kernel/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.sun.com/software/products/lustre/docs/GPLv2.pdf
  19  *
  20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  21  * CA 95054 USA or visit www.sun.com if you need additional information or
  22  * have any questions.
  23  *
  24  * GPL HEADER END
  25  */
  26 /*
  27  * Copyright (c) 2003 Hewlett-Packard Development Company LP.
  28  * Developed under the sponsorship of the US Government under
  29  * Subcontract No. B514193
  30  *
  31  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
  32  * Use is subject to license terms.
  33  *
  34  * Copyright (c) 2010, 2012, Intel Corporation.
  35  */
  36 /*
  37  * This file is part of Lustre, http://www.lustre.org/
  38  * Lustre is a trademark of Sun Microsystems, Inc.
  39  */
  40
  41 /**
  42  * This file implements POSIX lock type for Lustre.
  43  * Its policy properties are start and end of extent and PID.
  44  *
  45  * These locks are only done through MDS due to POSIX semantics requiring
  46  * e.g. that locks could be only partially released and as such split into
  47  * two parts, and also that two adjacent locks from the same process may be
  48  * merged into a single wider lock.
  49  *
  50  * Lock modes are mapped like this:
  51  * PR and PW for READ and WRITE locks
  52  * NL to request a releasing of a portion of the lock
  53  *
  54  * These flock locks never timeout.
  55  */
  56
  57 #define DEBUG_SUBSYSTEM S_LDLM
  58
  59 #include "../include/lustre_dlm.h"
  60 #include "../include/obd_support.h"
  61 #include "../include/obd_class.h"
  62 #include "../include/lustre_lib.h"
  63 #include <linux/list.h>
  64 #include "ldlm_internal.h"
  65
  66 /**
  67  * list_for_remaining_safe - iterate over the remaining entries in a list
  68  *            and safeguard against removal of a list entry.
  69  * \param pos   the &struct list_head to use as a loop counter. pos MUST
  70  *            have been initialized prior to using it in this macro.
  71  * \param n     another &struct list_head to use as temporary storage
  72  * \param head  the head for your list.
  73  */
  74 #define list_for_remaining_safe(pos, n, head) \
  75         for (n = pos->next; pos != (head); pos = n, n = pos->next)
  76
  77 static inline int
  78 ldlm_same_flock_owner(struct ldlm_lock *lock, struct ldlm_lock *new)
  79 {
  80         return((new->l_policy_data.l_flock.owner ==
  81                 lock->l_policy_data.l_flock.owner) &&
  82                (new->l_export == lock->l_export));
  83 }
  84
  85 static inline int
  86 ldlm_flocks_overlap(struct ldlm_lock *lock, struct ldlm_lock *new)
  87 {
  88         return((new->l_policy_data.l_flock.start <=
  89                 lock->l_policy_data.l_flock.end) &&
  90                (new->l_policy_data.l_flock.end >=
  91                 lock->l_policy_data.l_flock.start));
  92 }
  93
  94 static inline void
  95 ldlm_flock_destroy(struct ldlm_lock *lock, ldlm_mode_t mode, __u64 flags)
  96 {
  97         LDLM_DEBUG(lock, "ldlm_flock_destroy(mode: %d, flags: 0x%llx)",
  98                    mode, flags);
  99
 100         /* Safe to not lock here, since it should be empty anyway */
 101         LASSERT(hlist_unhashed(&lock->l_exp_flock_hash));
 102
 103         list_del_init(&lock->l_res_link);
 104         if (flags == LDLM_FL_WAIT_NOREPROC &&
 105             !(lock->l_flags & LDLM_FL_FAILED)) {
 106                 /* client side - set a flag to prevent sending a CANCEL */
 107                 lock->l_flags |= LDLM_FL_LOCAL_ONLY | LDLM_FL_CBPENDING;
 108
 109                 /* when reaching here, it is under lock_res_and_lock(). Thus,
 110                    need call the nolock version of ldlm_lock_decref_internal*/
 111                 ldlm_lock_decref_internal_nolock(lock, mode);
 112         }
 113
 114         ldlm_lock_destroy_nolock(lock);
 115 }
 116
 117 /**
 118  * Process a granting attempt for flock lock.
 119  * Must be called under ns lock held.
