#define MNT_NODEV 0x02
#define MNT_NOEXEC 0x04
#define MNT_SHARED 0x10 /* if the vfsmount is a shared mount */
+#define MNT_UNBINDABLE 0x20 /* if the vfsmount is a unbindable mount */
#define MNT_PNODE_MASK 0x30 /* propogation flag mask */
struct vfsmount {