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  *  Copyright (c) 2002, 2003 Cluster File Systems, Inc.
   5  *   Author: Peter Braam <braam@clusterfs.com>
   6  *   Author: Phil Schwan <phil@clusterfs.com>
   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 <libcfs/libcfs.h>
  31 # ifndef HAVE_VFS_INTENT_PATCHES
  32 # include <linux/lustre_intent.h>
  33 # endif
  34 #else
  35 # include <liblustre.h>
  36 # include <libcfs/kp30.h>
  37 #endif
  38
  39 #include <obd_class.h>
  40 #include "ldlm_internal.h"
  41
  42 /* lock's skip list pointers fix mode */
  43 #define LDLM_JOIN_NONE          0
  44 #define LDLM_MODE_JOIN_RIGHT    1
  45 #define LDLM_MODE_JOIN_LEFT     (1 << 1)
  46 #define LDLM_POLICY_JOIN_RIGHT  (1 << 2)
  47 #define LDLM_POLICY_JOIN_LEFT   (1 << 3)
  48
  49 /* lock types */
  50 char *ldlm_lockname[] = {
  51         [0] "--",
  52         [LCK_EX] "EX",
  53         [LCK_PW] "PW",
  54         [LCK_PR] "PR",
  55         [LCK_CW] "CW",
  56         [LCK_CR] "CR",
  57         [LCK_NL] "NL",
  58         [LCK_GROUP] "GROUP"
  59 };
  60
  61 char *ldlm_typename[] = {
  62         [LDLM_PLAIN] "PLN",
  63         [LDLM_EXTENT] "EXT",
  64         [LDLM_FLOCK] "FLK",
  65         [LDLM_IBITS] "IBT",
  66 };
  67
  68 char *ldlm_it2str(int it)
  69 {
  70         switch (it) {
  71         case IT_OPEN:
  72                 return "open";
  73         case IT_CREAT:
  74                 return "creat";
  75         case (IT_OPEN | IT_CREAT):
  76                 return "open|creat";
  77         case IT_READDIR:
  78                 return "readdir";
  79         case IT_GETATTR:
  80                 return "getattr";
  81         case IT_LOOKUP:
  82                 return "lookup";
  83         case IT_UNLINK:
  84                 return "unlink";
  85         case IT_GETXATTR:
  86                 return "getxattr";
  87         default:
  88                 CERROR("Unknown intent %d\n", it);
  89                 return "UNKNOWN";
  90         }
  91 }
  92
  93 extern cfs_mem_cache_t *ldlm_lock_slab;
  94
  95 static ldlm_processing_policy ldlm_processing_policy_table[] = {
  96         [LDLM_PLAIN] ldlm_process_plain_lock,
  97         [LDLM_EXTENT] ldlm_process_extent_lock,
  98 #ifdef __KERNEL__
  99         [LDLM_FLOCK] ldlm_process_flock_lock,
 100 #endif
 101         [LDLM_IBITS] ldlm_process_inodebits_lock,
 102 };
 103
 104 ldlm_processing_policy ldlm_get_processing_policy(struct ldlm_resource *res)
 105 {
 106         return ldlm_processing_policy_table[res->lr_type];
 107 }
 108
 109 void ldlm_register_intent(struct ldlm_namespace *ns, ldlm_res_policy arg)
 110 {
 111         ns->ns_policy = arg;
 112 }
 113
 114 /*
 115  * REFCOUNTED LOCK OBJECTS
 116  */
 117
 118
 119 /*
 120  * Lock refcounts, during creation:
 121  *   - one special one for allocation, dec'd only once in destroy
 122  *   - one for being a lock that's in-use
 123  *   - one for the addref associated with a new lock
 124  */
 125 struct ldlm_lock *ldlm_lock_get(struct ldlm_lock *lock)
 126 {
 127         atomic_inc(&lock->l_refc);
 128         return lock;
 129 }
 130
 131 static void ldlm_lock_free(struct ldlm_lock *lock, size_t size)
 132 {
 133         LASSERT(size == sizeof(*lock));
 134         OBD_SLAB_FREE(lock, ldlm_lock_slab, sizeof(*lock));
 135 }
 136
 137 void ldlm_lock_put(struct ldlm_lock *lock)
 138 {
 139         ENTRY;
 140
 141         LASSERT(lock->l_resource != LP_POISON);
 142         LASSERT(atomic_read(&lock->l_refc) > 0);
 143         if (atomic_dec_and_test(&lock->l_refc)) {
 144                 struct ldlm_resource *res;
 145
 146                 LDLM_DEBUG(lock,
 147                            "final lock_put on destroyed lock, freeing it.");
 148
 149                 res = lock->l_resource;
 150                 LASSERT(lock->l_destroyed);
 151                 LASSERT(list_empty(&lock->l_res_link));
 152                 LASSERT(list_empty(&lock->l_pending_chain));
 153
 154                 atomic_dec(&res->lr_namespace->ns_locks);
 155                 ldlm_resource_putref(res);
 156                 lock->l_resource = NULL;
 157                 if (lock->l_export) {
 158                         class_export_put(lock->l_export);
 159                         lock->l_export = NULL;
 160                 }
 161
 162                 if (lock->l_lvb_data != NULL)
 163                         OBD_FREE(lock->l_lvb_data, lock->l_lvb_len);
 164
 165                 ldlm_interval_free(ldlm_interval_detach(lock));
 166                 OBD_FREE_RCU_CB(lock, sizeof(*lock), &lock->l_handle,
 167                                 ldlm_lock_free);
 168         }
 169
 170         EXIT;
 171 }
 172
 173 int ldlm_lock_remove_from_lru_nolock(struct ldlm_lock *lock)
 174 {
 175         int rc = 0;
 176         if (!list_empty(&lock->l_lru)) {
 177                 struct ldlm_namespace *ns = lock->l_resource->lr_namespace;
 178                 LASSERT(lock->l_resource->lr_type != LDLM_FLOCK);
 179                 list_del_init(&lock->l_lru);
 180                 ns->ns_nr_unused--;
 181                 LASSERT(ns->ns_nr_unused >= 0);
 182                 rc = 1;
 183         }
 184         return rc;
 185 }
 186
 187 int ldlm_lock_remove_from_lru(struct ldlm_lock *lock)
 188 {
 189         struct ldlm_namespace *ns = lock->l_resource->lr_namespace;
 190         int rc;
 191         ENTRY;
 192         spin_lock(&ns->ns_unused_lock);
 193         rc = ldlm_lock_remove_from_lru_nolock(lock);
 194         spin_unlock(&ns->ns_unused_lock);
 195         EXIT;
 196         return rc;
 197 }
 198
 199 void ldlm_lock_add_to_lru_nolock(struct ldlm_lock *lock)
 200 {
 201         struct ldlm_namespace *ns = lock->l_resource->lr_namespace;
 202         lock->l_last_used = cfs_time_current();
 203         LASSERT(list_empty(&lock->l_lru));
 204         list_add_tail(&lock->l_lru, &ns->ns_unused_list);
 205         LASSERT(ns->ns_nr_unused >= 0);
 206         ns->ns_nr_unused++;
 207 }
 208
 209 void ldlm_lock_add_to_lru(struct ldlm_lock *lock)
 210 {
 211         struct ldlm_namespace *ns = lock->l_resource->lr_namespace;
 212         ENTRY;
 213         spin_lock(&ns->ns_unused_lock);
 214         ldlm_lock_add_to_lru_nolock(lock);
 215         spin_unlock(&ns->ns_unused_lock);
 216         EXIT;
 217 }
 218
 219 void ldlm_lock_touch_in_lru(struct ldlm_lock *lock)
 220 {
 221         struct ldlm_namespace *ns = lock->l_resource->lr_namespace;
 222         ENTRY;
 223         spin_lock(&ns->ns_unused_lock);
 224         if (!list_empty(&lock->l_lru)) {
 225                 ldlm_lock_remove_from_lru_nolock(lock);
 226                 ldlm_lock_add_to_lru_nolock(lock);
 227         }
 228         spin_unlock(&ns->ns_unused_lock);
 229         EXIT;
 230 }
 231
 232 /* This used to have a 'strict' flag, which recovery would use to mark an
 233  * in-use lock as needing-to-die.  Lest I am ever tempted to put it back, I
 234  * shall explain why it's gone: with the new hash table scheme, once you call
 235  * ldlm_lock_destroy, you can never drop your final references on this lock.
