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 #include <linux/obd_class.h>
  16
  17 kmem_cache_t *ldlm_resource_slab, *ldlm_lock_slab;
  18
  19 spinlock_t ldlm_namespace_lock = SPIN_LOCK_UNLOCKED;
  20 struct list_head ldlm_namespace_list = LIST_HEAD_INIT(ldlm_namespace_list);
  21 static struct proc_dir_entry *ldlm_ns_proc_dir = NULL;
  22
  23 int ldlm_proc_setup(struct obd_device *obd)
  24 {
  25         ENTRY;
  26
  27         if (obd->obd_proc_entry == NULL)
  28                 RETURN(-EINVAL);
  29
  30         ldlm_ns_proc_dir = proc_mkdir("namespaces", obd->obd_proc_entry);
  31         if (ldlm_ns_proc_dir == NULL) {
  32                 CERROR("Couldn't create /proc/lustre/ldlm/namespaces\n");
  33                 RETURN(-EPERM);
  34         }
  35         RETURN(0);
  36 }
  37
  38 void ldlm_proc_cleanup(struct obd_device *obd)
  39 {
  40         proc_lustre_remove_obd_entry("namespaces", obd);
  41 }
  42
  43 struct ldlm_namespace *ldlm_namespace_new(char *name, __u32 client)
  44 {
  45         struct ldlm_namespace *ns = NULL;
  46         struct list_head *bucket;
  47
  48         OBD_ALLOC(ns, sizeof(*ns));
  49         if (!ns) {
  50                 LBUG();
  51                 GOTO(out, NULL);
  52         }
  53
  54         ns->ns_hash = vmalloc(sizeof(*ns->ns_hash) * RES_HASH_SIZE);
  55         if (!ns->ns_hash) {
  56                 LBUG();
  57                 GOTO(out, ns);
  58         }
  59         obd_memory += sizeof(*ns->ns_hash) * RES_HASH_SIZE;
  60
  61         OBD_ALLOC(ns->ns_name, strlen(name) + 1);
  62         if (!ns->ns_name) {
  63                 LBUG();
  64                 GOTO(out, ns);
  65         }
  66         strcpy(ns->ns_name, name);
  67
  68         INIT_LIST_HEAD(&ns->ns_root_list);
  69         l_lock_init(&ns->ns_lock);
  70         ns->ns_refcount = 0;
  71         ns->ns_client = client;
  72
  73         for (bucket = ns->ns_hash + RES_HASH_SIZE - 1; bucket >= ns->ns_hash;
  74              bucket--)
  75                 INIT_LIST_HEAD(bucket);
  76
  77         spin_lock(&ldlm_namespace_lock);
  78         list_add(&ns->ns_list_chain, &ldlm_namespace_list);
  79         ns->ns_proc_dir = proc_mkdir(ns->ns_name, ldlm_ns_proc_dir);
  80         if (ns->ns_proc_dir == NULL)
  81                 CERROR("Unable to create proc directory for namespace.\n");
  82         spin_unlock(&ldlm_namespace_lock);
  83
  84         RETURN(ns);
  85
  86  out:
  87         if (ns && ns->ns_hash) {
  88                 vfree(ns->ns_hash);
  89                 obd_memory -= sizeof(*ns->ns_hash) * RES_HASH_SIZE;
  90         }
  91         if (ns && ns->ns_name)
  92                 OBD_FREE(ns->ns_name, strlen(name) + 1);
  93         if (ns)
  94                 OBD_FREE(ns, sizeof(*ns));
  95         return NULL;
  96 }
  97
  98 extern struct ldlm_lock *ldlm_lock_get(struct ldlm_lock *lock);
  99
 100 static void cleanup_resource(struct ldlm_resource *res, struct list_head *q)
 101 {
 102         struct list_head *tmp, *pos;
 103         int rc = 0, client = res->lr_namespace->ns_client;
 104         ENTRY;
 105
 106         list_for_each_safe(tmp, pos, q) {
 107                 struct ldlm_lock *lock;
 108                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 109                 LDLM_LOCK_GET(lock);
 110
 111                 if (client) {
 112                         struct lustre_handle lockh;
 113                         ldlm_lock2handle(lock, &lockh);
 114                         /* can we get away without a connh here? */
 115                         rc = ldlm_cli_cancel(&lockh);
 116                         if (rc != ELDLM_OK) {
 117                                 /* It failed remotely, but we'll force it to
 118                                  * cleanup locally. */
 119                                 CERROR("ldlm_cli_cancel: %d\n", rc);
 120                                 ldlm_lock_cancel(lock);
