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Ignore whitespace Rev 4054 → Rev 4055

/branches/dd/uspace/srv/fs/fat/fat_idx.c
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;
 
188,24 → 214,15
};
 
/** Allocate a VFS index which is not currently in use. */
static bool fat_idx_alloc(dev_handle_t dev_handle, fs_index_t *index)
static bool fat_index_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) {
/*
259,23 → 276,13
}
 
/** Free a VFS index, which is no longer in use. */
static void fat_idx_free(dev_handle_t dev_handle, fs_index_t index)
static void fat_index_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--;
331,6 → 338,52
futex_up(&unused_futex);
}
 
static fat_idx_t *fat_idx_create(dev_handle_t dev_handle)
{
fat_idx_t *fidx;
 
fidx = (fat_idx_t *) malloc(sizeof(fat_idx_t));
if (!fidx)
return NULL;
if (!fat_index_alloc(dev_handle, &fidx->index)) {
free(fidx);
return NULL;
}
link_initialize(&fidx->uph_link);
link_initialize(&fidx->uih_link);
futex_initialize(&fidx->lock, 1);
fidx->dev_handle = dev_handle;
fidx->pfc = FAT_CLST_RES0; /* no parent yet */
fidx->pdi = 0;
fidx->nodep = NULL;
 
return fidx;
}
 
fat_idx_t *fat_idx_get_new(dev_handle_t dev_handle)
{
fat_idx_t *fidx;
 
futex_down(&used_futex);
fidx = fat_idx_create(dev_handle);
if (!fidx) {
futex_up(&used_futex);
return NULL;
}
unsigned long ikey[] = {
[UIH_DH_KEY] = dev_handle,
[UIH_INDEX_KEY] = fidx->index,
};
hash_table_insert(&ui_hash, ikey, &fidx->uih_link);
futex_down(&fidx->lock);
futex_up(&used_futex);
 
return fidx;
}
 
fat_idx_t *
fat_idx_get_by_pos(dev_handle_t dev_handle, fat_cluster_t pfc, unsigned pdi)
{
347,16 → 400,11
if (l) {
fidx = hash_table_get_instance(l, fat_idx_t, uph_link);
} else {
fidx = (fat_idx_t *) malloc(sizeof(fat_idx_t));
fidx = fat_idx_create(dev_handle);
if (!fidx) {
futex_up(&used_futex);
return NULL;
}
if (!fat_idx_alloc(dev_handle, &fidx->index)) {
free(fidx);
futex_up(&used_futex);
return NULL;
}
unsigned long ikey[] = {
[UIH_DH_KEY] = dev_handle,
363,13 → 411,8
[UIH_INDEX_KEY] = fidx->index,
};
link_initialize(&fidx->uph_link);
link_initialize(&fidx->uih_link);
futex_initialize(&fidx->lock, 1);
fidx->dev_handle = dev_handle;
fidx->pfc = pfc;
fidx->pdi = pdi;
fidx->nodep = NULL;
 
hash_table_insert(&up_hash, pkey, &fidx->uph_link);
hash_table_insert(&ui_hash, ikey, &fidx->uih_link);
380,6 → 423,32
return fidx;
}
 
void fat_idx_hashin(fat_idx_t *idx)
{
unsigned long pkey[] = {
[UPH_DH_KEY] = idx->dev_handle,
[UPH_PFC_KEY] = idx->pfc,
[UPH_PDI_KEY] = idx->pdi,
};
 
futex_down(&used_futex);
hash_table_insert(&up_hash, pkey, &idx->uph_link);
futex_up(&used_futex);
}
 
void fat_idx_hashout(fat_idx_t *idx)
{
unsigned long pkey[] = {
[UPH_DH_KEY] = idx->dev_handle,
[UPH_PFC_KEY] = idx->pfc,
[UPH_PDI_KEY] = idx->pdi,
};
 
futex_down(&used_futex);
hash_table_remove(&up_hash, pkey, 3);
futex_up(&used_futex);
}
 
fat_idx_t *
fat_idx_get_by_index(dev_handle_t dev_handle, fs_index_t index)
{
401,3 → 470,87
return fidx;
}
 
/** Destroy the index structure.
*
* @param idx The index structure to be destroyed.
*/
void fat_idx_destroy(fat_idx_t *idx)
{
unsigned long ikey[] = {
[UIH_DH_KEY] = idx->dev_handle,
[UIH_INDEX_KEY] = idx->index,
};
 
assert(idx->pfc == FAT_CLST_RES0);
 
futex_down(&used_futex);
/*
* Since we can only free unlinked nodes, the index structure is not
* present in the position hash (uph). We therefore hash it out from
* the index hash only.
*/
hash_table_remove(&ui_hash, ikey, 2);
futex_up(&used_futex);
/* Release the VFS index. */
fat_index_free(idx->dev_handle, idx->index);
/* Deallocate the structure. */
free(idx);
}
 
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);
}
 
/**
* @}
*/