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_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         CFS_INIT_LIST_HEAD(&ns->ns_root_list);
 246         ns->ns_refcount = 0;
 247         ns->ns_client = client;
 248         spin_lock_init(&ns->ns_hash_lock);
 249         atomic_set(&ns->ns_locks, 0);
 250         ns->ns_resources = 0;
 251         cfs_waitq_init(&ns->ns_waitq);
 252
 253         for (bucket = ns->ns_hash + RES_HASH_SIZE - 1; bucket >= ns->ns_hash;
 254              bucket--)
 255                 CFS_INIT_LIST_HEAD(bucket);
 256
 257         CFS_INIT_LIST_HEAD(&ns->ns_unused_list);
 258         ns->ns_nr_unused = 0;
 259         ns->ns_max_unused = LDLM_DEFAULT_LRU_SIZE;
 260         spin_lock_init(&ns->ns_unused_lock);
 261
 262         mutex_down(&ldlm_namespace_lock);
 263         list_add(&ns->ns_list_chain, &ldlm_namespace_list);
 264         mutex_up(&ldlm_namespace_lock);
 265         ldlm_proc_namespace(ns);
 266         RETURN(ns);
 267
 268 out_hash:
 269         POISON(ns->ns_hash, 0x5a, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 270         OBD_VFREE(ns->ns_hash, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 271 out_ns:
 272         OBD_FREE(ns, sizeof(*ns));
 273 out_ref:
 274         ldlm_put_ref(0);
 275         RETURN(NULL);
 276 }
 277
 278 extern struct ldlm_lock *ldlm_lock_get(struct ldlm_lock *lock);
 279
 280 /* If flags contains FL_LOCAL_ONLY, don't try to tell the server, just cleanup.
 281  * This is currently only used for recovery, and we make certain assumptions
 282  * as a result--notably, that we shouldn't cancel locks with refs. -phil
 283  *
 284  * Called with the ns_lock held. */
 285 static void cleanup_resource(struct ldlm_resource *res, struct list_head *q,
 286                              int flags)
 287 {
 288         struct list_head *tmp;
 289         int rc = 0, client = res->lr_namespace->ns_client;
 290         int local_only = (flags & LDLM_FL_LOCAL_ONLY);
 291         ENTRY;
 292
 293
 294         do {
 295                 struct ldlm_lock *lock = NULL;
 296
 297                 /* first, we look for non-cleaned-yet lock
 298                  * all cleaned locks are marked by CLEANED flag */
 299                 lock_res(res);
 300                 list_for_each(tmp, q) {
 301                         lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 302                         if (lock->l_flags & LDLM_FL_CLEANED) {
 303                                 lock = NULL;
 304                                 continue;
 305                         }
 306                         LDLM_LOCK_GET(lock);
 307                         lock->l_flags |= LDLM_FL_CLEANED;
 308                         break;
 309                 }
 310
 311                 if (lock == NULL) {
 312                         unlock_res(res);
 313                         break;
 314                 }
 315
 316                 /* Set CBPENDING so nothing in the cancellation path
 317                  * can match this lock */
 318                 lock->l_flags |= LDLM_FL_CBPENDING;
 319                 lock->l_flags |= LDLM_FL_FAILED;
 320                 lock->l_flags |= flags;
 321
 322                 if (local_only && (lock->l_readers || lock->l_writers)) {
 323                         /* This is a little bit gross, but much better than the
 324                          * alternative: pretend that we got a blocking AST from
 325                          * the server, so that when the lock is decref'd, it
 326                          * will go away ... */
 327                         /* ... without sending a CANCEL message. */
 328                         lock->l_flags |= LDLM_FL_LOCAL_ONLY;
