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 kmem_cache_t *ldlm_lock_slab;
  23 int (*mds_reint_p)(int offset, struct ptlrpc_request *req) = NULL;
  24 int (*mds_getattr_name_p)(int offset, struct ptlrpc_request *req) = NULL;
  25
  26 static int ldlm_plain_compat(struct ldlm_lock *a, struct ldlm_lock *b);
  27 static int ldlm_intent_policy(struct ldlm_lock *lock, void *req_cookie,
  28                               ldlm_mode_t mode, void *data);
  29
  30 ldlm_res_compat ldlm_res_compat_table [] = {
  31         [LDLM_PLAIN] ldlm_plain_compat,
  32         [LDLM_EXTENT] ldlm_extent_compat,
  33         [LDLM_MDSINTENT] ldlm_plain_compat
  34 };
  35
  36 ldlm_res_policy ldlm_res_policy_table [] = {
  37         [LDLM_PLAIN] NULL,
  38         [LDLM_EXTENT] ldlm_extent_policy,
  39         [LDLM_MDSINTENT] ldlm_intent_policy
  40 };
  41
  42 void ldlm_lock2handle(struct ldlm_lock *lock, struct lustre_handle *lockh)
  43 {
  44         lockh->addr = (__u64)(unsigned long)lock;
  45         lockh->cookie = lock->l_random;
  46 }
  47
  48 struct ldlm_lock *ldlm_handle2lock(struct lustre_handle *handle)
  49 {
  50         struct ldlm_lock *lock = NULL;
  51         ENTRY;
  52
  53         if (!handle)
  54                 RETURN(NULL);
  55         lock = (struct ldlm_lock *)(unsigned long)(handle->addr);
  56
  57         if (!kmem_cache_validate(ldlm_lock_slab, (void *)lock))
  58                 RETURN(NULL);
  59
  60         l_lock(&lock->l_resource->lr_namespace->ns_lock);
  61         if (lock->l_random != handle->cookie)
  62                 GOTO(out, handle = NULL);
  63
  64         if (lock->l_flags & LDLM_FL_DESTROYED)
  65                 GOTO(out, handle = NULL);
  66
  67         lock->l_refc++;
  68         EXIT;
  69  out:
  70         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
  71         return  lock;
  72 }
  73
  74 struct ldlm_lock *ldlm_lock_get(struct ldlm_lock *lock)
  75 {
  76         l_lock(&lock->l_resource->lr_namespace->ns_lock);
  77         lock->l_refc++;
  78         ldlm_resource_getref(lock->l_resource);
  79         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
  80         return lock;
  81 }
  82
  83 void ldlm_lock_put(struct ldlm_lock *lock)
  84 {
  85         struct lustre_lock *nslock = &lock->l_resource->lr_namespace->ns_lock;
  86         ENTRY;
  87
  88         l_lock(nslock);
  89         lock->l_refc--;
  90         if (lock->l_refc < 0)
  91                 LBUG();
  92
  93         ldlm_resource_put(lock->l_resource);
  94         if (lock->l_parent)
  95                 ldlm_lock_put(lock->l_parent);
  96
  97         if (lock->l_refc == 0 && (lock->l_flags & LDLM_FL_DESTROYED)) {
  98                 if (lock->l_connection)
  99                         ptlrpc_put_connection(lock->l_connection);
 100                 kmem_cache_free(ldlm_lock_slab, lock);
 101         }
 102         l_unlock(nslock);
 103         EXIT;
 104         return;
 105 }
 106
 107 void ldlm_lock_destroy(struct ldlm_lock *lock)
 108 {
 109         ENTRY;
 110         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 111
 112         if (!list_empty(&lock->l_children)) {
 113                 CERROR("lock %p still has children (%p)!\n", lock,
 114                        lock->l_children.next);
 115                 ldlm_lock_dump(lock);
 116                 LBUG();
 117         }
 118         if (lock->l_readers || lock->l_writers) {
 119                 CDEBUG(D_INFO, "lock still has references (%d readers, %d "
 120                        "writers)\n", lock->l_readers, lock->l_writers);
 121                 LBUG();
 122         }
 123
 124         if (!list_empty(&lock->l_res_link))
 125                 LBUG();
 126
 127         lock->l_flags = LDLM_FL_DESTROYED;
 128         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 129         ldlm_lock_put(lock);
 130         EXIT;
 131         return;
 132 }
 133 /*
 134    usage: pass in a resource on which you have done get
 135           pass in a parent lock on which you have done a get
 136           do not put the resource or the parent
 137    returns: lock with refcount 1
 138 */
