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/slab.h>
  42 #include <linux/smp_lock.h>
  43 #include <linux/nfs_fs.h>
  44 #include <linux/nfs_idmap.h>
  45 #include <linux/kthread.h>
  46 #include <linux/module.h>
  47 #include <linux/workqueue.h>
  48 #include <linux/bitops.h>
  49
  50 #include "nfs4_fs.h"
  51 #include "callback.h"
  52 #include "delegation.h"
  53 #include "internal.h"
  54
  55 #define OPENOWNER_POOL_SIZE     8
  56
  57 const nfs4_stateid zero_stateid;
  58
  59 static LIST_HEAD(nfs4_clientid_list);
  60
  61 static int nfs4_init_client(struct nfs_client *clp, struct rpc_cred *cred)
  62 {
  63         int status = nfs4_proc_setclientid(clp, NFS4_CALLBACK,
  64                         nfs_callback_tcpport, cred);
  65         if (status == 0)
  66                 status = nfs4_proc_setclientid_confirm(clp, cred);
  67         if (status == 0)
  68                 nfs4_schedule_state_renewal(clp);
  69         return status;
  70 }
  71
  72 u32
  73 nfs4_alloc_lockowner_id(struct nfs_client *clp)
  74 {
  75         return clp->cl_lockowner_id ++;
  76 }
  77
  78 struct rpc_cred *nfs4_get_renew_cred(struct nfs_client *clp)
  79 {
  80         struct nfs4_state_owner *sp;
  81         struct rpc_cred *cred = NULL;
  82
  83         list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
  84                 if (list_empty(&sp->so_states))
  85                         continue;
  86                 cred = get_rpccred(sp->so_cred);
  87                 break;
  88         }
  89         return cred;
  90 }
  91
  92 static struct rpc_cred *nfs4_get_setclientid_cred(struct nfs_client *clp)
  93 {
  94         struct nfs4_state_owner *sp;
  95
  96         if (!list_empty(&clp->cl_state_owners)) {
  97                 sp = list_entry(clp->cl_state_owners.next,
  98                                 struct nfs4_state_owner, so_list);
  99                 return get_rpccred(sp->so_cred);
 100         }
 101         return NULL;
 102 }
 103
 104 static struct nfs4_state_owner *
 105 nfs4_find_state_owner(struct nfs_client *clp, struct rpc_cred *cred)
 106 {
 107         struct nfs4_state_owner *sp, *res = NULL;
 108
 109         list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
 110                 if (sp->so_cred != cred)
 111                         continue;
 112                 atomic_inc(&sp->so_count);
 113                 /* Move to the head of the list */
 114                 list_move(&sp->so_list, &clp->cl_state_owners);
 115                 res = sp;
 116                 break;
 117         }
 118         return res;
 119 }
 120
 121 /*
 122  * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
 123  * create a new state_owner.
 124  *
 125  */
 126 static struct nfs4_state_owner *
 127 nfs4_alloc_state_owner(void)
 128 {
 129         struct nfs4_state_owner *sp;
 130
 131         sp = kzalloc(sizeof(*sp),GFP_KERNEL);
 132         if (!sp)
 133                 return NULL;
 134         spin_lock_init(&sp->so_lock);
 135         INIT_LIST_HEAD(&sp->so_states);
 136         INIT_LIST_HEAD(&sp->so_delegations);
 137         rpc_init_wait_queue(&sp->so_sequence.wait, "Seqid_waitqueue");
 138         sp->so_seqid.sequence = &sp->so_sequence;
 139         spin_lock_init(&sp->so_sequence.lock);
 140         INIT_LIST_HEAD(&sp->so_sequence.list);
 141         atomic_set(&sp->so_count, 1);
 142         return sp;
 143 }
 144
 145 void
 146 nfs4_drop_state_owner(struct nfs4_state_owner *sp)
 147 {
 148         struct nfs_client *clp = sp->so_client;
 149         spin_lock(&clp->cl_lock);
 150         list_del_init(&sp->so_list);
 151         spin_unlock(&clp->cl_lock);
 152 }
 153
 154 /*
 155  * Note: must be called with clp->cl_sem held in order to prevent races
 156  *       with reboot recovery!
