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 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 Lustre, http://www.lustre.org.
   9  *
  10  *   Lustre is free software; you can redistribute it and/or
  11  *   modify it under the terms of version 2 of the GNU General Public
  12  *   License as published by the Free Software Foundation.
  13  *
  14  *   Lustre is distributed in the hope that it will be useful,
  15  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *   GNU General Public License for more details.
  18  *
  19  *   You should have received a copy of the GNU General Public License
  20  *   along with Lustre; if not, write to the Free Software
  21  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22  */
  23
  24 #define DEBUG_SUBSYSTEM S_LDLM
  25
  26 #include <linux/slab.h>
  27 #include <linux/module.h>
  28 #include <linux/random.h>
  29 #include <linux/lustre_dlm.h>
  30 #include <linux/lustre_mds.h>
  31
  32 /* lock types */
  33 char *ldlm_lockname[] = {
  34         [0] "--",
  35         [LCK_EX] "EX",
  36         [LCK_PW] "PW",
  37         [LCK_PR] "PR",
  38         [LCK_CW] "CW",
  39         [LCK_CR] "CR",
  40         [LCK_NL] "NL"
  41 };
  42 char *ldlm_typename[] = {
  43         [LDLM_PLAIN] "PLN",
  44         [LDLM_EXTENT] "EXT",
  45         [LDLM_MDSINTENT] "INT"
  46 };
  47
  48 char *ldlm_it2str(int it)
  49 {
  50         switch (it) {
  51         case IT_OPEN:
  52                 return "open";
  53         case IT_CREAT:
  54                 return "creat";
  55         case (IT_OPEN | IT_CREAT):
  56                 return "open|creat";
  57         case IT_MKDIR:
  58                 return "mkdir";
  59         case IT_LINK:
  60                 return "link";
  61         case IT_SYMLINK:
  62                 return "symlink";
  63         case IT_UNLINK:
  64                 return "unlink";
  65         case IT_RMDIR:
  66                 return "rmdir";
  67         case IT_RENAME:
  68                 return "rename";
  69         case IT_RENAME2:
  70                 return "rename2";
  71         case IT_READDIR:
  72                 return "readdir";
  73         case IT_GETATTR:
  74                 return "getattr";
  75         case IT_SETATTR:
  76                 return "setattr";
  77         case IT_READLINK:
  78                 return "readlink";
  79         case IT_MKNOD:
  80                 return "mknod";
  81         case IT_LOOKUP:
  82                 return "lookup";
  83         default:
  84                 CERROR("Unknown intent %d\n", it);
  85                 return "UNKNOWN";
  86         }
  87 }
  88
  89 extern kmem_cache_t *ldlm_lock_slab;
  90
  91 static int ldlm_plain_compat(struct ldlm_lock *a, struct ldlm_lock *b);
  92
  93 ldlm_res_compat ldlm_res_compat_table[] = {
  94         [LDLM_PLAIN] ldlm_plain_compat,
  95         [LDLM_EXTENT] ldlm_extent_compat,
  96         [LDLM_MDSINTENT] ldlm_plain_compat
  97 };
  98
  99 ldlm_res_policy ldlm_res_policy_table[] = {
 100         [LDLM_PLAIN] NULL,
 101         [LDLM_EXTENT] ldlm_extent_policy,
 102         [LDLM_MDSINTENT] NULL
 103 };
 104
 105 void ldlm_register_intent(int (*arg) (struct ldlm_lock * lock, void *req_cookie,
 106                                       ldlm_mode_t mode, void *data))
 107 {
 108         ldlm_res_policy_table[LDLM_MDSINTENT] = arg;
 109 }
 110
 111 void ldlm_unregister_intent(void)
 112 {
 113         ldlm_res_policy_table[LDLM_MDSINTENT] = NULL;
 114 }
 115
 116 /*
 117  * REFCOUNTED LOCK OBJECTS
 118  */
 119
 120
 121 /*
 122  * Lock refcounts, during creation:
 123  *   - one special one for allocation, dec'd only once in destroy
 124  *   - one for being a lock that's in-use
 125  *   - one for the addref associated with a new lock
 126  */
 127 struct ldlm_lock *ldlm_lock_get(struct ldlm_lock *lock)
 128 {
 129         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 130         lock->l_refc++;
