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