MNT_NS_LAST_INDEX
fd_mnt_ns_cur = fcntl(self->fd_mnt_ns[MNT_NS_LAST_INDEX], F_DUPFD_CLOEXEC);
ASSERT_EQ(count, MNT_NS_LAST_INDEX);
ASSERT_EQ(setns(self->fd_mnt_ns[MNT_NS_LAST_INDEX], CLONE_NEWNS), 0);
fd_mnt_ns_cur = self->fd_mnt_ns[MNT_NS_LAST_INDEX];
for (int i = MNT_NS_LAST_INDEX - 1; i >= 0; i--) {
ASSERT_EQ(count, MNT_NS_LAST_INDEX);