 131         ldlm_resource_getref(lock->l_resource);
 132         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 133         return lock;
 134 }
 135
 136 void ldlm_lock_put(struct ldlm_lock *lock)
 137 {
 138         struct lustre_lock *nslock = &lock->l_resource->lr_namespace->ns_lock;
 139         ENTRY;
 140
 141         l_lock(nslock);
 142         lock->l_refc--;
 143         //LDLM_DEBUG(lock, "after refc--");
 144         if (lock->l_refc < 0)
 145                 LBUG();
 146
 147         ldlm_resource_put(lock->l_resource);
 148         if (lock->l_parent)
 149                 LDLM_LOCK_PUT(lock->l_parent);
 150
 151         if (lock->l_refc == 0 && (lock->l_flags & LDLM_FL_DESTROYED)) {
 152                 lock->l_resource = NULL;
 153                 LDLM_DEBUG(lock, "final lock_put on destroyed lock, freeing");
 154                 if (lock->l_export && lock->l_export->exp_connection)
 155                         ptlrpc_put_connection(lock->l_export->exp_connection);
 156                 CDEBUG(D_MALLOC, "kfreed 'lock': %d at %p (tot 1).\n",
 157                        sizeof(*lock), lock);
 158                 kmem_cache_free(ldlm_lock_slab, lock);
 159         }
 160         l_unlock(nslock);
 161         EXIT;
 162 }
 163
 164 void ldlm_lock_destroy(struct ldlm_lock *lock)
 165 {
 166         ENTRY;
 167         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 168
 169         if (!list_empty(&lock->l_children)) {
 170                 LDLM_DEBUG(lock, "still has children (%p)!",
 171                            lock->l_children.next);
 172                 ldlm_lock_dump(lock);
 173                 LBUG();
 174         }
 175         if (lock->l_readers || lock->l_writers) {
 176                 LDLM_DEBUG(lock, "lock still has references");
 177                 ldlm_lock_dump(lock);
 178                 LBUG();
 179         }
 180
 181         if (!list_empty(&lock->l_res_link)) {
 182                 ldlm_lock_dump(lock);
 183                 LBUG();
 184         }
 185
 186         if (lock->l_flags & LDLM_FL_DESTROYED) {
 187                 l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 188                 EXIT;
 189                 return;
 190         }
 191
 192         lock->l_flags = LDLM_FL_DESTROYED;
 193         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 194         LDLM_LOCK_PUT(lock);
 195         EXIT;
 196 }
 197
 198 /*
 199    usage: pass in a resource on which you have done get
 200           pass in a parent lock on which you have done a get
 201           do not put the resource or the parent
 202    returns: lock with refcount 1
 203 */
 204 static struct ldlm_lock *ldlm_lock_new(struct ldlm_lock *parent,
 205                                        struct ldlm_resource *resource)
 206 {
 207         struct ldlm_lock *lock;
 208         ENTRY;
 209
 210         if (resource == NULL)
 211                 LBUG();
 212
 213         lock = kmem_cache_alloc(ldlm_lock_slab, SLAB_KERNEL);
 214         if (lock == NULL)
 215                 RETURN(NULL);
 216         CDEBUG(D_MALLOC, "kmalloced 'lock': %d at "
 217                "%p (tot %d).\n", sizeof(*lock), lock, 1);
 218
 219         memset(lock, 0, sizeof(*lock));
 220         get_random_bytes(&lock->l_random, sizeof(__u64));
 221
 222         lock->l_resource = resource;
 223         /* this refcount matches the one of the resource passed
 224            in which is not being put away */
 225         lock->l_refc = 1;
 226         INIT_LIST_HEAD(&lock->l_children);
 227         INIT_LIST_HEAD(&lock->l_res_link);
 228         INIT_LIST_HEAD(&lock->l_inode_link);
 229         init_waitqueue_head(&lock->l_waitq);
 230
 231         if (parent != NULL) {
 232                 l_lock(&parent->l_resource->lr_namespace->ns_lock);
 233                 lock->l_parent = parent;
 234                 list_add(&lock->l_childof, &parent->l_children);
 235                 l_unlock(&parent->l_resource->lr_namespace->ns_lock);
 236         }
