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 static int nfs4_setup_state_renewal(struct nfs_client *clp)
  91 {
  92         int status;
  93         struct nfs_fsinfo fsinfo;
  94         unsigned long now;
  95
  96         if (!test_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state)) {
  97                 nfs4_schedule_state_renewal(clp);
  98                 return 0;
  99         }
 100
 101         now = jiffies;
 102         status = nfs4_proc_get_lease_time(clp, &fsinfo);
 103         if (status == 0) {
 104                 nfs4_set_lease_period(clp, fsinfo.lease_time * HZ, now);
 105                 nfs4_schedule_state_renewal(clp);
 106         }
 107
 108         return status;
 109 }
 110
 111 int nfs4_init_clientid(struct nfs_client *clp, const struct cred *cred)
 112 {
 113         struct nfs4_setclientid_res clid = {
 114                 .clientid = clp->cl_clientid,
 115                 .confirm = clp->cl_confirm,
 116         };
 117         unsigned short port;
 118         int status;
 119         struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
 120
 121         if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
 122                 goto do_confirm;
 123         port = nn->nfs_callback_tcpport;
 124         if (clp->cl_addr.ss_family == AF_INET6)
 125                 port = nn->nfs_callback_tcpport6;
 126
 127         status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
 128         if (status != 0)
 129                 goto out;
 130         clp->cl_clientid = clid.clientid;
 131         clp->cl_confirm = clid.confirm;
 132         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 133 do_confirm:
 134         status = nfs4_proc_setclientid_confirm(clp, &clid, cred);
 135         if (status != 0)
 136                 goto out;
 137         clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 138         nfs4_setup_state_renewal(clp);
 139 out:
 140         return status;
 141 }
 142
 143 /**
 144  * nfs40_discover_server_trunking - Detect server IP address trunking (mv0)
 145  *
 146  * @clp: nfs_client under test
 147  * @result: OUT: found nfs_client, or clp
 148  * @cred: credential to use for trunking test
 149  *
 150  * Returns zero, a negative errno, or a negative NFS4ERR status.
 151  * If zero is returned, an nfs_client pointer is planted in
 152  * "result".
 153  *
 154  * Note: The returned client may not yet be marked ready.
 155  */
 156 int nfs40_discover_server_trunking(struct nfs_client *clp,
 157                                    struct nfs_client **result,
 158                                    const struct cred *cred)
 159 {
 160         struct nfs4_setclientid_res clid = {
 161                 .clientid = clp->cl_clientid,
 162                 .confirm = clp->cl_confirm,
 163         };
 164         struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
 165         unsigned short port;
 166         int status;
 167
 168         port = nn->nfs_callback_tcpport;
 169         if (clp->cl_addr.ss_family == AF_INET6)
 170                 port = nn->nfs_callback_tcpport6;
 171
 172         status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
 173         if (status != 0)
 174                 goto out;
 175         clp->cl_clientid = clid.clientid;
 176         clp->cl_confirm = clid.confirm;
 177
 178         status = nfs40_walk_client_list(clp, result, cred);
 179         if (status == 0) {
 180                 /* Sustain the lease, even if it's empty.  If the clientid4
 181                  * goes stale it's of no use for trunking discovery. */
 182                 nfs4_schedule_state_renewal(*result);
 183
 184                 /* If the client state need to recover, do it. */
 185                 if (clp->cl_state)
 186                         nfs4_schedule_state_manager(clp);
 187         }
 188 out:
 189         return status;
 190 }
 191
 192 const struct cred *nfs4_get_machine_cred(struct nfs_client *clp)
 193 {
 194         return get_cred(rpc_machine_cred());
 195 }
 196
 197 static void nfs4_root_machine_cred(struct nfs_client *clp)
 198 {
 199
 200         /* Force root creds instead of machine */
 201         clp->cl_principal = NULL;
 202         clp->cl_rpcclient->cl_principal = NULL;
 203 }
 204
 205 static const struct cred *
 206 nfs4_get_renew_cred_server_locked(struct nfs_server *server)
 207 {
 208         const struct cred *cred = NULL;
 209         struct nfs4_state_owner *sp;
 210         struct rb_node *pos;
 211
 212         for (pos = rb_first(&server->state_owners);
 213              pos != NULL;
 214              pos = rb_next(pos)) {
 215                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
 216                 if (list_empty(&sp->so_states))
 217                         continue;
 218                 cred = get_cred(sp->so_cred);
 219                 break;
 220         }
 221         return cred;
 222 }
 223
 224 /**
 225  * nfs4_get_renew_cred - Acquire credential for a renew operation
 226  * @clp: client state handle
 227  *
 228  * Returns an rpc_cred with reference count bumped, or NULL.
 229  * Caller must hold clp->cl_lock.
 230  */
 231 const struct cred *nfs4_get_renew_cred(struct nfs_client *clp)
 232 {
 233         const struct cred *cred = NULL;
 234         struct nfs_server *server;
 235
 236         /* Use machine credentials if available */
 237         cred = nfs4_get_machine_cred(clp);
 238         if (cred != NULL)
 239                 goto out;
 240
 241         spin_lock(&clp->cl_lock);
 242         rcu_read_lock();
 243         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 244                 cred = nfs4_get_renew_cred_server_locked(server);
 245                 if (cred != NULL)
 246                         break;
 247         }
 248         rcu_read_unlock();
 249         spin_unlock(&clp->cl_lock);
 250
 251 out:
 252         return cred;
 253 }
 254
 255 static void nfs4_end_drain_slot_table(struct nfs4_slot_table *tbl)
 256 {
 257         if (test_and_clear_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state)) {
 258                 spin_lock(&tbl->slot_tbl_lock);
 259                 nfs41_wake_slot_table(tbl);
 260                 spin_unlock(&tbl->slot_tbl_lock);
 261         }
 262 }
 263
 264 static void nfs4_end_drain_session(struct nfs_client *clp)
 265 {
 266         struct nfs4_session *ses = clp->cl_session;
 267
 268         if (clp->cl_slot_tbl) {
 269                 nfs4_end_drain_slot_table(clp->cl_slot_tbl);
 270                 return;
 271         }
 272
 273         if (ses != NULL) {
 274                 nfs4_end_drain_slot_table(&ses->bc_slot_table);
 275                 nfs4_end_drain_slot_table(&ses->fc_slot_table);
 276         }
 277 }
 278
 279 static int nfs4_drain_slot_tbl(struct nfs4_slot_table *tbl)
 280 {
 281         set_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
 282         spin_lock(&tbl->slot_tbl_lock);
 283         if (tbl->highest_used_slotid != NFS4_NO_SLOT) {
 284                 reinit_completion(&tbl->complete);
 285                 spin_unlock(&tbl->slot_tbl_lock);
 286                 return wait_for_completion_interruptible(&tbl->complete);
 287         }
 288         spin_unlock(&tbl->slot_tbl_lock);
 289         return 0;
 290 }
 291
 292 static int nfs4_begin_drain_session(struct nfs_client *clp)
 293 {
 294         struct nfs4_session *ses = clp->cl_session;
 295         int ret;
 296
 297         if (clp->cl_slot_tbl)
 298                 return nfs4_drain_slot_tbl(clp->cl_slot_tbl);
 299
 300         /* back channel */
 301         ret = nfs4_drain_slot_tbl(&ses->bc_slot_table);
 302         if (ret)
 303                 return ret;
 304         /* fore channel */
 305         return nfs4_drain_slot_tbl(&ses->fc_slot_table);
 306 }
 307
 308 #if defined(CONFIG_NFS_V4_1)
 309
 310 static void nfs41_finish_session_reset(struct nfs_client *clp)
 311 {
 312         clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 313         clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
 314         /* create_session negotiated new slot table */
 315         clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
 316         nfs4_setup_state_renewal(clp);
 317 }
 318
 319 int nfs41_init_clientid(struct nfs_client *clp, const struct cred *cred)
 320 {
 321         int status;
 322
 323         if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
 324                 goto do_confirm;
 325         status = nfs4_proc_exchange_id(clp, cred);
 326         if (status != 0)
 327                 goto out;
 328         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 329 do_confirm:
 330         status = nfs4_proc_create_session(clp, cred);
 331         if (status != 0)
 332                 goto out;
 333         nfs41_finish_session_reset(clp);
 334         nfs_mark_client_ready(clp, NFS_CS_READY);
 335 out:
 336         return status;
 337 }
 338
 339 /**
 340  * nfs41_discover_server_trunking - Detect server IP address trunking (mv1)
 341  *
 342  * @clp: nfs_client under test
 343  * @result: OUT: found nfs_client, or clp
 344  * @cred: credential to use for trunking test
 345  *
 346  * Returns NFS4_OK, a negative errno, or a negative NFS4ERR status.
 347  * If NFS4_OK is returned, an nfs_client pointer is planted in
 348  * "result".
 349  *
 350  * Note: The returned client may not yet be marked ready.
 351  */
 352 int nfs41_discover_server_trunking(struct nfs_client *clp,
 353                                    struct nfs_client **result,
 354                                    const struct cred *cred)
 355 {
 356         int status;
 357
 358         status = nfs4_proc_exchange_id(clp, cred);
 359         if (status != NFS4_OK)
 360                 return status;
 361
 362         status = nfs41_walk_client_list(clp, result, cred);
 363         if (status < 0)
 364                 return status;
 365         if (clp != *result)
 366                 return 0;
 367
 368         /*
 369          * Purge state if the client id was established in a prior
 370          * instance and the client id could not have arrived on the
 371          * server via Transparent State Migration.
