lustre/ldlm/ldlm_lock.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * GPL HEADER START
   5  *
   6  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License version 2 for more details (a copy is included
  16  * in the LICENSE file that accompanied this code).
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * version 2 along with this program; If not, see
  20  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  21  *
  22  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  23  * CA 95054 USA or visit www.sun.com if you need additional information or
  24  * have any questions.
  25  *
  26  * GPL HEADER END
  27  */
  28 /*
  29  * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
  30  * Use is subject to license terms.
  31  *
  32  * Copyright (c) 2011 Whamcloud, Inc.
  33  *
  34  */
  35 /*
  36  * This file is part of Lustre, http://www.lustre.org/
  37  * Lustre is a trademark of Sun Microsystems, Inc.
  38  *
  39  * lustre/ldlm/ldlm_lock.c
  40  *
  41  * Author: Peter Braam <braam@clusterfs.com>
  42  * Author: Phil Schwan <phil@clusterfs.com>
  43  */
  44
  45 #define DEBUG_SUBSYSTEM S_LDLM
  46
  47 #ifdef __KERNEL__
  48 # include <libcfs/libcfs.h>
  49 # include <linux/lustre_intent.h>
  50 #else
  51 # include <liblustre.h>
  52 #endif
  53
  54 #include <obd_class.h>
  55 #include "ldlm_internal.h"
  56
  57 /* lock types */
  58 char *ldlm_lockname[] = {
  59         [0] "--",
  60         [LCK_EX] "EX",
  61         [LCK_PW] "PW",
  62         [LCK_PR] "PR",
  63         [LCK_CW] "CW",
  64         [LCK_CR] "CR",
  65         [LCK_NL] "NL",
  66         [LCK_GROUP] "GROUP",
  67         [LCK_COS] "COS"
  68 };
  69
  70 char *ldlm_typename[] = {
  71         [LDLM_PLAIN] "PLN",
  72         [LDLM_EXTENT] "EXT",
  73         [LDLM_FLOCK] "FLK",
  74         [LDLM_IBITS] "IBT",
  75 };
  76
  77 static ldlm_policy_wire_to_local_t ldlm_policy_wire_to_local[] = {
  78         [LDLM_PLAIN - LDLM_MIN_TYPE] ldlm_plain_policy_wire_to_local,
  79         [LDLM_EXTENT - LDLM_MIN_TYPE] ldlm_extent_policy_wire_to_local,
  80         [LDLM_FLOCK - LDLM_MIN_TYPE] ldlm_flock_policy_wire_to_local,
  81         [LDLM_IBITS - LDLM_MIN_TYPE] ldlm_ibits_policy_wire_to_local,
  82 };
  83
  84 static ldlm_policy_local_to_wire_t ldlm_policy_local_to_wire[] = {
  85         [LDLM_PLAIN - LDLM_MIN_TYPE] ldlm_plain_policy_local_to_wire,
  86         [LDLM_EXTENT - LDLM_MIN_TYPE] ldlm_extent_policy_local_to_wire,
  87         [LDLM_FLOCK - LDLM_MIN_TYPE] ldlm_flock_policy_local_to_wire,
  88         [LDLM_IBITS - LDLM_MIN_TYPE] ldlm_ibits_policy_local_to_wire,
  89 };
  90
  91 /**
  92  * Converts lock policy from local format to on the wire lock_desc format
  93  */
  94 void ldlm_convert_policy_to_wire(ldlm_type_t type,
  95                                  const ldlm_policy_data_t *lpolicy,
  96                                  ldlm_wire_policy_data_t *wpolicy)
  97 {
  98         ldlm_policy_local_to_wire_t convert;
  99
 100         convert = ldlm_policy_local_to_wire[type - LDLM_MIN_TYPE];
 101
 102         convert(lpolicy, wpolicy);
 103 }
 104
 105 /**
 106  * Converts lock policy from on the wire lock_desc format to local format
 107  */
 108 void ldlm_convert_policy_to_local(ldlm_type_t type,
 109                                   const ldlm_wire_policy_data_t *wpolicy,
 110                                   ldlm_policy_data_t *lpolicy)
 111 {
 112         ldlm_policy_wire_to_local_t convert;
 113
 114         convert = ldlm_policy_wire_to_local[type - LDLM_MIN_TYPE];
 115
 116         convert(wpolicy, lpolicy);
 117 }
 118
 119 char *ldlm_it2str(int it)
 120 {
 121         switch (it) {
 122         case IT_OPEN:
 123                 return "open";
 124         case IT_CREAT:
 125                 return "creat";
 126         case (IT_OPEN | IT_CREAT):
 127                 return "open|creat";
 128         case IT_READDIR:
 129                 return "readdir";
 130         case IT_GETATTR:
 131                 return "getattr";
 132         case IT_LOOKUP:
 133                 return "lookup";
 134         case IT_UNLINK:
 135                 return "unlink";
 136         case IT_GETXATTR:
 137                 return "getxattr";
 138         default:
 139                 CERROR("Unknown intent %d\n", it);
 140                 return "UNKNOWN";
 141         }
 142 }
 143
 144 extern cfs_mem_cache_t *ldlm_lock_slab;
 145
 146 static ldlm_processing_policy ldlm_processing_policy_table[] = {
 147         [LDLM_PLAIN] ldlm_process_plain_lock,
 148         [LDLM_EXTENT] ldlm_process_extent_lock,
 149 #ifdef __KERNEL__
 150         [LDLM_FLOCK] ldlm_process_flock_lock,
 151 #endif
 152         [LDLM_IBITS] ldlm_process_inodebits_lock,
 153 };
 154
 155 ldlm_processing_policy ldlm_get_processing_policy(struct ldlm_resource *res)
 156 {
 157         return ldlm_processing_policy_table[res->lr_type];
 158 }
 159
 160 void ldlm_register_intent(struct ldlm_namespace *ns, ldlm_res_policy arg)
 161 {
 162         ns->ns_policy = arg;
 163 }
 164
 165 /*
 166  * REFCOUNTED LOCK OBJECTS
 167  */
 168
 169
 170 /*
 171  * Lock refcounts, during creation:
 172  *   - one special one for allocation, dec'd only once in destroy
 173  *   - one for being a lock that's in-use
 174  *   - one for the addref associated with a new lock
 175  */
 176 struct ldlm_lock *ldlm_lock_get(struct ldlm_lock *lock)
 177 {
 178         cfs_atomic_inc(&lock->l_refc);
 179         return lock;
 180 }
 181
 182 static void ldlm_lock_free(struct ldlm_lock *lock, size_t size)
 183 {
 184         LASSERT(size == sizeof(*lock));
 185         OBD_SLAB_FREE(lock, ldlm_lock_slab, sizeof(*lock));
 186 }
 187
 188 void ldlm_lock_put(struct ldlm_lock *lock)
 189 {
 190         ENTRY;
 191
 192         LASSERT(lock->l_resource != LP_POISON);
 193         LASSERT(cfs_atomic_read(&lock->l_refc) > 0);
 194         if (cfs_atomic_dec_and_test(&lock->l_refc)) {
 195                 struct ldlm_resource *res;
 196
 197                 LDLM_DEBUG(lock,
 198                            "final lock_put on destroyed lock, freeing it.");
 199
 200                 res = lock->l_resource;
 201                 LASSERT(lock->l_destroyed);
 202                 LASSERT(cfs_list_empty(&lock->l_res_link));
 203                 LASSERT(cfs_list_empty(&lock->l_pending_chain));
 204
 205                 lprocfs_counter_decr(ldlm_res_to_ns(res)->ns_stats,
 206                                      LDLM_NSS_LOCKS);
 207                 lu_ref_del(&res->lr_reference, "lock", lock);
 208                 ldlm_resource_putref(res);
 209                 lock->l_resource = NULL;
 210                 if (lock->l_export) {
 211                         class_export_lock_put(lock->l_export, lock);
 212                         lock->l_export = NULL;
 213                 }
 214
 215                 if (lock->l_lvb_data != NULL)
 216                         OBD_FREE(lock->l_lvb_data, lock->l_lvb_len);
 217
 218                 ldlm_interval_free(ldlm_interval_detach(lock));
 219                 lu_ref_fini(&lock->l_reference);
 220                 OBD_FREE_RCU_CB(lock, sizeof(*lock), &lock->l_handle,
 221                                 ldlm_lock_free);
 222         }
 223
 224         EXIT;
 225 }
 226
 227 int ldlm_lock_remove_from_lru_nolock(struct ldlm_lock *lock)
 228 {
 229         int rc = 0;
 230         if (!cfs_list_empty(&lock->l_lru)) {
 231                 struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
 232
 233                 LASSERT(lock->l_resource->lr_type != LDLM_FLOCK);
 234                 cfs_list_del_init(&lock->l_lru);
 235                 if (lock->l_flags & LDLM_FL_SKIPPED)
 236                         lock->l_flags &= ~LDLM_FL_SKIPPED;
 237                 LASSERT(ns->ns_nr_unused > 0);
 238                 ns->ns_nr_unused--;
 239                 rc = 1;
 240         }
 241         return rc;
 242 }
 243
 244 int ldlm_lock_remove_from_lru(struct ldlm_lock *lock)
 245 {
 246         struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
 247         int rc;
 248
 249         ENTRY;
 250         if (lock->l_ns_srv) {
 251                 LASSERT(cfs_list_empty(&lock->l_lru));
 252                 RETURN(0);
 253         }
 254
 255         cfs_spin_lock(&ns->ns_lock);
 256         rc = ldlm_lock_remove_from_lru_nolock(lock);
 257         cfs_spin_unlock(&ns->ns_lock);
 258         EXIT;
 259         return rc;
 260 }
 261
 262 void ldlm_lock_add_to_lru_nolock(struct ldlm_lock *lock)
 263 {
 264         struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
 265
 266         lock->l_last_used = cfs_time_current();
 267         LASSERT(cfs_list_empty(&lock->l_lru));
 268         LASSERT(lock->l_resource->lr_type != LDLM_FLOCK);
 269         cfs_list_add_tail(&lock->l_lru, &ns->ns_unused_list);
 270         LASSERT(ns->ns_nr_unused >= 0);
 271         ns->ns_nr_unused++;
 272 }
 273
 274 void ldlm_lock_add_to_lru(struct ldlm_lock *lock)
 275 {
 276         struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
 277
 278         ENTRY;
 279         cfs_spin_lock(&ns->ns_lock);
 280         ldlm_lock_add_to_lru_nolock(lock);
 281         cfs_spin_unlock(&ns->ns_lock);
 282         EXIT;
 283 }
 284
 285 void ldlm_lock_touch_in_lru(struct ldlm_lock *lock)
 286 {
 287         struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
 288
 289         ENTRY;
 290         if (lock->l_ns_srv) {
 291                 LASSERT(cfs_list_empty(&lock->l_lru));
 292                 EXIT;
 293                 return;
 294         }
 295
 296         cfs_spin_lock(&ns->ns_lock);
 297         if (!cfs_list_empty(&lock->l_lru)) {
 298                 ldlm_lock_remove_from_lru_nolock(lock);
 299                 ldlm_lock_add_to_lru_nolock(lock);
 300         }
 301         cfs_spin_unlock(&ns->ns_lock);
 302         EXIT;
 303 }
 304
 305 /* This used to have a 'strict' flag, which recovery would use to mark an
 306  * in-use lock as needing-to-die.  Lest I am ever tempted to put it back, I
 307  * shall explain why it's gone: with the new hash table scheme, once you call
 308  * ldlm_lock_destroy, you can never drop your final references on this lock.