 139 static struct ldlm_lock *ldlm_lock_new(struct ldlm_lock *parent,
 140                                        struct ldlm_resource *resource)
 141 {
 142         struct ldlm_lock *lock;
 143         ENTRY;
 144
 145         if (resource == NULL)
 146                 LBUG();
 147
 148         lock = kmem_cache_alloc(ldlm_lock_slab, SLAB_KERNEL);
 149         if (lock == NULL)
 150                 RETURN(NULL);
 151
 152         memset(lock, 0, sizeof(*lock));
 153         get_random_bytes(&lock->l_cookie, sizeof(__u64));
 154
 155         lock->l_resource = resource;
 156         lock->l_refc = 1;
 157         INIT_LIST_HEAD(&lock->l_children);
 158         INIT_LIST_HEAD(&lock->l_res_link);
 159         init_waitqueue_head(&lock->l_waitq);
 160
 161         if (parent != NULL) {
 162                 l_lock(&parent->l_resource->lr_namespace->ns_lock);
 163                 lock->l_parent = parent;
 164                 list_add(&lock->l_childof, &parent->l_children);
 165                 l_unlock(&parent->l_resource->lr_namespace->ns_lock);
 166         }
 167         RETURN(lock);
 168 }
 169
 170 int ldlm_lock_change_resource(struct ldlm_lock *lock, __u64 new_resid[3])
 171 {
 172         struct ldlm_namespace *ns = lock->l_resource->lr_namespace;
 173         int type, i;
 174         ENTRY;
 175
 176         l_lock(&ns->ns_lock);
 177         type = lock->l_resource->lr_type;
 178
 179         lock->l_resource = ldlm_resource_get(ns, NULL, new_resid, type, 1);
 180         if (lock->l_resource == NULL) {
 181                 LBUG();
 182                 RETURN(-ENOMEM);
 183         }
 184
 185         /* move references over */
 186         for (i = 0; i < lock->l_refc; i++) {
 187                 int rc;
 188                 ldlm_resource_getref(lock->l_resource);
 189                 rc = ldlm_resource_put(lock->l_resource);
 190                 if (rc == 1 && i != lock->l_refc - 1)
 191                         LBUG();
 192         }
 193
 194         l_unlock(&ns->ns_lock);
 195         RETURN(0);
 196 }
 197
 198 static int ldlm_intent_policy(struct ldlm_lock *lock, void *req_cookie,
 199                               ldlm_mode_t mode, void *data)
 200 {
 201         struct ptlrpc_request *req = req_cookie;
 202         int rc = 0;
 203         ENTRY;
 204
 205         if (!req_cookie)
 206                 RETURN(0);
 207
 208         if (req->rq_reqmsg->bufcount > 1) {
 209                 /* an intent needs to be considered */
 210                 struct ldlm_intent *it = lustre_msg_buf(req->rq_reqmsg, 1);
 211                 struct mds_body *mds_rep;
 212                 struct ldlm_reply *rep;
 213                 __u64 new_resid[3] = {0, 0, 0}, old_res;
 214                 int bufcount = -1, rc, size[3] = {sizeof(struct ldlm_reply),
 215                                                   sizeof(struct mds_body),
 216                                                   sizeof(struct obdo)};
 217
 218                 it->opc = NTOH__u64(it->opc);
 219
 220                 LDLM_DEBUG(lock, "intent policy, opc: %Ld", it->opc);
 221
 222                 /* prepare reply */
 223                 switch(it->opc) {
 224                 case IT_GETATTR:
 225                         /* Note that in the negative case you may be returning
 226                          * a file and its obdo */
 227                 case IT_CREAT:
 228                 case IT_CREAT|IT_OPEN:
 229                 case IT_MKDIR:
 230                 case IT_SYMLINK:
 231                 case IT_MKNOD:
 232                 case IT_LINK:
 233                 case IT_OPEN:
 234                 case IT_RENAME:
 235                         bufcount = 3;
 236                         break;
 237                 case IT_UNLINK:
 238                         bufcount = 2;
 239                         size[1] = sizeof(struct obdo);
 240                         break;
 241                 case IT_RMDIR:
 242                         bufcount = 1;
 243                         break;
 244                 default:
 245                         LBUG();
 246                 }
 247
 248                 rc = lustre_pack_msg(bufcount, size, NULL, &req->rq_replen,
