lustre/ldlm/ldlm_resource.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * Copyright (C) 2002, 2003 Cluster File Systems, Inc.
   5  *   Author: Phil Schwan <phil@clusterfs.com>
   6  *   Author: Peter Braam <braam@clusterfs.com>
   7  *
   8  *   This file is part of the Lustre file system, http://www.lustre.org
   9  *   Lustre is a trademark of Cluster File Systems, Inc.
  10  *
  11  *   You may have signed or agreed to another license before downloading
  12  *   this software.  If so, you are bound by the terms and conditions
  13  *   of that agreement, and the following does not apply to you.  See the
  14  *   LICENSE file included with this distribution for more information.
  15  *
  16  *   If you did not agree to a different license, then this copy of Lustre
  17  *   is open source software; you can redistribute it and/or modify it
  18  *   under the terms of version 2 of the GNU General Public License as
  19  *   published by the Free Software Foundation.
  20  *
  21  *   In either case, Lustre is distributed in the hope that it will be
  22  *   useful, but WITHOUT ANY WARRANTY; without even the implied warranty
  23  *   of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  *   license text for more details.
  25  */
  26
  27 #define DEBUG_SUBSYSTEM S_LDLM
  28 #ifdef __KERNEL__
  29 # include <lustre_dlm.h>
  30 #else
  31 # include <liblustre.h>
  32 #endif
  33
  34 #include <obd_class.h>
  35 #include "ldlm_internal.h"
  36
  37 cfs_mem_cache_t *ldlm_resource_slab, *ldlm_lock_slab;
  38
  39 struct semaphore ldlm_namespace_lock;
  40 struct list_head ldlm_namespace_list = CFS_LIST_HEAD_INIT(ldlm_namespace_list);
  41 cfs_proc_dir_entry_t *ldlm_type_proc_dir = NULL;
  42 cfs_proc_dir_entry_t *ldlm_ns_proc_dir = NULL;
  43 cfs_proc_dir_entry_t *ldlm_svc_proc_dir = NULL;
  44
  45 #ifdef LPROCFS
  46 static int ldlm_proc_dump_ns(struct file *file, const char *buffer,
  47                              unsigned long count, void *data)
  48 {
  49         ldlm_dump_all_namespaces(D_DLMTRACE);
  50         RETURN(count);
  51 }
  52
  53 int ldlm_proc_setup(void)
  54 {
  55         int rc;
  56         struct lprocfs_vars list[] = {
  57                 { "dump_namespaces", NULL, ldlm_proc_dump_ns, NULL },
  58                 { NULL }};
  59         ENTRY;
  60         LASSERT(ldlm_ns_proc_dir == NULL);
  61
  62         ldlm_type_proc_dir = lprocfs_register(OBD_LDLM_DEVICENAME,
  63                                               proc_lustre_root,
  64                                               NULL, NULL);
  65         if (IS_ERR(ldlm_type_proc_dir)) {
  66                 CERROR("LProcFS failed in ldlm-init\n");
  67                 rc = PTR_ERR(ldlm_type_proc_dir);
  68                 GOTO(err, rc);
  69         }
  70
  71         ldlm_ns_proc_dir = lprocfs_register("namespaces",
  72                                             ldlm_type_proc_dir,
  73                                             NULL, NULL);
  74         if (IS_ERR(ldlm_ns_proc_dir)) {
  75                 CERROR("LProcFS failed in ldlm-init\n");
  76                 rc = PTR_ERR(ldlm_ns_proc_dir);
  77                 GOTO(err_type, rc);
  78         }
  79
  80         ldlm_svc_proc_dir = lprocfs_register("services",
  81                                             ldlm_type_proc_dir,
  82                                             NULL, NULL);
  83         if (IS_ERR(ldlm_svc_proc_dir)) {
  84                 CERROR("LProcFS failed in ldlm-init\n");
  85                 rc = PTR_ERR(ldlm_svc_proc_dir);
  86                 GOTO(err_ns, rc);
  87         }
  88
  89         rc = lprocfs_add_vars(ldlm_type_proc_dir, list, NULL);
  90
  91         RETURN(0);
  92
  93 err_ns:
  94         lprocfs_remove(&ldlm_ns_proc_dir);
  95 err_type:
  96         lprocfs_remove(&ldlm_type_proc_dir);
  97 err:
  98         ldlm_svc_proc_dir = NULL;
  99         RETURN(rc);
 100 }
 101
 102 void ldlm_proc_cleanup(void)
 103 {
 104         if (ldlm_svc_proc_dir)
 105                 lprocfs_remove(&ldlm_svc_proc_dir);
 106
 107         if (ldlm_ns_proc_dir)
