git.oblomov.eu Git - linux-2.6/blob - 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 static struct nfs4_state_owner *
  79 nfs4_client_grab_unused(struct nfs_client *clp, struct rpc_cred *cred)
  80 {
  81         struct nfs4_state_owner *sp = NULL;
  82
  83         if (!list_empty(&clp->cl_unused)) {
  84                 sp = list_entry(clp->cl_unused.next, struct nfs4_state_owner, so_list);
  85                 atomic_inc(&sp->so_count);
  86                 sp->so_cred = cred;
  87                 list_move(&sp->so_list, &clp->cl_state_owners);
  88                 clp->cl_nunused--;
  89         }
  90         return sp;
  91 }
  92
  93 struct rpc_cred *nfs4_get_renew_cred(struct nfs_client *clp)
  94 {
  95         struct nfs4_state_owner *sp;
  96         struct rpc_cred *cred = NULL;
  97
  98         list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
  99                 if (list_empty(&sp->so_states))
 100                         continue;
 101                 cred = get_rpccred(sp->so_cred);
 102                 break;
 103         }
 104         return cred;
 105 }
 106
 107 static struct rpc_cred *nfs4_get_setclientid_cred(struct nfs_client *clp)
 108 {
 109         struct nfs4_state_owner *sp;
 110
 111         if (!list_empty(&clp->cl_state_owners)) {
 112                 sp = list_entry(clp->cl_state_owners.next,
 113                                 struct nfs4_state_owner, so_list);
 114                 return get_rpccred(sp->so_cred);
 115         }
 116         return NULL;
 117 }
 118
 119 static struct nfs4_state_owner *
 120 nfs4_find_state_owner(struct nfs_client *clp, struct rpc_cred *cred)
 121 {
 122         struct nfs4_state_owner *sp, *res = NULL;
 123
 124         list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
 125                 if (sp->so_cred != cred)
 126                         continue;
 127                 atomic_inc(&sp->so_count);
 128                 /* Move to the head of the list */
 129                 list_move(&sp->so_list, &clp->cl_state_owners);
 130                 res = sp;
 131                 break;
 132         }
 133         return res;
 134 }
 135
 136 /*
 137  * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
 138  * create a new state_owner.
 139  *
 140  */
 141 static struct nfs4_state_owner *
 142 nfs4_alloc_state_owner(void)
 143 {
 144         struct nfs4_state_owner *sp;
 145
 146         sp = kzalloc(sizeof(*sp),GFP_KERNEL);
 147         if (!sp)
 148                 return NULL;
 149         spin_lock_init(&sp->so_lock);
 150         INIT_LIST_HEAD(&sp->so_states);
 151         INIT_LIST_HEAD(&sp->so_delegations);
 152         rpc_init_wait_queue(&sp->so_sequence.wait, "Seqid_waitqueue");
 153         sp->so_seqid.sequence = &sp->so_sequence;
 154         spin_lock_init(&sp->so_sequence.lock);
 155         INIT_LIST_HEAD(&sp->so_sequence.list);
 156         atomic_set(&sp->so_count, 1);
 157         return sp;
 158 }
 159
 160 void
 161 nfs4_drop_state_owner(struct nfs4_state_owner *sp)
 162 {
 163         struct nfs_client *clp = sp->so_client;
 164         spin_lock(&clp->cl_lock);
 165         list_del_init(&sp->so_list);
 166         spin_unlock(&clp->cl_lock);
 167 }
 168
 169 /*
 170  * Note: must be called with clp->cl_sem held in order to prevent races
 171  *       with reboot recovery!