 237         /* this is the extra refcount, to prevent the lock
 238            evaporating */
 239         LDLM_LOCK_GET(lock);
 240         RETURN(lock);
 241 }
 242
 243 int ldlm_lock_change_resource(struct ldlm_lock *lock, __u64 new_resid[3])
 244 {
 245         struct ldlm_namespace *ns = lock->l_resource->lr_namespace;
 246         struct ldlm_resource *oldres = lock->l_resource;
 247         int type, i;
 248         ENTRY;
 249
 250         l_lock(&ns->ns_lock);
 251         if (memcmp(new_resid, lock->l_resource->lr_name,
 252                    sizeof(lock->l_resource->lr_name)) == 0) {
 253                 /* Nothing to do */
 254                 l_unlock(&ns->ns_lock);
 255                 RETURN(0);
 256         }
 257
 258         type = lock->l_resource->lr_type;
 259         if (new_resid[0] == 0)
 260                 LBUG();
 261         lock->l_resource = ldlm_resource_get(ns, NULL, new_resid, type, 1);
 262         if (lock->l_resource == NULL) {
 263                 LBUG();
 264                 RETURN(-ENOMEM);
 265         }
 266
 267         /* move references over */
 268         for (i = 0; i < lock->l_refc; i++) {
 269                 int rc;
 270                 ldlm_resource_getref(lock->l_resource);
 271                 rc = ldlm_resource_put(oldres);
 272                 if (rc == 1 && i != lock->l_refc - 1)
 273                         LBUG();
 274         }
 275         /* compensate for the initial get above.. */
 276         ldlm_resource_put(lock->l_resource);
 277
 278         l_unlock(&ns->ns_lock);
 279         RETURN(0);
 280 }
 281
 282 /*
 283  *  HANDLES
 284  */
 285
 286 void ldlm_lock2handle(struct ldlm_lock *lock, struct lustre_handle *lockh)
 287 {
 288         lockh->addr = (__u64) (unsigned long)lock;
 289         lockh->cookie = lock->l_random;
 290 }
 291
 292 struct ldlm_lock *ldlm_handle2lock(struct lustre_handle *handle)
 293 {
 294         struct ldlm_lock *lock = NULL, *retval = NULL;
 295         ENTRY;
 296
 297         if (!handle || !handle->addr)
 298                 RETURN(NULL);
 299
 300         lock = (struct ldlm_lock *)(unsigned long)(handle->addr);
 301         if (!kmem_cache_validate(ldlm_lock_slab, (void *)lock))
 302                 RETURN(NULL);
 303
 304         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 305         if (lock->l_random != handle->cookie)
 306                 GOTO(out, NULL);
 307
 308         if (lock->l_flags & LDLM_FL_DESTROYED)
 309                 GOTO(out, NULL);
 310
 311         retval = LDLM_LOCK_GET(lock);
 312         EXIT;
 313       out:
 314         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 315         return retval;
 316 }
 317
 318
 319
 320
 321 static int ldlm_plain_compat(struct ldlm_lock *a, struct ldlm_lock *b)
 322 {
 323         return lockmode_compat(a->l_req_mode, b->l_req_mode);
 324 }
 325
 326 void ldlm_lock2desc(struct ldlm_lock *lock, struct ldlm_lock_desc *desc)
 327 {
 328         ldlm_res2desc(lock->l_resource, &desc->l_resource);
 329         desc->l_req_mode = lock->l_req_mode;
 330         desc->l_granted_mode = lock->l_granted_mode;
 331         memcpy(&desc->l_extent, &lock->l_extent, sizeof(desc->l_extent));
 332         memcpy(desc->l_version, lock->l_version, sizeof(desc->l_version));
 333 }
 334
 335 static void ldlm_add_ast_work_item(struct ldlm_lock *lock,
 336                                    struct ldlm_lock *new)
 337 {
 338         struct ldlm_ast_work *w;
 339         ENTRY;
 340
 341         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 342         if (new && (lock->l_flags & LDLM_FL_AST_SENT))
 343                 GOTO(out, 0);
 344
 345         OBD_ALLOC(w, sizeof(*w));
 346         if (!w) {
 347                 LBUG();
 348                 GOTO(out, 0);
 349         }
 350
 351         if (new) {
 352                 lock->l_flags |= LDLM_FL_AST_SENT;
 353                 w->w_blocking = 1;
 354                 ldlm_lock2desc(new, &w->w_desc);
