Function do_rename 

fn do_rename(
    r: &Req<'_>,
    olddirfd: i32,
    old: &[u8],
    newdirfd: i32,
    new: &[u8],
    flags: i64,
) -> Result<Outcome, i32>

rename/renameat/renameat2. A mount point of the view is busy, as a mount point is.