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 atomic_t ldlm_srv_namespace_nr = ATOMIC_INIT(0);
  40 atomic_t ldlm_cli_namespace_nr = ATOMIC_INIT(0);
  41
  42 struct semaphore ldlm_srv_namespace_lock;
  43 struct list_head ldlm_srv_namespace_list =
  44         CFS_LIST_HEAD_INIT(ldlm_srv_namespace_list);
  45
  46 struct semaphore ldlm_cli_namespace_lock;
  47 struct list_head ldlm_cli_namespace_list =
  48         CFS_LIST_HEAD_INIT(ldlm_cli_namespace_list);
  49
  50 cfs_proc_dir_entry_t *ldlm_type_proc_dir = NULL;
  51 cfs_proc_dir_entry_t *ldlm_ns_proc_dir = NULL;
  52 cfs_proc_dir_entry_t *ldlm_svc_proc_dir = NULL;
  53
  54 #ifdef LPROCFS
  55 static int ldlm_proc_dump_ns(struct file *file, const char *buffer,
  56                              unsigned long count, void *data)
  57 {
  58         ldlm_dump_all_namespaces(LDLM_NAMESPACE_SERVER, D_DLMTRACE);
  59         ldlm_dump_all_namespaces(LDLM_NAMESPACE_CLIENT, D_DLMTRACE);
  60         RETURN(count);
  61 }
  62
  63 int ldlm_proc_setup(void)
  64 {
  65         int rc;
  66         struct lprocfs_vars list[] = {
  67                 { "dump_namespaces", NULL, ldlm_proc_dump_ns, NULL },
  68                 { NULL }};
  69         ENTRY;
  70         LASSERT(ldlm_ns_proc_dir == NULL);
  71
  72         ldlm_type_proc_dir = lprocfs_register(OBD_LDLM_DEVICENAME,
  73                                               proc_lustre_root,
  74                                               NULL, NULL);
  75         if (IS_ERR(ldlm_type_proc_dir)) {
  76                 CERROR("LProcFS failed in ldlm-init\n");
  77                 rc = PTR_ERR(ldlm_type_proc_dir);
  78                 GOTO(err, rc);
  79         }
  80
  81         ldlm_ns_proc_dir = lprocfs_register("namespaces",
  82                                             ldlm_type_proc_dir,
  83                                             NULL, NULL);
  84         if (IS_ERR(ldlm_ns_proc_dir)) {
  85                 CERROR("LProcFS failed in ldlm-init\n");
  86                 rc = PTR_ERR(ldlm_ns_proc_dir);
  87                 GOTO(err_type, rc);
  88         }
  89
  90         ldlm_svc_proc_dir = lprocfs_register("services",
  91                                             ldlm_type_proc_dir,
  92                                             NULL, NULL);
  93         if (IS_ERR(ldlm_svc_proc_dir)) {
  94                 CERROR("LProcFS failed in ldlm-init\n");
  95                 rc = PTR_ERR(ldlm_svc_proc_dir);
  96                 GOTO(err_ns, rc);
  97         }
  98
  99         rc = lprocfs_add_vars(ldlm_type_proc_dir, list, NULL);
 100
 101         RETURN(0);
 102
 103 err_ns:
 104         lprocfs_remove(&ldlm_ns_proc_dir);
 105 err_type:
 106         lprocfs_remove(&ldlm_type_proc_dir);
 107 err:
 108         ldlm_svc_proc_dir = NULL;
 109         RETURN(rc);
 110 }
 111
 112 void ldlm_proc_cleanup(void)
 113 {
 114         if (ldlm_svc_proc_dir)
 115                 lprocfs_remove(&ldlm_svc_proc_dir);
 116
 117         if (ldlm_ns_proc_dir)
 118                 lprocfs_remove(&ldlm_ns_proc_dir);
 119
 120         if (ldlm_type_proc_dir)
 121                 lprocfs_remove(&ldlm_type_proc_dir);
 122 }
 123
 124 static int lprocfs_rd_lru_size(char *page, char **start, off_t off,
 125                                int count, int *eof, void *data)
 126 {
 127         struct ldlm_namespace *ns = data;
 128         __u32 *nr = &ns->ns_max_unused;
 129
 130         if (ns_connect_lru_resize(ns))
 131                 nr = &ns->ns_nr_unused;
 132         return lprocfs_rd_uint(page, start, off, count, eof, nr);
 133 }
 134
 135 static int lprocfs_wr_lru_size(struct file *file, const char *buffer,
 136                                unsigned long count, void *data)
 137 {
 138         struct ldlm_namespace *ns = data;
 139         char dummy[MAX_STRING_SIZE + 1], *end;
 140         unsigned long tmp;
 141
 142         dummy[MAX_STRING_SIZE] = '\0';
 143         if (copy_from_user(dummy, buffer, MAX_STRING_SIZE))
 144                 return -EFAULT;
 145
 146         if (count == 6 && memcmp(dummy, "clear", 5) == 0) {
 147                 CDEBUG(D_DLMTRACE,
 148                        "dropping all unused locks from namespace %s\n",
 149                        ns->ns_name);
 150                 if (ns_connect_lru_resize(ns)) {
 151                         int canceled, unused  = ns->ns_nr_unused;
 152
 153                         /* Try to cancel all @ns_nr_unused locks. */
 154                         canceled = ldlm_cancel_lru(ns, unused, LDLM_SYNC);
