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/config.h>
  42 #include <linux/slab.h>
  43 #include <linux/smp_lock.h>
  44 #include <linux/nfs_fs.h>
  45 #include <linux/nfs_idmap.h>
  46 #include <linux/workqueue.h>
  47 #include <linux/bitops.h>
  48
  49 #include "nfs4_fs.h"
  50 #include "callback.h"
  51 #include "delegation.h"
  52
  53 #define OPENOWNER_POOL_SIZE     8
  54
  55 const nfs4_stateid zero_stateid;
  56
  57 static DEFINE_SPINLOCK(state_spinlock);
  58 static LIST_HEAD(nfs4_clientid_list);
  59
  60 static void nfs4_recover_state(void *);
  61
  62 void
  63 init_nfsv4_state(struct nfs_server *server)
  64 {
  65         server->nfs4_state = NULL;
  66         INIT_LIST_HEAD(&server->nfs4_siblings);
  67 }
  68
  69 void
  70 destroy_nfsv4_state(struct nfs_server *server)
  71 {
  72         kfree(server->mnt_path);
  73         server->mnt_path = NULL;
  74         if (server->nfs4_state) {
  75                 nfs4_put_client(server->nfs4_state);
  76                 server->nfs4_state = NULL;
  77         }
  78 }
  79
  80 /*
  81  * nfs4_get_client(): returns an empty client structure
  82  * nfs4_put_client(): drops reference to client structure
  83  *
  84  * Since these are allocated/deallocated very rarely, we don't
  85  * bother putting them in a slab cache...
  86  */
  87 static struct nfs4_client *
  88 nfs4_alloc_client(struct in_addr *addr)
  89 {
  90         struct nfs4_client *clp;
  91
  92         if (nfs_callback_up() < 0)
  93                 return NULL;
  94         if ((clp = kmalloc(sizeof(*clp), GFP_KERNEL)) == NULL) {
  95                 nfs_callback_down();
  96                 return NULL;
  97         }
  98         memset(clp, 0, sizeof(*clp));
  99         memcpy(&clp->cl_addr, addr, sizeof(clp->cl_addr));
 100         init_rwsem(&clp->cl_sem);
 101         INIT_LIST_HEAD(&clp->cl_delegations);
 102         INIT_LIST_HEAD(&clp->cl_state_owners);
 103         INIT_LIST_HEAD(&clp->cl_unused);
 104         spin_lock_init(&clp->cl_lock);
 105         atomic_set(&clp->cl_count, 1);
 106         INIT_WORK(&clp->cl_recoverd, nfs4_recover_state, clp);
 107         INIT_WORK(&clp->cl_renewd, nfs4_renew_state, clp);
 108         INIT_LIST_HEAD(&clp->cl_superblocks);
 109         init_waitqueue_head(&clp->cl_waitq);
 110         rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS4 client");
 111         clp->cl_rpcclient = ERR_PTR(-EINVAL);
 112         clp->cl_boot_time = CURRENT_TIME;
 113         clp->cl_state = 1 << NFS4CLNT_OK;
 114         return clp;
 115 }
 116
 117 static void
 118 nfs4_free_client(struct nfs4_client *clp)
 119 {
 120         struct nfs4_state_owner *sp;
 121
 122         while (!list_empty(&clp->cl_unused)) {
 123                 sp = list_entry(clp->cl_unused.next,
 124                                 struct nfs4_state_owner,
 125                                 so_list);
 126                 list_del(&sp->so_list);
 127                 kfree(sp);
 128         }
 129         BUG_ON(!list_empty(&clp->cl_state_owners));
 130         if (clp->cl_cred)
 131                 put_rpccred(clp->cl_cred);
 132         nfs_idmap_delete(clp);
 133         if (!IS_ERR(clp->cl_rpcclient))
 134                 rpc_shutdown_client(clp->cl_rpcclient);
 135         kfree(clp);
 136         nfs_callback_down();
 137 }
 138
 139 static struct nfs4_client *__nfs4_find_client(struct in_addr *addr)
 140 {
 141         struct nfs4_client *clp;
 142         list_for_each_entry(clp, &nfs4_clientid_list, cl_servers) {
 143                 if (memcmp(&clp->cl_addr, addr, sizeof(clp->cl_addr)) == 0) {
 144                         atomic_inc(&clp->cl_count);
 145                         return clp;