 121                         }
 122                 } else {
 123                         LDLM_DEBUG(lock, "Freeing a lock still held by a "
 124                                    "client node.\n");
 125
 126                         ldlm_resource_unlink_lock(lock);
 127                         ldlm_lock_destroy(lock);
 128                 }
 129                 LDLM_LOCK_PUT(lock);
 130         }
 131 }
 132
 133 int ldlm_namespace_free(struct ldlm_namespace *ns)
 134 {
 135         struct list_head *tmp, *pos;
 136         int i;
 137
 138         if (!ns)
 139                 RETURN(ELDLM_OK);
 140
 141         spin_lock(&ldlm_namespace_lock);
 142         list_del(&ns->ns_list_chain);
 143         remove_proc_entry(ns->ns_name, ldlm_ns_proc_dir);
 144         spin_unlock(&ldlm_namespace_lock);
 145
 146         l_lock(&ns->ns_lock);
 147
 148         for (i = 0; i < RES_HASH_SIZE; i++) {
 149                 list_for_each_safe(tmp, pos, &(ns->ns_hash[i])) {
 150                         struct ldlm_resource *res;
 151                         res = list_entry(tmp, struct ldlm_resource, lr_hash);
 152                         ldlm_resource_getref(res);
 153
 154                         cleanup_resource(res, &res->lr_granted);
 155                         cleanup_resource(res, &res->lr_converting);
 156                         cleanup_resource(res, &res->lr_waiting);
 157
 158                         if (!ldlm_resource_put(res)) {
 159                                 CERROR("Resource refcount nonzero (%d) after "
 160                                        "lock cleanup; forcing cleanup.\n",
 161                                        atomic_read(&res->lr_refcount));
 162                                 ldlm_resource_dump(res);
 163                                 atomic_set(&res->lr_refcount, 1);
 164                                 ldlm_resource_put(res);
 165                         }
 166                 }
 167         }
 168
 169         vfree(ns->ns_hash /* , sizeof(*ns->ns_hash) * RES_HASH_SIZE */);
 170         obd_memory -= sizeof(*ns->ns_hash) * RES_HASH_SIZE;
 171         OBD_FREE(ns->ns_name, strlen(ns->ns_name) + 1);
 172         OBD_FREE(ns, sizeof(*ns));
 173
 174         return ELDLM_OK;
 175 }
 176
 177 int ldlm_client_free(struct obd_export *exp)
 178 {
 179         struct ldlm_export_data *led = &exp->exp_ldlm_data;
 180         ptlrpc_cleanup_client(&led->led_client);
 181         RETURN(0);
 182 }
 183
 184 static __u32 ldlm_hash_fn(struct ldlm_resource *parent, __u64 *name)
 185 {
 186         __u32 hash = 0;
 187         int i;
 188
 189         for (i = 0; i < RES_NAME_SIZE; i++)
 190                 hash += name[i];
 191
 192         hash += (__u32)((unsigned long)parent >> 4);
 193
 194         return (hash & RES_HASH_MASK);
 195 }
 196
 197 static struct ldlm_resource *ldlm_resource_new(void)
 198 {
 199         struct ldlm_resource *res;
 200
 201         res = kmem_cache_alloc(ldlm_resource_slab, SLAB_KERNEL);
 202         if (res == NULL) {
 203                 LBUG();
 204                 return NULL;
 205         }
 206         memset(res, 0, sizeof(*res));
 207
 208         INIT_LIST_HEAD(&res->lr_children);
 209         INIT_LIST_HEAD(&res->lr_childof);
 210         INIT_LIST_HEAD(&res->lr_granted);
 211         INIT_LIST_HEAD(&res->lr_converting);
 212         INIT_LIST_HEAD(&res->lr_waiting);
 213
 214         atomic_set(&res->lr_refcount, 1);
 215
 216         return res;
 217 }
 218
 219 /* Args: locked namespace
 220  * Returns: newly-allocated, referenced, unlocked resource */
 221 static struct ldlm_resource *ldlm_resource_add(struct ldlm_namespace *ns,
 222                                                struct ldlm_resource *parent,
 223                                                __u64 *name, __u32 type)
 224 {
 225         struct list_head *bucket;
 226         struct ldlm_resource *res;
 227         ENTRY;
