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  * @head: resulting list of state owners
 628  *
 629  * Called at umount time.  Remaining state owners will be on
 630  * the LRU with ref count of zero.
 631  * Note that the state owners are not freed, but are added
 632  * to the list @head, which can later be used as an argument
 633  * to nfs4_free_state_owners.
 634  */
 635 void nfs4_purge_state_owners(struct nfs_server *server, struct list_head *head)
 636 {
 637         struct nfs_client *clp = server->nfs_client;
 638         struct nfs4_state_owner *sp, *tmp;
 639
 640         spin_lock(&clp->cl_lock);
 641         list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
 642                 list_move(&sp->so_lru, head);
 643                 nfs4_remove_state_owner_locked(sp);
 644         }
 645         spin_unlock(&clp->cl_lock);
 646 }
 647
 648 /**
 649  * nfs4_purge_state_owners - Release all cached state owners
 650  * @head: resulting list of state owners
 651  *
 652  * Frees a list of state owners that was generated by
 653  * nfs4_purge_state_owners
 654  */
 655 void nfs4_free_state_owners(struct list_head *head)
 656 {
 657         struct nfs4_state_owner *sp, *tmp;
 658
 659         list_for_each_entry_safe(sp, tmp, head, so_lru) {
 660                 list_del(&sp->so_lru);
 661                 nfs4_free_state_owner(sp);
 662         }
 663 }
 664
 665 static struct nfs4_state *
 666 nfs4_alloc_open_state(void)
 667 {
 668         struct nfs4_state *state;
 669
 670         state = kzalloc(sizeof(*state), GFP_NOFS);
 671         if (!state)
 672                 return NULL;
 673         refcount_set(&state->count, 1);
 674         INIT_LIST_HEAD(&state->lock_states);
 675         spin_lock_init(&state->state_lock);
 676         seqlock_init(&state->seqlock);
 677         init_waitqueue_head(&state->waitq);
 678         return state;
 679 }
 680
 681 void
 682 nfs4_state_set_mode_locked(struct nfs4_state *state, fmode_t fmode)
 683 {
 684         if (state->state == fmode)
 685                 return;
 686         /* NB! List reordering - see the reclaim code for why.  */
 687         if ((fmode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
 688                 if (fmode & FMODE_WRITE)
 689                         list_move(&state->open_states, &state->owner->so_states);
 690                 else
 691                         list_move_tail(&state->open_states, &state->owner->so_states);
 692         }
 693         state->state = fmode;
 694 }
 695
 696 static struct nfs4_state *
 697 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
 698 {
 699         struct nfs_inode *nfsi = NFS_I(inode);
 700         struct nfs4_state *state;
 701
 702         list_for_each_entry_rcu(state, &nfsi->open_states, inode_states) {
 703                 if (state->owner != owner)
 704                         continue;
 705                 if (!nfs4_valid_open_stateid(state))
 706                         continue;
 707                 if (refcount_inc_not_zero(&state->count))
 708                         return state;
 709         }
 710         return NULL;
 711 }
 712
 713 static void
 714 nfs4_free_open_state(struct nfs4_state *state)
 715 {
 716         kfree_rcu(state, rcu_head);
 717 }
 718
 719 struct nfs4_state *
 720 nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
 721 {
 722         struct nfs4_state *state, *new;
 723         struct nfs_inode *nfsi = NFS_I(inode);
 724
 725         rcu_read_lock();
 726         state = __nfs4_find_state_byowner(inode, owner);
 727         rcu_read_unlock();
 728         if (state)
 729                 goto out;
 730         new = nfs4_alloc_open_state();
 731         spin_lock(&owner->so_lock);
 732         spin_lock(&inode->i_lock);
 733         state = __nfs4_find_state_byowner(inode, owner);
 734         if (state == NULL && new != NULL) {
 735                 state = new;
 736                 state->owner = owner;
 737                 atomic_inc(&owner->so_count);
 738                 list_add_rcu(&state->inode_states, &nfsi->open_states);
 739                 ihold(inode);
 740                 state->inode = inode;
 741                 spin_unlock(&inode->i_lock);
 742                 /* Note: The reclaim code dictates that we add stateless
 743                  * and read-only stateids to the end of the list */
 744                 list_add_tail(&state->open_states, &owner->so_states);
 745                 spin_unlock(&owner->so_lock);
 746         } else {
 747                 spin_unlock(&inode->i_lock);
 748                 spin_unlock(&owner->so_lock);
 749                 if (new)
 750                         nfs4_free_open_state(new);
 751         }
 752 out:
 753         return state;
 754 }
 755
 756 void nfs4_put_open_state(struct nfs4_state *state)
 757 {
 758         struct inode *inode = state->inode;
 759         struct nfs4_state_owner *owner = state->owner;
 760
 761         if (!refcount_dec_and_lock(&state->count, &owner->so_lock))
 762                 return;
 763         spin_lock(&inode->i_lock);
 764         list_del_rcu(&state->inode_states);
 765         list_del(&state->open_states);
 766         spin_unlock(&inode->i_lock);
 767         spin_unlock(&owner->so_lock);
 768         iput(inode);
 769         nfs4_free_open_state(state);
 770         nfs4_put_state_owner(owner);
 771 }
 772
 773 /*
 774  * Close the current file.
 775  */
 776 static void __nfs4_close(struct nfs4_state *state,
 777                 fmode_t fmode, gfp_t gfp_mask, int wait)
 778 {
 779         struct nfs4_state_owner *owner = state->owner;
 780         int call_close = 0;
 781         fmode_t newstate;
 782
 783         atomic_inc(&owner->so_count);
 784         /* Protect against nfs4_find_state() */
 785         spin_lock(&owner->so_lock);
 786         switch (fmode & (FMODE_READ | FMODE_WRITE)) {
 787                 case FMODE_READ:
 788                         state->n_rdonly--;
 789                         break;
 790                 case FMODE_WRITE:
 791                         state->n_wronly--;
 792                         break;
 793                 case FMODE_READ|FMODE_WRITE:
 794                         state->n_rdwr--;
 795         }
 796         newstate = FMODE_READ|FMODE_WRITE;
 797         if (state->n_rdwr == 0) {
 798                 if (state->n_rdonly == 0) {
 799                         newstate &= ~FMODE_READ;
 800                         call_close |= test_bit(NFS_O_RDONLY_STATE, &state->flags);
 801                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
 802                 }
 803                 if (state->n_wronly == 0) {
 804                         newstate &= ~FMODE_WRITE;
 805                         call_close |= test_bit(NFS_O_WRONLY_STATE, &state->flags);
 806                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
 807                 }
 808                 if (newstate == 0)
 809                         clear_bit(NFS_DELEGATED_STATE, &state->flags);
 810         }
 811         nfs4_state_set_mode_locked(state, newstate);
 812         spin_unlock(&owner->so_lock);
 813
 814         if (!call_close) {
 815                 nfs4_put_open_state(state);
 816                 nfs4_put_state_owner(owner);
 817         } else
 818                 nfs4_do_close(state, gfp_mask, wait);
 819 }
 820
 821 void nfs4_close_state(struct nfs4_state *state, fmode_t fmode)
 822 {
 823         __nfs4_close(state, fmode, GFP_NOFS, 0);
 824 }
 825
 826 void nfs4_close_sync(struct nfs4_state *state, fmode_t fmode)
 827 {
 828         __nfs4_close(state, fmode, GFP_KERNEL, 1);
 829 }
 830
 831 /*
 832  * Search the state->lock_states for an existing lock_owner
 833  * that is compatible with either of the given owners.
 834  * If the second is non-zero, then the first refers to a Posix-lock
 835  * owner (current->files) and the second refers to a flock/OFD
 836  * owner (struct file*).  In that case, prefer a match for the first
 837  * owner.
 838  * If both sorts of locks are held on the one file we cannot know
 839  * which stateid was intended to be used, so a "correct" choice cannot
 840  * be made.  Failing that, a "consistent" choice is preferable.  The
 841  * consistent choice we make is to prefer the first owner, that of a
 842  * Posix lock.
 843  */
 844 static struct nfs4_lock_state *
 845 __nfs4_find_lock_state(struct nfs4_state *state,
 846                        fl_owner_t fl_owner, fl_owner_t fl_owner2)
 847 {
 848         struct nfs4_lock_state *pos, *ret = NULL;
 849         list_for_each_entry(pos, &state->lock_states, ls_locks) {
 850                 if (pos->ls_owner == fl_owner) {
 851                         ret = pos;
 852                         break;
 853                 }
 854                 if (pos->ls_owner == fl_owner2)
 855                         ret = pos;
 856         }
 857         if (ret)
 858                 refcount_inc(&ret->ls_count);
 859         return ret;
 860 }
 861
 862 /*
 863  * Return a compatible lock_state. If no initialized lock_state structure
 864  * exists, return an uninitialized one.