 120  *
 121  * This function looks for any conflicts for \a lock in the granted or
 122  * waiting queues. The lock is granted if no conflicts are found in
 123  * either queue.
 124  *
 125  * It is also responsible for splitting a lock if a portion of the lock
 126  * is released.
 127  *
 128  * If \a first_enq is 0 (ie, called from ldlm_reprocess_queue):
 129  *   - blocking ASTs have already been sent
 130  *
 131  * If \a first_enq is 1 (ie, called from ldlm_lock_enqueue):
 132  *   - blocking ASTs have not been sent yet, so list of conflicting locks
 133  *     would be collected and ASTs sent.
 134  */
 135 static int ldlm_process_flock_lock(struct ldlm_lock *req, __u64 *flags,
 136                                    int first_enq, ldlm_error_t *err,
 137                                    struct list_head *work_list)
 138 {
 139         struct ldlm_resource *res = req->l_resource;
 140         struct ldlm_namespace *ns = ldlm_res_to_ns(res);
 141         struct list_head *tmp;
 142         struct list_head *ownlocks = NULL;
 143         struct ldlm_lock *lock = NULL;
 144         struct ldlm_lock *new = req;
 145         struct ldlm_lock *new2 = NULL;
 146         ldlm_mode_t mode = req->l_req_mode;
 147         int added = (mode == LCK_NL);
 148         int overlaps = 0;
 149         int splitted = 0;
 150         const struct ldlm_callback_suite null_cbs = { NULL };
 151
 152         CDEBUG(D_DLMTRACE,
 153                "flags %#llx owner %llu pid %u mode %u start %llu end %llu\n",
 154                *flags, new->l_policy_data.l_flock.owner,
 155                new->l_policy_data.l_flock.pid, mode,
 156                req->l_policy_data.l_flock.start,
 157                req->l_policy_data.l_flock.end);
 158
 159         *err = ELDLM_OK;
 160
 161         /* No blocking ASTs are sent to the clients for
 162          * Posix file & record locks */
 163         req->l_blocking_ast = NULL;
 164
 165 reprocess:
 166         if ((*flags == LDLM_FL_WAIT_NOREPROC) || (mode == LCK_NL)) {
 167                 /* This loop determines where this processes locks start
 168                  * in the resource lr_granted list. */
 169                 list_for_each(tmp, &res->lr_granted) {
 170                         lock = list_entry(tmp, struct ldlm_lock,
 171                                               l_res_link);
 172                         if (ldlm_same_flock_owner(lock, req)) {
 173                                 ownlocks = tmp;
 174                                 break;
 175                         }
 176                 }
 177         } else {
 178                 int reprocess_failed = 0;
 179
 180                 lockmode_verify(mode);
 181
 182                 /* This loop determines if there are existing locks
 183                  * that conflict with the new lock request. */
 184                 list_for_each(tmp, &res->lr_granted) {
 185                         lock = list_entry(tmp, struct ldlm_lock,
 186                                               l_res_link);
 187
 188                         if (ldlm_same_flock_owner(lock, req)) {
 189                                 if (!ownlocks)
 190                                         ownlocks = tmp;
 191                                 continue;
 192                         }
 193
 194                         /* locks are compatible, overlap doesn't matter */
 195                         if (lockmode_compat(lock->l_granted_mode, mode))
 196                                 continue;
 197
 198                         if (!ldlm_flocks_overlap(lock, req))
 199                                 continue;
 200
 201                         if (!first_enq) {
 202                                 reprocess_failed = 1;
 203                                 continue;
 204                         }
 205
 206                         if (*flags & LDLM_FL_BLOCK_NOWAIT) {
 207                                 ldlm_flock_destroy(req, mode, *flags);
 208                                 *err = -EAGAIN;
 209                                 return LDLM_ITER_STOP;
 210                         }
 211
 212                         if (*flags & LDLM_FL_TEST_LOCK) {
 213                                 ldlm_flock_destroy(req, mode, *flags);
 214                                 req->l_req_mode = lock->l_granted_mode;
 215                                 req->l_policy_data.l_flock.pid =
 216                                         lock->l_policy_data.l_flock.pid;
 217                                 req->l_policy_data.l_flock.start =
 218                                         lock->l_policy_data.l_flock.start;
 219                                 req->l_policy_data.l_flock.end =
 220                                         lock->l_policy_data.l_flock.end;
 221                                 *flags |= LDLM_FL_LOCK_CHANGED;
 222                                 return LDLM_ITER_STOP;
 223                         }
 224
 225                         ldlm_resource_add_lock(res, &res->lr_waiting, req);
 226                         *flags |= LDLM_FL_BLOCK_GRANTED;
 227                         return LDLM_ITER_STOP;
 228                 }
 229                 if (reprocess_failed)
 230                         return LDLM_ITER_CONTINUE;
 231         }
 232
 233         if (*flags & LDLM_FL_TEST_LOCK) {
 234                 ldlm_flock_destroy(req, mode, *flags);
 235                 req->l_req_mode = LCK_NL;
 236                 *flags |= LDLM_FL_LOCK_CHANGED;
 237                 return LDLM_ITER_STOP;
 238         }
 239
 240         /* Scan the locks owned by this process that overlap this request.