 157  */
 158 struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server, struct rpc_cred *cred)
 159 {
 160         struct nfs_client *clp = server->nfs_client;
 161         struct nfs4_state_owner *sp, *new;
 162
 163         new = nfs4_alloc_state_owner();
 164         spin_lock(&clp->cl_lock);
 165         sp = nfs4_find_state_owner(clp, cred);
 166         if (sp == NULL && new != NULL) {
 167                 list_add(&new->so_list, &clp->cl_state_owners);
 168                 new->so_client = clp;
 169                 new->so_id = nfs4_alloc_lockowner_id(clp);
 170                 new->so_cred = get_rpccred(cred);
 171                 sp = new;
 172                 new = NULL;
 173         }
 174         spin_unlock(&clp->cl_lock);
 175         kfree(new);
 176         if (sp != NULL)
 177                 return sp;
 178         return NULL;
 179 }
 180
 181 /*
 182  * Must be called with clp->cl_sem held in order to avoid races
 183  * with state recovery...
 184  */
 185 void nfs4_put_state_owner(struct nfs4_state_owner *sp)
 186 {
 187         struct nfs_client *clp = sp->so_client;
 188         struct rpc_cred *cred = sp->so_cred;
 189
 190         if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
 191                 return;
 192         list_del(&sp->so_list);
 193         spin_unlock(&clp->cl_lock);
 194         put_rpccred(cred);
 195         kfree(sp);
 196 }
 197
 198 static struct nfs4_state *
 199 nfs4_alloc_open_state(void)
 200 {
 201         struct nfs4_state *state;
 202
 203         state = kzalloc(sizeof(*state), GFP_KERNEL);
 204         if (!state)
 205                 return NULL;
 206         atomic_set(&state->count, 1);
 207         INIT_LIST_HEAD(&state->lock_states);
 208         spin_lock_init(&state->state_lock);
 209         return state;
 210 }
 211
 212 void
 213 nfs4_state_set_mode_locked(struct nfs4_state *state, mode_t mode)
 214 {
 215         if (state->state == mode)
 216                 return;
 217         /* NB! List reordering - see the reclaim code for why.  */
 218         if ((mode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
 219                 if (mode & FMODE_WRITE)
 220                         list_move(&state->open_states, &state->owner->so_states);
 221                 else
 222                         list_move_tail(&state->open_states, &state->owner->so_states);
 223         }
 224         if (mode == 0)
 225                 list_del_init(&state->inode_states);
 226         state->state = mode;
 227 }
 228
 229 static struct nfs4_state *
 230 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
 231 {
 232         struct nfs_inode *nfsi = NFS_I(inode);
 233         struct nfs4_state *state;
 234
 235         list_for_each_entry(state, &nfsi->open_states, inode_states) {
 236                 /* Is this in the process of being freed? */
 237                 if (state->state == 0)
 238                         continue;
 239                 if (state->owner == owner) {
 240                         atomic_inc(&state->count);
 241                         return state;
 242                 }
 243         }
 244         return NULL;
 245 }
 246
 247 static void
 248 nfs4_free_open_state(struct nfs4_state *state)
 249 {
 250         kfree(state);
 251 }
 252
 253 struct nfs4_state *
 254 nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
 255 {
 256         struct nfs4_state *state, *new;
 257         struct nfs_inode *nfsi = NFS_I(inode);
 258
 259         spin_lock(&inode->i_lock);
 260         state = __nfs4_find_state_byowner(inode, owner);
 261         spin_unlock(&inode->i_lock);
 262         if (state)
 263                 goto out;
 264         new = nfs4_alloc_open_state();
 265         spin_lock(&owner->so_lock);
 266         spin_lock(&inode->i_lock);
 267         state = __nfs4_find_state_byowner(inode, owner);
 268         if (state == NULL && new != NULL) {
 269                 state = new;
 270                 state->owner = owner;
 271                 atomic_inc(&owner->so_count);
 272                 list_add(&state->inode_states, &nfsi->open_states);
 273                 state->inode = igrab(inode);
 274                 spin_unlock(&inode->i_lock);
 275                 /* Note: The reclaim code dictates that we add stateless
 276                  * and read-only stateids to the end of the list */
 277                 list_add_tail(&state->open_states, &owner->so_states);
 278                 spin_unlock(&owner->so_lock);
 279         } else {
 280                 spin_unlock(&inode->i_lock);
 281                 spin_unlock(&owner->so_lock);
 282                 if (new)
 283                         nfs4_free_open_state(new);
 284         }
 285 out:
 286         return state;
 287 }
 288
 289 /*
 290  * Beware! Caller must be holding exactly one
 291  * reference to clp->cl_sem!
