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 Lustre, http://www.lustre.org.
   9  *
  10  *   Lustre is free software; you can redistribute it and/or
  11  *   modify it under the terms of version 2 of the GNU General Public
  12  *   License as published by the Free Software Foundation.
  13  *
  14  *   Lustre is distributed in the hope that it will be useful,
  15  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *   GNU General Public License for more details.
  18  *
  19  *   You should have received a copy of the GNU General Public License
  20  *   along with Lustre; if not, write to the Free Software
  21  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22  */
  23
  24 #define DEBUG_SUBSYSTEM S_LDLM
  25 #ifdef __KERNEL__
  26 # include <linux/lustre_dlm.h>
  27 #else
  28 # include <liblustre.h>
  29 #endif
  30
  31 #include <linux/obd_class.h>
  32 #include "ldlm_internal.h"
  33
  34 kmem_cache_t *ldlm_resource_slab, *ldlm_lock_slab;
  35
  36 DECLARE_MUTEX(ldlm_namespace_lock);
  37 struct list_head ldlm_namespace_list = LIST_HEAD_INIT(ldlm_namespace_list);
  38 struct proc_dir_entry *ldlm_type_proc_dir = NULL;
  39 struct proc_dir_entry *ldlm_ns_proc_dir = NULL;
  40 struct proc_dir_entry *ldlm_svc_proc_dir = NULL;
  41
  42 #ifdef __KERNEL__
  43 static int ldlm_proc_dump_ns(struct file *file, const char *buffer,
  44                              unsigned long count, void *data)
  45 {
  46         ldlm_dump_all_namespaces(D_DLMTRACE);
  47         RETURN(count);
  48 }
  49
  50 int ldlm_proc_setup(void)
  51 {
  52         int rc;
  53         struct lprocfs_vars list[] = {
  54                 { "dump_namespaces", NULL, ldlm_proc_dump_ns, NULL },
  55                 { NULL }};
  56         ENTRY;
  57         LASSERT(ldlm_ns_proc_dir == NULL);
  58
  59         ldlm_type_proc_dir = lprocfs_register(OBD_LDLM_DEVICENAME,
  60                                               proc_lustre_root,
  61                                               NULL, NULL);
  62         if (IS_ERR(ldlm_type_proc_dir)) {
  63                 CERROR("LProcFS failed in ldlm-init\n");
  64                 rc = PTR_ERR(ldlm_type_proc_dir);
  65                 GOTO(err, rc);
  66         }
  67
  68         ldlm_ns_proc_dir = lprocfs_register("namespaces",
  69                                             ldlm_type_proc_dir,
  70                                             NULL, NULL);
  71         if (IS_ERR(ldlm_ns_proc_dir)) {
  72                 CERROR("LProcFS failed in ldlm-init\n");
  73                 rc = PTR_ERR(ldlm_ns_proc_dir);
  74                 GOTO(err_type, rc);
  75         }
  76
  77         ldlm_svc_proc_dir = lprocfs_register("services",
  78                                             ldlm_type_proc_dir,
  79                                             NULL, NULL);
  80         if (IS_ERR(ldlm_svc_proc_dir)) {
  81                 CERROR("LProcFS failed in ldlm-init\n");
  82                 rc = PTR_ERR(ldlm_svc_proc_dir);
  83                 GOTO(err_ns, rc);
  84         }
  85
  86         rc = lprocfs_add_vars(ldlm_type_proc_dir, list, NULL);
  87
  88         RETURN(0);
  89
  90 err_ns:
  91         lprocfs_remove(ldlm_ns_proc_dir);
  92 err_type:
  93         lprocfs_remove(ldlm_type_proc_dir);
  94 err:
  95         ldlm_type_proc_dir = NULL;
  96         ldlm_ns_proc_dir = NULL;
  97         ldlm_svc_proc_dir = NULL;
  98         RETURN(rc);
  99 }
 100
 101 void ldlm_proc_cleanup(void)
 102 {
 103         if (ldlm_svc_proc_dir) {
 104                 lprocfs_remove(ldlm_svc_proc_dir);
 105                 ldlm_svc_proc_dir = NULL;
 106         }
 107
 108         if (ldlm_ns_proc_dir) {
 109                 lprocfs_remove(ldlm_ns_proc_dir);
 110                 ldlm_ns_proc_dir = NULL;
 111         }
 112
 113         if (ldlm_type_proc_dir) {
 114                 lprocfs_remove(ldlm_type_proc_dir);
