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         int status = nfs4_proc_setclientid(clp, NFS4_CALLBACK,
  66                         nfs_callback_tcpport, cred);
  67         if (status == 0)
  68                 status = nfs4_proc_setclientid_confirm(clp, cred);
  69         if (status == 0)
  70                 nfs4_schedule_state_renewal(clp);
  71         return status;
  72 }
  73
  74 static struct rpc_cred *nfs4_get_machine_cred(struct nfs_client *clp)
  75 {
  76         struct rpc_cred *cred = NULL;
  77
  78         spin_lock(&clp->cl_lock);
  79         if (clp->cl_machine_cred != NULL)
  80                 cred = get_rpccred(clp->cl_machine_cred);
  81         spin_unlock(&clp->cl_lock);
  82         return cred;
  83 }
  84
  85 static void nfs4_clear_machine_cred(struct nfs_client *clp)
  86 {
  87         struct rpc_cred *cred;
  88
  89         spin_lock(&clp->cl_lock);
  90         cred = clp->cl_machine_cred;
  91         clp->cl_machine_cred = NULL;
  92         spin_unlock(&clp->cl_lock);
  93         if (cred != NULL)
  94                 put_rpccred(cred);
  95 }
  96
  97 struct rpc_cred *nfs4_get_renew_cred(struct nfs_client *clp)
  98 {
  99         struct nfs4_state_owner *sp;
 100         struct rb_node *pos;
 101         struct rpc_cred *cred = NULL;
 102
 103         for (pos = rb_first(&clp->cl_state_owners); pos != NULL; pos = rb_next(pos)) {
 104                 sp = rb_entry(pos, struct nfs4_state_owner, so_client_node);
 105                 if (list_empty(&sp->so_states))
 106                         continue;
 107                 cred = get_rpccred(sp->so_cred);
 108                 break;
 109         }
 110         return cred;
 111 }
 112
 113 static struct rpc_cred *nfs4_get_setclientid_cred(struct nfs_client *clp)
 114 {
 115         struct nfs4_state_owner *sp;
 116         struct rb_node *pos;
 117         struct rpc_cred *cred;
 118
 119         cred = nfs4_get_machine_cred(clp);
 120         if (cred != NULL)
 121                 goto out;
 122         pos = rb_first(&clp->cl_state_owners);
 123         if (pos != NULL) {
 124                 sp = rb_entry(pos, struct nfs4_state_owner, so_client_node);
 125                 cred = get_rpccred(sp->so_cred);
 126         }
 127 out:
 128         return cred;
 129 }
 130
 131 static void nfs_alloc_unique_id(struct rb_root *root, struct nfs_unique_id *new,
 132                 __u64 minval, int maxbits)
 133 {
 134         struct rb_node **p, *parent;
 135         struct nfs_unique_id *pos;
 136         __u64 mask = ~0ULL;
 137
 138         if (maxbits < 64)
 139                 mask = (1ULL << maxbits) - 1ULL;
 140
 141         /* Ensure distribution is more or less flat */
 142         get_random_bytes(&new->id, sizeof(new->id));
 143         new->id &= mask;
 144         if (new->id < minval)
 145                 new->id += minval;
 146 retry:
 147         p = &root->rb_node;
 148         parent = NULL;
 149
 150         while (*p != NULL) {
 151                 parent = *p;
 152                 pos = rb_entry(parent, struct nfs_unique_id, rb_node);
 153
 154                 if (new->id < pos->id)
 155                         p = &(*p)->rb_left;
 156                 else if (new->id > pos->id)
 157                         p = &(*p)->rb_right;
 158                 else
 159                         goto id_exists;
 160         }
 161         rb_link_node(&new->rb_node, parent, p);
 162         rb_insert_color(&new->rb_node, root);
 163         return;
 164 id_exists:
 165         for (;;) {
 166                 new->id++;
 167                 if (new->id < minval || (new->id & mask) != new->id) {
 168                         new->id = minval;
 169                         break;
 170                 }
 171                 parent = rb_next(parent);
 172                 if (parent == NULL)
 173                         break;
 174                 pos = rb_entry(parent, struct nfs_unique_id, rb_node);
 175                 if (new->id < pos->id)
 176                         break;
 177         }
 178         goto retry;
 179 }
 180
 181 static void nfs_free_unique_id(struct rb_root *root, struct nfs_unique_id *id)
 182 {
 183         rb_erase(&id->rb_node, root);
 184 }
 185
 186 static struct nfs4_state_owner *
