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/kernel.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/kthread.h>
  47 #include <linux/module.h>
  48 #include <linux/random.h>
  49 #include <linux/workqueue.h>
  50 #include <linux/bitops.h>
  51
  52 #include "nfs4_fs.h"
  53 #include "callback.h"
  54 #include "delegation.h"
  55 #include "internal.h"
  56
  57 #define OPENOWNER_POOL_SIZE     8
  58
  59 const nfs4_stateid zero_stateid;
  60
  61 static LIST_HEAD(nfs4_clientid_list);
  62
  63 static int nfs4_init_client(struct nfs_client *clp, struct rpc_cred *cred)
  64 {
  65         unsigned short port;
  66         int status;
  67
  68         port = nfs_callback_tcpport;
  69         if (clp->cl_addr.ss_family == AF_INET6)
  70                 port = nfs_callback_tcpport6;
  71
  72         status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred);
  73         if (status == 0)
  74                 status = nfs4_proc_setclientid_confirm(clp, cred);
  75         if (status == 0)
  76                 nfs4_schedule_state_renewal(clp);
  77         return status;
  78 }
  79
  80 static struct rpc_cred *nfs4_get_machine_cred_locked(struct nfs_client *clp)
  81 {
  82         struct rpc_cred *cred = NULL;
  83
  84         if (clp->cl_machine_cred != NULL)
  85                 cred = get_rpccred(clp->cl_machine_cred);
  86         return cred;
  87 }
  88
  89 static void nfs4_clear_machine_cred(struct nfs_client *clp)
  90 {
  91         struct rpc_cred *cred;
  92
  93         spin_lock(&clp->cl_lock);
  94         cred = clp->cl_machine_cred;
  95         clp->cl_machine_cred = NULL;
  96         spin_unlock(&clp->cl_lock);
  97         if (cred != NULL)
  98                 put_rpccred(cred);
  99 }
 100
 101 struct rpc_cred *nfs4_get_renew_cred_locked(struct nfs_client *clp)
 102 {
 103         struct nfs4_state_owner *sp;
 104         struct rb_node *pos;
 105         struct rpc_cred *cred = NULL;
 106
 107         for (pos = rb_first(&clp->cl_state_owners); pos != NULL; pos = rb_next(pos)) {
 108                 sp = rb_entry(pos, struct nfs4_state_owner, so_client_node);
 109                 if (list_empty(&sp->so_states))
 110                         continue;
 111                 cred = get_rpccred(sp->so_cred);
 112                 break;
 113         }
 114         return cred;
 115 }
 116
 117 static struct rpc_cred *nfs4_get_renew_cred(struct nfs_client *clp)
 118 {
 119         struct rpc_cred *cred;
 120
 121         spin_lock(&clp->cl_lock);
 122         cred = nfs4_get_renew_cred_locked(clp);
 123         spin_unlock(&clp->cl_lock);
 124         return cred;
 125 }
 126
 127 static struct rpc_cred *nfs4_get_setclientid_cred(struct nfs_client *clp)
 128 {
 129         struct nfs4_state_owner *sp;
 130         struct rb_node *pos;
 131         struct rpc_cred *cred;
 132
 133         spin_lock(&clp->cl_lock);
 134         cred = nfs4_get_machine_cred_locked(clp);
 135         if (cred != NULL)
 136                 goto out;
 137         pos = rb_first(&clp->cl_state_owners);
 138         if (pos != NULL) {
 139                 sp = rb_entry(pos, struct nfs4_state_owner, so_client_node);
 140                 cred = get_rpccred(sp->so_cred);
 141         }
 142 out:
 143         spin_unlock(&clp->cl_lock);
 144         return cred;
 145 }
 146
 147 static void nfs_alloc_unique_id(struct rb_root *root, struct nfs_unique_id *new,
 148                 __u64 minval, int maxbits)
 149 {
 150         struct rb_node **p, *parent;
 151         struct nfs_unique_id *pos;
 152         __u64 mask = ~0ULL;
 153
 154         if (maxbits < 64)
 155                 mask = (1ULL << maxbits) - 1ULL;
 156
 157         /* Ensure distribution is more or less flat */
 158         get_random_bytes(&new->id, sizeof(new->id));
 159         new->id &= mask;
 160         if (new->id < minval)
 161                 new->id += minval;
 162 retry:
 163         p = &root->rb_node;
 164         parent = NULL;
 165
 166         while (*p != NULL) {
 167                 parent = *p;
 168                 pos = rb_entry(parent, struct nfs_unique_id, rb_node);
 169
 170                 if (new->id < pos->id)
 171                         p = &(*p)->rb_left;
 172                 else if (new->id > pos->id)
 173                         p = &(*p)->rb_right;
 174                 else
 175                         goto id_exists;
 176         }
 177         rb_link_node(&new->rb_node, parent, p);
 178         rb_insert_color(&new->rb_node, root);
 179         return;
 180 id_exists:
 181         for (;;) {
 182                 new->id++;
 183                 if (new->id < minval || (new->id & mask) != new->id) {
 184                         new->id = minval;
 185                         break;
 186                 }
 187                 parent = rb_next(parent);
 188                 if (parent == NULL)
 189                         break;
 190                 pos = rb_entry(parent, struct nfs_unique_id, rb_node);
 191                 if (new->id < pos->id)
 192                         break;
 193         }
 194         goto retry;
 195 }
 196
 197 static void nfs_free_unique_id(struct rb_root *root, struct nfs_unique_id *id)
 198 {
 199         rb_erase(&id->rb_node, root);
 200 }
 201
 202 static struct nfs4_state_owner *
 203 nfs4_find_state_owner(struct nfs_server *server, struct rpc_cred *cred)
 204 {