 146                 }
 147         }
 148         return NULL;
 149 }
 150
 151 struct nfs4_client *nfs4_find_client(struct in_addr *addr)
 152 {
 153         struct nfs4_client *clp;
 154         spin_lock(&state_spinlock);
 155         clp = __nfs4_find_client(addr);
 156         spin_unlock(&state_spinlock);
 157         return clp;
 158 }
 159
 160 struct nfs4_client *
 161 nfs4_get_client(struct in_addr *addr)
 162 {
 163         struct nfs4_client *clp, *new = NULL;
 164
 165         spin_lock(&state_spinlock);
 166         for (;;) {
 167                 clp = __nfs4_find_client(addr);
 168                 if (clp != NULL)
 169                         break;
 170                 clp = new;
 171                 if (clp != NULL) {
 172                         list_add(&clp->cl_servers, &nfs4_clientid_list);
 173                         new = NULL;
 174                         break;
 175                 }
 176                 spin_unlock(&state_spinlock);
 177                 new = nfs4_alloc_client(addr);
 178                 spin_lock(&state_spinlock);
 179                 if (new == NULL)
 180                         break;
 181         }
 182         spin_unlock(&state_spinlock);
 183         if (new)
 184                 nfs4_free_client(new);
 185         return clp;
 186 }
 187
 188 void
 189 nfs4_put_client(struct nfs4_client *clp)
 190 {
 191         if (!atomic_dec_and_lock(&clp->cl_count, &state_spinlock))
 192                 return;
 193         list_del(&clp->cl_servers);
 194         spin_unlock(&state_spinlock);
 195         BUG_ON(!list_empty(&clp->cl_superblocks));
 196         wake_up_all(&clp->cl_waitq);
 197         rpc_wake_up(&clp->cl_rpcwaitq);
 198         nfs4_kill_renewd(clp);
 199         nfs4_free_client(clp);
 200 }
 201
 202 static int __nfs4_init_client(struct nfs4_client *clp)
 203 {
 204         int status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, nfs_callback_tcpport);
 205         if (status == 0)
 206                 status = nfs4_proc_setclientid_confirm(clp);
 207         if (status == 0)
 208                 nfs4_schedule_state_renewal(clp);
 209         return status;
 210 }
 211
 212 int nfs4_init_client(struct nfs4_client *clp)
 213 {
 214         return nfs4_map_errors(__nfs4_init_client(clp));
 215 }
 216
 217 u32
 218 nfs4_alloc_lockowner_id(struct nfs4_client *clp)
 219 {
 220         return clp->cl_lockowner_id ++;
 221 }
 222
 223 static struct nfs4_state_owner *
 224 nfs4_client_grab_unused(struct nfs4_client *clp, struct rpc_cred *cred)
 225 {
 226         struct nfs4_state_owner *sp = NULL;
 227
 228         if (!list_empty(&clp->cl_unused)) {
 229                 sp = list_entry(clp->cl_unused.next, struct nfs4_state_owner, so_list);
 230                 atomic_inc(&sp->so_count);
 231                 sp->so_cred = cred;
 232                 list_move(&sp->so_list, &clp->cl_state_owners);
 233                 clp->cl_nunused--;
 234         }
 235         return sp;
 236 }
 237
 238 static struct nfs4_state_owner *
 239 nfs4_find_state_owner(struct nfs4_client *clp, struct rpc_cred *cred)
 240 {
 241         struct nfs4_state_owner *sp, *res = NULL;
 242
 243         list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
 244                 if (sp->so_cred != cred)
 245                         continue;
 246                 atomic_inc(&sp->so_count);
 247                 /* Move to the head of the list */
 248                 list_move(&sp->so_list, &clp->cl_state_owners);
 249                 res = sp;
 250                 break;
 251         }
 252         return res;
 253 }
 254
 255 /*
 256  * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
 257  * create a new state_owner.
