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 "nfs4_fs.h"
  55 #include "callback.h"
  56 #include "delegation.h"
  57 #include "internal.h"
  58 #include "pnfs.h"
  59
  60 #define OPENOWNER_POOL_SIZE     8
  61
  62 const nfs4_stateid zero_stateid;
  63
  64 static LIST_HEAD(nfs4_clientid_list);
  65
  66 int nfs4_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
  67 {
  68         struct nfs4_setclientid_res clid = {
  69                 .clientid = clp->cl_clientid,
  70                 .confirm = clp->cl_confirm,
  71         };
  72         unsigned short port;
  73         int status;
  74
  75         if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
  76                 goto do_confirm;
  77         port = nfs_callback_tcpport;
  78         if (clp->cl_addr.ss_family == AF_INET6)
  79                 port = nfs_callback_tcpport6;
  80
  81         status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
  82         if (status != 0)
  83                 goto out;
  84         clp->cl_clientid = clid.clientid;
  85         clp->cl_confirm = clid.confirm;
  86         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
  87 do_confirm:
  88         status = nfs4_proc_setclientid_confirm(clp, &clid, cred);
  89         if (status != 0)
  90                 goto out;
  91         clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
  92         nfs4_schedule_state_renewal(clp);
  93 out:
  94         return status;
  95 }
  96
  97 struct rpc_cred *nfs4_get_machine_cred_locked(struct nfs_client *clp)
  98 {
  99         struct rpc_cred *cred = NULL;
 100
 101         if (clp->cl_machine_cred != NULL)
 102                 cred = get_rpccred(clp->cl_machine_cred);
 103         return cred;
 104 }
 105
 106 static void nfs4_clear_machine_cred(struct nfs_client *clp)
 107 {
 108         struct rpc_cred *cred;
 109
 110         spin_lock(&clp->cl_lock);
 111         cred = clp->cl_machine_cred;
 112         clp->cl_machine_cred = NULL;
 113         spin_unlock(&clp->cl_lock);
 114         if (cred != NULL)
 115                 put_rpccred(cred);
 116 }
 117
 118 static struct rpc_cred *
 119 nfs4_get_renew_cred_server_locked(struct nfs_server *server)
 120 {
 121         struct rpc_cred *cred = NULL;
 122         struct nfs4_state_owner *sp;
 123         struct rb_node *pos;
 124
 125         for (pos = rb_first(&server->state_owners);
 126              pos != NULL;
 127              pos = rb_next(pos)) {
 128                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
 129                 if (list_empty(&sp->so_states))
 130                         continue;
 131                 cred = get_rpccred(sp->so_cred);
 132                 break;
 133         }
 134         return cred;
 135 }
 136
 137 /**
 138  * nfs4_get_renew_cred_locked - Acquire credential for a renew operation
 139  * @clp: client state handle
 140  *
 141  * Returns an rpc_cred with reference count bumped, or NULL.
 142  * Caller must hold clp->cl_lock.
 143  */
 144 struct rpc_cred *nfs4_get_renew_cred_locked(struct nfs_client *clp)
 145 {
 146         struct rpc_cred *cred = NULL;
 147         struct nfs_server *server;
 148
 149         rcu_read_lock();
 150         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 151                 cred = nfs4_get_renew_cred_server_locked(server);
 152                 if (cred != NULL)
 153                         break;
 154         }
 155         rcu_read_unlock();
 156         return cred;
 157 }
 158
 159 #if defined(CONFIG_NFS_V4_1)
 160
 161 static int nfs41_setup_state_renewal(struct nfs_client *clp)
 162 {
 163         int status;
 164         struct nfs_fsinfo fsinfo;
 165
 166         if (!test_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state)) {
 167                 nfs4_schedule_state_renewal(clp);
 168                 return 0;
 169         }
 170
 171         status = nfs4_proc_get_lease_time(clp, &fsinfo);
 172         if (status == 0) {
 173                 /* Update lease time and schedule renewal */
 174                 spin_lock(&clp->cl_lock);
 175                 clp->cl_lease_time = fsinfo.lease_time * HZ;
 176                 clp->cl_last_renewal = jiffies;
 177                 spin_unlock(&clp->cl_lock);
 178
 179                 nfs4_schedule_state_renewal(clp);
 180         }
 181
 182         return status;
 183 }
 184
 185 /*
 186  * Back channel returns NFS4ERR_DELAY for new requests when
 187  * NFS4_SESSION_DRAINING is set so there is no work to be done when draining
 188  * is ended.
 189  */
 190 static void nfs4_end_drain_session(struct nfs_client *clp)
 191 {
 192         struct nfs4_session *ses = clp->cl_session;
 193         int max_slots;
 194
 195         if (ses == NULL)
 196                 return;
 197         if (test_and_clear_bit(NFS4_SESSION_DRAINING, &ses->session_state)) {
 198                 spin_lock(&ses->fc_slot_table.slot_tbl_lock);
 199                 max_slots = ses->fc_slot_table.max_slots;
 200                 while (max_slots--) {
 201                         struct rpc_task *task;
 202
 203                         task = rpc_wake_up_next(&ses->fc_slot_table.
 204                                                 slot_tbl_waitq);
 205                         if (!task)
 206                                 break;
 207                         rpc_task_set_priority(task, RPC_PRIORITY_PRIVILEGED);
 208                 }
 209                 spin_unlock(&ses->fc_slot_table.slot_tbl_lock);
 210         }
 211 }
 212
 213 static int nfs4_wait_on_slot_tbl(struct nfs4_slot_table *tbl)
 214 {
 215         spin_lock(&tbl->slot_tbl_lock);
 216         if (tbl->highest_used_slotid != -1) {
 217                 INIT_COMPLETION(tbl->complete);
 218                 spin_unlock(&tbl->slot_tbl_lock);
 219                 return wait_for_completion_interruptible(&tbl->complete);
 220         }
 221         spin_unlock(&tbl->slot_tbl_lock);
 222         return 0;
 223 }
 224
 225 static int nfs4_begin_drain_session(struct nfs_client *clp)
 226 {
 227         struct nfs4_session *ses = clp->cl_session;
 228         int ret = 0;
 229
 230         set_bit(NFS4_SESSION_DRAINING, &ses->session_state);
 231         /* back channel */
 232         ret = nfs4_wait_on_slot_tbl(&ses->bc_slot_table);
 233         if (ret)
 234                 return ret;
 235         /* fore channel */
 236         return nfs4_wait_on_slot_tbl(&ses->fc_slot_table);
 237 }
 238
 239 int nfs41_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
 240 {
 241         int status;
 242
 243         if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
 244                 goto do_confirm;
 245         nfs4_begin_drain_session(clp);
 246         status = nfs4_proc_exchange_id(clp, cred);
 247         if (status != 0)
 248                 goto out;
 249         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 250 do_confirm:
 251         status = nfs4_proc_create_session(clp);
 252         if (status != 0)
 253                 goto out;
 254         clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 255         nfs41_setup_state_renewal(clp);
 256         nfs_mark_client_ready(clp, NFS_CS_READY);
 257 out:
 258         return status;
 259 }
 260
 261 struct rpc_cred *nfs4_get_exchange_id_cred(struct nfs_client *clp)
 262 {
 263         struct rpc_cred *cred;
 264
 265         spin_lock(&clp->cl_lock);
 266         cred = nfs4_get_machine_cred_locked(clp);
 267         spin_unlock(&clp->cl_lock);
 268         return cred;
 269 }
 270
 271 #endif /* CONFIG_NFS_V4_1 */
 272
 273 static struct rpc_cred *
 274 nfs4_get_setclientid_cred_server(struct nfs_server *server)
 275 {
 276         struct nfs_client *clp = server->nfs_client;
 277         struct rpc_cred *cred = NULL;
 278         struct nfs4_state_owner *sp;
 279         struct rb_node *pos;
 280
 281         spin_lock(&clp->cl_lock);
 282         pos = rb_first(&server->state_owners);
 283         if (pos != NULL) {
 284                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
 285                 cred = get_rpccred(sp->so_cred);
 286         }
 287         spin_unlock(&clp->cl_lock);
 288         return cred;
 289 }
 290
 291 /**
 292  * nfs4_get_setclientid_cred - Acquire credential for a setclientid operation
 293  * @clp: client state handle
 294  *
 295  * Returns an rpc_cred with reference count bumped, or NULL.