 249                                      &req->rq_repmsg);
 250                 if (rc) {
 251                         rc = req->rq_status = -ENOMEM;
 252                         RETURN(rc);
 253                 }
 254
 255                 rep = lustre_msg_buf(req->rq_repmsg, 0);
 256                 rep->lock_policy_res1 = 1;
 257
 258                 /* execute policy */
 259                 switch (it->opc) {
 260                 case IT_CREAT:
 261                 case IT_CREAT|IT_OPEN:
 262                 case IT_MKDIR:
 263                 case IT_SETATTR:
 264                 case IT_SYMLINK:
 265                 case IT_MKNOD:
 266                 case IT_LINK:
 267                 case IT_UNLINK:
 268                 case IT_RMDIR:
 269                 case IT_RENAME2:
 270                         if (mds_reint_p == NULL)
 271                                 mds_reint_p =
 272                                         inter_module_get_request
 273                                         ("mds_reint", "mds");
 274                         if (IS_ERR(mds_reint_p)) {
 275                                 CERROR("MDSINTENT locks require the MDS "
 276                                        "module.\n");
 277                                 LBUG();
 278                                 RETURN(-EINVAL);
 279                         }
 280                         rc = mds_reint_p(2, req);
 281                         if (rc)
 282                                 LBUG();
 283                         break;
 284                 case IT_GETATTR:
 285                 case IT_READDIR:
 286                 case IT_RENAME:
 287                 case IT_OPEN:
 288                         if (mds_getattr_name_p == NULL)
 289                                 mds_getattr_name_p =
 290                                         inter_module_get_request
 291                                         ("mds_getattr_name", "mds");
 292                         if (IS_ERR(mds_getattr_name_p)) {
 293                                 CERROR("MDSINTENT locks require the MDS "
 294                                        "module.\n");
 295                                 LBUG();
 296                                 RETURN(-EINVAL);
 297                         }
 298                         rc = mds_getattr_name_p(2, req);
 299                         if (rc) {
 300                                 req->rq_status = rc;
 301                                 RETURN(rc);
 302                         }
 303                         break;
 304                 case IT_READDIR|IT_OPEN:
 305                         LBUG();
 306                         break;
 307                 default:
 308                         CERROR("Unhandled intent\n");
 309                         LBUG();
 310                 }
 311
 312                 if (it->opc == IT_UNLINK || it->opc == IT_RMDIR)
 313                         RETURN(ELDLM_LOCK_ABORTED);
 314
 315                 mds_rep = lustre_msg_buf(req->rq_repmsg, 1);
 316                 rep->lock_policy_res2 = req->rq_status;
 317                 new_resid[0] = mds_rep->ino;
 318                 old_res = lock->l_resource->lr_name[0];
 319
 320                 CDEBUG(D_INFO, "remote intent: locking %d instead of"
 321                        "%ld\n", mds_rep->ino, (long)old_res);
 322
 323                 ldlm_lock_change_resource(lock, new_resid);
 324                 if (lock->l_resource == NULL) {
 325                         LBUG();
 326                         RETURN(-ENOMEM);
 327                 }
 328                 LDLM_DEBUG(lock, "intent policy, old res %ld",
 329                            (long)old_res);
 330                 RETURN(ELDLM_LOCK_CHANGED);
 331         } else {
 332                 int size = sizeof(struct ldlm_reply);
 333                 rc = lustre_pack_msg(1, &size, NULL, &req->rq_replen,
 334                                      &req->rq_repmsg);
 335                 if (rc) {
 336                         CERROR("out of memory\n");
 337                         LBUG();
 338                         RETURN(-ENOMEM);
 339                 }
 340         }
 341         RETURN(rc);
