| 74,6 → 74,32 |
|---|
| /** List of unused structures. */ |
| static LIST_INITIALIZE(unused_head); |
| |
| static void unused_initialize(unused_t *u, dev_handle_t dev_handle) |
| { |
| link_initialize(&u->link); |
| u->dev_handle = dev_handle; |
| u->next = 0; |
| u->remaining = ((uint64_t)((fs_index_t)-1)) + 1; |
| list_initialize(&u->freed_head); |
| } |
| |
| static unused_t *unused_find(dev_handle_t dev_handle, bool lock) |
| { |
| unused_t *u; |
| link_t *l; |
| |
| if (lock) |
| futex_down(&unused_futex); |
| for (l = unused_head.next; l != &unused_head; l = l->next) { |
| u = list_get_instance(l, unused_t, link); |
| if (u->dev_handle == dev_handle) |
| return u; |
| } |
| if (lock) |
| futex_up(&unused_futex); |
| return NULL; |
| } |
| |
| /** Futex protecting the up_hash and ui_hash. */ |
| static futex_t used_futex = FUTEX_INITIALIZER; |
| |
| 190,22 → 216,13 |
|---|
| /** Allocate a VFS index which is not currently in use. */ |
| static bool fat_idx_alloc(dev_handle_t dev_handle, fs_index_t *index) |
| { |
| link_t *l; |
| unused_t *u; |
| |
| assert(index); |
| futex_down(&unused_futex); |
| for (l = unused_head.next; l != &unused_head; l = l->next) { |
| u = list_get_instance(l, unused_t, link); |
| if (u->dev_handle == dev_handle) |
| goto hit; |
| } |
| futex_up(&unused_futex); |
| |
| /* dev_handle not found */ |
| return false; |
| u = unused_find(dev_handle, true); |
| if (!u) |
| return false; |
| |
| hit: |
| if (list_empty(&u->freed_head)) { |
| if (u->remaining) { |
| /* |
| 261,21 → 278,11 |
|---|
| /** Free a VFS index, which is no longer in use. */ |
| static void fat_idx_free(dev_handle_t dev_handle, fs_index_t index) |
| { |
| link_t *l; |
| unused_t *u; |
| |
| futex_down(&unused_futex); |
| for (l = unused_head.next; l != &unused_head; l = l->next) { |
| u = list_get_instance(l, unused_t, link); |
| if (u->dev_handle == dev_handle) |
| goto hit; |
| } |
| futex_up(&unused_futex); |
| u = unused_find(dev_handle, true); |
| assert(u); |
| |
| /* should not happen */ |
| assert(0); |
| |
| hit: |
| if (u->next == index + 1) { |
| /* The index can be returned directly to the counter. */ |
| u->next--; |
| 401,3 → 408,60 |
|---|
| return fidx; |
| } |
| |
| int fat_idx_init(void) |
| { |
| if (!hash_table_create(&up_hash, UPH_BUCKETS, 3, &uph_ops)) |
| return ENOMEM; |
| if (!hash_table_create(&ui_hash, UIH_BUCKETS, 2, &uih_ops)) { |
| hash_table_destroy(&up_hash); |
| return ENOMEM; |
| } |
| return EOK; |
| } |
| |
| void fat_idx_fini(void) |
| { |
| /* We assume the hash tables are empty. */ |
| hash_table_destroy(&up_hash); |
| hash_table_destroy(&ui_hash); |
| } |
| |
| int fat_idx_init_by_dev_handle(dev_handle_t dev_handle) |
| { |
| unused_t *u; |
| int rc = EOK; |
| |
| u = (unused_t *) malloc(sizeof(unused_t)); |
| if (!u) |
| return ENOMEM; |
| unused_initialize(u, dev_handle); |
| futex_down(&unused_futex); |
| if (!unused_find(dev_handle, false)) |
| list_append(&u->link, &unused_head); |
| else |
| rc = EEXIST; |
| futex_up(&unused_futex); |
| return rc; |
| } |
| |
| void fat_idx_fini_by_dev_handle(dev_handle_t dev_handle) |
| { |
| unused_t *u; |
| |
| u = unused_find(dev_handle, true); |
| assert(u); |
| list_remove(&u->link); |
| futex_up(&unused_futex); |
| |
| while (!list_empty(&u->freed_head)) { |
| freed_t *f; |
| f = list_get_instance(u->freed_head.next, freed_t, link); |
| list_remove(&f->link); |
| free(f); |
| } |
| free(u); |
| } |
| |
| /** |
| * @} |
| */ |