err.no 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/random.h>
  48 #include <linux/workqueue.h>
  49 #include <linux/bitops.h>
  50
  51 #include "nfs4_fs.h"
  52 #include "callback.h"
  53 #include "delegation.h"
  54 #include "internal.h"
  55
  56 #define OPENOWNER_POOL_SIZE     8
  57
  58 const nfs4_stateid zero_stateid;
  59
  60 static LIST_HEAD(nfs4_clientid_list);
  61
  62 static int nfs4_init_client(struct nfs_client *clp, struct rpc_cred *cred)
  63 {
  64         int status = nfs4_proc_setclientid(clp, NFS4_CALLBACK,
  65                         nfs_callback_tcpport, cred);
  66         if (status == 0)
  67                 status = nfs4_proc_setclientid_confirm(clp, cred);
  68         if (status == 0)
  69                 nfs4_schedule_state_renewal(clp);
  70         return status;
  71 }
  72
  73 struct rpc_cred *nfs4_get_renew_cred(struct nfs_client *clp)
  74 {
  75         struct nfs4_state_owner *sp;
  76         struct rb_node *pos;
  77         struct rpc_cred *cred = NULL;
  78
  79         for (pos = rb_first(&clp->cl_state_owners); pos != NULL; pos = rb_next(pos)) {
  80                 sp = rb_entry(pos, struct nfs4_state_owner, so_client_node);
  81                 if (list_empty(&sp->so_states))
  82                         continue;
  83                 cred = get_rpccred(sp->so_cred);
  84                 break;
  85         }
  86         return cred;
  87 }
  88
  89 static struct rpc_cred *nfs4_get_setclientid_cred(struct nfs_client *clp)
  90 {
  91         struct nfs4_state_owner *sp;
  92         struct rb_node *pos;
  93
  94         pos = rb_first(&clp->cl_state_owners);
  95         if (pos != NULL) {
  96                 sp = rb_entry(pos, struct nfs4_state_owner, so_client_node);
  97                 return get_rpccred(sp->so_cred);
  98         }
  99         return NULL;
 100 }
 101
 102 static void nfs_alloc_unique_id(struct rb_root *root, struct nfs_unique_id *new,
 103                 __u64 minval, int maxbits)
 104 {
 105         struct rb_node **p, *parent;
 106         struct nfs_unique_id *pos;
 107         __u64 mask = ~0ULL;
 108
 109         if (maxbits < 64)
 110                 mask = (1ULL << maxbits) - 1ULL;
 111
 112         /* Ensure distribution is more or less flat */
 113         get_random_bytes(&new->id, sizeof(new->id));
 114         new->id &= mask;
 115         if (new->id < minval)
 116                 new->id += minval;
 117 retry:
 118         p = &root->rb_node;
 119         parent = NULL;
 120
 121         while (*p != NULL) {
 122                 parent = *p;
 123                 pos = rb_entry(parent, struct nfs_unique_id, rb_node);
 124
 125                 if (new->id < pos->id)
 126                         p = &(*p)->rb_left;
 127                 else if (new->id > pos->id)
 128                         p = &(*p)->rb_right;
 129                 else
 130                         goto id_exists;
 131         }
 132         rb_link_node(&new->rb_node, parent, p);
 133         rb_insert_color(&new->rb_node, root);
 134         return;
 135 id_exists:
 136         for (;;) {
 137                 new->id++;
 138                 if (new->id < minval || (new->id & mask) != new->id) {
 139                         new->id = minval;
 140                         break;
 141                 }
 142                 parent = rb_next(parent);
 143                 if (parent == NULL)
 144                         break;
 145                 pos = rb_entry(parent, struct nfs_unique_id, rb_node);
 146                 if (new->id < pos->id)
 147                         break;
 148         }
 149         goto retry;
 150 }
 151
 152 static void nfs_free_unique_id(struct rb_root *root, struct nfs_unique_id *id)
