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 snprintf(page, count, "%u\n", ns->ns_max_unused);
 126 }
 127
 128 #define MAX_STRING_SIZE 128
 129 static int lprocfs_write_lru_size(struct file *file, const char *buffer,
 130                                   unsigned long count, void *data)
 131 {
 132         struct ldlm_namespace *ns = data;
 133         char dummy[MAX_STRING_SIZE + 1], *end;
 134         unsigned long tmp;
 135
 136         dummy[MAX_STRING_SIZE] = '\0';
 137         if (copy_from_user(dummy, buffer, MAX_STRING_SIZE))
 138                 return -EFAULT;
 139
 140         if (count == 6 && memcmp(dummy, "clear", 5) == 0) {
 141                 CDEBUG(D_DLMTRACE,
 142                        "dropping all unused locks from namespace %s\n",
 143                        ns->ns_name);
 144                 tmp = ns->ns_max_unused;
 145                 ns->ns_max_unused = 0;
 146                 ldlm_cancel_lru(ns, LDLM_SYNC);
 147                 ns->ns_max_unused = tmp;
 148                 return count;
 149         }
 150
 151         tmp = simple_strtoul(dummy, &end, 0);
 152         if (tmp == 0 && *end) {
 153                 CERROR("invalid value written\n");
 154                 return -EINVAL;
 155         }
 156
 157         CDEBUG(D_DLMTRACE, "changing namespace %s max_unused from %u to %u\n",
 158                ns->ns_name, ns->ns_max_unused, (unsigned int)tmp);
 159         ns->ns_max_unused = (unsigned int)tmp;
 160
 161         ldlm_cancel_lru(ns, LDLM_ASYNC);
 162
 163         return count;
 164 }
 165
 166 void ldlm_proc_namespace(struct ldlm_namespace *ns)
 167 {
 168         struct lprocfs_vars lock_vars[2];
 169         char lock_name[MAX_STRING_SIZE + 1];
 170
 171         LASSERT(ns != NULL);
 172         LASSERT(ns->ns_name != NULL);
 173
 174         lock_name[MAX_STRING_SIZE] = '\0';
 175
 176         memset(lock_vars, 0, sizeof(lock_vars));
 177         lock_vars[0].name = lock_name;
 178
 179         snprintf(lock_name, MAX_STRING_SIZE, "%s/resource_count", ns->ns_name);
 180         lock_vars[0].data = &ns->ns_refcount;
 181         lock_vars[0].read_fptr = lprocfs_rd_atomic;
 182         lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
 183
 184         snprintf(lock_name, MAX_STRING_SIZE, "%s/lock_count", ns->ns_name);
 185         lock_vars[0].data = &ns->ns_locks;
 186         lock_vars[0].read_fptr = lprocfs_rd_atomic;
 187         lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
 188
 189         if (ns->ns_client) {
 190                 snprintf(lock_name, MAX_STRING_SIZE, "%s/lock_unused_count",
 191                          ns->ns_name);
 192                 lock_vars[0].data = &ns->ns_nr_unused;
 193                 lock_vars[0].read_fptr = lprocfs_uint_rd;
 194                 lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
 195
 196                 snprintf(lock_name, MAX_STRING_SIZE, "%s/lru_size",
 197                          ns->ns_name);
 198                 lock_vars[0].data = ns;
 199                 lock_vars[0].read_fptr = lprocfs_read_lru_size;
 200                 lock_vars[0].write_fptr = lprocfs_write_lru_size;
 201                 lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
 202         }
 203 }
 204 #undef MAX_STRING_SIZE
 205 #else
 206 #define ldlm_proc_namespace(ns) do {} while (0)
 207 #endif /* LPROCFS */
 208
 209 struct ldlm_namespace *ldlm_namespace_new(char *name, __u32 client)
 210 {
 211         struct ldlm_namespace *ns = NULL;
 212         struct list_head *bucket;
 213         int rc;
 214         ENTRY;
 215
 216         rc = ldlm_get_ref();
 217         if (rc) {
 218                 CERROR("ldlm_get_ref failed: %d\n", rc);
 219                 RETURN(NULL);
 220         }
 221
 222         OBD_ALLOC(ns, sizeof(*ns));
 223         if (!ns)
 224                 GOTO(out_ref, NULL);
 225
 226         OBD_VMALLOC(ns->ns_hash, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 227         if (!ns->ns_hash)