 187 nfs4_find_state_owner(struct nfs_server *server, struct rpc_cred *cred)
 188 {
 189         struct nfs_client *clp = server->nfs_client;
 190         struct rb_node **p = &clp->cl_state_owners.rb_node,
 191                        *parent = NULL;
 192         struct nfs4_state_owner *sp, *res = NULL;
 193
 194         while (*p != NULL) {
 195                 parent = *p;
 196                 sp = rb_entry(parent, struct nfs4_state_owner, so_client_node);
 197
 198                 if (server < sp->so_server) {
 199                         p = &parent->rb_left;
 200                         continue;
 201                 }
 202                 if (server > sp->so_server) {
 203                         p = &parent->rb_right;
 204                         continue;
 205                 }
 206                 if (cred < sp->so_cred)
 207                         p = &parent->rb_left;
 208                 else if (cred > sp->so_cred)
 209                         p = &parent->rb_right;
 210                 else {
 211                         atomic_inc(&sp->so_count);
 212                         res = sp;
 213                         break;
 214                 }
 215         }
 216         return res;
 217 }
 218
 219 static struct nfs4_state_owner *
 220 nfs4_insert_state_owner(struct nfs_client *clp, struct nfs4_state_owner *new)
 221 {
 222         struct rb_node **p = &clp->cl_state_owners.rb_node,
 223                        *parent = NULL;
 224         struct nfs4_state_owner *sp;
 225
 226         while (*p != NULL) {
 227                 parent = *p;
 228                 sp = rb_entry(parent, struct nfs4_state_owner, so_client_node);
 229
 230                 if (new->so_server < sp->so_server) {
 231                         p = &parent->rb_left;
 232                         continue;
 233                 }
 234                 if (new->so_server > sp->so_server) {
 235                         p = &parent->rb_right;
 236                         continue;
 237                 }
 238                 if (new->so_cred < sp->so_cred)
 239                         p = &parent->rb_left;
 240                 else if (new->so_cred > sp->so_cred)
 241                         p = &parent->rb_right;
 242                 else {
 243                         atomic_inc(&sp->so_count);
 244                         return sp;
 245                 }
 246         }
 247         nfs_alloc_unique_id(&clp->cl_openowner_id, &new->so_owner_id, 1, 64);
 248         rb_link_node(&new->so_client_node, parent, p);
 249         rb_insert_color(&new->so_client_node, &clp->cl_state_owners);
 250         return new;
 251 }
 252
 253 static void
 254 nfs4_remove_state_owner(struct nfs_client *clp, struct nfs4_state_owner *sp)
 255 {
 256         if (!RB_EMPTY_NODE(&sp->so_client_node))
 257                 rb_erase(&sp->so_client_node, &clp->cl_state_owners);
 258         nfs_free_unique_id(&clp->cl_openowner_id, &sp->so_owner_id);
 259 }
 260
 261 /*
 262  * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
 263  * create a new state_owner.
 264  *
 265  */
 266 static struct nfs4_state_owner *
 267 nfs4_alloc_state_owner(void)
 268 {
 269         struct nfs4_state_owner *sp;
 270
 271         sp = kzalloc(sizeof(*sp),GFP_KERNEL);
 272         if (!sp)
 273                 return NULL;
 274         spin_lock_init(&sp->so_lock);
 275         INIT_LIST_HEAD(&sp->so_states);
 276         INIT_LIST_HEAD(&sp->so_delegations);
 277         rpc_init_wait_queue(&sp->so_sequence.wait, "Seqid_waitqueue");
 278         sp->so_seqid.sequence = &sp->so_sequence;
 279         spin_lock_init(&sp->so_sequence.lock);
 280         INIT_LIST_HEAD(&sp->so_sequence.list);
 281         atomic_set(&sp->so_count, 1);
 282         return sp;
 283 }
 284
 285 static void
 286 nfs4_drop_state_owner(struct nfs4_state_owner *sp)
 287 {
 288         if (!RB_EMPTY_NODE(&sp->so_client_node)) {
 289                 struct nfs_client *clp = sp->so_client;
 290
 291                 spin_lock(&clp->cl_lock);
 292                 rb_erase(&sp->so_client_node, &clp->cl_state_owners);
 293                 RB_CLEAR_NODE(&sp->so_client_node);
 294                 spin_unlock(&clp->cl_lock);
 295         }
 296 }
 297
 298 /*
 299  * Note: must be called with clp->cl_sem held in order to prevent races
 300  *       with reboot recovery!
