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 <linux/lustre_dlm.h>
  30 #else
  31 # include <liblustre.h>
  32 #endif
  33
  34 #include <linux/obd_class.h>
  35 #include "ldlm_internal.h"
  36
  37 kmem_cache_t *ldlm_resource_slab, *ldlm_lock_slab;
  38
  39 DECLARE_MUTEX(ldlm_namespace_lock);
  40 struct list_head ldlm_namespace_list = LIST_HEAD_INIT(ldlm_namespace_list);
  41 struct proc_dir_entry *ldlm_type_proc_dir = NULL;
  42 struct proc_dir_entry *ldlm_ns_proc_dir = NULL;
  43 struct proc_dir_entry *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_type_proc_dir = NULL;
  99         ldlm_ns_proc_dir = NULL;
 100         ldlm_svc_proc_dir = NULL;
 101         RETURN(rc);
 102 }
 103
 104 void ldlm_proc_cleanup(void)
 105 {
 106         if (ldlm_svc_proc_dir) {
 107                 lprocfs_remove(ldlm_svc_proc_dir);
 108                 ldlm_svc_proc_dir = NULL;
 109         }
 110
 111         if (ldlm_ns_proc_dir) {
 112                 lprocfs_remove(ldlm_ns_proc_dir);
 113                 ldlm_ns_proc_dir = NULL;
 114         }
 115
 116         if (ldlm_type_proc_dir) {
 117                 lprocfs_remove(ldlm_type_proc_dir);
 118                 ldlm_type_proc_dir = NULL;
 119         }
 120 }
 121
 122 static int lprocfs_uint_rd(char *page, char **start, off_t off,
 123                            int count, int *eof, void *data)
 124 {
 125         unsigned int *temp = (unsigned int *)data;
 126         return snprintf(page, count, "%u\n", *temp);
 127 }
 128
 129 static int lprocfs_read_lru_size(char *page, char **start, off_t off,
 130                                  int count, int *eof, void *data)
 131 {
 132         struct ldlm_namespace *ns = data;
 133         return lprocfs_uint_rd(page, start, off, count, eof,
 134                                &ns->ns_max_unused);
 135 }
 136
 137 #define MAX_STRING_SIZE 128
 138 static int lprocfs_write_lru_size(struct file *file, const char *buffer,
 139                                   unsigned long count, void *data)
 140 {
 141         struct ldlm_namespace *ns = data;
 142         char dummy[MAX_STRING_SIZE + 1], *end;
 143         unsigned long tmp;
 144
 145         dummy[MAX_STRING_SIZE] = '\0';
 146         if (copy_from_user(dummy, buffer, MAX_STRING_SIZE))
 147                 return -EFAULT;
 148
 149         if (count == 6 && memcmp(dummy, "clear", 5) == 0) {
 150                 CDEBUG(D_DLMTRACE,
 151                        "dropping all unused locks from namespace %s\n",
 152                        ns->ns_name);
 153                 tmp = ns->ns_max_unused;
 154                 ns->ns_max_unused = 0;
 155                 ldlm_cancel_lru(ns, LDLM_SYNC);
 156                 ns->ns_max_unused = tmp;
 157                 return count;
 158         }
 159
 160         tmp = simple_strtoul(dummy, &end, 0);
 161         if (tmp == 0 && *end) {
 162                 CERROR("invalid value written\n");
 163                 return -EINVAL;
 164         }
 165
 166         CDEBUG(D_DLMTRACE, "changing namespace %s max_unused from %u to %u\n",
 167                ns->ns_name, ns->ns_max_unused, (unsigned int)tmp);
 168         ns->ns_max_unused = (unsigned int)tmp;
 169
 170         ldlm_cancel_lru(ns, LDLM_ASYNC);
 171
 172         return count;
 173 }
 174
 175 void ldlm_proc_namespace(struct ldlm_namespace *ns)
 176 {
 177         struct lprocfs_vars lock_vars[2];
 178         char lock_name[MAX_STRING_SIZE + 1];
 179
 180         LASSERT(ns != NULL);
 181         LASSERT(ns->ns_name != NULL);
 182
 183         lock_name[MAX_STRING_SIZE] = '\0';
 184
 185         memset(lock_vars, 0, sizeof(lock_vars));
