709         struct nfs4_state *state;
1710
1711         spin_lock(&clp->cl_lock);
1712         for (pos = rb_first(&server->state_owners);
1713              pos != NULL;
1714              pos = rb_next(pos)) {
1715                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1716                 spin_lock(&sp->so_lock);
1717                 list_for_each_entry(state, &sp->so_states, open_states) {
1718                         if (!test_and_clear_bit(NFS_STATE_RECLAIM_REBOOT,
1719                                                 &state->flags))
1720                                 continue;
1721                         nfs4_state_mark_reclaim_nograce(clp, state);
1722                 }
1723                 spin_unlock(&sp->so_lock);
1724         }
1725         spin_unlock(&clp->cl_lock);
1726 }
1727
1728 static int nfs4_state_clear_reclaim_reboot(struct nfs_client *clp)
1729 {
1730         struct nfs_server *server;
1731
1732         if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
1733                 return 0;
1734
1735         rcu_read_lock();
1736         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1737                 nfs4_clear_reclaim_server(server);
1738         rcu_read_unlock();
1739
1740         nfs_delegation_reap_unclaimed(clp);
1741         return 1;
1742 }
1743
1744 static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
1745 {
1746         const struct nfs4_state_recovery_ops *ops;
1747         struct rpc_cred *cred;
1748         int err;
1749
1750         if (!nfs4_state_clear_reclaim_reboot(clp))
1751                 return;
1752         ops = clp->cl_mvops->reboot_recovery_ops;
1753         cred = nfs4_get_clid_cred(clp);
1754         err = nfs4_reclaim_complete(clp, ops, cred);
1755         put_rpccred(cred);
1756         if (err == -NFS4ERR_CONN_NOT_BOUND_TO_SESSION)
1757                 set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1758 }
1759
1760 static void nfs4_state_start_reclaim_nograce(struct nfs_client *clp)
1761 {
1762         nfs_mark_test_expired_all_delegations(clp);
1763         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
1764 }
1765
1766 static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
1767 {
1768         switch (error) {
1769                 case 0:
1770                         break;
1771                 case -NFS4ERR_CB_PATH_DOWN:
1772                         nfs40_handle_cb_pathdown(clp);
1773                         break;
1774                 case -NFS4ERR_NO_GRACE:
1775                         nfs4_state_end_reclaim_reboot(clp);
1776                         break;
1777                 case -NFS4ERR_STALE_CLIENTID:
1778                         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1779                         nfs4_state_start_reclaim_reboot(clp);
1780                         break;
1781                 case -NFS4ERR_EXPIRED:
1782                         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1783                         nfs4_state_start_reclaim_nograce(clp);
1784                         break;
1785                 case -NFS4ERR_BADSESSION:
1786                 case -NFS4ERR_BADSLOT:
1787                 case -NFS4ERR_BAD_HIGH_SLOT:
1788                 case -NFS4ERR_DEADSESSION:
1789                 case -NFS4ERR_SEQ_FALSE_RETRY:
1790                 case -NFS4ERR_SEQ_MISORDERED:
1791                         set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
1792                         /* Zero session reset errors */
1793                         break;
1794                 case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1795                         set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
1796                         break;
1797                 default:
1798                         dprintk("%s: failed to handle error %d for server %s\n",
1799                                         __func__, error, clp->cl_hostname);
1800                         return error;
1801         }
1802         dprintk("%s: handled error %d for server %s\n", __func__, error,
1803                         clp->cl_hostname);
1804         return 0;
1805 }
1806
1807 static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recovery_ops *ops)
1808 {
1809         struct nfs4_state_owner *sp;
1810         struct nfs_server *server;
1811         struct rb_node *pos;
1812         int status = 0;
1813
1814 restart:
1815         rcu_read_lock();
1816         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1817                 nfs4_purge_state_owners(server);
1818                 spin_lock(&clp->cl_lock);
1819                 for (pos = rb_first(&server->state_owners);
1820                      pos != NULL;
1821                      pos = rb_next(pos)) {
1822                         sp = rb_entry(pos,
1823                                 struct nfs4_state_owner, so_server_node);
1824                         if (!test_and_clear_bit(ops->owner_flag_bit,
1825                                                         &sp->so_flags))
1826                                 continue;