 153 {
 154         rb_erase(&id->rb_node, root);
 155 }
 156
 157 static struct nfs4_state_owner *
 158 nfs4_find_state_owner(struct nfs_client *clp, struct rpc_cred *cred)
 159 {
 160         struct rb_node **p = &clp->cl_state_owners.rb_node,
 161                        *parent = NULL;
 162         struct nfs4_state_owner *sp, *res = NULL;
 163
 164         while (*p != NULL) {
 165                 parent = *p;
 166                 sp = rb_entry(parent, struct nfs4_state_owner, so_client_node);
 167
 168                 if (cred < sp->so_cred)
 169                         p = &parent->rb_left;
 170                 else if (cred > sp->so_cred)
 171                         p = &parent->rb_right;
 172                 else {
 173                         atomic_inc(&sp->so_count);
 174                         res = sp;
 175                         break;
 176                 }
 177         }
 178         return res;
 179 }
 180
 181 static struct nfs4_state_owner *
 182 nfs4_insert_state_owner(struct nfs_client *clp, struct nfs4_state_owner *new)
 183 {
 184         struct rb_node **p = &clp->cl_state_owners.rb_node,
 185                        *parent = NULL;
 186         struct nfs4_state_owner *sp;
 187
 188         while (*p != NULL) {
 189                 parent = *p;
 190                 sp = rb_entry(parent, struct nfs4_state_owner, so_client_node);
 191
 192                 if (new->so_cred < sp->so_cred)
 193                         p = &parent->rb_left;
 194                 else if (new->so_cred > sp->so_cred)
 195                         p = &parent->rb_right;
 196                 else {
 197                         atomic_inc(&sp->so_count);
 198                         return sp;
 199                 }
 200         }
 201         nfs_alloc_unique_id(&clp->cl_openowner_id, &new->so_owner_id, 1, 64);
 202         rb_link_node(&new->so_client_node, parent, p);
 203         rb_insert_color(&new->so_client_node, &clp->cl_state_owners);
 204         return new;
 205 }
 206
 207 static void
 208 nfs4_remove_state_owner(struct nfs_client *clp, struct nfs4_state_owner *sp)
 209 {
 210         if (!RB_EMPTY_NODE(&sp->so_client_node))
 211                 rb_erase(&sp->so_client_node, &clp->cl_state_owners);
 212         nfs_free_unique_id(&clp->cl_openowner_id, &sp->so_owner_id);
 213 }
 214
 215 /*
 216  * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
 217  * create a new state_owner.
 218  *
 219  */
 220 static struct nfs4_state_owner *
 221 nfs4_alloc_state_owner(void)
 222 {
 223         struct nfs4_state_owner *sp;
 224
 225         sp = kzalloc(sizeof(*sp),GFP_KERNEL);
 226         if (!sp)
 227                 return NULL;
 228         spin_lock_init(&sp->so_lock);
 229         INIT_LIST_HEAD(&sp->so_states);
 230         INIT_LIST_HEAD(&sp->so_delegations);
 231         rpc_init_wait_queue(&sp->so_sequence.wait, "Seqid_waitqueue");
 232         sp->so_seqid.sequence = &sp->so_sequence;
 233         spin_lock_init(&sp->so_sequence.lock);
 234         INIT_LIST_HEAD(&sp->so_sequence.list);
 235         atomic_set(&sp->so_count, 1);
 236         return sp;
 237 }
 238
 239 void
 240 nfs4_drop_state_owner(struct nfs4_state_owner *sp)
 241 {
 242         if (!RB_EMPTY_NODE(&sp->so_client_node)) {
 243                 struct nfs_client *clp = sp->so_client;
 244
 245                 spin_lock(&clp->cl_lock);
 246                 rb_erase(&sp->so_client_node, &clp->cl_state_owners);
 247                 RB_CLEAR_NODE(&sp->so_client_node);
 248                 spin_unlock(&clp->cl_lock);
 249         }
 250 }
 251
 252 /*
 253  * Note: must be called with clp->cl_sem held in order to prevent races
 254  *       with reboot recovery!