 186         lock_vars[0].name = lock_name;
 187
 188         snprintf(lock_name, MAX_STRING_SIZE, "%s/resource_count", ns->ns_name);
 189         lock_vars[0].data = &ns->ns_refcount;
 190         lock_vars[0].read_fptr = lprocfs_rd_atomic;
 191         lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
 192
 193         snprintf(lock_name, MAX_STRING_SIZE, "%s/lock_count", ns->ns_name);
 194         lock_vars[0].data = &ns->ns_locks;
 195         lock_vars[0].read_fptr = lprocfs_rd_u64;
 196         lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
 197
 198         if (ns->ns_client) {
 199                 snprintf(lock_name, MAX_STRING_SIZE, "%s/lock_unused_count",
 200                          ns->ns_name);
 201                 lock_vars[0].data = &ns->ns_nr_unused;
 202                 lock_vars[0].read_fptr = lprocfs_uint_rd;
 203                 lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
 204
 205                 snprintf(lock_name, MAX_STRING_SIZE, "%s/lru_size",
 206                          ns->ns_name);
 207                 lock_vars[0].data = ns;
 208                 lock_vars[0].read_fptr = lprocfs_read_lru_size;
 209                 lock_vars[0].write_fptr = lprocfs_write_lru_size;
 210                 lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
 211         }
 212 }
 213 #undef MAX_STRING_SIZE
 214 #else
 215 #define ldlm_proc_namespace(ns) do {} while (0)
 216 #endif /* LPROCFS */
 217
 218 struct ldlm_namespace *ldlm_namespace_new(char *name, __u32 client)
 219 {
 220         struct ldlm_namespace *ns = NULL;
 221         struct list_head *bucket;
 222         int rc;
 223         ENTRY;
 224
 225         rc = ldlm_get_ref();
 226         if (rc) {
 227                 CERROR("ldlm_get_ref failed: %d\n", rc);
 228                 RETURN(NULL);
 229         }
 230
 231         OBD_ALLOC(ns, sizeof(*ns));
 232         if (!ns)
 233                 GOTO(out_ref, NULL);
 234
 235         OBD_VMALLOC(ns->ns_hash, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 236         if (!ns->ns_hash)
 237                 GOTO(out_ns, NULL);
 238
 239         OBD_ALLOC(ns->ns_name, strlen(name) + 1);
 240         if (!ns->ns_name)
 241                 GOTO(out_hash, NULL);
 242
 243         strcpy(ns->ns_name, name);
 244
 245         INIT_LIST_HEAD(&ns->ns_root_list);
 246         l_lock_init(&ns->ns_lock);
 247         init_waitqueue_head(&ns->ns_refcount_waitq);
 248         atomic_set(&ns->ns_refcount, 0);
 249         ns->ns_client = client;
 250         spin_lock_init(&ns->ns_counter_lock);
 251         ns->ns_locks = 0;
 252
 253         for (bucket = ns->ns_hash + RES_HASH_SIZE - 1; bucket >= ns->ns_hash;
 254              bucket--)
 255                 INIT_LIST_HEAD(bucket);
 256
 257         INIT_LIST_HEAD(&ns->ns_unused_list);
 258         ns->ns_nr_unused = 0;
 259         ns->ns_max_unused = LDLM_DEFAULT_LRU_SIZE;
 260
 261         down(&ldlm_namespace_lock);
 262         list_add(&ns->ns_list_chain, &ldlm_namespace_list);
 263         up(&ldlm_namespace_lock);
 264         ldlm_proc_namespace(ns);
 265         RETURN(ns);
 266
 267 out_hash:
 268         POISON(ns->ns_hash, 0x5a, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 269         OBD_VFREE(ns->ns_hash, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 270 out_ns:
 271         OBD_FREE(ns, sizeof(*ns));
 272 out_ref:
 273         ldlm_put_ref(0);
 274         RETURN(NULL);
 275 }
 276
 277 extern struct ldlm_lock *ldlm_lock_get(struct ldlm_lock *lock);
 278
 279 /* If flags contains FL_LOCAL_ONLY, don't try to tell the server, just cleanup.