 115                 ldlm_type_proc_dir = NULL;
 116         }
 117 }
 118
 119 static int lprocfs_uint_rd(char *page, char **start, off_t off,
 120                            int count, int *eof, void *data)
 121 {
 122         unsigned int *temp = (unsigned int *)data;
 123         return snprintf(page, count, "%u\n", *temp);
 124 }
 125
 126 static int lprocfs_read_lru_size(char *page, char **start, off_t off,
 127                                  int count, int *eof, void *data)
 128 {
 129         struct ldlm_namespace *ns = data;
 130         return lprocfs_uint_rd(page, start, off, count, eof,
 131                                &ns->ns_max_unused);
 132 }
 133
 134 #define MAX_STRING_SIZE 128
 135 static int lprocfs_write_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                 tmp = ns->ns_max_unused;
 151                 ns->ns_max_unused = 0;
 152                 ldlm_cancel_lru(ns, LDLM_SYNC);
 153                 ns->ns_max_unused = tmp;
 154                 return count;
 155         }
 156
 157         tmp = simple_strtoul(dummy, &end, 0);
 158         if (tmp == 0 && *end) {
 159                 CERROR("invalid value written\n");
 160                 return -EINVAL;
 161         }
 162
 163         CDEBUG(D_DLMTRACE, "changing namespace %s max_unused from %u to %u\n",
 164                ns->ns_name, ns->ns_max_unused, (unsigned int)tmp);
 165
 166         ns->ns_max_unused = (unsigned int)tmp;
 167         ldlm_cancel_lru(ns, LDLM_ASYNC);
 168         return count;
 169 }
 170
 171 void ldlm_proc_namespace(struct ldlm_namespace *ns)
 172 {
 173         struct lprocfs_vars lock_vars[2];
 174         char lock_name[MAX_STRING_SIZE + 1];
 175
 176         LASSERT(ns != NULL);
 177         LASSERT(ns->ns_name != NULL);
 178
 179         lock_name[MAX_STRING_SIZE] = '\0';
 180
 181         memset(lock_vars, 0, sizeof(lock_vars));
 182         lock_vars[0].read_fptr = lprocfs_rd_u64;
 183         lock_vars[0].name = lock_name;
 184
 185         snprintf(lock_name, MAX_STRING_SIZE, "%s/resource_count", ns->ns_name);
 186         lock_vars[0].data = &ns->ns_resources;
 187         lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
 188
 189         snprintf(lock_name, MAX_STRING_SIZE, "%s/lock_count", ns->ns_name);
 190         lock_vars[0].data = &ns->ns_locks;
 191         lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
 192
 193         if (ns->ns_client) {
 194                 snprintf(lock_name, MAX_STRING_SIZE, "%s/lock_unused_count",
 195                          ns->ns_name);
 196                 lock_vars[0].data = &ns->ns_nr_unused;
 197                 lock_vars[0].read_fptr = lprocfs_uint_rd;
 198                 lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
 199
 200                 snprintf(lock_name, MAX_STRING_SIZE, "%s/lru_size",
 201                          ns->ns_name);
 202                 lock_vars[0].data = ns;
 203                 lock_vars[0].read_fptr = lprocfs_read_lru_size;
 204                 lock_vars[0].write_fptr = lprocfs_write_lru_size;
 205                 lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
 206         }
 207 }
 208 #endif
 209 #undef MAX_STRING_SIZE
 210
 211 struct ldlm_namespace *ldlm_namespace_new(char *name, __u32 client)
 212 {
 213         struct ldlm_namespace *ns = NULL;
 214         struct list_head *bucket;
 215         int rc;
 216         ENTRY;
 217
 218         rc = ldlm_get_ref();
 219         if (rc) {
 220                 CERROR("ldlm_get_ref failed: %d\n", rc);
 221                 RETURN(NULL);
 222         }
 223
 224         OBD_ALLOC(ns, sizeof(*ns));
 225         if (!ns)
 226                 GOTO(out_ref, NULL);
 227
 228         OBD_VMALLOC(ns->ns_hash, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 229         if (!ns->ns_hash)
 230                 GOTO(out_ns, NULL);