 865  *
 866  */
 867 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 868 {
 869         struct nfs4_lock_state *lsp;
 870         struct nfs_server *server = state->owner->so_server;
 871
 872         lsp = kzalloc(sizeof(*lsp), GFP_NOFS);
 873         if (lsp == NULL)
 874                 return NULL;
 875         nfs4_init_seqid_counter(&lsp->ls_seqid);
 876         refcount_set(&lsp->ls_count, 1);
 877         lsp->ls_state = state;
 878         lsp->ls_owner = fl_owner;
 879         lsp->ls_seqid.owner_id = ida_simple_get(&server->lockowner_id, 0, 0, GFP_NOFS);
 880         if (lsp->ls_seqid.owner_id < 0)
 881                 goto out_free;
 882         INIT_LIST_HEAD(&lsp->ls_locks);
 883         return lsp;
 884 out_free:
 885         kfree(lsp);
 886         return NULL;
 887 }
 888
 889 void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp)
 890 {
 891         ida_simple_remove(&server->lockowner_id, lsp->ls_seqid.owner_id);
 892         nfs4_destroy_seqid_counter(&lsp->ls_seqid);
 893         kfree(lsp);
 894 }
 895
 896 /*
 897  * Return a compatible lock_state. If no initialized lock_state structure
 898  * exists, return an uninitialized one.
 899  *
 900  */
 901 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
 902 {
 903         struct nfs4_lock_state *lsp, *new = NULL;
 904
 905         for(;;) {
 906                 spin_lock(&state->state_lock);
 907                 lsp = __nfs4_find_lock_state(state, owner, NULL);
 908                 if (lsp != NULL)
 909                         break;
 910                 if (new != NULL) {
 911                         list_add(&new->ls_locks, &state->lock_states);
 912                         set_bit(LK_STATE_IN_USE, &state->flags);
 913                         lsp = new;
 914                         new = NULL;
 915                         break;
 916                 }
 917                 spin_unlock(&state->state_lock);
 918                 new = nfs4_alloc_lock_state(state, owner);
 919                 if (new == NULL)
 920                         return NULL;
 921         }
 922         spin_unlock(&state->state_lock);
 923         if (new != NULL)
 924                 nfs4_free_lock_state(state->owner->so_server, new);
 925         return lsp;
 926 }
 927
 928 /*
 929  * Release reference to lock_state, and free it if we see that
 930  * it is no longer in use
 931  */
 932 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
 933 {
 934         struct nfs_server *server;
 935         struct nfs4_state *state;
 936
 937         if (lsp == NULL)
 938                 return;
 939         state = lsp->ls_state;
 940         if (!refcount_dec_and_lock(&lsp->ls_count, &state->state_lock))
 941                 return;
 942         list_del(&lsp->ls_locks);
 943         if (list_empty(&state->lock_states))
 944                 clear_bit(LK_STATE_IN_USE, &state->flags);
 945         spin_unlock(&state->state_lock);
 946         server = state->owner->so_server;
 947         if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) {
 948                 struct nfs_client *clp = server->nfs_client;
 949
 950                 clp->cl_mvops->free_lock_state(server, lsp);
 951         } else
 952                 nfs4_free_lock_state(server, lsp);
 953 }
 954
 955 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
 956 {
 957         struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
 958
 959         dst->fl_u.nfs4_fl.owner = lsp;
 960         refcount_inc(&lsp->ls_count);
 961 }
 962
 963 static void nfs4_fl_release_lock(struct file_lock *fl)
 964 {
 965         nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
 966 }
 967
 968 static const struct file_lock_operations nfs4_fl_lock_ops = {
 969         .fl_copy_lock = nfs4_fl_copy_lock,
 970         .fl_release_private = nfs4_fl_release_lock,
 971 };
 972
 973 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
 974 {
 975         struct nfs4_lock_state *lsp;
 976
 977         if (fl->fl_ops != NULL)
 978                 return 0;
 979         lsp = nfs4_get_lock_state(state, fl->fl_owner);
 980         if (lsp == NULL)
 981                 return -ENOMEM;
 982         fl->fl_u.nfs4_fl.owner = lsp;
 983         fl->fl_ops = &nfs4_fl_lock_ops;
 984         return 0;
 985 }
 986
 987 static int nfs4_copy_lock_stateid(nfs4_stateid *dst,
 988                 struct nfs4_state *state,
 989                 const struct nfs_lock_context *l_ctx)
 990 {
 991         struct nfs4_lock_state *lsp;
 992         fl_owner_t fl_owner, fl_flock_owner;
 993         int ret = -ENOENT;
 994
 995         if (l_ctx == NULL)
 996                 goto out;
 997
 998         if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
 999                 goto out;
1000
1001         fl_owner = l_ctx->lockowner;
1002         fl_flock_owner = l_ctx->open_context->flock_owner;
1003
1004         spin_lock(&state->state_lock);
1005         lsp = __nfs4_find_lock_state(state, fl_owner, fl_flock_owner);
1006         if (lsp && test_bit(NFS_LOCK_LOST, &lsp->ls_flags))
1007                 ret = -EIO;
1008         else if (lsp != NULL && test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) != 0) {
1009                 nfs4_stateid_copy(dst, &lsp->ls_stateid);
1010                 ret = 0;
1011         }
1012         spin_unlock(&state->state_lock);
1013         nfs4_put_lock_state(lsp);
1014 out:
1015         return ret;
1016 }
1017
1018 bool nfs4_copy_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
1019 {
1020         bool ret;
1021         const nfs4_stateid *src;
1022         int seq;
1023
1024         do {
1025                 ret = false;
1026                 src = &zero_stateid;
1027                 seq = read_seqbegin(&state->seqlock);
1028                 if (test_bit(NFS_OPEN_STATE, &state->flags)) {
1029                         src = &state->open_stateid;
1030                         ret = true;
1031                 }
1032                 nfs4_stateid_copy(dst, src);
1033         } while (read_seqretry(&state->seqlock, seq));
1034         return ret;
1035 }
1036
1037 /*
1038  * Byte-range lock aware utility to initialize the stateid of read/write
1039  * requests.
1040  */
1041 int nfs4_select_rw_stateid(struct nfs4_state *state,
1042                 fmode_t fmode, const struct nfs_lock_context *l_ctx,
1043                 nfs4_stateid *dst, const struct cred **cred)
1044 {
1045         int ret;
1046
1047         if (!nfs4_valid_open_stateid(state))
1048                 return -EIO;
1049         if (cred != NULL)
1050                 *cred = NULL;
1051         ret = nfs4_copy_lock_stateid(dst, state, l_ctx);
1052         if (ret == -EIO)
1053                 /* A lost lock - don't even consider delegations */
1054                 goto out;
1055         /* returns true if delegation stateid found and copied */
1056         if (nfs4_copy_delegation_stateid(state->inode, fmode, dst, cred)) {
1057                 ret = 0;
1058                 goto out;
1059         }
1060         if (ret != -ENOENT)
1061                 /* nfs4_copy_delegation_stateid() didn't over-write
1062                  * dst, so it still has the lock stateid which we now
1063                  * choose to use.
