drivers/staging/lustre/lustre/ldlm/ldlm_flock.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2003 Hewlett-Packard Development Company LP.
  24  * Developed under the sponsorship of the US Government under
  25  * Subcontract No. B514193
  26  *
  27  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
  28  * Use is subject to license terms.
  29  *
  30  * Copyright (c) 2010, 2012, Intel Corporation.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  */
  36
  37 /**
  38  * This file implements POSIX lock type for Lustre.
  39  * Its policy properties are start and end of extent and PID.
  40  *
  41  * These locks are only done through MDS due to POSIX semantics requiring
  42  * e.g. that locks could be only partially released and as such split into
  43  * two parts, and also that two adjacent locks from the same process may be
  44  * merged into a single wider lock.
  45  *
  46  * Lock modes are mapped like this:
  47  * PR and PW for READ and WRITE locks
  48  * NL to request a releasing of a portion of the lock
  49  *
  50  * These flock locks never timeout.
  51  */
  52
  53 #define DEBUG_SUBSYSTEM S_LDLM
  54
  55 #include "../include/lustre_dlm.h"
  56 #include "../include/obd_support.h"
  57 #include "../include/obd_class.h"
  58 #include "../include/lustre_lib.h"
  59 #include <linux/list.h>
  60 #include "ldlm_internal.h"
  61
  62 /**
  63  * list_for_remaining_safe - iterate over the remaining entries in a list
  64  *            and safeguard against removal of a list entry.
  65  * \param pos   the &struct list_head to use as a loop counter. pos MUST
  66  *            have been initialized prior to using it in this macro.
  67  * \param n     another &struct list_head to use as temporary storage
  68  * \param head  the head for your list.
  69  */
  70 #define list_for_remaining_safe(pos, n, head) \
  71         for (n = pos->next; pos != (head); pos = n, n = pos->next)
  72
  73 static inline int
  74 ldlm_same_flock_owner(struct ldlm_lock *lock, struct ldlm_lock *new)
  75 {
  76         return((new->l_policy_data.l_flock.owner ==
  77                 lock->l_policy_data.l_flock.owner) &&
  78                (new->l_export == lock->l_export));
  79 }
  80
  81 static inline int
  82 ldlm_flocks_overlap(struct ldlm_lock *lock, struct ldlm_lock *new)
  83 {
  84         return((new->l_policy_data.l_flock.start <=
  85                 lock->l_policy_data.l_flock.end) &&
  86                (new->l_policy_data.l_flock.end >=
  87                 lock->l_policy_data.l_flock.start));
  88 }
  89
  90 static inline void
  91 ldlm_flock_destroy(struct ldlm_lock *lock, enum ldlm_mode mode, __u64 flags)
  92 {
  93         LDLM_DEBUG(lock, "ldlm_flock_destroy(mode: %d, flags: 0x%llx)",
  94                    mode, flags);
  95
  96         /* Safe to not lock here, since it should be empty anyway */
  97         LASSERT(hlist_unhashed(&lock->l_exp_flock_hash));
  98
  99         list_del_init(&lock->l_res_link);
 100         if (flags == LDLM_FL_WAIT_NOREPROC && !ldlm_is_failed(lock)) {
 101                 /* client side - set a flag to prevent sending a CANCEL */
 102                 lock->l_flags |= LDLM_FL_LOCAL_ONLY | LDLM_FL_CBPENDING;
 103
 104                 /* when reaching here, it is under lock_res_and_lock(). Thus,
 105                  * need call the nolock version of ldlm_lock_decref_internal
 106                  */
 107                 ldlm_lock_decref_internal_nolock(lock, mode);
 108         }
 109
 110         ldlm_lock_destroy_nolock(lock);
 111 }
 112
 113 /**
 114  * Process a granting attempt for flock lock.
 115  * Must be called under ns lock held.
 116  *
 117  * This function looks for any conflicts for \a lock in the granted or
 118  * waiting queues. The lock is granted if no conflicts are found in
 119  * either queue.
 120  *
 121  * It is also responsible for splitting a lock if a portion of the lock
 122  * is released.