 228                 GOTO(out_ns, NULL);
 229
 230         OBD_ALLOC(ns->ns_name, strlen(name) + 1);
 231         if (!ns->ns_name)
 232                 GOTO(out_hash, NULL);
 233
 234         strcpy(ns->ns_name, name);
 235
 236         CFS_INIT_LIST_HEAD(&ns->ns_root_list);
 237         ns->ns_refcount = 0;
 238         ns->ns_client = client;
 239         spin_lock_init(&ns->ns_hash_lock);
 240         atomic_set(&ns->ns_locks, 0);
 241         ns->ns_resources = 0;
 242         cfs_waitq_init(&ns->ns_waitq);
 243
 244         for (bucket = ns->ns_hash + RES_HASH_SIZE - 1; bucket >= ns->ns_hash;
 245              bucket--)
 246                 CFS_INIT_LIST_HEAD(bucket);
 247
 248         CFS_INIT_LIST_HEAD(&ns->ns_unused_list);
 249         ns->ns_nr_unused = 0;
 250         ns->ns_max_unused = LDLM_DEFAULT_LRU_SIZE;
 251         spin_lock_init(&ns->ns_unused_lock);
 252
 253         mutex_down(&ldlm_namespace_lock);
 254         list_add(&ns->ns_list_chain, &ldlm_namespace_list);
 255         mutex_up(&ldlm_namespace_lock);
 256         ldlm_proc_namespace(ns);
 257         RETURN(ns);
 258
 259 out_hash:
 260         POISON(ns->ns_hash, 0x5a, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 261         OBD_VFREE(ns->ns_hash, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 262 out_ns:
 263         OBD_FREE(ns, sizeof(*ns));
 264 out_ref:
 265         ldlm_put_ref(0);
 266         RETURN(NULL);
 267 }
 268
 269 extern struct ldlm_lock *ldlm_lock_get(struct ldlm_lock *lock);
 270
 271 /* If flags contains FL_LOCAL_ONLY, don't try to tell the server, just cleanup.
 272  * This is currently only used for recovery, and we make certain assumptions
 273  * as a result--notably, that we shouldn't cancel locks with refs. -phil
 274  *
 275  * Called with the ns_lock held. */
 276 static void cleanup_resource(struct ldlm_resource *res, struct list_head *q,
 277                              int flags)
 278 {
 279         struct list_head *tmp;
 280         int rc = 0, client = res->lr_namespace->ns_client;
 281         int local_only = (flags & LDLM_FL_LOCAL_ONLY);
 282         ENTRY;
 283
 284
 285         do {
 286                 struct ldlm_lock *lock = NULL;
 287
 288                 /* first, we look for non-cleaned-yet lock
 289                  * all cleaned locks are marked by CLEANED flag */
 290                 lock_res(res);
 291                 list_for_each(tmp, q) {
 292                         lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 293                         if (lock->l_flags & LDLM_FL_CLEANED) {
 294                                 lock = NULL;
 295                                 continue;
 296                         }
 297                         LDLM_LOCK_GET(lock);
 298                         lock->l_flags |= LDLM_FL_CLEANED;
 299                         break;
 300                 }
 301
 302                 if (lock == NULL) {
 303                         unlock_res(res);
 304                         break;
 305                 }
 306
 307                 /* Set CBPENDING so nothing in the cancellation path
 308                  * can match this lock */
 309                 lock->l_flags |= LDLM_FL_CBPENDING;
 310                 lock->l_flags |= LDLM_FL_FAILED;
 311                 lock->l_flags |= flags;
 312
 313                 if (local_only && (lock->l_readers || lock->l_writers)) {
 314                         /* This is a little bit gross, but much better than the
 315                          * alternative: pretend that we got a blocking AST from
 316                          * the server, so that when the lock is decref'd, it
 317                          * will go away ... */
 318                         /* ... without sending a CANCEL message. */
 319                         lock->l_flags |= LDLM_FL_LOCAL_ONLY;
 320                         unlock_res(res);
 321                         LDLM_DEBUG(lock, "setting FL_LOCAL_ONLY");
 322                         if (lock->l_completion_ast)