 292  */
 293 void nfs4_put_open_state(struct nfs4_state *state)
 294 {
 295         struct inode *inode = state->inode;
 296         struct nfs4_state_owner *owner = state->owner;
 297
 298         if (!atomic_dec_and_lock(&state->count, &owner->so_lock))
 299                 return;
 300         spin_lock(&inode->i_lock);
 301         if (!list_empty(&state->inode_states))
 302                 list_del(&state->inode_states);
 303         list_del(&state->open_states);
 304         spin_unlock(&inode->i_lock);
 305         spin_unlock(&owner->so_lock);
 306         iput(inode);
 307         nfs4_free_open_state(state);
 308         nfs4_put_state_owner(owner);
 309 }
 310
 311 /*
 312  * Close the current file.
 313  */
 314 void nfs4_close_state(struct path *path, struct nfs4_state *state, mode_t mode)
 315 {
 316         struct inode *inode = state->inode;
 317         struct nfs4_state_owner *owner = state->owner;
 318         int oldstate, newstate = 0;
 319
 320         atomic_inc(&owner->so_count);
 321         /* Protect against nfs4_find_state() */
 322         spin_lock(&owner->so_lock);
 323         spin_lock(&inode->i_lock);
 324         switch (mode & (FMODE_READ | FMODE_WRITE)) {
 325                 case FMODE_READ:
 326                         state->n_rdonly--;
 327                         break;
 328                 case FMODE_WRITE:
 329                         state->n_wronly--;
 330                         break;
 331                 case FMODE_READ|FMODE_WRITE:
 332                         state->n_rdwr--;
 333         }
 334         oldstate = newstate = state->state;
 335         if (state->n_rdwr == 0) {
 336                 if (state->n_rdonly == 0)
 337                         newstate &= ~FMODE_READ;
 338                 if (state->n_wronly == 0)
 339                         newstate &= ~FMODE_WRITE;
 340         }
 341         if (test_bit(NFS_DELEGATED_STATE, &state->flags)) {
 342                 nfs4_state_set_mode_locked(state, newstate);
 343                 oldstate = newstate;
 344         }
 345         spin_unlock(&inode->i_lock);
 346         spin_unlock(&owner->so_lock);
 347
 348         if (oldstate == newstate) {
 349                 nfs4_put_open_state(state);
 350                 nfs4_put_state_owner(owner);
 351         } else
 352                 nfs4_do_close(path, state);
 353 }
 354
 355 /*
 356  * Search the state->lock_states for an existing lock_owner
 357  * that is compatible with current->files
 358  */
 359 static struct nfs4_lock_state *
 360 __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 361 {
 362         struct nfs4_lock_state *pos;
 363         list_for_each_entry(pos, &state->lock_states, ls_locks) {
 364                 if (pos->ls_owner != fl_owner)
 365                         continue;
 366                 atomic_inc(&pos->ls_count);
 367                 return pos;
 368         }
 369         return NULL;
 370 }
 371
 372 /*
 373  * Return a compatible lock_state. If no initialized lock_state structure
 374  * exists, return an uninitialized one.
