DS_FIND_SNAPSHOTS
NULL, DS_FIND_SNAPSHOTS | DS_FIND_CHILDREN);
DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS);
DS_FIND_SNAPSHOTS | DS_FIND_CHILDREN);
if (dcp->dc_flags & DS_FIND_SNAPSHOTS) {
if (flags & DS_FIND_SNAPSHOTS) {
&dvra, DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS);
zfs_unmount_snap_cb, NULL, DS_FIND_SNAPSHOTS);