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
  33 kmem_cache_t *ldlm_resource_slab, *ldlm_lock_slab;
  34
  35 spinlock_t ldlm_namespace_lock = SPIN_LOCK_UNLOCKED;
  36 struct list_head ldlm_namespace_list = LIST_HEAD_INIT(ldlm_namespace_list);
  37 static struct proc_dir_entry *ldlm_ns_proc_dir = NULL;
  38
  39 int ldlm_proc_setup(struct obd_device *obd)
  40 {
  41         int rc;
  42         ENTRY;
  43         LASSERT(ldlm_ns_proc_dir == NULL);
  44         LASSERT(obd != NULL);
  45         rc = lprocfs_obd_attach(obd, 0);
  46         if (rc) {
  47                 CERROR("LProcFS failed in ldlm-init\n");
  48                 RETURN(rc);
  49         }
  50         ldlm_ns_proc_dir = obd->obd_proc_entry;
  51         RETURN(0);
  52 }
  53
  54 void ldlm_proc_cleanup(struct obd_device *obd)
  55 {
  56         if (ldlm_ns_proc_dir) {
  57                 lprocfs_obd_detach(obd);
  58                 ldlm_ns_proc_dir = NULL;
  59         }
  60 }
  61
  62 #ifdef __KERNEL__
  63 static int lprocfs_uint_rd(char *page, char **start, off_t off,
  64                            int count, int *eof, void *data)
  65 {
  66         unsigned int *temp = (unsigned int *)data;
  67         return snprintf(page, count, "%u\n", *temp);
  68 }
  69
  70
  71 #define MAX_STRING_SIZE 128
  72 void ldlm_proc_namespace(struct ldlm_namespace *ns)
  73 {
  74         struct lprocfs_vars lock_vars[2];
  75         char lock_name[MAX_STRING_SIZE + 1];
  76
  77         LASSERT(ns != NULL);
  78         LASSERT(ns->ns_name != NULL);
  79
  80         lock_name[MAX_STRING_SIZE] = '\0';
  81
  82         memset(lock_vars, 0, sizeof(lock_vars));
  83         lock_vars[0].read_fptr = lprocfs_rd_u64;
  84
  85         lock_vars[0].name = lock_name;
  86
  87         snprintf(lock_name, MAX_STRING_SIZE, "%s/resource_count", ns->ns_name);
  88
  89         lock_vars[0].data = &ns->ns_resources;
  90         lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
  91
  92         snprintf(lock_name, MAX_STRING_SIZE, "%s/lock_count", ns->ns_name);
  93
  94         lock_vars[0].data = &ns->ns_locks;
  95         lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
  96
  97         snprintf(lock_name, MAX_STRING_SIZE, "%s/lock_unused_count",
  98                  ns->ns_name);
  99         lock_vars[0].data = &ns->ns_nr_unused;
 100         lock_vars[0].read_fptr = lprocfs_uint_rd;
 101         lprocfs_add_vars(ldlm_ns_proc_dir, lock_vars, 0);
 102 }
 103 #endif
 104 #undef MAX_STRING_SIZE
 105
 106 #define LDLM_MAX_UNUSED 100
 107 struct ldlm_namespace *ldlm_namespace_new(char *name, __u32 client)
 108 {
 109         struct ldlm_namespace *ns = NULL;
 110         struct list_head *bucket;
 111         ENTRY;
 112
 113         OBD_ALLOC(ns, sizeof(*ns));
 114         if (!ns)
 115                 RETURN(NULL);
 116
 117         OBD_VMALLOC(ns->ns_hash, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 118         if (!ns->ns_hash)
 119                 GOTO(out_ns, NULL);
 120
 121         OBD_ALLOC(ns->ns_name, strlen(name) + 1);
 122         if (!ns->ns_name)
 123                 GOTO(out_hash, NULL);
 124
 125         strcpy(ns->ns_name, name);
 126
 127         INIT_LIST_HEAD(&ns->ns_root_list);
 128         l_lock_init(&ns->ns_lock);
 129         ns->ns_refcount = 0;
 130         ns->ns_client = client;
 131         spin_lock_init(&ns->ns_counter_lock);
 132         ns->ns_locks = 0;
 133         ns->ns_resources = 0;
 134
 135         for (bucket = ns->ns_hash + RES_HASH_SIZE - 1; bucket >= ns->ns_hash;
 136              bucket--)
 137                 INIT_LIST_HEAD(bucket);
 138
 139         INIT_LIST_HEAD(&ns->ns_unused_list);
 140         ns->ns_nr_unused = 0;
 141         ns->ns_max_unused = LDLM_MAX_UNUSED;
 142
 143         spin_lock(&ldlm_namespace_lock);
 144         list_add(&ns->ns_list_chain, &ldlm_namespace_list);
 145         spin_unlock(&ldlm_namespace_lock);
 146 #ifdef __KERNEL__
 147         ldlm_proc_namespace(ns);
 148 #endif
 149         RETURN(ns);
 150
 151 out_hash:
 152         POISON(ns->ns_hash, 0x5a, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 153         OBD_VFREE(ns->ns_hash, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 154 out_ns:
 155         OBD_FREE(ns, sizeof(*ns));
 156         return NULL;
 157 }
 158
 159 extern struct ldlm_lock *ldlm_lock_get(struct ldlm_lock *lock);
 160
 161 /* If 'local_only' is true, don't try to tell the server, just cleanup.