 280  * This is currently only used for recovery, and we make certain assumptions
 281  * as a result--notably, that we shouldn't cancel locks with refs. -phil
 282  *
 283  * Called with the ns_lock held. */
 284 static void cleanup_resource(struct ldlm_resource *res, struct list_head *q,
 285                              int flags)
 286 {
 287         struct list_head *tmp, *pos;
 288         int rc = 0, client = res->lr_namespace->ns_client;
 289         int local_only = (flags & LDLM_FL_LOCAL_ONLY);
 290         ENTRY;
 291
 292         list_for_each_safe(tmp, pos, q) {
 293                 struct ldlm_lock *lock;
 294                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 295                 LDLM_LOCK_GET(lock);
 296
 297                 /* Set CBPENDING so nothing in the cancellation path
 298                  * can match this lock */
 299                 lock->l_flags |= LDLM_FL_CBPENDING;
 300                 lock->l_flags |= LDLM_FL_FAILED;
 301                 lock->l_flags |= flags;
 302
 303                 if (local_only && (lock->l_readers || lock->l_writers)) {
 304                         /* This is a little bit gross, but much better than the
 305                          * alternative: pretend that we got a blocking AST from
 306                          * the server, so that when the lock is decref'd, it
 307                          * will go away ... */
 308                         /* ... without sending a CANCEL message. */
 309                         lock->l_flags |= LDLM_FL_LOCAL_ONLY;
 310                         LDLM_DEBUG(lock, "setting FL_LOCAL_ONLY");
 311                         if (lock->l_completion_ast)
 312                                 lock->l_completion_ast(lock, 0, NULL);
 313                         LDLM_LOCK_PUT(lock);
 314                         continue;
 315                 }
 316
 317                 if (client) {
 318                         struct lustre_handle lockh;
 319                         ldlm_lock2handle(lock, &lockh);
 320                         if (!local_only) {
 321                                 rc = ldlm_cli_cancel(&lockh);
 322                                 if (rc)
 323                                         CERROR("ldlm_cli_cancel: %d\n", rc);
 324                         }
 325                         /* Force local cleanup on errors, too. */
 326                         if (local_only || rc != ELDLM_OK)
 327                                 ldlm_lock_cancel(lock);
 328                 } else {
 329                         LDLM_DEBUG(lock, "Freeing a lock still held by a "
 330                                    "client node");
 331
 332                         ldlm_resource_unlink_lock(lock);
 333                         ldlm_lock_destroy(lock);
 334                 }
 335                 LDLM_LOCK_PUT(lock);
 336         }
 337         EXIT;
 338 }
 339
 340 int ldlm_namespace_cleanup(struct ldlm_namespace *ns, int flags)
 341 {
 342         int i;
 343
 344         if (ns == NULL) {
 345                 CDEBUG(D_INFO, "NULL ns, skipping cleanup\n");
 346                 return ELDLM_OK;
 347         }
 348
 349         l_lock(&ns->ns_lock);
 350         for (i = 0; i < RES_HASH_SIZE; i++) {
 351                 struct list_head *tmp, *pos;
 352                 list_for_each_safe(tmp, pos, &(ns->ns_hash[i])) {
 353                         struct ldlm_resource *res;
 354                         res = list_entry(tmp, struct ldlm_resource, lr_hash);
 355                         ldlm_resource_getref(res);
 356
 357                         cleanup_resource(res, &res->lr_granted, flags);
 358                         cleanup_resource(res, &res->lr_converting, flags);
 359                         cleanup_resource(res, &res->lr_waiting, flags);
 360
 361                         if (!ldlm_resource_putref(res)) {
