static bool erase_entry(struct exfat* ef, struct exfat_node* node)
{
cluster_t cluster = node->entry_cluster;
off64_t offset = node->entry_offset;
int name_entries = DIV_ROUND_UP(utf16_length(node->name), EXFAT_ENAME_MAX);
uint8_t entry_type;
entry_type = EXFAT_ENTRY_FILE & ~EXFAT_ENTRY_VALID;
if (exfat_pwrite(ef->dev, &entry_type, 1, co2o(ef, cluster, offset)) < 0)
{
exfat_error("failed to erase meta1 entry");
return false;
}
next_entry(ef, node->parent, &cluster, &offset);
entry_type = EXFAT_ENTRY_FILE_INFO & ~EXFAT_ENTRY_VALID;
if (exfat_pwrite(ef->dev, &entry_type, 1, co2o(ef, cluster, offset)) < 0)
{
exfat_error("failed to erase meta2 entry");
return false;
}
while (name_entries--)
{
next_entry(ef, node->parent, &cluster, &offset);
entry_type = EXFAT_ENTRY_FILE_NAME & ~EXFAT_ENTRY_VALID;
if (exfat_pwrite(ef->dev, &entry_type, 1,
co2o(ef, cluster, offset)) < 0)
{
exfat_error("failed to erase name entry");
return false;
}
}
return true;
}
static int shrink_directory(struct exfat* ef, struct exfat_node* dir,
off64_t deleted_offset)
{
const struct exfat_node* node;
const struct exfat_node* last_node;
uint64_t entries = 1; /* a directory always has at leat 1 entry (EOD) */
uint64_t new_size;
struct exfat_entry eod;
off64_t eod_offset;
int rc;
if (!(dir->flags & EXFAT_ATTRIB_DIR))
exfat_bug("attempted to shrink a file");
if (!(dir->flags & EXFAT_ATTRIB_CACHED))
exfat_bug("attempted to shrink uncached directory");
for (last_node = node = dir->child; node; node = node->next)
{
if (deleted_offset < node->entry_offset)
{
/* there are other entries after the removed one, no way to shrink
this directory */
return 0;
}
if (last_node->entry_offset < node->entry_offset)
last_node = node;
}
if (last_node)
{
/* offset of the last entry */
entries += last_node->entry_offset / sizeof(struct exfat_entry);
/* two subentries with meta info */
entries += 2;
/* subentries with file name */
entries += DIV_ROUND_UP(utf16_length(last_node->name),
EXFAT_ENAME_MAX);
}
new_size = DIV_ROUND_UP(entries * sizeof(struct exfat_entry),
CLUSTER_SIZE(*ef->sb)) * CLUSTER_SIZE(*ef->sb);
if (new_size == dir->size)
return 0;
rc = exfat_truncate(ef, dir, new_size);
if (rc != 0)
return rc;
/* put EOD entry at the end of the last cluster */
memset(&eod, 0, sizeof(eod));
eod_offset = new_size - sizeof(struct exfat_entry);
if (last_node)
exfat_write_raw(&eod, sizeof(eod),
co2o(ef, last_node->entry_cluster, eod_offset), ef->fd);
else
exfat_write_raw(&eod, sizeof(eod),
co2o(ef, dir->start_cluster, eod_offset), ef->fd);
return 0;
}
static int shrink_directory(struct exfat* ef, struct exfat_node* dir,
off64_t deleted_offset)
{
const struct exfat_node* node;
const struct exfat_node* last_node;
uint64_t entries = 0;
uint64_t new_size;
int rc;
if (!(dir->flags & EXFAT_ATTRIB_DIR))
exfat_bug("attempted to shrink a file");
if (!(dir->flags & EXFAT_ATTRIB_CACHED))
exfat_bug("attempted to shrink uncached directory");
for (last_node = node = dir->child; node; node = node->next)
{
if (deleted_offset < node->entry_offset)
{
/* there are other entries after the removed one, no way to shrink
this directory */
return 0;
}
if (last_node->entry_offset < node->entry_offset)
last_node = node;
}
