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 Cluster File Systems, Inc.
   5  *
   6  * This code is issued under the GNU General Public License.
   7  * See the file COPYING in this distribution
   8  *
   9  * by Cluster File Systems, Inc.
  10  */
  11
  12 #define DEBUG_SUBSYSTEM S_LDLM
  13
  14 #include <linux/lustre_dlm.h>
  15 #include <linux/obd_class.h>
  16
  17 kmem_cache_t *ldlm_resource_slab, *ldlm_lock_slab;
  18
  19 spinlock_t ldlm_namespace_lock = SPIN_LOCK_UNLOCKED;
  20 struct list_head ldlm_namespace_list = LIST_HEAD_INIT(ldlm_namespace_list);
  21 static struct proc_dir_entry *ldlm_ns_proc_dir = NULL;
  22
  23 int ldlm_proc_setup(struct obd_device *obd)
  24 {
  25         ENTRY;
  26
  27         if (obd->obd_proc_entry == NULL)
  28                 RETURN(-EINVAL);
  29
  30         ldlm_ns_proc_dir = proc_mkdir("namespaces", obd->obd_proc_entry);
  31         if (ldlm_ns_proc_dir == NULL) {
  32                 CERROR("Couldn't create /proc/lustre/ldlm/namespaces\n");
  33                 RETURN(-EPERM);
  34         }
  35         RETURN(0);
  36 }
  37
  38 void ldlm_proc_cleanup(struct obd_device *obd)
  39 {
  40         proc_lustre_remove_obd_entry("namespaces", obd);
  41 }
  42
  43 /* FIXME: This can go away when we start to really use lprocfs */
  44 static int lprocfs_ll_rd(char *page, char **start, off_t off,
  45                          int count, int *eof, void *data)
  46 {
  47         int len;
  48         __u64 *temp = (__u64 *)data;
  49
  50         len = snprintf(page, count, "%Lu\n", *temp);
  51
  52         return len;
  53 }
  54
  55 struct ldlm_namespace *ldlm_namespace_new(char *name, __u32 client)
  56 {
  57         struct ldlm_namespace *ns = NULL;
  58         struct list_head *bucket;
  59         struct proc_dir_entry *proc_entry;
  60
  61         OBD_ALLOC(ns, sizeof(*ns));
  62         if (!ns) {
  63                 LBUG();
  64                 GOTO(out, NULL);
  65         }
  66
  67         ns->ns_hash = vmalloc(sizeof(*ns->ns_hash) * RES_HASH_SIZE);
  68         if (!ns->ns_hash) {
  69                 LBUG();
  70                 GOTO(out, ns);
  71         }
  72         obd_memory += sizeof(*ns->ns_hash) * RES_HASH_SIZE;
  73
  74         OBD_ALLOC(ns->ns_name, strlen(name) + 1);
  75         if (!ns->ns_name) {
  76                 LBUG();
  77                 GOTO(out, ns);
  78         }
  79         strcpy(ns->ns_name, name);
  80
  81         INIT_LIST_HEAD(&ns->ns_root_list);
  82         l_lock_init(&ns->ns_lock);
  83         ns->ns_refcount = 0;
  84         ns->ns_client = client;
  85         spin_lock_init(&ns->ns_counter_lock);
  86         ns->ns_locks = 0;
  87         ns->ns_resources = 0;
  88
  89         for (bucket = ns->ns_hash + RES_HASH_SIZE - 1; bucket >= ns->ns_hash;
  90              bucket--)
  91                 INIT_LIST_HEAD(bucket);
  92
  93         spin_lock(&ldlm_namespace_lock);
  94         list_add(&ns->ns_list_chain, &ldlm_namespace_list);
  95         spin_unlock(&ldlm_namespace_lock);
  96
  97         ns->ns_proc_dir = proc_mkdir(ns->ns_name, ldlm_ns_proc_dir);
  98         if (ns->ns_proc_dir == NULL)
  99                 CERROR("Unable to create proc directory for namespace.\n");
 100         proc_entry = create_proc_entry("resource_count", 0444, ns->ns_proc_dir);
 101         proc_entry->read_proc = lprocfs_ll_rd;
 102         proc_entry->data = &ns->ns_resources;
 103         proc_entry = create_proc_entry("lock_count", 0444, ns->ns_proc_dir);
 104         proc_entry->read_proc = lprocfs_ll_rd;
 105         proc_entry->data = &ns->ns_locks;
 106
 107         RETURN(ns);
 108
 109  out:
 110         if (ns && ns->ns_hash) {
 111                 vfree(ns->ns_hash);
 112                 obd_memory -= sizeof(*ns->ns_hash) * RES_HASH_SIZE;
 113         }
 114         if (ns && ns->ns_name)
 115                 OBD_FREE(ns->ns_name, strlen(name) + 1);
 116         if (ns)
 117                 OBD_FREE(ns, sizeof(*ns));
 118         return NULL;
 119 }
 120
 121 extern struct ldlm_lock *ldlm_lock_get(struct ldlm_lock *lock);
 122
 123 static void cleanup_resource(struct ldlm_resource *res, struct list_head *q)
 124 {
 125         struct list_head *tmp, *pos;
 126         int rc = 0, client = res->lr_namespace->ns_client;
 127         ENTRY;
 128
