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  *
   6  * This code is issued under the GNU General Public License.
   7  * See the file COPYING in this distribution
   8  *
   9  * by Cluster File Systems, Inc.
  10  * authors, Peter Braam <braam@clusterfs.com> &
  11  * Phil Schwan <phil@clusterfs.com>
  12  */
  13
  14 #define DEBUG_SUBSYSTEM S_LDLM
  15
  16 #include <linux/slab.h>
  17 #include <linux/module.h>
  18 #include <linux/random.h>
  19 #include <linux/lustre_dlm.h>
  20 #include <linux/lustre_mds.h>
  21
  22 /* lock types */
  23 char *ldlm_lockname[] = {
  24         [0] "--",
  25         [LCK_EX] "EX",
  26         [LCK_PW] "PW",
  27         [LCK_PR] "PR",
  28         [LCK_CW] "CW",
  29         [LCK_CR] "CR",
  30         [LCK_NL] "NL"
  31 };
  32 char *ldlm_typename[] = {
  33         [LDLM_PLAIN] "PLN",
  34         [LDLM_EXTENT] "EXT",
  35         [LDLM_MDSINTENT] "INT"
  36 };
  37
  38 char *ldlm_it2str(int it)
  39 {
  40         switch (it) {
  41         case IT_OPEN:
  42                 return "open";
  43         case IT_CREAT:
  44                 return "creat";
  45         case (IT_OPEN | IT_CREAT):
  46                 return "open|creat";
  47         case IT_MKDIR:
  48                 return "mkdir";
  49         case IT_LINK:
  50                 return "link";
  51         case IT_SYMLINK:
  52                 return "symlink";
  53         case IT_UNLINK:
  54                 return "unlink";
  55         case IT_RMDIR:
  56                 return "rmdir";
  57         case IT_RENAME:
  58                 return "rename";
  59         case IT_RENAME2:
  60                 return "rename2";
  61         case IT_READDIR:
  62                 return "readdir";
  63         case IT_GETATTR:
  64                 return "getattr";
  65         case IT_SETATTR:
  66                 return "setattr";
  67         case IT_READLINK:
  68                 return "readlink";
  69         case IT_MKNOD:
  70                 return "mknod";
  71         case IT_LOOKUP:
  72                 return "lookup";
  73         default:
  74                 CERROR("Unknown intent %d\n", it);
  75                 return "UNKNOWN";
  76         }
  77 }
  78
  79 extern kmem_cache_t *ldlm_lock_slab;
  80
  81 static int ldlm_plain_compat(struct ldlm_lock *a, struct ldlm_lock *b);
  82
  83 ldlm_res_compat ldlm_res_compat_table[] = {
  84         [LDLM_PLAIN] ldlm_plain_compat,
  85         [LDLM_EXTENT] ldlm_extent_compat,
  86         [LDLM_MDSINTENT] ldlm_plain_compat
  87 };
  88
  89 ldlm_res_policy ldlm_res_policy_table[] = {
  90         [LDLM_PLAIN] NULL,
  91         [LDLM_EXTENT] ldlm_extent_policy,
  92         [LDLM_MDSINTENT] NULL
  93 };
  94
  95 void ldlm_register_intent(int (*arg) (struct ldlm_lock * lock, void *req_cookie,
  96                                       ldlm_mode_t mode, void *data))
  97 {
  98         ldlm_res_policy_table[LDLM_MDSINTENT] = arg;
  99 }
 100
 101 void ldlm_unregister_intent()
 102 {
 103         ldlm_res_policy_table[LDLM_MDSINTENT] = NULL;
 104 }
 105
 106 /*
 107  * REFCOUNTED LOCK OBJECTS
 108  */
 109
 110
 111 /*
 112  * Lock refcounts, during creation:
 113  *   - one special one for allocation, dec'd only once in destroy
 114  *   - one for being a lock that's in-use
 115  *   - one for the addref associated with a new lock
 116  */
 117 struct ldlm_lock *ldlm_lock_get(struct ldlm_lock *lock)
 118 {
 119         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 120         lock->l_refc++;
 121         ldlm_resource_getref(lock->l_resource);
 122         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 123         return lock;
 124 }
 125
 126 void ldlm_lock_put(struct ldlm_lock *lock)
 127 {
 128         struct lustre_lock *nslock = &lock->l_resource->lr_namespace->ns_lock;
 129         ENTRY;
 130
 131         l_lock(nslock);