 205         struct nfs_client *clp = server->nfs_client;
 206         struct rb_node **p = &clp->cl_state_owners.rb_node,
 207                        *parent = NULL;
 208         struct nfs4_state_owner *sp, *res = NULL;
 209
 210         while (*p != NULL) {
 211                 parent = *p;
 212                 sp = rb_entry(parent, struct nfs4_state_owner, so_client_node);
 213
 214                 if (server < sp->so_server) {
 215                         p = &parent->rb_left;
 216                         continue;
 217                 }
 218                 if (server > sp->so_server) {
 219                         p = &parent->rb_right;
 220                         continue;
 221                 }
 222                 if (cred < sp->so_cred)
 223                         p = &parent->rb_left;
 224                 else if (cred > sp->so_cred)
 225                         p = &parent->rb_right;
 226                 else {
 227                         atomic_inc(&sp->so_count);
 228                         res = sp;
 229                         break;
 230                 }
 231         }
 232         return res;
 233 }
 234
 235 static struct nfs4_state_owner *
 236 nfs4_insert_state_owner(struct nfs_client *clp, struct nfs4_state_owner *new)
 237 {
 238         struct rb_node **p = &clp->cl_state_owners.rb_node,
 239                        *parent = NULL;
 240         struct nfs4_state_owner *sp;
 241
 242         while (*p != NULL) {
 243                 parent = *p;
 244                 sp = rb_entry(parent, struct nfs4_state_owner, so_client_node);
 245
 246                 if (new->so_server < sp->so_server) {
 247                         p = &parent->rb_left;
 248                         continue;
 249                 }
 250                 if (new->so_server > sp->so_server) {
 251                         p = &parent->rb_right;
 252                         continue;
 253                 }
 254                 if (new->so_cred < sp->so_cred)
 255                         p = &parent->rb_left;
 256                 else if (new->so_cred > sp->so_cred)
 257                         p = &parent->rb_right;
 258                 else {
 259                         atomic_inc(&sp->so_count);
 260                         return sp;
 261                 }
 262         }
 263         nfs_alloc_unique_id(&clp->cl_openowner_id, &new->so_owner_id, 1, 64);
 264         rb_link_node(&new->so_client_node, parent, p);
 265         rb_insert_color(&new->so_client_node, &clp->cl_state_owners);
 266         return new;
 267 }
 268
 269 static void
 270 nfs4_remove_state_owner(struct nfs_client *clp, struct nfs4_state_owner *sp)
 271 {
 272         if (!RB_EMPTY_NODE(&sp->so_client_node))
 273                 rb_erase(&sp->so_client_node, &clp->cl_state_owners);
 274         nfs_free_unique_id(&clp->cl_openowner_id, &sp->so_owner_id);
 275 }
 276
 277 /*
 278  * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
 279  * create a new state_owner.
 280  *
 281  */
 282 static struct nfs4_state_owner *
 283 nfs4_alloc_state_owner(void)
 284 {
 285         struct nfs4_state_owner *sp;
 286
 287         sp = kzalloc(sizeof(*sp),GFP_KERNEL);
 288         if (!sp)
 289                 return NULL;
 290         spin_lock_init(&sp->so_lock);
 291         INIT_LIST_HEAD(&sp->so_states);
 292         INIT_LIST_HEAD(&sp->so_delegations);
 293         rpc_init_wait_queue(&sp->so_sequence.wait, "Seqid_waitqueue");
 294         sp->so_seqid.sequence = &sp->so_sequence;
 295         spin_lock_init(&sp->so_sequence.lock);
 296         INIT_LIST_HEAD(&sp->so_sequence.list);
 297         atomic_set(&sp->so_count, 1);
 298         return sp;
 299 }
 300
 301 static void
 302 nfs4_drop_state_owner(struct nfs4_state_owner *sp)
 303 {
 304         if (!RB_EMPTY_NODE(&sp->so_client_node)) {
 305                 struct nfs_client *clp = sp->so_client;
 306
 307                 spin_lock(&clp->cl_lock);
 308                 rb_erase(&sp->so_client_node, &clp->cl_state_owners);
 309                 RB_CLEAR_NODE(&sp->so_client_node);
 310                 spin_unlock(&clp->cl_lock);
 311         }
 312 }
 313
 314 struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server, struct rpc_cred *cred)
 315 {
 316         struct nfs_client *clp = server->nfs_client;
 317         struct nfs4_state_owner *sp, *new;
 318
 319         spin_lock(&clp->cl_lock);
 320         sp = nfs4_find_state_owner(server, cred);
 321         spin_unlock(&clp->cl_lock);
 322         if (sp != NULL)
 323                 return sp;
 324         new = nfs4_alloc_state_owner();
 325         if (new == NULL)
 326                 return NULL;
 327         new->so_client = clp;
 328         new->so_server = server;
 329         new->so_cred = cred;
 330         spin_lock(&clp->cl_lock);
 331         sp = nfs4_insert_state_owner(clp, new);
 332         spin_unlock(&clp->cl_lock);
 333         if (sp == new)
 334                 get_rpccred(cred);
 335         else {
 336                 rpc_destroy_wait_queue(&new->so_sequence.wait);
 337                 kfree(new);
 338         }
 339         return sp;
 340 }
 341
 342 void nfs4_put_state_owner(struct nfs4_state_owner *sp)
 343 {
 344         struct nfs_client *clp = sp->so_client;
 345         struct rpc_cred *cred = sp->so_cred;
 346
 347         if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
 348                 return;