 241          * We may have to merge or split existing locks. */
 242
 243         if (!ownlocks)
 244                 ownlocks = &res->lr_granted;
 245
 246         list_for_remaining_safe(ownlocks, tmp, &res->lr_granted) {
 247                 lock = list_entry(ownlocks, struct ldlm_lock, l_res_link);
 248
 249                 if (!ldlm_same_flock_owner(lock, new))
 250                         break;
 251
 252                 if (lock->l_granted_mode == mode) {
 253                         /* If the modes are the same then we need to process
 254                          * locks that overlap OR adjoin the new lock. The extra
 255                          * logic condition is necessary to deal with arithmetic
 256                          * overflow and underflow. */
 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 !=
 260                                 OBD_OBJECT_EOF))
 261                                 continue;
 262
 263                         if ((new->l_policy_data.l_flock.end <
 264                              (lock->l_policy_data.l_flock.start - 1))
 265                             && (lock->l_policy_data.l_flock.start != 0))
 266                                 break;
 267
 268                         if (new->l_policy_data.l_flock.start <
 269                             lock->l_policy_data.l_flock.start) {
 270                                 lock->l_policy_data.l_flock.start =
 271                                         new->l_policy_data.l_flock.start;
 272                         } else {
 273                                 new->l_policy_data.l_flock.start =
 274                                         lock->l_policy_data.l_flock.start;
 275                         }
 276
 277                         if (new->l_policy_data.l_flock.end >
 278                             lock->l_policy_data.l_flock.end) {
 279                                 lock->l_policy_data.l_flock.end =
 280                                         new->l_policy_data.l_flock.end;
 281                         } else {
 282                                 new->l_policy_data.l_flock.end =
 283                                         lock->l_policy_data.l_flock.end;
 284                         }
 285
 286                         if (added) {
 287                                 ldlm_flock_destroy(lock, mode, *flags);
 288                         } else {
 289                                 new = lock;
 290                                 added = 1;
 291                         }
 292                         continue;
 293                 }
 294
 295                 if (new->l_policy_data.l_flock.start >
 296                     lock->l_policy_data.l_flock.end)
 297                         continue;
 298
 299                 if (new->l_policy_data.l_flock.end <
 300                     lock->l_policy_data.l_flock.start)
 301                         break;
 302
 303                 ++overlaps;
 304
 305                 if (new->l_policy_data.l_flock.start <=
 306                     lock->l_policy_data.l_flock.start) {
 307                         if (new->l_policy_data.l_flock.end <
 308                             lock->l_policy_data.l_flock.end) {
 309                                 lock->l_policy_data.l_flock.start =
 310                                         new->l_policy_data.l_flock.end + 1;
 311                                 break;
 312                         }
 313                         ldlm_flock_destroy(lock, lock->l_req_mode, *flags);
 314                         continue;
 315                 }
 316                 if (new->l_policy_data.l_flock.end >=
 317                     lock->l_policy_data.l_flock.end) {
 318                         lock->l_policy_data.l_flock.end =
 319                                 new->l_policy_data.l_flock.start - 1;
 320                         continue;
 321                 }
 322
 323                 /* split the existing lock into two locks */
 324
 325                 /* if this is an F_UNLCK operation then we could avoid
 326                  * allocating a new lock and use the req lock passed in
 327                  * with the request but this would complicate the reply
 328                  * processing since updates to req get reflected in the
 329                  * reply. The client side replays the lock request so
 330                  * it must see the original lock data in the reply. */
 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                 if (!new2) {
 336                         unlock_res_and_lock(req);
