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                         LDLM_DEBUG(lock, "Freeing a lock still held by a "
 123                                    "client node.\n");
 124
 125                         ldlm_resource_unlink_lock(lock);
 126                         ldlm_lock_destroy(lock);
 127                 }
 128                 LDLM_LOCK_PUT(lock);
 129         }
 130 }
 131
 132 int ldlm_namespace_free(struct ldlm_namespace *ns)
 133 {
 134         struct list_head *tmp, *pos;
 135         int i;
 136
 137         if (!ns)
 138                 RETURN(ELDLM_OK);
 139
 140         spin_lock(&ldlm_namespace_lock);
 141         list_del(&ns->ns_list_chain);
 142         remove_proc_entry(ns->ns_name, ldlm_ns_proc_dir);
 143         spin_unlock(&ldlm_namespace_lock);
 144
 145         l_lock(&ns->ns_lock);
 146
 147         for (i = 0; i < RES_HASH_SIZE; i++) {
 148                 list_for_each_safe(tmp, pos, &(ns->ns_hash[i])) {
 149                         struct ldlm_resource *res;
 150                         res = list_entry(tmp, struct ldlm_resource, lr_hash);
 151                         ldlm_resource_getref(res);
 152
 153                         cleanup_resource(res, &res->lr_granted);
 154                         cleanup_resource(res, &res->lr_converting);
 155                         cleanup_resource(res, &res->lr_waiting);
 156
 157                         if (!ldlm_resource_put(res)) {
 158                                 CERROR("Resource refcount nonzero (%d) after "
 159                                        "lock cleanup; forcing cleanup.\n",
 160                                        atomic_read(&res->lr_refcount));
 161                                 ldlm_resource_dump(res);
 162                                 atomic_set(&res->lr_refcount, 1);
 163                                 ldlm_resource_put(res);
 164                         }
 165                 }
 166         }
 167
 168         vfree(ns->ns_hash /* , sizeof(struct list_head) * RES_HASH_SIZE */);
 169         ptlrpc_cleanup_client(&ns->ns_rpc_client);
 170         OBD_FREE(ns->ns_name, strlen(ns->ns_name) + 1);
 171         OBD_FREE(ns, sizeof(*ns));
 172
 173         return ELDLM_OK;
 174 }
 175
 176 static __u32 ldlm_hash_fn(struct ldlm_resource *parent, __u64 *name)
 177 {
 178         __u32 hash = 0;
 179         int i;
 180
 181         for (i = 0; i < RES_NAME_SIZE; i++)
 182                 hash += name[i];
 183
 184         hash += (__u32)((unsigned long)parent >> 4);
 185
 186         return (hash & RES_HASH_MASK);
 187 }
 188
 189 static struct ldlm_resource *ldlm_resource_new(void)
 190 {
 191         struct ldlm_resource *res;
 192
 193         res = kmem_cache_alloc(ldlm_resource_slab, SLAB_KERNEL);
 194         if (res == NULL) {
 195                 LBUG();
 196                 return NULL;
 197         }
 198         memset(res, 0, sizeof(*res));
 199
 200         INIT_LIST_HEAD(&res->lr_children);
 201         INIT_LIST_HEAD(&res->lr_childof);
 202         INIT_LIST_HEAD(&res->lr_granted);
 203         INIT_LIST_HEAD(&res->lr_converting);
 204         INIT_LIST_HEAD(&res->lr_waiting);
 205
 206         atomic_set(&res->lr_refcount, 1);
 207
 208         return res;
 209 }
 210
 211 /* Args: locked namespace
 212  * Returns: newly-allocated, referenced, unlocked resource */
 213 static struct ldlm_resource *ldlm_resource_add(struct ldlm_namespace *ns,
 214                                                struct ldlm_resource *parent,
 215                                                __u64 *name, __u32 type)
 216 {
 217         struct list_head *bucket;
 218         struct ldlm_resource *res;
 219         ENTRY;
 220
 221         if (type < LDLM_MIN_TYPE || type > LDLM_MAX_TYPE) {
 222                 LBUG();
 223                 RETURN(NULL);
 224         }
 225
