Function psutil::disk::disk_usage

pub fn disk_usage<P>(path: P) -> Result<DiskUsage> where
    P: AsRef<Path>, 

Return disk usage associated with path.

Note: UNIX usually reserves 5% disk space which is not accessible by user. In this function "total" and "used" values reflect the total and used disk space whereas "free" and "percent" represent the "free" and "used percent" user disk space.