 355         }
 356
 357         w->w_lock = LDLM_LOCK_GET(lock);
 358         list_add(&w->w_list, lock->l_resource->lr_tmp);
 359       out:
 360         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 361         return;
 362 }
 363
 364 void ldlm_lock_addref(struct lustre_handle *lockh, __u32 mode)
 365 {
 366         struct ldlm_lock *lock;
 367
 368         lock = ldlm_handle2lock(lockh);
 369         ldlm_lock_addref_internal(lock, mode);
 370         LDLM_LOCK_PUT(lock);
 371 }
 372
 373 /* only called for local locks */
 374 void ldlm_lock_addref_internal(struct ldlm_lock *lock, __u32 mode)
 375 {
 376         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 377         if (mode == LCK_NL || mode == LCK_CR || mode == LCK_PR)
 378                 lock->l_readers++;
 379         else
 380                 lock->l_writers++;
 381         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 382         LDLM_LOCK_GET(lock);
 383         LDLM_DEBUG(lock, "ldlm_lock_addref(%s)", ldlm_lockname[mode]);
 384 }
 385
 386 /* Args: unlocked lock */
 387 void ldlm_lock_decref(struct lustre_handle *lockh, __u32 mode)
 388 {
 389         struct ldlm_lock *lock = ldlm_handle2lock(lockh);
 390         ENTRY;
 391
 392         if (lock == NULL)
 393                 LBUG();
 394
 395         LDLM_DEBUG(lock, "ldlm_lock_decref(%s)", ldlm_lockname[mode]);
 396         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 397         if (mode == LCK_NL || mode == LCK_CR || mode == LCK_PR)
 398                 lock->l_readers--;
 399         else
 400                 lock->l_writers--;
 401
 402         /* If we received a blocked AST and this was the last reference,
 403          * run the callback. */
 404         if (!lock->l_readers && !lock->l_writers &&
 405             (lock->l_flags & LDLM_FL_CBPENDING)) {
 406                 if (!lock->l_resource->lr_namespace->ns_client) {
 407                         CERROR("LDLM_FL_CBPENDING set on non-local lock!\n");
 408                         LBUG();
 409                 }
 410
 411                 LDLM_DEBUG(lock, "final decref done on cbpending lock");
 412                 l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 413
 414                 /* FIXME: need a real 'desc' here */
 415                 lock->l_blocking_ast(lock, NULL, lock->l_data,
 416                                      lock->l_data_len);
 417         } else
 418                 l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 419
 420         LDLM_LOCK_PUT(lock);    /* matches the ldlm_lock_get in addref */
 421         LDLM_LOCK_PUT(lock);    /* matches the handle2lock above */
 422
 423         EXIT;
 424 }
 425
 426 static int ldlm_lock_compat_list(struct ldlm_lock *lock, int send_cbs,
 427                                  struct list_head *queue)
 428 {
 429         struct list_head *tmp, *pos;
 430         int rc = 1;
 431
 432         list_for_each_safe(tmp, pos, queue) {
 433                 struct ldlm_lock *child;
 434                 ldlm_res_compat compat;
 435
 436                 child = list_entry(tmp, struct ldlm_lock, l_res_link);
 437                 if (lock == child)
 438                         continue;
 439
 440                 compat = ldlm_res_compat_table[child->l_resource->lr_type];
 441                 if (compat && compat(child, lock)) {
 442                         CDEBUG(D_OTHER, "compat function succeded, next.\n");
 443                         continue;
 444                 }
 445                 if (lockmode_compat(child->l_granted_mode, lock->l_req_mode)) {
 446                         CDEBUG(D_OTHER, "lock modes are compatible, next.\n");
 447                         continue;
 448                 }
 449
 450                 rc = 0;
 451
 452                 if (send_cbs && child->l_blocking_ast != NULL) {
 453                         CDEBUG(D_OTHER, "incompatible; sending blocking "
 454                                "AST.\n");