 375  *
 376  */
 377 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 378 {
 379         struct nfs4_lock_state *lsp;
 380         struct nfs_client *clp = state->owner->so_client;
 381
 382         lsp = kzalloc(sizeof(*lsp), GFP_KERNEL);
 383         if (lsp == NULL)
 384                 return NULL;
 385         lsp->ls_seqid.sequence = &state->owner->so_sequence;
 386         atomic_set(&lsp->ls_count, 1);
 387         lsp->ls_owner = fl_owner;
 388         spin_lock(&clp->cl_lock);
 389         lsp->ls_id = nfs4_alloc_lockowner_id(clp);
 390         spin_unlock(&clp->cl_lock);
 391         INIT_LIST_HEAD(&lsp->ls_locks);
 392         return lsp;
 393 }
 394
 395 /*
 396  * Return a compatible lock_state. If no initialized lock_state structure
 397  * exists, return an uninitialized one.
 398  *
 399  * The caller must be holding clp->cl_sem
 400  */
 401 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
 402 {
 403         struct nfs4_lock_state *lsp, *new = NULL;
 404
 405         for(;;) {
 406                 spin_lock(&state->state_lock);
 407                 lsp = __nfs4_find_lock_state(state, owner);
 408                 if (lsp != NULL)
 409                         break;
 410                 if (new != NULL) {
 411                         new->ls_state = state;
 412                         list_add(&new->ls_locks, &state->lock_states);
 413                         set_bit(LK_STATE_IN_USE, &state->flags);
 414                         lsp = new;
 415                         new = NULL;
 416                         break;
 417                 }
 418                 spin_unlock(&state->state_lock);
 419                 new = nfs4_alloc_lock_state(state, owner);
 420                 if (new == NULL)
 421                         return NULL;
 422         }
 423         spin_unlock(&state->state_lock);
 424         kfree(new);
 425         return lsp;
 426 }
 427
 428 /*
 429  * Release reference to lock_state, and free it if we see that
 430  * it is no longer in use
 431  */
 432 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
 433 {
 434         struct nfs4_state *state;
 435
 436         if (lsp == NULL)
 437                 return;
 438         state = lsp->ls_state;
 439         if (!atomic_dec_and_lock(&lsp->ls_count, &state->state_lock))
 440                 return;
 441         list_del(&lsp->ls_locks);
 442         if (list_empty(&state->lock_states))
 443                 clear_bit(LK_STATE_IN_USE, &state->flags);
 444         spin_unlock(&state->state_lock);
 445         kfree(lsp);
 446 }
 447
 448 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
 449 {
 450         struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
 451
 452         dst->fl_u.nfs4_fl.owner = lsp;
 453         atomic_inc(&lsp->ls_count);
 454 }
 455
 456 static void nfs4_fl_release_lock(struct file_lock *fl)
 457 {
 458         nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
 459 }
 460
 461 static struct file_lock_operations nfs4_fl_lock_ops = {
 462         .fl_copy_lock = nfs4_fl_copy_lock,
 463         .fl_release_private = nfs4_fl_release_lock,
 464 };
 465
 466 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
 467 {
 468         struct nfs4_lock_state *lsp;
 469
 470         if (fl->fl_ops != NULL)
 471                 return 0;
 472         lsp = nfs4_get_lock_state(state, fl->fl_owner);
 473         if (lsp == NULL)
 474                 return -ENOMEM;
 475         fl->fl_u.nfs4_fl.owner = lsp;
 476         fl->fl_ops = &nfs4_fl_lock_ops;
 477         return 0;
 478 }
 479
 480 /*
 481  * Byte-range lock aware utility to initialize the stateid of read/write
 482  * requests.
