Function is_mount_present_global 

pub fn is_mount_present_global(path: &Path) -> bool

Check if a path is mounted in the global mount namespace (/proc/mounts).

Uses /proc/mounts which reflects the global namespace, NOT the calling process’s namespace. This detects lazy unmounts (umount -l) that are invisible to /proc/self/mountinfo when the process holds the mount open.

Returns true if any mount point in /proc/mounts covers the given path.