 455                         ldlm_add_ast_work_item(child, lock);
 456                 }
 457         }
 458
 459         return rc;
 460 }
 461
 462 static int ldlm_lock_compat(struct ldlm_lock *lock, int send_cbs)
 463 {
 464         int rc;
 465         ENTRY;
 466
 467         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 468         rc = ldlm_lock_compat_list(lock, send_cbs,
 469                                    &lock->l_resource->lr_granted);
 470         /* FIXME: should we be sending ASTs to converting? */
 471         if (rc)
 472                 rc = ldlm_lock_compat_list
 473                         (lock, send_cbs, &lock->l_resource->lr_converting);
 474
 475         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 476         RETURN(rc);
 477 }
 478
 479 /* NOTE: called by
 480    - ldlm_handle_enqueuque - resource
 481 */
 482 void ldlm_grant_lock(struct ldlm_lock *lock)
 483 {
 484         struct ldlm_resource *res = lock->l_resource;
 485         ENTRY;
 486
 487         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 488         ldlm_resource_add_lock(res, &res->lr_granted, lock);
 489         lock->l_granted_mode = lock->l_req_mode;
 490
 491         if (lock->l_granted_mode < res->lr_most_restr)
 492                 res->lr_most_restr = lock->l_granted_mode;
 493
 494         if (lock->l_completion_ast) {
 495                 ldlm_add_ast_work_item(lock, NULL);
 496         }
 497         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 498         EXIT;
 499 }
 500
 501 /* returns a referenced lock or NULL */
 502 static struct ldlm_lock *search_queue(struct list_head *queue, ldlm_mode_t mode,
 503                                       struct ldlm_extent *extent)
 504 {
 505         struct ldlm_lock *lock;
 506         struct list_head *tmp;
 507
 508         list_for_each(tmp, queue) {
 509                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 510
 511                 if (lock->l_flags & LDLM_FL_CBPENDING)
 512                         continue;
 513
 514                 /* lock_convert() takes the resource lock, so we're sure that
 515                  * req_mode, lr_type, and l_cookie won't change beneath us */
 516                 if (lock->l_req_mode != mode)
 517                         continue;
 518
 519                 if (lock->l_resource->lr_type == LDLM_EXTENT &&
 520                     (lock->l_extent.start > extent->start ||
 521                      lock->l_extent.end < extent->end))
 522                         continue;
 523
 524                 ldlm_lock_addref_internal(lock, mode);
 525                 return lock;
 526         }
 527
 528         return NULL;
 529 }
 530
 531 /* Must be called with no resource or lock locks held.
 532  *
 533  * Returns 1 if it finds an already-existing lock that is compatible; in this
 534  * case, lockh is filled in with a addref()ed lock
 535 */
 536 int ldlm_lock_match(struct ldlm_namespace *ns, __u64 * res_id, __u32 type,
 537                     void *cookie, int cookielen, ldlm_mode_t mode,
 538                     struct lustre_handle *lockh)
 539 {
 540         struct ldlm_resource *res;
 541         struct ldlm_lock *lock;
 542         int rc = 0;
 543         ENTRY;
 544
 545         res = ldlm_resource_get(ns, NULL, res_id, type, 0);
 546         if (res == NULL)
 547                 RETURN(0);
 548
 549         ns = res->lr_namespace;
 550         l_lock(&ns->ns_lock);
 551
 552         if ((lock = search_queue(&res->lr_granted, mode, cookie)))
 553                 GOTO(out, rc = 1);
 554         if ((lock = search_queue(&res->lr_converting, mode, cookie)))
 555                 GOTO(out, rc = 1);
 556         if ((lock = search_queue(&res->lr_waiting, mode, cookie)))
 557                 GOTO(out, rc = 1);
 558
 559         EXIT;
 560       out:
 561         ldlm_resource_put(res);
 562         l_unlock(&ns->ns_lock);
 563
 564         if (lock) {
 565                 ldlm_lock2handle(lock, lockh);