 236  * Because it's not in the hash table anymore.  -phil */
 237 int ldlm_lock_destroy_internal(struct ldlm_lock *lock)
 238 {
 239         ENTRY;
 240
 241         if (lock->l_readers || lock->l_writers) {
 242                 LDLM_ERROR(lock, "lock still has references");
 243                 ldlm_lock_dump(D_ERROR, lock, 0);
 244                 LBUG();
 245         }
 246
 247         if (!list_empty(&lock->l_res_link)) {
 248                 LDLM_ERROR(lock, "lock still on resource");
 249                 ldlm_lock_dump(D_ERROR, lock, 0);
 250                 LBUG();
 251         }
 252
 253         if (lock->l_destroyed) {
 254                 LASSERT(list_empty(&lock->l_lru));
 255                 EXIT;
 256                 return 0;
 257         }
 258         lock->l_destroyed = 1;
 259
 260         if (lock->l_export)
 261                 spin_lock(&lock->l_export->exp_ldlm_data.led_lock);
 262         list_del_init(&lock->l_export_chain);
 263         if (lock->l_export)
 264                 spin_unlock(&lock->l_export->exp_ldlm_data.led_lock);
 265
 266         ldlm_lock_remove_from_lru(lock);
 267         class_handle_unhash(&lock->l_handle);
 268
 269 #if 0
 270         /* Wake anyone waiting for this lock */
 271         /* FIXME: I should probably add yet another flag, instead of using
 272          * l_export to only call this on clients */
 273         if (lock->l_export)
 274                 class_export_put(lock->l_export);
 275         lock->l_export = NULL;
 276         if (lock->l_export && lock->l_completion_ast)
 277                 lock->l_completion_ast(lock, 0);
 278 #endif
 279         EXIT;
 280         return 1;
 281 }
 282
 283 void ldlm_lock_destroy(struct ldlm_lock *lock)
 284 {
 285         int first;
 286         ENTRY;
 287         lock_res_and_lock(lock);
 288         first = ldlm_lock_destroy_internal(lock);
 289         unlock_res_and_lock(lock);
 290
 291         /* drop reference from hashtable only for first destroy */
 292         if (first)
 293                 LDLM_LOCK_PUT(lock);
 294         EXIT;
 295 }
 296
 297 void ldlm_lock_destroy_nolock(struct ldlm_lock *lock)
 298 {
 299         int first;
 300         ENTRY;
 301         first = ldlm_lock_destroy_internal(lock);
 302         /* drop reference from hashtable only for first destroy */
 303         if (first)
 304                 LDLM_LOCK_PUT(lock);
 305         EXIT;
 306 }
 307
 308 /* this is called by portals_handle2object with the handle lock taken */
 309 static void lock_handle_addref(void *lock)
 310 {
 311         LDLM_LOCK_GET((struct ldlm_lock *)lock);
 312 }
 313
 314 /*
 315  * usage: pass in a resource on which you have done ldlm_resource_get
 316  *        pass in a parent lock on which you have done a ldlm_lock_get
 317  *        after return, ldlm_*_put the resource and parent
 318  * returns: lock with refcount 2 - one for current caller and one for remote
 319  */
 320 static struct ldlm_lock *ldlm_lock_new(struct ldlm_resource *resource)
 321 {
 322         struct ldlm_lock *lock;
 323         ENTRY;
 324
 325         if (resource == NULL)
 326                 LBUG();
 327
 328         OBD_SLAB_ALLOC(lock, ldlm_lock_slab, CFS_ALLOC_IO, sizeof(*lock));
 329         if (lock == NULL)
 330                 RETURN(NULL);
 331
 332         spin_lock_init(&lock->l_lock);
 333         lock->l_resource = ldlm_resource_getref(resource);
 334
 335         atomic_set(&lock->l_refc, 2);
 336         CFS_INIT_LIST_HEAD(&lock->l_res_link);
 337         CFS_INIT_LIST_HEAD(&lock->l_lru);
 338         CFS_INIT_LIST_HEAD(&lock->l_export_chain);
 339         CFS_INIT_LIST_HEAD(&lock->l_pending_chain);
 340         CFS_INIT_LIST_HEAD(&lock->l_bl_ast);
 341         CFS_INIT_LIST_HEAD(&lock->l_cp_ast);
 342         cfs_waitq_init(&lock->l_waitq);
 343         lock->l_blocking_lock = NULL;
 344         lock->l_sl_mode.prev = NULL;
 345         lock->l_sl_mode.next = NULL;
 346         lock->l_sl_policy.prev = NULL;
 347         lock->l_sl_policy.next = NULL;
 348
 349         atomic_inc(&resource->lr_namespace->ns_locks);
 350         CFS_INIT_LIST_HEAD(&lock->l_handle.h_link);
 351         class_handle_hash(&lock->l_handle, lock_handle_addref);
 352
 353         RETURN(lock);
 354 }
 355
 356 int ldlm_lock_change_resource(struct ldlm_namespace *ns, struct ldlm_lock *lock,
 357                               const struct ldlm_res_id *new_resid)
 358 {
 359         struct ldlm_resource *oldres = lock->l_resource;
 360         struct ldlm_resource *newres;
 361         int type;
 362         ENTRY;
 363
 364         LASSERT(ns_is_client(ns));
 365
 366         lock_res_and_lock(lock);
 367         if (memcmp(new_resid, &lock->l_resource->lr_name,
 368                    sizeof(lock->l_resource->lr_name)) == 0) {
 369                 /* Nothing to do */
 370                 unlock_res_and_lock(lock);
 371                 RETURN(0);
 372         }
 373
 374         LASSERT(new_resid->name[0] != 0);
 375
 376         /* This function assumes that the lock isn't on any lists */
 377         LASSERT(list_empty(&lock->l_res_link));
 378
 379         type = oldres->lr_type;
 380         unlock_res_and_lock(lock);
 381
 382         newres = ldlm_resource_get(ns, NULL, new_resid, type, 1);
 383         if (newres == NULL) {
 384                 LBUG();
 385                 RETURN(-ENOMEM);
 386         }
 387
 388         lock_res_and_lock(lock);
 389         LASSERT(memcmp(new_resid, &lock->l_resource->lr_name,
 390                        sizeof(lock->l_resource->lr_name)) != 0);
 391         lock_res(newres);
 392         lock->l_resource = newres;
 393         unlock_res(oldres);
 394         unlock_res_and_lock(lock);
 395
 396         /* ...and the flowers are still standing! */
 397         ldlm_resource_putref(oldres);
 398
 399         RETURN(0);
 400 }
 401
 402 /*
 403  *  HANDLES
 404  */
 405
 406 void ldlm_lock2handle(const struct ldlm_lock *lock, struct lustre_handle *lockh)
 407 {
 408         lockh->cookie = lock->l_handle.h_cookie;
 409 }
 410
 411 /* if flags: atomically get the lock and set the flags.
 412  *           Return NULL if flag already set
 413  */
 414
 415 struct ldlm_lock *__ldlm_handle2lock(const struct lustre_handle *handle,
 416                                      int flags)
 417 {
 418         struct ldlm_namespace *ns;
 419         struct ldlm_lock *lock, *retval = NULL;
 420         ENTRY;
 421
 422         LASSERT(handle);
 423
 424         lock = class_handle2object(handle->cookie);
 425         if (lock == NULL)
 426                 RETURN(NULL);
 427
 428         LASSERT(lock->l_resource != NULL);
 429         ns = lock->l_resource->lr_namespace;
 430         LASSERT(ns != NULL);
 431
 432         lock_res_and_lock(lock);
 433
 434         /* It's unlikely but possible that someone marked the lock as
 435          * destroyed after we did handle2object on it */
 436         if (lock->l_destroyed) {
 437                 unlock_res_and_lock(lock);
 438                 CDEBUG(D_INFO, "lock already destroyed: lock %p\n", lock);
 439                 LDLM_LOCK_PUT(lock);
 440                 GOTO(out, retval);
 441         }
 442
 443         if (flags && (lock->l_flags & flags)) {
 444                 unlock_res_and_lock(lock);
 445                 LDLM_LOCK_PUT(lock);
 446                 GOTO(out, retval);
 447         }
 448
 449         if (flags)
 450                 lock->l_flags |= flags;
 451
 452         unlock_res_and_lock(lock);
 453         retval = lock;
 454         EXIT;
 455  out:
 456         return retval;
 457 }
 458
 459 struct ldlm_lock *ldlm_handle2lock_ns(struct ldlm_namespace *ns,
 460                                       const struct lustre_handle *handle)
 461 {
 462         struct ldlm_lock *retval = NULL;
 463         retval = __ldlm_handle2lock(handle, 0);
 464         return retval;
 465 }
 466
 467 void ldlm_lock2desc(struct ldlm_lock *lock, struct ldlm_lock_desc *desc)
 468 {
 469         struct obd_export *exp = lock->l_export?:lock->l_conn_export;
 470         /* INODEBITS_INTEROP: If the other side does not support
 471          * inodebits, reply with a plain lock descriptor.
 472          */
 473         if ((lock->l_resource->lr_type == LDLM_IBITS) &&
 474             (exp && !(exp->exp_connect_flags & OBD_CONNECT_IBITS))) {
 475                 struct ldlm_resource res = *lock->l_resource;
 476
 477                 /* Make sure all the right bits are set in this lock we
 478                    are going to pass to client */
 479                 LASSERTF(lock->l_policy_data.l_inodebits.bits ==
 480                          (MDS_INODELOCK_LOOKUP|MDS_INODELOCK_UPDATE),
 481                          "Inappropriate inode lock bits during "
 482                          "conversion " LPU64 "\n",
 483                          lock->l_policy_data.l_inodebits.bits);
 484                 res.lr_type = LDLM_PLAIN;
 485                 ldlm_res2desc(&res, &desc->l_resource);
 486                 /* Convert "new" lock mode to something old client can
 487                    understand */
 488                 if ((lock->l_req_mode == LCK_CR) ||
 489                     (lock->l_req_mode == LCK_CW))
 490                         desc->l_req_mode = LCK_PR;
 491                 else
 492                         desc->l_req_mode = lock->l_req_mode;
 493                 if ((lock->l_granted_mode == LCK_CR) ||
 494                     (lock->l_granted_mode == LCK_CW)) {
 495                         desc->l_granted_mode = LCK_PR;
 496                 } else {
 497                         /* We never grant PW/EX locks to clients */
 498                         LASSERT((lock->l_granted_mode != LCK_PW) &&
 499                                 (lock->l_granted_mode != LCK_EX));
 500                         desc->l_granted_mode = lock->l_granted_mode;
 501                 }
 502
 503                 /* We do not copy policy here, because there is no
 504                    policy for plain locks */
 505         } else {
 506                 ldlm_res2desc(lock->l_resource, &desc->l_resource);
 507                 desc->l_req_mode = lock->l_req_mode;
 508                 desc->l_granted_mode = lock->l_granted_mode;
 509                 desc->l_policy_data = lock->l_policy_data;
 510         }
 511 }
 512
 513 void ldlm_add_bl_work_item(struct ldlm_lock *lock, struct ldlm_lock *new,
 514                            struct list_head *work_list)
 515 {
 516         if ((lock->l_flags & LDLM_FL_AST_SENT) == 0) {
 517                 LDLM_DEBUG(lock, "lock incompatible; sending blocking AST.");
 518                 lock->l_flags |= LDLM_FL_AST_SENT;
 519                 /* If the enqueuing client said so, tell the AST recipient to
 520                  * discard dirty data, rather than writing back. */
 521                 if (new->l_flags & LDLM_AST_DISCARD_DATA)
 522                         lock->l_flags |= LDLM_FL_DISCARD_DATA;
 523                 LASSERT(list_empty(&lock->l_bl_ast));
 524                 list_add(&lock->l_bl_ast, work_list);
 525                 LDLM_LOCK_GET(lock);
 526                 LASSERT(lock->l_blocking_lock == NULL);
 527                 lock->l_blocking_lock = LDLM_LOCK_GET(new);
 528         }
 529 }
 530
 531 void ldlm_add_cp_work_item(struct ldlm_lock *lock, struct list_head *work_list)
 532 {
 533         if ((lock->l_flags & LDLM_FL_CP_REQD) == 0) {
 534                 lock->l_flags |= LDLM_FL_CP_REQD;
 535                 LDLM_DEBUG(lock, "lock granted; sending completion AST.");
 536                 LASSERT(list_empty(&lock->l_cp_ast));
 537                 list_add(&lock->l_cp_ast, work_list);
 538                 LDLM_LOCK_GET(lock);
 539         }
 540 }
 541
 542 /* must be called with lr_lock held */
 543 void ldlm_add_ast_work_item(struct ldlm_lock *lock, struct ldlm_lock *new,
 544                                 struct list_head *work_list)