 132         lock->l_refc--;
 133         LDLM_DEBUG(lock, "after refc--");
 134         if (lock->l_refc < 0)
 135                 LBUG();
 136
 137         ldlm_resource_put(lock->l_resource);
 138         if (lock->l_parent)
 139                 LDLM_LOCK_PUT(lock->l_parent);
 140
 141         if (lock->l_refc == 0 && (lock->l_flags & LDLM_FL_DESTROYED)) {
 142                 lock->l_resource = NULL;
 143                 LDLM_DEBUG(lock, "final lock_put on destroyed lock, freeing");
 144                 if (lock->l_connection)
 145                         ptlrpc_put_connection(lock->l_connection);
 146                 CDEBUG(D_MALLOC, "kfreed 'lock': %d at %p (tot 1).\n",
 147                        sizeof(*lock), lock);
 148                 kmem_cache_free(ldlm_lock_slab, lock);
 149         }
 150         l_unlock(nslock);
 151         EXIT;
 152 }
 153
 154 void ldlm_lock_destroy(struct ldlm_lock *lock)
 155 {
 156         ENTRY;
 157         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 158
 159         if (!list_empty(&lock->l_children)) {
 160                 LDLM_DEBUG(lock, "still has children (%p)!",
 161                            lock->l_children.next);
 162                 ldlm_lock_dump(lock);
 163                 LBUG();
 164         }
 165         if (lock->l_readers || lock->l_writers) {
 166                 LDLM_DEBUG(lock, "lock still has references");
 167                 ldlm_lock_dump(lock);
 168                 LBUG();
 169         }
 170
 171         if (!list_empty(&lock->l_res_link)) {
 172                 ldlm_lock_dump(lock);
 173                 LBUG();
 174         }
 175
 176         if (lock->l_flags & LDLM_FL_DESTROYED) {
 177                 l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 178                 EXIT;
 179                 return;
 180         }
 181
 182         lock->l_flags = LDLM_FL_DESTROYED;
 183         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 184         LDLM_LOCK_PUT(lock);
 185         EXIT;
 186 }
 187
 188 /*
 189    usage: pass in a resource on which you have done get
 190           pass in a parent lock on which you have done a get
 191           do not put the resource or the parent
 192    returns: lock with refcount 1
 193 */
 194 static struct ldlm_lock *ldlm_lock_new(struct ldlm_lock *parent,
 195                                        struct ldlm_resource *resource)
 196 {
 197         struct ldlm_lock *lock;
 198         ENTRY;
 199
 200         if (resource == NULL)
 201                 LBUG();
 202
 203         lock = kmem_cache_alloc(ldlm_lock_slab, SLAB_KERNEL);
 204         if (lock == NULL)
 205                 RETURN(NULL);
 206         CDEBUG(D_MALLOC, "kmalloced 'lock': %d at "
 207                "%p (tot %d).\n", sizeof(*lock), lock, 1);
 208
 209         memset(lock, 0, sizeof(*lock));
 210         get_random_bytes(&lock->l_random, sizeof(__u64));
 211
 212         lock->l_resource = resource;
 213         /* this refcount matches the one of the resource passed
 214            in which is not being put away */
 215         lock->l_refc = 1;
 216         INIT_LIST_HEAD(&lock->l_children);
 217         INIT_LIST_HEAD(&lock->l_res_link);
 218         init_waitqueue_head(&lock->l_waitq);
 219
 220         if (parent != NULL) {
 221                 l_lock(&parent->l_resource->lr_namespace->ns_lock);
 222                 lock->l_parent = parent;
 223                 list_add(&lock->l_childof, &parent->l_children);
 224                 l_unlock(&parent->l_resource->lr_namespace->ns_lock);
 225         }
 226         /* this is the extra refcount, to prevent the lock
 227            evaporating */
 228         LDLM_LOCK_GET(lock);
 229         RETURN(lock);
 230 }
 231
 232 int ldlm_lock_change_resource(struct ldlm_lock *lock, __u64 new_resid[3])
 233 {
 234         struct ldlm_namespace *ns = lock->l_resource->lr_namespace;
