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/nfs_idmap.h>
  46 #include <linux/kthread.h>
  47 #include <linux/module.h>
  48 #include <linux/random.h>
  49 #include <linux/ratelimit.h>
  50 #include <linux/workqueue.h>
  51 #include <linux/bitops.h>
  52 #include <linux/jiffies.h>
  53
  54 #include <linux/sunrpc/clnt.h>
  55
  56 #include "nfs4_fs.h"
  57 #include "callback.h"
  58 #include "delegation.h"
  59 #include "internal.h"
  60 #include "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 static DEFINE_MUTEX(nfs_clid_init_mutex);
  70
  71 int nfs4_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
  72 {
  73         struct nfs4_setclientid_res clid = {
  74                 .clientid = clp->cl_clientid,
  75                 .confirm = clp->cl_confirm,
  76         };
  77         unsigned short port;
  78         int status;
  79         struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
  80
  81         if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
  82                 goto do_confirm;
  83         port = nn->nfs_callback_tcpport;
  84         if (clp->cl_addr.ss_family == AF_INET6)
  85                 port = nn->nfs_callback_tcpport6;
  86
  87         status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
  88         if (status != 0)
  89                 goto out;
  90         clp->cl_clientid = clid.clientid;
  91         clp->cl_confirm = clid.confirm;
  92         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
  93 do_confirm:
  94         status = nfs4_proc_setclientid_confirm(clp, &clid, cred);
  95         if (status != 0)
  96                 goto out;
  97         clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
  98         nfs4_schedule_state_renewal(clp);
  99 out:
 100         return status;
 101 }
 102
 103 /**
 104  * nfs40_discover_server_trunking - Detect server IP address trunking (mv0)
 105  *
 106  * @clp: nfs_client under test
 107  * @result: OUT: found nfs_client, or clp
 108  * @cred: credential to use for trunking test
 109  *
 110  * Returns zero, a negative errno, or a negative NFS4ERR status.
 111  * If zero is returned, an nfs_client pointer is planted in
 112  * "result".
 113  *
 114  * Note: The returned client may not yet be marked ready.
 115  */
 116 int nfs40_discover_server_trunking(struct nfs_client *clp,
 117                                    struct nfs_client **result,
 118                                    struct rpc_cred *cred)
 119 {
 120         struct nfs4_setclientid_res clid = {
 121                 .clientid = clp->cl_clientid,
 122                 .confirm = clp->cl_confirm,
 123         };
 124         struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
 125         unsigned short port;
 126         int status;
 127
 128         port = nn->nfs_callback_tcpport;
 129         if (clp->cl_addr.ss_family == AF_INET6)
 130                 port = nn->nfs_callback_tcpport6;
 131
 132         status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
 133         if (status != 0)
 134                 goto out;
 135         clp->cl_clientid = clid.clientid;
 136         clp->cl_confirm = clid.confirm;
 137
 138         status = nfs40_walk_client_list(clp, result, cred);
 139         if (status == 0) {
 140                 /* Sustain the lease, even if it's empty.  If the clientid4
 141                  * goes stale it's of no use for trunking discovery. */
 142                 nfs4_schedule_state_renewal(*result);
 143         }
 144 out:
 145         return status;
 146 }
 147
 148 struct rpc_cred *nfs4_get_machine_cred_locked(struct nfs_client *clp)
 149 {
 150         struct rpc_cred *cred = NULL;
 151
 152         if (clp->cl_machine_cred != NULL)
 153                 cred = get_rpccred(clp->cl_machine_cred);
 154         return cred;
 155 }
 156
 157 static void nfs4_clear_machine_cred(struct nfs_client *clp)
 158 {
 159         struct rpc_cred *cred;
 160
 161         spin_lock(&clp->cl_lock);
 162         cred = clp->cl_machine_cred;
 163         clp->cl_machine_cred = NULL;
 164         spin_unlock(&clp->cl_lock);
 165         if (cred != NULL)
 166                 put_rpccred(cred);
 167 }
 168
 169 static struct rpc_cred *
 170 nfs4_get_renew_cred_server_locked(struct nfs_server *server)
 171 {
 172         struct rpc_cred *cred = NULL;
 173         struct nfs4_state_owner *sp;
 174         struct rb_node *pos;
 175
 176         for (pos = rb_first(&server->state_owners);
 177              pos != NULL;
 178              pos = rb_next(pos)) {
 179                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
 180                 if (list_empty(&sp->so_states))
 181                         continue;
 182                 cred = get_rpccred(sp->so_cred);
 183                 break;
 184         }
 185         return cred;
 186 }
 187
 188 /**
 189  * nfs4_get_renew_cred_locked - Acquire credential for a renew operation
 190  * @clp: client state handle
 191  *
 192  * Returns an rpc_cred with reference count bumped, or NULL.
 193  * Caller must hold clp->cl_lock.
 194  */
 195 struct rpc_cred *nfs4_get_renew_cred_locked(struct nfs_client *clp)
 196 {
 197         struct rpc_cred *cred = NULL;
 198         struct nfs_server *server;
 199
 200         /* Use machine credentials if available */
 201         cred = nfs4_get_machine_cred_locked(clp);
 202         if (cred != NULL)
 203                 goto out;
 204
 205         rcu_read_lock();
 206         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 207                 cred = nfs4_get_renew_cred_server_locked(server);
 208                 if (cred != NULL)
 209                         break;
 210         }
 211         rcu_read_unlock();
 212
 213 out:
 214         return cred;
 215 }
 216
 217 #if defined(CONFIG_NFS_V4_1)
 218
 219 static int nfs41_setup_state_renewal(struct nfs_client *clp)
 220 {
 221         int status;
 222         struct nfs_fsinfo fsinfo;
 223
 224         if (!test_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state)) {
 225                 nfs4_schedule_state_renewal(clp);
 226                 return 0;
 227         }
 228
 229         status = nfs4_proc_get_lease_time(clp, &fsinfo);
 230         if (status == 0) {
 231                 /* Update lease time and schedule renewal */
 232                 spin_lock(&clp->cl_lock);
 233                 clp->cl_lease_time = fsinfo.lease_time * HZ;
 234                 clp->cl_last_renewal = jiffies;
 235                 spin_unlock(&clp->cl_lock);
 236
 237                 nfs4_schedule_state_renewal(clp);
 238         }
 239
 240         return status;
 241 }
 242
 243 /*
 244  * Back channel returns NFS4ERR_DELAY for new requests when
 245  * NFS4_SESSION_DRAINING is set so there is no work to be done when draining
 246  * is ended.
 247  */
 248 static void nfs4_end_drain_session(struct nfs_client *clp)
 249 {
 250         struct nfs4_session *ses = clp->cl_session;
 251         struct nfs4_slot_table *tbl;
 252
 253         if (ses == NULL)
 254                 return;
 255         tbl = &ses->fc_slot_table;
 256         if (test_and_clear_bit(NFS4_SESSION_DRAINING, &ses->session_state)) {
 257                 spin_lock(&tbl->slot_tbl_lock);
 258                 nfs41_wake_slot_table(tbl);
 259                 spin_unlock(&tbl->slot_tbl_lock);
 260         }
 261 }
 262
 263 /*
 264  * Signal state manager thread if session fore channel is drained
 265  */
 266 void nfs4_session_drain_complete(struct nfs4_session *session,
 267                 struct nfs4_slot_table *tbl)
 268 {
 269         if (nfs4_session_draining(session))
 270                 complete(&tbl->complete);
 271 }
 272
 273 static int nfs4_wait_on_slot_tbl(struct nfs4_slot_table *tbl)
 274 {
 275         spin_lock(&tbl->slot_tbl_lock);
 276         if (tbl->highest_used_slotid != NFS4_NO_SLOT) {
 277                 INIT_COMPLETION(tbl->complete);
 278                 spin_unlock(&tbl->slot_tbl_lock);
 279                 return wait_for_completion_interruptible(&tbl->complete);
 280         }
 281         spin_unlock(&tbl->slot_tbl_lock);
 282         return 0;
 283 }
 284
 285 static int nfs4_begin_drain_session(struct nfs_client *clp)
 286 {
 287         struct nfs4_session *ses = clp->cl_session;
 288         int ret = 0;
 289
 290         set_bit(NFS4_SESSION_DRAINING, &ses->session_state);
 291         /* back channel */
 292         ret = nfs4_wait_on_slot_tbl(&ses->bc_slot_table);
 293         if (ret)
 294                 return ret;
 295         /* fore channel */
 296         return nfs4_wait_on_slot_tbl(&ses->fc_slot_table);
 297 }
 298
 299 static void nfs41_finish_session_reset(struct nfs_client *clp)
 300 {
 301         clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 302         clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
 303         /* create_session negotiated new slot table */
 304         clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
 305         nfs41_setup_state_renewal(clp);
 306 }
 307
 308 int nfs41_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
 309 {
 310         int status;
 311
 312         if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
 313                 goto do_confirm;
 314         nfs4_begin_drain_session(clp);
 315         status = nfs4_proc_exchange_id(clp, cred);
 316         if (status != 0)
 317                 goto out;
 318         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 319 do_confirm:
 320         status = nfs4_proc_create_session(clp, cred);
 321         if (status != 0)
 322                 goto out;
 323         nfs41_finish_session_reset(clp);
 324         nfs_mark_client_ready(clp, NFS_CS_READY);
 325 out:
 326         return status;
 327 }
 328
 329 /**
 330  * nfs41_discover_server_trunking - Detect server IP address trunking (mv1)
 331  *
 332  * @clp: nfs_client under test
 333  * @result: OUT: found nfs_client, or clp
 334  * @cred: credential to use for trunking test
 335  *
 336  * Returns NFS4_OK, a negative errno, or a negative NFS4ERR status.
 337  * If NFS4_OK is returned, an nfs_client pointer is planted in
 338  * "result".
 339  *
 340  * Note: The returned client may not yet be marked ready.
