git.oblomov.eu Git - linux-2.6/blob - fs/nfs/nfs4state.c

   1 /*
   2  *  fs/nfs/nfs4state.c
   3  *
   4  *  Client-side XDR for NFSv4.
   5  *
   6  *  Copyright (c) 2002 The Regents of the University of Michigan.
   7  *  All rights reserved.
   8  *
   9  *  Kendrick Smith <kmsmith@umich.edu>
  10  *
  11  *  Redistribution and use in source and binary forms, with or without
  12  *  modification, are permitted provided that the following conditions
  13  *  are met:
  14  *
  15  *  1. Redistributions of source code must retain the above copyright
  16  *     notice, this list of conditions and the following disclaimer.
  17  *  2. Redistributions in binary form must reproduce the above copyright
  18  *     notice, this list of conditions and the following disclaimer in the
  19  *     documentation and/or other materials provided with the distribution.
  20  *  3. Neither the name of the University nor the names of its
  21  *     contributors may be used to endorse or promote products derived
  22  *     from this software without specific prior written permission.
  23  *
  24  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  25  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  26  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  27  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  31  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  32  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  33  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  34  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35  *
  36  * Implementation of the NFSv4 state model.  For the time being,
  37  * this is minimal, but will be made much more complex in a
  38  * subsequent patch.
  39  */
  40
  41 #include <linux/config.h>
  42 #include <linux/slab.h>
  43 #include <linux/smp_lock.h>
  44 #include <linux/nfs_fs.h>
  45 #include <linux/nfs_idmap.h>
  46 #include <linux/workqueue.h>
  47 #include <linux/bitops.h>
  48
  49 #include "nfs4_fs.h"
  50 #include "callback.h"
  51 #include "delegation.h"
  52
  53 #define OPENOWNER_POOL_SIZE     8
  54
  55 const nfs4_stateid zero_stateid;
  56
  57 static DEFINE_SPINLOCK(state_spinlock);
  58 static LIST_HEAD(nfs4_clientid_list);
  59
  60 static void nfs4_recover_state(void *);
  61
  62 void
  63 init_nfsv4_state(struct nfs_server *server)
  64 {
  65         server->nfs4_state = NULL;
  66         INIT_LIST_HEAD(&server->nfs4_siblings);
  67 }
  68
  69 void
  70 destroy_nfsv4_state(struct nfs_server *server)
  71 {
  72         if (server->mnt_path) {
  73                 kfree(server->mnt_path);
  74                 server->mnt_path = NULL;
  75         }
  76         if (server->nfs4_state) {
  77                 nfs4_put_client(server->nfs4_state);
  78                 server->nfs4_state = NULL;
  79         }
  80 }
  81
  82 /*
  83  * nfs4_get_client(): returns an empty client structure
  84  * nfs4_put_client(): drops reference to client structure
  85  *
  86  * Since these are allocated/deallocated very rarely, we don't
  87  * bother putting them in a slab cache...
  88  */
  89 static struct nfs4_client *
  90 nfs4_alloc_client(struct in_addr *addr)
  91 {
  92         struct nfs4_client *clp;
  93
  94         if (nfs_callback_up() < 0)
  95                 return NULL;
  96         if ((clp = kmalloc(sizeof(*clp), GFP_KERNEL)) == NULL) {
  97                 nfs_callback_down();
  98                 return NULL;
  99         }
 100         memset(clp, 0, sizeof(*clp));
 101         memcpy(&clp->cl_addr, addr, sizeof(clp->cl_addr));
 102         init_rwsem(&clp->cl_sem);
 103         INIT_LIST_HEAD(&clp->cl_delegations);
 104         INIT_LIST_HEAD(&clp->cl_state_owners);
 105         INIT_LIST_HEAD(&clp->cl_unused);
 106         spin_lock_init(&clp->cl_lock);
 107         atomic_set(&clp->cl_count, 1);
 108         INIT_WORK(&clp->cl_recoverd, nfs4_recover_state, clp);
 109         INIT_WORK(&clp->cl_renewd, nfs4_renew_state, clp);
 110         INIT_LIST_HEAD(&clp->cl_superblocks);
 111         init_waitqueue_head(&clp->cl_waitq);
 112         rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS4 client");
 113         clp->cl_rpcclient = ERR_PTR(-EINVAL);
 114         clp->cl_boot_time = CURRENT_TIME;
 115         clp->cl_state = 1 << NFS4CLNT_OK;
 116         return clp;
 117 }
 118
 119 static void
 120 nfs4_free_client(struct nfs4_client *clp)
 121 {
 122         struct nfs4_state_owner *sp;
 123
 124         while (!list_empty(&clp->cl_unused)) {
 125                 sp = list_entry(clp->cl_unused.next,