 235         struct ldlm_resource *oldres = lock->l_resource;
 236         int type, i;
 237         ENTRY;
 238
 239         l_lock(&ns->ns_lock);
 240         if (memcmp(new_resid, lock->l_resource->lr_name,
 241                    sizeof(lock->l_resource->lr_name)) == 0) {
 242                 /* Nothing to do */
 243                 l_unlock(&ns->ns_lock);
 244                 RETURN(0);
 245         }
 246
 247         type = lock->l_resource->lr_type;
 248         if (new_resid[0] == 0)
 249                 LBUG();
 250         lock->l_resource = ldlm_resource_get(ns, NULL, new_resid, type, 1);
 251         if (lock->l_resource == NULL) {
 252                 LBUG();
 253                 RETURN(-ENOMEM);
 254         }
 255
 256         /* move references over */
 257         for (i = 0; i < lock->l_refc; i++) {
 258                 int rc;
 259                 ldlm_resource_getref(lock->l_resource);
 260                 rc = ldlm_resource_put(oldres);
 261                 if (rc == 1 && i != lock->l_refc - 1)
 262                         LBUG();
 263         }
 264         /* compensate for the initial get above.. */
 265         ldlm_resource_put(lock->l_resource);
 266
 267         l_unlock(&ns->ns_lock);
 268         RETURN(0);
 269 }
 270
 271 /*
 272  *  HANDLES
 273  */
 274
 275 void ldlm_lock2handle(struct ldlm_lock *lock, struct lustre_handle *lockh)
 276 {
 277         lockh->addr = (__u64) (unsigned long)lock;
 278         lockh->cookie = lock->l_random;
 279 }
 280
 281 struct ldlm_lock *ldlm_handle2lock(struct lustre_handle *handle)
 282 {
 283         struct ldlm_lock *lock = NULL, *retval = NULL;
 284         ENTRY;
 285
 286         if (!handle || !handle->addr)
 287                 RETURN(NULL);
 288
 289         lock = (struct ldlm_lock *)(unsigned long)(handle->addr);
 290         if (!kmem_cache_validate(ldlm_lock_slab, (void *)lock))
 291                 RETURN(NULL);
 292
 293         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 294         if (lock->l_random != handle->cookie)
 295                 GOTO(out, NULL);
 296
 297         if (lock->l_flags & LDLM_FL_DESTROYED)
 298                 GOTO(out, NULL);
 299
 300         retval = LDLM_LOCK_GET(lock);
 301         EXIT;
 302       out:
 303         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 304         return retval;
 305 }
 306
 307
 308
 309
 310 static int ldlm_plain_compat(struct ldlm_lock *a, struct ldlm_lock *b)
 311 {
 312         return lockmode_compat(a->l_req_mode, b->l_req_mode);
 313 }
 314
 315 void ldlm_lock2desc(struct ldlm_lock *lock, struct ldlm_lock_desc *desc)
 316 {
 317         ldlm_res2desc(lock->l_resource, &desc->l_resource);
 318         desc->l_req_mode = lock->l_req_mode;
 319         desc->l_granted_mode = lock->l_granted_mode;
 320         memcpy(&desc->l_extent, &lock->l_extent, sizeof(desc->l_extent));
 321         memcpy(desc->l_version, lock->l_version, sizeof(desc->l_version));
 322 }
 323
 324 static void ldlm_add_ast_work_item(struct ldlm_lock *lock,
 325                                    struct ldlm_lock *new)
 326 {
 327         struct ldlm_ast_work *w;
 328         ENTRY;
 329
 330         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 331         if (new && (lock->l_flags & LDLM_FL_AST_SENT))
 332                 GOTO(out, 0);
 333
 334         OBD_ALLOC(w, sizeof(*w));
 335         if (!w) {
 336                 LBUG();
 337                 GOTO(out, 0);
 338         }
 339
 340         if (new) {
 341                 lock->l_flags |= LDLM_FL_AST_SENT;
 342                 w->w_blocking = 1;
 343                 ldlm_lock2desc(new, &w->w_desc);
 344         }
 345
 346         w->w_lock = LDLM_LOCK_GET(lock);
 347         list_add(&w->w_list, lock->l_resource->lr_tmp);
 348       out:
 349         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 350         return;
 351 }
 352