 255  */
 256 struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server, struct rpc_cred *cred)
 257 {
 258         struct nfs_client *clp = server->nfs_client;
 259         struct nfs4_state_owner *sp, *new;
 260
 261         spin_lock(&clp->cl_lock);
 262         sp = nfs4_find_state_owner(clp, cred);
 263         spin_unlock(&clp->cl_lock);
 264         if (sp != NULL)
 265                 return sp;
 266         new = nfs4_alloc_state_owner();
 267         if (new == NULL)
 268                 return NULL;
 269         new->so_client = clp;
 270         new->so_cred = cred;
 271         spin_lock(&clp->cl_lock);
 272         sp = nfs4_insert_state_owner(clp, new);
 273         spin_unlock(&clp->cl_lock);
 274         if (sp == new)
 275                 get_rpccred(cred);
 276         else
 277                 kfree(new);
 278         return sp;
 279 }
 280
 281 /*
 282  * Must be called with clp->cl_sem held in order to avoid races
 283  * with state recovery...
 284  */
 285 void nfs4_put_state_owner(struct nfs4_state_owner *sp)
 286 {
 287         struct nfs_client *clp = sp->so_client;
 288         struct rpc_cred *cred = sp->so_cred;
 289
 290         if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
 291                 return;
 292         nfs4_remove_state_owner(clp, sp);
 293         spin_unlock(&clp->cl_lock);
 294         put_rpccred(cred);
 295         kfree(sp);
 296 }
 297
 298 static struct nfs4_state *
 299 nfs4_alloc_open_state(void)
 300 {
 301         struct nfs4_state *state;
 302
 303         state = kzalloc(sizeof(*state), GFP_KERNEL);
 304         if (!state)
 305                 return NULL;
 306         atomic_set(&state->count, 1);
 307         INIT_LIST_HEAD(&state->lock_states);
 308         spin_lock_init(&state->state_lock);
 309         return state;
 310 }
 311
 312 void
 313 nfs4_state_set_mode_locked(struct nfs4_state *state, mode_t mode)
 314 {
 315         if (state->state == mode)
 316                 return;
 317         /* NB! List reordering - see the reclaim code for why.  */
 318         if ((mode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
 319                 if (mode & FMODE_WRITE)
 320                         list_move(&state->open_states, &state->owner->so_states);
 321                 else
 322                         list_move_tail(&state->open_states, &state->owner->so_states);
 323         }
 324         if (mode == 0)
 325                 list_del_init(&state->inode_states);
 326         state->state = mode;
 327 }
 328
 329 static struct nfs4_state *
 330 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
 331 {
 332         struct nfs_inode *nfsi = NFS_I(inode);
 333         struct nfs4_state *state;
 334
 335         list_for_each_entry(state, &nfsi->open_states, inode_states) {
 336                 if (state->owner != owner)
 337                         continue;
 338                 if (atomic_inc_not_zero(&state->count))
 339                         return state;
 340         }
 341         return NULL;
 342 }
 343
 344 static void
 345 nfs4_free_open_state(struct nfs4_state *state)
 346 {
 347         kfree(state);
 348 }
 349
 350 struct nfs4_state *
 351 nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
 352 {
 353         struct nfs4_state *state, *new;
 354         struct nfs_inode *nfsi = NFS_I(inode);
 355
 356         spin_lock(&inode->i_lock);
 357         state = __nfs4_find_state_byowner(inode, owner);
 358         spin_unlock(&inode->i_lock);
 359         if (state)
 360                 goto out;
 361         new = nfs4_alloc_open_state();
 362         spin_lock(&owner->so_lock);
 363         spin_lock(&inode->i_lock);
 364         state = __nfs4_find_state_byowner(inode, owner);
 365         if (state == NULL && new != NULL) {
 366                 state = new;
 367                 state->owner = owner;
 368                 atomic_inc(&owner->so_count);
 369                 list_add(&state->inode_states, &nfsi->open_states);
 370                 state->inode = igrab(inode);
 371                 spin_unlock(&inode->i_lock);
 372                 /* Note: The reclaim code dictates that we add stateless
 373                  * and read-only stateids to the end of the list */
 374                 list_add_tail(&state->open_states, &owner->so_states);
 375                 spin_unlock(&owner->so_lock);
 376         } else {
 377                 spin_unlock(&inode->i_lock);
 378                 spin_unlock(&owner->so_lock);
 379                 if (new)
 380                         nfs4_free_open_state(new);
 381         }
 382 out:
 383         return state;
 384 }
 385
 386 /*
 387  * Beware! Caller must be holding exactly one
 388  * reference to clp->cl_sem!