 108                 lprocfs_remove(&ldlm_ns_proc_dir);
 109
 110         if (ldlm_type_proc_dir)
 111                 lprocfs_remove(&ldlm_type_proc_dir);
 112 }
 113
 114 static int lprocfs_uint_rd(char *page, char **start, off_t off,
 115                            int count, int *eof, void *data)
 116 {
 117         unsigned int *temp = (unsigned int *)data;
 118         return snprintf(page, count, "%u\n", *temp);
 119 }
 120
 121 static int lprocfs_read_lru_size(char *page, char **start, off_t off,
 122                                  int count, int *eof, void *data)
 123 {
 124         struct ldlm_namespace *ns = data;
 125         return lprocfs_uint_rd(page, start, off, count, eof,
 126                                &ns->ns_max_unused);
 127 }
 128
 129 #define MAX_STRING_SIZE 128
 130 static int lprocfs_write_lru_size(struct file *file, const char *buffer,
 131                                   unsigned long count, void *data)
 132 {
 133         struct ldlm_namespace *ns = data;
 134         char dummy[MAX_STRING_SIZE + 1], *end;
 135         unsigned long tmp;
 136
 137         dummy[MAX_STRING_SIZE] = '\0';
 138         if (copy_from_user(dummy, buffer, MAX_STRING_SIZE))
 139                 return -EFAULT;
 140
 141         if (count == 6 && memcmp(dummy, "clear", 5) == 0) {
 142                 CDEBUG(D_DLMTRACE,
 143                        "dropping all unused locks from namespace %s\n",
 144                        ns->ns_name);
 145                 tmp = ns->ns_max_unused;
 146                 ns->ns_max_unused = 0;
 147                 ldlm_cancel_lru(ns, LDLM_SYNC);
 148                 ns->ns_max_unused = tmp;
 149                 return count;
 150         }
 151
 152         tmp = simple_strtoul(dummy, &end, 0);
 153         if (tmp == 0 && *end) {
 154                 CERROR("invalid value written\n");
 155                 return -EINVAL;
 156         }
 157
 158         CDEBUG(D_DLMTRACE, "changing namespace %s max_unused from %u to %u\n",
 159                ns->ns_name, ns->ns_max_unused, (unsigned int)tmp);
 160         ns->ns_max_unused = (unsigned int)tmp;
 161
 162         ldlm_cancel_lru(ns, LDLM_ASYNC);
 163
 164         return count;
 165 }
 166
 167 void ldlm_proc_namespace(struct ldlm_namespace *ns)
 168 {
 169         struct lprocfs_vars lock_vars[2];
 170         char lock_name[MAX_STRING_SIZE + 1];
 171
 172         LASSERT(ns != NULL);
 173         LASSERT(ns->ns_name != NULL);
 174
 175         lock_name[MAX_STRING_SIZE] = '\0';
 176
 177         memset(lock_vars, 0, sizeof(lock_vars));
 178         lock_vars[0].name = lock_name;
 179
 180         snprintf(lock_name, MAX_STRING_SIZE, "%s/resource_count", ns->ns_name);
 181         lock_vars[0].data = &ns->ns_refcount;
 182         lock_vars[0].read_fptr = lprocfs_rd_atomic;
 183         lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
 184
 185         snprintf(lock_name, MAX_STRING_SIZE, "%s/lock_count", ns->ns_name);
 186         lock_vars[0].data = &ns->ns_locks;
 187         lock_vars[0].read_fptr = lprocfs_rd_u64;
 188         lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
 189
 190         if (ns->ns_client) {
 191                 snprintf(lock_name, MAX_STRING_SIZE, "%s/lock_unused_count",
 192                          ns->ns_name);
 193                 lock_vars[0].data = &ns->ns_nr_unused;
 194                 lock_vars[0].read_fptr = lprocfs_uint_rd;
 195                 lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
 196
 197                 snprintf(lock_name, MAX_STRING_SIZE, "%s/lru_size",
 198                          ns->ns_name);
 199                 lock_vars[0].data = ns;
 200                 lock_vars[0].read_fptr = lprocfs_read_lru_size;
 201                 lock_vars[0].write_fptr = lprocfs_write_lru_size;
 202                 lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
 203         }
 204 }
 205 #undef MAX_STRING_SIZE
 206 #else
 207 #define ldlm_proc_namespace(ns) do {} while (0)
 208 #endif /* LPROCFS */
 209
 210 struct ldlm_namespace *ldlm_namespace_new(char *name, __u32 client)
 211 {
 212         struct ldlm_namespace *ns = NULL;