 353 void ldlm_lock_addref(struct lustre_handle *lockh, __u32 mode)
 354 {
 355         struct ldlm_lock *lock;
 356
 357         lock = ldlm_handle2lock(lockh);
 358         ldlm_lock_addref_internal(lock, mode);
 359         LDLM_LOCK_PUT(lock);
 360 }
 361
 362 /* only called for local locks */
 363 void ldlm_lock_addref_internal(struct ldlm_lock *lock, __u32 mode)
 364 {
 365         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 366         if (mode == LCK_NL || mode == LCK_CR || mode == LCK_PR)
 367                 lock->l_readers++;
 368         else
 369                 lock->l_writers++;
 370         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 371         LDLM_LOCK_GET(lock);
 372         LDLM_DEBUG(lock, "ldlm_lock_addref(%s)", ldlm_lockname[mode]);
 373 }
 374
 375 /* Args: unlocked lock */
 376 void ldlm_lock_decref(struct lustre_handle *lockh, __u32 mode)
 377 {
 378         struct ldlm_lock *lock = ldlm_handle2lock(lockh);
 379         ENTRY;
 380
 381         if (lock == NULL)
 382                 LBUG();
 383
 384         LDLM_DEBUG(lock, "ldlm_lock_decref(%s)", ldlm_lockname[mode]);
 385         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 386         if (mode == LCK_NL || mode == LCK_CR || mode == LCK_PR)
 387                 lock->l_readers--;
 388         else
 389                 lock->l_writers--;
 390
 391         /* If we received a blocked AST and this was the last reference,
 392          * run the callback. */
 393         if (!lock->l_readers && !lock->l_writers &&
 394             (lock->l_flags & LDLM_FL_CBPENDING)) {
 395                 if (!lock->l_resource->lr_namespace->ns_client) {
 396                         CERROR("LDLM_FL_CBPENDING set on non-local lock!\n");
 397                         LBUG();
 398                 }
 399
 400                 LDLM_DEBUG(lock, "final decref done on cbpending lock");
 401                 l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 402
 403                 /* FIXME: need a real 'desc' here */
 404                 lock->l_blocking_ast(lock, NULL, lock->l_data,
 405                                      lock->l_data_len);
 406         } else
 407                 l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 408
 409         LDLM_LOCK_PUT(lock);    /* matches the ldlm_lock_get in addref */
 410         LDLM_LOCK_PUT(lock);    /* matches the handle2lock above */
 411
 412         EXIT;
 413 }
 414
 415 static int ldlm_lock_compat_list(struct ldlm_lock *lock, int send_cbs,
 416                                  struct list_head *queue)
 417 {
 418         struct list_head *tmp, *pos;
 419         int rc = 1;
 420
 421         list_for_each_safe(tmp, pos, queue) {
 422                 struct ldlm_lock *child;
 423                 ldlm_res_compat compat;
 424
 425                 child = list_entry(tmp, struct ldlm_lock, l_res_link);
 426                 if (lock == child)
 427                         continue;
 428
 429                 compat = ldlm_res_compat_table[child->l_resource->lr_type];
 430                 if (compat && compat(child, lock)) {
 431                         CDEBUG(D_OTHER, "compat function succeded, next.\n");
 432                         continue;
 433                 }
 434                 if (lockmode_compat(child->l_granted_mode, lock->l_req_mode)) {
 435                         CDEBUG(D_OTHER, "lock modes are compatible, next.\n");
 436                         continue;
 437                 }
 438
 439                 rc = 0;
 440
 441                 if (send_cbs && child->l_blocking_ast != NULL) {
 442                         CDEBUG(D_OTHER, "incompatible; sending blocking "
 443                                "AST.\n");
 444                         ldlm_add_ast_work_item(child, lock);
 445                 }
 446         }
 447
 448         return rc;
 449 }
 450
 451 static int ldlm_lock_compat(struct ldlm_lock *lock, int send_cbs)