 228
 229         if (type < LDLM_MIN_TYPE || type > LDLM_MAX_TYPE) {
 230                 LBUG();
 231                 RETURN(NULL);
 232         }
 233
 234         res = ldlm_resource_new();
 235         if (!res) {
 236                 LBUG();
 237                 RETURN(NULL);
 238         }
 239
 240         memcpy(res->lr_name, name, sizeof(res->lr_name));
 241         res->lr_namespace = ns;
 242         ns->ns_refcount++;
 243
 244         res->lr_type = type;
 245         res->lr_most_restr = LCK_NL;
 246
 247         bucket = ns->ns_hash + ldlm_hash_fn(parent, name);
 248         list_add(&res->lr_hash, bucket);
 249
 250         if (parent == NULL)
 251                 list_add(&res->lr_childof, &ns->ns_root_list);
 252         else {
 253                 res->lr_parent = parent;
 254                 list_add(&res->lr_childof, &parent->lr_children);
 255         }
 256
 257         RETURN(res);
 258 }
 259
 260 /* Args: unlocked namespace
 261  * Locks: takes and releases ns->ns_lock and res->lr_lock
 262  * Returns: referenced, unlocked ldlm_resource or NULL */
 263 struct ldlm_resource *ldlm_resource_get(struct ldlm_namespace *ns,
 264                                         struct ldlm_resource *parent,
 265                                         __u64 *name, __u32 type, int create)
 266 {
 267         struct list_head *bucket;
 268         struct list_head *tmp = bucket;
 269         struct ldlm_resource *res = NULL;
 270         ENTRY;
 271
 272         if (ns == NULL || ns->ns_hash == NULL) {
 273                 LBUG();
 274                 RETURN(NULL);
 275         }
 276
 277         l_lock(&ns->ns_lock);
 278         bucket = ns->ns_hash + ldlm_hash_fn(parent, name);
 279
 280         list_for_each(tmp, bucket) {
 281                 struct ldlm_resource *chk;
 282                 chk = list_entry(tmp, struct ldlm_resource, lr_hash);
 283
 284                 if (memcmp(chk->lr_name, name, sizeof(chk->lr_name)) == 0) {
 285                         res = chk;
 286                         atomic_inc(&res->lr_refcount);
 287                         EXIT;
 288                         break;
 289                 }
 290         }
 291
 292         if (res == NULL && create)
 293                 res = ldlm_resource_add(ns, parent, name, type);
 294         l_unlock(&ns->ns_lock);
 295
 296         RETURN(res);
 297 }
 298
 299 struct ldlm_resource *ldlm_resource_getref(struct ldlm_resource *res)
 300 {
 301         atomic_inc(&res->lr_refcount);
 302         return res;
 303 }
 304
 305 /* Returns 1 if the resource was freed, 0 if it remains. */
 306 int ldlm_resource_put(struct ldlm_resource *res)
 307 {
 308         int rc = 0;
 309
 310         if (atomic_dec_and_test(&res->lr_refcount)) {
 311                 struct ldlm_namespace *ns = res->lr_namespace;
 312                 ENTRY;
 313
 314                 l_lock(&ns->ns_lock);
 315
 316                 if (atomic_read(&res->lr_refcount) != 0) {
 317                         /* We lost the race. */
 318                         l_unlock(&ns->ns_lock);
 319                         goto out;
 320                 }
 321
 322                 if (!list_empty(&res->lr_granted))
 323                         LBUG();
 324
 325                 if (!list_empty(&res->lr_converting))
 326                         LBUG();
 327
 328                 if (!list_empty(&res->lr_waiting))
 329                         LBUG();
 330
 331                 if (!list_empty(&res->lr_children))
 332                         LBUG();
 333
 334                 ns->ns_refcount--;
 335                 list_del(&res->lr_hash);
 336                 list_del(&res->lr_childof);
 337
 338                 kmem_cache_free(ldlm_resource_slab, res);
 339                 l_unlock(&ns->ns_lock);
 340                 rc = 1;
 341         } else {
 342                 ENTRY;
 343         out:
 344                 if (atomic_read(&res->lr_refcount) < 0)