1827                         if (!atomic_inc_not_zero(&sp->so_count))
1828                                 continue;
1829                         spin_unlock(&clp->cl_lock);
1830                         rcu_read_unlock();
1831
1832                         status = nfs4_reclaim_open_state(sp, ops);
1833                         if (status < 0) {
1834                                 set_bit(ops->owner_flag_bit, &sp->so_flags);
1835                                 nfs4_put_state_owner(sp);
1836                                 status = nfs4_recovery_handle_error(clp, status);
1837                                 return (status != 0) ? status : -EAGAIN;
1838                         }
1839
1840                         nfs4_put_state_owner(sp);
1841                         goto restart;
1842                 }
1843                 spin_unlock(&clp->cl_lock);
1844         }
1845         rcu_read_unlock();
1846         return 0;
1847 }
1848
1849 static int nfs4_check_lease(struct nfs_client *clp)
1850 {
1851         struct rpc_cred *cred;
1852         const struct nfs4_state_maintenance_ops *ops =
1853                 clp->cl_mvops->state_renewal_ops;
1854         int status;
1855
1856         /* Is the client already known to have an expired lease? */
1857         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1858                 return 0;
1859         spin_lock(&clp->cl_lock);
1860         cred = ops->get_state_renewal_cred_locked(clp);
1861         spin_unlock(&clp->cl_lock);
1862         if (cred == NULL) {
1863                 cred = nfs4_get_clid_cred(clp);
1864                 status = -ENOKEY;
1865                 if (cred == NULL)
1866                         goto out;
1867         }
1868         status = ops->renew_lease(clp, cred);
1869         put_rpccred(cred);
1870         if (status == -ETIMEDOUT) {
1871                 set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1872                 return 0;
1873         }
1874 out:
1875         return nfs4_recovery_handle_error(clp, status);
1876 }
1877
1878 /* Set NFS4CLNT_LEASE_EXPIRED and reclaim reboot state for all v4.0 errors
1879  * and for recoverable errors on EXCHANGE_ID for v4.1
1880  */
1881 static int nfs4_handle_reclaim_lease_error(struct nfs_client *clp, int status)
1882 {
1883         switch (status) {
1884         case -NFS4ERR_SEQ_MISORDERED:
1885                 if (test_and_set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state))
1886                         return -ESERVERFAULT;
1887                 /* Lease confirmation error: retry after purging the lease */
1888                 ssleep(1);
1889                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1890                 break;
1891         case -NFS4ERR_STALE_CLIENTID:
1892                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1893                 nfs4_state_start_reclaim_reboot(clp);
1894                 break;
1895         case -NFS4ERR_CLID_INUSE:
1896                 pr_err("NFS: Server %s reports our clientid is in use\n",
1897                         clp->cl_hostname);
1898                 nfs_mark_client_ready(clp, -EPERM);
1899                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1900                 return -EPERM;
1901         case -EACCES:
1902         case -NFS4ERR_DELAY:
1903         case -ETIMEDOUT:
1904         case -EAGAIN:
1905                 ssleep(1);
1906                 break;
1907
1908         case -NFS4ERR_MINOR_VERS_MISMATCH:
1909                 if (clp->cl_cons_state == NFS_CS_SESSION_INITING)
1910                         nfs_mark_client_ready(clp, -EPROTONOSUPPORT);
1911                 dprintk("%s: exit with error %d for server %s\n",
1912                                 __func__, -EPROTONOSUPPORT, clp->cl_hostname);
1913                 return -EPROTONOSUPPORT;
1914         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
1915                                  * in nfs4_exchange_id */
1916         default:
1917                 dprintk("%s: exit with error %d for server %s\n", __func__,
1918                                 status, clp->cl_hostname);
1919                 return status;
1920         }
1921         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1922         dprintk("%s: handled error %d for server %s\n", __func__, status,
1923                         clp->cl_hostname);
1924         return 0;
1925 }
1926
1927 static int nfs4_establish_lease(struct nfs_client *clp)
1928 {
1929         struct rpc_cred *cred;
1930         const struct nfs4_state_recovery_ops *ops =
1931                 clp->cl_mvops->reboot_recovery_ops;
1932         int status;
1933
1934         nfs4_begin_drain_session(clp);
1935         cred = nfs4_get_clid_cred(clp);
1936         if (cred == NULL)
1937                 return -ENOENT;
1938         status = ops->establish_clid(clp, cred);
1939         put_rpccred(cred);
1940         if (status != 0)
1941                 return status;
1942         pnfs_destroy_all_layouts(clp);
1943         return 0;
1944 }
1945
1946 /*
1947  * Returns zero or a negative errno.  NFS4ERR values are converted
1948  * to local errno values.