 309  * Because it's not in the hash table anymore.  -phil */
 310 int ldlm_lock_destroy_internal(struct ldlm_lock *lock)
 311 {
 312         ENTRY;
 313
 314         if (lock->l_readers || lock->l_writers) {
 315                 LDLM_ERROR(lock, "lock still has references");
 316                 ldlm_lock_dump(D_ERROR, lock, 0);
 317                 LBUG();
 318         }
 319
 320         if (!cfs_list_empty(&lock->l_res_link)) {
 321                 LDLM_ERROR(lock, "lock still on resource");
 322                 ldlm_lock_dump(D_ERROR, lock, 0);
 323                 LBUG();
 324         }
 325
 326         if (lock->l_destroyed) {
 327                 LASSERT(cfs_list_empty(&lock->l_lru));
 328                 EXIT;
 329                 return 0;
 330         }
 331         lock->l_destroyed = 1;
 332
 333         if (lock->l_export && lock->l_export->exp_lock_hash &&
 334             !cfs_hlist_unhashed(&lock->l_exp_hash))
 335                 cfs_hash_del(lock->l_export->exp_lock_hash,
 336                              &lock->l_remote_handle, &lock->l_exp_hash);
 337
 338         ldlm_lock_remove_from_lru(lock);
 339         class_handle_unhash(&lock->l_handle);
 340
 341 #if 0
 342         /* Wake anyone waiting for this lock */
 343         /* FIXME: I should probably add yet another flag, instead of using
 344          * l_export to only call this on clients */
 345         if (lock->l_export)
 346                 class_export_put(lock->l_export);
 347         lock->l_export = NULL;
 348         if (lock->l_export && lock->l_completion_ast)
 349                 lock->l_completion_ast(lock, 0);
 350 #endif
 351         EXIT;
 352         return 1;
 353 }
 354
 355 void ldlm_lock_destroy(struct ldlm_lock *lock)
 356 {
 357         int first;
 358         ENTRY;
 359         lock_res_and_lock(lock);
 360         first = ldlm_lock_destroy_internal(lock);
 361         unlock_res_and_lock(lock);
 362
 363         /* drop reference from hashtable only for first destroy */
 364         if (first) {
 365                 lu_ref_del(&lock->l_reference, "hash", lock);
 366                 LDLM_LOCK_RELEASE(lock);
 367         }
 368         EXIT;
 369 }
 370
 371 void ldlm_lock_destroy_nolock(struct ldlm_lock *lock)
 372 {
 373         int first;
 374         ENTRY;
 375         first = ldlm_lock_destroy_internal(lock);
 376         /* drop reference from hashtable only for first destroy */
 377         if (first) {
 378                 lu_ref_del(&lock->l_reference, "hash", lock);
 379                 LDLM_LOCK_RELEASE(lock);
 380         }
 381         EXIT;
 382 }
 383
 384 /* this is called by portals_handle2object with the handle lock taken */
 385 static void lock_handle_addref(void *lock)
 386 {
 387         LDLM_LOCK_GET((struct ldlm_lock *)lock);
 388 }
 389
 390 /*
 391  * usage: pass in a resource on which you have done ldlm_resource_get
 392  *        new lock will take over the refcount.
 393  * returns: lock with refcount 2 - one for current caller and one for remote
 394  */
 395 static struct ldlm_lock *ldlm_lock_new(struct ldlm_resource *resource)
 396 {
 397         struct ldlm_lock *lock;
 398         ENTRY;
 399
 400         if (resource == NULL)
 401                 LBUG();
 402
 403         OBD_SLAB_ALLOC_PTR_GFP(lock, ldlm_lock_slab, CFS_ALLOC_IO);
 404         if (lock == NULL)
 405                 RETURN(NULL);
 406
 407         cfs_spin_lock_init(&lock->l_lock);
 408         lock->l_resource = resource;
 409         lu_ref_add(&resource->lr_reference, "lock", lock);
 410
 411         cfs_atomic_set(&lock->l_refc, 2);
 412         CFS_INIT_LIST_HEAD(&lock->l_res_link);
 413         CFS_INIT_LIST_HEAD(&lock->l_lru);
 414         CFS_INIT_LIST_HEAD(&lock->l_pending_chain);
 415         CFS_INIT_LIST_HEAD(&lock->l_bl_ast);
 416         CFS_INIT_LIST_HEAD(&lock->l_cp_ast);
 417         CFS_INIT_LIST_HEAD(&lock->l_rk_ast);
 418         cfs_waitq_init(&lock->l_waitq);
 419         lock->l_blocking_lock = NULL;
 420         CFS_INIT_LIST_HEAD(&lock->l_sl_mode);
 421         CFS_INIT_LIST_HEAD(&lock->l_sl_policy);
 422         CFS_INIT_HLIST_NODE(&lock->l_exp_hash);
 423
 424         lprocfs_counter_incr(ldlm_res_to_ns(resource)->ns_stats,
 425                              LDLM_NSS_LOCKS);
 426         CFS_INIT_LIST_HEAD(&lock->l_handle.h_link);
 427         class_handle_hash(&lock->l_handle, lock_handle_addref);
 428
 429         lu_ref_init(&lock->l_reference);
 430         lu_ref_add(&lock->l_reference, "hash", lock);
 431         lock->l_callback_timeout = 0;
 432
 433 #if LUSTRE_TRACKS_LOCK_EXP_REFS
 434         CFS_INIT_LIST_HEAD(&lock->l_exp_refs_link);
 435         lock->l_exp_refs_nr = 0;
 436         lock->l_exp_refs_target = NULL;
 437 #endif
 438
 439         RETURN(lock);
 440 }
 441
 442 int ldlm_lock_change_resource(struct ldlm_namespace *ns, struct ldlm_lock *lock,
 443                               const struct ldlm_res_id *new_resid)
 444 {
 445         struct ldlm_resource *oldres = lock->l_resource;
 446         struct ldlm_resource *newres;
 447         int type;
 448         ENTRY;
 449
 450         LASSERT(ns_is_client(ns));
 451
 452         lock_res_and_lock(lock);
 453         if (memcmp(new_resid, &lock->l_resource->lr_name,
 454                    sizeof(lock->l_resource->lr_name)) == 0) {
 455                 /* Nothing to do */
 456                 unlock_res_and_lock(lock);
 457                 RETURN(0);
 458         }
 459
 460         LASSERT(new_resid->name[0] != 0);
 461
 462         /* This function assumes that the lock isn't on any lists */
 463         LASSERT(cfs_list_empty(&lock->l_res_link));
 464
 465         type = oldres->lr_type;
 466         unlock_res_and_lock(lock);
 467
 468         newres = ldlm_resource_get(ns, NULL, new_resid, type, 1);
 469         if (newres == NULL)
 470                 RETURN(-ENOMEM);
 471
 472         lu_ref_add(&newres->lr_reference, "lock", lock);
 473         /*
 474          * To flip the lock from the old to the new resource, lock, oldres and
 475          * newres have to be locked. Resource spin-locks are nested within
 476          * lock->l_lock, and are taken in the memory address order to avoid
 477          * dead-locks.
 478          */
 479         cfs_spin_lock(&lock->l_lock);
 480         oldres = lock->l_resource;
 481         if (oldres < newres) {
 482                 lock_res(oldres);
 483                 lock_res_nested(newres, LRT_NEW);
 484         } else {
 485                 lock_res(newres);
 486                 lock_res_nested(oldres, LRT_NEW);
 487         }
 488         LASSERT(memcmp(new_resid, &oldres->lr_name,
 489                        sizeof oldres->lr_name) != 0);
 490         lock->l_resource = newres;
 491         unlock_res(oldres);
 492         unlock_res_and_lock(lock);
 493
 494         /* ...and the flowers are still standing! */
 495         lu_ref_del(&oldres->lr_reference, "lock", lock);
 496         ldlm_resource_putref(oldres);
 497
 498         RETURN(0);
 499 }
 500
 501 /*
 502  *  HANDLES
 503  */
 504
 505 void ldlm_lock2handle(const struct ldlm_lock *lock, struct lustre_handle *lockh)
 506 {
 507         lockh->cookie = lock->l_handle.h_cookie;
 508 }
 509
 510 /* if flags: atomically get the lock and set the flags.
 511  *           Return NULL if flag already set
 512  */
 513
 514 struct ldlm_lock *__ldlm_handle2lock(const struct lustre_handle *handle,
 515                                      int flags)
 516 {
 517         struct ldlm_lock *lock;
 518         ENTRY;
 519
 520         LASSERT(handle);
 521
 522         lock = class_handle2object(handle->cookie);
 523         if (lock == NULL)
 524                 RETURN(NULL);
 525
 526         /* It's unlikely but possible that someone marked the lock as
 527          * destroyed after we did handle2object on it */
 528         if (flags == 0 && !lock->l_destroyed) {
 529                 lu_ref_add(&lock->l_reference, "handle", cfs_current());
 530                 RETURN(lock);
 531         }
 532
 533         lock_res_and_lock(lock);
 534
 535         LASSERT(lock->l_resource != NULL);
 536
 537         lu_ref_add_atomic(&lock->l_reference, "handle", cfs_current());
 538         if (unlikely(lock->l_destroyed)) {
 539                 unlock_res_and_lock(lock);
 540                 CDEBUG(D_INFO, "lock already destroyed: lock %p\n", lock);
 541                 LDLM_LOCK_PUT(lock);
 542                 RETURN(NULL);
 543         }
 544
 545         if (flags && (lock->l_flags & flags)) {
 546                 unlock_res_and_lock(lock);
 547                 LDLM_LOCK_PUT(lock);
 548                 RETURN(NULL);
 549         }
 550
 551         if (flags)
 552                 lock->l_flags |= flags;
 553
 554         unlock_res_and_lock(lock);
 555         RETURN(lock);
 556 }
 557
 558 void ldlm_lock2desc(struct ldlm_lock *lock, struct ldlm_lock_desc *desc)
 559 {
 560         struct obd_export *exp = lock->l_export?:lock->l_conn_export;
 561         /* INODEBITS_INTEROP: If the other side does not support
 562          * inodebits, reply with a plain lock descriptor.
