lustre/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
  14 #include <linux/version.h>
  15 #include <linux/module.h>
  16 #include <linux/slab.h>
  17 #include <asm/unistd.h>
  18
  19 #define DEBUG_SUBSYSTEM S_LDLM
  20
  21 #include <linux/obd_support.h>
  22 #include <linux/obd_class.h>
  23
  24 #include <linux/lustre_dlm.h>
  25
  26 static kmem_cache_t *ldlm_resource_slab;
  27 kmem_cache_t *ldlm_lock_slab;
  28
  29 struct ldlm_namespace *ldlm_namespace_find(struct obd_device *obddev, __u32 id)
  30 {
  31         struct list_head *tmp;
  32         struct ldlm_namespace *res;
  33
  34         ldlm_lock(obddev);
  35
  36         res = NULL;
  37         list_for_each(tmp, &obddev->u.ldlm.ldlm_namespaces) {
  38                 struct ldlm_namespace *chk;
  39                 chk = list_entry(tmp, struct ldlm_namespace, ns_link);
  40
  41                 if ( chk->ns_id == id ) {
  42                         res = chk;
  43                         break;
  44                 }
  45         }
  46
  47         ldlm_unlock(obddev);
  48
  49         return res;
  50 }
  51
  52 /* this must be called with ldlm_lock(obddev) held */
  53 static void res_hash_init(struct ldlm_namespace *ns)
  54 {
  55         struct list_head *res_hash;
  56         struct list_head *bucket;
  57
  58         if (ns->ns_hash != NULL)
  59                 return;
  60
  61         OBD_ALLOC(res_hash, sizeof(struct list_head) * RES_HASH_SIZE);
  62         if (!res_hash)
  63                 BUG();
  64
  65         for (bucket = res_hash + RES_HASH_SIZE-1 ; bucket >= res_hash ;
  66              bucket--) {
  67                 INIT_LIST_HEAD(bucket);
  68         }
  69
  70         ns->ns_hash = res_hash;
  71 }
  72
  73 struct ldlm_namespace *ldlm_namespace_new(struct obd_device *obddev, __u32 id)
  74 {
  75         struct ldlm_namespace *ns;
  76
  77         ldlm_lock(obddev);
  78
  79         if (ldlm_namespace_find(obddev, id))
  80                 BUG();
  81
  82         OBD_ALLOC(ns, sizeof(*ns));
  83         if (!ns)
  84                 BUG();
  85
  86         ns->ns_id = id;
  87         INIT_LIST_HEAD(&ns->ns_root_list);
  88
  89         list_add(&ns->ns_link, &obddev->u.ldlm.ldlm_namespaces);
  90
  91         res_hash_init(ns);
  92
  93         ldlm_unlock(obddev);
  94
  95         return ns;
  96 }
  97
  98 static __u32 ldlm_hash_fn(struct ldlm_resource *parent, __u32 *name)
  99 {
 100         __u32 hash = 0;
 101         int i;
 102
 103         for (i = 0; i < RES_NAME_SIZE; i++) {
 104                 hash += name[i];
 105         }
 106
 107         hash += (__u32)((unsigned long)parent >> 4);
 108
 109         return (hash & RES_HASH_MASK);
 110 }
 111
 112 static struct ldlm_resource *ldlm_resource_new(void)
 113 {
 114         struct ldlm_resource *res;
 115
 116         res = kmem_cache_alloc(ldlm_resource_slab, SLAB_KERNEL);
 117         if (res == NULL)
 118                 BUG();
 119         memset(res, 0, sizeof(*res));
 120
 121         INIT_LIST_HEAD(&res->lr_children);
 122         INIT_LIST_HEAD(&res->lr_granted);
 123         INIT_LIST_HEAD(&res->lr_converting);
 124         INIT_LIST_HEAD(&res->lr_waiting);
 125
 126         res->lr_lock = SPIN_LOCK_UNLOCKED;
 127
 128         atomic_set(&res->lr_refcount, 1);
 129
 130         return res;
 131 }
 132
 133 /* ldlm_lock(obddev) must be taken before calling resource_add */
 134 static struct ldlm_resource *ldlm_resource_add(struct ldlm_namespace *ns,
 135                                                struct ldlm_resource *parent,
 136                                                __u32 *name)
 137 {
 138         struct list_head *bucket;
