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   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 void
 370 nfs4_state_set_mode_locked(struct nfs4_state *state, mode_t mode)
 371 {
 372         if (state->state == mode)
 373                 return;
 374         /* NB! List reordering - see the reclaim code for why.  */
 375         if ((mode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
 376                 if (mode & FMODE_WRITE)
 377                         list_move(&state->open_states, &state->owner->so_states);
 378                 else
 379                         list_move_tail(&state->open_states, &state->owner->so_states);
 380         }
 381         if (mode == 0)
 382                 list_del_init(&state->inode_states);
 383         state->state = mode;
 384 }
 385
 386 static struct nfs4_state *
 387 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
 388 {
 389         struct nfs_inode *nfsi = NFS_I(inode);
 390         struct nfs4_state *state;
 391
 392         list_for_each_entry(state, &nfsi->open_states, inode_states) {
 393                 /* Is this in the process of being freed? */
 394                 if (state->state == 0)
 395                         continue;
 396                 if (state->owner == owner) {
 397                         atomic_inc(&state->count);
 398                         return state;
 399                 }
 400         }
 401         return NULL;
 402 }
 403
 404 static void
 405 nfs4_free_open_state(struct nfs4_state *state)
 406 {
 407         kfree(state);
 408 }
 409
 410 struct nfs4_state *
 411 nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
 412 {
 413         struct nfs4_state *state, *new;
 414         struct nfs_inode *nfsi = NFS_I(inode);
 415
 416         spin_lock(&inode->i_lock);
 417         state = __nfs4_find_state_byowner(inode, owner);
 418         spin_unlock(&inode->i_lock);
 419         if (state)
 420                 goto out;
 421         new = nfs4_alloc_open_state();
 422         spin_lock(&owner->so_lock);
 423         spin_lock(&inode->i_lock);
 424         state = __nfs4_find_state_byowner(inode, owner);
 425         if (state == NULL && new != NULL) {
 426                 state = new;
 427                 state->owner = owner;
 428                 atomic_inc(&owner->so_count);
 429                 list_add(&state->inode_states, &nfsi->open_states);
 430                 state->inode = igrab(inode);
 431                 spin_unlock(&inode->i_lock);
 432                 /* Note: The reclaim code dictates that we add stateless
 433                  * and read-only stateids to the end of the list */
 434                 list_add_tail(&state->open_states, &owner->so_states);
 435                 spin_unlock(&owner->so_lock);
 436         } else {
 437                 spin_unlock(&inode->i_lock);
 438                 spin_unlock(&owner->so_lock);
 439                 if (new)
 440                         nfs4_free_open_state(new);
 441         }
 442 out:
 443         return state;
 444 }
 445
 446 /*
 447  * Beware! Caller must be holding exactly one
 448  * reference to clp->cl_sem!
 449  */
 450 void nfs4_put_open_state(struct nfs4_state *state)
 451 {
 452         struct inode *inode = state->inode;
 453         struct nfs4_state_owner *owner = state->owner;
 454
 455         if (!atomic_dec_and_lock(&state->count, &owner->so_lock))
 456                 return;
 457         spin_lock(&inode->i_lock);
 458         if (!list_empty(&state->inode_states))
 459                 list_del(&state->inode_states);
 460         list_del(&state->open_states);
 461         spin_unlock(&inode->i_lock);
 462         spin_unlock(&owner->so_lock);
 463         iput(inode);
 464         nfs4_free_open_state(state);
 465         nfs4_put_state_owner(owner);
 466 }
 467
 468 /*
 469  * Close the current file.