 563          */
 564         if ((lock->l_resource->lr_type == LDLM_IBITS) &&
 565             (exp && !(exp->exp_connect_flags & OBD_CONNECT_IBITS))) {
 566                 /* Make sure all the right bits are set in this lock we
 567                    are going to pass to client */
 568                 LASSERTF(lock->l_policy_data.l_inodebits.bits ==
 569                          (MDS_INODELOCK_LOOKUP|MDS_INODELOCK_UPDATE),
 570                          "Inappropriate inode lock bits during "
 571                          "conversion " LPU64 "\n",
 572                          lock->l_policy_data.l_inodebits.bits);
 573
 574                 ldlm_res2desc(lock->l_resource, &desc->l_resource);
 575                 desc->l_resource.lr_type = LDLM_PLAIN;
 576
 577                 /* Convert "new" lock mode to something old client can
 578                    understand */
 579                 if ((lock->l_req_mode == LCK_CR) ||
 580                     (lock->l_req_mode == LCK_CW))
 581                         desc->l_req_mode = LCK_PR;
 582                 else
 583                         desc->l_req_mode = lock->l_req_mode;
 584                 if ((lock->l_granted_mode == LCK_CR) ||
 585                     (lock->l_granted_mode == LCK_CW)) {
 586                         desc->l_granted_mode = LCK_PR;
 587                 } else {
 588                         /* We never grant PW/EX locks to clients */
 589                         LASSERT((lock->l_granted_mode != LCK_PW) &&
 590                                 (lock->l_granted_mode != LCK_EX));
 591                         desc->l_granted_mode = lock->l_granted_mode;
 592                 }
 593
 594                 /* We do not copy policy here, because there is no
 595                    policy for plain locks */
 596         } else {
 597                 ldlm_res2desc(lock->l_resource, &desc->l_resource);
 598                 desc->l_req_mode = lock->l_req_mode;
 599                 desc->l_granted_mode = lock->l_granted_mode;
 600                 ldlm_convert_policy_to_wire(lock->l_resource->lr_type,
 601                                             &lock->l_policy_data,
 602                                             &desc->l_policy_data);
 603         }
 604 }
 605
 606 void ldlm_add_bl_work_item(struct ldlm_lock *lock, struct ldlm_lock *new,
 607                            cfs_list_t *work_list)
 608 {
 609         if ((lock->l_flags & LDLM_FL_AST_SENT) == 0) {
 610                 LDLM_DEBUG(lock, "lock incompatible; sending blocking AST.");
 611                 lock->l_flags |= LDLM_FL_AST_SENT;
 612                 /* If the enqueuing client said so, tell the AST recipient to
 613                  * discard dirty data, rather than writing back. */
 614                 if (new->l_flags & LDLM_AST_DISCARD_DATA)
 615                         lock->l_flags |= LDLM_FL_DISCARD_DATA;
 616                 LASSERT(cfs_list_empty(&lock->l_bl_ast));
 617                 cfs_list_add(&lock->l_bl_ast, work_list);
 618                 LDLM_LOCK_GET(lock);
 619                 LASSERT(lock->l_blocking_lock == NULL);
 620                 lock->l_blocking_lock = LDLM_LOCK_GET(new);
 621         }
 622 }
 623
 624 void ldlm_add_cp_work_item(struct ldlm_lock *lock, cfs_list_t *work_list)
 625 {
 626         if ((lock->l_flags & LDLM_FL_CP_REQD) == 0) {
 627                 lock->l_flags |= LDLM_FL_CP_REQD;
 628                 LDLM_DEBUG(lock, "lock granted; sending completion AST.");
 629                 LASSERT(cfs_list_empty(&lock->l_cp_ast));
 630                 cfs_list_add(&lock->l_cp_ast, work_list);
 631                 LDLM_LOCK_GET(lock);
 632         }
 633 }
 634
 635 /* must be called with lr_lock held */
 636 void ldlm_add_ast_work_item(struct ldlm_lock *lock, struct ldlm_lock *new,
 637                             cfs_list_t *work_list)
 638 {
 639         ENTRY;
 640         check_res_locked(lock->l_resource);
 641         if (new)
 642                 ldlm_add_bl_work_item(lock, new, work_list);
 643         else
 644                 ldlm_add_cp_work_item(lock, work_list);
 645         EXIT;
 646 }
 647
 648 void ldlm_lock_addref(struct lustre_handle *lockh, __u32 mode)
 649 {
 650         struct ldlm_lock *lock;
 651
 652         lock = ldlm_handle2lock(lockh);
 653         LASSERT(lock != NULL);
 654         ldlm_lock_addref_internal(lock, mode);
 655         LDLM_LOCK_PUT(lock);
 656 }
 657
 658 void ldlm_lock_addref_internal_nolock(struct ldlm_lock *lock, __u32 mode)
 659 {
 660         ldlm_lock_remove_from_lru(lock);
 661         if (mode & (LCK_NL | LCK_CR | LCK_PR)) {
 662                 lock->l_readers++;
 663                 lu_ref_add_atomic(&lock->l_reference, "reader", lock);
 664         }
 665         if (mode & (LCK_EX | LCK_CW | LCK_PW | LCK_GROUP | LCK_COS)) {
 666                 lock->l_writers++;
 667                 lu_ref_add_atomic(&lock->l_reference, "writer", lock);
 668         }
 669         LDLM_LOCK_GET(lock);
 670         lu_ref_add_atomic(&lock->l_reference, "user", lock);
 671         LDLM_DEBUG(lock, "ldlm_lock_addref(%s)", ldlm_lockname[mode]);
 672 }
 673
 674 /**
 675  * Attempts to addref a lock, and fails if lock is already LDLM_FL_CBPENDING
 676  * or destroyed.
 677  *
 678  * \retval 0 success, lock was addref-ed
 679  *
 680  * \retval -EAGAIN lock is being canceled.
 681  */
 682 int ldlm_lock_addref_try(struct lustre_handle *lockh, __u32 mode)
 683 {
 684         struct ldlm_lock *lock;
 685         int               result;
 686
 687         result = -EAGAIN;
 688         lock = ldlm_handle2lock(lockh);
 689         if (lock != NULL) {
 690                 lock_res_and_lock(lock);
 691                 if (lock->l_readers != 0 || lock->l_writers != 0 ||
 692                     !(lock->l_flags & LDLM_FL_CBPENDING)) {
 693                         ldlm_lock_addref_internal_nolock(lock, mode);
 694                         result = 0;
 695                 }
 696                 unlock_res_and_lock(lock);
 697                 LDLM_LOCK_PUT(lock);
 698         }
 699         return result;
 700 }
 701
 702 /* only called for local locks */
 703 void ldlm_lock_addref_internal(struct ldlm_lock *lock, __u32 mode)
 704 {
 705         lock_res_and_lock(lock);
 706         ldlm_lock_addref_internal_nolock(lock, mode);
 707         unlock_res_and_lock(lock);
 708 }
 709
 710 /* only called in ldlm_flock_destroy and for local locks.
 711  *  * for LDLM_FLOCK type locks, l_blocking_ast is null, and
 712  *   * ldlm_lock_remove_from_lru() does nothing, it is safe
 713  *    * for ldlm_flock_destroy usage by dropping some code */
 714 void ldlm_lock_decref_internal_nolock(struct ldlm_lock *lock, __u32 mode)
 715 {
 716         LDLM_DEBUG(lock, "ldlm_lock_decref(%s)", ldlm_lockname[mode]);
 717         if (mode & (LCK_NL | LCK_CR | LCK_PR)) {
 718                 LASSERT(lock->l_readers > 0);
 719                 lu_ref_del(&lock->l_reference, "reader", lock);
 720                 lock->l_readers--;
 721         }
 722         if (mode & (LCK_EX | LCK_CW | LCK_PW | LCK_GROUP | LCK_COS)) {
 723                 LASSERT(lock->l_writers > 0);
 724                 lu_ref_del(&lock->l_reference, "writer", lock);
 725                 lock->l_writers--;
 726         }
 727
 728         lu_ref_del(&lock->l_reference, "user", lock);
 729         LDLM_LOCK_RELEASE(lock);    /* matches the LDLM_LOCK_GET() in addref */
 730 }
 731
 732 void ldlm_lock_decref_internal(struct ldlm_lock *lock, __u32 mode)
 733 {
 734         struct ldlm_namespace *ns;
 735         ENTRY;
 736
 737         lock_res_and_lock(lock);
 738
 739         ns = ldlm_lock_to_ns(lock);
 740
 741         ldlm_lock_decref_internal_nolock(lock, mode);
 742
 743         if (lock->l_flags & LDLM_FL_LOCAL &&
 744             !lock->l_readers && !lock->l_writers) {
 745                 /* If this is a local lock on a server namespace and this was
 746                  * the last reference, cancel the lock. */
 747                 CDEBUG(D_INFO, "forcing cancel of local lock\n");
 748                 lock->l_flags |= LDLM_FL_CBPENDING;
 749         }
 750
 751         if (!lock->l_readers && !lock->l_writers &&
 752             (lock->l_flags & LDLM_FL_CBPENDING)) {
 753                 /* If we received a blocked AST and this was the last reference,
 754                  * run the callback. */
 755                 if (lock->l_ns_srv && lock->l_export)
 756                         CERROR("FL_CBPENDING set on non-local lock--just a "
 757                                "warning\n");
 758
 759                 LDLM_DEBUG(lock, "final decref done on cbpending lock");
 760
 761                 LDLM_LOCK_GET(lock); /* dropped by bl thread */
 762                 ldlm_lock_remove_from_lru(lock);
 763                 unlock_res_and_lock(lock);
 764
 765                 if (lock->l_flags & LDLM_FL_FAIL_LOC)
 766                         OBD_RACE(OBD_FAIL_LDLM_CP_BL_RACE);
 767
 768                 if ((lock->l_flags & LDLM_FL_ATOMIC_CB) ||
 769                     ldlm_bl_to_thread_lock(ns, NULL, lock) != 0)
 770                         ldlm_handle_bl_callback(ns, NULL, lock);
 771         } else if (ns_is_client(ns) &&
 772                    !lock->l_readers && !lock->l_writers &&
 773                    !(lock->l_flags & LDLM_FL_NO_LRU) &&
 774                    !(lock->l_flags & LDLM_FL_BL_AST)) {
 775
 776                 LDLM_DEBUG(lock, "add lock into lru list");
 777
 778                 /* If this is a client-side namespace and this was the last
 779                  * reference, put it on the LRU. */
 780                 ldlm_lock_add_to_lru(lock);
 781                 unlock_res_and_lock(lock);
 782
 783                 if (lock->l_flags & LDLM_FL_FAIL_LOC)
 784                         OBD_RACE(OBD_FAIL_LDLM_CP_BL_RACE);
 785
 786                 /* Call ldlm_cancel_lru() only if EARLY_CANCEL and LRU RESIZE
 787                  * are not supported by the server, otherwise, it is done on
 788                  * enqueue. */
 789                 if (!exp_connect_cancelset(lock->l_conn_export) &&
 790                     !ns_connect_lru_resize(ns))
 791                         ldlm_cancel_lru(ns, 0, LDLM_ASYNC, 0);
 792         } else {
 793                 LDLM_DEBUG(lock, "do not add lock into lru list");
 794                 unlock_res_and_lock(lock);
 795         }
 796
 797         EXIT;
 798 }
 799
 800 void ldlm_lock_decref(struct lustre_handle *lockh, __u32 mode)
 801 {
 802         struct ldlm_lock *lock = __ldlm_handle2lock(lockh, 0);
 803         LASSERTF(lock != NULL, "Non-existing lock: "LPX64"\n", lockh->cookie);
 804         ldlm_lock_decref_internal(lock, mode);
 805         LDLM_LOCK_PUT(lock);
 806 }
 807
 808 /* This will drop a lock reference and mark it for destruction, but will not
 809  * necessarily cancel the lock before returning. */
 810 void ldlm_lock_decref_and_cancel(struct lustre_handle *lockh, __u32 mode)
 811 {
 812         struct ldlm_lock *lock = __ldlm_handle2lock(lockh, 0);
 813         ENTRY;
 814
 815         LASSERT(lock != NULL);
 816
 817         LDLM_DEBUG(lock, "ldlm_lock_decref(%s)", ldlm_lockname[mode]);
 818         lock_res_and_lock(lock);
 819         lock->l_flags |= LDLM_FL_CBPENDING;
 820         unlock_res_and_lock(lock);
 821         ldlm_lock_decref_internal(lock, mode);
 822         LDLM_LOCK_PUT(lock);
 823 }
 824
 825 struct sl_insert_point {
 826         cfs_list_t *res_link;
 827         cfs_list_t *mode_link;
 828         cfs_list_t *policy_link;
 829 };
 830
 831 /*
 832  * search_granted_lock
 833  *
 834  * Description:
 835  *      Finds a position to insert the new lock.