 566                 if (lock->l_completion_ast)
 567                         lock->l_completion_ast(lock, LDLM_FL_WAIT_NOREPROC);
 568         }
 569         if (rc)
 570                 LDLM_DEBUG(lock, "matched");
 571         else
 572                 LDLM_DEBUG_NOLOCK("not matched");
 573         return rc;
 574 }
 575
 576 /* Returns a referenced lock */
 577 struct ldlm_lock *ldlm_lock_create(struct ldlm_namespace *ns,
 578                                    struct lustre_handle *parent_lock_handle,
 579                                    __u64 * res_id, __u32 type,
 580                                    ldlm_mode_t mode, void *data, __u32 data_len)
 581 {
 582         struct ldlm_resource *res, *parent_res = NULL;
 583         struct ldlm_lock *lock, *parent_lock;
 584
 585         parent_lock = ldlm_handle2lock(parent_lock_handle);
 586         if (parent_lock)
 587                 parent_res = parent_lock->l_resource;
 588
 589         res = ldlm_resource_get(ns, parent_res, res_id, type, 1);
 590         if (res == NULL)
 591                 RETURN(NULL);
 592
 593         lock = ldlm_lock_new(parent_lock, res);
 594         if (lock == NULL) {
 595                 ldlm_resource_put(res);
 596                 RETURN(NULL);
 597         }
 598
 599         lock->l_req_mode = mode;
 600         lock->l_data = data;
 601         lock->l_data_len = data_len;
 602
 603         return lock;
 604 }
 605
 606 /* Must be called with lock->l_lock and lock->l_resource->lr_lock not held */
 607 ldlm_error_t ldlm_lock_enqueue(struct ldlm_lock * lock,
 608                                void *cookie, int cookie_len,
 609                                int *flags,
 610                                ldlm_completion_callback completion,
 611                                ldlm_blocking_callback blocking)
 612 {
 613         struct ldlm_resource *res;
 614         int local;
 615         ldlm_res_policy policy;
 616         ENTRY;
 617
 618         res = lock->l_resource;
 619         lock->l_blocking_ast = blocking;
 620
 621         if (res->lr_type == LDLM_EXTENT)
 622                 memcpy(&lock->l_extent, cookie, sizeof(lock->l_extent));
 623
 624         /* policies are not executed on the client */
 625         local = res->lr_namespace->ns_client;
 626         if (!local && (policy = ldlm_res_policy_table[res->lr_type])) {
 627                 int rc;
 628                 rc = policy(lock, cookie, lock->l_req_mode, NULL);
 629
 630                 if (rc == ELDLM_LOCK_CHANGED) {
 631                         res = lock->l_resource;
 632                         *flags |= LDLM_FL_LOCK_CHANGED;
 633                 } else if (rc == ELDLM_LOCK_ABORTED) {
 634                         ldlm_lock_destroy(lock);
 635                         RETURN(rc);
 636                 }
 637         }
 638
 639         lock->l_cookie = cookie;
 640         lock->l_cookie_len = cookie_len;
 641
 642         if (local && lock->l_req_mode == lock->l_granted_mode) {
 643                 /* The server returned a blocked lock, but it was granted before
 644                  * we got a chance to actually enqueue it.  We don't need to do
 645                  * anything else. */
 646                 GOTO(out, ELDLM_OK);
 647         }
 648
 649         /* This distinction between local lock trees is very important; a client
 650          * namespace only has information about locks taken by that client, and
 651          * thus doesn't have enough information to decide for itself if it can
 652          * be granted (below).  In this case, we do exactly what the server
 653          * tells us to do, as dictated by the 'flags' */
 654         ldlm_resource_unlink_lock(lock);
 655         if (local) {
 656                 if (*flags & LDLM_FL_BLOCK_CONV)
 657                         ldlm_resource_add_lock(res, res->lr_converting.prev,
 658                                                lock);
 659                 else if (*flags & (LDLM_FL_BLOCK_WAIT | LDLM_FL_BLOCK_GRANTED))
