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Rev 3011 Rev 3424
Line 72... Line 72...
72 
static futex_t unused_futex = FUTEX_INITIALIZER;
 72 
static futex_t unused_futex = FUTEX_INITIALIZER;
73 
 
 73 
 
74 
/** List of unused structures. */
 74 
/** List of unused structures. */
75 
static LIST_INITIALIZE(unused_head);
 75 
static LIST_INITIALIZE(unused_head);
76 
 
 76 
 
- 
 
 77 
static void unused_initialize(unused_t *u, dev_handle_t dev_handle)
- 
 
 78 
{
- 
 
 79 
    link_initialize(&u->link);
- 
 
 80 
    u->dev_handle = dev_handle;
- 
 
 81 
    u->next = 0;
- 
 
 82 
    u->remaining = ((uint64_t)((fs_index_t)-1)) + 1;
- 
 
 83 
    list_initialize(&u->freed_head);
- 
 
 84 
}
- 
 
 85 
 
- 
 
 86 
static unused_t *unused_find(dev_handle_t dev_handle, bool lock)
- 
 
 87 
{
- 
 
 88 
    unused_t *u;
- 
 
 89 
    link_t *l;
- 
 
 90 
 
- 
 
 91 
    if (lock)
- 
 
 92 
        futex_down(&unused_futex);
- 
 
 93 
    for (l = unused_head.next; l != &unused_head; l = l->next) {
- 
 
 94 
        u = list_get_instance(l, unused_t, link);
- 
 
 95 
        if (u->dev_handle == dev_handle)
- 
 
 96 
            return u;
- 
 
 97 
    }
- 
 
 98 
    if (lock)
- 
 
 99 
        futex_up(&unused_futex);
- 
 
 100 
    return NULL;
- 
 
 101 
}
- 
 
 102 
 
77 
/** Futex protecting the up_hash and ui_hash. */
 103 
/** Futex protecting the up_hash and ui_hash. */
78 
static futex_t used_futex = FUTEX_INITIALIZER;
 104 
static futex_t used_futex = FUTEX_INITIALIZER;
79 
 
 105 
 
80 
/**
 106 
/**
81 
 * Global hash table of all used fat_idx_t structures.
 107 
 * Global hash table of all used fat_idx_t structures.
Line 188... Line 214...
188 
};
 214 
};
189 
 
 215 
 
190 
/** Allocate a VFS index which is not currently in use. */
 216 
/** Allocate a VFS index which is not currently in use. */
191 
static bool fat_idx_alloc(dev_handle_t dev_handle, fs_index_t *index)
 217 
static bool fat_idx_alloc(dev_handle_t dev_handle, fs_index_t *index)
192 
{
 218 
{
193 
    link_t *l;
 - 
 
194 
    unused_t *u;
 219 
    unused_t *u;
195 
   
 220 
   
196 
    assert(index);
 221 
    assert(index);
197 
    futex_down(&unused_futex);
 - 
 
198 
    for (l = unused_head.next; l != &unused_head; l = l->next) {
 - 
 
199 
        u = list_get_instance(l, unused_t, link);
 - 
 
200 
        if (u->dev_handle == dev_handle)
 222 
    u = unused_find(dev_handle, true);
201 
            goto hit;
 223 
    if (!u)
202 
    }
 - 
 
203 
    futex_up(&unused_futex);
 - 
 
204 
   
 - 
 
205 
    /* dev_handle not found */
 - 
 
206 
    return false;  
 224 
        return false;  
207 
 
 225 
 
208 
hit:
 - 
 
209 
    if (list_empty(&u->freed_head)) {
 226 
    if (list_empty(&u->freed_head)) {
210 
        if (u->remaining) {
 227 
        if (u->remaining) {
211 
            /*
 228 
            /*
212 
             * There are no freed indices, allocate one directly
 229 
             * There are no freed indices, allocate one directly
213 
             * from the counter.
 230 
             * from the counter.
Line 259... Line 276...
259 
}
 276 
}
260 
 
 277 
 
261 
/** Free a VFS index, which is no longer in use. */
 278 
/** Free a VFS index, which is no longer in use. */
262 
static void fat_idx_free(dev_handle_t dev_handle, fs_index_t index)
 279 
static void fat_idx_free(dev_handle_t dev_handle, fs_index_t index)
263 
{
 280 
{
264 
    link_t *l;
 - 
 