 545 {
 546         ENTRY;
 547         check_res_locked(lock->l_resource);
 548         if (new)
 549                 ldlm_add_bl_work_item(lock, new, work_list);
 550         else
 551                 ldlm_add_cp_work_item(lock, work_list);
 552         EXIT;
 553 }
 554
 555 void ldlm_lock_addref(struct lustre_handle *lockh, __u32 mode)
 556 {
 557         struct ldlm_lock *lock;
 558
 559         lock = ldlm_handle2lock(lockh);
 560         LASSERT(lock != NULL);
 561         ldlm_lock_addref_internal(lock, mode);
 562         LDLM_LOCK_PUT(lock);
 563 }
 564
 565 void ldlm_lock_addref_internal_nolock(struct ldlm_lock *lock, __u32 mode)
 566 {
 567         ldlm_lock_remove_from_lru(lock);
 568         if (mode & (LCK_NL | LCK_CR | LCK_PR))
 569                 lock->l_readers++;
 570         if (mode & (LCK_EX | LCK_CW | LCK_PW | LCK_GROUP))
 571                 lock->l_writers++;
 572         LDLM_LOCK_GET(lock);
 573         LDLM_DEBUG(lock, "ldlm_lock_addref(%s)", ldlm_lockname[mode]);
 574 }
 575
 576 /* only called for local locks */
 577 void ldlm_lock_addref_internal(struct ldlm_lock *lock, __u32 mode)
 578 {
 579         lock_res_and_lock(lock);
 580         ldlm_lock_addref_internal_nolock(lock, mode);
 581         unlock_res_and_lock(lock);
 582 }
 583
 584 void ldlm_lock_decref_internal(struct ldlm_lock *lock, __u32 mode)
 585 {
 586         struct ldlm_namespace *ns;
 587         ENTRY;
 588
 589         lock_res_and_lock(lock);
 590
 591         ns = lock->l_resource->lr_namespace;
 592
 593         LDLM_DEBUG(lock, "ldlm_lock_decref(%s)", ldlm_lockname[mode]);
 594         if (mode & (LCK_NL | LCK_CR | LCK_PR)) {
 595                 LASSERT(lock->l_readers > 0);
 596                 lock->l_readers--;
 597         }
 598         if (mode & (LCK_EX | LCK_CW | LCK_PW | LCK_GROUP)) {
 599                 LASSERT(lock->l_writers > 0);
 600                 lock->l_writers--;
 601         }
 602
 603         if (lock->l_flags & LDLM_FL_LOCAL &&
 604             !lock->l_readers && !lock->l_writers) {
 605                 /* If this is a local lock on a server namespace and this was
 606                  * the last reference, cancel the lock. */
 607                 CDEBUG(D_INFO, "forcing cancel of local lock\n");
 608                 lock->l_flags |= LDLM_FL_CBPENDING;
 609         }
 610
 611         if (!lock->l_readers && !lock->l_writers &&
 612             (lock->l_flags & LDLM_FL_CBPENDING)) {
 613                 /* If we received a blocked AST and this was the last reference,
 614                  * run the callback. */
 615                 if (ns_is_server(ns) && lock->l_export)
 616                         CERROR("FL_CBPENDING set on non-local lock--just a "
 617                                "warning\n");
 618
 619                 LDLM_DEBUG(lock, "final decref done on cbpending lock");
 620
 621                 LDLM_LOCK_GET(lock); /* dropped by bl thread */
 622                 ldlm_lock_remove_from_lru(lock);
 623                 unlock_res_and_lock(lock);
 624                 if ((lock->l_flags & LDLM_FL_ATOMIC_CB) ||
 625                     ldlm_bl_to_thread_lock(ns, NULL, lock) != 0)
 626                         ldlm_handle_bl_callback(ns, NULL, lock);
 627         } else if (ns_is_client(ns) &&
 628                    !lock->l_readers && !lock->l_writers &&
 629                    !(lock->l_flags & LDLM_FL_NO_LRU)) {
 630                 /* If this is a client-side namespace and this was the last
 631                  * reference, put it on the LRU. */
 632                 ldlm_lock_add_to_lru(lock);
 633                 unlock_res_and_lock(lock);
 634                 /* Call ldlm_cancel_lru() only if EARLY_CANCEL and LRU RESIZE
 635                  * are not supported by the server, otherwise, it is done on
 636                  * enqueue. */
 637                 if (!exp_connect_cancelset(lock->l_conn_export) &&
 638                     !ns_connect_lru_resize(ns))
 639                         ldlm_cancel_lru(ns, 0, LDLM_ASYNC, 0);
 640         } else {
 641                 unlock_res_and_lock(lock);
 642         }
 643
 644         LDLM_LOCK_PUT(lock);    /* matches the ldlm_lock_get in addref */
 645
 646         EXIT;
 647 }
 648
 649 void ldlm_lock_decref(struct lustre_handle *lockh, __u32 mode)
 650 {
 651         struct ldlm_lock *lock = __ldlm_handle2lock(lockh, 0);
 652         LASSERTF(lock != NULL, "Non-existing lock: "LPX64"\n", lockh->cookie);
 653         ldlm_lock_decref_internal(lock, mode);
 654         LDLM_LOCK_PUT(lock);
 655 }
 656
 657 /* This will drop a lock reference and mark it for destruction, but will not
 658  * necessarily cancel the lock before returning. */
 659 void ldlm_lock_decref_and_cancel(struct lustre_handle *lockh, __u32 mode)
 660 {
 661         struct ldlm_lock *lock = __ldlm_handle2lock(lockh, 0);
 662         ENTRY;
 663
 664         LASSERT(lock != NULL);
 665
 666         LDLM_DEBUG(lock, "ldlm_lock_decref(%s)", ldlm_lockname[mode]);
 667         lock_res_and_lock(lock);
 668         lock->l_flags |= LDLM_FL_CBPENDING;
 669         unlock_res_and_lock(lock);
 670         ldlm_lock_decref_internal(lock, mode);
 671         LDLM_LOCK_PUT(lock);
 672 }
 673
 674 /*
 675  * search_granted_lock
 676  *
 677  * Description:
 678  *      Finds a position to insert the new lock.
 679  * Parameters:
 680  *      queue [input]:  the granted list where search acts on;
 681  *      req [input]:    the lock whose position to be located;
 682  *      lockp [output]: the position where the lock should be inserted before, or
 683  *                      NULL indicating @req should be appended to @queue.
 684  * Return Values:
 685  *      Bit-masks combination of following values indicating in which way the
 686  *      lock need to be inserted.
 687  *      - LDLM_JOIN_NONE:       noting about skip list needs to be fixed;
 688  *      - LDLM_MODE_JOIN_RIGHT: @req needs join right becoming the head of a
 689  *                              mode group;
 690  *      - LDLM_POLICY_JOIN_RIGHT: @req needs join right becoming the head of
 691  *                                a policy group.
 692  * NOTE: called by
 693  *  - ldlm_grant_lock_with_skiplist
 694  */
 695 static int search_granted_lock(struct list_head *queue,
 696                         struct ldlm_lock *req,
 697                         struct ldlm_lock **lockp)
 698 {
 699         struct list_head *tmp, *tmp_tail;
 700         struct ldlm_lock *lock, *mode_head_lock;
 701         int rc = LDLM_JOIN_NONE;
 702         ENTRY;
 703
 704         list_for_each(tmp, queue) {
 705                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 706
 707                 if (lock->l_req_mode != req->l_req_mode) {
 708                         if (LDLM_SL_HEAD(&lock->l_sl_mode))
 709                                 tmp = &list_entry(lock->l_sl_mode.next,
 710                                                   struct ldlm_lock,
 711                                                   l_sl_mode)->l_res_link;
 712                         continue;
 713                 }
 714
 715                 /* found the same mode group */
 716                 if (lock->l_resource->lr_type == LDLM_PLAIN) {
 717                         *lockp = lock;
 718                         rc = LDLM_MODE_JOIN_RIGHT;
 719                         GOTO(out, rc);
 720                 } else if (lock->l_resource->lr_type == LDLM_IBITS) {
 721                         tmp_tail = tmp;
 722                         if (LDLM_SL_HEAD(&lock->l_sl_mode))
 723                                 tmp_tail = &list_entry(lock->l_sl_mode.next,
 724                                                        struct ldlm_lock,
 725                                                        l_sl_mode)->l_res_link;
 726                         mode_head_lock = lock;
 727                         for (;;) {
 728                                 if (lock->l_policy_data.l_inodebits.bits ==
 729                                     req->l_policy_data.l_inodebits.bits) {
 730                                         /* matched policy lock is found */
 731                                         *lockp = lock;
 732                                         rc |= LDLM_POLICY_JOIN_RIGHT;
 733
 734                                         /* if the policy group head is also a
 735                                          * mode group head or a single mode
 736                                          * group lock */
 737                                         if (LDLM_SL_HEAD(&lock->l_sl_mode) ||
 738                                             (tmp == tmp_tail &&
 739                                              LDLM_SL_EMPTY(&lock->l_sl_mode)))
 740                                                 rc |= LDLM_MODE_JOIN_RIGHT;
 741                                         GOTO(out, rc);
 742                                 }
 743
 744                                 if (LDLM_SL_HEAD(&lock->l_sl_policy))
 745                                         tmp = &list_entry(lock->l_sl_policy.next,
 746                                                           struct ldlm_lock,
 747                                                           l_sl_policy)->l_res_link;
 748
 749                                 if (tmp == tmp_tail)
 750                                         break;
 751                                 else
 752                                         tmp = tmp->next;
 753                                 lock = list_entry(tmp, struct ldlm_lock,
 754                                                   l_res_link);
 755                         }  /* for all locks in the matched mode group */
 756
 757                         /* no matched policy group is found, insert before
 758                          * the mode group head lock */
 759                         *lockp = mode_head_lock;
 760                         rc = LDLM_MODE_JOIN_RIGHT;
 761                         GOTO(out, rc);
 762                 } else {
 763                         LDLM_ERROR(lock, "is not LDLM_PLAIN or LDLM_IBITS lock");
 764                         LBUG();
 765                 }
 766         }
 767
 768         /* no matched mode group is found, append to the end */
 769         *lockp = NULL;
 770         rc = LDLM_JOIN_NONE;
 771         EXIT;
 772 out:
 773         return rc;
 774 }
 775
 776 static void ldlm_granted_list_add_lock(struct ldlm_lock *lock,
 777                                        struct ldlm_lock *lockp,
 778                                        int join)
 779 {
 780         struct ldlm_resource *res = lock->l_resource;
 781         ENTRY;
 782
 783         LASSERT(lockp || join == LDLM_JOIN_NONE);
 784
 785         check_res_locked(res);
 786
 787         ldlm_resource_dump(D_OTHER, res);
 788         CDEBUG(D_OTHER, "About to add this lock:\n");
 789         ldlm_lock_dump(D_OTHER, lock, 0);
 790
 791         if (lock->l_destroyed) {
 792                 CDEBUG(D_OTHER, "Lock destroyed, not adding to resource\n");
 793                 return;
 794         }
 795
 796         LASSERT(list_empty(&lock->l_res_link));
 797
 798         if (!lockp)
 799                 list_add_tail(&lock->l_res_link, &lock->l_resource->lr_granted);
 800         else if ((join & LDLM_MODE_JOIN_LEFT) || (join & LDLM_POLICY_JOIN_LEFT))
 801                 list_add(&lock->l_res_link, &lockp->l_res_link);
 802         else
 803                 list_add_tail(&lock->l_res_link, &lockp->l_res_link);
 804
 805         /* fix skip lists */
 806         if (join & LDLM_MODE_JOIN_RIGHT) {
 807                 LASSERT(! LDLM_SL_TAIL(&lockp->l_sl_mode));
 808                 if (LDLM_SL_EMPTY(&lockp->l_sl_mode)) {
 809                         lock->l_sl_mode.next = &lockp->l_sl_mode;
 810                         lockp->l_sl_mode.prev = &lock->l_sl_mode;
 811                 } else if (LDLM_SL_HEAD(&lockp->l_sl_mode)) {