 126                                 struct nfs4_state_owner,
 127                                 so_list);
 128                 list_del(&sp->so_list);
 129                 kfree(sp);
 130         }
 131         BUG_ON(!list_empty(&clp->cl_state_owners));
 132         if (clp->cl_cred)
 133                 put_rpccred(clp->cl_cred);
 134         nfs_idmap_delete(clp);
 135         if (!IS_ERR(clp->cl_rpcclient))
 136                 rpc_shutdown_client(clp->cl_rpcclient);
 137         kfree(clp);
 138         nfs_callback_down();
 139 }
 140
 141 static struct nfs4_client *__nfs4_find_client(struct in_addr *addr)
 142 {
 143         struct nfs4_client *clp;
 144         list_for_each_entry(clp, &nfs4_clientid_list, cl_servers) {
 145                 if (memcmp(&clp->cl_addr, addr, sizeof(clp->cl_addr)) == 0) {
 146                         atomic_inc(&clp->cl_count);
 147                         return clp;
 148                 }
 149         }
 150         return NULL;
 151 }
 152
 153 struct nfs4_client *nfs4_find_client(struct in_addr *addr)
 154 {
 155         struct nfs4_client *clp;
 156         spin_lock(&state_spinlock);
 157         clp = __nfs4_find_client(addr);
 158         spin_unlock(&state_spinlock);
 159         return clp;
 160 }
 161
 162 struct nfs4_client *
 163 nfs4_get_client(struct in_addr *addr)
 164 {
 165         struct nfs4_client *clp, *new = NULL;
 166
 167         spin_lock(&state_spinlock);
 168         for (;;) {
 169                 clp = __nfs4_find_client(addr);
 170                 if (clp != NULL)
 171                         break;
 172                 clp = new;
 173                 if (clp != NULL) {
 174                         list_add(&clp->cl_servers, &nfs4_clientid_list);
 175                         new = NULL;
 176                         break;
 177                 }
 178                 spin_unlock(&state_spinlock);
 179                 new = nfs4_alloc_client(addr);
 180                 spin_lock(&state_spinlock);
 181                 if (new == NULL)
 182                         break;
 183         }
 184         spin_unlock(&state_spinlock);
 185         if (new)
 186                 nfs4_free_client(new);
 187         return clp;
 188 }
 189
 190 void
 191 nfs4_put_client(struct nfs4_client *clp)
 192 {
 193         if (!atomic_dec_and_lock(&clp->cl_count, &state_spinlock))
 194                 return;
 195         list_del(&clp->cl_servers);
 196         spin_unlock(&state_spinlock);
 197         BUG_ON(!list_empty(&clp->cl_superblocks));
 198         wake_up_all(&clp->cl_waitq);
 199         rpc_wake_up(&clp->cl_rpcwaitq);
 200         nfs4_kill_renewd(clp);
 201         nfs4_free_client(clp);
 202 }
 203
 204 static int __nfs4_init_client(struct nfs4_client *clp)
 205 {
 206         int status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, nfs_callback_tcpport);
 207         if (status == 0)
 208                 status = nfs4_proc_setclientid_confirm(clp);
 209         if (status == 0)
 210                 nfs4_schedule_state_renewal(clp);
 211         return status;
 212 }
 213
 214 int nfs4_init_client(struct nfs4_client *clp)
 215 {
 216         return nfs4_map_errors(__nfs4_init_client(clp));
 217 }
 218
 219 u32
 220 nfs4_alloc_lockowner_id(struct nfs4_client *clp)
 221 {
 222         return clp->cl_lockowner_id ++;
 223 }
 224
 225 static struct nfs4_state_owner *
 226 nfs4_client_grab_unused(struct nfs4_client *clp, struct rpc_cred *cred)
 227 {
 228         struct nfs4_state_owner *sp = NULL;
 229
 230         if (!list_empty(&clp->cl_unused)) {
 231                 sp = list_entry(clp->cl_unused.next, struct nfs4_state_owner, so_list);
 232                 atomic_inc(&sp->so_count);
 233                 sp->so_cred = cred;
 234                 list_move(&sp->so_list, &clp->cl_state_owners);
 235                 clp->cl_nunused--;
 236         }
 237         return sp;
 238 }
 239
 240 static struct nfs4_state_owner *
 241 nfs4_find_state_owner(struct nfs4_client *clp, struct rpc_cred *cred)
 242 {
 243         struct nfs4_state_owner *sp, *res = NULL;
 244
 245         list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
 246                 if (sp->so_cred != cred)
 247                         continue;
 248                 atomic_inc(&sp->so_count);
 249                 /* Move to the head of the list */
 250                 list_move(&sp->so_list, &clp->cl_state_owners);
 251                 res = sp;
 252                 break;
 253         }
 254         return res;
 255 }
 256
 257 /*
 258  * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
 259  * create a new state_owner.