 362                                 CERROR("Namespace %s resource refcount %d "
 363                                        "after lock cleanup; forcing cleanup.\n",
 364                                        ns->ns_name,
 365                                        atomic_read(&res->lr_refcount));
 366                         }
 367                 }
 368         }
 369         l_unlock(&ns->ns_lock);
 370
 371         return ELDLM_OK;
 372 }
 373
 374 /* Cleanup, but also free, the namespace */
 375 int ldlm_namespace_free(struct ldlm_namespace *ns, int force)
 376 {
 377         if (!ns)
 378                 RETURN(ELDLM_OK);
 379
 380         down(&ldlm_namespace_lock);
 381         list_del(&ns->ns_list_chain);
 382         up(&ldlm_namespace_lock);
 383
 384         /* At shutdown time, don't call the cancellation callback */
 385         ldlm_namespace_cleanup(ns, 0);
 386
 387 #ifdef LPROCFS
 388         {
 389                 struct proc_dir_entry *dir;
 390                 dir = lprocfs_srch(ldlm_ns_proc_dir, ns->ns_name);
 391                 if (dir == NULL) {
 392                         CERROR("dlm namespace %s has no procfs dir?\n",
 393                                ns->ns_name);
 394                 } else {
 395                         lprocfs_remove(dir);
 396                 }
 397         }
 398 #endif
 399
 400         if (atomic_read(&ns->ns_refcount) > 0) {
 401                 struct l_wait_info lwi = LWI_INTR(NULL, NULL);
 402                 int rc;
 403                 CDEBUG(D_DLMTRACE,
 404                        "dlm namespace %s free waiting on refcount %d\n",
 405                        ns->ns_name, atomic_read(&ns->ns_refcount));
 406                 rc = l_wait_event(ns->ns_refcount_waitq,
 407                                   atomic_read(&ns->ns_refcount) == 0, &lwi);
 408                 if (atomic_read(&ns->ns_refcount)) {
 409                         LCONSOLE_ERROR("Lock manager: wait for %s namespace "
 410                                        "cleanup aborted with %d resources in "
 411                                        "use. (%d)\nI'm going to try to clean "
 412                                        "up anyway, but I might need a reboot "
 413                                        "of this node.\n", ns->ns_name,
 414                                        atomic_read(&ns->ns_refcount), rc);
 415                 }
 416                 CDEBUG(D_DLMTRACE,
 417                        "dlm namespace %s free done waiting\n", ns->ns_name);
 418         }
 419
 420         POISON(ns->ns_hash, 0x5a, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 421         OBD_VFREE(ns->ns_hash, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 422         OBD_FREE(ns->ns_name, strlen(ns->ns_name) + 1);
 423         OBD_FREE(ns, sizeof(*ns));
 424
 425         ldlm_put_ref(force);
 426
 427         return ELDLM_OK;
 428 }
 429
 430 static __u32 ldlm_hash_fn(struct ldlm_resource *parent, struct ldlm_res_id name)
 431 {
 432         __u32 hash = 0;
 433         int i;
 434
 435         for (i = 0; i < RES_NAME_SIZE; i++)
 436                 hash += name.name[i];
 437
 438         hash += (__u32)((unsigned long)parent >> 4);
 439
 440         return (hash & RES_HASH_MASK);
 441 }
 442
 443 static struct ldlm_resource *ldlm_resource_new(void)
 444 {
 445         struct ldlm_resource *res;
 446
 447         OBD_SLAB_ALLOC(res, ldlm_resource_slab, SLAB_NOFS, sizeof *res);
 448         if (res == NULL)
 449                 return NULL;
 450
 451         memset(res, 0, sizeof(*res));
 452
 453         INIT_LIST_HEAD(&res->lr_children);
 454         INIT_LIST_HEAD(&res->lr_childof);
 455         INIT_LIST_HEAD(&res->lr_granted);
 456         INIT_LIST_HEAD(&res->lr_converting);
 457         INIT_LIST_HEAD(&res->lr_waiting);
 458         sema_init(&res->lr_lvb_sem, 1);
 459         atomic_set(&res->lr_refcount, 1);