 213         struct list_head *bucket;
 214         int rc;
 215         ENTRY;
 216
 217         rc = ldlm_get_ref();
 218         if (rc) {
 219                 CERROR("ldlm_get_ref failed: %d\n", rc);
 220                 RETURN(NULL);
 221         }
 222
 223         OBD_ALLOC(ns, sizeof(*ns));
 224         if (!ns)
 225                 GOTO(out_ref, NULL);
 226
 227         OBD_VMALLOC(ns->ns_hash, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 228         if (!ns->ns_hash)
 229                 GOTO(out_ns, NULL);
 230
 231         OBD_ALLOC(ns->ns_name, strlen(name) + 1);
 232         if (!ns->ns_name)
 233                 GOTO(out_hash, NULL);
 234
 235         strcpy(ns->ns_name, name);
 236
 237         CFS_INIT_LIST_HEAD(&ns->ns_root_list);
 238         ns->ns_refcount = 0;
 239         ns->ns_client = client;
 240         spin_lock_init(&ns->ns_hash_lock);
 241         atomic_set(&ns->ns_locks, 0);
 242         ns->ns_resources = 0;
 243         cfs_waitq_init(&ns->ns_waitq);
 244
 245         for (bucket = ns->ns_hash + RES_HASH_SIZE - 1; bucket >= ns->ns_hash;
 246              bucket--)
 247                 CFS_INIT_LIST_HEAD(bucket);
 248
 249         CFS_INIT_LIST_HEAD(&ns->ns_unused_list);
 250         ns->ns_nr_unused = 0;
 251         ns->ns_max_unused = LDLM_DEFAULT_LRU_SIZE;
 252         spin_lock_init(&ns->ns_unused_lock);
 253
 254         mutex_down(&ldlm_namespace_lock);
 255         list_add(&ns->ns_list_chain, &ldlm_namespace_list);
 256         mutex_up(&ldlm_namespace_lock);
 257         ldlm_proc_namespace(ns);
 258         RETURN(ns);
 259
 260 out_hash:
 261         POISON(ns->ns_hash, 0x5a, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 262         OBD_VFREE(ns->ns_hash, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 263 out_ns:
 264         OBD_FREE(ns, sizeof(*ns));
 265 out_ref:
 266         ldlm_put_ref(0);
 267         RETURN(NULL);
 268 }
 269
 270 extern struct ldlm_lock *ldlm_lock_get(struct ldlm_lock *lock);
 271
 272 /* If flags contains FL_LOCAL_ONLY, don't try to tell the server, just cleanup.
 273  * This is currently only used for recovery, and we make certain assumptions
 274  * as a result--notably, that we shouldn't cancel locks with refs. -phil
 275  *
 276  * Called with the ns_lock held. */
 277 static void cleanup_resource(struct ldlm_resource *res, struct list_head *q,
 278                              int flags)
 279 {
 280         struct list_head *tmp;
 281         int rc = 0, client = res->lr_namespace->ns_client;
 282         int local_only = (flags & LDLM_FL_LOCAL_ONLY);
 283         ENTRY;
 284
 285
 286         do {
 287                 struct ldlm_lock *lock = NULL;
 288
 289                 /* first, we look for non-cleaned-yet lock
 290                  * all cleaned locks are marked by CLEANED flag */
 291                 lock_res(res);
 292                 list_for_each(tmp, q) {
 293                         lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 294                         if (lock->l_flags & LDLM_FL_CLEANED) {
 295                                 lock = NULL;
 296                                 continue;
 297                         }
 298                         LDLM_LOCK_GET(lock);
 299                         lock->l_flags |= LDLM_FL_CLEANED;
 300                         break;
 301                 }
 302
 303                 if (lock == NULL) {
 304                         unlock_res(res);
 305                         break;
 306                 }
 307
 308                 /* Set CBPENDING so nothing in the cancellation path
 309                  * can match this lock */
 310                 lock->l_flags |= LDLM_FL_CBPENDING;
 311                 lock->l_flags |= LDLM_FL_FAILED;
 312                 lock->l_flags |= flags;
 313
 314                 if (local_only && (lock->l_readers || lock->l_writers)) {
 315                         /* This is a little bit gross, but much better than the
 316                          * alternative: pretend that we got a blocking AST from
 317                          * the server, so that when the lock is decref'd, it