 341  */
 342 int nfs41_discover_server_trunking(struct nfs_client *clp,
 343                                    struct nfs_client **result,
 344                                    struct rpc_cred *cred)
 345 {
 346         int status;
 347
 348         status = nfs4_proc_exchange_id(clp, cred);
 349         if (status != NFS4_OK)
 350                 return status;
 351         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 352
 353         return nfs41_walk_client_list(clp, result, cred);
 354 }
 355
 356 struct rpc_cred *nfs4_get_exchange_id_cred(struct nfs_client *clp)
 357 {
 358         struct rpc_cred *cred;
 359
 360         spin_lock(&clp->cl_lock);
 361         cred = nfs4_get_machine_cred_locked(clp);
 362         spin_unlock(&clp->cl_lock);
 363         return cred;
 364 }
 365
 366 #endif /* CONFIG_NFS_V4_1 */
 367
 368 static struct rpc_cred *
 369 nfs4_get_setclientid_cred_server(struct nfs_server *server)
 370 {
 371         struct nfs_client *clp = server->nfs_client;
 372         struct rpc_cred *cred = NULL;
 373         struct nfs4_state_owner *sp;
 374         struct rb_node *pos;
 375
 376         spin_lock(&clp->cl_lock);
 377         pos = rb_first(&server->state_owners);
 378         if (pos != NULL) {
 379                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
 380                 cred = get_rpccred(sp->so_cred);
 381         }
 382         spin_unlock(&clp->cl_lock);
 383         return cred;
 384 }
 385
 386 /**
 387  * nfs4_get_setclientid_cred - Acquire credential for a setclientid operation
 388  * @clp: client state handle
 389  *
 390  * Returns an rpc_cred with reference count bumped, or NULL.
 391  */
 392 struct rpc_cred *nfs4_get_setclientid_cred(struct nfs_client *clp)
 393 {
 394         struct nfs_server *server;
 395         struct rpc_cred *cred;
 396
 397         spin_lock(&clp->cl_lock);
 398         cred = nfs4_get_machine_cred_locked(clp);
 399         spin_unlock(&clp->cl_lock);
 400         if (cred != NULL)
 401                 goto out;
 402
 403         rcu_read_lock();
 404         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 405                 cred = nfs4_get_setclientid_cred_server(server);
 406                 if (cred != NULL)
 407                         break;
 408         }
 409         rcu_read_unlock();
 410
 411 out:
 412         return cred;
 413 }
 414
 415 static struct nfs4_state_owner *
 416 nfs4_find_state_owner_locked(struct nfs_server *server, struct rpc_cred *cred)
 417 {
 418         struct rb_node **p = &server->state_owners.rb_node,
 419                        *parent = NULL;
 420         struct nfs4_state_owner *sp;
 421
 422         while (*p != NULL) {
 423                 parent = *p;
 424                 sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
 425
 426                 if (cred < sp->so_cred)
 427                         p = &parent->rb_left;
 428                 else if (cred > sp->so_cred)
 429                         p = &parent->rb_right;
 430                 else {
 431                         if (!list_empty(&sp->so_lru))
 432                                 list_del_init(&sp->so_lru);
 433                         atomic_inc(&sp->so_count);
 434                         return sp;
 435                 }
 436         }
 437         return NULL;
 438 }
 439
 440 static struct nfs4_state_owner *
 441 nfs4_insert_state_owner_locked(struct nfs4_state_owner *new)
 442 {
 443         struct nfs_server *server = new->so_server;
 444         struct rb_node **p = &server->state_owners.rb_node,
 445                        *parent = NULL;
 446         struct nfs4_state_owner *sp;
 447         int err;
 448
 449         while (*p != NULL) {
 450                 parent = *p;
 451                 sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
 452
 453                 if (new->so_cred < sp->so_cred)
 454                         p = &parent->rb_left;
 455                 else if (new->so_cred > sp->so_cred)
 456                         p = &parent->rb_right;
 457                 else {
 458                         if (!list_empty(&sp->so_lru))
 459                                 list_del_init(&sp->so_lru);
 460                         atomic_inc(&sp->so_count);
 461                         return sp;
 462                 }
 463         }
 464         err = ida_get_new(&server->openowner_id, &new->so_seqid.owner_id);
 465         if (err)
 466                 return ERR_PTR(err);
 467         rb_link_node(&new->so_server_node, parent, p);
 468         rb_insert_color(&new->so_server_node, &server->state_owners);
 469         return new;
 470 }
 471
 472 static void
 473 nfs4_remove_state_owner_locked(struct nfs4_state_owner *sp)
 474 {
 475         struct nfs_server *server = sp->so_server;
 476
 477         if (!RB_EMPTY_NODE(&sp->so_server_node))
 478                 rb_erase(&sp->so_server_node, &server->state_owners);
 479         ida_remove(&server->openowner_id, sp->so_seqid.owner_id);
 480 }
 481
 482 static void
 483 nfs4_init_seqid_counter(struct nfs_seqid_counter *sc)
 484 {
 485         sc->create_time = ktime_get();
 486         sc->flags = 0;
 487         sc->counter = 0;
 488         spin_lock_init(&sc->lock);
 489         INIT_LIST_HEAD(&sc->list);
 490         rpc_init_wait_queue(&sc->wait, "Seqid_waitqueue");
 491 }
 492
 493 static void
 494 nfs4_destroy_seqid_counter(struct nfs_seqid_counter *sc)
 495 {
 496         rpc_destroy_wait_queue(&sc->wait);
 497 }
 498
 499 /*
 500  * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
 501  * create a new state_owner.
 502  *
 503  */
 504 static struct nfs4_state_owner *
 505 nfs4_alloc_state_owner(struct nfs_server *server,
 506                 struct rpc_cred *cred,
 507                 gfp_t gfp_flags)
 508 {
 509         struct nfs4_state_owner *sp;
 510
 511         sp = kzalloc(sizeof(*sp), gfp_flags);
 512         if (!sp)
 513                 return NULL;
 514         sp->so_server = server;
 515         sp->so_cred = get_rpccred(cred);
 516         spin_lock_init(&sp->so_lock);
 517         INIT_LIST_HEAD(&sp->so_states);
 518         nfs4_init_seqid_counter(&sp->so_seqid);
 519         atomic_set(&sp->so_count, 1);
 520         INIT_LIST_HEAD(&sp->so_lru);
 521         seqcount_init(&sp->so_reclaim_seqcount);
 522         mutex_init(&sp->so_delegreturn_mutex);
 523         return sp;
 524 }
 525
 526 static void
 527 nfs4_drop_state_owner(struct nfs4_state_owner *sp)
 528 {
 529         struct rb_node *rb_node = &sp->so_server_node;
 530
 531         if (!RB_EMPTY_NODE(rb_node)) {
 532                 struct nfs_server *server = sp->so_server;
 533                 struct nfs_client *clp = server->nfs_client;
 534
 535                 spin_lock(&clp->cl_lock);
 536                 if (!RB_EMPTY_NODE(rb_node)) {
 537                         rb_erase(rb_node, &server->state_owners);
 538                         RB_CLEAR_NODE(rb_node);
 539                 }
 540                 spin_unlock(&clp->cl_lock);
 541         }
 542 }
 543
 544 static void nfs4_free_state_owner(struct nfs4_state_owner *sp)
 545 {
 546         nfs4_destroy_seqid_counter(&sp->so_seqid);
 547         put_rpccred(sp->so_cred);
 548         kfree(sp);
 549 }
 550
 551 static void nfs4_gc_state_owners(struct nfs_server *server)
 552 {
 553         struct nfs_client *clp = server->nfs_client;
 554         struct nfs4_state_owner *sp, *tmp;
 555         unsigned long time_min, time_max;
 556         LIST_HEAD(doomed);
 557
 558         spin_lock(&clp->cl_lock);
 559         time_max = jiffies;
 560         time_min = (long)time_max - (long)clp->cl_lease_time;
 561         list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
 562                 /* NB: LRU is sorted so that oldest is at the head */
 563                 if (time_in_range(sp->so_expires, time_min, time_max))
 564                         break;
 565                 list_move(&sp->so_lru, &doomed);
 566                 nfs4_remove_state_owner_locked(sp);
 567         }
 568         spin_unlock(&clp->cl_lock);
 569
 570         list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
 571                 list_del(&sp->so_lru);
 572                 nfs4_free_state_owner(sp);
 573         }
 574 }
 575
 576 /**
 577  * nfs4_get_state_owner - Look up a state owner given a credential
 578  * @server: nfs_server to search
 579  * @cred: RPC credential to match
 580  *
 581  * Returns a pointer to an instantiated nfs4_state_owner struct, or NULL.
 582  */
 583 struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server,
 584                                               struct rpc_cred *cred,
 585                                               gfp_t gfp_flags)
 586 {
 587         struct nfs_client *clp = server->nfs_client;
 588         struct nfs4_state_owner *sp, *new;
 589
 590         spin_lock(&clp->cl_lock);
 591         sp = nfs4_find_state_owner_locked(server, cred);
 592         spin_unlock(&clp->cl_lock);
 593         if (sp != NULL)
 594                 goto out;
 595         new = nfs4_alloc_state_owner(server, cred, gfp_flags);
 596         if (new == NULL)
 597                 goto out;
 598         do {
 599                 if (ida_pre_get(&server->openowner_id, gfp_flags) == 0)
 600                         break;
 601                 spin_lock(&clp->cl_lock);
 602                 sp = nfs4_insert_state_owner_locked(new);
 603                 spin_unlock(&clp->cl_lock);
 604         } while (sp == ERR_PTR(-EAGAIN));
 605         if (sp != new)
 606                 nfs4_free_state_owner(new);
 607 out:
 608         nfs4_gc_state_owners(server);
 609         return sp;
 610 }
 611
 612 /**
 613  * nfs4_put_state_owner - Release a nfs4_state_owner
 614  * @sp: state owner data to release
 615  *
 616  * Note that we keep released state owners on an LRU
 617  * list.