 389  */
 390 void nfs4_put_open_state(struct nfs4_state *state)
 391 {
 392         struct inode *inode = state->inode;
 393         struct nfs4_state_owner *owner = state->owner;
 394
 395         if (!atomic_dec_and_lock(&state->count, &owner->so_lock))
 396                 return;
 397         spin_lock(&inode->i_lock);
 398         if (!list_empty(&state->inode_states))
 399                 list_del(&state->inode_states);
 400         list_del(&state->open_states);
 401         spin_unlock(&inode->i_lock);
 402         spin_unlock(&owner->so_lock);
 403         iput(inode);
 404         nfs4_free_open_state(state);
 405         nfs4_put_state_owner(owner);
 406 }
 407
 408 /*
 409  * Close the current file.
 410  */
 411 void nfs4_close_state(struct path *path, struct nfs4_state *state, mode_t mode)
 412 {
 413         struct inode *inode = state->inode;
 414         struct nfs4_state_owner *owner = state->owner;
 415         int oldstate, newstate = 0;
 416
 417         atomic_inc(&owner->so_count);
 418         /* Protect against nfs4_find_state() */
 419         spin_lock(&owner->so_lock);
 420         spin_lock(&inode->i_lock);
 421         switch (mode & (FMODE_READ | FMODE_WRITE)) {
 422                 case FMODE_READ:
 423                         state->n_rdonly--;
 424                         break;
 425                 case FMODE_WRITE:
 426                         state->n_wronly--;
 427                         break;
 428                 case FMODE_READ|FMODE_WRITE:
 429                         state->n_rdwr--;
 430         }
 431         oldstate = newstate = state->state;
 432         if (state->n_rdwr == 0) {
 433                 if (state->n_rdonly == 0)
 434                         newstate &= ~FMODE_READ;
 435                 if (state->n_wronly == 0)
 436                         newstate &= ~FMODE_WRITE;
 437         }
 438         if (test_bit(NFS_DELEGATED_STATE, &state->flags)) {
 439                 nfs4_state_set_mode_locked(state, newstate);
 440                 oldstate = newstate;
 441         }
 442         spin_unlock(&inode->i_lock);
 443         spin_unlock(&owner->so_lock);
 444
 445         if (oldstate == newstate) {
 446                 nfs4_put_open_state(state);
 447                 nfs4_put_state_owner(owner);
 448         } else
 449                 nfs4_do_close(path, state);
 450 }
 451
 452 /*
 453  * Search the state->lock_states for an existing lock_owner
 454  * that is compatible with current->files
 455  */
 456 static struct nfs4_lock_state *
 457 __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 458 {
 459         struct nfs4_lock_state *pos;
 460         list_for_each_entry(pos, &state->lock_states, ls_locks) {
 461                 if (pos->ls_owner != fl_owner)
 462                         continue;
 463                 atomic_inc(&pos->ls_count);
 464                 return pos;
 465         }
 466         return NULL;
 467 }
 468
 469 /*
 470  * Return a compatible lock_state. If no initialized lock_state structure
 471  * exists, return an uninitialized one.
 472  *
 473  */
 474 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 475 {
 476         struct nfs4_lock_state *lsp;
 477         struct nfs_client *clp = state->owner->so_client;
 478
 479         lsp = kzalloc(sizeof(*lsp), GFP_KERNEL);
 480         if (lsp == NULL)
 481                 return NULL;
 482         lsp->ls_seqid.sequence = &state->owner->so_sequence;
 483         atomic_set(&lsp->ls_count, 1);
 484         lsp->ls_owner = fl_owner;
 485         spin_lock(&clp->cl_lock);
 486         nfs_alloc_unique_id(&clp->cl_lockowner_id, &lsp->ls_id, 1, 64);
 487         spin_unlock(&clp->cl_lock);
 488         INIT_LIST_HEAD(&lsp->ls_locks);
 489         return lsp;
 490 }
 491
 492 static void nfs4_free_lock_state(struct nfs4_lock_state *lsp)
 493 {
 494         struct nfs_client *clp = lsp->ls_state->owner->so_client;
 495
 496         spin_lock(&clp->cl_lock);
 497         nfs_free_unique_id(&clp->cl_lockowner_id, &lsp->ls_id);
 498         spin_unlock(&clp->cl_lock);
 499         kfree(lsp);
 500 }
 501
 502 /*
 503  * Return a compatible lock_state. If no initialized lock_state structure
 504  * exists, return an uninitialized one.