 260  *
 261  */
 262 static struct nfs4_state_owner *
 263 nfs4_alloc_state_owner(void)
 264 {
 265         struct nfs4_state_owner *sp;
 266
 267         sp = kzalloc(sizeof(*sp),GFP_KERNEL);
 268         if (!sp)
 269                 return NULL;
 270         spin_lock_init(&sp->so_lock);
 271         INIT_LIST_HEAD(&sp->so_states);
 272         INIT_LIST_HEAD(&sp->so_delegations);
 273         rpc_init_wait_queue(&sp->so_sequence.wait, "Seqid_waitqueue");
 274         sp->so_seqid.sequence = &sp->so_sequence;
 275         spin_lock_init(&sp->so_sequence.lock);
 276         INIT_LIST_HEAD(&sp->so_sequence.list);
 277         atomic_set(&sp->so_count, 1);
 278         return sp;
 279 }
 280
 281 void
 282 nfs4_drop_state_owner(struct nfs4_state_owner *sp)
 283 {
 284         struct nfs4_client *clp = sp->so_client;
 285         spin_lock(&clp->cl_lock);
 286         list_del_init(&sp->so_list);
 287         spin_unlock(&clp->cl_lock);
 288 }
 289
 290 /*
 291  * Note: must be called with clp->cl_sem held in order to prevent races
 292  *       with reboot recovery!
 293  */
 294 struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server, struct rpc_cred *cred)
 295 {
 296         struct nfs4_client *clp = server->nfs4_state;
 297         struct nfs4_state_owner *sp, *new;
 298
 299         get_rpccred(cred);
 300         new = nfs4_alloc_state_owner();
 301         spin_lock(&clp->cl_lock);
 302         sp = nfs4_find_state_owner(clp, cred);
 303         if (sp == NULL)
 304                 sp = nfs4_client_grab_unused(clp, cred);
 305         if (sp == NULL && new != NULL) {
 306                 list_add(&new->so_list, &clp->cl_state_owners);
 307                 new->so_client = clp;
 308                 new->so_id = nfs4_alloc_lockowner_id(clp);
 309                 new->so_cred = cred;
 310                 sp = new;
 311                 new = NULL;
 312         }
 313         spin_unlock(&clp->cl_lock);
 314         if (new)
 315                 kfree(new);
 316         if (sp != NULL)
 317                 return sp;
 318         put_rpccred(cred);
 319         return NULL;
 320 }
 321
 322 /*
 323  * Must be called with clp->cl_sem held in order to avoid races
 324  * with state recovery...
 325  */
 326 void nfs4_put_state_owner(struct nfs4_state_owner *sp)
 327 {
 328         struct nfs4_client *clp = sp->so_client;
 329         struct rpc_cred *cred = sp->so_cred;
 330
 331         if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
 332                 return;
 333         if (clp->cl_nunused >= OPENOWNER_POOL_SIZE)
 334                 goto out_free;
 335         if (list_empty(&sp->so_list))
 336                 goto out_free;
 337         list_move(&sp->so_list, &clp->cl_unused);
 338         clp->cl_nunused++;
 339         spin_unlock(&clp->cl_lock);
 340         put_rpccred(cred);
 341         cred = NULL;
 342         return;
 343 out_free:
 344         list_del(&sp->so_list);
 345         spin_unlock(&clp->cl_lock);
 346         put_rpccred(cred);
 347         kfree(sp);
 348 }
 349
 350 static struct nfs4_state *
 351 nfs4_alloc_open_state(void)
 352 {
 353         struct nfs4_state *state;
 354
 355         state = kmalloc(sizeof(*state), GFP_KERNEL);
 356         if (!state)
 357                 return NULL;
 358         state->state = 0;
 359         state->nreaders = 0;
 360         state->nwriters = 0;
 361         state->flags = 0;
 362         memset(state->stateid.data, 0, sizeof(state->stateid.data));
 363         atomic_set(&state->count, 1);
 364         INIT_LIST_HEAD(&state->lock_states);
 365         spin_lock_init(&state->state_lock);
 366         return state;
 367 }
 368
 369 static struct nfs4_state *
 370 __nfs4_find_state(struct inode *inode, struct rpc_cred *cred, mode_t mode)
 371 {
 372         struct nfs_inode *nfsi = NFS_I(inode);
 373         struct nfs4_state *state;
 374
 375         mode &= (FMODE_READ|FMODE_WRITE);
 376         list_for_each_entry(state, &nfsi->open_states, inode_states) {
 377                 if (state->owner->so_cred != cred)
 378                         continue;