 337                         new2 = ldlm_lock_create(ns, &res->lr_name, LDLM_FLOCK,
 338                                                 lock->l_granted_mode, &null_cbs,
 339                                                 NULL, 0, LVB_T_NONE);
 340                         lock_res_and_lock(req);
 341                         if (!new2) {
 342                                 ldlm_flock_destroy(req, lock->l_granted_mode,
 343                                                    *flags);
 344                                 *err = -ENOLCK;
 345                                 return LDLM_ITER_STOP;
 346                         }
 347                         goto reprocess;
 348                 }
 349
 350                 splitted = 1;
 351
 352                 new2->l_granted_mode = lock->l_granted_mode;
 353                 new2->l_policy_data.l_flock.pid =
 354                         new->l_policy_data.l_flock.pid;
 355                 new2->l_policy_data.l_flock.owner =
 356                         new->l_policy_data.l_flock.owner;
 357                 new2->l_policy_data.l_flock.start =
 358                         lock->l_policy_data.l_flock.start;
 359                 new2->l_policy_data.l_flock.end =
 360                         new->l_policy_data.l_flock.start - 1;
 361                 lock->l_policy_data.l_flock.start =
 362                         new->l_policy_data.l_flock.end + 1;
 363                 new2->l_conn_export = lock->l_conn_export;
 364                 if (lock->l_export != NULL) {
 365                         new2->l_export = class_export_lock_get(lock->l_export,
 366                                                                new2);
 367                         if (new2->l_export->exp_lock_hash &&
 368                             hlist_unhashed(&new2->l_exp_hash))
 369                                 cfs_hash_add(new2->l_export->exp_lock_hash,
 370                                              &new2->l_remote_handle,
 371                                              &new2->l_exp_hash);
 372                 }
 373                 if (*flags == LDLM_FL_WAIT_NOREPROC)
 374                         ldlm_lock_addref_internal_nolock(new2,
 375                                                          lock->l_granted_mode);
 376
 377                 /* insert new2 at lock */
 378                 ldlm_resource_add_lock(res, ownlocks, new2);
 379                 LDLM_LOCK_RELEASE(new2);
 380                 break;
 381         }
 382
 383         /* if new2 is created but never used, destroy it*/
 384         if (splitted == 0 && new2 != NULL)
 385                 ldlm_lock_destroy_nolock(new2);
 386
 387         /* At this point we're granting the lock request. */
 388         req->l_granted_mode = req->l_req_mode;
 389
 390         if (!added) {
 391                 list_del_init(&req->l_res_link);
 392                 /* insert new lock before ownlocks in list. */
 393                 ldlm_resource_add_lock(res, ownlocks, req);
 394         }
 395
 396         if (*flags != LDLM_FL_WAIT_NOREPROC) {
 397                 /* The only one possible case for client-side calls flock
 398                  * policy function is ldlm_flock_completion_ast inside which
 399                  * carries LDLM_FL_WAIT_NOREPROC flag. */
 400                 CERROR("Illegal parameter for client-side-only module.\n");
 401                 LBUG();
 402         }
 403
 404         /* In case we're reprocessing the requested lock we can't destroy
 405          * it until after calling ldlm_add_ast_work_item() above so that laawi()
 406          * can bump the reference count on \a req. Otherwise \a req
 407          * could be freed before the completion AST can be sent.  */
 408         if (added)
 409                 ldlm_flock_destroy(req, mode, *flags);
 410
 411         ldlm_resource_dump(D_INFO, res);
 412         return LDLM_ITER_CONTINUE;
 413 }
 414
 415 struct ldlm_flock_wait_data {
 416         struct ldlm_lock *fwd_lock;
 417         int            fwd_generation;
 418 };
 419
 420 static void
 421 ldlm_flock_interrupted_wait(void *data)
 422 {
 423         struct ldlm_lock *lock;
 424
 425         lock = ((struct ldlm_flock_wait_data *)data)->fwd_lock;
 426
 427         lock_res_and_lock(lock);
 428
 429         /* client side - set flag to prevent lock from being put on LRU list */
 430         lock->l_flags |= LDLM_FL_CBPENDING;
 431         unlock_res_and_lock(lock);
 432 }
 433
 434 /**
 435  * Flock completion callback function.