 452 {
 453         int rc;
 454         ENTRY;
 455
 456         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 457         rc = ldlm_lock_compat_list(lock, send_cbs,
 458                                    &lock->l_resource->lr_granted);
 459         /* FIXME: should we be sending ASTs to converting? */
 460         if (rc)
 461                 rc = ldlm_lock_compat_list
 462                         (lock, send_cbs, &lock->l_resource->lr_converting);
 463
 464         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 465         RETURN(rc);
 466 }
 467
 468 /* NOTE: called by
 469    - ldlm_handle_enqueuque - resource
 470 */
 471 void ldlm_grant_lock(struct ldlm_lock *lock)
 472 {
 473         struct ldlm_resource *res = lock->l_resource;
 474         ENTRY;
 475
 476         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 477         ldlm_resource_add_lock(res, &res->lr_granted, lock);
 478         lock->l_granted_mode = lock->l_req_mode;
 479
 480         if (lock->l_granted_mode < res->lr_most_restr)
 481                 res->lr_most_restr = lock->l_granted_mode;
 482
 483         if (lock->l_completion_ast) {
 484                 ldlm_add_ast_work_item(lock, NULL);
 485         }
 486         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 487         EXIT;
 488 }
 489
 490 /* returns a referenced lock or NULL */
 491 static struct ldlm_lock *search_queue(struct list_head *queue, ldlm_mode_t mode,
 492                                       struct ldlm_extent *extent)
 493 {
 494         struct ldlm_lock *lock;
 495         struct list_head *tmp;
 496
 497         list_for_each(tmp, queue) {
 498                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 499
 500                 if (lock->l_flags & LDLM_FL_CBPENDING)
 501                         continue;
 502
 503                 /* lock_convert() takes the resource lock, so we're sure that
 504                  * req_mode, lr_type, and l_cookie won't change beneath us */
 505                 if (lock->l_req_mode != mode)
 506                         continue;
 507
 508                 if (lock->l_resource->lr_type == LDLM_EXTENT &&
 509                     (lock->l_extent.start > extent->start ||
 510                      lock->l_extent.end < extent->end))
 511                         continue;
 512
 513                 ldlm_lock_addref_internal(lock, mode);
 514                 return lock;
 515         }
 516
 517         return NULL;
 518 }
 519
 520 /* Must be called with no resource or lock locks held.
 521  *
 522  * Returns 1 if it finds an already-existing lock that is compatible; in this
 523  * case, lockh is filled in with a addref()ed lock
 524 */
 525 int ldlm_lock_match(struct ldlm_namespace *ns, __u64 * res_id, __u32 type,
 526                     void *cookie, int cookielen, ldlm_mode_t mode,
 527                     struct lustre_handle *lockh)
 528 {
 529         struct ldlm_resource *res;
 530         struct ldlm_lock *lock;
 531         int rc = 0;
 532         ENTRY;
 533
 534         res = ldlm_resource_get(ns, NULL, res_id, type, 0);
 535         if (res == NULL)
 536                 RETURN(0);
 537
 538         ns = res->lr_namespace;
 539         l_lock(&ns->ns_lock);
 540
 541         if ((lock = search_queue(&res->lr_granted, mode, cookie)))
 542                 GOTO(out, rc = 1);
 543         if ((lock = search_queue(&res->lr_converting, mode, cookie)))
 544                 GOTO(out, rc = 1);
 545         if ((lock = search_queue(&res->lr_waiting, mode, cookie)))
 546                 GOTO(out, rc = 1);
 547
 548         EXIT;
 549       out:
 550         ldlm_resource_put(res);
 551         l_unlock(&ns->ns_lock);
 552
 553         if (lock) {
 554                 ldlm_lock2handle(lock, lockh);
 555                 if (lock->l_completion_ast)
 556                         lock->l_completion_ast(lock, LDLM_FL_WAIT_NOREPROC);