 618  * This caches valid state owners so that they can be
 619  * reused, to avoid the OPEN_CONFIRM on minor version 0.
 620  * It also pins the uniquifier of dropped state owners for
 621  * a while, to ensure that those state owner names are
 622  * never reused.
 623  */
 624 void nfs4_put_state_owner(struct nfs4_state_owner *sp)
 625 {
 626         struct nfs_server *server = sp->so_server;
 627         struct nfs_client *clp = server->nfs_client;
 628
 629         if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
 630                 return;
 631
 632         sp->so_expires = jiffies;
 633         list_add_tail(&sp->so_lru, &server->state_owners_lru);
 634         spin_unlock(&clp->cl_lock);
 635 }
 636
 637 /**
 638  * nfs4_purge_state_owners - Release all cached state owners
 639  * @server: nfs_server with cached state owners to release
 640  *
 641  * Called at umount time.  Remaining state owners will be on
 642  * the LRU with ref count of zero.
 643  */
 644 void nfs4_purge_state_owners(struct nfs_server *server)
 645 {
 646         struct nfs_client *clp = server->nfs_client;
 647         struct nfs4_state_owner *sp, *tmp;
 648         LIST_HEAD(doomed);
 649
 650         spin_lock(&clp->cl_lock);
 651         list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
 652                 list_move(&sp->so_lru, &doomed);
 653                 nfs4_remove_state_owner_locked(sp);
 654         }
 655         spin_unlock(&clp->cl_lock);
 656
 657         list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
 658                 list_del(&sp->so_lru);
 659                 nfs4_free_state_owner(sp);
 660         }
 661 }
 662
 663 static struct nfs4_state *
 664 nfs4_alloc_open_state(void)
 665 {
 666         struct nfs4_state *state;
 667
 668         state = kzalloc(sizeof(*state), GFP_NOFS);
 669         if (!state)
 670                 return NULL;
 671         atomic_set(&state->count, 1);
 672         INIT_LIST_HEAD(&state->lock_states);
 673         spin_lock_init(&state->state_lock);
 674         seqlock_init(&state->seqlock);
 675         return state;
 676 }
 677
 678 void
 679 nfs4_state_set_mode_locked(struct nfs4_state *state, fmode_t fmode)
 680 {
 681         if (state->state == fmode)
 682                 return;
 683         /* NB! List reordering - see the reclaim code for why.  */
 684         if ((fmode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
 685                 if (fmode & FMODE_WRITE)
 686                         list_move(&state->open_states, &state->owner->so_states);
 687                 else
 688                         list_move_tail(&state->open_states, &state->owner->so_states);
 689         }
 690         state->state = fmode;
 691 }
 692
 693 static struct nfs4_state *
 694 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
 695 {
 696         struct nfs_inode *nfsi = NFS_I(inode);
 697         struct nfs4_state *state;
 698
 699         list_for_each_entry(state, &nfsi->open_states, inode_states) {
 700                 if (state->owner != owner)
 701                         continue;
 702                 if (!nfs4_valid_open_stateid(state))
 703                         continue;
 704                 if (atomic_inc_not_zero(&state->count))
 705                         return state;
 706         }
 707         return NULL;
 708 }
 709
 710 static void
 711 nfs4_free_open_state(struct nfs4_state *state)
 712 {
 713         kfree(state);
 714 }
 715
 716 struct nfs4_state *
 717 nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
 718 {
 719         struct nfs4_state *state, *new;
 720         struct nfs_inode *nfsi = NFS_I(inode);
 721
 722         spin_lock(&inode->i_lock);
 723         state = __nfs4_find_state_byowner(inode, owner);
 724         spin_unlock(&inode->i_lock);
 725         if (state)
 726                 goto out;
 727         new = nfs4_alloc_open_state();
 728         spin_lock(&owner->so_lock);
 729         spin_lock(&inode->i_lock);
 730         state = __nfs4_find_state_byowner(inode, owner);
 731         if (state == NULL && new != NULL) {
 732                 state = new;
 733                 state->owner = owner;
 734                 atomic_inc(&owner->so_count);
 735                 list_add(&state->inode_states, &nfsi->open_states);
 736                 ihold(inode);
 737                 state->inode = inode;
 738                 spin_unlock(&inode->i_lock);
 739                 /* Note: The reclaim code dictates that we add stateless
 740                  * and read-only stateids to the end of the list */
 741                 list_add_tail(&state->open_states, &owner->so_states);
 742                 spin_unlock(&owner->so_lock);
 743         } else {
 744                 spin_unlock(&inode->i_lock);
 745                 spin_unlock(&owner->so_lock);
 746                 if (new)
 747                         nfs4_free_open_state(new);
 748         }
 749 out:
 750         return state;
 751 }
 752
 753 void nfs4_put_open_state(struct nfs4_state *state)
 754 {
 755         struct inode *inode = state->inode;
 756         struct nfs4_state_owner *owner = state->owner;
 757
 758         if (!atomic_dec_and_lock(&state->count, &owner->so_lock))
 759                 return;
 760         spin_lock(&inode->i_lock);
 761         list_del(&state->inode_states);
 762         list_del(&state->open_states);
 763         spin_unlock(&inode->i_lock);
 764         spin_unlock(&owner->so_lock);
 765         iput(inode);
 766         nfs4_free_open_state(state);
 767         nfs4_put_state_owner(owner);
 768 }
 769
 770 /*
 771  * Close the current file.
 772  */
 773 static void __nfs4_close(struct nfs4_state *state,
 774                 fmode_t fmode, gfp_t gfp_mask, int wait)
 775 {
 776         struct nfs4_state_owner *owner = state->owner;
 777         int call_close = 0;
 778         fmode_t newstate;
 779
 780         atomic_inc(&owner->so_count);
 781         /* Protect against nfs4_find_state() */
 782         spin_lock(&owner->so_lock);
 783         switch (fmode & (FMODE_READ | FMODE_WRITE)) {
 784                 case FMODE_READ:
 785                         state->n_rdonly--;
 786                         break;
 787                 case FMODE_WRITE:
 788                         state->n_wronly--;
 789                         break;
 790                 case FMODE_READ|FMODE_WRITE:
 791                         state->n_rdwr--;
 792         }
 793         newstate = FMODE_READ|FMODE_WRITE;
 794         if (state->n_rdwr == 0) {
 795                 if (state->n_rdonly == 0) {
 796                         newstate &= ~FMODE_READ;
 797                         call_close |= test_bit(NFS_O_RDONLY_STATE, &state->flags);
 798                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
 799                 }
 800                 if (state->n_wronly == 0) {
 801                         newstate &= ~FMODE_WRITE;
 802                         call_close |= test_bit(NFS_O_WRONLY_STATE, &state->flags);
 803                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
 804                 }
 805                 if (newstate == 0)
 806                         clear_bit(NFS_DELEGATED_STATE, &state->flags);
 807         }
 808         nfs4_state_set_mode_locked(state, newstate);
 809         spin_unlock(&owner->so_lock);
 810
 811         if (!call_close) {
 812                 nfs4_put_open_state(state);
 813                 nfs4_put_state_owner(owner);
 814         } else
 815                 nfs4_do_close(state, gfp_mask, wait);
 816 }
 817
 818 void nfs4_close_state(struct nfs4_state *state, fmode_t fmode)
 819 {
 820         __nfs4_close(state, fmode, GFP_NOFS, 0);
 821 }
 822
 823 void nfs4_close_sync(struct nfs4_state *state, fmode_t fmode)
 824 {
 825         __nfs4_close(state, fmode, GFP_KERNEL, 1);
 826 }
 827
 828 /*
 829  * Search the state->lock_states for an existing lock_owner
 830  * that is compatible with current->files
 831  */
 832 static struct nfs4_lock_state *
 833 __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner, pid_t fl_pid, unsigned int type)
 834 {
 835         struct nfs4_lock_state *pos;
 836         list_for_each_entry(pos, &state->lock_states, ls_locks) {
 837                 if (type != NFS4_ANY_LOCK_TYPE && pos->ls_owner.lo_type != type)
 838                         continue;
 839                 switch (pos->ls_owner.lo_type) {
 840                 case NFS4_POSIX_LOCK_TYPE:
 841                         if (pos->ls_owner.lo_u.posix_owner != fl_owner)
 842                                 continue;
 843                         break;
 844                 case NFS4_FLOCK_LOCK_TYPE:
 845                         if (pos->ls_owner.lo_u.flock_owner != fl_pid)
 846                                 continue;
 847                 }
 848                 atomic_inc(&pos->ls_count);
 849                 return pos;
 850         }
 851         return NULL;
 852 }
 853
 854 /*
 855  * Return a compatible lock_state. If no initialized lock_state structure
 856  * exists, return an uninitialized one.
 857  *
 858  */
 859 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner, pid_t fl_pid, unsigned int type)
 860 {
 861         struct nfs4_lock_state *lsp;
 862         struct nfs_server *server = state->owner->so_server;
 863
 864         lsp = kzalloc(sizeof(*lsp), GFP_NOFS);
 865         if (lsp == NULL)
 866                 return NULL;
 867         nfs4_init_seqid_counter(&lsp->ls_seqid);
 868         atomic_set(&lsp->ls_count, 1);
 869         lsp->ls_state = state;
 870         lsp->ls_owner.lo_type = type;
 871         switch (lsp->ls_owner.lo_type) {
 872         case NFS4_FLOCK_LOCK_TYPE:
 873                 lsp->ls_owner.lo_u.flock_owner = fl_pid;
 874                 break;
 875         case NFS4_POSIX_LOCK_TYPE:
 876                 lsp->ls_owner.lo_u.posix_owner = fl_owner;
 877                 break;
 878         default:
 879                 goto out_free;
 880         }
 881         lsp->ls_seqid.owner_id = ida_simple_get(&server->lockowner_id, 0, 0, GFP_NOFS);
 882         if (lsp->ls_seqid.owner_id < 0)
 883                 goto out_free;
 884         INIT_LIST_HEAD(&lsp->ls_locks);
 885         return lsp;
 886 out_free:
 887         kfree(lsp);
 888         return NULL;
 889 }
 890
 891 void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp)
 892 {
 893         ida_simple_remove(&server->lockowner_id, lsp->ls_seqid.owner_id);
 894         nfs4_destroy_seqid_counter(&lsp->ls_seqid);
 895         kfree(lsp);
 896 }
 897
 898 /*
 899  * Return a compatible lock_state. If no initialized lock_state structure
 900  * exists, return an uninitialized one.