 123  *
 124  * If \a first_enq is 0 (ie, called from ldlm_reprocess_queue):
 125  *   - blocking ASTs have already been sent
 126  *
 127  * If \a first_enq is 1 (ie, called from ldlm_lock_enqueue):
 128  *   - blocking ASTs have not been sent yet, so list of conflicting locks
 129  *     would be collected and ASTs sent.
 130  */
 131 static int ldlm_process_flock_lock(struct ldlm_lock *req, __u64 *flags,
 132                                    int first_enq, enum ldlm_error *err,
 133                                    struct list_head *work_list)
 134 {
 135         struct ldlm_resource *res = req->l_resource;
 136         struct ldlm_namespace *ns = ldlm_res_to_ns(res);
 137         struct list_head *tmp;
 138         struct list_head *ownlocks = NULL;
 139         struct ldlm_lock *lock = NULL;
 140         struct ldlm_lock *new = req;
 141         struct ldlm_lock *new2 = NULL;
 142         enum ldlm_mode mode = req->l_req_mode;
 143         int added = (mode == LCK_NL);
 144         int overlaps = 0;
 145         int splitted = 0;
 146         const struct ldlm_callback_suite null_cbs = { NULL };
 147
 148         CDEBUG(D_DLMTRACE,
 149                "flags %#llx owner %llu pid %u mode %u start %llu end %llu\n",
 150                *flags, new->l_policy_data.l_flock.owner,
 151                new->l_policy_data.l_flock.pid, mode,
 152                req->l_policy_data.l_flock.start,
 153                req->l_policy_data.l_flock.end);
 154
 155         *err = ELDLM_OK;
 156
 157         /* No blocking ASTs are sent to the clients for
 158          * Posix file & record locks
 159          */
 160         req->l_blocking_ast = NULL;
 161
 162 reprocess:
 163         if ((*flags == LDLM_FL_WAIT_NOREPROC) || (mode == LCK_NL)) {
 164                 /* This loop determines where this processes locks start
 165                  * in the resource lr_granted list.
 166                  */
 167                 list_for_each(tmp, &res->lr_granted) {
 168                         lock = list_entry(tmp, struct ldlm_lock,
 169                                               l_res_link);
 170                         if (ldlm_same_flock_owner(lock, req)) {
 171                                 ownlocks = tmp;
 172                                 break;
 173                         }
 174                 }
 175         } else {
 176                 int reprocess_failed = 0;
 177
 178                 lockmode_verify(mode);
 179
 180                 /* This loop determines if there are existing locks
 181                  * that conflict with the new lock request.
 182                  */
 183                 list_for_each(tmp, &res->lr_granted) {
 184                         lock = list_entry(tmp, struct ldlm_lock,
 185                                               l_res_link);
 186
 187                         if (ldlm_same_flock_owner(lock, req)) {
 188                                 if (!ownlocks)
 189                                         ownlocks = tmp;
 190                                 continue;
 191                         }
 192
 193                         /* locks are compatible, overlap doesn't matter */
 194                         if (lockmode_compat(lock->l_granted_mode, mode))
 195                                 continue;
 196
 197                         if (!ldlm_flocks_overlap(lock, req))
 198                                 continue;
 199
 200                         if (!first_enq) {
 201                                 reprocess_failed = 1;
 202                                 continue;
 203                         }
 204
 205                         if (*flags & LDLM_FL_BLOCK_NOWAIT) {
 206                                 ldlm_flock_destroy(req, mode, *flags);
 207                                 *err = -EAGAIN;
 208                                 return LDLM_ITER_STOP;
 209                         }
 210
 211                         if (*flags & LDLM_FL_TEST_LOCK) {
 212                                 ldlm_flock_destroy(req, mode, *flags);
 213                                 req->l_req_mode = lock->l_granted_mode;
 214                                 req->l_policy_data.l_flock.pid =
 215                                         lock->l_policy_data.l_flock.pid;
 216                                 req->l_policy_data.l_flock.start =
 217                                         lock->l_policy_data.l_flock.start;
 218                                 req->l_policy_data.l_flock.end =
 219                                         lock->l_policy_data.l_flock.end;
 220                                 *flags |= LDLM_FL_LOCK_CHANGED;
 221                                 return LDLM_ITER_STOP;
 222                         }
 223
 224                         ldlm_resource_add_lock(res, &res->lr_waiting, req);
 225                         *flags |= LDLM_FL_BLOCK_GRANTED;
 226                         return LDLM_ITER_STOP;
 227                 }
 228                 if (reprocess_failed)
 229                         return LDLM_ITER_CONTINUE;
 230         }
 231
 232         if (*flags & LDLM_FL_TEST_LOCK) {
 233                 ldlm_flock_destroy(req, mode, *flags);
 234                 req->l_req_mode = LCK_NL;
 235                 *flags |= LDLM_FL_LOCK_CHANGED;
 236                 return LDLM_ITER_STOP;
 237         }
 238
 239         /* Scan the locks owned by this process that overlap this request.