 342 }
 343
 344 static int ldlm_plain_compat(struct ldlm_lock *a, struct ldlm_lock *b)
 345 {
 346         return lockmode_compat(a->l_req_mode, b->l_req_mode);
 347 }
 348
 349 void ldlm_lock2desc(struct ldlm_lock *lock, struct ldlm_lock_desc *desc)
 350 {
 351         ldlm_res2desc(lock->l_resource, &desc->l_resource);
 352         desc->l_req_mode = lock->l_req_mode;
 353         desc->l_granted_mode = lock->l_granted_mode;
 354         memcpy(&desc->l_extent, &lock->l_extent, sizeof(desc->l_extent));
 355         memcpy(desc->l_version, lock->l_version, sizeof(desc->l_version));
 356 }
 357
 358 static int ldlm_send_blocking_ast(struct ldlm_lock *lock, struct ldlm_lock *new)
 359 {
 360         struct ldlm_lock_desc desc;
 361         struct ptlrpc_request *req = NULL;
 362         ENTRY;
 363
 364         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 365         if (lock->l_flags & LDLM_FL_AST_SENT) {
 366                 l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 367                 RETURN(0);
 368         }
 369
 370         lock->l_flags |= LDLM_FL_AST_SENT;
 371         /* FIXME: this should merely add the lock to the lr_tmp list */
 372         ldlm_lock2desc(new, &desc);
 373         lock->l_blocking_ast(lock, &desc, lock->l_data, lock->l_data_len, &req);
 374         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 375
 376         if (req != NULL) {
 377                 struct list_head *list = lock->l_resource->lr_tmp;
 378                 list_add(&req->rq_multi, list);
 379         }
 380         RETURN(1);
 381 }
 382
 383 /* Args: unlocked lock */
 384 void ldlm_lock_addref(struct ldlm_lock *lock, __u32 mode)
 385 {
 386         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 387         if (mode == LCK_NL || mode == LCK_CR || mode == LCK_PR)
 388                 lock->l_readers++;
 389         else
 390                 lock->l_writers++;
 391         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 392         ldlm_lock_get(lock);
 393 }
 394
 395 /* Args: unlocked lock */
 396 void ldlm_lock_decref(struct ldlm_lock *lock, __u32 mode)
 397 {
 398         ENTRY;
 399
 400         if (lock == NULL)
 401                 LBUG();
 402
 403         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 404         if (mode == LCK_NL || mode == LCK_CR || mode == LCK_PR)
 405                 lock->l_readers--;
 406         else
 407                 lock->l_writers--;
 408
 409         /* If we received a blocked AST and this was the last reference,
 410          * run the callback. */
 411         if (!lock->l_readers && !lock->l_writers &&
 412             (lock->l_flags & LDLM_FL_CBPENDING)) {
 413                 if (!lock->l_resource->lr_namespace->ns_client) {
 414                         CERROR("LDLM_FL_CBPENDING set on non-local lock!\n");
 415                         LBUG();
 416                 }
 417
 418                 CDEBUG(D_INFO, "final decref done on cbpending lock, "
 419                        "calling callback.\n");
 420                 l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 421
 422                 lock->l_blocking_ast(lock, NULL, lock->l_data,
 423                                      lock->l_data_len, NULL);
 424         } else
 425                 l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 426
 427         ldlm_lock_put(lock);
 428
 429         EXIT;
 430 }
 431
 432 static int ldlm_lock_compat_list(struct ldlm_lock *lock, int send_cbs,
 433                              struct list_head *queue)
 434 {
 435         struct list_head *tmp, *pos;
 436         int rc = 1;
 437
 438         list_for_each_safe(tmp, pos, queue) {
 439                 struct ldlm_lock *child;
 440                 ldlm_res_compat compat;
 441
 442                 child = list_entry(tmp, struct ldlm_lock, l_res_link);
 443                 if (lock == child)
 444                         continue;
 445
 446                 compat = ldlm_res_compat_table[child->l_resource->lr_type];
 447                 if (compat && compat(child, lock)) {
 448                         CDEBUG(D_OTHER, "compat function succeded, next.\n");