 557         }
 558         if (rc)
 559                 LDLM_DEBUG(lock, "matched");
 560         else
 561                 LDLM_DEBUG_NOLOCK("not matched");
 562         return rc;
 563 }
 564
 565 /*   Returns a referenced, lock */
 566 struct ldlm_lock *ldlm_lock_create(struct ldlm_namespace *ns,
 567                                    struct lustre_handle *parent_lock_handle,
 568                                    __u64 * res_id, __u32 type,
 569                                    ldlm_mode_t mode, void *data, __u32 data_len)
 570 {
 571         struct ldlm_resource *res, *parent_res = NULL;
 572         struct ldlm_lock *lock, *parent_lock;
 573
 574         parent_lock = ldlm_handle2lock(parent_lock_handle);
 575         if (parent_lock)
 576                 parent_res = parent_lock->l_resource;
 577
 578         res = ldlm_resource_get(ns, parent_res, res_id, type, 1);
 579         if (res == NULL)
 580                 RETURN(NULL);
 581
 582         lock = ldlm_lock_new(parent_lock, res);
 583         if (lock == NULL) {
 584                 ldlm_resource_put(res);
 585                 RETURN(NULL);
 586         }
 587
 588         lock->l_req_mode = mode;
 589         lock->l_data = data;
 590         lock->l_data_len = data_len;
 591
 592         return lock;
 593 }
 594
 595 /* Must be called with lock->l_lock and lock->l_resource->lr_lock not held */
 596 ldlm_error_t ldlm_lock_enqueue(struct ldlm_lock * lock,
 597                                void *cookie, int cookie_len,
 598                                int *flags,
 599                                ldlm_completion_callback completion,
 600                                ldlm_blocking_callback blocking)
 601 {
 602         struct ldlm_resource *res;
 603         int local;
 604         ldlm_res_policy policy;
 605         ENTRY;
 606
 607         res = lock->l_resource;
 608         lock->l_blocking_ast = blocking;
 609
 610         if (res->lr_type == LDLM_EXTENT)
 611                 memcpy(&lock->l_extent, cookie, sizeof(lock->l_extent));
 612
 613         /* policies are not executed on the client */
 614         local = res->lr_namespace->ns_client;
 615         if (!local && (policy = ldlm_res_policy_table[res->lr_type])) {
 616                 int rc;
 617                 rc = policy(lock, cookie, lock->l_req_mode, NULL);
 618
 619                 if (rc == ELDLM_LOCK_CHANGED) {
 620                         res = lock->l_resource;
 621                         *flags |= LDLM_FL_LOCK_CHANGED;
 622                 } else if (rc == ELDLM_LOCK_ABORTED) {
 623                         ldlm_lock_destroy(lock);
 624                         RETURN(rc);
 625                 }
 626         }
 627
 628         lock->l_cookie = cookie;
 629         lock->l_cookie_len = cookie_len;
 630
 631         if (local && lock->l_req_mode == lock->l_granted_mode) {
 632                 /* The server returned a blocked lock, but it was granted before
 633                  * we got a chance to actually enqueue it.  We don't need to do
 634                  * anything else. */
 635                 GOTO(out, ELDLM_OK);
 636         }
 637
 638         /* This distinction between local lock trees is very important; a client
 639          * namespace only has information about locks taken by that client, and
 640          * thus doesn't have enough information to decide for itself if it can
 641          * be granted (below).  In this case, we do exactly what the server
 642          * tells us to do, as dictated by the 'flags' */
 643         ldlm_resource_unlink_lock(lock);
 644         if (local) {
 645                 if (*flags & LDLM_FL_BLOCK_CONV)
 646                         ldlm_resource_add_lock(res, res->lr_converting.prev,
 647                                                lock);
 648                 else if (*flags & (LDLM_FL_BLOCK_WAIT | LDLM_FL_BLOCK_GRANTED))