 301  */
 302 struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server, struct rpc_cred *cred)
 303 {
 304         struct nfs_client *clp = server->nfs_client;
 305         struct nfs4_state_owner *sp, *new;
 306
 307         spin_lock(&clp->cl_lock);
 308         sp = nfs4_find_state_owner(server, cred);
 309         spin_unlock(&clp->cl_lock);
 310         if (sp != NULL)
 311                 return sp;
 312         new = nfs4_alloc_state_owner();
 313         if (new == NULL)
 314                 return NULL;
 315         new->so_client = clp;
 316         new->so_server = server;
 317         new->so_cred = cred;
 318         spin_lock(&clp->cl_lock);
 319         sp = nfs4_insert_state_owner(clp, new);
 320         spin_unlock(&clp->cl_lock);
 321         if (sp == new)
 322                 get_rpccred(cred);
 323         else {
 324                 rpc_destroy_wait_queue(&new->so_sequence.wait);
 325                 kfree(new);
 326         }
 327         return sp;
 328 }
 329
 330 /*
 331  * Must be called with clp->cl_sem held in order to avoid races
 332  * with state recovery...
 333  */
 334 void nfs4_put_state_owner(struct nfs4_state_owner *sp)
 335 {
 336         struct nfs_client *clp = sp->so_client;
 337         struct rpc_cred *cred = sp->so_cred;
 338
 339         if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
 340                 return;
 341         nfs4_remove_state_owner(clp, sp);
 342         spin_unlock(&clp->cl_lock);
 343         rpc_destroy_wait_queue(&sp->so_sequence.wait);
 344         put_rpccred(cred);
 345         kfree(sp);
 346 }
 347
 348 static struct nfs4_state *
 349 nfs4_alloc_open_state(void)
 350 {
 351         struct nfs4_state *state;
 352
 353         state = kzalloc(sizeof(*state), GFP_KERNEL);
 354         if (!state)
 355                 return NULL;
 356         atomic_set(&state->count, 1);
 357         INIT_LIST_HEAD(&state->lock_states);
 358         spin_lock_init(&state->state_lock);
 359         seqlock_init(&state->seqlock);
 360         return state;
 361 }
 362
 363 void
 364 nfs4_state_set_mode_locked(struct nfs4_state *state, mode_t mode)
 365 {
 366         if (state->state == mode)
 367                 return;
 368         /* NB! List reordering - see the reclaim code for why.  */
 369         if ((mode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
 370                 if (mode & FMODE_WRITE)
 371                         list_move(&state->open_states, &state->owner->so_states);
 372                 else
 373                         list_move_tail(&state->open_states, &state->owner->so_states);
 374         }
 375         state->state = mode;
 376 }
 377
 378 static struct nfs4_state *
 379 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
 380 {
 381         struct nfs_inode *nfsi = NFS_I(inode);
 382         struct nfs4_state *state;
 383
 384         list_for_each_entry(state, &nfsi->open_states, inode_states) {
 385                 if (state->owner != owner)
 386                         continue;
 387                 if (atomic_inc_not_zero(&state->count))
 388                         return state;
 389         }
 390         return NULL;
 391 }
 392
 393 static void
 394 nfs4_free_open_state(struct nfs4_state *state)
 395 {
 396         kfree(state);
 397 }
 398
 399 struct nfs4_state *
 400 nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
 401 {
 402         struct nfs4_state *state, *new;
 403         struct nfs_inode *nfsi = NFS_I(inode);
 404
 405         spin_lock(&inode->i_lock);
 406         state = __nfs4_find_state_byowner(inode, owner);
 407         spin_unlock(&inode->i_lock);
 408         if (state)
 409                 goto out;
 410         new = nfs4_alloc_open_state();
 411         spin_lock(&owner->so_lock);
 412         spin_lock(&inode->i_lock);
 413         state = __nfs4_find_state_byowner(inode, owner);
 414         if (state == NULL && new != NULL) {
 415                 state = new;
 416                 state->owner = owner;
 417                 atomic_inc(&owner->so_count);
 418                 list_add(&state->inode_states, &nfsi->open_states);
 419                 state->inode = igrab(inode);
 420                 spin_unlock(&inode->i_lock);
 421                 /* Note: The reclaim code dictates that we add stateless
 422                  * and read-only stateids to the end of the list */
 423                 list_add_tail(&state->open_states, &owner->so_states);
 424                 spin_unlock(&owner->so_lock);
 425         } else {
 426                 spin_unlock(&inode->i_lock);
 427                 spin_unlock(&owner->so_lock);
 428                 if (new)
 429                         nfs4_free_open_state(new);
 430         }
 431 out:
 432         return state;
 433 }
 434
 435 /*
 436  * Beware! Caller must be holding exactly one
 437  * reference to clp->cl_sem!
