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
  54 #define OPENOWNER_POOL_SIZE     8
  55
  56 const nfs4_stateid zero_stateid;
  57
  58 static DEFINE_SPINLOCK(state_spinlock);
  59 static LIST_HEAD(nfs4_clientid_list);
  60
  61 void
  62 init_nfsv4_state(struct nfs_server *server)
  63 {
  64         server->nfs4_state = NULL;
  65         INIT_LIST_HEAD(&server->nfs4_siblings);
  66 }
  67
  68 void
  69 destroy_nfsv4_state(struct nfs_server *server)
  70 {
  71         kfree(server->mnt_path);
  72         server->mnt_path = NULL;
  73         if (server->nfs4_state) {
  74                 nfs4_put_client(server->nfs4_state);
  75                 server->nfs4_state = NULL;
  76         }
  77 }
  78
  79 /*
  80  * nfs4_get_client(): returns an empty client structure
  81  * nfs4_put_client(): drops reference to client structure
  82  *
  83  * Since these are allocated/deallocated very rarely, we don't
  84  * bother putting them in a slab cache...
  85  */
  86 static struct nfs4_client *
  87 nfs4_alloc_client(struct in_addr *addr)
  88 {
  89         struct nfs4_client *clp;
  90
  91         if (nfs_callback_up() < 0)
  92                 return NULL;
  93         if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL) {
  94                 nfs_callback_down();
  95                 return NULL;
  96         }
  97         memcpy(&clp->cl_addr, addr, sizeof(clp->cl_addr));
  98         init_rwsem(&clp->cl_sem);
  99         INIT_LIST_HEAD(&clp->cl_delegations);
 100         INIT_LIST_HEAD(&clp->cl_state_owners);
 101         INIT_LIST_HEAD(&clp->cl_unused);
 102         spin_lock_init(&clp->cl_lock);
 103         atomic_set(&clp->cl_count, 1);
 104         INIT_WORK(&clp->cl_renewd, nfs4_renew_state, clp);
 105         INIT_LIST_HEAD(&clp->cl_superblocks);
 106         rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS4 client");
 107         clp->cl_rpcclient = ERR_PTR(-EINVAL);
 108         clp->cl_boot_time = CURRENT_TIME;
 109         clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
 110         return clp;
 111 }
 112
 113 static void
 114 nfs4_free_client(struct nfs4_client *clp)
 115 {
 116         struct nfs4_state_owner *sp;
 117
 118         while (!list_empty(&clp->cl_unused)) {
 119                 sp = list_entry(clp->cl_unused.next,
 120                                 struct nfs4_state_owner,
 121                                 so_list);
 122                 list_del(&sp->so_list);
 123                 kfree(sp);
 124         }
 125         BUG_ON(!list_empty(&clp->cl_state_owners));
 126         nfs_idmap_delete(clp);
 127         if (!IS_ERR(clp->cl_rpcclient))
 128                 rpc_shutdown_client(clp->cl_rpcclient);
 129         kfree(clp);
 130         nfs_callback_down();
 131 }
 132
 133 static struct nfs4_client *__nfs4_find_client(struct in_addr *addr)
 134 {
 135         struct nfs4_client *clp;
 136         list_for_each_entry(clp, &nfs4_clientid_list, cl_servers) {
 137                 if (memcmp(&clp->cl_addr, addr, sizeof(clp->cl_addr)) == 0) {
 138                         atomic_inc(&clp->cl_count);
 139                         return clp;
 140                 }
 141         }
 142         return NULL;
 143 }
 144
 145 struct nfs4_client *nfs4_find_client(struct in_addr *addr)
 146 {
 147         struct nfs4_client *clp;
 148         spin_lock(&state_spinlock);
 149         clp = __nfs4_find_client(addr);
 150         spin_unlock(&state_spinlock);
 151         return clp;
 152 }
 153
 154 struct nfs4_client *
 155 nfs4_get_client(struct in_addr *addr)
 156 {
 157         struct nfs4_client *clp, *new = NULL;
 158
 159         spin_lock(&state_spinlock);
 160         for (;;) {
 161                 clp = __nfs4_find_client(addr);
 162                 if (clp != NULL)
 163                         break;
