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         ns->ns_lock = SPIN_LOCK_UNLOCKED;
  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                         rc = ldlm_cli_cancel(lock->l_client, lock);
  77                         if (rc < 0) {
  78                                 CERROR("ldlm_cli_cancel: %d\n", rc);
  79                                 LBUG();
  80                         }
  81                         if (rc == ELDLM_RESOURCE_FREED)
  82                                 rc = 1;
  83                 } else {
  84                         CERROR("Freeing a lock still held by a client node.\n");
  85
  86                         spin_lock(&lock->l_lock);
  87                         ldlm_resource_del_lock(lock);
  88                         ldlm_lock_free(lock);
  89
  90                         rc = ldlm_resource_put(res);
  91                 }
  92         }
  93
  94         RETURN(rc);
  95 }
  96
  97 int ldlm_namespace_free(struct ldlm_namespace *ns)
  98 {
  99         struct list_head *tmp, *pos;
 100         int i, rc;
 101
 102         if (!ns)
 103                 RETURN(ELDLM_OK);
 104         /* We should probably take the ns_lock, but then ldlm_resource_put
 105          * couldn't take it.  Hmm. */
 106         for (i = 0; i < RES_HASH_SIZE; i++) {
 107                 list_for_each_safe(tmp, pos, &(ns->ns_hash[i])) {
 108                         struct ldlm_resource *res;
 109                         res = list_entry(tmp, struct ldlm_resource, lr_hash);
 110
 111                         spin_lock(&res->lr_lock);
 112                         rc = cleanup_resource(res, &res->lr_granted);
 113                         if (!rc)
 114                                 rc = cleanup_resource(res, &res->lr_converting);
 115                         if (!rc)
 116                                 rc = cleanup_resource(res, &res->lr_waiting);
 117
 118                         if (rc == 0) {
 119                                 CERROR("Resource refcount nonzero after lock "
 120                                        "cleanup; forcing cleanup.\n");
 121                                 res->lr_refcount = 1;
 122                                 rc = ldlm_resource_put(res);
 123                         }
 124                 }
 125         }
 126
 127         vfree(ns->ns_hash /* , sizeof(struct list_head) * RES_HASH_SIZE */);
 128         ptlrpc_cleanup_client(&ns->ns_rpc_client);
 129         OBD_FREE(ns->ns_name, strlen(ns->ns_name) + 1);
 130         OBD_FREE(ns, sizeof(*ns));
 131
 132         return ELDLM_OK;
 133 }
 134
 135 static __u32 ldlm_hash_fn(struct ldlm_resource *parent, __u64 *name)
 136 {
 137         __u32 hash = 0;
 138         int i;
 139
 140         for (i = 0; i < RES_NAME_SIZE; i++)
 141                 hash += name[i];
 142
 143         hash += (__u32)((unsigned long)parent >> 4);
 144
 145         return (hash & RES_HASH_MASK);
 146 }
 147
 148 static struct ldlm_resource *ldlm_resource_new(void)
 149 {
 150         struct ldlm_resource *res;
 151
 152         res = kmem_cache_alloc(ldlm_resource_slab, SLAB_KERNEL);
 153         if (res == NULL) {
 154                 LBUG();
 155                 return NULL;
 156         }
 157         memset(res, 0, sizeof(*res));
 158
 159         INIT_LIST_HEAD(&res->lr_children);
 160         INIT_LIST_HEAD(&res->lr_childof);
 161         INIT_LIST_HEAD(&res->lr_granted);
 162         INIT_LIST_HEAD(&res->lr_converting);
 163         INIT_LIST_HEAD(&res->lr_waiting);
 164
 165         res->lr_lock = SPIN_LOCK_UNLOCKED;
 166         res->lr_refcount = 1;
 167
 168         return res;
 169 }
 170
 171 /* Args: locked namespace
 172  * Returns: newly-allocated, referenced, unlocked resource */
 173 static struct ldlm_resource *ldlm_resource_add(struct ldlm_namespace *ns,
 174                                                struct ldlm_resource *parent,
 175                                                __u64 *name, __u32 type)
 176 {
 177         struct list_head *bucket;
 178         struct ldlm_resource *res;
 179         ENTRY;
 180
 181         if (type < LDLM_MIN_TYPE || type > LDLM_MAX_TYPE) {
 182                 LBUG();
 183                 RETURN(NULL);
 184         }
 185
 186         res = ldlm_resource_new();
 187         if (!res) {
 188                 LBUG();
 189                 RETURN(NULL);
 190         }
 191
 192         memcpy(res->lr_name, name, sizeof(res->lr_name));
 193         res->lr_namespace = ns;
 194         ns->ns_refcount++;
 195
 196         res->lr_type = type;
 197         res->lr_most_restr = LCK_NL;
 198
 199         bucket = ns->ns_hash + ldlm_hash_fn(parent, name);
 200         list_add(&res->lr_hash, bucket);
 201
 202         if (parent == NULL) {
 203                 res->lr_parent = res;
 204                 list_add(&res->lr_rootlink, &ns->ns_root_list);
 205         } else {
 206                 res->lr_parent = parent;
 207                 list_add(&res->lr_childof, &parent->lr_children);
 208         }
 209
 210         RETURN(res);
 211 }
 212
 213 /* Args: unlocked namespace