 172  */
 173 struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server, struct rpc_cred *cred)
 174 {
 175         struct nfs_client *clp = server->nfs_client;
 176         struct nfs4_state_owner *sp, *new;
 177
 178         get_rpccred(cred);
 179         new = nfs4_alloc_state_owner();
 180         spin_lock(&clp->cl_lock);
 181         sp = nfs4_find_state_owner(clp, cred);
 182         if (sp == NULL)
 183                 sp = nfs4_client_grab_unused(clp, cred);
 184         if (sp == NULL && new != NULL) {
 185                 list_add(&new->so_list, &clp->cl_state_owners);
 186                 new->so_client = clp;
 187                 new->so_id = nfs4_alloc_lockowner_id(clp);
 188                 new->so_cred = cred;
 189                 sp = new;
 190                 new = NULL;
 191         }
 192         spin_unlock(&clp->cl_lock);
 193         kfree(new);
 194         if (sp != NULL)
 195                 return sp;
 196         put_rpccred(cred);
 197         return NULL;
 198 }
 199
 200 /*
 201  * Must be called with clp->cl_sem held in order to avoid races
 202  * with state recovery...
 203  */
 204 void nfs4_put_state_owner(struct nfs4_state_owner *sp)
 205 {
 206         struct nfs_client *clp = sp->so_client;
 207         struct rpc_cred *cred = sp->so_cred;
 208
 209         if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
 210                 return;
 211         if (clp->cl_nunused >= OPENOWNER_POOL_SIZE)
 212                 goto out_free;
 213         if (list_empty(&sp->so_list))
 214                 goto out_free;
 215         list_move(&sp->so_list, &clp->cl_unused);
 216         clp->cl_nunused++;
 217         spin_unlock(&clp->cl_lock);
 218         put_rpccred(cred);
 219         cred = NULL;
 220         return;
 221 out_free:
 222         list_del(&sp->so_list);
 223         spin_unlock(&clp->cl_lock);
 224         put_rpccred(cred);
 225         kfree(sp);
 226 }
 227
 228 static struct nfs4_state *
 229 nfs4_alloc_open_state(void)
 230 {
 231         struct nfs4_state *state;
 232
 233         state = kzalloc(sizeof(*state), GFP_KERNEL);
 234         if (!state)
 235                 return NULL;
 236         atomic_set(&state->count, 1);
 237         INIT_LIST_HEAD(&state->lock_states);
 238         spin_lock_init(&state->state_lock);
 239         return state;
 240 }
 241
 242 void
 243 nfs4_state_set_mode_locked(struct nfs4_state *state, mode_t mode)
 244 {
 245         if (state->state == mode)
 246                 return;
 247         /* NB! List reordering - see the reclaim code for why.  */
 248         if ((mode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
 249                 if (mode & FMODE_WRITE)
 250                         list_move(&state->open_states, &state->owner->so_states);
 251                 else
 252                         list_move_tail(&state->open_states, &state->owner->so_states);
 253         }
 254         if (mode == 0)
 255                 list_del_init(&state->inode_states);
 256         state->state = mode;
 257 }
 258
 259 static struct nfs4_state *
 260 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
 261 {
 262         struct nfs_inode *nfsi = NFS_I(inode);
 263         struct nfs4_state *state;
 264
 265         list_for_each_entry(state, &nfsi->open_states, inode_states) {
 266                 /* Is this in the process of being freed? */
 267                 if (state->state == 0)
 268                         continue;
 269                 if (state->owner == owner) {
 270                         atomic_inc(&state->count);
 271                         return state;
 272                 }
 273         }
 274         return NULL;
 275 }
 276
 277 static void
 278 nfs4_free_open_state(struct nfs4_state *state)
 279 {
 280         kfree(state);
 281 }
 282
 283 struct nfs4_state *
 284 nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
 285 {
 286         struct nfs4_state *state, *new;
 287         struct nfs_inode *nfsi = NFS_I(inode);
 288
 289         spin_lock(&inode->i_lock);
 290         state = __nfs4_find_state_byowner(inode, owner);
 291         spin_unlock(&inode->i_lock);
 292         if (state)
 293                 goto out;
 294         new = nfs4_alloc_open_state();
 295         spin_lock(&owner->so_lock);
 296         spin_lock(&inode->i_lock);
 297         state = __nfs4_find_state_byowner(inode, owner);
 298         if (state == NULL && new != NULL) {
 299                 state = new;
 300                 state->owner = owner;
 301                 atomic_inc(&owner->so_count);
 302                 list_add(&state->inode_states, &nfsi->open_states);
 303                 state->inode = igrab(inode);
 304                 spin_unlock(&inode->i_lock);
 305                 /* Note: The reclaim code dictates that we add stateless
 306                  * and read-only stateids to the end of the list */
 307                 list_add_tail(&state->open_states, &owner->so_states);
 308                 spin_unlock(&owner->so_lock);
 309         } else {
 310                 spin_unlock(&inode->i_lock);
 311                 spin_unlock(&owner->so_lock);
 312                 if (new)
 313                         nfs4_free_open_state(new);
 314         }
 315 out:
 316         return state;
 317 }
 318
 319 /*
 320  * Beware! Caller must be holding exactly one
 321  * reference to clp->cl_sem!