 660                         ldlm_resource_add_lock(res, res->lr_waiting.prev, lock);
 661                 else
 662                         ldlm_grant_lock(lock);
 663                 GOTO(out, ELDLM_OK);
 664         }
 665
 666         /* FIXME: We may want to optimize by checking lr_most_restr */
 667         if (!list_empty(&res->lr_converting)) {
 668                 ldlm_resource_add_lock(res, res->lr_waiting.prev, lock);
 669                 *flags |= LDLM_FL_BLOCK_CONV;
 670                 GOTO(out, ELDLM_OK);
 671         }
 672         if (!list_empty(&res->lr_waiting)) {
 673                 ldlm_resource_add_lock(res, res->lr_waiting.prev, lock);
 674                 *flags |= LDLM_FL_BLOCK_WAIT;
 675                 GOTO(out, ELDLM_OK);
 676         }
 677         if (!ldlm_lock_compat(lock, 0)) {
 678                 ldlm_resource_add_lock(res, res->lr_waiting.prev, lock);
 679                 *flags |= LDLM_FL_BLOCK_GRANTED;
 680                 GOTO(out, ELDLM_OK);
 681         }
 682
 683         ldlm_grant_lock(lock);
 684         EXIT;
 685       out:
 686         /* Don't set 'completion_ast' until here so that if the lock is granted
 687          * immediately we don't do an unnecessary completion call. */
 688         lock->l_completion_ast = completion;
 689         return ELDLM_OK;
 690 }
 691
 692 /* Must be called with namespace taken: queue is waiting or converting. */
 693 static int ldlm_reprocess_queue(struct ldlm_resource *res,
 694                                 struct list_head *queue)
 695 {
 696         struct list_head *tmp, *pos;
 697         ENTRY;
 698
 699         list_for_each_safe(tmp, pos, queue) {
 700                 struct ldlm_lock *pending;
 701                 pending = list_entry(tmp, struct ldlm_lock, l_res_link);
 702
 703                 CDEBUG(D_INFO, "Reprocessing lock %p\n", pending);
 704
 705                 if (!ldlm_lock_compat(pending, 1))
 706                         RETURN(1);
 707
 708                 list_del_init(&pending->l_res_link);
 709                 ldlm_grant_lock(pending);
 710         }
 711
 712         RETURN(0);
 713 }
 714
 715 void ldlm_run_ast_work(struct list_head *rpc_list)
 716 {
 717         struct list_head *tmp, *pos;
 718         int rc;
 719         ENTRY;
 720
 721         list_for_each_safe(tmp, pos, rpc_list) {
 722                 struct ldlm_ast_work *w =
 723                         list_entry(tmp, struct ldlm_ast_work, w_list);
 724
 725                 if (w->w_blocking)
 726                         rc = w->w_lock->l_blocking_ast
 727                                 (w->w_lock, &w->w_desc, w->w_data,
 728                                  w->w_datalen);
 729                 else
 730                         rc = w->w_lock->l_completion_ast(w->w_lock, w->w_flags);
 731                 if (rc)
 732                         CERROR("Failed AST - should clean & disconnect "
 733                                "client\n");
 734                 LDLM_LOCK_PUT(w->w_lock);
 735                 list_del(&w->w_list);
 736                 OBD_FREE(w, sizeof(*w));
 737         }
 738         EXIT;
 739 }
 740
 741 /* Must be called with resource->lr_lock not taken. */
 742 void ldlm_reprocess_all(struct ldlm_resource *res)
 743 {
 744         struct list_head rpc_list = LIST_HEAD_INIT(rpc_list);
 745         ENTRY;
 746
 747         /* Local lock trees don't get reprocessed. */
 748         if (res->lr_namespace->ns_client) {
 749                 EXIT;
 750                 return;
 751         }
 752
 753         l_lock(&res->lr_namespace->ns_lock);
 754         res->lr_tmp = &rpc_list;
 755
 756         ldlm_reprocess_queue(res, &res->lr_converting);
 757         if (list_empty(&res->lr_converting))
 758                 ldlm_reprocess_queue(res, &res->lr_waiting);
 759
 760         res->lr_tmp = NULL;
 761         l_unlock(&res->lr_namespace->ns_lock);
 762
 763         ldlm_run_ast_work(&rpc_list);
 764         EXIT;