 162  * This is currently only used for recovery, and we make certain assumptions
 163  * as a result--notably, that we shouldn't cancel locks with refs. -phil
 164  *
 165  * Called with the ns_lock held. */
 166 static void cleanup_resource(struct ldlm_resource *res, struct list_head *q,
 167                              int local_only)
 168 {
 169         struct list_head *tmp, *pos;
 170         int rc = 0, client = res->lr_namespace->ns_client;
 171         ENTRY;
 172
 173         list_for_each_safe(tmp, pos, q) {
 174                 struct ldlm_lock *lock;
 175                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 176                 LDLM_LOCK_GET(lock);
 177
 178                 if (local_only && (lock->l_readers || lock->l_writers)) {
 179                         /* This is a little bit gross, but much better than the
 180                          * alternative: pretend that we got a blocking AST from
 181                          * the server, so that when the lock is decref'd, it
 182                          * will go away ... */
 183                         lock->l_flags |= LDLM_FL_CBPENDING;
 184                         /* ... without sending a CANCEL message. */
 185                         lock->l_flags |= LDLM_FL_LOCAL_ONLY;
 186                         LDLM_DEBUG(lock, "setting FL_LOCAL_ONLY");
 187                         /* ... and without calling the cancellation callback */
 188                         lock->l_flags |= LDLM_FL_CANCEL;
 189                         LDLM_LOCK_PUT(lock);
 190                         continue;
 191                 }
 192
 193                 /* At shutdown time, don't call the cancellation callback */
 194                 lock->l_flags |= LDLM_FL_CANCEL;
 195
 196                 if (client) {
 197                         struct lustre_handle lockh;
 198                         ldlm_lock2handle(lock, &lockh);
 199                         if (!local_only) {
 200                                 rc = ldlm_cli_cancel(&lockh);
 201                                 if (rc)
 202                                         CERROR("ldlm_cli_cancel: %d\n", rc);
 203                         }
 204                         /* Force local cleanup on errors, too. */
 205                         if (local_only || rc != ELDLM_OK)
 206                                 ldlm_lock_cancel(lock);
 207                 } else {
 208                         LDLM_DEBUG(lock, "Freeing a lock still held by a "
 209                                    "client node");
 210
 211                         ldlm_resource_unlink_lock(lock);
 212                         ldlm_lock_destroy(lock);
 213                 }
 214                 LDLM_LOCK_PUT(lock);
 215         }
 216         EXIT;
 217 }
 218
 219 int ldlm_namespace_cleanup(struct ldlm_namespace *ns, int local_only)
 220 {
 221         int i;
 222
 223         if (ns == NULL) {
 224                 CDEBUG(D_INFO, "NULL ns, skipping cleanup\n");
 225                 return ELDLM_OK;
 226         }
 227
 228         l_lock(&ns->ns_lock);
 229         for (i = 0; i < RES_HASH_SIZE; i++) {
 230                 struct list_head *tmp, *pos;
 231                 list_for_each_safe(tmp, pos, &(ns->ns_hash[i])) {
 232                         struct ldlm_resource *res;
 233                         res = list_entry(tmp, struct ldlm_resource, lr_hash);
 234                         ldlm_resource_getref(res);
 235
 236                         cleanup_resource(res, &res->lr_granted, local_only);
 237                         cleanup_resource(res, &res->lr_converting, local_only);
 238                         cleanup_resource(res, &res->lr_waiting, local_only);
 239
 240                         /* XXX what a mess: don't force cleanup if we're
 241                          * local_only (which is only used by recovery).  In that
 242                          * case, we probably still have outstanding lock refs