 460
 461         return res;
 462 }
 463
 464 /* Args: locked namespace
 465  * Returns: newly-allocated, referenced, unlocked resource */
 466 static struct ldlm_resource *
 467 ldlm_resource_add(struct ldlm_namespace *ns, struct ldlm_resource *parent,
 468                   struct ldlm_res_id name, ldlm_type_t type)
 469 {
 470         struct list_head *bucket;
 471         struct ldlm_resource *res;
 472         ENTRY;
 473
 474         LASSERTF(type >= LDLM_MIN_TYPE && type < LDLM_MAX_TYPE,
 475                  "type: %d\n", type);
 476
 477         res = ldlm_resource_new();
 478         if (!res)
 479                 RETURN(NULL);
 480
 481         l_lock(&ns->ns_lock);
 482         memcpy(&res->lr_name, &name, sizeof(res->lr_name));
 483         res->lr_namespace = ns;
 484         atomic_inc(&ns->ns_refcount);
 485
 486         res->lr_type = type;
 487         res->lr_most_restr = LCK_NL;
 488
 489         bucket = ns->ns_hash + ldlm_hash_fn(parent, name);
 490         list_add(&res->lr_hash, bucket);
 491
 492         if (parent == NULL) {
 493                 list_add(&res->lr_childof, &ns->ns_root_list);
 494         } else {
 495                 res->lr_parent = parent;
 496                 list_add(&res->lr_childof, &parent->lr_children);
 497         }
 498         l_unlock(&ns->ns_lock);
 499
 500
 501         RETURN(res);
 502 }
 503
 504 /* Args: unlocked namespace
 505  * Locks: takes and releases ns->ns_lock and res->lr_lock
 506  * Returns: referenced, unlocked ldlm_resource or NULL */
 507 struct ldlm_resource *
 508 ldlm_resource_get(struct ldlm_namespace *ns, struct ldlm_resource *parent,
 509                   struct ldlm_res_id name, ldlm_type_t type, int create)
 510 {
 511         struct list_head *bucket, *tmp;
 512         struct ldlm_resource *res = NULL;
 513         ENTRY;
 514
 515         LASSERT(ns != NULL);
 516         LASSERT(ns->ns_hash != NULL);
 517         LASSERT(name.name[0] != 0);
 518
 519         l_lock(&ns->ns_lock);
 520         bucket = ns->ns_hash + ldlm_hash_fn(parent, name);
 521
 522         list_for_each(tmp, bucket) {
 523                 res = list_entry(tmp, struct ldlm_resource, lr_hash);
 524
 525                 if (memcmp(&res->lr_name, &name, sizeof(res->lr_name)) == 0) {
 526                         ldlm_resource_getref(res);
 527                         l_unlock(&ns->ns_lock);
 528                         RETURN(res);
 529                 }
 530         }
 531
 532         if (create) {
 533                 res = ldlm_resource_add(ns, parent, name, type);
 534                 if (res == NULL)
 535                         GOTO(out, NULL);
 536         } else {
 537                 res = NULL;
 538         }
 539
 540         if (create && ns->ns_lvbo && ns->ns_lvbo->lvbo_init) {
 541                 int rc;
 542
 543                 /* Although this is technically a lock inversion risk (lvb_sem
 544                  * should be taken before DLM lock), this resource was just
 545                  * created, so nobody else can take the lvb_sem yet. -p */
 546                 down(&res->lr_lvb_sem);
 547                 /* Drop the dlm lock, because lvbo_init can touch the disk */
 548                 l_unlock(&ns->ns_lock);
 549                 OBD_FAIL_TIMEOUT(OBD_FAIL_LDLM_CREATE_RESOURCE, 2);
 550                 rc = ns->ns_lvbo->lvbo_init(res);
 551                 up(&res->lr_lvb_sem);
 552                 if (rc)
 553                         CERROR("lvbo_init failed for resource "LPU64"/"LPU64
 554                                ": rc %d\n", name.name[0], name.name[1], rc);
 555         } else {
 556 out:
 557                 l_unlock(&ns->ns_lock);
 558         }
 559
 560         RETURN(res);
 561 }
 562
 563 struct ldlm_resource *ldlm_resource_getref(struct ldlm_resource *res)
 564 {
 565         LASSERT(res != NULL);
 566         LASSERT(res != LP_POISON);