 372          */
 373         if (clp->cl_exchange_flags & EXCHGID4_FLAG_CONFIRMED_R) {
 374                 if (!test_bit(NFS_CS_TSM_POSSIBLE, &clp->cl_flags))
 375                         set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
 376                 else
 377                         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 378         }
 379         nfs4_schedule_state_manager(clp);
 380         status = nfs_wait_client_init_complete(clp);
 381         if (status < 0)
 382                 nfs_put_client(clp);
 383         return status;
 384 }
 385
 386 #endif /* CONFIG_NFS_V4_1 */
 387
 388 /**
 389  * nfs4_get_clid_cred - Acquire credential for a setclientid operation
 390  * @clp: client state handle
 391  *
 392  * Returns a cred with reference count bumped, or NULL.
 393  */
 394 const struct cred *nfs4_get_clid_cred(struct nfs_client *clp)
 395 {
 396         const struct cred *cred;
 397
 398         cred = nfs4_get_machine_cred(clp);
 399         return cred;
 400 }
 401
 402 static struct nfs4_state_owner *
 403 nfs4_find_state_owner_locked(struct nfs_server *server, const struct cred *cred)
 404 {
 405         struct rb_node **p = &server->state_owners.rb_node,
 406                        *parent = NULL;
 407         struct nfs4_state_owner *sp;
 408         int cmp;
 409
 410         while (*p != NULL) {
 411                 parent = *p;
 412                 sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
 413                 cmp = cred_fscmp(cred, sp->so_cred);
 414
 415                 if (cmp < 0)
 416                         p = &parent->rb_left;
 417                 else if (cmp > 0)
 418                         p = &parent->rb_right;
 419                 else {
 420                         if (!list_empty(&sp->so_lru))
 421                                 list_del_init(&sp->so_lru);
 422                         atomic_inc(&sp->so_count);
 423                         return sp;
 424                 }
 425         }
 426         return NULL;
 427 }
 428
 429 static struct nfs4_state_owner *
 430 nfs4_insert_state_owner_locked(struct nfs4_state_owner *new)
 431 {
 432         struct nfs_server *server = new->so_server;
 433         struct rb_node **p = &server->state_owners.rb_node,
 434                        *parent = NULL;
 435         struct nfs4_state_owner *sp;
 436         int cmp;
 437
 438         while (*p != NULL) {
 439                 parent = *p;
 440                 sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
 441                 cmp = cred_fscmp(new->so_cred, sp->so_cred);
 442
 443                 if (cmp < 0)
 444                         p = &parent->rb_left;
 445                 else if (cmp > 0)
 446                         p = &parent->rb_right;
 447                 else {
 448                         if (!list_empty(&sp->so_lru))
 449                                 list_del_init(&sp->so_lru);
 450                         atomic_inc(&sp->so_count);
 451                         return sp;
 452                 }
 453         }
 454         rb_link_node(&new->so_server_node, parent, p);
 455         rb_insert_color(&new->so_server_node, &server->state_owners);
 456         return new;
 457 }
 458
 459 static void
 460 nfs4_remove_state_owner_locked(struct nfs4_state_owner *sp)
 461 {
 462         struct nfs_server *server = sp->so_server;
 463
 464         if (!RB_EMPTY_NODE(&sp->so_server_node))
 465                 rb_erase(&sp->so_server_node, &server->state_owners);
 466 }
 467
 468 static void
 469 nfs4_init_seqid_counter(struct nfs_seqid_counter *sc)
 470 {
 471         sc->create_time = ktime_get();
 472         sc->flags = 0;
 473         sc->counter = 0;
 474         spin_lock_init(&sc->lock);
 475         INIT_LIST_HEAD(&sc->list);
 476         rpc_init_wait_queue(&sc->wait, "Seqid_waitqueue");
 477 }
 478
 479 static void
 480 nfs4_destroy_seqid_counter(struct nfs_seqid_counter *sc)
 481 {
 482         rpc_destroy_wait_queue(&sc->wait);
 483 }
 484
 485 /*
 486  * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
 487  * create a new state_owner.
 488  *
 489  */
 490 static struct nfs4_state_owner *
 491 nfs4_alloc_state_owner(struct nfs_server *server,
 492                 const struct cred *cred,
 493                 gfp_t gfp_flags)
 494 {
 495         struct nfs4_state_owner *sp;
 496
 497         sp = kzalloc(sizeof(*sp), gfp_flags);
 498         if (!sp)
 499                 return NULL;
 500         sp->so_seqid.owner_id = ida_simple_get(&server->openowner_id, 0, 0,
 501                                                 gfp_flags);
 502         if (sp->so_seqid.owner_id < 0) {
 503                 kfree(sp);
 504                 return NULL;
 505         }
 506         sp->so_server = server;
 507         sp->so_cred = get_cred(cred);
 508         spin_lock_init(&sp->so_lock);
 509         INIT_LIST_HEAD(&sp->so_states);
 510         nfs4_init_seqid_counter(&sp->so_seqid);
 511         atomic_set(&sp->so_count, 1);
 512         INIT_LIST_HEAD(&sp->so_lru);
 513         seqcount_init(&sp->so_reclaim_seqcount);
 514         mutex_init(&sp->so_delegreturn_mutex);
 515         return sp;
 516 }
 517
 518 static void
 519 nfs4_reset_state_owner(struct nfs4_state_owner *sp)
 520 {
 521         /* This state_owner is no longer usable, but must
 522          * remain in place so that state recovery can find it
 523          * and the opens associated with it.
 524          * It may also be used for new 'open' request to
 525          * return a delegation to the server.
 526          * So update the 'create_time' so that it looks like
 527          * a new state_owner.  This will cause the server to
 528          * request an OPEN_CONFIRM to start a new sequence.
 529          */
 530         sp->so_seqid.create_time = ktime_get();
 531 }
 532
 533 static void nfs4_free_state_owner(struct nfs4_state_owner *sp)
 534 {
 535         nfs4_destroy_seqid_counter(&sp->so_seqid);
 536         put_cred(sp->so_cred);
 537         ida_simple_remove(&sp->so_server->openowner_id, sp->so_seqid.owner_id);
 538         kfree(sp);
 539 }
 540
 541 static void nfs4_gc_state_owners(struct nfs_server *server)
 542 {
 543         struct nfs_client *clp = server->nfs_client;
 544         struct nfs4_state_owner *sp, *tmp;
 545         unsigned long time_min, time_max;
 546         LIST_HEAD(doomed);
 547
 548         spin_lock(&clp->cl_lock);
 549         time_max = jiffies;
 550         time_min = (long)time_max - (long)clp->cl_lease_time;
 551         list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
 552                 /* NB: LRU is sorted so that oldest is at the head */
 553                 if (time_in_range(sp->so_expires, time_min, time_max))
 554                         break;
 555                 list_move(&sp->so_lru, &doomed);
 556                 nfs4_remove_state_owner_locked(sp);
 557         }
 558         spin_unlock(&clp->cl_lock);
 559
 560         list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
 561                 list_del(&sp->so_lru);
 562                 nfs4_free_state_owner(sp);
 563         }
 564 }
 565
 566 /**
 567  * nfs4_get_state_owner - Look up a state owner given a credential
 568  * @server: nfs_server to search
 569  * @cred: RPC credential to match
 570  * @gfp_flags: allocation mode
 571  *
 572  * Returns a pointer to an instantiated nfs4_state_owner struct, or NULL.