 258  *
 259  */
 260 static struct nfs4_state_owner *
 261 nfs4_alloc_state_owner(void)
 262 {
 263         struct nfs4_state_owner *sp;
 264
 265         sp = kzalloc(sizeof(*sp),GFP_KERNEL);
 266         if (!sp)
 267                 return NULL;
 268         spin_lock_init(&sp->so_lock);
 269         INIT_LIST_HEAD(&sp->so_states);
 270         INIT_LIST_HEAD(&sp->so_delegations);
 271         rpc_init_wait_queue(&sp->so_sequence.wait, "Seqid_waitqueue");
 272         sp->so_seqid.sequence = &sp->so_sequence;
 273         spin_lock_init(&sp->so_sequence.lock);
 274         INIT_LIST_HEAD(&sp->so_sequence.list);
 275         atomic_set(&sp->so_count, 1);
 276         return sp;
 277 }
 278
 279 void
 280 nfs4_drop_state_owner(struct nfs4_state_owner *sp)
 281 {
 282         struct nfs4_client *clp = sp->so_client;
 283         spin_lock(&clp->cl_lock);
 284         list_del_init(&sp->so_list);
 285         spin_unlock(&clp->cl_lock);
 286 }
 287
 288 /*
 289  * Note: must be called with clp->cl_sem held in order to prevent races
 290  *       with reboot recovery!
 291  */
 292 struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server, struct rpc_cred *cred)
 293 {
 294         struct nfs4_client *clp = server->nfs4_state;
 295         struct nfs4_state_owner *sp, *new;
 296
 297         get_rpccred(cred);
 298         new = nfs4_alloc_state_owner();
 299         spin_lock(&clp->cl_lock);
 300         sp = nfs4_find_state_owner(clp, cred);
 301         if (sp == NULL)
 302                 sp = nfs4_client_grab_unused(clp, cred);
 303         if (sp == NULL && new != NULL) {
 304                 list_add(&new->so_list, &clp->cl_state_owners);
 305                 new->so_client = clp;
 306                 new->so_id = nfs4_alloc_lockowner_id(clp);
 307                 new->so_cred = cred;
 308                 sp = new;
 309                 new = NULL;
 310         }
 311         spin_unlock(&clp->cl_lock);
 312         kfree(new);
 313         if (sp != NULL)
 314                 return sp;
 315         put_rpccred(cred);
 316         return NULL;
 317 }
 318
 319 /*
 320  * Must be called with clp->cl_sem held in order to avoid races
 321  * with state recovery...
 322  */
 323 void nfs4_put_state_owner(struct nfs4_state_owner *sp)
 324 {
 325         struct nfs4_client *clp = sp->so_client;
 326         struct rpc_cred *cred = sp->so_cred;
 327
 328         if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
 329                 return;
 330         if (clp->cl_nunused >= OPENOWNER_POOL_SIZE)
 331                 goto out_free;
 332         if (list_empty(&sp->so_list))
 333                 goto out_free;
 334         list_move(&sp->so_list, &clp->cl_unused);
 335         clp->cl_nunused++;
 336         spin_unlock(&clp->cl_lock);
 337         put_rpccred(cred);
 338         cred = NULL;
 339         return;
 340 out_free:
 341         list_del(&sp->so_list);
 342         spin_unlock(&clp->cl_lock);
 343         put_rpccred(cred);
 344         kfree(sp);
 345 }
 346
 347 static struct nfs4_state *
 348 nfs4_alloc_open_state(void)
 349 {
 350         struct nfs4_state *state;
 351
 352         state = kmalloc(sizeof(*state), GFP_KERNEL);
 353         if (!state)
 354                 return NULL;
 355         state->state = 0;
 356         state->nreaders = 0;
 357         state->nwriters = 0;
 358         state->flags = 0;
 359         memset(state->stateid.data, 0, sizeof(state->stateid.data));
 360         atomic_set(&state->count, 1);
 361         INIT_LIST_HEAD(&state->lock_states);
 362         spin_lock_init(&state->state_lock);
 363         return state;
 364 }
 365
 366 void
 367 nfs4_state_set_mode_locked(struct nfs4_state *state, mode_t mode)
 368 {
 369         if (state->state == mode)
 370                 return;
 371         /* NB! List reordering - see the reclaim code for why.  */
 372         if ((mode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
 373                 if (mode & FMODE_WRITE)
 374                         list_move(&state->open_states, &state->owner->so_states);
 375                 else
 376                         list_move_tail(&state->open_states, &state->owner->so_states);
 377         }
 378         if (mode == 0)
 379                 list_del_init(&state->inode_states);
 380         state->state = mode;
 381 }
 382
 383 static struct nfs4_state *
 384 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
 385 {
 386         struct nfs_inode *nfsi = NFS_I(inode);
 387         struct nfs4_state *state;
 388
 389         list_for_each_entry(state, &nfsi->open_states, inode_states) {
 390                 /* Is this in the process of being freed? */