 243                          * which reference these resources. -phil */
 244                         if (!ldlm_resource_putref(res) && !local_only) {
 245                                 CERROR("Resource refcount nonzero (%d) after "
 246                                        "lock cleanup; forcing cleanup.\n",
 247                                        atomic_read(&res->lr_refcount));
 248                                 ldlm_resource_dump(res);
 249                                 atomic_set(&res->lr_refcount, 1);
 250                                 ldlm_resource_putref(res);
 251                         }
 252                 }
 253         }
 254         l_unlock(&ns->ns_lock);
 255
 256         return ELDLM_OK;
 257 }
 258
 259 /* Cleanup, but also free, the namespace */
 260 int ldlm_namespace_free(struct ldlm_namespace *ns)
 261 {
 262         if (!ns)
 263                 RETURN(ELDLM_OK);
 264
 265         spin_lock(&ldlm_namespace_lock);
 266         list_del(&ns->ns_list_chain);
 267
 268         spin_unlock(&ldlm_namespace_lock);
 269
 270         ldlm_namespace_cleanup(ns, 0);
 271
 272         POISON(ns->ns_hash, 0x5a, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 273         OBD_VFREE(ns->ns_hash, sizeof(*ns->ns_hash) * RES_HASH_SIZE);
 274         OBD_FREE(ns->ns_name, strlen(ns->ns_name) + 1);
 275         OBD_FREE(ns, sizeof(*ns));
 276
 277         return ELDLM_OK;
 278 }
 279
 280 static __u32 ldlm_hash_fn(struct ldlm_resource *parent, struct ldlm_res_id name)
 281 {
 282         __u32 hash = 0;
 283         int i;
 284
 285         for (i = 0; i < RES_NAME_SIZE; i++)
 286                 hash += name.name[i];
 287
 288         hash += (__u32)((unsigned long)parent >> 4);
 289
 290         return (hash & RES_HASH_MASK);
 291 }
 292
 293 static struct ldlm_resource *ldlm_resource_new(void)
 294 {
 295         struct ldlm_resource *res;
 296
 297         OBD_SLAB_ALLOC(res, ldlm_resource_slab, SLAB_KERNEL, sizeof *res);
 298         if (res == NULL) {
 299                 LBUG();
 300                 return NULL;
 301         }
 302         memset(res, 0, sizeof(*res));
 303
 304         INIT_LIST_HEAD(&res->lr_children);
 305         INIT_LIST_HEAD(&res->lr_childof);
 306         INIT_LIST_HEAD(&res->lr_granted);
 307         INIT_LIST_HEAD(&res->lr_converting);
 308         INIT_LIST_HEAD(&res->lr_waiting);
 309
 310         atomic_set(&res->lr_refcount, 1);
 311
 312         return res;
 313 }
 314
 315 /* Args: locked namespace
 316  * Returns: newly-allocated, referenced, unlocked resource */
 317 static struct ldlm_resource *
 318 ldlm_resource_add(struct ldlm_namespace *ns, struct ldlm_resource *parent,
 319                   struct ldlm_res_id name, __u32 type)
 320 {
 321         struct list_head *bucket;
 322         struct ldlm_resource *res;
 323         ENTRY;
 324
 325         if (type < LDLM_MIN_TYPE || type > LDLM_MAX_TYPE) {
 326                 LBUG();
 327                 RETURN(NULL);
 328         }
 329
 330         res = ldlm_resource_new();
 331         if (!res) {
 332                 LBUG();
 333                 RETURN(NULL);
 334         }
 335
 336         spin_lock(&ns->ns_counter_lock);
 337         ns->ns_resources++;
 338         spin_unlock(&ns->ns_counter_lock);
 339
 340         l_lock(&ns->ns_lock);
 341         memcpy(&res->lr_name, &name, sizeof(res->lr_name));
 342         res->lr_namespace = ns;
 343         ns->ns_refcount++;
 344
 345         res->lr_type = type;
 346         res->lr_most_restr = LCK_NL;
 347
 348         bucket = ns->ns_hash + ldlm_hash_fn(parent, name);
 349         list_add(&res->lr_hash, bucket);
 350
 351         if (parent == NULL) {
 352                 list_add(&res->lr_childof, &ns->ns_root_list);
 353         } else {
 354                 res->lr_parent = parent;
 355                 list_add(&res->lr_childof, &parent->lr_children);
 356         }