 573  */
 574 struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server,
 575                                               const struct cred *cred,
 576                                               gfp_t gfp_flags)
 577 {
 578         struct nfs_client *clp = server->nfs_client;
 579         struct nfs4_state_owner *sp, *new;
 580
 581         spin_lock(&clp->cl_lock);
 582         sp = nfs4_find_state_owner_locked(server, cred);
 583         spin_unlock(&clp->cl_lock);
 584         if (sp != NULL)
 585                 goto out;
 586         new = nfs4_alloc_state_owner(server, cred, gfp_flags);
 587         if (new == NULL)
 588                 goto out;
 589         spin_lock(&clp->cl_lock);
 590         sp = nfs4_insert_state_owner_locked(new);
 591         spin_unlock(&clp->cl_lock);
 592         if (sp != new)
 593                 nfs4_free_state_owner(new);
 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, const struct 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         ret = nfs4_copy_open_stateid(dst, state) ? 0 : -EAGAIN;
1068 out:
1069         if (nfs_server_capable(state->inode, NFS_CAP_STATEID_NFSV41))
1070                 dst->seqid = 0;
1071         return ret;
1072 }
1073
1074 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask)
1075 {
1076         struct nfs_seqid *new;
1077
1078         new = kmalloc(sizeof(*new), gfp_mask);
1079         if (new == NULL)
1080                 return ERR_PTR(-ENOMEM);
1081         new->sequence = counter;
1082         INIT_LIST_HEAD(&new->list);
1083         new->task = NULL;
1084         return new;
1085 }
1086
1087 void nfs_release_seqid(struct nfs_seqid *seqid)
1088 {
1089         struct nfs_seqid_counter *sequence;
1090
1091         if (seqid == NULL || list_empty(&seqid->list))
1092                 return;
1093         sequence = seqid->sequence;
1094         spin_lock(&sequence->lock);
1095         list_del_init(&seqid->list);
1096         if (!list_empty(&sequence->list)) {
1097                 struct nfs_seqid *next;
1098
1099                 next = list_first_entry(&sequence->list,
1100                                 struct nfs_seqid, list);
1101                 rpc_wake_up_queued_task(&sequence->wait, next->task);
1102         }
1103         spin_unlock(&sequence->lock);
1104 }
1105
1106 void nfs_free_seqid(struct nfs_seqid *seqid)
1107 {
1108         nfs_release_seqid(seqid);
1109         kfree(seqid);
1110 }
1111
1112 /*
1113  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
1114  * failed with a seqid incrementing error -
1115  * see comments nfs4.h:seqid_mutating_error()
1116  */
1117 static void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
1118 {
1119         switch (status) {
1120                 case 0:
1121                         break;
1122                 case -NFS4ERR_BAD_SEQID:
1123                         if (seqid->sequence->flags & NFS_SEQID_CONFIRMED)
1124                                 return;
1125                         pr_warn_ratelimited("NFS: v4 server returned a bad"
1126                                         " sequence-id error on an"
1127                                         " unconfirmed sequence %p!\n",
1128                                         seqid->sequence);
1129                 case -NFS4ERR_STALE_CLIENTID:
1130                 case -NFS4ERR_STALE_STATEID:
1131                 case -NFS4ERR_BAD_STATEID:
1132                 case -NFS4ERR_BADXDR:
1133                 case -NFS4ERR_RESOURCE:
1134                 case -NFS4ERR_NOFILEHANDLE:
1135                 case -NFS4ERR_MOVED:
1136                         /* Non-seqid mutating errors */
1137                         return;
1138         };
1139         /*
1140          * Note: no locking needed as we are guaranteed to be first
1141          * on the sequence list
1142          */
1143         seqid->sequence->counter++;
1144 }
1145
1146 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
1147 {
1148         struct nfs4_state_owner *sp;
1149
1150         if (seqid == NULL)
1151                 return;
1152
1153         sp = container_of(seqid->sequence, struct nfs4_state_owner, so_seqid);
1154         if (status == -NFS4ERR_BAD_SEQID)
1155                 nfs4_reset_state_owner(sp);
1156         if (!nfs4_has_session(sp->so_server->nfs_client))
1157                 nfs_increment_seqid(status, seqid);
1158 }
1159
1160 /*
1161  * Increment the seqid if the LOCK/LOCKU succeeded, or
1162  * failed with a seqid incrementing error -
1163  * see comments nfs4.h:seqid_mutating_error()
1164  */
1165 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
1166 {
1167         if (seqid != NULL)
1168                 nfs_increment_seqid(status, seqid);
1169 }
1170
1171 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
1172 {
1173         struct nfs_seqid_counter *sequence;
1174         int status = 0;
1175
1176         if (seqid == NULL)
1177                 goto out;
1178         sequence = seqid->sequence;
1179         spin_lock(&sequence->lock);
1180         seqid->task = task;
1181         if (list_empty(&seqid->list))
1182                 list_add_tail(&seqid->list, &sequence->list);
1183         if (list_first_entry(&sequence->list, struct nfs_seqid, list) == seqid)
1184                 goto unlock;
1185         rpc_sleep_on(&sequence->wait, task, NULL);
1186         status = -EAGAIN;
1187 unlock:
1188         spin_unlock(&sequence->lock);
1189 out:
1190         return status;
1191 }
1192
1193 static int nfs4_run_state_manager(void *);
1194
1195 static void nfs4_clear_state_manager_bit(struct nfs_client *clp)
1196 {
1197         smp_mb__before_atomic();
1198         clear_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state);
1199         smp_mb__after_atomic();
1200         wake_up_bit(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING);
1201         rpc_wake_up(&clp->cl_rpcwaitq);
1202 }
1203
1204 /*
1205  * Schedule the nfs_client asynchronous state management routine
1206  */
1207 void nfs4_schedule_state_manager(struct nfs_client *clp)
1208 {
1209         struct task_struct *task;
1210         char buf[INET6_ADDRSTRLEN + sizeof("-manager") + 1];
1211
1212         set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
1213         if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
1214                 return;
1215         __module_get(THIS_MODULE);
1216         refcount_inc(&clp->cl_count);
1217
1218         /* The rcu_read_lock() is not strictly necessary, as the state
1219          * manager is the only thread that ever changes the rpc_xprt
1220          * after it's initialized.  At this point, we're single threaded. */
1221         rcu_read_lock();
1222         snprintf(buf, sizeof(buf), "%s-manager",
1223                         rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
1224         rcu_read_unlock();
1225         task = kthread_run(nfs4_run_state_manager, clp, "%s", buf);
1226         if (IS_ERR(task)) {
1227                 printk(KERN_ERR "%s: kthread_run: %ld\n",
1228                         __func__, PTR_ERR(task));
1229                 nfs4_clear_state_manager_bit(clp);
1230                 nfs_put_client(clp);
1231                 module_put(THIS_MODULE);
1232         }
1233 }
1234
1235 /*
1236  * Schedule a lease recovery attempt
1237  */
1238 void nfs4_schedule_lease_recovery(struct nfs_client *clp)
1239 {
1240         if (!clp)
1241                 return;
1242         if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1243                 set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1244         dprintk("%s: scheduling lease recovery for server %s\n", __func__,
1245                         clp->cl_hostname);
1246         nfs4_schedule_state_manager(clp);
1247 }
1248 EXPORT_SYMBOL_GPL(nfs4_schedule_lease_recovery);
1249
1250 /**
1251  * nfs4_schedule_migration_recovery - trigger migration recovery
1252  *
1253  * @server: FSID that is migrating
1254  *
1255  * Returns zero if recovery has started, otherwise a negative NFS4ERR
1256  * value is returned.
1257  */
1258 int nfs4_schedule_migration_recovery(const struct nfs_server *server)
1259 {
1260         struct nfs_client *clp = server->nfs_client;
1261
1262         if (server->fh_expire_type != NFS4_FH_PERSISTENT) {
1263                 pr_err("NFS: volatile file handles not supported (server %s)\n",
1264                                 clp->cl_hostname);
1265                 return -NFS4ERR_IO;
1266         }
1267
1268         if (test_bit(NFS_MIG_FAILED, &server->mig_status))
1269                 return -NFS4ERR_IO;
1270
1271         dprintk("%s: scheduling migration recovery for (%llx:%llx) on %s\n",
1272                         __func__,
1273                         (unsigned long long)server->fsid.major,
1274                         (unsigned long long)server->fsid.minor,
1275                         clp->cl_hostname);
1276
1277         set_bit(NFS_MIG_IN_TRANSITION,
1278                         &((struct nfs_server *)server)->mig_status);
1279         set_bit(NFS4CLNT_MOVED, &clp->cl_state);
1280
1281         nfs4_schedule_state_manager(clp);
1282         return 0;
1283 }
1284 EXPORT_SYMBOL_GPL(nfs4_schedule_migration_recovery);
1285
1286 /**
1287  * nfs4_schedule_lease_moved_recovery - start lease-moved recovery
1288  *
1289  * @clp: server to check for moved leases
1290  *
1291  */
1292 void nfs4_schedule_lease_moved_recovery(struct nfs_client *clp)
1293 {
1294         dprintk("%s: scheduling lease-moved recovery for client ID %llx on %s\n",
1295                 __func__, clp->cl_clientid, clp->cl_hostname);
1296
1297         set_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state);
1298         nfs4_schedule_state_manager(clp);
1299 }
1300 EXPORT_SYMBOL_GPL(nfs4_schedule_lease_moved_recovery);
1301
1302 int nfs4_wait_clnt_recover(struct nfs_client *clp)
1303 {
1304         int res;
1305
1306         might_sleep();
1307
1308         refcount_inc(&clp->cl_count);
1309         res = wait_on_bit_action(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING,
1310                                  nfs_wait_bit_killable, TASK_KILLABLE);
1311         if (res)
1312                 goto out;
1313         if (clp->cl_cons_state < 0)
1314                 res = clp->cl_cons_state;
1315 out:
1316         nfs_put_client(clp);
1317         return res;
1318 }
1319
1320 int nfs4_client_recover_expired_lease(struct nfs_client *clp)
1321 {
1322         unsigned int loop;
1323         int ret;
1324
1325         for (loop = NFS4_MAX_LOOP_ON_RECOVER; loop != 0; loop--) {
1326                 ret = nfs4_wait_clnt_recover(clp);
1327                 if (ret != 0)
1328                         break;
1329                 if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) &&
1330                     !test_bit(NFS4CLNT_CHECK_LEASE,&clp->cl_state))
1331                         break;
1332                 nfs4_schedule_state_manager(clp);
1333                 ret = -EIO;
1334         }
1335         return ret;
1336 }
1337
1338 /*
1339  * nfs40_handle_cb_pathdown - return all delegations after NFS4ERR_CB_PATH_DOWN
1340  * @clp: client to process
1341  *
1342  * Set the NFS4CLNT_LEASE_EXPIRED state in order to force a
1343  * resend of the SETCLIENTID and hence re-establish the
1344  * callback channel. Then return all existing delegations.