 164                 clp = new;
 165                 if (clp != NULL) {
 166                         list_add(&clp->cl_servers, &nfs4_clientid_list);
 167                         new = NULL;
 168                         break;
 169                 }
 170                 spin_unlock(&state_spinlock);
 171                 new = nfs4_alloc_client(addr);
 172                 spin_lock(&state_spinlock);
 173                 if (new == NULL)
 174                         break;
 175         }
 176         spin_unlock(&state_spinlock);
 177         if (new)
 178                 nfs4_free_client(new);
 179         return clp;
 180 }
 181
 182 void
 183 nfs4_put_client(struct nfs4_client *clp)
 184 {
 185         if (!atomic_dec_and_lock(&clp->cl_count, &state_spinlock))
 186                 return;
 187         list_del(&clp->cl_servers);
 188         spin_unlock(&state_spinlock);
 189         BUG_ON(!list_empty(&clp->cl_superblocks));
 190         rpc_wake_up(&clp->cl_rpcwaitq);
 191         nfs4_kill_renewd(clp);
 192         nfs4_free_client(clp);
 193 }
 194
 195 static int nfs4_init_client(struct nfs4_client *clp, struct rpc_cred *cred)
 196 {
 197         int status = nfs4_proc_setclientid(clp, NFS4_CALLBACK,
 198                         nfs_callback_tcpport, cred);
 199         if (status == 0)
 200                 status = nfs4_proc_setclientid_confirm(clp, cred);
 201         if (status == 0)
 202                 nfs4_schedule_state_renewal(clp);
 203         return status;
 204 }
 205
 206 u32
 207 nfs4_alloc_lockowner_id(struct nfs4_client *clp)
 208 {
 209         return clp->cl_lockowner_id ++;
 210 }
 211
 212 static struct nfs4_state_owner *
 213 nfs4_client_grab_unused(struct nfs4_client *clp, struct rpc_cred *cred)
 214 {
 215         struct nfs4_state_owner *sp = NULL;
 216
 217         if (!list_empty(&clp->cl_unused)) {
 218                 sp = list_entry(clp->cl_unused.next, struct nfs4_state_owner, so_list);
 219                 atomic_inc(&sp->so_count);
 220                 sp->so_cred = cred;
 221                 list_move(&sp->so_list, &clp->cl_state_owners);
 222                 clp->cl_nunused--;
 223         }
 224         return sp;
 225 }
 226
 227 struct rpc_cred *nfs4_get_renew_cred(struct nfs4_client *clp)
 228 {
 229         struct nfs4_state_owner *sp;
 230         struct rpc_cred *cred = NULL;
 231
 232         list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
 233                 if (list_empty(&sp->so_states))
 234                         continue;
 235                 cred = get_rpccred(sp->so_cred);
 236                 break;
 237         }
 238         return cred;
 239 }
 240
 241 struct rpc_cred *nfs4_get_setclientid_cred(struct nfs4_client *clp)
 242 {
 243         struct nfs4_state_owner *sp;
 244
 245         if (!list_empty(&clp->cl_state_owners)) {
 246                 sp = list_entry(clp->cl_state_owners.next,
 247                                 struct nfs4_state_owner, so_list);
 248                 return get_rpccred(sp->so_cred);
 249         }
 250         return NULL;
 251 }
 252
 253 static struct nfs4_state_owner *
 254 nfs4_find_state_owner(struct nfs4_client *clp, struct rpc_cred *cred)
 255 {
 256         struct nfs4_state_owner *sp, *res = NULL;
 257
 258         list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
 259                 if (sp->so_cred != cred)
 260                         continue;
 261                 atomic_inc(&sp->so_count);
 262                 /* Move to the head of the list */
 263                 list_move(&sp->so_list, &clp->cl_state_owners);
 264                 res = sp;
 265                 break;
 266         }
 267         return res;
 268 }
 269
 270 /*
 271  * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
 272  * create a new state_owner.