 323                                 lock->l_completion_ast(lock, 0, NULL);
 324                         LDLM_LOCK_PUT(lock);
 325                         continue;
 326                 }
 327
 328                 if (client) {
 329                         struct lustre_handle lockh;
 330
 331                         unlock_res(res);
 332                         ldlm_lock2handle(lock, &lockh);
 333                         if (!local_only) {
 334                                 rc = ldlm_cli_cancel(&lockh);
 335                                 if (rc)
 336                                         CERROR("ldlm_cli_cancel: %d\n", rc);
 337                         }
 338                         /* Force local cleanup on errors, too. */
 339                         if (local_only || rc != ELDLM_OK)
 340                                 ldlm_lock_cancel(lock);
 341                 } else {
 342                         ldlm_resource_unlink_lock(lock);
 343                         unlock_res(res);
 344                         LDLM_DEBUG(lock, "Freeing a lock still held by a "
 345                                    "client node");
 346                         ldlm_lock_destroy(lock);
 347                 }
 348                 LDLM_LOCK_PUT(lock);
 349         } while (1);
 350
 351         EXIT;
 352 }
 353
 354 int ldlm_namespace_cleanup(struct ldlm_namespace *ns, int flags)
 355 {
 356         struct list_head *tmp;
 357         int i;
 358
 359         if (ns == NULL) {
 360                 CDEBUG(D_INFO, "NULL ns, skipping cleanup\n");
 361                 return ELDLM_OK;
 362         }
 363
 364         for (i = 0; i < RES_HASH_SIZE; i++) {
 365                 spin_lock(&ns->ns_hash_lock);
 366                 tmp = ns->ns_hash[i].next;
 367                 while (tmp != &(ns->ns_hash[i])) {
 368                         struct ldlm_resource *res;
 369                         res = list_entry(tmp, struct ldlm_resource, lr_hash);
 370                         ldlm_resource_getref(res);
 371                         spin_unlock(&ns->ns_hash_lock);
 372
 373                         cleanup_resource(res, &res->lr_granted, flags);
 374                         cleanup_resource(res, &res->lr_converting, flags);
 375                         cleanup_resource(res, &res->lr_waiting, flags);
 376
 377                         spin_lock(&ns->ns_hash_lock);
 378                         tmp  = tmp->next;
 379
 380                         /* XXX: former stuff caused issues in case of race
 381                          * between ldlm_namespace_cleanup() and lockd() when
 382                          * client gets blocking ast when lock gets distracted by
 383                          * server. This is 1_4 branch solution, let's see how
 384                          * will it behave. */
 385                         if (!ldlm_resource_putref_locked(res))
 386                                 CDEBUG(D_INFO,
 387                                        "Namespace %s resource refcount nonzero "
 388                                        "(%d) after lock cleanup; forcing cleanup.\n",
 389                                        ns->ns_name, atomic_read(&res->lr_refcount));
 390                 }
 391                 spin_unlock(&ns->ns_hash_lock);
 392         }
 393
 394         return ELDLM_OK;
 395 }
 396
 397 /* Cleanup, but also free, the namespace */
 398 int ldlm_namespace_free(struct ldlm_namespace *ns, int force)
 399 {
 400         ENTRY;
 401         if (!ns)
 402                 RETURN(ELDLM_OK);
 403
 404         mutex_down(&ldlm_namespace_lock);
 405         list_del(&ns->ns_list_chain);
 406         mutex_up(&ldlm_namespace_lock);
 407
 408         /* At shutdown time, don't call the cancellation callback */
 409         ldlm_namespace_cleanup(ns, 0);
 410
 411 #ifdef LPROCFS
 412         {
 413                 struct proc_dir_entry *dir;
 414                 dir = lprocfs_srch(ldlm_ns_proc_dir, ns->ns_name);
 415                 if (dir == NULL) {