1345  */
1346 static void nfs40_handle_cb_pathdown(struct nfs_client *clp)
1347 {
1348         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1349         nfs_expire_all_delegations(clp);
1350         dprintk("%s: handling CB_PATHDOWN recovery for server %s\n", __func__,
1351                         clp->cl_hostname);
1352 }
1353
1354 void nfs4_schedule_path_down_recovery(struct nfs_client *clp)
1355 {
1356         nfs40_handle_cb_pathdown(clp);
1357         nfs4_schedule_state_manager(clp);
1358 }
1359
1360 static int nfs4_state_mark_reclaim_reboot(struct nfs_client *clp, struct nfs4_state *state)
1361 {
1362
1363         if (!nfs4_valid_open_stateid(state))
1364                 return 0;
1365         set_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1366         /* Don't recover state that expired before the reboot */
1367         if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags)) {
1368                 clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1369                 return 0;
1370         }
1371         set_bit(NFS_OWNER_RECLAIM_REBOOT, &state->owner->so_flags);
1372         set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1373         return 1;
1374 }
1375
1376 int nfs4_state_mark_reclaim_nograce(struct nfs_client *clp, struct nfs4_state *state)
1377 {
1378         if (!nfs4_valid_open_stateid(state))
1379                 return 0;
1380         set_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1381         clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1382         set_bit(NFS_OWNER_RECLAIM_NOGRACE, &state->owner->so_flags);
1383         set_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
1384         return 1;
1385 }
1386
1387 int nfs4_schedule_stateid_recovery(const struct nfs_server *server, struct nfs4_state *state)
1388 {
1389         struct nfs_client *clp = server->nfs_client;
1390
1391         if (!nfs4_state_mark_reclaim_nograce(clp, state))
1392                 return -EBADF;
1393         nfs_inode_find_delegation_state_and_recover(state->inode,
1394                         &state->stateid);
1395         dprintk("%s: scheduling stateid recovery for server %s\n", __func__,
1396                         clp->cl_hostname);
1397         nfs4_schedule_state_manager(clp);
1398         return 0;
1399 }
1400 EXPORT_SYMBOL_GPL(nfs4_schedule_stateid_recovery);
1401
1402 static struct nfs4_lock_state *
1403 nfs_state_find_lock_state_by_stateid(struct nfs4_state *state,
1404                 const nfs4_stateid *stateid)
1405 {
1406         struct nfs4_lock_state *pos;
1407
1408         list_for_each_entry(pos, &state->lock_states, ls_locks) {
1409                 if (!test_bit(NFS_LOCK_INITIALIZED, &pos->ls_flags))
1410                         continue;
1411                 if (nfs4_stateid_match_other(&pos->ls_stateid, stateid))
1412                         return pos;
1413         }
1414         return NULL;
1415 }
1416
1417 static bool nfs_state_lock_state_matches_stateid(struct nfs4_state *state,
1418                 const nfs4_stateid *stateid)
1419 {
1420         bool found = false;
1421
1422         if (test_bit(LK_STATE_IN_USE, &state->flags)) {
1423                 spin_lock(&state->state_lock);
1424                 if (nfs_state_find_lock_state_by_stateid(state, stateid))
1425                         found = true;
1426                 spin_unlock(&state->state_lock);
1427         }
1428         return found;
1429 }
1430
1431 void nfs_inode_find_state_and_recover(struct inode *inode,
1432                 const nfs4_stateid *stateid)
1433 {
1434         struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
1435         struct nfs_inode *nfsi = NFS_I(inode);
1436         struct nfs_open_context *ctx;
1437         struct nfs4_state *state;
1438         bool found = false;
1439
1440         rcu_read_lock();
1441         list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1442                 state = ctx->state;
1443                 if (state == NULL)
1444                         continue;
1445                 if (nfs4_stateid_match_other(&state->stateid, stateid) &&
1446                     nfs4_state_mark_reclaim_nograce(clp, state)) {
1447                         found = true;
1448                         continue;
1449                 }
1450                 if (nfs4_stateid_match_other(&state->open_stateid, stateid) &&
1451                     nfs4_state_mark_reclaim_nograce(clp, state)) {
1452                         found = true;
1453                         continue;
1454                 }
1455                 if (nfs_state_lock_state_matches_stateid(state, stateid) &&
1456                     nfs4_state_mark_reclaim_nograce(clp, state))
1457                         found = true;
1458         }
1459         rcu_read_unlock();
1460
1461         nfs_inode_find_delegation_state_and_recover(inode, stateid);
1462         if (found)
1463                 nfs4_schedule_state_manager(clp);
1464 }
1465
1466 static void nfs4_state_mark_open_context_bad(struct nfs4_state *state)
1467 {
1468         struct inode *inode = state->inode;
1469         struct nfs_inode *nfsi = NFS_I(inode);
1470         struct nfs_open_context *ctx;
1471
1472         rcu_read_lock();
1473         list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1474                 if (ctx->state != state)
1475                         continue;
1476                 set_bit(NFS_CONTEXT_BAD, &ctx->flags);
1477         }
1478         rcu_read_unlock();
1479 }
1480
1481 static void nfs4_state_mark_recovery_failed(struct nfs4_state *state, int error)
1482 {
1483         set_bit(NFS_STATE_RECOVERY_FAILED, &state->flags);
1484         nfs4_state_mark_open_context_bad(state);
1485 }
1486
1487
1488 static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_recovery_ops *ops)
1489 {
1490         struct inode *inode = state->inode;
1491         struct nfs_inode *nfsi = NFS_I(inode);
1492         struct file_lock *fl;
1493         struct nfs4_lock_state *lsp;
1494         int status = 0;
1495         struct file_lock_context *flctx = inode->i_flctx;
1496         struct list_head *list;
1497
1498         if (flctx == NULL)
1499                 return 0;
1500
1501         list = &flctx->flc_posix;
1502
1503         /* Guard against delegation returns and new lock/unlock calls */
1504         down_write(&nfsi->rwsem);
1505         spin_lock(&flctx->flc_lock);
1506 restart:
1507         list_for_each_entry(fl, list, fl_list) {
1508                 if (nfs_file_open_context(fl->fl_file)->state != state)
1509                         continue;
1510                 spin_unlock(&flctx->flc_lock);
1511                 status = ops->recover_lock(state, fl);
1512                 switch (status) {
1513                 case 0:
1514                         break;
1515                 case -ESTALE:
1516                 case -NFS4ERR_ADMIN_REVOKED:
1517                 case -NFS4ERR_STALE_STATEID:
1518                 case -NFS4ERR_BAD_STATEID:
1519                 case -NFS4ERR_EXPIRED:
1520                 case -NFS4ERR_NO_GRACE:
1521                 case -NFS4ERR_STALE_CLIENTID:
1522                 case -NFS4ERR_BADSESSION:
1523                 case -NFS4ERR_BADSLOT:
1524                 case -NFS4ERR_BAD_HIGH_SLOT:
1525                 case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1526                         goto out;
1527                 default:
1528                         pr_err("NFS: %s: unhandled error %d\n",
1529                                         __func__, status);
1530                         /* Fall through */
1531                 case -ENOMEM:
1532                 case -NFS4ERR_DENIED:
1533                 case -NFS4ERR_RECLAIM_BAD:
1534                 case -NFS4ERR_RECLAIM_CONFLICT:
1535                         lsp = fl->fl_u.nfs4_fl.owner;
1536                         if (lsp)
1537                                 set_bit(NFS_LOCK_LOST, &lsp->ls_flags);
1538                         status = 0;
1539                 }
1540                 spin_lock(&flctx->flc_lock);
1541         }
1542         if (list == &flctx->flc_posix) {
1543                 list = &flctx->flc_flock;
1544                 goto restart;
1545         }
1546         spin_unlock(&flctx->flc_lock);
1547 out:
1548         up_write(&nfsi->rwsem);
1549         return status;
1550 }
1551
1552 #ifdef CONFIG_NFS_V4_2
1553 static void nfs42_complete_copies(struct nfs4_state_owner *sp, struct nfs4_state *state)
1554 {
1555         struct nfs4_copy_state *copy;
1556
1557         if (!test_bit(NFS_CLNT_DST_SSC_COPY_STATE, &state->flags))
1558                 return;
1559
1560         spin_lock(&sp->so_server->nfs_client->cl_lock);
1561         list_for_each_entry(copy, &sp->so_server->ss_copies, copies) {
1562                 if (!nfs4_stateid_match_other(&state->stateid, &copy->parent_state->stateid))
1563                         continue;
1564                 copy->flags = 1;
1565                 complete(&copy->completion);
1566                 break;
1567         }
1568         spin_unlock(&sp->so_server->nfs_client->cl_lock);
1569 }
1570 #else /* !CONFIG_NFS_V4_2 */
1571 static inline void nfs42_complete_copies(struct nfs4_state_owner *sp,
1572                                          struct nfs4_state *state)
1573 {
1574 }
1575 #endif /* CONFIG_NFS_V4_2 */
1576
1577 static int __nfs4_reclaim_open_state(struct nfs4_state_owner *sp, struct nfs4_state *state,
1578                                      const struct nfs4_state_recovery_ops *ops)
1579 {
1580         struct nfs4_lock_state *lock;
1581         int status;
1582
1583         status = ops->recover_open(sp, state);
1584         if (status < 0)
1585                 return status;
1586
1587         status = nfs4_reclaim_locks(state, ops);
1588         if (status < 0)
1589                 return status;
1590
1591         if (!test_bit(NFS_DELEGATED_STATE, &state->flags)) {
1592                 spin_lock(&state->state_lock);
1593                 list_for_each_entry(lock, &state->lock_states, ls_locks) {
1594                         if (!test_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags))
1595                                 pr_warn_ratelimited("NFS: %s: Lock reclaim failed!\n", __func__);
1596                 }
1597                 spin_unlock(&state->state_lock);
1598         }
1599
1600         nfs42_complete_copies(sp, state);
1601         clear_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1602         return status;
1603 }
1604
1605 static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs4_state_recovery_ops *ops)
1606 {
1607         struct nfs4_state *state;
1608         int status = 0;
1609
1610         /* Note: we rely on the sp->so_states list being ordered
1611          * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
1612          * states first.