 379                 if ((mode & FMODE_READ) != 0 && state->nreaders == 0)
 380                         continue;
 381                 if ((mode & FMODE_WRITE) != 0 && state->nwriters == 0)
 382                         continue;
 383                 if ((state->state & mode) != mode)
 384                         continue;
 385                 atomic_inc(&state->count);
 386                 if (mode & FMODE_READ)
 387                         state->nreaders++;
 388                 if (mode & FMODE_WRITE)
 389                         state->nwriters++;
 390                 return state;
 391         }
 392         return NULL;
 393 }
 394
 395 static struct nfs4_state *
 396 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
 397 {
 398         struct nfs_inode *nfsi = NFS_I(inode);
 399         struct nfs4_state *state;
 400
 401         list_for_each_entry(state, &nfsi->open_states, inode_states) {
 402                 /* Is this in the process of being freed? */
 403                 if (state->nreaders == 0 && state->nwriters == 0)
 404                         continue;
 405                 if (state->owner == owner) {
 406                         atomic_inc(&state->count);
 407                         return state;
 408                 }
 409         }
 410         return NULL;
 411 }
 412
 413 struct nfs4_state *
 414 nfs4_find_state(struct inode *inode, struct rpc_cred *cred, mode_t mode)
 415 {
 416         struct nfs4_state *state;
 417
 418         spin_lock(&inode->i_lock);
 419         state = __nfs4_find_state(inode, cred, mode);
 420         spin_unlock(&inode->i_lock);
 421         return state;
 422 }
 423
 424 static void
 425 nfs4_free_open_state(struct nfs4_state *state)
 426 {
 427         kfree(state);
 428 }
 429
 430 struct nfs4_state *
 431 nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
 432 {
 433         struct nfs4_state *state, *new;
 434         struct nfs_inode *nfsi = NFS_I(inode);
 435
 436         spin_lock(&inode->i_lock);
 437         state = __nfs4_find_state_byowner(inode, owner);
 438         spin_unlock(&inode->i_lock);
 439         if (state)
 440                 goto out;
 441         new = nfs4_alloc_open_state();
 442         spin_lock(&owner->so_lock);
 443         spin_lock(&inode->i_lock);
 444         state = __nfs4_find_state_byowner(inode, owner);
 445         if (state == NULL && new != NULL) {
 446                 state = new;
 447                 state->owner = owner;
 448                 atomic_inc(&owner->so_count);
 449                 list_add(&state->inode_states, &nfsi->open_states);
 450                 state->inode = igrab(inode);
 451                 spin_unlock(&inode->i_lock);
 452                 /* Note: The reclaim code dictates that we add stateless
 453                  * and read-only stateids to the end of the list */
 454                 list_add_tail(&state->open_states, &owner->so_states);
 455                 spin_unlock(&owner->so_lock);
 456         } else {
 457                 spin_unlock(&inode->i_lock);
 458                 spin_unlock(&owner->so_lock);
 459                 if (new)
 460                         nfs4_free_open_state(new);
 461         }
 462 out:
 463         return state;
 464 }
 465
 466 /*
 467  * Beware! Caller must be holding exactly one
 468  * reference to clp->cl_sem!
 469  */
 470 void nfs4_put_open_state(struct nfs4_state *state)
 471 {
 472         struct inode *inode = state->inode;
 473         struct nfs4_state_owner *owner = state->owner;
 474
 475         if (!atomic_dec_and_lock(&state->count, &owner->so_lock))
 476                 return;
 477         spin_lock(&inode->i_lock);
 478         if (!list_empty(&state->inode_states))
 479                 list_del(&state->inode_states);
 480         list_del(&state->open_states);
 481         spin_unlock(&inode->i_lock);
 482         spin_unlock(&owner->so_lock);
 483         iput(inode);
 484         BUG_ON (state->state != 0);
 485         nfs4_free_open_state(state);
 486         nfs4_put_state_owner(owner);
 487 }
 488
 489 /*
 490  * Close the current file.