 231
 232         OBD_ALLOC(ns->ns_name, strlen(name) + 1);
 233         if (!ns->ns_name)
 234                 GOTO(out_hash, NULL);
 235
 236         strcpy(ns->ns_name, name);
 237
 238         INIT_LIST_HEAD(&ns->ns_root_list);
 239         ns->ns_refcount = 0;
 240         ns->ns_client = client;
 241         spin_lock_init(&ns->ns_hash_lock);
 242         atomic_set(&ns->ns_locks, 0);
 243         ns->ns_resources = 0;
 244         init_waitqueue_head(&ns->ns_waitq);
 245
 246         for (bucket = ns->ns_hash + RES_HASH_SIZE - 1; bucket >= ns->ns_hash;
 247              bucket--)
 248                 INIT_LIST_HEAD(bucket);
 249
 250         INIT_LIST_HEAD(&ns->ns_unused_list);
 251         ns->ns_nr_unused = 0;
 252         ns->ns_max_unused = LDLM_DEFAULT_LRU_SIZE;
 253         spin_lock_init(&ns->ns_unused_lock);
 254
 255         down(&ldlm_namespace_lock);
 256         list_add(&ns->ns_list_chain, &ldlm_namespace_list);
 257         up(&ldlm_namespace_lock);
 258 #ifdef __KERNEL__
 259         ldlm_proc_namespace(ns);
 260 #endif
 261         RETURN(ns);
 262
 263 out_hash:
 264         POISON(ns->ns_hash, 0x5a, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 265         OBD_VFREE(ns->ns_hash, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 266 out_ns:
 267         OBD_FREE(ns, sizeof(*ns));
 268 out_ref:
 269         ldlm_put_ref(0);
 270         RETURN(NULL);
 271 }
 272
 273 extern struct ldlm_lock *ldlm_lock_get(struct ldlm_lock *lock);
 274
 275 /* If flags contains FL_LOCAL_ONLY, don't try to tell the server, just cleanup.
 276  * This is currently only used for recovery, and we make certain assumptions
 277  * as a result--notably, that we shouldn't cancel locks with refs. -phil
 278  *
 279  * Called with the ns_lock held. */
 280 static void cleanup_resource(struct ldlm_resource *res, struct list_head *q,
 281                              int flags)
 282 {
 283         struct list_head *tmp;
 284         int rc = 0, client = res->lr_namespace->ns_client;
 285         int local_only = (flags & LDLM_FL_LOCAL_ONLY);
 286         ENTRY;
 287
 288
 289         do {
 290                 struct ldlm_lock *lock = NULL;
 291
 292                 /* first, we look for non-cleaned-yet lock
 293                  * all cleaned locks are marked by CLEANED flag */
 294                 lock_res(res);
 295                 list_for_each(tmp, q) {
 296                         lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 297                         if (lock->l_flags & LDLM_FL_CLEANED) {
 298                                 lock = NULL;
 299                                 continue;
 300                         }
 301                         LDLM_LOCK_GET(lock);
 302                         lock->l_flags |= LDLM_FL_CLEANED;
 303                         break;
 304                 }
 305
 306                 if (lock == NULL) {
 307                         unlock_res(res);
 308                         break;
 309                 }
 310
 311                 /* Set CBPENDING so nothing in the cancellation path
 312                  * can match this lock */
 313                 lock->l_flags |= LDLM_FL_CBPENDING;
 314                 lock->l_flags |= LDLM_FL_FAILED;
 315                 lock->l_flags |= flags;
 316
 317                 if (local_only && (lock->l_readers || lock->l_writers)) {
 318                         /* This is a little bit gross, but much better than the
 319                          * alternative: pretend that we got a blocking AST from
 320                          * the server, so that when the lock is decref'd, it
 321                          * will go away ... */
 322                         /* ... without sending a CANCEL message. */
 323                         lock->l_flags |= LDLM_FL_LOCAL_ONLY;
 324                         unlock_res(res);