 240          * We may have to merge or split existing locks.
 241          */
 242         if (!ownlocks)
 243                 ownlocks = &res->lr_granted;
 244
 245         list_for_remaining_safe(ownlocks, tmp, &res->lr_granted) {
 246                 lock = list_entry(ownlocks, struct ldlm_lock, l_res_link);
 247
 248                 if (!ldlm_same_flock_owner(lock, new))
 249                         break;
 250
 251                 if (lock->l_granted_mode == mode) {
 252                         /* If the modes are the same then we need to process
 253                          * locks that overlap OR adjoin the new lock. The extra
 254                          * logic condition is necessary to deal with arithmetic
 255                          * overflow and underflow.
 256                          */
 257                         if ((new->l_policy_data.l_flock.start >
 258                              (lock->l_policy_data.l_flock.end + 1)) &&
 259                             (lock->l_policy_data.l_flock.end != OBD_OBJECT_EOF))
 260                                 continue;
 261
 262                         if ((new->l_policy_data.l_flock.end <
 263                              (lock->l_policy_data.l_flock.start - 1)) &&
 264                             (lock->l_policy_data.l_flock.start != 0))
 265                                 break;
 266
 267                         if (new->l_policy_data.l_flock.start <
 268                             lock->l_policy_data.l_flock.start) {
 269                                 lock->l_policy_data.l_flock.start =
 270                                         new->l_policy_data.l_flock.start;
 271                         } else {
 272                                 new->l_policy_data.l_flock.start =
 273                                         lock->l_policy_data.l_flock.start;
 274                         }
 275
 276                         if (new->l_policy_data.l_flock.end >
 277                             lock->l_policy_data.l_flock.end) {
 278                                 lock->l_policy_data.l_flock.end =
 279                                         new->l_policy_data.l_flock.end;
 280                         } else {
 281                                 new->l_policy_data.l_flock.end =
 282                                         lock->l_policy_data.l_flock.end;
 283                         }
 284
 285                         if (added) {
 286                                 ldlm_flock_destroy(lock, mode, *flags);
 287                         } else {
 288                                 new = lock;
 289                                 added = 1;
 290                         }
 291                         continue;
 292                 }
 293
 294                 if (new->l_policy_data.l_flock.start >
 295                     lock->l_policy_data.l_flock.end)
 296                         continue;
 297
 298                 if (new->l_policy_data.l_flock.end <
 299                     lock->l_policy_data.l_flock.start)
 300                         break;
 301
 302                 ++overlaps;
 303
 304                 if (new->l_policy_data.l_flock.start <=
 305                     lock->l_policy_data.l_flock.start) {
 306                         if (new->l_policy_data.l_flock.end <
 307                             lock->l_policy_data.l_flock.end) {
 308                                 lock->l_policy_data.l_flock.start =
 309                                         new->l_policy_data.l_flock.end + 1;
 310                                 break;
 311                         }
 312                         ldlm_flock_destroy(lock, lock->l_req_mode, *flags);
 313                         continue;
 314                 }
 315                 if (new->l_policy_data.l_flock.end >=
 316                     lock->l_policy_data.l_flock.end) {
 317                         lock->l_policy_data.l_flock.end =
 318                                 new->l_policy_data.l_flock.start - 1;
 319                         continue;
 320                 }
 321
 322                 /* split the existing lock into two locks */
 323
 324                 /* if this is an F_UNLCK operation then we could avoid
 325                  * allocating a new lock and use the req lock passed in
 326                  * with the request but this would complicate the reply
 327                  * processing since updates to req get reflected in the
 328                  * reply. The client side replays the lock request so
 329                  * it must see the original lock data in the reply.