 349         nfs4_remove_state_owner(clp, sp);
 350         spin_unlock(&clp->cl_lock);
 351         rpc_destroy_wait_queue(&sp->so_sequence.wait);
 352         put_rpccred(cred);
 353         kfree(sp);
 354 }
 355
 356 static struct nfs4_state *
 357 nfs4_alloc_open_state(void)
 358 {
 359         struct nfs4_state *state;
 360
 361         state = kzalloc(sizeof(*state), GFP_KERNEL);
 362         if (!state)
 363                 return NULL;
 364         atomic_set(&state->count, 1);
 365         INIT_LIST_HEAD(&state->lock_states);
 366         spin_lock_init(&state->state_lock);
 367         seqlock_init(&state->seqlock);
 368         return state;
 369 }
 370
 371 void
 372 nfs4_state_set_mode_locked(struct nfs4_state *state, fmode_t fmode)
 373 {
 374         if (state->state == fmode)
 375                 return;
 376         /* NB! List reordering - see the reclaim code for why.  */
 377         if ((fmode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
 378                 if (fmode & FMODE_WRITE)
 379                         list_move(&state->open_states, &state->owner->so_states);
 380                 else
 381                         list_move_tail(&state->open_states, &state->owner->so_states);
 382         }
 383         state->state = fmode;
 384 }
 385
 386 static struct nfs4_state *
 387 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
 388 {
 389         struct nfs_inode *nfsi = NFS_I(inode);
 390         struct nfs4_state *state;
 391
 392         list_for_each_entry(state, &nfsi->open_states, inode_states) {
 393                 if (state->owner != owner)
 394                         continue;
 395                 if (atomic_inc_not_zero(&state->count))
 396                         return state;
 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 void nfs4_put_open_state(struct nfs4_state *state)
 444 {
 445         struct inode *inode = state->inode;
 446         struct nfs4_state_owner *owner = state->owner;
 447
 448         if (!atomic_dec_and_lock(&state->count, &owner->so_lock))
 449                 return;
 450         spin_lock(&inode->i_lock);
 451         list_del(&state->inode_states);
 452         list_del(&state->open_states);
 453         spin_unlock(&inode->i_lock);
 454         spin_unlock(&owner->so_lock);
 455         iput(inode);
 456         nfs4_free_open_state(state);
 457         nfs4_put_state_owner(owner);
 458 }
 459
 460 /*
 461  * Close the current file.
 462  */
 463 static void __nfs4_close(struct path *path, struct nfs4_state *state, fmode_t fmode, int wait)
 464 {
 465         struct nfs4_state_owner *owner = state->owner;
 466         int call_close = 0;
 467         fmode_t newstate;
 468
 469         atomic_inc(&owner->so_count);
 470         /* Protect against nfs4_find_state() */
 471         spin_lock(&owner->so_lock);
 472         switch (fmode & (FMODE_READ | FMODE_WRITE)) {
 473                 case FMODE_READ:
 474                         state->n_rdonly--;
 475                         break;
 476                 case FMODE_WRITE:
 477                         state->n_wronly--;
 478                         break;
 479                 case FMODE_READ|FMODE_WRITE:
 480                         state->n_rdwr--;
 481         }
 482         newstate = FMODE_READ|FMODE_WRITE;
 483         if (state->n_rdwr == 0) {
 484                 if (state->n_rdonly == 0) {
 485                         newstate &= ~FMODE_READ;
 486                         call_close |= test_bit(NFS_O_RDONLY_STATE, &state->flags);
 487                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
 488                 }
 489                 if (state->n_wronly == 0) {
 490                         newstate &= ~FMODE_WRITE;
 491                         call_close |= test_bit(NFS_O_WRONLY_STATE, &state->flags);
 492                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
 493                 }
 494                 if (newstate == 0)
 495                         clear_bit(NFS_DELEGATED_STATE, &state->flags);
 496         }
 497         nfs4_state_set_mode_locked(state, newstate);
 498         spin_unlock(&owner->so_lock);
 499
 500         if (!call_close) {
 501                 nfs4_put_open_state(state);
 502                 nfs4_put_state_owner(owner);
 503         } else
 504                 nfs4_do_close(path, state, wait);
 505 }
 506
 507 void nfs4_close_state(struct path *path, struct nfs4_state *state, fmode_t fmode)
 508 {
 509         __nfs4_close(path, state, fmode, 0);
 510 }
 511
 512 void nfs4_close_sync(struct path *path, struct nfs4_state *state, fmode_t fmode)
 513 {
 514         __nfs4_close(path, state, fmode, 1);
 515 }
 516
 517 /*
 518  * Search the state->lock_states for an existing lock_owner
 519  * that is compatible with current->files
 520  */
 521 static struct nfs4_lock_state *
 522 __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 523 {
 524         struct nfs4_lock_state *pos;
 525         list_for_each_entry(pos, &state->lock_states, ls_locks) {
 526                 if (pos->ls_owner != fl_owner)
 527                         continue;
 528                 atomic_inc(&pos->ls_count);
 529                 return pos;
 530         }
 531         return NULL;
 532 }
 533
 534 /*
 535  * Return a compatible lock_state. If no initialized lock_state structure
 536  * exists, return an uninitialized one.