 318                          * will go away ... */
 319                         /* ... without sending a CANCEL message. */
 320                         lock->l_flags |= LDLM_FL_LOCAL_ONLY;
 321                         unlock_res(res);
 322                         LDLM_DEBUG(lock, "setting FL_LOCAL_ONLY");
 323                         if (lock->l_completion_ast)
 324                                 lock->l_completion_ast(lock, 0, NULL);
 325                         LDLM_LOCK_PUT(lock);
 326                         continue;
 327                 }
 328
 329                 if (client) {
 330                         struct lustre_handle lockh;
 331
 332                         unlock_res(res);
 333                         ldlm_lock2handle(lock, &lockh);
 334                         if (!local_only) {
 335                                 rc = ldlm_cli_cancel(&lockh);
 336                                 if (rc)
 337                                         CERROR("ldlm_cli_cancel: %d\n", rc);
 338                         }
 339                         /* Force local cleanup on errors, too. */
 340                         if (local_only || rc != ELDLM_OK)
 341                                 ldlm_lock_cancel(lock);
 342                 } else {
 343                         ldlm_resource_unlink_lock(lock);
 344                         unlock_res(res);
 345                         LDLM_DEBUG(lock, "Freeing a lock still held by a "
 346                                    "client node");
 347                         ldlm_lock_destroy(lock);
 348                 }
 349                 LDLM_LOCK_PUT(lock);
 350         } while (1);
 351
 352         EXIT;
 353 }
 354
 355 int ldlm_namespace_cleanup(struct ldlm_namespace *ns, int flags)
 356 {
 357         struct list_head *tmp;
 358         int i;
 359
 360         if (ns == NULL) {
 361                 CDEBUG(D_INFO, "NULL ns, skipping cleanup\n");
 362                 return ELDLM_OK;
 363         }
 364
 365         for (i = 0; i < RES_HASH_SIZE; i++) {
 366                 spin_lock(&ns->ns_hash_lock);
 367                 tmp = ns->ns_hash[i].next;
 368                 while (tmp != &(ns->ns_hash[i])) {
 369                         struct ldlm_resource *res;
 370                         res = list_entry(tmp, struct ldlm_resource, lr_hash);
 371                         ldlm_resource_getref(res);
 372                         spin_unlock(&ns->ns_hash_lock);
 373
 374                         cleanup_resource(res, &res->lr_granted, flags);
 375                         cleanup_resource(res, &res->lr_converting, flags);
 376                         cleanup_resource(res, &res->lr_waiting, flags);
 377
 378                         spin_lock(&ns->ns_hash_lock);
 379                         tmp  = tmp->next;
 380
 381                         /* XXX: former stuff caused issues in case of race
 382                          * between ldlm_namespace_cleanup() and lockd() when
 383                          * client gets blocking ast when lock gets distracted by
 384                          * server. This is 1_4 branch solution, let's see how
 385                          * will it behave. */
 386                         if (!ldlm_resource_putref_locked(res))
 387                                 CDEBUG(D_INFO,
 388                                        "Namespace %s resource refcount nonzero "
 389                                        "(%d) after lock cleanup; forcing cleanup.\n",
 390                                        ns->ns_name, atomic_read(&res->lr_refcount));
 391                 }
 392                 spin_unlock(&ns->ns_hash_lock);
 393         }
 394
 395         return ELDLM_OK;
 396 }
 397
 398 /* Cleanup, but also free, the namespace */
 399 int ldlm_namespace_free(struct ldlm_namespace *ns, int force)
 400 {
 401         ENTRY;
 402         if (!ns)
 403                 RETURN(ELDLM_OK);
 404
 405         mutex_down(&ldlm_namespace_lock);
 406         list_del(&ns->ns_list_chain);
 407         mutex_up(&ldlm_namespace_lock);
 408
 409         /* At shutdown time, don't call the cancellation callback */