 345                         LBUG();
 346         }
 347
 348         RETURN(rc);
 349 }
 350
 351 void ldlm_resource_add_lock(struct ldlm_resource *res, struct list_head *head,
 352                             struct ldlm_lock *lock)
 353 {
 354         l_lock(&res->lr_namespace->ns_lock);
 355
 356         ldlm_resource_dump(res);
 357         ldlm_lock_dump(lock);
 358
 359         if (!list_empty(&lock->l_res_link))
 360                 LBUG();
 361
 362         list_add(&lock->l_res_link, head);
 363         l_unlock(&res->lr_namespace->ns_lock);
 364 }
 365
 366 void ldlm_resource_unlink_lock(struct ldlm_lock *lock)
 367 {
 368         l_lock(&lock->l_resource->lr_namespace->ns_lock);
 369         list_del_init(&lock->l_res_link);
 370         l_unlock(&lock->l_resource->lr_namespace->ns_lock);
 371 }
 372
 373 void ldlm_res2desc(struct ldlm_resource *res, struct ldlm_resource_desc *desc)
 374 {
 375         desc->lr_type = res->lr_type;
 376         memcpy(desc->lr_name, res->lr_name, sizeof(desc->lr_name));
 377         memcpy(desc->lr_version, res->lr_version, sizeof(desc->lr_version));
 378 }
 379
 380 void ldlm_dump_all_namespaces(void)
 381 {
 382         struct list_head *tmp;
 383
 384         spin_lock(&ldlm_namespace_lock);
 385
 386         list_for_each(tmp, &ldlm_namespace_list) {
 387                 struct ldlm_namespace *ns;
 388                 ns = list_entry(tmp, struct ldlm_namespace, ns_list_chain);
 389                 ldlm_namespace_dump(ns);
 390         }
 391
 392         spin_unlock(&ldlm_namespace_lock);
 393 }
 394
 395 void ldlm_namespace_dump(struct ldlm_namespace *ns)
 396 {
 397         struct list_head *tmp;
 398
 399         l_lock(&ns->ns_lock);
 400         CDEBUG(D_OTHER, "--- Namespace: %s (rc: %d, client: %d)\n", ns->ns_name,
 401                ns->ns_refcount, ns->ns_client);
 402
 403         list_for_each(tmp, &ns->ns_root_list) {
 404                 struct ldlm_resource *res;
 405                 res = list_entry(tmp, struct ldlm_resource, lr_childof);
 406
 407                 /* Once we have resources with children, this should really dump
 408                  * them recursively. */
 409                 ldlm_resource_dump(res);
 410         }
 411         l_unlock(&ns->ns_lock);
 412 }
 413
 414 void ldlm_resource_dump(struct ldlm_resource *res)
 415 {
 416         struct list_head *tmp;
 417         char name[256];
 418
 419         if (RES_NAME_SIZE != 3)
 420                 LBUG();
 421
 422         snprintf(name, sizeof(name), "%Lx %Lx %Lx",
 423                  (unsigned long long)res->lr_name[0],
 424                  (unsigned long long)res->lr_name[1],
 425                  (unsigned long long)res->lr_name[2]);
 426
 427         CDEBUG(D_OTHER, "--- Resource: %p (%s) (rc: %d)\n", res, name,
 428                atomic_read(&res->lr_refcount));
 429         CDEBUG(D_OTHER, "Namespace: %p (%s)\n", res->lr_namespace,
 430                res->lr_namespace->ns_name);
 431         CDEBUG(D_OTHER, "Parent: %p, root: %p\n", res->lr_parent, res->lr_root);
 432
 433         CDEBUG(D_OTHER, "Granted locks:\n");
 434         list_for_each(tmp, &res->lr_granted) {
 435                 struct ldlm_lock *lock;
 436                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 437                 ldlm_lock_dump(lock);
 438         }
 439
 440         CDEBUG(D_OTHER, "Converting locks:\n");
 441         list_for_each(tmp, &res->lr_converting) {
 442                 struct ldlm_lock *lock;
 443                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 444                 ldlm_lock_dump(lock);
 445         }
 446
 447         CDEBUG(D_OTHER, "Waiting locks:\n");
 448         list_for_each(tmp, &res->lr_waiting) {
 449                 struct ldlm_lock *lock;
 450                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 451                 ldlm_lock_dump(lock);
 452         }
 453 }