 155                         if (canceled < unused) {
 156                                 CERROR("not all requested locks are canceled, "
 157                                        "requested: %d, canceled: %d\n", unused,
 158                                        canceled);
 159                                 return -EINVAL;
 160                         }
 161                 } else {
 162                         tmp = ns->ns_max_unused;
 163                         ns->ns_max_unused = 0;
 164                         ldlm_cancel_lru(ns, 0, LDLM_SYNC);
 165                         ns->ns_max_unused = tmp;
 166                 }
 167                 return count;
 168         }
 169
 170         tmp = simple_strtoul(dummy, &end, 0);
 171         if (dummy == end) {
 172                 CERROR("invalid value written\n");
 173                 return -EINVAL;
 174         }
 175
 176         if (ns_connect_lru_resize(ns)) {
 177                 if (tmp > ns->ns_nr_unused)
 178                         tmp = ns->ns_nr_unused;
 179                 tmp = ns->ns_nr_unused - tmp;
 180
 181                 CDEBUG(D_DLMTRACE, "changing namespace %s unused locks from %u to %u\n",
 182                        ns->ns_name, ns->ns_nr_unused, (unsigned int)tmp);
 183                 ldlm_cancel_lru(ns, (unsigned int)tmp, LDLM_ASYNC);
 184         } else {
 185                 CDEBUG(D_DLMTRACE, "changing namespace %s max_unused from %u to %u\n",
 186                        ns->ns_name, ns->ns_max_unused, (unsigned int)tmp);
 187                 ns->ns_max_unused = (unsigned int)tmp;
 188                 ldlm_cancel_lru(ns, 0, LDLM_ASYNC);
 189         }
 190
 191         return count;
 192 }
 193
 194 void ldlm_proc_namespace(struct ldlm_namespace *ns)
 195 {
 196         struct lprocfs_vars lock_vars[2];
 197         char lock_name[MAX_STRING_SIZE + 1];
 198
 199         LASSERT(ns != NULL);
 200         LASSERT(ns->ns_name != NULL);
 201
 202         lock_name[MAX_STRING_SIZE] = '\0';
 203
 204         memset(lock_vars, 0, sizeof(lock_vars));
 205         lock_vars[0].name = lock_name;
 206
 207         snprintf(lock_name, MAX_STRING_SIZE, "%s/resource_count", ns->ns_name);
 208         lock_vars[0].data = &ns->ns_refcount;
 209         lock_vars[0].read_fptr = lprocfs_rd_atomic;
 210         lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
 211
 212         snprintf(lock_name, MAX_STRING_SIZE, "%s/lock_count", ns->ns_name);
 213         lock_vars[0].data = &ns->ns_locks;
 214         lock_vars[0].read_fptr = lprocfs_rd_atomic;
 215         lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
 216
 217         if (ns->ns_client) {
 218                 snprintf(lock_name, MAX_STRING_SIZE, "%s/lock_unused_count",
 219                          ns->ns_name);
 220                 lock_vars[0].data = &ns->ns_nr_unused;
 221                 lock_vars[0].read_fptr = lprocfs_rd_uint;
 222                 lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
 223
 224                 snprintf(lock_name, MAX_STRING_SIZE, "%s/lru_size",
 225                          ns->ns_name);
 226                 lock_vars[0].data = ns;
 227                 lock_vars[0].read_fptr = lprocfs_rd_lru_size;
 228                 lock_vars[0].write_fptr = lprocfs_wr_lru_size;
 229                 lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
 230
 231                 snprintf(lock_name, MAX_STRING_SIZE, "%s/lru_max_age",
 232                          ns->ns_name);
 233                 lock_vars[0].data = &ns->ns_max_age;
 234                 lock_vars[0].read_fptr = lprocfs_rd_uint;
 235                 lock_vars[0].write_fptr = lprocfs_wr_uint;
 236                 lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
 237
 238         }
 239 }
 240 #undef MAX_STRING_SIZE
 241 #else
 242 #define ldlm_proc_namespace(ns) do {} while (0)
 243 #endif /* LPROCFS */
 244
 245 struct ldlm_namespace *ldlm_namespace_new(char *name, ldlm_side_t client,
 246                                           ldlm_appetite_t apt)
 247 {
 248         struct ldlm_namespace *ns = NULL;
 249         struct list_head *bucket;
 250         int rc, idx;
 251         ENTRY;
 252
 253         rc = ldlm_get_ref(client);
 254         if (rc) {
 255                 CERROR("ldlm_get_ref failed: %d\n", rc);
 256                 RETURN(NULL);
 257         }
 258
 259         OBD_ALLOC_PTR(ns);
 260         if (!ns)
 261                 GOTO(out_ref, NULL);
 262