 836  * Parameters:
 837  *      queue [input]:  the granted list where search acts on;
 838  *      req [input]:    the lock whose position to be located;
 839  *      prev [output]:  positions within 3 lists to insert @req to
 840  * Return Value:
 841  *      filled @prev
 842  * NOTE: called by
 843  *  - ldlm_grant_lock_with_skiplist
 844  */
 845 static void search_granted_lock(cfs_list_t *queue,
 846                                 struct ldlm_lock *req,
 847                                 struct sl_insert_point *prev)
 848 {
 849         cfs_list_t *tmp;
 850         struct ldlm_lock *lock, *mode_end, *policy_end;
 851         ENTRY;
 852
 853         cfs_list_for_each(tmp, queue) {
 854                 lock = cfs_list_entry(tmp, struct ldlm_lock, l_res_link);
 855
 856                 mode_end = cfs_list_entry(lock->l_sl_mode.prev,
 857                                           struct ldlm_lock, l_sl_mode);
 858
 859                 if (lock->l_req_mode != req->l_req_mode) {
 860                         /* jump to last lock of mode group */
 861                         tmp = &mode_end->l_res_link;
 862                         continue;
 863                 }
 864
 865                 /* suitable mode group is found */
 866                 if (lock->l_resource->lr_type == LDLM_PLAIN) {
 867                         /* insert point is last lock of the mode group */
 868                         prev->res_link = &mode_end->l_res_link;
 869                         prev->mode_link = &mode_end->l_sl_mode;
 870                         prev->policy_link = &req->l_sl_policy;
 871                         EXIT;
 872                         return;
 873                 } else if (lock->l_resource->lr_type == LDLM_IBITS) {
 874                         for (;;) {
 875                                 policy_end =
 876                                         cfs_list_entry(lock->l_sl_policy.prev,
 877                                                        struct ldlm_lock,
 878                                                        l_sl_policy);
 879
 880                                 if (lock->l_policy_data.l_inodebits.bits ==
 881                                     req->l_policy_data.l_inodebits.bits) {
 882                                         /* insert point is last lock of
 883                                          * the policy group */
 884                                         prev->res_link =
 885                                                 &policy_end->l_res_link;
 886                                         prev->mode_link =
 887                                                 &policy_end->l_sl_mode;
 888                                         prev->policy_link =
 889                                                 &policy_end->l_sl_policy;
 890                                         EXIT;
 891                                         return;
 892                                 }
 893
 894                                 if (policy_end == mode_end)
 895                                         /* done with mode group */
 896                                         break;
 897
 898                                 /* go to next policy group within mode group */
 899                                 tmp = policy_end->l_res_link.next;
 900                                 lock = cfs_list_entry(tmp, struct ldlm_lock,
 901                                                       l_res_link);
 902                         }  /* loop over policy groups within the mode group */
 903
 904                         /* insert point is last lock of the mode group,
 905                          * new policy group is started */
 906                         prev->res_link = &mode_end->l_res_link;
 907                         prev->mode_link = &mode_end->l_sl_mode;
 908                         prev->policy_link = &req->l_sl_policy;
 909                         EXIT;
 910                         return;
 911                 } else {
 912                         LDLM_ERROR(lock,"is not LDLM_PLAIN or LDLM_IBITS lock");
 913                         LBUG();
 914                 }
 915         }
 916
 917         /* insert point is last lock on the queue,
 918          * new mode group and new policy group are started */
 919         prev->res_link = queue->prev;
 920         prev->mode_link = &req->l_sl_mode;
 921         prev->policy_link = &req->l_sl_policy;
 922         EXIT;
 923         return;
 924 }
 925
 926 static void ldlm_granted_list_add_lock(struct ldlm_lock *lock,
 927                                        struct sl_insert_point *prev)
 928 {
 929         struct ldlm_resource *res = lock->l_resource;
 930         ENTRY;
 931
 932         check_res_locked(res);
 933
 934         ldlm_resource_dump(D_INFO, res);
 935         CDEBUG(D_OTHER, "About to add this lock:\n");
 936         ldlm_lock_dump(D_OTHER, lock, 0);
 937
 938         if (lock->l_destroyed) {
 939                 CDEBUG(D_OTHER, "Lock destroyed, not adding to resource\n");
 940                 return;
 941         }
 942
 943         LASSERT(cfs_list_empty(&lock->l_res_link));
 944         LASSERT(cfs_list_empty(&lock->l_sl_mode));
 945         LASSERT(cfs_list_empty(&lock->l_sl_policy));
 946
 947         cfs_list_add(&lock->l_res_link, prev->res_link);
 948         cfs_list_add(&lock->l_sl_mode, prev->mode_link);
 949         cfs_list_add(&lock->l_sl_policy, prev->policy_link);
 950
 951         EXIT;
 952 }
 953
 954 static void ldlm_grant_lock_with_skiplist(struct ldlm_lock *lock)
 955 {
 956         struct sl_insert_point prev;
 957         ENTRY;
 958
 959         LASSERT(lock->l_req_mode == lock->l_granted_mode);
 960
 961         search_granted_lock(&lock->l_resource->lr_granted, lock, &prev);
 962         ldlm_granted_list_add_lock(lock, &prev);
 963         EXIT;
 964 }
 965
 966 /* NOTE: called by
 967  *  - ldlm_lock_enqueue
 968  *  - ldlm_reprocess_queue
 969  *  - ldlm_lock_convert
 970  *
 971  * must be called with lr_lock held
 972  */
 973 void ldlm_grant_lock(struct ldlm_lock *lock, cfs_list_t *work_list)
 974 {
 975         struct ldlm_resource *res = lock->l_resource;
 976         ENTRY;
 977
 978         check_res_locked(res);
 979
 980         lock->l_granted_mode = lock->l_req_mode;
 981         if (res->lr_type == LDLM_PLAIN || res->lr_type == LDLM_IBITS)
 982                 ldlm_grant_lock_with_skiplist(lock);
 983         else if (res->lr_type == LDLM_EXTENT)
 984                 ldlm_extent_add_lock(res, lock);
 985         else
 986                 ldlm_resource_add_lock(res, &res->lr_granted, lock);
 987
 988         if (lock->l_granted_mode < res->lr_most_restr)
 989                 res->lr_most_restr = lock->l_granted_mode;
 990
 991         if (work_list && lock->l_completion_ast != NULL)
 992                 ldlm_add_ast_work_item(lock, NULL, work_list);
 993
 994         ldlm_pool_add(&ldlm_res_to_ns(res)->ns_pool, lock);
 995         EXIT;
 996 }
 997
 998 /* returns a referenced lock or NULL.  See the flag descriptions below, in the
 999  * comment above ldlm_lock_match */
1000 static struct ldlm_lock *search_queue(cfs_list_t *queue,
1001                                       ldlm_mode_t *mode,
1002                                       ldlm_policy_data_t *policy,
1003                                       struct ldlm_lock *old_lock,
1004                                       int flags, int unref)
1005 {
1006         struct ldlm_lock *lock;
1007         cfs_list_t       *tmp;
1008
1009         cfs_list_for_each(tmp, queue) {
1010                 ldlm_mode_t match;
1011
1012                 lock = cfs_list_entry(tmp, struct ldlm_lock, l_res_link);
1013
1014                 if (lock == old_lock)
1015                         break;
1016
1017                 /* llite sometimes wants to match locks that will be
1018                  * canceled when their users drop, but we allow it to match
1019                  * if it passes in CBPENDING and the lock still has users.
1020                  * this is generally only going to be used by children
1021                  * whose parents already hold a lock so forward progress
1022                  * can still happen. */
1023                 if (lock->l_flags & LDLM_FL_CBPENDING &&
1024                     !(flags & LDLM_FL_CBPENDING))
1025                         continue;
1026                 if (!unref && lock->l_flags & LDLM_FL_CBPENDING &&
1027                     lock->l_readers == 0 && lock->l_writers == 0)
1028                         continue;
1029
1030                 if (!(lock->l_req_mode & *mode))
1031                         continue;
1032                 match = lock->l_req_mode;
1033
1034                 if (lock->l_resource->lr_type == LDLM_EXTENT &&
1035                     (lock->l_policy_data.l_extent.start >
1036                      policy->l_extent.start ||
1037                      lock->l_policy_data.l_extent.end < policy->l_extent.end))
1038                         continue;
1039
1040                 if (unlikely(match == LCK_GROUP) &&
1041                     lock->l_resource->lr_type == LDLM_EXTENT &&
1042                     lock->l_policy_data.l_extent.gid != policy->l_extent.gid)
1043                         continue;
1044
1045                 /* We match if we have existing lock with same or wider set
1046                    of bits. */
1047                 if (lock->l_resource->lr_type == LDLM_IBITS &&
1048                      ((lock->l_policy_data.l_inodebits.bits &
1049                       policy->l_inodebits.bits) !=
1050                       policy->l_inodebits.bits))
1051                         continue;
1052
1053                 if (!unref &&
1054                     (lock->l_destroyed || lock->l_flags & LDLM_FL_FAILED ||
1055                      lock->l_fail_value != 0))
1056                         continue;
1057
1058                 if ((flags & LDLM_FL_LOCAL_ONLY) &&
1059                     !(lock->l_flags & LDLM_FL_LOCAL))
1060                         continue;
1061
1062                 if (flags & LDLM_FL_TEST_LOCK) {
1063                         LDLM_LOCK_GET(lock);
1064                         ldlm_lock_touch_in_lru(lock);
1065                 } else {
1066                         ldlm_lock_addref_internal_nolock(lock, match);
1067                 }
1068                 *mode = match;
1069                 return lock;
1070         }
1071
1072         return NULL;
1073 }
1074
1075 void ldlm_lock_fail_match_locked(struct ldlm_lock *lock, int rc)
1076 {
1077         if (lock->l_fail_value == 0) {
1078                 lock->l_fail_value = rc;
1079                 cfs_waitq_signal(&lock->l_waitq);
1080         }
1081 }
1082 EXPORT_SYMBOL(ldlm_lock_fail_match_locked);
1083
1084 void ldlm_lock_fail_match(struct ldlm_lock *lock, int rc)
1085 {
1086         lock_res_and_lock(lock);
1087         ldlm_lock_fail_match_locked(lock, rc);
1088         unlock_res_and_lock(lock);
1089 }
1090 EXPORT_SYMBOL(ldlm_lock_fail_match);
1091
1092 void ldlm_lock_allow_match_locked(struct ldlm_lock *lock)
1093 {
1094         lock->l_flags |= LDLM_FL_LVB_READY;
1095         cfs_waitq_signal(&lock->l_waitq);
1096 }
1097
1098 void ldlm_lock_allow_match(struct ldlm_lock *lock)
1099 {
1100         lock_res_and_lock(lock);
1101         ldlm_lock_allow_match_locked(lock);
1102         unlock_res_and_lock(lock);
1103 }
1104
1105 /* Can be called in two ways:
1106  *
1107  * If 'ns' is NULL, then lockh describes an existing lock that we want to look
1108  * for a duplicate of.
1109  *
1110  * Otherwise, all of the fields must be filled in, to match against.