 812                         lock->l_sl_mode.next = lockp->l_sl_mode.next;
 813                         lockp->l_sl_mode.next = NULL;
 814                         lock->l_sl_mode.next->prev = &lock->l_sl_mode;
 815                 }
 816         } else if (join & LDLM_MODE_JOIN_LEFT) {
 817                 LASSERT(! LDLM_SL_HEAD(&lockp->l_sl_mode));
 818                if (LDLM_SL_EMPTY(&lockp->l_sl_mode)) {
 819                         lock->l_sl_mode.prev = &lockp->l_sl_mode;
 820                         lockp->l_sl_mode.next = &lock->l_sl_mode;
 821                 } else if (LDLM_SL_TAIL(&lockp->l_sl_mode)) {
 822                         lock->l_sl_mode.prev = lockp->l_sl_mode.prev;
 823                         lockp->l_sl_mode.prev = NULL;
 824                         lock->l_sl_mode.prev->next = &lock->l_sl_mode;
 825                 }
 826         }
 827
 828         if (join & LDLM_POLICY_JOIN_RIGHT) {
 829                 LASSERT(! LDLM_SL_TAIL(&lockp->l_sl_policy));
 830                 if (LDLM_SL_EMPTY(&lockp->l_sl_policy)) {
 831                         lock->l_sl_policy.next = &lockp->l_sl_policy;
 832                         lockp->l_sl_policy.prev = &lock->l_sl_policy;
 833                 } else if (LDLM_SL_HEAD(&lockp->l_sl_policy)) {
 834                         lock->l_sl_policy.next = lockp->l_sl_policy.next;
 835                         lockp->l_sl_policy.next = NULL;
 836                         lock->l_sl_policy.next->prev = &lock->l_sl_policy;
 837                 }
 838         } else if (join & LDLM_POLICY_JOIN_LEFT) {
 839                 LASSERT(! LDLM_SL_HEAD(&lockp->l_sl_policy));
 840                 if (LDLM_SL_EMPTY(&lockp->l_sl_policy)) {
 841                         lock->l_sl_policy.prev = &lockp->l_sl_policy;
 842                         lockp->l_sl_policy.next = &lock->l_sl_policy;
 843                 } else if (LDLM_SL_TAIL(&lockp->l_sl_policy)) {
 844                         lock->l_sl_policy.prev = lockp->l_sl_policy.prev;
 845                         lockp->l_sl_policy.prev = NULL;
 846                         lock->l_sl_policy.prev->next = &lock->l_sl_policy;
 847                 }
 848         }
 849
 850         EXIT;
 851 }
 852
 853 static void ldlm_grant_lock_with_skiplist(struct ldlm_lock *lock)
 854 {
 855         int join = LDLM_JOIN_NONE;
 856         struct ldlm_lock *lockp = NULL;
 857         ENTRY;
 858
 859         LASSERT(lock->l_req_mode == lock->l_granted_mode);
 860
 861         join = search_granted_lock(&lock->l_resource->lr_granted, lock, &lockp);
 862         ldlm_granted_list_add_lock(lock, lockp, join);
 863         EXIT;
 864 }
 865
 866 /* NOTE: called by
 867  *  - ldlm_lock_enqueue
 868  *  - ldlm_reprocess_queue
 869  *  - ldlm_lock_convert
 870  *
 871  * must be called with lr_lock held
 872  */
 873 void ldlm_grant_lock(struct ldlm_lock *lock, struct list_head *work_list)
 874 {
 875         struct ldlm_resource *res = lock->l_resource;
 876         ENTRY;
 877
 878         check_res_locked(res);
 879
 880         lock->l_granted_mode = lock->l_req_mode;
 881         if (res->lr_type == LDLM_PLAIN || res->lr_type == LDLM_IBITS)
 882                 ldlm_grant_lock_with_skiplist(lock);
 883         else if (res->lr_type == LDLM_EXTENT)
 884                 ldlm_extent_add_lock(res, lock);
 885         else
 886                 ldlm_resource_add_lock(res, &res->lr_granted, lock);
 887
 888         if (lock->l_granted_mode < res->lr_most_restr)
 889                 res->lr_most_restr = lock->l_granted_mode;
 890
 891         if (work_list && lock->l_completion_ast != NULL)
 892                 ldlm_add_ast_work_item(lock, NULL, work_list);
 893
 894         ldlm_pool_add(&res->lr_namespace->ns_pool, lock);
 895         EXIT;
 896 }
 897
 898 /* returns a referenced lock or NULL.  See the flag descriptions below, in the
 899  * comment above ldlm_lock_match */
 900 static struct ldlm_lock *search_queue(struct list_head *queue,
 901                                       ldlm_mode_t *mode,
 902                                       ldlm_policy_data_t *policy,
 903                                       struct ldlm_lock *old_lock, int flags)
 904 {
 905         struct ldlm_lock *lock;
 906         struct list_head *tmp;
 907
 908         list_for_each(tmp, queue) {
 909                 ldlm_mode_t match;
 910
 911                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 912
 913                 if (lock == old_lock)
 914                         break;
 915
 916                 /* llite sometimes wants to match locks that will be
 917                  * canceled when their users drop, but we allow it to match
 918                  * if it passes in CBPENDING and the lock still has users.
 919                  * this is generally only going to be used by children
 920                  * whose parents already hold a lock so forward progress
 921                  * can still happen. */
 922                 if (lock->l_flags & LDLM_FL_CBPENDING &&
 923                     !(flags & LDLM_FL_CBPENDING))
 924                         continue;
 925                 if (lock->l_flags & LDLM_FL_CBPENDING &&
 926                     lock->l_readers == 0 && lock->l_writers == 0)
 927                         continue;
 928
 929                 if (!(lock->l_req_mode & *mode))
 930                         continue;
 931                 match = lock->l_req_mode;
 932
 933                 if (lock->l_resource->lr_type == LDLM_EXTENT &&
 934                     (lock->l_policy_data.l_extent.start >
 935                      policy->l_extent.start ||
 936                      lock->l_policy_data.l_extent.end < policy->l_extent.end))
 937                         continue;
 938
 939                 if (unlikely(match == LCK_GROUP) &&
 940                     lock->l_resource->lr_type == LDLM_EXTENT &&
 941                     lock->l_policy_data.l_extent.gid != policy->l_extent.gid)
 942                         continue;
 943
 944                 /* We match if we have existing lock with same or wider set
 945                    of bits. */
 946                 if (lock->l_resource->lr_type == LDLM_IBITS &&
 947                      ((lock->l_policy_data.l_inodebits.bits &
 948                       policy->l_inodebits.bits) !=
 949                       policy->l_inodebits.bits))
 950                         continue;
 951
 952                 if (lock->l_destroyed || (lock->l_flags & LDLM_FL_FAILED))
 953                         continue;
 954
 955                 if ((flags & LDLM_FL_LOCAL_ONLY) &&
 956                     !(lock->l_flags & LDLM_FL_LOCAL))
 957                         continue;
 958
 959                 if (flags & LDLM_FL_TEST_LOCK) {
 960                         LDLM_LOCK_GET(lock);
 961                         ldlm_lock_touch_in_lru(lock);
 962                 } else {
 963                         ldlm_lock_addref_internal_nolock(lock, match);
 964                 }
 965                 *mode = match;
 966                 return lock;
 967         }
 968
 969         return NULL;
 970 }
 971
 972 void ldlm_lock_allow_match(struct ldlm_lock *lock)
 973 {
 974         lock_res_and_lock(lock);
 975         lock->l_flags |= LDLM_FL_LVB_READY;
 976         cfs_waitq_signal(&lock->l_waitq);
 977         unlock_res_and_lock(lock);
 978 }
 979
 980 /* Can be called in two ways:
 981  *
 982  * If 'ns' is NULL, then lockh describes an existing lock that we want to look
 983  * for a duplicate of.
 984  *
 985  * Otherwise, all of the fields must be filled in, to match against.
 986  *
 987  * If 'flags' contains LDLM_FL_LOCAL_ONLY, then only match local locks on the
 988  *     server (ie, connh is NULL)
 989  * If 'flags' contains LDLM_FL_BLOCK_GRANTED, then only locks on the granted
 990  *     list will be considered
 991  * If 'flags' contains LDLM_FL_CBPENDING, then locks that have been marked
 992  *     to be canceled can still be matched as long as they still have reader
 993  *     or writer refernces
 994  * If 'flags' contains LDLM_FL_TEST_LOCK, then don't actually reference a lock,
 995  *     just tell us if we would have matched.
 996  *
 997  * Returns 1 if it finds an already-existing lock that is compatible; in this
 998  * case, lockh is filled in with a addref()ed lock
 999  *
1000  * we also check security context, if that failed we simply return 0 (to keep
1001  * caller code unchanged), the context failure will be discovered by caller
1002  * sometime later.
1003  */
1004 ldlm_mode_t ldlm_lock_match(struct ldlm_namespace *ns, int flags,
1005                             const struct ldlm_res_id *res_id, ldlm_type_t type,
1006                             ldlm_policy_data_t *policy, ldlm_mode_t mode,
1007                             struct lustre_handle *lockh)
1008 {
1009         struct ldlm_resource *res;
1010         struct ldlm_lock *lock, *old_lock = NULL;
1011         int rc = 0;
1012         ENTRY;
1013
1014         if (ns == NULL) {
1015                 old_lock = ldlm_handle2lock(lockh);
1016                 LASSERT(old_lock);
1017
1018                 ns = old_lock->l_resource->lr_namespace;
1019                 res_id = &old_lock->l_resource->lr_name;
1020                 type = old_lock->l_resource->lr_type;
1021                 mode = old_lock->l_req_mode;
1022         }
1023
1024         res = ldlm_resource_get(ns, NULL, res_id, type, 0);
1025         if (res == NULL) {
1026                 LASSERT(old_lock == NULL);
1027                 RETURN(0);
1028         }
1029
1030         lock_res(res);
1031
1032         lock = search_queue(&res->lr_granted, &mode, policy, old_lock, flags);
1033         if (lock != NULL)
1034                 GOTO(out, rc = 1);
1035         if (flags & LDLM_FL_BLOCK_GRANTED)
1036                 GOTO(out, rc = 0);
1037         lock = search_queue(&res->lr_converting, &mode, policy, old_lock, flags);
1038         if (lock != NULL)
1039                 GOTO(out, rc = 1);
1040         lock = search_queue(&res->lr_waiting, &mode, policy, old_lock, flags);
1041         if (lock != NULL)
1042                 GOTO(out, rc = 1);
1043
1044         EXIT;
1045  out:
1046         unlock_res(res);
1047         ldlm_resource_putref(res);
1048
1049         if (lock) {
1050                 ldlm_lock2handle(lock, lockh);
1051                 if ((flags & LDLM_FL_LVB_READY) &&
1052                     (!(lock->l_flags & LDLM_FL_LVB_READY))) {
1053                         struct l_wait_info lwi;
1054                         if (lock->l_completion_ast) {
1055                                 int err = lock->l_completion_ast(lock,
1056                                                           LDLM_FL_WAIT_NOREPROC,
1057                                                                  NULL);
1058                                 if (err) {
1059                                         if (flags & LDLM_FL_TEST_LOCK)
1060                                                 LDLM_LOCK_PUT(lock);
1061                                         else
1062                                                 ldlm_lock_decref_internal(lock, mode);
1063                                         rc = 0;
1064                                         goto out2;
1065                                 }
1066                         }
1067
1068                         lwi = LWI_TIMEOUT_INTR(cfs_time_seconds(obd_timeout), NULL,
1069                                                LWI_ON_SIGNAL_NOOP, NULL);
1070
1071                         /* XXX FIXME see comment on CAN_MATCH in lustre_dlm.h */
1072                         l_wait_event(lock->l_waitq,
1073                                      (lock->l_flags & LDLM_FL_LVB_READY), &lwi);
1074                 }
1075         }
1076  out2:
1077         if (rc) {
1078                 LDLM_DEBUG(lock, "matched ("LPU64" "LPU64")",
1079                            (type == LDLM_PLAIN || type == LDLM_IBITS) ?