 438  */
 439 void nfs4_put_open_state(struct nfs4_state *state)
 440 {
 441         struct inode *inode = state->inode;
 442         struct nfs4_state_owner *owner = state->owner;
 443
 444         if (!atomic_dec_and_lock(&state->count, &owner->so_lock))
 445                 return;
 446         spin_lock(&inode->i_lock);
 447         list_del(&state->inode_states);
 448         list_del(&state->open_states);
 449         spin_unlock(&inode->i_lock);
 450         spin_unlock(&owner->so_lock);
 451         iput(inode);
 452         nfs4_free_open_state(state);
 453         nfs4_put_state_owner(owner);
 454 }
 455
 456 /*
 457  * Close the current file.
 458  */
 459 static void __nfs4_close(struct path *path, struct nfs4_state *state, mode_t mode, int wait)
 460 {
 461         struct nfs4_state_owner *owner = state->owner;
 462         int call_close = 0;
 463         int newstate;
 464
 465         atomic_inc(&owner->so_count);
 466         /* Protect against nfs4_find_state() */
 467         spin_lock(&owner->so_lock);
 468         switch (mode & (FMODE_READ | FMODE_WRITE)) {
 469                 case FMODE_READ:
 470                         state->n_rdonly--;
 471                         break;
 472                 case FMODE_WRITE:
 473                         state->n_wronly--;
 474                         break;
 475                 case FMODE_READ|FMODE_WRITE:
 476                         state->n_rdwr--;
 477         }
 478         newstate = FMODE_READ|FMODE_WRITE;
 479         if (state->n_rdwr == 0) {
 480                 if (state->n_rdonly == 0) {
 481                         newstate &= ~FMODE_READ;
 482                         call_close |= test_bit(NFS_O_RDONLY_STATE, &state->flags);
 483                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
 484                 }
 485                 if (state->n_wronly == 0) {
 486                         newstate &= ~FMODE_WRITE;
 487                         call_close |= test_bit(NFS_O_WRONLY_STATE, &state->flags);
 488                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
 489                 }
 490                 if (newstate == 0)
 491                         clear_bit(NFS_DELEGATED_STATE, &state->flags);
 492         }
 493         nfs4_state_set_mode_locked(state, newstate);
 494         spin_unlock(&owner->so_lock);
 495
 496         if (!call_close) {
 497                 nfs4_put_open_state(state);
 498                 nfs4_put_state_owner(owner);
 499         } else
 500                 nfs4_do_close(path, state, wait);
 501 }
 502
 503 void nfs4_close_state(struct path *path, struct nfs4_state *state, mode_t mode)
 504 {
 505         __nfs4_close(path, state, mode, 0);
 506 }
 507
 508 void nfs4_close_sync(struct path *path, struct nfs4_state *state, mode_t mode)
 509 {
 510         __nfs4_close(path, state, mode, 1);
 511 }
 512
 513 /*
 514  * Search the state->lock_states for an existing lock_owner
 515  * that is compatible with current->files
 516  */
 517 static struct nfs4_lock_state *
 518 __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 519 {
 520         struct nfs4_lock_state *pos;
 521         list_for_each_entry(pos, &state->lock_states, ls_locks) {
 522                 if (pos->ls_owner != fl_owner)
 523                         continue;
 524                 atomic_inc(&pos->ls_count);
 525                 return pos;
 526         }
 527         return NULL;
 528 }
 529
 530 /*
 531  * Return a compatible lock_state. If no initialized lock_state structure
 532  * exists, return an uninitialized one.