 436  *
 437  * \param lock [in,out]: A lock to be handled
 438  * \param flags    [in]: flags
 439  * \param *data    [in]: ldlm_work_cp_ast_lock() will use ldlm_cb_set_arg
 440  *
 441  * \retval 0    : success
 442  * \retval <0   : failure
 443  */
 444 int
 445 ldlm_flock_completion_ast(struct ldlm_lock *lock, __u64 flags, void *data)
 446 {
 447         struct file_lock                *getlk = lock->l_ast_data;
 448         struct obd_device             *obd;
 449         struct obd_import             *imp = NULL;
 450         struct ldlm_flock_wait_data     fwd;
 451         struct l_wait_info            lwi;
 452         ldlm_error_t                err;
 453         int                          rc = 0;
 454
 455         CDEBUG(D_DLMTRACE, "flags: 0x%llx data: %p getlk: %p\n",
 456                flags, data, getlk);
 457
 458         /* Import invalidation. We need to actually release the lock
 459          * references being held, so that it can go away. No point in
 460          * holding the lock even if app still believes it has it, since
 461          * server already dropped it anyway. Only for granted locks too. */
 462         if ((lock->l_flags & (LDLM_FL_FAILED|LDLM_FL_LOCAL_ONLY)) ==
 463             (LDLM_FL_FAILED|LDLM_FL_LOCAL_ONLY)) {
 464                 if (lock->l_req_mode == lock->l_granted_mode &&
 465                     lock->l_granted_mode != LCK_NL &&
 466                     data == NULL)
 467                         ldlm_lock_decref_internal(lock, lock->l_req_mode);
 468
 469                 /* Need to wake up the waiter if we were evicted */
 470                 wake_up(&lock->l_waitq);
 471                 return 0;
 472         }
 473
 474         LASSERT(flags != LDLM_FL_WAIT_NOREPROC);
 475
 476         if (!(flags & (LDLM_FL_BLOCK_WAIT | LDLM_FL_BLOCK_GRANTED |
 477                        LDLM_FL_BLOCK_CONV))) {
 478                 if (data == NULL)
 479                         /* mds granted the lock in the reply */
 480                         goto granted;
 481                 /* CP AST RPC: lock get granted, wake it up */
 482                 wake_up(&lock->l_waitq);
 483                 return 0;
 484         }
 485
 486         LDLM_DEBUG(lock, "client-side enqueue returned a blocked lock, sleeping");
 487         fwd.fwd_lock = lock;
 488         obd = class_exp2obd(lock->l_conn_export);
 489
 490         /* if this is a local lock, there is no import */
 491         if (obd != NULL)
 492                 imp = obd->u.cli.cl_import;
 493
 494         if (imp != NULL) {
 495                 spin_lock(&imp->imp_lock);
 496                 fwd.fwd_generation = imp->imp_generation;
 497                 spin_unlock(&imp->imp_lock);
 498         }
 499
 500         lwi = LWI_TIMEOUT_INTR(0, NULL, ldlm_flock_interrupted_wait, &fwd);
 501
 502         /* Go to sleep until the lock is granted. */
 503         rc = l_wait_event(lock->l_waitq, is_granted_or_cancelled(lock), &lwi);
 504
 505         if (rc) {
 506                 LDLM_DEBUG(lock, "client-side enqueue waking up: failed (%d)",
 507                            rc);
 508                 return rc;
 509         }
 510
 511 granted:
 512         OBD_FAIL_TIMEOUT(OBD_FAIL_LDLM_CP_CB_WAIT, 10);
 513
 514         if (lock->l_flags & LDLM_FL_DESTROYED) {
 515                 LDLM_DEBUG(lock, "client-side enqueue waking up: destroyed");
 516                 return 0;
 517         }
 518
 519         if (lock->l_flags & LDLM_FL_FAILED) {
 520                 LDLM_DEBUG(lock, "client-side enqueue waking up: failed");
 521                 return -EIO;
 522         }
 523
 524         if (rc) {