 226         res = ldlm_resource_new();
 227         if (!res) {
 228                 LBUG();
 229                 RETURN(NULL);
 230         }
 231
 232         memcpy(res->lr_name, name, sizeof(res->lr_name));
 233         res->lr_namespace = ns;
 234         ns->ns_refcount++;
 235
 236         res->lr_type = type;
 237         res->lr_most_restr = LCK_NL;
 238
 239         bucket = ns->ns_hash + ldlm_hash_fn(parent, name);
 240         list_add(&res->lr_hash, bucket);
 241
 242         if (parent == NULL)
 243                 list_add(&res->lr_childof, &ns->ns_root_list);
 244         else {
 245                 res->lr_parent = parent;
 246                 list_add(&res->lr_childof, &parent->lr_children);
 247         }
 248
 249         RETURN(res);
 250 }
 251
 252 /* Args: unlocked namespace
 253  * Locks: takes and releases ns->ns_lock and res->lr_lock
 254  * Returns: referenced, unlocked ldlm_resource or NULL */
 255 struct ldlm_resource *ldlm_resource_get(struct ldlm_namespace *ns,
 256                                         struct ldlm_resource *parent,
 257                                         __u64 *name, __u32 type, int create)
 258 {
 259         struct list_head *bucket;
 260         struct list_head *tmp = bucket;
 261         struct ldlm_resource *res = NULL;
 262         ENTRY;
 263
 264         if (ns == NULL || ns->ns_hash == NULL) {
 265                 LBUG();
 266                 RETURN(NULL);
 267         }
 268
 269         l_lock(&ns->ns_lock);
 270         bucket = ns->ns_hash + ldlm_hash_fn(parent, name);
 271
 272         list_for_each(tmp, bucket) {
 273                 struct ldlm_resource *chk;
 274                 chk = list_entry(tmp, struct ldlm_resource, lr_hash);
 275
 276                 if (memcmp(chk->lr_name, name, sizeof(chk->lr_name)) == 0) {
 277                         res = chk;
 278                         atomic_inc(&res->lr_refcount);
 279                         EXIT;
 280                         break;
 281                 }
 282         }
 283
 284         if (res == NULL && create)
 285                 res = ldlm_resource_add(ns, parent, name, type);
 286         l_unlock(&ns->ns_lock);
 287
 288         RETURN(res);
 289 }
 290
 291 struct ldlm_resource *ldlm_resource_getref(struct ldlm_resource *res)
 292 {
 293         atomic_inc(&res->lr_refcount);
 294         return res;
 295 }
 296
 297 /* Returns 1 if the resource was freed, 0 if it remains. */
 298 int ldlm_resource_put(struct ldlm_resource *res)
 299 {
 300         int rc = 0;
 301
 302         if (atomic_dec_and_test(&res->lr_refcount)) {
 303                 struct ldlm_namespace *ns = res->lr_namespace;
 304                 ENTRY;
 305
 306                 l_lock(&ns->ns_lock);
 307
 308                 if (atomic_read(&res->lr_refcount) != 0) {
 309                         /* We lost the race. */
 310                         l_unlock(&ns->ns_lock);
 311                         goto out;
 312                 }
 313
 314                 if (!list_empty(&res->lr_granted))
 315                         LBUG();
 316
 317                 if (!list_empty(&res->lr_converting))
 318                         LBUG();
 319
 320                 if (!list_empty(&res->lr_waiting))
 321                         LBUG();
 322
 323                 if (!list_empty(&res->lr_children))
 324                         LBUG();
 325
 326                 ns->ns_refcount--;
 327                 list_del(&res->lr_hash);
 328                 list_del(&res->lr_childof);
 329
 330                 kmem_cache_free(ldlm_resource_slab, res);
 331                 l_unlock(&ns->ns_lock);
 332                 rc = 1;
 333         } else {
 334                 ENTRY;
 335         out:
 336                 if (atomic_read(&res->lr_refcount) < 0)
 337                         LBUG();
 338         }
 339
 340         RETURN(rc);