 322  */
 323 void nfs4_put_open_state(struct nfs4_state *state)
 324 {
 325         struct inode *inode = state->inode;
 326         struct nfs4_state_owner *owner = state->owner;
 327
 328         if (!atomic_dec_and_lock(&state->count, &owner->so_lock))
 329                 return;
 330         spin_lock(&inode->i_lock);
 331         if (!list_empty(&state->inode_states))
 332                 list_del(&state->inode_states);
 333         list_del(&state->open_states);
 334         spin_unlock(&inode->i_lock);
 335         spin_unlock(&owner->so_lock);
 336         iput(inode);
 337         nfs4_free_open_state(state);
 338         nfs4_put_state_owner(owner);
 339 }
 340
 341 /*
 342  * Close the current file.
 343  */
 344 void nfs4_close_state(struct nfs4_state *state, mode_t mode)
 345 {
 346         struct inode *inode = state->inode;
 347         struct nfs4_state_owner *owner = state->owner;
 348         int oldstate, newstate = 0;
 349
 350         atomic_inc(&owner->so_count);
 351         /* Protect against nfs4_find_state() */
 352         spin_lock(&owner->so_lock);
 353         spin_lock(&inode->i_lock);
 354         switch (mode & (FMODE_READ | FMODE_WRITE)) {
 355                 case FMODE_READ:
 356                         state->n_rdonly--;
 357                         break;
 358                 case FMODE_WRITE:
 359                         state->n_wronly--;
 360                         break;
 361                 case FMODE_READ|FMODE_WRITE:
 362                         state->n_rdwr--;
 363         }
 364         oldstate = newstate = state->state;
 365         if (state->n_rdwr == 0) {
 366                 if (state->n_rdonly == 0)
 367                         newstate &= ~FMODE_READ;
 368                 if (state->n_wronly == 0)
 369                         newstate &= ~FMODE_WRITE;
 370         }
 371         if (test_bit(NFS_DELEGATED_STATE, &state->flags)) {
 372                 nfs4_state_set_mode_locked(state, newstate);
 373                 oldstate = newstate;
 374         }
 375         spin_unlock(&inode->i_lock);
 376         spin_unlock(&owner->so_lock);
 377
 378         if (oldstate != newstate && nfs4_do_close(inode, state) == 0)
 379                 return;
 380         nfs4_put_open_state(state);
 381         nfs4_put_state_owner(owner);
 382 }
 383
 384 /*
 385  * Search the state->lock_states for an existing lock_owner
 386  * that is compatible with current->files
 387  */
 388 static struct nfs4_lock_state *
 389 __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 390 {
 391         struct nfs4_lock_state *pos;
 392         list_for_each_entry(pos, &state->lock_states, ls_locks) {
 393                 if (pos->ls_owner != fl_owner)
 394                         continue;
 395                 atomic_inc(&pos->ls_count);
 396                 return pos;
 397         }
 398         return NULL;
 399 }
 400
 401 /*
 402  * Return a compatible lock_state. If no initialized lock_state structure
 403  * exists, return an uninitialized one.
