mntdata
mntdata_t *mntdata = MTOD(VTOM(vp));
old_mtime = mntdata->mnt_hidden_mtime;
old_size = mntdata->mnt_hidden_size;
old_mtime = mntdata->mnt_mtime;
old_size = mntdata->mnt_size;
vap->va_nlink = mntdata->mnt_nopen + 1;
mntdata_t *mntdata = MTOD(mnp);
zone_t *zone = mntdata->mnt_zone_ref.zref_zone;
#define MTOD(pnp) ((struct mntdata *)MTOV(pnp)->v_vfsp->vfs_data)