 491  */
 492 void nfs4_close_state(struct nfs4_state *state, mode_t mode)
 493 {
 494         struct inode *inode = state->inode;
 495         struct nfs4_state_owner *owner = state->owner;
 496         int newstate;
 497
 498         atomic_inc(&owner->so_count);
 499         /* Protect against nfs4_find_state() */
 500         spin_lock(&owner->so_lock);
 501         spin_lock(&inode->i_lock);
 502         if (mode & FMODE_READ)
 503                 state->nreaders--;
 504         if (mode & FMODE_WRITE)
 505                 state->nwriters--;
 506         if (state->nwriters == 0) {
 507                 if (state->nreaders == 0)
 508                         list_del_init(&state->inode_states);
 509                 /* See reclaim code */
 510                 list_move_tail(&state->open_states, &owner->so_states);
 511         }
 512         spin_unlock(&inode->i_lock);
 513         spin_unlock(&owner->so_lock);
 514         newstate = 0;
 515         if (state->state != 0) {
 516                 if (state->nreaders)
 517                         newstate |= FMODE_READ;
 518                 if (state->nwriters)
 519                         newstate |= FMODE_WRITE;
 520                 if (state->state == newstate)
 521                         goto out;
 522                 if (test_bit(NFS_DELEGATED_STATE, &state->flags)) {
 523                         state->state = newstate;
 524                         goto out;
 525                 }
 526                 if (nfs4_do_close(inode, state, newstate) == 0)
 527                         return;
 528         }
 529 out:
 530         nfs4_put_open_state(state);
 531         nfs4_put_state_owner(owner);
 532 }
 533
 534 /*
 535  * Search the state->lock_states for an existing lock_owner
 536  * that is compatible with current->files
 537  */
 538 static struct nfs4_lock_state *
 539 __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 540 {
 541         struct nfs4_lock_state *pos;
 542         list_for_each_entry(pos, &state->lock_states, ls_locks) {
 543                 if (pos->ls_owner != fl_owner)
 544                         continue;
 545                 atomic_inc(&pos->ls_count);
 546                 return pos;
 547         }
 548         return NULL;
 549 }
 550
 551 /*
 552  * Return a compatible lock_state. If no initialized lock_state structure
 553  * exists, return an uninitialized one.
 554  *
 555  */
 556 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 557 {
 558         struct nfs4_lock_state *lsp;
 559         struct nfs4_client *clp = state->owner->so_client;
 560
 561         lsp = kzalloc(sizeof(*lsp), GFP_KERNEL);
 562         if (lsp == NULL)
 563                 return NULL;
 564         lsp->ls_seqid.sequence = &state->owner->so_sequence;
 565         atomic_set(&lsp->ls_count, 1);
 566         lsp->ls_owner = fl_owner;
 567         spin_lock(&clp->cl_lock);
 568         lsp->ls_id = nfs4_alloc_lockowner_id(clp);
 569         spin_unlock(&clp->cl_lock);
 570         INIT_LIST_HEAD(&lsp->ls_locks);
 571         return lsp;
 572 }
 573
 574 /*
 575  * Return a compatible lock_state. If no initialized lock_state structure
 576  * exists, return an uninitialized one.
 577  *
 578  * The caller must be holding clp->cl_sem
 579  */
 580 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
 581 {
 582         struct nfs4_lock_state *lsp, *new = NULL;
 583
 584         for(;;) {
 585                 spin_lock(&state->state_lock);
 586                 lsp = __nfs4_find_lock_state(state, owner);
 587                 if (lsp != NULL)
 588                         break;
 589                 if (new != NULL) {
 590                         new->ls_state = state;
 591                         list_add(&new->ls_locks, &state->lock_states);
 592                         set_bit(LK_STATE_IN_USE, &state->flags);
 593                         lsp = new;
 594                         new = NULL;
 595                         break;
 596                 }
 597                 spin_unlock(&state->state_lock);
 598                 new = nfs4_alloc_lock_state(state, owner);
 599                 if (new == NULL)
 600                         return NULL;
 601         }
 602         spin_unlock(&state->state_lock);
 603         kfree(new);
 604         return lsp;
 605 }
 606
 607 /*
 608  * Release reference to lock_state, and free it if we see that
 609  * it is no longer in use
 610  */
 611 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
 612 {
 613         struct nfs4_state *state;
 614
 615         if (lsp == NULL)
 616                 return;
 617         state = lsp->ls_state;
 618         if (!atomic_dec_and_lock(&lsp->ls_count, &state->state_lock))
 619                 return;
 620         list_del(&lsp->ls_locks);
 621         if (list_empty(&state->lock_states))
 622                 clear_bit(LK_STATE_IN_USE, &state->flags);
 623         spin_unlock(&state->state_lock);
 624         kfree(lsp);
 625 }
 626
 627 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
 628 {
 629         struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
 630
 631         dst->fl_u.nfs4_fl.owner = lsp;
 632         atomic_inc(&lsp->ls_count);
 633 }
 634
 635 static void nfs4_fl_release_lock(struct file_lock *fl)
 636 {
 637         nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
 638 }
 639
 640 static struct file_lock_operations nfs4_fl_lock_ops = {
 641         .fl_copy_lock = nfs4_fl_copy_lock,
 642         .fl_release_private = nfs4_fl_release_lock,
 643 };
 644
 645 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
 646 {
 647         struct nfs4_lock_state *lsp;
 648
 649         if (fl->fl_ops != NULL)
 650                 return 0;
 651         lsp = nfs4_get_lock_state(state, fl->fl_owner);
 652         if (lsp == NULL)
 653                 return -ENOMEM;
 654         fl->fl_u.nfs4_fl.owner = lsp;
 655         fl->fl_ops = &nfs4_fl_lock_ops;
 656         return 0;
 657 }
 658
 659 /*
 660  * Byte-range lock aware utility to initialize the stateid of read/write
 661  * requests.
