fs/nfs/nfs4state.c

   1 /*
   2  *  fs/nfs/nfs4state.c
   3  *
   4  *  Client-side XDR for NFSv4.
   5  *
   6  *  Copyright (c) 2002 The Regents of the University of Michigan.
   7  *  All rights reserved.
   8  *
   9  *  Kendrick Smith <kmsmith@umich.edu>
  10  *
  11  *  Redistribution and use in source and binary forms, with or without
  12  *  modification, are permitted provided that the following conditions
  13  *  are met:
  14  *
  15  *  1. Redistributions of source code must retain the above copyright
  16  *     notice, this list of conditions and the following disclaimer.
  17  *  2. Redistributions in binary form must reproduce the above copyright
  18  *     notice, this list of conditions and the following disclaimer in the
  19  *     documentation and/or other materials provided with the distribution.
  20  *  3. Neither the name of the University nor the names of its
  21  *     contributors may be used to endorse or promote products derived
  22  *     from this software without specific prior written permission.
  23  *
  24  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  25  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  26  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  27  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  31  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  32  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  33  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  34  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35  *
  36  * Implementation of the NFSv4 state model.  For the time being,
  37  * this is minimal, but will be made much more complex in a
  38  * subsequent patch.
  39  */
  40
  41 #include <linux/kernel.h>
  42 #include <linux/slab.h>
  43 #include <linux/fs.h>
  44 #include <linux/nfs_fs.h>
  45 #include <linux/kthread.h>
  46 #include <linux/module.h>
  47 #include <linux/random.h>
  48 #include <linux/ratelimit.h>
  49 #include <linux/workqueue.h>
  50 #include <linux/bitops.h>
  51 #include <linux/jiffies.h>
  52
  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 const nfs4_stateid current_stateid = {
  81         {
  82                 /* Funky initialiser keeps older gcc versions happy */
  83                 .data = { 0x0, 0x0, 0x0, 0x1, 0 },
  84         },
  85         .type = NFS4_SPECIAL_STATEID_TYPE,
  86 };
  87
  88 static DEFINE_MUTEX(nfs_clid_init_mutex);
  89
  90 int nfs4_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
  91 {
  92         struct nfs4_setclientid_res clid = {
  93                 .clientid = clp->cl_clientid,
  94                 .confirm = clp->cl_confirm,
  95         };
  96         unsigned short port;
  97         int status;
  98         struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
  99
 100         if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
 101                 goto do_confirm;
 102         port = nn->nfs_callback_tcpport;
 103         if (clp->cl_addr.ss_family == AF_INET6)
 104                 port = nn->nfs_callback_tcpport6;
 105
 106         status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
 107         if (status != 0)
 108                 goto out;
 109         clp->cl_clientid = clid.clientid;
 110         clp->cl_confirm = clid.confirm;
 111         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 112 do_confirm:
 113         status = nfs4_proc_setclientid_confirm(clp, &clid, cred);
 114         if (status != 0)
 115                 goto out;
 116         clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 117         nfs4_schedule_state_renewal(clp);
 118 out:
 119         return status;
 120 }
 121
 122 /**
 123  * nfs40_discover_server_trunking - Detect server IP address trunking (mv0)
 124  *
 125  * @clp: nfs_client under test
 126  * @result: OUT: found nfs_client, or clp
 127  * @cred: credential to use for trunking test
 128  *
 129  * Returns zero, a negative errno, or a negative NFS4ERR status.
 130  * If zero is returned, an nfs_client pointer is planted in
 131  * "result".
 132  *
 133  * Note: The returned client may not yet be marked ready.
 134  */
 135 int nfs40_discover_server_trunking(struct nfs_client *clp,
 136                                    struct nfs_client **result,
 137                                    struct rpc_cred *cred)
 138 {
 139         struct nfs4_setclientid_res clid = {
 140                 .clientid = clp->cl_clientid,
 141                 .confirm = clp->cl_confirm,
 142         };
 143         struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
 144         unsigned short port;
 145         int status;
 146
 147         port = nn->nfs_callback_tcpport;
 148         if (clp->cl_addr.ss_family == AF_INET6)
 149                 port = nn->nfs_callback_tcpport6;
 150
 151         status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
 152         if (status != 0)
 153                 goto out;
 154         clp->cl_clientid = clid.clientid;
 155         clp->cl_confirm = clid.confirm;
 156
 157         status = nfs40_walk_client_list(clp, result, cred);
 158         if (status == 0) {
 159                 /* Sustain the lease, even if it's empty.  If the clientid4
 160                  * goes stale it's of no use for trunking discovery. */
 161                 nfs4_schedule_state_renewal(*result);
 162         }
 163 out:
 164         return status;
 165 }
 166
 167 struct rpc_cred *nfs4_get_machine_cred_locked(struct nfs_client *clp)
 168 {
 169         struct rpc_cred *cred = NULL;
 170
 171         if (clp->cl_machine_cred != NULL)
 172                 cred = get_rpccred(clp->cl_machine_cred);
 173         return cred;
 174 }
 175
 176 static void nfs4_root_machine_cred(struct nfs_client *clp)
 177 {
 178         struct rpc_cred *cred, *new;
 179
 180         new = rpc_lookup_machine_cred(NULL);
 181         spin_lock(&clp->cl_lock);
 182         cred = clp->cl_machine_cred;
 183         clp->cl_machine_cred = new;
 184         spin_unlock(&clp->cl_lock);
 185         if (cred != NULL)
 186                 put_rpccred(cred);
 187 }
 188
 189 static struct rpc_cred *
 190 nfs4_get_renew_cred_server_locked(struct nfs_server *server)
 191 {
 192         struct rpc_cred *cred = NULL;
 193         struct nfs4_state_owner *sp;
 194         struct rb_node *pos;
 195
 196         for (pos = rb_first(&server->state_owners);
 197              pos != NULL;
 198              pos = rb_next(pos)) {
 199                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
 200                 if (list_empty(&sp->so_states))
 201                         continue;
 202                 cred = get_rpccred(sp->so_cred);
 203                 break;
 204         }
 205         return cred;
 206 }
 207
 208 /**
 209  * nfs4_get_renew_cred_locked - Acquire credential for a renew operation
 210  * @clp: client state handle
 211  *
 212  * Returns an rpc_cred with reference count bumped, or NULL.
 213  * Caller must hold clp->cl_lock.
 214  */
 215 struct rpc_cred *nfs4_get_renew_cred_locked(struct nfs_client *clp)
 216 {
 217         struct rpc_cred *cred = NULL;
 218         struct nfs_server *server;
 219
 220         /* Use machine credentials if available */
 221         cred = nfs4_get_machine_cred_locked(clp);
 222         if (cred != NULL)
 223                 goto out;
 224
 225         rcu_read_lock();
 226         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 227                 cred = nfs4_get_renew_cred_server_locked(server);
 228                 if (cred != NULL)
 229                         break;
 230         }
 231         rcu_read_unlock();
 232
 233 out:
 234         return cred;
 235 }
 236
 237 static void nfs4_end_drain_slot_table(struct nfs4_slot_table *tbl)
 238 {
 239         if (test_and_clear_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state)) {
 240                 spin_lock(&tbl->slot_tbl_lock);
 241                 nfs41_wake_slot_table(tbl);
 242                 spin_unlock(&tbl->slot_tbl_lock);
 243         }
 244 }
 245
 246 static void nfs4_end_drain_session(struct nfs_client *clp)
 247 {
 248         struct nfs4_session *ses = clp->cl_session;
 249
 250         if (clp->cl_slot_tbl) {
 251                 nfs4_end_drain_slot_table(clp->cl_slot_tbl);
 252                 return;
 253         }
 254
 255         if (ses != NULL) {
 256                 nfs4_end_drain_slot_table(&ses->bc_slot_table);
 257                 nfs4_end_drain_slot_table(&ses->fc_slot_table);
 258         }
 259 }
 260
 261 static int nfs4_drain_slot_tbl(struct nfs4_slot_table *tbl)
 262 {
 263         set_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
 264         spin_lock(&tbl->slot_tbl_lock);
 265         if (tbl->highest_used_slotid != NFS4_NO_SLOT) {
 266                 reinit_completion(&tbl->complete);
 267                 spin_unlock(&tbl->slot_tbl_lock);
 268                 return wait_for_completion_interruptible(&tbl->complete);
 269         }
 270         spin_unlock(&tbl->slot_tbl_lock);
 271         return 0;
 272 }
 273
 274 static int nfs4_begin_drain_session(struct nfs_client *clp)
 275 {
 276         struct nfs4_session *ses = clp->cl_session;
 277         int ret;
 278
 279         if (clp->cl_slot_tbl)
 280                 return nfs4_drain_slot_tbl(clp->cl_slot_tbl);
 281
 282         /* back channel */
 283         ret = nfs4_drain_slot_tbl(&ses->bc_slot_table);
 284         if (ret)
 285                 return ret;
 286         /* fore channel */
 287         return nfs4_drain_slot_tbl(&ses->fc_slot_table);
 288 }
 289
 290 #if defined(CONFIG_NFS_V4_1)
 291
 292 static int nfs41_setup_state_renewal(struct nfs_client *clp)
 293 {
 294         int status;
 295         struct nfs_fsinfo fsinfo;
 296         unsigned long now;
 297
 298         if (!test_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state)) {
 299                 nfs4_schedule_state_renewal(clp);
 300                 return 0;
 301         }
 302
 303         now = jiffies;
 304         status = nfs4_proc_get_lease_time(clp, &fsinfo);
 305         if (status == 0) {
 306                 nfs4_set_lease_period(clp, fsinfo.lease_time * HZ, now);
 307                 nfs4_schedule_state_renewal(clp);
 308         }
 309
 310         return status;
 311 }
 312
 313 static void nfs41_finish_session_reset(struct nfs_client *clp)
 314 {
 315         clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 316         clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
 317         /* create_session negotiated new slot table */
 318         clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
 319         nfs41_setup_state_renewal(clp);
 320 }
 321
 322 int nfs41_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
 323 {
 324         int status;
 325
 326         if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
 327                 goto do_confirm;
 328         status = nfs4_proc_exchange_id(clp, cred);
 329         if (status != 0)
 330                 goto out;
 331         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 332 do_confirm:
 333         status = nfs4_proc_create_session(clp, cred);
 334         if (status != 0)
 335                 goto out;
 336         nfs41_finish_session_reset(clp);
 337         nfs_mark_client_ready(clp, NFS_CS_READY);
 338 out:
 339         return status;
 340 }
 341
 342 /**
 343  * nfs41_discover_server_trunking - Detect server IP address trunking (mv1)
 344  *
 345  * @clp: nfs_client under test
 346  * @result: OUT: found nfs_client, or clp
 347  * @cred: credential to use for trunking test
 348  *
 349  * Returns NFS4_OK, a negative errno, or a negative NFS4ERR status.
 350  * If NFS4_OK is returned, an nfs_client pointer is planted in
 351  * "result".
 352  *
 353  * Note: The returned client may not yet be marked ready.
 354  */
 355 int nfs41_discover_server_trunking(struct nfs_client *clp,
 356                                    struct nfs_client **result,
 357                                    struct rpc_cred *cred)
 358 {
 359         int status;
 360
 361         status = nfs4_proc_exchange_id(clp, cred);
 362         if (status != NFS4_OK)
 363                 return status;
 364
 365         status = nfs41_walk_client_list(clp, result, cred);
 366         if (status < 0)
 367                 return status;
 368         if (clp != *result)
 369                 return 0;
 370
 371         /*
 372          * Purge state if the client id was established in a prior
 373          * instance and the client id could not have arrived on the
 374          * server via Transparent State Migration.
