lustre/ldlm/ldlm_flock.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  *  Copyright (c) 2003 Hewlett-Packard Development Company LP.
   5  *   Developed under the sponsorship of the US Government under
   6  *   Subcontract No. B514193
   7  *
   8  *   This file is part of the Lustre file system, http://www.lustre.org
   9  *   Lustre is a trademark of Cluster File Systems, Inc.
  10  *
  11  *   You may have signed or agreed to another license before downloading
  12  *   this software.  If so, you are bound by the terms and conditions
  13  *   of that agreement, and the following does not apply to you.  See the
  14  *   LICENSE file included with this distribution for more information.
  15  *
  16  *   If you did not agree to a different license, then this copy of Lustre
  17  *   is open source software; you can redistribute it and/or modify it
  18  *   under the terms of version 2 of the GNU General Public License as
  19  *   published by the Free Software Foundation.
  20  *
  21  *   In either case, Lustre is distributed in the hope that it will be
  22  *   useful, but WITHOUT ANY WARRANTY; without even the implied warranty
  23  *   of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  *   license text for more details.
  25  */
  26
  27 #define DEBUG_SUBSYSTEM S_LDLM
  28
  29 #ifdef __KERNEL__
  30 #include <lustre_dlm.h>
  31 #include <obd_support.h>
  32 #include <obd_class.h>
  33 #include <lustre_lib.h>
  34 #include <libcfs/list.h>
  35 #else
  36 #include <liblustre.h>
  37 #include <obd_class.h>
  38 #endif
  39
  40 #include "ldlm_internal.h"
  41
  42 #define l_flock_waitq   l_lru
  43
  44 /**
  45  * Wait queue for Posix lock deadlock detection, added with
  46  * ldlm_lock::l_flock_waitq.
  47  */
  48 static CFS_LIST_HEAD(ldlm_flock_waitq);
  49 /**
  50  * Lock protecting access to ldlm_flock_waitq.
  51  */
  52 spinlock_t ldlm_flock_waitq_lock = SPIN_LOCK_UNLOCKED;
  53
  54 int ldlm_flock_blocking_ast(struct ldlm_lock *lock, struct ldlm_lock_desc *desc,
  55                             void *data, int flag);
  56
  57 /**
  58  * list_for_remaining_safe - iterate over the remaining entries in a list
  59  *              and safeguard against removal of a list entry.
  60  * @pos:        the &struct list_head to use as a loop counter. pos MUST
  61  *              have been initialized prior to using it in this macro.
  62  * @n:          another &struct list_head to use as temporary storage
  63  * @head:       the head for your list.
  64  */
  65 #define list_for_remaining_safe(pos, n, head) \
  66         for (n = pos->next; pos != (head); pos = n, n = pos->next)
  67
  68 static inline int
  69 ldlm_same_flock_owner(struct ldlm_lock *lock, struct ldlm_lock *new)
  70 {
  71         return((new->l_policy_data.l_flock.pid ==
  72                 lock->l_policy_data.l_flock.pid) &&
  73                (new->l_export == lock->l_export));
  74 }
  75
  76 static inline int
  77 ldlm_flocks_overlap(struct ldlm_lock *lock, struct ldlm_lock *new)
  78 {
  79         return((new->l_policy_data.l_flock.start <=
  80                 lock->l_policy_data.l_flock.end) &&
  81                (new->l_policy_data.l_flock.end >=
  82                 lock->l_policy_data.l_flock.start));
  83 }
  84
  85 static inline void
  86 ldlm_flock_destroy(struct ldlm_lock *lock, ldlm_mode_t mode, int flags)
  87 {
  88         ENTRY;
  89
  90         LDLM_DEBUG(lock, "ldlm_flock_destroy(mode: %d, flags: 0x%x)",
  91                    mode, flags);
  92
  93         /* Safe to not lock here, since it should be empty anyway */
  94         LASSERT(list_empty(&lock->l_flock_waitq));
  95
  96         list_del_init(&lock->l_res_link);
  97         if (flags == LDLM_FL_WAIT_NOREPROC) {
  98                 /* client side - set a flag to prevent sending a CANCEL */
  99                 lock->l_flags |= LDLM_FL_LOCAL_ONLY | LDLM_FL_CBPENDING;
 100                 ldlm_lock_decref_internal(lock, mode);
 101         }
 102
 103         ldlm_lock_destroy_nolock(lock);
 104         EXIT;
 105 }
 106
 107 static int
 108 ldlm_flock_deadlock(struct ldlm_lock *req, struct ldlm_lock *blocking_lock)
 109 {
 110         struct obd_export *req_export = req->l_export;
 111         struct obd_export *blocking_export = blocking_lock->l_export;
 112         pid_t req_pid = req->l_policy_data.l_flock.pid;