 357         l_unlock(&ns->ns_lock);
 358
 359         RETURN(res);
 360 }
 361
 362 /* Args: unlocked namespace
 363  * Locks: takes and releases ns->ns_lock and res->lr_lock
 364  * Returns: referenced, unlocked ldlm_resource or NULL */
 365 struct ldlm_resource *
 366 ldlm_resource_get(struct ldlm_namespace *ns, struct ldlm_resource *parent,
 367                   struct ldlm_res_id name, __u32 type, int create)
 368 {
 369         struct list_head *bucket, *tmp;
 370         struct ldlm_resource *res = NULL;
 371         ENTRY;
 372
 373         LASSERT(ns != NULL);
 374         LASSERT(ns->ns_hash != NULL);
 375
 376         l_lock(&ns->ns_lock);
 377         bucket = ns->ns_hash + ldlm_hash_fn(parent, name);
 378
 379         list_for_each(tmp, bucket) {
 380                 res = list_entry(tmp, struct ldlm_resource, lr_hash);
 381
 382                 if (memcmp(&res->lr_name, &name, sizeof(res->lr_name)) == 0) {
 383                         ldlm_resource_getref(res);
 384                         l_unlock(&ns->ns_lock);
 385                         RETURN(res);
 386                 }
 387         }
 388
 389         if (create)
 390                 res = ldlm_resource_add(ns, parent, name, type);
 391         else
 392                 res = NULL;
 393
 394         l_unlock(&ns->ns_lock);
 395
 396         RETURN(res);
 397 }
 398
 399 struct ldlm_resource *ldlm_resource_getref(struct ldlm_resource *res)
 400 {
 401         atomic_inc(&res->lr_refcount);
 402         CDEBUG(D_INFO, "getref res: %p count: %d\n", res,
 403                atomic_read(&res->lr_refcount));
 404         return res;
 405 }
 406
 407 /* Returns 1 if the resource was freed, 0 if it remains. */
 408 int ldlm_resource_putref(struct ldlm_resource *res)
 409 {
 410         int rc = 0;
 411         ENTRY;
 412
 413         CDEBUG(D_INFO, "putref res: %p count: %d\n", res,
 414                atomic_read(&res->lr_refcount) - 1);
 415         LASSERT(atomic_read(&res->lr_refcount) > 0);
 416         LASSERT(atomic_read(&res->lr_refcount) < 0x5a5a5a5a);
 417
 418         if (atomic_dec_and_test(&res->lr_refcount)) {
 419                 struct ldlm_namespace *ns = res->lr_namespace;
 420                 ENTRY;
 421
 422                 l_lock(&ns->ns_lock);
 423
 424                 if (atomic_read(&res->lr_refcount) != 0) {
 425                         /* We lost the race. */
 426                         l_unlock(&ns->ns_lock);
 427                         RETURN(rc);
 428                 }
 429
 430                 if (!list_empty(&res->lr_granted)) {
 431                         ldlm_resource_dump(res);
 432                         LBUG();
 433                 }
 434
 435                 if (!list_empty(&res->lr_converting)) {
 436                         ldlm_resource_dump(res);
 437                         LBUG();
 438                 }
 439
 440                 if (!list_empty(&res->lr_waiting)) {
 441                         ldlm_resource_dump(res);
 442                         LBUG();
 443                 }
 444
 445                 if (!list_empty(&res->lr_children)) {
 446                         ldlm_resource_dump(res);
 447                         LBUG();
 448                 }
 449
 450                 ns->ns_refcount--;
 451                 list_del_init(&res->lr_hash);
 452                 list_del_init(&res->lr_childof);
 453
 454                 OBD_SLAB_FREE(res, ldlm_resource_slab, sizeof *res);
 455                 l_unlock(&ns->ns_lock);
 456
 457                 spin_lock(&ns->ns_counter_lock);
 458                 ns->ns_resources--;
 459                 spin_unlock(&ns->ns_counter_lock);
 460
 461                 rc = 1;
 462                 EXIT;
 463         }
 464
 465         RETURN(rc);
 466 }
 467
 468 void ldlm_resource_add_lock(struct ldlm_resource *res, struct list_head *head,
 469                             struct ldlm_lock *lock)
 470 {