 330                  */
 331
 332                 /* XXX - if ldlm_lock_new() can sleep we should
 333                  * release the lr_lock, allocate the new lock,
 334                  * and restart processing this lock.
 335                  */
 336                 if (!new2) {
 337                         unlock_res_and_lock(req);
 338                         new2 = ldlm_lock_create(ns, &res->lr_name, LDLM_FLOCK,
 339                                                 lock->l_granted_mode, &null_cbs,
 340                                                 NULL, 0, LVB_T_NONE);
 341                         lock_res_and_lock(req);
 342                         if (!new2) {
 343                                 ldlm_flock_destroy(req, lock->l_granted_mode,
 344                                                    *flags);
 345                                 *err = -ENOLCK;
 346                                 return LDLM_ITER_STOP;
 347                         }
 348                         goto reprocess;
 349                 }
 350
 351                 splitted = 1;
 352
 353                 new2->l_granted_mode = lock->l_granted_mode;
 354                 new2->l_policy_data.l_flock.pid =
 355                         new->l_policy_data.l_flock.pid;
 356                 new2->l_policy_data.l_flock.owner =
 357                         new->l_policy_data.l_flock.owner;
 358                 new2->l_policy_data.l_flock.start =
 359                         lock->l_policy_data.l_flock.start;
 360                 new2->l_policy_data.l_flock.end =
 361                         new->l_policy_data.l_flock.start - 1;
 362                 lock->l_policy_data.l_flock.start =
 363                         new->l_policy_data.l_flock.end + 1;
 364                 new2->l_conn_export = lock->l_conn_export;
 365                 if (lock->l_export) {
 366                         new2->l_export = class_export_lock_get(lock->l_export,
 367                                                                new2);
 368                         if (new2->l_export->exp_lock_hash &&
 369                             hlist_unhashed(&new2->l_exp_hash))
 370                                 cfs_hash_add(new2->l_export->exp_lock_hash,
 371                                              &new2->l_remote_handle,
 372                                              &new2->l_exp_hash);
 373                 }
 374                 if (*flags == LDLM_FL_WAIT_NOREPROC)
 375                         ldlm_lock_addref_internal_nolock(new2,
 376                                                          lock->l_granted_mode);
 377
 378                 /* insert new2 at lock */
 379                 ldlm_resource_add_lock(res, ownlocks, new2);
 380                 LDLM_LOCK_RELEASE(new2);
 381                 break;
 382         }
 383
 384         /* if new2 is created but never used, destroy it*/
 385         if (splitted == 0 && new2)
 386                 ldlm_lock_destroy_nolock(new2);
 387
 388         /* At this point we're granting the lock request. */
 389         req->l_granted_mode = req->l_req_mode;
 390
 391         if (!added) {
 392                 list_del_init(&req->l_res_link);
 393                 /* insert new lock before ownlocks in list. */
 394                 ldlm_resource_add_lock(res, ownlocks, req);
 395         }
 396
 397         if (*flags != LDLM_FL_WAIT_NOREPROC) {
 398                 /* The only one possible case for client-side calls flock
 399                  * policy function is ldlm_flock_completion_ast inside which
 400                  * carries LDLM_FL_WAIT_NOREPROC flag.
 401                  */
 402                 CERROR("Illegal parameter for client-side-only module.\n");
 403                 LBUG();
 404         }
 405
 406         /* In case we're reprocessing the requested lock we can't destroy
 407          * it until after calling ldlm_add_ast_work_item() above so that laawi()
 408          * can bump the reference count on \a req. Otherwise \a req
 409          * could be freed before the completion AST can be sent.
 410          */
 411         if (added)
 412                 ldlm_flock_destroy(req, mode, *flags);
 413
 414         ldlm_resource_dump(D_INFO, res);
 415         return LDLM_ITER_CONTINUE;
 416 }
 417
 418 struct ldlm_flock_wait_data {
 419         struct ldlm_lock *fwd_lock;
 420         int            fwd_generation;
 421 };
 422
 423 static void
 424 ldlm_flock_interrupted_wait(void *data)
 425 {
 426         struct ldlm_lock *lock;
 427
 428         lock = ((struct ldlm_flock_wait_data *)data)->fwd_lock;
 429
 430         lock_res_and_lock(lock);
 431
 432         /* client side - set flag to prevent lock from being put on LRU list */
 433         ldlm_set_cbpending(lock);
 434         unlock_res_and_lock(lock);
 435 }
 436
 437 /**
 438  * Flock completion callback function.