 129         list_for_each_safe(tmp, pos, q) {
 130                 struct ldlm_lock *lock;
 131                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 132                 LDLM_LOCK_GET(lock);
 133
 134                 if (client) {
 135                         struct lustre_handle lockh;
 136                         ldlm_lock2handle(lock, &lockh);
 137                         /* can we get away without a connh here? */
 138                         rc = ldlm_cli_cancel(&lockh);
 139                         if (rc != ELDLM_OK) {
 140                                 /* It failed remotely, but we'll force it to
 141                                  * cleanup locally. */
 142                                 CERROR("ldlm_cli_cancel: %d\n", rc);
 143                                 ldlm_lock_cancel(lock);
 144                         }
 145                 } else {
 146                         LDLM_DEBUG(lock, "Freeing a lock still held by a "
 147                                    "client node.\n");
 148
 149                         ldlm_resource_unlink_lock(lock);
 150                         ldlm_lock_destroy(lock);
 151                 }
 152                 LDLM_LOCK_PUT(lock);
 153         }
 154 }
 155
 156 int ldlm_namespace_free(struct ldlm_namespace *ns)
 157 {
 158         struct list_head *tmp, *pos;
 159         int i;
 160
 161         if (!ns)
 162                 RETURN(ELDLM_OK);
 163
 164         spin_lock(&ldlm_namespace_lock);
 165         list_del(&ns->ns_list_chain);
 166         remove_proc_entry("resource_count", ns->ns_proc_dir);
 167         remove_proc_entry("lock_count", ns->ns_proc_dir);
 168         remove_proc_entry(ns->ns_name, ldlm_ns_proc_dir);
 169         spin_unlock(&ldlm_namespace_lock);
 170
 171         l_lock(&ns->ns_lock);
 172
 173         for (i = 0; i < RES_HASH_SIZE; i++) {
 174                 list_for_each_safe(tmp, pos, &(ns->ns_hash[i])) {
 175                         struct ldlm_resource *res;
 176                         res = list_entry(tmp, struct ldlm_resource, lr_hash);
 177                         ldlm_resource_getref(res);
 178
 179                         cleanup_resource(res, &res->lr_granted);
 180                         cleanup_resource(res, &res->lr_converting);
 181                         cleanup_resource(res, &res->lr_waiting);
 182
 183                         if (!ldlm_resource_put(res)) {
 184                                 CERROR("Resource refcount nonzero (%d) after "
 185                                        "lock cleanup; forcing cleanup.\n",
 186                                        atomic_read(&res->lr_refcount));
 187                                 ldlm_resource_dump(res);
 188                                 atomic_set(&res->lr_refcount, 1);
 189                                 ldlm_resource_put(res);
 190                         }
 191                 }
 192         }
 193
 194         vfree(ns->ns_hash /* , sizeof(*ns->ns_hash) * RES_HASH_SIZE */);
 195         obd_memory -= sizeof(*ns->ns_hash) * RES_HASH_SIZE;
 196         OBD_FREE(ns->ns_name, strlen(ns->ns_name) + 1);
 197         OBD_FREE(ns, sizeof(*ns));
 198
 199         return ELDLM_OK;
 200 }
 201
 202 int ldlm_client_free(struct obd_export *exp)
 203 {
 204         struct ldlm_export_data *led = &exp->exp_ldlm_data;
 205         ptlrpc_cleanup_client(&led->led_import);
 206         RETURN(0);
 207 }
 208
 209 static __u32 ldlm_hash_fn(struct ldlm_resource *parent, __u64 *name)
 210 {
 211         __u32 hash = 0;
 212         int i;
 213
 214         for (i = 0; i < RES_NAME_SIZE; i++)
 215                 hash += name[i];
 216
 217         hash += (__u32)((unsigned long)parent >> 4);
 218
 219         return (hash & RES_HASH_MASK);
 220 }
 221
 222 static struct ldlm_resource *ldlm_resource_new(void)
 223 {
 224         struct ldlm_resource *res;
 225
 226         res = kmem_cache_alloc(ldlm_resource_slab, SLAB_KERNEL);
 227         if (res == NULL) {
 228                 LBUG();
 229                 return NULL;
 230         }
 231         memset(res, 0, sizeof(*res));
 232
 233         INIT_LIST_HEAD(&res->lr_children);
 234         INIT_LIST_HEAD(&res->lr_childof);
 235         INIT_LIST_HEAD(&res->lr_granted);
 236         INIT_LIST_HEAD(&res->lr_converting);
 237         INIT_LIST_HEAD(&res->lr_waiting);
 238