 901  *
 902  */
 903 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner, pid_t pid, unsigned int type)
 904 {
 905         struct nfs4_lock_state *lsp, *new = NULL;
 906
 907         for(;;) {
 908                 spin_lock(&state->state_lock);
 909                 lsp = __nfs4_find_lock_state(state, owner, pid, type);
 910                 if (lsp != NULL)
 911                         break;
 912                 if (new != NULL) {
 913                         list_add(&new->ls_locks, &state->lock_states);
 914                         set_bit(LK_STATE_IN_USE, &state->flags);
 915                         lsp = new;
 916                         new = NULL;
 917                         break;
 918                 }
 919                 spin_unlock(&state->state_lock);
 920                 new = nfs4_alloc_lock_state(state, owner, pid, type);
 921                 if (new == NULL)
 922                         return NULL;
 923         }
 924         spin_unlock(&state->state_lock);
 925         if (new != NULL)
 926                 nfs4_free_lock_state(state->owner->so_server, new);
 927         return lsp;
 928 }
 929
 930 /*
 931  * Release reference to lock_state, and free it if we see that
 932  * it is no longer in use
 933  */
 934 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
 935 {
 936         struct nfs4_state *state;
 937
 938         if (lsp == NULL)
 939                 return;
 940         state = lsp->ls_state;
 941         if (!atomic_dec_and_lock(&lsp->ls_count, &state->state_lock))
 942                 return;
 943         list_del(&lsp->ls_locks);
 944         if (list_empty(&state->lock_states))
 945                 clear_bit(LK_STATE_IN_USE, &state->flags);
 946         spin_unlock(&state->state_lock);
 947         if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) {
 948                 if (nfs4_release_lockowner(lsp) == 0)
 949                         return;
 950         }
 951         nfs4_free_lock_state(lsp->ls_state->owner->so_server, lsp);
 952 }
 953
 954 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
 955 {
 956         struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
 957
 958         dst->fl_u.nfs4_fl.owner = lsp;
 959         atomic_inc(&lsp->ls_count);
 960 }
 961
 962 static void nfs4_fl_release_lock(struct file_lock *fl)
 963 {
 964         nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
 965 }
 966
 967 static const struct file_lock_operations nfs4_fl_lock_ops = {
 968         .fl_copy_lock = nfs4_fl_copy_lock,
 969         .fl_release_private = nfs4_fl_release_lock,
 970 };
 971
 972 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
 973 {
 974         struct nfs4_lock_state *lsp;
 975
 976         if (fl->fl_ops != NULL)
 977                 return 0;
 978         if (fl->fl_flags & FL_POSIX)
 979                 lsp = nfs4_get_lock_state(state, fl->fl_owner, 0, NFS4_POSIX_LOCK_TYPE);
 980         else if (fl->fl_flags & FL_FLOCK)
 981                 lsp = nfs4_get_lock_state(state, NULL, fl->fl_pid,
 982                                 NFS4_FLOCK_LOCK_TYPE);
 983         else
 984                 return -EINVAL;
 985         if (lsp == NULL)
 986                 return -ENOMEM;
 987         fl->fl_u.nfs4_fl.owner = lsp;
 988         fl->fl_ops = &nfs4_fl_lock_ops;
 989         return 0;
 990 }
 991
 992 static int nfs4_copy_lock_stateid(nfs4_stateid *dst,
 993                 struct nfs4_state *state,
 994                 const struct nfs_lockowner *lockowner)
 995 {
 996         struct nfs4_lock_state *lsp;
 997         fl_owner_t fl_owner;
 998         pid_t fl_pid;
 999         int ret = -ENOENT;
1000
1001
1002         if (lockowner == NULL)
1003                 goto out;
1004
1005         if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
1006                 goto out;
1007
1008         fl_owner = lockowner->l_owner;
1009         fl_pid = lockowner->l_pid;
1010         spin_lock(&state->state_lock);
1011         lsp = __nfs4_find_lock_state(state, fl_owner, fl_pid, NFS4_ANY_LOCK_TYPE);
1012         if (lsp != NULL && test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) != 0) {
1013                 nfs4_stateid_copy(dst, &lsp->ls_stateid);
1014                 ret = 0;
1015                 smp_rmb();
1016                 if (!list_empty(&lsp->ls_seqid.list))
1017                         ret = -EWOULDBLOCK;
1018         }
1019         spin_unlock(&state->state_lock);
1020         nfs4_put_lock_state(lsp);
1021 out:
1022         return ret;
1023 }
1024
1025 static int nfs4_copy_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
1026 {
1027         int ret;
1028         int seq;
1029
1030         do {
1031                 seq = read_seqbegin(&state->seqlock);
1032                 nfs4_stateid_copy(dst, &state->stateid);
1033                 ret = 0;
1034                 smp_rmb();
1035                 if (!list_empty(&state->owner->so_seqid.list))
1036                         ret = -EWOULDBLOCK;
1037         } while (read_seqretry(&state->seqlock, seq));
1038         return ret;
1039 }
1040
1041 /*
1042  * Byte-range lock aware utility to initialize the stateid of read/write
1043  * requests.
1044  */
1045 int nfs4_select_rw_stateid(nfs4_stateid *dst, struct nfs4_state *state,
1046                 fmode_t fmode, const struct nfs_lockowner *lockowner)
1047 {
1048         int ret = 0;
1049         if (nfs4_copy_delegation_stateid(dst, state->inode, fmode))
1050                 goto out;
1051         ret = nfs4_copy_lock_stateid(dst, state, lockowner);
1052         if (ret != -ENOENT)
1053                 goto out;
1054         ret = nfs4_copy_open_stateid(dst, state);
1055 out:
1056         if (nfs_server_capable(state->inode, NFS_CAP_STATEID_NFSV41))
1057                 dst->seqid = 0;
1058         return ret;
1059 }
1060
1061 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask)
1062 {
1063         struct nfs_seqid *new;
1064
1065         new = kmalloc(sizeof(*new), gfp_mask);
1066         if (new != NULL) {
1067                 new->sequence = counter;
1068                 INIT_LIST_HEAD(&new->list);
1069                 new->task = NULL;
1070         }
1071         return new;
1072 }
1073
1074 void nfs_release_seqid(struct nfs_seqid *seqid)
1075 {
1076         struct nfs_seqid_counter *sequence;
1077
1078         if (list_empty(&seqid->list))
1079                 return;
1080         sequence = seqid->sequence;
1081         spin_lock(&sequence->lock);
1082         list_del_init(&seqid->list);
1083         if (!list_empty(&sequence->list)) {
1084                 struct nfs_seqid *next;
1085
1086                 next = list_first_entry(&sequence->list,
1087                                 struct nfs_seqid, list);
1088                 rpc_wake_up_queued_task(&sequence->wait, next->task);
1089         }
1090         spin_unlock(&sequence->lock);
1091 }
1092
1093 void nfs_free_seqid(struct nfs_seqid *seqid)
1094 {
1095         nfs_release_seqid(seqid);
1096         kfree(seqid);
1097 }
1098
1099 /*
1100  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
1101  * failed with a seqid incrementing error -
1102  * see comments nfs_fs.h:seqid_mutating_error()
1103  */
1104 static void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
1105 {
1106         switch (status) {
1107                 case 0:
1108                         break;
1109                 case -NFS4ERR_BAD_SEQID:
1110                         if (seqid->sequence->flags & NFS_SEQID_CONFIRMED)
1111                                 return;
1112                         pr_warn_ratelimited("NFS: v4 server returned a bad"
1113                                         " sequence-id error on an"
1114                                         " unconfirmed sequence %p!\n",
1115                                         seqid->sequence);
1116                 case -NFS4ERR_STALE_CLIENTID:
1117                 case -NFS4ERR_STALE_STATEID:
1118                 case -NFS4ERR_BAD_STATEID:
1119                 case -NFS4ERR_BADXDR:
1120                 case -NFS4ERR_RESOURCE:
1121                 case -NFS4ERR_NOFILEHANDLE:
1122                         /* Non-seqid mutating errors */
1123                         return;
1124         };
1125         /*
1126          * Note: no locking needed as we are guaranteed to be first
1127          * on the sequence list
1128          */
1129         seqid->sequence->counter++;
1130 }
1131
1132 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
1133 {
1134         struct nfs4_state_owner *sp = container_of(seqid->sequence,
1135                                         struct nfs4_state_owner, so_seqid);
1136         struct nfs_server *server = sp->so_server;
1137
1138         if (status == -NFS4ERR_BAD_SEQID)
1139                 nfs4_drop_state_owner(sp);
1140         if (!nfs4_has_session(server->nfs_client))
1141                 nfs_increment_seqid(status, seqid);
1142 }
1143
1144 /*
1145  * Increment the seqid if the LOCK/LOCKU succeeded, or
1146  * failed with a seqid incrementing error -
1147  * see comments nfs_fs.h:seqid_mutating_error()
1148  */
1149 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
1150 {
1151         nfs_increment_seqid(status, seqid);
1152 }
1153
1154 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
1155 {
1156         struct nfs_seqid_counter *sequence = seqid->sequence;
1157         int status = 0;
1158
1159         spin_lock(&sequence->lock);
1160         seqid->task = task;
1161         if (list_empty(&seqid->list))
1162                 list_add_tail(&seqid->list, &sequence->list);
1163         if (list_first_entry(&sequence->list, struct nfs_seqid, list) == seqid)
1164                 goto unlock;
1165         rpc_sleep_on(&sequence->wait, task, NULL);
1166         status = -EAGAIN;
1167 unlock:
1168         spin_unlock(&sequence->lock);
1169         return status;
1170 }
1171
1172 static int nfs4_run_state_manager(void *);
1173
1174 static void nfs4_clear_state_manager_bit(struct nfs_client *clp)
1175 {
1176         smp_mb__before_clear_bit();
1177         clear_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state);
1178         smp_mb__after_clear_bit();
