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                         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                         ldlm_resource_del_lock(lock);
  87                         ldlm_lock_free(lock);
  88
  89                         rc = ldlm_resource_put(res);
  90                 }
  91         }
  92
  93         RETURN(rc);
  94 }
  95
  96 int ldlm_namespace_free(struct ldlm_namespace *ns)
  97 {
  98         struct list_head *tmp, *pos;
  99         int i, rc;
 100
 101         if (!ns)
 102                 RETURN(ELDLM_OK);
 103
 104         l_lock(&ns->ns_lock);
 105
 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                         rc = cleanup_resource(res, &res->lr_granted);
 112                         if (!rc)
 113                                 rc = cleanup_resource(res, &res->lr_converting);
 114                         if (!rc)
 115                                 rc = cleanup_resource(res, &res->lr_waiting);
 116
 117                         if (rc == 0) {
 118                                 CERROR("Resource refcount nonzero (%d) after "
 119                                        "lock cleanup; forcing cleanup.\n",
 120                                        atomic_read(&res->lr_refcount));
 121                                 ldlm_resource_dump(res);
 122                                 atomic_set(&res->lr_refcount, 1);
 123                                 rc = ldlm_resource_put(res);
 124                         }
 125                 }
 126         }
 127
 128         vfree(ns->ns_hash /* , sizeof(struct list_head) * RES_HASH_SIZE */);
 129         ptlrpc_cleanup_client(&ns->ns_rpc_client);
 130         OBD_FREE(ns->ns_name, strlen(ns->ns_name) + 1);
 131         OBD_FREE(ns, sizeof(*ns));
 132
 133         return ELDLM_OK;
 134 }
 135
 136 static __u32 ldlm_hash_fn(struct ldlm_resource *parent, __u64 *name)
 137 {
 138         __u32 hash = 0;
 139         int i;
 140
 141         for (i = 0; i < RES_NAME_SIZE; i++)
 142                 hash += name[i];
 143
 144         hash += (__u32)((unsigned long)parent >> 4);
 145
 146         return (hash & RES_HASH_MASK);
 147 }
 148
 149 static struct ldlm_resource *ldlm_resource_new(void)
 150 {
 151         struct ldlm_resource *res;
 152
 153         res = kmem_cache_alloc(ldlm_resource_slab, SLAB_KERNEL);
 154         if (res == NULL) {
 155                 LBUG();
 156                 return NULL;
 157         }
 158         memset(res, 0, sizeof(*res));
 159
 160         INIT_LIST_HEAD(&res->lr_children);
 161         INIT_LIST_HEAD(&res->lr_childof);
 162         INIT_LIST_HEAD(&res->lr_granted);
 163         INIT_LIST_HEAD(&res->lr_converting);
 164         INIT_LIST_HEAD(&res->lr_waiting);
 165
 166         atomic_set(&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         l_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                         atomic_inc(&res->lr_refcount);
 240                         EXIT;
 241                         break;
 242                 }
 243         }
 244
 245         if (res == NULL && create)
 246                 res = ldlm_resource_add(ns, parent, name, type);
 247         l_unlock(&ns->ns_lock);
 248
 249         RETURN(res);
 250 }
 251
 252 struct ldlm_resource *ldlm_resource_addref(struct ldlm_resource *res)
 253 {
 254         atomic_inc(&res->lr_refcount);
 255         return res;
 256 }
 257
 258 /* Returns 1 if the resource was freed, 0 if it remains. */
 259 int ldlm_resource_put(struct ldlm_resource *res)
 260 {
 261         int rc = 0;
 262
 263         if (atomic_dec_and_test(&res->lr_refcount)) {
 264                 struct ldlm_namespace *ns = res->lr_namespace;
 265                 ENTRY;
 266
 267                 l_lock(&ns->ns_lock);
 268
 269                 if (atomic_read(&res->lr_refcount) != 0) {
 270                         /* We lost the race. */
 271                         l_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                 l_unlock(&ns->ns_lock);
 294                 rc = 1;
 295         } else {
 296                 ENTRY;
 297         out:
 298                 if (atomic_read(&res->lr_refcount) < 0)
 299                         LBUG();
 300         }
 301
 302         RETURN(rc);
 303 }
 304
 305 void ldlm_resource_add_lock(struct ldlm_resource *res, struct list_head *head,
 306                             struct ldlm_lock *lock)
 307 {
 308         l_lock(&res->lr_namespace->ns_lock);
 309
 310         ldlm_resource_dump(res);
 311         ldlm_lock_dump(lock);
 312
 313         if (!list_empty(&lock->l_res_link))
 314                 LBUG();
 315
 316         list_add(&lock->l_res_link, head);
 317         l_unlock(&res->lr_namespace->ns_lock);
 318 }
 319
 320 void ldlm_resource_del_lock(struct ldlm_lock *lock)
 321 {
 322         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 323         list_del_init(&lock->l_res_link);
 324         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 325 }
 326
 327 int ldlm_get_resource_handle(struct ldlm_resource *res, struct lustre_handle *h)
 328 {
 329         LBUG();
 330         return 0;
 331 }
 332
 333 void ldlm_res2desc(struct ldlm_resource *res, struct ldlm_resource_desc *desc)
 334 {
 335         desc->lr_type = res->lr_type;
 336         memcpy(desc->lr_name, res->lr_name, sizeof(desc->lr_name));
 337         memcpy(desc->lr_version, res->lr_version, sizeof(desc->lr_version));
 338 }
 339
 340 void ldlm_resource_dump(struct ldlm_resource *res)
 341 {
 342         struct list_head *tmp;
 343         char name[256];
 344
 345         if (RES_NAME_SIZE != 3)
 346                 LBUG();
 347
 348         snprintf(name, sizeof(name), "%Lx %Lx %Lx",
 349                  (unsigned long long)res->lr_name[0],
 350                  (unsigned long long)res->lr_name[1],
 351                  (unsigned long long)res->lr_name[2]);
 352
 353         CDEBUG(D_OTHER, "--- Resource: %p (%s) (rc: %d)\n", res, name,
 354                atomic_read(&res->lr_refcount));
 355         CDEBUG(D_OTHER, "Namespace: %p (%s)\n", res->lr_namespace,
 356                res->lr_namespace->ns_name);
 357         CDEBUG(D_OTHER, "Parent: %p, root: %p\n", res->lr_parent, res->lr_root);
 358
 359         CDEBUG(D_OTHER, "Granted locks:\n");
 360         list_for_each(tmp, &res->lr_granted) {
 361                 struct ldlm_lock *lock;
 362                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 363                 ldlm_lock_dump(lock);
 364         }
 365
 366         CDEBUG(D_OTHER, "Converting locks:\n");
 367         list_for_each(tmp, &res->lr_converting) {
 368                 struct ldlm_lock *lock;
 369                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 370                 ldlm_lock_dump(lock);
 371         }
 372
 373         CDEBUG(D_OTHER, "Waiting locks:\n");
 374         list_for_each(tmp, &res->lr_waiting) {
 375                 struct ldlm_lock *lock;
 376                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 377                 ldlm_lock_dump(lock);
 378         }
 379 }