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