 537  *
 538  */
 539 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 540 {
 541         struct nfs4_lock_state *lsp;
 542         struct nfs_client *clp = state->owner->so_client;
 543
 544         lsp = kzalloc(sizeof(*lsp), GFP_KERNEL);
 545         if (lsp == NULL)
 546                 return NULL;
 547         rpc_init_wait_queue(&lsp->ls_sequence.wait, "lock_seqid_waitqueue");
 548         spin_lock_init(&lsp->ls_sequence.lock);
 549         INIT_LIST_HEAD(&lsp->ls_sequence.list);
 550         lsp->ls_seqid.sequence = &lsp->ls_sequence;
 551         atomic_set(&lsp->ls_count, 1);
 552         lsp->ls_owner = fl_owner;
 553         spin_lock(&clp->cl_lock);
 554         nfs_alloc_unique_id(&clp->cl_lockowner_id, &lsp->ls_id, 1, 64);
 555         spin_unlock(&clp->cl_lock);
 556         INIT_LIST_HEAD(&lsp->ls_locks);
 557         return lsp;
 558 }
 559
 560 static void nfs4_free_lock_state(struct nfs4_lock_state *lsp)
 561 {
 562         struct nfs_client *clp = lsp->ls_state->owner->so_client;
 563
 564         spin_lock(&clp->cl_lock);
 565         nfs_free_unique_id(&clp->cl_lockowner_id, &lsp->ls_id);
 566         spin_unlock(&clp->cl_lock);
 567         rpc_destroy_wait_queue(&lsp->ls_sequence.wait);
 568         kfree(lsp);
 569 }
 570
 571 /*
 572  * Return a compatible lock_state. If no initialized lock_state structure
 573  * exists, return an uninitialized one.
 574  *
 575  */
 576 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
 577 {
 578         struct nfs4_lock_state *lsp, *new = NULL;
 579
 580         for(;;) {
 581                 spin_lock(&state->state_lock);
 582                 lsp = __nfs4_find_lock_state(state, owner);
 583                 if (lsp != NULL)
 584                         break;
 585                 if (new != NULL) {
 586                         new->ls_state = state;
 587                         list_add(&new->ls_locks, &state->lock_states);
 588                         set_bit(LK_STATE_IN_USE, &state->flags);
 589                         lsp = new;
 590                         new = NULL;
 591                         break;
 592                 }
 593                 spin_unlock(&state->state_lock);
 594                 new = nfs4_alloc_lock_state(state, owner);
 595                 if (new == NULL)
 596                         return NULL;
 597         }
 598         spin_unlock(&state->state_lock);
 599         if (new != NULL)
 600                 nfs4_free_lock_state(new);
 601         return lsp;
 602 }
 603
 604 /*
 605  * Release reference to lock_state, and free it if we see that
 606  * it is no longer in use
 607  */
 608 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
 609 {
 610         struct nfs4_state *state;
 611
 612         if (lsp == NULL)
 613                 return;
 614         state = lsp->ls_state;
 615         if (!atomic_dec_and_lock(&lsp->ls_count, &state->state_lock))
 616                 return;
 617         list_del(&lsp->ls_locks);
 618         if (list_empty(&state->lock_states))
 619                 clear_bit(LK_STATE_IN_USE, &state->flags);
 620         spin_unlock(&state->state_lock);
 621         nfs4_free_lock_state(lsp);
 622 }
 623
 624 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
 625 {
 626         struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
 627
 628         dst->fl_u.nfs4_fl.owner = lsp;
 629         atomic_inc(&lsp->ls_count);
 630 }
 631
 632 static void nfs4_fl_release_lock(struct file_lock *fl)
 633 {
 634         nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
 635 }
 636
 637 static struct file_lock_operations nfs4_fl_lock_ops = {
 638         .fl_copy_lock = nfs4_fl_copy_lock,
 639         .fl_release_private = nfs4_fl_release_lock,
 640 };
 641
 642 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
 643 {
 644         struct nfs4_lock_state *lsp;
 645
 646         if (fl->fl_ops != NULL)
 647                 return 0;
 648         lsp = nfs4_get_lock_state(state, fl->fl_owner);
 649         if (lsp == NULL)
 650                 return -ENOMEM;
 651         fl->fl_u.nfs4_fl.owner = lsp;
 652         fl->fl_ops = &nfs4_fl_lock_ops;
 653         return 0;
 654 }
 655
 656 /*
 657  * Byte-range lock aware utility to initialize the stateid of read/write
 658  * requests.