 410         ldlm_namespace_cleanup(ns, 0);
 411
 412 #ifdef LPROCFS
 413         {
 414                 struct proc_dir_entry *dir;
 415                 dir = lprocfs_srch(ldlm_ns_proc_dir, ns->ns_name);
 416                 if (dir == NULL) {
 417                         CERROR("dlm namespace %s has no procfs dir?\n",
 418                                ns->ns_name);
 419                 } else {
 420                         lprocfs_remove(&dir);
 421                 }
 422         }
 423 #endif
 424
 425         if (ns->ns_refcount > 0) {
 426                 struct l_wait_info lwi = LWI_INTR(LWI_ON_SIGNAL_NOOP, NULL);
 427                 int rc;
 428                 CDEBUG(D_DLMTRACE,
 429                        "dlm namespace %s free waiting on refcount %d\n",
 430                        ns->ns_name, ns->ns_refcount);
 431                 rc = l_wait_event(ns->ns_waitq,
 432                                   ns->ns_refcount == 0, &lwi);
 433                 if (ns->ns_refcount)
 434                         LCONSOLE_ERROR("Lock manager: wait for %s namespace "
 435                                        "cleanup aborted with %d resources in "
 436                                        "use. (%d)\nI'm going to try to clean "
 437                                        "up anyway, but I might need a reboot "
 438                                        "of this node.\n", ns->ns_name,
 439                                        (int) ns->ns_refcount, rc);
 440                 CDEBUG(D_DLMTRACE,
 441                        "dlm namespace %s free done waiting\n", ns->ns_name);
 442         }
 443
 444         POISON(ns->ns_hash, 0x5a, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 445         OBD_VFREE(ns->ns_hash, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 446         OBD_FREE(ns->ns_name, strlen(ns->ns_name) + 1);
 447         OBD_FREE(ns, sizeof(*ns));
 448
 449         ldlm_put_ref(force);
 450
 451         return ELDLM_OK;
 452 }
 453
 454 static __u32 ldlm_hash_fn(struct ldlm_resource *parent, struct ldlm_res_id name)
 455 {
 456         __u32 hash = 0;
 457         int i;
 458
 459         for (i = 0; i < RES_NAME_SIZE; i++)
 460                 hash += name.name[i];
 461
 462         hash += (__u32)((unsigned long)parent >> 4);
 463
 464         return (hash & RES_HASH_MASK);
 465 }
 466
 467 static struct ldlm_resource *ldlm_resource_new(void)
 468 {
 469         struct ldlm_resource *res;
 470
 471         OBD_SLAB_ALLOC(res, ldlm_resource_slab, CFS_ALLOC_IO, sizeof *res);
 472         if (res == NULL)
 473                 return NULL;
 474
 475         memset(res, 0, sizeof(*res));
 476
 477         CFS_INIT_LIST_HEAD(&res->lr_children);
 478         CFS_INIT_LIST_HEAD(&res->lr_childof);
 479         CFS_INIT_LIST_HEAD(&res->lr_granted);
 480         CFS_INIT_LIST_HEAD(&res->lr_converting);
 481         CFS_INIT_LIST_HEAD(&res->lr_waiting);
 482         atomic_set(&res->lr_refcount, 1);
 483         spin_lock_init(&res->lr_lock);
 484
 485         /* one who creates the resource must unlock
 486          * the semaphore after lvb initialization */
 487         init_MUTEX_LOCKED(&res->lr_lvb_sem);
 488
 489         return res;
 490 }
 491
 492 /* must be called with hash lock held */
 493 static struct ldlm_resource *
 494 ldlm_resource_find(struct ldlm_namespace *ns, struct ldlm_res_id name, __u32 hash)
 495 {
 496         struct list_head *bucket, *tmp;
 497         struct ldlm_resource *res;
 498
 499         LASSERT_SPIN_LOCKED(&ns->ns_hash_lock);
 500         bucket = ns->ns_hash + hash;
 501
 502         list_for_each(tmp, bucket) {
 503                 res = list_entry(tmp, struct ldlm_resource, lr_hash);
 504                 if (memcmp(&res->lr_name, &name, sizeof(res->lr_name)) == 0)
 505                         return res;
 506         }
 507
 508         return NULL;
 509 }
 510
 511 /* Args: locked namespace
 512  * Returns: newly-allocated, referenced, unlocked resource */
 513 static struct ldlm_resource *
 514 ldlm_resource_add(struct ldlm_namespace *ns, struct ldlm_resource *parent,