1949  */
1950 static int nfs4_reclaim_lease(struct nfs_client *clp)
1951 {
1952         int status;
1953
1954         status = nfs4_establish_lease(clp);
1955         if (status < 0)
1956                 return nfs4_handle_reclaim_lease_error(clp, status);
1957         if (test_and_clear_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH, &clp->cl_state))
1958                 nfs4_state_start_reclaim_nograce(clp);
1959         if (!test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
1960                 set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1961         clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1962         clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1963         return 0;
1964 }
1965
1966 static int nfs4_purge_lease(struct nfs_client *clp)
1967 {
1968         int status;
1969
1970         status = nfs4_establish_lease(clp);
1971         if (status < 0)
1972                 return nfs4_handle_reclaim_lease_error(clp, status);
1973         clear_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
1974         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1975         nfs4_state_start_reclaim_nograce(clp);
1976         return 0;
1977 }
1978
1979 /*
1980  * Try remote migration of one FSID from a source server to a
1981  * destination server.  The source server provides a list of
1982  * potential destinations.
1983  *
1984  * Returns zero or a negative NFS4ERR status code.
1985  */
1986 static int nfs4_try_migration(struct nfs_server *server, struct rpc_cred *cred)
1987 {
1988         struct nfs_client *clp = server->nfs_client;
1989         struct nfs4_fs_locations *locations = NULL;
1990         struct inode *inode;
1991         struct page *page;
1992         int status, result;
1993
1994         dprintk("--> %s: FSID %llx:%llx on \"%s\"\n", __func__,
1995                         (unsigned long long)server->fsid.major,
1996                         (unsigned long long)server->fsid.minor,
1997                         clp->cl_hostname);
1998
1999         result = 0;
2000         page = alloc_page(GFP_KERNEL);
2001         locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
2002         if (page == NULL || locations == NULL) {
2003                 dprintk("<-- %s: no memory\n", __func__);
2004                 goto out;
2005         }
2006
2007         inode = d_inode(server->super->s_root);
2008         result = nfs4_proc_get_locations(inode, locations, page, cred);
2009         if (result) {
2010                 dprintk("<-- %s: failed to retrieve fs_locations: %d\n",
2011                         __func__, result);
2012                 goto out;
2013         }
2014
2015         result = -NFS4ERR_NXIO;
2016         if (!(locations->fattr.valid & NFS_ATTR_FATTR_V4_LOCATIONS)) {
2017                 dprintk("<-- %s: No fs_locations data, migration skipped\n",
2018                         __func__);
2019                 goto out;
2020         }
2021
2022         nfs4_begin_drain_session(clp);
2023
2024         status = nfs4_replace_transport(server, locations);
2025         if (status != 0) {
2026                 dprintk("<-- %s: failed to replace transport: %d\n",
2027                         __func__, status);
2028                 goto out;
2029         }
2030
2031         result = 0;
2032         dprintk("<-- %s: migration succeeded\n", __func__);
2033
2034 out:
2035         if (page != NULL)
2036                 __free_page(page);
2037         kfree(locations);
2038         if (result) {
2039                 pr_err("NFS: migration recovery failed (server %s)\n",
2040                                 clp->cl_hostname);
2041                 set_bit(NFS_MIG_FAILED, &server->mig_status);
2042         }
2043         return result;
2044 }
2045
2046 /*
2047  * Returns zero or a negative NFS4ERR status code.