 263         OBD_VMALLOC(ns->ns_hash, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 264         if (!ns->ns_hash)
 265                 GOTO(out_ns, NULL);
 266
 267         ns->ns_appetite = apt;
 268         OBD_ALLOC(ns->ns_name, strlen(name) + 1);
 269         if (!ns->ns_name)
 270                 GOTO(out_hash, NULL);
 271
 272         strcpy(ns->ns_name, name);
 273
 274         CFS_INIT_LIST_HEAD(&ns->ns_root_list);
 275         ns->ns_refcount = 0;
 276         ns->ns_client = client;
 277         spin_lock_init(&ns->ns_hash_lock);
 278         atomic_set(&ns->ns_locks, 0);
 279         ns->ns_resources = 0;
 280         cfs_waitq_init(&ns->ns_waitq);
 281
 282         for (bucket = ns->ns_hash + RES_HASH_SIZE - 1; bucket >= ns->ns_hash;
 283              bucket--)
 284                 CFS_INIT_LIST_HEAD(bucket);
 285
 286         CFS_INIT_LIST_HEAD(&ns->ns_unused_list);
 287         ns->ns_nr_unused = 0;
 288         ns->ns_max_unused = LDLM_DEFAULT_LRU_SIZE;
 289         ns->ns_max_age = LDLM_DEFAULT_MAX_ALIVE;
 290         spin_lock_init(&ns->ns_unused_lock);
 291
 292         ns->ns_connect_flags = 0;
 293         mutex_down(ldlm_namespace_lock(client));
 294         list_add(&ns->ns_list_chain, ldlm_namespace_list(client));
 295         idx = atomic_read(ldlm_namespace_nr(client));
 296         atomic_inc(ldlm_namespace_nr(client));
 297         mutex_up(ldlm_namespace_lock(client));
 298         ldlm_proc_namespace(ns);
 299
 300         rc = ldlm_pool_init(&ns->ns_pool, ns, idx, client);
 301         if (rc) {
 302                 CERROR("can't initialize lock pool, rc %d\n", rc);
 303                 GOTO(out_del, rc);
 304         }
 305         RETURN(ns);
 306
 307 out_del:
 308         mutex_down(ldlm_namespace_lock(client));
 309         list_del(&ns->ns_list_chain);
 310         atomic_dec(ldlm_namespace_nr(client));
 311         mutex_up(ldlm_namespace_lock(client));
 312 out_hash:
 313         POISON(ns->ns_hash, 0x5a, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 314         OBD_VFREE(ns->ns_hash, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 315 out_ns:
 316         OBD_FREE_PTR(ns);
 317 out_ref:
 318         ldlm_put_ref(client, 0);
 319         RETURN(NULL);
 320 }
 321
 322 extern struct ldlm_lock *ldlm_lock_get(struct ldlm_lock *lock);
 323
 324 /* If flags contains FL_LOCAL_ONLY, don't try to tell the server, just cleanup.
 325  * This is currently only used for recovery, and we make certain assumptions
 326  * as a result--notably, that we shouldn't cancel locks with refs. -phil
 327  *
 328  * Called with the ns_lock held. */
 329 static void cleanup_resource(struct ldlm_resource *res, struct list_head *q,
 330                              int flags)
 331 {
 332         struct list_head *tmp;
 333         int rc = 0, client = res->lr_namespace->ns_client;
 334         int local_only = (flags & LDLM_FL_LOCAL_ONLY);
 335         ENTRY;
 336
 337
 338         do {
 339                 struct ldlm_lock *lock = NULL;
 340
 341                 /* first, we look for non-cleaned-yet lock
 342                  * all cleaned locks are marked by CLEANED flag */
 343                 lock_res(res);
 344                 list_for_each(tmp, q) {
 345                         lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 346                         if (lock->l_flags & LDLM_FL_CLEANED) {
 347                                 lock = NULL;
 348                                 continue;
 349                         }
 350                         LDLM_LOCK_GET(lock);
 351                         lock->l_flags |= LDLM_FL_CLEANED;
 352                         break;
 353                 }
 354
 355                 if (lock == NULL) {
 356                         unlock_res(res);
 357                         break;
 358                 }
 359
 360                 /* Set CBPENDING so nothing in the cancellation path
 361                  * can match this lock */
 362                 lock->l_flags |= LDLM_FL_CBPENDING;
 363                 lock->l_flags |= LDLM_FL_FAILED;
 364                 lock->l_flags |= flags;
 365
 366                 /* ... without sending a CANCEL message for local_only. */
 367                 if (local_only)
 368                         lock->l_flags |= LDLM_FL_LOCAL_ONLY;
 369
 370                 if (local_only && (lock->l_readers || lock->l_writers)) {
 371                         /* This is a little bit gross, but much better than the
 372                          * alternative: pretend that we got a blocking AST from