 325                         LDLM_DEBUG(lock, "setting FL_LOCAL_ONLY");
 326                         if (lock->l_completion_ast)
 327                                 lock->l_completion_ast(lock, 0, NULL);
 328                         LDLM_LOCK_PUT(lock);
 329                         continue;
 330                 }
 331
 332                 if (client) {
 333                         struct lustre_handle lockh;
 334
 335                         unlock_res(res);
 336                         ldlm_lock2handle(lock, &lockh);
 337                         if (!local_only) {
 338                                 rc = ldlm_cli_cancel(&lockh);
 339                                 if (rc)
 340                                         CERROR("ldlm_cli_cancel: %d\n", rc);
 341                         }
 342                         /* Force local cleanup on errors, too. */
 343                         if (local_only || rc != ELDLM_OK)
 344                                 ldlm_lock_cancel(lock);
 345                 } else {
 346                         ldlm_resource_unlink_lock(lock);
 347                         unlock_res(res);
 348                         LDLM_DEBUG(lock, "Freeing a lock still held by a "
 349                                    "client node");
 350                         ldlm_lock_destroy(lock);
 351                 }
 352                 LDLM_LOCK_PUT(lock);
 353         } while (1);
 354
 355         EXIT;
 356 }
 357
 358 int ldlm_namespace_cleanup(struct ldlm_namespace *ns, int flags)
 359 {
 360         struct list_head *tmp;
 361         int i;
 362
 363         if (ns == NULL) {
 364                 CDEBUG(D_INFO, "NULL ns, skipping cleanup\n");
 365                 return ELDLM_OK;
 366         }
 367
 368         for (i = 0; i < RES_HASH_SIZE; i++) {
 369                 spin_lock(&ns->ns_hash_lock);
 370                 tmp = ns->ns_hash[i].next;
 371                 while (tmp != &(ns->ns_hash[i])) {
 372                         struct ldlm_resource *res;
 373                         res = list_entry(tmp, struct ldlm_resource, lr_hash);
 374                         ldlm_resource_getref(res);
 375                         spin_unlock(&ns->ns_hash_lock);
 376
 377                         cleanup_resource(res, &res->lr_granted, flags);
 378                         cleanup_resource(res, &res->lr_converting, flags);
 379                         cleanup_resource(res, &res->lr_waiting, flags);
 380
 381                         spin_lock(&ns->ns_hash_lock);
 382                         tmp  = tmp->next;
 383
 384                         /* XXX: former stuff caused issues in case of race
 385                          * between ldlm_namespace_cleanup() and lockd() when
 386                          * client gets blocking ast when lock gets distracted by
 387                          * server. This is 1_4 branch solution, let's see how
 388                          * will it behave. */
 389                         if (!ldlm_resource_putref_locked(res))
 390                                 CDEBUG(D_INFO,
 391                                        "Namespace %s resource refcount nonzero "
 392                                        "(%d) after lock cleanup; forcing cleanup.\n",
 393                                        ns->ns_name, atomic_read(&res->lr_refcount));
 394                 }
 395                 spin_unlock(&ns->ns_hash_lock);
 396         }
 397
 398         return ELDLM_OK;
 399 }
 400
 401 static inline int ldlm_ns_refcount_atomic(struct ldlm_namespace *ns)
 402 {
 403         int refcount;
 404         spin_lock(&ns->ns_hash_lock);
 405         refcount = ns->ns_refcount;
 406         spin_unlock(&ns->ns_hash_lock);
 407         return refcount;
 408 }
 409
 410 /* Cleanup, but also free, the namespace */
 411 int ldlm_namespace_free(struct ldlm_namespace *ns, int force)
 412 {
 413         if (!ns)
 414                 RETURN(ELDLM_OK);