 391                 if (state->state == 0)
 392                         continue;
 393                 if (state->owner == owner) {
 394                         atomic_inc(&state->count);
 395                         return state;
 396                 }
 397         }
 398         return NULL;
 399 }
 400
 401 static void
 402 nfs4_free_open_state(struct nfs4_state *state)
 403 {
 404         kfree(state);
 405 }
 406
 407 struct nfs4_state *
 408 nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
 409 {
 410         struct nfs4_state *state, *new;
 411         struct nfs_inode *nfsi = NFS_I(inode);
 412
 413         spin_lock(&inode->i_lock);
 414         state = __nfs4_find_state_byowner(inode, owner);
 415         spin_unlock(&inode->i_lock);
 416         if (state)
 417                 goto out;
 418         new = nfs4_alloc_open_state();
 419         spin_lock(&owner->so_lock);
 420         spin_lock(&inode->i_lock);
 421         state = __nfs4_find_state_byowner(inode, owner);
 422         if (state == NULL && new != NULL) {
 423                 state = new;
 424                 state->owner = owner;
 425                 atomic_inc(&owner->so_count);
 426                 list_add(&state->inode_states, &nfsi->open_states);
 427                 state->inode = igrab(inode);
 428                 spin_unlock(&inode->i_lock);
 429                 /* Note: The reclaim code dictates that we add stateless
 430                  * and read-only stateids to the end of the list */
 431                 list_add_tail(&state->open_states, &owner->so_states);
 432                 spin_unlock(&owner->so_lock);
 433         } else {
 434                 spin_unlock(&inode->i_lock);
 435                 spin_unlock(&owner->so_lock);
 436                 if (new)
 437                         nfs4_free_open_state(new);
 438         }
 439 out:
 440         return state;
 441 }
 442
 443 /*
 444  * Beware! Caller must be holding exactly one
 445  * reference to clp->cl_sem!
 446  */
 447 void nfs4_put_open_state(struct nfs4_state *state)
 448 {
 449         struct inode *inode = state->inode;
 450         struct nfs4_state_owner *owner = state->owner;
 451
 452         if (!atomic_dec_and_lock(&state->count, &owner->so_lock))
 453                 return;
 454         spin_lock(&inode->i_lock);
 455         if (!list_empty(&state->inode_states))
 456                 list_del(&state->inode_states);
 457         list_del(&state->open_states);
 458         spin_unlock(&inode->i_lock);
 459         spin_unlock(&owner->so_lock);
 460         iput(inode);
 461         nfs4_free_open_state(state);
 462         nfs4_put_state_owner(owner);
 463 }
 464
 465 /*
 466  * Close the current file.
 467  */
 468 void nfs4_close_state(struct nfs4_state *state, mode_t mode)
 469 {
 470         struct inode *inode = state->inode;
 471         struct nfs4_state_owner *owner = state->owner;
 472         int oldstate, newstate = 0;
 473
 474         atomic_inc(&owner->so_count);
 475         /* Protect against nfs4_find_state() */
 476         spin_lock(&owner->so_lock);
 477         spin_lock(&inode->i_lock);
 478         if (mode & FMODE_READ)
 479                 state->nreaders--;
 480         if (mode & FMODE_WRITE)
 481                 state->nwriters--;
 482         oldstate = newstate = state->state;
 483         if (state->nreaders == 0)
 484                 newstate &= ~FMODE_READ;
 485         if (state->nwriters == 0)
 486                 newstate &= ~FMODE_WRITE;
 487         if (test_bit(NFS_DELEGATED_STATE, &state->flags)) {
 488                 nfs4_state_set_mode_locked(state, newstate);
 489                 oldstate = newstate;
 490         }
 491         spin_unlock(&inode->i_lock);
 492         spin_unlock(&owner->so_lock);
 493
 494         if (oldstate != newstate && nfs4_do_close(inode, state) == 0)
 495                 return;
 496         nfs4_put_open_state(state);
 497         nfs4_put_state_owner(owner);
 498 }
 499
 500 /*
 501  * Search the state->lock_states for an existing lock_owner
 502  * that is compatible with current->files
 503  */
 504 static struct nfs4_lock_state *
 505 __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 506 {
 507         struct nfs4_lock_state *pos;
 508         list_for_each_entry(pos, &state->lock_states, ls_locks) {
 509                 if (pos->ls_owner != fl_owner)
 510                         continue;
 511                 atomic_inc(&pos->ls_count);
 512                 return pos;
 513         }
 514         return NULL;
 515 }
 516
 517 /*
 518  * Return a compatible lock_state. If no initialized lock_state structure
 519  * exists, return an uninitialized one.