2048  */
2049 static int nfs4_handle_migration(struct nfs_client *clp)
2050 {
2051         const struct nfs4_state_maintenance_ops *ops =
2052                                 clp->cl_mvops->state_renewal_ops;
2053         struct nfs_server *server;
2054         struct rpc_cred *cred;
2055
2056         dprintk("%s: migration reported on \"%s\"\n", __func__,
2057                         clp->cl_hostname);
2058
2059         spin_lock(&clp->cl_lock);
2060         cred = ops->get_state_renewal_cred_locked(clp);
2061         spin_unlock(&clp->cl_lock);
2062         if (cred == NULL)
2063                 return -NFS4ERR_NOENT;
2064
2065         clp->cl_mig_gen++;
2066 restart:
2067         rcu_read_lock();
2068         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2069                 int status;
2070
2071                 if (server->mig_gen == clp->cl_mig_gen)
2072                         continue;
2073                 server->mig_gen = clp->cl_mig_gen;
2074
2075                 if (!test_and_clear_bit(NFS_MIG_IN_TRANSITION,
2076                                                 &server->mig_status))
2077                         continue;
2078
2079                 rcu_read_unlock();
2080                 status = nfs4_try_migration(server, cred);
2081                 if (status < 0) {
2082                         put_rpccred(cred);
2083                         return status;
2084                 }
2085                 goto restart;
2086         }
2087         rcu_read_unlock();
2088         put_rpccred(cred);
2089         return 0;
2090 }
2091
2092 /*
2093  * Test each nfs_server on the clp's cl_superblocks list to see
2094  * if it's moved to another server.  Stop when the server no longer
2095  * returns NFS4ERR_LEASE_MOVED.
2096  */
2097 static int nfs4_handle_lease_moved(struct nfs_client *clp)
2098 {
2099         const struct nfs4_state_maintenance_ops *ops =
2100                                 clp->cl_mvops->state_renewal_ops;
2101         struct nfs_server *server;
2102         struct rpc_cred *cred;
2103
2104         dprintk("%s: lease moved reported on \"%s\"\n", __func__,
2105                         clp->cl_hostname);
2106
2107         spin_lock(&clp->cl_lock);
2108         cred = ops->get_state_renewal_cred_locked(clp);
2109         spin_unlock(&clp->cl_lock);
2110         if (cred == NULL)
2111                 return -NFS4ERR_NOENT;
2112
2113         clp->cl_mig_gen++;
2114 restart:
2115         rcu_read_lock();
2116         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2117                 struct inode *inode;
2118                 int status;
2119
2120                 if (server->mig_gen == clp->cl_mig_gen)
2121                         continue;
2122                 server->mig_gen = clp->cl_mig_gen;
2123
2124                 rcu_read_unlock();
2125
2126                 inode = d_inode(server->super->s_root);
2127                 status = nfs4_proc_fsid_present(inode, cred);
2128                 if (status != -NFS4ERR_MOVED)
2129                         goto restart;   /* wasn't this one */
2130                 if (nfs4_try_migration(server, cred) == -NFS4ERR_LEASE_MOVED)
2131                         goto restart;   /* there are more */
2132                 goto out;
2133         }
2134         rcu_read_unlock();
2135
2136 out:
2137         put_rpccred(cred);
2138         return 0;
2139 }
2140
2141 /**
2142  * nfs4_discover_server_trunking - Detect server IP address trunking
2143  *
2144  * @clp: nfs_client under test
2145  * @result: OUT: found nfs_client, or clp
2146  *
2147  * Returns zero or a negative errno.  If zero is returned,
2148  * an nfs_client pointer is planted in "result".