 483  */
 484 void nfs4_copy_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t fl_owner)
 485 {
 486         struct nfs4_lock_state *lsp;
 487
 488         memcpy(dst, &state->stateid, sizeof(*dst));
 489         if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
 490                 return;
 491
 492         spin_lock(&state->state_lock);
 493         lsp = __nfs4_find_lock_state(state, fl_owner);
 494         if (lsp != NULL && (lsp->ls_flags & NFS_LOCK_INITIALIZED) != 0)
 495                 memcpy(dst, &lsp->ls_stateid, sizeof(*dst));
 496         spin_unlock(&state->state_lock);
 497         nfs4_put_lock_state(lsp);
 498 }
 499
 500 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter)
 501 {
 502         struct rpc_sequence *sequence = counter->sequence;
 503         struct nfs_seqid *new;
 504
 505         new = kmalloc(sizeof(*new), GFP_KERNEL);
 506         if (new != NULL) {
 507                 new->sequence = counter;
 508                 spin_lock(&sequence->lock);
 509                 list_add_tail(&new->list, &sequence->list);
 510                 spin_unlock(&sequence->lock);
 511         }
 512         return new;
 513 }
 514
 515 void nfs_free_seqid(struct nfs_seqid *seqid)
 516 {
 517         struct rpc_sequence *sequence = seqid->sequence->sequence;
 518
 519         spin_lock(&sequence->lock);
 520         list_del(&seqid->list);
 521         spin_unlock(&sequence->lock);
 522         rpc_wake_up(&sequence->wait);
 523         kfree(seqid);
 524 }
 525
 526 /*
 527  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
 528  * failed with a seqid incrementing error -
 529  * see comments nfs_fs.h:seqid_mutating_error()
 530  */
 531 static void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
 532 {
 533         switch (status) {
 534                 case 0:
 535                         break;
 536                 case -NFS4ERR_BAD_SEQID:
 537                 case -NFS4ERR_STALE_CLIENTID:
 538                 case -NFS4ERR_STALE_STATEID:
 539                 case -NFS4ERR_BAD_STATEID:
 540                 case -NFS4ERR_BADXDR:
 541                 case -NFS4ERR_RESOURCE:
 542                 case -NFS4ERR_NOFILEHANDLE:
 543                         /* Non-seqid mutating errors */
 544                         return;
 545         };
 546         /*
 547          * Note: no locking needed as we are guaranteed to be first
 548          * on the sequence list
 549          */
 550         seqid->sequence->counter++;
 551 }
 552
 553 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
 554 {
 555         if (status == -NFS4ERR_BAD_SEQID) {
 556                 struct nfs4_state_owner *sp = container_of(seqid->sequence,
 557                                 struct nfs4_state_owner, so_seqid);
 558                 nfs4_drop_state_owner(sp);
 559         }
 560         nfs_increment_seqid(status, seqid);
 561 }
 562
 563 /*
 564  * Increment the seqid if the LOCK/LOCKU succeeded, or
 565  * failed with a seqid incrementing error -
 566  * see comments nfs_fs.h:seqid_mutating_error()
 567  */
 568 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
 569 {
 570         nfs_increment_seqid(status, seqid);
 571 }
 572
 573 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
 574 {
 575         struct rpc_sequence *sequence = seqid->sequence->sequence;
 576         int status = 0;
 577
 578         if (sequence->list.next == &seqid->list)
 579                 goto out;
 580         spin_lock(&sequence->lock);
 581         if (sequence->list.next != &seqid->list) {
 582                 rpc_sleep_on(&sequence->wait, task, NULL, NULL);
 583                 status = -EAGAIN;
 584         }
 585         spin_unlock(&sequence->lock);
 586 out:
 587         return status;
 588 }
 589
 590 static int reclaimer(void *);
 591
 592 static inline void nfs4_clear_recover_bit(struct nfs_client *clp)
 593 {
 594         smp_mb__before_clear_bit();
 595         clear_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state);
 596         smp_mb__after_clear_bit();
 597         wake_up_bit(&clp->cl_state, NFS4CLNT_STATE_RECOVER);
 598         rpc_wake_up(&clp->cl_rpcwaitq);
 599 }
 600
 601 /*
 602  * State recovery routine
 603  */
 604 static void nfs4_recover_state(struct nfs_client *clp)
 605 {
 606         struct task_struct *task;
 607
 608         __module_get(THIS_MODULE);