 329                         unlock_res(res);
 330                         LDLM_DEBUG(lock, "setting FL_LOCAL_ONLY");
 331                         if (lock->l_completion_ast)
 332                                 lock->l_completion_ast(lock, 0, NULL);
 333                         LDLM_LOCK_PUT(lock);
 334                         continue;
 335                 }
 336
 337                 if (client) {
 338                         struct lustre_handle lockh;
 339
 340                         unlock_res(res);
 341                         ldlm_lock2handle(lock, &lockh);
 342                         if (!local_only) {
 343                                 rc = ldlm_cli_cancel(&lockh);
 344                                 if (rc)
 345                                         CERROR("ldlm_cli_cancel: %d\n", rc);
 346                         }
 347                         /* Force local cleanup on errors, too. */
 348                         if (local_only || rc != ELDLM_OK)
 349                                 ldlm_lock_cancel(lock);
 350                 } else {
 351                         ldlm_resource_unlink_lock(lock);
 352                         unlock_res(res);
 353                         LDLM_DEBUG(lock, "Freeing a lock still held by a "
 354                                    "client node");
 355                         ldlm_lock_destroy(lock);
 356                 }
 357                 LDLM_LOCK_PUT(lock);
 358         } while (1);
 359
 360         EXIT;
 361 }
 362
 363 int ldlm_namespace_cleanup(struct ldlm_namespace *ns, int flags)
 364 {
 365         struct list_head *tmp;
 366         int i;
 367
 368         if (ns == NULL) {
 369                 CDEBUG(D_INFO, "NULL ns, skipping cleanup\n");
 370                 return ELDLM_OK;
 371         }
 372
 373         for (i = 0; i < RES_HASH_SIZE; i++) {
 374                 spin_lock(&ns->ns_hash_lock);
 375                 tmp = ns->ns_hash[i].next;
 376                 while (tmp != &(ns->ns_hash[i])) {
 377                         struct ldlm_resource *res;
 378                         res = list_entry(tmp, struct ldlm_resource, lr_hash);
 379                         ldlm_resource_getref(res);
 380                         spin_unlock(&ns->ns_hash_lock);
 381
 382                         cleanup_resource(res, &res->lr_granted, flags);
 383                         cleanup_resource(res, &res->lr_converting, flags);
 384                         cleanup_resource(res, &res->lr_waiting, flags);
 385
 386                         spin_lock(&ns->ns_hash_lock);
 387                         tmp  = tmp->next;
 388
 389                         /* XXX: former stuff caused issues in case of race
 390                          * between ldlm_namespace_cleanup() and lockd() when
 391                          * client gets blocking ast when lock gets distracted by
 392                          * server. This is 1_4 branch solution, let's see how
 393                          * will it behave. */
 394                         if (!ldlm_resource_putref_locked(res))
 395                                 CDEBUG(D_INFO,
 396                                        "Namespace %s resource refcount nonzero "
 397                                        "(%d) after lock cleanup; forcing cleanup.\n",
 398                                        ns->ns_name, atomic_read(&res->lr_refcount));
 399                 }
 400                 spin_unlock(&ns->ns_hash_lock);
 401         }
 402
 403         return ELDLM_OK;
 404 }
 405
 406 /* Cleanup, but also free, the namespace */
 407 int ldlm_namespace_free(struct ldlm_namespace *ns, int force)
 408 {
 409         ENTRY;
 410         if (!ns)
 411                 RETURN(ELDLM_OK);
 412