 515                   struct ldlm_res_id name, __u32 hash, ldlm_type_t type)
 516 {
 517         struct list_head *bucket;
 518         struct ldlm_resource *res, *old_res;
 519         ENTRY;
 520
 521         LASSERTF(type >= LDLM_MIN_TYPE && type < LDLM_MAX_TYPE,
 522                  "type: %d\n", type);
 523
 524         res = ldlm_resource_new();
 525         if (!res)
 526                 RETURN(NULL);
 527
 528         res->lr_name = name;
 529         res->lr_namespace = ns;
 530         res->lr_type = type;
 531         res->lr_most_restr = LCK_NL;
 532
 533         spin_lock(&ns->ns_hash_lock);
 534         old_res = ldlm_resource_find(ns, name, hash);
 535         if (old_res) {
 536                 /* someone won the race and added the resource before */
 537                 ldlm_resource_getref(old_res);
 538                 spin_unlock(&ns->ns_hash_lock);
 539                 OBD_SLAB_FREE(res, ldlm_resource_slab, sizeof *res);
 540                 /* synchronize WRT resource creation */
 541                 if (ns->ns_lvbo && ns->ns_lvbo->lvbo_init) {
 542                         down(&old_res->lr_lvb_sem);
 543                         up(&old_res->lr_lvb_sem);
 544                 }
 545                 RETURN(old_res);
 546         }
 547
 548         /* we won! let's add the resource */
 549         bucket = ns->ns_hash + hash;
 550         list_add(&res->lr_hash, bucket);
 551         ns->ns_resources++;
 552         ns->ns_refcount++;
 553
 554         if (parent == NULL) {
 555                 list_add(&res->lr_childof, &ns->ns_root_list);
 556         } else {
 557                 res->lr_parent = parent;
 558                 list_add(&res->lr_childof, &parent->lr_children);
 559         }
 560         spin_unlock(&ns->ns_hash_lock);
 561
 562         if (ns->ns_lvbo && ns->ns_lvbo->lvbo_init) {
 563                 int rc;
 564
 565                 OBD_FAIL_TIMEOUT(OBD_FAIL_LDLM_CREATE_RESOURCE, 2);
 566                 rc = ns->ns_lvbo->lvbo_init(res);
 567                 if (rc)
 568                         CERROR("lvbo_init failed for resource "
 569                                LPU64": rc %d\n", name.name[0], rc);
 570                 /* we create resource with locked lr_lvb_sem */
 571                 up(&res->lr_lvb_sem);
 572         }
 573
 574         RETURN(res);
 575 }
 576
 577 /* Args: unlocked namespace
 578  * Locks: takes and releases ns->ns_lock and res->lr_lock
 579  * Returns: referenced, unlocked ldlm_resource or NULL */
 580 struct ldlm_resource *
 581 ldlm_resource_get(struct ldlm_namespace *ns, struct ldlm_resource *parent,
 582                   struct ldlm_res_id name, ldlm_type_t type, int create)
 583 {
 584         __u32 hash = ldlm_hash_fn(parent, name);
 585         struct ldlm_resource *res = NULL;
 586         ENTRY;
 587
 588         LASSERT(ns != NULL);
 589         LASSERT(ns->ns_hash != NULL);
 590         LASSERT(name.name[0] != 0);
 591
 592         spin_lock(&ns->ns_hash_lock);
 593         res = ldlm_resource_find(ns, name, hash);
 594         if (res) {
 595                 ldlm_resource_getref(res);
 596                 spin_unlock(&ns->ns_hash_lock);
 597                 /* synchronize WRT resource creation */
 598                 if (ns->ns_lvbo && ns->ns_lvbo->lvbo_init) {
 599                         down(&res->lr_lvb_sem);
 600                         up(&res->lr_lvb_sem);
 601                 }
 602                 RETURN(res);
 603         }
 604         spin_unlock(&ns->ns_hash_lock);
 605
 606         if (create == 0)
 607                 RETURN(NULL);
 608
 609         res = ldlm_resource_add(ns, parent, name, hash, type);
 610         RETURN(res);
 611 }
 612
 613 struct ldlm_resource *ldlm_resource_getref(struct ldlm_resource *res)
 614 {
 615         LASSERT(res != NULL);
 616         LASSERT(res != LP_POISON);
 617         atomic_inc(&res->lr_refcount);
 618         CDEBUG(D_INFO, "getref res: %p count: %d\n", res,
 619                atomic_read(&res->lr_refcount));
 620         return res;
 621 }
 622
 623 void __ldlm_resource_putref_final(struct ldlm_resource *res)
 624 {