1080                                 res_id->name[2] : policy->l_extent.start,
1081                            (type == LDLM_PLAIN || type == LDLM_IBITS) ?
1082                                 res_id->name[3] : policy->l_extent.end);
1083
1084                 /* check user's security context */
1085                 if (lock->l_conn_export &&
1086                     sptlrpc_import_check_ctx(
1087                                 class_exp2cliimp(lock->l_conn_export))) {
1088                         if (!(flags & LDLM_FL_TEST_LOCK))
1089                                 ldlm_lock_decref_internal(lock, mode);
1090                         rc = 0;
1091                 }
1092
1093                 if (flags & LDLM_FL_TEST_LOCK)
1094                         LDLM_LOCK_PUT(lock);
1095
1096         } else if (!(flags & LDLM_FL_TEST_LOCK)) {/*less verbose for test-only*/
1097                 LDLM_DEBUG_NOLOCK("not matched ns %p type %u mode %u res "
1098                                   LPU64"/"LPU64" ("LPU64" "LPU64")", ns,
1099                                   type, mode, res_id->name[0], res_id->name[1],
1100                                   (type == LDLM_PLAIN || type == LDLM_IBITS) ?
1101                                         res_id->name[2] :policy->l_extent.start,
1102                                 (type == LDLM_PLAIN || type == LDLM_IBITS) ?
1103                                         res_id->name[3] : policy->l_extent.end);
1104         }
1105         if (old_lock)
1106                 LDLM_LOCK_PUT(old_lock);
1107
1108         return rc ? mode : 0;
1109 }
1110
1111 /* Returns a referenced lock */
1112 struct ldlm_lock *ldlm_lock_create(struct ldlm_namespace *ns,
1113                                    const struct ldlm_res_id *res_id,
1114                                    ldlm_type_t type,
1115                                    ldlm_mode_t mode,
1116                                    ldlm_blocking_callback blocking,
1117                                    ldlm_completion_callback completion,
1118                                    ldlm_glimpse_callback glimpse,
1119                                    void *data, __u32 lvb_len)
1120 {
1121         struct ldlm_lock *lock;
1122         struct ldlm_resource *res;
1123         ENTRY;
1124
1125         res = ldlm_resource_get(ns, NULL, res_id, type, 1);
1126         if (res == NULL)
1127                 RETURN(NULL);
1128
1129         lock = ldlm_lock_new(res);
1130         ldlm_resource_putref(res);
1131
1132         if (lock == NULL)
1133                 RETURN(NULL);
1134
1135         lock->l_req_mode = mode;
1136         lock->l_ast_data = data;
1137         lock->l_blocking_ast = blocking;
1138         lock->l_completion_ast = completion;
1139         lock->l_glimpse_ast = glimpse;
1140         lock->l_pid = cfs_curproc_pid();
1141
1142         lock->l_tree_node = NULL;
1143         /* if this is the extent lock, allocate the interval tree node */
1144         if (type == LDLM_EXTENT) {
1145                 if (ldlm_interval_alloc(lock) == NULL)
1146                         GOTO(out, 0);
1147         }
1148
1149         if (lvb_len) {
1150                 lock->l_lvb_len = lvb_len;
1151                 OBD_ALLOC(lock->l_lvb_data, lvb_len);
1152                 if (lock->l_lvb_data == NULL)
1153                         GOTO(out, 0);
1154         }
1155
1156         RETURN(lock);
1157
1158 out:
1159         if (lock->l_lvb_data)
1160                 OBD_FREE(lock->l_lvb_data, lvb_len);
1161         ldlm_interval_free(ldlm_interval_detach(lock));
1162         OBD_SLAB_FREE(lock, ldlm_lock_slab, sizeof(*lock));
1163         return NULL;
1164 }
1165
1166 ldlm_error_t ldlm_lock_enqueue(struct ldlm_namespace *ns,
1167                                struct ldlm_lock **lockp,
1168                                void *cookie, int *flags)
1169 {
1170         struct ldlm_lock *lock = *lockp;
1171         struct ldlm_resource *res = lock->l_resource;
1172         int local = ns_is_client(res->lr_namespace);
1173         ldlm_processing_policy policy;
1174         ldlm_error_t rc = ELDLM_OK;
1175         struct ldlm_interval *node = NULL;
1176         ENTRY;
1177
1178         do_gettimeofday(&lock->l_enqueued_time);
1179         /* policies are not executed on the client or during replay */
1180         if ((*flags & (LDLM_FL_HAS_INTENT|LDLM_FL_REPLAY)) == LDLM_FL_HAS_INTENT
1181             && !local && ns->ns_policy) {
1182                 rc = ns->ns_policy(ns, lockp, cookie, lock->l_req_mode, *flags,
1183                                    NULL);
1184                 if (rc == ELDLM_LOCK_REPLACED) {
1185                         /* The lock that was returned has already been granted,
1186                          * and placed into lockp.  If it's not the same as the
1187                          * one we passed in, then destroy the old one and our
1188                          * work here is done. */
1189                         if (lock != *lockp) {
1190                                 ldlm_lock_destroy(lock);
1191                                 LDLM_LOCK_PUT(lock);
1192                         }
1193                         *flags |= LDLM_FL_LOCK_CHANGED;
1194                         RETURN(0);
1195                 } else if (rc != ELDLM_OK ||
1196                            (rc == ELDLM_OK && (*flags & LDLM_FL_INTENT_ONLY))) {
1197                         ldlm_lock_destroy(lock);
1198                         RETURN(rc);
1199                 }
1200         }
1201
1202         /* For a replaying lock, it might be already in granted list. So
1203          * unlinking the lock will cause the interval node to be freed, we
1204          * have to allocate the interval node early otherwise we can't regrant
1205          * this lock in the future. - jay */
1206         if (!local && (*flags & LDLM_FL_REPLAY) && res->lr_type == LDLM_EXTENT)
1207                 OBD_SLAB_ALLOC(node, ldlm_interval_slab, CFS_ALLOC_IO,
1208                                sizeof(*node));
1209
1210         lock_res_and_lock(lock);
1211         if (local && lock->l_req_mode == lock->l_granted_mode) {
1212                 /* The server returned a blocked lock, but it was granted
1213                  * before we got a chance to actually enqueue it.  We don't
1214                  * need to do anything else. */
1215                 *flags &= ~(LDLM_FL_BLOCK_GRANTED |
1216                             LDLM_FL_BLOCK_CONV | LDLM_FL_BLOCK_WAIT);
1217                 GOTO(out, ELDLM_OK);
1218         }
1219
1220         ldlm_resource_unlink_lock(lock);
1221         if (res->lr_type == LDLM_EXTENT && lock->l_tree_node == NULL) {
1222                 if (node == NULL) {
1223                         ldlm_lock_destroy_nolock(lock);
1224                         GOTO(out, rc = -ENOMEM);
1225                 }
1226
1227                 ldlm_interval_attach(node, lock);
1228                 node = NULL;
1229         }
1230
1231         /* Some flags from the enqueue want to make it into the AST, via the
1232          * lock's l_flags. */
1233         lock->l_flags |= *flags & LDLM_AST_DISCARD_DATA;
1234
1235         /* This distinction between local lock trees is very important; a client
1236          * namespace only has information about locks taken by that client, and
1237          * thus doesn't have enough information to decide for itself if it can
1238          * be granted (below).  In this case, we do exactly what the server
1239          * tells us to do, as dictated by the 'flags'.
1240          *
1241          * We do exactly the same thing during recovery, when the server is
1242          * more or less trusting the clients not to lie.
1243          *
1244          * FIXME (bug 268): Detect obvious lies by checking compatibility in
1245          * granted/converting queues. */
1246         if (local) {
1247                 if (*flags & LDLM_FL_BLOCK_CONV)
1248                         ldlm_resource_add_lock(res, &res->lr_converting, lock);
1249                 else if (*flags & (LDLM_FL_BLOCK_WAIT | LDLM_FL_BLOCK_GRANTED))
1250                         ldlm_resource_add_lock(res, &res->lr_waiting, lock);
1251                 else
1252                         ldlm_grant_lock(lock, NULL);
1253                 GOTO(out, ELDLM_OK);
1254         } else if (*flags & LDLM_FL_REPLAY) {
1255                 if (*flags & LDLM_FL_BLOCK_CONV) {
1256                         ldlm_resource_add_lock(res, &res->lr_converting, lock);
1257                         GOTO(out, ELDLM_OK);
1258                 } else if (*flags & LDLM_FL_BLOCK_WAIT) {
1259                         ldlm_resource_add_lock(res, &res->lr_waiting, lock);
1260                         GOTO(out, ELDLM_OK);
1261                 } else if (*flags & LDLM_FL_BLOCK_GRANTED) {
1262                         ldlm_grant_lock(lock, NULL);
1263                         GOTO(out, ELDLM_OK);
1264                 }
1265                 /* If no flags, fall through to normal enqueue path. */
1266         }
1267
1268         policy = ldlm_processing_policy_table[res->lr_type];
1269         policy(lock, flags, 1, &rc, NULL);
1270         GOTO(out, rc);
1271 out:
1272         unlock_res_and_lock(lock);
1273         if (node)
1274                 OBD_SLAB_FREE(node, ldlm_interval_slab, sizeof(*node));
1275         return rc;
1276 }
1277
1278 /* Must be called with namespace taken: queue is waiting or converting. */
1279 int ldlm_reprocess_queue(struct ldlm_resource *res, struct list_head *queue,
1280                          struct list_head *work_list)
1281 {
1282         struct list_head *tmp, *pos;
1283         ldlm_processing_policy policy;
1284         int flags;
1285         int rc = LDLM_ITER_CONTINUE;
1286         ldlm_error_t err;
1287         ENTRY;
1288
1289         check_res_locked(res);
1290
1291         policy = ldlm_processing_policy_table[res->lr_type];
1292         LASSERT(policy);
1293
1294         list_for_each_safe(tmp, pos, queue) {
1295                 struct ldlm_lock *pending;
1296                 pending = list_entry(tmp, struct ldlm_lock, l_res_link);
1297
1298                 CDEBUG(D_INFO, "Reprocessing lock %p\n", pending);
1299
1300                 flags = 0;
1301                 rc = policy(pending, &flags, 0, &err, work_list);
1302                 if (rc != LDLM_ITER_CONTINUE)
1303                         break;
1304         }
1305
1306         RETURN(rc);
1307 }
1308
1309 /* Helper function for ldlm_run_ast_work().
