251,127 → 251,16 |
/* TODO */ |
} |
|
/** Instantiate a FAT in-core node. |
* |
* FAT stores the info necessary for instantiation of a node in the parent of |
* that node. This design necessitated the addition of the parent node index |
* parameter to this otherwise generic libfs API. |
*/ |
/** Instantiate a FAT in-core node. */ |
static void * |
fat_node_get(dev_handle_t dev_handle, fs_index_t index, fs_index_t pindex) |
fat_node_get(dev_handle_t dev_handle, fs_index_t index) |
{ |
link_t *lnk; |
fat_node_t *node = NULL; |
block_t *b; |
unsigned bps; |
unsigned dps; |
fat_dentry_t *d; |
unsigned i, j; |
|
unsigned long key[] = { |
[FIN_KEY_DEV_HANDLE] = dev_handle, |
[FIN_KEY_INDEX] = index |
}; |
|
futex_down(&fin_futex); |
lnk = hash_table_find(&fin_hash, key); |
if (lnk) { |
/* |
* The in-core node was found in the hash table. |
*/ |
node = hash_table_get_instance(lnk, fat_node_t, fin_link); |
if (!node->refcnt++) |
list_remove(&node->ffn_link); |
futex_up(&fin_futex); |
|
/* Make sure that the node is fully instantiated. */ |
futex_down(&node->lock); |
futex_up(&node->lock); |
|
return (void *) node; |
return NULL; /* TODO */ |
} |
|
bps = fat_bps_get(dev_handle); |
dps = bps / sizeof(fat_dentry_t); |
|
if (!list_empty(&ffn_head)) { |
/* |
* We are going to reuse a node from the free list. |
*/ |
lnk = ffn_head.next; |
list_remove(lnk); |
node = list_get_instance(lnk, fat_node_t, ffn_link); |
assert(!node->refcnt); |
if (node->dirty) |
fat_sync_node(node); |
key[FIN_KEY_DEV_HANDLE] = node->dev_handle; |
key[FIN_KEY_INDEX] = node->index; |
hash_table_remove(&fin_hash, key, sizeof(key)/sizeof(*key)); |
} else { |
/* |
* We need to allocate a new node. |
*/ |
node = malloc(sizeof(fat_node_t)); |
if (!node) |
return NULL; |
} |
fat_node_initialize(node); |
node->refcnt++; |
node->lnkcnt++; |
node->dev_handle = dev_handle; |
node->index = index; |
node->pindex = pindex; |
key[FIN_KEY_DEV_HANDLE] = node->dev_handle; |
key[FIN_KEY_INDEX] = node->index; |
hash_table_insert(&fin_hash, key, &node->fin_link); |
|
/* |
* We have already put the node back to fin_hash. |
* The node is not yet fully instantiated so we lock it prior to |
* unlocking fin_hash. |
*/ |
futex_down(&node->lock); |
futex_up(&fin_futex); |
|
/* |
* Because of the design of the FAT file system, we have no clue about |
* how big (i.e. how many directory entries it contains) is the parent |
* of the node we are trying to instantiate. However, we know that it |
* must contain a directory entry for our node of interest. We simply |
* scan the parent until we find it. |
*/ |
for (i = 0; ; i++) { |
b = fat_block_get(node->dev_handle, node->pindex, i); |
for (j = 0; j < dps; j++) { |
d = ((fat_dentry_t *)b->data) + j; |
if (d->firstc == node->index) |
goto found; |
} |
block_put(b); |
} |
|
found: |
if (!(d->attr & (FAT_ATTR_SUBDIR | FAT_ATTR_VOLLABEL))) |
node->type = FAT_FILE; |
if ((d->attr & FAT_ATTR_SUBDIR) || !index) |
node->type = FAT_DIRECTORY; |
assert((node->type == FAT_FILE) || (node->type == FAT_DIRECTORY)); |
|
node->size = uint32_t_le2host(d->size); |
block_put(b); |
|
futex_up(&node->lock); |
return node; |
} |
|
static void fat_node_put(void *node) |
{ |
fat_node_t *nodep = (fat_node_t *)node; |
|
futex_down(&fin_futex); |
if (!--nodep->refcnt) |
list_append(&nodep->ffn_link, &ffn_head); |
futex_up(&fin_futex); |
/* TODO */ |
} |
|
static void *fat_create(int flags) |
431,8 → 320,7 |
if (strcmp(name, component) == 0) { |
/* hit */ |
void *node = fat_node_get(parentp->dev_handle, |
(fs_index_t)uint16_t_le2host(d->firstc), |
parentp->index); |
(fs_index_t)uint16_t_le2host(d->firstc)); |
block_put(b); |
return node; |
} |
510,7 → 398,7 |
|
static void *fat_root_get(dev_handle_t dev_handle) |
{ |
return fat_node_get(dev_handle, 0, 0); |
return fat_node_get(dev_handle, 0); |
} |
|
static char fat_plb_get_char(unsigned pos) |