 649                         ldlm_resource_add_lock(res, res->lr_waiting.prev, lock);
 650                 else
 651                         ldlm_grant_lock(lock);
 652                 GOTO(out, ELDLM_OK);
 653         }
 654
 655         /* FIXME: We may want to optimize by checking lr_most_restr */
 656         if (!list_empty(&res->lr_converting)) {
 657                 ldlm_resource_add_lock(res, res->lr_waiting.prev, lock);
 658                 *flags |= LDLM_FL_BLOCK_CONV;
 659                 GOTO(out, ELDLM_OK);
 660         }
 661         if (!list_empty(&res->lr_waiting)) {
 662                 ldlm_resource_add_lock(res, res->lr_waiting.prev, lock);
 663                 *flags |= LDLM_FL_BLOCK_WAIT;
 664                 GOTO(out, ELDLM_OK);
 665         }
 666         if (!ldlm_lock_compat(lock, 0)) {
 667                 ldlm_resource_add_lock(res, res->lr_waiting.prev, lock);
 668                 *flags |= LDLM_FL_BLOCK_GRANTED;
 669                 GOTO(out, ELDLM_OK);
 670         }
 671
 672         ldlm_grant_lock(lock);
 673         EXIT;
 674       out:
 675         /* Don't set 'completion_ast' until here so that if the lock is granted
 676          * immediately we don't do an unnecessary completion call. */
 677         lock->l_completion_ast = completion;
 678         return ELDLM_OK;
 679 }
 680
 681 /* Must be called with namespace taken: queue is waiting or converting. */
 682 static int ldlm_reprocess_queue(struct ldlm_resource *res,
 683                                 struct list_head *queue)
 684 {
 685         struct list_head *tmp, *pos;
 686         ENTRY;
 687
 688         list_for_each_safe(tmp, pos, queue) {
 689                 struct ldlm_lock *pending;
 690                 pending = list_entry(tmp, struct ldlm_lock, l_res_link);
 691
 692                 CDEBUG(D_INFO, "Reprocessing lock %p\n", pending);
 693
 694                 if (!ldlm_lock_compat(pending, 1))
 695                         RETURN(1);
 696
 697                 list_del_init(&pending->l_res_link);
 698                 ldlm_grant_lock(pending);
 699         }
 700
 701         RETURN(0);
 702 }
 703
 704 void ldlm_run_ast_work(struct list_head *rpc_list)
 705 {
 706         struct list_head *tmp, *pos;
 707         int rc;
 708         ENTRY;
 709
 710         list_for_each_safe(tmp, pos, rpc_list) {
 711                 struct ldlm_ast_work *w =
 712                         list_entry(tmp, struct ldlm_ast_work, w_list);
 713
 714                 if (w->w_blocking)
 715                         rc = w->w_lock->l_blocking_ast
 716                                 (w->w_lock, &w->w_desc, w->w_data,
 717                                  w->w_datalen);
 718                 else
 719                         rc = w->w_lock->l_completion_ast(w->w_lock, w->w_flags);
 720                 if (rc)
 721                         CERROR("Failed AST - should clean & disconnect "
 722                                "client\n");
 723                 LDLM_LOCK_PUT(w->w_lock);
 724                 list_del(&w->w_list);
 725                 OBD_FREE(w, sizeof(*w));
 726         }
 727         EXIT;
 728 }
 729
 730 /* Must be called with resource->lr_lock not taken. */
 731 void ldlm_reprocess_all(struct ldlm_resource *res)
 732 {
 733         struct list_head rpc_list = LIST_HEAD_INIT(rpc_list);
 734         ENTRY;
 735
 736         /* Local lock trees don't get reprocessed. */
 737         if (res->lr_namespace->ns_client) {
 738                 EXIT;
 739                 return;
 740         }
 741
 742         l_lock(&res->lr_namespace->ns_lock);
 743         res->lr_tmp = &rpc_list;
 744
 745         ldlm_reprocess_queue(res, &res->lr_converting);
 746         if (list_empty(&res->lr_converting))
 747                 ldlm_reprocess_queue(res, &res->lr_waiting);
 748
 749         res->lr_tmp = NULL;