1310  *
1311  * Send an existing rpc set specified by @arg->set and then
1312  * destroy it. Create new one if @do_create flag is set. */
1313 static void
1314 ldlm_send_and_maybe_create_set(struct ldlm_cb_set_arg *arg, int do_create)
1315 {
1316         ENTRY;
1317
1318         ptlrpc_set_wait(arg->set);
1319         if (arg->type == LDLM_BL_CALLBACK)
1320                 OBD_FAIL_TIMEOUT(OBD_FAIL_LDLM_GLIMPSE, 2);
1321         ptlrpc_set_destroy(arg->set);
1322
1323         if (do_create)
1324                 arg->set = ptlrpc_prep_set();
1325
1326         EXIT;
1327 }
1328
1329 static int
1330 ldlm_work_bl_ast_lock(struct list_head *tmp, struct ldlm_cb_set_arg *arg)
1331 {
1332         struct ldlm_lock_desc d;
1333         struct ldlm_lock *lock = list_entry(tmp, struct ldlm_lock, l_bl_ast);
1334         ENTRY;
1335
1336         /* nobody should touch l_bl_ast */
1337         lock_res_and_lock(lock);
1338         list_del_init(&lock->l_bl_ast);
1339
1340         LASSERT(lock->l_flags & LDLM_FL_AST_SENT);
1341         LASSERT(lock->l_bl_ast_run == 0);
1342         LASSERT(lock->l_blocking_lock);
1343         lock->l_bl_ast_run++;
1344         unlock_res_and_lock(lock);
1345
1346         ldlm_lock2desc(lock->l_blocking_lock, &d);
1347
1348         LDLM_LOCK_PUT(lock->l_blocking_lock);
1349         lock->l_blocking_lock = NULL;
1350         lock->l_blocking_ast(lock, &d, (void *)arg,
1351                              LDLM_CB_BLOCKING);
1352         LDLM_LOCK_PUT(lock);
1353
1354         RETURN(1);
1355 }
1356
1357 static int
1358 ldlm_work_cp_ast_lock(struct list_head *tmp, struct ldlm_cb_set_arg *arg)
1359 {
1360         struct ldlm_lock *lock = list_entry(tmp, struct ldlm_lock, l_cp_ast);
1361         ldlm_completion_callback completion_callback;
1362         int rc = 0;
1363         ENTRY;
1364
1365         /* It's possible to receive a completion AST before we've set
1366          * the l_completion_ast pointer: either because the AST arrived
1367          * before the reply, or simply because there's a small race
1368          * window between receiving the reply and finishing the local
1369          * enqueue. (bug 842)
1370          *
1371          * This can't happen with the blocking_ast, however, because we
1372          * will never call the local blocking_ast until we drop our
1373          * reader/writer reference, which we won't do until we get the
1374          * reply and finish enqueueing. */
1375
1376         /* nobody should touch l_cp_ast */
1377         lock_res_and_lock(lock);
1378         list_del_init(&lock->l_cp_ast);
1379         LASSERT(lock->l_flags & LDLM_FL_CP_REQD);
1380         /* save l_completion_ast since it can be changed by
1381          * mds_intent_policy(), see bug 14225 */
1382         completion_callback = lock->l_completion_ast;
1383         lock->l_flags &= ~LDLM_FL_CP_REQD;
1384         unlock_res_and_lock(lock);
1385
1386         if (completion_callback != NULL) {
1387                 completion_callback(lock, 0, (void *)arg);
1388                 rc = 1;
1389         }
1390         LDLM_LOCK_PUT(lock);
1391
1392         RETURN(rc);
1393 }
1394
1395 static int
1396 ldlm_work_revoke_ast_lock(struct list_head *tmp, struct ldlm_cb_set_arg *arg)
1397 {
1398         struct ldlm_lock_desc desc;
1399         struct ldlm_lock *lock = list_entry(tmp, struct ldlm_lock, l_export_chain);
1400         ENTRY;
1401
1402         list_del_init(&lock->l_export_chain);
1403
1404         /* the desc just pretend to exclusive */
1405         ldlm_lock2desc(lock, &desc);
1406         desc.l_req_mode = LCK_EX;
1407         desc.l_granted_mode = 0;
1408
1409         lock->l_blocking_ast(lock, &desc, (void*)arg, LDLM_CB_BLOCKING);
1410         LDLM_LOCK_PUT(lock);
1411
1412         RETURN(1);
1413 }
1414
1415 int ldlm_run_ast_work(struct list_head *rpc_list, ldlm_desc_ast_t ast_type)
1416 {
1417         struct ldlm_cb_set_arg arg;
1418         struct list_head *tmp, *pos;
1419         int (*work_ast_lock)(struct list_head *tmp, struct ldlm_cb_set_arg *arg);
1420         int ast_count;
1421         ENTRY;
1422
1423         arg.set = ptlrpc_prep_set();
1424         atomic_set(&arg.restart, 0);
1425         switch (ast_type) {
1426         case LDLM_WORK_BL_AST:
1427                 arg.type = LDLM_BL_CALLBACK;
1428                 work_ast_lock = ldlm_work_bl_ast_lock;
1429                 break;
1430         case LDLM_WORK_CP_AST:
1431                 arg.type = LDLM_CP_CALLBACK;
1432                 work_ast_lock = ldlm_work_cp_ast_lock;
1433                 break;
1434         case LDLM_WORK_REVOKE_AST:
1435                 arg.type = LDLM_BL_CALLBACK;
1436                 work_ast_lock = ldlm_work_revoke_ast_lock;
1437                 break;
1438         default:
1439                 LBUG();
1440         }
1441
1442         ast_count = 0;
1443         list_for_each_safe(tmp, pos, rpc_list) {
1444                 ast_count += work_ast_lock(tmp, &arg);
1445
1446                 /* Send the request set if it exceeds the PARALLEL_AST_LIMIT,
1447                  * and create a new set for requests that remained in
1448                  * @rpc_list */
1449                 if (unlikely(ast_count == PARALLEL_AST_LIMIT)) {
1450                         ldlm_send_and_maybe_create_set(&arg, 1);
1451                         ast_count = 0;
1452                 }
1453         }
1454
1455         if (ast_count > 0)
1456                 ldlm_send_and_maybe_create_set(&arg, 0);
1457         else
1458                 /* In case when number of ASTs is multiply of
1459                  * PARALLEL_AST_LIMIT or @rpc_list was initially empty,
1460                  * @arg.set must be destroyed here, otherwise we get
1461                  * write memory leaking. */
1462                 ptlrpc_set_destroy(arg.set);
1463
1464         RETURN(atomic_read(&arg.restart) ? -ERESTART : 0);
1465 }
1466
1467 static int reprocess_one_queue(struct ldlm_resource *res, void *closure)
1468 {
1469         ldlm_reprocess_all(res);
1470         return LDLM_ITER_CONTINUE;
1471 }
1472
1473 void ldlm_reprocess_all_ns(struct ldlm_namespace *ns)
1474 {
1475         struct list_head *tmp;
1476         int i, rc;
1477
1478         if (ns == NULL)
1479                 return;
1480
1481         ENTRY;
1482         spin_lock(&ns->ns_hash_lock);
1483         for (i = 0; i < RES_HASH_SIZE; i++) {
1484                 tmp = ns->ns_hash[i].next;
1485                 while (tmp != &(ns->ns_hash[i])) {
1486                         struct ldlm_resource *res =
1487                                 list_entry(tmp, struct ldlm_resource, lr_hash);
1488
1489                         ldlm_resource_getref(res);
1490                         spin_unlock(&ns->ns_hash_lock);
1491
1492                         rc = reprocess_one_queue(res, NULL);
1493
1494                         spin_lock(&ns->ns_hash_lock);
1495                         tmp = tmp->next;
1496                         ldlm_resource_putref_locked(res);
1497
1498                         if (rc == LDLM_ITER_STOP)
1499                                 GOTO(out, rc);
1500                 }
1501         }
1502  out:
1503         spin_unlock(&ns->ns_hash_lock);
1504         EXIT;
1505 }
1506
1507 void ldlm_reprocess_all(struct ldlm_resource *res)
1508 {
1509         struct list_head rpc_list = LIST_HEAD_INIT(rpc_list);
1510         int rc;
1511         ENTRY;
1512
1513         /* Local lock trees don't get reprocessed. */
1514         if (ns_is_client(res->lr_namespace)) {
1515                 EXIT;
1516                 return;
1517         }
1518
1519  restart:
1520         lock_res(res);
1521         rc = ldlm_reprocess_queue(res, &res->lr_converting, &rpc_list);
1522         if (rc == LDLM_ITER_CONTINUE)
1523                 ldlm_reprocess_queue(res, &res->lr_waiting, &rpc_list);
1524         unlock_res(res);
1525
1526         rc = ldlm_run_ast_work(&rpc_list, LDLM_WORK_CP_AST);
1527         if (rc == -ERESTART) {
1528                 LASSERT(list_empty(&rpc_list));
1529                 goto restart;
1530         }
1531         EXIT;
1532 }
1533
1534 void ldlm_cancel_callback(struct ldlm_lock *lock)
1535 {
1536         check_res_locked(lock->l_resource);
1537         if (!(lock->l_flags & LDLM_FL_CANCEL)) {
1538                 lock->l_flags |= LDLM_FL_CANCEL;
1539                 if (lock->l_blocking_ast) {
1540                         // l_check_no_ns_lock(ns);
1541                         unlock_res_and_lock(lock);
1542                         lock->l_blocking_ast(lock, NULL, lock->l_ast_data,
1543                                              LDLM_CB_CANCELING);
1544                         lock_res_and_lock(lock);
1545                 } else {
1546                         LDLM_DEBUG(lock, "no blocking ast");
1547                 }
1548         }
1549         lock->l_flags |= LDLM_FL_BL_DONE;
1550 }
1551
1552 void ldlm_unlink_lock_skiplist(struct ldlm_lock *req)
1553 {
1554         struct ldlm_lock *lock;
1555
1556         if (req->l_resource->lr_type != LDLM_PLAIN &&
1557             req->l_resource->lr_type != LDLM_IBITS)
1558                 return;
1559
1560         if (LDLM_SL_HEAD(&req->l_sl_mode)) {
1561                 lock = list_entry(req->l_res_link.next, struct ldlm_lock,
1562                                   l_res_link);
1563                 if (req->l_sl_mode.next == &lock->l_sl_mode) {
1564                         lock->l_sl_mode.prev = NULL;
1565                 } else {
1566                         lock->l_sl_mode.next = req->l_sl_mode.next;
1567                         lock->l_sl_mode.next->prev = &lock->l_sl_mode;
1568                 }
1569                 req->l_sl_mode.next = NULL;
1570         } else if (LDLM_SL_TAIL(&req->l_sl_mode)) {
1571                 lock = list_entry(req->l_res_link.prev, struct ldlm_lock,
1572                                   l_res_link);
1573                 if (req->l_sl_mode.prev == &lock->l_sl_mode) {
1574                         lock->l_sl_mode.next = NULL;
1575                 } else {
1576                         lock->l_sl_mode.prev = req->l_sl_mode.prev;
1577                         lock->l_sl_mode.prev->next = &lock->l_sl_mode;
1578                 }
