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, enum ldlm_mode 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 && !ldlm_is_failed(lock)) {
 105                 /* client side - set a flag to prevent sending a CANCEL */
 106                 lock->l_flags |= LDLM_FL_LOCAL_ONLY | LDLM_FL_CBPENDING;
 107
 108                 /* when reaching here, it is under lock_res_and_lock(). Thus,
 109                  * need call the nolock version of ldlm_lock_decref_internal
 110                  */
 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, enum ldlm_error *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         enum ldlm_mode 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          */
 164         req->l_blocking_ast = NULL;
 165
 166 reprocess:
 167         if ((*flags == LDLM_FL_WAIT_NOREPROC) || (mode == LCK_NL)) {
 168                 /* This loop determines where this processes locks start
 169                  * in the resource lr_granted list.
 170                  */
 171                 list_for_each(tmp, &res->lr_granted) {
 172                         lock = list_entry(tmp, struct ldlm_lock,
 173                                               l_res_link);
 174                         if (ldlm_same_flock_owner(lock, req)) {
 175                                 ownlocks = tmp;
 176                                 break;
 177                         }
 178                 }
 179         } else {
 180                 int reprocess_failed = 0;
 181
 182                 lockmode_verify(mode);
 183
 184                 /* This loop determines if there are existing locks
 185                  * that conflict with the new lock request.
 186                  */
 187                 list_for_each(tmp, &res->lr_granted) {
 188                         lock = list_entry(tmp, struct ldlm_lock,
 189                                               l_res_link);
 190
 191                         if (ldlm_same_flock_owner(lock, req)) {
 192                                 if (!ownlocks)
 193                                         ownlocks = tmp;
 194                                 continue;
 195                         }
 196
 197                         /* locks are compatible, overlap doesn't matter */
 198                         if (lockmode_compat(lock->l_granted_mode, mode))
 199                                 continue;
 200
 201                         if (!ldlm_flocks_overlap(lock, req))
 202                                 continue;
 203
 204                         if (!first_enq) {
 205                                 reprocess_failed = 1;
 206                                 continue;
 207                         }
 208
 209                         if (*flags & LDLM_FL_BLOCK_NOWAIT) {
 210                                 ldlm_flock_destroy(req, mode, *flags);
 211                                 *err = -EAGAIN;
 212                                 return LDLM_ITER_STOP;
 213                         }
 214
 215                         if (*flags & LDLM_FL_TEST_LOCK) {
 216                                 ldlm_flock_destroy(req, mode, *flags);
 217                                 req->l_req_mode = lock->l_granted_mode;
 218                                 req->l_policy_data.l_flock.pid =
 219                                         lock->l_policy_data.l_flock.pid;
 220                                 req->l_policy_data.l_flock.start =
 221                                         lock->l_policy_data.l_flock.start;
 222                                 req->l_policy_data.l_flock.end =
 223                                         lock->l_policy_data.l_flock.end;
 224                                 *flags |= LDLM_FL_LOCK_CHANGED;
 225                                 return LDLM_ITER_STOP;
 226                         }
 227
 228                         ldlm_resource_add_lock(res, &res->lr_waiting, req);
 229                         *flags |= LDLM_FL_BLOCK_GRANTED;
 230                         return LDLM_ITER_STOP;
 231                 }
 232                 if (reprocess_failed)
 233                         return LDLM_ITER_CONTINUE;
 234         }
 235
 236         if (*flags & LDLM_FL_TEST_LOCK) {
 237                 ldlm_flock_destroy(req, mode, *flags);
 238                 req->l_req_mode = LCK_NL;
 239                 *flags |= LDLM_FL_LOCK_CHANGED;
 240                 return LDLM_ITER_STOP;
 241         }
 242
 243         /* Scan the locks owned by this process that overlap this request.
 244          * We may have to merge or split existing locks.