 113         pid_t blocking_pid = blocking_lock->l_policy_data.l_flock.pid;
 114         struct ldlm_lock *lock;
 115
 116         spin_lock(&ldlm_flock_waitq_lock);
 117 restart:
 118         list_for_each_entry(lock, &ldlm_flock_waitq, l_flock_waitq) {
 119                 if ((lock->l_policy_data.l_flock.pid != blocking_pid) ||
 120                     (lock->l_export != blocking_export))
 121                         continue;
 122
 123                 blocking_pid = lock->l_policy_data.l_flock.blocking_pid;
 124                 blocking_export = (struct obd_export *)(long)
 125                         lock->l_policy_data.l_flock.blocking_export;
 126                 if (blocking_pid == req_pid && blocking_export == req_export) {
 127                         spin_unlock(&ldlm_flock_waitq_lock);
 128                         return 1;
 129                 }
 130
 131                 goto restart;
 132         }
 133         spin_unlock(&ldlm_flock_waitq_lock);
 134
 135         return 0;
 136 }
 137
 138 int
 139 ldlm_process_flock_lock(struct ldlm_lock *req, int *flags, int first_enq,
 140                         ldlm_error_t *err, struct list_head *work_list)
 141 {
 142         struct ldlm_resource *res = req->l_resource;
 143         struct ldlm_namespace *ns = res->lr_namespace;
 144         struct list_head *tmp;
 145         struct list_head *ownlocks = NULL;
 146         struct ldlm_lock *lock = NULL;
 147         struct ldlm_lock *new = req;
 148         struct ldlm_lock *new2 = NULL;
 149         ldlm_mode_t mode = req->l_req_mode;
 150         int local = ns_is_client(ns);
 151         int added = (mode == LCK_NL);
 152         int overlaps = 0;
 153         ENTRY;
 154
 155         CDEBUG(D_DLMTRACE, "flags %#x pid %u mode %u start "LPU64" end "LPU64
 156                "\n", *flags, new->l_policy_data.l_flock.pid, mode,
 157                req->l_policy_data.l_flock.start,
 158                req->l_policy_data.l_flock.end);
 159
 160         *err = ELDLM_OK;
 161
 162         if (local) {
 163                 /* No blocking ASTs are sent to the clients for
 164                  * Posix file & record locks */
 165                 req->l_blocking_ast = NULL;
 166         } else {
 167                 /* Called on the server for lock cancels. */
 168                 req->l_blocking_ast = ldlm_flock_blocking_ast;
 169         }
 170
 171         if ((*flags == LDLM_FL_WAIT_NOREPROC) || (mode == LCK_NL)) {
 172                 /* This loop determines where this processes locks start
 173                  * in the resource lr_granted list. */
 174                 list_for_each(tmp, &res->lr_granted) {
 175                         lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 176                         if (ldlm_same_flock_owner(lock, req)) {
 177                                 ownlocks = tmp;
 178                                 break;
 179                         }
 180                 }
 181         } else {
 182                 lockmode_verify(mode);
 183
 184                 /* This loop determines if there are existing locks
 185                  * that conflict with the new lock request. */
 186                 list_for_each(tmp, &res->lr_granted) {
 187                         lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 188
 189                         if (ldlm_same_flock_owner(lock, req)) {
 190                                 if (!ownlocks)
 191                                         ownlocks = tmp;
 192                                 continue;
 193                         }
 194
 195                         /* locks are compatible, overlap doesn't matter */
 196                         if (lockmode_compat(lock->l_granted_mode, mode))
 197                                 continue;
 198
 199                         if (!ldlm_flocks_overlap(lock, req))
 200                                 continue;
 201
 202                         if (!first_enq)
 203                                 RETURN(LDLM_ITER_CONTINUE);
 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                         if (ldlm_flock_deadlock(req, lock)) {
 225                                 ldlm_flock_destroy(req, mode, *flags);
 226                                 *err = -EDEADLK;
 227                                 RETURN(LDLM_ITER_STOP);