1064                  */
1065                 goto out;
1066         ret = nfs4_copy_open_stateid(dst, state) ? 0 : -EAGAIN;
1067 out:
1068         if (nfs_server_capable(state->inode, NFS_CAP_STATEID_NFSV41))
1069                 dst->seqid = 0;
1070         return ret;
1071 }
1072
1073 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask)
1074 {
1075         struct nfs_seqid *new;
1076
1077         new = kmalloc(sizeof(*new), gfp_mask);
1078         if (new == NULL)
1079                 return ERR_PTR(-ENOMEM);
1080         new->sequence = counter;
1081         INIT_LIST_HEAD(&new->list);
1082         new->task = NULL;
1083         return new;
1084 }
1085
1086 void nfs_release_seqid(struct nfs_seqid *seqid)
1087 {
1088         struct nfs_seqid_counter *sequence;
1089
1090         if (seqid == NULL || list_empty(&seqid->list))
1091                 return;
1092         sequence = seqid->sequence;
1093         spin_lock(&sequence->lock);
1094         list_del_init(&seqid->list);
1095         if (!list_empty(&sequence->list)) {
1096                 struct nfs_seqid *next;
1097
1098                 next = list_first_entry(&sequence->list,
1099                                 struct nfs_seqid, list);
1100                 rpc_wake_up_queued_task(&sequence->wait, next->task);
1101         }
1102         spin_unlock(&sequence->lock);
1103 }
1104
1105 void nfs_free_seqid(struct nfs_seqid *seqid)
1106 {
1107         nfs_release_seqid(seqid);
1108         kfree(seqid);
1109 }
1110
1111 /*
1112  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
1113  * failed with a seqid incrementing error -
1114  * see comments nfs4.h:seqid_mutating_error()
1115  */
1116 static void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
1117 {
1118         switch (status) {
1119                 case 0:
1120                         break;
1121                 case -NFS4ERR_BAD_SEQID:
1122                         if (seqid->sequence->flags & NFS_SEQID_CONFIRMED)
1123                                 return;
1124                         pr_warn_ratelimited("NFS: v4 server returned a bad"
1125                                         " sequence-id error on an"
1126                                         " unconfirmed sequence %p!\n",
1127                                         seqid->sequence);
1128                 case -NFS4ERR_STALE_CLIENTID:
1129                 case -NFS4ERR_STALE_STATEID:
1130                 case -NFS4ERR_BAD_STATEID:
1131                 case -NFS4ERR_BADXDR:
1132                 case -NFS4ERR_RESOURCE:
1133                 case -NFS4ERR_NOFILEHANDLE:
1134                 case -NFS4ERR_MOVED:
1135                         /* Non-seqid mutating errors */
1136                         return;
1137         };
1138         /*
1139          * Note: no locking needed as we are guaranteed to be first
1140          * on the sequence list
1141          */
1142         seqid->sequence->counter++;
1143 }
1144
1145 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
1146 {
1147         struct nfs4_state_owner *sp;
1148
1149         if (seqid == NULL)
1150                 return;
1151
1152         sp = container_of(seqid->sequence, struct nfs4_state_owner, so_seqid);
1153         if (status == -NFS4ERR_BAD_SEQID)
1154                 nfs4_reset_state_owner(sp);
1155         if (!nfs4_has_session(sp->so_server->nfs_client))
1156                 nfs_increment_seqid(status, seqid);
1157 }
1158
1159 /*
1160  * Increment the seqid if the LOCK/LOCKU succeeded, or
1161  * failed with a seqid incrementing error -
1162  * see comments nfs4.h:seqid_mutating_error()
1163  */
1164 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
1165 {
1166         if (seqid != NULL)
1167                 nfs_increment_seqid(status, seqid);
1168 }
1169
1170 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
1171 {
1172         struct nfs_seqid_counter *sequence;
1173         int status = 0;
1174
1175         if (seqid == NULL)
1176                 goto out;
1177         sequence = seqid->sequence;
1178         spin_lock(&sequence->lock);
1179         seqid->task = task;
1180         if (list_empty(&seqid->list))
1181                 list_add_tail(&seqid->list, &sequence->list);
1182         if (list_first_entry(&sequence->list, struct nfs_seqid, list) == seqid)
1183                 goto unlock;
1184         rpc_sleep_on(&sequence->wait, task, NULL);
1185         status = -EAGAIN;
1186 unlock:
1187         spin_unlock(&sequence->lock);
1188 out:
1189         return status;
1190 }
1191
1192 static int nfs4_run_state_manager(void *);
1193
1194 static void nfs4_clear_state_manager_bit(struct nfs_client *clp)
1195 {
1196         smp_mb__before_atomic();
1197         clear_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state);
1198         smp_mb__after_atomic();
1199         wake_up_bit(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING);
1200         rpc_wake_up(&clp->cl_rpcwaitq);
1201 }
1202
1203 /*
1204  * Schedule the nfs_client asynchronous state management routine
1205  */
1206 void nfs4_schedule_state_manager(struct nfs_client *clp)
1207 {
1208         struct task_struct *task;
1209         char buf[INET6_ADDRSTRLEN + sizeof("-manager") + 1];
1210
1211         set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
1212         if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
1213                 return;
1214         __module_get(THIS_MODULE);
1215         refcount_inc(&clp->cl_count);
1216
1217         /* The rcu_read_lock() is not strictly necessary, as the state
1218          * manager is the only thread that ever changes the rpc_xprt
1219          * after it's initialized.  At this point, we're single threaded. */
1220         rcu_read_lock();
1221         snprintf(buf, sizeof(buf), "%s-manager",
1222                         rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
1223         rcu_read_unlock();
1224         task = kthread_run(nfs4_run_state_manager, clp, "%s", buf);
1225         if (IS_ERR(task)) {
1226                 printk(KERN_ERR "%s: kthread_run: %ld\n",
1227                         __func__, PTR_ERR(task));
1228                 nfs4_clear_state_manager_bit(clp);
1229                 nfs_put_client(clp);
1230                 module_put(THIS_MODULE);
1231         }
1232 }
1233
1234 /*
1235  * Schedule a lease recovery attempt
1236  */
1237 void nfs4_schedule_lease_recovery(struct nfs_client *clp)
1238 {
1239         if (!clp)
1240                 return;
1241         if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1242                 set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1243         dprintk("%s: scheduling lease recovery for server %s\n", __func__,
1244                         clp->cl_hostname);
1245         nfs4_schedule_state_manager(clp);
1246 }
1247 EXPORT_SYMBOL_GPL(nfs4_schedule_lease_recovery);
1248
1249 /**
1250  * nfs4_schedule_migration_recovery - trigger migration recovery
1251  *
1252  * @server: FSID that is migrating
1253  *
1254  * Returns zero if recovery has started, otherwise a negative NFS4ERR
1255  * value is returned.
1256  */
1257 int nfs4_schedule_migration_recovery(const struct nfs_server *server)
1258 {
1259         struct nfs_client *clp = server->nfs_client;
1260
1261         if (server->fh_expire_type != NFS4_FH_PERSISTENT) {
1262                 pr_err("NFS: volatile file handles not supported (server %s)\n",
1263                                 clp->cl_hostname);
1264                 return -NFS4ERR_IO;
1265         }
1266
1267         if (test_bit(NFS_MIG_FAILED, &server->mig_status))
1268                 return -NFS4ERR_IO;
1269
1270         dprintk("%s: scheduling migration recovery for (%llx:%llx) on %s\n",
1271                         __func__,
1272                         (unsigned long long)server->fsid.major,
1273                         (unsigned long long)server->fsid.minor,
1274                         clp->cl_hostname);
1275
1276         set_bit(NFS_MIG_IN_TRANSITION,
1277                         &((struct nfs_server *)server)->mig_status);
1278         set_bit(NFS4CLNT_MOVED, &clp->cl_state);
1279
1280         nfs4_schedule_state_manager(clp);
1281         return 0;
1282 }
1283 EXPORT_SYMBOL_GPL(nfs4_schedule_migration_recovery);
1284
1285 /**
1286  * nfs4_schedule_lease_moved_recovery - start lease-moved recovery
1287  *
1288  * @clp: server to check for moved leases
1289  *
1290  */
1291 void nfs4_schedule_lease_moved_recovery(struct nfs_client *clp)
1292 {
1293         dprintk("%s: scheduling lease-moved recovery for client ID %llx on %s\n",
1294                 __func__, clp->cl_clientid, clp->cl_hostname);
1295
1296         set_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state);
1297         nfs4_schedule_state_manager(clp);
1298 }
1299 EXPORT_SYMBOL_GPL(nfs4_schedule_lease_moved_recovery);
1300
1301 int nfs4_wait_clnt_recover(struct nfs_client *clp)
1302 {
1303         int res;
1304
1305         might_sleep();
1306
1307         refcount_inc(&clp->cl_count);
1308         res = wait_on_bit_action(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING,
1309                                  nfs_wait_bit_killable, TASK_KILLABLE);
1310         if (res)
1311                 goto out;
1312         if (clp->cl_cons_state < 0)
1313                 res = clp->cl_cons_state;
1314 out:
1315         nfs_put_client(clp);
1316         return res;
1317 }
1318
1319 int nfs4_client_recover_expired_lease(struct nfs_client *clp)
1320 {
1321         unsigned int loop;
1322         int ret;
1323
1324         for (loop = NFS4_MAX_LOOP_ON_RECOVER; loop != 0; loop--) {
1325                 ret = nfs4_wait_clnt_recover(clp);
1326                 if (ret != 0)
1327                         break;
1328                 if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) &&
1329                     !test_bit(NFS4CLNT_CHECK_LEASE,&clp->cl_state))
1330                         break;
1331                 nfs4_schedule_state_manager(clp);
1332                 ret = -EIO;
1333         }
1334         return ret;
1335 }
1336
1337 /*
1338  * nfs40_handle_cb_pathdown - return all delegations after NFS4ERR_CB_PATH_DOWN
1339  * @clp: client to process
1340  *
1341  * Set the NFS4CLNT_LEASE_EXPIRED state in order to force a
1342  * resend of the SETCLIENTID and hence re-establish the
1343  * callback channel. Then return all existing delegations.