 296  */
 297 struct rpc_cred *nfs4_get_setclientid_cred(struct nfs_client *clp)
 298 {
 299         struct nfs_server *server;
 300         struct rpc_cred *cred;
 301
 302         spin_lock(&clp->cl_lock);
 303         cred = nfs4_get_machine_cred_locked(clp);
 304         spin_unlock(&clp->cl_lock);
 305         if (cred != NULL)
 306                 goto out;
 307
 308         rcu_read_lock();
 309         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 310                 cred = nfs4_get_setclientid_cred_server(server);
 311                 if (cred != NULL)
 312                         break;
 313         }
 314         rcu_read_unlock();
 315
 316 out:
 317         return cred;
 318 }
 319
 320 static void nfs_alloc_unique_id_locked(struct rb_root *root,
 321                                        struct nfs_unique_id *new,
 322                                        __u64 minval, int maxbits)
 323 {
 324         struct rb_node **p, *parent;
 325         struct nfs_unique_id *pos;
 326         __u64 mask = ~0ULL;
 327
 328         if (maxbits < 64)
 329                 mask = (1ULL << maxbits) - 1ULL;
 330
 331         /* Ensure distribution is more or less flat */
 332         get_random_bytes(&new->id, sizeof(new->id));
 333         new->id &= mask;
 334         if (new->id < minval)
 335                 new->id += minval;
 336 retry:
 337         p = &root->rb_node;
 338         parent = NULL;
 339
 340         while (*p != NULL) {
 341                 parent = *p;
 342                 pos = rb_entry(parent, struct nfs_unique_id, rb_node);
 343
 344                 if (new->id < pos->id)
 345                         p = &(*p)->rb_left;
 346                 else if (new->id > pos->id)
 347                         p = &(*p)->rb_right;
 348                 else
 349                         goto id_exists;
 350         }
 351         rb_link_node(&new->rb_node, parent, p);
 352         rb_insert_color(&new->rb_node, root);
 353         return;
 354 id_exists:
 355         for (;;) {
 356                 new->id++;
 357                 if (new->id < minval || (new->id & mask) != new->id) {
 358                         new->id = minval;
 359                         break;
 360                 }
 361                 parent = rb_next(parent);
 362                 if (parent == NULL)
 363                         break;
 364                 pos = rb_entry(parent, struct nfs_unique_id, rb_node);
 365                 if (new->id < pos->id)
 366                         break;
 367         }
 368         goto retry;
 369 }
 370
 371 static void nfs_free_unique_id(struct rb_root *root, struct nfs_unique_id *id)
 372 {
 373         rb_erase(&id->rb_node, root);
 374 }
 375
 376 static struct nfs4_state_owner *
 377 nfs4_find_state_owner_locked(struct nfs_server *server, struct rpc_cred *cred)
 378 {
 379         struct rb_node **p = &server->state_owners.rb_node,
 380                        *parent = NULL;
 381         struct nfs4_state_owner *sp;
 382
 383         while (*p != NULL) {
 384                 parent = *p;
 385                 sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
 386
 387                 if (cred < sp->so_cred)
 388                         p = &parent->rb_left;
 389                 else if (cred > sp->so_cred)
 390                         p = &parent->rb_right;
 391                 else {
 392                         if (!list_empty(&sp->so_lru))
 393                                 list_del_init(&sp->so_lru);
 394                         atomic_inc(&sp->so_count);
 395                         return sp;
 396                 }
 397         }
 398         return NULL;
 399 }
 400
 401 static struct nfs4_state_owner *
 402 nfs4_insert_state_owner_locked(struct nfs4_state_owner *new)
 403 {
 404         struct nfs_server *server = new->so_server;
 405         struct rb_node **p = &server->state_owners.rb_node,
 406                        *parent = NULL;
 407         struct nfs4_state_owner *sp;
 408
 409         while (*p != NULL) {
 410                 parent = *p;
 411                 sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
 412
 413                 if (new->so_cred < sp->so_cred)
 414                         p = &parent->rb_left;
 415                 else if (new->so_cred > sp->so_cred)
 416                         p = &parent->rb_right;
 417                 else {
 418                         if (!list_empty(&sp->so_lru))
 419                                 list_del_init(&sp->so_lru);
 420                         atomic_inc(&sp->so_count);
 421                         return sp;
 422                 }
 423         }
 424         nfs_alloc_unique_id_locked(&server->openowner_id,
 425                                         &new->so_owner_id, 1, 64);
 426         rb_link_node(&new->so_server_node, parent, p);
 427         rb_insert_color(&new->so_server_node, &server->state_owners);
 428         return new;
 429 }
 430
 431 static void
 432 nfs4_remove_state_owner_locked(struct nfs4_state_owner *sp)
 433 {
 434         struct nfs_server *server = sp->so_server;
 435
 436         if (!RB_EMPTY_NODE(&sp->so_server_node))
 437                 rb_erase(&sp->so_server_node, &server->state_owners);
 438         nfs_free_unique_id(&server->openowner_id, &sp->so_owner_id);
 439 }
 440
 441 /*
 442  * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
 443  * create a new state_owner.
 444  *
 445  */
 446 static struct nfs4_state_owner *
 447 nfs4_alloc_state_owner(void)
 448 {
 449         struct nfs4_state_owner *sp;
 450
 451         sp = kzalloc(sizeof(*sp),GFP_NOFS);
 452         if (!sp)
 453                 return NULL;
 454         spin_lock_init(&sp->so_lock);
 455         INIT_LIST_HEAD(&sp->so_states);
 456         rpc_init_wait_queue(&sp->so_sequence.wait, "Seqid_waitqueue");
 457         sp->so_seqid.sequence = &sp->so_sequence;
 458         spin_lock_init(&sp->so_sequence.lock);
 459         INIT_LIST_HEAD(&sp->so_sequence.list);
 460         atomic_set(&sp->so_count, 1);
 461         INIT_LIST_HEAD(&sp->so_lru);
 462         return sp;
 463 }
 464
 465 static void
 466 nfs4_drop_state_owner(struct nfs4_state_owner *sp)
 467 {
 468         if (!RB_EMPTY_NODE(&sp->so_server_node)) {
 469                 struct nfs_server *server = sp->so_server;
 470                 struct nfs_client *clp = server->nfs_client;
 471
 472                 spin_lock(&clp->cl_lock);
 473                 rb_erase(&sp->so_server_node, &server->state_owners);
 474                 RB_CLEAR_NODE(&sp->so_server_node);
 475                 spin_unlock(&clp->cl_lock);
 476         }
 477 }
 478
 479 static void nfs4_free_state_owner(struct nfs4_state_owner *sp)
 480 {
 481         rpc_destroy_wait_queue(&sp->so_sequence.wait);
 482         put_rpccred(sp->so_cred);
 483         kfree(sp);
 484 }
 485
 486 static void nfs4_gc_state_owners(struct nfs_server *server)
 487 {
 488         struct nfs_client *clp = server->nfs_client;
 489         struct nfs4_state_owner *sp, *tmp;
 490         unsigned long time_min, time_max;
 491         LIST_HEAD(doomed);
 492
 493         spin_lock(&clp->cl_lock);
 494         time_max = jiffies;
 495         time_min = (long)time_max - (long)clp->cl_lease_time;
 496         list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
 497                 /* NB: LRU is sorted so that oldest is at the head */
 498                 if (time_in_range(sp->so_expires, time_min, time_max))
 499                         break;
 500                 list_move(&sp->so_lru, &doomed);
 501                 nfs4_remove_state_owner_locked(sp);
 502         }
 503         spin_unlock(&clp->cl_lock);
 504
 505         list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
 506                 list_del(&sp->so_lru);
 507                 nfs4_free_state_owner(sp);
 508         }
 509 }
 510
 511 /**
 512  * nfs4_get_state_owner - Look up a state owner given a credential
 513  * @server: nfs_server to search
 514  * @cred: RPC credential to match
 515  *
 516  * Returns a pointer to an instantiated nfs4_state_owner struct, or NULL.