 228                         }
 229
 230                         req->l_policy_data.l_flock.blocking_pid =
 231                                 lock->l_policy_data.l_flock.pid;
 232                         req->l_policy_data.l_flock.blocking_export =
 233                                 (long)(void *)lock->l_export;
 234
 235                         LASSERT(list_empty(&req->l_flock_waitq));
 236                         spin_lock(&ldlm_flock_waitq_lock);
 237                         list_add_tail(&req->l_flock_waitq, &ldlm_flock_waitq);
 238                         spin_unlock(&ldlm_flock_waitq_lock);
 239
 240                         ldlm_resource_add_lock(res, &res->lr_waiting, req);
 241                         *flags |= LDLM_FL_BLOCK_GRANTED;
 242                         RETURN(LDLM_ITER_STOP);
 243                 }
 244         }
 245
 246         if (*flags & LDLM_FL_TEST_LOCK) {
 247                 ldlm_flock_destroy(req, mode, *flags);
 248                 req->l_req_mode = LCK_NL;
 249                 *flags |= LDLM_FL_LOCK_CHANGED;
 250                 RETURN(LDLM_ITER_STOP);
 251         }
 252
 253         /* In case we had slept on this lock request take it off of the
 254          * deadlock detection waitq. */
 255         spin_lock(&ldlm_flock_waitq_lock);
 256         list_del_init(&req->l_flock_waitq);
 257         spin_unlock(&ldlm_flock_waitq_lock);
 258
 259         /* Scan the locks owned by this process that overlap this request.
 260          * We may have to merge or split existing locks. */
 261
 262         if (!ownlocks)
 263                 ownlocks = &res->lr_granted;
 264
 265         list_for_remaining_safe(ownlocks, tmp, &res->lr_granted) {
 266                 lock = list_entry(ownlocks, struct ldlm_lock, l_res_link);
 267
 268                 if (!ldlm_same_flock_owner(lock, new))
 269                         break;
 270
 271                 if (lock->l_granted_mode == mode) {
 272                         /* If the modes are the same then we need to process
 273                          * locks that overlap OR adjoin the new lock. The extra
 274                          * logic condition is necessary to deal with arithmetic
 275                          * overflow and underflow. */
 276                         if ((new->l_policy_data.l_flock.start >
 277                              (lock->l_policy_data.l_flock.end + 1))
 278                             && (lock->l_policy_data.l_flock.end !=
 279                                 OBD_OBJECT_EOF))
 280                                 continue;
 281
 282                         if ((new->l_policy_data.l_flock.end <
 283                              (lock->l_policy_data.l_flock.start - 1))
 284                             && (lock->l_policy_data.l_flock.start != 0))
 285                                 break;
 286
 287                         if (new->l_policy_data.l_flock.start <
 288                             lock->l_policy_data.l_flock.start) {
 289                                 lock->l_policy_data.l_flock.start =
 290                                         new->l_policy_data.l_flock.start;
 291                         } else {
 292                                 new->l_policy_data.l_flock.start =
 293                                         lock->l_policy_data.l_flock.start;
 294                         }
 295
 296                         if (new->l_policy_data.l_flock.end >
 297                             lock->l_policy_data.l_flock.end) {
 298                                 lock->l_policy_data.l_flock.end =
 299                                         new->l_policy_data.l_flock.end;
 300                         } else {
 301                                 new->l_policy_data.l_flock.end =
 302                                         lock->l_policy_data.l_flock.end;
 303                         }
 304
 305                         if (added) {
 306                                 ldlm_flock_destroy(lock, mode, *flags);
 307                         } else {
 308                                 new = lock;
 309                                 added = 1;
 310                         }
 311                         continue;
 312                 }
 313
 314                 if (new->l_policy_data.l_flock.start >
 315                     lock->l_policy_data.l_flock.end)
 316                         continue;