 505  *
 506  * The caller must be holding clp->cl_sem
 507  */
 508 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
 509 {
 510         struct nfs4_lock_state *lsp, *new = NULL;
 511
 512         for(;;) {
 513                 spin_lock(&state->state_lock);
 514                 lsp = __nfs4_find_lock_state(state, owner);
 515                 if (lsp != NULL)
 516                         break;
 517                 if (new != NULL) {
 518                         new->ls_state = state;
 519                         list_add(&new->ls_locks, &state->lock_states);
 520                         set_bit(LK_STATE_IN_USE, &state->flags);
 521                         lsp = new;
 522                         new = NULL;
 523                         break;
 524                 }
 525                 spin_unlock(&state->state_lock);
 526                 new = nfs4_alloc_lock_state(state, owner);
 527                 if (new == NULL)
 528                         return NULL;
 529         }
 530         spin_unlock(&state->state_lock);
 531         if (new != NULL)
 532                 nfs4_free_lock_state(new);
 533         return lsp;
 534 }
 535
 536 /*
 537  * Release reference to lock_state, and free it if we see that
 538  * it is no longer in use
 539  */
 540 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
 541 {
 542         struct nfs4_state *state;
 543
 544         if (lsp == NULL)
 545                 return;
 546         state = lsp->ls_state;
 547         if (!atomic_dec_and_lock(&lsp->ls_count, &state->state_lock))
 548                 return;
 549         list_del(&lsp->ls_locks);
 550         if (list_empty(&state->lock_states))
 551                 clear_bit(LK_STATE_IN_USE, &state->flags);
 552         spin_unlock(&state->state_lock);
 553         nfs4_free_lock_state(lsp);
 554 }
 555
 556 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
 557 {
 558         struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
 559
 560         dst->fl_u.nfs4_fl.owner = lsp;
 561         atomic_inc(&lsp->ls_count);
 562 }
 563
 564 static void nfs4_fl_release_lock(struct file_lock *fl)
 565 {
 566         nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
 567 }
 568
 569 static struct file_lock_operations nfs4_fl_lock_ops = {
 570         .fl_copy_lock = nfs4_fl_copy_lock,
 571         .fl_release_private = nfs4_fl_release_lock,
 572 };
 573
 574 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
 575 {
 576         struct nfs4_lock_state *lsp;
 577
 578         if (fl->fl_ops != NULL)
 579                 return 0;
 580         lsp = nfs4_get_lock_state(state, fl->fl_owner);
 581         if (lsp == NULL)
 582                 return -ENOMEM;
 583         fl->fl_u.nfs4_fl.owner = lsp;
 584         fl->fl_ops = &nfs4_fl_lock_ops;
 585         return 0;
 586 }
 587
 588 /*
 589  * Byte-range lock aware utility to initialize the stateid of read/write
 590  * requests.