 214  * Locks: takes and releases ns->ns_lock and res->lr_lock
 215  * Returns: referenced, unlocked ldlm_resource or NULL */
 216 struct ldlm_resource *ldlm_resource_get(struct ldlm_namespace *ns,
 217                                         struct ldlm_resource *parent,
 218                                         __u64 *name, __u32 type, int create)
 219 {
 220         struct list_head *bucket;
 221         struct list_head *tmp = bucket;
 222         struct ldlm_resource *res = NULL;
 223         ENTRY;
 224
 225         if (ns == NULL || ns->ns_hash == NULL) {
 226                 LBUG();
 227                 RETURN(NULL);
 228         }
 229
 230         spin_lock(&ns->ns_lock);
 231         bucket = ns->ns_hash + ldlm_hash_fn(parent, name);
 232
 233         list_for_each(tmp, bucket) {
 234                 struct ldlm_resource *chk;
 235                 chk = list_entry(tmp, struct ldlm_resource, lr_hash);
 236
 237                 if (memcmp(chk->lr_name, name, sizeof(chk->lr_name)) == 0) {
 238                         res = chk;
 239                         spin_lock(&res->lr_lock);
 240                         res->lr_refcount++;
 241                         spin_unlock(&res->lr_lock);
 242                         EXIT;
 243                         break;
 244                 }
 245         }
 246
 247         if (res == NULL && create)
 248                 res = ldlm_resource_add(ns, parent, name, type);
 249         spin_unlock(&ns->ns_lock);
 250
 251         RETURN(res);
 252 }
 253
 254 /* Args: locked resource
 255  * Locks: takes and releases res->lr_lock
 256  *        takes and releases ns->ns_lock iff res->lr_refcount falls to 0
 257  */
 258 int ldlm_resource_put(struct ldlm_resource *res)
 259 {
 260         int rc = 0;
 261
 262         if (res->lr_refcount == 1) {
 263                 struct ldlm_namespace *ns = res->lr_namespace;
 264                 ENTRY;
 265
 266                 spin_unlock(&res->lr_lock);
 267                 spin_lock(&ns->ns_lock);
 268                 spin_lock(&res->lr_lock);
 269
 270                 if (res->lr_refcount != 1) {
 271                         spin_unlock(&ns->ns_lock);
 272                         goto out;
 273                 }
 274
 275                 if (!list_empty(&res->lr_granted))
 276                         LBUG();
 277
 278                 if (!list_empty(&res->lr_converting))
 279                         LBUG();
 280
 281                 if (!list_empty(&res->lr_waiting))
 282                         LBUG();
 283
 284                 if (!list_empty(&res->lr_children))
 285                         LBUG();
 286
 287                 ns->ns_refcount--;
 288                 list_del(&res->lr_hash);
 289                 list_del(&res->lr_rootlink);
 290                 list_del(&res->lr_childof);
 291
 292                 kmem_cache_free(ldlm_resource_slab, res);
 293                 spin_unlock(&ns->ns_lock);
 294                 rc = 1;
 295         } else {
 296                 ENTRY;
 297         out:
 298                 res->lr_refcount--;
 299                 if (res->lr_refcount < 0)
 300                         LBUG();
 301         }
 302
 303         RETURN(rc);
 304 }
 305
 306 /* Must be called with resource->lr_lock taken */
 307 void ldlm_resource_add_lock(struct ldlm_resource *res, struct list_head *head,
 308                             struct ldlm_lock *lock)
 309 {
 310         ldlm_resource_dump(res);
 311         ldlm_lock_dump(lock);
 312         if (!list_empty(&lock->l_res_link))
 313                 LBUG();
 314
 315         list_add(&lock->l_res_link, head);
 316         res->lr_refcount++;
 317 }
 318
 319 /* Must be called with resource->lr_lock taken */
 320 int ldlm_resource_del_lock(struct ldlm_lock *lock)
 321 {
 322         if (!list_empty(&lock->l_res_link)) {
 323                 list_del_init(&lock->l_res_link);
 324                 return ldlm_resource_put(lock->l_resource);
 325         }
 326         return 0;
 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)\n", res, name);
 356         CDEBUG(D_OTHER, "Namespace: %p (%s)\n", res->lr_namespace,
 357                res->lr_namespace->ns_name);
 358         CDEBUG(D_OTHER, "Parent: %p, root: %p\n", res->lr_parent, res->lr_root);
 359
 360         CDEBUG(D_OTHER, "Granted locks:\n");
 361         list_for_each(tmp, &res->lr_granted) {
 362                 struct ldlm_lock *lock;
 363                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 364                 ldlm_lock_dump(lock);
 365         }
 366
 367         CDEBUG(D_OTHER, "Converting locks:\n");
 368         list_for_each(tmp, &res->lr_converting) {
 369                 struct ldlm_lock *lock;
 370                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 371                 ldlm_lock_dump(lock);
 372         }
 373
 374         CDEBUG(D_OTHER, "Waiting locks:\n");
 375         list_for_each(tmp, &res->lr_waiting) {
 376                 struct ldlm_lock *lock;
 377                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 378                 ldlm_lock_dump(lock);
 379         }
 380 }