 139         struct ldlm_resource *res;
 140
 141         bucket = ns->ns_hash + ldlm_hash_fn(parent, name);
 142
 143         res = ldlm_resource_new();
 144         if (!res)
 145                 BUG();
 146
 147         memcpy(res->lr_name, name, RES_NAME_SIZE * sizeof(__u32));
 148         res->lr_namespace = ns;
 149         list_add(&res->lr_hash, bucket);
 150         if (parent == NULL) {
 151                 res->lr_parent = res;
 152                 list_add(&res->lr_rootlink, &ns->ns_root_list);
 153         } else {
 154                 res->lr_parent = parent;
 155                 list_add(&res->lr_childof, &parent->lr_children);
 156         }
 157
 158         return res;
 159 }
 160
 161 struct ldlm_resource *ldlm_resource_get(struct ldlm_namespace *ns,
 162                                         struct ldlm_resource *parent,
 163                                         __u32 *name, int create)
 164 {
 165         struct list_head *bucket;
 166         struct list_head *tmp = bucket;
 167         struct ldlm_resource *res;
 168
 169         if (ns->ns_hash == NULL)
 170                 BUG();
 171         bucket = ns->ns_hash + ldlm_hash_fn(parent, name);
 172
 173         ldlm_lock(ns->ns_obddev);
 174
 175         res = NULL;
 176         list_for_each(tmp, bucket) {
 177                 struct ldlm_resource *chk;
 178                 chk = list_entry(tmp, struct ldlm_resource, lr_hash);
 179
 180                 if (memcmp(chk->lr_name, name,
 181                            RES_NAME_SIZE * sizeof(__u32)) == 0) {
 182                         res = chk;
 183                         atomic_inc(&res->lr_refcount);
 184                         break;
 185                 }
 186         }
 187
 188         if (res == NULL && create)
 189                 res = ldlm_resource_add(ns, parent, name);
 190
 191         ldlm_unlock(ns->ns_obddev);
 192
 193         return res;
 194 }
 195
 196 int ldlm_resource_put(struct ldlm_resource *res)
 197 {
 198         int rc = 0;
 199         ldlm_lock(res->lr_namespace->ns_obddev);
 200
 201         if (atomic_dec_and_test(&res->lr_refcount)) {
 202                 if (!list_empty(&res->lr_granted))
 203                         BUG();
 204
 205                 if (!list_empty(&res->lr_converting))
 206                         BUG();
 207
 208                 if (!list_empty(&res->lr_waiting))
 209                         BUG();
 210
 211                 list_del(&res->lr_hash);
 212                 list_del(&res->lr_rootlink);
 213                 list_del(&res->lr_childof);
 214
 215                 kmem_cache_free(ldlm_resource_slab, res);
 216                 rc = 1;
 217         }
 218         ldlm_unlock(res->lr_namespace->ns_obddev);
 219         return rc;
 220 }
 221
 222 int ldlm_get_resource_handle(struct ldlm_resource *res, struct ldlm_handle *h)
 223 {
 224         BUG();
 225         return 0;
 226 }
 227
 228 void ldlm_resource_dump(struct ldlm_resource *res)
 229 {
 230         struct list_head *tmp;
 231         char name[256];
 232
 233         if (RES_NAME_SIZE != 6)
 234                 BUG();
 235
 236         snprintf(name, sizeof(name), "%x %x %x %x %x %x",
 237                  res->lr_name[0], res->lr_name[1], res->lr_name[2],
 238                  res->lr_name[3], res->lr_name[4], res->lr_name[5]);
 239
 240         CDEBUG(D_OTHER, "--- Resource: %p (%s)\n", res, name);
 241         CDEBUG(D_OTHER, "Namespace: %p (%u)\n", res->lr_namespace,
 242                res->lr_namespace->ns_id);
 243         CDEBUG(D_OTHER, "Parent: %p, root: %p\n", res->lr_parent, res->lr_root);
 244
 245         CDEBUG(D_OTHER, "Granted locks:\n");