 520  *
 521  */
 522 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 523 {
 524         struct nfs4_lock_state *lsp;
 525         struct nfs4_client *clp = state->owner->so_client;
 526
 527         lsp = kzalloc(sizeof(*lsp), GFP_KERNEL);
 528         if (lsp == NULL)
 529                 return NULL;
 530         lsp->ls_seqid.sequence = &state->owner->so_sequence;
 531         atomic_set(&lsp->ls_count, 1);
 532         lsp->ls_owner = fl_owner;
 533         spin_lock(&clp->cl_lock);
 534         lsp->ls_id = nfs4_alloc_lockowner_id(clp);
 535         spin_unlock(&clp->cl_lock);
 536         INIT_LIST_HEAD(&lsp->ls_locks);
 537         return lsp;
 538 }
 539
 540 /*
 541  * Return a compatible lock_state. If no initialized lock_state structure
 542  * exists, return an uninitialized one.
 543  *
 544  * The caller must be holding clp->cl_sem
 545  */
 546 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
 547 {
 548         struct nfs4_lock_state *lsp, *new = NULL;
 549
 550         for(;;) {
 551                 spin_lock(&state->state_lock);
 552                 lsp = __nfs4_find_lock_state(state, owner);
 553                 if (lsp != NULL)
 554                         break;
 555                 if (new != NULL) {
 556                         new->ls_state = state;
 557                         list_add(&new->ls_locks, &state->lock_states);
 558                         set_bit(LK_STATE_IN_USE, &state->flags);
 559                         lsp = new;
 560                         new = NULL;
 561                         break;
 562                 }
 563                 spin_unlock(&state->state_lock);
 564                 new = nfs4_alloc_lock_state(state, owner);
 565                 if (new == NULL)
 566                         return NULL;
 567         }
 568         spin_unlock(&state->state_lock);
 569         kfree(new);
 570         return lsp;
 571 }
 572
 573 /*
 574  * Release reference to lock_state, and free it if we see that
 575  * it is no longer in use
 576  */
 577 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
 578 {
 579         struct nfs4_state *state;
 580
 581         if (lsp == NULL)
 582                 return;
 583         state = lsp->ls_state;
 584         if (!atomic_dec_and_lock(&lsp->ls_count, &state->state_lock))
 585                 return;
 586         list_del(&lsp->ls_locks);
 587         if (list_empty(&state->lock_states))
 588                 clear_bit(LK_STATE_IN_USE, &state->flags);
 589         spin_unlock(&state->state_lock);
 590         kfree(lsp);
 591 }
 592
 593 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
 594 {
 595         struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
 596
 597         dst->fl_u.nfs4_fl.owner = lsp;
 598         atomic_inc(&lsp->ls_count);
 599 }
 600
 601 static void nfs4_fl_release_lock(struct file_lock *fl)
 602 {
 603         nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
 604 }
 605
 606 static struct file_lock_operations nfs4_fl_lock_ops = {
 607         .fl_copy_lock = nfs4_fl_copy_lock,
 608         .fl_release_private = nfs4_fl_release_lock,
 609 };
 610
 611 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
 612 {
 613         struct nfs4_lock_state *lsp;
 614
 615         if (fl->fl_ops != NULL)
 616                 return 0;
 617         lsp = nfs4_get_lock_state(state, fl->fl_owner);
 618         if (lsp == NULL)
 619                 return -ENOMEM;
 620         fl->fl_u.nfs4_fl.owner = lsp;
 621         fl->fl_ops = &nfs4_fl_lock_ops;
 622         return 0;
 623 }
 624
 625 /*
 626  * Byte-range lock aware utility to initialize the stateid of read/write
 627  * requests.