 591  */
 592 void nfs4_copy_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t fl_owner)
 593 {
 594         struct nfs4_lock_state *lsp;
 595
 596         memcpy(dst, &state->stateid, sizeof(*dst));
 597         if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
 598                 return;
 599
 600         spin_lock(&state->state_lock);
 601         lsp = __nfs4_find_lock_state(state, fl_owner);
 602         if (lsp != NULL && (lsp->ls_flags & NFS_LOCK_INITIALIZED) != 0)
 603                 memcpy(dst, &lsp->ls_stateid, sizeof(*dst));
 604         spin_unlock(&state->state_lock);
 605         nfs4_put_lock_state(lsp);
 606 }
 607
 608 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter)
 609 {
 610         struct rpc_sequence *sequence = counter->sequence;
 611         struct nfs_seqid *new;
 612
 613         new = kmalloc(sizeof(*new), GFP_KERNEL);
 614         if (new != NULL) {
 615                 new->sequence = counter;
 616                 spin_lock(&sequence->lock);
 617                 list_add_tail(&new->list, &sequence->list);
 618                 spin_unlock(&sequence->lock);
 619         }
 620         return new;
 621 }
 622
 623 void nfs_free_seqid(struct nfs_seqid *seqid)
 624 {
 625         struct rpc_sequence *sequence = seqid->sequence->sequence;
 626
 627         spin_lock(&sequence->lock);
 628         list_del(&seqid->list);
 629         spin_unlock(&sequence->lock);
 630         rpc_wake_up(&sequence->wait);
 631         kfree(seqid);
 632 }
 633
 634 /*
 635  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
 636  * failed with a seqid incrementing error -
 637  * see comments nfs_fs.h:seqid_mutating_error()
 638  */
 639 static void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
 640 {
 641         switch (status) {
 642                 case 0:
 643                         break;
 644                 case -NFS4ERR_BAD_SEQID:
 645                 case -NFS4ERR_STALE_CLIENTID:
 646                 case -NFS4ERR_STALE_STATEID:
 647                 case -NFS4ERR_BAD_STATEID:
 648                 case -NFS4ERR_BADXDR:
 649                 case -NFS4ERR_RESOURCE:
 650                 case -NFS4ERR_NOFILEHANDLE:
 651                         /* Non-seqid mutating errors */
 652                         return;
 653         };
 654         /*
 655          * Note: no locking needed as we are guaranteed to be first
 656          * on the sequence list
 657          */
 658         seqid->sequence->counter++;
 659 }
 660
 661 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
 662 {
 663         if (status == -NFS4ERR_BAD_SEQID) {
 664                 struct nfs4_state_owner *sp = container_of(seqid->sequence,
 665                                 struct nfs4_state_owner, so_seqid);
 666                 nfs4_drop_state_owner(sp);
 667         }
 668         nfs_increment_seqid(status, seqid);
 669 }
 670
 671 /*
 672  * Increment the seqid if the LOCK/LOCKU succeeded, or
 673  * failed with a seqid incrementing error -
 674  * see comments nfs_fs.h:seqid_mutating_error()
 675  */
 676 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
 677 {
 678         nfs_increment_seqid(status, seqid);
 679 }
 680
 681 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
 682 {
 683         struct rpc_sequence *sequence = seqid->sequence->sequence;
 684         int status = 0;
 685
 686         if (sequence->list.next == &seqid->list)
 687                 goto out;
 688         spin_lock(&sequence->lock);
 689         if (sequence->list.next != &seqid->list) {
 690                 rpc_sleep_on(&sequence->wait, task, NULL, NULL);
 691                 status = -EAGAIN;
 692         }
 693         spin_unlock(&sequence->lock);
 694 out:
 695         return status;
 696 }
 697
 698 static int reclaimer(void *);
 699
 700 static inline void nfs4_clear_recover_bit(struct nfs_client *clp)
 701 {
 702         smp_mb__before_clear_bit();
 703         clear_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state);
 704         smp_mb__after_clear_bit();
 705         wake_up_bit(&clp->cl_state, NFS4CLNT_STATE_RECOVER);
 706         rpc_wake_up(&clp->cl_rpcwaitq);
 707 }
 708
 709 /*
 710  * State recovery routine
 711  */
 712 static void nfs4_recover_state(struct nfs_client *clp)
 713 {
 714         struct task_struct *task;
 715
 716         __module_get(THIS_MODULE);