 609         atomic_inc(&clp->cl_count);
 610         task = kthread_run(reclaimer, clp, "%u.%u.%u.%u-reclaim",
 611                         NIPQUAD(clp->cl_addr.sin_addr));
 612         if (!IS_ERR(task))
 613                 return;
 614         nfs4_clear_recover_bit(clp);
 615         nfs_put_client(clp);
 616         module_put(THIS_MODULE);
 617 }
 618
 619 /*
 620  * Schedule a state recovery attempt
 621  */
 622 void nfs4_schedule_state_recovery(struct nfs_client *clp)
 623 {
 624         if (!clp)
 625                 return;
 626         if (test_and_set_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state) == 0)
 627                 nfs4_recover_state(clp);
 628 }
 629
 630 static int nfs4_reclaim_locks(struct nfs4_state_recovery_ops *ops, struct nfs4_state *state)
 631 {
 632         struct inode *inode = state->inode;
 633         struct file_lock *fl;
 634         int status = 0;
 635
 636         for (fl = inode->i_flock; fl != 0; fl = fl->fl_next) {
 637                 if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
 638                         continue;
 639                 if (((struct nfs_open_context *)fl->fl_file->private_data)->state != state)
 640                         continue;
 641                 status = ops->recover_lock(state, fl);
 642                 if (status >= 0)
 643                         continue;
 644                 switch (status) {
 645                         default:
 646                                 printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
 647                                                 __FUNCTION__, status);
 648                         case -NFS4ERR_EXPIRED:
 649                         case -NFS4ERR_NO_GRACE:
 650                         case -NFS4ERR_RECLAIM_BAD:
 651                         case -NFS4ERR_RECLAIM_CONFLICT:
 652                                 /* kill_proc(fl->fl_pid, SIGLOST, 1); */
 653                                 break;
 654                         case -NFS4ERR_STALE_CLIENTID:
 655                                 goto out_err;
 656                 }
 657         }
 658         return 0;
 659 out_err:
 660         return status;
 661 }
 662
 663 static int nfs4_reclaim_open_state(struct nfs4_state_recovery_ops *ops, struct nfs4_state_owner *sp)
 664 {
 665         struct nfs4_state *state;
 666         struct nfs4_lock_state *lock;
 667         int status = 0;
 668
 669         /* Note: we rely on the sp->so_states list being ordered
 670          * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
 671          * states first.
 672          * This is needed to ensure that the server won't give us any
 673          * read delegations that we have to return if, say, we are
 674          * recovering after a network partition or a reboot from a
 675          * server that doesn't support a grace period.
 676          */
 677         list_for_each_entry(state, &sp->so_states, open_states) {
 678                 if (state->state == 0)
 679                         continue;
 680                 status = ops->recover_open(sp, state);
 681                 if (status >= 0) {
 682                         status = nfs4_reclaim_locks(ops, state);
 683                         if (status < 0)
 684                                 goto out_err;
 685                         list_for_each_entry(lock, &state->lock_states, ls_locks) {
 686                                 if (!(lock->ls_flags & NFS_LOCK_INITIALIZED))
 687                                         printk("%s: Lock reclaim failed!\n",
 688                                                         __FUNCTION__);
 689                         }
 690                         continue;
 691                 }
 692                 switch (status) {
 693                         default:
 694                                 printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
 695                                                 __FUNCTION__, status);
 696                         case -ENOENT:
 697                         case -NFS4ERR_RECLAIM_BAD:
 698                         case -NFS4ERR_RECLAIM_CONFLICT:
 699                                 /*
 700                                  * Open state on this file cannot be recovered
 701                                  * All we can do is revert to using the zero stateid.