 245          */
 246         if (!ownlocks)
 247                 ownlocks = &res->lr_granted;
 248
 249         list_for_remaining_safe(ownlocks, tmp, &res->lr_granted) {
 250                 lock = list_entry(ownlocks, struct ldlm_lock, l_res_link);
 251
 252                 if (!ldlm_same_flock_owner(lock, new))
 253                         break;
 254
 255                 if (lock->l_granted_mode == mode) {
 256                         /* If the modes are the same then we need to process
 257                          * locks that overlap OR adjoin the new lock. The extra
 258                          * logic condition is necessary to deal with arithmetic
 259                          * overflow and underflow.
 260                          */
 261                         if ((new->l_policy_data.l_flock.start >
 262                              (lock->l_policy_data.l_flock.end + 1))
 263                             && (lock->l_policy_data.l_flock.end !=
 264                                 OBD_OBJECT_EOF))
 265                                 continue;
 266
 267                         if ((new->l_policy_data.l_flock.end <
 268                              (lock->l_policy_data.l_flock.start - 1))
 269                             && (lock->l_policy_data.l_flock.start != 0))
 270                                 break;
 271
 272                         if (new->l_policy_data.l_flock.start <
 273                             lock->l_policy_data.l_flock.start) {
 274                                 lock->l_policy_data.l_flock.start =
 275                                         new->l_policy_data.l_flock.start;
 276                         } else {
 277                                 new->l_policy_data.l_flock.start =
 278                                         lock->l_policy_data.l_flock.start;
 279                         }
 280
 281                         if (new->l_policy_data.l_flock.end >
 282                             lock->l_policy_data.l_flock.end) {
 283                                 lock->l_policy_data.l_flock.end =
 284                                         new->l_policy_data.l_flock.end;
 285                         } else {
 286                                 new->l_policy_data.l_flock.end =
 287                                         lock->l_policy_data.l_flock.end;
 288                         }
 289
 290                         if (added) {
 291                                 ldlm_flock_destroy(lock, mode, *flags);
 292                         } else {
 293                                 new = lock;
 294                                 added = 1;
 295                         }
 296                         continue;
 297                 }
 298
 299                 if (new->l_policy_data.l_flock.start >
 300                     lock->l_policy_data.l_flock.end)
 301                         continue;
 302
 303                 if (new->l_policy_data.l_flock.end <
 304                     lock->l_policy_data.l_flock.start)
 305                         break;
 306
 307                 ++overlaps;
 308
 309                 if (new->l_policy_data.l_flock.start <=
 310                     lock->l_policy_data.l_flock.start) {
 311                         if (new->l_policy_data.l_flock.end <
 312                             lock->l_policy_data.l_flock.end) {
 313                                 lock->l_policy_data.l_flock.start =
 314                                         new->l_policy_data.l_flock.end + 1;
 315                                 break;
 316                         }
 317                         ldlm_flock_destroy(lock, lock->l_req_mode, *flags);
 318                         continue;
 319                 }
 320                 if (new->l_policy_data.l_flock.end >=
 321                     lock->l_policy_data.l_flock.end) {
 322                         lock->l_policy_data.l_flock.end =
 323                                 new->l_policy_data.l_flock.start - 1;
 324                         continue;
 325                 }
 326
 327                 /* split the existing lock into two locks */
 328
 329                 /* if this is an F_UNLCK operation then we could avoid
 330                  * allocating a new lock and use the req lock passed in
 331                  * with the request but this would complicate the reply
 332                  * processing since updates to req get reflected in the
 333                  * reply. The client side replays the lock request so
 334                  * it must see the original lock data in the reply.
 335                  */
 336
 337                 /* XXX - if ldlm_lock_new() can sleep we should
 338                  * release the lr_lock, allocate the new lock,
 339                  * and restart processing this lock.
