zfs_root
bool zfs_root = false;
zfs_root = true;
zfs_root = false;
zfs_root = false;
if (zfs_root == true)
if (mb2 == false && zfs_root == true) {
VFSNAME_ROOT, { .vfs_root = zfs_root },
static int zfs_root(vfs_t *vfsp, vnode_t **vpp);