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 EXPORT_SYMTAB
  13 #define DEBUG_SUBSYSTEM S_LDLM
  14
  15 #include <linux/slab.h>
  16 #include <linux/lustre_dlm.h>
  17
  18 kmem_cache_t *ldlm_resource_slab, *ldlm_lock_slab;
  19
  20 LIST_HEAD(ldlm_namespaces);
  21 spinlock_t ldlm_spinlock;
  22
  23 struct ldlm_namespace *ldlm_namespace_find(__u32 id)
  24 {
  25         struct list_head *tmp;
  26         struct ldlm_namespace *res;
  27
  28         res = NULL;
  29         list_for_each(tmp, &ldlm_namespaces) {
  30                 struct ldlm_namespace *chk;
  31                 chk = list_entry(tmp, struct ldlm_namespace, ns_link);
  32
  33                 if ( chk->ns_id == id ) {
  34                         res = chk;
  35                         break;
  36                 }
  37         }
  38
  39         return res;
  40 }
  41
  42 /* this must be called with ldlm_lock() held */
  43 static int res_hash_init(struct ldlm_namespace *ns)
  44 {
  45         struct list_head *res_hash;
  46         struct list_head *bucket;
  47
  48         if (ns->ns_hash != NULL)
  49                 RETURN(0);
  50
  51         /* FIXME: this memory appears to be leaked */
  52         OBD_ALLOC(res_hash, sizeof(*res_hash) * RES_HASH_SIZE);
  53         if (!res_hash) {
  54                 LBUG();
  55                 RETURN(-ENOMEM);
  56         }
  57
  58         for (bucket = res_hash + RES_HASH_SIZE - 1; bucket >= res_hash;
  59              bucket--)
  60                 INIT_LIST_HEAD(bucket);
  61
  62         ns->ns_hash = res_hash;
  63
  64         return 0;
  65 }
  66
  67 ldlm_error_t ldlm_namespace_new(struct obd_device *obddev, __u32 id,
  68                                 struct ldlm_namespace **ns_out)
  69 {
  70         struct ldlm_namespace *ns;
  71         int rc;
  72
  73         if (ldlm_namespace_find(id))
  74                 RETURN(-ELDLM_NAMESPACE_EXISTS);
  75
  76         OBD_ALLOC(ns, sizeof(*ns));
  77         if (!ns) {
  78                 LBUG();
  79                 RETURN(-ENOMEM);
  80         }
  81
  82         ns->ns_id = id;
  83         ns->ns_obddev = obddev;
  84         INIT_LIST_HEAD(&ns->ns_root_list);
  85
  86         rc = res_hash_init(ns);
  87         if (rc) {
  88                 OBD_FREE(ns, sizeof(*ns));
  89                 RETURN(rc);
  90         }
  91         list_add(&ns->ns_link, &ldlm_namespaces);
  92         atomic_set(&ns->ns_refcount, 0);
  93
  94         *ns_out = ns;
  95         return ELDLM_OK;
  96 }
  97
  98 int ldlm_namespace_free(struct ldlm_namespace *ns)
  99 {
 100         if (atomic_read(&ns->ns_refcount))
 101                 RETURN(-EBUSY);
 102
 103         list_del(&ns->ns_link);
 104         OBD_FREE(ns->ns_hash, sizeof(struct list_head) * RES_HASH_SIZE);
 105         OBD_FREE(ns, sizeof(*ns));
 106
 107         return 0;
 108 }
 109
 110 static __u32 ldlm_hash_fn(struct ldlm_resource *parent, __u64 *name)
 111 {
 112         __u32 hash = 0;
 113         int i;
 114
 115         for (i = 0; i < RES_NAME_SIZE; i++)
 116                 hash += name[i];
 117
 118         hash += (__u32)((unsigned long)parent >> 4);
 119
 120         return (hash & RES_HASH_MASK);
 121 }
 122
 123 static struct ldlm_resource *ldlm_resource_new(void)
 124 {
 125         struct ldlm_resource *res;
 126
 127         res = kmem_cache_alloc(ldlm_resource_slab, SLAB_KERNEL);
 128         if (res == NULL)
 129                 LBUG();
 130         memset(res, 0, sizeof(*res));
 131
 132         INIT_LIST_HEAD(&res->lr_children);
 133         INIT_LIST_HEAD(&res->lr_childof);
 134         INIT_LIST_HEAD(&res->lr_granted);
 135         INIT_LIST_HEAD(&res->lr_converting);
 136         INIT_LIST_HEAD(&res->lr_waiting);
 137
 138         res->lr_lock = SPIN_LOCK_UNLOCKED;
 139
 140         atomic_set(&res->lr_refcount, 1);
 141
 142         return res;
 143 }
 144
 145 /* ldlm_lock() must be taken before calling resource_add */
 146 static struct ldlm_resource *ldlm_resource_add(struct ldlm_namespace *ns,
 147                                                struct ldlm_resource *parent,
 148                                                __u64 *name, __u32 type)
 149 {
 150         struct list_head *bucket;
 151         struct ldlm_resource *res;
 152
 153         bucket = ns->ns_hash + ldlm_hash_fn(parent, name);
 154
 155         res = ldlm_resource_new();
 156         if (!res)
 157                 LBUG();
 158
 159         memcpy(res->lr_name, name, sizeof(res->lr_name));
 160         res->lr_namespace = ns;
 161         if (type < 0 || type > LDLM_MAX_TYPE)
 162                 LBUG();
 163
 164         res->lr_type = type;
 165         res->lr_most_restr = LCK_NL;
 166         list_add(&res->lr_hash, bucket);
 167         atomic_inc(&ns->ns_refcount);
 168         if (parent == NULL) {