1111  *
1112  * If 'flags' contains LDLM_FL_LOCAL_ONLY, then only match local locks on the
1113  *     server (ie, connh is NULL)
1114  * If 'flags' contains LDLM_FL_BLOCK_GRANTED, then only locks on the granted
1115  *     list will be considered
1116  * If 'flags' contains LDLM_FL_CBPENDING, then locks that have been marked
1117  *     to be canceled can still be matched as long as they still have reader
1118  *     or writer refernces
1119  * If 'flags' contains LDLM_FL_TEST_LOCK, then don't actually reference a lock,
1120  *     just tell us if we would have matched.
1121  *
1122  * Returns 1 if it finds an already-existing lock that is compatible; in this
1123  * case, lockh is filled in with a addref()ed lock
1124  *
1125  * we also check security context, if that failed we simply return 0 (to keep
1126  * caller code unchanged), the context failure will be discovered by caller
1127  * sometime later.
1128  */
1129 ldlm_mode_t ldlm_lock_match(struct ldlm_namespace *ns, int flags,
1130                             const struct ldlm_res_id *res_id, ldlm_type_t type,
1131                             ldlm_policy_data_t *policy, ldlm_mode_t mode,
1132                             struct lustre_handle *lockh, int unref)
1133 {
1134         struct ldlm_resource *res;
1135         struct ldlm_lock *lock, *old_lock = NULL;
1136         int rc = 0;
1137         ENTRY;
1138
1139         if (ns == NULL) {
1140                 old_lock = ldlm_handle2lock(lockh);
1141                 LASSERT(old_lock);
1142
1143                 ns = ldlm_lock_to_ns(old_lock);
1144                 res_id = &old_lock->l_resource->lr_name;
1145                 type = old_lock->l_resource->lr_type;
1146                 mode = old_lock->l_req_mode;
1147         }
1148
1149         res = ldlm_resource_get(ns, NULL, res_id, type, 0);
1150         if (res == NULL) {
1151                 LASSERT(old_lock == NULL);
1152                 RETURN(0);
1153         }
1154
1155         LDLM_RESOURCE_ADDREF(res);
1156         lock_res(res);
1157
1158         lock = search_queue(&res->lr_granted, &mode, policy, old_lock,
1159                             flags, unref);
1160         if (lock != NULL)
1161                 GOTO(out, rc = 1);
1162         if (flags & LDLM_FL_BLOCK_GRANTED)
1163                 GOTO(out, rc = 0);
1164         lock = search_queue(&res->lr_converting, &mode, policy, old_lock,
1165                             flags, unref);
1166         if (lock != NULL)
1167                 GOTO(out, rc = 1);
1168         lock = search_queue(&res->lr_waiting, &mode, policy, old_lock,
1169                             flags, unref);
1170         if (lock != NULL)
1171                 GOTO(out, rc = 1);
1172
1173         EXIT;
1174  out:
1175         unlock_res(res);
1176         LDLM_RESOURCE_DELREF(res);
1177         ldlm_resource_putref(res);
1178
1179         if (lock) {
1180                 ldlm_lock2handle(lock, lockh);
1181                 if ((flags & LDLM_FL_LVB_READY) &&
1182                     (!(lock->l_flags & LDLM_FL_LVB_READY))) {
1183                         struct l_wait_info lwi;
1184                         if (lock->l_completion_ast) {
1185                                 int err = lock->l_completion_ast(lock,
1186                                                           LDLM_FL_WAIT_NOREPROC,
1187                                                                  NULL);
1188                                 if (err) {
1189                                         if (flags & LDLM_FL_TEST_LOCK)
1190                                                 LDLM_LOCK_RELEASE(lock);
1191                                         else
1192                                                 ldlm_lock_decref_internal(lock,
1193                                                                           mode);
1194                                         rc = 0;
1195                                         goto out2;
1196                                 }
1197                         }
1198
1199                         lwi = LWI_TIMEOUT_INTR(cfs_time_seconds(obd_timeout),
1200                                                NULL, LWI_ON_SIGNAL_NOOP, NULL);
1201
1202                         /* XXX FIXME see comment on CAN_MATCH in lustre_dlm.h */
1203                         l_wait_event(lock->l_waitq,
1204                                      lock->l_flags & LDLM_FL_LVB_READY ||
1205                                      lock->l_fail_value != 0,
1206                                      &lwi);
1207                         if (!(lock->l_flags & LDLM_FL_LVB_READY)) {
1208                                 if (flags & LDLM_FL_TEST_LOCK)
1209                                         LDLM_LOCK_RELEASE(lock);
1210                                 else
1211                                         ldlm_lock_decref_internal(lock, mode);
1212                                 rc = 0;
1213                         }
1214                 }
1215         }
1216  out2:
1217         if (rc) {
1218                 LDLM_DEBUG(lock, "matched ("LPU64" "LPU64")",
1219                            (type == LDLM_PLAIN || type == LDLM_IBITS) ?
1220                                 res_id->name[2] : policy->l_extent.start,
1221                            (type == LDLM_PLAIN || type == LDLM_IBITS) ?
1222                                 res_id->name[3] : policy->l_extent.end);
1223
1224                 /* check user's security context */
1225                 if (lock->l_conn_export &&
1226                     sptlrpc_import_check_ctx(
1227                                 class_exp2cliimp(lock->l_conn_export))) {
1228                         if (!(flags & LDLM_FL_TEST_LOCK))
1229                                 ldlm_lock_decref_internal(lock, mode);
1230                         rc = 0;
1231                 }
1232
1233                 if (flags & LDLM_FL_TEST_LOCK)
1234                         LDLM_LOCK_RELEASE(lock);
1235
1236         } else if (!(flags & LDLM_FL_TEST_LOCK)) {/*less verbose for test-only*/
1237                 LDLM_DEBUG_NOLOCK("not matched ns %p type %u mode %u res "
1238                                   LPU64"/"LPU64" ("LPU64" "LPU64")", ns,
1239                                   type, mode, res_id->name[0], res_id->name[1],
1240                                   (type == LDLM_PLAIN || type == LDLM_IBITS) ?
1241                                         res_id->name[2] :policy->l_extent.start,
1242                                   (type == LDLM_PLAIN || type == LDLM_IBITS) ?
1243                                         res_id->name[3] : policy->l_extent.end);
1244         }
1245         if (old_lock)
1246                 LDLM_LOCK_PUT(old_lock);
1247
1248         return rc ? mode : 0;
1249 }
1250
1251 ldlm_mode_t ldlm_revalidate_lock_handle(struct lustre_handle *lockh,
1252                                         __u64 *bits)
1253 {
1254         struct ldlm_lock *lock;
1255         ldlm_mode_t mode = 0;
1256         ENTRY;
1257
1258         lock = ldlm_handle2lock(lockh);
1259         if (lock != NULL) {
1260                 lock_res_and_lock(lock);
1261                 if (lock->l_destroyed || lock->l_flags & LDLM_FL_FAILED ||
1262                     lock->l_fail_value != 0)
1263                         GOTO(out, mode);
1264
1265                 if (lock->l_flags & LDLM_FL_CBPENDING &&
1266                     lock->l_readers == 0 && lock->l_writers == 0)
1267                         GOTO(out, mode);
1268
1269                 if (bits)
1270                         *bits = lock->l_policy_data.l_inodebits.bits;
1271                 mode = lock->l_granted_mode;
1272                 ldlm_lock_addref_internal_nolock(lock, mode);
1273         }
1274
1275         EXIT;
1276
1277 out:
1278         if (lock != NULL) {
1279                 unlock_res_and_lock(lock);
1280                 LDLM_LOCK_PUT(lock);
1281         }
1282         return mode;
1283 }
1284 EXPORT_SYMBOL(ldlm_revalidate_lock_handle);
1285
1286 /* Returns a referenced lock */
1287 struct ldlm_lock *ldlm_lock_create(struct ldlm_namespace *ns,
1288                                    const struct ldlm_res_id *res_id,
1289                                    ldlm_type_t type,
1290                                    ldlm_mode_t mode,
1291                                    const struct ldlm_callback_suite *cbs,
1292                                    void *data, __u32 lvb_len)
1293 {
1294         struct ldlm_lock *lock;
1295         struct ldlm_resource *res;
1296         ENTRY;
1297
1298         res = ldlm_resource_get(ns, NULL, res_id, type, 1);
1299         if (res == NULL)
1300                 RETURN(NULL);
1301
1302         lock = ldlm_lock_new(res);
1303
1304         if (lock == NULL)
1305                 RETURN(NULL);
1306
1307         lock->l_req_mode = mode;
1308         lock->l_ast_data = data;
1309         lock->l_pid = cfs_curproc_pid();
1310         lock->l_ns_srv = ns_is_server(ns);
1311         if (cbs) {
1312                 lock->l_blocking_ast = cbs->lcs_blocking;
1313                 lock->l_completion_ast = cbs->lcs_completion;
1314                 lock->l_glimpse_ast = cbs->lcs_glimpse;
1315                 lock->l_weigh_ast = cbs->lcs_weigh;
1316         }
1317
1318         lock->l_tree_node = NULL;
1319         /* if this is the extent lock, allocate the interval tree node */
1320         if (type == LDLM_EXTENT) {
1321                 if (ldlm_interval_alloc(lock) == NULL)
1322                         GOTO(out, 0);
1323         }
1324
1325         if (lvb_len) {
1326                 lock->l_lvb_len = lvb_len;
1327                 OBD_ALLOC(lock->l_lvb_data, lvb_len);
1328                 if (lock->l_lvb_data == NULL)
1329                         GOTO(out, 0);
1330         }
1331
1332         if (OBD_FAIL_CHECK(OBD_FAIL_LDLM_NEW_LOCK))
1333                 GOTO(out, 0);
1334
1335         RETURN(lock);
1336
1337 out:
1338         ldlm_lock_destroy(lock);
1339         LDLM_LOCK_RELEASE(lock);
1340         return NULL;
1341 }
1342
1343 ldlm_error_t ldlm_lock_enqueue(struct ldlm_namespace *ns,
1344                                struct ldlm_lock **lockp,
1345                                void *cookie, int *flags)
1346 {
1347         struct ldlm_lock *lock = *lockp;
1348         struct ldlm_resource *res = lock->l_resource;
1349         int local = ns_is_client(ldlm_res_to_ns(res));
1350         ldlm_processing_policy policy;
1351         ldlm_error_t rc = ELDLM_OK;
1352         struct ldlm_interval *node = NULL;
1353         ENTRY;
1354
1355         lock->l_last_activity = cfs_time_current_sec();
1356         /* policies are not executed on the client or during replay */
1357         if ((*flags & (LDLM_FL_HAS_INTENT|LDLM_FL_REPLAY)) == LDLM_FL_HAS_INTENT
1358             && !local && ns->ns_policy) {
1359                 rc = ns->ns_policy(ns, lockp, cookie, lock->l_req_mode, *flags,
1360                                    NULL);
1361                 if (rc == ELDLM_LOCK_REPLACED) {
1362                         /* The lock that was returned has already been granted,
1363                          * and placed into lockp.  If it's not the same as the
1364                          * one we passed in, then destroy the old one and our
1365                          * work here is done. */
1366                         if (lock != *lockp) {
1367                                 ldlm_lock_destroy(lock);
1368                                 LDLM_LOCK_RELEASE(lock);
1369                         }
1370                         *flags |= LDLM_FL_LOCK_CHANGED;
1371                         RETURN(0);
1372                 } else if (rc != ELDLM_OK ||
1373                            (rc == ELDLM_OK && (*flags & LDLM_FL_INTENT_ONLY))) {
1374                         ldlm_lock_destroy(lock);
1375                         RETURN(rc);
1376                 }
1377         }
1378
1379         /* For a replaying lock, it might be already in granted list. So
1380          * unlinking the lock will cause the interval node to be freed, we
1381          * have to allocate the interval node early otherwise we can't regrant
1382          * this lock in the future. - jay */
1383         if (!local && (*flags & LDLM_FL_REPLAY) && res->lr_type == LDLM_EXTENT)
1384                 OBD_SLAB_ALLOC_PTR_GFP(node, ldlm_interval_slab, CFS_ALLOC_IO);
1385
1386         lock_res_and_lock(lock);
1387         if (local && lock->l_req_mode == lock->l_granted_mode) {
1388                 /* The server returned a blocked lock, but it was granted
1389                  * before we got a chance to actually enqueue it.  We don't
1390                  * need to do anything else. */
1391                 *flags &= ~(LDLM_FL_BLOCK_GRANTED |
1392                             LDLM_FL_BLOCK_CONV | LDLM_FL_BLOCK_WAIT);
1393                 GOTO(out, ELDLM_OK);
1394         }
1395
1396         ldlm_resource_unlink_lock(lock);
1397         if (res->lr_type == LDLM_EXTENT && lock->l_tree_node == NULL) {
1398                 if (node == NULL) {
1399                         ldlm_lock_destroy_nolock(lock);
1400                         GOTO(out, rc = -ENOMEM);
1401                 }
1402
1403                 CFS_INIT_LIST_HEAD(&node->li_group);
1404                 ldlm_interval_attach(node, lock);
1405                 node = NULL;
1406         }
1407
1408         /* Some flags from the enqueue want to make it into the AST, via the
1409          * lock's l_flags. */
1410         lock->l_flags |= *flags & LDLM_AST_DISCARD_DATA;
1411
1412         /* This distinction between local lock trees is very important; a client
1413          * namespace only has information about locks taken by that client, and
1414          * thus doesn't have enough information to decide for itself if it can
1415          * be granted (below).  In this case, we do exactly what the server
1416          * tells us to do, as dictated by the 'flags'.
