static int setup(struct exfat_dev* dev, int sector_bits, int spc_bits,
const char* volume_label, uint32_t volume_serial,
uint64_t first_sector)
{
param.sector_bits = sector_bits;
param.first_sector = first_sector;
param.volume_size = exfat_get_size(dev);
param.spc_bits = setup_spc_bits(sector_bits, spc_bits, param.volume_size);
if (param.spc_bits == -1)
return 1;
if (setup_volume_label(param.volume_label, volume_label) != 0)
return 1;
param.volume_serial = setup_volume_serial(volume_serial);
if (param.volume_serial == 0)
return 1;
return mkfs(dev, param.volume_size);
}
int exfat_mount(struct exfat* ef, const char* spec, const char* options)
{
int rc;
enum exfat_mode mode;
exfat_tzset();
memset(ef, 0, sizeof(struct exfat));
parse_options(ef, options);
if (match_option(options, "ro"))
mode = EXFAT_MODE_RO;
else if (match_option(options, "ro_fallback"))
mode = EXFAT_MODE_ANY;
else
mode = EXFAT_MODE_RW;
ef->dev = exfat_open(spec, mode);
if (ef->dev == NULL)
return -EIO;
if (exfat_get_mode(ef->dev) == EXFAT_MODE_RO)
{
if (mode == EXFAT_MODE_ANY)
ef->ro = -1;
else
ef->ro = 1;
}
ef->sb = malloc(sizeof(struct exfat_super_block));
if (ef->sb == NULL)
{
exfat_close(ef->dev);
exfat_error("failed to allocate memory for the super block");
return -ENOMEM;
}
memset(ef->sb, 0, sizeof(struct exfat_super_block));
if (exfat_pread(ef->dev, ef->sb, sizeof(struct exfat_super_block), 0) < 0)
{
exfat_close(ef->dev);
free(ef->sb);
exfat_error("failed to read boot sector");
return -EIO;
}
if (memcmp(ef->sb->oem_name, "EXFAT ", 8) != 0)
{
exfat_close(ef->dev);
free(ef->sb);
exfat_error("exFAT file system is not found");
return -EIO;
}
/* sector cannot be smaller than 512 bytes */
if (ef->sb->sector_bits < 9)
{
exfat_close(ef->dev);
exfat_error("too small sector size: 2^%hhd", ef->sb->sector_bits);
free(ef->sb);
return -EIO;
}
/* officially exFAT supports cluster size up to 32 MB */
if ((int) ef->sb->sector_bits + (int) ef->sb->spc_bits > 25)
{
exfat_close(ef->dev);
exfat_error("too big cluster size: 2^(%hhd+%hhd)",
ef->sb->sector_bits, ef->sb->spc_bits);
free(ef->sb);
return -EIO;
}
ef->zero_cluster = malloc(CLUSTER_SIZE(*ef->sb));
if (ef->zero_cluster == NULL)
{
exfat_close(ef->dev);
free(ef->sb);
exfat_error("failed to allocate zero sector");
return -ENOMEM;
}
/* use zero_cluster as a temporary buffer for VBR checksum verification */
if (!verify_vbr_checksum(ef->dev, ef->zero_cluster, SECTOR_SIZE(*ef->sb)))
{
free(ef->zero_cluster);
exfat_close(ef->dev);
free(ef->sb);
return -EIO;
}
memset(ef->zero_cluster, 0, CLUSTER_SIZE(*ef->sb));
if (ef->sb->version.major != 1 || ef->sb->version.minor != 0)
{
free(ef->zero_cluster);
exfat_close(ef->dev);
exfat_error("unsupported exFAT version: %hhu.%hhu",
ef->sb->version.major, ef->sb->version.minor);
free(ef->sb);
return -EIO;
}
if (ef->sb->fat_count != 1)
{
free(ef->zero_cluster);
exfat_close(ef->dev);
exfat_error("unsupported FAT count: %hhu", ef->sb->fat_count);
free(ef->sb);
return -EIO;
}
if (le64_to_cpu(ef->sb->sector_count) * SECTOR_SIZE(*ef->sb) >
exfat_get_size(ef->dev))
{
/* this can cause I/O errors later but we don't fail mounting to let
user rescue data */
exfat_warn("file system is larger than underlying device: "
"%"PRIu64" > %"PRIu64,
le64_to_cpu(ef->sb->sector_count) * SECTOR_SIZE(*ef->sb),
exfat_get_size(ef->dev));
}
ef->root = malloc(sizeof(struct exfat_node));
if (ef->root == NULL)
{
free(ef->zero_cluster);
exfat_close(ef->dev);
free(ef->sb);
exfat_error("failed to allocate root node");
return -ENOMEM;
}
memset(ef->root, 0, sizeof(struct exfat_node));
ef->root->flags = EXFAT_ATTRIB_DIR;
ef->root->start_cluster = le32_to_cpu(ef->sb->rootdir_cluster);
ef->root->fptr_cluster = ef->root->start_cluster;
ef->root->name[0] = cpu_to_le16('\0');
ef->root->size = rootdir_size(ef);
if (ef->root->size == 0)
{
free(ef->root);
free(ef->zero_cluster);
exfat_close(ef->dev);
free(ef->sb);
return -EIO;
}
/* exFAT does not have time attributes for the root directory */
ef->root->mtime = 0;
ef->root->atime = 0;
/* always keep at least 1 reference to the root node */
exfat_get_node(ef->root);
rc = exfat_cache_directory(ef, ef->root);
if (rc != 0)
goto error;
if (ef->upcase == NULL)
{
exfat_error("upcase table is not found");
goto error;
}
if (ef->cmap.chunk == NULL)
{
exfat_error("clusters bitmap is not found");
goto error;
}
if (prepare_super_block(ef) != 0)
goto error;
return 0;
error:
exfat_put_node(ef, ef->root);
exfat_reset_cache(ef);
free(ef->root);
free(ef->zero_cluster);
exfat_close(ef->dev);
free(ef->sb);
return -EIO;
}