1179         wake_up_bit(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING);
1180         rpc_wake_up(&clp->cl_rpcwaitq);
1181 }
1182
1183 /*
1184  * Schedule the nfs_client asynchronous state management routine
1185  */
1186 void nfs4_schedule_state_manager(struct nfs_client *clp)
1187 {
1188         struct task_struct *task;
1189         char buf[INET6_ADDRSTRLEN + sizeof("-manager") + 1];
1190
1191         if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
1192                 return;
1193         __module_get(THIS_MODULE);
1194         atomic_inc(&clp->cl_count);
1195
1196         /* The rcu_read_lock() is not strictly necessary, as the state
1197          * manager is the only thread that ever changes the rpc_xprt
1198          * after it's initialized.  At this point, we're single threaded. */
1199         rcu_read_lock();
1200         snprintf(buf, sizeof(buf), "%s-manager",
1201                         rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
1202         rcu_read_unlock();
1203         task = kthread_run(nfs4_run_state_manager, clp, buf);
1204         if (IS_ERR(task)) {
1205                 printk(KERN_ERR "%s: kthread_run: %ld\n",
1206                         __func__, PTR_ERR(task));
1207                 nfs4_clear_state_manager_bit(clp);
1208                 nfs_put_client(clp);
1209                 module_put(THIS_MODULE);
1210         }
1211 }
1212
1213 /*
1214  * Schedule a lease recovery attempt
1215  */
1216 void nfs4_schedule_lease_recovery(struct nfs_client *clp)
1217 {
1218         if (!clp)
1219                 return;
1220         if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1221                 set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1222         dprintk("%s: scheduling lease recovery for server %s\n", __func__,
1223                         clp->cl_hostname);
1224         nfs4_schedule_state_manager(clp);
1225 }
1226 EXPORT_SYMBOL_GPL(nfs4_schedule_lease_recovery);
1227
1228 int nfs4_wait_clnt_recover(struct nfs_client *clp)
1229 {
1230         int res;
1231
1232         might_sleep();
1233
1234         res = wait_on_bit(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING,
1235                         nfs_wait_bit_killable, TASK_KILLABLE);
1236         if (res)
1237                 return res;
1238
1239         if (clp->cl_cons_state < 0)
1240                 return clp->cl_cons_state;
1241         return 0;
1242 }
1243
1244 int nfs4_client_recover_expired_lease(struct nfs_client *clp)
1245 {
1246         unsigned int loop;
1247         int ret;
1248
1249         for (loop = NFS4_MAX_LOOP_ON_RECOVER; loop != 0; loop--) {
1250                 ret = nfs4_wait_clnt_recover(clp);
1251                 if (ret != 0)
1252                         break;
1253                 if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) &&
1254                     !test_bit(NFS4CLNT_CHECK_LEASE,&clp->cl_state))
1255                         break;
1256                 nfs4_schedule_state_manager(clp);
1257                 ret = -EIO;
1258         }
1259         return ret;
1260 }
1261
1262 /*
1263  * nfs40_handle_cb_pathdown - return all delegations after NFS4ERR_CB_PATH_DOWN
1264  * @clp: client to process
1265  *
1266  * Set the NFS4CLNT_LEASE_EXPIRED state in order to force a
1267  * resend of the SETCLIENTID and hence re-establish the
1268  * callback channel. Then return all existing delegations.
1269  */
1270 static void nfs40_handle_cb_pathdown(struct nfs_client *clp)
1271 {
1272         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1273         nfs_expire_all_delegations(clp);
1274         dprintk("%s: handling CB_PATHDOWN recovery for server %s\n", __func__,
1275                         clp->cl_hostname);
1276 }
1277
1278 void nfs4_schedule_path_down_recovery(struct nfs_client *clp)
1279 {
1280         nfs40_handle_cb_pathdown(clp);
1281         nfs4_schedule_state_manager(clp);
1282 }
1283
1284 static int nfs4_state_mark_reclaim_reboot(struct nfs_client *clp, struct nfs4_state *state)
1285 {
1286
1287         set_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1288         /* Don't recover state that expired before the reboot */
1289         if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags)) {
1290                 clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1291                 return 0;
1292         }
1293         set_bit(NFS_OWNER_RECLAIM_REBOOT, &state->owner->so_flags);
1294         set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1295         return 1;
1296 }
1297
1298 static int nfs4_state_mark_reclaim_nograce(struct nfs_client *clp, struct nfs4_state *state)
1299 {
1300         set_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1301         clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1302         set_bit(NFS_OWNER_RECLAIM_NOGRACE, &state->owner->so_flags);
1303         set_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
1304         return 1;
1305 }
1306
1307 int nfs4_schedule_stateid_recovery(const struct nfs_server *server, struct nfs4_state *state)
1308 {
1309         struct nfs_client *clp = server->nfs_client;
1310
1311         if (!nfs4_valid_open_stateid(state))
1312                 return -EBADF;
1313         nfs4_state_mark_reclaim_nograce(clp, state);
1314         dprintk("%s: scheduling stateid recovery for server %s\n", __func__,
1315                         clp->cl_hostname);
1316         nfs4_schedule_state_manager(clp);
1317         return 0;
1318 }
1319 EXPORT_SYMBOL_GPL(nfs4_schedule_stateid_recovery);
1320
1321 void nfs_inode_find_state_and_recover(struct inode *inode,
1322                 const nfs4_stateid *stateid)
1323 {
1324         struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
1325         struct nfs_inode *nfsi = NFS_I(inode);
1326         struct nfs_open_context *ctx;
1327         struct nfs4_state *state;
1328         bool found = false;
1329
1330         spin_lock(&inode->i_lock);
1331         list_for_each_entry(ctx, &nfsi->open_files, list) {
1332                 state = ctx->state;
1333                 if (state == NULL)
1334                         continue;
1335                 if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
1336                         continue;
1337                 if (!nfs4_stateid_match(&state->stateid, stateid))
1338                         continue;
1339                 nfs4_state_mark_reclaim_nograce(clp, state);
1340                 found = true;
1341         }
1342         spin_unlock(&inode->i_lock);
1343         if (found)
1344                 nfs4_schedule_state_manager(clp);
1345 }
1346
1347 static void nfs4_state_mark_open_context_bad(struct nfs4_state *state)
1348 {
1349         struct inode *inode = state->inode;
1350         struct nfs_inode *nfsi = NFS_I(inode);
1351         struct nfs_open_context *ctx;
1352
1353         spin_lock(&inode->i_lock);
1354         list_for_each_entry(ctx, &nfsi->open_files, list) {
1355                 if (ctx->state != state)
1356                         continue;
1357                 set_bit(NFS_CONTEXT_BAD, &ctx->flags);
1358         }
1359         spin_unlock(&inode->i_lock);
1360 }
1361
1362 static void nfs4_state_mark_recovery_failed(struct nfs4_state *state, int error)
1363 {
1364         set_bit(NFS_STATE_RECOVERY_FAILED, &state->flags);
1365         nfs4_state_mark_open_context_bad(state);
1366 }
1367
1368
1369 static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_recovery_ops *ops)
1370 {
1371         struct inode *inode = state->inode;
1372         struct nfs_inode *nfsi = NFS_I(inode);
1373         struct file_lock *fl;
1374         int status = 0;
1375
1376         if (inode->i_flock == NULL)
1377                 return 0;
1378
1379         /* Guard against delegation returns and new lock/unlock calls */
1380         down_write(&nfsi->rwsem);
1381         /* Protect inode->i_flock using the BKL */
1382         lock_flocks();
1383         for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
1384                 if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
1385                         continue;
1386                 if (nfs_file_open_context(fl->fl_file)->state != state)
1387                         continue;
1388                 unlock_flocks();
1389                 status = ops->recover_lock(state, fl);
1390                 switch (status) {
1391                         case 0:
1392                                 break;
1393                         case -ESTALE:
1394                         case -NFS4ERR_ADMIN_REVOKED:
1395                         case -NFS4ERR_STALE_STATEID:
1396                         case -NFS4ERR_BAD_STATEID:
1397                         case -NFS4ERR_EXPIRED:
1398                         case -NFS4ERR_NO_GRACE:
1399                         case -NFS4ERR_STALE_CLIENTID:
1400                         case -NFS4ERR_BADSESSION:
1401                         case -NFS4ERR_BADSLOT:
1402                         case -NFS4ERR_BAD_HIGH_SLOT:
1403                         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1404                                 goto out;
1405                         default:
1406                                 printk(KERN_ERR "NFS: %s: unhandled error %d. "
1407                                         "Zeroing state\n", __func__, status);
1408                         case -ENOMEM:
1409                         case -NFS4ERR_DENIED:
1410                         case -NFS4ERR_RECLAIM_BAD:
1411                         case -NFS4ERR_RECLAIM_CONFLICT:
1412                                 /* kill_proc(fl->fl_pid, SIGLOST, 1); */
1413                                 status = 0;
1414                 }
1415                 lock_flocks();
1416         }
1417         unlock_flocks();
1418 out:
1419         up_write(&nfsi->rwsem);
1420         return status;
1421 }
1422
1423 static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs4_state_recovery_ops *ops)
1424 {
1425         struct nfs4_state *state;
1426         struct nfs4_lock_state *lock;
1427         int status = 0;
1428
1429         /* Note: we rely on the sp->so_states list being ordered
1430          * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
1431          * states first.