 375          */
 376         if (clp->cl_exchange_flags & EXCHGID4_FLAG_CONFIRMED_R) {
 377                 if (!test_bit(NFS_CS_TSM_POSSIBLE, &clp->cl_flags))
 378                         set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
 379                 else
 380                         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 381         }
 382         nfs4_schedule_state_manager(clp);
 383         status = nfs_wait_client_init_complete(clp);
 384         if (status < 0)
 385                 nfs_put_client(clp);
 386         return status;
 387 }
 388
 389 #endif /* CONFIG_NFS_V4_1 */
 390
 391 /**
 392  * nfs4_get_clid_cred - Acquire credential for a setclientid operation
 393  * @clp: client state handle
 394  *
 395  * Returns an rpc_cred with reference count bumped, or NULL.
 396  */
 397 struct rpc_cred *nfs4_get_clid_cred(struct nfs_client *clp)
 398 {
 399         struct rpc_cred *cred;
 400
 401         spin_lock(&clp->cl_lock);
 402         cred = nfs4_get_machine_cred_locked(clp);
 403         spin_unlock(&clp->cl_lock);
 404         return cred;
 405 }
 406
 407 static struct nfs4_state_owner *
 408 nfs4_find_state_owner_locked(struct nfs_server *server, struct rpc_cred *cred)
 409 {
 410         struct rb_node **p = &server->state_owners.rb_node,
 411                        *parent = NULL;
 412         struct nfs4_state_owner *sp;
 413
 414         while (*p != NULL) {
 415                 parent = *p;
 416                 sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
 417
 418                 if (cred < sp->so_cred)
 419                         p = &parent->rb_left;
 420                 else if (cred > sp->so_cred)
 421                         p = &parent->rb_right;
 422                 else {
 423                         if (!list_empty(&sp->so_lru))
 424                                 list_del_init(&sp->so_lru);
 425                         atomic_inc(&sp->so_count);
 426                         return sp;
 427                 }
 428         }
 429         return NULL;
 430 }
 431
 432 static struct nfs4_state_owner *
 433 nfs4_insert_state_owner_locked(struct nfs4_state_owner *new)
 434 {
 435         struct nfs_server *server = new->so_server;
 436         struct rb_node **p = &server->state_owners.rb_node,
 437                        *parent = NULL;
 438         struct nfs4_state_owner *sp;
 439
 440         while (*p != NULL) {
 441                 parent = *p;
 442                 sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
 443
 444                 if (new->so_cred < sp->so_cred)
 445                         p = &parent->rb_left;
 446                 else if (new->so_cred > sp->so_cred)
 447                         p = &parent->rb_right;
 448                 else {
 449                         if (!list_empty(&sp->so_lru))
 450                                 list_del_init(&sp->so_lru);
 451                         atomic_inc(&sp->so_count);
 452                         return sp;
 453                 }
 454         }
 455         rb_link_node(&new->so_server_node, parent, p);
 456         rb_insert_color(&new->so_server_node, &server->state_owners);
 457         return new;
 458 }
 459
 460 static void
 461 nfs4_remove_state_owner_locked(struct nfs4_state_owner *sp)
 462 {
 463         struct nfs_server *server = sp->so_server;
 464
 465         if (!RB_EMPTY_NODE(&sp->so_server_node))
 466                 rb_erase(&sp->so_server_node, &server->state_owners);
 467 }
 468
 469 static void
 470 nfs4_init_seqid_counter(struct nfs_seqid_counter *sc)
 471 {
 472         sc->create_time = ktime_get();
 473         sc->flags = 0;
 474         sc->counter = 0;
 475         spin_lock_init(&sc->lock);
 476         INIT_LIST_HEAD(&sc->list);
 477         rpc_init_wait_queue(&sc->wait, "Seqid_waitqueue");
 478 }
 479
 480 static void
 481 nfs4_destroy_seqid_counter(struct nfs_seqid_counter *sc)
 482 {
 483         rpc_destroy_wait_queue(&sc->wait);
 484 }
 485
 486 /*
 487  * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
 488  * create a new state_owner.
 489  *
 490  */
 491 static struct nfs4_state_owner *
 492 nfs4_alloc_state_owner(struct nfs_server *server,
 493                 struct rpc_cred *cred,
 494                 gfp_t gfp_flags)
 495 {
 496         struct nfs4_state_owner *sp;
 497
 498         sp = kzalloc(sizeof(*sp), gfp_flags);
 499         if (!sp)
 500                 return NULL;
 501         sp->so_seqid.owner_id = ida_simple_get(&server->openowner_id, 0, 0,
 502                                                 gfp_flags);
 503         if (sp->so_seqid.owner_id < 0) {
 504                 kfree(sp);
 505                 return NULL;
 506         }
 507         sp->so_server = server;
 508         sp->so_cred = get_rpccred(cred);
 509         spin_lock_init(&sp->so_lock);
 510         INIT_LIST_HEAD(&sp->so_states);
 511         nfs4_init_seqid_counter(&sp->so_seqid);
 512         atomic_set(&sp->so_count, 1);
 513         INIT_LIST_HEAD(&sp->so_lru);
 514         seqcount_init(&sp->so_reclaim_seqcount);
 515         mutex_init(&sp->so_delegreturn_mutex);
 516         return sp;
 517 }
 518
 519 static void
 520 nfs4_reset_state_owner(struct nfs4_state_owner *sp)
 521 {
 522         /* This state_owner is no longer usable, but must
 523          * remain in place so that state recovery can find it
 524          * and the opens associated with it.
 525          * It may also be used for new 'open' request to
 526          * return a delegation to the server.
 527          * So update the 'create_time' so that it looks like
 528          * a new state_owner.  This will cause the server to
 529          * request an OPEN_CONFIRM to start a new sequence.
 530          */
 531         sp->so_seqid.create_time = ktime_get();
 532 }
 533
 534 static void nfs4_free_state_owner(struct nfs4_state_owner *sp)
 535 {
 536         nfs4_destroy_seqid_counter(&sp->so_seqid);
 537         put_rpccred(sp->so_cred);
 538         ida_simple_remove(&sp->so_server->openowner_id, sp->so_seqid.owner_id);
 539         kfree(sp);
 540 }
 541
 542 static void nfs4_gc_state_owners(struct nfs_server *server)
 543 {
 544         struct nfs_client *clp = server->nfs_client;
 545         struct nfs4_state_owner *sp, *tmp;
 546         unsigned long time_min, time_max;
 547         LIST_HEAD(doomed);
 548
 549         spin_lock(&clp->cl_lock);
 550         time_max = jiffies;
 551         time_min = (long)time_max - (long)clp->cl_lease_time;
 552         list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
 553                 /* NB: LRU is sorted so that oldest is at the head */
 554                 if (time_in_range(sp->so_expires, time_min, time_max))
 555                         break;
 556                 list_move(&sp->so_lru, &doomed);
 557                 nfs4_remove_state_owner_locked(sp);
 558         }
 559         spin_unlock(&clp->cl_lock);
 560
 561         list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
 562                 list_del(&sp->so_lru);
 563                 nfs4_free_state_owner(sp);
 564         }
 565 }
 566
 567 /**
 568  * nfs4_get_state_owner - Look up a state owner given a credential
 569  * @server: nfs_server to search
 570  * @cred: RPC credential to match
 571  *
 572  * Returns a pointer to an instantiated nfs4_state_owner struct, or NULL.
 573  */
 574 struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server,
 575                                               struct rpc_cred *cred,
 576                                               gfp_t gfp_flags)
 577 {
 578         struct nfs_client *clp = server->nfs_client;
 579         struct nfs4_state_owner *sp, *new;
 580
 581         spin_lock(&clp->cl_lock);
 582         sp = nfs4_find_state_owner_locked(server, cred);
 583         spin_unlock(&clp->cl_lock);
 584         if (sp != NULL)
 585                 goto out;
 586         new = nfs4_alloc_state_owner(server, cred, gfp_flags);
 587         if (new == NULL)
 588                 goto out;
 589         spin_lock(&clp->cl_lock);
 590         sp = nfs4_insert_state_owner_locked(new);
 591         spin_unlock(&clp->cl_lock);
 592         if (sp != new)
 593                 nfs4_free_state_owner(new);
 594 out:
 595         nfs4_gc_state_owners(server);
 596         return sp;
 597 }
 598
 599 /**
 600  * nfs4_put_state_owner - Release a nfs4_state_owner
 601  * @sp: state owner data to release
 602  *
 603  * Note that we keep released state owners on an LRU
 604  * list.
 605  * This caches valid state owners so that they can be
 606  * reused, to avoid the OPEN_CONFIRM on minor version 0.
 607  * It also pins the uniquifier of dropped state owners for
 608  * a while, to ensure that those state owner names are
 609  * never reused.
 610  */
 611 void nfs4_put_state_owner(struct nfs4_state_owner *sp)
 612 {
 613         struct nfs_server *server = sp->so_server;
 614         struct nfs_client *clp = server->nfs_client;
 615
 616         if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
 617                 return;
 618
 619         sp->so_expires = jiffies;
 620         list_add_tail(&sp->so_lru, &server->state_owners_lru);
 621         spin_unlock(&clp->cl_lock);
 622 }
 623
 624 /**
 625  * nfs4_purge_state_owners - Release all cached state owners
 626  * @server: nfs_server with cached state owners to release
 627  *
 628  * Called at umount time.  Remaining state owners will be on
 629  * the LRU with ref count of zero.
 630  */
 631 void nfs4_purge_state_owners(struct nfs_server *server)
 632 {
 633         struct nfs_client *clp = server->nfs_client;
 634         struct nfs4_state_owner *sp, *tmp;
 635         LIST_HEAD(doomed);
 636
 637         spin_lock(&clp->cl_lock);
 638         list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
 639                 list_move(&sp->so_lru, &doomed);
 640                 nfs4_remove_state_owner_locked(sp);
 641         }
 642         spin_unlock(&clp->cl_lock);
 643
 644         list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
 645                 list_del(&sp->so_lru);
 646                 nfs4_free_state_owner(sp);
 647         }
 648 }
 649
 650 static struct nfs4_state *
 651 nfs4_alloc_open_state(void)
 652 {
 653         struct nfs4_state *state;
 654
 655         state = kzalloc(sizeof(*state), GFP_NOFS);
 656         if (!state)
 657                 return NULL;
 658         refcount_set(&state->count, 1);
 659         INIT_LIST_HEAD(&state->lock_states);
 660         spin_lock_init(&state->state_lock);
 661         seqlock_init(&state->seqlock);
 662         init_waitqueue_head(&state->waitq);
 663         return state;
 664 }
 665
 666 void
 667 nfs4_state_set_mode_locked(struct nfs4_state *state, fmode_t fmode)
 668 {
 669         if (state->state == fmode)
 670                 return;
 671         /* NB! List reordering - see the reclaim code for why.  */
 672         if ((fmode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
 673                 if (fmode & FMODE_WRITE)
 674                         list_move(&state->open_states, &state->owner->so_states);
 675                 else
 676                         list_move_tail(&state->open_states, &state->owner->so_states);
 677         }
 678         state->state = fmode;
 679 }
 680
 681 static struct nfs4_state *
 682 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
 683 {
 684         struct nfs_inode *nfsi = NFS_I(inode);
 685         struct nfs4_state *state;
 686
 687         list_for_each_entry_rcu(state, &nfsi->open_states, inode_states) {
 688                 if (state->owner != owner)
 689                         continue;
 690                 if (!nfs4_valid_open_stateid(state))
 691                         continue;
 692                 if (refcount_inc_not_zero(&state->count))
 693                         return state;
 694         }
 695         return NULL;
 696 }
 697
 698 static void
 699 nfs4_free_open_state(struct nfs4_state *state)
 700 {
 701         kfree_rcu(state, rcu_head);
 702 }
 703
 704 struct nfs4_state *
 705 nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
 706 {
 707         struct nfs4_state *state, *new;
 708         struct nfs_inode *nfsi = NFS_I(inode);
 709
 710         rcu_read_lock();
 711         state = __nfs4_find_state_byowner(inode, owner);
 712         rcu_read_unlock();
 713         if (state)
 714                 goto out;
 715         new = nfs4_alloc_open_state();
 716         spin_lock(&owner->so_lock);
 717         spin_lock(&inode->i_lock);
 718         state = __nfs4_find_state_byowner(inode, owner);
 719         if (state == NULL && new != NULL) {
 720                 state = new;
 721                 state->owner = owner;
 722                 atomic_inc(&owner->so_count);
 723                 list_add_rcu(&state->inode_states, &nfsi->open_states);
 724                 ihold(inode);
 725                 state->inode = inode;
 726                 spin_unlock(&inode->i_lock);
 727                 /* Note: The reclaim code dictates that we add stateless
 728                  * and read-only stateids to the end of the list */
 729                 list_add_tail(&state->open_states, &owner->so_states);
 730                 spin_unlock(&owner->so_lock);
 731         } else {
 732                 spin_unlock(&inode->i_lock);
 733                 spin_unlock(&owner->so_lock);
 734                 if (new)
 735                         nfs4_free_open_state(new);
 736         }
 737 out:
 738         return state;
 739 }
 740
 741 void nfs4_put_open_state(struct nfs4_state *state)
 742 {
 743         struct inode *inode = state->inode;
 744         struct nfs4_state_owner *owner = state->owner;
 745
 746         if (!refcount_dec_and_lock(&state->count, &owner->so_lock))
 747                 return;
 748         spin_lock(&inode->i_lock);
 749         list_del_rcu(&state->inode_states);
 750         list_del(&state->open_states);
 751         spin_unlock(&inode->i_lock);
 752         spin_unlock(&owner->so_lock);
 753         iput(inode);
 754         nfs4_free_open_state(state);
 755         nfs4_put_state_owner(owner);
 756 }
 757
 758 /*
 759  * Close the current file.