 373                          * the server, so that when the lock is decref'd, it
 374                          * will go away ... */
 375                         unlock_res(res);
 376                         LDLM_DEBUG(lock, "setting FL_LOCAL_ONLY");
 377                         if (lock->l_completion_ast)
 378                                 lock->l_completion_ast(lock, 0, NULL);
 379                         LDLM_LOCK_PUT(lock);
 380                         continue;
 381                 }
 382
 383                 if (client) {
 384                         struct lustre_handle lockh;
 385
 386                         unlock_res(res);
 387                         ldlm_lock2handle(lock, &lockh);
 388                         rc = ldlm_cli_cancel(&lockh);
 389                         if (rc)
 390                                 CERROR("ldlm_cli_cancel: %d\n", rc);
 391                 } else {
 392                         ldlm_resource_unlink_lock(lock);
 393                         unlock_res(res);
 394                         LDLM_DEBUG(lock, "Freeing a lock still held by a "
 395                                    "client node");
 396                         ldlm_lock_destroy(lock);
 397                 }
 398                 LDLM_LOCK_PUT(lock);
 399         } while (1);
 400
 401         EXIT;
 402 }
 403
 404 int ldlm_namespace_cleanup(struct ldlm_namespace *ns, int flags)
 405 {
 406         struct list_head *tmp;
 407         int i;
 408
 409         if (ns == NULL) {
 410                 CDEBUG(D_INFO, "NULL ns, skipping cleanup\n");
 411                 return ELDLM_OK;
 412         }
 413
 414         for (i = 0; i < RES_HASH_SIZE; i++) {
 415                 spin_lock(&ns->ns_hash_lock);
 416                 tmp = ns->ns_hash[i].next;
 417                 while (tmp != &(ns->ns_hash[i])) {
 418                         struct ldlm_resource *res;
 419                         res = list_entry(tmp, struct ldlm_resource, lr_hash);
 420                         ldlm_resource_getref(res);
 421                         spin_unlock(&ns->ns_hash_lock);
 422
 423                         cleanup_resource(res, &res->lr_granted, flags);
 424                         cleanup_resource(res, &res->lr_converting, flags);
 425                         cleanup_resource(res, &res->lr_waiting, flags);
 426
 427                         spin_lock(&ns->ns_hash_lock);
 428                         tmp  = tmp->next;
 429
 430                         /* XXX: former stuff caused issues in case of race
 431                          * between ldlm_namespace_cleanup() and lockd() when
 432                          * client gets blocking ast when lock gets distracted by
 433                          * server. This is 1_4 branch solution, let's see how
 434                          * will it behave. */
 435                         if (!ldlm_resource_putref_locked(res))
 436                                 CDEBUG(D_INFO,
 437                                        "Namespace %s resource refcount nonzero "
 438                                        "(%d) after lock cleanup; forcing cleanup.\n",
 439                                        ns->ns_name, atomic_read(&res->lr_refcount));
 440                 }
 441                 spin_unlock(&ns->ns_hash_lock);
 442         }
 443
 444         return ELDLM_OK;
 445 }
 446
 447 /* Cleanup, but also free, the namespace */
 448 int ldlm_namespace_free(struct ldlm_namespace *ns, int force)
 449 {
 450         ldlm_side_t client;
 451         ENTRY;
 452         if (!ns)
 453                 RETURN(ELDLM_OK);
 454
 455         client = ns->ns_client;
 456         mutex_down(ldlm_namespace_lock(client));
 457         list_del(&ns->ns_list_chain);
 458         atomic_dec(ldlm_namespace_nr(ns->ns_client));
 459         ldlm_pool_fini(&ns->ns_pool);
 460         mutex_up(ldlm_namespace_lock(client));
 461
 462         /* At shutdown time, don't call the cancellation callback */
 463         ldlm_namespace_cleanup(ns, 0);
 464
 465 #ifdef LPROCFS
 466         {
 467                 struct proc_dir_entry *dir;
 468                 dir = lprocfs_srch(ldlm_ns_proc_dir, ns->ns_name);
 469                 if (dir == NULL) {
 470                         CERROR("dlm namespace %s has no procfs dir?\n",
 471                                ns->ns_name);
 472                 } else {
 473                         lprocfs_remove(&dir);
 474                 }
 475         }
 476 #endif
 477
 478         if (ns->ns_refcount > 0) {