 662  */
 663 void nfs4_copy_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t fl_owner)
 664 {
 665         struct nfs4_lock_state *lsp;
 666
 667         memcpy(dst, &state->stateid, sizeof(*dst));
 668         if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
 669                 return;
 670
 671         spin_lock(&state->state_lock);
 672         lsp = __nfs4_find_lock_state(state, fl_owner);
 673         if (lsp != NULL && (lsp->ls_flags & NFS_LOCK_INITIALIZED) != 0)
 674                 memcpy(dst, &lsp->ls_stateid, sizeof(*dst));
 675         spin_unlock(&state->state_lock);
 676         nfs4_put_lock_state(lsp);
 677 }
 678
 679 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter)
 680 {
 681         struct nfs_seqid *new;
 682
 683         new = kmalloc(sizeof(*new), GFP_KERNEL);
 684         if (new != NULL) {
 685                 new->sequence = counter;
 686                 INIT_LIST_HEAD(&new->list);
 687         }
 688         return new;
 689 }
 690
 691 void nfs_free_seqid(struct nfs_seqid *seqid)
 692 {
 693         struct rpc_sequence *sequence = seqid->sequence->sequence;
 694
 695         if (!list_empty(&seqid->list)) {
 696                 spin_lock(&sequence->lock);
 697                 list_del(&seqid->list);
 698                 spin_unlock(&sequence->lock);
 699         }
 700         rpc_wake_up_next(&sequence->wait);
 701         kfree(seqid);
 702 }
 703
 704 /*
 705  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
 706  * failed with a seqid incrementing error -
 707  * see comments nfs_fs.h:seqid_mutating_error()
 708  */
 709 static inline void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
 710 {
 711         switch (status) {
 712                 case 0:
 713                         break;
 714                 case -NFS4ERR_BAD_SEQID:
 715                 case -NFS4ERR_STALE_CLIENTID:
 716                 case -NFS4ERR_STALE_STATEID:
 717                 case -NFS4ERR_BAD_STATEID:
 718                 case -NFS4ERR_BADXDR:
 719                 case -NFS4ERR_RESOURCE:
 720                 case -NFS4ERR_NOFILEHANDLE:
 721                         /* Non-seqid mutating errors */
 722                         return;
 723         };
 724         /*
 725          * Note: no locking needed as we are guaranteed to be first
 726          * on the sequence list
 727          */
 728         seqid->sequence->counter++;
 729 }
 730
 731 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
 732 {
 733         if (status == -NFS4ERR_BAD_SEQID) {
 734                 struct nfs4_state_owner *sp = container_of(seqid->sequence,
 735                                 struct nfs4_state_owner, so_seqid);
 736                 nfs4_drop_state_owner(sp);
 737         }
 738         return nfs_increment_seqid(status, seqid);
 739 }
 740
 741 /*
 742  * Increment the seqid if the LOCK/LOCKU succeeded, or
 743  * failed with a seqid incrementing error -
 744  * see comments nfs_fs.h:seqid_mutating_error()
 745  */
 746 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
 747 {
 748         return nfs_increment_seqid(status, seqid);
 749 }
 750
 751 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
 752 {
 753         struct rpc_sequence *sequence = seqid->sequence->sequence;
 754         int status = 0;
 755
 756         if (sequence->list.next == &seqid->list)
 757                 goto out;
 758         spin_lock(&sequence->lock);
 759         if (!list_empty(&sequence->list)) {
 760                 rpc_sleep_on(&sequence->wait, task, NULL, NULL);
 761                 status = -EAGAIN;
 762         } else
 763                 list_add(&seqid->list, &sequence->list);
 764         spin_unlock(&sequence->lock);
 765 out:
 766         return status;
 767 }
 768
 769 static int reclaimer(void *);
 770 struct reclaimer_args {
 771         struct nfs4_client *clp;
 772         struct completion complete;
 773 };
 774
 775 /*
 776  * State recovery routine
 777  */
 778 void
 779 nfs4_recover_state(void *data)
 780 {
 781         struct nfs4_client *clp = (struct nfs4_client *)data;
 782         struct reclaimer_args args = {
 783                 .clp = clp,
 784         };
 785         might_sleep();
 786
 787         init_completion(&args.complete);
 788