 760  */
 761 static void __nfs4_close(struct nfs4_state *state,
 762                 fmode_t fmode, gfp_t gfp_mask, int wait)
 763 {
 764         struct nfs4_state_owner *owner = state->owner;
 765         int call_close = 0;
 766         fmode_t newstate;
 767
 768         atomic_inc(&owner->so_count);
 769         /* Protect against nfs4_find_state() */
 770         spin_lock(&owner->so_lock);
 771         switch (fmode & (FMODE_READ | FMODE_WRITE)) {
 772                 case FMODE_READ:
 773                         state->n_rdonly--;
 774                         break;
 775                 case FMODE_WRITE:
 776                         state->n_wronly--;
 777                         break;
 778                 case FMODE_READ|FMODE_WRITE:
 779                         state->n_rdwr--;
 780         }
 781         newstate = FMODE_READ|FMODE_WRITE;
 782         if (state->n_rdwr == 0) {
 783                 if (state->n_rdonly == 0) {
 784                         newstate &= ~FMODE_READ;
 785                         call_close |= test_bit(NFS_O_RDONLY_STATE, &state->flags);
 786                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
 787                 }
 788                 if (state->n_wronly == 0) {
 789                         newstate &= ~FMODE_WRITE;
 790                         call_close |= test_bit(NFS_O_WRONLY_STATE, &state->flags);
 791                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
 792                 }
 793                 if (newstate == 0)
 794                         clear_bit(NFS_DELEGATED_STATE, &state->flags);
 795         }
 796         nfs4_state_set_mode_locked(state, newstate);
 797         spin_unlock(&owner->so_lock);
 798
 799         if (!call_close) {
 800                 nfs4_put_open_state(state);
 801                 nfs4_put_state_owner(owner);
 802         } else
 803                 nfs4_do_close(state, gfp_mask, wait);
 804 }
 805
 806 void nfs4_close_state(struct nfs4_state *state, fmode_t fmode)
 807 {
 808         __nfs4_close(state, fmode, GFP_NOFS, 0);
 809 }
 810
 811 void nfs4_close_sync(struct nfs4_state *state, fmode_t fmode)
 812 {
 813         __nfs4_close(state, fmode, GFP_KERNEL, 1);
 814 }
 815
 816 /*
 817  * Search the state->lock_states for an existing lock_owner
 818  * that is compatible with either of the given owners.
 819  * If the second is non-zero, then the first refers to a Posix-lock
 820  * owner (current->files) and the second refers to a flock/OFD
 821  * owner (struct file*).  In that case, prefer a match for the first
 822  * owner.
 823  * If both sorts of locks are held on the one file we cannot know
 824  * which stateid was intended to be used, so a "correct" choice cannot
 825  * be made.  Failing that, a "consistent" choice is preferable.  The
 826  * consistent choice we make is to prefer the first owner, that of a
 827  * Posix lock.
 828  */
 829 static struct nfs4_lock_state *
 830 __nfs4_find_lock_state(struct nfs4_state *state,
 831                        fl_owner_t fl_owner, fl_owner_t fl_owner2)
 832 {
 833         struct nfs4_lock_state *pos, *ret = NULL;
 834         list_for_each_entry(pos, &state->lock_states, ls_locks) {
 835                 if (pos->ls_owner == fl_owner) {
 836                         ret = pos;
 837                         break;
 838                 }
 839                 if (pos->ls_owner == fl_owner2)
 840                         ret = pos;
 841         }
 842         if (ret)
 843                 refcount_inc(&ret->ls_count);
 844         return ret;
 845 }
 846
 847 /*
 848  * Return a compatible lock_state. If no initialized lock_state structure
 849  * exists, return an uninitialized one.
 850  *
 851  */
 852 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 853 {
 854         struct nfs4_lock_state *lsp;
 855         struct nfs_server *server = state->owner->so_server;
 856
 857         lsp = kzalloc(sizeof(*lsp), GFP_NOFS);
 858         if (lsp == NULL)
 859                 return NULL;
 860         nfs4_init_seqid_counter(&lsp->ls_seqid);
 861         refcount_set(&lsp->ls_count, 1);
 862         lsp->ls_state = state;
 863         lsp->ls_owner = fl_owner;
 864         lsp->ls_seqid.owner_id = ida_simple_get(&server->lockowner_id, 0, 0, GFP_NOFS);
 865         if (lsp->ls_seqid.owner_id < 0)
 866                 goto out_free;
 867         INIT_LIST_HEAD(&lsp->ls_locks);
 868         return lsp;
 869 out_free:
 870         kfree(lsp);
 871         return NULL;
 872 }
 873
 874 void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp)
 875 {
 876         ida_simple_remove(&server->lockowner_id, lsp->ls_seqid.owner_id);
 877         nfs4_destroy_seqid_counter(&lsp->ls_seqid);
 878         kfree(lsp);
 879 }
 880
 881 /*
 882  * Return a compatible lock_state. If no initialized lock_state structure
 883  * exists, return an uninitialized one.
 884  *
 885  */
 886 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
 887 {
 888         struct nfs4_lock_state *lsp, *new = NULL;
 889
 890         for(;;) {
 891                 spin_lock(&state->state_lock);
 892                 lsp = __nfs4_find_lock_state(state, owner, NULL);
 893                 if (lsp != NULL)
 894                         break;
 895                 if (new != NULL) {
 896                         list_add(&new->ls_locks, &state->lock_states);
 897                         set_bit(LK_STATE_IN_USE, &state->flags);
 898                         lsp = new;
 899                         new = NULL;
 900                         break;
 901                 }
 902                 spin_unlock(&state->state_lock);
 903                 new = nfs4_alloc_lock_state(state, owner);
 904                 if (new == NULL)
 905                         return NULL;
 906         }
 907         spin_unlock(&state->state_lock);
 908         if (new != NULL)
 909                 nfs4_free_lock_state(state->owner->so_server, new);
 910         return lsp;
 911 }
 912
 913 /*
 914  * Release reference to lock_state, and free it if we see that
 915  * it is no longer in use
 916  */
 917 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
 918 {
 919         struct nfs_server *server;
 920         struct nfs4_state *state;
 921
 922         if (lsp == NULL)
 923                 return;
 924         state = lsp->ls_state;
 925         if (!refcount_dec_and_lock(&lsp->ls_count, &state->state_lock))
 926                 return;
 927         list_del(&lsp->ls_locks);
 928         if (list_empty(&state->lock_states))
 929                 clear_bit(LK_STATE_IN_USE, &state->flags);
 930         spin_unlock(&state->state_lock);
 931         server = state->owner->so_server;
 932         if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) {
 933                 struct nfs_client *clp = server->nfs_client;
 934
 935                 clp->cl_mvops->free_lock_state(server, lsp);
 936         } else
 937                 nfs4_free_lock_state(server, lsp);
 938 }
 939
 940 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
 941 {
 942         struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
 943
 944         dst->fl_u.nfs4_fl.owner = lsp;
 945         refcount_inc(&lsp->ls_count);
 946 }
 947
 948 static void nfs4_fl_release_lock(struct file_lock *fl)
 949 {
 950         nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
 951 }
 952
 953 static const struct file_lock_operations nfs4_fl_lock_ops = {
 954         .fl_copy_lock = nfs4_fl_copy_lock,
 955         .fl_release_private = nfs4_fl_release_lock,
 956 };
 957
 958 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
 959 {
 960         struct nfs4_lock_state *lsp;
 961
 962         if (fl->fl_ops != NULL)
 963                 return 0;
 964         lsp = nfs4_get_lock_state(state, fl->fl_owner);
 965         if (lsp == NULL)
 966                 return -ENOMEM;
 967         fl->fl_u.nfs4_fl.owner = lsp;
 968         fl->fl_ops = &nfs4_fl_lock_ops;
 969         return 0;
 970 }
 971
 972 static int nfs4_copy_lock_stateid(nfs4_stateid *dst,
 973                 struct nfs4_state *state,
 974                 const struct nfs_lock_context *l_ctx)
 975 {
 976         struct nfs4_lock_state *lsp;
 977         fl_owner_t fl_owner, fl_flock_owner;
 978         int ret = -ENOENT;
 979
 980         if (l_ctx == NULL)
 981                 goto out;
 982
 983         if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
 984                 goto out;
 985
 986         fl_owner = l_ctx->lockowner;
 987         fl_flock_owner = l_ctx->open_context->flock_owner;
 988
 989         spin_lock(&state->state_lock);
 990         lsp = __nfs4_find_lock_state(state, fl_owner, fl_flock_owner);
 991         if (lsp && test_bit(NFS_LOCK_LOST, &lsp->ls_flags))
 992                 ret = -EIO;
 993         else if (lsp != NULL && test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) != 0) {
 994                 nfs4_stateid_copy(dst, &lsp->ls_stateid);
 995                 ret = 0;
 996         }
 997         spin_unlock(&state->state_lock);
 998         nfs4_put_lock_state(lsp);
 999 out:
1000         return ret;
1001 }
1002
1003 bool nfs4_refresh_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
1004 {
1005         bool ret;
1006         int seq;
1007
1008         do {
1009                 ret = false;
1010                 seq = read_seqbegin(&state->seqlock);
1011                 if (nfs4_state_match_open_stateid_other(state, dst)) {
1012                         dst->seqid = state->open_stateid.seqid;
1013                         ret = true;
1014                 }
1015         } while (read_seqretry(&state->seqlock, seq));
1016         return ret;
1017 }
1018
1019 bool nfs4_copy_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
1020 {
1021         bool ret;
1022         const nfs4_stateid *src;
1023         int seq;
1024
1025         do {
1026                 ret = false;
1027                 src = &zero_stateid;
1028                 seq = read_seqbegin(&state->seqlock);
1029                 if (test_bit(NFS_OPEN_STATE, &state->flags)) {
1030                         src = &state->open_stateid;
1031                         ret = true;
1032                 }
1033                 nfs4_stateid_copy(dst, src);
1034         } while (read_seqretry(&state->seqlock, seq));
1035         return ret;
1036 }
1037
1038 /*
1039  * Byte-range lock aware utility to initialize the stateid of read/write
1040  * requests.