 239         atomic_set(&res->lr_refcount, 1);
 240
 241         return res;
 242 }
 243
 244 /* Args: locked namespace
 245  * Returns: newly-allocated, referenced, unlocked resource */
 246 static struct ldlm_resource *ldlm_resource_add(struct ldlm_namespace *ns,
 247                                                struct ldlm_resource *parent,
 248                                                __u64 *name, __u32 type)
 249 {
 250         struct list_head *bucket;
 251         struct ldlm_resource *res;
 252         ENTRY;
 253
 254         if (type < LDLM_MIN_TYPE || type > LDLM_MAX_TYPE) {
 255                 LBUG();
 256                 RETURN(NULL);
 257         }
 258
 259         res = ldlm_resource_new();
 260         if (!res) {
 261                 LBUG();
 262                 RETURN(NULL);
 263         }
 264
 265         spin_lock(&ns->ns_counter_lock);
 266         ns->ns_resources++;
 267         spin_unlock(&ns->ns_counter_lock);
 268
 269         memcpy(res->lr_name, name, sizeof(res->lr_name));
 270         res->lr_namespace = ns;
 271         ns->ns_refcount++;
 272
 273         res->lr_type = type;
 274         res->lr_most_restr = LCK_NL;
 275
 276         bucket = ns->ns_hash + ldlm_hash_fn(parent, name);
 277         list_add(&res->lr_hash, bucket);
 278
 279         if (parent == NULL)
 280                 list_add(&res->lr_childof, &ns->ns_root_list);
 281         else {
 282                 res->lr_parent = parent;
 283                 list_add(&res->lr_childof, &parent->lr_children);
 284         }
 285
 286         RETURN(res);
 287 }
 288
 289 /* Args: unlocked namespace
 290  * Locks: takes and releases ns->ns_lock and res->lr_lock
 291  * Returns: referenced, unlocked ldlm_resource or NULL */
 292 struct ldlm_resource *ldlm_resource_get(struct ldlm_namespace *ns,
 293                                         struct ldlm_resource *parent,
 294                                         __u64 *name, __u32 type, int create)
 295 {
 296         struct list_head *bucket;
 297         struct list_head *tmp = bucket;
 298         struct ldlm_resource *res = NULL;
 299         ENTRY;
 300
 301         if (ns == NULL || ns->ns_hash == NULL) {
 302                 LBUG();
 303                 RETURN(NULL);
 304         }
 305
 306         l_lock(&ns->ns_lock);
 307         bucket = ns->ns_hash + ldlm_hash_fn(parent, name);
 308
 309         list_for_each(tmp, bucket) {
 310                 struct ldlm_resource *chk;
 311                 chk = list_entry(tmp, struct ldlm_resource, lr_hash);
 312
 313                 if (memcmp(chk->lr_name, name, sizeof(chk->lr_name)) == 0) {
 314                         res = chk;
 315                         atomic_inc(&res->lr_refcount);
 316                         EXIT;
 317                         break;
 318                 }
 319         }
 320
 321         if (res == NULL && create)
 322                 res = ldlm_resource_add(ns, parent, name, type);
 323         l_unlock(&ns->ns_lock);
 324
 325         RETURN(res);
 326 }
 327
 328 struct ldlm_resource *ldlm_resource_getref(struct ldlm_resource *res)
 329 {
 330         atomic_inc(&res->lr_refcount);
 331         return res;
 332 }
 333
 334 /* Returns 1 if the resource was freed, 0 if it remains. */
 335 int ldlm_resource_put(struct ldlm_resource *res)
 336 {
 337         int rc = 0;
 338
 339         if (atomic_dec_and_test(&res->lr_refcount)) {
 340                 struct ldlm_namespace *ns = res->lr_namespace;
 341                 ENTRY;
 342
 343                 l_lock(&ns->ns_lock);
 344
 345                 if (atomic_read(&res->lr_refcount) != 0) {
 346                         /* We lost the race. */
 347                         l_unlock(&ns->ns_lock);
 348                         goto out;
 349                 }
 350
 351                 if (!list_empty(&res->lr_granted))
 352                         LBUG();
 353
 354                 if (!list_empty(&res->lr_converting))
 355                         LBUG();
 356
 357                 if (!list_empty(&res->lr_waiting))
 358                         LBUG();
 359
 360                 if (!list_empty(&res->lr_children))
 361                         LBUG();
 362
 363                 ns->ns_refcount--;
 364                 list_del(&res->lr_hash);
 365                 list_del(&res->lr_childof);
 366
