Function safe_create_dir_all_in 

pub async fn safe_create_dir_all_in(
    root: impl AsRef<Path>,
    path: impl AsRef<Path>,
) -> Result<(), Error>

Available on crate feature std only.

Create a directory and all missing parents below root.

path is treated as relative to root; absolute paths, .. traversal, reserved device names, smuggled prefixes, and symbolic links that resolve outside root are rejected. root itself must exist.