 479                 struct l_wait_info lwi = LWI_INTR(LWI_ON_SIGNAL_NOOP, NULL);
 480                 int rc;
 481                 CDEBUG(D_DLMTRACE,
 482                        "dlm namespace %s free waiting on refcount %d\n",
 483                        ns->ns_name, ns->ns_refcount);
 484                 rc = l_wait_event(ns->ns_waitq,
 485                                   ns->ns_refcount == 0, &lwi);
 486                 if (ns->ns_refcount)
 487                         LCONSOLE_ERROR_MSG(0x139, "Lock manager: wait for %s "
 488                                            "namespace cleanup aborted with %d "
 489                                            "resources in use. (%d)\nI'm going "
 490                                            "to try to clean up anyway, but I "
 491                                            "might need a reboot of this node.\n",
 492                                             ns->ns_name, (int) ns->ns_refcount,
 493                                             rc);
 494                 CDEBUG(D_DLMTRACE,
 495                        "dlm namespace %s free done waiting\n", ns->ns_name);
 496         }
 497
 498         POISON(ns->ns_hash, 0x5a, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 499         OBD_VFREE(ns->ns_hash, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 500         OBD_FREE(ns->ns_name, strlen(ns->ns_name) + 1);
 501         OBD_FREE_PTR(ns);
 502
 503         ldlm_put_ref(client, force);
 504
 505         RETURN(ELDLM_OK);
 506 }
 507
 508 void ldlm_namespace_get_nolock(struct ldlm_namespace *ns)
 509 {
 510         LASSERT(ns->ns_refcount >= 0);
 511         ns->ns_refcount++;
 512 }
 513
 514 void ldlm_namespace_get(struct ldlm_namespace *ns)
 515 {
 516         spin_lock(&ns->ns_hash_lock);
 517         ldlm_namespace_get_nolock(ns);
 518         spin_unlock(&ns->ns_hash_lock);
 519 }
 520
 521 void ldlm_namespace_put_nolock(struct ldlm_namespace *ns, int wakeup)
 522 {
 523         LASSERT(ns->ns_refcount > 0);
 524         ns->ns_refcount--;
 525         if (ns->ns_refcount == 0 && wakeup)
 526                 wake_up(&ns->ns_waitq);
 527 }
 528
 529 void ldlm_namespace_put(struct ldlm_namespace *ns, int wakeup)
 530 {
 531         spin_lock(&ns->ns_hash_lock);
 532         ldlm_namespace_put_nolock(ns, wakeup);
 533         spin_unlock(&ns->ns_hash_lock);
 534 }
 535
 536 /* Should be called under ldlm_namespace_lock(client) taken */
 537 void ldlm_namespace_move(struct ldlm_namespace *ns, ldlm_side_t client)
 538 {
 539         LASSERT(!list_empty(&ns->ns_list_chain));
 540         LASSERT_SEM_LOCKED(ldlm_namespace_lock(client));
 541         list_move_tail(&ns->ns_list_chain, ldlm_namespace_list(client));
 542 }
 543
 544 /* Should be called under ldlm_namespace_lock(client) taken */
 545 struct ldlm_namespace *ldlm_namespace_first(ldlm_side_t client)
 546 {
 547         LASSERT_SEM_LOCKED(ldlm_namespace_lock(client));
 548         LASSERT(!list_empty(ldlm_namespace_list(client)));
 549         return container_of(ldlm_namespace_list(client)->next,
 550                 struct ldlm_namespace, ns_list_chain);
 551 }
 552 static __u32 ldlm_hash_fn(struct ldlm_resource *parent,
 553                           const struct ldlm_res_id *name)
 554 {
 555         __u32 hash = 0;
 556         int i;
 557
 558         for (i = 0; i < RES_NAME_SIZE; i++)
 559                 hash += name->name[i];
 560
 561         hash += (__u32)((unsigned long)parent >> 4);
 562
 563         return (hash & RES_HASH_MASK);
 564 }
 565
 566 static struct ldlm_resource *ldlm_resource_new(void)
 567 {
 568         struct ldlm_resource *res;
 569
 570         OBD_SLAB_ALLOC(res, ldlm_resource_slab, CFS_ALLOC_IO, sizeof *res);
 571         if (res == NULL)
 572                 return NULL;
 573
 574         memset(res, 0, sizeof(*res));
 575
 576         CFS_INIT_LIST_HEAD(&res->lr_children);
 577         CFS_INIT_LIST_HEAD(&res->lr_childof);
 578         CFS_INIT_LIST_HEAD(&res->lr_granted);
 579         CFS_INIT_LIST_HEAD(&res->lr_converting);
 580         CFS_INIT_LIST_HEAD(&res->lr_waiting);
 581         atomic_set(&res->lr_refcount, 1);
 582         spin_lock_init(&res->lr_lock);
 583
 584         /* one who creates the resource must unlock
 585          * the semaphore after lvb initialization */
 586         init_MUTEX_LOCKED(&res->lr_lvb_sem);
 587
 588         return res;
 589 }
 590
 591 /* must be called with hash lock held */
 592 static struct ldlm_resource *