 449                         continue;
 450                 }
 451                 if (lockmode_compat(child->l_granted_mode, lock->l_req_mode)) {
 452                         CDEBUG(D_OTHER, "lock modes are compatible, next.\n");
 453                         continue;
 454                 }
 455
 456                 rc = 0;
 457
 458                 CDEBUG(D_OTHER, "compat function failed and lock modes "
 459                        "incompat\n");
 460                 if (send_cbs && child->l_blocking_ast != NULL) {
 461                         CDEBUG(D_OTHER, "incompatible; sending blocking "
 462                                "AST.\n");
 463                         /* It's very difficult to actually send the AST from
 464                          * here, because we'd have to drop the lock before going
 465                          * to sleep to wait for the reply.  Instead we build the
 466                          * packet and send it later. */
 467                         ldlm_send_blocking_ast(child, lock);
 468                 }
 469         }
 470
 471         return rc;
 472 }
 473
 474 static int ldlm_lock_compat(struct ldlm_lock *lock, int send_cbs)
 475 {
 476         int rc;
 477         ENTRY;
 478
 479         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 480         rc = ldlm_lock_compat_list(lock, send_cbs, &lock->l_resource->lr_granted);
 481         /* FIXME: should we be sending ASTs to converting? */
 482         if (rc)
 483                 rc = ldlm_lock_compat_list
 484                         (lock, send_cbs, &lock->l_resource->lr_converting);
 485
 486         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 487         RETURN(rc);
 488 }
 489
 490 /* NOTE: called by
 491    - ldlm_handle_enqueuque - resource
 492 */
 493 void ldlm_grant_lock(struct ldlm_lock *lock)
 494 {
 495         struct ldlm_resource *res = lock->l_resource;
 496         struct ptlrpc_request *req = NULL;
 497         ENTRY;
 498
 499         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 500         ldlm_resource_add_lock(res, &res->lr_granted, lock);
 501         lock->l_granted_mode = lock->l_req_mode;
 502
 503         if (lock->l_granted_mode < res->lr_most_restr)
 504                 res->lr_most_restr = lock->l_granted_mode;
 505
 506         if (lock->l_completion_ast) {
 507                 /* FIXME: this should merely add lock to lr_tmp list */
 508                 lock->l_completion_ast(lock, NULL, lock->l_data,
 509                                        lock->l_data_len, &req);
 510                 if (req != NULL) {
 511                         struct list_head *list = res->lr_tmp;
 512                         if (list == NULL) {
 513                                 LBUG();
 514                                 return;
 515                         }
 516                         list_add(&req->rq_multi, list);
 517                 }
 518         }
 519         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 520         EXIT;
 521 }
 522
 523 static struct ldlm_lock *search_queue(struct list_head *queue, ldlm_mode_t mode,
 524                                       struct ldlm_extent *extent)
 525 {
 526         struct ldlm_lock *lock;
 527         struct list_head *tmp;
 528
 529         list_for_each(tmp, queue) {
 530                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 531
 532                 if (lock->l_flags & LDLM_FL_CBPENDING)
 533                         continue;
 534
 535                 /* lock_convert() takes the resource lock, so we're sure that
 536                  * req_mode, lr_type, and l_cookie won't change beneath us */
 537                 if (lock->l_req_mode != mode)
 538                         continue;
 539
 540                 if (lock->l_resource->lr_type == LDLM_EXTENT &&
 541                     (lock->l_extent.start > extent->start ||
 542                      lock->l_extent.end < extent->end))
 543                         continue;
 544
 545                 ldlm_lock_addref(lock, mode);
 546                 return lock;
 547         }
 548
 549         return NULL;
 550 }
 551
 552 /* Must be called with no resource or lock locks held.