 517  */
 518 struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server,
 519                                               struct rpc_cred *cred)
 520 {
 521         struct nfs_client *clp = server->nfs_client;
 522         struct nfs4_state_owner *sp, *new;
 523
 524         spin_lock(&clp->cl_lock);
 525         sp = nfs4_find_state_owner_locked(server, cred);
 526         spin_unlock(&clp->cl_lock);
 527         if (sp != NULL)
 528                 goto out;
 529         new = nfs4_alloc_state_owner();
 530         if (new == NULL)
 531                 goto out;
 532         new->so_server = server;
 533         new->so_cred = cred;
 534         spin_lock(&clp->cl_lock);
 535         sp = nfs4_insert_state_owner_locked(new);
 536         spin_unlock(&clp->cl_lock);
 537         if (sp == new)
 538                 get_rpccred(cred);
 539         else {
 540                 rpc_destroy_wait_queue(&new->so_sequence.wait);
 541                 kfree(new);
 542         }
 543 out:
 544         nfs4_gc_state_owners(server);
 545         return sp;
 546 }
 547
 548 /**
 549  * nfs4_put_state_owner - Release a nfs4_state_owner
 550  * @sp: state owner data to release
 551  */
 552 void nfs4_put_state_owner(struct nfs4_state_owner *sp)
 553 {
 554         struct nfs_server *server = sp->so_server;
 555         struct nfs_client *clp = server->nfs_client;
 556
 557         if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
 558                 return;
 559
 560         if (!RB_EMPTY_NODE(&sp->so_server_node)) {
 561                 sp->so_expires = jiffies;
 562                 list_add_tail(&sp->so_lru, &server->state_owners_lru);
 563                 spin_unlock(&clp->cl_lock);
 564         } else {
 565                 nfs4_remove_state_owner_locked(sp);
 566                 spin_unlock(&clp->cl_lock);
 567                 nfs4_free_state_owner(sp);
 568         }
 569 }
 570
 571 /**
 572  * nfs4_purge_state_owners - Release all cached state owners
 573  * @server: nfs_server with cached state owners to release
 574  *
 575  * Called at umount time.  Remaining state owners will be on
 576  * the LRU with ref count of zero.
 577  */
 578 void nfs4_purge_state_owners(struct nfs_server *server)
 579 {
 580         struct nfs_client *clp = server->nfs_client;
 581         struct nfs4_state_owner *sp, *tmp;
 582         LIST_HEAD(doomed);
 583
 584         spin_lock(&clp->cl_lock);
 585         list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
 586                 list_move(&sp->so_lru, &doomed);
 587                 nfs4_remove_state_owner_locked(sp);
 588         }
 589         spin_unlock(&clp->cl_lock);
 590
 591         list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
 592                 list_del(&sp->so_lru);
 593                 nfs4_free_state_owner(sp);
 594         }
 595 }
 596
 597 static struct nfs4_state *
 598 nfs4_alloc_open_state(void)
 599 {
 600         struct nfs4_state *state;
 601
 602         state = kzalloc(sizeof(*state), GFP_NOFS);
 603         if (!state)
 604                 return NULL;
 605         atomic_set(&state->count, 1);
 606         INIT_LIST_HEAD(&state->lock_states);
 607         spin_lock_init(&state->state_lock);
 608         seqlock_init(&state->seqlock);
 609         return state;
 610 }
 611
 612 void
 613 nfs4_state_set_mode_locked(struct nfs4_state *state, fmode_t fmode)
 614 {
 615         if (state->state == fmode)
 616                 return;
 617         /* NB! List reordering - see the reclaim code for why.  */
 618         if ((fmode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
 619                 if (fmode & FMODE_WRITE)
 620                         list_move(&state->open_states, &state->owner->so_states);
 621                 else
 622                         list_move_tail(&state->open_states, &state->owner->so_states);
 623         }
 624         state->state = fmode;
 625 }
 626
 627 static struct nfs4_state *
 628 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
 629 {
 630         struct nfs_inode *nfsi = NFS_I(inode);
 631         struct nfs4_state *state;
 632
 633         list_for_each_entry(state, &nfsi->open_states, inode_states) {
 634                 if (state->owner != owner)
 635                         continue;
 636                 if (atomic_inc_not_zero(&state->count))
 637                         return state;
 638         }
 639         return NULL;
 640 }
 641
 642 static void
 643 nfs4_free_open_state(struct nfs4_state *state)
 644 {
 645         kfree(state);
 646 }
 647
 648 struct nfs4_state *
 649 nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
 650 {
 651         struct nfs4_state *state, *new;
 652         struct nfs_inode *nfsi = NFS_I(inode);
 653
 654         spin_lock(&inode->i_lock);
 655         state = __nfs4_find_state_byowner(inode, owner);
 656         spin_unlock(&inode->i_lock);
 657         if (state)
 658                 goto out;
 659         new = nfs4_alloc_open_state();
 660         spin_lock(&owner->so_lock);
 661         spin_lock(&inode->i_lock);
 662         state = __nfs4_find_state_byowner(inode, owner);
 663         if (state == NULL && new != NULL) {
 664                 state = new;
 665                 state->owner = owner;
 666                 atomic_inc(&owner->so_count);
 667                 list_add(&state->inode_states, &nfsi->open_states);
 668                 ihold(inode);
 669                 state->inode = inode;
 670                 spin_unlock(&inode->i_lock);
 671                 /* Note: The reclaim code dictates that we add stateless
 672                  * and read-only stateids to the end of the list */
 673                 list_add_tail(&state->open_states, &owner->so_states);
 674                 spin_unlock(&owner->so_lock);
 675         } else {
 676                 spin_unlock(&inode->i_lock);
 677                 spin_unlock(&owner->so_lock);
 678                 if (new)
 679                         nfs4_free_open_state(new);
 680         }
 681 out:
 682         return state;
 683 }
 684
 685 void nfs4_put_open_state(struct nfs4_state *state)
 686 {
 687         struct inode *inode = state->inode;
 688         struct nfs4_state_owner *owner = state->owner;
 689
 690         if (!atomic_dec_and_lock(&state->count, &owner->so_lock))
 691                 return;
 692         spin_lock(&inode->i_lock);
 693         list_del(&state->inode_states);
 694         list_del(&state->open_states);
 695         spin_unlock(&inode->i_lock);
 696         spin_unlock(&owner->so_lock);
 697         iput(inode);
 698         nfs4_free_open_state(state);
 699         nfs4_put_state_owner(owner);
 700 }
 701
 702 /*
 703  * Close the current file.
