+int ext4fs_probe(block_dev_desc_t *fs_dev_desc,
+ disk_partition_t *fs_partition);
+int ext4_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
+ loff_t *actread);
+int ext4_read_superblock(char *buffer);
+int ext4fs_uuid(char *uuid_str);