 553  *
 554  * Returns 1 if it finds an already-existing lock that is compatible; in this
 555  * case, lockh is filled in with a addref()ed lock */
 556 int ldlm_lock_match(struct ldlm_namespace *ns, __u64 *res_id, __u32 type,
 557                     void *cookie, int cookielen, ldlm_mode_t mode,
 558                     struct lustre_handle *lockh)
 559 {
 560         struct ldlm_resource *res;
 561         struct ldlm_lock *lock;
 562         int rc = 0;
 563         ENTRY;
 564
 565         res = ldlm_resource_get(ns, NULL, res_id, type, 0);
 566         if (res == NULL)
 567                 RETURN(0);
 568
 569         ns = res->lr_namespace;
 570         l_lock(&ns->ns_lock);
 571
 572         if ((lock = search_queue(&res->lr_granted, mode, cookie)))
 573                 GOTO(out, rc = 1);
 574         if ((lock = search_queue(&res->lr_converting, mode, cookie)))
 575                 GOTO(out, rc = 1);
 576         if ((lock = search_queue(&res->lr_waiting, mode, cookie)))
 577                 GOTO(out, rc = 1);
 578
 579         EXIT;
 580  out:
 581         ldlm_resource_put(res);
 582         l_unlock(&ns->ns_lock);
 583
 584         if (lock)
 585                 wait_event_interruptible(lock->l_waitq, lock->l_req_mode ==
 586                                          lock->l_granted_mode);
 587
 588         return rc;
 589 }
 590
 591 /* Must be called without the resource lock held.  Returns a referenced,
 592  * unlocked ldlm_lock. */
 593 struct ldlm_lock *ldlm_lock_create(struct ldlm_namespace *ns,
 594                                    struct lustre_handle *parent_lock_handle,
 595                                    __u64 *res_id, __u32 type,
 596                                    ldlm_mode_t mode,
 597                                    void *data,
 598                                    __u32 data_len)
 599 {
 600         struct ldlm_resource *res, *parent_res = NULL;
 601         struct ldlm_lock *lock, *parent_lock;
 602
 603         parent_lock = lustre_handle2object(parent_lock_handle);
 604         if (parent_lock)
 605                 parent_res = parent_lock->l_resource;
 606
 607         res = ldlm_resource_get(ns, parent_res, res_id, type, 1);
 608         if (res == NULL)
 609                 RETURN(NULL);
 610
 611         lock = ldlm_lock_new(parent_lock, res);
 612         if (lock == NULL) {
 613                 ldlm_resource_put(res);
 614                 RETURN(NULL);
 615         }
 616
 617         lock->l_req_mode = mode;
 618         lock->l_data = data;
 619         lock->l_data_len = data_len;
 620         ldlm_lock_addref(lock, mode);
 621
 622         return lock;
 623 }
 624
 625 /* Must be called with lock->l_lock and lock->l_resource->lr_lock not held */
 626 ldlm_error_t ldlm_lock_enqueue(struct ldlm_lock *lock,
 627                                void *cookie, int cookie_len,
 628                                int *flags,
 629                                ldlm_lock_callback completion,
 630                                ldlm_lock_callback blocking)
 631 {
 632         struct ldlm_resource *res;
 633         int local;
 634         ldlm_res_policy policy;
 635         ENTRY;
 636
 637         res = lock->l_resource;
 638         local = res->lr_namespace->ns_client;
 639
 640         lock->l_blocking_ast = blocking;
 641
 642         if (res->lr_type == LDLM_EXTENT)
 643                 memcpy(&lock->l_extent, cookie, sizeof(lock->l_extent));
 644
 645         /* policies are not executed on the client */
 646         if (!local && (policy = ldlm_res_policy_table[res->lr_type])) {
 647                 int rc;
 648
 649                 /* We do this dancing with refcounts and locks because the
 650                  * policy function could send an RPC */
 651                 ldlm_resource_getref(res);
 652
 653                 rc = policy(lock, cookie, lock->l_req_mode, NULL);
 654
 655                 if (ldlm_resource_put(res) && rc != ELDLM_LOCK_CHANGED)
 656                         /* ldlm_resource_put() should not destroy 'res' unless
 657                          * 'res' is no longer the resource for this lock. */
 658                         LBUG();
 659
 660                 if (rc == ELDLM_LOCK_CHANGED) {