 470  */
 471 void nfs4_close_state(struct nfs4_state *state, mode_t mode)
 472 {
 473         struct inode *inode = state->inode;
 474         struct nfs4_state_owner *owner = state->owner;
 475         int oldstate, newstate = 0;
 476
 477         atomic_inc(&owner->so_count);
 478         /* Protect against nfs4_find_state() */
 479         spin_lock(&owner->so_lock);
 480         spin_lock(&inode->i_lock);
 481         if (mode & FMODE_READ)
 482                 state->nreaders--;
 483         if (mode & FMODE_WRITE)
 484                 state->nwriters--;
 485         oldstate = newstate = state->state;
 486         if (state->nreaders == 0)
 487                 newstate &= ~FMODE_READ;
 488         if (state->nwriters == 0)
 489                 newstate &= ~FMODE_WRITE;
 490         if (test_bit(NFS_DELEGATED_STATE, &state->flags)) {
 491                 nfs4_state_set_mode_locked(state, newstate);
 492                 oldstate = newstate;
 493         }
 494         spin_unlock(&inode->i_lock);
 495         spin_unlock(&owner->so_lock);
 496
 497         if (oldstate != newstate && nfs4_do_close(inode, state) == 0)
 498                 return;
 499         nfs4_put_open_state(state);
 500         nfs4_put_state_owner(owner);
 501 }
 502
 503 /*
 504  * Search the state->lock_states for an existing lock_owner
 505  * that is compatible with current->files
 506  */
 507 static struct nfs4_lock_state *
 508 __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 509 {
 510         struct nfs4_lock_state *pos;
 511         list_for_each_entry(pos, &state->lock_states, ls_locks) {
 512                 if (pos->ls_owner != fl_owner)
 513                         continue;
 514                 atomic_inc(&pos->ls_count);
 515                 return pos;
 516         }
 517         return NULL;
 518 }
 519
 520 /*
 521  * Return a compatible lock_state. If no initialized lock_state structure
 522  * exists, return an uninitialized one.
 523  *
 524  */
 525 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
 526 {
 527         struct nfs4_lock_state *lsp;
 528         struct nfs4_client *clp = state->owner->so_client;
 529
 530         lsp = kzalloc(sizeof(*lsp), GFP_KERNEL);
 531         if (lsp == NULL)
 532                 return NULL;
 533         lsp->ls_seqid.sequence = &state->owner->so_sequence;
 534         atomic_set(&lsp->ls_count, 1);
 535         lsp->ls_owner = fl_owner;
 536         spin_lock(&clp->cl_lock);
 537         lsp->ls_id = nfs4_alloc_lockowner_id(clp);
 538         spin_unlock(&clp->cl_lock);
 539         INIT_LIST_HEAD(&lsp->ls_locks);
 540         return lsp;
 541 }
 542
 543 /*
 544  * Return a compatible lock_state. If no initialized lock_state structure
 545  * exists, return an uninitialized one.
 546  *
 547  * The caller must be holding clp->cl_sem
 548  */
 549 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
 550 {
 551         struct nfs4_lock_state *lsp, *new = NULL;
 552
 553         for(;;) {
 554                 spin_lock(&state->state_lock);
 555                 lsp = __nfs4_find_lock_state(state, owner);
 556                 if (lsp != NULL)
 557                         break;
 558                 if (new != NULL) {
 559                         new->ls_state = state;
 560                         list_add(&new->ls_locks, &state->lock_states);
 561                         set_bit(LK_STATE_IN_USE, &state->flags);
 562                         lsp = new;
 563                         new = NULL;
 564                         break;
 565                 }
 566                 spin_unlock(&state->state_lock);
 567                 new = nfs4_alloc_lock_state(state, owner);
 568                 if (new == NULL)
 569                         return NULL;
 570         }
 571         spin_unlock(&state->state_lock);
 572         kfree(new);
 573         return lsp;
 574 }
 575
 576 /*
 577  * Release reference to lock_state, and free it if we see that
 578  * it is no longer in use
 579  */
 580 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
 581 {
 582         struct nfs4_state *state;
 583
 584         if (lsp == NULL)
 585                 return;
 586         state = lsp->ls_state;
 587         if (!atomic_dec_and_lock(&lsp->ls_count, &state->state_lock))
 588                 return;
 589         list_del(&lsp->ls_locks);
 590         if (list_empty(&state->lock_states))
 591                 clear_bit(LK_STATE_IN_USE, &state->flags);
 592         spin_unlock(&state->state_lock);
 593         kfree(lsp);
 594 }
 595
 596 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
 597 {
 598         struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
 599
 600         dst->fl_u.nfs4_fl.owner = lsp;
 601         atomic_inc(&lsp->ls_count);
 602 }
 603
 604 static void nfs4_fl_release_lock(struct file_lock *fl)
 605 {
 606         nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
 607 }
 608
 609 static struct file_lock_operations nfs4_fl_lock_ops = {
 610         .fl_copy_lock = nfs4_fl_copy_lock,
 611         .fl_release_private = nfs4_fl_release_lock,
 612 };
 613
 614 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
 615 {
 616         struct nfs4_lock_state *lsp;
 617
 618         if (fl->fl_ops != NULL)
 619                 return 0;
 620         lsp = nfs4_get_lock_state(state, fl->fl_owner);
 621         if (lsp == NULL)
 622                 return -ENOMEM;
 623         fl->fl_u.nfs4_fl.owner = lsp;
 624         fl->fl_ops = &nfs4_fl_lock_ops;
 625         return 0;
 626 }
 627
 628 /*
 629  * Byte-range lock aware utility to initialize the stateid of read/write
 630  * requests.