 317
 318                 if (new->l_policy_data.l_flock.end <
 319                     lock->l_policy_data.l_flock.start)
 320                         break;
 321
 322                 ++overlaps;
 323
 324                 if (new->l_policy_data.l_flock.start <=
 325                     lock->l_policy_data.l_flock.start) {
 326                         if (new->l_policy_data.l_flock.end <
 327                             lock->l_policy_data.l_flock.end) {
 328                                 lock->l_policy_data.l_flock.start =
 329                                         new->l_policy_data.l_flock.end + 1;
 330                                 break;
 331                         }
 332                         ldlm_flock_destroy(lock, lock->l_req_mode, *flags);
 333                         continue;
 334                 }
 335                 if (new->l_policy_data.l_flock.end >=
 336                     lock->l_policy_data.l_flock.end) {
 337                         lock->l_policy_data.l_flock.end =
 338                                 new->l_policy_data.l_flock.start - 1;
 339                         continue;
 340                 }
 341
 342                 /* split the existing lock into two locks */
 343
 344                 /* if this is an F_UNLCK operation then we could avoid
 345                  * allocating a new lock and use the req lock passed in
 346                  * with the request but this would complicate the reply
 347                  * processing since updates to req get reflected in the
 348                  * reply. The client side replays the lock request so
 349                  * it must see the original lock data in the reply. */
 350
 351                 /* XXX - if ldlm_lock_new() can sleep we should
 352                  * release the ns_lock, allocate the new lock,
 353                  * and restart processing this lock. */
 354                 new2 = ldlm_lock_create(ns, &res->lr_name, LDLM_FLOCK,
 355                                         lock->l_granted_mode, NULL, NULL, NULL,
 356                                         NULL, 0);
 357                 if (!new2) {
 358                         ldlm_flock_destroy(req, lock->l_granted_mode, *flags);
 359                         *err = -ENOLCK;
 360                         RETURN(LDLM_ITER_STOP);
 361                 }
 362
 363                 new2->l_granted_mode = lock->l_granted_mode;
 364                 new2->l_policy_data.l_flock.pid =
 365                         new->l_policy_data.l_flock.pid;
 366                 new2->l_policy_data.l_flock.start =
 367                         lock->l_policy_data.l_flock.start;
 368                 new2->l_policy_data.l_flock.end =
 369                         new->l_policy_data.l_flock.start - 1;
 370                 lock->l_policy_data.l_flock.start =
 371                         new->l_policy_data.l_flock.end + 1;
 372                 new2->l_conn_export = lock->l_conn_export;
 373                 if (lock->l_export != NULL) {
 374                         new2->l_export = class_export_get(lock->l_export);
 375                         spin_lock(&new2->l_export->exp_ldlm_data.led_lock);
 376                         list_add(&new2->l_export_chain,
 377                                  &new2->l_export->exp_ldlm_data.led_held_locks);
 378                         spin_unlock(&new2->l_export->exp_ldlm_data.led_lock);
 379                 }
 380                 if (*flags == LDLM_FL_WAIT_NOREPROC)
 381                         ldlm_lock_addref_internal(new2, lock->l_granted_mode);
 382
 383                 /* insert new2 at lock */
 384                 ldlm_resource_add_lock(res, ownlocks, new2);
 385                 LDLM_LOCK_PUT(new2);
 386                 break;
 387         }
 388
 389         /* At this point we're granting the lock request. */
 390         req->l_granted_mode = req->l_req_mode;
 391
 392         /* Add req to the granted queue before calling ldlm_reprocess_all(). */
 393         if (!added) {
 394                 list_del_init(&req->l_res_link);
 395                 /* insert new lock before ownlocks in list. */
 396                 ldlm_resource_add_lock(res, ownlocks, req);
 397         }
 398
 399         if (*flags != LDLM_FL_WAIT_NOREPROC) {
 400                 if (first_enq) {
 401                         /* If this is an unlock, reprocess the waitq and