1344  */
1345 static void nfs40_handle_cb_pathdown(struct nfs_client *clp)
1346 {
1347         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1348         nfs_expire_all_delegations(clp);
1349         dprintk("%s: handling CB_PATHDOWN recovery for server %s\n", __func__,
1350                         clp->cl_hostname);
1351 }
1352
1353 void nfs4_schedule_path_down_recovery(struct nfs_client *clp)
1354 {
1355         nfs40_handle_cb_pathdown(clp);
1356         nfs4_schedule_state_manager(clp);
1357 }
1358
1359 static int nfs4_state_mark_reclaim_reboot(struct nfs_client *clp, struct nfs4_state *state)
1360 {
1361
1362         if (!nfs4_valid_open_stateid(state))
1363                 return 0;
1364         set_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1365         /* Don't recover state that expired before the reboot */
1366         if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags)) {
1367                 clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1368                 return 0;
1369         }
1370         set_bit(NFS_OWNER_RECLAIM_REBOOT, &state->owner->so_flags);
1371         set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1372         return 1;
1373 }
1374
1375 int nfs4_state_mark_reclaim_nograce(struct nfs_client *clp, struct nfs4_state *state)
1376 {
1377         if (!nfs4_valid_open_stateid(state))
1378                 return 0;
1379         set_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1380         clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1381         set_bit(NFS_OWNER_RECLAIM_NOGRACE, &state->owner->so_flags);
1382         set_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
1383         return 1;
1384 }
1385
1386 int nfs4_schedule_stateid_recovery(const struct nfs_server *server, struct nfs4_state *state)
1387 {
1388         struct nfs_client *clp = server->nfs_client;
1389
1390         if (!nfs4_state_mark_reclaim_nograce(clp, state))
1391                 return -EBADF;
1392         nfs_inode_find_delegation_state_and_recover(state->inode,
1393                         &state->stateid);
1394         dprintk("%s: scheduling stateid recovery for server %s\n", __func__,
1395                         clp->cl_hostname);
1396         nfs4_schedule_state_manager(clp);
1397         return 0;
1398 }
1399 EXPORT_SYMBOL_GPL(nfs4_schedule_stateid_recovery);
1400
1401 static struct nfs4_lock_state *
1402 nfs_state_find_lock_state_by_stateid(struct nfs4_state *state,
1403                 const nfs4_stateid *stateid)
1404 {
1405         struct nfs4_lock_state *pos;
1406
1407         list_for_each_entry(pos, &state->lock_states, ls_locks) {
1408                 if (!test_bit(NFS_LOCK_INITIALIZED, &pos->ls_flags))
1409                         continue;
1410                 if (nfs4_stateid_match_other(&pos->ls_stateid, stateid))
1411                         return pos;
1412         }
1413         return NULL;
1414 }
1415
1416 static bool nfs_state_lock_state_matches_stateid(struct nfs4_state *state,
1417                 const nfs4_stateid *stateid)
1418 {
1419         bool found = false;
1420
1421         if (test_bit(LK_STATE_IN_USE, &state->flags)) {
1422                 spin_lock(&state->state_lock);
1423                 if (nfs_state_find_lock_state_by_stateid(state, stateid))
1424                         found = true;
1425                 spin_unlock(&state->state_lock);
1426         }
1427         return found;
1428 }
1429
1430 void nfs_inode_find_state_and_recover(struct inode *inode,
1431                 const nfs4_stateid *stateid)
1432 {
1433         struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
1434         struct nfs_inode *nfsi = NFS_I(inode);
1435         struct nfs_open_context *ctx;
1436         struct nfs4_state *state;
1437         bool found = false;
1438
1439         rcu_read_lock();
1440         list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1441                 state = ctx->state;
1442                 if (state == NULL)
1443                         continue;
1444                 if (nfs4_stateid_match_other(&state->stateid, stateid) &&
1445                     nfs4_state_mark_reclaim_nograce(clp, state)) {
1446                         found = true;
1447                         continue;
1448                 }
1449                 if (nfs4_stateid_match_other(&state->open_stateid, stateid) &&
1450                     nfs4_state_mark_reclaim_nograce(clp, state)) {
1451                         found = true;
1452                         continue;
1453                 }
1454                 if (nfs_state_lock_state_matches_stateid(state, stateid) &&
1455                     nfs4_state_mark_reclaim_nograce(clp, state))
1456                         found = true;
1457         }
1458         rcu_read_unlock();
1459
1460         nfs_inode_find_delegation_state_and_recover(inode, stateid);
1461         if (found)
1462                 nfs4_schedule_state_manager(clp);
1463 }
1464
1465 static void nfs4_state_mark_open_context_bad(struct nfs4_state *state, int err)
1466 {
1467         struct inode *inode = state->inode;
1468         struct nfs_inode *nfsi = NFS_I(inode);
1469         struct nfs_open_context *ctx;
1470
1471         rcu_read_lock();
1472         list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1473                 if (ctx->state != state)
1474                         continue;
1475                 set_bit(NFS_CONTEXT_BAD, &ctx->flags);
1476                 pr_warn("NFSv4: state recovery failed for open file %pd2, "
1477                                 "error = %d\n", ctx->dentry, err);
1478         }
1479         rcu_read_unlock();
1480 }
1481
1482 static void nfs4_state_mark_recovery_failed(struct nfs4_state *state, int error)
1483 {
1484         set_bit(NFS_STATE_RECOVERY_FAILED, &state->flags);
1485         nfs4_state_mark_open_context_bad(state, error);
1486 }
1487
1488
1489 static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_recovery_ops *ops)
1490 {
1491         struct inode *inode = state->inode;
1492         struct nfs_inode *nfsi = NFS_I(inode);
1493         struct file_lock *fl;
1494         struct nfs4_lock_state *lsp;
1495         int status = 0;
1496         struct file_lock_context *flctx = inode->i_flctx;
1497         struct list_head *list;
1498
1499         if (flctx == NULL)
1500                 return 0;
1501
1502         list = &flctx->flc_posix;
1503
1504         /* Guard against delegation returns and new lock/unlock calls */
1505         down_write(&nfsi->rwsem);
1506         spin_lock(&flctx->flc_lock);
1507 restart:
1508         list_for_each_entry(fl, list, fl_list) {
1509                 if (nfs_file_open_context(fl->fl_file)->state != state)
1510                         continue;
1511                 spin_unlock(&flctx->flc_lock);
1512                 status = ops->recover_lock(state, fl);
1513                 switch (status) {
1514                 case 0:
1515                         break;
1516                 case -ETIMEDOUT:
1517                 case -ESTALE:
1518                 case -NFS4ERR_ADMIN_REVOKED:
1519                 case -NFS4ERR_STALE_STATEID:
1520                 case -NFS4ERR_BAD_STATEID:
1521                 case -NFS4ERR_EXPIRED:
1522                 case -NFS4ERR_NO_GRACE:
1523                 case -NFS4ERR_STALE_CLIENTID:
1524                 case -NFS4ERR_BADSESSION:
1525                 case -NFS4ERR_BADSLOT:
1526                 case -NFS4ERR_BAD_HIGH_SLOT:
1527                 case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1528                         goto out;
1529                 default:
1530                         pr_err("NFS: %s: unhandled error %d\n",
1531                                         __func__, status);
1532                         /* Fall through */
1533                 case -ENOMEM:
1534                 case -NFS4ERR_DENIED:
1535                 case -NFS4ERR_RECLAIM_BAD:
1536                 case -NFS4ERR_RECLAIM_CONFLICT:
1537                         lsp = fl->fl_u.nfs4_fl.owner;
1538                         if (lsp)
1539                                 set_bit(NFS_LOCK_LOST, &lsp->ls_flags);
1540                         status = 0;
1541                 }
1542                 spin_lock(&flctx->flc_lock);
1543         }
1544         if (list == &flctx->flc_posix) {
1545                 list = &flctx->flc_flock;
1546                 goto restart;
1547         }
1548         spin_unlock(&flctx->flc_lock);
1549 out:
1550         up_write(&nfsi->rwsem);
1551         return status;
1552 }
1553
1554 #ifdef CONFIG_NFS_V4_2
1555 static void nfs42_complete_copies(struct nfs4_state_owner *sp, struct nfs4_state *state)
1556 {
1557         struct nfs4_copy_state *copy;
1558
1559         if (!test_bit(NFS_CLNT_DST_SSC_COPY_STATE, &state->flags))
1560                 return;
1561
1562         spin_lock(&sp->so_server->nfs_client->cl_lock);
1563         list_for_each_entry(copy, &sp->so_server->ss_copies, copies) {
1564                 if (!nfs4_stateid_match_other(&state->stateid, &copy->parent_state->stateid))
1565                         continue;
1566                 copy->flags = 1;
1567                 complete(&copy->completion);
1568                 break;
1569         }
1570         spin_unlock(&sp->so_server->nfs_client->cl_lock);
1571 }
1572 #else /* !CONFIG_NFS_V4_2 */
1573 static inline void nfs42_complete_copies(struct nfs4_state_owner *sp,
1574                                          struct nfs4_state *state)
1575 {
1576 }
1577 #endif /* CONFIG_NFS_V4_2 */
1578
1579 static int __nfs4_reclaim_open_state(struct nfs4_state_owner *sp, struct nfs4_state *state,
1580                                      const struct nfs4_state_recovery_ops *ops)
1581 {
1582         struct nfs4_lock_state *lock;
1583         int status;
1584
1585         status = ops->recover_open(sp, state);
1586         if (status < 0)
1587                 return status;
1588
1589         status = nfs4_reclaim_locks(state, ops);
1590         if (status < 0)
1591                 return status;
1592
1593         if (!test_bit(NFS_DELEGATED_STATE, &state->flags)) {
1594                 spin_lock(&state->state_lock);
1595                 list_for_each_entry(lock, &state->lock_states, ls_locks) {
1596                         if (!test_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags))
1597                                 pr_warn_ratelimited("NFS: %s: Lock reclaim failed!\n", __func__);
1598                 }
1599                 spin_unlock(&state->state_lock);
1600         }
1601
1602         nfs42_complete_copies(sp, state);
1603         clear_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1604         return status;
1605 }
1606
1607 static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs4_state_recovery_ops *ops)
1608 {
1609         struct nfs4_state *state;
1610         unsigned int loop = 0;
1611         int status = 0;
1612
1613         /* Note: we rely on the sp->so_states list being ordered
1614          * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
1615          * states first.