 567         atomic_inc(&res->lr_refcount);
 568         CDEBUG(D_INFO, "getref res: %p count: %d\n", res,
 569                atomic_read(&res->lr_refcount));
 570         return res;
 571 }
 572
 573 /* Returns 1 if the resource was freed, 0 if it remains. */
 574 int ldlm_resource_putref(struct ldlm_resource *res)
 575 {
 576         int rc = 0;
 577         ENTRY;
 578
 579         CDEBUG(D_INFO, "putref res: %p count: %d\n", res,
 580                atomic_read(&res->lr_refcount) - 1);
 581         LASSERT(atomic_read(&res->lr_refcount) > 0);
 582         LASSERT(atomic_read(&res->lr_refcount) < LI_POISON);
 583
 584         if (atomic_dec_and_test(&res->lr_refcount)) {
 585                 struct ldlm_namespace *ns = res->lr_namespace;
 586                 ENTRY;
 587
 588                 l_lock(&ns->ns_lock);
 589
 590                 if (atomic_read(&res->lr_refcount) != 0) {
 591                         /* We lost the race. */
 592                         l_unlock(&ns->ns_lock);
 593                         RETURN(rc);
 594                 }
 595
 596                 if (!list_empty(&res->lr_granted)) {
 597                         ldlm_resource_dump(D_ERROR, res);
 598                         LBUG();
 599                 }
 600
 601                 if (!list_empty(&res->lr_converting)) {
 602                         ldlm_resource_dump(D_ERROR, res);
 603                         LBUG();
 604                 }
 605
 606                 if (!list_empty(&res->lr_waiting)) {
 607                         ldlm_resource_dump(D_ERROR, res);
 608                         LBUG();
 609                 }
 610
 611                 if (!list_empty(&res->lr_children)) {
 612                         ldlm_resource_dump(D_ERROR, res);
 613                         LBUG();
 614                 }
 615
 616                 list_del_init(&res->lr_hash);
 617                 list_del_init(&res->lr_childof);
 618                 if (res->lr_lvb_data)
 619                         OBD_FREE(res->lr_lvb_data, res->lr_lvb_len);
 620                 l_unlock(&ns->ns_lock);
 621
 622                 OBD_SLAB_FREE(res, ldlm_resource_slab, sizeof *res);
 623
 624                 if (atomic_dec_and_test(&ns->ns_refcount)) {
 625                         CDEBUG(D_DLMTRACE, "last ref on ns %s\n", ns->ns_name);
 626                         wake_up(&ns->ns_refcount_waitq);
 627                 }
 628
 629                 rc = 1;
 630                 EXIT;
 631         }
 632
 633         RETURN(rc);
 634 }
 635
 636 void ldlm_resource_add_lock(struct ldlm_resource *res, struct list_head *head,
 637                             struct ldlm_lock *lock)
 638 {
 639         l_lock(&res->lr_namespace->ns_lock);
 640
 641         ldlm_resource_dump(D_OTHER, res);
 642         CDEBUG(D_OTHER, "About to add this lock:\n");
 643         ldlm_lock_dump(D_OTHER, lock, 0);
 644
 645         if (lock->l_destroyed) {
 646                 CDEBUG(D_OTHER, "Lock destroyed, not adding to resource\n");
 647                 goto out;
 648         }
 649
 650         LASSERT(list_empty(&lock->l_res_link));
 651
 652         list_add_tail(&lock->l_res_link, head);
 653  out:
 654         l_unlock(&res->lr_namespace->ns_lock);
 655 }
 656
 657 void ldlm_resource_insert_lock_after(struct ldlm_lock *original,
 658                                      struct ldlm_lock *new)
 659 {
 660         struct ldlm_resource *res = original->l_resource;
 661
 662         l_lock(&res->lr_namespace->ns_lock);
 663
 664         ldlm_resource_dump(D_OTHER, res);
 665         CDEBUG(D_OTHER, "About to insert this lock after %p:\n", original);
 666         ldlm_lock_dump(D_OTHER, new, 0);
 667
 668         if (new->l_destroyed) {
 669                 CDEBUG(D_OTHER, "Lock destroyed, not adding to resource\n");
 670                 goto out;
 671         }
 672