 525                 LDLM_DEBUG(lock, "client-side enqueue waking up: failed (%d)",
 526                            rc);
 527                 return rc;
 528         }
 529
 530         LDLM_DEBUG(lock, "client-side enqueue granted");
 531
 532         lock_res_and_lock(lock);
 533
 534         /* ldlm_lock_enqueue() has already placed lock on the granted list. */
 535         list_del_init(&lock->l_res_link);
 536
 537         if (lock->l_flags & LDLM_FL_FLOCK_DEADLOCK) {
 538                 LDLM_DEBUG(lock, "client-side enqueue deadlock received");
 539                 rc = -EDEADLK;
 540         } else if (flags & LDLM_FL_TEST_LOCK) {
 541                 /* fcntl(F_GETLK) request */
 542                 /* The old mode was saved in getlk->fl_type so that if the mode
 543                  * in the lock changes we can decref the appropriate refcount.*/
 544                 ldlm_flock_destroy(lock, getlk->fl_type, LDLM_FL_WAIT_NOREPROC);
 545                 switch (lock->l_granted_mode) {
 546                 case LCK_PR:
 547                         getlk->fl_type = F_RDLCK;
 548                         break;
 549                 case LCK_PW:
 550                         getlk->fl_type = F_WRLCK;
 551                         break;
 552                 default:
 553                         getlk->fl_type = F_UNLCK;
 554                 }
 555                 getlk->fl_pid = (pid_t)lock->l_policy_data.l_flock.pid;
 556                 getlk->fl_start = (loff_t)lock->l_policy_data.l_flock.start;
 557                 getlk->fl_end = (loff_t)lock->l_policy_data.l_flock.end;
 558         } else {
 559                 __u64 noreproc = LDLM_FL_WAIT_NOREPROC;
 560
 561                 /* We need to reprocess the lock to do merges or splits
 562                  * with existing locks owned by this process. */
 563                 ldlm_process_flock_lock(lock, &noreproc, 1, &err, NULL);
 564         }
 565         unlock_res_and_lock(lock);
 566         return rc;
 567 }
 568 EXPORT_SYMBOL(ldlm_flock_completion_ast);
 569
 570 void ldlm_flock_policy_wire18_to_local(const ldlm_wire_policy_data_t *wpolicy,
 571                                        ldlm_policy_data_t *lpolicy)
 572 {
 573         memset(lpolicy, 0, sizeof(*lpolicy));
 574         lpolicy->l_flock.start = wpolicy->l_flock.lfw_start;
 575         lpolicy->l_flock.end = wpolicy->l_flock.lfw_end;
 576         lpolicy->l_flock.pid = wpolicy->l_flock.lfw_pid;
 577         /* Compat code, old clients had no idea about owner field and
 578          * relied solely on pid for ownership. Introduced in LU-104, 2.1,
 579          * April 2011 */
 580         lpolicy->l_flock.owner = wpolicy->l_flock.lfw_pid;
 581 }
 582
 583 void ldlm_flock_policy_wire21_to_local(const ldlm_wire_policy_data_t *wpolicy,
 584                                        ldlm_policy_data_t *lpolicy)
 585 {
 586         memset(lpolicy, 0, sizeof(*lpolicy));
 587         lpolicy->l_flock.start = wpolicy->l_flock.lfw_start;
 588         lpolicy->l_flock.end = wpolicy->l_flock.lfw_end;
 589         lpolicy->l_flock.pid = wpolicy->l_flock.lfw_pid;
 590         lpolicy->l_flock.owner = wpolicy->l_flock.lfw_owner;
 591 }
 592
 593 void ldlm_flock_policy_local_to_wire(const ldlm_policy_data_t *lpolicy,
 594                                      ldlm_wire_policy_data_t *wpolicy)
 595 {
 596         memset(wpolicy, 0, sizeof(*wpolicy));
 597         wpolicy->l_flock.lfw_start = lpolicy->l_flock.start;
 598         wpolicy->l_flock.lfw_end = lpolicy->l_flock.end;
 599         wpolicy->l_flock.lfw_pid = lpolicy->l_flock.pid;
 600         wpolicy->l_flock.lfw_owner = lpolicy->l_flock.owner;
 601 }