1616          * This is needed to ensure that the server won't give us any
1617          * read delegations that we have to return if, say, we are
1618          * recovering after a network partition or a reboot from a
1619          * server that doesn't support a grace period.
1620          */
1621         spin_lock(&sp->so_lock);
1622         raw_write_seqcount_begin(&sp->so_reclaim_seqcount);
1623 restart:
1624         list_for_each_entry(state, &sp->so_states, open_states) {
1625                 if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
1626                         continue;
1627                 if (!nfs4_valid_open_stateid(state))
1628                         continue;
1629                 if (state->state == 0)
1630                         continue;
1631                 refcount_inc(&state->count);
1632                 spin_unlock(&sp->so_lock);
1633                 status = __nfs4_reclaim_open_state(sp, state, ops);
1634
1635                 switch (status) {
1636                 default:
1637                         if (status >= 0) {
1638                                 loop = 0;
1639                                 break;
1640                         }
1641                         printk(KERN_ERR "NFS: %s: unhandled error %d\n", __func__, status);
1642                         /* Fall through */
1643                 case -ENOENT:
1644                 case -ENOMEM:
1645                 case -EACCES:
1646                 case -EROFS:
1647                 case -EIO:
1648                 case -ESTALE:
1649                         /* Open state on this file cannot be recovered */
1650                         nfs4_state_mark_recovery_failed(state, status);
1651                         break;
1652                 case -EAGAIN:
1653                         ssleep(1);
1654                         if (loop++ < 10) {
1655                                 set_bit(ops->state_flag_bit, &state->flags);
1656                                 break;
1657                         }
1658                         /* Fall through */
1659                 case -NFS4ERR_ADMIN_REVOKED:
1660                 case -NFS4ERR_STALE_STATEID:
1661                 case -NFS4ERR_OLD_STATEID:
1662                 case -NFS4ERR_BAD_STATEID:
1663                 case -NFS4ERR_RECLAIM_BAD:
1664                 case -NFS4ERR_RECLAIM_CONFLICT:
1665                         nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1666                         break;
1667                 case -NFS4ERR_EXPIRED:
1668                 case -NFS4ERR_NO_GRACE:
1669                         nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1670                         /* Fall through */
1671                 case -NFS4ERR_STALE_CLIENTID:
1672                 case -NFS4ERR_BADSESSION:
1673                 case -NFS4ERR_BADSLOT:
1674                 case -NFS4ERR_BAD_HIGH_SLOT:
1675                 case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1676                 case -ETIMEDOUT:
1677                         goto out_err;
1678                 }
1679                 nfs4_put_open_state(state);
1680                 spin_lock(&sp->so_lock);
1681                 goto restart;
1682         }
1683         raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1684         spin_unlock(&sp->so_lock);
1685         return 0;
1686 out_err:
1687         nfs4_put_open_state(state);
1688         spin_lock(&sp->so_lock);
1689         raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1690         spin_unlock(&sp->so_lock);
1691         return status;
1692 }
1693
1694 static void nfs4_clear_open_state(struct nfs4_state *state)
1695 {
1696         struct nfs4_lock_state *lock;
1697
1698         clear_bit(NFS_DELEGATED_STATE, &state->flags);
1699         clear_bit(NFS_O_RDONLY_STATE, &state->flags);
1700         clear_bit(NFS_O_WRONLY_STATE, &state->flags);
1701         clear_bit(NFS_O_RDWR_STATE, &state->flags);
1702         spin_lock(&state->state_lock);
1703         list_for_each_entry(lock, &state->lock_states, ls_locks) {
1704                 lock->ls_seqid.flags = 0;
1705                 clear_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags);
1706         }
1707         spin_unlock(&state->state_lock);
1708 }
1709
1710 static void nfs4_reset_seqids(struct nfs_server *server,
1711         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1712 {
1713         struct nfs_client *clp = server->nfs_client;
1714         struct nfs4_state_owner *sp;
1715         struct rb_node *pos;
1716         struct nfs4_state *state;
1717
1718         spin_lock(&clp->cl_lock);
1719         for (pos = rb_first(&server->state_owners);
1720              pos != NULL;
1721              pos = rb_next(pos)) {
1722                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1723                 sp->so_seqid.flags = 0;
1724                 spin_lock(&sp->so_lock);
1725                 list_for_each_entry(state, &sp->so_states, open_states) {
1726                         if (mark_reclaim(clp, state))
1727                                 nfs4_clear_open_state(state);
1728                 }
1729                 spin_unlock(&sp->so_lock);
1730         }
1731         spin_unlock(&clp->cl_lock);
1732 }
1733
1734 static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp,
1735         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1736 {
1737         struct nfs_server *server;
1738
1739         rcu_read_lock();
1740         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1741                 nfs4_reset_seqids(server, mark_reclaim);
1742         rcu_read_unlock();
1743 }
1744
1745 static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp)
1746 {
1747         /* Mark all delegations for reclaim */
1748         nfs_delegation_mark_reclaim(clp);
1749         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_reboot);
1750 }
1751
1752 static int nfs4_reclaim_complete(struct nfs_client *clp,
1753                                  const struct nfs4_state_recovery_ops *ops,
1754                                  const struct cred *cred)
1755 {
1756         /* Notify the server we're done reclaiming our state */
1757         if (ops->reclaim_complete)
1758                 return ops->reclaim_complete(clp, cred);
1759         return 0;
1760 }
1761
1762 static void nfs4_clear_reclaim_server(struct nfs_server *server)
1763 {
1764         struct nfs_client *clp = server->nfs_client;
1765         struct nfs4_state_owner *sp;
1766         struct rb_node *pos;
1767         struct nfs4_state *state;
1768
1769         spin_lock(&clp->cl_lock);
1770         for (pos = rb_first(&server->state_owners);
1771              pos != NULL;
1772              pos = rb_next(pos)) {
1773                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1774                 spin_lock(&sp->so_lock);
1775                 list_for_each_entry(state, &sp->so_states, open_states) {
1776                         if (!test_and_clear_bit(NFS_STATE_RECLAIM_REBOOT,
1777                                                 &state->flags))
1778                                 continue;
1779                         nfs4_state_mark_reclaim_nograce(clp, state);
1780                 }
1781                 spin_unlock(&sp->so_lock);
1782         }
1783         spin_unlock(&clp->cl_lock);
1784 }
1785
1786 static int nfs4_state_clear_reclaim_reboot(struct nfs_client *clp)
1787 {
1788         struct nfs_server *server;
1789
1790         if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
1791                 return 0;
1792
1793         rcu_read_lock();
1794         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1795                 nfs4_clear_reclaim_server(server);
1796         rcu_read_unlock();
1797
1798         nfs_delegation_reap_unclaimed(clp);
1799         return 1;
1800 }
1801
1802 static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
1803 {
1804         const struct nfs4_state_recovery_ops *ops;
1805         const struct cred *cred;
1806         int err;
1807
1808         if (!nfs4_state_clear_reclaim_reboot(clp))
1809                 return;
1810         ops = clp->cl_mvops->reboot_recovery_ops;
1811         cred = nfs4_get_clid_cred(clp);
1812         err = nfs4_reclaim_complete(clp, ops, cred);
1813         put_cred(cred);
1814         if (err == -NFS4ERR_CONN_NOT_BOUND_TO_SESSION)
1815                 set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1816 }
1817
1818 static void nfs4_state_start_reclaim_nograce(struct nfs_client *clp)
1819 {
1820         nfs_mark_test_expired_all_delegations(clp);
1821         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
1822 }
1823
1824 static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
1825 {
1826         switch (error) {
1827         case 0:
1828                 break;
1829         case -NFS4ERR_CB_PATH_DOWN:
1830                 nfs40_handle_cb_pathdown(clp);
1831                 break;
1832         case -NFS4ERR_NO_GRACE:
1833                 nfs4_state_end_reclaim_reboot(clp);
1834                 break;
1835         case -NFS4ERR_STALE_CLIENTID:
1836                 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1837                 nfs4_state_start_reclaim_reboot(clp);
1838                 break;
1839         case -NFS4ERR_EXPIRED:
1840                 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1841                 nfs4_state_start_reclaim_nograce(clp);
1842                 break;
1843         case -NFS4ERR_BADSESSION:
1844         case -NFS4ERR_BADSLOT:
1845         case -NFS4ERR_BAD_HIGH_SLOT:
1846         case -NFS4ERR_DEADSESSION:
1847         case -NFS4ERR_SEQ_FALSE_RETRY:
1848         case -NFS4ERR_SEQ_MISORDERED:
1849                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
1850                 /* Zero session reset errors */
1851                 break;
1852         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1853                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
1854                 break;
1855         default:
1856                 dprintk("%s: failed to handle error %d for server %s\n",
1857                                 __func__, error, clp->cl_hostname);
1858                 return error;