 702                                  */
 703                                 memset(state->stateid.data, 0,
 704                                         sizeof(state->stateid.data));
 705                                 /* Mark the file as being 'closed' */
 706                                 state->state = 0;
 707                                 break;
 708                         case -NFS4ERR_EXPIRED:
 709                         case -NFS4ERR_NO_GRACE:
 710                         case -NFS4ERR_STALE_CLIENTID:
 711                                 goto out_err;
 712                 }
 713         }
 714         return 0;
 715 out_err:
 716         return status;
 717 }
 718
 719 static void nfs4_state_mark_reclaim(struct nfs_client *clp)
 720 {
 721         struct nfs4_state_owner *sp;
 722         struct nfs4_state *state;
 723         struct nfs4_lock_state *lock;
 724
 725         /* Reset all sequence ids to zero */
 726         list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
 727                 sp->so_seqid.counter = 0;
 728                 sp->so_seqid.flags = 0;
 729                 spin_lock(&sp->so_lock);
 730                 list_for_each_entry(state, &sp->so_states, open_states) {
 731                         list_for_each_entry(lock, &state->lock_states, ls_locks) {
 732                                 lock->ls_seqid.counter = 0;
 733                                 lock->ls_seqid.flags = 0;
 734                                 lock->ls_flags &= ~NFS_LOCK_INITIALIZED;
 735                         }
 736                 }
 737                 spin_unlock(&sp->so_lock);
 738         }
 739 }
 740
 741 static int reclaimer(void *ptr)
 742 {
 743         struct nfs_client *clp = ptr;
 744         struct nfs4_state_owner *sp;
 745         struct nfs4_state_recovery_ops *ops;
 746         struct rpc_cred *cred;
 747         int status = 0;
 748
 749         allow_signal(SIGKILL);
 750
 751         /* Ensure exclusive access to NFSv4 state */
 752         lock_kernel();
 753         down_write(&clp->cl_sem);
 754         /* Are there any NFS mounts out there? */
 755         if (list_empty(&clp->cl_superblocks))
 756                 goto out;
 757 restart_loop:
 758         ops = &nfs4_network_partition_recovery_ops;
 759         /* Are there any open files on this volume? */
 760         cred = nfs4_get_renew_cred(clp);
 761         if (cred != NULL) {
 762                 /* Yes there are: try to renew the old lease */
 763                 status = nfs4_proc_renew(clp, cred);
 764                 switch (status) {
 765                         case 0:
 766                         case -NFS4ERR_CB_PATH_DOWN:
 767                                 put_rpccred(cred);
 768                                 goto out;
 769                         case -NFS4ERR_STALE_CLIENTID:
 770                         case -NFS4ERR_LEASE_MOVED:
 771                                 ops = &nfs4_reboot_recovery_ops;
 772                 }
 773         } else {
 774                 /* "reboot" to ensure we clear all state on the server */
 775                 clp->cl_boot_time = CURRENT_TIME;
 776                 cred = nfs4_get_setclientid_cred(clp);
 777         }
 778         /* We're going to have to re-establish a clientid */
 779         nfs4_state_mark_reclaim(clp);
 780         status = -ENOENT;
 781         if (cred != NULL) {
 782                 status = nfs4_init_client(clp, cred);
 783                 put_rpccred(cred);
 784         }
 785         if (status)
 786                 goto out_error;
 787         /* Mark all delegations for reclaim */
 788         nfs_delegation_mark_reclaim(clp);
 789         /* Note: list is protected by exclusive lock on cl->cl_sem */
 790         list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
 791                 status = nfs4_reclaim_open_state(ops, sp);
 792                 if (status < 0) {
 793                         if (status == -NFS4ERR_NO_GRACE) {
 794                                 ops = &nfs4_network_partition_recovery_ops;
 795                                 status = nfs4_reclaim_open_state(ops, sp);
 796                         }
 797                         if (status == -NFS4ERR_STALE_CLIENTID)
 798                                 goto restart_loop;
 799                         if (status == -NFS4ERR_EXPIRED)
 800                                 goto restart_loop;
 801                 }
 802         }
 803         nfs_delegation_reap_unclaimed(clp);
 804 out:
 805         up_write(&clp->cl_sem);
 806         unlock_kernel();
 807         if (status == -NFS4ERR_CB_PATH_DOWN)
 808                 nfs_handle_cb_pathdown(clp);
 809         nfs4_clear_recover_bit(clp);
 810         nfs_put_client(clp);
 811         module_put_and_exit(0);
 812         return 0;
 813 out_error:
 814         printk(KERN_WARNING "Error: state recovery failed on NFSv4 server %u.%u.%u.%u with error %d\n",
 815                                 NIPQUAD(clp->cl_addr.sin_addr), -status);
 816         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
 817         goto out;
 818 }
 819
 820 /*
 821  * Local variables:
 822  *  c-basic-offset: 8
 823  * End:
 824  */