 659  */
 660 void nfs4_copy_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t fl_owner)
 661 {
 662         struct nfs4_lock_state *lsp;
 663         int seq;
 664
 665         do {
 666                 seq = read_seqbegin(&state->seqlock);
 667                 memcpy(dst, &state->stateid, sizeof(*dst));
 668         } while (read_seqretry(&state->seqlock, seq));
 669         if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
 670                 return;
 671
 672         spin_lock(&state->state_lock);
 673         lsp = __nfs4_find_lock_state(state, fl_owner);
 674         if (lsp != NULL && (lsp->ls_flags & NFS_LOCK_INITIALIZED) != 0)
 675                 memcpy(dst, &lsp->ls_stateid, sizeof(*dst));
 676         spin_unlock(&state->state_lock);
 677         nfs4_put_lock_state(lsp);
 678 }
 679
 680 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter)
 681 {
 682         struct nfs_seqid *new;
 683
 684         new = kmalloc(sizeof(*new), GFP_KERNEL);
 685         if (new != NULL) {
 686                 new->sequence = counter;
 687                 INIT_LIST_HEAD(&new->list);
 688         }
 689         return new;
 690 }
 691
 692 void nfs_free_seqid(struct nfs_seqid *seqid)
 693 {
 694         if (!list_empty(&seqid->list)) {
 695                 struct rpc_sequence *sequence = seqid->sequence->sequence;
 696
 697                 spin_lock(&sequence->lock);
 698                 list_del(&seqid->list);
 699                 spin_unlock(&sequence->lock);
 700                 rpc_wake_up(&sequence->wait);
 701         }
 702         kfree(seqid);
 703 }
 704
 705 /*
 706  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
 707  * failed with a seqid incrementing error -
 708  * see comments nfs_fs.h:seqid_mutating_error()
 709  */
 710 static void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
 711 {
 712         BUG_ON(list_first_entry(&seqid->sequence->sequence->list, struct nfs_seqid, list) != seqid);
 713         switch (status) {
 714                 case 0:
 715                         break;
 716                 case -NFS4ERR_BAD_SEQID:
 717                         if (seqid->sequence->flags & NFS_SEQID_CONFIRMED)
 718                                 return;
 719                         printk(KERN_WARNING "NFS: v4 server returned a bad"
 720                                         " sequence-id error on an"
 721                                         " unconfirmed sequence %p!\n",
 722                                         seqid->sequence);
 723                 case -NFS4ERR_STALE_CLIENTID:
 724                 case -NFS4ERR_STALE_STATEID:
 725                 case -NFS4ERR_BAD_STATEID:
 726                 case -NFS4ERR_BADXDR:
 727                 case -NFS4ERR_RESOURCE:
 728                 case -NFS4ERR_NOFILEHANDLE:
 729                         /* Non-seqid mutating errors */
 730                         return;
 731         };
 732         /*
 733          * Note: no locking needed as we are guaranteed to be first
 734          * on the sequence list
 735          */
 736         seqid->sequence->counter++;
 737 }
 738
 739 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
 740 {
 741         if (status == -NFS4ERR_BAD_SEQID) {
 742                 struct nfs4_state_owner *sp = container_of(seqid->sequence,
 743                                 struct nfs4_state_owner, so_seqid);
 744                 nfs4_drop_state_owner(sp);
 745         }
 746         nfs_increment_seqid(status, seqid);
 747 }
 748
 749 /*
 750  * Increment the seqid if the LOCK/LOCKU succeeded, or
 751  * failed with a seqid incrementing error -
 752  * see comments nfs_fs.h:seqid_mutating_error()
 753  */
 754 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
 755 {
 756         nfs_increment_seqid(status, seqid);
 757 }
 758
 759 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
 760 {
 761         struct rpc_sequence *sequence = seqid->sequence->sequence;
 762         int status = 0;
 763
 764         spin_lock(&sequence->lock);
 765         if (list_empty(&seqid->list))
 766                 list_add_tail(&seqid->list, &sequence->list);
 767         if (list_first_entry(&sequence->list, struct nfs_seqid, list) == seqid)
 768                 goto unlock;
 769         rpc_sleep_on(&sequence->wait, task, NULL);
 770         status = -EAGAIN;
 771 unlock:
 772         spin_unlock(&sequence->lock);
 773         return status;
 774 }
 775
 776 static int nfs4_run_state_manager(void *);
 777
 778 static void nfs4_clear_state_manager_bit(struct nfs_client *clp)
 779 {
 780         smp_mb__before_clear_bit();
 781         clear_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state);
 782         smp_mb__after_clear_bit();
 783         wake_up_bit(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING);
 784         rpc_wake_up(&clp->cl_rpcwaitq);
 785 }
 786
 787 /*
 788  * Schedule the nfs_client asynchronous state management routine
 789  */
 790 void nfs4_schedule_state_manager(struct nfs_client *clp)
 791 {
 792         struct task_struct *task;
 793
 794         if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
 795                 return;
 796         __module_get(THIS_MODULE);
 797         atomic_inc(&clp->cl_count);
 798         task = kthread_run(nfs4_run_state_manager, clp, "%s-manager",
 799                                 rpc_peeraddr2str(clp->cl_rpcclient,
 800                                                         RPC_DISPLAY_ADDR));
 801         if (!IS_ERR(task))
 802                 return;
 803         nfs4_clear_state_manager_bit(clp);