 340                  */
 341                 if (!new2) {
 342                         unlock_res_and_lock(req);
 343                         new2 = ldlm_lock_create(ns, &res->lr_name, LDLM_FLOCK,
 344                                                 lock->l_granted_mode, &null_cbs,
 345                                                 NULL, 0, LVB_T_NONE);
 346                         lock_res_and_lock(req);
 347                         if (!new2) {
 348                                 ldlm_flock_destroy(req, lock->l_granted_mode,
 349                                                    *flags);
 350                                 *err = -ENOLCK;
 351                                 return LDLM_ITER_STOP;
 352                         }
 353                         goto reprocess;
 354                 }
 355
 356                 splitted = 1;
 357
 358                 new2->l_granted_mode = lock->l_granted_mode;
 359                 new2->l_policy_data.l_flock.pid =
 360                         new->l_policy_data.l_flock.pid;
 361                 new2->l_policy_data.l_flock.owner =
 362                         new->l_policy_data.l_flock.owner;
 363                 new2->l_policy_data.l_flock.start =
 364                         lock->l_policy_data.l_flock.start;
 365                 new2->l_policy_data.l_flock.end =
 366                         new->l_policy_data.l_flock.start - 1;
 367                 lock->l_policy_data.l_flock.start =
 368                         new->l_policy_data.l_flock.end + 1;
 369                 new2->l_conn_export = lock->l_conn_export;
 370                 if (lock->l_export) {
 371                         new2->l_export = class_export_lock_get(lock->l_export,
 372                                                                new2);
 373                         if (new2->l_export->exp_lock_hash &&
 374                             hlist_unhashed(&new2->l_exp_hash))
 375                                 cfs_hash_add(new2->l_export->exp_lock_hash,
 376                                              &new2->l_remote_handle,
 377                                              &new2->l_exp_hash);
 378                 }
 379                 if (*flags == LDLM_FL_WAIT_NOREPROC)
 380                         ldlm_lock_addref_internal_nolock(new2,
 381                                                          lock->l_granted_mode);
 382
 383                 /* insert new2 at lock */
 384                 ldlm_resource_add_lock(res, ownlocks, new2);
 385                 LDLM_LOCK_RELEASE(new2);
 386                 break;
 387         }
 388
 389         /* if new2 is created but never used, destroy it*/
 390         if (splitted == 0 && new2)
 391                 ldlm_lock_destroy_nolock(new2);
 392
 393         /* At this point we're granting the lock request. */
 394         req->l_granted_mode = req->l_req_mode;
 395
 396         if (!added) {
 397                 list_del_init(&req->l_res_link);
 398                 /* insert new lock before ownlocks in list. */
 399                 ldlm_resource_add_lock(res, ownlocks, req);
 400         }
 401
 402         if (*flags != LDLM_FL_WAIT_NOREPROC) {
 403                 /* The only one possible case for client-side calls flock
 404                  * policy function is ldlm_flock_completion_ast inside which
 405                  * carries LDLM_FL_WAIT_NOREPROC flag.
 406                  */
 407                 CERROR("Illegal parameter for client-side-only module.\n");
 408                 LBUG();
 409         }
 410
 411         /* In case we're reprocessing the requested lock we can't destroy
 412          * it until after calling ldlm_add_ast_work_item() above so that laawi()
 413          * can bump the reference count on \a req. Otherwise \a req
 414          * could be freed before the completion AST can be sent.
 415          */
 416         if (added)
 417                 ldlm_flock_destroy(req, mode, *flags);
 418
 419         ldlm_resource_dump(D_INFO, res);
 420         return LDLM_ITER_CONTINUE;
 421 }
 422
 423 struct ldlm_flock_wait_data {
 424         struct ldlm_lock *fwd_lock;
 425         int            fwd_generation;
 426 };
 427
 428 static void
 429 ldlm_flock_interrupted_wait(void *data)
 430 {
 431         struct ldlm_lock *lock;
 432
 433         lock = ((struct ldlm_flock_wait_data *)data)->fwd_lock;
 434
 435         lock_res_and_lock(lock);
 436
 437         /* client side - set flag to prevent lock from being put on LRU list */
 438         ldlm_set_cbpending(lock);
 439         unlock_res_and_lock(lock);
 440 }
 441
 442 /**
 443  * Flock completion callback function.