1613          * This is needed to ensure that the server won't give us any
1614          * read delegations that we have to return if, say, we are
1615          * recovering after a network partition or a reboot from a
1616          * server that doesn't support a grace period.
1617          */
1618         spin_lock(&sp->so_lock);
1619         raw_write_seqcount_begin(&sp->so_reclaim_seqcount);
1620 restart:
1621         list_for_each_entry(state, &sp->so_states, open_states) {
1622                 if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
1623                         continue;
1624                 if (!nfs4_valid_open_stateid(state))
1625                         continue;
1626                 if (state->state == 0)
1627                         continue;
1628                 refcount_inc(&state->count);
1629                 spin_unlock(&sp->so_lock);
1630                 status = __nfs4_reclaim_open_state(sp, state, ops);
1631
1632                 switch (status) {
1633                 default:
1634                         if (status >= 0)
1635                                 break;
1636                         printk(KERN_ERR "NFS: %s: unhandled error %d\n", __func__, status);
1637                         /* Fall through */
1638                 case -ENOENT:
1639                 case -ENOMEM:
1640                 case -EACCES:
1641                 case -EROFS:
1642                 case -EIO:
1643                 case -ESTALE:
1644                         /* Open state on this file cannot be recovered */
1645                         nfs4_state_mark_recovery_failed(state, status);
1646                         break;
1647                 case -EAGAIN:
1648                         ssleep(1);
1649                         /* Fall through */
1650                 case -NFS4ERR_ADMIN_REVOKED:
1651                 case -NFS4ERR_STALE_STATEID:
1652                 case -NFS4ERR_OLD_STATEID:
1653                 case -NFS4ERR_BAD_STATEID:
1654                 case -NFS4ERR_RECLAIM_BAD:
1655                 case -NFS4ERR_RECLAIM_CONFLICT:
1656                         nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1657                         break;
1658                 case -NFS4ERR_EXPIRED:
1659                 case -NFS4ERR_NO_GRACE:
1660                         nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1661                 case -NFS4ERR_STALE_CLIENTID:
1662                 case -NFS4ERR_BADSESSION:
1663                 case -NFS4ERR_BADSLOT:
1664                 case -NFS4ERR_BAD_HIGH_SLOT:
1665                 case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1666                         goto out_err;
1667                 }
1668                 nfs4_put_open_state(state);
1669                 spin_lock(&sp->so_lock);
1670                 goto restart;
1671         }
1672         raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1673         spin_unlock(&sp->so_lock);
1674         return 0;
1675 out_err:
1676         nfs4_put_open_state(state);
1677         spin_lock(&sp->so_lock);
1678         raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1679         spin_unlock(&sp->so_lock);
1680         return status;
1681 }
1682
1683 static void nfs4_clear_open_state(struct nfs4_state *state)
1684 {
1685         struct nfs4_lock_state *lock;
1686
1687         clear_bit(NFS_DELEGATED_STATE, &state->flags);
1688         clear_bit(NFS_O_RDONLY_STATE, &state->flags);
1689         clear_bit(NFS_O_WRONLY_STATE, &state->flags);
1690         clear_bit(NFS_O_RDWR_STATE, &state->flags);
1691         spin_lock(&state->state_lock);
1692         list_for_each_entry(lock, &state->lock_states, ls_locks) {
1693                 lock->ls_seqid.flags = 0;
1694                 clear_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags);
1695         }
1696         spin_unlock(&state->state_lock);
1697 }
1698
1699 static void nfs4_reset_seqids(struct nfs_server *server,
1700         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1701 {
1702         struct nfs_client *clp = server->nfs_client;
1703         struct nfs4_state_owner *sp;
1704         struct rb_node *pos;
1705         struct nfs4_state *state;
1706
1707         spin_lock(&clp->cl_lock);
1708         for (pos = rb_first(&server->state_owners);
1709              pos != NULL;
1710              pos = rb_next(pos)) {
1711                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1712                 sp->so_seqid.flags = 0;
1713                 spin_lock(&sp->so_lock);
1714                 list_for_each_entry(state, &sp->so_states, open_states) {
1715                         if (mark_reclaim(clp, state))
1716                                 nfs4_clear_open_state(state);
1717                 }
1718                 spin_unlock(&sp->so_lock);
1719         }
1720         spin_unlock(&clp->cl_lock);
1721 }
1722
1723 static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp,
1724         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1725 {
1726         struct nfs_server *server;
1727
1728         rcu_read_lock();
1729         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1730                 nfs4_reset_seqids(server, mark_reclaim);
1731         rcu_read_unlock();
1732 }
1733
1734 static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp)
1735 {
1736         /* Mark all delegations for reclaim */
1737         nfs_delegation_mark_reclaim(clp);
1738         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_reboot);
1739 }
1740
1741 static int nfs4_reclaim_complete(struct nfs_client *clp,
1742                                  const struct nfs4_state_recovery_ops *ops,
1743                                  const struct cred *cred)
1744 {
1745         /* Notify the server we're done reclaiming our state */
1746         if (ops->reclaim_complete)
1747                 return ops->reclaim_complete(clp, cred);
1748         return 0;
1749 }
1750
1751 static void nfs4_clear_reclaim_server(struct nfs_server *server)
1752 {
1753         struct nfs_client *clp = server->nfs_client;
1754         struct nfs4_state_owner *sp;
1755         struct rb_node *pos;
1756         struct nfs4_state *state;
1757
1758         spin_lock(&clp->cl_lock);
1759         for (pos = rb_first(&server->state_owners);
1760              pos != NULL;
1761              pos = rb_next(pos)) {
1762                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1763                 spin_lock(&sp->so_lock);
1764                 list_for_each_entry(state, &sp->so_states, open_states) {
1765                         if (!test_and_clear_bit(NFS_STATE_RECLAIM_REBOOT,
1766                                                 &state->flags))
1767                                 continue;
1768                         nfs4_state_mark_reclaim_nograce(clp, state);
1769                 }
1770                 spin_unlock(&sp->so_lock);
1771         }
1772         spin_unlock(&clp->cl_lock);
1773 }
1774
1775 static int nfs4_state_clear_reclaim_reboot(struct nfs_client *clp)
1776 {
1777         struct nfs_server *server;
1778
1779         if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
1780                 return 0;
1781
1782         rcu_read_lock();
1783         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1784                 nfs4_clear_reclaim_server(server);
1785         rcu_read_unlock();
1786
1787         nfs_delegation_reap_unclaimed(clp);
1788         return 1;
1789 }
1790
1791 static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
1792 {
1793         const struct nfs4_state_recovery_ops *ops;
1794         const struct cred *cred;
1795         int err;
1796
1797         if (!nfs4_state_clear_reclaim_reboot(clp))
1798                 return;
1799         ops = clp->cl_mvops->reboot_recovery_ops;
1800         cred = nfs4_get_clid_cred(clp);
1801         err = nfs4_reclaim_complete(clp, ops, cred);
1802         put_cred(cred);
1803         if (err == -NFS4ERR_CONN_NOT_BOUND_TO_SESSION)
1804                 set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1805 }
1806
1807 static void nfs4_state_start_reclaim_nograce(struct nfs_client *clp)
1808 {
1809         nfs_mark_test_expired_all_delegations(clp);
1810         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
1811 }
1812
1813 static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
1814 {
1815         switch (error) {
1816         case 0:
1817                 break;
1818         case -NFS4ERR_CB_PATH_DOWN:
1819                 nfs40_handle_cb_pathdown(clp);
1820                 break;
1821         case -NFS4ERR_NO_GRACE:
1822                 nfs4_state_end_reclaim_reboot(clp);
1823                 break;
1824         case -NFS4ERR_STALE_CLIENTID:
1825                 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1826                 nfs4_state_start_reclaim_reboot(clp);
1827                 break;
1828         case -NFS4ERR_EXPIRED:
1829                 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1830                 nfs4_state_start_reclaim_nograce(clp);
1831                 break;
1832         case -NFS4ERR_BADSESSION:
1833         case -NFS4ERR_BADSLOT:
1834         case -NFS4ERR_BAD_HIGH_SLOT:
1835         case -NFS4ERR_DEADSESSION:
1836         case -NFS4ERR_SEQ_FALSE_RETRY:
1837         case -NFS4ERR_SEQ_MISORDERED:
1838                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
1839                 /* Zero session reset errors */
1840                 break;
1841         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1842                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
1843                 break;
1844         default:
1845                 dprintk("%s: failed to handle error %d for server %s\n",
1846                                 __func__, error, clp->cl_hostname);
1847                 return error;
1848         }
1849         dprintk("%s: handled error %d for server %s\n", __func__, error,
1850                         clp->cl_hostname);