 416                         CERROR("dlm namespace %s has no procfs dir?\n",
 417                                ns->ns_name);
 418                 } else {
 419                         lprocfs_remove(&dir);
 420                 }
 421         }
 422 #endif
 423
 424         if (ns->ns_refcount > 0) {
 425                 struct l_wait_info lwi = LWI_INTR(LWI_ON_SIGNAL_NOOP, NULL);
 426                 int rc;
 427                 CDEBUG(D_DLMTRACE,
 428                        "dlm namespace %s free waiting on refcount %d\n",
 429                        ns->ns_name, ns->ns_refcount);
 430                 rc = l_wait_event(ns->ns_waitq,
 431                                   ns->ns_refcount == 0, &lwi);
 432                 if (ns->ns_refcount)
 433                         LCONSOLE_ERROR_MSG(0x139, "Lock manager: wait for %s "
 434                                            "namespace cleanup aborted with %d "
 435                                            "resources in use. (%d)\nI'm going "
 436                                            "to try to clean up anyway, but I "
 437                                            "might need a reboot of this node.\n",
 438                                             ns->ns_name, (int) ns->ns_refcount,
 439                                             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,
 455                           const struct ldlm_res_id *name)
 456 {
 457         __u32 hash = 0;
 458         int i;
 459
 460         for (i = 0; i < RES_NAME_SIZE; i++)
 461                 hash += name->name[i];
 462
 463         hash += (__u32)((unsigned long)parent >> 4);
 464
 465         return (hash & RES_HASH_MASK);
 466 }
 467
 468 static struct ldlm_resource *ldlm_resource_new(void)
 469 {
 470         struct ldlm_resource *res;
 471
 472         OBD_SLAB_ALLOC(res, ldlm_resource_slab, CFS_ALLOC_IO, sizeof *res);
 473         if (res == NULL)
 474                 return NULL;
 475
 476         memset(res, 0, sizeof(*res));
 477
 478         CFS_INIT_LIST_HEAD(&res->lr_children);
 479         CFS_INIT_LIST_HEAD(&res->lr_childof);
 480         CFS_INIT_LIST_HEAD(&res->lr_granted);
 481         CFS_INIT_LIST_HEAD(&res->lr_converting);
 482         CFS_INIT_LIST_HEAD(&res->lr_waiting);
 483         atomic_set(&res->lr_refcount, 1);
 484         spin_lock_init(&res->lr_lock);
 485
 486         /* one who creates the resource must unlock
 487          * the semaphore after lvb initialization */
 488         init_MUTEX_LOCKED(&res->lr_lvb_sem);
 489
 490         return res;
 491 }
 492
 493 /* must be called with hash lock held */
 494 static struct ldlm_resource *
 495 ldlm_resource_find(struct ldlm_namespace *ns, const struct ldlm_res_id *name,
 496                    __u32 hash)
 497 {
 498         struct list_head *bucket, *tmp;
 499         struct ldlm_resource *res;
 500
 501         LASSERT_SPIN_LOCKED(&ns->ns_hash_lock);
 502         bucket = ns->ns_hash + hash;
 503
 504         list_for_each(tmp, bucket) {
 505                 res = list_entry(tmp, struct ldlm_resource, lr_hash);
 506                 if (memcmp(&res->lr_name, name, sizeof(res->lr_name)) == 0)
 507                         return res;
 508         }
 509
 510         return NULL;
 511 }
 512
 513 /* Args: locked namespace
 514  * Returns: newly-allocated, referenced, unlocked resource */
 515 static struct ldlm_resource *
 516 ldlm_resource_add(struct ldlm_namespace *ns, struct ldlm_resource *parent,
 517                   const struct ldlm_res_id *name, __u32 hash, ldlm_type_t type)
 518 {
 519         struct list_head *bucket;
 520         struct ldlm_resource *res, *old_res;
 521         ENTRY;
 522
 523         LASSERTF(type >= LDLM_MIN_TYPE && type < LDLM_MAX_TYPE,
 524                  "type: %d\n", type);
 525
 526         res = ldlm_resource_new();
 527         if (!res)
 528                 RETURN(NULL);
 529
 530         res->lr_name = *name;
 531         res->lr_namespace = ns;
 532         res->lr_type = type;