1041  */
1042 int nfs4_select_rw_stateid(struct nfs4_state *state,
1043                 fmode_t fmode, const struct nfs_lock_context *l_ctx,
1044                 nfs4_stateid *dst, struct rpc_cred **cred)
1045 {
1046         int ret;
1047
1048         if (!nfs4_valid_open_stateid(state))
1049                 return -EIO;
1050         if (cred != NULL)
1051                 *cred = NULL;
1052         ret = nfs4_copy_lock_stateid(dst, state, l_ctx);
1053         if (ret == -EIO)
1054                 /* A lost lock - don't even consider delegations */
1055                 goto out;
1056         /* returns true if delegation stateid found and copied */
1057         if (nfs4_copy_delegation_stateid(state->inode, fmode, dst, cred)) {
1058                 ret = 0;
1059                 goto out;
1060         }
1061         if (ret != -ENOENT)
1062                 /* nfs4_copy_delegation_stateid() didn't over-write
1063                  * dst, so it still has the lock stateid which we now
1064                  * choose to use.
1065                  */
1066                 goto out;
1067         nfs4_copy_open_stateid(dst, state);
1068         ret = 0;
1069 out:
1070         if (nfs_server_capable(state->inode, NFS_CAP_STATEID_NFSV41))
1071                 dst->seqid = 0;
1072         return ret;
1073 }
1074
1075 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask)
1076 {
1077         struct nfs_seqid *new;
1078
1079         new = kmalloc(sizeof(*new), gfp_mask);
1080         if (new == NULL)
1081                 return ERR_PTR(-ENOMEM);
1082         new->sequence = counter;
1083         INIT_LIST_HEAD(&new->list);
1084         new->task = NULL;
1085         return new;
1086 }
1087
1088 void nfs_release_seqid(struct nfs_seqid *seqid)
1089 {
1090         struct nfs_seqid_counter *sequence;
1091
1092         if (seqid == NULL || list_empty(&seqid->list))
1093                 return;
1094         sequence = seqid->sequence;
1095         spin_lock(&sequence->lock);
1096         list_del_init(&seqid->list);
1097         if (!list_empty(&sequence->list)) {
1098                 struct nfs_seqid *next;
1099
1100                 next = list_first_entry(&sequence->list,
1101                                 struct nfs_seqid, list);
1102                 rpc_wake_up_queued_task(&sequence->wait, next->task);
1103         }
1104         spin_unlock(&sequence->lock);
1105 }
1106
1107 void nfs_free_seqid(struct nfs_seqid *seqid)
1108 {
1109         nfs_release_seqid(seqid);
1110         kfree(seqid);
1111 }
1112
1113 /*
1114  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
1115  * failed with a seqid incrementing error -
1116  * see comments nfs4.h:seqid_mutating_error()
1117  */
1118 static void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
1119 {
1120         switch (status) {
1121                 case 0:
1122                         break;
1123                 case -NFS4ERR_BAD_SEQID:
1124                         if (seqid->sequence->flags & NFS_SEQID_CONFIRMED)
1125                                 return;
1126                         pr_warn_ratelimited("NFS: v4 server returned a bad"
1127                                         " sequence-id error on an"
1128                                         " unconfirmed sequence %p!\n",
1129                                         seqid->sequence);
1130                 case -NFS4ERR_STALE_CLIENTID:
1131                 case -NFS4ERR_STALE_STATEID:
1132                 case -NFS4ERR_BAD_STATEID:
1133                 case -NFS4ERR_BADXDR:
1134                 case -NFS4ERR_RESOURCE:
1135                 case -NFS4ERR_NOFILEHANDLE:
1136                 case -NFS4ERR_MOVED:
1137                         /* Non-seqid mutating errors */
1138                         return;
1139         };
1140         /*
1141          * Note: no locking needed as we are guaranteed to be first
1142          * on the sequence list
1143          */
1144         seqid->sequence->counter++;
1145 }
1146
1147 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
1148 {
1149         struct nfs4_state_owner *sp;
1150
1151         if (seqid == NULL)
1152                 return;
1153
1154         sp = container_of(seqid->sequence, struct nfs4_state_owner, so_seqid);
1155         if (status == -NFS4ERR_BAD_SEQID)
1156                 nfs4_reset_state_owner(sp);
1157         if (!nfs4_has_session(sp->so_server->nfs_client))
1158                 nfs_increment_seqid(status, seqid);
1159 }
1160
1161 /*
1162  * Increment the seqid if the LOCK/LOCKU succeeded, or
1163  * failed with a seqid incrementing error -
1164  * see comments nfs4.h:seqid_mutating_error()
1165  */
1166 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
1167 {
1168         if (seqid != NULL)
1169                 nfs_increment_seqid(status, seqid);
1170 }
1171
1172 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
1173 {
1174         struct nfs_seqid_counter *sequence;
1175         int status = 0;
1176
1177         if (seqid == NULL)
1178                 goto out;
1179         sequence = seqid->sequence;
1180         spin_lock(&sequence->lock);
1181         seqid->task = task;
1182         if (list_empty(&seqid->list))
1183                 list_add_tail(&seqid->list, &sequence->list);
1184         if (list_first_entry(&sequence->list, struct nfs_seqid, list) == seqid)
1185                 goto unlock;
1186         rpc_sleep_on(&sequence->wait, task, NULL);
1187         status = -EAGAIN;
1188 unlock:
1189         spin_unlock(&sequence->lock);
1190 out:
1191         return status;
1192 }
1193
1194 static int nfs4_run_state_manager(void *);
1195
1196 static void nfs4_clear_state_manager_bit(struct nfs_client *clp)
1197 {
1198         smp_mb__before_atomic();
1199         clear_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state);
1200         smp_mb__after_atomic();
1201         wake_up_bit(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING);
1202         rpc_wake_up(&clp->cl_rpcwaitq);
1203 }
1204
1205 /*
1206  * Schedule the nfs_client asynchronous state management routine
1207  */
1208 void nfs4_schedule_state_manager(struct nfs_client *clp)
1209 {
1210         struct task_struct *task;
1211         char buf[INET6_ADDRSTRLEN + sizeof("-manager") + 1];
1212
1213         set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
1214         if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
1215                 return;
1216         __module_get(THIS_MODULE);
1217         refcount_inc(&clp->cl_count);
1218
1219         /* The rcu_read_lock() is not strictly necessary, as the state
1220          * manager is the only thread that ever changes the rpc_xprt
1221          * after it's initialized.  At this point, we're single threaded. */
1222         rcu_read_lock();
1223         snprintf(buf, sizeof(buf), "%s-manager",
1224                         rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
1225         rcu_read_unlock();
1226         task = kthread_run(nfs4_run_state_manager, clp, "%s", buf);
1227         if (IS_ERR(task)) {
1228                 printk(KERN_ERR "%s: kthread_run: %ld\n",
1229                         __func__, PTR_ERR(task));
1230                 nfs4_clear_state_manager_bit(clp);
1231                 nfs_put_client(clp);
1232                 module_put(THIS_MODULE);
1233         }
1234 }
1235
1236 /*
1237  * Schedule a lease recovery attempt
1238  */
1239 void nfs4_schedule_lease_recovery(struct nfs_client *clp)
1240 {
1241         if (!clp)
1242                 return;
1243         if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1244                 set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1245         dprintk("%s: scheduling lease recovery for server %s\n", __func__,
1246                         clp->cl_hostname);
1247         nfs4_schedule_state_manager(clp);
1248 }
1249 EXPORT_SYMBOL_GPL(nfs4_schedule_lease_recovery);
1250
1251 /**
1252  * nfs4_schedule_migration_recovery - trigger migration recovery
1253  *
1254  * @server: FSID that is migrating
1255  *
1256  * Returns zero if recovery has started, otherwise a negative NFS4ERR
1257  * value is returned.
1258  */
1259 int nfs4_schedule_migration_recovery(const struct nfs_server *server)
1260 {
1261         struct nfs_client *clp = server->nfs_client;
1262
1263         if (server->fh_expire_type != NFS4_FH_PERSISTENT) {
1264                 pr_err("NFS: volatile file handles not supported (server %s)\n",
1265                                 clp->cl_hostname);
1266                 return -NFS4ERR_IO;
1267         }
1268
1269         if (test_bit(NFS_MIG_FAILED, &server->mig_status))
1270                 return -NFS4ERR_IO;
1271
1272         dprintk("%s: scheduling migration recovery for (%llx:%llx) on %s\n",
1273                         __func__,
1274                         (unsigned long long)server->fsid.major,
1275                         (unsigned long long)server->fsid.minor,
1276                         clp->cl_hostname);
1277
1278         set_bit(NFS_MIG_IN_TRANSITION,
1279                         &((struct nfs_server *)server)->mig_status);
1280         set_bit(NFS4CLNT_MOVED, &clp->cl_state);
1281
1282         nfs4_schedule_state_manager(clp);
1283         return 0;
1284 }
1285 EXPORT_SYMBOL_GPL(nfs4_schedule_migration_recovery);
1286
1287 /**
1288  * nfs4_schedule_lease_moved_recovery - start lease-moved recovery
1289  *
1290  * @clp: server to check for moved leases
1291  *
1292  */
1293 void nfs4_schedule_lease_moved_recovery(struct nfs_client *clp)
1294 {
1295         dprintk("%s: scheduling lease-moved recovery for client ID %llx on %s\n",
1296                 __func__, clp->cl_clientid, clp->cl_hostname);
1297
1298         set_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state);
1299         nfs4_schedule_state_manager(clp);
1300 }
1301 EXPORT_SYMBOL_GPL(nfs4_schedule_lease_moved_recovery);
1302
1303 int nfs4_wait_clnt_recover(struct nfs_client *clp)
1304 {
1305         int res;
1306
1307         might_sleep();
1308
1309         refcount_inc(&clp->cl_count);
1310         res = wait_on_bit_action(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING,
1311                                  nfs_wait_bit_killable, TASK_KILLABLE);
1312         if (res)
1313                 goto out;
1314         if (clp->cl_cons_state < 0)
1315                 res = clp->cl_cons_state;
1316 out:
1317         nfs_put_client(clp);
1318         return res;
1319 }
1320
1321 int nfs4_client_recover_expired_lease(struct nfs_client *clp)
1322 {
1323         unsigned int loop;
1324         int ret;
1325
1326         for (loop = NFS4_MAX_LOOP_ON_RECOVER; loop != 0; loop--) {
1327                 ret = nfs4_wait_clnt_recover(clp);
1328                 if (ret != 0)
1329                         break;
1330                 if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) &&
1331                     !test_bit(NFS4CLNT_CHECK_LEASE,&clp->cl_state))
1332                         break;
1333                 nfs4_schedule_state_manager(clp);
1334                 ret = -EIO;
1335         }
1336         return ret;
1337 }
1338
1339 /*
1340  * nfs40_handle_cb_pathdown - return all delegations after NFS4ERR_CB_PATH_DOWN
1341  * @clp: client to process
1342  *
1343  * Set the NFS4CLNT_LEASE_EXPIRED state in order to force a
1344  * resend of the SETCLIENTID and hence re-establish the
1345  * callback channel. Then return all existing delegations.