 628  */
 629 void nfs4_copy_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t fl_owner)
 630 {
 631         struct nfs4_lock_state *lsp;
 632
 633         memcpy(dst, &state->stateid, sizeof(*dst));
 634         if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
 635                 return;
 636
 637         spin_lock(&state->state_lock);
 638         lsp = __nfs4_find_lock_state(state, fl_owner);
 639         if (lsp != NULL && (lsp->ls_flags & NFS_LOCK_INITIALIZED) != 0)
 640                 memcpy(dst, &lsp->ls_stateid, sizeof(*dst));
 641         spin_unlock(&state->state_lock);
 642         nfs4_put_lock_state(lsp);
 643 }
 644
 645 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter)
 646 {
 647         struct nfs_seqid *new;
 648
 649         new = kmalloc(sizeof(*new), GFP_KERNEL);
 650         if (new != NULL) {
 651                 new->sequence = counter;
 652                 INIT_LIST_HEAD(&new->list);
 653         }
 654         return new;
 655 }
 656
 657 void nfs_free_seqid(struct nfs_seqid *seqid)
 658 {
 659         struct rpc_sequence *sequence = seqid->sequence->sequence;
 660
 661         if (!list_empty(&seqid->list)) {
 662                 spin_lock(&sequence->lock);
 663                 list_del(&seqid->list);
 664                 spin_unlock(&sequence->lock);
 665         }
 666         rpc_wake_up_next(&sequence->wait);
 667         kfree(seqid);
 668 }
 669
 670 /*
 671  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
 672  * failed with a seqid incrementing error -
 673  * see comments nfs_fs.h:seqid_mutating_error()
 674  */
 675 static inline void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
 676 {
 677         switch (status) {
 678                 case 0:
 679                         break;
 680                 case -NFS4ERR_BAD_SEQID:
 681                 case -NFS4ERR_STALE_CLIENTID:
 682                 case -NFS4ERR_STALE_STATEID:
 683                 case -NFS4ERR_BAD_STATEID:
 684                 case -NFS4ERR_BADXDR:
 685                 case -NFS4ERR_RESOURCE:
 686                 case -NFS4ERR_NOFILEHANDLE:
 687                         /* Non-seqid mutating errors */
 688                         return;
 689         };
 690         /*
 691          * Note: no locking needed as we are guaranteed to be first
 692          * on the sequence list
 693          */
 694         seqid->sequence->counter++;
 695 }
 696
 697 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
 698 {
 699         if (status == -NFS4ERR_BAD_SEQID) {
 700                 struct nfs4_state_owner *sp = container_of(seqid->sequence,
 701                                 struct nfs4_state_owner, so_seqid);
 702                 nfs4_drop_state_owner(sp);
 703         }
 704         return nfs_increment_seqid(status, seqid);
 705 }
 706
 707 /*
 708  * Increment the seqid if the LOCK/LOCKU succeeded, or
 709  * failed with a seqid incrementing error -
 710  * see comments nfs_fs.h:seqid_mutating_error()
 711  */
 712 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
 713 {
 714         return nfs_increment_seqid(status, seqid);
 715 }
 716
 717 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
 718 {
 719         struct rpc_sequence *sequence = seqid->sequence->sequence;
 720         int status = 0;
 721
 722         if (sequence->list.next == &seqid->list)
 723                 goto out;
 724         spin_lock(&sequence->lock);
 725         if (!list_empty(&sequence->list)) {
 726                 rpc_sleep_on(&sequence->wait, task, NULL, NULL);
 727                 status = -EAGAIN;
 728         } else
 729                 list_add(&seqid->list, &sequence->list);
 730         spin_unlock(&sequence->lock);
 731 out:
 732         return status;
 733 }
 734
 735 static int reclaimer(void *);
 736 struct reclaimer_args {
 737         struct nfs4_client *clp;
 738         struct completion complete;
 739 };
 740
 741 /*
 742  * State recovery routine
 743  */
 744 void
 745 nfs4_recover_state(void *data)
 746 {
 747         struct nfs4_client *clp = (struct nfs4_client *)data;
 748         struct reclaimer_args args = {
 749                 .clp = clp,
 750         };
 751         might_sleep();
 752
 753         init_completion(&args.complete);
 754