 533         res->lr_most_restr = LCK_NL;
 534
 535         spin_lock(&ns->ns_hash_lock);
 536         old_res = ldlm_resource_find(ns, name, hash);
 537         if (old_res) {
 538                 /* someone won the race and added the resource before */
 539                 ldlm_resource_getref(old_res);
 540                 spin_unlock(&ns->ns_hash_lock);
 541                 OBD_SLAB_FREE(res, ldlm_resource_slab, sizeof *res);
 542                 /* synchronize WRT resource creation */
 543                 if (ns->ns_lvbo && ns->ns_lvbo->lvbo_init) {
 544                         down(&old_res->lr_lvb_sem);
 545                         up(&old_res->lr_lvb_sem);
 546                 }
 547                 RETURN(old_res);
 548         }
 549
 550         /* we won! let's add the resource */
 551         bucket = ns->ns_hash + hash;
 552         list_add(&res->lr_hash, bucket);
 553         ns->ns_resources++;
 554         ns->ns_refcount++;
 555
 556         if (parent == NULL) {
 557                 list_add(&res->lr_childof, &ns->ns_root_list);
 558         } else {
 559                 res->lr_parent = parent;
 560                 list_add(&res->lr_childof, &parent->lr_children);
 561         }
 562         spin_unlock(&ns->ns_hash_lock);
 563
 564         if (ns->ns_lvbo && ns->ns_lvbo->lvbo_init) {
 565                 int rc;
 566
 567                 OBD_FAIL_TIMEOUT(OBD_FAIL_LDLM_CREATE_RESOURCE, 2);
 568                 rc = ns->ns_lvbo->lvbo_init(res);
 569                 if (rc)
 570                         CERROR("lvbo_init failed for resource "
 571                                LPU64": rc %d\n", name->name[0], rc);
 572                 /* we create resource with locked lr_lvb_sem */
 573                 up(&res->lr_lvb_sem);
 574         }
 575
 576         RETURN(res);
 577 }
 578
 579 /* Args: unlocked namespace
 580  * Locks: takes and releases ns->ns_lock and res->lr_lock
 581  * Returns: referenced, unlocked ldlm_resource or NULL */
 582 struct ldlm_resource *
 583 ldlm_resource_get(struct ldlm_namespace *ns, struct ldlm_resource *parent,
 584                   const struct ldlm_res_id *name, ldlm_type_t type, int create)
 585 {
 586         __u32 hash = ldlm_hash_fn(parent, name);
 587         struct ldlm_resource *res = NULL;
 588         ENTRY;
 589
 590         LASSERT(ns != NULL);
 591         LASSERT(ns->ns_hash != NULL);
 592         LASSERT(name->name[0] != 0);
 593
 594         spin_lock(&ns->ns_hash_lock);
 595         res = ldlm_resource_find(ns, name, hash);
 596         if (res) {
 597                 ldlm_resource_getref(res);
 598                 spin_unlock(&ns->ns_hash_lock);
 599                 /* synchronize WRT resource creation */
 600                 if (ns->ns_lvbo && ns->ns_lvbo->lvbo_init) {
 601                         down(&res->lr_lvb_sem);
 602                         up(&res->lr_lvb_sem);
 603                 }
 604                 RETURN(res);
 605         }
 606         spin_unlock(&ns->ns_hash_lock);
 607
 608         if (create == 0)
 609                 RETURN(NULL);
 610
 611         res = ldlm_resource_add(ns, parent, name, hash, type);
 612         RETURN(res);
 613 }
 614
 615 struct ldlm_resource *ldlm_resource_getref(struct ldlm_resource *res)
 616 {
 617         LASSERT(res != NULL);
 618         LASSERT(res != LP_POISON);
 619         atomic_inc(&res->lr_refcount);
 620         CDEBUG(D_INFO, "getref res: %p count: %d\n", res,
 621                atomic_read(&res->lr_refcount));
 622         return res;
 623 }
 624
 625 void __ldlm_resource_putref_final(struct ldlm_resource *res)
 626 {
 627         struct ldlm_namespace *ns = res->lr_namespace;
 628
 629         LASSERT_SPIN_LOCKED(&ns->ns_hash_lock);
 630
 631         if (!list_empty(&res->lr_granted)) {
 632                 ldlm_resource_dump(D_ERROR, res);
 633                 LBUG();
 634         }
 635
 636         if (!list_empty(&res->lr_converting)) {
 637                 ldlm_resource_dump(D_ERROR, res);