 631  */
 632 void nfs4_copy_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t fl_owner)
 633 {
 634         struct nfs4_lock_state *lsp;
 635
 636         memcpy(dst, &state->stateid, sizeof(*dst));
 637         if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
 638                 return;
 639
 640         spin_lock(&state->state_lock);
 641         lsp = __nfs4_find_lock_state(state, fl_owner);
 642         if (lsp != NULL && (lsp->ls_flags & NFS_LOCK_INITIALIZED) != 0)
 643                 memcpy(dst, &lsp->ls_stateid, sizeof(*dst));
 644         spin_unlock(&state->state_lock);
 645         nfs4_put_lock_state(lsp);
 646 }
 647
 648 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter)
 649 {
 650         struct nfs_seqid *new;
 651
 652         new = kmalloc(sizeof(*new), GFP_KERNEL);
 653         if (new != NULL) {
 654                 new->sequence = counter;
 655                 INIT_LIST_HEAD(&new->list);
 656         }
 657         return new;
 658 }
 659
 660 void nfs_free_seqid(struct nfs_seqid *seqid)
 661 {
 662         struct rpc_sequence *sequence = seqid->sequence->sequence;
 663
 664         if (!list_empty(&seqid->list)) {
 665                 spin_lock(&sequence->lock);
 666                 list_del(&seqid->list);
 667                 spin_unlock(&sequence->lock);
 668         }
 669         rpc_wake_up_next(&sequence->wait);
 670         kfree(seqid);
 671 }
 672
 673 /*
 674  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
 675  * failed with a seqid incrementing error -
 676  * see comments nfs_fs.h:seqid_mutating_error()
 677  */
 678 static inline void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
 679 {
 680         switch (status) {
 681                 case 0:
 682                         break;
 683                 case -NFS4ERR_BAD_SEQID:
 684                 case -NFS4ERR_STALE_CLIENTID:
 685                 case -NFS4ERR_STALE_STATEID:
 686                 case -NFS4ERR_BAD_STATEID:
 687                 case -NFS4ERR_BADXDR:
 688                 case -NFS4ERR_RESOURCE:
 689                 case -NFS4ERR_NOFILEHANDLE:
 690                         /* Non-seqid mutating errors */
 691                         return;
 692         };
 693         /*
 694          * Note: no locking needed as we are guaranteed to be first
 695          * on the sequence list
 696          */
 697         seqid->sequence->counter++;
 698 }
 699
 700 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
 701 {
 702         if (status == -NFS4ERR_BAD_SEQID) {
 703                 struct nfs4_state_owner *sp = container_of(seqid->sequence,
 704                                 struct nfs4_state_owner, so_seqid);
 705                 nfs4_drop_state_owner(sp);
 706         }
 707         return nfs_increment_seqid(status, seqid);
 708 }
 709
 710 /*
 711  * Increment the seqid if the LOCK/LOCKU succeeded, or
 712  * failed with a seqid incrementing error -
 713  * see comments nfs_fs.h:seqid_mutating_error()
 714  */
 715 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
 716 {
 717         return nfs_increment_seqid(status, seqid);
 718 }
 719
 720 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
 721 {
 722         struct rpc_sequence *sequence = seqid->sequence->sequence;
 723         int status = 0;
 724
 725         if (sequence->list.next == &seqid->list)
 726                 goto out;
 727         spin_lock(&sequence->lock);
 728         if (!list_empty(&sequence->list)) {
 729                 rpc_sleep_on(&sequence->wait, task, NULL, NULL);
 730                 status = -EAGAIN;
 731         } else
 732                 list_add(&seqid->list, &sequence->list);
 733         spin_unlock(&sequence->lock);
 734 out:
 735         return status;
 736 }
 737
 738 static int reclaimer(void *);
 739 struct reclaimer_args {
 740         struct nfs4_client *clp;
 741         struct completion complete;
 742 };
 743
 744 /*
 745  * State recovery routine
 746  */
 747 void
 748 nfs4_recover_state(void *data)
 749 {
 750         struct nfs4_client *clp = (struct nfs4_client *)data;
 751         struct reclaimer_args args = {
 752                 .clp = clp,
 753         };
 754         might_sleep();
 755
 756         init_completion(&args.complete);
 757