 755         if (kernel_thread(reclaimer, &args, CLONE_KERNEL) < 0)
 756                 goto out_failed_clear;
 757         wait_for_completion(&args.complete);
 758         return;
 759 out_failed_clear:
 760         set_bit(NFS4CLNT_OK, &clp->cl_state);
 761         wake_up_all(&clp->cl_waitq);
 762         rpc_wake_up(&clp->cl_rpcwaitq);
 763 }
 764
 765 /*
 766  * Schedule a state recovery attempt
 767  */
 768 void
 769 nfs4_schedule_state_recovery(struct nfs4_client *clp)
 770 {
 771         if (!clp)
 772                 return;
 773         if (test_and_clear_bit(NFS4CLNT_OK, &clp->cl_state))
 774                 schedule_work(&clp->cl_recoverd);
 775 }
 776
 777 static int nfs4_reclaim_locks(struct nfs4_state_recovery_ops *ops, struct nfs4_state *state)
 778 {
 779         struct inode *inode = state->inode;
 780         struct file_lock *fl;
 781         int status = 0;
 782
 783         for (fl = inode->i_flock; fl != 0; fl = fl->fl_next) {
 784                 if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
 785                         continue;
 786                 if (((struct nfs_open_context *)fl->fl_file->private_data)->state != state)
 787                         continue;
 788                 status = ops->recover_lock(state, fl);
 789                 if (status >= 0)
 790                         continue;
 791                 switch (status) {
 792                         default:
 793                                 printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
 794                                                 __FUNCTION__, status);
 795                         case -NFS4ERR_EXPIRED:
 796                         case -NFS4ERR_NO_GRACE:
 797                         case -NFS4ERR_RECLAIM_BAD:
 798                         case -NFS4ERR_RECLAIM_CONFLICT:
 799                                 /* kill_proc(fl->fl_pid, SIGLOST, 1); */
 800                                 break;
 801                         case -NFS4ERR_STALE_CLIENTID:
 802                                 goto out_err;
 803                 }
 804         }
 805         return 0;
 806 out_err:
 807         return status;
 808 }
 809
 810 static int nfs4_reclaim_open_state(struct nfs4_state_recovery_ops *ops, struct nfs4_state_owner *sp)
 811 {
 812         struct nfs4_state *state;
 813         struct nfs4_lock_state *lock;
 814         int status = 0;
 815
 816         /* Note: we rely on the sp->so_states list being ordered
 817          * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
 818          * states first.
 819          * This is needed to ensure that the server won't give us any
 820          * read delegations that we have to return if, say, we are
 821          * recovering after a network partition or a reboot from a
 822          * server that doesn't support a grace period.
 823          */
 824         list_for_each_entry(state, &sp->so_states, open_states) {
 825                 if (state->state == 0)
 826                         continue;
 827                 status = ops->recover_open(sp, state);
 828                 if (status >= 0) {
 829                         status = nfs4_reclaim_locks(ops, state);
 830                         if (status < 0)
 831                                 goto out_err;
 832                         list_for_each_entry(lock, &state->lock_states, ls_locks) {
 833                                 if (!(lock->ls_flags & NFS_LOCK_INITIALIZED))
 834                                         printk("%s: Lock reclaim failed!\n",
 835                                                         __FUNCTION__);
 836                         }
 837                         continue;
 838                 }
 839                 switch (status) {
 840                         default:
 841                                 printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
 842                                                 __FUNCTION__, status);
 843                         case -ENOENT:
 844                         case -NFS4ERR_RECLAIM_BAD:
 845                         case -NFS4ERR_RECLAIM_CONFLICT:
 846                                 /*
 847                                  * Open state on this file cannot be recovered
 848                                  * All we can do is revert to using the zero stateid.