 593 ldlm_resource_find(struct ldlm_namespace *ns, const struct ldlm_res_id *name,
 594                    __u32 hash)
 595 {
 596         struct list_head *bucket, *tmp;
 597         struct ldlm_resource *res;
 598
 599         LASSERT_SPIN_LOCKED(&ns->ns_hash_lock);
 600         bucket = ns->ns_hash + hash;
 601
 602         list_for_each(tmp, bucket) {
 603                 res = list_entry(tmp, struct ldlm_resource, lr_hash);
 604                 if (memcmp(&res->lr_name, name, sizeof(res->lr_name)) == 0)
 605                         return res;
 606         }
 607
 608         return NULL;
 609 }
 610
 611 /* Args: locked namespace
 612  * Returns: newly-allocated, referenced, unlocked resource */
 613 static struct ldlm_resource *
 614 ldlm_resource_add(struct ldlm_namespace *ns, struct ldlm_resource *parent,
 615                   const struct ldlm_res_id *name, __u32 hash, ldlm_type_t type)
 616 {
 617         struct list_head *bucket;
 618         struct ldlm_resource *res, *old_res;
 619         ENTRY;
 620
 621         LASSERTF(type >= LDLM_MIN_TYPE && type < LDLM_MAX_TYPE,
 622                  "type: %d\n", type);
 623
 624         res = ldlm_resource_new();
 625         if (!res)
 626                 RETURN(NULL);
 627
 628         res->lr_name = *name;
 629         res->lr_namespace = ns;
 630         res->lr_type = type;
 631         res->lr_most_restr = LCK_NL;
 632
 633         spin_lock(&ns->ns_hash_lock);
 634         old_res = ldlm_resource_find(ns, name, hash);
 635         if (old_res) {
 636                 /* someone won the race and added the resource before */
 637                 ldlm_resource_getref(old_res);
 638                 spin_unlock(&ns->ns_hash_lock);
 639                 OBD_SLAB_FREE(res, ldlm_resource_slab, sizeof *res);
 640                 /* synchronize WRT resource creation */
 641                 if (ns->ns_lvbo && ns->ns_lvbo->lvbo_init) {
 642                         down(&old_res->lr_lvb_sem);
 643                         up(&old_res->lr_lvb_sem);
 644                 }
 645                 RETURN(old_res);
 646         }
 647
 648         /* we won! let's add the resource */
 649         bucket = ns->ns_hash + hash;
 650         list_add(&res->lr_hash, bucket);
 651         ns->ns_resources++;
 652         ldlm_namespace_get_nolock(ns);
 653
 654         if (parent == NULL) {
 655                 list_add(&res->lr_childof, &ns->ns_root_list);
 656         } else {
 657                 res->lr_parent = parent;
 658                 list_add(&res->lr_childof, &parent->lr_children);
 659         }
 660         spin_unlock(&ns->ns_hash_lock);
 661
 662         if (ns->ns_lvbo && ns->ns_lvbo->lvbo_init) {
 663                 int rc;
 664
 665                 OBD_FAIL_TIMEOUT(OBD_FAIL_LDLM_CREATE_RESOURCE, 2);
 666                 rc = ns->ns_lvbo->lvbo_init(res);
 667                 if (rc)
 668                         CERROR("lvbo_init failed for resource "
 669                                LPU64": rc %d\n", name->name[0], rc);
 670                 /* we create resource with locked lr_lvb_sem */
 671                 up(&res->lr_lvb_sem);
 672         }
 673
 674         RETURN(res);
 675 }
 676
 677 /* Args: unlocked namespace
 678  * Locks: takes and releases ns->ns_lock and res->lr_lock
 679  * Returns: referenced, unlocked ldlm_resource or NULL */
 680 struct ldlm_resource *
 681 ldlm_resource_get(struct ldlm_namespace *ns, struct ldlm_resource *parent,
 682                   const struct ldlm_res_id *name, ldlm_type_t type, int create)
 683 {
 684         __u32 hash = ldlm_hash_fn(parent, name);
 685         struct ldlm_resource *res = NULL;
 686         ENTRY;
 687
 688         LASSERT(ns != NULL);
 689         LASSERT(ns->ns_hash != NULL);
 690         LASSERT(name->name[0] != 0);
 691
 692         spin_lock(&ns->ns_hash_lock);
 693         res = ldlm_resource_find(ns, name, hash);
 694         if (res) {
 695                 ldlm_resource_getref(res);
 696                 spin_unlock(&ns->ns_hash_lock);
 697                 /* synchronize WRT resource creation */
 698                 if (ns->ns_lvbo && ns->ns_lvbo->lvbo_init) {
 699                         down(&res->lr_lvb_sem);
 700                         up(&res->lr_lvb_sem);
 701                 }
 702                 RETURN(res);
 703         }
 704         spin_unlock(&ns->ns_hash_lock);
 705
 706         if (create == 0)
 707                 RETURN(NULL);
 708
 709         res = ldlm_resource_add(ns, parent, name, hash, type);