 341 }
 342
 343 void ldlm_resource_add_lock(struct ldlm_resource *res, struct list_head *head,
 344                             struct ldlm_lock *lock)
 345 {
 346         l_lock(&res->lr_namespace->ns_lock);
 347
 348         ldlm_resource_dump(res);
 349         ldlm_lock_dump(lock);
 350
 351         if (!list_empty(&lock->l_res_link))
 352                 LBUG();
 353
 354         list_add(&lock->l_res_link, head);
 355         l_unlock(&res->lr_namespace->ns_lock);
 356 }
 357
 358 void ldlm_resource_unlink_lock(struct ldlm_lock *lock)
 359 {
 360         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 361         list_del_init(&lock->l_res_link);
 362         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 363 }
 364
 365 void ldlm_res2desc(struct ldlm_resource *res, struct ldlm_resource_desc *desc)
 366 {
 367         desc->lr_type = res->lr_type;
 368         memcpy(desc->lr_name, res->lr_name, sizeof(desc->lr_name));
 369         memcpy(desc->lr_version, res->lr_version, sizeof(desc->lr_version));
 370 }
 371
 372 void ldlm_dump_all_namespaces(void)
 373 {
 374         struct list_head *tmp;
 375
 376         spin_lock(&ldlm_namespace_lock);
 377
 378         list_for_each(tmp, &ldlm_namespace_list) {
 379                 struct ldlm_namespace *ns;
 380                 ns = list_entry(tmp, struct ldlm_namespace, ns_list_chain);
 381                 ldlm_namespace_dump(ns);
 382         }
 383
 384         spin_unlock(&ldlm_namespace_lock);
 385 }
 386
 387 void ldlm_namespace_dump(struct ldlm_namespace *ns)
 388 {
 389         struct list_head *tmp;
 390
 391         l_lock(&ns->ns_lock);
 392         CDEBUG(D_OTHER, "--- Namespace: %s (rc: %d, client: %d)\n", ns->ns_name,
 393                ns->ns_refcount, ns->ns_client);
 394
 395         list_for_each(tmp, &ns->ns_root_list) {
 396                 struct ldlm_resource *res;
 397                 res = list_entry(tmp, struct ldlm_resource, lr_childof);
 398
 399                 /* Once we have resources with children, this should really dump
 400                  * them recursively. */
 401                 ldlm_resource_dump(res);
 402         }
 403         l_unlock(&ns->ns_lock);
 404 }
 405
 406 void ldlm_resource_dump(struct ldlm_resource *res)
 407 {
 408         struct list_head *tmp;
 409         char name[256];
 410
 411         if (RES_NAME_SIZE != 3)
 412                 LBUG();
 413
 414         snprintf(name, sizeof(name), "%Lx %Lx %Lx",
 415                  (unsigned long long)res->lr_name[0],
 416                  (unsigned long long)res->lr_name[1],
 417                  (unsigned long long)res->lr_name[2]);
 418
 419         CDEBUG(D_OTHER, "--- Resource: %p (%s) (rc: %d)\n", res, name,
 420                atomic_read(&res->lr_refcount));
 421         CDEBUG(D_OTHER, "Namespace: %p (%s)\n", res->lr_namespace,
 422                res->lr_namespace->ns_name);
 423         CDEBUG(D_OTHER, "Parent: %p, root: %p\n", res->lr_parent, res->lr_root);
 424
 425         CDEBUG(D_OTHER, "Granted locks:\n");
 426         list_for_each(tmp, &res->lr_granted) {
 427                 struct ldlm_lock *lock;
 428                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 429                 ldlm_lock_dump(lock);
 430         }
 431
 432         CDEBUG(D_OTHER, "Converting locks:\n");
 433         list_for_each(tmp, &res->lr_converting) {
 434                 struct ldlm_lock *lock;
 435                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 436                 ldlm_lock_dump(lock);
 437         }
 438
 439         CDEBUG(D_OTHER, "Waiting locks:\n");
 440         list_for_each(tmp, &res->lr_waiting) {
 441                 struct ldlm_lock *lock;
 442                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 443                 ldlm_lock_dump(lock);
 444         }
 445 }