1859         }
1860         dprintk("%s: handled error %d for server %s\n", __func__, error,
1861                         clp->cl_hostname);
1862         return 0;
1863 }
1864
1865 static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recovery_ops *ops)
1866 {
1867         struct nfs4_state_owner *sp;
1868         struct nfs_server *server;
1869         struct rb_node *pos;
1870         LIST_HEAD(freeme);
1871         int status = 0;
1872
1873 restart:
1874         rcu_read_lock();
1875         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1876                 nfs4_purge_state_owners(server, &freeme);
1877                 spin_lock(&clp->cl_lock);
1878                 for (pos = rb_first(&server->state_owners);
1879                      pos != NULL;
1880                      pos = rb_next(pos)) {
1881                         sp = rb_entry(pos,
1882                                 struct nfs4_state_owner, so_server_node);
1883                         if (!test_and_clear_bit(ops->owner_flag_bit,
1884                                                         &sp->so_flags))
1885                                 continue;
1886                         if (!atomic_inc_not_zero(&sp->so_count))
1887                                 continue;
1888                         spin_unlock(&clp->cl_lock);
1889                         rcu_read_unlock();
1890
1891                         status = nfs4_reclaim_open_state(sp, ops);
1892                         if (status < 0) {
1893                                 set_bit(ops->owner_flag_bit, &sp->so_flags);
1894                                 nfs4_put_state_owner(sp);
1895                                 status = nfs4_recovery_handle_error(clp, status);
1896                                 return (status != 0) ? status : -EAGAIN;
1897                         }
1898
1899                         nfs4_put_state_owner(sp);
1900                         goto restart;
1901                 }
1902                 spin_unlock(&clp->cl_lock);
1903         }
1904         rcu_read_unlock();
1905         nfs4_free_state_owners(&freeme);
1906         return 0;
1907 }
1908
1909 static int nfs4_check_lease(struct nfs_client *clp)
1910 {
1911         const struct cred *cred;
1912         const struct nfs4_state_maintenance_ops *ops =
1913                 clp->cl_mvops->state_renewal_ops;
1914         int status;
1915
1916         /* Is the client already known to have an expired lease? */
1917         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1918                 return 0;
1919         cred = ops->get_state_renewal_cred(clp);
1920         if (cred == NULL) {
1921                 cred = nfs4_get_clid_cred(clp);
1922                 status = -ENOKEY;
1923                 if (cred == NULL)
1924                         goto out;
1925         }
1926         status = ops->renew_lease(clp, cred);
1927         put_cred(cred);
1928         if (status == -ETIMEDOUT) {
1929                 set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1930                 return 0;
1931         }
1932 out:
1933         return nfs4_recovery_handle_error(clp, status);
1934 }
1935
1936 /* Set NFS4CLNT_LEASE_EXPIRED and reclaim reboot state for all v4.0 errors
1937  * and for recoverable errors on EXCHANGE_ID for v4.1
1938  */
1939 static int nfs4_handle_reclaim_lease_error(struct nfs_client *clp, int status)
1940 {
1941         switch (status) {
1942         case -NFS4ERR_SEQ_MISORDERED:
1943                 if (test_and_set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state))
1944                         return -ESERVERFAULT;
1945                 /* Lease confirmation error: retry after purging the lease */
1946                 ssleep(1);
1947                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1948                 break;
1949         case -NFS4ERR_STALE_CLIENTID:
1950                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1951                 nfs4_state_start_reclaim_reboot(clp);
1952                 break;
1953         case -NFS4ERR_CLID_INUSE:
1954                 pr_err("NFS: Server %s reports our clientid is in use\n",
1955                         clp->cl_hostname);
1956                 nfs_mark_client_ready(clp, -EPERM);
1957                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1958                 return -EPERM;
1959         case -EACCES:
1960         case -NFS4ERR_DELAY:
1961         case -EAGAIN:
1962                 ssleep(1);
1963                 break;
1964
1965         case -NFS4ERR_MINOR_VERS_MISMATCH:
1966                 if (clp->cl_cons_state == NFS_CS_SESSION_INITING)
1967                         nfs_mark_client_ready(clp, -EPROTONOSUPPORT);
1968                 dprintk("%s: exit with error %d for server %s\n",
1969                                 __func__, -EPROTONOSUPPORT, clp->cl_hostname);
1970                 return -EPROTONOSUPPORT;
1971         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
1972                                  * in nfs4_exchange_id */
1973         default:
1974                 dprintk("%s: exit with error %d for server %s\n", __func__,
1975                                 status, clp->cl_hostname);
1976                 return status;
1977         }
1978         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1979         dprintk("%s: handled error %d for server %s\n", __func__, status,
1980                         clp->cl_hostname);
1981         return 0;
1982 }
1983
1984 static int nfs4_establish_lease(struct nfs_client *clp)
1985 {
1986         const struct cred *cred;
1987         const struct nfs4_state_recovery_ops *ops =
1988                 clp->cl_mvops->reboot_recovery_ops;
1989         int status;
1990
1991         status = nfs4_begin_drain_session(clp);
1992         if (status != 0)
1993                 return status;
1994         cred = nfs4_get_clid_cred(clp);
1995         if (cred == NULL)
1996                 return -ENOENT;
1997         status = ops->establish_clid(clp, cred);
1998         put_cred(cred);
1999         if (status != 0)
2000                 return status;
2001         pnfs_destroy_all_layouts(clp);
2002         return 0;
2003 }
2004
2005 /*
2006  * Returns zero or a negative errno.  NFS4ERR values are converted
2007  * to local errno values.
2008  */
2009 static int nfs4_reclaim_lease(struct nfs_client *clp)
2010 {
2011         int status;
2012
2013         status = nfs4_establish_lease(clp);
2014         if (status < 0)
2015                 return nfs4_handle_reclaim_lease_error(clp, status);
2016         if (test_and_clear_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH, &clp->cl_state))
2017                 nfs4_state_start_reclaim_nograce(clp);
2018         if (!test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
2019                 set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
2020         clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2021         clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2022         return 0;
2023 }
2024
2025 static int nfs4_purge_lease(struct nfs_client *clp)
2026 {
2027         int status;
2028
2029         status = nfs4_establish_lease(clp);
2030         if (status < 0)
2031                 return nfs4_handle_reclaim_lease_error(clp, status);
2032         clear_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2033         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2034         nfs4_state_start_reclaim_nograce(clp);
2035         return 0;
2036 }
2037
2038 /*
2039  * Try remote migration of one FSID from a source server to a
2040  * destination server.  The source server provides a list of
2041  * potential destinations.
2042  *
2043  * Returns zero or a negative NFS4ERR status code.
2044  */
2045 static int nfs4_try_migration(struct nfs_server *server, const struct cred *cred)
2046 {
2047         struct nfs_client *clp = server->nfs_client;
2048         struct nfs4_fs_locations *locations = NULL;
2049         struct inode *inode;
2050         struct page *page;
2051         int status, result;
2052
2053         dprintk("--> %s: FSID %llx:%llx on \"%s\"\n", __func__,
2054                         (unsigned long long)server->fsid.major,
2055                         (unsigned long long)server->fsid.minor,
2056                         clp->cl_hostname);
2057
2058         result = 0;
2059         page = alloc_page(GFP_KERNEL);
2060         locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
2061         if (page == NULL || locations == NULL) {
2062                 dprintk("<-- %s: no memory\n", __func__);
2063                 goto out;
2064         }
2065
2066         inode = d_inode(server->super->s_root);
2067         result = nfs4_proc_get_locations(inode, locations, page, cred);
2068         if (result) {
2069                 dprintk("<-- %s: failed to retrieve fs_locations: %d\n",
2070                         __func__, result);
2071                 goto out;
2072         }
2073
2074         result = -NFS4ERR_NXIO;
2075         if (!(locations->fattr.valid & NFS_ATTR_FATTR_V4_LOCATIONS)) {
2076                 dprintk("<-- %s: No fs_locations data, migration skipped\n",
2077                         __func__);
2078                 goto out;
2079         }
2080
2081         status = nfs4_begin_drain_session(clp);
2082         if (status != 0) {
2083                 result = status;
2084                 goto out;
2085         }
2086
2087         status = nfs4_replace_transport(server, locations);
2088         if (status != 0) {
2089                 dprintk("<-- %s: failed to replace transport: %d\n",
2090                         __func__, status);
2091                 goto out;
2092         }
2093
2094         result = 0;
2095         dprintk("<-- %s: migration succeeded\n", __func__);
2096
2097 out:
2098         if (page != NULL)
2099                 __free_page(page);
2100         kfree(locations);
2101         if (result) {
2102                 pr_err("NFS: migration recovery failed (server %s)\n",
2103                                 clp->cl_hostname);
2104                 set_bit(NFS_MIG_FAILED, &server->mig_status);
2105         }
2106         return result;
2107 }
2108
2109 /*
2110  * Returns zero or a negative NFS4ERR status code.