 717         atomic_inc(&clp->cl_count);
 718         task = kthread_run(reclaimer, clp, "%u.%u.%u.%u-reclaim",
 719                         NIPQUAD(clp->cl_addr.sin_addr));
 720         if (!IS_ERR(task))
 721                 return;
 722         nfs4_clear_recover_bit(clp);
 723         nfs_put_client(clp);
 724         module_put(THIS_MODULE);
 725 }
 726
 727 /*
 728  * Schedule a state recovery attempt
 729  */
 730 void nfs4_schedule_state_recovery(struct nfs_client *clp)
 731 {
 732         if (!clp)
 733                 return;
 734         if (test_and_set_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state) == 0)
 735                 nfs4_recover_state(clp);
 736 }
 737
 738 static int nfs4_reclaim_locks(struct nfs4_state_recovery_ops *ops, struct nfs4_state *state)
 739 {
 740         struct inode *inode = state->inode;
 741         struct file_lock *fl;
 742         int status = 0;
 743
 744         for (fl = inode->i_flock; fl != 0; fl = fl->fl_next) {
 745                 if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
 746                         continue;
 747                 if (((struct nfs_open_context *)fl->fl_file->private_data)->state != state)
 748                         continue;
 749                 status = ops->recover_lock(state, fl);
 750                 if (status >= 0)
 751                         continue;
 752                 switch (status) {
 753                         default:
 754                                 printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
 755                                                 __FUNCTION__, status);
 756                         case -NFS4ERR_EXPIRED:
 757                         case -NFS4ERR_NO_GRACE:
 758                         case -NFS4ERR_RECLAIM_BAD:
 759                         case -NFS4ERR_RECLAIM_CONFLICT:
 760                                 /* kill_proc(fl->fl_pid, SIGLOST, 1); */
 761                                 break;
 762                         case -NFS4ERR_STALE_CLIENTID:
 763                                 goto out_err;
 764                 }
 765         }
 766         return 0;
 767 out_err:
 768         return status;
 769 }
 770
 771 static int nfs4_reclaim_open_state(struct nfs4_state_recovery_ops *ops, struct nfs4_state_owner *sp)
 772 {
 773         struct nfs4_state *state;
 774         struct nfs4_lock_state *lock;
 775         int status = 0;
 776
 777         /* Note: we rely on the sp->so_states list being ordered
 778          * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
 779          * states first.
 780          * This is needed to ensure that the server won't give us any
 781          * read delegations that we have to return if, say, we are
 782          * recovering after a network partition or a reboot from a
 783          * server that doesn't support a grace period.
 784          */
 785         list_for_each_entry(state, &sp->so_states, open_states) {
 786                 if (state->state == 0)
 787                         continue;
 788                 status = ops->recover_open(sp, state);
 789                 if (status >= 0) {
 790                         status = nfs4_reclaim_locks(ops, state);
 791                         if (status < 0)
 792                                 goto out_err;
 793                         list_for_each_entry(lock, &state->lock_states, ls_locks) {
 794                                 if (!(lock->ls_flags & NFS_LOCK_INITIALIZED))
 795                                         printk("%s: Lock reclaim failed!\n",
 796                                                         __FUNCTION__);
 797                         }
 798                         continue;
 799                 }
 800                 switch (status) {
 801                         default:
 802                                 printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
 803                                                 __FUNCTION__, status);
 804                         case -ENOENT:
 805                         case -NFS4ERR_RECLAIM_BAD:
 806                         case -NFS4ERR_RECLAIM_CONFLICT:
 807                                 /*
 808                                  * Open state on this file cannot be recovered
 809                                  * All we can do is revert to using the zero stateid.