 413         mutex_down(&ldlm_namespace_lock);
 414         list_del(&ns->ns_list_chain);
 415         mutex_up(&ldlm_namespace_lock);
 416
 417         /* At shutdown time, don't call the cancellation callback */
 418         ldlm_namespace_cleanup(ns, 0);
 419
 420 #ifdef LPROCFS
 421         {
 422                 struct proc_dir_entry *dir;
 423                 dir = lprocfs_srch(ldlm_ns_proc_dir, ns->ns_name);
 424                 if (dir == NULL) {
 425                         CERROR("dlm namespace %s has no procfs dir?\n",
 426                                ns->ns_name);
 427                 } else {
 428                         lprocfs_remove(dir);
 429                 }
 430         }
 431 #endif
 432
 433         if (ns->ns_refcount > 0) {
 434                 struct l_wait_info lwi = LWI_INTR(LWI_ON_SIGNAL_NOOP, NULL);
 435                 int rc;
 436                 CDEBUG(D_DLMTRACE,
 437                        "dlm namespace %s free waiting on refcount %d\n",
 438                        ns->ns_name, ns->ns_refcount);
 439                 rc = l_wait_event(ns->ns_waitq,
 440                                   ns->ns_refcount == 0, &lwi);
 441                 if (ns->ns_refcount)
 442                         LCONSOLE_ERROR("Lock manager: wait for %s namespace "
 443                                        "cleanup aborted with %d resources in "
 444                                        "use. (%d)\nI'm going to try to clean "
 445                                        "up anyway, but I might need a reboot "
 446                                        "of this node.\n", ns->ns_name,
 447                                        (int) ns->ns_refcount, rc);
 448                 CDEBUG(D_DLMTRACE,
 449                        "dlm namespace %s free done waiting\n", ns->ns_name);
 450         }
 451
 452         POISON(ns->ns_hash, 0x5a, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 453         OBD_VFREE(ns->ns_hash, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 454         OBD_FREE(ns->ns_name, strlen(ns->ns_name) + 1);
 455         OBD_FREE(ns, sizeof(*ns));
 456
 457         ldlm_put_ref(force);
 458
 459         return ELDLM_OK;
 460 }
 461
 462 static __u32 ldlm_hash_fn(struct ldlm_resource *parent, struct ldlm_res_id name)
 463 {
 464         __u32 hash = 0;
 465         int i;
 466
 467         for (i = 0; i < RES_NAME_SIZE; i++)
 468                 hash += name.name[i];
 469
 470         hash += (__u32)((unsigned long)parent >> 4);
 471
 472         return (hash & RES_HASH_MASK);
 473 }
 474
 475 static struct ldlm_resource *ldlm_resource_new(void)
 476 {
 477         struct ldlm_resource *res;
 478
 479         OBD_SLAB_ALLOC(res, ldlm_resource_slab, CFS_ALLOC_IO, sizeof *res);
 480         if (res == NULL)
 481                 return NULL;
 482
 483         memset(res, 0, sizeof(*res));
 484
 485         CFS_INIT_LIST_HEAD(&res->lr_children);
 486         CFS_INIT_LIST_HEAD(&res->lr_childof);
 487         CFS_INIT_LIST_HEAD(&res->lr_granted);
 488         CFS_INIT_LIST_HEAD(&res->lr_converting);
 489         CFS_INIT_LIST_HEAD(&res->lr_waiting);
 490         atomic_set(&res->lr_refcount, 1);
 491         spin_lock_init(&res->lr_lock);
 492
 493         /* one who creates the resource must unlock
 494          * the semaphore after lvb initialization */
 495         init_MUTEX_LOCKED(&res->lr_lvb_sem);
 496
 497         return res;
 498 }
 499
 500 /* must be called with hash lock held */
 501 static struct ldlm_resource *
 502 ldlm_resource_find(struct ldlm_namespace *ns, struct ldlm_res_id name, __u32 hash)
 503 {
 504         struct list_head *bucket, *tmp;
 505         struct ldlm_resource *res;
 506
 507         LASSERT_SPIN_LOCKED(&ns->ns_hash_lock);