 273  *
 274  */
 275 static struct nfs4_state_owner *
 276 nfs4_alloc_state_owner(void)
 277 {
 278         struct nfs4_state_owner *sp;
 279
 280         sp = kzalloc(sizeof(*sp),GFP_KERNEL);
 281         if (!sp)
 282                 return NULL;
 283         spin_lock_init(&sp->so_lock);
 284         INIT_LIST_HEAD(&sp->so_states);
 285         INIT_LIST_HEAD(&sp->so_delegations);
 286         rpc_init_wait_queue(&sp->so_sequence.wait, "Seqid_waitqueue");
 287         sp->so_seqid.sequence = &sp->so_sequence;
 288         spin_lock_init(&sp->so_sequence.lock);
 289         INIT_LIST_HEAD(&sp->so_sequence.list);
 290         atomic_set(&sp->so_count, 1);
 291         return sp;
 292 }
 293
 294 void
 295 nfs4_drop_state_owner(struct nfs4_state_owner *sp)
 296 {
 297         struct nfs4_client *clp = sp->so_client;
 298         spin_lock(&clp->cl_lock);
 299         list_del_init(&sp->so_list);
 300         spin_unlock(&clp->cl_lock);
 301 }
 302
 303 /*
 304  * Note: must be called with clp->cl_sem held in order to prevent races
 305  *       with reboot recovery!
 306  */
 307 struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server, struct rpc_cred *cred)
 308 {
 309         struct nfs4_client *clp = server->nfs4_state;
 310         struct nfs4_state_owner *sp, *new;
 311
 312         get_rpccred(cred);
 313         new = nfs4_alloc_state_owner();
 314         spin_lock(&clp->cl_lock);
 315         sp = nfs4_find_state_owner(clp, cred);
 316         if (sp == NULL)
 317                 sp = nfs4_client_grab_unused(clp, cred);
 318         if (sp == NULL && new != NULL) {
 319                 list_add(&new->so_list, &clp->cl_state_owners);
 320                 new->so_client = clp;
 321                 new->so_id = nfs4_alloc_lockowner_id(clp);
 322                 new->so_cred = cred;
 323                 sp = new;
 324                 new = NULL;
 325         }
 326         spin_unlock(&clp->cl_lock);
 327         kfree(new);
 328         if (sp != NULL)
 329                 return sp;
 330         put_rpccred(cred);
 331         return NULL;
 332 }
 333
 334 /*
 335  * Must be called with clp->cl_sem held in order to avoid races
 336  * with state recovery...
 337  */
 338 void nfs4_put_state_owner(struct nfs4_state_owner *sp)
 339 {
 340         struct nfs4_client *clp = sp->so_client;
 341         struct rpc_cred *cred = sp->so_cred;
 342
 343         if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
 344                 return;
 345         if (clp->cl_nunused >= OPENOWNER_POOL_SIZE)
 346                 goto out_free;
 347         if (list_empty(&sp->so_list))
 348                 goto out_free;
 349         list_move(&sp->so_list, &clp->cl_unused);
 350         clp->cl_nunused++;
 351         spin_unlock(&clp->cl_lock);
 352         put_rpccred(cred);
 353         cred = NULL;
 354         return;
 355 out_free:
 356         list_del(&sp->so_list);
 357         spin_unlock(&clp->cl_lock);
 358         put_rpccred(cred);
 359         kfree(sp);
 360 }
 361
 362 static struct nfs4_state *
 363 nfs4_alloc_open_state(void)
 364 {
 365         struct nfs4_state *state;
 366
 367         state = kzalloc(sizeof(*state), GFP_KERNEL);
 368         if (!state)
 369                 return NULL;
 370         atomic_set(&state->count, 1);
 371         INIT_LIST_HEAD(&state->lock_states);
 372         spin_lock_init(&state->state_lock);
 373         return state;
 374 }
 375
 376 void
 377 nfs4_state_set_mode_locked(struct nfs4_state *state, mode_t mode)
 378 {
 379         if (state->state == mode)
 380                 return;
 381         /* NB! List reordering - see the reclaim code for why.  */
 382         if ((mode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
 383                 if (mode & FMODE_WRITE)
 384                         list_move(&state->open_states, &state->owner->so_states);
 385                 else
 386                         list_move_tail(&state->open_states, &state->owner->so_states);
 387         }
 388         if (mode == 0)
 389                 list_del_init(&state->inode_states);
 390         state->state = mode;
 391 }
 392
 393 static struct nfs4_state *
 394 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
 395 {
 396         struct nfs_inode *nfsi = NFS_I(inode);
 397         struct nfs4_state *state;
 398
 399         list_for_each_entry(state, &nfsi->open_states, inode_states) {
 400                 /* Is this in the process of being freed? */
 401                 if (state->state == 0)
 402                         continue;
 403                 if (state->owner == owner) {
 404                         atomic_inc(&state->count);
 405                         return state;
 406                 }
 407         }