1851         return 0;
1852 }
1853
1854 static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recovery_ops *ops)
1855 {
1856         struct nfs4_state_owner *sp;
1857         struct nfs_server *server;
1858         struct rb_node *pos;
1859         int status = 0;
1860
1861 restart:
1862         rcu_read_lock();
1863         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1864                 nfs4_purge_state_owners(server);
1865                 spin_lock(&clp->cl_lock);
1866                 for (pos = rb_first(&server->state_owners);
1867                      pos != NULL;
1868                      pos = rb_next(pos)) {
1869                         sp = rb_entry(pos,
1870                                 struct nfs4_state_owner, so_server_node);
1871                         if (!test_and_clear_bit(ops->owner_flag_bit,
1872                                                         &sp->so_flags))
1873                                 continue;
1874                         if (!atomic_inc_not_zero(&sp->so_count))
1875                                 continue;
1876                         spin_unlock(&clp->cl_lock);
1877                         rcu_read_unlock();
1878
1879                         status = nfs4_reclaim_open_state(sp, ops);
1880                         if (status < 0) {
1881                                 set_bit(ops->owner_flag_bit, &sp->so_flags);
1882                                 nfs4_put_state_owner(sp);
1883                                 status = nfs4_recovery_handle_error(clp, status);
1884                                 return (status != 0) ? status : -EAGAIN;
1885                         }
1886
1887                         nfs4_put_state_owner(sp);
1888                         goto restart;
1889                 }
1890                 spin_unlock(&clp->cl_lock);
1891         }
1892         rcu_read_unlock();
1893         return 0;
1894 }
1895
1896 static int nfs4_check_lease(struct nfs_client *clp)
1897 {
1898         const struct cred *cred;
1899         const struct nfs4_state_maintenance_ops *ops =
1900                 clp->cl_mvops->state_renewal_ops;
1901         int status;
1902
1903         /* Is the client already known to have an expired lease? */
1904         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1905                 return 0;
1906         cred = ops->get_state_renewal_cred(clp);
1907         if (cred == NULL) {
1908                 cred = nfs4_get_clid_cred(clp);
1909                 status = -ENOKEY;
1910                 if (cred == NULL)
1911                         goto out;
1912         }
1913         status = ops->renew_lease(clp, cred);
1914         put_cred(cred);
1915         if (status == -ETIMEDOUT) {
1916                 set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1917                 return 0;
1918         }
1919 out:
1920         return nfs4_recovery_handle_error(clp, status);
1921 }
1922
1923 /* Set NFS4CLNT_LEASE_EXPIRED and reclaim reboot state for all v4.0 errors
1924  * and for recoverable errors on EXCHANGE_ID for v4.1
1925  */
1926 static int nfs4_handle_reclaim_lease_error(struct nfs_client *clp, int status)
1927 {
1928         switch (status) {
1929         case -NFS4ERR_SEQ_MISORDERED:
1930                 if (test_and_set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state))
1931                         return -ESERVERFAULT;
1932                 /* Lease confirmation error: retry after purging the lease */
1933                 ssleep(1);
1934                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1935                 break;
1936         case -NFS4ERR_STALE_CLIENTID:
1937                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1938                 nfs4_state_start_reclaim_reboot(clp);
1939                 break;
1940         case -NFS4ERR_CLID_INUSE:
1941                 pr_err("NFS: Server %s reports our clientid is in use\n",
1942                         clp->cl_hostname);
1943                 nfs_mark_client_ready(clp, -EPERM);
1944                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1945                 return -EPERM;
1946         case -EACCES:
1947         case -NFS4ERR_DELAY:
1948         case -ETIMEDOUT:
1949         case -EAGAIN:
1950                 ssleep(1);
1951                 break;
1952
1953         case -NFS4ERR_MINOR_VERS_MISMATCH:
1954                 if (clp->cl_cons_state == NFS_CS_SESSION_INITING)
1955                         nfs_mark_client_ready(clp, -EPROTONOSUPPORT);
1956                 dprintk("%s: exit with error %d for server %s\n",
1957                                 __func__, -EPROTONOSUPPORT, clp->cl_hostname);
1958                 return -EPROTONOSUPPORT;
1959         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
1960                                  * in nfs4_exchange_id */
1961         default:
1962                 dprintk("%s: exit with error %d for server %s\n", __func__,
1963                                 status, clp->cl_hostname);
1964                 return status;
1965         }
1966         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1967         dprintk("%s: handled error %d for server %s\n", __func__, status,
1968                         clp->cl_hostname);
1969         return 0;
1970 }
1971
1972 static int nfs4_establish_lease(struct nfs_client *clp)
1973 {
1974         const struct cred *cred;
1975         const struct nfs4_state_recovery_ops *ops =
1976                 clp->cl_mvops->reboot_recovery_ops;
1977         int status;
1978
1979         status = nfs4_begin_drain_session(clp);
1980         if (status != 0)
1981                 return status;
1982         cred = nfs4_get_clid_cred(clp);
1983         if (cred == NULL)
1984                 return -ENOENT;
1985         status = ops->establish_clid(clp, cred);
1986         put_cred(cred);
1987         if (status != 0)
1988                 return status;
1989         pnfs_destroy_all_layouts(clp);
1990         return 0;
1991 }
1992
1993 /*
1994  * Returns zero or a negative errno.  NFS4ERR values are converted
1995  * to local errno values.
1996  */
1997 static int nfs4_reclaim_lease(struct nfs_client *clp)
1998 {
1999         int status;
2000
2001         status = nfs4_establish_lease(clp);
2002         if (status < 0)
2003                 return nfs4_handle_reclaim_lease_error(clp, status);
2004         if (test_and_clear_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH, &clp->cl_state))
2005                 nfs4_state_start_reclaim_nograce(clp);
2006         if (!test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
2007                 set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
2008         clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2009         clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2010         return 0;
2011 }
2012
2013 static int nfs4_purge_lease(struct nfs_client *clp)
2014 {
2015         int status;
2016
2017         status = nfs4_establish_lease(clp);
2018         if (status < 0)
2019                 return nfs4_handle_reclaim_lease_error(clp, status);
2020         clear_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2021         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2022         nfs4_state_start_reclaim_nograce(clp);
2023         return 0;
2024 }
2025
2026 /*
2027  * Try remote migration of one FSID from a source server to a
2028  * destination server.  The source server provides a list of
2029  * potential destinations.
2030  *
2031  * Returns zero or a negative NFS4ERR status code.
2032  */
2033 static int nfs4_try_migration(struct nfs_server *server, const struct cred *cred)
2034 {
2035         struct nfs_client *clp = server->nfs_client;
2036         struct nfs4_fs_locations *locations = NULL;
2037         struct inode *inode;
2038         struct page *page;
2039         int status, result;
2040
2041         dprintk("--> %s: FSID %llx:%llx on \"%s\"\n", __func__,
2042                         (unsigned long long)server->fsid.major,
2043                         (unsigned long long)server->fsid.minor,
2044                         clp->cl_hostname);
2045
2046         result = 0;
2047         page = alloc_page(GFP_KERNEL);
2048         locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
2049         if (page == NULL || locations == NULL) {
2050                 dprintk("<-- %s: no memory\n", __func__);
2051                 goto out;
2052         }
2053
2054         inode = d_inode(server->super->s_root);
2055         result = nfs4_proc_get_locations(inode, locations, page, cred);
2056         if (result) {
2057                 dprintk("<-- %s: failed to retrieve fs_locations: %d\n",
2058                         __func__, result);
2059                 goto out;
2060         }
2061
2062         result = -NFS4ERR_NXIO;
2063         if (!(locations->fattr.valid & NFS_ATTR_FATTR_V4_LOCATIONS)) {
2064                 dprintk("<-- %s: No fs_locations data, migration skipped\n",
2065                         __func__);
2066                 goto out;
2067         }
2068
2069         status = nfs4_begin_drain_session(clp);
2070         if (status != 0)
2071                 return status;
2072
2073         status = nfs4_replace_transport(server, locations);
2074         if (status != 0) {
2075                 dprintk("<-- %s: failed to replace transport: %d\n",
2076                         __func__, status);
2077                 goto out;
2078         }
2079
2080         result = 0;
2081         dprintk("<-- %s: migration succeeded\n", __func__);
2082
2083 out:
2084         if (page != NULL)
2085                 __free_page(page);
2086         kfree(locations);
2087         if (result) {
2088                 pr_err("NFS: migration recovery failed (server %s)\n",
2089                                 clp->cl_hostname);
2090                 set_bit(NFS_MIG_FAILED, &server->mig_status);
2091         }
2092         return result;
2093 }
2094
2095 /*
2096  * Returns zero or a negative NFS4ERR status code.