 789         if (kernel_thread(reclaimer, &args, CLONE_KERNEL) < 0)
 790                 goto out_failed_clear;
 791         wait_for_completion(&args.complete);
 792         return;
 793 out_failed_clear:
 794         set_bit(NFS4CLNT_OK, &clp->cl_state);
 795         wake_up_all(&clp->cl_waitq);
 796         rpc_wake_up(&clp->cl_rpcwaitq);
 797 }
 798
 799 /*
 800  * Schedule a state recovery attempt
 801  */
 802 void
 803 nfs4_schedule_state_recovery(struct nfs4_client *clp)
 804 {
 805         if (!clp)
 806                 return;
 807         if (test_and_clear_bit(NFS4CLNT_OK, &clp->cl_state))
 808                 schedule_work(&clp->cl_recoverd);
 809 }
 810
 811 static int nfs4_reclaim_locks(struct nfs4_state_recovery_ops *ops, struct nfs4_state *state)
 812 {
 813         struct inode *inode = state->inode;
 814         struct file_lock *fl;
 815         int status = 0;
 816
 817         for (fl = inode->i_flock; fl != 0; fl = fl->fl_next) {
 818                 if (!(fl->fl_flags & FL_POSIX))
 819                         continue;
 820                 if (((struct nfs_open_context *)fl->fl_file->private_data)->state != state)
 821                         continue;
 822                 status = ops->recover_lock(state, fl);
 823                 if (status >= 0)
 824                         continue;
 825                 switch (status) {
 826                         default:
 827                                 printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
 828                                                 __FUNCTION__, status);
 829                         case -NFS4ERR_EXPIRED:
 830                         case -NFS4ERR_NO_GRACE:
 831                         case -NFS4ERR_RECLAIM_BAD:
 832                         case -NFS4ERR_RECLAIM_CONFLICT:
 833                                 /* kill_proc(fl->fl_owner, SIGLOST, 1); */
 834                                 break;
 835                         case -NFS4ERR_STALE_CLIENTID:
 836                                 goto out_err;
 837                 }
 838         }
 839         return 0;
 840 out_err:
 841         return status;
 842 }
 843
 844 static int nfs4_reclaim_open_state(struct nfs4_state_recovery_ops *ops, struct nfs4_state_owner *sp)
 845 {
 846         struct nfs4_state *state;
 847         struct nfs4_lock_state *lock;
 848         int status = 0;
 849
 850         /* Note: we rely on the sp->so_states list being ordered
 851          * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
 852          * states first.
 853          * This is needed to ensure that the server won't give us any
 854          * read delegations that we have to return if, say, we are
 855          * recovering after a network partition or a reboot from a
 856          * server that doesn't support a grace period.
 857          */
 858         list_for_each_entry(state, &sp->so_states, open_states) {
 859                 if (state->state == 0)
 860                         continue;
 861                 status = ops->recover_open(sp, state);
 862                 if (status >= 0) {
 863                         status = nfs4_reclaim_locks(ops, state);
 864                         if (status < 0)
 865                                 goto out_err;
 866                         list_for_each_entry(lock, &state->lock_states, ls_locks) {
 867                                 if (!(lock->ls_flags & NFS_LOCK_INITIALIZED))
 868                                         printk("%s: Lock reclaim failed!\n",
 869                                                         __FUNCTION__);
 870                         }
 871                         continue;
 872                 }
 873                 switch (status) {
 874                         default:
 875                                 printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
 876                                                 __FUNCTION__, status);
 877                         case -ENOENT:
 878                         case -NFS4ERR_RECLAIM_BAD:
 879                         case -NFS4ERR_RECLAIM_CONFLICT:
 880                                 /*
 881                                  * Open state on this file cannot be recovered
 882                                  * All we can do is revert to using the zero stateid.