 750         l_unlock(&res->lr_namespace->ns_lock);
 751
 752         ldlm_run_ast_work(&rpc_list);
 753         EXIT;
 754 }
 755
 756 void ldlm_lock_cancel(struct ldlm_lock *lock)
 757 {
 758         struct ldlm_resource *res;
 759         struct ldlm_namespace *ns;
 760         ENTRY;
 761
 762         res = lock->l_resource;
 763         ns = res->lr_namespace;
 764
 765         l_lock(&ns->ns_lock);
 766         if (lock->l_readers || lock->l_writers)
 767                 CDEBUG(D_INFO, "lock still has references (%d readers, %d "
 768                        "writers)\n", lock->l_readers, lock->l_writers);
 769
 770         ldlm_resource_unlink_lock(lock);
 771         ldlm_lock_destroy(lock);
 772         l_unlock(&ns->ns_lock);
 773         EXIT;
 774 }
 775
 776 struct ldlm_resource *ldlm_lock_convert(struct ldlm_lock *lock, int new_mode,
 777                                         int *flags)
 778 {
 779         struct list_head rpc_list = LIST_HEAD_INIT(rpc_list);
 780         struct ldlm_resource *res;
 781         struct ldlm_namespace *ns;
 782         int granted = 0;
 783         ENTRY;
 784
 785         res = lock->l_resource;
 786         ns = res->lr_namespace;
 787
 788         l_lock(&ns->ns_lock);
 789
 790         lock->l_req_mode = new_mode;
 791         ldlm_resource_unlink_lock(lock);
 792
 793         /* If this is a local resource, put it on the appropriate list. */
 794         if (res->lr_namespace->ns_client) {
 795                 if (*flags & (LDLM_FL_BLOCK_CONV | LDLM_FL_BLOCK_GRANTED))
 796                         ldlm_resource_add_lock(res, res->lr_converting.prev,
 797                                                lock);
 798                 else {
 799                         res->lr_tmp = &rpc_list;
 800                         ldlm_grant_lock(lock);
 801                         res->lr_tmp = NULL;
 802                         granted = 1;
 803                         /* FIXME: completion handling not with ns_lock held ! */
 804                         if (lock->l_completion_ast)
 805                                 lock->l_completion_ast(lock, 0);
 806                 }
 807         } else
 808                 list_add(&lock->l_res_link, res->lr_converting.prev);
 809
 810         l_unlock(&ns->ns_lock);
 811
 812         if (granted)
 813                 ldlm_run_ast_work(&rpc_list);
 814         RETURN(res);
 815 }
 816
 817 void ldlm_lock_dump(struct ldlm_lock *lock)
 818 {
 819         char ver[128];
 820
 821         if (!(portal_debug & D_OTHER))
 822                 return;
 823
 824         if (RES_VERSION_SIZE != 4)
 825                 LBUG();
 826
 827         if (!lock) {
 828                 CDEBUG(D_OTHER, "  NULL LDLM lock\n");
 829                 return;
 830         }
 831
 832         snprintf(ver, sizeof(ver), "%x %x %x %x",
 833                  lock->l_version[0], lock->l_version[1],
 834                  lock->l_version[2], lock->l_version[3]);
 835
 836         CDEBUG(D_OTHER, "  -- Lock dump: %p (%s)\n", lock, ver);
 837         CDEBUG(D_OTHER, "  Node: NID %x (rhandle: %Lx)\n",
 838                lock->l_connection->c_peer.peer_nid,
 839                lock->l_remote_handle.addr);
 840         CDEBUG(D_OTHER, "  Parent: %p\n", lock->l_parent);
 841         CDEBUG(D_OTHER, "  Resource: %p (%Ld)\n", lock->l_resource,
 842                lock->l_resource->lr_name[0]);
 843         CDEBUG(D_OTHER, "  Requested mode: %d, granted mode: %d\n",
 844                (int)lock->l_req_mode, (int)lock->l_granted_mode);
 845         CDEBUG(D_OTHER, "  Readers: %u ; Writers; %u\n",
 846                lock->l_readers, lock->l_writers);
 847         if (lock->l_resource->lr_type == LDLM_EXTENT)
 848                 CDEBUG(D_OTHER, "  Extent: %Lu -> %Lu\n",
 849                        (unsigned long long)lock->l_extent.start,
 850                        (unsigned long long)lock->l_extent.end);
 851 }