265 
    unused_t *u;
 281 
    unused_t *u;
266 
 
 282 
 
267 
    futex_down(&unused_futex);
 - 
 
268 
    for (l = unused_head.next; l != &unused_head; l = l->next) {
 - 
 
269 
        u = list_get_instance(l, unused_t, link);
 - 
 
270 
        if (u->dev_handle == dev_handle)
 283 
    u = unused_find(dev_handle, true);
271 
            goto hit;
 - 
 
272 
    }
 - 
 
273 
    futex_up(&unused_futex);
 - 
 
274 
 
 - 
 
275 
    /* should not happen */
 - 
 
276 
    assert(0);
 284 
    assert(u);
277 
 
 285 
 
278 
hit:
 - 
 
279 
    if (u->next == index + 1) {
 286 
    if (u->next == index + 1) {
280 
        /* The index can be returned directly to the counter. */
 287 
        /* The index can be returned directly to the counter. */
281 
        u->next--;
 288 
        u->next--;
282 
        u->remaining++;
 289 
        u->remaining++;
283 
    } else {
 290 
    } else {
Line 399... Line 406...
399 
    futex_up(&used_futex);
 406 
    futex_up(&used_futex);
400 
 
 407 
 
401 
    return fidx;
 408 
    return fidx;
402 
}
 409 
}
403 
 
 410 
 
- 
 
 411 
int fat_idx_init(void)
- 
 
 412 
{
- 
 
 413 
    if (!hash_table_create(&up_hash, UPH_BUCKETS, 3, &uph_ops))
- 
 
 414 
        return ENOMEM;
- 
 
 415 
    if (!hash_table_create(&ui_hash, UIH_BUCKETS, 2, &uih_ops)) {
- 
 
 416 
        hash_table_destroy(&up_hash);
- 
 
 417 
        return ENOMEM;
- 
 
 418 
    }
- 
 
 419 
    return EOK;
- 
 
 420 
}
- 
 
 421 
 
- 
 
 422 
void fat_idx_fini(void)
- 
 
 423 
{
- 
 
 424 
    /* We assume the hash tables are empty. */
- 
 
 425 
    hash_table_destroy(&up_hash);
- 
 
 426 
    hash_table_destroy(&ui_hash);
- 
 
 427 
}
- 
 
 428 
 
- 
 
 429 
int fat_idx_init_by_dev_handle(dev_handle_t dev_handle)
- 
 
 430 
{
- 
 
 431 
    unused_t *u;
- 
 
 432 
    int rc = EOK;
- 
 
 433 
 
- 
 
 434 
    u = (unused_t *) malloc(sizeof(unused_t));
- 
 
 435 
    if (!u)
- 
 
 436 
        return ENOMEM;
- 
 
 437 
    unused_initialize(u, dev_handle);
- 
 
 438 
    futex_down(&unused_futex);
- 
 
 439 
    if (!unused_find(dev_handle, false))
- 
 
 440 
        list_append(&u->link, &unused_head);
- 
 
 441 
    else
- 
 
 442 
        rc = EEXIST;
- 
 
 443 
    futex_up(&unused_futex);
- 
 
 444 
    return rc;
- 
 
 445 
}
- 
 
 446 
 
- 
 
 447 
void fat_idx_fini_by_dev_handle(dev_handle_t dev_handle)
- 
 
 448 
{
- 
 
 449 
    unused_t *u;
- 
 
 450 
 
- 
 
 451 
    u = unused_find(dev_handle, true);
- 
 
 452 
    assert(u);
- 
 
 453 
    list_remove(&u->link);
- 
 
 454 
    futex_up(&unused_futex);
- 
 
 455 
 
- 
 
 456 
    while (!list_empty(&u->freed_head)) {
- 
 
 457 
        freed_t *f;
- 
 
 458 
        f = list_get_instance(u->freed_head.next, freed_t, link);
- 
 
 459 
        list_remove(&f->link);
- 
 
 460 
        free(f);
- 
 
 461 
    }
- 
 
 462 
    free(u);
- 
 
 463 
}
- 
 
 464 
 
- 
 
 465 
/**
- 
 
 466 
 * @}
- 
 
 467 
 */