2097  */
2098 static int nfs4_handle_migration(struct nfs_client *clp)
2099 {
2100         const struct nfs4_state_maintenance_ops *ops =
2101                                 clp->cl_mvops->state_renewal_ops;
2102         struct nfs_server *server;
2103         const struct cred *cred;
2104
2105         dprintk("%s: migration reported on \"%s\"\n", __func__,
2106                         clp->cl_hostname);
2107
2108         cred = ops->get_state_renewal_cred(clp);
2109         if (cred == NULL)
2110                 return -NFS4ERR_NOENT;
2111
2112         clp->cl_mig_gen++;
2113 restart:
2114         rcu_read_lock();
2115         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2116                 int status;
2117
2118                 if (server->mig_gen == clp->cl_mig_gen)
2119                         continue;
2120                 server->mig_gen = clp->cl_mig_gen;
2121
2122                 if (!test_and_clear_bit(NFS_MIG_IN_TRANSITION,
2123                                                 &server->mig_status))
2124                         continue;
2125
2126                 rcu_read_unlock();
2127                 status = nfs4_try_migration(server, cred);
2128                 if (status < 0) {
2129                         put_cred(cred);
2130                         return status;
2131                 }
2132                 goto restart;
2133         }
2134         rcu_read_unlock();
2135         put_cred(cred);
2136         return 0;
2137 }
2138
2139 /*
2140  * Test each nfs_server on the clp's cl_superblocks list to see
2141  * if it's moved to another server.  Stop when the server no longer
2142  * returns NFS4ERR_LEASE_MOVED.
2143  */
2144 static int nfs4_handle_lease_moved(struct nfs_client *clp)
2145 {
2146         const struct nfs4_state_maintenance_ops *ops =
2147                                 clp->cl_mvops->state_renewal_ops;
2148         struct nfs_server *server;
2149         const struct cred *cred;
2150
2151         dprintk("%s: lease moved reported on \"%s\"\n", __func__,
2152                         clp->cl_hostname);
2153
2154         cred = ops->get_state_renewal_cred(clp);
2155         if (cred == NULL)
2156                 return -NFS4ERR_NOENT;
2157
2158         clp->cl_mig_gen++;
2159 restart:
2160         rcu_read_lock();
2161         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2162                 struct inode *inode;
2163                 int status;
2164
2165                 if (server->mig_gen == clp->cl_mig_gen)
2166                         continue;
2167                 server->mig_gen = clp->cl_mig_gen;
2168
2169                 rcu_read_unlock();
2170
2171                 inode = d_inode(server->super->s_root);
2172                 status = nfs4_proc_fsid_present(inode, cred);
2173                 if (status != -NFS4ERR_MOVED)
2174                         goto restart;   /* wasn't this one */
2175                 if (nfs4_try_migration(server, cred) == -NFS4ERR_LEASE_MOVED)
2176                         goto restart;   /* there are more */
2177                 goto out;
2178         }
2179         rcu_read_unlock();
2180
2181 out:
2182         put_cred(cred);
2183         return 0;
2184 }
2185
2186 /**
2187  * nfs4_discover_server_trunking - Detect server IP address trunking
2188  *
2189  * @clp: nfs_client under test
2190  * @result: OUT: found nfs_client, or clp
2191  *
2192  * Returns zero or a negative errno.  If zero is returned,
2193  * an nfs_client pointer is planted in "result".
2194  *
2195  * Note: since we are invoked in process context, and
2196  * not from inside the state manager, we cannot use
2197  * nfs4_handle_reclaim_lease_error().
2198  */
2199 int nfs4_discover_server_trunking(struct nfs_client *clp,
2200                                   struct nfs_client **result)
2201 {
2202         const struct nfs4_state_recovery_ops *ops =
2203                                 clp->cl_mvops->reboot_recovery_ops;
2204         struct rpc_clnt *clnt;
2205         const struct cred *cred;
2206         int i, status;
2207
2208         dprintk("NFS: %s: testing '%s'\n", __func__, clp->cl_hostname);
2209
2210         clnt = clp->cl_rpcclient;
2211         i = 0;
2212
2213         mutex_lock(&nfs_clid_init_mutex);
2214 again:
2215         status  = -ENOENT;
2216         cred = nfs4_get_clid_cred(clp);
2217         if (cred == NULL)
2218                 goto out_unlock;
2219
2220         status = ops->detect_trunking(clp, result, cred);
2221         put_cred(cred);
2222         switch (status) {
2223         case 0:
2224         case -EINTR:
2225         case -ERESTARTSYS:
2226                 break;
2227         case -ETIMEDOUT:
2228                 if (clnt->cl_softrtry)
2229                         break;
2230                 /* Fall through */
2231         case -NFS4ERR_DELAY:
2232         case -EAGAIN:
2233                 ssleep(1);
2234                 /* Fall through */
2235         case -NFS4ERR_STALE_CLIENTID:
2236                 dprintk("NFS: %s after status %d, retrying\n",
2237                         __func__, status);
2238                 goto again;
2239         case -EACCES:
2240                 if (i++ == 0) {
2241                         nfs4_root_machine_cred(clp);
2242                         goto again;
2243                 }
2244                 if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX)
2245                         break;
2246                 /* Fall through */
2247         case -NFS4ERR_CLID_INUSE:
2248         case -NFS4ERR_WRONGSEC:
2249                 /* No point in retrying if we already used RPC_AUTH_UNIX */
2250                 if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX) {
2251                         status = -EPERM;
2252                         break;
2253                 }
2254                 clnt = rpc_clone_client_set_auth(clnt, RPC_AUTH_UNIX);
2255                 if (IS_ERR(clnt)) {
2256                         status = PTR_ERR(clnt);
2257                         break;
2258                 }
2259                 /* Note: this is safe because we haven't yet marked the
2260                  * client as ready, so we are the only user of
2261                  * clp->cl_rpcclient
2262                  */
2263                 clnt = xchg(&clp->cl_rpcclient, clnt);
2264                 rpc_shutdown_client(clnt);
2265                 clnt = clp->cl_rpcclient;
2266                 goto again;
2267
2268         case -NFS4ERR_MINOR_VERS_MISMATCH:
2269                 status = -EPROTONOSUPPORT;
2270                 break;
2271
2272         case -EKEYEXPIRED:
2273         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
2274                                  * in nfs4_exchange_id */
2275                 status = -EKEYEXPIRED;
2276                 break;
2277         default:
2278                 pr_warn("NFS: %s unhandled error %d. Exiting with error EIO\n",
2279                                 __func__, status);
2280                 status = -EIO;
2281         }
2282
2283 out_unlock:
2284         mutex_unlock(&nfs_clid_init_mutex);
2285         dprintk("NFS: %s: status = %d\n", __func__, status);
2286         return status;
2287 }
2288
2289 #ifdef CONFIG_NFS_V4_1
2290 void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
2291 {
2292         struct nfs_client *clp = session->clp;
2293
2294         switch (err) {
2295         default:
2296                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2297                 break;
2298         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
2299                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2300         }
2301         nfs4_schedule_state_manager(clp);
2302 }
2303 EXPORT_SYMBOL_GPL(nfs4_schedule_session_recovery);
2304
2305 void nfs41_notify_server(struct nfs_client *clp)
2306 {
2307         /* Use CHECK_LEASE to ping the server with a SEQUENCE */
2308         set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2309         nfs4_schedule_state_manager(clp);
2310 }
2311
2312 static void nfs4_reset_all_state(struct nfs_client *clp)
2313 {
2314         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2315                 set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2316                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2317                 nfs4_state_start_reclaim_nograce(clp);
2318                 dprintk("%s: scheduling reset of all state for server %s!\n",
2319                                 __func__, clp->cl_hostname);
2320                 nfs4_schedule_state_manager(clp);
2321         }
2322 }
2323
2324 static void nfs41_handle_server_reboot(struct nfs_client *clp)
2325 {
2326         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2327                 nfs4_state_start_reclaim_reboot(clp);
2328                 dprintk("%s: server %s rebooted!\n", __func__,
2329                                 clp->cl_hostname);
2330                 nfs4_schedule_state_manager(clp);
2331         }
2332 }
2333
2334 static void nfs41_handle_all_state_revoked(struct nfs_client *clp)
2335 {
2336         nfs4_reset_all_state(clp);
2337         dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2338 }
2339
2340 static void nfs41_handle_some_state_revoked(struct nfs_client *clp)
2341 {
2342         nfs4_state_start_reclaim_nograce(clp);
2343         nfs4_schedule_state_manager(clp);
2344
2345         dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2346 }
2347
2348 static void nfs41_handle_recallable_state_revoked(struct nfs_client *clp)
2349 {
2350         /* FIXME: For now, we destroy all layouts. */
2351         pnfs_destroy_all_layouts(clp);
2352         nfs_test_expired_all_delegations(clp);
2353         dprintk("%s: Recallable state revoked on server %s!\n", __func__,
2354                         clp->cl_hostname);
2355 }
2356
2357 static void nfs41_handle_backchannel_fault(struct nfs_client *clp)
2358 {
2359         set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2360         nfs4_schedule_state_manager(clp);
2361
2362         dprintk("%s: server %s declared a backchannel fault\n", __func__,
2363                         clp->cl_hostname);
2364 }
2365
2366 static void nfs41_handle_cb_path_down(struct nfs_client *clp)
2367 {
2368         if (test_and_set_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2369                 &clp->cl_state) == 0)
2370                 nfs4_schedule_state_manager(clp);
2371 }
2372
2373 void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags,
2374                 bool recovery)
2375 {
2376         if (!flags)
2377                 return;
2378
2379         dprintk("%s: \"%s\" (client ID %llx) flags=0x%08x\n",
2380                 __func__, clp->cl_hostname, clp->cl_clientid, flags);
2381         /*
2382          * If we're called from the state manager thread, then assume we're
2383          * already handling the RECLAIM_NEEDED and/or STATE_REVOKED.