 415
 416         down(&ldlm_namespace_lock);
 417         list_del(&ns->ns_list_chain);
 418         up(&ldlm_namespace_lock);
 419
 420         /* At shutdown time, don't call the cancellation callback */
 421         ldlm_namespace_cleanup(ns, 0);
 422
 423 #ifdef __KERNEL__
 424         {
 425                 struct proc_dir_entry *dir;
 426                 dir = lprocfs_srch(ldlm_ns_proc_dir, ns->ns_name);
 427                 if (dir == NULL) {
 428                         CERROR("dlm namespace %s has no procfs dir?\n",
 429                                ns->ns_name);
 430                 } else {
 431                         lprocfs_remove(dir);
 432                 }
 433         }
 434 #endif
 435
 436         if (ldlm_ns_refcount_atomic(ns) > 0) {
 437                 struct l_wait_info lwi = LWI_INTR(NULL, NULL);
 438                 int rc;
 439                 CDEBUG(D_DLMTRACE,
 440                        "dlm namespace %s free waiting on refcount %d\n",
 441                        ns->ns_name, ns->ns_refcount);
 442                 rc = l_wait_event(ns->ns_waitq,
 443                                   ldlm_ns_refcount_atomic(ns) == 0, &lwi);
 444                 if (ldlm_ns_refcount_atomic(ns)) {
 445                         CDEBUG(D_ERROR, "Lock manager: wait for %s namespace "
 446                                "cleanup aborted with %d resources in "
 447                                "use. (%d)\nI'm going to try to clean "
 448                                "up anyway, but I might need a reboot "
 449                                "of this node.\n", ns->ns_name,
 450                                ldlm_ns_refcount_atomic(ns), rc);
 451                 }
 452                 CDEBUG(D_DLMTRACE,
 453                        "dlm namespace %s free done waiting\n", ns->ns_name);
 454         }
 455
 456         POISON(ns->ns_hash, 0x5a, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 457         OBD_VFREE(ns->ns_hash, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 458         OBD_FREE(ns->ns_name, strlen(ns->ns_name) + 1);
 459         OBD_FREE(ns, sizeof(*ns));
 460
 461         ldlm_put_ref(force);
 462
 463         return ELDLM_OK;
 464 }
 465
 466 static __u32 ldlm_hash_fn(struct ldlm_resource *parent, struct ldlm_res_id name)
 467 {
 468         __u32 hash = 0;
 469         int i;
 470
 471         for (i = 0; i < RES_NAME_SIZE; i++)
 472                 hash += name.name[i];
 473
 474         hash += (__u32)((unsigned long)parent >> 4);
 475
 476         return (hash & RES_HASH_MASK);
 477 }
 478
 479 static struct ldlm_resource *ldlm_resource_new(void)
 480 {
 481         struct ldlm_resource *res;
 482
 483         OBD_SLAB_ALLOC(res, ldlm_resource_slab, SLAB_NOFS, sizeof *res);
 484         if (res == NULL)
 485                 return NULL;
 486
 487         memset(res, 0, sizeof(*res));
 488
 489         INIT_LIST_HEAD(&res->lr_children);
 490         INIT_LIST_HEAD(&res->lr_childof);
 491         INIT_LIST_HEAD(&res->lr_granted);
 492         INIT_LIST_HEAD(&res->lr_converting);
 493         INIT_LIST_HEAD(&res->lr_waiting);
 494         atomic_set(&res->lr_refcount, 1);
 495         spin_lock_init(&res->lr_lock);
 496
 497         /* one who creates the resource must unlock
 498          * the semaphore after lvb initialization */
 499         init_MUTEX_LOCKED(&res->lr_lvb_sem);
 500
 501         return res;
 502 }
 503
 504 /* must be called with hash lock held */
 505 static struct ldlm_resource *
 506 ldlm_resource_find(struct ldlm_namespace *ns, struct ldlm_res_id name, __u32 hash)
 507 {
 508         struct list_head *bucket, *tmp;
 509         struct ldlm_resource *res;
 510
 511         LASSERT_SPIN_LOCKED(&ns->ns_hash_lock);
 512         bucket = ns->ns_hash + hash;
 513
 514         list_for_each(tmp, bucket) {
 515                 res = list_entry(tmp, struct ldlm_resource, lr_hash);