 673         LASSERT(list_empty(&new->l_res_link));
 674
 675         list_add(&new->l_res_link, &original->l_res_link);
 676  out:
 677         l_unlock(&res->lr_namespace->ns_lock);
 678 }
 679
 680 void ldlm_resource_unlink_lock(struct ldlm_lock *lock)
 681 {
 682         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 683         list_del_init(&lock->l_res_link);
 684         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 685 }
 686 EXPORT_SYMBOL(ldlm_resource_unlink_lock);
 687
 688 void ldlm_res2desc(struct ldlm_resource *res, struct ldlm_resource_desc *desc)
 689 {
 690         desc->lr_type = res->lr_type;
 691         memcpy(&desc->lr_name, &res->lr_name, sizeof(desc->lr_name));
 692 }
 693
 694 void ldlm_dump_all_namespaces(int level)
 695 {
 696         struct list_head *tmp;
 697
 698         down(&ldlm_namespace_lock);
 699
 700         list_for_each(tmp, &ldlm_namespace_list) {
 701                 struct ldlm_namespace *ns;
 702                 ns = list_entry(tmp, struct ldlm_namespace, ns_list_chain);
 703                 ldlm_namespace_dump(level, ns);
 704         }
 705
 706         up(&ldlm_namespace_lock);
 707 }
 708
 709 void ldlm_namespace_dump(int level, struct ldlm_namespace *ns)
 710 {
 711         struct list_head *tmp;
 712
 713         CDEBUG(level, "--- Namespace: %s (rc: %d, client: %d)\n", ns->ns_name,
 714                atomic_read(&ns->ns_refcount), ns->ns_client);
 715
 716         l_lock(&ns->ns_lock);
 717         if (time_after(jiffies, ns->ns_next_dump)) {
 718                 list_for_each(tmp, &ns->ns_root_list) {
 719                         struct ldlm_resource *res;
 720                         res = list_entry(tmp, struct ldlm_resource, lr_childof);
 721
 722                         /* Once we have resources with children, this should
 723                          * really dump them recursively. */
 724                         ldlm_resource_dump(level, res);
 725                 }
 726                 ns->ns_next_dump = jiffies + 10 * HZ;
 727         }
 728         l_unlock(&ns->ns_lock);
 729 }
 730
 731 void ldlm_resource_dump(int level, struct ldlm_resource *res)
 732 {
 733         struct list_head *tmp;
 734         int pos;
 735
 736         if (RES_NAME_SIZE != 4)
 737                 LBUG();
 738
 739         CDEBUG(level, "--- Resource: %p ("LPU64"/"LPU64"/"LPU64"/"LPU64
 740                ") (rc: %d)\n", res, res->lr_name.name[0], res->lr_name.name[1],
 741                res->lr_name.name[2], res->lr_name.name[3],
 742                atomic_read(&res->lr_refcount));
 743
 744         if (!list_empty(&res->lr_granted)) {
 745                 pos = 0;
 746                 CDEBUG(level, "Granted locks:\n");
 747                 list_for_each(tmp, &res->lr_granted) {
 748                         struct ldlm_lock *lock;
 749                         lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 750                         ldlm_lock_dump(level, lock, ++pos);
 751                 }
 752         }
 753         if (!list_empty(&res->lr_converting)) {
 754                 pos = 0;
 755                 CDEBUG(level, "Converting locks:\n");
 756                 list_for_each(tmp, &res->lr_converting) {
 757                         struct ldlm_lock *lock;
 758                         lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 759                         ldlm_lock_dump(level, lock, ++pos);
 760                 }
 761         }
 762         if (!list_empty(&res->lr_waiting)) {
 763                 pos = 0;
 764                 CDEBUG(level, "Waiting locks:\n");
 765                 list_for_each(tmp, &res->lr_waiting) {
 766                         struct ldlm_lock *lock;
 767                         lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 768                         ldlm_lock_dump(level, lock, ++pos);
 769                 }
 770         }
 771 }