1346  */
1347 static void nfs40_handle_cb_pathdown(struct nfs_client *clp)
1348 {
1349         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1350         nfs_expire_all_delegations(clp);
1351         dprintk("%s: handling CB_PATHDOWN recovery for server %s\n", __func__,
1352                         clp->cl_hostname);
1353 }
1354
1355 void nfs4_schedule_path_down_recovery(struct nfs_client *clp)
1356 {
1357         nfs40_handle_cb_pathdown(clp);
1358         nfs4_schedule_state_manager(clp);
1359 }
1360
1361 static int nfs4_state_mark_reclaim_reboot(struct nfs_client *clp, struct nfs4_state *state)
1362 {
1363
1364         if (!nfs4_valid_open_stateid(state))
1365                 return 0;
1366         set_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1367         /* Don't recover state that expired before the reboot */
1368         if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags)) {
1369                 clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1370                 return 0;
1371         }
1372         set_bit(NFS_OWNER_RECLAIM_REBOOT, &state->owner->so_flags);
1373         set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1374         return 1;
1375 }
1376
1377 int nfs4_state_mark_reclaim_nograce(struct nfs_client *clp, struct nfs4_state *state)
1378 {
1379         if (!nfs4_valid_open_stateid(state))
1380                 return 0;
1381         set_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1382         clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1383         set_bit(NFS_OWNER_RECLAIM_NOGRACE, &state->owner->so_flags);
1384         set_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
1385         return 1;
1386 }
1387
1388 int nfs4_schedule_stateid_recovery(const struct nfs_server *server, struct nfs4_state *state)
1389 {
1390         struct nfs_client *clp = server->nfs_client;
1391
1392         if (!nfs4_state_mark_reclaim_nograce(clp, state))
1393                 return -EBADF;
1394         nfs_inode_find_delegation_state_and_recover(state->inode,
1395                         &state->stateid);
1396         dprintk("%s: scheduling stateid recovery for server %s\n", __func__,
1397                         clp->cl_hostname);
1398         nfs4_schedule_state_manager(clp);
1399         return 0;
1400 }
1401 EXPORT_SYMBOL_GPL(nfs4_schedule_stateid_recovery);
1402
1403 static struct nfs4_lock_state *
1404 nfs_state_find_lock_state_by_stateid(struct nfs4_state *state,
1405                 const nfs4_stateid *stateid)
1406 {
1407         struct nfs4_lock_state *pos;
1408
1409         list_for_each_entry(pos, &state->lock_states, ls_locks) {
1410                 if (!test_bit(NFS_LOCK_INITIALIZED, &pos->ls_flags))
1411                         continue;
1412                 if (nfs4_stateid_match_other(&pos->ls_stateid, stateid))
1413                         return pos;
1414         }
1415         return NULL;
1416 }
1417
1418 static bool nfs_state_lock_state_matches_stateid(struct nfs4_state *state,
1419                 const nfs4_stateid *stateid)
1420 {
1421         bool found = false;
1422
1423         if (test_bit(LK_STATE_IN_USE, &state->flags)) {
1424                 spin_lock(&state->state_lock);
1425                 if (nfs_state_find_lock_state_by_stateid(state, stateid))
1426                         found = true;
1427                 spin_unlock(&state->state_lock);
1428         }
1429         return found;
1430 }
1431
1432 void nfs_inode_find_state_and_recover(struct inode *inode,
1433                 const nfs4_stateid *stateid)
1434 {
1435         struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
1436         struct nfs_inode *nfsi = NFS_I(inode);
1437         struct nfs_open_context *ctx;
1438         struct nfs4_state *state;
1439         bool found = false;
1440
1441         rcu_read_lock();
1442         list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1443                 state = ctx->state;
1444                 if (state == NULL)
1445                         continue;
1446                 if (nfs4_stateid_match_other(&state->stateid, stateid) &&
1447                     nfs4_state_mark_reclaim_nograce(clp, state)) {
1448                         found = true;
1449                         continue;
1450                 }
1451                 if (nfs4_stateid_match_other(&state->open_stateid, stateid) &&
1452                     nfs4_state_mark_reclaim_nograce(clp, state)) {
1453                         found = true;
1454                         continue;
1455                 }
1456                 if (nfs_state_lock_state_matches_stateid(state, stateid) &&
1457                     nfs4_state_mark_reclaim_nograce(clp, state))
1458                         found = true;
1459         }
1460         rcu_read_unlock();
1461
1462         nfs_inode_find_delegation_state_and_recover(inode, stateid);
1463         if (found)
1464                 nfs4_schedule_state_manager(clp);
1465 }
1466
1467 static void nfs4_state_mark_open_context_bad(struct nfs4_state *state)
1468 {
1469         struct inode *inode = state->inode;
1470         struct nfs_inode *nfsi = NFS_I(inode);
1471         struct nfs_open_context *ctx;
1472
1473         rcu_read_lock();
1474         list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1475                 if (ctx->state != state)
1476                         continue;
1477                 set_bit(NFS_CONTEXT_BAD, &ctx->flags);
1478         }
1479         rcu_read_unlock();
1480 }
1481
1482 static void nfs4_state_mark_recovery_failed(struct nfs4_state *state, int error)
1483 {
1484         set_bit(NFS_STATE_RECOVERY_FAILED, &state->flags);
1485         nfs4_state_mark_open_context_bad(state);
1486 }
1487
1488
1489 static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_recovery_ops *ops)
1490 {
1491         struct inode *inode = state->inode;
1492         struct nfs_inode *nfsi = NFS_I(inode);
1493         struct file_lock *fl;
1494         struct nfs4_lock_state *lsp;
1495         int status = 0;
1496         struct file_lock_context *flctx = inode->i_flctx;
1497         struct list_head *list;
1498
1499         if (flctx == NULL)
1500                 return 0;
1501
1502         list = &flctx->flc_posix;
1503
1504         /* Guard against delegation returns and new lock/unlock calls */
1505         down_write(&nfsi->rwsem);
1506         spin_lock(&flctx->flc_lock);
1507 restart:
1508         list_for_each_entry(fl, list, fl_list) {
1509                 if (nfs_file_open_context(fl->fl_file)->state != state)
1510                         continue;
1511                 spin_unlock(&flctx->flc_lock);
1512                 status = ops->recover_lock(state, fl);
1513                 switch (status) {
1514                 case 0:
1515                         break;
1516                 case -ESTALE:
1517                 case -NFS4ERR_ADMIN_REVOKED:
1518                 case -NFS4ERR_STALE_STATEID:
1519                 case -NFS4ERR_BAD_STATEID:
1520                 case -NFS4ERR_EXPIRED:
1521                 case -NFS4ERR_NO_GRACE:
1522                 case -NFS4ERR_STALE_CLIENTID:
1523                 case -NFS4ERR_BADSESSION:
1524                 case -NFS4ERR_BADSLOT:
1525                 case -NFS4ERR_BAD_HIGH_SLOT:
1526                 case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1527                         goto out;
1528                 default:
1529                         pr_err("NFS: %s: unhandled error %d\n",
1530                                         __func__, status);
1531                         /* Fall through */
1532                 case -ENOMEM:
1533                 case -NFS4ERR_DENIED:
1534                 case -NFS4ERR_RECLAIM_BAD:
1535                 case -NFS4ERR_RECLAIM_CONFLICT:
1536                         lsp = fl->fl_u.nfs4_fl.owner;
1537                         if (lsp)
1538                                 set_bit(NFS_LOCK_LOST, &lsp->ls_flags);
1539                         status = 0;
1540                 }
1541                 spin_lock(&flctx->flc_lock);
1542         }
1543         if (list == &flctx->flc_posix) {
1544                 list = &flctx->flc_flock;
1545                 goto restart;
1546         }
1547         spin_unlock(&flctx->flc_lock);
1548 out:
1549         up_write(&nfsi->rwsem);
1550         return status;
1551 }
1552
1553 #ifdef CONFIG_NFS_V4_2
1554 static void nfs42_complete_copies(struct nfs4_state_owner *sp, struct nfs4_state *state)
1555 {
1556         struct nfs4_copy_state *copy;
1557
1558         if (!test_bit(NFS_CLNT_DST_SSC_COPY_STATE, &state->flags))
1559                 return;
1560
1561         spin_lock(&sp->so_server->nfs_client->cl_lock);
1562         list_for_each_entry(copy, &sp->so_server->ss_copies, copies) {
1563                 if (nfs4_stateid_match_other(&state->stateid, &copy->parent_state->stateid))
1564                         continue;
1565                 copy->flags = 1;
1566                 complete(&copy->completion);
1567                 break;
1568         }
1569         spin_unlock(&sp->so_server->nfs_client->cl_lock);
1570 }
1571 #else /* !CONFIG_NFS_V4_2 */
1572 static inline void nfs42_complete_copies(struct nfs4_state_owner *sp,
1573                                          struct nfs4_state *state)
1574 {
1575 }
1576 #endif /* CONFIG_NFS_V4_2 */
1577
1578 static int __nfs4_reclaim_open_state(struct nfs4_state_owner *sp, struct nfs4_state *state,
1579                                      const struct nfs4_state_recovery_ops *ops)
1580 {
1581         struct nfs4_lock_state *lock;
1582         int status;
1583
1584         status = ops->recover_open(sp, state);
1585         if (status < 0)
1586                 return status;
1587
1588         status = nfs4_reclaim_locks(state, ops);
1589         if (status < 0)
1590                 return status;
1591
1592         if (!test_bit(NFS_DELEGATED_STATE, &state->flags)) {
1593                 spin_lock(&state->state_lock);
1594                 list_for_each_entry(lock, &state->lock_states, ls_locks) {
1595                         if (!test_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags))
1596                                 pr_warn_ratelimited("NFS: %s: Lock reclaim failed!\n", __func__);
1597                 }
1598                 spin_unlock(&state->state_lock);
1599         }
1600
1601         nfs42_complete_copies(sp, state);
1602         clear_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1603         return status;
1604 }
1605
1606 static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs4_state_recovery_ops *ops)
1607 {
1608         struct nfs4_state *state;
1609         int status = 0;
1610
1611         /* Note: we rely on the sp->so_states list being ordered
1612          * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
1613          * states first.
1614          * This is needed to ensure that the server won't give us any
1615          * read delegations that we have to return if, say, we are
1616          * recovering after a network partition or a reboot from a
1617          * server that doesn't support a grace period.