 704  */
 705 static void __nfs4_close(struct nfs4_state *state,
 706                 fmode_t fmode, gfp_t gfp_mask, int wait)
 707 {
 708         struct nfs4_state_owner *owner = state->owner;
 709         int call_close = 0;
 710         fmode_t newstate;
 711
 712         atomic_inc(&owner->so_count);
 713         /* Protect against nfs4_find_state() */
 714         spin_lock(&owner->so_lock);
 715         switch (fmode & (FMODE_READ | FMODE_WRITE)) {
 716                 case FMODE_READ:
 717                         state->n_rdonly--;
 718                         break;
 719                 case FMODE_WRITE:
 720                         state->n_wronly--;
 721                         break;
 722                 case FMODE_READ|FMODE_WRITE:
 723                         state->n_rdwr--;
 724         }
 725         newstate = FMODE_READ|FMODE_WRITE;
 726         if (state->n_rdwr == 0) {
 727                 if (state->n_rdonly == 0) {
 728                         newstate &= ~FMODE_READ;
 729                         call_close |= test_bit(NFS_O_RDONLY_STATE, &state->flags);
 730                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
 731                 }
 732                 if (state->n_wronly == 0) {
 733                         newstate &= ~FMODE_WRITE;
 734                         call_close |= test_bit(NFS_O_WRONLY_STATE, &state->flags);
 735                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
 736                 }
 737                 if (newstate == 0)
 738                         clear_bit(NFS_DELEGATED_STATE, &state->flags);
 739         }
 740         nfs4_state_set_mode_locked(state, newstate);
 741         spin_unlock(&owner->so_lock);
 742
 743         if (!call_close) {
 744                 nfs4_put_open_state(state);
 745                 nfs4_put_state_owner(owner);
 746         } else {
 747                 bool roc = pnfs_roc(state->inode);
 748
 749                 nfs4_do_close(state, gfp_mask, wait, roc);
 750         }
 751 }
 752
 753 void nfs4_close_state(struct nfs4_state *state, fmode_t fmode)
 754 {
 755         __nfs4_close(state, fmode, GFP_NOFS, 0);
 756 }
 757
 758 void nfs4_close_sync(struct nfs4_state *state, fmode_t fmode)
 759 {
 760         __nfs4_close(state, fmode, GFP_KERNEL, 1);
 761 }
 762
 763 /*
 764  * Search the state->lock_states for an existing lock_owner
 765  * that is compatible with current->files
 766  */
 767 static struct nfs4_lock_state *
 768 __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner, pid_t fl_pid, unsigned int type)
 769 {
 770         struct nfs4_lock_state *pos;
 771         list_for_each_entry(pos, &state->lock_states, ls_locks) {
 772                 if (type != NFS4_ANY_LOCK_TYPE && pos->ls_owner.lo_type != type)
 773                         continue;
 774                 switch (pos->ls_owner.lo_type) {
 775                 case NFS4_POSIX_LOCK_TYPE:
 776                         if (pos->ls_owner.lo_u.posix_owner != fl_owner)
 777                                 continue;
 778                         break;
 779                 case NFS4_FLOCK_LOCK_TYPE:
 780                         if (pos->ls_owner.lo_u.flock_owner != fl_pid)
 781                                 continue;
 782                 }
 783                 atomic_inc(&pos->ls_count);
 784                 return pos;
 785         }
 786         return NULL;
 787 }
 788
 789 /*
 790  * Return a compatible lock_state. If no initialized lock_state structure
 791  * exists, return an uninitialized one.
 792  *
 793  */
 794 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)
 795 {
 796         struct nfs4_lock_state *lsp;
 797         struct nfs_server *server = state->owner->so_server;
 798         struct nfs_client *clp = server->nfs_client;
 799
 800         lsp = kzalloc(sizeof(*lsp), GFP_NOFS);
 801         if (lsp == NULL)
 802                 return NULL;
 803         rpc_init_wait_queue(&lsp->ls_sequence.wait, "lock_seqid_waitqueue");
 804         spin_lock_init(&lsp->ls_sequence.lock);
 805         INIT_LIST_HEAD(&lsp->ls_sequence.list);
 806         lsp->ls_seqid.sequence = &lsp->ls_sequence;
 807         atomic_set(&lsp->ls_count, 1);
 808         lsp->ls_state = state;
 809         lsp->ls_owner.lo_type = type;
 810         switch (lsp->ls_owner.lo_type) {
 811         case NFS4_FLOCK_LOCK_TYPE:
 812                 lsp->ls_owner.lo_u.flock_owner = fl_pid;
 813                 break;
 814         case NFS4_POSIX_LOCK_TYPE:
 815                 lsp->ls_owner.lo_u.posix_owner = fl_owner;
 816                 break;
 817         default:
 818                 kfree(lsp);
 819                 return NULL;
 820         }
 821         spin_lock(&clp->cl_lock);
 822         nfs_alloc_unique_id_locked(&server->lockowner_id, &lsp->ls_id, 1, 64);
 823         spin_unlock(&clp->cl_lock);
 824         INIT_LIST_HEAD(&lsp->ls_locks);
 825         return lsp;
 826 }
 827
 828 static void nfs4_free_lock_state(struct nfs4_lock_state *lsp)
 829 {
 830         struct nfs_server *server = lsp->ls_state->owner->so_server;
 831         struct nfs_client *clp = server->nfs_client;
 832
 833         spin_lock(&clp->cl_lock);
 834         nfs_free_unique_id(&server->lockowner_id, &lsp->ls_id);
 835         spin_unlock(&clp->cl_lock);
 836         rpc_destroy_wait_queue(&lsp->ls_sequence.wait);
 837         kfree(lsp);
 838 }
 839
 840 /*
 841  * Return a compatible lock_state. If no initialized lock_state structure
 842  * exists, return an uninitialized one.
 843  *
 844  */
 845 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner, pid_t pid, unsigned int type)
 846 {
 847         struct nfs4_lock_state *lsp, *new = NULL;
 848
 849         for(;;) {
 850                 spin_lock(&state->state_lock);
 851                 lsp = __nfs4_find_lock_state(state, owner, pid, type);
 852                 if (lsp != NULL)
 853                         break;
 854                 if (new != NULL) {
 855                         list_add(&new->ls_locks, &state->lock_states);
 856                         set_bit(LK_STATE_IN_USE, &state->flags);
 857                         lsp = new;
 858                         new = NULL;
 859                         break;
 860                 }
 861                 spin_unlock(&state->state_lock);
 862                 new = nfs4_alloc_lock_state(state, owner, pid, type);
 863                 if (new == NULL)
 864                         return NULL;
 865         }
 866         spin_unlock(&state->state_lock);
 867         if (new != NULL)
 868                 nfs4_free_lock_state(new);
 869         return lsp;
 870 }
 871
 872 /*
 873  * Release reference to lock_state, and free it if we see that
 874  * it is no longer in use
 875  */
 876 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
 877 {
 878         struct nfs4_state *state;
 879
 880         if (lsp == NULL)
 881                 return;
 882         state = lsp->ls_state;
 883         if (!atomic_dec_and_lock(&lsp->ls_count, &state->state_lock))
 884                 return;
 885         list_del(&lsp->ls_locks);
 886         if (list_empty(&state->lock_states))
 887                 clear_bit(LK_STATE_IN_USE, &state->flags);
 888         spin_unlock(&state->state_lock);
 889         if (lsp->ls_flags & NFS_LOCK_INITIALIZED)
 890                 nfs4_release_lockowner(lsp);
 891         nfs4_free_lock_state(lsp);
 892 }
 893
 894 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
 895 {
 896         struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
 897
 898         dst->fl_u.nfs4_fl.owner = lsp;
 899         atomic_inc(&lsp->ls_count);
 900 }
 901
 902 static void nfs4_fl_release_lock(struct file_lock *fl)
 903 {
 904         nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
 905 }
 906
 907 static const struct file_lock_operations nfs4_fl_lock_ops = {
 908         .fl_copy_lock = nfs4_fl_copy_lock,
 909         .fl_release_private = nfs4_fl_release_lock,
 910 };
 911
 912 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
 913 {
 914         struct nfs4_lock_state *lsp;
 915
 916         if (fl->fl_ops != NULL)
 917                 return 0;
 918         if (fl->fl_flags & FL_POSIX)
 919                 lsp = nfs4_get_lock_state(state, fl->fl_owner, 0, NFS4_POSIX_LOCK_TYPE);
 920         else if (fl->fl_flags & FL_FLOCK)
 921                 lsp = nfs4_get_lock_state(state, 0, fl->fl_pid, NFS4_FLOCK_LOCK_TYPE);
 922         else
 923                 return -EINVAL;
 924         if (lsp == NULL)
 925                 return -ENOMEM;
 926         fl->fl_u.nfs4_fl.owner = lsp;
 927         fl->fl_ops = &nfs4_fl_lock_ops;
 928         return 0;
 929 }
 930
 931 /*
 932  * Byte-range lock aware utility to initialize the stateid of read/write
 933  * requests.
