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