 661                         res = lock->l_resource;
 662                         *flags |= LDLM_FL_LOCK_CHANGED;
 663                 } else if (rc == ELDLM_LOCK_ABORTED) {
 664                         ldlm_lock_destroy(lock);
 665                         RETURN(rc);
 666                 }
 667         }
 668
 669         lock->l_cookie = cookie;
 670         lock->l_cookie_len = cookie_len;
 671
 672         if (local && lock->l_req_mode == lock->l_granted_mode) {
 673                 /* The server returned a blocked lock, but it was granted before
 674                  * we got a chance to actually enqueue it.  We don't need to do
 675                  * anything else. */
 676                 GOTO(out, ELDLM_OK);
 677         }
 678
 679         /* If this is a local resource, put it on the appropriate list. */
 680         list_del_init(&lock->l_res_link);
 681         if (local) {
 682                 if (*flags & LDLM_FL_BLOCK_CONV)
 683                         ldlm_resource_add_lock(res, res->lr_converting.prev,
 684                                                lock);
 685                 else if (*flags & (LDLM_FL_BLOCK_WAIT | LDLM_FL_BLOCK_GRANTED))
 686                         ldlm_resource_add_lock(res, res->lr_waiting.prev, lock);
 687                 else
 688                         ldlm_grant_lock(lock);
 689                 GOTO(out, ELDLM_OK);
 690         }
 691
 692         /* FIXME: We may want to optimize by checking lr_most_restr */
 693         if (!list_empty(&res->lr_converting)) {
 694                 ldlm_resource_add_lock(res, res->lr_waiting.prev, lock);
 695                 *flags |= LDLM_FL_BLOCK_CONV;
 696                 GOTO(out, ELDLM_OK);
 697         }
 698         if (!list_empty(&res->lr_waiting)) {
 699                 ldlm_resource_add_lock(res, res->lr_waiting.prev, lock);
 700                 *flags |= LDLM_FL_BLOCK_WAIT;
 701                 GOTO(out, ELDLM_OK);
 702         }
 703         if (!ldlm_lock_compat(lock,0)) {
 704                 ldlm_resource_add_lock(res, res->lr_waiting.prev, lock);
 705                 *flags |= LDLM_FL_BLOCK_GRANTED;
 706                 GOTO(out, ELDLM_OK);
 707         }
 708
 709         ldlm_grant_lock(lock);
 710         EXIT;
 711  out:
 712         /* Don't set 'completion_ast' until here so that if the lock is granted
 713          * immediately we don't do an unnecessary completion call. */
 714         lock->l_completion_ast = completion;
 715         return ELDLM_OK;
 716 }
 717
 718 /* Must be called with namespace taken: queue is waiting or converting. */
 719 static int ldlm_reprocess_queue(struct ldlm_resource *res,
 720                                 struct list_head *queue)
 721 {
 722         struct list_head *tmp, *pos;
 723         ENTRY;
 724
 725         list_for_each_safe(tmp, pos, queue) {
 726                 struct ldlm_lock *pending;
 727                 pending = list_entry(tmp, struct ldlm_lock, l_res_link);
 728
 729                 CDEBUG(D_INFO, "Reprocessing lock %p\n", pending);
 730
 731                 if (!ldlm_lock_compat(pending, 1))
 732                         RETURN(1);
 733
 734                 list_del_init(&pending->l_res_link);
 735                 ldlm_grant_lock(pending);
 736
 737                 ldlm_lock_addref(pending, pending->l_req_mode);
 738                 ldlm_lock_decref(pending, pending->l_granted_mode);
 739         }
 740
 741         RETURN(0);
 742 }
 743
 744 static void ldlm_send_delayed_asts(struct list_head *rpc_list)
 745 {
 746         struct list_head *tmp, *pos;
 747         ENTRY;
 748
 749         list_for_each_safe(tmp, pos, rpc_list) {
 750                 int rc;
 751                 struct ptlrpc_request *req =
 752                         list_entry(tmp, struct ptlrpc_request, rq_multi);
 753
 754                 CDEBUG(D_INFO, "Sending callback.\n");
 755
 756                 rc = ptlrpc_queue_wait(req);
 757                 rc = ptlrpc_check_status(req, rc);
 758                 ptlrpc_free_req(req);
 759                 if (rc)
 760                         CERROR("Callback send failed: %d\n", rc);
 761         }
 762         EXIT;
 763 }
 764