 408         return NULL;
 409 }
 410
 411 static void
 412 nfs4_free_open_state(struct nfs4_state *state)
 413 {
 414         kfree(state);
 415 }
 416
 417 struct nfs4_state *
 418 nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
 419 {
 420         struct nfs4_state *state, *new;
 421         struct nfs_inode *nfsi = NFS_I(inode);
 422
 423         spin_lock(&inode->i_lock);
 424         state = __nfs4_find_state_byowner(inode, owner);
 425         spin_unlock(&inode->i_lock);
 426         if (state)
 427                 goto out;
 428         new = nfs4_alloc_open_state();
 429         spin_lock(&owner->so_lock);
 430         spin_lock(&inode->i_lock);
 431         state = __nfs4_find_state_byowner(inode, owner);
 432         if (state == NULL && new != NULL) {
 433                 state = new;
 434                 state->owner = owner;
 435                 atomic_inc(&owner->so_count);
 436                 list_add(&state->inode_states, &nfsi->open_states);
 437                 state->inode = igrab(inode);
 438                 spin_unlock(&inode->i_lock);
 439                 /* Note: The reclaim code dictates that we add stateless
 440                  * and read-only stateids to the end of the list */
 441                 list_add_tail(&state->open_states, &owner->so_states);
 442                 spin_unlock(&owner->so_lock);
 443         } else {
 444                 spin_unlock(&inode->i_lock);
 445                 spin_unlock(&owner->so_lock);
 446                 if (new)
 447                         nfs4_free_open_state(new);
 448         }
 449 out:
 450         return state;
 451 }
 452
 453 /*
 454  * Beware! Caller must be holding exactly one
 455  * reference to clp->cl_sem!
 456  */
 457 void nfs4_put_open_state(struct nfs4_state *state)
 458 {
 459         struct inode *inode = state->inode;
 460         struct nfs4_state_owner *owner = state->owner;
 461
 462         if (!atomic_dec_and_lock(&state->count, &owner->so_lock))
 463                 return;
 464         spin_lock(&inode->i_lock);
 465         if (!list_empty(&state->inode_states))
 466                 list_del(&state->inode_states);
 467         list_del(&state->open_states);
 468         spin_unlock(&inode->i_lock);
 469         spin_unlock(&owner->so_lock);
 470         iput(inode);
 471         nfs4_free_open_state(state);
 472         nfs4_put_state_owner(owner);
 473 }
 474
 475 /*
 476  * Close the current file.
 477  */
 478 void nfs4_close_state(struct nfs4_state *state, mode_t mode)
 479 {
 480         struct inode *inode = state->inode;
 481         struct nfs4_state_owner *owner = state->owner;
 482         int oldstate, newstate = 0;
 483
 484         atomic_inc(&owner->so_count);
 485         /* Protect against nfs4_find_state() */
 486         spin_lock(&owner->so_lock);
 487         spin_lock(&inode->i_lock);
 488         switch (mode & (FMODE_READ | FMODE_WRITE)) {
 489                 case FMODE_READ:
 490                         state->n_rdonly--;
 491                         break;
 492                 case FMODE_WRITE:
 493                         state->n_wronly--;
 494                         break;
 495                 case FMODE_READ|FMODE_WRITE:
 496                         state->n_rdwr--;
 497         }
 498         oldstate = newstate = state->state;
 499         if (state->n_rdwr == 0) {
 500                 if (state->n_rdonly == 0)
 501                         newstate &= ~FMODE_READ;
 502                 if (state->n_wronly == 0)
 503                         newstate &= ~FMODE_WRITE;
 504         }
 505         if (test_bit(NFS_DELEGATED_STATE, &state->flags)) {
 506                 nfs4_state_set_mode_locked(state, newstate);
 507                 oldstate = newstate;
 508         }
 509         spin_unlock(&inode->i_lock);
 510         spin_unlock(&owner->so_lock);
 511
 512         if (oldstate != newstate && nfs4_do_close(inode, state) == 0)
 513                 return;
 514         nfs4_put_open_state(state);
 515         nfs4_put_state_owner(owner);
 516 }
 517
 518 /*
 519  * Search the state->lock_states for an existing lock_owner
 520  * that is compatible with current->files
 521  */
 522 static struct nfs4_lock_state *
 523 __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 524 {
 525         struct nfs4_lock_state *pos;
 526         list_for_each_entry(pos, &state->lock_states, ls_locks) {
 527                 if (pos->ls_owner != fl_owner)
 528                         continue;
 529                 atomic_inc(&pos->ls_count);
 530                 return pos;
 531         }
 532         return NULL;
 533 }
 534
 535 /*
 536  * Return a compatible lock_state. If no initialized lock_state structure
 537  * exists, return an uninitialized one.