 508         bucket = ns->ns_hash + hash;
 509
 510         list_for_each(tmp, bucket) {
 511                 res = list_entry(tmp, struct ldlm_resource, lr_hash);
 512                 if (memcmp(&res->lr_name, &name, sizeof(res->lr_name)) == 0)
 513                         return res;
 514         }
 515
 516         return NULL;
 517 }
 518
 519 /* Args: locked namespace
 520  * Returns: newly-allocated, referenced, unlocked resource */
 521 static struct ldlm_resource *
 522 ldlm_resource_add(struct ldlm_namespace *ns, struct ldlm_resource *parent,
 523                   struct ldlm_res_id name, __u32 hash, ldlm_type_t type)
 524 {
 525         struct list_head *bucket;
 526         struct ldlm_resource *res, *old_res;
 527         ENTRY;
 528
 529         LASSERTF(type >= LDLM_MIN_TYPE && type < LDLM_MAX_TYPE,
 530                  "type: %d\n", type);
 531
 532         res = ldlm_resource_new();
 533         if (!res)
 534                 RETURN(NULL);
 535
 536         res->lr_name = name;
 537         res->lr_namespace = ns;
 538         res->lr_type = type;
 539         res->lr_most_restr = LCK_NL;
 540
 541         spin_lock(&ns->ns_hash_lock);
 542         old_res = ldlm_resource_find(ns, name, hash);
 543         if (old_res) {
 544                 /* someone won the race and added the resource before */
 545                 ldlm_resource_getref(old_res);
 546                 spin_unlock(&ns->ns_hash_lock);
 547                 OBD_SLAB_FREE(res, ldlm_resource_slab, sizeof *res);
 548                 /* synchronize WRT resource creation */
 549                 if (ns->ns_lvbo && ns->ns_lvbo->lvbo_init) {
 550                         down(&old_res->lr_lvb_sem);
 551                         up(&old_res->lr_lvb_sem);
 552                 }
 553                 RETURN(old_res);
 554         }
 555
 556         /* we won! let's add the resource */
 557         bucket = ns->ns_hash + hash;
 558         list_add(&res->lr_hash, bucket);
 559         ns->ns_resources++;
 560         ns->ns_refcount++;
 561
 562         if (parent == NULL) {
 563                 list_add(&res->lr_childof, &ns->ns_root_list);
 564         } else {
 565                 res->lr_parent = parent;
 566                 list_add(&res->lr_childof, &parent->lr_children);
 567         }
 568         spin_unlock(&ns->ns_hash_lock);
 569
 570         if (ns->ns_lvbo && ns->ns_lvbo->lvbo_init) {
 571                 int rc;
 572
 573                 OBD_FAIL_TIMEOUT(OBD_FAIL_LDLM_CREATE_RESOURCE, 2);
 574                 rc = ns->ns_lvbo->lvbo_init(res);
 575                 if (rc)
 576                         CERROR("lvbo_init failed for resource "
 577                                LPU64": rc %d\n", name.name[0], rc);
 578                 /* we create resource with locked lr_lvb_sem */
 579                 up(&res->lr_lvb_sem);
 580         }
 581
 582         RETURN(res);
 583 }
 584
 585 /* Args: unlocked namespace
 586  * Locks: takes and releases ns->ns_lock and res->lr_lock
 587  * Returns: referenced, unlocked ldlm_resource or NULL */
 588 struct ldlm_resource *
 589 ldlm_resource_get(struct ldlm_namespace *ns, struct ldlm_resource *parent,
 590                   struct ldlm_res_id name, ldlm_type_t type, int create)
 591 {
 592         __u32 hash = ldlm_hash_fn(parent, name);
 593         struct ldlm_resource *res = NULL;
 594         ENTRY;
 595
 596         LASSERT(ns != NULL);
 597         LASSERT(ns->ns_hash != NULL);
 598         LASSERT(name.name[0] != 0);
 599
 600         spin_lock(&ns->ns_hash_lock);
 601         res = ldlm_resource_find(ns, name, hash);
 602         if (res) {
 603                 ldlm_resource_getref(res);
 604                 spin_unlock(&ns->ns_hash_lock);