 402                          * send completions ASTs for locks that can now be
 403                          * granted. The only problem with doing this
 404                          * reprocessing here is that the completion ASTs for
 405                          * newly granted locks will be sent before the unlock
 406                          * completion is sent. It shouldn't be an issue. Also
 407                          * note that ldlm_process_flock_lock() will recurse,
 408                          * but only once because first_enq will be false from
 409                          * ldlm_reprocess_queue. */
 410                         if ((mode == LCK_NL) && overlaps) {
 411                                 CFS_LIST_HEAD(rpc_list);
 412                                 int rc;
 413 restart:
 414                                 ldlm_reprocess_queue(res, &res->lr_waiting,
 415                                                      &rpc_list);
 416
 417                                 unlock_res(res);
 418                                 rc = ldlm_run_ast_work(&rpc_list, LDLM_WORK_BL_AST);
 419                                 lock_res(res);
 420                                 if (rc == -ERESTART)
 421                                         GOTO(restart, -ERESTART);
 422                        }
 423                 } else {
 424                         LASSERT(req->l_completion_ast);
 425                         ldlm_add_ast_work_item(req, NULL, work_list);
 426                 }
 427         }
 428
 429         /* In case we're reprocessing the requested lock we can't destroy
 430          * it until after calling ldlm_ast_work_item() above so that lawi()
 431          * can bump the reference count on req. Otherwise req could be freed
 432          * before the completion AST can be sent.  */
 433         if (added)
 434                 ldlm_flock_destroy(req, mode, *flags);
 435
 436         ldlm_resource_dump(D_OTHER, res);
 437         RETURN(LDLM_ITER_CONTINUE);
 438 }
 439
 440 struct ldlm_flock_wait_data {
 441         struct ldlm_lock *fwd_lock;
 442         int               fwd_generation;
 443 };
 444
 445 static void
 446 ldlm_flock_interrupted_wait(void *data)
 447 {
 448         struct ldlm_lock *lock;
 449         struct lustre_handle lockh;
 450         int rc;
 451         ENTRY;
 452
 453         lock = ((struct ldlm_flock_wait_data *)data)->fwd_lock;
 454
 455         /* take lock off the deadlock detection waitq. */
 456         spin_lock(&ldlm_flock_waitq_lock);
 457         list_del_init(&lock->l_flock_waitq);
 458         spin_unlock(&ldlm_flock_waitq_lock);
 459
 460         /* client side - set flag to prevent lock from being put on lru list */
 461         lock->l_flags |= LDLM_FL_CBPENDING;
 462
 463         ldlm_lock_decref_internal(lock, lock->l_req_mode);
 464         ldlm_lock2handle(lock, &lockh);
 465         rc = ldlm_cli_cancel(&lockh);
 466         if (rc != ELDLM_OK)
 467                 CERROR("ldlm_cli_cancel: %d\n", rc);
 468
 469         EXIT;
 470 }
 471
 472 int
 473 ldlm_flock_completion_ast(struct ldlm_lock *lock, int flags, void *data)
 474 {
 475         struct ldlm_namespace *ns;
 476         cfs_flock_t *getlk = lock->l_ast_data;
 477         struct ldlm_flock_wait_data fwd;
 478         struct obd_device *obd;
 479         struct obd_import *imp = NULL;
 480         ldlm_error_t err;
 481         int rc = 0;
 482         struct l_wait_info lwi;
 483         ENTRY;
 484
 485         CDEBUG(D_DLMTRACE, "flags: 0x%x data: %p getlk: %p\n",
 486                flags, data, getlk);
 487
 488         /* Import invalidation. We need to actually release the lock
 489          * references being held, so that it can go away. No point in
 490          * holding the lock even if app still believes it has it, since
 491          * server already dropped it anyway. Only for granted locks too. */
 492         lock_res_and_lock(lock);
 493         if ((lock->l_flags & (LDLM_FL_FAILED|LDLM_FL_LOCAL_ONLY)) ==
 494             (LDLM_FL_FAILED|LDLM_FL_LOCAL_ONLY)) {
 495                 unlock_res_and_lock(lock);
 496                 if (lock->l_req_mode == lock->l_granted_mode &&
 497                     lock->l_granted_mode != LCK_NL)
 498                         ldlm_lock_decref_internal(lock, lock->l_req_mode);