 934  */
 935 void nfs4_copy_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t fl_owner, pid_t fl_pid)
 936 {
 937         struct nfs4_lock_state *lsp;
 938         int seq;
 939
 940         do {
 941                 seq = read_seqbegin(&state->seqlock);
 942                 memcpy(dst, &state->stateid, sizeof(*dst));
 943         } while (read_seqretry(&state->seqlock, seq));
 944         if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
 945                 return;
 946
 947         spin_lock(&state->state_lock);
 948         lsp = __nfs4_find_lock_state(state, fl_owner, fl_pid, NFS4_ANY_LOCK_TYPE);
 949         if (lsp != NULL && (lsp->ls_flags & NFS_LOCK_INITIALIZED) != 0)
 950                 memcpy(dst, &lsp->ls_stateid, sizeof(*dst));
 951         spin_unlock(&state->state_lock);
 952         nfs4_put_lock_state(lsp);
 953 }
 954
 955 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask)
 956 {
 957         struct nfs_seqid *new;
 958
 959         new = kmalloc(sizeof(*new), gfp_mask);
 960         if (new != NULL) {
 961                 new->sequence = counter;
 962                 INIT_LIST_HEAD(&new->list);
 963         }
 964         return new;
 965 }
 966
 967 void nfs_release_seqid(struct nfs_seqid *seqid)
 968 {
 969         if (!list_empty(&seqid->list)) {
 970                 struct rpc_sequence *sequence = seqid->sequence->sequence;
 971
 972                 spin_lock(&sequence->lock);
 973                 list_del_init(&seqid->list);
 974                 spin_unlock(&sequence->lock);
 975                 rpc_wake_up(&sequence->wait);
 976         }
 977 }
 978
 979 void nfs_free_seqid(struct nfs_seqid *seqid)
 980 {
 981         nfs_release_seqid(seqid);
 982         kfree(seqid);
 983 }
 984
 985 /*
 986  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
 987  * failed with a seqid incrementing error -
 988  * see comments nfs_fs.h:seqid_mutating_error()
 989  */
 990 static void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
 991 {
 992         BUG_ON(list_first_entry(&seqid->sequence->sequence->list, struct nfs_seqid, list) != seqid);
 993         switch (status) {
 994                 case 0:
 995                         break;
 996                 case -NFS4ERR_BAD_SEQID:
 997                         if (seqid->sequence->flags & NFS_SEQID_CONFIRMED)
 998                                 return;
 999                         printk(KERN_WARNING "NFS: v4 server returned a bad"
1000                                         " sequence-id error on an"
1001                                         " unconfirmed sequence %p!\n",
1002                                         seqid->sequence);
1003                 case -NFS4ERR_STALE_CLIENTID:
1004                 case -NFS4ERR_STALE_STATEID:
1005                 case -NFS4ERR_BAD_STATEID:
1006                 case -NFS4ERR_BADXDR:
1007                 case -NFS4ERR_RESOURCE:
1008                 case -NFS4ERR_NOFILEHANDLE:
1009                         /* Non-seqid mutating errors */
1010                         return;
1011         };
1012         /*
1013          * Note: no locking needed as we are guaranteed to be first
1014          * on the sequence list
1015          */
1016         seqid->sequence->counter++;
1017 }
1018
1019 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
1020 {
1021         struct nfs4_state_owner *sp = container_of(seqid->sequence,
1022                                         struct nfs4_state_owner, so_seqid);
1023         struct nfs_server *server = sp->so_server;
1024
1025         if (status == -NFS4ERR_BAD_SEQID)
1026                 nfs4_drop_state_owner(sp);
1027         if (!nfs4_has_session(server->nfs_client))
1028                 nfs_increment_seqid(status, seqid);
1029 }
1030
1031 /*
1032  * Increment the seqid if the LOCK/LOCKU succeeded, or
1033  * failed with a seqid incrementing error -
1034  * see comments nfs_fs.h:seqid_mutating_error()
1035  */
1036 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
1037 {
1038         nfs_increment_seqid(status, seqid);
1039 }
1040
1041 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
1042 {
1043         struct rpc_sequence *sequence = seqid->sequence->sequence;
1044         int status = 0;
1045
1046         spin_lock(&sequence->lock);
1047         if (list_empty(&seqid->list))
1048                 list_add_tail(&seqid->list, &sequence->list);
1049         if (list_first_entry(&sequence->list, struct nfs_seqid, list) == seqid)
1050                 goto unlock;
1051         rpc_sleep_on(&sequence->wait, task, NULL);
1052         status = -EAGAIN;
1053 unlock:
1054         spin_unlock(&sequence->lock);
1055         return status;
1056 }
1057
1058 static int nfs4_run_state_manager(void *);
1059
1060 static void nfs4_clear_state_manager_bit(struct nfs_client *clp)
1061 {
1062         smp_mb__before_clear_bit();
1063         clear_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state);
1064         smp_mb__after_clear_bit();
1065         wake_up_bit(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING);
1066         rpc_wake_up(&clp->cl_rpcwaitq);
1067 }
1068
1069 /*
1070  * Schedule the nfs_client asynchronous state management routine
1071  */
1072 void nfs4_schedule_state_manager(struct nfs_client *clp)
1073 {
1074         struct task_struct *task;
1075
1076         if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
1077                 return;
1078         __module_get(THIS_MODULE);
1079         atomic_inc(&clp->cl_count);
1080         task = kthread_run(nfs4_run_state_manager, clp, "%s-manager",
1081                                 rpc_peeraddr2str(clp->cl_rpcclient,
1082                                                         RPC_DISPLAY_ADDR));
1083         if (!IS_ERR(task))
1084                 return;
1085         nfs4_clear_state_manager_bit(clp);
1086         nfs_put_client(clp);
1087         module_put(THIS_MODULE);
1088 }
1089
1090 /*
1091  * Schedule a lease recovery attempt
1092  */
1093 void nfs4_schedule_lease_recovery(struct nfs_client *clp)
1094 {
1095         if (!clp)
1096                 return;
1097         if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1098                 set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1099         nfs4_schedule_state_manager(clp);
1100 }
1101
1102 void nfs4_schedule_path_down_recovery(struct nfs_client *clp)
1103 {
1104         nfs_handle_cb_pathdown(clp);
1105         nfs4_schedule_state_manager(clp);
1106 }
1107
1108 static int nfs4_state_mark_reclaim_reboot(struct nfs_client *clp, struct nfs4_state *state)
1109 {
1110
1111         set_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1112         /* Don't recover state that expired before the reboot */
1113         if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags)) {
1114                 clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1115                 return 0;
1116         }
1117         set_bit(NFS_OWNER_RECLAIM_REBOOT, &state->owner->so_flags);
1118         set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1119         return 1;
1120 }
1121
1122 static int nfs4_state_mark_reclaim_nograce(struct nfs_client *clp, struct nfs4_state *state)
1123 {
1124         set_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1125         clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1126         set_bit(NFS_OWNER_RECLAIM_NOGRACE, &state->owner->so_flags);
1127         set_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
1128         return 1;
1129 }
1130
1131 void nfs4_schedule_stateid_recovery(const struct nfs_server *server, struct nfs4_state *state)
1132 {
1133         struct nfs_client *clp = server->nfs_client;
1134
1135         nfs4_state_mark_reclaim_nograce(clp, state);
1136         nfs4_schedule_state_manager(clp);
1137 }
1138
1139 static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_recovery_ops *ops)
1140 {
1141         struct inode *inode = state->inode;
1142         struct nfs_inode *nfsi = NFS_I(inode);
1143         struct file_lock *fl;
1144         int status = 0;
1145
1146         if (inode->i_flock == NULL)
1147                 return 0;
1148
1149         /* Guard against delegation returns and new lock/unlock calls */
1150         down_write(&nfsi->rwsem);
1151         /* Protect inode->i_flock using the BKL */
1152         lock_flocks();
1153         for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
1154                 if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
1155                         continue;
1156                 if (nfs_file_open_context(fl->fl_file)->state != state)
1157                         continue;
1158                 unlock_flocks();
1159                 status = ops->recover_lock(state, fl);
1160                 switch (status) {
1161                         case 0:
1162                                 break;
1163                         case -ESTALE:
1164                         case -NFS4ERR_ADMIN_REVOKED:
1165                         case -NFS4ERR_STALE_STATEID:
1166                         case -NFS4ERR_BAD_STATEID:
1167                         case -NFS4ERR_EXPIRED:
1168                         case -NFS4ERR_NO_GRACE:
1169                         case -NFS4ERR_STALE_CLIENTID:
1170                         case -NFS4ERR_BADSESSION:
1171                         case -NFS4ERR_BADSLOT:
1172                         case -NFS4ERR_BAD_HIGH_SLOT:
1173                         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1174                                 goto out;
1175                         default:
1176                                 printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
1177                                                 __func__, status);
1178                         case -ENOMEM:
1179                         case -NFS4ERR_DENIED:
1180                         case -NFS4ERR_RECLAIM_BAD:
1181                         case -NFS4ERR_RECLAIM_CONFLICT:
1182                                 /* kill_proc(fl->fl_pid, SIGLOST, 1); */
1183                                 status = 0;
1184                 }
1185                 lock_flocks();
1186         }
1187         unlock_flocks();
1188 out:
1189         up_write(&nfsi->rwsem);
1190         return status;
1191 }
1192
1193 static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs4_state_recovery_ops *ops)
1194 {
1195         struct nfs4_state *state;
1196         struct nfs4_lock_state *lock;
1197         int status = 0;
1198
1199         /* Note: we rely on the sp->so_states list being ordered
1200          * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
1201          * states first.
