Function statx

pub fn statx<P: Arg, Fd: AsFd>(
    dirfd: Fd,
    path: P,
    flags: AtFlags,
    mask: StatxFlags,
) -> Result<Statx>

statx(dirfd, path, flags, mask, statxbuf)

This function returns io::Errno::NOSYS if statx is not available on the platform, such as Linux before 4.11. This also includes older Docker versions where the actual syscall fails with different error codes; rustix handles this and translates them into NOSYS.

References

• Linux

Examples

/// Try to determine if the provided path is a mount root. Will return
/// `Ok(None)` if the kernel is not new enough to support `statx` or
/// [`libc::STATX_ATTR_MOUNT_ROOT`].
fn is_mountpoint(root: BorrowedFd<'_>, path: &Path) -> io::Result<Option<bool>> {
    use rustix::fs::{AtFlags, StatxFlags};

    let mountroot_flag = libc::STATX_ATTR_MOUNT_ROOT as u64;
    match rustix::fs::statx(
        root,
        path,
        AtFlags::NO_AUTOMOUNT | AtFlags::SYMLINK_NOFOLLOW,
        StatxFlags::empty(),
    ) {
        Ok(r) => {
            let present = (r.stx_attributes_mask & mountroot_flag) > 0;
            Ok(present.then(|| r.stx_attributes & mountroot_flag > 0))
        }
        Err(rustix::io::Errno::NOSYS) => Ok(None),
        Err(e) => Err(e.into()),
    }
}