 516                 if (memcmp(&res->lr_name, &name, sizeof(res->lr_name)) == 0)
 517                         return res;
 518         }
 519
 520         return NULL;
 521 }
 522
 523 /* Args: locked namespace
 524  * Returns: newly-allocated, referenced, unlocked resource */
 525 static struct ldlm_resource *
 526 ldlm_resource_add(struct ldlm_namespace *ns, struct ldlm_resource *parent,
 527                   struct ldlm_res_id name, __u32 hash, __u32 type)
 528 {
 529         struct list_head *bucket;
 530         struct ldlm_resource *res, *old_res;
 531         ENTRY;
 532
 533         LASSERTF(type >= LDLM_MIN_TYPE && type <= LDLM_MAX_TYPE,
 534                  "type: %d", type);
 535
 536         res = ldlm_resource_new();
 537         if (!res)
 538                 RETURN(NULL);
 539
 540         memcpy(&res->lr_name, &name, sizeof(res->lr_name));
 541         res->lr_namespace = ns;
 542         res->lr_type = type;
 543         res->lr_most_restr = LCK_NL;
 544
 545         spin_lock(&ns->ns_hash_lock);
 546         old_res = ldlm_resource_find(ns, name, hash);
 547         if (old_res) {
 548                 /* someone won the race and added the resource before */
 549                 ldlm_resource_getref(old_res);
 550                 spin_unlock(&ns->ns_hash_lock);
 551                 OBD_SLAB_FREE(res, ldlm_resource_slab, sizeof *res);
 552                 /* synchronize WRT resource creation */
 553                 if (ns->ns_lvbo && ns->ns_lvbo->lvbo_init) {
 554                         down(&old_res->lr_lvb_sem);
 555                         up(&old_res->lr_lvb_sem);
 556                 }
 557                 RETURN(old_res);
 558         }
 559
 560         /* we won! let's add the resource */
 561         bucket = ns->ns_hash + hash;
 562         list_add(&res->lr_hash, bucket);
 563         ns->ns_resources++;
 564         ns->ns_refcount++;
 565
 566         if (parent == NULL) {
 567                 list_add(&res->lr_childof, &ns->ns_root_list);
 568         } else {
 569                 res->lr_parent = parent;
 570                 list_add(&res->lr_childof, &parent->lr_children);
 571         }
 572         spin_unlock(&ns->ns_hash_lock);
 573
 574         if (ns->ns_lvbo && ns->ns_lvbo->lvbo_init) {
 575                 int rc;
 576
 577                 OBD_FAIL_TIMEOUT(OBD_FAIL_LDLM_CREATE_RESOURCE, 2);
 578                 rc = ns->ns_lvbo->lvbo_init(res);
 579                 if (rc)
 580                         CERROR("lvbo_init failed for resource "
 581                                LPU64": rc %d\n", name.name[0], rc);
 582                 /* we create resource with locked lr_lvb_sem */
 583                 up(&res->lr_lvb_sem);
 584         }
 585
 586         RETURN(res);
 587 }
 588
 589 /* Args: unlocked namespace
 590  * Locks: takes and releases ns->ns_lock and res->lr_lock
 591  * Returns: referenced, unlocked ldlm_resource or NULL */
 592 struct ldlm_resource *
 593 ldlm_resource_get(struct ldlm_namespace *ns, struct ldlm_resource *parent,
 594                   struct ldlm_res_id name, __u32 type, int create)
 595 {
 596         __u32 hash = ldlm_hash_fn(parent, name);
 597         struct ldlm_resource *res = NULL;
 598         ENTRY;
 599
 600         LASSERT(ns != NULL);
 601         LASSERT(ns->ns_hash != NULL);
 602         LASSERT(name.name[0] != 0);
 603
 604         spin_lock(&ns->ns_hash_lock);
 605         res = ldlm_resource_find(ns, name, hash);
 606         if (res) {
 607                 ldlm_resource_getref(res);
 608                 spin_unlock(&ns->ns_hash_lock);
 609                 /* synchronize WRT resource creation */
 610                 if (ns->ns_lvbo && ns->ns_lvbo->lvbo_init) {
 611                         down(&res->lr_lvb_sem);
 612                         up(&res->lr_lvb_sem);
 613                 }
 614                 RETURN(res);