 710         RETURN(res);
 711 }
 712
 713 struct ldlm_resource *ldlm_resource_getref(struct ldlm_resource *res)
 714 {
 715         LASSERT(res != NULL);
 716         LASSERT(res != LP_POISON);
 717         atomic_inc(&res->lr_refcount);
 718         CDEBUG(D_INFO, "getref res: %p count: %d\n", res,
 719                atomic_read(&res->lr_refcount));
 720         return res;
 721 }
 722
 723 void __ldlm_resource_putref_final(struct ldlm_resource *res)
 724 {
 725         struct ldlm_namespace *ns = res->lr_namespace;
 726
 727         LASSERT_SPIN_LOCKED(&ns->ns_hash_lock);
 728
 729         if (!list_empty(&res->lr_granted)) {
 730                 ldlm_resource_dump(D_ERROR, res);
 731                 LBUG();
 732         }
 733
 734         if (!list_empty(&res->lr_converting)) {
 735                 ldlm_resource_dump(D_ERROR, res);
 736                 LBUG();
 737         }
 738
 739         if (!list_empty(&res->lr_waiting)) {
 740                 ldlm_resource_dump(D_ERROR, res);
 741                 LBUG();
 742         }
 743
 744         if (!list_empty(&res->lr_children)) {
 745                 ldlm_resource_dump(D_ERROR, res);
 746                 LBUG();
 747         }
 748
 749         /* Pass 0 here to not wake ->ns_waitq up yet, we will do it few
 750          * lines below when all children are freed. */
 751         ldlm_namespace_put_nolock(ns, 0);
 752         list_del_init(&res->lr_hash);
 753         list_del_init(&res->lr_childof);
 754
 755         ns->ns_resources--;
 756         if (ns->ns_resources == 0)
 757                 wake_up(&ns->ns_waitq);
 758 }
 759
 760 /* Returns 1 if the resource was freed, 0 if it remains. */
 761 int ldlm_resource_putref(struct ldlm_resource *res)
 762 {
 763         struct ldlm_namespace *ns = res->lr_namespace;
 764         int rc = 0;
 765         ENTRY;
 766
 767         CDEBUG(D_INFO, "putref res: %p count: %d\n", res,
 768                atomic_read(&res->lr_refcount) - 1);
 769         LASSERTF(atomic_read(&res->lr_refcount) > 0, "%d",
 770                  atomic_read(&res->lr_refcount));
 771         LASSERTF(atomic_read(&res->lr_refcount) < LI_POISON, "%d",
 772                  atomic_read(&res->lr_refcount));
 773
 774         if (atomic_dec_and_lock(&res->lr_refcount, &ns->ns_hash_lock)) {
 775                 __ldlm_resource_putref_final(res);
 776                 spin_unlock(&ns->ns_hash_lock);
 777                 if (res->lr_lvb_data)
 778                         OBD_FREE(res->lr_lvb_data, res->lr_lvb_len);
 779                 OBD_SLAB_FREE(res, ldlm_resource_slab, sizeof *res);
 780                 rc = 1;
 781         }
 782
 783         RETURN(rc);
 784 }
 785
 786 /* Returns 1 if the resource was freed, 0 if it remains. */
 787 int ldlm_resource_putref_locked(struct ldlm_resource *res)
 788 {
 789         int rc = 0;
 790         ENTRY;
 791
 792         CDEBUG(D_INFO, "putref res: %p count: %d\n", res,
 793                atomic_read(&res->lr_refcount) - 1);
 794         LASSERT(atomic_read(&res->lr_refcount) > 0);
 795         LASSERT(atomic_read(&res->lr_refcount) < LI_POISON);
 796
 797         LASSERT(atomic_read(&res->lr_refcount) >= 0);
 798         if (atomic_dec_and_test(&res->lr_refcount)) {
 799                 __ldlm_resource_putref_final(res);
 800                 if (res->lr_lvb_data)
 801                         OBD_FREE(res->lr_lvb_data, res->lr_lvb_len);
 802                 OBD_SLAB_FREE(res, ldlm_resource_slab, sizeof *res);
 803                 rc = 1;
 804         }
 805
 806         RETURN(rc);
 807 }
 808
 809 void ldlm_resource_add_lock(struct ldlm_resource *res, struct list_head *head,
 810                             struct ldlm_lock *lock)
 811 {
 812         check_res_locked(res);
 813
 814         ldlm_resource_dump(D_OTHER, res);
 815         CDEBUG(D_OTHER, "About to add this lock:\n");
 816         ldlm_lock_dump(D_OTHER, lock, 0);
 817
 818         if (lock->l_destroyed) {
 819                 CDEBUG(D_OTHER, "Lock destroyed, not adding to resource\n");
 820                 return;
 821         }
 822
 823         LASSERT(list_empty(&lock->l_res_link));
 824
 825         list_add_tail(&lock->l_res_link, head);
 826 }
 827
 828 void ldlm_resource_insert_lock_after(struct ldlm_lock *original,
 829                                      struct ldlm_lock *new)
 830 {
 831         struct ldlm_resource *res = original->l_resource;
 832
 833         check_res_locked(res);
 834
 835         ldlm_resource_dump(D_OTHER, res);