 367                 kmem_cache_free(ldlm_resource_slab, res);
 368                 l_unlock(&ns->ns_lock);
 369
 370                 spin_lock(&ns->ns_counter_lock);
 371                 ns->ns_resources--;
 372                 spin_unlock(&ns->ns_counter_lock);
 373
 374                 rc = 1;
 375         } else {
 376                 ENTRY;
 377         out:
 378                 if (atomic_read(&res->lr_refcount) < 0)
 379                         LBUG();
 380         }
 381
 382         RETURN(rc);
 383 }
 384
 385 void ldlm_resource_add_lock(struct ldlm_resource *res, struct list_head *head,
 386                             struct ldlm_lock *lock)
 387 {
 388         l_lock(&res->lr_namespace->ns_lock);
 389
 390         ldlm_resource_dump(res);
 391         ldlm_lock_dump(lock);
 392
 393         if (!list_empty(&lock->l_res_link))
 394                 LBUG();
 395
 396         list_add(&lock->l_res_link, head);
 397         l_unlock(&res->lr_namespace->ns_lock);
 398 }
 399
 400 void ldlm_resource_unlink_lock(struct ldlm_lock *lock)
 401 {
 402         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 403         list_del_init(&lock->l_res_link);
 404         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 405 }
 406
 407 void ldlm_res2desc(struct ldlm_resource *res, struct ldlm_resource_desc *desc)
 408 {
 409         desc->lr_type = res->lr_type;
 410         memcpy(desc->lr_name, res->lr_name, sizeof(desc->lr_name));
 411         memcpy(desc->lr_version, res->lr_version, sizeof(desc->lr_version));
 412 }
 413
 414 void ldlm_dump_all_namespaces(void)
 415 {
 416         struct list_head *tmp;
 417
 418         spin_lock(&ldlm_namespace_lock);
 419
 420         list_for_each(tmp, &ldlm_namespace_list) {
 421                 struct ldlm_namespace *ns;
 422                 ns = list_entry(tmp, struct ldlm_namespace, ns_list_chain);
 423                 ldlm_namespace_dump(ns);
 424         }
 425
 426         spin_unlock(&ldlm_namespace_lock);
 427 }
 428
 429 void ldlm_namespace_dump(struct ldlm_namespace *ns)
 430 {
 431         struct list_head *tmp;
 432
 433         l_lock(&ns->ns_lock);
 434         CDEBUG(D_OTHER, "--- Namespace: %s (rc: %d, client: %d)\n", ns->ns_name,
 435                ns->ns_refcount, ns->ns_client);
 436
 437         list_for_each(tmp, &ns->ns_root_list) {
 438                 struct ldlm_resource *res;
 439                 res = list_entry(tmp, struct ldlm_resource, lr_childof);
 440
 441                 /* Once we have resources with children, this should really dump
 442                  * them recursively. */
 443                 ldlm_resource_dump(res);
 444         }
 445         l_unlock(&ns->ns_lock);
 446 }
 447
 448 void ldlm_resource_dump(struct ldlm_resource *res)
 449 {
 450         struct list_head *tmp;
 451         char name[256];
 452
 453         if (RES_NAME_SIZE != 3)
 454                 LBUG();
 455
 456         snprintf(name, sizeof(name), "%Lx %Lx %Lx",
 457                  (unsigned long long)res->lr_name[0],
 458                  (unsigned long long)res->lr_name[1],
 459                  (unsigned long long)res->lr_name[2]);
 460
 461         CDEBUG(D_OTHER, "--- Resource: %p (%s) (rc: %d)\n", res, name,
 462                atomic_read(&res->lr_refcount));
 463         CDEBUG(D_OTHER, "Namespace: %p (%s)\n", res->lr_namespace,
 464                res->lr_namespace->ns_name);
 465         CDEBUG(D_OTHER, "Parent: %p, root: %p\n", res->lr_parent, res->lr_root);
 466
 467         CDEBUG(D_OTHER, "Granted locks:\n");
 468         list_for_each(tmp, &res->lr_granted) {
 469                 struct ldlm_lock *lock;
 470                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 471                 ldlm_lock_dump(lock);
 472         }
 473
 474         CDEBUG(D_OTHER, "Converting locks:\n");
 475         list_for_each(tmp, &res->lr_converting) {
 476                 struct ldlm_lock *lock;
 477                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 478                 ldlm_lock_dump(lock);
 479         }
 480
 481         CDEBUG(D_OTHER, "Waiting locks:\n");
 482         list_for_each(tmp, &res->lr_waiting) {
 483                 struct ldlm_lock *lock;
 484                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 485                 ldlm_lock_dump(lock);
 486         }
 487 }