get_usage.sh

#!/usr/bin/env bash

set -euo pipefail

target_snapshot_id=$1
parent_id=""
snapshot_ids=""

# ensure that it is valid input
ctr -n k8s.io snapshot usage $target_snapshot_id > /dev/null

snapshot_ids=$target_snapshot_id
while true; do
  parent_id=$(ctr -n k8s.io snapshot info $target_snapshot_id | jq '.Parent | if . then . else "" end' -r)
  if [[ ${parent_id} == "" ]]; then
    break
  fi
  target_snapshot_id=$parent_id
  parent_id=""

  snapshot_ids="${snapshot_ids} ${target_snapshot_id}"
done

ctr -n k8s.io snapshot usage $snapshot_ids