 615         }
 616         spin_unlock(&ns->ns_hash_lock);
 617
 618         if (create == 0)
 619                 RETURN(NULL);
 620
 621         res = ldlm_resource_add(ns, parent, name, hash, type);
 622         RETURN(res);
 623 }
 624
 625 struct ldlm_resource *ldlm_resource_getref(struct ldlm_resource *res)
 626 {
 627         LASSERT(res != NULL);
 628         LASSERT(res != LP_POISON);
 629         atomic_inc(&res->lr_refcount);
 630         CDEBUG(D_INFO, "getref res: %p count: %d\n", res,
 631                atomic_read(&res->lr_refcount));
 632         return res;
 633 }
 634
 635 void __ldlm_resource_putref_final(struct ldlm_resource *res)
 636 {
 637         struct ldlm_namespace *ns = res->lr_namespace;
 638
 639         LASSERT_SPIN_LOCKED(&ns->ns_hash_lock);
 640
 641         if (!list_empty(&res->lr_granted)) {
 642                 ldlm_resource_dump(D_ERROR, res);
 643                 LBUG();
 644         }
 645
 646         if (!list_empty(&res->lr_converting)) {
 647                 ldlm_resource_dump(D_ERROR, res);
 648                 LBUG();
 649         }
 650
 651         if (!list_empty(&res->lr_waiting)) {
 652                 ldlm_resource_dump(D_ERROR, res);
 653                 LBUG();
 654         }
 655
 656         if (!list_empty(&res->lr_children)) {
 657                 ldlm_resource_dump(D_ERROR, res);
 658                 LBUG();
 659         }
 660
 661         ns->ns_refcount--;
 662         list_del_init(&res->lr_hash);
 663         list_del_init(&res->lr_childof);
 664
 665         ns->ns_resources--;
 666         if (ns->ns_resources == 0)
 667                 wake_up(&ns->ns_waitq);
 668 }
 669
 670 /* Returns 1 if the resource was freed, 0 if it remains. */
 671 int ldlm_resource_putref(struct ldlm_resource *res)
 672 {
 673         struct ldlm_namespace *ns = res->lr_namespace;
 674         int rc = 0;
 675         ENTRY;
 676
 677         CDEBUG(D_INFO, "putref res: %p count: %d\n", res,
 678                atomic_read(&res->lr_refcount) - 1);
 679         LASSERT(atomic_read(&res->lr_refcount) > 0);
 680         LASSERT(atomic_read(&res->lr_refcount) < LI_POISON);
 681
 682         LASSERT(atomic_read(&res->lr_refcount) >= 0);
 683         if (atomic_dec_and_lock(&res->lr_refcount, &ns->ns_hash_lock)) {
 684                 __ldlm_resource_putref_final(res);
 685                 spin_unlock(&ns->ns_hash_lock);
 686                 if (res->lr_lvb_data)
 687                         OBD_FREE(res->lr_lvb_data, res->lr_lvb_len);
 688                 OBD_SLAB_FREE(res, ldlm_resource_slab, sizeof *res);
 689                 rc = 1;
 690         }
 691
 692         RETURN(rc);
 693 }
 694
 695 /* Returns 1 if the resource was freed, 0 if it remains. */
 696 int ldlm_resource_putref_locked(struct ldlm_resource *res)
 697 {
 698         int rc = 0;
 699         ENTRY;
 700
 701         CDEBUG(D_INFO, "putref res: %p count: %d\n", res,
 702                atomic_read(&res->lr_refcount) - 1);
 703         LASSERT(atomic_read(&res->lr_refcount) > 0);
 704         LASSERT(atomic_read(&res->lr_refcount) < LI_POISON);
 705
 706         LASSERT(atomic_read(&res->lr_refcount) >= 0);
 707         if (atomic_dec_and_test(&res->lr_refcount)) {
 708                 __ldlm_resource_putref_final(res);
 709                 if (res->lr_lvb_data)
 710                         OBD_FREE(res->lr_lvb_data, res->lr_lvb_len);
 711                 OBD_SLAB_FREE(res, ldlm_resource_slab, sizeof *res);
 712                 rc = 1;
 713         }
 714
 715         RETURN(rc);
 716 }
 717
 718 void ldlm_resource_add_lock(struct ldlm_resource *res, struct list_head *head,
 719                             struct ldlm_lock *lock)
 720 {
 721         check_res_locked(res);
 722
 723         ldlm_resource_dump(D_OTHER, res);
 724         CDEBUG(D_OTHER, "About to add this lock:\n");
 725         ldlm_lock_dump(D_OTHER, lock, 0);