 246         list_for_each(tmp, &res->lr_granted) {
 247                 struct ldlm_lock *lock;
 248                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 249                 ldlm_lock_dump(lock);
 250         }
 251
 252         CDEBUG(D_OTHER, "Converting locks:\n");
 253         list_for_each(tmp, &res->lr_converting) {
 254                 struct ldlm_lock *lock;
 255                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 256                 ldlm_lock_dump(lock);
 257         }
 258
 259         CDEBUG(D_OTHER, "Waiting locks:\n");
 260         list_for_each(tmp, &res->lr_waiting) {
 261                 struct ldlm_lock *lock;
 262                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 263                 ldlm_lock_dump(lock);
 264         }
 265 }
 266
 267 static int ldlm_obd_setup(struct obd_device *obddev, obd_count len, void *data)
 268 {
 269         INIT_LIST_HEAD(&obddev->u.ldlm.ldlm_namespaces);
 270         obddev->u.ldlm.ldlm_lock = SPIN_LOCK_UNLOCKED;
 271
 272         return 0;
 273 }
 274
 275 static int ldlm_iocontrol(int cmd, struct obd_conn *conn, int len, void *karg,
 276                           void *uarg)
 277 {
 278         struct obd_device *obddev = conn->oc_dev;
 279         int err;
 280
 281         ENTRY;
 282
 283         if ( _IOC_TYPE(cmd) != IOC_LDLM_TYPE ||
 284              _IOC_NR(cmd) < IOC_LDLM_MIN_NR  ||
 285              _IOC_NR(cmd) > IOC_LDLM_MAX_NR ) {
 286                 CDEBUG(D_IOCTL, "invalid ioctl ( type %d, nr %d, size %d )\n",
 287                                 _IOC_TYPE(cmd), _IOC_NR(cmd), _IOC_SIZE(cmd));
 288                 EXIT;
 289                 return -EINVAL;
 290         }
 291
 292         switch (cmd) {
 293         case IOC_LDLM_TEST: {
 294                 err = ldlm_test(obddev);
 295                 CERROR("-- done err %d\n", err);
 296                 EXIT;
 297                 break;
 298         }
 299         default:
 300                 err = -EINVAL;
 301                 EXIT;
 302                 break;
 303         }
 304
 305         return err;
 306 }
 307
 308 struct obd_ops ldlm_obd_ops = {
 309         o_iocontrol:   ldlm_iocontrol,
 310         o_setup:       ldlm_obd_setup,
 311         o_connect:     gen_connect,
 312         o_disconnect:  gen_disconnect
 313 };
 314
 315 static int __init ldlm_init(void)
 316 {
 317         int rc = obd_register_type(&ldlm_obd_ops, OBD_LDLM_DEVICENAME);
 318         if (rc != 0)
 319                 return rc;
 320
 321         ldlm_resource_slab = kmem_cache_create("ldlm_resources",
 322                                                sizeof(struct ldlm_resource), 0,
 323                                                SLAB_HWCACHE_ALIGN, NULL, NULL);
 324         if (ldlm_resource_slab == NULL)
 325                 return -ENOMEM;
 326
 327         ldlm_lock_slab = kmem_cache_create("ldlm_locks",
 328                                            sizeof(struct ldlm_lock), 0,
 329                                            SLAB_HWCACHE_ALIGN, NULL, NULL);
 330         if (ldlm_lock_slab == NULL) {
 331                 kmem_cache_destroy(ldlm_resource_slab);
 332                 return -ENOMEM;
 333         }
 334
 335         return 0;
 336 }
 337
 338 static void __exit ldlm_exit(void)
 339 {
 340         obd_unregister_type(OBD_LDLM_DEVICENAME);
 341         kmem_cache_destroy(ldlm_resource_slab);
 342         kmem_cache_destroy(ldlm_lock_slab);
 343 }
 344
 345 MODULE_AUTHOR("Cluster File Systems, Inc. <braam@clusterfs.com>");
 346 MODULE_DESCRIPTION("Lustre Lock Management Module v0.1");
 347 MODULE_LICENSE("GPL");
 348
 349 module_init(ldlm_init);
 350 module_exit(ldlm_exit);