 538  *
 539  */
 540 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 541 {
 542         struct nfs4_lock_state *lsp;
 543         struct nfs4_client *clp = state->owner->so_client;
 544
 545         lsp = kzalloc(sizeof(*lsp), GFP_KERNEL);
 546         if (lsp == NULL)
 547                 return NULL;
 548         lsp->ls_seqid.sequence = &state->owner->so_sequence;
 549         atomic_set(&lsp->ls_count, 1);
 550         lsp->ls_owner = fl_owner;
 551         spin_lock(&clp->cl_lock);
 552         lsp->ls_id = nfs4_alloc_lockowner_id(clp);
 553         spin_unlock(&clp->cl_lock);
 554         INIT_LIST_HEAD(&lsp->ls_locks);
 555         return lsp;
 556 }
 557
 558 /*
 559  * Return a compatible lock_state. If no initialized lock_state structure
 560  * exists, return an uninitialized one.
 561  *
 562  * The caller must be holding clp->cl_sem
 563  */
 564 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
 565 {
 566         struct nfs4_lock_state *lsp, *new = NULL;
 567
 568         for(;;) {
 569                 spin_lock(&state->state_lock);
 570                 lsp = __nfs4_find_lock_state(state, owner);
 571                 if (lsp != NULL)
 572                         break;
 573                 if (new != NULL) {
 574                         new->ls_state = state;
 575                         list_add(&new->ls_locks, &state->lock_states);
 576                         set_bit(LK_STATE_IN_USE, &state->flags);
 577                         lsp = new;
 578                         new = NULL;
 579                         break;
 580                 }
 581                 spin_unlock(&state->state_lock);
 582                 new = nfs4_alloc_lock_state(state, owner);
 583                 if (new == NULL)
 584                         return NULL;
 585         }
 586         spin_unlock(&state->state_lock);
 587         kfree(new);
 588         return lsp;
 589 }
 590
 591 /*
 592  * Release reference to lock_state, and free it if we see that
 593  * it is no longer in use
 594  */
 595 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
 596 {
 597         struct nfs4_state *state;
 598
 599         if (lsp == NULL)
 600                 return;
 601         state = lsp->ls_state;
 602         if (!atomic_dec_and_lock(&lsp->ls_count, &state->state_lock))
 603                 return;
 604         list_del(&lsp->ls_locks);
 605         if (list_empty(&state->lock_states))
 606                 clear_bit(LK_STATE_IN_USE, &state->flags);
 607         spin_unlock(&state->state_lock);
 608         kfree(lsp);
 609 }
 610
 611 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
 612 {
 613         struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
 614
 615         dst->fl_u.nfs4_fl.owner = lsp;
 616         atomic_inc(&lsp->ls_count);
 617 }
 618
 619 static void nfs4_fl_release_lock(struct file_lock *fl)
 620 {
 621         nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
 622 }
 623
 624 static struct file_lock_operations nfs4_fl_lock_ops = {
 625         .fl_copy_lock = nfs4_fl_copy_lock,
 626         .fl_release_private = nfs4_fl_release_lock,
 627 };
 628
 629 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
 630 {
 631         struct nfs4_lock_state *lsp;
 632
 633         if (fl->fl_ops != NULL)
 634                 return 0;
 635         lsp = nfs4_get_lock_state(state, fl->fl_owner);
 636         if (lsp == NULL)
 637                 return -ENOMEM;
 638         fl->fl_u.nfs4_fl.owner = lsp;
 639         fl->fl_ops = &nfs4_fl_lock_ops;
 640         return 0;
 641 }
 642
 643 /*
 644  * Byte-range lock aware utility to initialize the stateid of read/write
 645  * requests.