 638                 LBUG();
 639         }
 640
 641         if (!list_empty(&res->lr_waiting)) {
 642                 ldlm_resource_dump(D_ERROR, res);
 643                 LBUG();
 644         }
 645
 646         if (!list_empty(&res->lr_children)) {
 647                 ldlm_resource_dump(D_ERROR, res);
 648                 LBUG();
 649         }
 650
 651         ns->ns_refcount--;
 652         list_del_init(&res->lr_hash);
 653         list_del_init(&res->lr_childof);
 654
 655         ns->ns_resources--;
 656         if (ns->ns_resources == 0)
 657                 wake_up(&ns->ns_waitq);
 658 }
 659
 660 /* Returns 1 if the resource was freed, 0 if it remains. */
 661 int ldlm_resource_putref(struct ldlm_resource *res)
 662 {
 663         struct ldlm_namespace *ns = res->lr_namespace;
 664         int rc = 0;
 665         ENTRY;
 666
 667         CDEBUG(D_INFO, "putref res: %p count: %d\n", res,
 668                atomic_read(&res->lr_refcount) - 1);
 669         LASSERTF(atomic_read(&res->lr_refcount) > 0, "%d",
 670                  atomic_read(&res->lr_refcount));
 671         LASSERTF(atomic_read(&res->lr_refcount) < LI_POISON, "%d",
 672                  atomic_read(&res->lr_refcount));
 673
 674         if (atomic_dec_and_lock(&res->lr_refcount, &ns->ns_hash_lock)) {
 675                 __ldlm_resource_putref_final(res);
 676                 spin_unlock(&ns->ns_hash_lock);
 677                 if (res->lr_lvb_data)
 678                         OBD_FREE(res->lr_lvb_data, res->lr_lvb_len);
 679                 OBD_SLAB_FREE(res, ldlm_resource_slab, sizeof *res);
 680                 rc = 1;
 681         }
 682
 683         RETURN(rc);
 684 }
 685
 686 /* Returns 1 if the resource was freed, 0 if it remains. */
 687 int ldlm_resource_putref_locked(struct ldlm_resource *res)
 688 {
 689         int rc = 0;
 690         ENTRY;
 691
 692         CDEBUG(D_INFO, "putref res: %p count: %d\n", res,
 693                atomic_read(&res->lr_refcount) - 1);
 694         LASSERT(atomic_read(&res->lr_refcount) > 0);
 695         LASSERT(atomic_read(&res->lr_refcount) < LI_POISON);
 696
 697         LASSERT(atomic_read(&res->lr_refcount) >= 0);
 698         if (atomic_dec_and_test(&res->lr_refcount)) {
 699                 __ldlm_resource_putref_final(res);
 700                 if (res->lr_lvb_data)
 701                         OBD_FREE(res->lr_lvb_data, res->lr_lvb_len);
 702                 OBD_SLAB_FREE(res, ldlm_resource_slab, sizeof *res);
 703                 rc = 1;
 704         }
 705
 706         RETURN(rc);
 707 }
 708
 709 void ldlm_resource_add_lock(struct ldlm_resource *res, struct list_head *head,
 710                             struct ldlm_lock *lock)
 711 {
 712         check_res_locked(res);
 713
 714         ldlm_resource_dump(D_OTHER, res);
 715         CDEBUG(D_OTHER, "About to add this lock:\n");
 716         ldlm_lock_dump(D_OTHER, lock, 0);
 717
 718         if (lock->l_destroyed) {
 719                 CDEBUG(D_OTHER, "Lock destroyed, not adding to resource\n");
 720                 return;
 721         }
 722
 723         LASSERT(list_empty(&lock->l_res_link));
 724
 725         list_add_tail(&lock->l_res_link, head);
 726 }
 727
 728 void ldlm_resource_insert_lock_after(struct ldlm_lock *original,
 729                                      struct ldlm_lock *new)
 730 {
 731         struct ldlm_resource *res = original->l_resource;
 732
 733         check_res_locked(res);
 734
 735         ldlm_resource_dump(D_OTHER, res);
 736         CDEBUG(D_OTHER, "About to insert this lock after %p:\n", original);
 737         ldlm_lock_dump(D_OTHER, new, 0);
 738
 739         if (new->l_destroyed) {
 740                 CDEBUG(D_OTHER, "Lock destroyed, not adding to resource\n");
 741                 goto out;
 742         }
 743
 744         LASSERT(list_empty(&new->l_res_link));
 745
 746         list_add(&new->l_res_link, &original->l_res_link);
 747  out:;
 748 }
 749
 750 void ldlm_resource_unlink_lock(struct ldlm_lock *lock)