 439  *
 440  * \param lock [in,out]: A lock to be handled
 441  * \param flags    [in]: flags
 442  * \param *data    [in]: ldlm_work_cp_ast_lock() will use ldlm_cb_set_arg
 443  *
 444  * \retval 0    : success
 445  * \retval <0   : failure
 446  */
 447 int
 448 ldlm_flock_completion_ast(struct ldlm_lock *lock, __u64 flags, void *data)
 449 {
 450         struct file_lock                *getlk = lock->l_ast_data;
 451         struct obd_device             *obd;
 452         struct obd_import             *imp = NULL;
 453         struct ldlm_flock_wait_data     fwd;
 454         struct l_wait_info            lwi;
 455         enum ldlm_error             err;
 456         int                          rc = 0;
 457
 458         CDEBUG(D_DLMTRACE, "flags: 0x%llx data: %p getlk: %p\n",
 459                flags, data, getlk);
 460
 461         /* Import invalidation. We need to actually release the lock
 462          * references being held, so that it can go away. No point in
 463          * holding the lock even if app still believes it has it, since
 464          * server already dropped it anyway. Only for granted locks too.
 465          */
 466         if ((lock->l_flags & (LDLM_FL_FAILED|LDLM_FL_LOCAL_ONLY)) ==
 467             (LDLM_FL_FAILED|LDLM_FL_LOCAL_ONLY)) {
 468                 if (lock->l_req_mode == lock->l_granted_mode &&
 469                     lock->l_granted_mode != LCK_NL && !data)
 470                         ldlm_lock_decref_internal(lock, lock->l_req_mode);
 471
 472                 /* Need to wake up the waiter if we were evicted */
 473                 wake_up(&lock->l_waitq);
 474                 return 0;
 475         }
 476
 477         LASSERT(flags != LDLM_FL_WAIT_NOREPROC);
 478
 479         if (!(flags & (LDLM_FL_BLOCK_WAIT | LDLM_FL_BLOCK_GRANTED |
 480                        LDLM_FL_BLOCK_CONV))) {
 481                 if (!data)
 482                         /* mds granted the lock in the reply */
 483                         goto granted;
 484                 /* CP AST RPC: lock get granted, wake it up */
 485                 wake_up(&lock->l_waitq);
 486                 return 0;
 487         }
 488
 489         LDLM_DEBUG(lock, "client-side enqueue returned a blocked lock, sleeping");
 490         fwd.fwd_lock = lock;
 491         obd = class_exp2obd(lock->l_conn_export);
 492
 493         /* if this is a local lock, there is no import */
 494         if (obd)
 495                 imp = obd->u.cli.cl_import;
 496
 497         if (imp) {
 498                 spin_lock(&imp->imp_lock);
 499                 fwd.fwd_generation = imp->imp_generation;
 500                 spin_unlock(&imp->imp_lock);
 501         }
 502
 503         lwi = LWI_TIMEOUT_INTR(0, NULL, ldlm_flock_interrupted_wait, &fwd);
 504
 505         /* Go to sleep until the lock is granted. */
 506         rc = l_wait_event(lock->l_waitq, is_granted_or_cancelled(lock), &lwi);
 507
 508         if (rc) {
 509                 LDLM_DEBUG(lock, "client-side enqueue waking up: failed (%d)",
 510                            rc);
 511                 return rc;
 512         }
 513
 514 granted:
 515         OBD_FAIL_TIMEOUT(OBD_FAIL_LDLM_CP_CB_WAIT, 10);
 516
 517         if (ldlm_is_failed(lock)) {
 518                 LDLM_DEBUG(lock, "client-side enqueue waking up: failed");
 519                 return -EIO;
 520         }
 521
 522         LDLM_DEBUG(lock, "client-side enqueue granted");
 523
 524         lock_res_and_lock(lock);
 525
 526         /*
 527          * Protect against race where lock could have been just destroyed
 528          * due to overlap in ldlm_process_flock_lock().