 646  */
 647 void nfs4_copy_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t fl_owner)
 648 {
 649         struct nfs4_lock_state *lsp;
 650
 651         memcpy(dst, &state->stateid, sizeof(*dst));
 652         if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
 653                 return;
 654
 655         spin_lock(&state->state_lock);
 656         lsp = __nfs4_find_lock_state(state, fl_owner);
 657         if (lsp != NULL && (lsp->ls_flags & NFS_LOCK_INITIALIZED) != 0)
 658                 memcpy(dst, &lsp->ls_stateid, sizeof(*dst));
 659         spin_unlock(&state->state_lock);
 660         nfs4_put_lock_state(lsp);
 661 }
 662
 663 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter)
 664 {
 665         struct rpc_sequence *sequence = counter->sequence;
 666         struct nfs_seqid *new;
 667
 668         new = kmalloc(sizeof(*new), GFP_KERNEL);
 669         if (new != NULL) {
 670                 new->sequence = counter;
 671                 spin_lock(&sequence->lock);
 672                 list_add_tail(&new->list, &sequence->list);
 673                 spin_unlock(&sequence->lock);
 674         }
 675         return new;
 676 }
 677
 678 void nfs_free_seqid(struct nfs_seqid *seqid)
 679 {
 680         struct rpc_sequence *sequence = seqid->sequence->sequence;
 681
 682         spin_lock(&sequence->lock);
 683         list_del(&seqid->list);
 684         spin_unlock(&sequence->lock);
 685         rpc_wake_up(&sequence->wait);
 686         kfree(seqid);
 687 }
 688
 689 /*
 690  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
 691  * failed with a seqid incrementing error -
 692  * see comments nfs_fs.h:seqid_mutating_error()
 693  */
 694 static inline void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
 695 {
 696         switch (status) {
 697                 case 0:
 698                         break;
 699                 case -NFS4ERR_BAD_SEQID:
 700                 case -NFS4ERR_STALE_CLIENTID:
 701                 case -NFS4ERR_STALE_STATEID:
 702                 case -NFS4ERR_BAD_STATEID:
 703                 case -NFS4ERR_BADXDR:
 704                 case -NFS4ERR_RESOURCE:
 705                 case -NFS4ERR_NOFILEHANDLE:
 706                         /* Non-seqid mutating errors */
 707                         return;
 708         };
 709         /*
 710          * Note: no locking needed as we are guaranteed to be first
 711          * on the sequence list
 712          */
 713         seqid->sequence->counter++;
 714 }
 715
 716 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
 717 {
 718         if (status == -NFS4ERR_BAD_SEQID) {
 719                 struct nfs4_state_owner *sp = container_of(seqid->sequence,
 720                                 struct nfs4_state_owner, so_seqid);
 721                 nfs4_drop_state_owner(sp);
 722         }
 723         return nfs_increment_seqid(status, seqid);
 724 }
 725
 726 /*
 727  * Increment the seqid if the LOCK/LOCKU succeeded, or
 728  * failed with a seqid incrementing error -
 729  * see comments nfs_fs.h:seqid_mutating_error()
 730  */
 731 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
 732 {
 733         return nfs_increment_seqid(status, seqid);
 734 }
 735
 736 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
 737 {
 738         struct rpc_sequence *sequence = seqid->sequence->sequence;
 739         int status = 0;
 740
 741         if (sequence->list.next == &seqid->list)
 742                 goto out;
 743         spin_lock(&sequence->lock);
 744         if (sequence->list.next != &seqid->list) {
 745                 rpc_sleep_on(&sequence->wait, task, NULL, NULL);
 746                 status = -EAGAIN;
 747         }
 748         spin_unlock(&sequence->lock);
 749 out:
 750         return status;
 751 }
 752
 753 static int reclaimer(void *);
 754
 755 static inline void nfs4_clear_recover_bit(struct nfs4_client *clp)
 756 {
 757         smp_mb__before_clear_bit();
 758         clear_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state);
 759         smp_mb__after_clear_bit();
 760         wake_up_bit(&clp->cl_state, NFS4CLNT_STATE_RECOVER);
 761         rpc_wake_up(&clp->cl_rpcwaitq);
 762 }
 763
 764 /*
 765  * State recovery routine
 766  */
 767 static void nfs4_recover_state(struct nfs4_client *clp)
 768 {
 769         struct task_struct *task;
 770