 751 {
 752         check_res_locked(lock->l_resource);
 753         ldlm_unlink_lock_skiplist(lock);
 754         list_del_init(&lock->l_res_link);
 755 }
 756
 757 void ldlm_res2desc(struct ldlm_resource *res, struct ldlm_resource_desc *desc)
 758 {
 759         desc->lr_type = res->lr_type;
 760         desc->lr_name = res->lr_name;
 761 }
 762
 763 void ldlm_dump_all_namespaces(int level)
 764 {
 765         struct list_head *tmp;
 766
 767         if (!((libcfs_debug | D_ERROR) & level))
 768                 return;
 769
 770         mutex_down(&ldlm_namespace_lock);
 771
 772         list_for_each(tmp, &ldlm_namespace_list) {
 773                 struct ldlm_namespace *ns;
 774                 ns = list_entry(tmp, struct ldlm_namespace, ns_list_chain);
 775                 ldlm_namespace_dump(level, ns);
 776         }
 777
 778         mutex_up(&ldlm_namespace_lock);
 779 }
 780
 781 void ldlm_namespace_dump(int level, struct ldlm_namespace *ns)
 782 {
 783         struct list_head *tmp;
 784
 785         if (!((libcfs_debug | D_ERROR) & level))
 786                 return;
 787
 788         CDEBUG(level, "--- Namespace: %s (rc: %d, client: %d)\n",
 789                   ns->ns_name, ns->ns_refcount, ns->ns_client);
 790
 791         if (cfs_time_before(cfs_time_current(), ns->ns_next_dump))
 792                 return;
 793
 794         spin_lock(&ns->ns_hash_lock);
 795         tmp = ns->ns_root_list.next;
 796         while (tmp != &ns->ns_root_list) {
 797                 struct ldlm_resource *res;
 798                 res = list_entry(tmp, struct ldlm_resource, lr_childof);
 799
 800                 ldlm_resource_getref(res);
 801                 spin_unlock(&ns->ns_hash_lock);
 802
 803                 lock_res(res);
 804                 ldlm_resource_dump(level, res);
 805                 unlock_res(res);
 806
 807                 spin_lock(&ns->ns_hash_lock);
 808                 tmp = tmp->next;
 809                 ldlm_resource_putref_locked(res);
 810         }
 811         ns->ns_next_dump = cfs_time_shift(10);
 812         spin_unlock(&ns->ns_hash_lock);
 813 }
 814
 815 void ldlm_resource_dump(int level, struct ldlm_resource *res)
 816 {
 817         struct list_head *tmp;
 818         int pos;
 819
 820         CLASSERT(RES_NAME_SIZE == 4);
 821
 822         if (!((libcfs_debug | D_ERROR) & level))
 823                 return;
 824
 825         CDEBUG(level, "--- Resource: %p ("LPU64"/"LPU64"/"LPU64"/"LPU64
 826                ") (rc: %d)\n", res, res->lr_name.name[0], res->lr_name.name[1],
 827                res->lr_name.name[2], res->lr_name.name[3],
 828                atomic_read(&res->lr_refcount));
 829
 830         if (!list_empty(&res->lr_granted)) {
 831                 pos = 0;
 832                 CDEBUG(level, "Granted locks:\n");
 833                 list_for_each(tmp, &res->lr_granted) {
 834                         struct ldlm_lock *lock;
 835                         lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 836                         ldlm_lock_dump(level, lock, ++pos);
 837                 }
 838         }
 839         if (!list_empty(&res->lr_converting)) {
 840                 pos = 0;
 841                 CDEBUG(level, "Converting locks:\n");
 842                 list_for_each(tmp, &res->lr_converting) {
 843                         struct ldlm_lock *lock;
 844                         lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 845                         ldlm_lock_dump(level, lock, ++pos);
 846                 }
 847         }
 848         if (!list_empty(&res->lr_waiting)) {
 849                 pos = 0;
 850                 CDEBUG(level, "Waiting locks:\n");
 851                 list_for_each(tmp, &res->lr_waiting) {
 852                         struct ldlm_lock *lock;
 853                         lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 854                         ldlm_lock_dump(level, lock, ++pos);
 855                 }
 856         }
 857 }