 605                 /* synchronize WRT resource creation */
 606                 if (ns->ns_lvbo && ns->ns_lvbo->lvbo_init) {
 607                         down(&res->lr_lvb_sem);
 608                         up(&res->lr_lvb_sem);
 609                 }
 610                 RETURN(res);
 611         }
 612         spin_unlock(&ns->ns_hash_lock);
 613
 614         if (create == 0)
 615                 RETURN(NULL);
 616
 617         res = ldlm_resource_add(ns, parent, name, hash, type);
 618         RETURN(res);
 619 }
 620
 621 struct ldlm_resource *ldlm_resource_getref(struct ldlm_resource *res)
 622 {
 623         LASSERT(res != NULL);
 624         LASSERT(res != LP_POISON);
 625         atomic_inc(&res->lr_refcount);
 626         CDEBUG(D_INFO, "getref res: %p count: %d\n", res,
 627                atomic_read(&res->lr_refcount));
 628         return res;
 629 }
 630
 631 void __ldlm_resource_putref_final(struct ldlm_resource *res)
 632 {
 633         struct ldlm_namespace *ns = res->lr_namespace;
 634
 635         LASSERT_SPIN_LOCKED(&ns->ns_hash_lock);
 636
 637         if (!list_empty(&res->lr_granted)) {
 638                 ldlm_resource_dump(D_ERROR, res);
 639                 LBUG();
 640         }
 641
 642         if (!list_empty(&res->lr_converting)) {
 643                 ldlm_resource_dump(D_ERROR, res);
 644                 LBUG();
 645         }
 646
 647         if (!list_empty(&res->lr_waiting)) {
 648                 ldlm_resource_dump(D_ERROR, res);
 649                 LBUG();
 650         }
 651
 652         if (!list_empty(&res->lr_children)) {
 653                 ldlm_resource_dump(D_ERROR, res);
 654                 LBUG();
 655         }
 656
 657         ns->ns_refcount--;
 658         list_del_init(&res->lr_hash);
 659         list_del_init(&res->lr_childof);
 660
 661         ns->ns_resources--;
 662         if (ns->ns_resources == 0)
 663                 wake_up(&ns->ns_waitq);
 664 }
 665
 666 /* Returns 1 if the resource was freed, 0 if it remains. */
 667 int ldlm_resource_putref(struct ldlm_resource *res)
 668 {
 669         struct ldlm_namespace *ns = res->lr_namespace;
 670         int rc = 0;
 671         ENTRY;
 672
 673         CDEBUG(D_INFO, "putref res: %p count: %d\n", res,
 674                atomic_read(&res->lr_refcount) - 1);
 675         LASSERT(atomic_read(&res->lr_refcount) > 0);
 676         LASSERT(atomic_read(&res->lr_refcount) < LI_POISON);
 677
 678         LASSERT(atomic_read(&res->lr_refcount) >= 0);
 679         if (atomic_dec_and_lock(&res->lr_refcount, &ns->ns_hash_lock)) {
 680                 __ldlm_resource_putref_final(res);
 681                 spin_unlock(&ns->ns_hash_lock);
 682                 if (res->lr_lvb_data)
 683                         OBD_FREE(res->lr_lvb_data, res->lr_lvb_len);
 684                 OBD_SLAB_FREE(res, ldlm_resource_slab, sizeof *res);
 685                 rc = 1;
 686         }
 687
 688         RETURN(rc);
 689 }
 690
 691 /* Returns 1 if the resource was freed, 0 if it remains. */
 692 int ldlm_resource_putref_locked(struct ldlm_resource *res)
 693 {
 694         int rc = 0;
 695         ENTRY;
 696
 697         CDEBUG(D_INFO, "putref res: %p count: %d\n", res,
 698                atomic_read(&res->lr_refcount) - 1);
 699         LASSERT(atomic_read(&res->lr_refcount) > 0);
 700         LASSERT(atomic_read(&res->lr_refcount) < LI_POISON);
 701
 702         LASSERT(atomic_read(&res->lr_refcount) >= 0);
 703         if (atomic_dec_and_test(&res->lr_refcount)) {
 704                 __ldlm_resource_putref_final(res);
 705                 if (res->lr_lvb_data)
 706                         OBD_FREE(res->lr_lvb_data, res->lr_lvb_len);