 404  *
 405  */
 406 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 407 {
 408         struct nfs4_lock_state *lsp;
 409         struct nfs_client *clp = state->owner->so_client;
 410
 411         lsp = kzalloc(sizeof(*lsp), GFP_KERNEL);
 412         if (lsp == NULL)
 413                 return NULL;
 414         lsp->ls_seqid.sequence = &state->owner->so_sequence;
 415         atomic_set(&lsp->ls_count, 1);
 416         lsp->ls_owner = fl_owner;
 417         spin_lock(&clp->cl_lock);
 418         lsp->ls_id = nfs4_alloc_lockowner_id(clp);
 419         spin_unlock(&clp->cl_lock);
 420         INIT_LIST_HEAD(&lsp->ls_locks);
 421         return lsp;
 422 }
 423
 424 /*
 425  * Return a compatible lock_state. If no initialized lock_state structure
 426  * exists, return an uninitialized one.
 427  *
 428  * The caller must be holding clp->cl_sem
 429  */
 430 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
 431 {
 432         struct nfs4_lock_state *lsp, *new = NULL;
 433
 434         for(;;) {
 435                 spin_lock(&state->state_lock);
 436                 lsp = __nfs4_find_lock_state(state, owner);
 437                 if (lsp != NULL)
 438                         break;
 439                 if (new != NULL) {
 440                         new->ls_state = state;
 441                         list_add(&new->ls_locks, &state->lock_states);
 442                         set_bit(LK_STATE_IN_USE, &state->flags);
 443                         lsp = new;
 444                         new = NULL;
 445                         break;
 446                 }
 447                 spin_unlock(&state->state_lock);
 448                 new = nfs4_alloc_lock_state(state, owner);
 449                 if (new == NULL)
 450                         return NULL;
 451         }
 452         spin_unlock(&state->state_lock);
 453         kfree(new);
 454         return lsp;
 455 }
 456
 457 /*
 458  * Release reference to lock_state, and free it if we see that
 459  * it is no longer in use
 460  */
 461 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
 462 {
 463         struct nfs4_state *state;
 464
 465         if (lsp == NULL)
 466                 return;
 467         state = lsp->ls_state;
 468         if (!atomic_dec_and_lock(&lsp->ls_count, &state->state_lock))
 469                 return;
 470         list_del(&lsp->ls_locks);
 471         if (list_empty(&state->lock_states))
 472                 clear_bit(LK_STATE_IN_USE, &state->flags);
 473         spin_unlock(&state->state_lock);
 474         kfree(lsp);
 475 }
 476
 477 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
 478 {
 479         struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
 480
 481         dst->fl_u.nfs4_fl.owner = lsp;
 482         atomic_inc(&lsp->ls_count);
 483 }
 484
 485 static void nfs4_fl_release_lock(struct file_lock *fl)
 486 {
 487         nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
 488 }
 489
 490 static struct file_lock_operations nfs4_fl_lock_ops = {
 491         .fl_copy_lock = nfs4_fl_copy_lock,
 492         .fl_release_private = nfs4_fl_release_lock,
 493 };
 494
 495 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
 496 {
 497         struct nfs4_lock_state *lsp;
 498
 499         if (fl->fl_ops != NULL)
 500                 return 0;
 501         lsp = nfs4_get_lock_state(state, fl->fl_owner);
 502         if (lsp == NULL)
 503                 return -ENOMEM;
 504         fl->fl_u.nfs4_fl.owner = lsp;
 505         fl->fl_ops = &nfs4_fl_lock_ops;
 506         return 0;
 507 }
 508
 509 /*
 510  * Byte-range lock aware utility to initialize the stateid of read/write
 511  * requests.