 771         __module_get(THIS_MODULE);
 772         atomic_inc(&clp->cl_count);
 773         task = kthread_run(reclaimer, clp, "%u.%u.%u.%u-reclaim",
 774                         NIPQUAD(clp->cl_addr));
 775         if (!IS_ERR(task))
 776                 return;
 777         nfs4_clear_recover_bit(clp);
 778         nfs4_put_client(clp);
 779         module_put(THIS_MODULE);
 780 }
 781
 782 /*
 783  * Schedule a state recovery attempt
 784  */
 785 void nfs4_schedule_state_recovery(struct nfs4_client *clp)
 786 {
 787         if (!clp)
 788                 return;
 789         if (test_and_set_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state) == 0)
 790                 nfs4_recover_state(clp);
 791 }
 792
 793 static int nfs4_reclaim_locks(struct nfs4_state_recovery_ops *ops, struct nfs4_state *state)
 794 {
 795         struct inode *inode = state->inode;
 796         struct file_lock *fl;
 797         int status = 0;
 798
 799         for (fl = inode->i_flock; fl != 0; fl = fl->fl_next) {
 800                 if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
 801                         continue;
 802                 if (((struct nfs_open_context *)fl->fl_file->private_data)->state != state)
 803                         continue;
 804                 status = ops->recover_lock(state, fl);
 805                 if (status >= 0)
 806                         continue;
 807                 switch (status) {
 808                         default:
 809                                 printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
 810                                                 __FUNCTION__, status);
 811                         case -NFS4ERR_EXPIRED:
 812                         case -NFS4ERR_NO_GRACE:
 813                         case -NFS4ERR_RECLAIM_BAD:
 814                         case -NFS4ERR_RECLAIM_CONFLICT:
 815                                 /* kill_proc(fl->fl_pid, SIGLOST, 1); */
 816                                 break;
 817                         case -NFS4ERR_STALE_CLIENTID:
 818                                 goto out_err;
 819                 }
 820         }
 821         return 0;
 822 out_err:
 823         return status;
 824 }
 825
 826 static int nfs4_reclaim_open_state(struct nfs4_state_recovery_ops *ops, struct nfs4_state_owner *sp)
 827 {
 828         struct nfs4_state *state;
 829         struct nfs4_lock_state *lock;
 830         int status = 0;
 831
 832         /* Note: we rely on the sp->so_states list being ordered
 833          * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
 834          * states first.
 835          * This is needed to ensure that the server won't give us any
 836          * read delegations that we have to return if, say, we are
 837          * recovering after a network partition or a reboot from a
 838          * server that doesn't support a grace period.
 839          */
 840         list_for_each_entry(state, &sp->so_states, open_states) {
 841                 if (state->state == 0)
 842                         continue;
 843                 status = ops->recover_open(sp, state);
 844                 if (status >= 0) {
 845                         status = nfs4_reclaim_locks(ops, state);
 846                         if (status < 0)
 847                                 goto out_err;
 848                         list_for_each_entry(lock, &state->lock_states, ls_locks) {
 849                                 if (!(lock->ls_flags & NFS_LOCK_INITIALIZED))
 850                                         printk("%s: Lock reclaim failed!\n",
 851                                                         __FUNCTION__);
 852                         }
 853                         continue;
 854                 }
 855                 switch (status) {
 856                         default:
 857                                 printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
 858                                                 __FUNCTION__, status);
 859                         case -ENOENT:
 860                         case -NFS4ERR_RECLAIM_BAD:
 861                         case -NFS4ERR_RECLAIM_CONFLICT:
 862                                 /*
 863                                  * Open state on this file cannot be recovered
 864                                  * All we can do is revert to using the zero stateid.