1432          * This is needed to ensure that the server won't give us any
1433          * read delegations that we have to return if, say, we are
1434          * recovering after a network partition or a reboot from a
1435          * server that doesn't support a grace period.
1436          */
1437         spin_lock(&sp->so_lock);
1438         write_seqcount_begin(&sp->so_reclaim_seqcount);
1439 restart:
1440         list_for_each_entry(state, &sp->so_states, open_states) {
1441                 if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
1442                         continue;
1443                 if (!nfs4_valid_open_stateid(state))
1444                         continue;
1445                 if (state->state == 0)
1446                         continue;
1447                 atomic_inc(&state->count);
1448                 spin_unlock(&sp->so_lock);
1449                 status = ops->recover_open(sp, state);
1450                 if (status >= 0) {
1451                         status = nfs4_reclaim_locks(state, ops);
1452                         if (status >= 0) {
1453                                 spin_lock(&state->state_lock);
1454                                 list_for_each_entry(lock, &state->lock_states, ls_locks) {
1455                                         if (!test_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags))
1456                                                 pr_warn_ratelimited("NFS: "
1457                                                         "%s: Lock reclaim "
1458                                                         "failed!\n", __func__);
1459                                 }
1460                                 spin_unlock(&state->state_lock);
1461                                 nfs4_put_open_state(state);
1462                                 spin_lock(&sp->so_lock);
1463                                 goto restart;
1464                         }
1465                 }
1466                 switch (status) {
1467                         default:
1468                                 printk(KERN_ERR "NFS: %s: unhandled error %d. "
1469                                         "Zeroing state\n", __func__, status);
1470                         case -ENOENT:
1471                         case -ENOMEM:
1472                         case -ESTALE:
1473                                 /*
1474                                  * Open state on this file cannot be recovered
1475                                  * All we can do is revert to using the zero stateid.
1476                                  */
1477                                 nfs4_state_mark_recovery_failed(state, status);
1478                                 break;
1479                         case -NFS4ERR_ADMIN_REVOKED:
1480                         case -NFS4ERR_STALE_STATEID:
1481                         case -NFS4ERR_BAD_STATEID:
1482                         case -NFS4ERR_RECLAIM_BAD:
1483                         case -NFS4ERR_RECLAIM_CONFLICT:
1484                                 nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1485                                 break;
1486                         case -NFS4ERR_EXPIRED:
1487                         case -NFS4ERR_NO_GRACE:
1488                                 nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1489                         case -NFS4ERR_STALE_CLIENTID:
1490                         case -NFS4ERR_BADSESSION:
1491                         case -NFS4ERR_BADSLOT:
1492                         case -NFS4ERR_BAD_HIGH_SLOT:
1493                         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1494                                 goto out_err;
1495                 }
1496                 nfs4_put_open_state(state);
1497                 spin_lock(&sp->so_lock);
1498                 goto restart;
1499         }
1500         write_seqcount_end(&sp->so_reclaim_seqcount);
1501         spin_unlock(&sp->so_lock);
1502         return 0;
1503 out_err:
1504         nfs4_put_open_state(state);
1505         spin_lock(&sp->so_lock);
1506         write_seqcount_end(&sp->so_reclaim_seqcount);
1507         spin_unlock(&sp->so_lock);
1508         return status;
1509 }
1510
1511 static void nfs4_clear_open_state(struct nfs4_state *state)
1512 {
1513         struct nfs4_lock_state *lock;
1514
1515         clear_bit(NFS_DELEGATED_STATE, &state->flags);
1516         clear_bit(NFS_O_RDONLY_STATE, &state->flags);
1517         clear_bit(NFS_O_WRONLY_STATE, &state->flags);
1518         clear_bit(NFS_O_RDWR_STATE, &state->flags);
1519         spin_lock(&state->state_lock);
1520         list_for_each_entry(lock, &state->lock_states, ls_locks) {
1521                 lock->ls_seqid.flags = 0;
1522                 clear_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags);
1523         }
1524         spin_unlock(&state->state_lock);
1525 }
1526
1527 static void nfs4_reset_seqids(struct nfs_server *server,
1528         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1529 {
1530         struct nfs_client *clp = server->nfs_client;
1531         struct nfs4_state_owner *sp;
1532         struct rb_node *pos;
1533         struct nfs4_state *state;
1534
1535         spin_lock(&clp->cl_lock);
1536         for (pos = rb_first(&server->state_owners);
1537              pos != NULL;
1538              pos = rb_next(pos)) {
1539                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1540                 sp->so_seqid.flags = 0;
1541                 spin_lock(&sp->so_lock);
1542                 list_for_each_entry(state, &sp->so_states, open_states) {
1543                         if (mark_reclaim(clp, state))
1544                                 nfs4_clear_open_state(state);
1545                 }
1546                 spin_unlock(&sp->so_lock);
1547         }
1548         spin_unlock(&clp->cl_lock);
1549 }
1550
1551 static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp,
1552         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1553 {
1554         struct nfs_server *server;
1555
1556         rcu_read_lock();
1557         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1558                 nfs4_reset_seqids(server, mark_reclaim);
1559         rcu_read_unlock();
1560 }
1561
1562 static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp)
1563 {
1564         /* Mark all delegations for reclaim */
1565         nfs_delegation_mark_reclaim(clp);
1566         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_reboot);
1567 }
1568
1569 static void nfs4_reclaim_complete(struct nfs_client *clp,
1570                                  const struct nfs4_state_recovery_ops *ops)
1571 {
1572         /* Notify the server we're done reclaiming our state */
1573         if (ops->reclaim_complete)
1574                 (void)ops->reclaim_complete(clp);
1575 }
1576
1577 static void nfs4_clear_reclaim_server(struct nfs_server *server)
1578 {
1579         struct nfs_client *clp = server->nfs_client;
1580         struct nfs4_state_owner *sp;
1581         struct rb_node *pos;
1582         struct nfs4_state *state;
1583
1584         spin_lock(&clp->cl_lock);
1585         for (pos = rb_first(&server->state_owners);
1586              pos != NULL;
1587              pos = rb_next(pos)) {
1588                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1589                 spin_lock(&sp->so_lock);
1590                 list_for_each_entry(state, &sp->so_states, open_states) {
1591                         if (!test_and_clear_bit(NFS_STATE_RECLAIM_REBOOT,
1592                                                 &state->flags))
1593                                 continue;
1594                         nfs4_state_mark_reclaim_nograce(clp, state);
1595                 }
1596                 spin_unlock(&sp->so_lock);
1597         }
1598         spin_unlock(&clp->cl_lock);
1599 }
1600
1601 static int nfs4_state_clear_reclaim_reboot(struct nfs_client *clp)
1602 {
1603         struct nfs_server *server;
1604
1605         if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
1606                 return 0;
1607
1608         rcu_read_lock();
1609         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1610                 nfs4_clear_reclaim_server(server);
1611         rcu_read_unlock();
1612
1613         nfs_delegation_reap_unclaimed(clp);
1614         return 1;
1615 }
1616
1617 static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
1618 {
1619         if (!nfs4_state_clear_reclaim_reboot(clp))
1620                 return;
1621         nfs4_reclaim_complete(clp, clp->cl_mvops->reboot_recovery_ops);
1622 }
1623
1624 static void nfs_delegation_clear_all(struct nfs_client *clp)
1625 {
1626         nfs_delegation_mark_reclaim(clp);
1627         nfs_delegation_reap_unclaimed(clp);
1628 }
1629
1630 static void nfs4_state_start_reclaim_nograce(struct nfs_client *clp)
1631 {
1632         nfs_delegation_clear_all(clp);
1633         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
1634 }
1635
1636 static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
1637 {
1638         switch (error) {
1639                 case 0:
1640                         break;
1641                 case -NFS4ERR_CB_PATH_DOWN:
1642                         nfs40_handle_cb_pathdown(clp);
1643                         break;
1644                 case -NFS4ERR_NO_GRACE:
1645                         nfs4_state_end_reclaim_reboot(clp);
1646                         break;
1647                 case -NFS4ERR_STALE_CLIENTID:
1648                 case -NFS4ERR_LEASE_MOVED:
1649                         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1650                         nfs4_state_clear_reclaim_reboot(clp);
1651                         nfs4_state_start_reclaim_reboot(clp);
1652                         break;
1653                 case -NFS4ERR_EXPIRED:
1654                         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1655                         nfs4_state_start_reclaim_nograce(clp);
1656                         break;
1657                 case -NFS4ERR_BADSESSION:
1658                 case -NFS4ERR_BADSLOT:
1659                 case -NFS4ERR_BAD_HIGH_SLOT:
1660                 case -NFS4ERR_DEADSESSION:
1661                 case -NFS4ERR_SEQ_FALSE_RETRY:
1662                 case -NFS4ERR_SEQ_MISORDERED:
1663                         set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
1664                         /* Zero session reset errors */
1665                         break;
1666                 case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1667                         set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
1668                         break;
1669                 default:
1670                         dprintk("%s: failed to handle error %d for server %s\n",
1671                                         __func__, error, clp->cl_hostname);
1672                         return error;
1673         }
1674         dprintk("%s: handled error %d for server %s\n", __func__, error,
1675                         clp->cl_hostname);
1676         return 0;
1677 }
1678
1679 static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recovery_ops *ops)
1680 {
1681         struct nfs4_state_owner *sp;
1682         struct nfs_server *server;
1683         struct rb_node *pos;
1684         int status = 0;
1685
1686 restart:
1687         rcu_read_lock();
1688         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1689                 nfs4_purge_state_owners(server);
1690                 spin_lock(&clp->cl_lock);
1691                 for (pos = rb_first(&server->state_owners);
1692                      pos != NULL;