 804         nfs_put_client(clp);
 805         module_put(THIS_MODULE);
 806 }
 807
 808 /*
 809  * Schedule a state recovery attempt
 810  */
 811 void nfs4_schedule_state_recovery(struct nfs_client *clp)
 812 {
 813         if (!clp)
 814                 return;
 815         if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
 816                 set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
 817         nfs4_schedule_state_manager(clp);
 818 }
 819
 820 static int nfs4_state_mark_reclaim_reboot(struct nfs_client *clp, struct nfs4_state *state)
 821 {
 822
 823         set_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
 824         /* Don't recover state that expired before the reboot */
 825         if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags)) {
 826                 clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
 827                 return 0;
 828         }
 829         set_bit(NFS_OWNER_RECLAIM_REBOOT, &state->owner->so_flags);
 830         set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
 831         return 1;
 832 }
 833
 834 int nfs4_state_mark_reclaim_nograce(struct nfs_client *clp, struct nfs4_state *state)
 835 {
 836         set_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
 837         clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
 838         set_bit(NFS_OWNER_RECLAIM_NOGRACE, &state->owner->so_flags);
 839         set_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
 840         return 1;
 841 }
 842
 843 static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_recovery_ops *ops)
 844 {
 845         struct inode *inode = state->inode;
 846         struct nfs_inode *nfsi = NFS_I(inode);
 847         struct file_lock *fl;
 848         int status = 0;
 849
 850         down_write(&nfsi->rwsem);
 851         for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
 852                 if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
 853                         continue;
 854                 if (nfs_file_open_context(fl->fl_file)->state != state)
 855                         continue;
 856                 status = ops->recover_lock(state, fl);
 857                 if (status >= 0)
 858                         continue;
 859                 switch (status) {
 860                         default:
 861                                 printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
 862                                                 __func__, status);
 863                         case -NFS4ERR_EXPIRED:
 864                         case -NFS4ERR_NO_GRACE:
 865                         case -NFS4ERR_RECLAIM_BAD:
 866                         case -NFS4ERR_RECLAIM_CONFLICT:
 867                                 /* kill_proc(fl->fl_pid, SIGLOST, 1); */
 868                                 break;
 869                         case -NFS4ERR_STALE_CLIENTID:
 870                                 goto out_err;
 871                 }
 872         }
 873         up_write(&nfsi->rwsem);
 874         return 0;
 875 out_err:
 876         up_write(&nfsi->rwsem);
 877         return status;
 878 }
 879
 880 static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs4_state_recovery_ops *ops)
 881 {
 882         struct nfs4_state *state;
 883         struct nfs4_lock_state *lock;
 884         int status = 0;
 885
 886         /* Note: we rely on the sp->so_states list being ordered
 887          * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
 888          * states first.
 889          * This is needed to ensure that the server won't give us any
 890          * read delegations that we have to return if, say, we are
 891          * recovering after a network partition or a reboot from a
 892          * server that doesn't support a grace period.
 893          */
 894 restart:
 895         spin_lock(&sp->so_lock);
 896         list_for_each_entry(state, &sp->so_states, open_states) {
 897                 if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
 898                         continue;
 899                 if (state->state == 0)
 900                         continue;
 901                 atomic_inc(&state->count);
 902                 spin_unlock(&sp->so_lock);
 903                 status = ops->recover_open(sp, state);
 904                 if (status >= 0) {
 905                         status = nfs4_reclaim_locks(state, ops);
 906                         if (status >= 0) {
 907                                 list_for_each_entry(lock, &state->lock_states, ls_locks) {
 908                                         if (!(lock->ls_flags & NFS_LOCK_INITIALIZED))
 909                                                 printk("%s: Lock reclaim failed!\n",
 910                                                         __func__);
 911                                 }
 912                                 nfs4_put_open_state(state);
 913                                 goto restart;
 914                         }
 915                 }
 916                 switch (status) {
 917                         default:
 918                                 printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
 919                                                 __func__, status);
 920                         case -ENOENT:
 921                         case -ESTALE:
 922                                 /*
 923                                  * Open state on this file cannot be recovered
 924                                  * All we can do is revert to using the zero stateid.