 471         l_lock(&res->lr_namespace->ns_lock);
 472
 473         ldlm_resource_dump(res);
 474         CDEBUG(D_OTHER, "About to add this lock:\n");
 475         ldlm_lock_dump(D_OTHER, lock);
 476
 477         if (lock->l_destroyed) {
 478                 CDEBUG(D_OTHER, "Lock destroyed, not adding to resource\n");
 479                 return;
 480         }
 481
 482         LASSERT(list_empty(&lock->l_res_link));
 483
 484         list_add_tail(&lock->l_res_link, head);
 485         l_unlock(&res->lr_namespace->ns_lock);
 486 }
 487
 488 void ldlm_resource_unlink_lock(struct ldlm_lock *lock)
 489 {
 490         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 491         list_del_init(&lock->l_res_link);
 492         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 493 }
 494
 495 void ldlm_res2desc(struct ldlm_resource *res, struct ldlm_resource_desc *desc)
 496 {
 497         desc->lr_type = res->lr_type;
 498         memcpy(&desc->lr_name, &res->lr_name, sizeof(desc->lr_name));
 499         memcpy(desc->lr_version, res->lr_version, sizeof(desc->lr_version));
 500 }
 501
 502 void ldlm_dump_all_namespaces(void)
 503 {
 504         struct list_head *tmp;
 505
 506         spin_lock(&ldlm_namespace_lock);
 507
 508         list_for_each(tmp, &ldlm_namespace_list) {
 509                 struct ldlm_namespace *ns;
 510                 ns = list_entry(tmp, struct ldlm_namespace, ns_list_chain);
 511                 ldlm_namespace_dump(ns);
 512         }
 513
 514         spin_unlock(&ldlm_namespace_lock);
 515 }
 516
 517 void ldlm_namespace_dump(struct ldlm_namespace *ns)
 518 {
 519         struct list_head *tmp;
 520
 521         l_lock(&ns->ns_lock);
 522         CDEBUG(D_OTHER, "--- Namespace: %s (rc: %d, client: %d)\n", ns->ns_name,
 523                ns->ns_refcount, ns->ns_client);
 524
 525         list_for_each(tmp, &ns->ns_root_list) {
 526                 struct ldlm_resource *res;
 527                 res = list_entry(tmp, struct ldlm_resource, lr_childof);
 528
 529                 /* Once we have resources with children, this should really dump
 530                  * them recursively. */
 531                 ldlm_resource_dump(res);
 532         }
 533         l_unlock(&ns->ns_lock);
 534 }
 535
 536 void ldlm_resource_dump(struct ldlm_resource *res)
 537 {
 538         struct list_head *tmp;
 539         char name[256];
 540
 541         if (RES_NAME_SIZE != 3)
 542                 LBUG();
 543
 544         snprintf(name, sizeof(name), "%Lx %Lx %Lx",
 545                  (unsigned long long)res->lr_name.name[0],
 546                  (unsigned long long)res->lr_name.name[1],
 547                  (unsigned long long)res->lr_name.name[2]);
 548
 549         CDEBUG(D_OTHER, "--- Resource: %p (%s) (rc: %d)\n", res, name,
 550                atomic_read(&res->lr_refcount));
 551         CDEBUG(D_OTHER, "Namespace: %p (%s)\n", res->lr_namespace,
 552                res->lr_namespace->ns_name);
 553         CDEBUG(D_OTHER, "Parent: %p, root: %p\n", res->lr_parent, res->lr_root);
 554
 555         CDEBUG(D_OTHER, "Granted locks:\n");
 556         list_for_each(tmp, &res->lr_granted) {
 557                 struct ldlm_lock *lock;
 558                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 559                 ldlm_lock_dump(D_OTHER, lock);
 560         }
 561
 562         CDEBUG(D_OTHER, "Converting locks:\n");
 563         list_for_each(tmp, &res->lr_converting) {
 564                 struct ldlm_lock *lock;
 565                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 566                 ldlm_lock_dump(D_OTHER, lock);
 567         }
 568
 569         CDEBUG(D_OTHER, "Waiting locks:\n");
 570         list_for_each(tmp, &res->lr_waiting) {
 571                 struct ldlm_lock *lock;
 572                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 573                 ldlm_lock_dump(D_OTHER, lock);
 574         }
 575 }