1618          */
1619         spin_lock(&sp->so_lock);
1620         raw_write_seqcount_begin(&sp->so_reclaim_seqcount);
1621 restart:
1622         list_for_each_entry(state, &sp->so_states, open_states) {
1623                 if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
1624                         continue;
1625                 if (!nfs4_valid_open_stateid(state))
1626                         continue;
1627                 if (state->state == 0)
1628                         continue;
1629                 refcount_inc(&state->count);
1630                 spin_unlock(&sp->so_lock);
1631                 status = __nfs4_reclaim_open_state(sp, state, ops);
1632
1633                 switch (status) {
1634                 default:
1635                         if (status >= 0)
1636                                 break;
1637                         printk(KERN_ERR "NFS: %s: unhandled error %d\n", __func__, status);
1638                         /* Fall through */
1639                 case -ENOENT:
1640                 case -ENOMEM:
1641                 case -EACCES:
1642                 case -EROFS:
1643                 case -EIO:
1644                 case -ESTALE:
1645                         /* Open state on this file cannot be recovered */
1646                         nfs4_state_mark_recovery_failed(state, status);
1647                         break;
1648                 case -EAGAIN:
1649                         ssleep(1);
1650                         /* Fall through */
1651                 case -NFS4ERR_ADMIN_REVOKED:
1652                 case -NFS4ERR_STALE_STATEID:
1653                 case -NFS4ERR_OLD_STATEID:
1654                 case -NFS4ERR_BAD_STATEID:
1655                 case -NFS4ERR_RECLAIM_BAD:
1656                 case -NFS4ERR_RECLAIM_CONFLICT:
1657                         nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1658                         break;
1659                 case -NFS4ERR_EXPIRED:
1660                 case -NFS4ERR_NO_GRACE:
1661                         nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1662                 case -NFS4ERR_STALE_CLIENTID:
1663                 case -NFS4ERR_BADSESSION:
1664                 case -NFS4ERR_BADSLOT:
1665                 case -NFS4ERR_BAD_HIGH_SLOT:
1666                 case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1667                         goto out_err;
1668                 }
1669                 nfs4_put_open_state(state);
1670                 spin_lock(&sp->so_lock);
1671                 goto restart;
1672         }
1673         raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1674         spin_unlock(&sp->so_lock);
1675         return 0;
1676 out_err:
1677         nfs4_put_open_state(state);
1678         spin_lock(&sp->so_lock);
1679         raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1680         spin_unlock(&sp->so_lock);
1681         return status;
1682 }
1683
1684 static void nfs4_clear_open_state(struct nfs4_state *state)
1685 {
1686         struct nfs4_lock_state *lock;
1687
1688         clear_bit(NFS_DELEGATED_STATE, &state->flags);
1689         clear_bit(NFS_O_RDONLY_STATE, &state->flags);
1690         clear_bit(NFS_O_WRONLY_STATE, &state->flags);
1691         clear_bit(NFS_O_RDWR_STATE, &state->flags);
1692         spin_lock(&state->state_lock);
1693         list_for_each_entry(lock, &state->lock_states, ls_locks) {
1694                 lock->ls_seqid.flags = 0;
1695                 clear_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags);
1696         }
1697         spin_unlock(&state->state_lock);
1698 }
1699
1700 static void nfs4_reset_seqids(struct nfs_server *server,
1701         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1702 {
1703         struct nfs_client *clp = server->nfs_client;
1704         struct nfs4_state_owner *sp;
1705         struct rb_node *pos;
1706         struct nfs4_state *state;
1707
1708         spin_lock(&clp->cl_lock);
1709         for (pos = rb_first(&server->state_owners);
1710              pos != NULL;
1711              pos = rb_next(pos)) {
1712                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1713                 sp->so_seqid.flags = 0;
1714                 spin_lock(&sp->so_lock);
1715                 list_for_each_entry(state, &sp->so_states, open_states) {
1716                         if (mark_reclaim(clp, state))
1717                                 nfs4_clear_open_state(state);
1718                 }
1719                 spin_unlock(&sp->so_lock);
1720         }
1721         spin_unlock(&clp->cl_lock);
1722 }
1723
1724 static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp,
1725         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1726 {
1727         struct nfs_server *server;
1728
1729         rcu_read_lock();
1730         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1731                 nfs4_reset_seqids(server, mark_reclaim);
1732         rcu_read_unlock();
1733 }
1734
1735 static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp)
1736 {
1737         /* Mark all delegations for reclaim */
1738         nfs_delegation_mark_reclaim(clp);
1739         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_reboot);
1740 }
1741
1742 static int nfs4_reclaim_complete(struct nfs_client *clp,
1743                                  const struct nfs4_state_recovery_ops *ops,
1744                                  struct rpc_cred *cred)
1745 {
1746         /* Notify the server we're done reclaiming our state */
1747         if (ops->reclaim_complete)
1748                 return ops->reclaim_complete(clp, cred);
1749         return 0;
1750 }
1751
1752 static void nfs4_clear_reclaim_server(struct nfs_server *server)
1753 {
1754         struct nfs_client *clp = server->nfs_client;
1755         struct nfs4_state_owner *sp;
1756         struct rb_node *pos;
1757         struct nfs4_state *state;
1758
1759         spin_lock(&clp->cl_lock);
1760         for (pos = rb_first(&server->state_owners);
1761              pos != NULL;
1762              pos = rb_next(pos)) {
1763                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1764                 spin_lock(&sp->so_lock);
1765                 list_for_each_entry(state, &sp->so_states, open_states) {
1766                         if (!test_and_clear_bit(NFS_STATE_RECLAIM_REBOOT,
1767                                                 &state->flags))
1768                                 continue;
1769                         nfs4_state_mark_reclaim_nograce(clp, state);
1770                 }
1771                 spin_unlock(&sp->so_lock);
1772         }
1773         spin_unlock(&clp->cl_lock);
1774 }
1775
1776 static int nfs4_state_clear_reclaim_reboot(struct nfs_client *clp)
1777 {
1778         struct nfs_server *server;
1779
1780         if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
1781                 return 0;
1782
1783         rcu_read_lock();
1784         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1785                 nfs4_clear_reclaim_server(server);
1786         rcu_read_unlock();
1787
1788         nfs_delegation_reap_unclaimed(clp);
1789         return 1;
1790 }
1791
1792 static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
1793 {
1794         const struct nfs4_state_recovery_ops *ops;
1795         struct rpc_cred *cred;
1796         int err;
1797
1798         if (!nfs4_state_clear_reclaim_reboot(clp))
1799                 return;
1800         ops = clp->cl_mvops->reboot_recovery_ops;
1801         cred = nfs4_get_clid_cred(clp);
1802         err = nfs4_reclaim_complete(clp, ops, cred);
1803         put_rpccred(cred);
1804         if (err == -NFS4ERR_CONN_NOT_BOUND_TO_SESSION)
1805                 set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1806 }
1807
1808 static void nfs4_state_start_reclaim_nograce(struct nfs_client *clp)
1809 {
1810         nfs_mark_test_expired_all_delegations(clp);
1811         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
1812 }
1813
1814 static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
1815 {
1816         switch (error) {
1817         case 0:
1818                 break;
1819         case -NFS4ERR_CB_PATH_DOWN:
1820                 nfs40_handle_cb_pathdown(clp);
1821                 break;
1822         case -NFS4ERR_NO_GRACE:
1823                 nfs4_state_end_reclaim_reboot(clp);
1824                 break;
1825         case -NFS4ERR_STALE_CLIENTID:
1826                 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1827                 nfs4_state_start_reclaim_reboot(clp);
1828                 break;
1829         case -NFS4ERR_EXPIRED:
1830                 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1831                 nfs4_state_start_reclaim_nograce(clp);
1832                 break;
1833         case -NFS4ERR_BADSESSION:
1834         case -NFS4ERR_BADSLOT:
1835         case -NFS4ERR_BAD_HIGH_SLOT:
1836         case -NFS4ERR_DEADSESSION:
1837         case -NFS4ERR_SEQ_FALSE_RETRY:
1838         case -NFS4ERR_SEQ_MISORDERED:
1839                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
1840                 /* Zero session reset errors */
1841                 break;
1842         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1843                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
1844                 break;
1845         default:
1846                 dprintk("%s: failed to handle error %d for server %s\n",
1847                                 __func__, error, clp->cl_hostname);
1848                 return error;
1849         }
1850         dprintk("%s: handled error %d for server %s\n", __func__, error,
1851                         clp->cl_hostname);
1852         return 0;
1853 }
1854
1855 static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recovery_ops *ops)
1856 {
1857         struct nfs4_state_owner *sp;
1858         struct nfs_server *server;
1859         struct rb_node *pos;
1860         int status = 0;
1861
1862 restart:
1863         rcu_read_lock();
1864         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1865                 nfs4_purge_state_owners(server);
1866                 spin_lock(&clp->cl_lock);
1867                 for (pos = rb_first(&server->state_owners);
1868                      pos != NULL;
1869                      pos = rb_next(pos)) {
1870                         sp = rb_entry(pos,
1871                                 struct nfs4_state_owner, so_server_node);
1872                         if (!test_and_clear_bit(ops->owner_flag_bit,
1873                                                         &sp->so_flags))
1874                                 continue;
1875                         if (!atomic_inc_not_zero(&sp->so_count))
1876                                 continue;
1877                         spin_unlock(&clp->cl_lock);
1878                         rcu_read_unlock();
1879
1880                         status = nfs4_reclaim_open_state(sp, ops);
1881                         if (status < 0) {
1882                                 set_bit(ops->owner_flag_bit, &sp->so_flags);
1883                                 nfs4_put_state_owner(sp);
1884                                 status = nfs4_recovery_handle_error(clp, status);
1885                                 return (status != 0) ? status : -EAGAIN;
1886                         }
1887
1888                         nfs4_put_state_owner(sp);
1889                         goto restart;
1890                 }
1891                 spin_unlock(&clp->cl_lock);
1892         }
1893         rcu_read_unlock();
1894         return 0;
1895 }
1896
1897 static int nfs4_check_lease(struct nfs_client *clp)
1898 {
1899         struct rpc_cred *cred;
1900         const struct nfs4_state_maintenance_ops *ops =
1901                 clp->cl_mvops->state_renewal_ops;
1902         int status;
1903
1904         /* Is the client already known to have an expired lease? */
1905         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1906                 return 0;
1907         spin_lock(&clp->cl_lock);
1908         cred = ops->get_state_renewal_cred_locked(clp);
1909         spin_unlock(&clp->cl_lock);
1910         if (cred == NULL) {
1911                 cred = nfs4_get_clid_cred(clp);
1912                 status = -ENOKEY;
1913                 if (cred == NULL)
1914                         goto out;
1915         }
1916         status = ops->renew_lease(clp, cred);
1917         put_rpccred(cred);
1918         if (status == -ETIMEDOUT) {
1919                 set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1920                 return 0;
1921         }
1922 out:
1923         return nfs4_recovery_handle_error(clp, status);
1924 }
1925
1926 /* Set NFS4CLNT_LEASE_EXPIRED and reclaim reboot state for all v4.0 errors
1927  * and for recoverable errors on EXCHANGE_ID for v4.1
1928  */
1929 static int nfs4_handle_reclaim_lease_error(struct nfs_client *clp, int status)
1930 {
1931         switch (status) {
1932         case -NFS4ERR_SEQ_MISORDERED:
1933                 if (test_and_set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state))
1934                         return -ESERVERFAULT;
1935                 /* Lease confirmation error: retry after purging the lease */
1936                 ssleep(1);
1937                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1938                 break;
1939         case -NFS4ERR_STALE_CLIENTID:
1940                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1941                 nfs4_state_start_reclaim_reboot(clp);
1942                 break;
1943         case -NFS4ERR_CLID_INUSE:
1944                 pr_err("NFS: Server %s reports our clientid is in use\n",
1945                         clp->cl_hostname);
1946                 nfs_mark_client_ready(clp, -EPERM);
1947                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1948                 return -EPERM;
1949         case -EACCES:
1950         case -NFS4ERR_DELAY:
1951         case -ETIMEDOUT:
1952         case -EAGAIN:
1953                 ssleep(1);
1954                 break;
1955
1956         case -NFS4ERR_MINOR_VERS_MISMATCH:
1957                 if (clp->cl_cons_state == NFS_CS_SESSION_INITING)
1958                         nfs_mark_client_ready(clp, -EPROTONOSUPPORT);
1959                 dprintk("%s: exit with error %d for server %s\n",
1960                                 __func__, -EPROTONOSUPPORT, clp->cl_hostname);
1961                 return -EPROTONOSUPPORT;
1962         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
1963                                  * in nfs4_exchange_id */
1964         default:
1965                 dprintk("%s: exit with error %d for server %s\n", __func__,
1966                                 status, clp->cl_hostname);
1967                 return status;
1968         }
1969         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1970         dprintk("%s: handled error %d for server %s\n", __func__, status,
1971                         clp->cl_hostname);
1972         return 0;
1973 }
1974
1975 static int nfs4_establish_lease(struct nfs_client *clp)
1976 {
1977         struct rpc_cred *cred;
1978         const struct nfs4_state_recovery_ops *ops =
1979                 clp->cl_mvops->reboot_recovery_ops;
1980         int status;
1981
1982         status = nfs4_begin_drain_session(clp);
1983         if (status != 0)
1984                 return status;
1985         cred = nfs4_get_clid_cred(clp);
1986         if (cred == NULL)
1987                 return -ENOENT;
1988         status = ops->establish_clid(clp, cred);
1989         put_rpccred(cred);
1990         if (status != 0)
1991                 return status;
1992         pnfs_destroy_all_layouts(clp);
1993         return 0;
1994 }
1995
1996 /*
1997  * Returns zero or a negative errno.  NFS4ERR values are converted
1998  * to local errno values.