 533  *
 534  */
 535 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 536 {
 537         struct nfs4_lock_state *lsp;
 538         struct nfs_client *clp = state->owner->so_client;
 539
 540         lsp = kzalloc(sizeof(*lsp), GFP_KERNEL);
 541         if (lsp == NULL)
 542                 return NULL;
 543         rpc_init_wait_queue(&lsp->ls_sequence.wait, "lock_seqid_waitqueue");
 544         spin_lock_init(&lsp->ls_sequence.lock);
 545         INIT_LIST_HEAD(&lsp->ls_sequence.list);
 546         lsp->ls_seqid.sequence = &lsp->ls_sequence;
 547         atomic_set(&lsp->ls_count, 1);
 548         lsp->ls_owner = fl_owner;
 549         spin_lock(&clp->cl_lock);
 550         nfs_alloc_unique_id(&clp->cl_lockowner_id, &lsp->ls_id, 1, 64);
 551         spin_unlock(&clp->cl_lock);
 552         INIT_LIST_HEAD(&lsp->ls_locks);
 553         return lsp;
 554 }
 555
 556 static void nfs4_free_lock_state(struct nfs4_lock_state *lsp)
 557 {
 558         struct nfs_client *clp = lsp->ls_state->owner->so_client;
 559
 560         spin_lock(&clp->cl_lock);
 561         nfs_free_unique_id(&clp->cl_lockowner_id, &lsp->ls_id);
 562         spin_unlock(&clp->cl_lock);
 563         rpc_destroy_wait_queue(&lsp->ls_sequence.wait);
 564         kfree(lsp);
 565 }
 566
 567 /*
 568  * Return a compatible lock_state. If no initialized lock_state structure
 569  * exists, return an uninitialized one.
 570  *
 571  * The caller must be holding clp->cl_sem
 572  */
 573 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
 574 {
 575         struct nfs4_lock_state *lsp, *new = NULL;
 576
 577         for(;;) {
 578                 spin_lock(&state->state_lock);
 579                 lsp = __nfs4_find_lock_state(state, owner);
 580                 if (lsp != NULL)
 581                         break;
 582                 if (new != NULL) {
 583                         new->ls_state = state;
 584                         list_add(&new->ls_locks, &state->lock_states);
 585                         set_bit(LK_STATE_IN_USE, &state->flags);
 586                         lsp = new;
 587                         new = NULL;
 588                         break;
 589                 }
 590                 spin_unlock(&state->state_lock);
 591                 new = nfs4_alloc_lock_state(state, owner);
 592                 if (new == NULL)
 593                         return NULL;
 594         }
 595         spin_unlock(&state->state_lock);
 596         if (new != NULL)
 597                 nfs4_free_lock_state(new);
 598         return lsp;
 599 }
 600
 601 /*
 602  * Release reference to lock_state, and free it if we see that
 603  * it is no longer in use
 604  */
 605 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
 606 {
 607         struct nfs4_state *state;
 608
 609         if (lsp == NULL)
 610                 return;
 611         state = lsp->ls_state;
 612         if (!atomic_dec_and_lock(&lsp->ls_count, &state->state_lock))
 613                 return;
 614         list_del(&lsp->ls_locks);
 615         if (list_empty(&state->lock_states))
 616                 clear_bit(LK_STATE_IN_USE, &state->flags);
 617         spin_unlock(&state->state_lock);
 618         nfs4_free_lock_state(lsp);
 619 }
 620
 621 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
 622 {
 623         struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
 624
 625         dst->fl_u.nfs4_fl.owner = lsp;
 626         atomic_inc(&lsp->ls_count);
 627 }
 628
 629 static void nfs4_fl_release_lock(struct file_lock *fl)
 630 {
 631         nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
 632 }
 633
 634 static struct file_lock_operations nfs4_fl_lock_ops = {
 635         .fl_copy_lock = nfs4_fl_copy_lock,
 636         .fl_release_private = nfs4_fl_release_lock,
 637 };
 638
 639 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
 640 {
 641         struct nfs4_lock_state *lsp;
 642
 643         if (fl->fl_ops != NULL)
 644                 return 0;
 645         lsp = nfs4_get_lock_state(state, fl->fl_owner);
 646         if (lsp == NULL)
 647                 return -ENOMEM;
 648         fl->fl_u.nfs4_fl.owner = lsp;
 649         fl->fl_ops = &nfs4_fl_lock_ops;
 650         return 0;
 651 }
 652
 653 /*
 654  * Byte-range lock aware utility to initialize the stateid of read/write
 655  * requests.