 925                                  */
 926                                 memset(state->stateid.data, 0,
 927                                         sizeof(state->stateid.data));
 928                                 /* Mark the file as being 'closed' */
 929                                 state->state = 0;
 930                                 break;
 931                         case -NFS4ERR_RECLAIM_BAD:
 932                         case -NFS4ERR_RECLAIM_CONFLICT:
 933                                 nfs4_state_mark_reclaim_nograce(sp->so_client, state);
 934                                 break;
 935                         case -NFS4ERR_EXPIRED:
 936                         case -NFS4ERR_NO_GRACE:
 937                                 nfs4_state_mark_reclaim_nograce(sp->so_client, state);
 938                         case -NFS4ERR_STALE_CLIENTID:
 939                                 goto out_err;
 940                 }
 941                 nfs4_put_open_state(state);
 942                 goto restart;
 943         }
 944         spin_unlock(&sp->so_lock);
 945         return 0;
 946 out_err:
 947         nfs4_put_open_state(state);
 948         return status;
 949 }
 950
 951 static void nfs4_clear_open_state(struct nfs4_state *state)
 952 {
 953         struct nfs4_lock_state *lock;
 954
 955         clear_bit(NFS_DELEGATED_STATE, &state->flags);
 956         clear_bit(NFS_O_RDONLY_STATE, &state->flags);
 957         clear_bit(NFS_O_WRONLY_STATE, &state->flags);
 958         clear_bit(NFS_O_RDWR_STATE, &state->flags);
 959         list_for_each_entry(lock, &state->lock_states, ls_locks) {
 960                 lock->ls_seqid.flags = 0;
 961                 lock->ls_flags &= ~NFS_LOCK_INITIALIZED;
 962         }
 963 }
 964
 965 static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp, int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
 966 {
 967         struct nfs4_state_owner *sp;
 968         struct rb_node *pos;
 969         struct nfs4_state *state;
 970
 971         /* Reset all sequence ids to zero */
 972         for (pos = rb_first(&clp->cl_state_owners); pos != NULL; pos = rb_next(pos)) {
 973                 sp = rb_entry(pos, struct nfs4_state_owner, so_client_node);
 974                 sp->so_seqid.flags = 0;
 975                 spin_lock(&sp->so_lock);
 976                 list_for_each_entry(state, &sp->so_states, open_states) {
 977                         if (mark_reclaim(clp, state))
 978                                 nfs4_clear_open_state(state);
 979                 }
 980                 spin_unlock(&sp->so_lock);
 981         }
 982 }
 983
 984 static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp)
 985 {
 986         /* Mark all delegations for reclaim */
 987         nfs_delegation_mark_reclaim(clp);
 988         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_reboot);
 989 }
 990
 991 static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
 992 {
 993         struct nfs4_state_owner *sp;
 994         struct rb_node *pos;
 995         struct nfs4_state *state;
 996
 997         if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
 998                 return;
 999
1000         for (pos = rb_first(&clp->cl_state_owners); pos != NULL; pos = rb_next(pos)) {
1001                 sp = rb_entry(pos, struct nfs4_state_owner, so_client_node);
1002                 spin_lock(&sp->so_lock);
1003                 list_for_each_entry(state, &sp->so_states, open_states) {
1004                         if (!test_and_clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags))
1005                                 continue;
1006                         nfs4_state_mark_reclaim_nograce(clp, state);
1007                 }
1008                 spin_unlock(&sp->so_lock);
1009         }
1010
1011         nfs_delegation_reap_unclaimed(clp);
1012 }
1013
1014 static void nfs_delegation_clear_all(struct nfs_client *clp)
1015 {
1016         nfs_delegation_mark_reclaim(clp);
1017         nfs_delegation_reap_unclaimed(clp);
1018 }
1019
1020 static void nfs4_state_start_reclaim_nograce(struct nfs_client *clp)
1021 {
1022         nfs_delegation_clear_all(clp);
1023         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
1024 }
1025
1026 static void nfs4_state_end_reclaim_nograce(struct nfs_client *clp)
1027 {
1028         clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
1029 }
1030
1031 static void nfs4_recovery_handle_error(struct nfs_client *clp, int error)
1032 {
1033         switch (error) {
1034                 case -NFS4ERR_CB_PATH_DOWN:
1035                         nfs_handle_cb_pathdown(clp);
1036                         break;
1037                 case -NFS4ERR_STALE_CLIENTID:
1038                 case -NFS4ERR_LEASE_MOVED:
1039                         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1040                         nfs4_state_start_reclaim_reboot(clp);
1041                         break;
1042                 case -NFS4ERR_EXPIRED:
1043                         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1044                         nfs4_state_start_reclaim_nograce(clp);
1045         }
1046 }
1047
1048 static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recovery_ops *ops)
1049 {
1050         struct rb_node *pos;
1051         int status = 0;
1052
1053 restart:
1054         spin_lock(&clp->cl_lock);
1055         for (pos = rb_first(&clp->cl_state_owners); pos != NULL; pos = rb_next(pos)) {
1056                 struct nfs4_state_owner *sp = rb_entry(pos, struct nfs4_state_owner, so_client_node);
1057                 if (!test_and_clear_bit(ops->owner_flag_bit, &sp->so_flags))
1058                         continue;
1059                 atomic_inc(&sp->so_count);
1060                 spin_unlock(&clp->cl_lock);