 499                 RETURN(0);
 500         }
 501         unlock_res_and_lock(lock);
 502
 503         LASSERT(flags != LDLM_FL_WAIT_NOREPROC);
 504
 505         if (!(flags & (LDLM_FL_BLOCK_WAIT | LDLM_FL_BLOCK_GRANTED |
 506                        LDLM_FL_BLOCK_CONV)))
 507                 goto  granted;
 508
 509         LDLM_DEBUG(lock, "client-side enqueue returned a blocked lock, "
 510                    "sleeping");
 511
 512         fwd.fwd_lock = lock;
 513         obd = class_exp2obd(lock->l_conn_export);
 514
 515         /* if this is a local lock, then there is no import */
 516         if (obd != NULL)
 517                 imp = obd->u.cli.cl_import;
 518
 519         if (imp != NULL) {
 520                 spin_lock(&imp->imp_lock);
 521                 fwd.fwd_generation = imp->imp_generation;
 522                 spin_unlock(&imp->imp_lock);
 523         }
 524
 525         lwi = LWI_TIMEOUT_INTR(0, NULL, ldlm_flock_interrupted_wait, &fwd);
 526
 527         /* Go to sleep until the lock is granted. */
 528         rc = l_wait_event(lock->l_waitq,
 529                           ((lock->l_req_mode == lock->l_granted_mode) ||
 530                            lock->l_destroyed), &lwi);
 531
 532         LDLM_DEBUG(lock, "client-side enqueue waking up: rc = %d", rc);
 533         RETURN(rc);
 534
 535 granted:
 536         /* before flock's complete ast gets here, the flock
 537          * can possibly be freed by another thread
 538          */
 539         if (lock->l_destroyed) {
 540                 LDLM_DEBUG(lock, "already destroyed by another thread");
 541                 RETURN(0);
 542         }
 543
 544         LDLM_DEBUG(lock, "client-side enqueue granted");
 545         ns = lock->l_resource->lr_namespace;
 546         lock_res(lock->l_resource);
 547
 548         /* take lock off the deadlock detection waitq. */
 549         spin_lock(&ldlm_flock_waitq_lock);
 550         list_del_init(&lock->l_flock_waitq);
 551         spin_unlock(&ldlm_flock_waitq_lock);
 552
 553         /* ldlm_lock_enqueue() has already placed lock on the granted list. */
 554         list_del_init(&lock->l_res_link);
 555
 556         if (flags & LDLM_FL_TEST_LOCK) {
 557                 /* fcntl(F_GETLK) request */
 558                 /* The old mode was saved in getlk->fl_type so that if the mode
 559                  * in the lock changes we can decref the approprate refcount. */
 560                 ldlm_flock_destroy(lock, cfs_flock_type(getlk), LDLM_FL_WAIT_NOREPROC);
 561                 switch (lock->l_granted_mode) {
 562                 case LCK_PR:
 563                         cfs_flock_set_type(getlk, F_RDLCK);
 564                         break;
 565                 case LCK_PW:
 566                         cfs_flock_set_type(getlk, F_WRLCK);
 567                         break;
 568                 default:
 569                         cfs_flock_set_type(getlk, F_UNLCK);
 570                 }
 571                 cfs_flock_set_pid(getlk, (pid_t)lock->l_policy_data.l_flock.pid);
 572                 cfs_flock_set_start(getlk, (loff_t)lock->l_policy_data.l_flock.start);
 573                 cfs_flock_set_end(getlk, (loff_t)lock->l_policy_data.l_flock.end);
 574         } else {
 575                 int noreproc = LDLM_FL_WAIT_NOREPROC;
 576
 577                 /* We need to reprocess the lock to do merges or splits
 578                  * with existing locks owned by this process. */
 579                 ldlm_process_flock_lock(lock, &noreproc, 1, &err, NULL);
 580                 if (flags == 0)
 581                         cfs_waitq_signal(&lock->l_waitq);
 582         }
 583         unlock_res(lock->l_resource);
 584         RETURN(0);
 585 }
 586 EXPORT_SYMBOL(ldlm_flock_completion_ast);
 587
 588 int ldlm_flock_blocking_ast(struct ldlm_lock *lock, struct ldlm_lock_desc *desc,
 589                             void *data, int flag)
 590 {
 591         struct ldlm_namespace *ns;
 592         ENTRY;
 593
 594         LASSERT(lock);
 595         LASSERT(flag == LDLM_CB_CANCELING);
 596
 597         ns = lock->l_resource->lr_namespace;
 598
 599         /* take lock off the deadlock detection waitq. */
 600         spin_lock(&ldlm_flock_waitq_lock);
 601         list_del_init(&lock->l_flock_waitq);
 602         spin_unlock(&ldlm_flock_waitq_lock);
 603         RETURN(0);
 604 }