1202          * This is needed to ensure that the server won't give us any
1203          * read delegations that we have to return if, say, we are
1204          * recovering after a network partition or a reboot from a
1205          * server that doesn't support a grace period.
1206          */
1207 restart:
1208         spin_lock(&sp->so_lock);
1209         list_for_each_entry(state, &sp->so_states, open_states) {
1210                 if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
1211                         continue;
1212                 if (state->state == 0)
1213                         continue;
1214                 atomic_inc(&state->count);
1215                 spin_unlock(&sp->so_lock);
1216                 status = ops->recover_open(sp, state);
1217                 if (status >= 0) {
1218                         status = nfs4_reclaim_locks(state, ops);
1219                         if (status >= 0) {
1220                                 spin_lock(&state->state_lock);
1221                                 list_for_each_entry(lock, &state->lock_states, ls_locks) {
1222                                         if (!(lock->ls_flags & NFS_LOCK_INITIALIZED))
1223                                                 printk("%s: Lock reclaim failed!\n",
1224                                                         __func__);
1225                                 }
1226                                 spin_unlock(&state->state_lock);
1227                                 nfs4_put_open_state(state);
1228                                 goto restart;
1229                         }
1230                 }
1231                 switch (status) {
1232                         default:
1233                                 printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
1234                                                 __func__, status);
1235                         case -ENOENT:
1236                         case -ENOMEM:
1237                         case -ESTALE:
1238                                 /*
1239                                  * Open state on this file cannot be recovered
1240                                  * All we can do is revert to using the zero stateid.
1241                                  */
1242                                 memset(state->stateid.data, 0,
1243                                         sizeof(state->stateid.data));
1244                                 /* Mark the file as being 'closed' */
1245                                 state->state = 0;
1246                                 break;
1247                         case -EKEYEXPIRED:
1248                                 /*
1249                                  * User RPCSEC_GSS context has expired.
1250                                  * We cannot recover this stateid now, so
1251                                  * skip it and allow recovery thread to
1252                                  * proceed.
1253                                  */
1254                                 break;
1255                         case -NFS4ERR_ADMIN_REVOKED:
1256                         case -NFS4ERR_STALE_STATEID:
1257                         case -NFS4ERR_BAD_STATEID:
1258                         case -NFS4ERR_RECLAIM_BAD:
1259                         case -NFS4ERR_RECLAIM_CONFLICT:
1260                                 nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1261                                 break;
1262                         case -NFS4ERR_EXPIRED:
1263                         case -NFS4ERR_NO_GRACE:
1264                                 nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1265                         case -NFS4ERR_STALE_CLIENTID:
1266                         case -NFS4ERR_BADSESSION:
1267                         case -NFS4ERR_BADSLOT:
1268                         case -NFS4ERR_BAD_HIGH_SLOT:
1269                         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1270                                 goto out_err;
1271                 }
1272                 nfs4_put_open_state(state);
1273                 goto restart;
1274         }
1275         spin_unlock(&sp->so_lock);
1276         return 0;
1277 out_err:
1278         nfs4_put_open_state(state);
1279         return status;
1280 }
1281
1282 static void nfs4_clear_open_state(struct nfs4_state *state)
1283 {
1284         struct nfs4_lock_state *lock;
1285
1286         clear_bit(NFS_DELEGATED_STATE, &state->flags);
1287         clear_bit(NFS_O_RDONLY_STATE, &state->flags);
1288         clear_bit(NFS_O_WRONLY_STATE, &state->flags);
1289         clear_bit(NFS_O_RDWR_STATE, &state->flags);
1290         spin_lock(&state->state_lock);
1291         list_for_each_entry(lock, &state->lock_states, ls_locks) {
1292                 lock->ls_seqid.flags = 0;
1293                 lock->ls_flags &= ~NFS_LOCK_INITIALIZED;
1294         }
1295         spin_unlock(&state->state_lock);
1296 }
1297
1298 static void nfs4_reset_seqids(struct nfs_server *server,
1299         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1300 {
1301         struct nfs_client *clp = server->nfs_client;
1302         struct nfs4_state_owner *sp;
1303         struct rb_node *pos;
1304         struct nfs4_state *state;
1305
1306         spin_lock(&clp->cl_lock);
1307         for (pos = rb_first(&server->state_owners);
1308              pos != NULL;
1309              pos = rb_next(pos)) {
1310                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1311                 sp->so_seqid.flags = 0;
1312                 spin_lock(&sp->so_lock);
1313                 list_for_each_entry(state, &sp->so_states, open_states) {
1314                         if (mark_reclaim(clp, state))
1315                                 nfs4_clear_open_state(state);
1316                 }
1317                 spin_unlock(&sp->so_lock);
1318         }
1319         spin_unlock(&clp->cl_lock);
1320 }
1321
1322 static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp,
1323         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1324 {
1325         struct nfs_server *server;
1326
1327         rcu_read_lock();
1328         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1329                 nfs4_reset_seqids(server, mark_reclaim);
1330         rcu_read_unlock();
1331 }
1332
1333 static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp)
1334 {
1335         /* Mark all delegations for reclaim */
1336         nfs_delegation_mark_reclaim(clp);
1337         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_reboot);
1338 }
1339
1340 static void nfs4_reclaim_complete(struct nfs_client *clp,
1341                                  const struct nfs4_state_recovery_ops *ops)
1342 {
1343         /* Notify the server we're done reclaiming our state */
1344         if (ops->reclaim_complete)
1345                 (void)ops->reclaim_complete(clp);
1346 }
1347
1348 static void nfs4_clear_reclaim_server(struct nfs_server *server)
1349 {
1350         struct nfs_client *clp = server->nfs_client;
1351         struct nfs4_state_owner *sp;
1352         struct rb_node *pos;
1353         struct nfs4_state *state;
1354
1355         spin_lock(&clp->cl_lock);
1356         for (pos = rb_first(&server->state_owners);
1357              pos != NULL;
1358              pos = rb_next(pos)) {
1359                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1360                 spin_lock(&sp->so_lock);
1361                 list_for_each_entry(state, &sp->so_states, open_states) {
1362                         if (!test_and_clear_bit(NFS_STATE_RECLAIM_REBOOT,
1363                                                 &state->flags))
1364                                 continue;
1365                         nfs4_state_mark_reclaim_nograce(clp, state);
1366                 }
1367                 spin_unlock(&sp->so_lock);
1368         }
1369         spin_unlock(&clp->cl_lock);
1370 }
1371
1372 static int nfs4_state_clear_reclaim_reboot(struct nfs_client *clp)
1373 {
1374         struct nfs_server *server;
1375
1376         if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
1377                 return 0;
1378
1379         rcu_read_lock();
1380         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1381                 nfs4_clear_reclaim_server(server);
1382         rcu_read_unlock();
1383
1384         nfs_delegation_reap_unclaimed(clp);
1385         return 1;
1386 }
1387
1388 static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
1389 {
1390         if (!nfs4_state_clear_reclaim_reboot(clp))
1391                 return;
1392         nfs4_reclaim_complete(clp, clp->cl_mvops->reboot_recovery_ops);
1393 }
1394
1395 static void nfs_delegation_clear_all(struct nfs_client *clp)
1396 {
1397         nfs_delegation_mark_reclaim(clp);
1398         nfs_delegation_reap_unclaimed(clp);
1399 }
1400
1401 static void nfs4_state_start_reclaim_nograce(struct nfs_client *clp)
1402 {
1403         nfs_delegation_clear_all(clp);