 169                 res->lr_parent = res;
 170                 list_add(&res->lr_rootlink, &ns->ns_root_list);
 171         } else {
 172                 res->lr_parent = parent;
 173                 list_add(&res->lr_childof, &parent->lr_children);
 174         }
 175
 176         return res;
 177 }
 178
 179 struct ldlm_resource *ldlm_resource_get(struct ldlm_namespace *ns,
 180                                         struct ldlm_resource *parent,
 181                                         __u64 *name, __u32 type, int create)
 182 {
 183         struct list_head *bucket;
 184         struct list_head *tmp = bucket;
 185         struct ldlm_resource *res;
 186
 187         ENTRY;
 188
 189         if (ns->ns_hash == NULL)
 190                 RETURN(NULL);
 191         bucket = ns->ns_hash + ldlm_hash_fn(parent, name);
 192
 193         res = NULL;
 194         list_for_each(tmp, bucket) {
 195                 struct ldlm_resource *chk;
 196                 chk = list_entry(tmp, struct ldlm_resource, lr_hash);
 197
 198                 if (memcmp(chk->lr_name, name, sizeof(chk->lr_name)) == 0) {
 199                         res = chk;
 200                         atomic_inc(&res->lr_refcount);
 201                         break;
 202                 }
 203         }
 204
 205         if (res == NULL && create)
 206                 res = ldlm_resource_add(ns, parent, name, type);
 207
 208         RETURN(res);
 209 }
 210
 211 int ldlm_resource_put(struct ldlm_resource *res)
 212 {
 213         int rc = 0;
 214
 215         if (atomic_read(&res->lr_refcount) <= 0)
 216                 LBUG();
 217
 218         if (atomic_dec_and_test(&res->lr_refcount)) {
 219                 if (!list_empty(&res->lr_granted))
 220                         LBUG();
 221
 222                 if (!list_empty(&res->lr_converting))
 223                         LBUG();
 224
 225                 if (!list_empty(&res->lr_waiting))
 226                         LBUG();
 227
 228                 atomic_dec(&res->lr_namespace->ns_refcount);
 229                 list_del(&res->lr_hash);
 230                 list_del(&res->lr_rootlink);
 231                 list_del(&res->lr_childof);
 232
 233                 kmem_cache_free(ldlm_resource_slab, res);
 234                 rc = 1;
 235         }
 236
 237         return rc;
 238 }
 239
 240 void ldlm_resource_add_lock(struct ldlm_resource *res, struct list_head *head,
 241                             struct ldlm_lock *lock)
 242 {
 243         list_add(&lock->l_res_link, head);
 244         atomic_inc(&res->lr_refcount);
 245 }
 246
 247 void ldlm_resource_del_lock(struct ldlm_lock *lock)
 248 {
 249         list_del(&lock->l_res_link);
 250         atomic_dec(&lock->l_resource->lr_refcount);
 251 }
 252
 253 int ldlm_get_resource_handle(struct ldlm_resource *res, struct ldlm_handle *h)
 254 {
 255         LBUG();
 256         return 0;
 257 }
 258
 259 void ldlm_res2desc(struct ldlm_resource *res, struct ldlm_resource_desc *desc)
 260 {
 261         desc->lr_ns_id = res->lr_namespace->ns_id;
 262         desc->lr_type = res->lr_type;
 263         memcpy(desc->lr_name, res->lr_name, sizeof(desc->lr_name));
 264         memcpy(desc->lr_version, res->lr_version, sizeof(desc->lr_version));
 265 }
 266
 267 void ldlm_resource_dump(struct ldlm_resource *res)
 268 {
 269         struct list_head *tmp;
 270         char name[256];
 271
 272         if (RES_NAME_SIZE != 3)
 273                 LBUG();
 274
 275         snprintf(name, sizeof(name), "%Lx %Lx %Lx",
 276                  (unsigned long long)res->lr_name[0],
 277                  (unsigned long long)res->lr_name[1],
 278                  (unsigned long long)res->lr_name[2]);
 279
 280         CDEBUG(D_OTHER, "--- Resource: %p (%s)\n", res, name);
 281         CDEBUG(D_OTHER, "Namespace: %p (%u)\n", res->lr_namespace,
 282                res->lr_namespace->ns_id);
 283         CDEBUG(D_OTHER, "Parent: %p, root: %p\n", res->lr_parent, res->lr_root);
 284
 285         CDEBUG(D_OTHER, "Granted locks:\n");
 286         list_for_each(tmp, &res->lr_granted) {
 287                 struct ldlm_lock *lock;
 288                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 289                 ldlm_lock_dump(lock);
 290         }
 291
 292         CDEBUG(D_OTHER, "Converting locks:\n");
 293         list_for_each(tmp, &res->lr_converting) {
 294                 struct ldlm_lock *lock;
 295                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 296                 ldlm_lock_dump(lock);
 297         }
 298
 299         CDEBUG(D_OTHER, "Waiting locks:\n");
 300         list_for_each(tmp, &res->lr_waiting) {
 301                 struct ldlm_lock *lock;
 302                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 303                 ldlm_lock_dump(lock);
 304         }
 305 }
 306