1999  */
2000 static int nfs4_reclaim_lease(struct nfs_client *clp)
2001 {
2002         int status;
2003
2004         status = nfs4_establish_lease(clp);
2005         if (status < 0)
2006                 return nfs4_handle_reclaim_lease_error(clp, status);
2007         if (test_and_clear_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH, &clp->cl_state))
2008                 nfs4_state_start_reclaim_nograce(clp);
2009         if (!test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
2010                 set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
2011         clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2012         clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2013         return 0;
2014 }
2015
2016 static int nfs4_purge_lease(struct nfs_client *clp)
2017 {
2018         int status;
2019
2020         status = nfs4_establish_lease(clp);
2021         if (status < 0)
2022                 return nfs4_handle_reclaim_lease_error(clp, status);
2023         clear_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2024         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2025         nfs4_state_start_reclaim_nograce(clp);
2026         return 0;
2027 }
2028
2029 /*
2030  * Try remote migration of one FSID from a source server to a
2031  * destination server.  The source server provides a list of
2032  * potential destinations.
2033  *
2034  * Returns zero or a negative NFS4ERR status code.
2035  */
2036 static int nfs4_try_migration(struct nfs_server *server, struct rpc_cred *cred)
2037 {
2038         struct nfs_client *clp = server->nfs_client;
2039         struct nfs4_fs_locations *locations = NULL;
2040         struct inode *inode;
2041         struct page *page;
2042         int status, result;
2043
2044         dprintk("--> %s: FSID %llx:%llx on \"%s\"\n", __func__,
2045                         (unsigned long long)server->fsid.major,
2046                         (unsigned long long)server->fsid.minor,
2047                         clp->cl_hostname);
2048
2049         result = 0;
2050         page = alloc_page(GFP_KERNEL);
2051         locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
2052         if (page == NULL || locations == NULL) {
2053                 dprintk("<-- %s: no memory\n", __func__);
2054                 goto out;
2055         }
2056
2057         inode = d_inode(server->super->s_root);
2058         result = nfs4_proc_get_locations(inode, locations, page, cred);
2059         if (result) {
2060                 dprintk("<-- %s: failed to retrieve fs_locations: %d\n",
2061                         __func__, result);
2062                 goto out;
2063         }
2064
2065         result = -NFS4ERR_NXIO;
2066         if (!(locations->fattr.valid & NFS_ATTR_FATTR_V4_LOCATIONS)) {
2067                 dprintk("<-- %s: No fs_locations data, migration skipped\n",
2068                         __func__);
2069                 goto out;
2070         }
2071
2072         status = nfs4_begin_drain_session(clp);
2073         if (status != 0)
2074                 return status;
2075
2076         status = nfs4_replace_transport(server, locations);
2077         if (status != 0) {
2078                 dprintk("<-- %s: failed to replace transport: %d\n",
2079                         __func__, status);
2080                 goto out;
2081         }
2082
2083         result = 0;
2084         dprintk("<-- %s: migration succeeded\n", __func__);
2085
2086 out:
2087         if (page != NULL)
2088                 __free_page(page);
2089         kfree(locations);
2090         if (result) {
2091                 pr_err("NFS: migration recovery failed (server %s)\n",
2092                                 clp->cl_hostname);
2093                 set_bit(NFS_MIG_FAILED, &server->mig_status);
2094         }
2095         return result;
2096 }
2097
2098 /*
2099  * Returns zero or a negative NFS4ERR status code.
2100  */
2101 static int nfs4_handle_migration(struct nfs_client *clp)
2102 {
2103         const struct nfs4_state_maintenance_ops *ops =
2104                                 clp->cl_mvops->state_renewal_ops;
2105         struct nfs_server *server;
2106         struct rpc_cred *cred;
2107
2108         dprintk("%s: migration reported on \"%s\"\n", __func__,
2109                         clp->cl_hostname);
2110
2111         spin_lock(&clp->cl_lock);
2112         cred = ops->get_state_renewal_cred_locked(clp);
2113         spin_unlock(&clp->cl_lock);
2114         if (cred == NULL)
2115                 return -NFS4ERR_NOENT;
2116
2117         clp->cl_mig_gen++;
2118 restart:
2119         rcu_read_lock();
2120         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2121                 int status;
2122
2123                 if (server->mig_gen == clp->cl_mig_gen)
2124                         continue;
2125                 server->mig_gen = clp->cl_mig_gen;
2126
2127                 if (!test_and_clear_bit(NFS_MIG_IN_TRANSITION,
2128                                                 &server->mig_status))
2129                         continue;
2130
2131                 rcu_read_unlock();
2132                 status = nfs4_try_migration(server, cred);
2133                 if (status < 0) {
2134                         put_rpccred(cred);
2135                         return status;
2136                 }
2137                 goto restart;
2138         }
2139         rcu_read_unlock();
2140         put_rpccred(cred);
2141         return 0;
2142 }
2143
2144 /*
2145  * Test each nfs_server on the clp's cl_superblocks list to see
2146  * if it's moved to another server.  Stop when the server no longer
2147  * returns NFS4ERR_LEASE_MOVED.
2148  */
2149 static int nfs4_handle_lease_moved(struct nfs_client *clp)
2150 {
2151         const struct nfs4_state_maintenance_ops *ops =
2152                                 clp->cl_mvops->state_renewal_ops;
2153         struct nfs_server *server;
2154         struct rpc_cred *cred;
2155
2156         dprintk("%s: lease moved reported on \"%s\"\n", __func__,
2157                         clp->cl_hostname);
2158
2159         spin_lock(&clp->cl_lock);
2160         cred = ops->get_state_renewal_cred_locked(clp);
2161         spin_unlock(&clp->cl_lock);
2162         if (cred == NULL)
2163                 return -NFS4ERR_NOENT;
2164
2165         clp->cl_mig_gen++;
2166 restart:
2167         rcu_read_lock();
2168         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2169                 struct inode *inode;
2170                 int status;
2171
2172                 if (server->mig_gen == clp->cl_mig_gen)
2173                         continue;
2174                 server->mig_gen = clp->cl_mig_gen;
2175
2176                 rcu_read_unlock();
2177
2178                 inode = d_inode(server->super->s_root);
2179                 status = nfs4_proc_fsid_present(inode, cred);
2180                 if (status != -NFS4ERR_MOVED)
2181                         goto restart;   /* wasn't this one */
2182                 if (nfs4_try_migration(server, cred) == -NFS4ERR_LEASE_MOVED)
2183                         goto restart;   /* there are more */
2184                 goto out;
2185         }
2186         rcu_read_unlock();
2187
2188 out:
2189         put_rpccred(cred);
2190         return 0;
2191 }
2192
2193 /**
2194  * nfs4_discover_server_trunking - Detect server IP address trunking
2195  *
2196  * @clp: nfs_client under test
2197  * @result: OUT: found nfs_client, or clp
2198  *
2199  * Returns zero or a negative errno.  If zero is returned,
2200  * an nfs_client pointer is planted in "result".
2201  *
2202  * Note: since we are invoked in process context, and
2203  * not from inside the state manager, we cannot use
2204  * nfs4_handle_reclaim_lease_error().
2205  */
2206 int nfs4_discover_server_trunking(struct nfs_client *clp,
2207                                   struct nfs_client **result)
2208 {
2209         const struct nfs4_state_recovery_ops *ops =
2210                                 clp->cl_mvops->reboot_recovery_ops;
2211         struct rpc_clnt *clnt;
2212         struct rpc_cred *cred;
2213         int i, status;
2214
2215         dprintk("NFS: %s: testing '%s'\n", __func__, clp->cl_hostname);
2216
2217         clnt = clp->cl_rpcclient;
2218         i = 0;
2219
2220         mutex_lock(&nfs_clid_init_mutex);
2221 again:
2222         status  = -ENOENT;
2223         cred = nfs4_get_clid_cred(clp);
2224         if (cred == NULL)
2225                 goto out_unlock;
2226
2227         status = ops->detect_trunking(clp, result, cred);
2228         put_rpccred(cred);
2229         switch (status) {
2230         case 0:
2231         case -EINTR:
2232         case -ERESTARTSYS:
2233                 break;
2234         case -ETIMEDOUT:
2235                 if (clnt->cl_softrtry)
2236                         break;
2237                 /* Fall through */
2238         case -NFS4ERR_DELAY:
2239         case -EAGAIN:
2240                 ssleep(1);
2241                 /* Fall through */
2242         case -NFS4ERR_STALE_CLIENTID:
2243                 dprintk("NFS: %s after status %d, retrying\n",
2244                         __func__, status);
2245                 goto again;
2246         case -EACCES:
2247                 if (i++ == 0) {
2248                         nfs4_root_machine_cred(clp);
2249                         goto again;
2250                 }
2251                 if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX)
2252                         break;
2253                 /* Fall through */
2254         case -NFS4ERR_CLID_INUSE:
2255         case -NFS4ERR_WRONGSEC:
2256                 /* No point in retrying if we already used RPC_AUTH_UNIX */
2257                 if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX) {
2258                         status = -EPERM;
2259                         break;
2260                 }
2261                 clnt = rpc_clone_client_set_auth(clnt, RPC_AUTH_UNIX);
2262                 if (IS_ERR(clnt)) {
2263                         status = PTR_ERR(clnt);
2264                         break;
2265                 }
2266                 /* Note: this is safe because we haven't yet marked the
2267                  * client as ready, so we are the only user of
2268                  * clp->cl_rpcclient
2269                  */
2270                 clnt = xchg(&clp->cl_rpcclient, clnt);
2271                 rpc_shutdown_client(clnt);
2272                 clnt = clp->cl_rpcclient;
2273                 goto again;
2274
2275         case -NFS4ERR_MINOR_VERS_MISMATCH:
2276                 status = -EPROTONOSUPPORT;
2277                 break;
2278
2279         case -EKEYEXPIRED:
2280         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
2281                                  * in nfs4_exchange_id */
2282                 status = -EKEYEXPIRED;
2283                 break;
2284         default:
2285                 pr_warn("NFS: %s unhandled error %d. Exiting with error EIO\n",
2286                                 __func__, status);
2287                 status = -EIO;
2288         }
2289
2290 out_unlock:
2291         mutex_unlock(&nfs_clid_init_mutex);
2292         dprintk("NFS: %s: status = %d\n", __func__, status);
2293         return status;
2294 }
2295
2296 #ifdef CONFIG_NFS_V4_1
2297 void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
2298 {
2299         struct nfs_client *clp = session->clp;
2300
2301         switch (err) {
2302         default:
2303                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2304                 break;
2305         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
2306                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2307         }
2308         nfs4_schedule_state_manager(clp);
2309 }
2310 EXPORT_SYMBOL_GPL(nfs4_schedule_session_recovery);
2311
2312 void nfs41_notify_server(struct nfs_client *clp)
2313 {
2314         /* Use CHECK_LEASE to ping the server with a SEQUENCE */
2315         set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2316         nfs4_schedule_state_manager(clp);
2317 }
2318
2319 static void nfs4_reset_all_state(struct nfs_client *clp)
2320 {
2321         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2322                 set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2323                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2324                 nfs4_state_start_reclaim_nograce(clp);
2325                 dprintk("%s: scheduling reset of all state for server %s!\n",
2326                                 __func__, clp->cl_hostname);
2327                 nfs4_schedule_state_manager(clp);
2328         }
2329 }
2330
2331 static void nfs41_handle_server_reboot(struct nfs_client *clp)
2332 {
2333         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2334                 nfs4_state_start_reclaim_reboot(clp);
2335                 dprintk("%s: server %s rebooted!\n", __func__,
2336                                 clp->cl_hostname);
2337                 nfs4_schedule_state_manager(clp);
2338         }
2339 }
2340
2341 static void nfs41_handle_all_state_revoked(struct nfs_client *clp)
2342 {
2343         nfs4_reset_all_state(clp);
2344         dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2345 }
2346
2347 static void nfs41_handle_some_state_revoked(struct nfs_client *clp)
2348 {
2349         nfs4_state_start_reclaim_nograce(clp);
2350         nfs4_schedule_state_manager(clp);
2351
2352         dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2353 }
2354
2355 static void nfs41_handle_recallable_state_revoked(struct nfs_client *clp)
2356 {
2357         /* FIXME: For now, we destroy all layouts. */
2358         pnfs_destroy_all_layouts(clp);
2359         /* FIXME: For now, we test all delegations+open state+locks. */
2360         nfs41_handle_some_state_revoked(clp);
2361         dprintk("%s: Recallable state revoked on server %s!\n", __func__,
2362                         clp->cl_hostname);
2363 }
2364
2365 static void nfs41_handle_backchannel_fault(struct nfs_client *clp)
2366 {
2367         set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2368         nfs4_schedule_state_manager(clp);
2369
2370         dprintk("%s: server %s declared a backchannel fault\n", __func__,
2371                         clp->cl_hostname);
2372 }
2373
2374 static void nfs41_handle_cb_path_down(struct nfs_client *clp)
2375 {
2376         if (test_and_set_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2377                 &clp->cl_state) == 0)
2378                 nfs4_schedule_state_manager(clp);
2379 }
2380
2381 void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags,
2382                 bool recovery)
2383 {
2384         if (!flags)
2385                 return;
2386
2387         dprintk("%s: \"%s\" (client ID %llx) flags=0x%08x\n",
2388                 __func__, clp->cl_hostname, clp->cl_clientid, flags);
2389         /*
2390          * If we're called from the state manager thread, then assume we're
2391          * already handling the RECLAIM_NEEDED and/or STATE_REVOKED.