 656  */
 657 void nfs4_copy_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t fl_owner)
 658 {
 659         struct nfs4_lock_state *lsp;
 660         int seq;
 661
 662         do {
 663                 seq = read_seqbegin(&state->seqlock);
 664                 memcpy(dst, &state->stateid, sizeof(*dst));
 665         } while (read_seqretry(&state->seqlock, seq));
 666         if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
 667                 return;
 668
 669         spin_lock(&state->state_lock);
 670         lsp = __nfs4_find_lock_state(state, fl_owner);
 671         if (lsp != NULL && (lsp->ls_flags & NFS_LOCK_INITIALIZED) != 0)
 672                 memcpy(dst, &lsp->ls_stateid, sizeof(*dst));
 673         spin_unlock(&state->state_lock);
 674         nfs4_put_lock_state(lsp);
 675 }
 676
 677 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter)
 678 {
 679         struct nfs_seqid *new;
 680
 681         new = kmalloc(sizeof(*new), GFP_KERNEL);
 682         if (new != NULL) {
 683                 new->sequence = counter;
 684                 INIT_LIST_HEAD(&new->list);
 685         }
 686         return new;
 687 }
 688
 689 void nfs_free_seqid(struct nfs_seqid *seqid)
 690 {
 691         if (!list_empty(&seqid->list)) {
 692                 struct rpc_sequence *sequence = seqid->sequence->sequence;
 693
 694                 spin_lock(&sequence->lock);
 695                 list_del(&seqid->list);
 696                 spin_unlock(&sequence->lock);
 697                 rpc_wake_up(&sequence->wait);
 698         }
 699         kfree(seqid);
 700 }
 701
 702 /*
 703  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
 704  * failed with a seqid incrementing error -
 705  * see comments nfs_fs.h:seqid_mutating_error()
 706  */
 707 static void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
 708 {
 709         BUG_ON(list_first_entry(&seqid->sequence->sequence->list, struct nfs_seqid, list) != seqid);
 710         switch (status) {
 711                 case 0:
 712                         break;
 713                 case -NFS4ERR_BAD_SEQID:
 714                         if (seqid->sequence->flags & NFS_SEQID_CONFIRMED)
 715                                 return;
 716                         printk(KERN_WARNING "NFS: v4 server returned a bad"
 717                                         " sequence-id error on an"
 718                                         " unconfirmed sequence %p!\n",
 719                                         seqid->sequence);
 720                 case -NFS4ERR_STALE_CLIENTID:
 721                 case -NFS4ERR_STALE_STATEID:
 722                 case -NFS4ERR_BAD_STATEID:
 723                 case -NFS4ERR_BADXDR:
 724                 case -NFS4ERR_RESOURCE:
 725                 case -NFS4ERR_NOFILEHANDLE:
 726                         /* Non-seqid mutating errors */
 727                         return;
 728         };
 729         /*
 730          * Note: no locking needed as we are guaranteed to be first
 731          * on the sequence list
 732          */
 733         seqid->sequence->counter++;
 734 }
 735
 736 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
 737 {
 738         if (status == -NFS4ERR_BAD_SEQID) {
 739                 struct nfs4_state_owner *sp = container_of(seqid->sequence,
 740                                 struct nfs4_state_owner, so_seqid);
 741                 nfs4_drop_state_owner(sp);
 742         }
 743         nfs_increment_seqid(status, seqid);
 744 }
 745
 746 /*
 747  * Increment the seqid if the LOCK/LOCKU succeeded, or
 748  * failed with a seqid incrementing error -
 749  * see comments nfs_fs.h:seqid_mutating_error()
 750  */
 751 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
 752 {
 753         nfs_increment_seqid(status, seqid);
 754 }
 755
 756 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
 757 {
 758         struct rpc_sequence *sequence = seqid->sequence->sequence;
 759         int status = 0;
 760
 761         spin_lock(&sequence->lock);
 762         if (list_empty(&seqid->list))
 763                 list_add_tail(&seqid->list, &sequence->list);
 764         if (list_first_entry(&sequence->list, struct nfs_seqid, list) == seqid)
 765                 goto unlock;
 766         rpc_sleep_on(&sequence->wait, task, NULL);
 767         status = -EAGAIN;
 768 unlock:
 769         spin_unlock(&sequence->lock);
 770         return status;
 771 }
 772
 773 static int reclaimer(void *);
 774
 775 static inline void nfs4_clear_recover_bit(struct nfs_client *clp)
 776 {
 777         smp_mb__before_clear_bit();
 778         clear_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state);
 779         smp_mb__after_clear_bit();