 758         if (kernel_thread(reclaimer, &args, CLONE_KERNEL) < 0)
 759                 goto out_failed_clear;
 760         wait_for_completion(&args.complete);
 761         return;
 762 out_failed_clear:
 763         set_bit(NFS4CLNT_OK, &clp->cl_state);
 764         wake_up_all(&clp->cl_waitq);
 765         rpc_wake_up(&clp->cl_rpcwaitq);
 766 }
 767
 768 /*
 769  * Schedule a state recovery attempt
 770  */
 771 void
 772 nfs4_schedule_state_recovery(struct nfs4_client *clp)
 773 {
 774         if (!clp)
 775                 return;
 776         if (test_and_clear_bit(NFS4CLNT_OK, &clp->cl_state))
 777                 schedule_work(&clp->cl_recoverd);
 778 }
 779
 780 static int nfs4_reclaim_locks(struct nfs4_state_recovery_ops *ops, struct nfs4_state *state)
 781 {
 782         struct inode *inode = state->inode;
 783         struct file_lock *fl;
 784         int status = 0;
 785
 786         for (fl = inode->i_flock; fl != 0; fl = fl->fl_next) {
 787                 if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
 788                         continue;
 789                 if (((struct nfs_open_context *)fl->fl_file->private_data)->state != state)
 790                         continue;
 791                 status = ops->recover_lock(state, fl);
 792                 if (status >= 0)
 793                         continue;
 794                 switch (status) {
 795                         default:
 796                                 printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
 797                                                 __FUNCTION__, status);
 798                         case -NFS4ERR_EXPIRED:
 799                         case -NFS4ERR_NO_GRACE:
 800                         case -NFS4ERR_RECLAIM_BAD:
 801                         case -NFS4ERR_RECLAIM_CONFLICT:
 802                                 /* kill_proc(fl->fl_pid, SIGLOST, 1); */
 803                                 break;
 804                         case -NFS4ERR_STALE_CLIENTID:
 805                                 goto out_err;
 806                 }
 807         }
 808         return 0;
 809 out_err:
 810         return status;
 811 }
 812
 813 static int nfs4_reclaim_open_state(struct nfs4_state_recovery_ops *ops, struct nfs4_state_owner *sp)
 814 {
 815         struct nfs4_state *state;
 816         struct nfs4_lock_state *lock;
 817         int status = 0;
 818
 819         /* Note: we rely on the sp->so_states list being ordered
 820          * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
 821          * states first.
 822          * This is needed to ensure that the server won't give us any
 823          * read delegations that we have to return if, say, we are
 824          * recovering after a network partition or a reboot from a
 825          * server that doesn't support a grace period.
 826          */
 827         list_for_each_entry(state, &sp->so_states, open_states) {
 828                 if (state->state == 0)
 829                         continue;
 830                 status = ops->recover_open(sp, state);
 831                 if (status >= 0) {
 832                         status = nfs4_reclaim_locks(ops, state);
 833                         if (status < 0)
 834                                 goto out_err;
 835                         list_for_each_entry(lock, &state->lock_states, ls_locks) {
 836                                 if (!(lock->ls_flags & NFS_LOCK_INITIALIZED))
 837                                         printk("%s: Lock reclaim failed!\n",
 838                                                         __FUNCTION__);
 839                         }
 840                         continue;
 841                 }
 842                 switch (status) {
 843                         default:
 844                                 printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
 845                                                 __FUNCTION__, status);
 846                         case -ENOENT:
 847                         case -NFS4ERR_RECLAIM_BAD:
 848                         case -NFS4ERR_RECLAIM_CONFLICT:
 849                                 /*
 850                                  * Open state on this file cannot be recovered
 851                                  * All we can do is revert to using the zero stateid.