 444  *
 445  * \param lock [in,out]: A lock to be handled
 446  * \param flags    [in]: flags
 447  * \param *data    [in]: ldlm_work_cp_ast_lock() will use ldlm_cb_set_arg
 448  *
 449  * \retval 0    : success
 450  * \retval <0   : failure
 451  */
 452 int
 453 ldlm_flock_completion_ast(struct ldlm_lock *lock, __u64 flags, void *data)
 454 {
 455         struct file_lock                *getlk = lock->l_ast_data;
 456         struct obd_device             *obd;
 457         struct obd_import             *imp = NULL;
 458         struct ldlm_flock_wait_data     fwd;
 459         struct l_wait_info            lwi;
 460         enum ldlm_error             err;
 461         int                          rc = 0;
 462
 463         CDEBUG(D_DLMTRACE, "flags: 0x%llx data: %p getlk: %p\n",
 464                flags, data, getlk);
 465
 466         /* Import invalidation. We need to actually release the lock
 467          * references being held, so that it can go away. No point in
 468          * holding the lock even if app still believes it has it, since
 469          * server already dropped it anyway. Only for granted locks too.
 470          */
 471         if ((lock->l_flags & (LDLM_FL_FAILED|LDLM_FL_LOCAL_ONLY)) ==
 472             (LDLM_FL_FAILED|LDLM_FL_LOCAL_ONLY)) {
 473                 if (lock->l_req_mode == lock->l_granted_mode &&
 474                     lock->l_granted_mode != LCK_NL && !data)
 475                         ldlm_lock_decref_internal(lock, lock->l_req_mode);
 476
 477                 /* Need to wake up the waiter if we were evicted */
 478                 wake_up(&lock->l_waitq);
 479                 return 0;
 480         }
 481
 482         LASSERT(flags != LDLM_FL_WAIT_NOREPROC);
 483
 484         if (!(flags & (LDLM_FL_BLOCK_WAIT | LDLM_FL_BLOCK_GRANTED |
 485                        LDLM_FL_BLOCK_CONV))) {
 486                 if (!data)
 487                         /* mds granted the lock in the reply */
 488                         goto granted;
 489                 /* CP AST RPC: lock get granted, wake it up */
 490                 wake_up(&lock->l_waitq);
 491                 return 0;
 492         }
 493
 494         LDLM_DEBUG(lock, "client-side enqueue returned a blocked lock, sleeping");
 495         fwd.fwd_lock = lock;
 496         obd = class_exp2obd(lock->l_conn_export);
 497
 498         /* if this is a local lock, there is no import */
 499         if (obd)
 500                 imp = obd->u.cli.cl_import;
 501
 502         if (imp) {
 503                 spin_lock(&imp->imp_lock);
 504                 fwd.fwd_generation = imp->imp_generation;
 505                 spin_unlock(&imp->imp_lock);
 506         }
 507
 508         lwi = LWI_TIMEOUT_INTR(0, NULL, ldlm_flock_interrupted_wait, &fwd);
 509
 510         /* Go to sleep until the lock is granted. */
 511         rc = l_wait_event(lock->l_waitq, is_granted_or_cancelled(lock), &lwi);
 512
 513         if (rc) {
 514                 LDLM_DEBUG(lock, "client-side enqueue waking up: failed (%d)",
 515                            rc);
 516                 return rc;
 517         }
 518
 519 granted:
 520         OBD_FAIL_TIMEOUT(OBD_FAIL_LDLM_CP_CB_WAIT, 10);
 521
 522         if (ldlm_is_failed(lock)) {
 523                 LDLM_DEBUG(lock, "client-side enqueue waking up: failed");
 524                 return -EIO;
 525         }
 526
 527         LDLM_DEBUG(lock, "client-side enqueue granted");
 528
 529         lock_res_and_lock(lock);
 530
 531         /*
 532          * Protect against race where lock could have been just destroyed
 533          * due to overlap in ldlm_process_flock_lock().