 512  */
 513 void nfs4_copy_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t fl_owner)
 514 {
 515         struct nfs4_lock_state *lsp;
 516
 517         memcpy(dst, &state->stateid, sizeof(*dst));
 518         if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
 519                 return;
 520
 521         spin_lock(&state->state_lock);
 522         lsp = __nfs4_find_lock_state(state, fl_owner);
 523         if (lsp != NULL && (lsp->ls_flags & NFS_LOCK_INITIALIZED) != 0)
 524                 memcpy(dst, &lsp->ls_stateid, sizeof(*dst));
 525         spin_unlock(&state->state_lock);
 526         nfs4_put_lock_state(lsp);
 527 }
 528
 529 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter)
 530 {
 531         struct rpc_sequence *sequence = counter->sequence;
 532         struct nfs_seqid *new;
 533
 534         new = kmalloc(sizeof(*new), GFP_KERNEL);
 535         if (new != NULL) {
 536                 new->sequence = counter;
 537                 spin_lock(&sequence->lock);
 538                 list_add_tail(&new->list, &sequence->list);
 539                 spin_unlock(&sequence->lock);
 540         }
 541         return new;
 542 }
 543
 544 void nfs_free_seqid(struct nfs_seqid *seqid)
 545 {
 546         struct rpc_sequence *sequence = seqid->sequence->sequence;
 547
 548         spin_lock(&sequence->lock);
 549         list_del(&seqid->list);
 550         spin_unlock(&sequence->lock);
 551         rpc_wake_up(&sequence->wait);
 552         kfree(seqid);
 553 }
 554
 555 /*
 556  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
 557  * failed with a seqid incrementing error -
 558  * see comments nfs_fs.h:seqid_mutating_error()
 559  */
 560 static inline void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
 561 {
 562         switch (status) {
 563                 case 0:
 564                         break;
 565                 case -NFS4ERR_BAD_SEQID:
 566                 case -NFS4ERR_STALE_CLIENTID:
 567                 case -NFS4ERR_STALE_STATEID:
 568                 case -NFS4ERR_BAD_STATEID:
 569                 case -NFS4ERR_BADXDR:
 570                 case -NFS4ERR_RESOURCE:
 571                 case -NFS4ERR_NOFILEHANDLE:
 572                         /* Non-seqid mutating errors */
 573                         return;
 574         };
 575         /*
 576          * Note: no locking needed as we are guaranteed to be first
 577          * on the sequence list
 578          */
 579         seqid->sequence->counter++;
 580 }
 581
 582 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
 583 {
 584         if (status == -NFS4ERR_BAD_SEQID) {
 585                 struct nfs4_state_owner *sp = container_of(seqid->sequence,
 586                                 struct nfs4_state_owner, so_seqid);
 587                 nfs4_drop_state_owner(sp);
 588         }
 589         return nfs_increment_seqid(status, seqid);
 590 }
 591
 592 /*
 593  * Increment the seqid if the LOCK/LOCKU succeeded, or
 594  * failed with a seqid incrementing error -
 595  * see comments nfs_fs.h:seqid_mutating_error()
 596  */
 597 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
 598 {
 599         return nfs_increment_seqid(status, seqid);
 600 }
 601
 602 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
 603 {
 604         struct rpc_sequence *sequence = seqid->sequence->sequence;
 605         int status = 0;
 606
 607         if (sequence->list.next == &seqid->list)
 608                 goto out;
 609         spin_lock(&sequence->lock);
 610         if (sequence->list.next != &seqid->list) {
 611                 rpc_sleep_on(&sequence->wait, task, NULL, NULL);
 612                 status = -EAGAIN;
 613         }
 614         spin_unlock(&sequence->lock);
 615 out:
 616         return status;
 617 }
 618
 619 static int reclaimer(void *);
 620
 621 static inline void nfs4_clear_recover_bit(struct nfs_client *clp)
 622 {
 623         smp_mb__before_clear_bit();
 624         clear_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state);
 625         smp_mb__after_clear_bit();
 626         wake_up_bit(&clp->cl_state, NFS4CLNT_STATE_RECOVER);
 627         rpc_wake_up(&clp->cl_rpcwaitq);
 628 }
 629
 630 /*
 631  * State recovery routine
 632  */
 633 static void nfs4_recover_state(struct nfs_client *clp)
 634 {
 635         struct task_struct *task;
 636