 625         struct ldlm_namespace *ns = res->lr_namespace;
 626
 627         LASSERT_SPIN_LOCKED(&ns->ns_hash_lock);
 628
 629         if (!list_empty(&res->lr_granted)) {
 630                 ldlm_resource_dump(D_ERROR, res);
 631                 LBUG();
 632         }
 633
 634         if (!list_empty(&res->lr_converting)) {
 635                 ldlm_resource_dump(D_ERROR, res);
 636                 LBUG();
 637         }
 638
 639         if (!list_empty(&res->lr_waiting)) {
 640                 ldlm_resource_dump(D_ERROR, res);
 641                 LBUG();
 642         }
 643
 644         if (!list_empty(&res->lr_children)) {
 645                 ldlm_resource_dump(D_ERROR, res);
 646                 LBUG();
 647         }
 648
 649         ns->ns_refcount--;
 650         list_del_init(&res->lr_hash);
 651         list_del_init(&res->lr_childof);
 652
 653         ns->ns_resources--;
 654         if (ns->ns_resources == 0)
 655                 wake_up(&ns->ns_waitq);
 656 }
 657
 658 /* Returns 1 if the resource was freed, 0 if it remains. */
 659 int ldlm_resource_putref(struct ldlm_resource *res)
 660 {
 661         struct ldlm_namespace *ns = res->lr_namespace;
 662         int rc = 0;
 663         ENTRY;
 664
 665         CDEBUG(D_INFO, "putref res: %p count: %d\n", res,
 666                atomic_read(&res->lr_refcount) - 1);
 667         LASSERT(atomic_read(&res->lr_refcount) > 0);
 668         LASSERT(atomic_read(&res->lr_refcount) < LI_POISON);
 669
 670         LASSERT(atomic_read(&res->lr_refcount) >= 0);
 671         if (atomic_dec_and_lock(&res->lr_refcount, &ns->ns_hash_lock)) {
 672                 __ldlm_resource_putref_final(res);
 673                 spin_unlock(&ns->ns_hash_lock);
 674                 if (res->lr_lvb_data)
 675                         OBD_FREE(res->lr_lvb_data, res->lr_lvb_len);
 676                 OBD_SLAB_FREE(res, ldlm_resource_slab, sizeof *res);
 677                 rc = 1;
 678         }
 679
 680         RETURN(rc);
 681 }
 682
 683 /* Returns 1 if the resource was freed, 0 if it remains. */
 684 int ldlm_resource_putref_locked(struct ldlm_resource *res)
 685 {
 686         int rc = 0;
 687         ENTRY;
 688
 689         CDEBUG(D_INFO, "putref res: %p count: %d\n", res,
 690                atomic_read(&res->lr_refcount) - 1);
 691         LASSERT(atomic_read(&res->lr_refcount) > 0);
 692         LASSERT(atomic_read(&res->lr_refcount) < LI_POISON);
 693
 694         LASSERT(atomic_read(&res->lr_refcount) >= 0);
 695         if (atomic_dec_and_test(&res->lr_refcount)) {
 696                 __ldlm_resource_putref_final(res);
 697                 if (res->lr_lvb_data)
 698                         OBD_FREE(res->lr_lvb_data, res->lr_lvb_len);
 699                 OBD_SLAB_FREE(res, ldlm_resource_slab, sizeof *res);
 700                 rc = 1;
 701         }
 702
 703         RETURN(rc);
 704 }
 705
 706 void ldlm_resource_add_lock(struct ldlm_resource *res, struct list_head *head,
 707                             struct ldlm_lock *lock)
 708 {
 709         check_res_locked(res);
 710
 711         ldlm_resource_dump(D_OTHER, res);
 712         CDEBUG(D_OTHER, "About to add this lock:\n");
 713         ldlm_lock_dump(D_OTHER, lock, 0);
 714
 715         if (lock->l_destroyed) {
 716                 CDEBUG(D_OTHER, "Lock destroyed, not adding to resource\n");
 717                 return;
 718         }
 719
 720         LASSERT(list_empty(&lock->l_res_link));
 721
 722         list_add_tail(&lock->l_res_link, head);
 723 }
 724
 725 void ldlm_resource_insert_lock_after(struct ldlm_lock *original,
 726                                      struct ldlm_lock *new)
 727 {
 728         struct ldlm_resource *res = original->l_resource;
 729
 730         check_res_locked(res);
 731
 732         ldlm_resource_dump(D_OTHER, res);
 733         CDEBUG(D_OTHER, "About to insert this lock after %p:\n", original);
 734         ldlm_lock_dump(D_OTHER, new, 0);
 735
 736         if (new->l_destroyed) {
 737                 CDEBUG(D_OTHER, "Lock destroyed, not adding to resource\n");
 738                 goto out;
 739         }
 740