2149  *
2150  * Note: since we are invoked in process context, and
2151  * not from inside the state manager, we cannot use
2152  * nfs4_handle_reclaim_lease_error().
2153  */
2154 int nfs4_discover_server_trunking(struct nfs_client *clp,
2155                                   struct nfs_client **result)
2156 {
2157         const struct nfs4_state_recovery_ops *ops =
2158                                 clp->cl_mvops->reboot_recovery_ops;
2159         struct rpc_clnt *clnt;
2160         struct rpc_cred *cred;
2161         int i, status;
2162
2163         dprintk("NFS: %s: testing '%s'\n", __func__, clp->cl_hostname);
2164
2165         clnt = clp->cl_rpcclient;
2166         i = 0;
2167
2168         mutex_lock(&nfs_clid_init_mutex);
2169 again:
2170         status  = -ENOENT;
2171         cred = nfs4_get_clid_cred(clp);
2172         if (cred == NULL)
2173                 goto out_unlock;
2174
2175         status = ops->detect_trunking(clp, result, cred);
2176         put_rpccred(cred);
2177         switch (status) {
2178         case 0:
2179         case -EINTR:
2180         case -ERESTARTSYS:
2181                 break;
2182         case -ETIMEDOUT:
2183                 if (clnt->cl_softrtry)
2184                         break;
2185         case -NFS4ERR_DELAY:
2186         case -EAGAIN:
2187                 ssleep(1);
2188         case -NFS4ERR_STALE_CLIENTID:
2189                 dprintk("NFS: %s after status %d, retrying\n",
2190                         __func__, status);
2191                 goto again;
2192         case -EACCES:
2193                 if (i++ == 0) {
2194                         nfs4_root_machine_cred(clp);
2195                         goto again;
2196                 }
2197                 if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX)
2198                         break;
2199         case -NFS4ERR_CLID_INUSE:
2200         case -NFS4ERR_WRONGSEC:
2201                 /* No point in retrying if we already used RPC_AUTH_UNIX */
2202                 if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX) {
2203                         status = -EPERM;
2204                         break;
2205                 }
2206                 clnt = rpc_clone_client_set_auth(clnt, RPC_AUTH_UNIX);
2207                 if (IS_ERR(clnt)) {
2208                         status = PTR_ERR(clnt);
2209                         break;
2210                 }
2211                 /* Note: this is safe because we haven't yet marked the
2212                  * client as ready, so we are the only user of
2213                  * clp->cl_rpcclient
2214                  */
2215                 clnt = xchg(&clp->cl_rpcclient, clnt);
2216                 rpc_shutdown_client(clnt);
2217                 clnt = clp->cl_rpcclient;
2218                 goto again;
2219
2220         case -NFS4ERR_MINOR_VERS_MISMATCH:
2221                 status = -EPROTONOSUPPORT;
2222                 break;
2223
2224         case -EKEYEXPIRED:
2225         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
2226                                  * in nfs4_exchange_id */
2227                 status = -EKEYEXPIRED;
2228                 break;
2229         default:
2230                 pr_warn("NFS: %s unhandled error %d. Exiting with error EIO\n",
2231                                 __func__, status);
2232                 status = -EIO;
2233         }
2234
2235 out_unlock:
2236         mutex_unlock(&nfs_clid_init_mutex);
2237         dprintk("NFS: %s: status = %d\n", __func__, status);
2238         return status;
2239 }
2240
2241 #ifdef CONFIG_NFS_V4_1
2242 void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
2243 {
2244         struct nfs_client *clp = session->clp;
2245
2246         switch (err) {
2247         default:
2248                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2249                 break;
2250         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
2251                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2252         }
2253         nfs4_schedule_state_manager(clp);
2254 }
2255 EXPORT_SYMBOL_GPL(nfs4_schedule_session_recovery);
2256
2257 void nfs41_notify_server(struct nfs_client *clp)
2258 {
2259         /* Use CHECK_LEASE to ping the server with a SEQUENCE */
2260         set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2261         nfs4_schedule_state_manager(clp);
2262 }
2263
2264 static void nfs4_reset_all_state(struct nfs_client *clp)
2265 {
2266         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2267                 set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2268                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2269                 nfs4_state_start_reclaim_nograce(clp);
2270                 dprintk("%s: scheduling reset of all state for server %s!\n",
2271                                 __func__, clp->cl_hostname);
2272                 nfs4_schedule_state_manager(clp);
2273         }
2274 }
2275
2276 static void nfs41_handle_server_reboot(struct nfs_client *clp)
2277 {
2278         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2279                 nfs4_state_start_reclaim_reboot(clp);
2280                 dprintk("%s: server %s rebooted!\n", __func__,
2281                                 clp->cl_hostname);
2282                 nfs4_schedule_state_manager(clp);
2283         }
2284 }
2285
2286 static void nfs41_handle_all_state_revoked(struct nfs_client *clp)
2287 {
2288         nfs4_reset_all_state(clp);
2289         dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2290 }
2291
2292 static void nfs41_handle_some_state_revoked(struct nfs_client *clp)
2293 {
2294         nfs4_state_start_reclaim_nograce(clp);
2295         nfs4_schedule_state_manager(clp);
2296
2297         dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2298 }
2299
2300 static void nfs41_handle_recallable_state_revoked(struct nfs_client *clp)
2301 {
2302         /* FIXME: For now, we destroy all layouts. */
2303         pnfs_destroy_all_layouts(clp);
2304         /* FIXME: For now, we test all delegations+open state+locks. */
2305         nfs41_handle_some_state_revoked(clp);
2306         dprintk("%s: Recallable state revoked on server %s!\n", __func__,
2307                         clp->cl_hostname);
2308 }
2309
2310 static void nfs41_handle_backchannel_fault(struct nfs_client *clp)
2311 {
2312         set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2313         nfs4_schedule_state_manager(clp);
2314
2315         dprintk("%s: server %s declared a backchannel fault\n", __func__,
2316                         clp->cl_hostname);
2317 }
2318
2319 static void nfs41_handle_cb_path_down(struct nfs_client *clp)
2320 {
2321         if (test_and_set_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2322                 &clp->cl_state) == 0)
2323                 nfs4_schedule_state_manager(clp);
2324 }
2325
2326 void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags,
2327                 bool recovery)
2328 {
2329         if (!flags)
2330                 return;
2331
2332         dprintk("%s: \"%s\" (client ID %llx) flags=0x%08x\n",
2333                 __func__, clp->cl_hostname, clp->cl_clientid, flags);
2334         /*
2335          * If we're called from the state manager thread, then assume we're
2336          * already handling the RECLAIM_NEEDED and/or STATE_REVOKED.
2337          * Those flags are expected to remain set until we're done
2338          * recovering (see RFC5661, section 18.46.3).