1404         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
1405 }
1406
1407 static void nfs4_warn_keyexpired(const char *s)
1408 {
1409         printk_ratelimited(KERN_WARNING "Error: state manager"
1410                         " encountered RPCSEC_GSS session"
1411                         " expired against NFSv4 server %s.\n",
1412                         s);
1413 }
1414
1415 static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
1416 {
1417         switch (error) {
1418                 case 0:
1419                         break;
1420                 case -NFS4ERR_CB_PATH_DOWN:
1421                         nfs_handle_cb_pathdown(clp);
1422                         break;
1423                 case -NFS4ERR_NO_GRACE:
1424                         nfs4_state_end_reclaim_reboot(clp);
1425                         break;
1426                 case -NFS4ERR_STALE_CLIENTID:
1427                 case -NFS4ERR_LEASE_MOVED:
1428                         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1429                         nfs4_state_clear_reclaim_reboot(clp);
1430                         nfs4_state_start_reclaim_reboot(clp);
1431                         break;
1432                 case -NFS4ERR_EXPIRED:
1433                         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1434                         nfs4_state_start_reclaim_nograce(clp);
1435                         break;
1436                 case -NFS4ERR_BADSESSION:
1437                 case -NFS4ERR_BADSLOT:
1438                 case -NFS4ERR_BAD_HIGH_SLOT:
1439                 case -NFS4ERR_DEADSESSION:
1440                 case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1441                 case -NFS4ERR_SEQ_FALSE_RETRY:
1442                 case -NFS4ERR_SEQ_MISORDERED:
1443                         set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
1444                         /* Zero session reset errors */
1445                         break;
1446                 case -EKEYEXPIRED:
1447                         /* Nothing we can do */
1448                         nfs4_warn_keyexpired(clp->cl_hostname);
1449                         break;
1450                 default:
1451                         return error;
1452         }
1453         return 0;
1454 }
1455
1456 static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recovery_ops *ops)
1457 {
1458         struct nfs4_state_owner *sp;
1459         struct nfs_server *server;
1460         struct rb_node *pos;
1461         int status = 0;
1462
1463 restart:
1464         rcu_read_lock();
1465         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1466                 nfs4_purge_state_owners(server);
1467                 spin_lock(&clp->cl_lock);
1468                 for (pos = rb_first(&server->state_owners);
1469                      pos != NULL;
1470                      pos = rb_next(pos)) {
1471                         sp = rb_entry(pos,
1472                                 struct nfs4_state_owner, so_server_node);
1473                         if (!test_and_clear_bit(ops->owner_flag_bit,
1474                                                         &sp->so_flags))
1475                                 continue;
1476                         atomic_inc(&sp->so_count);
1477                         spin_unlock(&clp->cl_lock);
1478                         rcu_read_unlock();
1479
1480                         status = nfs4_reclaim_open_state(sp, ops);
1481                         if (status < 0) {
1482                                 set_bit(ops->owner_flag_bit, &sp->so_flags);
1483                                 nfs4_put_state_owner(sp);
1484                                 return nfs4_recovery_handle_error(clp, status);
1485                         }
1486
1487                         nfs4_put_state_owner(sp);
1488                         goto restart;
1489                 }
1490                 spin_unlock(&clp->cl_lock);
1491         }
1492         rcu_read_unlock();
1493         return status;
1494 }
1495
1496 static int nfs4_check_lease(struct nfs_client *clp)
1497 {
1498         struct rpc_cred *cred;
1499         const struct nfs4_state_maintenance_ops *ops =
1500                 clp->cl_mvops->state_renewal_ops;
1501         int status;
1502
1503         /* Is the client already known to have an expired lease? */
1504         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1505                 return 0;
1506         spin_lock(&clp->cl_lock);
1507         cred = ops->get_state_renewal_cred_locked(clp);
1508         spin_unlock(&clp->cl_lock);
1509         if (cred == NULL) {
1510                 cred = nfs4_get_setclientid_cred(clp);
1511                 status = -ENOKEY;
1512                 if (cred == NULL)
1513                         goto out;
1514         }
1515         status = ops->renew_lease(clp, cred);
1516         put_rpccred(cred);
1517 out:
1518         return nfs4_recovery_handle_error(clp, status);
1519 }
1520
1521 static int nfs4_reclaim_lease(struct nfs_client *clp)
1522 {
1523         struct rpc_cred *cred;
1524         const struct nfs4_state_recovery_ops *ops =
1525                 clp->cl_mvops->reboot_recovery_ops;
1526         int status = -ENOENT;
1527
1528         cred = ops->get_clid_cred(clp);
1529         if (cred != NULL) {
1530                 status = ops->establish_clid(clp, cred);
1531                 put_rpccred(cred);
1532                 /* Handle case where the user hasn't set up machine creds */
1533                 if (status == -EACCES && cred == clp->cl_machine_cred) {
1534                         nfs4_clear_machine_cred(clp);
1535                         status = -EAGAIN;
1536                 }
1537                 if (status == -NFS4ERR_MINOR_VERS_MISMATCH)
1538                         status = -EPROTONOSUPPORT;
1539         }
1540         return status;
1541 }
1542
1543 #ifdef CONFIG_NFS_V4_1
1544 void nfs4_schedule_session_recovery(struct nfs4_session *session)
1545 {
1546         struct nfs_client *clp = session->clp;
1547
1548         set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
1549         nfs4_schedule_lease_recovery(clp);
1550 }
1551 EXPORT_SYMBOL_GPL(nfs4_schedule_session_recovery);
1552
1553 void nfs41_handle_recall_slot(struct nfs_client *clp)
1554 {
1555         set_bit(NFS4CLNT_RECALL_SLOT, &clp->cl_state);
1556         nfs4_schedule_state_manager(clp);
1557 }
1558
1559 static void nfs4_reset_all_state(struct nfs_client *clp)
1560 {
1561         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
1562                 clp->cl_boot_time = CURRENT_TIME;
1563                 nfs4_state_start_reclaim_nograce(clp);
1564                 nfs4_schedule_state_manager(clp);
1565         }
1566 }
1567
1568 static void nfs41_handle_server_reboot(struct nfs_client *clp)
1569 {
1570         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
1571                 nfs4_state_start_reclaim_reboot(clp);
1572                 nfs4_schedule_state_manager(clp);
1573         }
1574 }
1575
1576 static void nfs41_handle_state_revoked(struct nfs_client *clp)
1577 {
1578         /* Temporary */
1579         nfs4_reset_all_state(clp);
1580 }
1581
1582 static void nfs41_handle_recallable_state_revoked(struct nfs_client *clp)
1583 {
1584         /* This will need to handle layouts too */
1585         nfs_expire_all_delegations(clp);
1586 }
1587
1588 static void nfs41_handle_cb_path_down(struct nfs_client *clp)
1589 {
1590         nfs_expire_all_delegations(clp);
1591         if (test_and_set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state) == 0)
1592                 nfs4_schedule_state_manager(clp);
1593 }
1594
1595 void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags)
1596 {
1597         if (!flags)
1598                 return;
1599         if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED)
1600                 nfs41_handle_server_reboot(clp);
1601         if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED |
1602                             SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED |
1603                             SEQ4_STATUS_ADMIN_STATE_REVOKED |
1604                             SEQ4_STATUS_LEASE_MOVED))
1605                 nfs41_handle_state_revoked(clp);
1606         if (flags & SEQ4_STATUS_RECALLABLE_STATE_REVOKED)
1607                 nfs41_handle_recallable_state_revoked(clp);
1608         if (flags & (SEQ4_STATUS_CB_PATH_DOWN |
1609                             SEQ4_STATUS_BACKCHANNEL_FAULT |
1610                             SEQ4_STATUS_CB_PATH_DOWN_SESSION))
1611                 nfs41_handle_cb_path_down(clp);
1612 }
1613
1614 static int nfs4_reset_session(struct nfs_client *clp)
1615 {
1616         int status;
1617
1618         nfs4_begin_drain_session(clp);
1619         status = nfs4_proc_destroy_session(clp->cl_session);
1620         if (status && status != -NFS4ERR_BADSESSION &&
1621             status != -NFS4ERR_DEADSESSION) {