 741         LASSERT(list_empty(&new->l_res_link));
 742
 743         list_add(&new->l_res_link, &original->l_res_link);
 744  out:;
 745 }
 746
 747 void ldlm_resource_unlink_lock(struct ldlm_lock *lock)
 748 {
 749         check_res_locked(lock->l_resource);
 750         list_del_init(&lock->l_res_link);
 751 }
 752
 753 void ldlm_res2desc(struct ldlm_resource *res, struct ldlm_resource_desc *desc)
 754 {
 755         desc->lr_type = res->lr_type;
 756         desc->lr_name = res->lr_name;
 757 }
 758
 759 void ldlm_dump_all_namespaces(int level)
 760 {
 761         struct list_head *tmp;
 762
 763         if (!((libcfs_debug | D_ERROR) & level))
 764                 return;
 765
 766         mutex_down(&ldlm_namespace_lock);
 767
 768         list_for_each(tmp, &ldlm_namespace_list) {
 769                 struct ldlm_namespace *ns;
 770                 ns = list_entry(tmp, struct ldlm_namespace, ns_list_chain);
 771                 ldlm_namespace_dump(level, ns);
 772         }
 773
 774         mutex_up(&ldlm_namespace_lock);
 775 }
 776
 777 void ldlm_namespace_dump(int level, struct ldlm_namespace *ns)
 778 {
 779         struct list_head *tmp;
 780
 781         if (!((libcfs_debug | D_ERROR) & level))
 782                 return;
 783
 784         CDEBUG(level, "--- Namespace: %s (rc: %d, client: %d)\n",
 785                ns->ns_name, ns->ns_refcount, ns->ns_client);
 786
 787         if (cfs_time_before(cfs_time_current(), ns->ns_next_dump))
 788                 return;
 789
 790         spin_lock(&ns->ns_hash_lock);
 791         tmp = ns->ns_root_list.next;
 792         while (tmp != &ns->ns_root_list) {
 793                 struct ldlm_resource *res;
 794                 res = list_entry(tmp, struct ldlm_resource, lr_childof);
 795
 796                 ldlm_resource_getref(res);
 797                 spin_unlock(&ns->ns_hash_lock);
 798
 799                 lock_res(res);
 800                 ldlm_resource_dump(level, res);
 801                 unlock_res(res);
 802
 803                 spin_lock(&ns->ns_hash_lock);
 804                 tmp = tmp->next;
 805                 ldlm_resource_putref_locked(res);
 806         }
 807         ns->ns_next_dump = cfs_time_shift(10);
 808         spin_unlock(&ns->ns_hash_lock);
 809 }
 810
 811 void ldlm_resource_dump(int level, struct ldlm_resource *res)
 812 {
 813         struct list_head *tmp;
 814         int pos;
 815
 816         CLASSERT(RES_NAME_SIZE == 4);
 817
 818         if (!((libcfs_debug | D_ERROR) & level))
 819                 return;
 820
 821         CDEBUG(level, "--- Resource: %p ("LPU64"/"LPU64"/"LPU64"/"LPU64
 822                ") (rc: %d)\n", res, res->lr_name.name[0], res->lr_name.name[1],
 823                res->lr_name.name[2], res->lr_name.name[3],
 824                atomic_read(&res->lr_refcount));
 825
 826         if (!list_empty(&res->lr_granted)) {
 827                 pos = 0;
 828                 CDEBUG(level, "Granted locks:\n");
 829                 list_for_each(tmp, &res->lr_granted) {
 830                         struct ldlm_lock *lock;
 831                         lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 832                         ldlm_lock_dump(level, lock, ++pos);
 833                 }
 834         }
 835         if (!list_empty(&res->lr_converting)) {
 836                 pos = 0;
 837                 CDEBUG(level, "Converting locks:\n");
 838                 list_for_each(tmp, &res->lr_converting) {
 839                         struct ldlm_lock *lock;
 840                         lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 841                         ldlm_lock_dump(level, lock, ++pos);
 842                 }
 843         }
 844         if (!list_empty(&res->lr_waiting)) {
 845                 pos = 0;
 846                 CDEBUG(level, "Waiting locks:\n");
 847                 list_for_each(tmp, &res->lr_waiting) {
 848                         struct ldlm_lock *lock;
 849                         lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 850                         ldlm_lock_dump(level, lock, ++pos);
 851                 }
 852         }
 853 }