1417          *
1418          * We do exactly the same thing during recovery, when the server is
1419          * more or less trusting the clients not to lie.
1420          *
1421          * FIXME (bug 268): Detect obvious lies by checking compatibility in
1422          * granted/converting queues. */
1423         if (local) {
1424                 if (*flags & LDLM_FL_BLOCK_CONV)
1425                         ldlm_resource_add_lock(res, &res->lr_converting, lock);
1426                 else if (*flags & (LDLM_FL_BLOCK_WAIT | LDLM_FL_BLOCK_GRANTED))
1427                         ldlm_resource_add_lock(res, &res->lr_waiting, lock);
1428                 else
1429                         ldlm_grant_lock(lock, NULL);
1430                 GOTO(out, ELDLM_OK);
1431         } else if (*flags & LDLM_FL_REPLAY) {
1432                 if (*flags & LDLM_FL_BLOCK_CONV) {
1433                         ldlm_resource_add_lock(res, &res->lr_converting, lock);
1434                         GOTO(out, ELDLM_OK);
1435                 } else if (*flags & LDLM_FL_BLOCK_WAIT) {
1436                         ldlm_resource_add_lock(res, &res->lr_waiting, lock);
1437                         GOTO(out, ELDLM_OK);
1438                 } else if (*flags & LDLM_FL_BLOCK_GRANTED) {
1439                         ldlm_grant_lock(lock, NULL);
1440                         GOTO(out, ELDLM_OK);
1441                 }
1442                 /* If no flags, fall through to normal enqueue path. */
1443         }
1444
1445         policy = ldlm_processing_policy_table[res->lr_type];
1446         policy(lock, flags, 1, &rc, NULL);
1447         GOTO(out, rc);
1448 out:
1449         unlock_res_and_lock(lock);
1450         if (node)
1451                 OBD_SLAB_FREE(node, ldlm_interval_slab, sizeof(*node));
1452         return rc;
1453 }
1454
1455 /* Must be called with namespace taken: queue is waiting or converting. */
1456 int ldlm_reprocess_queue(struct ldlm_resource *res, cfs_list_t *queue,
1457                          cfs_list_t *work_list)
1458 {
1459         cfs_list_t *tmp, *pos;
1460         ldlm_processing_policy policy;
1461         int flags;
1462         int rc = LDLM_ITER_CONTINUE;
1463         ldlm_error_t err;
1464         ENTRY;
1465
1466         check_res_locked(res);
1467
1468         policy = ldlm_processing_policy_table[res->lr_type];
1469         LASSERT(policy);
1470
1471         cfs_list_for_each_safe(tmp, pos, queue) {
1472                 struct ldlm_lock *pending;
1473                 pending = cfs_list_entry(tmp, struct ldlm_lock, l_res_link);
1474
1475                 CDEBUG(D_INFO, "Reprocessing lock %p\n", pending);
1476
1477                 flags = 0;
1478                 rc = policy(pending, &flags, 0, &err, work_list);
1479                 if (rc != LDLM_ITER_CONTINUE)
1480                         break;
1481         }
1482
1483         RETURN(rc);
1484 }
1485
1486 static int
1487 ldlm_work_bl_ast_lock(cfs_list_t *tmp, struct ldlm_cb_set_arg *arg)
1488 {
1489         struct ldlm_lock_desc d;
1490         struct ldlm_lock *lock = cfs_list_entry(tmp, struct ldlm_lock,
1491                                                 l_bl_ast);
1492         int rc;
1493         ENTRY;
1494
1495         /* nobody should touch l_bl_ast */
1496         lock_res_and_lock(lock);
1497         cfs_list_del_init(&lock->l_bl_ast);
1498
1499         LASSERT(lock->l_flags & LDLM_FL_AST_SENT);
1500         LASSERT(lock->l_bl_ast_run == 0);
1501         LASSERT(lock->l_blocking_lock);
1502         lock->l_bl_ast_run++;
1503         unlock_res_and_lock(lock);
1504
1505         ldlm_lock2desc(lock->l_blocking_lock, &d);
1506
1507         rc = lock->l_blocking_ast(lock, &d, (void *)arg,
1508                                   LDLM_CB_BLOCKING);
1509         LDLM_LOCK_RELEASE(lock->l_blocking_lock);
1510         lock->l_blocking_lock = NULL;
1511         LDLM_LOCK_RELEASE(lock);
1512
1513         RETURN(rc);
1514 }
1515
1516 static int
1517 ldlm_work_cp_ast_lock(cfs_list_t *tmp, struct ldlm_cb_set_arg *arg)
1518 {
1519         struct ldlm_lock *lock = cfs_list_entry(tmp, struct ldlm_lock, l_cp_ast);
1520         ldlm_completion_callback completion_callback;
1521         int rc = 0;
1522         ENTRY;
1523
1524         /* It's possible to receive a completion AST before we've set
1525          * the l_completion_ast pointer: either because the AST arrived
1526          * before the reply, or simply because there's a small race
1527          * window between receiving the reply and finishing the local
1528          * enqueue. (bug 842)
1529          *
1530          * This can't happen with the blocking_ast, however, because we
1531          * will never call the local blocking_ast until we drop our
1532          * reader/writer reference, which we won't do until we get the
1533          * reply and finish enqueueing. */
1534
1535         /* nobody should touch l_cp_ast */
1536         lock_res_and_lock(lock);
1537         cfs_list_del_init(&lock->l_cp_ast);
1538         LASSERT(lock->l_flags & LDLM_FL_CP_REQD);
1539         /* save l_completion_ast since it can be changed by
1540          * mds_intent_policy(), see bug 14225 */
1541         completion_callback = lock->l_completion_ast;
1542         lock->l_flags &= ~LDLM_FL_CP_REQD;
1543         unlock_res_and_lock(lock);
1544
1545         if (completion_callback != NULL)
1546                 rc = completion_callback(lock, 0, (void *)arg);
1547         LDLM_LOCK_RELEASE(lock);
1548
1549         RETURN(rc);
1550 }
1551
1552 static int
1553 ldlm_work_revoke_ast_lock(cfs_list_t *tmp, struct ldlm_cb_set_arg *arg)
1554 {
1555         struct ldlm_lock_desc desc;
1556         struct ldlm_lock *lock = cfs_list_entry(tmp, struct ldlm_lock,
1557                                                 l_rk_ast);
1558         int rc;
1559         ENTRY;
1560
1561         cfs_list_del_init(&lock->l_rk_ast);
1562
1563         /* the desc just pretend to exclusive */
1564         ldlm_lock2desc(lock, &desc);
1565         desc.l_req_mode = LCK_EX;
1566         desc.l_granted_mode = 0;
1567
1568         rc = lock->l_blocking_ast(lock, &desc, (void*)arg, LDLM_CB_BLOCKING);
1569         LDLM_LOCK_RELEASE(lock);
1570
1571         RETURN(rc);
1572 }
1573
1574 int ldlm_run_ast_work(struct ldlm_namespace *ns, cfs_list_t *rpc_list,
1575                       ldlm_desc_ast_t ast_type)
1576 {
1577         struct ldlm_cb_set_arg arg = { 0 };
1578         struct l_wait_info     lwi = { 0 };
1579         cfs_list_t *tmp, *pos;
1580         int (*work_ast_lock)(cfs_list_t *tmp, struct ldlm_cb_set_arg *arg);
1581         unsigned int max_ast_count;
1582         ENTRY;
1583
1584         if (cfs_list_empty(rpc_list))
1585                 RETURN(0);
1586
1587         cfs_atomic_set(&arg.restart, 0);
1588         cfs_atomic_set(&arg.rpcs, 0);
1589         cfs_waitq_init(&arg.waitq);
1590
1591         switch (ast_type) {
1592         case LDLM_WORK_BL_AST:
1593                 arg.type = LDLM_BL_CALLBACK;
1594                 work_ast_lock = ldlm_work_bl_ast_lock;
1595                 break;
1596         case LDLM_WORK_CP_AST:
1597                 arg.type = LDLM_CP_CALLBACK;
1598                 work_ast_lock = ldlm_work_cp_ast_lock;
1599                 break;
1600         case LDLM_WORK_REVOKE_AST:
1601                 arg.type = LDLM_BL_CALLBACK;
1602                 work_ast_lock = ldlm_work_revoke_ast_lock;
1603                 break;
1604         default:
1605                 LBUG();
1606         }
1607
1608         max_ast_count = ns->ns_max_parallel_ast ? : UINT_MAX;
1609         arg.threshold = max_ast_count;
1610
1611         cfs_list_for_each_safe(tmp, pos, rpc_list) {
1612                 (void)work_ast_lock(tmp, &arg);
1613                 if (cfs_atomic_read(&arg.rpcs) < max_ast_count)
1614                         continue;
1615
1616                 l_wait_event(arg.waitq,
1617                              cfs_atomic_read(&arg.rpcs) < arg.threshold,
1618                              &lwi);
1619         }
1620
1621         arg.threshold = 1;
1622         l_wait_event(arg.waitq, cfs_atomic_read(&arg.rpcs) == 0, &lwi);
1623
1624         RETURN(cfs_atomic_read(&arg.restart) ? -ERESTART : 0);
1625 }
1626
1627 static int reprocess_one_queue(struct ldlm_resource *res, void *closure)
1628 {
1629         ldlm_reprocess_all(res);
1630         return LDLM_ITER_CONTINUE;
1631 }
1632
1633 static int ldlm_reprocess_res(cfs_hash_t *hs, cfs_hash_bd_t *bd,
1634                               cfs_hlist_node_t *hnode, void *arg)
1635 {
1636         struct ldlm_resource *res = cfs_hash_object(hs, hnode);
1637         int    rc;
1638
1639         rc = reprocess_one_queue(res, arg);
1640
1641         return rc == LDLM_ITER_STOP;
1642 }
1643
1644 void ldlm_reprocess_all_ns(struct ldlm_namespace *ns)
1645 {
1646         ENTRY;
1647
1648         if (ns != NULL) {
1649                 cfs_hash_for_each_nolock(ns->ns_rs_hash,
1650                                          ldlm_reprocess_res, NULL);
1651         }
1652         EXIT;
1653 }
1654
1655 void ldlm_reprocess_all(struct ldlm_resource *res)
1656 {
1657         CFS_LIST_HEAD(rpc_list);
1658         int rc;
1659         ENTRY;
1660
1661         /* Local lock trees don't get reprocessed. */
1662         if (ns_is_client(ldlm_res_to_ns(res))) {
1663                 EXIT;
1664                 return;
1665         }
1666
1667  restart:
1668         lock_res(res);
1669         rc = ldlm_reprocess_queue(res, &res->lr_converting, &rpc_list);
1670         if (rc == LDLM_ITER_CONTINUE)
1671                 ldlm_reprocess_queue(res, &res->lr_waiting, &rpc_list);
1672         unlock_res(res);
1673
1674         rc = ldlm_run_ast_work(ldlm_res_to_ns(res), &rpc_list,
1675                                LDLM_WORK_CP_AST);
1676         if (rc == -ERESTART) {
1677                 LASSERT(cfs_list_empty(&rpc_list));
1678                 goto restart;
1679         }
1680         EXIT;
1681 }
1682
1683 void ldlm_cancel_callback(struct ldlm_lock *lock)
1684 {
1685         check_res_locked(lock->l_resource);
1686         if (!(lock->l_flags & LDLM_FL_CANCEL)) {
1687                 lock->l_flags |= LDLM_FL_CANCEL;
1688                 if (lock->l_blocking_ast) {