1622                 status = nfs4_recovery_handle_error(clp, status);
1623                 goto out;
1624         }
1625
1626         memset(clp->cl_session->sess_id.data, 0, NFS4_MAX_SESSIONID_LEN);
1627         status = nfs4_proc_create_session(clp);
1628         if (status) {
1629                 status = nfs4_recovery_handle_error(clp, status);
1630                 goto out;
1631         }
1632         clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
1633         /* create_session negotiated new slot table */
1634         clear_bit(NFS4CLNT_RECALL_SLOT, &clp->cl_state);
1635
1636          /* Let the state manager reestablish state */
1637         if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1638                 nfs41_setup_state_renewal(clp);
1639 out:
1640         return status;
1641 }
1642
1643 static int nfs4_recall_slot(struct nfs_client *clp)
1644 {
1645         struct nfs4_slot_table *fc_tbl = &clp->cl_session->fc_slot_table;
1646         struct nfs4_channel_attrs *fc_attrs = &clp->cl_session->fc_attrs;
1647         struct nfs4_slot *new, *old;
1648         int i;
1649
1650         nfs4_begin_drain_session(clp);
1651         new = kmalloc(fc_tbl->target_max_slots * sizeof(struct nfs4_slot),
1652                       GFP_NOFS);
1653         if (!new)
1654                 return -ENOMEM;
1655
1656         spin_lock(&fc_tbl->slot_tbl_lock);
1657         for (i = 0; i < fc_tbl->target_max_slots; i++)
1658                 new[i].seq_nr = fc_tbl->slots[i].seq_nr;
1659         old = fc_tbl->slots;
1660         fc_tbl->slots = new;
1661         fc_tbl->max_slots = fc_tbl->target_max_slots;
1662         fc_tbl->target_max_slots = 0;
1663         fc_attrs->max_reqs = fc_tbl->max_slots;
1664         spin_unlock(&fc_tbl->slot_tbl_lock);
1665
1666         kfree(old);
1667         nfs4_end_drain_session(clp);
1668         return 0;
1669 }
1670
1671 #else /* CONFIG_NFS_V4_1 */
1672 static int nfs4_reset_session(struct nfs_client *clp) { return 0; }
1673 static int nfs4_end_drain_session(struct nfs_client *clp) { return 0; }
1674 static int nfs4_recall_slot(struct nfs_client *clp) { return 0; }
1675 #endif /* CONFIG_NFS_V4_1 */
1676
1677 /* Set NFS4CLNT_LEASE_EXPIRED for all v4.0 errors and for recoverable errors
1678  * on EXCHANGE_ID for v4.1
1679  */
1680 static void nfs4_set_lease_expired(struct nfs_client *clp, int status)
1681 {
1682         switch (status) {
1683         case -NFS4ERR_CLID_INUSE:
1684         case -NFS4ERR_STALE_CLIENTID:
1685                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1686                 break;
1687         case -NFS4ERR_DELAY:
1688         case -ETIMEDOUT:
1689         case -EAGAIN:
1690                 ssleep(1);
1691                 break;
1692
1693         case -EKEYEXPIRED:
1694                 nfs4_warn_keyexpired(clp->cl_hostname);
1695         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
1696                                  * in nfs4_exchange_id */
1697         default:
1698                 return;
1699         }
1700         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1701 }
1702
1703 static void nfs4_state_manager(struct nfs_client *clp)
1704 {
1705         int status = 0;
1706
1707         /* Ensure exclusive access to NFSv4 state */
1708         do {
1709                 if (test_and_clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
1710                         /* We're going to have to re-establish a clientid */
1711                         status = nfs4_reclaim_lease(clp);
1712                         if (status) {
1713                                 nfs4_set_lease_expired(clp, status);
1714                                 if (test_bit(NFS4CLNT_LEASE_EXPIRED,
1715                                                         &clp->cl_state))
1716                                         continue;
1717                                 if (clp->cl_cons_state ==
1718                                                         NFS_CS_SESSION_INITING)
1719                                         nfs_mark_client_ready(clp, status);
1720                                 goto out_error;
1721                         }
1722                         clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1723
1724                         if (test_and_clear_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH,
1725                                                &clp->cl_state))
1726                                 nfs4_state_start_reclaim_nograce(clp);
1727                         else
1728                                 set_bit(NFS4CLNT_RECLAIM_REBOOT,
1729                                         &clp->cl_state);
1730
1731                         pnfs_destroy_all_layouts(clp);
1732                 }
1733
1734                 if (test_and_clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state)) {
1735                         status = nfs4_check_lease(clp);
1736                         if (status < 0)
1737                                 goto out_error;
1738                         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1739                                 continue;
1740                 }
1741
1742                 /* Initialize or reset the session */
1743                 if (test_and_clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state)
1744                    && nfs4_has_session(clp)) {
1745                         status = nfs4_reset_session(clp);
1746                         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1747                                 continue;
1748                         if (status < 0)
1749                                 goto out_error;
1750                 }
1751
1752                 /* First recover reboot state... */
1753                 if (test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {
1754                         status = nfs4_do_reclaim(clp,
1755                                 clp->cl_mvops->reboot_recovery_ops);
1756                         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) ||
1757                             test_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state))
1758                                 continue;
1759                         nfs4_state_end_reclaim_reboot(clp);
1760                         if (test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
1761                                 continue;
1762                         if (status < 0)
1763                                 goto out_error;
1764                 }
1765
1766                 /* Now recover expired state... */
1767                 if (test_and_clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state)) {
1768                         status = nfs4_do_reclaim(clp,
1769                                 clp->cl_mvops->nograce_recovery_ops);
1770                         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) ||
1771                             test_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state) ||
1772                             test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
1773                                 continue;
1774                         if (status < 0)
1775                                 goto out_error;
1776                 }
1777
1778                 nfs4_end_drain_session(clp);
1779                 if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
1780                         nfs_client_return_marked_delegations(clp);
1781                         continue;
1782                 }
1783                 /* Recall session slots */
1784                 if (test_and_clear_bit(NFS4CLNT_RECALL_SLOT, &clp->cl_state)
1785                    && nfs4_has_session(clp)) {
1786                         status = nfs4_recall_slot(clp);
1787                         if (status < 0)
1788                                 goto out_error;
1789                         continue;
1790                 }
1791
1792
1793                 nfs4_clear_state_manager_bit(clp);
1794                 /* Did we race with an attempt to give us more work? */
1795                 if (clp->cl_state == 0)
1796                         break;
1797                 if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
1798                         break;
1799         } while (atomic_read(&clp->cl_count) > 1);
1800         return;
1801 out_error:
1802         printk(KERN_WARNING "Error: state manager failed on NFSv4 server %s"
1803                         " with error %d\n", clp->cl_hostname, -status);
1804         nfs4_end_drain_session(clp);
1805         nfs4_clear_state_manager_bit(clp);
1806 }
1807
1808 static int nfs4_run_state_manager(void *ptr)
1809 {
1810         struct nfs_client *clp = ptr;
1811
1812         allow_signal(SIGKILL);
1813         nfs4_state_manager(clp);
1814         nfs_put_client(clp);
1815         module_put_and_exit(0);
1816         return 0;
1817 }
1818
1819 /*
1820  * Local variables:
1821  *  c-basic-offset: 8
1822  * End:
1823  */