2339          */
2340         if (recovery)
2341                 goto out_recovery;
2342
2343         if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED)
2344                 nfs41_handle_server_reboot(clp);
2345         if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED))
2346                 nfs41_handle_all_state_revoked(clp);
2347         if (flags & (SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED |
2348                             SEQ4_STATUS_ADMIN_STATE_REVOKED))
2349                 nfs41_handle_some_state_revoked(clp);
2350         if (flags & SEQ4_STATUS_LEASE_MOVED)
2351                 nfs4_schedule_lease_moved_recovery(clp);
2352         if (flags & SEQ4_STATUS_RECALLABLE_STATE_REVOKED)
2353                 nfs41_handle_recallable_state_revoked(clp);
2354 out_recovery:
2355         if (flags & SEQ4_STATUS_BACKCHANNEL_FAULT)
2356                 nfs41_handle_backchannel_fault(clp);
2357         else if (flags & (SEQ4_STATUS_CB_PATH_DOWN |
2358                                 SEQ4_STATUS_CB_PATH_DOWN_SESSION))
2359                 nfs41_handle_cb_path_down(clp);
2360 }
2361
2362 static int nfs4_reset_session(struct nfs_client *clp)
2363 {
2364         struct rpc_cred *cred;
2365         int status;
2366
2367         if (!nfs4_has_session(clp))
2368                 return 0;
2369         nfs4_begin_drain_session(clp);
2370         cred = nfs4_get_clid_cred(clp);
2371         status = nfs4_proc_destroy_session(clp->cl_session, cred);
2372         switch (status) {
2373         case 0:
2374         case -NFS4ERR_BADSESSION:
2375         case -NFS4ERR_DEADSESSION:
2376                 break;
2377         case -NFS4ERR_BACK_CHAN_BUSY:
2378         case -NFS4ERR_DELAY:
2379                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2380                 status = 0;
2381                 ssleep(1);
2382                 goto out;
2383         default:
2384                 status = nfs4_recovery_handle_error(clp, status);
2385                 goto out;
2386         }
2387
2388         memset(clp->cl_session->sess_id.data, 0, NFS4_MAX_SESSIONID_LEN);
2389         status = nfs4_proc_create_session(clp, cred);
2390         if (status) {
2391                 dprintk("%s: session reset failed with status %d for server %s!\n",
2392                         __func__, status, clp->cl_hostname);
2393                 status = nfs4_handle_reclaim_lease_error(clp, status);
2394                 goto out;
2395         }
2396         nfs41_finish_session_reset(clp);
2397         dprintk("%s: session reset was successful for server %s!\n",
2398                         __func__, clp->cl_hostname);
2399 out:
2400         if (cred)
2401                 put_rpccred(cred);
2402         return status;
2403 }
2404
2405 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2406 {
2407         struct rpc_cred *cred;
2408         int ret;
2409
2410         if (!nfs4_has_session(clp))
2411                 return 0;
2412         nfs4_begin_drain_session(clp);
2413         cred = nfs4_get_clid_cred(clp);
2414         ret = nfs4_proc_bind_conn_to_session(clp, cred);
2415         if (cred)
2416                 put_rpccred(cred);
2417         clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2418         switch (ret) {
2419         case 0:
2420                 dprintk("%s: bind_conn_to_session was successful for server %s!\n",
2421                         __func__, clp->cl_hostname);
2422                 break;
2423         case -NFS4ERR_DELAY:
2424                 ssleep(1);
2425                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2426                 break;
2427         default:
2428                 return nfs4_recovery_handle_error(clp, ret);
2429         }
2430         return 0;
2431 }
2432 #else /* CONFIG_NFS_V4_1 */
2433 static int nfs4_reset_session(struct nfs_client *clp) { return 0; }
2434
2435 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2436 {
2437         return 0;
2438 }
2439 #endif /* CONFIG_NFS_V4_1 */
2440
2441 static void nfs4_state_manager(struct nfs_client *clp)
2442 {
2443         int status = 0;
2444         const char *section = "", *section_sep = "";
2445
2446         /* Ensure exclusive access to NFSv4 state */
2447         do {
2448                 if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
2449                         section = "purge state";
2450                         status = nfs4_purge_lease(clp);
2451                         if (status < 0)
2452                                 goto out_error;
2453                         continue;
2454                 }
2455
2456                 if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
2457                         section = "lease expired";
2458                         /* We're going to have to re-establish a clientid */
2459                         status = nfs4_reclaim_lease(clp);
2460                         if (status < 0)
2461                                 goto out_error;
2462                         continue;
2463                 }
2464