1689                         // l_check_no_ns_lock(ns);
1690                         unlock_res_and_lock(lock);
1691                         lock->l_blocking_ast(lock, NULL, lock->l_ast_data,
1692                                              LDLM_CB_CANCELING);
1693                         lock_res_and_lock(lock);
1694                 } else {
1695                         LDLM_DEBUG(lock, "no blocking ast");
1696                 }
1697         }
1698         lock->l_flags |= LDLM_FL_BL_DONE;
1699 }
1700
1701 void ldlm_unlink_lock_skiplist(struct ldlm_lock *req)
1702 {
1703         if (req->l_resource->lr_type != LDLM_PLAIN &&
1704             req->l_resource->lr_type != LDLM_IBITS)
1705                 return;
1706
1707         cfs_list_del_init(&req->l_sl_policy);
1708         cfs_list_del_init(&req->l_sl_mode);
1709 }
1710
1711 void ldlm_lock_cancel(struct ldlm_lock *lock)
1712 {
1713         struct ldlm_resource *res;
1714         struct ldlm_namespace *ns;
1715         ENTRY;
1716
1717         lock_res_and_lock(lock);
1718
1719         res = lock->l_resource;
1720         ns  = ldlm_res_to_ns(res);
1721
1722         /* Please do not, no matter how tempting, remove this LBUG without
1723          * talking to me first. -phik */
1724         if (lock->l_readers || lock->l_writers) {
1725                 LDLM_ERROR(lock, "lock still has references");
1726                 LBUG();
1727         }
1728
1729         ldlm_del_waiting_lock(lock);
1730
1731         /* Releases cancel callback. */
1732         ldlm_cancel_callback(lock);
1733
1734         /* Yes, second time, just in case it was added again while we were
1735            running with no res lock in ldlm_cancel_callback */
1736         ldlm_del_waiting_lock(lock);
1737         ldlm_resource_unlink_lock(lock);
1738         ldlm_lock_destroy_nolock(lock);
1739
1740         if (lock->l_granted_mode == lock->l_req_mode)
1741                 ldlm_pool_del(&ns->ns_pool, lock);
1742
1743         /* Make sure we will not be called again for same lock what is possible
1744          * if not to zero out lock->l_granted_mode */
1745         lock->l_granted_mode = LCK_MINMODE;
1746         unlock_res_and_lock(lock);
1747
1748         EXIT;
1749 }
1750
1751 int ldlm_lock_set_data(struct lustre_handle *lockh, void *data)
1752 {
1753         struct ldlm_lock *lock = ldlm_handle2lock(lockh);
1754         int rc = -EINVAL;
1755         ENTRY;
1756
1757         if (lock) {
1758                 if (lock->l_ast_data == NULL)
1759                         lock->l_ast_data = data;
1760                 if (lock->l_ast_data == data)
1761                         rc = 0;
1762                 LDLM_LOCK_PUT(lock);
1763         }
1764         RETURN(rc);
1765 }
1766 EXPORT_SYMBOL(ldlm_lock_set_data);
1767
1768 int ldlm_cancel_locks_for_export_cb(cfs_hash_t *hs, cfs_hash_bd_t *bd,
1769                                     cfs_hlist_node_t *hnode, void *data)
1770
1771 {
1772         struct obd_export    *exp  = data;
1773         struct ldlm_lock     *lock = cfs_hash_object(hs, hnode);
1774         struct ldlm_resource *res;
1775
1776         res = ldlm_resource_getref(lock->l_resource);
1777         LDLM_LOCK_GET(lock);
1778
1779         LDLM_DEBUG(lock, "export %p", exp);
1780         ldlm_res_lvbo_update(res, NULL, 1);
1781         ldlm_lock_cancel(lock);
1782         ldlm_reprocess_all(res);
1783         ldlm_resource_putref(res);
1784         LDLM_LOCK_RELEASE(lock);
1785         return 0;
1786 }
1787
1788 void ldlm_cancel_locks_for_export(struct obd_export *exp)
1789 {
1790         cfs_hash_for_each_empty(exp->exp_lock_hash,
1791                                 ldlm_cancel_locks_for_export_cb, exp);
1792 }
1793
1794 /**
1795  * Downgrade an exclusive lock.
1796  *
1797  * A fast variant of ldlm_lock_convert for convertion of exclusive
1798  * locks. The convertion is always successful.
1799  *
1800  * \param lock A lock to convert
1801  * \param new_mode new lock mode
1802  */
1803 void ldlm_lock_downgrade(struct ldlm_lock *lock, int new_mode)
1804 {
1805         ENTRY;
1806
1807         LASSERT(lock->l_granted_mode & (LCK_PW | LCK_EX));
1808         LASSERT(new_mode == LCK_COS);
1809
1810         lock_res_and_lock(lock);
1811         ldlm_resource_unlink_lock(lock);
1812         /*
1813          * Remove the lock from pool as it will be added again in
1814          * ldlm_grant_lock() called below.
1815          */
1816         ldlm_pool_del(&ldlm_lock_to_ns(lock)->ns_pool, lock);
1817
1818         lock->l_req_mode = new_mode;
1819         ldlm_grant_lock(lock, NULL);
1820         unlock_res_and_lock(lock);
1821         ldlm_reprocess_all(lock->l_resource);
1822
1823         EXIT;
1824 }
1825
1826 struct ldlm_resource *ldlm_lock_convert(struct ldlm_lock *lock, int new_mode,
1827                                         __u32 *flags)
1828 {
1829         CFS_LIST_HEAD(rpc_list);
1830         struct ldlm_resource *res;
1831         struct ldlm_namespace *ns;
1832         int granted = 0;
1833         int old_mode, rc;
1834         struct sl_insert_point prev;
1835         ldlm_error_t err;
1836         struct ldlm_interval *node;
1837         ENTRY;
1838
1839         if (new_mode == lock->l_granted_mode) { // No changes? Just return.
1840                 *flags |= LDLM_FL_BLOCK_GRANTED;
1841                 RETURN(lock->l_resource);
1842         }
1843
1844         /* I can't check the type of lock here because the bitlock of lock
1845          * is not held here, so do the allocation blindly. -jay */
1846         OBD_SLAB_ALLOC_PTR_GFP(node, ldlm_interval_slab, CFS_ALLOC_IO);
1847         if (node == NULL)  /* Actually, this causes EDEADLOCK to be returned */
1848                 RETURN(NULL);
1849
1850         LASSERTF((new_mode == LCK_PW && lock->l_granted_mode == LCK_PR),
1851                  "new_mode %u, granted %u\n", new_mode, lock->l_granted_mode);
1852
1853         lock_res_and_lock(lock);
1854
1855         res = lock->l_resource;
1856         ns  = ldlm_res_to_ns(res);
1857
1858         old_mode = lock->l_req_mode;
1859         lock->l_req_mode = new_mode;
1860         if (res->lr_type == LDLM_PLAIN || res->lr_type == LDLM_IBITS) {
1861                 /* remember the lock position where the lock might be
1862                  * added back to the granted list later and also
1863                  * remember the join mode for skiplist fixing. */
1864                 prev.res_link = lock->l_res_link.prev;
1865                 prev.mode_link = lock->l_sl_mode.prev;
1866                 prev.policy_link = lock->l_sl_policy.prev;
1867                 ldlm_resource_unlink_lock(lock);
1868         } else {
1869                 ldlm_resource_unlink_lock(lock);
1870                 if (res->lr_type == LDLM_EXTENT) {
1871                         /* FIXME: ugly code, I have to attach the lock to a
1872                          * interval node again since perhaps it will be granted
1873                          * soon */
1874                         CFS_INIT_LIST_HEAD(&node->li_group);
1875                         ldlm_interval_attach(node, lock);
1876                         node = NULL;
1877                 }
1878         }
1879
1880         /*
1881          * Remove old lock from the pool before adding the lock with new
1882          * mode below in ->policy()
1883          */
1884         ldlm_pool_del(&ns->ns_pool, lock);
1885
1886         /* If this is a local resource, put it on the appropriate list. */
1887         if (ns_is_client(ldlm_res_to_ns(res))) {
1888                 if (*flags & (LDLM_FL_BLOCK_CONV | LDLM_FL_BLOCK_GRANTED)) {
1889                         ldlm_resource_add_lock(res, &res->lr_converting, lock);
1890                 } else {
1891                         /* This should never happen, because of the way the
1892                          * server handles conversions. */
1893                         LDLM_ERROR(lock, "Erroneous flags %d on local lock\n",
1894                                    *flags);
1895                         LBUG();
1896
1897                         ldlm_grant_lock(lock, &rpc_list);
1898                         granted = 1;
1899                         /* FIXME: completion handling not with lr_lock held ! */
1900                         if (lock->l_completion_ast)
1901                                 lock->l_completion_ast(lock, 0, NULL);
1902                 }
1903         } else {
1904                 int pflags = 0;
1905                 ldlm_processing_policy policy;
1906                 policy = ldlm_processing_policy_table[res->lr_type];
1907                 rc = policy(lock, &pflags, 0, &err, &rpc_list);
1908                 if (rc == LDLM_ITER_STOP) {
1909                         lock->l_req_mode = old_mode;
1910                         if (res->lr_type == LDLM_EXTENT)
1911                                 ldlm_extent_add_lock(res, lock);
1912                         else
1913                                 ldlm_granted_list_add_lock(lock, &prev);
1914
1915                         res = NULL;
1916                 } else {
1917                         *flags |= LDLM_FL_BLOCK_GRANTED;
1918                         granted = 1;
1919                 }
1920         }
1921         unlock_res_and_lock(lock);
1922
1923         if (granted)
1924                 ldlm_run_ast_work(ns, &rpc_list, LDLM_WORK_CP_AST);
1925         if (node)
1926                 OBD_SLAB_FREE(node, ldlm_interval_slab, sizeof(*node));
1927         RETURN(res);
1928 }
1929
1930 void ldlm_lock_dump(int level, struct ldlm_lock *lock, int pos)
1931 {
1932         struct obd_device *obd = NULL;
1933
1934         if (!((libcfs_debug | D_ERROR) & level))
1935                 return;
1936
1937         if (!lock) {
1938                 CDEBUG(level, "  NULL LDLM lock\n");
1939                 return;
1940         }
1941
1942         CDEBUG(level," -- Lock dump: %p/"LPX64" (rc: %d) (pos: %d) (pid: %d)\n",
1943                lock, lock->l_handle.h_cookie, cfs_atomic_read(&lock->l_refc),
1944                pos, lock->l_pid);
1945         if (lock->l_conn_export != NULL)
1946                 obd = lock->l_conn_export->exp_obd;
1947         if (lock->l_export && lock->l_export->exp_connection) {