2111  */
2112 static int nfs4_handle_migration(struct nfs_client *clp)
2113 {
2114         const struct nfs4_state_maintenance_ops *ops =
2115                                 clp->cl_mvops->state_renewal_ops;
2116         struct nfs_server *server;
2117         const struct cred *cred;
2118
2119         dprintk("%s: migration reported on \"%s\"\n", __func__,
2120                         clp->cl_hostname);
2121
2122         cred = ops->get_state_renewal_cred(clp);
2123         if (cred == NULL)
2124                 return -NFS4ERR_NOENT;
2125
2126         clp->cl_mig_gen++;
2127 restart:
2128         rcu_read_lock();
2129         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2130                 int status;
2131
2132                 if (server->mig_gen == clp->cl_mig_gen)
2133                         continue;
2134                 server->mig_gen = clp->cl_mig_gen;
2135
2136                 if (!test_and_clear_bit(NFS_MIG_IN_TRANSITION,
2137                                                 &server->mig_status))
2138                         continue;
2139
2140                 rcu_read_unlock();
2141                 status = nfs4_try_migration(server, cred);
2142                 if (status < 0) {
2143                         put_cred(cred);
2144                         return status;
2145                 }
2146                 goto restart;
2147         }
2148         rcu_read_unlock();
2149         put_cred(cred);
2150         return 0;
2151 }
2152
2153 /*
2154  * Test each nfs_server on the clp's cl_superblocks list to see
2155  * if it's moved to another server.  Stop when the server no longer
2156  * returns NFS4ERR_LEASE_MOVED.
2157  */
2158 static int nfs4_handle_lease_moved(struct nfs_client *clp)
2159 {
2160         const struct nfs4_state_maintenance_ops *ops =
2161                                 clp->cl_mvops->state_renewal_ops;
2162         struct nfs_server *server;
2163         const struct cred *cred;
2164
2165         dprintk("%s: lease moved reported on \"%s\"\n", __func__,
2166                         clp->cl_hostname);
2167
2168         cred = ops->get_state_renewal_cred(clp);
2169         if (cred == NULL)
2170                 return -NFS4ERR_NOENT;
2171
2172         clp->cl_mig_gen++;
2173 restart:
2174         rcu_read_lock();
2175         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2176                 struct inode *inode;
2177                 int status;
2178
2179                 if (server->mig_gen == clp->cl_mig_gen)
2180                         continue;
2181                 server->mig_gen = clp->cl_mig_gen;
2182
2183                 rcu_read_unlock();
2184
2185                 inode = d_inode(server->super->s_root);
2186                 status = nfs4_proc_fsid_present(inode, cred);
2187                 if (status != -NFS4ERR_MOVED)
2188                         goto restart;   /* wasn't this one */
2189                 if (nfs4_try_migration(server, cred) == -NFS4ERR_LEASE_MOVED)
2190                         goto restart;   /* there are more */
2191                 goto out;
2192         }
2193         rcu_read_unlock();
2194
2195 out:
2196         put_cred(cred);
2197         return 0;
2198 }
2199
2200 /**
2201  * nfs4_discover_server_trunking - Detect server IP address trunking
2202  *
2203  * @clp: nfs_client under test
2204  * @result: OUT: found nfs_client, or clp
2205  *
2206  * Returns zero or a negative errno.  If zero is returned,
2207  * an nfs_client pointer is planted in "result".
2208  *
2209  * Note: since we are invoked in process context, and
2210  * not from inside the state manager, we cannot use
2211  * nfs4_handle_reclaim_lease_error().
2212  */
2213 int nfs4_discover_server_trunking(struct nfs_client *clp,
2214                                   struct nfs_client **result)
2215 {
2216         const struct nfs4_state_recovery_ops *ops =
2217                                 clp->cl_mvops->reboot_recovery_ops;
2218         struct rpc_clnt *clnt;
2219         const struct cred *cred;
2220         int i, status;
2221
2222         dprintk("NFS: %s: testing '%s'\n", __func__, clp->cl_hostname);
2223
2224         clnt = clp->cl_rpcclient;
2225         i = 0;
2226
2227         mutex_lock(&nfs_clid_init_mutex);
2228 again:
2229         status  = -ENOENT;
2230         cred = nfs4_get_clid_cred(clp);
2231         if (cred == NULL)
2232                 goto out_unlock;
2233
2234         status = ops->detect_trunking(clp, result, cred);
2235         put_cred(cred);
2236         switch (status) {
2237         case 0:
2238         case -EINTR:
2239         case -ERESTARTSYS:
2240                 break;
2241         case -ETIMEDOUT:
2242                 if (clnt->cl_softrtry)
2243                         break;
2244                 /* Fall through */
2245         case -NFS4ERR_DELAY:
2246         case -EAGAIN:
2247                 ssleep(1);
2248                 /* Fall through */
2249         case -NFS4ERR_STALE_CLIENTID:
2250                 dprintk("NFS: %s after status %d, retrying\n",
2251                         __func__, status);
2252                 goto again;
2253         case -EACCES:
2254                 if (i++ == 0) {
2255                         nfs4_root_machine_cred(clp);
2256                         goto again;
2257                 }
2258                 if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX)
2259                         break;
2260                 /* Fall through */
2261         case -NFS4ERR_CLID_INUSE:
2262         case -NFS4ERR_WRONGSEC:
2263                 /* No point in retrying if we already used RPC_AUTH_UNIX */
2264                 if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX) {
2265                         status = -EPERM;
2266                         break;
2267                 }
2268                 clnt = rpc_clone_client_set_auth(clnt, RPC_AUTH_UNIX);
2269                 if (IS_ERR(clnt)) {
2270                         status = PTR_ERR(clnt);
2271                         break;
2272                 }
2273                 /* Note: this is safe because we haven't yet marked the
2274                  * client as ready, so we are the only user of
2275                  * clp->cl_rpcclient
2276                  */
2277                 clnt = xchg(&clp->cl_rpcclient, clnt);
2278                 rpc_shutdown_client(clnt);
2279                 clnt = clp->cl_rpcclient;
2280                 goto again;
2281
2282         case -NFS4ERR_MINOR_VERS_MISMATCH:
2283                 status = -EPROTONOSUPPORT;
2284                 break;
2285
2286         case -EKEYEXPIRED:
2287         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
2288                                  * in nfs4_exchange_id */
2289                 status = -EKEYEXPIRED;
2290                 break;
2291         default:
2292                 pr_warn("NFS: %s unhandled error %d. Exiting with error EIO\n",
2293                                 __func__, status);
2294                 status = -EIO;
2295         }
2296
2297 out_unlock:
2298         mutex_unlock(&nfs_clid_init_mutex);
2299         dprintk("NFS: %s: status = %d\n", __func__, status);
2300         return status;
2301 }
2302
2303 #ifdef CONFIG_NFS_V4_1
2304 void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
2305 {
2306         struct nfs_client *clp = session->clp;
2307
2308         switch (err) {
2309         default:
2310                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2311                 break;
2312         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
2313                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2314         }
2315         nfs4_schedule_state_manager(clp);
2316 }
2317 EXPORT_SYMBOL_GPL(nfs4_schedule_session_recovery);
2318
2319 void nfs41_notify_server(struct nfs_client *clp)
2320 {
2321         /* Use CHECK_LEASE to ping the server with a SEQUENCE */
2322         set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2323         nfs4_schedule_state_manager(clp);
2324 }
2325
2326 static void nfs4_reset_all_state(struct nfs_client *clp)
2327 {
2328         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2329                 set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2330                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2331                 nfs4_state_start_reclaim_nograce(clp);
2332                 dprintk("%s: scheduling reset of all state for server %s!\n",
2333                                 __func__, clp->cl_hostname);
2334                 nfs4_schedule_state_manager(clp);
2335         }
2336 }
2337
2338 static void nfs41_handle_server_reboot(struct nfs_client *clp)
2339 {
2340         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2341                 nfs4_state_start_reclaim_reboot(clp);
2342                 dprintk("%s: server %s rebooted!\n", __func__,
2343                                 clp->cl_hostname);
2344                 nfs4_schedule_state_manager(clp);
2345         }
2346 }
2347
2348 static void nfs41_handle_all_state_revoked(struct nfs_client *clp)
2349 {
2350         nfs4_reset_all_state(clp);
2351         dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2352 }
2353
2354 static void nfs41_handle_some_state_revoked(struct nfs_client *clp)
2355 {
2356         nfs4_state_start_reclaim_nograce(clp);
2357         nfs4_schedule_state_manager(clp);
2358
2359         dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2360 }
2361
2362 static void nfs41_handle_recallable_state_revoked(struct nfs_client *clp)
2363 {
2364         /* FIXME: For now, we destroy all layouts. */
2365         pnfs_destroy_all_layouts(clp);
2366         nfs_test_expired_all_delegations(clp);
2367         dprintk("%s: Recallable state revoked on server %s!\n", __func__,
2368                         clp->cl_hostname);
2369 }
2370
2371 static void nfs41_handle_backchannel_fault(struct nfs_client *clp)
2372 {
2373         set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2374         nfs4_schedule_state_manager(clp);
2375
2376         dprintk("%s: server %s declared a backchannel fault\n", __func__,
2377                         clp->cl_hostname);
2378 }
2379
2380 static void nfs41_handle_cb_path_down(struct nfs_client *clp)
2381 {
2382         if (test_and_set_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2383                 &clp->cl_state) == 0)
2384                 nfs4_schedule_state_manager(clp);
2385 }
2386
2387 void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags,
2388                 bool recovery)
2389 {
2390         if (!flags)
2391                 return;
2392
2393         dprintk("%s: \"%s\" (client ID %llx) flags=0x%08x\n",
2394                 __func__, clp->cl_hostname, clp->cl_clientid, flags);
2395         /*
2396          * If we're called from the state manager thread, then assume we're
2397          * already handling the RECLAIM_NEEDED and/or STATE_REVOKED.