 852                                  */
 853                                 memset(state->stateid.data, 0,
 854                                         sizeof(state->stateid.data));
 855                                 /* Mark the file as being 'closed' */
 856                                 state->state = 0;
 857                                 break;
 858                         case -NFS4ERR_EXPIRED:
 859                         case -NFS4ERR_NO_GRACE:
 860                         case -NFS4ERR_STALE_CLIENTID:
 861                                 goto out_err;
 862                 }
 863         }
 864         return 0;
 865 out_err:
 866         return status;
 867 }
 868
 869 static void nfs4_state_mark_reclaim(struct nfs4_client *clp)
 870 {
 871         struct nfs4_state_owner *sp;
 872         struct nfs4_state *state;
 873         struct nfs4_lock_state *lock;
 874
 875         /* Reset all sequence ids to zero */
 876         list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
 877                 sp->so_seqid.counter = 0;
 878                 sp->so_seqid.flags = 0;
 879                 spin_lock(&sp->so_lock);
 880                 list_for_each_entry(state, &sp->so_states, open_states) {
 881                         list_for_each_entry(lock, &state->lock_states, ls_locks) {
 882                                 lock->ls_seqid.counter = 0;
 883                                 lock->ls_seqid.flags = 0;
 884                                 lock->ls_flags &= ~NFS_LOCK_INITIALIZED;
 885                         }
 886                 }
 887                 spin_unlock(&sp->so_lock);
 888         }
 889 }
 890
 891 static int reclaimer(void *ptr)
 892 {
 893         struct reclaimer_args *args = (struct reclaimer_args *)ptr;
 894         struct nfs4_client *clp = args->clp;
 895         struct nfs4_state_owner *sp;
 896         struct nfs4_state_recovery_ops *ops;
 897         int status = 0;
 898
 899         daemonize("%u.%u.%u.%u-reclaim", NIPQUAD(clp->cl_addr));
 900         allow_signal(SIGKILL);
 901
 902         atomic_inc(&clp->cl_count);
 903         complete(&args->complete);
 904
 905         /* Ensure exclusive access to NFSv4 state */
 906         lock_kernel();
 907         down_write(&clp->cl_sem);
 908         /* Are there any NFS mounts out there? */
 909         if (list_empty(&clp->cl_superblocks))
 910                 goto out;
 911 restart_loop:
 912         status = nfs4_proc_renew(clp);
 913         switch (status) {
 914                 case 0:
 915                 case -NFS4ERR_CB_PATH_DOWN:
 916                         goto out;
 917                 case -NFS4ERR_STALE_CLIENTID:
 918                 case -NFS4ERR_LEASE_MOVED:
 919                         ops = &nfs4_reboot_recovery_ops;
 920                         break;
 921                 default:
 922                         ops = &nfs4_network_partition_recovery_ops;
 923         };
 924         nfs4_state_mark_reclaim(clp);
 925         status = __nfs4_init_client(clp);
 926         if (status)
 927                 goto out_error;
 928         /* Mark all delegations for reclaim */
 929         nfs_delegation_mark_reclaim(clp);
 930         /* Note: list is protected by exclusive lock on cl->cl_sem */
 931         list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
 932                 status = nfs4_reclaim_open_state(ops, sp);
 933                 if (status < 0) {
 934                         if (status == -NFS4ERR_NO_GRACE) {
 935                                 ops = &nfs4_network_partition_recovery_ops;
 936                                 status = nfs4_reclaim_open_state(ops, sp);
 937                         }
 938                         if (status == -NFS4ERR_STALE_CLIENTID)
 939                                 goto restart_loop;
 940                         if (status == -NFS4ERR_EXPIRED)
 941                                 goto restart_loop;
 942                 }
 943         }
 944         nfs_delegation_reap_unclaimed(clp);
 945 out:
 946         set_bit(NFS4CLNT_OK, &clp->cl_state);
 947         up_write(&clp->cl_sem);
 948         unlock_kernel();
 949         wake_up_all(&clp->cl_waitq);
 950         rpc_wake_up(&clp->cl_rpcwaitq);
 951         if (status == -NFS4ERR_CB_PATH_DOWN)
 952                 nfs_handle_cb_pathdown(clp);
 953         nfs4_put_client(clp);
 954         return 0;
 955 out_error:
 956         printk(KERN_WARNING "Error: state recovery failed on NFSv4 server %u.%u.%u.%u with error %d\n",
 957                                 NIPQUAD(clp->cl_addr.s_addr), -status);
 958         goto out;
 959 }
 960
 961 /*
 962  * Local variables:
 963  *  c-basic-offset: 8
 964  * End:
 965  */