 780         wake_up_bit(&clp->cl_state, NFS4CLNT_STATE_RECOVER);
 781         rpc_wake_up(&clp->cl_rpcwaitq);
 782 }
 783
 784 /*
 785  * State recovery routine
 786  */
 787 static void nfs4_recover_state(struct nfs_client *clp)
 788 {
 789         struct task_struct *task;
 790
 791         __module_get(THIS_MODULE);
 792         atomic_inc(&clp->cl_count);
 793         task = kthread_run(reclaimer, clp, "%s-reclaim",
 794                                 rpc_peeraddr2str(clp->cl_rpcclient,
 795                                                         RPC_DISPLAY_ADDR));
 796         if (!IS_ERR(task))
 797                 return;
 798         nfs4_clear_recover_bit(clp);
 799         nfs_put_client(clp);
 800         module_put(THIS_MODULE);
 801 }
 802
 803 /*
 804  * Schedule a state recovery attempt
 805  */
 806 void nfs4_schedule_state_recovery(struct nfs_client *clp)
 807 {
 808         if (!clp)
 809                 return;
 810         if (test_and_set_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state) == 0)
 811                 nfs4_recover_state(clp);
 812 }
 813
 814 static int nfs4_reclaim_locks(struct nfs4_state_recovery_ops *ops, struct nfs4_state *state)
 815 {
 816         struct inode *inode = state->inode;
 817         struct file_lock *fl;
 818         int status = 0;
 819
 820         for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
 821                 if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
 822                         continue;
 823                 if (nfs_file_open_context(fl->fl_file)->state != state)
 824                         continue;
 825                 status = ops->recover_lock(state, fl);
 826                 if (status >= 0)
 827                         continue;
 828                 switch (status) {
 829                         default:
 830                                 printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
 831                                                 __func__, status);
 832                         case -NFS4ERR_EXPIRED:
 833                         case -NFS4ERR_NO_GRACE:
 834                         case -NFS4ERR_RECLAIM_BAD:
 835                         case -NFS4ERR_RECLAIM_CONFLICT:
 836                                 /* kill_proc(fl->fl_pid, SIGLOST, 1); */
 837                                 break;
 838                         case -NFS4ERR_STALE_CLIENTID:
 839                                 goto out_err;
 840                 }
 841         }
 842         return 0;
 843 out_err:
 844         return status;
 845 }
 846
 847 static int nfs4_reclaim_open_state(struct nfs4_state_recovery_ops *ops, struct nfs4_state_owner *sp)
 848 {
 849         struct nfs4_state *state;
 850         struct nfs4_lock_state *lock;
 851         int status = 0;
 852
 853         /* Note: we rely on the sp->so_states list being ordered
 854          * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
 855          * states first.
 856          * This is needed to ensure that the server won't give us any
 857          * read delegations that we have to return if, say, we are
 858          * recovering after a network partition or a reboot from a
 859          * server that doesn't support a grace period.
 860          */
 861         list_for_each_entry(state, &sp->so_states, open_states) {
 862                 if (state->state == 0)
 863                         continue;
 864                 status = ops->recover_open(sp, state);
 865                 if (status >= 0) {
 866                         status = nfs4_reclaim_locks(ops, state);
 867                         if (status < 0)
 868                                 goto out_err;
 869                         list_for_each_entry(lock, &state->lock_states, ls_locks) {
 870                                 if (!(lock->ls_flags & NFS_LOCK_INITIALIZED))
 871                                         printk("%s: Lock reclaim failed!\n",
 872                                                         __func__);
 873                         }
 874                         continue;
 875                 }
 876                 switch (status) {
 877                         default:
 878                                 printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
 879                                                 __func__, status);
 880                         case -ENOENT:
 881                         case -NFS4ERR_RECLAIM_BAD:
 882                         case -NFS4ERR_RECLAIM_CONFLICT:
 883                                 /*
 884                                  * Open state on this file cannot be recovered
 885                                  * All we can do is revert to using the zero stateid.