1948                 CDEBUG(level, "  Node: NID %s (rhandle: "LPX64")\n",
1949                      libcfs_nid2str(lock->l_export->exp_connection->c_peer.nid),
1950                      lock->l_remote_handle.cookie);
1951         } else if (obd == NULL) {
1952                 CDEBUG(level, "  Node: local\n");
1953         } else {
1954                 struct obd_import *imp = obd->u.cli.cl_import;
1955                 CDEBUG(level, "  Node: NID %s (rhandle: "LPX64")\n",
1956                        libcfs_nid2str(imp->imp_connection->c_peer.nid),
1957                        lock->l_remote_handle.cookie);
1958         }
1959         CDEBUG(level, "  Resource: %p ("LPU64"/"LPU64"/"LPU64")\n",
1960                   lock->l_resource,
1961                   lock->l_resource->lr_name.name[0],
1962                   lock->l_resource->lr_name.name[1],
1963                   lock->l_resource->lr_name.name[2]);
1964         CDEBUG(level, "  Req mode: %s, grant mode: %s, rc: %u, read: %d, "
1965                "write: %d flags: "LPX64"\n", ldlm_lockname[lock->l_req_mode],
1966                ldlm_lockname[lock->l_granted_mode],
1967                cfs_atomic_read(&lock->l_refc), lock->l_readers, lock->l_writers,
1968                lock->l_flags);
1969         if (lock->l_resource->lr_type == LDLM_EXTENT)
1970                 CDEBUG(level, "  Extent: "LPU64" -> "LPU64
1971                        " (req "LPU64"-"LPU64")\n",
1972                        lock->l_policy_data.l_extent.start,
1973                        lock->l_policy_data.l_extent.end,
1974                        lock->l_req_extent.start, lock->l_req_extent.end);
1975         else if (lock->l_resource->lr_type == LDLM_FLOCK)
1976                 CDEBUG(level, "  Pid: %d Extent: "LPU64" -> "LPU64"\n",
1977                        lock->l_policy_data.l_flock.pid,
1978                        lock->l_policy_data.l_flock.start,
1979                        lock->l_policy_data.l_flock.end);
1980        else if (lock->l_resource->lr_type == LDLM_IBITS)
1981                 CDEBUG(level, "  Bits: "LPX64"\n",
1982                        lock->l_policy_data.l_inodebits.bits);
1983 }
1984
1985 void ldlm_lock_dump_handle(int level, struct lustre_handle *lockh)
1986 {
1987         struct ldlm_lock *lock;
1988
1989         if (!((libcfs_debug | D_ERROR) & level))
1990                 return;
1991
1992         lock = ldlm_handle2lock(lockh);
1993         if (lock == NULL)
1994                 return;
1995
1996         ldlm_lock_dump(D_OTHER, lock, 0);
1997
1998         LDLM_LOCK_PUT(lock);
1999 }
2000
2001 void _ldlm_lock_debug(struct ldlm_lock *lock, __u32 level,
2002                       struct libcfs_debug_msg_data *data, const char *fmt,
2003                       ...)
2004 {
2005         va_list args;
2006         cfs_debug_limit_state_t *cdls = data->msg_cdls;
2007
2008         va_start(args, fmt);
2009
2010         if (lock->l_resource == NULL) {
2011                 libcfs_debug_vmsg2(cdls, data->msg_subsys, level,data->msg_file,
2012                                    data->msg_fn, data->msg_line, fmt, args,
2013                        " ns: \?\? lock: %p/"LPX64" lrc: %d/%d,%d mode: %s/%s "
2014                        "res: \?\? rrc=\?\? type: \?\?\? flags: "LPX64" remote: "
2015                        LPX64" expref: %d pid: %u timeout: %lu\n", lock,
2016                        lock->l_handle.h_cookie, cfs_atomic_read(&lock->l_refc),
2017                        lock->l_readers, lock->l_writers,
2018                        ldlm_lockname[lock->l_granted_mode],
2019                        ldlm_lockname[lock->l_req_mode],
2020                        lock->l_flags, lock->l_remote_handle.cookie,
2021                        lock->l_export ?
2022                        cfs_atomic_read(&lock->l_export->exp_refcount) : -99,
2023                        lock->l_pid, lock->l_callback_timeout);
2024                 va_end(args);
2025                 return;
2026         }
2027
2028         switch (lock->l_resource->lr_type) {
2029         case LDLM_EXTENT:
2030                 libcfs_debug_vmsg2(cdls, data->msg_subsys, level,data->msg_file,
2031                                    data->msg_fn, data->msg_line, fmt, args,
2032                        " ns: %s lock: %p/"LPX64" lrc: %d/%d,%d mode: %s/%s "
2033                        "res: "LPU64"/"LPU64" rrc: %d type: %s ["LPU64"->"LPU64
2034                        "] (req "LPU64"->"LPU64") flags: "LPX64" remote: "LPX64
2035                        " expref: %d pid: %u timeout %lu\n",
2036                        ldlm_lock_to_ns_name(lock), lock,
2037                        lock->l_handle.h_cookie, cfs_atomic_read(&lock->l_refc),
2038                        lock->l_readers, lock->l_writers,
2039                        ldlm_lockname[lock->l_granted_mode],
2040                        ldlm_lockname[lock->l_req_mode],
2041                        lock->l_resource->lr_name.name[0],
2042                        lock->l_resource->lr_name.name[1],
2043                        cfs_atomic_read(&lock->l_resource->lr_refcount),
2044                        ldlm_typename[lock->l_resource->lr_type],
2045                        lock->l_policy_data.l_extent.start,
2046                        lock->l_policy_data.l_extent.end,
2047                        lock->l_req_extent.start, lock->l_req_extent.end,
2048                        lock->l_flags, lock->l_remote_handle.cookie,
2049                        lock->l_export ?
2050                        cfs_atomic_read(&lock->l_export->exp_refcount) : -99,
2051                        lock->l_pid, lock->l_callback_timeout);
2052                 break;
2053
2054         case LDLM_FLOCK:
2055                 libcfs_debug_vmsg2(cdls, data->msg_subsys, level,data->msg_file,
2056                                    data->msg_fn, data->msg_line, fmt, args,
2057                        " ns: %s lock: %p/"LPX64" lrc: %d/%d,%d mode: %s/%s "
2058                        "res: "LPU64"/"LPU64" rrc: %d type: %s pid: %d "
2059                        "["LPU64"->"LPU64"] flags: "LPX64" remote: "LPX64
2060                        " expref: %d pid: %u timeout: %lu\n",
2061                        ldlm_lock_to_ns_name(lock), lock,
2062                        lock->l_handle.h_cookie, cfs_atomic_read(&lock->l_refc),
2063                        lock->l_readers, lock->l_writers,
2064                        ldlm_lockname[lock->l_granted_mode],
2065                        ldlm_lockname[lock->l_req_mode],
2066                        lock->l_resource->lr_name.name[0],
2067                        lock->l_resource->lr_name.name[1],
2068                        cfs_atomic_read(&lock->l_resource->lr_refcount),
2069                        ldlm_typename[lock->l_resource->lr_type],
2070                        lock->l_policy_data.l_flock.pid,
2071                        lock->l_policy_data.l_flock.start,
2072                        lock->l_policy_data.l_flock.end,
2073                        lock->l_flags, lock->l_remote_handle.cookie,
2074                        lock->l_export ?
2075                        cfs_atomic_read(&lock->l_export->exp_refcount) : -99,
2076                        lock->l_pid, lock->l_callback_timeout);
2077                 break;
2078
2079         case LDLM_IBITS:
2080                 libcfs_debug_vmsg2(cdls, data->msg_subsys, level,data->msg_file,
2081                                    data->msg_fn, data->msg_line, fmt, args,
2082                        " ns: %s lock: %p/"LPX64" lrc: %d/%d,%d mode: %s/%s "
2083                        "res: "LPU64"/"LPU64" bits "LPX64" rrc: %d type: %s "
2084                        "flags: "LPX64" remote: "LPX64" expref: %d "
2085                        "pid: %u timeout: %lu\n",
2086                        ldlm_lock_to_ns_name(lock),
2087                        lock, lock->l_handle.h_cookie,
2088                        cfs_atomic_read (&lock->l_refc),
2089                        lock->l_readers, lock->l_writers,
2090                        ldlm_lockname[lock->l_granted_mode],
2091                        ldlm_lockname[lock->l_req_mode],
2092                        lock->l_resource->lr_name.name[0],
2093                        lock->l_resource->lr_name.name[1],
2094                        lock->l_policy_data.l_inodebits.bits,
2095                        cfs_atomic_read(&lock->l_resource->lr_refcount),
2096                        ldlm_typename[lock->l_resource->lr_type],
2097                        lock->l_flags, lock->l_remote_handle.cookie,
2098                        lock->l_export ?
2099                        cfs_atomic_read(&lock->l_export->exp_refcount) : -99,
2100                        lock->l_pid, lock->l_callback_timeout);
2101                 break;
2102
2103         default:
2104                 libcfs_debug_vmsg2(cdls, data->msg_subsys, level,data->msg_file,
2105                                    data->msg_fn, data->msg_line, fmt, args,
2106                        " ns: %s lock: %p/"LPX64" lrc: %d/%d,%d mode: %s/%s "
2107                        "res: "LPU64"/"LPU64" rrc: %d type: %s flags: "LPX64" "
2108                        "remote: "LPX64" expref: %d pid: %u timeout %lu\n",
2109                        ldlm_lock_to_ns_name(lock),
2110                        lock, lock->l_handle.h_cookie,
2111                        cfs_atomic_read (&lock->l_refc),
2112                        lock->l_readers, lock->l_writers,
2113                        ldlm_lockname[lock->l_granted_mode],
2114                        ldlm_lockname[lock->l_req_mode],
2115                        lock->l_resource->lr_name.name[0],
2116                        lock->l_resource->lr_name.name[1],
2117                        cfs_atomic_read(&lock->l_resource->lr_refcount),
2118                        ldlm_typename[lock->l_resource->lr_type],
2119                        lock->l_flags, lock->l_remote_handle.cookie,
2120                        lock->l_export ?
2121                        cfs_atomic_read(&lock->l_export->exp_refcount) : -99,
2122                        lock->l_pid, lock->l_callback_timeout);
2123                 break;
2124         }
2125         va_end(args);
2126 }
2127 EXPORT_SYMBOL(_ldlm_lock_debug);