1579                 req->l_sl_mode.prev = NULL;
1580         }
1581
1582         if (LDLM_SL_HEAD(&req->l_sl_policy)) {
1583                 lock = list_entry(req->l_res_link.next, struct ldlm_lock,
1584                                   l_res_link);
1585                 if (req->l_sl_policy.next == &lock->l_sl_policy) {
1586                         lock->l_sl_policy.prev = NULL;
1587                 } else {
1588                         lock->l_sl_policy.next = req->l_sl_policy.next;
1589                         lock->l_sl_policy.next->prev = &lock->l_sl_policy;
1590                 }
1591                 req->l_sl_policy.next = NULL;
1592         } else if (LDLM_SL_TAIL(&req->l_sl_policy)) {
1593                 lock = list_entry(req->l_res_link.prev, struct ldlm_lock,
1594                                   l_res_link);
1595                 if (req->l_sl_policy.prev == &lock->l_sl_policy) {
1596                         lock->l_sl_policy.next = NULL;
1597                 } else {
1598                         lock->l_sl_policy.prev = req->l_sl_policy.prev;
1599                         lock->l_sl_policy.prev->next = &lock->l_sl_policy;
1600                 }
1601                 req->l_sl_policy.prev = NULL;
1602         }
1603 }
1604
1605 void ldlm_lock_cancel(struct ldlm_lock *lock)
1606 {
1607         struct ldlm_resource *res;
1608         struct ldlm_namespace *ns;
1609         ENTRY;
1610
1611         lock_res_and_lock(lock);
1612
1613         res = lock->l_resource;
1614         ns = res->lr_namespace;
1615
1616         /* Please do not, no matter how tempting, remove this LBUG without
1617          * talking to me first. -phik */
1618         if (lock->l_readers || lock->l_writers) {
1619                 LDLM_ERROR(lock, "lock still has references");
1620                 LBUG();
1621         }
1622
1623         ldlm_del_waiting_lock(lock);
1624
1625         /* Releases cancel callback. */
1626         ldlm_cancel_callback(lock);
1627
1628         /* Yes, second time, just in case it was added again while we were
1629            running with no res lock in ldlm_cancel_callback */
1630         ldlm_del_waiting_lock(lock);
1631         ldlm_resource_unlink_lock(lock);
1632         ldlm_lock_destroy_nolock(lock);
1633
1634         if (lock->l_granted_mode == lock->l_req_mode)
1635                 ldlm_pool_del(&ns->ns_pool, lock);
1636
1637         /* Make sure we will not be called again for same lock what is possible
1638          * if not to zero out lock->l_granted_mode */
1639         lock->l_granted_mode = 0;
1640         unlock_res_and_lock(lock);
1641
1642         EXIT;
1643 }
1644
1645 int ldlm_lock_set_data(struct lustre_handle *lockh, void *data)
1646 {
1647         struct ldlm_lock *lock = ldlm_handle2lock(lockh);
1648         ENTRY;
1649
1650         if (lock == NULL)
1651                 RETURN(-EINVAL);
1652
1653         lock->l_ast_data = data;
1654         LDLM_LOCK_PUT(lock);
1655         RETURN(0);
1656 }
1657
1658 void ldlm_cancel_locks_for_export(struct obd_export *exp)
1659 {
1660         struct ldlm_lock *lock;
1661         struct ldlm_resource *res;
1662
1663         spin_lock(&exp->exp_ldlm_data.led_lock);
1664         while(!list_empty(&exp->exp_ldlm_data.led_held_locks)) {
1665                 lock = list_entry(exp->exp_ldlm_data.led_held_locks.next,
1666                                   struct ldlm_lock, l_export_chain);
1667                 res = ldlm_resource_getref(lock->l_resource);
1668                 LDLM_LOCK_GET(lock);
1669                 spin_unlock(&exp->exp_ldlm_data.led_lock);
1670
1671                 LDLM_DEBUG(lock, "export %p", exp);
1672                 ldlm_res_lvbo_update(res, NULL, 0, 1);
1673
1674                 ldlm_lock_cancel(lock);
1675                 ldlm_reprocess_all(res);
1676
1677                 ldlm_resource_putref(res);
1678                 LDLM_LOCK_PUT(lock);
1679                 spin_lock(&exp->exp_ldlm_data.led_lock);
1680         }
1681         spin_unlock(&exp->exp_ldlm_data.led_lock);
1682 }
1683
1684 struct ldlm_resource *ldlm_lock_convert(struct ldlm_lock *lock, int new_mode,
1685                                         __u32 *flags)
1686 {
1687         struct list_head rpc_list = LIST_HEAD_INIT(rpc_list);
1688         struct ldlm_resource *res;
1689         struct ldlm_namespace *ns;
1690         int granted = 0;
1691         int old_mode, rc;
1692         struct ldlm_lock *mark_lock = NULL;
1693         int join = LDLM_JOIN_NONE;
1694         ldlm_error_t err;
1695         struct ldlm_interval *node;
1696         ENTRY;
1697
1698         if (new_mode == lock->l_granted_mode) { // No changes? Just return.
1699                 *flags |= LDLM_FL_BLOCK_GRANTED;
1700                 RETURN(lock->l_resource);
1701         }
1702
1703         /* I can't check the type of lock here because the bitlock of lock
1704          * is not held here, so do the allocation blindly. -jay */
1705         OBD_SLAB_ALLOC(node, ldlm_interval_slab, CFS_ALLOC_IO, sizeof(*node));
1706         if (node == NULL)  /* Actually, this causes EDEADLOCK to be returned */
1707                 RETURN(NULL);
1708
1709         LASSERTF(new_mode == LCK_PW && lock->l_granted_mode == LCK_PR,
1710                  "new_mode %u, granted %u\n", new_mode, lock->l_granted_mode);
1711
1712         lock_res_and_lock(lock);
1713
1714         res = lock->l_resource;
1715         ns = res->lr_namespace;
1716
1717         old_mode = lock->l_req_mode;
1718         lock->l_req_mode = new_mode;
1719         if (res->lr_type == LDLM_PLAIN || res->lr_type == LDLM_IBITS) {
1720                 /* remember the lock position where the lock might be
1721                  * added back to the granted list later and also
1722                  * remember the join mode for skiplist fixing. */
1723                 if (LDLM_SL_HEAD(&lock->l_sl_mode))
1724                         join = LDLM_MODE_JOIN_RIGHT;
1725                 else if (LDLM_SL_TAIL(&lock->l_sl_mode))
1726                         join = LDLM_MODE_JOIN_LEFT;
1727                 if (LDLM_SL_HEAD(&lock->l_sl_policy))
1728                         join |= LDLM_POLICY_JOIN_RIGHT;
1729                 else if (LDLM_SL_TAIL(&lock->l_sl_policy))
1730                         join |= LDLM_POLICY_JOIN_LEFT;
1731
1732                 LASSERT(!((join & LDLM_MODE_JOIN_RIGHT) &&
1733                           (join & LDLM_POLICY_JOIN_LEFT)));
1734                 LASSERT(!((join & LDLM_MODE_JOIN_LEFT) &&
1735                           (join & LDLM_POLICY_JOIN_RIGHT)));
1736
1737                 if ((join & LDLM_MODE_JOIN_LEFT) ||
1738                     (join & LDLM_POLICY_JOIN_LEFT))
1739                         mark_lock = list_entry(lock->l_res_link.prev,
1740                                                struct ldlm_lock, l_res_link);
1741                 else if (lock->l_res_link.next != &res->lr_granted)
1742                         mark_lock = list_entry(lock->l_res_link.next,
1743                                                struct ldlm_lock, l_res_link);
1744         } else {
1745                 ldlm_resource_unlink_lock(lock);
1746                 if (res->lr_type == LDLM_EXTENT) {
1747                         /* FIXME: ugly code, I have to attach the lock to a
1748                          * interval node again since perhaps it will be granted
1749                          * soon */
1750                         CFS_INIT_LIST_HEAD(&node->li_group);
1751                         ldlm_interval_attach(node, lock);
1752                         node = NULL;
1753                 }
1754         }
1755
1756         /* If this is a local resource, put it on the appropriate list. */
1757         if (ns_is_client(res->lr_namespace)) {
1758                 if (*flags & (LDLM_FL_BLOCK_CONV | LDLM_FL_BLOCK_GRANTED)) {
1759                         ldlm_resource_add_lock(res, &res->lr_converting, lock);
1760                 } else {
1761                         /* This should never happen, because of the way the
1762                          * server handles conversions. */
1763                         LDLM_ERROR(lock, "Erroneous flags %d on local lock\n",
1764                                    *flags);
1765                         LBUG();
1766
1767                         ldlm_grant_lock(lock, &rpc_list);
1768                         granted = 1;
1769                         /* FIXME: completion handling not with ns_lock held ! */
1770                         if (lock->l_completion_ast)
1771                                 lock->l_completion_ast(lock, 0, NULL);
1772                 }
1773         } else {
1774                 int pflags = 0;
1775                 ldlm_processing_policy policy;
1776                 policy = ldlm_processing_policy_table[res->lr_type];
1777                 rc = policy(lock, &pflags, 0, &err, &rpc_list);
1778                 if (rc == LDLM_ITER_STOP) {
1779                         lock->l_req_mode = old_mode;
1780                         if (res->lr_type == LDLM_EXTENT)
1781                                 ldlm_extent_add_lock(res, lock);
1782                         else
1783                                 ldlm_granted_list_add_lock(lock, mark_lock,
1784                                                            join);
1785                         res = NULL;
1786                 } else {
1787                         *flags |= LDLM_FL_BLOCK_GRANTED;
1788                         granted = 1;
1789                 }
1790         }
1791         unlock_res_and_lock(lock);
1792
1793         if (granted)
1794                 ldlm_run_ast_work(&rpc_list, LDLM_WORK_CP_AST);
1795         if (node)
1796                 OBD_SLAB_FREE(node, ldlm_interval_slab, sizeof(*node));
1797         RETURN(res);
1798 }
1799
1800 void ldlm_lock_dump(int level, struct ldlm_lock *lock, int pos)
1801 {
1802         struct obd_device *obd = NULL;
1803
1804         if (!((libcfs_debug | D_ERROR) & level))
1805                 return;
1806
1807         if (!lock) {
1808                 CDEBUG(level, "  NULL LDLM lock\n");
1809                 return;
1810         }
1811
1812         CDEBUG(level," -- Lock dump: %p/"LPX64" (rc: %d) (pos: %d) (pid: %d)\n",