 849                                  */
 850                                 memset(state->stateid.data, 0,
 851                                         sizeof(state->stateid.data));
 852                                 /* Mark the file as being 'closed' */
 853                                 state->state = 0;
 854                                 break;
 855                         case -NFS4ERR_EXPIRED:
 856                         case -NFS4ERR_NO_GRACE:
 857                         case -NFS4ERR_STALE_CLIENTID:
 858                                 goto out_err;
 859                 }
 860         }
 861         return 0;
 862 out_err:
 863         return status;
 864 }
 865
 866 static void nfs4_state_mark_reclaim(struct nfs4_client *clp)
 867 {
 868         struct nfs4_state_owner *sp;
 869         struct nfs4_state *state;
 870         struct nfs4_lock_state *lock;
 871
 872         /* Reset all sequence ids to zero */
 873         list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
 874                 sp->so_seqid.counter = 0;
 875                 sp->so_seqid.flags = 0;
 876                 spin_lock(&sp->so_lock);
 877                 list_for_each_entry(state, &sp->so_states, open_states) {
 878                         list_for_each_entry(lock, &state->lock_states, ls_locks) {
 879                                 lock->ls_seqid.counter = 0;
 880                                 lock->ls_seqid.flags = 0;
 881                                 lock->ls_flags &= ~NFS_LOCK_INITIALIZED;
 882                         }
 883                 }
 884                 spin_unlock(&sp->so_lock);
 885         }
 886 }
 887
 888 static int reclaimer(void *ptr)
 889 {
 890         struct reclaimer_args *args = (struct reclaimer_args *)ptr;
 891         struct nfs4_client *clp = args->clp;
 892         struct nfs4_state_owner *sp;
 893         struct nfs4_state_recovery_ops *ops;
 894         int status = 0;
 895
 896         daemonize("%u.%u.%u.%u-reclaim", NIPQUAD(clp->cl_addr));
 897         allow_signal(SIGKILL);
 898
 899         atomic_inc(&clp->cl_count);
 900         complete(&args->complete);
 901
 902         /* Ensure exclusive access to NFSv4 state */
 903         lock_kernel();
 904         down_write(&clp->cl_sem);
 905         /* Are there any NFS mounts out there? */
 906         if (list_empty(&clp->cl_superblocks))
 907                 goto out;
 908 restart_loop:
 909         status = nfs4_proc_renew(clp);
 910         switch (status) {
 911                 case 0:
 912                 case -NFS4ERR_CB_PATH_DOWN:
 913                         goto out;
 914                 case -NFS4ERR_STALE_CLIENTID:
 915                 case -NFS4ERR_LEASE_MOVED:
 916                         ops = &nfs4_reboot_recovery_ops;
 917                         break;
 918                 default:
 919                         ops = &nfs4_network_partition_recovery_ops;
 920         };
 921         nfs4_state_mark_reclaim(clp);
 922         status = __nfs4_init_client(clp);
 923         if (status)
 924                 goto out_error;
 925         /* Mark all delegations for reclaim */
 926         nfs_delegation_mark_reclaim(clp);
 927         /* Note: list is protected by exclusive lock on cl->cl_sem */
 928         list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
 929                 status = nfs4_reclaim_open_state(ops, sp);
 930                 if (status < 0) {
 931                         if (status == -NFS4ERR_NO_GRACE) {
 932                                 ops = &nfs4_network_partition_recovery_ops;
 933                                 status = nfs4_reclaim_open_state(ops, sp);
 934                         }
 935                         if (status == -NFS4ERR_STALE_CLIENTID)
 936                                 goto restart_loop;
 937                         if (status == -NFS4ERR_EXPIRED)
 938                                 goto restart_loop;
 939                 }
 940         }
 941         nfs_delegation_reap_unclaimed(clp);
 942 out:
 943         set_bit(NFS4CLNT_OK, &clp->cl_state);
 944         up_write(&clp->cl_sem);
 945         unlock_kernel();
 946         wake_up_all(&clp->cl_waitq);
 947         rpc_wake_up(&clp->cl_rpcwaitq);
 948         if (status == -NFS4ERR_CB_PATH_DOWN)
 949                 nfs_handle_cb_pathdown(clp);
 950         nfs4_put_client(clp);
 951         return 0;
 952 out_error:
 953         printk(KERN_WARNING "Error: state recovery failed on NFSv4 server %u.%u.%u.%u with error %d\n",
 954                                 NIPQUAD(clp->cl_addr.s_addr), -status);
 955         goto out;
 956 }
 957
 958 /*
 959  * Local variables:
 960  *  c-basic-offset: 8
 961  * End:
 962  */