if (last_node)
{
/* offset of the last entry */
entries += last_node->entry_offset / sizeof(struct exfat_entry);
/* two subentries with meta info */
entries += 2;
/* subentries with file name */
entries += DIV_ROUND_UP(utf16_length(last_node->name),
EXFAT_ENAME_MAX);
}
new_size = DIV_ROUND_UP(entries * sizeof(struct exfat_entry),
CLUSTER_SIZE(*ef->sb)) * CLUSTER_SIZE(*ef->sb);
if (new_size == 0) /* directory always has at least 1 cluster */
new_size = CLUSTER_SIZE(*ef->sb);
if (new_size == dir->size)
return 0;
rc = exfat_truncate(ef, dir, new_size, true);
if (rc != 0)
return rc;
return 0;
}
static void erase_entry(struct exfat* ef, struct exfat_node* node)
{
cluster_t cluster = node->entry_cluster;
off64_t offset = node->entry_offset;
int name_entries = DIV_ROUND_UP(utf16_length(node->name), EXFAT_ENAME_MAX);
uint8_t entry_type;
entry_type = EXFAT_ENTRY_FILE & ~EXFAT_ENTRY_VALID;
exfat_write_raw(&entry_type, 1, co2o(ef, cluster, offset), ef->fd);
next_entry(ef, node->parent, &cluster, &offset);
entry_type = EXFAT_ENTRY_FILE_INFO & ~EXFAT_ENTRY_VALID;
exfat_write_raw(&entry_type, 1, co2o(ef, cluster, offset), ef->fd);
while (name_entries--)
{
next_entry(ef, node->parent, &cluster, &offset);
entry_type = EXFAT_ENTRY_FILE_NAME & ~EXFAT_ENTRY_VALID;
exfat_write_raw(&entry_type, 1, co2o(ef, cluster, offset), ef->fd);
}
}
int fat_directory_write(fat_directory_t *di, const char *name, fat_dentry_t *de)
{
int rc;
void *data;
fat_instance_t *instance;
rc = fs_instance_get(di->nodep->idx->service_id, &data);
assert(rc == EOK);
instance = (fat_instance_t *) data;
if (fat_valid_short_name(name)) {
/*
* NAME could be directly stored in dentry without creating
* LFN.
*/
fat_dentry_name_set(de, name);
if (fat_directory_is_sfn_exist(di, de))
return EEXIST;
rc = fat_directory_lookup_free(di, 1);
if (rc != EOK)
return rc;
rc = fat_directory_write_dentry(di, de);
return rc;
} else if (instance->lfn_enabled && fat_valid_name(name)) {
/* We should create long entries to store name */
int long_entry_count;
uint8_t checksum;
uint16_t wname[FAT_LFN_NAME_SIZE];
size_t lfn_size, lfn_offset;
rc = str_to_utf16(wname, FAT_LFN_NAME_SIZE, name);
if (rc != EOK)
return rc;
lfn_size = utf16_length(wname);
long_entry_count = lfn_size / FAT_LFN_ENTRY_SIZE;
if (lfn_size % FAT_LFN_ENTRY_SIZE)
long_entry_count++;
rc = fat_directory_lookup_free(di, long_entry_count + 1);
if (rc != EOK)
return rc;
aoff64_t start_pos = di->pos;
/* Write Short entry */
rc = fat_directory_create_sfn(di, de, name);
if (rc != EOK)
return rc;
checksum = fat_dentry_chksum(de->name);
rc = fat_directory_seek(di, start_pos + long_entry_count);
if (rc != EOK)
return rc;
rc = fat_directory_write_dentry(di, de);
if (rc != EOK)
return rc;
/* Write Long entry by parts */
lfn_offset = 0;
fat_dentry_t *d;
size_t idx = 0;
do {
rc = fat_directory_prev(di);
if (rc != EOK)
return rc;
rc = fat_directory_get(di, &d);
if (rc != EOK)
return rc;
fat_lfn_set_entry(wname, &lfn_offset, lfn_size + 1, d);
FAT_LFN_CHKSUM(d) = checksum;
FAT_LFN_ORDER(d) = ++idx;
di->b->dirty = true;
} while (lfn_offset < lfn_size);
FAT_LFN_ORDER(d) |= FAT_LFN_LAST;
rc = fat_directory_seek(di, start_pos + long_entry_count);
return rc;
}
return ENOTSUP;
}