 726
 727         if (lock->l_destroyed) {
 728                 CDEBUG(D_OTHER, "Lock destroyed, not adding to resource\n");
 729                 return;
 730         }
 731
 732         LASSERT(list_empty(&lock->l_res_link));
 733
 734         list_add_tail(&lock->l_res_link, head);
 735 }
 736
 737 void ldlm_resource_unlink_lock(struct ldlm_lock *lock)
 738 {
 739         check_res_locked(lock->l_resource);
 740         list_del_init(&lock->l_res_link);
 741 }
 742
 743 void ldlm_res2desc(struct ldlm_resource *res, struct ldlm_resource_desc *desc)
 744 {
 745         desc->lr_type = res->lr_type;
 746         memcpy(&desc->lr_name, &res->lr_name, sizeof(desc->lr_name));
 747 }
 748
 749 void ldlm_dump_all_namespaces(int level)
 750 {
 751         struct list_head *tmp;
 752
 753         down(&ldlm_namespace_lock);
 754
 755         list_for_each(tmp, &ldlm_namespace_list) {
 756                 struct ldlm_namespace *ns;
 757                 ns = list_entry(tmp, struct ldlm_namespace, ns_list_chain);
 758                 ldlm_namespace_dump(level, ns);
 759         }
 760
 761         up(&ldlm_namespace_lock);
 762 }
 763
 764 void ldlm_namespace_dump(int level, struct ldlm_namespace *ns)
 765 {
 766         struct list_head *tmp;
 767
 768         CDEBUG(level, "--- Namespace: %s (rc: %d, client: %d)\n",
 769                ns->ns_name, ns->ns_refcount, ns->ns_client);
 770
 771         if (time_before(jiffies, ns->ns_next_dump))
 772                 return;
 773
 774         spin_lock(&ns->ns_hash_lock);
 775         tmp = ns->ns_root_list.next;
 776         while (tmp != &ns->ns_root_list) {
 777                 struct ldlm_resource *res;
 778                 res = list_entry(tmp, struct ldlm_resource, lr_childof);
 779
 780                 ldlm_resource_getref(res);
 781                 spin_unlock(&ns->ns_hash_lock);
 782
 783                 lock_res(res);
 784                 ldlm_resource_dump(level, res);
 785                 unlock_res(res);
 786
 787                 spin_lock(&ns->ns_hash_lock);
 788                 tmp = tmp->next;
 789                 ldlm_resource_putref_locked(res);
 790         }
 791         ns->ns_next_dump = jiffies + 10 * HZ;
 792         spin_unlock(&ns->ns_hash_lock);
 793 }
 794
 795 void ldlm_resource_dump(int level, struct ldlm_resource *res)
 796 {
 797         struct list_head *tmp;
 798         int pos;
 799
 800         if (RES_NAME_SIZE != 4)
 801                 LBUG();
 802
 803         CDEBUG(level, "--- Resource: %p ("LPU64"/"LPU64"/"LPU64"/"LPU64
 804                ") (rc: %d)\n", res, res->lr_name.name[0], res->lr_name.name[1],
 805                res->lr_name.name[2], res->lr_name.name[3],
 806                atomic_read(&res->lr_refcount));
 807
 808         if (!list_empty(&res->lr_granted)) {
 809                 pos = 0;
 810                 CDEBUG(level, "Granted locks:\n");
 811                 list_for_each(tmp, &res->lr_granted) {
 812                         struct ldlm_lock *lock;
 813                         lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 814                         ldlm_lock_dump(level, lock, ++pos);
 815                 }
 816         }
 817         if (!list_empty(&res->lr_converting)) {
 818                 pos = 0;
 819                 CDEBUG(level, "Converting locks:\n");
 820                 list_for_each(tmp, &res->lr_converting) {
 821                         struct ldlm_lock *lock;
 822                         lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 823                         ldlm_lock_dump(level, lock, ++pos);
 824                 }
 825         }
 826         if (!list_empty(&res->lr_waiting)) {
 827                 pos = 0;
 828                 CDEBUG(level, "Waiting locks:\n");
 829                 list_for_each(tmp, &res->lr_waiting) {
 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 }