 883                                  */
 884                                 memset(state->stateid.data, 0,
 885                                         sizeof(state->stateid.data));
 886                                 /* Mark the file as being 'closed' */
 887                                 state->state = 0;
 888                                 break;
 889                         case -NFS4ERR_EXPIRED:
 890                         case -NFS4ERR_NO_GRACE:
 891                         case -NFS4ERR_STALE_CLIENTID:
 892                                 goto out_err;
 893                 }
 894         }
 895         return 0;
 896 out_err:
 897         return status;
 898 }
 899
 900 static void nfs4_state_mark_reclaim(struct nfs4_client *clp)
 901 {
 902         struct nfs4_state_owner *sp;
 903         struct nfs4_state *state;
 904         struct nfs4_lock_state *lock;
 905
 906         /* Reset all sequence ids to zero */
 907         list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
 908                 sp->so_seqid.counter = 0;
 909                 sp->so_seqid.flags = 0;
 910                 spin_lock(&sp->so_lock);
 911                 list_for_each_entry(state, &sp->so_states, open_states) {
 912                         list_for_each_entry(lock, &state->lock_states, ls_locks) {
 913                                 lock->ls_seqid.counter = 0;
 914                                 lock->ls_seqid.flags = 0;
 915                                 lock->ls_flags &= ~NFS_LOCK_INITIALIZED;
 916                         }
 917                 }
 918                 spin_unlock(&sp->so_lock);
 919         }
 920 }
 921
 922 static int reclaimer(void *ptr)
 923 {
 924         struct reclaimer_args *args = (struct reclaimer_args *)ptr;
 925         struct nfs4_client *clp = args->clp;
 926         struct nfs4_state_owner *sp;
 927         struct nfs4_state_recovery_ops *ops;
 928         int status = 0;
 929
 930         daemonize("%u.%u.%u.%u-reclaim", NIPQUAD(clp->cl_addr));
 931         allow_signal(SIGKILL);
 932
 933         atomic_inc(&clp->cl_count);
 934         complete(&args->complete);
 935
 936         /* Ensure exclusive access to NFSv4 state */
 937         lock_kernel();
 938         down_write(&clp->cl_sem);
 939         /* Are there any NFS mounts out there? */
 940         if (list_empty(&clp->cl_superblocks))
 941                 goto out;
 942 restart_loop:
 943         status = nfs4_proc_renew(clp);
 944         switch (status) {
 945                 case 0:
 946                 case -NFS4ERR_CB_PATH_DOWN:
 947                         goto out;
 948                 case -NFS4ERR_STALE_CLIENTID:
 949                 case -NFS4ERR_LEASE_MOVED:
 950                         ops = &nfs4_reboot_recovery_ops;
 951                         break;
 952                 default:
 953                         ops = &nfs4_network_partition_recovery_ops;
 954         };
 955         nfs4_state_mark_reclaim(clp);
 956         status = __nfs4_init_client(clp);
 957         if (status)
 958                 goto out_error;
 959         /* Mark all delegations for reclaim */
 960         nfs_delegation_mark_reclaim(clp);
 961         /* Note: list is protected by exclusive lock on cl->cl_sem */
 962         list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
 963                 status = nfs4_reclaim_open_state(ops, sp);
 964                 if (status < 0) {
 965                         if (status == -NFS4ERR_NO_GRACE) {
 966                                 ops = &nfs4_network_partition_recovery_ops;
 967                                 status = nfs4_reclaim_open_state(ops, sp);
 968                         }
 969                         if (status == -NFS4ERR_STALE_CLIENTID)
 970                                 goto restart_loop;
 971                         if (status == -NFS4ERR_EXPIRED)
 972                                 goto restart_loop;
 973                 }
 974         }
 975         nfs_delegation_reap_unclaimed(clp);
 976 out:
 977         set_bit(NFS4CLNT_OK, &clp->cl_state);
 978         up_write(&clp->cl_sem);
 979         unlock_kernel();
 980         wake_up_all(&clp->cl_waitq);
 981         rpc_wake_up(&clp->cl_rpcwaitq);
 982         if (status == -NFS4ERR_CB_PATH_DOWN)
 983                 nfs_handle_cb_pathdown(clp);
 984         nfs4_put_client(clp);
 985         return 0;
 986 out_error:
 987         printk(KERN_WARNING "Error: state recovery failed on NFSv4 server %u.%u.%u.%u with error %d\n",
 988                                 NIPQUAD(clp->cl_addr.s_addr), -status);
 989         goto out;
 990 }
 991
 992 /*
 993  * Local variables:
 994  *  c-basic-offset: 8
 995  * End:
 996  */