 534          */
 535         if (ldlm_is_destroyed(lock)) {
 536                 unlock_res_and_lock(lock);
 537                 LDLM_DEBUG(lock, "client-side enqueue waking up: destroyed");
 538                 return 0;
 539         }
 540
 541         /* ldlm_lock_enqueue() has already placed lock on the granted list. */
 542         list_del_init(&lock->l_res_link);
 543
 544         if (ldlm_is_flock_deadlock(lock)) {
 545                 LDLM_DEBUG(lock, "client-side enqueue deadlock received");
 546                 rc = -EDEADLK;
 547         } else if (flags & LDLM_FL_TEST_LOCK) {
 548                 /* fcntl(F_GETLK) request */
 549                 /* The old mode was saved in getlk->fl_type so that if the mode
 550                  * in the lock changes we can decref the appropriate refcount.
 551                  */
 552                 ldlm_flock_destroy(lock, getlk->fl_type, LDLM_FL_WAIT_NOREPROC);
 553                 switch (lock->l_granted_mode) {
 554                 case LCK_PR:
 555                         getlk->fl_type = F_RDLCK;
 556                         break;
 557                 case LCK_PW:
 558                         getlk->fl_type = F_WRLCK;
 559                         break;
 560                 default:
 561                         getlk->fl_type = F_UNLCK;
 562                 }
 563                 getlk->fl_pid = (pid_t)lock->l_policy_data.l_flock.pid;
 564                 getlk->fl_start = (loff_t)lock->l_policy_data.l_flock.start;
 565                 getlk->fl_end = (loff_t)lock->l_policy_data.l_flock.end;
 566         } else {
 567                 __u64 noreproc = LDLM_FL_WAIT_NOREPROC;
 568
 569                 /* We need to reprocess the lock to do merges or splits
 570                  * with existing locks owned by this process.
 571                  */
 572                 ldlm_process_flock_lock(lock, &noreproc, 1, &err, NULL);
 573         }
 574         unlock_res_and_lock(lock);
 575         return rc;
 576 }
 577 EXPORT_SYMBOL(ldlm_flock_completion_ast);
 578
 579 void ldlm_flock_policy_wire18_to_local(const ldlm_wire_policy_data_t *wpolicy,
 580                                        ldlm_policy_data_t *lpolicy)
 581 {
 582         memset(lpolicy, 0, sizeof(*lpolicy));
 583         lpolicy->l_flock.start = wpolicy->l_flock.lfw_start;
 584         lpolicy->l_flock.end = wpolicy->l_flock.lfw_end;
 585         lpolicy->l_flock.pid = wpolicy->l_flock.lfw_pid;
 586         /* Compat code, old clients had no idea about owner field and
 587          * relied solely on pid for ownership. Introduced in LU-104, 2.1,
 588          * April 2011
 589          */
 590         lpolicy->l_flock.owner = wpolicy->l_flock.lfw_pid;
 591 }
 592
 593 void ldlm_flock_policy_wire21_to_local(const ldlm_wire_policy_data_t *wpolicy,
 594                                        ldlm_policy_data_t *lpolicy)
 595 {
 596         memset(lpolicy, 0, sizeof(*lpolicy));
 597         lpolicy->l_flock.start = wpolicy->l_flock.lfw_start;
 598         lpolicy->l_flock.end = wpolicy->l_flock.lfw_end;
 599         lpolicy->l_flock.pid = wpolicy->l_flock.lfw_pid;
 600         lpolicy->l_flock.owner = wpolicy->l_flock.lfw_owner;
 601 }
 602
 603 void ldlm_flock_policy_local_to_wire(const ldlm_policy_data_t *lpolicy,
 604                                      ldlm_wire_policy_data_t *wpolicy)
 605 {
 606         memset(wpolicy, 0, sizeof(*wpolicy));
 607         wpolicy->l_flock.lfw_start = lpolicy->l_flock.start;
 608         wpolicy->l_flock.lfw_end = lpolicy->l_flock.end;
 609         wpolicy->l_flock.lfw_pid = lpolicy->l_flock.pid;
 610         wpolicy->l_flock.lfw_owner = lpolicy->l_flock.owner;
 611 }