1693                      pos = rb_next(pos)) {
1694                         sp = rb_entry(pos,
1695                                 struct nfs4_state_owner, so_server_node);
1696                         if (!test_and_clear_bit(ops->owner_flag_bit,
1697                                                         &sp->so_flags))
1698                                 continue;
1699                         atomic_inc(&sp->so_count);
1700                         spin_unlock(&clp->cl_lock);
1701                         rcu_read_unlock();
1702
1703                         status = nfs4_reclaim_open_state(sp, ops);
1704                         if (status < 0) {
1705                                 set_bit(ops->owner_flag_bit, &sp->so_flags);
1706                                 nfs4_put_state_owner(sp);
1707                                 return nfs4_recovery_handle_error(clp, status);
1708                         }
1709
1710                         nfs4_put_state_owner(sp);
1711                         goto restart;
1712                 }
1713                 spin_unlock(&clp->cl_lock);
1714         }
1715         rcu_read_unlock();
1716         return status;
1717 }
1718
1719 static int nfs4_check_lease(struct nfs_client *clp)
1720 {
1721         struct rpc_cred *cred;
1722         const struct nfs4_state_maintenance_ops *ops =
1723                 clp->cl_mvops->state_renewal_ops;
1724         int status;
1725
1726         /* Is the client already known to have an expired lease? */
1727         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1728                 return 0;
1729         spin_lock(&clp->cl_lock);
1730         cred = ops->get_state_renewal_cred_locked(clp);
1731         spin_unlock(&clp->cl_lock);
1732         if (cred == NULL) {
1733                 cred = nfs4_get_setclientid_cred(clp);
1734                 status = -ENOKEY;
1735                 if (cred == NULL)
1736                         goto out;
1737         }
1738         status = ops->renew_lease(clp, cred);
1739         put_rpccred(cred);
1740 out:
1741         return nfs4_recovery_handle_error(clp, status);
1742 }
1743
1744 /* Set NFS4CLNT_LEASE_EXPIRED and reclaim reboot state for all v4.0 errors
1745  * and for recoverable errors on EXCHANGE_ID for v4.1
1746  */
1747 static int nfs4_handle_reclaim_lease_error(struct nfs_client *clp, int status)
1748 {
1749         switch (status) {
1750         case -NFS4ERR_SEQ_MISORDERED:
1751                 if (test_and_set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state))
1752                         return -ESERVERFAULT;
1753                 /* Lease confirmation error: retry after purging the lease */
1754                 ssleep(1);
1755                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1756                 break;
1757         case -NFS4ERR_STALE_CLIENTID:
1758                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1759                 nfs4_state_clear_reclaim_reboot(clp);
1760                 nfs4_state_start_reclaim_reboot(clp);
1761                 break;
1762         case -NFS4ERR_CLID_INUSE:
1763                 pr_err("NFS: Server %s reports our clientid is in use\n",
1764                         clp->cl_hostname);
1765                 nfs_mark_client_ready(clp, -EPERM);
1766                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1767                 return -EPERM;
1768         case -EACCES:
1769                 if (clp->cl_machine_cred == NULL)
1770                         return -EACCES;
1771                 /* Handle case where the user hasn't set up machine creds */
1772                 nfs4_clear_machine_cred(clp);
1773         case -NFS4ERR_DELAY:
1774         case -ETIMEDOUT:
1775         case -EAGAIN:
1776                 ssleep(1);
1777                 break;
1778
1779         case -NFS4ERR_MINOR_VERS_MISMATCH:
1780                 if (clp->cl_cons_state == NFS_CS_SESSION_INITING)
1781                         nfs_mark_client_ready(clp, -EPROTONOSUPPORT);
1782                 dprintk("%s: exit with error %d for server %s\n",
1783                                 __func__, -EPROTONOSUPPORT, clp->cl_hostname);
1784                 return -EPROTONOSUPPORT;
1785         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
1786                                  * in nfs4_exchange_id */
1787         default:
1788                 dprintk("%s: exit with error %d for server %s\n", __func__,
1789                                 status, clp->cl_hostname);
1790                 return status;
1791         }
1792         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1793         dprintk("%s: handled error %d for server %s\n", __func__, status,
1794                         clp->cl_hostname);
1795         return 0;
1796 }
1797
1798 static int nfs4_establish_lease(struct nfs_client *clp)
1799 {
1800         struct rpc_cred *cred;
1801         const struct nfs4_state_recovery_ops *ops =
1802                 clp->cl_mvops->reboot_recovery_ops;
1803         int status;
1804
1805         cred = ops->get_clid_cred(clp);
1806         if (cred == NULL)
1807                 return -ENOENT;
1808         status = ops->establish_clid(clp, cred);
1809         put_rpccred(cred);
1810         if (status != 0)
1811                 return status;
1812         pnfs_destroy_all_layouts(clp);
1813         return 0;
1814 }
1815
1816 /*
1817  * Returns zero or a negative errno.  NFS4ERR values are converted
1818  * to local errno values.
1819  */
1820 static int nfs4_reclaim_lease(struct nfs_client *clp)
1821 {
1822         int status;
1823
1824         status = nfs4_establish_lease(clp);
1825         if (status < 0)
1826                 return nfs4_handle_reclaim_lease_error(clp, status);
1827         if (test_and_clear_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH, &clp->cl_state))
1828                 nfs4_state_start_reclaim_nograce(clp);
1829         if (!test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
1830                 set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1831         clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1832         clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1833         return 0;
1834 }
1835
1836 static int nfs4_purge_lease(struct nfs_client *clp)
1837 {
1838         int status;
1839
1840         status = nfs4_establish_lease(clp);
1841         if (status < 0)
1842                 return nfs4_handle_reclaim_lease_error(clp, status);
1843         clear_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
1844         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1845         nfs4_state_start_reclaim_nograce(clp);
1846         return 0;
1847 }
1848
1849 /**
1850  * nfs4_discover_server_trunking - Detect server IP address trunking
1851  *
1852  * @clp: nfs_client under test
1853  * @result: OUT: found nfs_client, or clp
1854  *
1855  * Returns zero or a negative errno.  If zero is returned,
1856  * an nfs_client pointer is planted in "result".
1857  *
1858  * Note: since we are invoked in process context, and
1859  * not from inside the state manager, we cannot use
1860  * nfs4_handle_reclaim_lease_error().
1861  */
1862 int nfs4_discover_server_trunking(struct nfs_client *clp,
1863                                   struct nfs_client **result)
1864 {
1865         const struct nfs4_state_recovery_ops *ops =
1866                                 clp->cl_mvops->reboot_recovery_ops;
1867         rpc_authflavor_t *flavors, flav, save;
1868         struct rpc_clnt *clnt;
1869         struct rpc_cred *cred;
1870         int i, len, status;
1871
1872         dprintk("NFS: %s: testing '%s'\n", __func__, clp->cl_hostname);
1873
1874         len = NFS_MAX_SECFLAVORS;
1875         flavors = kcalloc(len, sizeof(*flavors), GFP_KERNEL);
1876         if (flavors == NULL) {
1877                 status = -ENOMEM;
1878                 goto out;
1879         }
1880         len = rpcauth_list_flavors(flavors, len);
1881         if (len < 0) {
1882                 status = len;
1883                 goto out_free;
1884         }
1885         clnt = clp->cl_rpcclient;
1886         save = clnt->cl_auth->au_flavor;
1887         i = 0;
1888
1889         mutex_lock(&nfs_clid_init_mutex);
1890         status  = -ENOENT;
1891 again:
1892         cred = ops->get_clid_cred(clp);
1893         if (cred == NULL)
1894                 goto out_unlock;
1895
1896         status = ops->detect_trunking(clp, result, cred);
1897         put_rpccred(cred);
1898         switch (status) {
1899         case 0:
1900                 break;
1901
1902         case -EACCES:
1903                 if (clp->cl_machine_cred == NULL)
1904                         break;
1905                 /* Handle case where the user hasn't set up machine creds */
1906                 nfs4_clear_machine_cred(clp);
1907         case -NFS4ERR_DELAY:
1908         case -ETIMEDOUT:
1909         case -EAGAIN:
1910                 ssleep(1);
1911         case -NFS4ERR_STALE_CLIENTID:
1912                 dprintk("NFS: %s after status %d, retrying\n",
1913                         __func__, status);
1914                 goto again;
1915
1916         case -NFS4ERR_CLID_INUSE:
1917         case -NFS4ERR_WRONGSEC:
1918                 status = -EPERM;
1919                 if (i >= len)
1920                         break;
1921
1922                 flav = flavors[i++];
1923                 if (flav == save)
1924                         flav = flavors[i++];
1925                 clnt = rpc_clone_client_set_auth(clnt, flav);
1926                 if (IS_ERR(clnt)) {
1927                         status = PTR_ERR(clnt);
1928                         break;
1929                 }
1930                 clp->cl_rpcclient = clnt;
1931                 goto again;
1932
1933         case -NFS4ERR_MINOR_VERS_MISMATCH:
1934                 status = -EPROTONOSUPPORT;
1935                 break;
1936
1937         case -EKEYEXPIRED:
1938         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
1939                                  * in nfs4_exchange_id */
1940                 status = -EKEYEXPIRED;
1941         }
1942
1943 out_unlock:
1944         mutex_unlock(&nfs_clid_init_mutex);
1945 out_free:
1946         kfree(flavors);
1947 out:
1948         dprintk("NFS: %s: status = %d\n", __func__, status);
1949         return status;
1950 }
1951
1952 #ifdef CONFIG_NFS_V4_1
1953 void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
1954 {
1955         struct nfs_client *clp = session->clp;
1956
1957         switch (err) {
1958         default:
1959                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
1960                 break;
1961         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1962                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
1963         }
1964         nfs4_schedule_lease_recovery(clp);
1965 }
1966 EXPORT_SYMBOL_GPL(nfs4_schedule_session_recovery);
1967
1968 static void nfs41_ping_server(struct nfs_client *clp)
1969 {
1970         /* Use CHECK_LEASE to ping the server with a SEQUENCE */
1971         set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1972         nfs4_schedule_state_manager(clp);
1973 }
1974
1975 void nfs41_server_notify_target_slotid_update(struct nfs_client *clp)
1976 {
1977         nfs41_ping_server(clp);
1978 }
1979
1980 void nfs41_server_notify_highest_slotid_update(struct nfs_client *clp)
1981 {
1982         nfs41_ping_server(clp);
1983 }
1984
1985 static void nfs4_reset_all_state(struct nfs_client *clp)
1986 {
1987         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
1988                 set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