2384          * Those flags are expected to remain set until we're done
2385          * recovering (see RFC5661, section 18.46.3).
2386          */
2387         if (recovery)
2388                 goto out_recovery;
2389
2390         if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED)
2391                 nfs41_handle_server_reboot(clp);
2392         if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED))
2393                 nfs41_handle_all_state_revoked(clp);
2394         if (flags & (SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED |
2395                             SEQ4_STATUS_ADMIN_STATE_REVOKED))
2396                 nfs41_handle_some_state_revoked(clp);
2397         if (flags & SEQ4_STATUS_LEASE_MOVED)
2398                 nfs4_schedule_lease_moved_recovery(clp);
2399         if (flags & SEQ4_STATUS_RECALLABLE_STATE_REVOKED)
2400                 nfs41_handle_recallable_state_revoked(clp);
2401 out_recovery:
2402         if (flags & SEQ4_STATUS_BACKCHANNEL_FAULT)
2403                 nfs41_handle_backchannel_fault(clp);
2404         else if (flags & (SEQ4_STATUS_CB_PATH_DOWN |
2405                                 SEQ4_STATUS_CB_PATH_DOWN_SESSION))
2406                 nfs41_handle_cb_path_down(clp);
2407 }
2408
2409 static int nfs4_reset_session(struct nfs_client *clp)
2410 {
2411         const struct cred *cred;
2412         int status;
2413
2414         if (!nfs4_has_session(clp))
2415                 return 0;
2416         status = nfs4_begin_drain_session(clp);
2417         if (status != 0)
2418                 return status;
2419         cred = nfs4_get_clid_cred(clp);
2420         status = nfs4_proc_destroy_session(clp->cl_session, cred);
2421         switch (status) {
2422         case 0:
2423         case -NFS4ERR_BADSESSION:
2424         case -NFS4ERR_DEADSESSION:
2425                 break;
2426         case -NFS4ERR_BACK_CHAN_BUSY:
2427         case -NFS4ERR_DELAY:
2428                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2429                 status = 0;
2430                 ssleep(1);
2431                 goto out;
2432         default:
2433                 status = nfs4_recovery_handle_error(clp, status);
2434                 goto out;
2435         }
2436
2437         memset(clp->cl_session->sess_id.data, 0, NFS4_MAX_SESSIONID_LEN);
2438         status = nfs4_proc_create_session(clp, cred);
2439         if (status) {
2440                 dprintk("%s: session reset failed with status %d for server %s!\n",
2441                         __func__, status, clp->cl_hostname);
2442                 status = nfs4_handle_reclaim_lease_error(clp, status);
2443                 goto out;
2444         }
2445         nfs41_finish_session_reset(clp);
2446         dprintk("%s: session reset was successful for server %s!\n",
2447                         __func__, clp->cl_hostname);
2448 out:
2449         put_cred(cred);
2450         return status;
2451 }
2452
2453 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2454 {
2455         const struct cred *cred;
2456         int ret;
2457
2458         if (!nfs4_has_session(clp))
2459                 return 0;
2460         ret = nfs4_begin_drain_session(clp);
2461         if (ret != 0)
2462                 return ret;
2463         cred = nfs4_get_clid_cred(clp);
2464         ret = nfs4_proc_bind_conn_to_session(clp, cred);
2465         put_cred(cred);
2466         clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2467         switch (ret) {
2468         case 0:
2469                 dprintk("%s: bind_conn_to_session was successful for server %s!\n",
2470                         __func__, clp->cl_hostname);
2471                 break;
2472         case -NFS4ERR_DELAY:
2473                 ssleep(1);
2474                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2475                 break;
2476         default:
2477                 return nfs4_recovery_handle_error(clp, ret);
2478         }
2479         return 0;
2480 }
2481 #else /* CONFIG_NFS_V4_1 */
2482 static int nfs4_reset_session(struct nfs_client *clp) { return 0; }
2483
2484 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2485 {
2486         return 0;
2487 }
2488 #endif /* CONFIG_NFS_V4_1 */
2489
2490 static void nfs4_state_manager(struct nfs_client *clp)
2491 {
2492         int status = 0;
2493         const char *section = "", *section_sep = "";
2494
2495         /* Ensure exclusive access to NFSv4 state */
2496         do {
2497                 clear_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2498                 if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
2499                         section = "purge state";
2500                         status = nfs4_purge_lease(clp);
2501                         if (status < 0)
2502                                 goto out_error;
2503                         continue;
2504                 }
2505
2506                 if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
2507                         section = "lease expired";
2508                         /* We're going to have to re-establish a clientid */
2509                         status = nfs4_reclaim_lease(clp);
2510                         if (status < 0)
2511                                 goto out_error;
2512                         continue;
2513                 }
2514
2515                 /* Initialize or reset the session */
2516                 if (test_and_clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state)) {
2517                         section = "reset session";
2518                         status = nfs4_reset_session(clp);
2519                         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
2520                                 continue;
2521                         if (status < 0)
2522                                 goto out_error;
2523                 }
2524
2525                 /* Send BIND_CONN_TO_SESSION */
2526                 if (test_and_clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2527                                 &clp->cl_state)) {
2528                         section = "bind conn to session";
2529                         status = nfs4_bind_conn_to_session(clp);
2530                         if (status < 0)
2531                                 goto out_error;
2532                         continue;
2533                 }
2534
2535                 if (test_and_clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state)) {
2536                         section = "check lease";
2537                         status = nfs4_check_lease(clp);
2538                         if (status < 0)
2539                                 goto out_error;
2540                         continue;
2541                 }
2542
2543                 if (test_and_clear_bit(NFS4CLNT_MOVED, &clp->cl_state)) {
2544                         section = "migration";
2545                         status = nfs4_handle_migration(clp);
2546                         if (status < 0)
2547                                 goto out_error;
2548                 }
2549
2550                 if (test_and_clear_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state)) {
2551                         section = "lease moved";
2552                         status = nfs4_handle_lease_moved(clp);
2553                         if (status < 0)
2554                                 goto out_error;
2555                 }
2556
2557                 /* First recover reboot state... */
2558                 if (test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {
2559                         section = "reclaim reboot";
2560                         status = nfs4_do_reclaim(clp,
2561                                 clp->cl_mvops->reboot_recovery_ops);
2562                         if (status == -EAGAIN)
2563                                 continue;
2564                         if (status < 0)
2565                                 goto out_error;
2566                         nfs4_state_end_reclaim_reboot(clp);
2567                 }
2568
2569                 /* Detect expired delegations... */
2570                 if (test_and_clear_bit(NFS4CLNT_DELEGATION_EXPIRED, &clp->cl_state)) {
2571                         section = "detect expired delegations";
2572                         nfs_reap_expired_delegations(clp);
2573                         continue;
2574                 }
2575
2576                 /* Now recover expired state... */
2577                 if (test_and_clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state)) {
2578                         section = "reclaim nograce";
2579                         status = nfs4_do_reclaim(clp,
2580                                 clp->cl_mvops->nograce_recovery_ops);
2581                         if (status == -EAGAIN)
2582                                 continue;
2583                         if (status < 0)
2584                                 goto out_error;
2585                 }
2586
2587                 nfs4_end_drain_session(clp);
2588                 nfs4_clear_state_manager_bit(clp);
2589
2590                 if (!test_and_set_bit(NFS4CLNT_DELEGRETURN_RUNNING, &clp->cl_state)) {
2591                         if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
2592                                 nfs_client_return_marked_delegations(clp);
2593                                 set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2594                         }
2595                         clear_bit(NFS4CLNT_DELEGRETURN_RUNNING, &clp->cl_state);
2596                 }
2597
2598                 /* Did we race with an attempt to give us more work? */
2599                 if (!test_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state))
2600                         return;
2601                 if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
2602                         return;
2603         } while (refcount_read(&clp->cl_count) > 1 && !signalled());
2604         goto out_drain;
2605
2606 out_error:
2607         if (strlen(section))
2608                 section_sep = ": ";
2609         pr_warn_ratelimited("NFS: state manager%s%s failed on NFSv4 server %s"
2610                         " with error %d\n", section_sep, section,
2611                         clp->cl_hostname, -status);
2612         ssleep(1);
2613 out_drain:
2614         nfs4_end_drain_session(clp);
2615         nfs4_clear_state_manager_bit(clp);
2616 }
2617
2618 static int nfs4_run_state_manager(void *ptr)
2619 {
2620         struct nfs_client *clp = ptr;
2621
2622         allow_signal(SIGKILL);
2623         nfs4_state_manager(clp);
2624         nfs_put_client(clp);
2625         module_put_and_exit(0);
2626         return 0;
2627 }
2628
2629 /*
2630  * Local variables:
2631  *  c-basic-offset: 8
2632  * End:
2633  */