1813                lock, lock->l_handle.h_cookie, atomic_read(&lock->l_refc),
1814                pos, lock->l_pid);
1815         if (lock->l_conn_export != NULL)
1816                 obd = lock->l_conn_export->exp_obd;
1817         if (lock->l_export && lock->l_export->exp_connection) {
1818                 CDEBUG(level, "  Node: NID %s (rhandle: "LPX64")\n",
1819                      libcfs_nid2str(lock->l_export->exp_connection->c_peer.nid),
1820                      lock->l_remote_handle.cookie);
1821         } else if (obd == NULL) {
1822                 CDEBUG(level, "  Node: local\n");
1823         } else {
1824                 struct obd_import *imp = obd->u.cli.cl_import;
1825                 CDEBUG(level, "  Node: NID %s (rhandle: "LPX64")\n",
1826                        libcfs_nid2str(imp->imp_connection->c_peer.nid),
1827                        lock->l_remote_handle.cookie);
1828         }
1829         CDEBUG(level, "  Resource: %p ("LPU64"/"LPU64"/"LPU64")\n",
1830                   lock->l_resource,
1831                   lock->l_resource->lr_name.name[0],
1832                   lock->l_resource->lr_name.name[1],
1833                   lock->l_resource->lr_name.name[2]);
1834         CDEBUG(level, "  Req mode: %s, grant mode: %s, rc: %u, read: %d, "
1835                "write: %d flags: %#x\n", ldlm_lockname[lock->l_req_mode],
1836                ldlm_lockname[lock->l_granted_mode],
1837                atomic_read(&lock->l_refc), lock->l_readers, lock->l_writers,
1838                lock->l_flags);
1839         if (lock->l_resource->lr_type == LDLM_EXTENT)
1840                 CDEBUG(level, "  Extent: "LPU64" -> "LPU64
1841                        " (req "LPU64"-"LPU64")\n",
1842                        lock->l_policy_data.l_extent.start,
1843                        lock->l_policy_data.l_extent.end,
1844                        lock->l_req_extent.start, lock->l_req_extent.end);
1845         else if (lock->l_resource->lr_type == LDLM_FLOCK)
1846                 CDEBUG(level, "  Pid: %d Extent: "LPU64" -> "LPU64"\n",
1847                        lock->l_policy_data.l_flock.pid,
1848                        lock->l_policy_data.l_flock.start,
1849                        lock->l_policy_data.l_flock.end);
1850        else if (lock->l_resource->lr_type == LDLM_IBITS)
1851                 CDEBUG(level, "  Bits: "LPX64"\n",
1852                        lock->l_policy_data.l_inodebits.bits);
1853 }
1854
1855 void ldlm_lock_dump_handle(int level, struct lustre_handle *lockh)
1856 {
1857         struct ldlm_lock *lock;
1858
1859         if (!((libcfs_debug | D_ERROR) & level))
1860                 return;
1861
1862         lock = ldlm_handle2lock(lockh);
1863         if (lock == NULL)
1864                 return;
1865
1866         ldlm_lock_dump(D_OTHER, lock, 0);
1867
1868         LDLM_LOCK_PUT(lock);
1869 }
1870
1871 void _ldlm_lock_debug(struct ldlm_lock *lock, __u32 level,
1872                       struct libcfs_debug_msg_data *data, const char *fmt,
1873                       ...)
1874 {
1875         va_list args;
1876         cfs_debug_limit_state_t *cdls = data->msg_cdls;
1877
1878         va_start(args, fmt);
1879
1880         if (lock->l_resource == NULL) {
1881                 libcfs_debug_vmsg2(cdls, data->msg_subsys, level, data->msg_file,
1882                                    data->msg_fn, data->msg_line, fmt, args,
1883                        " ns: \?\? lock: %p/"LPX64" lrc: %d/%d,%d mode: %s/%s "
1884                        "res: \?\? rrc=\?\? type: \?\?\? flags: %x remote: "
1885                        LPX64" expref: %d pid: %u\n", lock,
1886                        lock->l_handle.h_cookie, atomic_read(&lock->l_refc),
1887                        lock->l_readers, lock->l_writers,
1888                        ldlm_lockname[lock->l_granted_mode],
1889                        ldlm_lockname[lock->l_req_mode],
1890                        lock->l_flags, lock->l_remote_handle.cookie,
1891                        lock->l_export ?
1892                        atomic_read(&lock->l_export->exp_refcount) : -99,
1893                        lock->l_pid);
1894                 va_end(args);
1895                 return;
1896         }
1897
1898         switch (lock->l_resource->lr_type) {
1899         case LDLM_EXTENT:
1900                 libcfs_debug_vmsg2(cdls, data->msg_subsys, level, data->msg_file,
1901                                    data->msg_fn, data->msg_line, fmt, args,
1902                        " ns: %s lock: %p/"LPX64" lrc: %d/%d,%d mode: %s/%s "
1903                        "res: "LPU64"/"LPU64" rrc: %d type: %s ["LPU64"->"LPU64
1904                        "] (req "LPU64"->"LPU64") flags: %x remote: "LPX64
1905                        " expref: %d pid: %u\n",
1906                        lock->l_resource->lr_namespace->ns_name, lock,
1907                        lock->l_handle.h_cookie, atomic_read(&lock->l_refc),
1908                        lock->l_readers, lock->l_writers,
1909                        ldlm_lockname[lock->l_granted_mode],
1910                        ldlm_lockname[lock->l_req_mode],
1911                        lock->l_resource->lr_name.name[0],
1912                        lock->l_resource->lr_name.name[1],
1913                        atomic_read(&lock->l_resource->lr_refcount),
1914                        ldlm_typename[lock->l_resource->lr_type],
1915                        lock->l_policy_data.l_extent.start,
1916                        lock->l_policy_data.l_extent.end,
1917                        lock->l_req_extent.start, lock->l_req_extent.end,
1918                        lock->l_flags, lock->l_remote_handle.cookie,
1919                        lock->l_export ?
1920                        atomic_read(&lock->l_export->exp_refcount) : -99,
1921                        lock->l_pid);
1922                 break;
1923
1924         case LDLM_FLOCK:
1925                 libcfs_debug_vmsg2(cdls, data->msg_subsys, level, data->msg_file,
1926                                    data->msg_fn, data->msg_line, fmt, args,
1927                        " ns: %s lock: %p/"LPX64" lrc: %d/%d,%d mode: %s/%s "
1928                        "res: "LPU64"/"LPU64" rrc: %d type: %s pid: %d "
1929                        "["LPU64"->"LPU64"] flags: %x remote: "LPX64
1930                        " expref: %d pid: %u\n",
1931                        lock->l_resource->lr_namespace->ns_name, lock,
1932                        lock->l_handle.h_cookie, atomic_read(&lock->l_refc),
1933                        lock->l_readers, lock->l_writers,
1934                        ldlm_lockname[lock->l_granted_mode],
1935                        ldlm_lockname[lock->l_req_mode],
1936                        lock->l_resource->lr_name.name[0],
1937                        lock->l_resource->lr_name.name[1],
1938                        atomic_read(&lock->l_resource->lr_refcount),
1939                        ldlm_typename[lock->l_resource->lr_type],
1940                        lock->l_policy_data.l_flock.pid,
1941                        lock->l_policy_data.l_flock.start,
1942                        lock->l_policy_data.l_flock.end,
1943                        lock->l_flags, lock->l_remote_handle.cookie,
1944                        lock->l_export ?
1945                        atomic_read(&lock->l_export->exp_refcount) : -99,
1946                        lock->l_pid);
1947                 break;
1948
1949         case LDLM_IBITS:
1950                 libcfs_debug_vmsg2(cdls, data->msg_subsys, level, data->msg_file,
1951                                    data->msg_fn, data->msg_line, fmt, args,
1952                        " ns: %s lock: %p/"LPX64" lrc: %d/%d,%d mode: %s/%s "
1953                        "res: "LPU64"/"LPU64" bits "LPX64" rrc: %d type: %s "
1954                        "flags: %x remote: "LPX64" expref: %d "
1955                        "pid %u\n",
1956                        lock->l_resource->lr_namespace->ns_name,
1957                        lock, lock->l_handle.h_cookie,
1958                        atomic_read (&lock->l_refc),
1959                        lock->l_readers, lock->l_writers,
1960                        ldlm_lockname[lock->l_granted_mode],
1961                        ldlm_lockname[lock->l_req_mode],
1962                        lock->l_resource->lr_name.name[0],
1963                        lock->l_resource->lr_name.name[1],
1964                        lock->l_policy_data.l_inodebits.bits,
1965                        atomic_read(&lock->l_resource->lr_refcount),
1966                        ldlm_typename[lock->l_resource->lr_type],
1967                        lock->l_flags, lock->l_remote_handle.cookie,
1968                        lock->l_export ?
1969                        atomic_read(&lock->l_export->exp_refcount) : -99,
1970                        lock->l_pid);
1971                 break;
1972
1973         default:
1974                 libcfs_debug_vmsg2(cdls, data->msg_subsys, level, data->msg_file,
1975                                    data->msg_fn, data->msg_line, fmt, args,
1976                        " ns: %s lock: %p/"LPX64" lrc: %d/%d,%d mode: %s/%s "
1977                        "res: "LPU64"/"LPU64" rrc: %d type: %s flags: %x "
1978                        "remote: "LPX64" expref: %d pid: %u\n",
1979                        lock->l_resource->lr_namespace->ns_name,
1980                        lock, lock->l_handle.h_cookie,
1981                        atomic_read (&lock->l_refc),
1982                        lock->l_readers, lock->l_writers,
1983                        ldlm_lockname[lock->l_granted_mode],
1984                        ldlm_lockname[lock->l_req_mode],
1985                        lock->l_resource->lr_name.name[0],
1986                        lock->l_resource->lr_name.name[1],
1987                        atomic_read(&lock->l_resource->lr_refcount),
1988                        ldlm_typename[lock->l_resource->lr_type],
1989                        lock->l_flags, lock->l_remote_handle.cookie,
1990                        lock->l_export ?
1991                        atomic_read(&lock->l_export->exp_refcount) : -99,
1992                        lock->l_pid);
1993                 break;
1994         }
1995         va_end(args);
1996 }
1997 EXPORT_SYMBOL(_ldlm_lock_debug);