C_UNMOUNTING
#define IS_UNMOUNTING(cp) ((cp)->c_flags & C_UNMOUNTING)
VTOC(mi->mi_rootvp)->c_flags |= C_UNMOUNTING;
cp->c_flags |= C_UNMOUNTING;
if (cp && !(cp->c_flags & C_UNMOUNTING)) {
cp->c_flags |= C_UNMOUNTING;