 810                                  */
 811                                 memset(state->stateid.data, 0,
 812                                         sizeof(state->stateid.data));
 813                                 /* Mark the file as being 'closed' */
 814                                 state->state = 0;
 815                                 break;
 816                         case -NFS4ERR_EXPIRED:
 817                         case -NFS4ERR_NO_GRACE:
 818                         case -NFS4ERR_STALE_CLIENTID:
 819                                 goto out_err;
 820                 }
 821         }
 822         return 0;
 823 out_err:
 824         return status;
 825 }
 826
 827 static void nfs4_state_mark_reclaim(struct nfs_client *clp)
 828 {
 829         struct nfs4_state_owner *sp;
 830         struct rb_node *pos;
 831         struct nfs4_state *state;
 832         struct nfs4_lock_state *lock;
 833
 834         /* Reset all sequence ids to zero */
 835         for (pos = rb_first(&clp->cl_state_owners); pos != NULL; pos = rb_next(pos)) {
 836                 sp = rb_entry(pos, struct nfs4_state_owner, so_client_node);
 837                 sp->so_seqid.counter = 0;
 838                 sp->so_seqid.flags = 0;
 839                 spin_lock(&sp->so_lock);
 840                 list_for_each_entry(state, &sp->so_states, open_states) {
 841                         list_for_each_entry(lock, &state->lock_states, ls_locks) {
 842                                 lock->ls_seqid.counter = 0;
 843                                 lock->ls_seqid.flags = 0;
 844                                 lock->ls_flags &= ~NFS_LOCK_INITIALIZED;
 845                         }
 846                 }
 847                 spin_unlock(&sp->so_lock);
 848         }
 849 }
 850
 851 static int reclaimer(void *ptr)
 852 {
 853         struct nfs_client *clp = ptr;
 854         struct nfs4_state_owner *sp;
 855         struct rb_node *pos;
 856         struct nfs4_state_recovery_ops *ops;
 857         struct rpc_cred *cred;
 858         int status = 0;
 859
 860         allow_signal(SIGKILL);
 861
 862         /* Ensure exclusive access to NFSv4 state */
 863         lock_kernel();
 864         down_write(&clp->cl_sem);
 865         /* Are there any NFS mounts out there? */
 866         if (list_empty(&clp->cl_superblocks))
 867                 goto out;
 868 restart_loop:
 869         ops = &nfs4_network_partition_recovery_ops;
 870         /* Are there any open files on this volume? */
 871         cred = nfs4_get_renew_cred(clp);
 872         if (cred != NULL) {
 873                 /* Yes there are: try to renew the old lease */
 874                 status = nfs4_proc_renew(clp, cred);
 875                 switch (status) {
 876                         case 0:
 877                         case -NFS4ERR_CB_PATH_DOWN:
 878                                 put_rpccred(cred);
 879                                 goto out;
 880                         case -NFS4ERR_STALE_CLIENTID:
 881                         case -NFS4ERR_LEASE_MOVED:
 882                                 ops = &nfs4_reboot_recovery_ops;
 883                 }
 884         } else {
 885                 /* "reboot" to ensure we clear all state on the server */
 886                 clp->cl_boot_time = CURRENT_TIME;
 887                 cred = nfs4_get_setclientid_cred(clp);
 888         }
 889         /* We're going to have to re-establish a clientid */
 890         nfs4_state_mark_reclaim(clp);
 891         status = -ENOENT;
 892         if (cred != NULL) {
 893                 status = nfs4_init_client(clp, cred);
 894                 put_rpccred(cred);
 895         }
 896         if (status)
 897                 goto out_error;
 898         /* Mark all delegations for reclaim */
 899         nfs_delegation_mark_reclaim(clp);
 900         /* Note: list is protected by exclusive lock on cl->cl_sem */
 901         for (pos = rb_first(&clp->cl_state_owners); pos != NULL; pos = rb_next(pos)) {
 902                 sp = rb_entry(pos, struct nfs4_state_owner, so_client_node);
 903                 status = nfs4_reclaim_open_state(ops, sp);
 904                 if (status < 0) {
 905                         if (status == -NFS4ERR_NO_GRACE) {
 906                                 ops = &nfs4_network_partition_recovery_ops;
 907                                 status = nfs4_reclaim_open_state(ops, sp);
 908                         }
 909                         if (status == -NFS4ERR_STALE_CLIENTID)
 910                                 goto restart_loop;
 911                         if (status == -NFS4ERR_EXPIRED)
 912                                 goto restart_loop;
 913                 }
 914         }
 915         nfs_delegation_reap_unclaimed(clp);
 916 out:
 917         up_write(&clp->cl_sem);
 918         unlock_kernel();
 919         if (status == -NFS4ERR_CB_PATH_DOWN)
 920                 nfs_handle_cb_pathdown(clp);
 921         nfs4_clear_recover_bit(clp);
 922         nfs_put_client(clp);
 923         module_put_and_exit(0);
 924         return 0;
 925 out_error:
 926         printk(KERN_WARNING "Error: state recovery failed on NFSv4 server %u.%u.%u.%u with error %d\n",
 927                                 NIPQUAD(clp->cl_addr.sin_addr), -status);
 928         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
 929         goto out;
 930 }
 931
 932 /*
 933  * Local variables:
 934  *  c-basic-offset: 8
 935  * End:
 936  */