 529          */
 530         if (ldlm_is_destroyed(lock)) {
 531                 unlock_res_and_lock(lock);
 532                 LDLM_DEBUG(lock, "client-side enqueue waking up: destroyed");
 533                 return 0;
 534         }
 535
 536         /* ldlm_lock_enqueue() has already placed lock on the granted list. */
 537         list_del_init(&lock->l_res_link);
 538
 539         if (ldlm_is_flock_deadlock(lock)) {
 540                 LDLM_DEBUG(lock, "client-side enqueue deadlock received");
 541                 rc = -EDEADLK;
 542         } else if (flags & LDLM_FL_TEST_LOCK) {
 543                 /* fcntl(F_GETLK) request */
 544                 /* The old mode was saved in getlk->fl_type so that if the mode
 545                  * in the lock changes we can decref the appropriate refcount.
 546                  */
 547                 ldlm_flock_destroy(lock, getlk->fl_type, LDLM_FL_WAIT_NOREPROC);
 548                 switch (lock->l_granted_mode) {
 549                 case LCK_PR:
 550                         getlk->fl_type = F_RDLCK;
 551                         break;
 552                 case LCK_PW:
 553                         getlk->fl_type = F_WRLCK;
 554                         break;
 555                 default:
 556                         getlk->fl_type = F_UNLCK;
 557                 }
 558                 getlk->fl_pid = (pid_t)lock->l_policy_data.l_flock.pid;
 559                 getlk->fl_start = (loff_t)lock->l_policy_data.l_flock.start;
 560                 getlk->fl_end = (loff_t)lock->l_policy_data.l_flock.end;
 561         } else {
 562                 __u64 noreproc = LDLM_FL_WAIT_NOREPROC;
 563
 564                 /* We need to reprocess the lock to do merges or splits
 565                  * with existing locks owned by this process.
 566                  */
 567                 ldlm_process_flock_lock(lock, &noreproc, 1, &err, NULL);
 568         }
 569         unlock_res_and_lock(lock);
 570         return rc;
 571 }
 572 EXPORT_SYMBOL(ldlm_flock_completion_ast);
 573
 574 void ldlm_flock_policy_wire18_to_local(const ldlm_wire_policy_data_t *wpolicy,
 575                                        ldlm_policy_data_t *lpolicy)
 576 {
 577         memset(lpolicy, 0, sizeof(*lpolicy));
 578         lpolicy->l_flock.start = wpolicy->l_flock.lfw_start;
 579         lpolicy->l_flock.end = wpolicy->l_flock.lfw_end;
 580         lpolicy->l_flock.pid = wpolicy->l_flock.lfw_pid;
 581         /* Compat code, old clients had no idea about owner field and
 582          * relied solely on pid for ownership. Introduced in LU-104, 2.1,
 583          * April 2011
 584          */
 585         lpolicy->l_flock.owner = wpolicy->l_flock.lfw_pid;
 586 }
 587
 588 void ldlm_flock_policy_wire21_to_local(const ldlm_wire_policy_data_t *wpolicy,
 589                                        ldlm_policy_data_t *lpolicy)
 590 {
 591         memset(lpolicy, 0, sizeof(*lpolicy));
 592         lpolicy->l_flock.start = wpolicy->l_flock.lfw_start;
 593         lpolicy->l_flock.end = wpolicy->l_flock.lfw_end;
 594         lpolicy->l_flock.pid = wpolicy->l_flock.lfw_pid;
 595         lpolicy->l_flock.owner = wpolicy->l_flock.lfw_owner;
 596 }
 597
 598 void ldlm_flock_policy_local_to_wire(const ldlm_policy_data_t *lpolicy,
 599                                      ldlm_wire_policy_data_t *wpolicy)
 600 {
 601         memset(wpolicy, 0, sizeof(*wpolicy));
 602         wpolicy->l_flock.lfw_start = lpolicy->l_flock.start;
 603         wpolicy->l_flock.lfw_end = lpolicy->l_flock.end;
 604         wpolicy->l_flock.lfw_pid = lpolicy->l_flock.pid;
 605         wpolicy->l_flock.lfw_owner = lpolicy->l_flock.owner;
 606 }