2398          * Those flags are expected to remain set until we're done
2399          * recovering (see RFC5661, section 18.46.3).
2400          */
2401         if (recovery)
2402                 goto out_recovery;
2403
2404         if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED)
2405                 nfs41_handle_server_reboot(clp);
2406         if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED))
2407                 nfs41_handle_all_state_revoked(clp);
2408         if (flags & (SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED |
2409                             SEQ4_STATUS_ADMIN_STATE_REVOKED))
2410                 nfs41_handle_some_state_revoked(clp);
2411         if (flags & SEQ4_STATUS_LEASE_MOVED)
2412                 nfs4_schedule_lease_moved_recovery(clp);
2413         if (flags & SEQ4_STATUS_RECALLABLE_STATE_REVOKED)
2414                 nfs41_handle_recallable_state_revoked(clp);
2415 out_recovery:
2416         if (flags & SEQ4_STATUS_BACKCHANNEL_FAULT)
2417                 nfs41_handle_backchannel_fault(clp);
2418         else if (flags & (SEQ4_STATUS_CB_PATH_DOWN |
2419                                 SEQ4_STATUS_CB_PATH_DOWN_SESSION))
2420                 nfs41_handle_cb_path_down(clp);
2421 }
2422
2423 static int nfs4_reset_session(struct nfs_client *clp)
2424 {
2425         const struct cred *cred;
2426         int status;
2427
2428         if (!nfs4_has_session(clp))
2429                 return 0;
2430         status = nfs4_begin_drain_session(clp);
2431         if (status != 0)
2432                 return status;
2433         cred = nfs4_get_clid_cred(clp);
2434         status = nfs4_proc_destroy_session(clp->cl_session, cred);
2435         switch (status) {
2436         case 0:
2437         case -NFS4ERR_BADSESSION:
2438         case -NFS4ERR_DEADSESSION:
2439                 break;
2440         case -NFS4ERR_BACK_CHAN_BUSY:
2441         case -NFS4ERR_DELAY:
2442                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2443                 status = 0;
2444                 ssleep(1);
2445                 goto out;
2446         default:
2447                 status = nfs4_recovery_handle_error(clp, status);
2448                 goto out;
2449         }
2450
2451         memset(clp->cl_session->sess_id.data, 0, NFS4_MAX_SESSIONID_LEN);
2452         status = nfs4_proc_create_session(clp, cred);
2453         if (status) {
2454                 dprintk("%s: session reset failed with status %d for server %s!\n",
2455                         __func__, status, clp->cl_hostname);
2456                 status = nfs4_handle_reclaim_lease_error(clp, status);
2457                 goto out;
2458         }
2459         nfs41_finish_session_reset(clp);
2460         dprintk("%s: session reset was successful for server %s!\n",
2461                         __func__, clp->cl_hostname);
2462 out:
2463         put_cred(cred);
2464         return status;
2465 }
2466
2467 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2468 {
2469         const struct cred *cred;
2470         int ret;
2471
2472         if (!nfs4_has_session(clp))
2473                 return 0;
2474         ret = nfs4_begin_drain_session(clp);
2475         if (ret != 0)
2476                 return ret;
2477         cred = nfs4_get_clid_cred(clp);
2478         ret = nfs4_proc_bind_conn_to_session(clp, cred);
2479         put_cred(cred);
2480         clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2481         switch (ret) {
2482         case 0:
2483                 dprintk("%s: bind_conn_to_session was successful for server %s!\n",
2484                         __func__, clp->cl_hostname);
2485                 break;
2486         case -NFS4ERR_DELAY:
2487                 ssleep(1);
2488                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2489                 break;
2490         default:
2491                 return nfs4_recovery_handle_error(clp, ret);
2492         }
2493         return 0;
2494 }
2495 #else /* CONFIG_NFS_V4_1 */
2496 static int nfs4_reset_session(struct nfs_client *clp) { return 0; }
2497
2498 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2499 {
2500         return 0;
2501 }
2502 #endif /* CONFIG_NFS_V4_1 */
2503
2504 static void nfs4_state_manager(struct nfs_client *clp)
2505 {
2506         int status = 0;
2507         const char *section = "", *section_sep = "";
2508
2509         /* Ensure exclusive access to NFSv4 state */
2510         do {
2511                 clear_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2512                 if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
2513                         section = "purge state";
2514                         status = nfs4_purge_lease(clp);
2515                         if (status < 0)
2516                                 goto out_error;
2517                         continue;
2518                 }
2519
2520                 if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
2521                         section = "lease expired";
2522                         /* We're going to have to re-establish a clientid */
2523                         status = nfs4_reclaim_lease(clp);
2524                         if (status < 0)
2525                                 goto out_error;
2526                         continue;
2527                 }
2528
2529                 /* Initialize or reset the session */
2530                 if (test_and_clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state)) {
2531                         section = "reset session";
2532                         status = nfs4_reset_session(clp);
2533                         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
2534                                 continue;
2535                         if (status < 0)
2536                                 goto out_error;
2537                 }
2538
2539                 /* Send BIND_CONN_TO_SESSION */
2540                 if (test_and_clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2541                                 &clp->cl_state)) {
2542                         section = "bind conn to session";
2543                         status = nfs4_bind_conn_to_session(clp);
2544                         if (status < 0)
2545                                 goto out_error;
2546                         continue;
2547                 }
2548
2549                 if (test_and_clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state)) {
2550                         section = "check lease";
2551                         status = nfs4_check_lease(clp);
2552                         if (status < 0)
2553                                 goto out_error;
2554                         continue;
2555                 }
2556
2557                 if (test_and_clear_bit(NFS4CLNT_MOVED, &clp->cl_state)) {
2558                         section = "migration";
2559                         status = nfs4_handle_migration(clp);
2560                         if (status < 0)
2561                                 goto out_error;
2562                 }
2563
2564                 if (test_and_clear_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state)) {
2565                         section = "lease moved";
2566                         status = nfs4_handle_lease_moved(clp);
2567                         if (status < 0)
2568                                 goto out_error;
2569                 }
2570
2571                 /* First recover reboot state... */
2572                 if (test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {
2573                         section = "reclaim reboot";
2574                         status = nfs4_do_reclaim(clp,
2575                                 clp->cl_mvops->reboot_recovery_ops);
2576                         if (status == -EAGAIN)
2577                                 continue;
2578                         if (status < 0)
2579                                 goto out_error;
2580                         nfs4_state_end_reclaim_reboot(clp);
2581                 }
2582
2583                 /* Detect expired delegations... */
2584                 if (test_and_clear_bit(NFS4CLNT_DELEGATION_EXPIRED, &clp->cl_state)) {
2585                         section = "detect expired delegations";
2586                         nfs_reap_expired_delegations(clp);
2587                         continue;
2588                 }
2589
2590                 /* Now recover expired state... */
2591                 if (test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state)) {
2592                         section = "reclaim nograce";
2593                         status = nfs4_do_reclaim(clp,
2594                                 clp->cl_mvops->nograce_recovery_ops);
2595                         if (status == -EAGAIN)
2596                                 continue;
2597                         if (status < 0)
2598                                 goto out_error;
2599                         clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
2600                 }
2601
2602                 nfs4_end_drain_session(clp);
2603                 nfs4_clear_state_manager_bit(clp);
2604
2605                 if (!test_and_set_bit(NFS4CLNT_DELEGRETURN_RUNNING, &clp->cl_state)) {
2606                         if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
2607                                 nfs_client_return_marked_delegations(clp);
2608                                 set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2609                         }
2610                         clear_bit(NFS4CLNT_DELEGRETURN_RUNNING, &clp->cl_state);
2611                 }
2612
2613                 /* Did we race with an attempt to give us more work? */
2614                 if (!test_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state))
2615                         return;
2616                 if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
2617                         return;
2618         } while (refcount_read(&clp->cl_count) > 1 && !signalled());
2619         goto out_drain;
2620
2621 out_error:
2622         if (strlen(section))
2623                 section_sep = ": ";
2624         pr_warn_ratelimited("NFS: state manager%s%s failed on NFSv4 server %s"
2625                         " with error %d\n", section_sep, section,
2626                         clp->cl_hostname, -status);
2627         ssleep(1);
2628 out_drain:
2629         nfs4_end_drain_session(clp);
2630         nfs4_clear_state_manager_bit(clp);
2631 }
2632
2633 static int nfs4_run_state_manager(void *ptr)
2634 {
2635         struct nfs_client *clp = ptr;
2636
2637         allow_signal(SIGKILL);
2638         nfs4_state_manager(clp);
2639         nfs_put_client(clp);
2640         module_put_and_exit(0);
2641         return 0;
2642 }
2643
2644 /*
2645  * Local variables:
2646  *  c-basic-offset: 8
2647  * End:
2648  */