 637         __module_get(THIS_MODULE);
 638         atomic_inc(&clp->cl_count);
 639         task = kthread_run(reclaimer, clp, "%u.%u.%u.%u-reclaim",
 640                         NIPQUAD(clp->cl_addr.sin_addr));
 641         if (!IS_ERR(task))
 642                 return;
 643         nfs4_clear_recover_bit(clp);
 644         nfs_put_client(clp);
 645         module_put(THIS_MODULE);
 646 }
 647
 648 /*
 649  * Schedule a state recovery attempt
 650  */
 651 void nfs4_schedule_state_recovery(struct nfs_client *clp)
 652 {
 653         if (!clp)
 654                 return;
 655         if (test_and_set_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state) == 0)
 656                 nfs4_recover_state(clp);
 657 }
 658
 659 static int nfs4_reclaim_locks(struct nfs4_state_recovery_ops *ops, struct nfs4_state *state)
 660 {
 661         struct inode *inode = state->inode;
 662         struct file_lock *fl;
 663         int status = 0;
 664
 665         for (fl = inode->i_flock; fl != 0; fl = fl->fl_next) {
 666                 if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
 667                         continue;
 668                 if (((struct nfs_open_context *)fl->fl_file->private_data)->state != state)
 669                         continue;
 670                 status = ops->recover_lock(state, fl);
 671                 if (status >= 0)
 672                         continue;
 673                 switch (status) {
 674                         default:
 675                                 printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
 676                                                 __FUNCTION__, status);
 677                         case -NFS4ERR_EXPIRED:
 678                         case -NFS4ERR_NO_GRACE:
 679                         case -NFS4ERR_RECLAIM_BAD:
 680                         case -NFS4ERR_RECLAIM_CONFLICT:
 681                                 /* kill_proc(fl->fl_pid, SIGLOST, 1); */
 682                                 break;
 683                         case -NFS4ERR_STALE_CLIENTID:
 684                                 goto out_err;
 685                 }
 686         }
 687         return 0;
 688 out_err:
 689         return status;
 690 }
 691
 692 static int nfs4_reclaim_open_state(struct nfs4_state_recovery_ops *ops, struct nfs4_state_owner *sp)
 693 {
 694         struct nfs4_state *state;
 695         struct nfs4_lock_state *lock;
 696         int status = 0;
 697
 698         /* Note: we rely on the sp->so_states list being ordered
 699          * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
 700          * states first.
 701          * This is needed to ensure that the server won't give us any
 702          * read delegations that we have to return if, say, we are
 703          * recovering after a network partition or a reboot from a
 704          * server that doesn't support a grace period.
 705          */
 706         list_for_each_entry(state, &sp->so_states, open_states) {
 707                 if (state->state == 0)
 708                         continue;
 709                 status = ops->recover_open(sp, state);
 710                 if (status >= 0) {
 711                         status = nfs4_reclaim_locks(ops, state);
 712                         if (status < 0)
 713                                 goto out_err;
 714                         list_for_each_entry(lock, &state->lock_states, ls_locks) {
 715                                 if (!(lock->ls_flags & NFS_LOCK_INITIALIZED))
 716                                         printk("%s: Lock reclaim failed!\n",
 717                                                         __FUNCTION__);
 718                         }
 719                         continue;
 720                 }
 721                 switch (status) {
 722                         default:
 723                                 printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
 724                                                 __FUNCTION__, status);
 725                         case -ENOENT:
 726                         case -NFS4ERR_RECLAIM_BAD:
 727                         case -NFS4ERR_RECLAIM_CONFLICT:
 728                                 /*
 729                                  * Open state on this file cannot be recovered
 730                                  * All we can do is revert to using the zero stateid.