 765 /* Must be called with resource->lr_lock not taken. */
 766 void ldlm_reprocess_all(struct ldlm_resource *res)
 767 {
 768         struct list_head rpc_list = LIST_HEAD_INIT(rpc_list);
 769         ENTRY;
 770
 771         /* Local lock trees don't get reprocessed. */
 772         if (res->lr_namespace->ns_client) {
 773                 EXIT;
 774                 return;
 775         }
 776
 777         l_lock(&res->lr_namespace->ns_lock);
 778         res->lr_tmp = &rpc_list;
 779
 780         ldlm_reprocess_queue(res, &res->lr_converting);
 781         if (list_empty(&res->lr_converting))
 782                 ldlm_reprocess_queue(res, &res->lr_waiting);
 783
 784         res->lr_tmp = NULL;
 785         l_unlock(&res->lr_namespace->ns_lock);
 786
 787         ldlm_send_delayed_asts(&rpc_list);
 788         EXIT;
 789 }
 790
 791 /* Must be called with lock and lock->l_resource unlocked */
 792 void ldlm_lock_cancel(struct ldlm_lock *lock)
 793 {
 794         struct ldlm_resource *res;
 795         struct ldlm_namespace *ns;
 796         ENTRY;
 797
 798         res = lock->l_resource;
 799         ns = res->lr_namespace;
 800
 801         l_lock(&ns->ns_lock);
 802         if (lock->l_readers || lock->l_writers)
 803                 CDEBUG(D_INFO, "lock still has references (%d readers, %d "
 804                        "writers)\n", lock->l_readers, lock->l_writers);
 805
 806         ldlm_resource_unlink_lock(lock);
 807         ldlm_lock_destroy(lock);
 808         l_unlock(&ns->ns_lock);
 809 }
 810
 811 /* Must be called with lock and lock->l_resource unlocked */
 812 struct ldlm_resource *ldlm_convert(struct lustre_handle *lockh, int new_mode, int *flags)
 813 {
 814         struct ldlm_lock *lock;
 815         struct ldlm_resource *res;
 816         struct ldlm_namespace *ns;
 817         ENTRY;
 818
 819         lock = lustre_handle2object(lockh);
 820         res = lock->l_resource;
 821         ns = res->lr_namespace;
 822
 823         l_lock(&ns->ns_lock);
 824
 825         lock->l_req_mode = new_mode;
 826         ldlm_resource_unlink_lock(lock);
 827
 828         /* If this is a local resource, put it on the appropriate list. */
 829         if (res->lr_namespace->ns_client) {
 830                 if (*flags & (LDLM_FL_BLOCK_CONV | LDLM_FL_BLOCK_GRANTED))
 831                         ldlm_resource_add_lock(res, res->lr_converting.prev,
 832                                                lock);
 833                 else {
 834                         ldlm_grant_lock(lock);
 835                         /* FIXME: completion handling not with ns_lock held ! */
 836                         wake_up(&lock->l_waitq);
 837                 }
 838         } else {
 839                 list_add(&lock->l_res_link, res->lr_converting.prev);
 840         }
 841
 842         l_unlock(&ns->ns_lock);
 843
 844         RETURN(res);
 845 }
 846
 847 void ldlm_lock_dump(struct ldlm_lock *lock)
 848 {
 849         char ver[128];
 850
 851         if (!(portal_debug & D_OTHER))
 852                 return;
 853
 854         if (RES_VERSION_SIZE != 4)
 855                 LBUG();
 856
 857         if (!lock) {
 858                 CDEBUG(D_OTHER, "  NULL LDLM lock\n");
 859                 return;
 860         }
 861
 862         snprintf(ver, sizeof(ver), "%x %x %x %x",
 863                  lock->l_version[0], lock->l_version[1],
 864                  lock->l_version[2], lock->l_version[3]);
 865
 866         CDEBUG(D_OTHER, "  -- Lock dump: %p (%s)\n", lock, ver);
 867         CDEBUG(D_OTHER, "  Parent: %p\n", lock->l_parent);
 868         CDEBUG(D_OTHER, "  Resource: %p (%Ld)\n", lock->l_resource,
 869                lock->l_resource->lr_name[0]);
 870         CDEBUG(D_OTHER, "  Requested mode: %d, granted mode: %d\n",
 871                (int)lock->l_req_mode, (int)lock->l_granted_mode);
 872         CDEBUG(D_OTHER, "  Readers: %u ; Writers; %u\n",
 873                lock->l_readers, lock->l_writers);
 874         if (lock->l_resource->lr_type == LDLM_EXTENT)
 875                 CDEBUG(D_OTHER, "  Extent: %Lu -> %Lu\n",
 876                        (unsigned long long)lock->l_extent.start,
 877                        (unsigned long long)lock->l_extent.end);
 878 }