2465                 /* Initialize or reset the session */
2466                 if (test_and_clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state)) {
2467                         section = "reset session";
2468                         status = nfs4_reset_session(clp);
2469                         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
2470                                 continue;
2471                         if (status < 0)
2472                                 goto out_error;
2473                 }
2474
2475                 /* Send BIND_CONN_TO_SESSION */
2476                 if (test_and_clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2477                                 &clp->cl_state)) {
2478                         section = "bind conn to session";
2479                         status = nfs4_bind_conn_to_session(clp);
2480                         if (status < 0)
2481                                 goto out_error;
2482                         continue;
2483                 }
2484
2485                 if (test_and_clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state)) {
2486                         section = "check lease";
2487                         status = nfs4_check_lease(clp);
2488                         if (status < 0)
2489                                 goto out_error;
2490                         continue;
2491                 }
2492
2493                 if (test_and_clear_bit(NFS4CLNT_MOVED, &clp->cl_state)) {
2494                         section = "migration";
2495                         status = nfs4_handle_migration(clp);
2496                         if (status < 0)
2497                                 goto out_error;
2498                 }
2499
2500                 if (test_and_clear_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state)) {
2501                         section = "lease moved";
2502                         status = nfs4_handle_lease_moved(clp);
2503                         if (status < 0)
2504                                 goto out_error;
2505                 }
2506
2507                 /* First recover reboot state... */
2508                 if (test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {
2509                         section = "reclaim reboot";
2510                         status = nfs4_do_reclaim(clp,
2511                                 clp->cl_mvops->reboot_recovery_ops);
2512                         if (status == -EAGAIN)
2513                                 continue;
2514                         if (status < 0)
2515                                 goto out_error;
2516                         nfs4_state_end_reclaim_reboot(clp);
2517                 }
2518
2519                 /* Detect expired delegations... */
2520                 if (test_and_clear_bit(NFS4CLNT_DELEGATION_EXPIRED, &clp->cl_state)) {
2521                         section = "detect expired delegations";
2522                         nfs_reap_expired_delegations(clp);
2523                         continue;
2524                 }
2525
2526                 /* Now recover expired state... */
2527                 if (test_and_clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state)) {
2528                         section = "reclaim nograce";
2529                         status = nfs4_do_reclaim(clp,
2530                                 clp->cl_mvops->nograce_recovery_ops);
2531                         if (status == -EAGAIN)
2532                                 continue;
2533                         if (status < 0)
2534                                 goto out_error;
2535                 }
2536
2537                 nfs4_end_drain_session(clp);
2538                 if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
2539                         nfs_client_return_marked_delegations(clp);
2540                         continue;
2541                 }
2542
2543                 nfs4_clear_state_manager_bit(clp);
2544                 /* Did we race with an attempt to give us more work? */
2545                 if (clp->cl_state == 0)
2546                         break;
2547                 if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
2548                         break;
2549         } while (refcount_read(&clp->cl_count) > 1);
2550         return;
2551 out_error:
2552         if (strlen(section))
2553                 section_sep = ": ";
2554         pr_warn_ratelimited("NFS: state manager%s%s failed on NFSv4 server %s"
2555                         " with error %d\n", section_sep, section,
2556                         clp->cl_hostname, -status);
2557         ssleep(1);
2558         nfs4_end_drain_session(clp);
2559         nfs4_clear_state_manager_bit(clp);
2560 }
2561
2562 static int nfs4_run_state_manager(void *ptr)
2563 {
2564         struct nfs_client *clp = ptr;
2565
2566         allow_signal(SIGKILL);
2567         nfs4_state_manager(clp);
2568         nfs_put_client(clp);
2569         module_put_and_exit(0);
2570         return 0;
2571 }
2572
2573 /*
2574  * Local variables:
2575  *  c-basic-offset: 8
2576  * End:
2577  */