2392          * Those flags are expected to remain set until we're done
2393          * recovering (see RFC5661, section 18.46.3).
2394          */
2395         if (recovery)
2396                 goto out_recovery;
2397
2398         if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED)
2399                 nfs41_handle_server_reboot(clp);
2400         if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED))
2401                 nfs41_handle_all_state_revoked(clp);
2402         if (flags & (SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED |
2403                             SEQ4_STATUS_ADMIN_STATE_REVOKED))
2404                 nfs41_handle_some_state_revoked(clp);
2405         if (flags & SEQ4_STATUS_LEASE_MOVED)
2406                 nfs4_schedule_lease_moved_recovery(clp);
2407         if (flags & SEQ4_STATUS_RECALLABLE_STATE_REVOKED)
2408                 nfs41_handle_recallable_state_revoked(clp);
2409 out_recovery:
2410         if (flags & SEQ4_STATUS_BACKCHANNEL_FAULT)
2411                 nfs41_handle_backchannel_fault(clp);
2412         else if (flags & (SEQ4_STATUS_CB_PATH_DOWN |
2413                                 SEQ4_STATUS_CB_PATH_DOWN_SESSION))
2414                 nfs41_handle_cb_path_down(clp);
2415 }
2416
2417 static int nfs4_reset_session(struct nfs_client *clp)
2418 {
2419         struct rpc_cred *cred;
2420         int status;
2421
2422         if (!nfs4_has_session(clp))
2423                 return 0;
2424         status = nfs4_begin_drain_session(clp);
2425         if (status != 0)
2426                 return status;
2427         cred = nfs4_get_clid_cred(clp);
2428         status = nfs4_proc_destroy_session(clp->cl_session, cred);
2429         switch (status) {
2430         case 0:
2431         case -NFS4ERR_BADSESSION:
2432         case -NFS4ERR_DEADSESSION:
2433                 break;
2434         case -NFS4ERR_BACK_CHAN_BUSY:
2435         case -NFS4ERR_DELAY:
2436                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2437                 status = 0;
2438                 ssleep(1);
2439                 goto out;
2440         default:
2441                 status = nfs4_recovery_handle_error(clp, status);
2442                 goto out;
2443         }
2444
2445         memset(clp->cl_session->sess_id.data, 0, NFS4_MAX_SESSIONID_LEN);
2446         status = nfs4_proc_create_session(clp, cred);
2447         if (status) {
2448                 dprintk("%s: session reset failed with status %d for server %s!\n",
2449                         __func__, status, clp->cl_hostname);
2450                 status = nfs4_handle_reclaim_lease_error(clp, status);
2451                 goto out;
2452         }
2453         nfs41_finish_session_reset(clp);
2454         dprintk("%s: session reset was successful for server %s!\n",
2455                         __func__, clp->cl_hostname);
2456 out:
2457         if (cred)
2458                 put_rpccred(cred);
2459         return status;
2460 }
2461
2462 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2463 {
2464         struct rpc_cred *cred;
2465         int ret;
2466
2467         if (!nfs4_has_session(clp))
2468                 return 0;
2469         ret = nfs4_begin_drain_session(clp);
2470         if (ret != 0)
2471                 return ret;
2472         cred = nfs4_get_clid_cred(clp);
2473         ret = nfs4_proc_bind_conn_to_session(clp, cred);
2474         if (cred)
2475                 put_rpccred(cred);
2476         clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2477         switch (ret) {
2478         case 0:
2479                 dprintk("%s: bind_conn_to_session was successful for server %s!\n",
2480                         __func__, clp->cl_hostname);
2481                 break;
2482         case -NFS4ERR_DELAY:
2483                 ssleep(1);
2484                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2485                 break;
2486         default:
2487                 return nfs4_recovery_handle_error(clp, ret);
2488         }
2489         return 0;
2490 }
2491 #else /* CONFIG_NFS_V4_1 */
2492 static int nfs4_reset_session(struct nfs_client *clp) { return 0; }
2493
2494 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2495 {
2496         return 0;
2497 }
2498 #endif /* CONFIG_NFS_V4_1 */
2499
2500 static void nfs4_state_manager(struct nfs_client *clp)
2501 {
2502         int status = 0;
2503         const char *section = "", *section_sep = "";
2504
2505         /* Ensure exclusive access to NFSv4 state */
2506         do {
2507                 clear_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2508                 if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
2509                         section = "purge state";
2510                         status = nfs4_purge_lease(clp);
2511                         if (status < 0)
2512                                 goto out_error;
2513                         continue;
2514                 }
2515
2516                 if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
2517                         section = "lease expired";
2518                         /* We're going to have to re-establish a clientid */
2519                         status = nfs4_reclaim_lease(clp);
2520                         if (status < 0)
2521                                 goto out_error;
2522                         continue;
2523                 }
2524
2525                 /* Initialize or reset the session */
2526                 if (test_and_clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state)) {
2527                         section = "reset session";
2528                         status = nfs4_reset_session(clp);
2529                         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
2530                                 continue;
2531                         if (status < 0)
2532                                 goto out_error;
2533                 }
2534
2535                 /* Send BIND_CONN_TO_SESSION */
2536                 if (test_and_clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2537                                 &clp->cl_state)) {
2538                         section = "bind conn to session";
2539                         status = nfs4_bind_conn_to_session(clp);
2540                         if (status < 0)
2541                                 goto out_error;
2542                         continue;
2543                 }
2544
2545                 if (test_and_clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state)) {
2546                         section = "check lease";
2547                         status = nfs4_check_lease(clp);
2548                         if (status < 0)
2549                                 goto out_error;
2550                         continue;
2551                 }
2552
2553                 if (test_and_clear_bit(NFS4CLNT_MOVED, &clp->cl_state)) {
2554                         section = "migration";
2555                         status = nfs4_handle_migration(clp);
2556                         if (status < 0)
2557                                 goto out_error;
2558                 }
2559
2560                 if (test_and_clear_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state)) {
2561                         section = "lease moved";
2562                         status = nfs4_handle_lease_moved(clp);
2563                         if (status < 0)
2564                                 goto out_error;
2565                 }
2566
2567                 /* First recover reboot state... */
2568                 if (test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {
2569                         section = "reclaim reboot";
2570                         status = nfs4_do_reclaim(clp,
2571                                 clp->cl_mvops->reboot_recovery_ops);
2572                         if (status == -EAGAIN)
2573                                 continue;
2574                         if (status < 0)
2575                                 goto out_error;
2576                         nfs4_state_end_reclaim_reboot(clp);
2577                 }
2578
2579                 /* Detect expired delegations... */
2580                 if (test_and_clear_bit(NFS4CLNT_DELEGATION_EXPIRED, &clp->cl_state)) {
2581                         section = "detect expired delegations";
2582                         nfs_reap_expired_delegations(clp);
2583                         continue;
2584                 }
2585
2586                 /* Now recover expired state... */
2587                 if (test_and_clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state)) {
2588                         section = "reclaim nograce";
2589                         status = nfs4_do_reclaim(clp,
2590                                 clp->cl_mvops->nograce_recovery_ops);
2591                         if (status == -EAGAIN)
2592                                 continue;
2593                         if (status < 0)
2594                                 goto out_error;
2595                 }
2596
2597                 nfs4_end_drain_session(clp);
2598                 nfs4_clear_state_manager_bit(clp);
2599
2600                 if (!test_and_set_bit(NFS4CLNT_DELEGRETURN_RUNNING, &clp->cl_state)) {
2601                         if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
2602                                 nfs_client_return_marked_delegations(clp);
2603                                 set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2604                         }
2605                         clear_bit(NFS4CLNT_DELEGRETURN_RUNNING, &clp->cl_state);
2606                 }
2607
2608                 /* Did we race with an attempt to give us more work? */
2609                 if (!test_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state))
2610                         return;
2611                 if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
2612                         return;
2613         } while (refcount_read(&clp->cl_count) > 1 && !signalled());
2614         goto out_drain;
2615
2616 out_error:
2617         if (strlen(section))
2618                 section_sep = ": ";
2619         pr_warn_ratelimited("NFS: state manager%s%s failed on NFSv4 server %s"
2620                         " with error %d\n", section_sep, section,
2621                         clp->cl_hostname, -status);
2622         ssleep(1);
2623 out_drain:
2624         nfs4_end_drain_session(clp);
2625         nfs4_clear_state_manager_bit(clp);
2626 }
2627
2628 static int nfs4_run_state_manager(void *ptr)
2629 {
2630         struct nfs_client *clp = ptr;
2631
2632         allow_signal(SIGKILL);
2633         nfs4_state_manager(clp);
2634         nfs_put_client(clp);
2635         module_put_and_exit(0);
2636         return 0;
2637 }
2638
2639 /*
2640  * Local variables:
2641  *  c-basic-offset: 8
2642  * End:
2643  */