 707                 OBD_SLAB_FREE(res, ldlm_resource_slab, sizeof *res);
 708                 rc = 1;
 709         }
 710
 711         RETURN(rc);
 712 }
 713
 714 void ldlm_resource_add_lock(struct ldlm_resource *res, struct list_head *head,
 715                             struct ldlm_lock *lock)
 716 {
 717         check_res_locked(res);
 718
 719         ldlm_resource_dump(D_OTHER, res);
 720         CDEBUG(D_OTHER, "About to add this lock:\n");
 721         ldlm_lock_dump(D_OTHER, lock, 0);
 722
 723         if (lock->l_destroyed) {
 724                 CDEBUG(D_OTHER, "Lock destroyed, not adding to resource\n");
 725                 return;
 726         }
 727
 728         LASSERT(list_empty(&lock->l_res_link));
 729
 730         list_add_tail(&lock->l_res_link, head);
 731 }
 732
 733 void ldlm_resource_insert_lock_after(struct ldlm_lock *original,
 734                                      struct ldlm_lock *new)
 735 {
 736         struct ldlm_resource *res = original->l_resource;
 737
 738         check_res_locked(res);
 739
 740         ldlm_resource_dump(D_OTHER, res);
 741         CDEBUG(D_OTHER, "About to insert this lock after %p:\n", original);
 742         ldlm_lock_dump(D_OTHER, new, 0);
 743
 744         if (new->l_destroyed) {
 745                 CDEBUG(D_OTHER, "Lock destroyed, not adding to resource\n");
 746                 goto out;
 747         }
 748
 749         LASSERT(list_empty(&new->l_res_link));
 750
 751         list_add(&new->l_res_link, &original->l_res_link);
 752  out:;
 753 }
 754
 755 void ldlm_resource_unlink_lock(struct ldlm_lock *lock)
 756 {
 757         check_res_locked(lock->l_resource);
 758         list_del_init(&lock->l_res_link);
 759 }
 760
 761 void ldlm_res2desc(struct ldlm_resource *res, struct ldlm_resource_desc *desc)
 762 {
 763         desc->lr_type = res->lr_type;
 764         desc->lr_name = res->lr_name;
 765 }
 766
 767 void ldlm_dump_all_namespaces(int level)
 768 {
 769         struct list_head *tmp;
 770
 771         mutex_down(&ldlm_namespace_lock);
 772
 773         list_for_each(tmp, &ldlm_namespace_list) {
 774                 struct ldlm_namespace *ns;
 775                 ns = list_entry(tmp, struct ldlm_namespace, ns_list_chain);
 776                 ldlm_namespace_dump(level, ns);
 777         }
 778
 779         mutex_up(&ldlm_namespace_lock);
 780 }
 781
 782 void ldlm_namespace_dump(int level, struct ldlm_namespace *ns)
 783 {
 784         struct list_head *tmp;
 785
 786         CDEBUG(level, "--- Namespace: %s (rc: %d, client: %d)\n",
 787                   ns->ns_name, ns->ns_refcount, ns->ns_client);
 788
 789         if (cfs_time_before(cfs_time_current(), ns->ns_next_dump))
 790                 return;
 791
 792         spin_lock(&ns->ns_hash_lock);
 793         tmp = ns->ns_root_list.next;
 794         while (tmp != &ns->ns_root_list) {
 795                 struct ldlm_resource *res;
 796                 res = list_entry(tmp, struct ldlm_resource, lr_childof);
 797
 798                 ldlm_resource_getref(res);
 799                 spin_unlock(&ns->ns_hash_lock);
 800
 801                 lock_res(res);
 802                 ldlm_resource_dump(level, res);
 803                 unlock_res(res);
 804
 805                 spin_lock(&ns->ns_hash_lock);
 806                 tmp = tmp->next;
 807                 ldlm_resource_putref_locked(res);
 808         }
 809         ns->ns_next_dump = cfs_time_shift(10);
 810         spin_unlock(&ns->ns_hash_lock);
 811 }
 812
 813 void ldlm_resource_dump(int level, struct ldlm_resource *res)
 814 {
 815         struct list_head *tmp;
 816         int pos;
 817
 818         if (RES_NAME_SIZE != 4)
 819                 LBUG();
 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 }