 731                                  */
 732                                 memset(state->stateid.data, 0,
 733                                         sizeof(state->stateid.data));
 734                                 /* Mark the file as being 'closed' */
 735                                 state->state = 0;
 736                                 break;
 737                         case -NFS4ERR_EXPIRED:
 738                         case -NFS4ERR_NO_GRACE:
 739                         case -NFS4ERR_STALE_CLIENTID:
 740                                 goto out_err;
 741                 }
 742         }
 743         return 0;
 744 out_err:
 745         return status;
 746 }
 747
 748 static void nfs4_state_mark_reclaim(struct nfs_client *clp)
 749 {
 750         struct nfs4_state_owner *sp;
 751         struct nfs4_state *state;
 752         struct nfs4_lock_state *lock;
 753
 754         /* Reset all sequence ids to zero */
 755         list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
 756                 sp->so_seqid.counter = 0;
 757                 sp->so_seqid.flags = 0;
 758                 spin_lock(&sp->so_lock);
 759                 list_for_each_entry(state, &sp->so_states, open_states) {
 760                         list_for_each_entry(lock, &state->lock_states, ls_locks) {
 761                                 lock->ls_seqid.counter = 0;
 762                                 lock->ls_seqid.flags = 0;
 763                                 lock->ls_flags &= ~NFS_LOCK_INITIALIZED;
 764                         }
 765                 }
 766                 spin_unlock(&sp->so_lock);
 767         }
 768 }
 769
 770 static int reclaimer(void *ptr)
 771 {
 772         struct nfs_client *clp = ptr;
 773         struct nfs4_state_owner *sp;
 774         struct nfs4_state_recovery_ops *ops;
 775         struct rpc_cred *cred;
 776         int status = 0;
 777
 778         allow_signal(SIGKILL);
 779
 780         /* Ensure exclusive access to NFSv4 state */
 781         lock_kernel();
 782         down_write(&clp->cl_sem);
 783         /* Are there any NFS mounts out there? */
 784         if (list_empty(&clp->cl_superblocks))
 785                 goto out;
 786 restart_loop:
 787         ops = &nfs4_network_partition_recovery_ops;
 788         /* Are there any open files on this volume? */
 789         cred = nfs4_get_renew_cred(clp);
 790         if (cred != NULL) {
 791                 /* Yes there are: try to renew the old lease */
 792                 status = nfs4_proc_renew(clp, cred);
 793                 switch (status) {
 794                         case 0:
 795                         case -NFS4ERR_CB_PATH_DOWN:
 796                                 put_rpccred(cred);
 797                                 goto out;
 798                         case -NFS4ERR_STALE_CLIENTID:
 799                         case -NFS4ERR_LEASE_MOVED:
 800                                 ops = &nfs4_reboot_recovery_ops;
 801                 }
 802         } else {
 803                 /* "reboot" to ensure we clear all state on the server */
 804                 clp->cl_boot_time = CURRENT_TIME;
 805                 cred = nfs4_get_setclientid_cred(clp);
 806         }
 807         /* We're going to have to re-establish a clientid */
 808         nfs4_state_mark_reclaim(clp);
 809         status = -ENOENT;
 810         if (cred != NULL) {
 811                 status = nfs4_init_client(clp, cred);
 812                 put_rpccred(cred);
 813         }
 814         if (status)
 815                 goto out_error;
 816         /* Mark all delegations for reclaim */
 817         nfs_delegation_mark_reclaim(clp);
 818         /* Note: list is protected by exclusive lock on cl->cl_sem */
 819         list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
 820                 status = nfs4_reclaim_open_state(ops, sp);
 821                 if (status < 0) {
 822                         if (status == -NFS4ERR_NO_GRACE) {
 823                                 ops = &nfs4_network_partition_recovery_ops;
 824                                 status = nfs4_reclaim_open_state(ops, sp);
 825                         }
 826                         if (status == -NFS4ERR_STALE_CLIENTID)
 827                                 goto restart_loop;
 828                         if (status == -NFS4ERR_EXPIRED)
 829                                 goto restart_loop;
 830                 }
 831         }
 832         nfs_delegation_reap_unclaimed(clp);
 833 out:
 834         up_write(&clp->cl_sem);
 835         unlock_kernel();
 836         if (status == -NFS4ERR_CB_PATH_DOWN)
 837                 nfs_handle_cb_pathdown(clp);
 838         nfs4_clear_recover_bit(clp);
 839         nfs_put_client(clp);
 840         module_put_and_exit(0);
 841         return 0;
 842 out_error:
 843         printk(KERN_WARNING "Error: state recovery failed on NFSv4 server %u.%u.%u.%u with error %d\n",
 844                                 NIPQUAD(clp->cl_addr.sin_addr), -status);
 845         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
 846         goto out;
 847 }
 848
 849 /*
 850  * Local variables:
 851  *  c-basic-offset: 8
 852  * End:
 853  */