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