1989                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1990                 nfs4_state_start_reclaim_nograce(clp);
1991                 dprintk("%s: scheduling reset of all state for server %s!\n",
1992                                 __func__, clp->cl_hostname);
1993                 nfs4_schedule_state_manager(clp);
1994         }
1995 }
1996
1997 static void nfs41_handle_server_reboot(struct nfs_client *clp)
1998 {
1999         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2000                 nfs4_state_start_reclaim_reboot(clp);
2001                 dprintk("%s: server %s rebooted!\n", __func__,
2002                                 clp->cl_hostname);
2003                 nfs4_schedule_state_manager(clp);
2004         }
2005 }
2006
2007 static void nfs41_handle_state_revoked(struct nfs_client *clp)
2008 {
2009         nfs4_reset_all_state(clp);
2010         dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2011 }
2012
2013 static void nfs41_handle_recallable_state_revoked(struct nfs_client *clp)
2014 {
2015         /* This will need to handle layouts too */
2016         nfs_expire_all_delegations(clp);
2017         dprintk("%s: Recallable state revoked on server %s!\n", __func__,
2018                         clp->cl_hostname);
2019 }
2020
2021 static void nfs41_handle_backchannel_fault(struct nfs_client *clp)
2022 {
2023         nfs_expire_all_delegations(clp);
2024         if (test_and_set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state) == 0)
2025                 nfs4_schedule_state_manager(clp);
2026         dprintk("%s: server %s declared a backchannel fault\n", __func__,
2027                         clp->cl_hostname);
2028 }
2029
2030 static void nfs41_handle_cb_path_down(struct nfs_client *clp)
2031 {
2032         if (test_and_set_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2033                 &clp->cl_state) == 0)
2034                 nfs4_schedule_state_manager(clp);
2035 }
2036
2037 void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags)
2038 {
2039         if (!flags)
2040                 return;
2041
2042         dprintk("%s: \"%s\" (client ID %llx) flags=0x%08x\n",
2043                 __func__, clp->cl_hostname, clp->cl_clientid, flags);
2044
2045         if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED)
2046                 nfs41_handle_server_reboot(clp);
2047         if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED |
2048                             SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED |
2049                             SEQ4_STATUS_ADMIN_STATE_REVOKED |
2050                             SEQ4_STATUS_LEASE_MOVED))
2051                 nfs41_handle_state_revoked(clp);
2052         if (flags & SEQ4_STATUS_RECALLABLE_STATE_REVOKED)
2053                 nfs41_handle_recallable_state_revoked(clp);
2054         if (flags & SEQ4_STATUS_BACKCHANNEL_FAULT)
2055                 nfs41_handle_backchannel_fault(clp);
2056         else if (flags & (SEQ4_STATUS_CB_PATH_DOWN |
2057                                 SEQ4_STATUS_CB_PATH_DOWN_SESSION))
2058                 nfs41_handle_cb_path_down(clp);
2059 }
2060
2061 static int nfs4_reset_session(struct nfs_client *clp)
2062 {
2063         struct rpc_cred *cred;
2064         int status;
2065
2066         if (!nfs4_has_session(clp))
2067                 return 0;
2068         nfs4_begin_drain_session(clp);
2069         cred = nfs4_get_exchange_id_cred(clp);
2070         status = nfs4_proc_destroy_session(clp->cl_session, cred);
2071         switch (status) {
2072         case 0:
2073         case -NFS4ERR_BADSESSION:
2074         case -NFS4ERR_DEADSESSION:
2075                 break;
2076         case -NFS4ERR_BACK_CHAN_BUSY:
2077         case -NFS4ERR_DELAY:
2078                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2079                 status = 0;
2080                 ssleep(1);
2081                 goto out;
2082         default:
2083                 status = nfs4_recovery_handle_error(clp, status);
2084                 goto out;
2085         }
2086
2087         memset(clp->cl_session->sess_id.data, 0, NFS4_MAX_SESSIONID_LEN);
2088         status = nfs4_proc_create_session(clp, cred);
2089         if (status) {
2090                 dprintk("%s: session reset failed with status %d for server %s!\n",
2091                         __func__, status, clp->cl_hostname);
2092                 status = nfs4_handle_reclaim_lease_error(clp, status);
2093                 goto out;
2094         }
2095         nfs41_finish_session_reset(clp);
2096         dprintk("%s: session reset was successful for server %s!\n",
2097                         __func__, clp->cl_hostname);
2098 out:
2099         if (cred)
2100                 put_rpccred(cred);
2101         return status;
2102 }
2103
2104 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2105 {
2106         struct rpc_cred *cred;
2107         int ret;
2108
2109         if (!nfs4_has_session(clp))
2110                 return 0;
2111         nfs4_begin_drain_session(clp);
2112         cred = nfs4_get_exchange_id_cred(clp);
2113         ret = nfs4_proc_bind_conn_to_session(clp, cred);
2114         if (cred)
2115                 put_rpccred(cred);
2116         clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2117         switch (ret) {
2118         case 0:
2119                 dprintk("%s: bind_conn_to_session was successful for server %s!\n",
2120                         __func__, clp->cl_hostname);
2121                 break;
2122         case -NFS4ERR_DELAY:
2123                 ssleep(1);
2124                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2125                 break;
2126         default:
2127                 return nfs4_recovery_handle_error(clp, ret);
2128         }
2129         return 0;
2130 }
2131 #else /* CONFIG_NFS_V4_1 */
2132 static int nfs4_reset_session(struct nfs_client *clp) { return 0; }
2133 static int nfs4_end_drain_session(struct nfs_client *clp) { return 0; }
2134
2135 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2136 {
2137         return 0;
2138 }
2139 #endif /* CONFIG_NFS_V4_1 */
2140
2141 static void nfs4_state_manager(struct nfs_client *clp)
2142 {
2143         int status = 0;
2144         const char *section = "", *section_sep = "";
2145
2146         /* Ensure exclusive access to NFSv4 state */
2147         do {
2148                 if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
2149                         section = "purge state";
2150                         status = nfs4_purge_lease(clp);
2151                         if (status < 0)
2152                                 goto out_error;
2153                         continue;
2154                 }
2155
2156                 if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
2157                         section = "lease expired";
2158                         /* We're going to have to re-establish a clientid */
2159                         status = nfs4_reclaim_lease(clp);
2160                         if (status < 0)
2161                                 goto out_error;
2162                         continue;
2163                 }
2164
2165                 /* Initialize or reset the session */
2166                 if (test_and_clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state)) {
2167                         section = "reset session";
2168                         status = nfs4_reset_session(clp);
2169                         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
2170                                 continue;
2171                         if (status < 0)
2172                                 goto out_error;
2173                 }
2174
2175                 /* Send BIND_CONN_TO_SESSION */
2176                 if (test_and_clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2177                                 &clp->cl_state)) {
2178                         section = "bind conn to session";
2179                         status = nfs4_bind_conn_to_session(clp);
2180                         if (status < 0)
2181                                 goto out_error;
2182                         continue;
2183                 }
2184
2185                 if (test_and_clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state)) {
2186                         section = "check lease";
2187                         status = nfs4_check_lease(clp);
2188                         if (status < 0)
2189                                 goto out_error;
2190                         continue;
2191                 }
2192
2193                 /* First recover reboot state... */
2194                 if (test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {
2195                         section = "reclaim reboot";
2196                         status = nfs4_do_reclaim(clp,
2197                                 clp->cl_mvops->reboot_recovery_ops);
2198                         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) ||
2199                             test_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state))
2200                                 continue;
2201                         nfs4_state_end_reclaim_reboot(clp);
2202                         if (test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
2203                                 continue;
2204                         if (status < 0)
2205                                 goto out_error;
2206                 }
2207
2208                 /* Now recover expired state... */
2209                 if (test_and_clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state)) {
2210                         section = "reclaim nograce";
2211                         status = nfs4_do_reclaim(clp,
2212                                 clp->cl_mvops->nograce_recovery_ops);
2213                         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) ||
2214                             test_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state) ||
2215                             test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
2216                                 continue;
2217                         if (status < 0)
2218                                 goto out_error;
2219                 }
2220
2221                 nfs4_end_drain_session(clp);
2222                 if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
2223                         nfs_client_return_marked_delegations(clp);
2224                         continue;
2225                 }
2226
2227                 nfs4_clear_state_manager_bit(clp);
2228                 /* Did we race with an attempt to give us more work? */
2229                 if (clp->cl_state == 0)
2230                         break;
2231                 if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
2232                         break;
2233         } while (atomic_read(&clp->cl_count) > 1);
2234         return;
2235 out_error:
2236         if (strlen(section))
2237                 section_sep = ": ";
2238         pr_warn_ratelimited("NFS: state manager%s%s failed on NFSv4 server %s"
2239                         " with error %d\n", section_sep, section,
2240                         clp->cl_hostname, -status);
2241         ssleep(1);
2242         nfs4_end_drain_session(clp);
2243         nfs4_clear_state_manager_bit(clp);
2244 }
2245
2246 static int nfs4_run_state_manager(void *ptr)
2247 {
2248         struct nfs_client *clp = ptr;
2249
2250         allow_signal(SIGKILL);
2251         nfs4_state_manager(clp);
2252         nfs_put_client(clp);
2253         module_put_and_exit(0);
2254         return 0;
2255 }
2256
2257 /*
2258  * Local variables:
2259  *  c-basic-offset: 8
2260  * End:
2261  */