1061                 status = nfs4_reclaim_open_state(sp, ops);
1062                 if (status < 0) {
1063                         set_bit(ops->owner_flag_bit, &sp->so_flags);
1064                         nfs4_put_state_owner(sp);
1065                         nfs4_recovery_handle_error(clp, status);
1066                         return status;
1067                 }
1068                 nfs4_put_state_owner(sp);
1069                 goto restart;
1070         }
1071         spin_unlock(&clp->cl_lock);
1072         return status;
1073 }
1074
1075 static int nfs4_check_lease(struct nfs_client *clp)
1076 {
1077         struct rpc_cred *cred;
1078         int status = -NFS4ERR_EXPIRED;
1079
1080         /* Is the client already known to have an expired lease? */
1081         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1082                 return 0;
1083         cred = nfs4_get_renew_cred(clp);
1084         if (cred == NULL) {
1085                 cred = nfs4_get_setclientid_cred(clp);
1086                 if (cred == NULL)
1087                         goto out;
1088         }
1089         status = nfs4_proc_renew(clp, cred);
1090         put_rpccred(cred);
1091 out:
1092         nfs4_recovery_handle_error(clp, status);
1093         return status;
1094 }
1095
1096 static int nfs4_reclaim_lease(struct nfs_client *clp)
1097 {
1098         struct rpc_cred *cred;
1099         int status = -ENOENT;
1100
1101         cred = nfs4_get_setclientid_cred(clp);
1102         if (cred != NULL) {
1103                 status = nfs4_init_client(clp, cred);
1104                 put_rpccred(cred);
1105                 /* Handle case where the user hasn't set up machine creds */
1106                 if (status == -EACCES && cred == clp->cl_machine_cred) {
1107                         nfs4_clear_machine_cred(clp);
1108                         status = -EAGAIN;
1109                 }
1110         }
1111         return status;
1112 }
1113
1114 static void nfs4_state_manager(struct nfs_client *clp)
1115 {
1116         int status = 0;
1117
1118         /* Ensure exclusive access to NFSv4 state */
1119         for(;;) {
1120                 if (test_and_clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
1121                         /* We're going to have to re-establish a clientid */
1122                         status = nfs4_reclaim_lease(clp);
1123                         if (status) {
1124                                 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1125                                 if (status == -EAGAIN)
1126                                         continue;
1127                                 goto out_error;
1128                         }
1129                         clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1130                 }
1131
1132                 if (test_and_clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state)) {
1133                         status = nfs4_check_lease(clp);
1134                         if (status != 0)
1135                                 continue;
1136                 }
1137
1138                 /* First recover reboot state... */
1139                 if (test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {
1140                         status = nfs4_do_reclaim(clp, &nfs4_reboot_recovery_ops);
1141                         if (status == -NFS4ERR_STALE_CLIENTID)
1142                                 continue;
1143                         nfs4_state_end_reclaim_reboot(clp);
1144                         continue;
1145                 }
1146
1147                 /* Now recover expired state... */
1148                 if (test_and_clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state)) {
1149                         status = nfs4_do_reclaim(clp, &nfs4_nograce_recovery_ops);
1150                         if (status < 0) {
1151                                 set_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
1152                                 if (status == -NFS4ERR_STALE_CLIENTID)
1153                                         continue;
1154                                 if (status == -NFS4ERR_EXPIRED)
1155                                         continue;
1156                                 goto out_error;
1157                         } else
1158                                 nfs4_state_end_reclaim_nograce(clp);
1159                         continue;
1160                 }
1161
1162                 if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
1163                         nfs_client_return_marked_delegations(clp);
1164                         continue;
1165                 }
1166
1167                 nfs4_clear_state_manager_bit(clp);
1168                 /* Did we race with an attempt to give us more work? */
1169                 if (clp->cl_state == 0)
1170                         break;
1171                 if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
1172                         break;
1173         }
1174         return;
1175 out_error:
1176         printk(KERN_WARNING "Error: state manager failed on NFSv4 server %s"
1177                         " with error %d\n", clp->cl_hostname, -status);
1178         if (test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
1179                 nfs4_state_end_reclaim_reboot(clp);
1180         nfs4_clear_state_manager_bit(clp);
1181 }
1182
1183 static int nfs4_run_state_manager(void *ptr)
1184 {
1185         struct nfs_client *clp = ptr;
1186
1187         allow_signal(SIGKILL);
1188         nfs4_state_manager(clp);
1189         nfs_put_client(clp);
1190         module_put_and_exit(0);
1191         return 0;
1192 }
1193
1194 /*
1195  * Local variables:
1196  *  c-basic-offset: 8
1197  * End:
1198  */