 886                                  */
 887                                 memset(state->stateid.data, 0,
 888                                         sizeof(state->stateid.data));
 889                                 /* Mark the file as being 'closed' */
 890                                 state->state = 0;
 891                                 break;
 892                         case -NFS4ERR_EXPIRED:
 893                         case -NFS4ERR_NO_GRACE:
 894                         case -NFS4ERR_STALE_CLIENTID:
 895                                 goto out_err;
 896                 }
 897         }
 898         return 0;
 899 out_err:
 900         return status;
 901 }
 902
 903 static void nfs4_state_mark_reclaim(struct nfs_client *clp)
 904 {
 905         struct nfs4_state_owner *sp;
 906         struct rb_node *pos;
 907         struct nfs4_state *state;
 908         struct nfs4_lock_state *lock;
 909
 910         /* Reset all sequence ids to zero */
 911         for (pos = rb_first(&clp->cl_state_owners); pos != NULL; pos = rb_next(pos)) {
 912                 sp = rb_entry(pos, struct nfs4_state_owner, so_client_node);
 913                 sp->so_seqid.counter = 0;
 914                 sp->so_seqid.flags = 0;
 915                 spin_lock(&sp->so_lock);
 916                 list_for_each_entry(state, &sp->so_states, open_states) {
 917                         clear_bit(NFS_DELEGATED_STATE, &state->flags);
 918                         clear_bit(NFS_O_RDONLY_STATE, &state->flags);
 919                         clear_bit(NFS_O_WRONLY_STATE, &state->flags);
 920                         clear_bit(NFS_O_RDWR_STATE, &state->flags);
 921                         list_for_each_entry(lock, &state->lock_states, ls_locks) {
 922                                 lock->ls_seqid.counter = 0;
 923                                 lock->ls_seqid.flags = 0;
 924                                 lock->ls_flags &= ~NFS_LOCK_INITIALIZED;
 925                         }
 926                 }
 927                 spin_unlock(&sp->so_lock);
 928         }
 929 }
 930
 931 static int reclaimer(void *ptr)
 932 {
 933         struct nfs_client *clp = ptr;
 934         struct nfs4_state_owner *sp;
 935         struct rb_node *pos;
 936         struct nfs4_state_recovery_ops *ops;
 937         struct rpc_cred *cred;
 938         int status = 0;
 939
 940         allow_signal(SIGKILL);
 941
 942         /* Ensure exclusive access to NFSv4 state */
 943         lock_kernel();
 944         down_write(&clp->cl_sem);
 945         /* Are there any NFS mounts out there? */
 946         if (list_empty(&clp->cl_superblocks))
 947                 goto out;
 948 restart_loop:
 949         ops = &nfs4_network_partition_recovery_ops;
 950         /* Are there any open files on this volume? */
 951         cred = nfs4_get_renew_cred(clp);
 952         if (cred != NULL) {
 953                 /* Yes there are: try to renew the old lease */
 954                 status = nfs4_proc_renew(clp, cred);
 955                 put_rpccred(cred);
 956                 switch (status) {
 957                         case 0:
 958                         case -NFS4ERR_CB_PATH_DOWN:
 959                                 goto out;
 960                         case -NFS4ERR_STALE_CLIENTID:
 961                         case -NFS4ERR_LEASE_MOVED:
 962                                 ops = &nfs4_reboot_recovery_ops;
 963                 }
 964         } else {
 965                 /* "reboot" to ensure we clear all state on the server */
 966                 clp->cl_boot_time = CURRENT_TIME;
 967         }
 968         /* We're going to have to re-establish a clientid */
 969         nfs4_state_mark_reclaim(clp);
 970         status = -ENOENT;
 971         cred = nfs4_get_setclientid_cred(clp);
 972         if (cred != NULL) {
 973                 status = nfs4_init_client(clp, cred);
 974                 put_rpccred(cred);
 975                 /* Handle case where the user hasn't set up machine creds */
 976                 if (status == -EACCES && cred == clp->cl_machine_cred) {
 977                         nfs4_clear_machine_cred(clp);
 978                         goto restart_loop;
 979                 }
 980         }
 981         if (status)
 982                 goto out_error;
 983         /* Mark all delegations for reclaim */
 984         nfs_delegation_mark_reclaim(clp);
 985         /* Note: list is protected by exclusive lock on cl->cl_sem */
 986         for (pos = rb_first(&clp->cl_state_owners); pos != NULL; pos = rb_next(pos)) {
 987                 sp = rb_entry(pos, struct nfs4_state_owner, so_client_node);
 988                 status = nfs4_reclaim_open_state(ops, sp);
 989                 if (status < 0) {
 990                         if (status == -NFS4ERR_NO_GRACE) {
 991                                 ops = &nfs4_network_partition_recovery_ops;
 992                                 status = nfs4_reclaim_open_state(ops, sp);
 993                         }
 994                         if (status == -NFS4ERR_STALE_CLIENTID)
 995                                 goto restart_loop;
 996                         if (status == -NFS4ERR_EXPIRED)
 997                                 goto restart_loop;
 998                 }
 999         }
1000         nfs_delegation_reap_unclaimed(clp);
1001 out:
1002         up_write(&clp->cl_sem);
1003         unlock_kernel();
1004         if (status == -NFS4ERR_CB_PATH_DOWN)
1005                 nfs_handle_cb_pathdown(clp);
1006         nfs4_clear_recover_bit(clp);
1007         nfs_put_client(clp);
1008         module_put_and_exit(0);
1009         return 0;
1010 out_error:
1011         printk(KERN_WARNING "Error: state recovery failed on NFSv4 server %s"
1012                         " with error %d\n", clp->cl_hostname, -status);
1013         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1014         goto out;
1015 }
1016
1017 /*
1018  * Local variables:
1019  *  c-basic-offset: 8
1020  * End:
1021  */