 836         CDEBUG(D_OTHER, "About to insert this lock after %p:\n", original);
 837         ldlm_lock_dump(D_OTHER, new, 0);
 838
 839         if (new->l_destroyed) {
 840                 CDEBUG(D_OTHER, "Lock destroyed, not adding to resource\n");
 841                 goto out;
 842         }
 843
 844         LASSERT(list_empty(&new->l_res_link));
 845
 846         list_add(&new->l_res_link, &original->l_res_link);
 847  out:;
 848 }
 849
 850 void ldlm_resource_unlink_lock(struct ldlm_lock *lock)
 851 {
 852         check_res_locked(lock->l_resource);
 853         ldlm_unlink_lock_skiplist(lock);
 854         list_del_init(&lock->l_res_link);
 855 }
 856
 857 void ldlm_res2desc(struct ldlm_resource *res, struct ldlm_resource_desc *desc)
 858 {
 859         desc->lr_type = res->lr_type;
 860         desc->lr_name = res->lr_name;
 861 }
 862
 863 void ldlm_dump_all_namespaces(ldlm_side_t client, int level)
 864 {
 865         struct list_head *tmp;
 866
 867         if (!((libcfs_debug | D_ERROR) & level))
 868                 return;
 869
 870         mutex_down(ldlm_namespace_lock(client));
 871
 872         list_for_each(tmp, ldlm_namespace_list(client)) {
 873                 struct ldlm_namespace *ns;
 874                 ns = list_entry(tmp, struct ldlm_namespace, ns_list_chain);
 875                 ldlm_namespace_dump(level, ns);
 876         }
 877
 878         mutex_up(ldlm_namespace_lock(client));
 879 }
 880
 881 void ldlm_namespace_dump(int level, struct ldlm_namespace *ns)
 882 {
 883         struct list_head *tmp;
 884
 885         if (!((libcfs_debug | D_ERROR) & level))
 886                 return;
 887
 888         CDEBUG(level, "--- Namespace: %s (rc: %d, client: %d)\n",
 889                   ns->ns_name, ns->ns_refcount, ns->ns_client);
 890
 891         if (cfs_time_before(cfs_time_current(), ns->ns_next_dump))
 892                 return;
 893
 894         spin_lock(&ns->ns_hash_lock);
 895         tmp = ns->ns_root_list.next;
 896         while (tmp != &ns->ns_root_list) {
 897                 struct ldlm_resource *res;
 898                 res = list_entry(tmp, struct ldlm_resource, lr_childof);
 899
 900                 ldlm_resource_getref(res);
 901                 spin_unlock(&ns->ns_hash_lock);
 902
 903                 lock_res(res);
 904                 ldlm_resource_dump(level, res);
 905                 unlock_res(res);
 906
 907                 spin_lock(&ns->ns_hash_lock);
 908                 tmp = tmp->next;
 909                 ldlm_resource_putref_locked(res);
 910         }
 911         ns->ns_next_dump = cfs_time_shift(10);
 912         spin_unlock(&ns->ns_hash_lock);
 913 }
 914
 915 void ldlm_resource_dump(int level, struct ldlm_resource *res)
 916 {
 917         struct list_head *tmp;
 918         int pos;
 919
 920         CLASSERT(RES_NAME_SIZE == 4);
 921
 922         if (!((libcfs_debug | D_ERROR) & level))
 923                 return;
 924
 925         CDEBUG(level, "--- Resource: %p ("LPU64"/"LPU64"/"LPU64"/"LPU64
 926                ") (rc: %d)\n", res, res->lr_name.name[0], res->lr_name.name[1],
 927                res->lr_name.name[2], res->lr_name.name[3],
 928                atomic_read(&res->lr_refcount));
 929
 930         if (!list_empty(&res->lr_granted)) {
 931                 pos = 0;
 932                 CDEBUG(level, "Granted locks:\n");
 933                 list_for_each(tmp, &res->lr_granted) {
 934                         struct ldlm_lock *lock;
 935                         lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 936                         ldlm_lock_dump(level, lock, ++pos);
 937                 }
 938         }
 939         if (!list_empty(&res->lr_converting)) {
 940                 pos = 0;
 941                 CDEBUG(level, "Converting locks:\n");
 942                 list_for_each(tmp, &res->lr_converting) {
 943                         struct ldlm_lock *lock;
 944                         lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 945                         ldlm_lock_dump(level, lock, ++pos);
 946                 }
 947         }
 948         if (!list_empty(&res->lr_waiting)) {
 949                 pos = 0;
 950                 CDEBUG(level, "Waiting locks:\n");
 951                 list_for_each(tmp, &res->lr_waiting) {
 952                         struct ldlm_lock *lock;
 953                         lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 954                         ldlm_lock_dump(level, lock, ++pos);
 955                 }
 956         }
 957 }