 765 }
 766
 767 void ldlm_lock_cancel(struct ldlm_lock *lock)
 768 {
 769         struct ldlm_resource *res;
 770         struct ldlm_namespace *ns;
 771         ENTRY;
 772
 773         res = lock->l_resource;
 774         ns = res->lr_namespace;
 775
 776         l_lock(&ns->ns_lock);
 777         if (lock->l_readers || lock->l_writers)
 778                 CDEBUG(D_INFO, "lock still has references (%d readers, %d "
 779                        "writers)\n", lock->l_readers, lock->l_writers);
 780
 781         ldlm_resource_unlink_lock(lock);
 782         ldlm_lock_destroy(lock);
 783         l_unlock(&ns->ns_lock);
 784         EXIT;
 785 }
 786
 787 struct ldlm_resource *ldlm_lock_convert(struct ldlm_lock *lock, int new_mode,
 788                                         int *flags)
 789 {
 790         struct list_head rpc_list = LIST_HEAD_INIT(rpc_list);
 791         struct ldlm_resource *res;
 792         struct ldlm_namespace *ns;
 793         int granted = 0;
 794         ENTRY;
 795
 796         res = lock->l_resource;
 797         ns = res->lr_namespace;
 798
 799         l_lock(&ns->ns_lock);
 800
 801         lock->l_req_mode = new_mode;
 802         ldlm_resource_unlink_lock(lock);
 803
 804         /* If this is a local resource, put it on the appropriate list. */
 805         if (res->lr_namespace->ns_client) {
 806                 if (*flags & (LDLM_FL_BLOCK_CONV | LDLM_FL_BLOCK_GRANTED))
 807                         ldlm_resource_add_lock(res, res->lr_converting.prev,
 808                                                lock);
 809                 else {
 810                         res->lr_tmp = &rpc_list;
 811                         ldlm_grant_lock(lock);
 812                         res->lr_tmp = NULL;
 813                         granted = 1;
 814                         /* FIXME: completion handling not with ns_lock held ! */
 815                         if (lock->l_completion_ast)
 816                                 lock->l_completion_ast(lock, 0);
 817                 }
 818         } else
 819                 list_add_tail(&lock->l_res_link, &res->lr_converting);
 820
 821         l_unlock(&ns->ns_lock);
 822
 823         if (granted)
 824                 ldlm_run_ast_work(&rpc_list);
 825         RETURN(res);
 826 }
 827
 828 void ldlm_lock_dump(struct ldlm_lock *lock)
 829 {
 830         char ver[128];
 831
 832         if (!(portal_debug & D_OTHER))
 833                 return;
 834
 835         if (RES_VERSION_SIZE != 4)
 836                 LBUG();
 837
 838         if (!lock) {
 839                 CDEBUG(D_OTHER, "  NULL LDLM lock\n");
 840                 return;
 841         }
 842
 843         snprintf(ver, sizeof(ver), "%x %x %x %x",
 844                  lock->l_version[0], lock->l_version[1],
 845                  lock->l_version[2], lock->l_version[3]);
 846
 847         CDEBUG(D_OTHER, "  -- Lock dump: %p (%s)\n", lock, ver);
 848         if (lock->l_export && lock->l_export->exp_connection)
 849                 CDEBUG(D_OTHER, "  Node: NID %x (rhandle: %Lx)\n",
 850                        lock->l_export->exp_connection->c_peer.peer_nid,
 851                        lock->l_remote_handle.addr);
 852         else
 853                 CDEBUG(D_OTHER, "  Node: local\n");
 854         CDEBUG(D_OTHER, "  Parent: %p\n", lock->l_parent);
 855         CDEBUG(D_OTHER, "  Resource: %p (%Ld)\n", lock->l_resource,
 856                lock->l_resource->lr_name[0]);
 857         CDEBUG(D_OTHER, "  Requested mode: %d, granted mode: %d\n",
 858                (int)lock->l_req_mode, (int)lock->l_granted_mode);
 859         CDEBUG(D_OTHER, "  Readers: %u ; Writers; %u\n",
 860                lock->l_readers, lock->l_writers);
 861         if (lock->l_resource->lr_type == LDLM_EXTENT)
 862                 CDEBUG(D_OTHER, "  Extent: %Lu -> %Lu\n",
 863                        (unsigned long long)lock->l_extent.start,
 864                        (unsigned long long)lock->l_extent.end);
 865 }