 865                                  */
 866                                 memset(state->stateid.data, 0,
 867                                         sizeof(state->stateid.data));
 868                                 /* Mark the file as being 'closed' */
 869                                 state->state = 0;
 870                                 break;
 871                         case -NFS4ERR_EXPIRED:
 872                         case -NFS4ERR_NO_GRACE:
 873                         case -NFS4ERR_STALE_CLIENTID:
 874                                 goto out_err;
 875                 }
 876         }
 877         return 0;
 878 out_err:
 879         return status;
 880 }
 881
 882 static void nfs4_state_mark_reclaim(struct nfs4_client *clp)
 883 {
 884         struct nfs4_state_owner *sp;
 885         struct nfs4_state *state;
 886         struct nfs4_lock_state *lock;
 887
 888         /* Reset all sequence ids to zero */
 889         list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
 890                 sp->so_seqid.counter = 0;
 891                 sp->so_seqid.flags = 0;
 892                 spin_lock(&sp->so_lock);
 893                 list_for_each_entry(state, &sp->so_states, open_states) {
 894                         list_for_each_entry(lock, &state->lock_states, ls_locks) {
 895                                 lock->ls_seqid.counter = 0;
 896                                 lock->ls_seqid.flags = 0;
 897                                 lock->ls_flags &= ~NFS_LOCK_INITIALIZED;
 898                         }
 899                 }
 900                 spin_unlock(&sp->so_lock);
 901         }
 902 }
 903
 904 static int reclaimer(void *ptr)
 905 {
 906         struct nfs4_client *clp = ptr;
 907         struct nfs4_state_owner *sp;
 908         struct nfs4_state_recovery_ops *ops;
 909         struct rpc_cred *cred;
 910         int status = 0;
 911
 912         allow_signal(SIGKILL);
 913
 914         /* Ensure exclusive access to NFSv4 state */
 915         lock_kernel();
 916         down_write(&clp->cl_sem);
 917         /* Are there any NFS mounts out there? */
 918         if (list_empty(&clp->cl_superblocks))
 919                 goto out;
 920 restart_loop:
 921         ops = &nfs4_network_partition_recovery_ops;
 922         /* Are there any open files on this volume? */
 923         cred = nfs4_get_renew_cred(clp);
 924         if (cred != NULL) {
 925                 /* Yes there are: try to renew the old lease */
 926                 status = nfs4_proc_renew(clp, cred);
 927                 switch (status) {
 928                         case 0:
 929                         case -NFS4ERR_CB_PATH_DOWN:
 930                                 put_rpccred(cred);
 931                                 goto out;
 932                         case -NFS4ERR_STALE_CLIENTID:
 933                         case -NFS4ERR_LEASE_MOVED:
 934                                 ops = &nfs4_reboot_recovery_ops;
 935                 }
 936         } else {
 937                 /* "reboot" to ensure we clear all state on the server */
 938                 clp->cl_boot_time = CURRENT_TIME;
 939                 cred = nfs4_get_setclientid_cred(clp);
 940         }
 941         /* We're going to have to re-establish a clientid */
 942         nfs4_state_mark_reclaim(clp);
 943         status = -ENOENT;
 944         if (cred != NULL) {
 945                 status = nfs4_init_client(clp, cred);
 946                 put_rpccred(cred);
 947         }
 948         if (status)
 949                 goto out_error;
 950         /* Mark all delegations for reclaim */
 951         nfs_delegation_mark_reclaim(clp);
 952         /* Note: list is protected by exclusive lock on cl->cl_sem */
 953         list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
 954                 status = nfs4_reclaim_open_state(ops, sp);
 955                 if (status < 0) {
 956                         if (status == -NFS4ERR_NO_GRACE) {
 957                                 ops = &nfs4_network_partition_recovery_ops;
 958                                 status = nfs4_reclaim_open_state(ops, sp);
 959                         }
 960                         if (status == -NFS4ERR_STALE_CLIENTID)
 961                                 goto restart_loop;
 962                         if (status == -NFS4ERR_EXPIRED)
 963                                 goto restart_loop;
 964                 }
 965         }
 966         nfs_delegation_reap_unclaimed(clp);
 967 out:
 968         up_write(&clp->cl_sem);
 969         unlock_kernel();
 970         if (status == -NFS4ERR_CB_PATH_DOWN)
 971                 nfs_handle_cb_pathdown(clp);
 972         nfs4_clear_recover_bit(clp);
 973         nfs4_put_client(clp);
 974         module_put_and_exit(0);
 975         return 0;
 976 out_error:
 977         printk(KERN_WARNING "Error: state recovery failed on NFSv4 server %u.%u.%u.%u with error %d\n",
 978                                 NIPQUAD(clp->cl_addr.s_addr), -status);
 979         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
 980         goto out;
 981 }
 982
 983 /*
 984  * Local variables:
 985  *  c-basic-offset: 8
 986  * End:
 987  */