#!/bin/bash
for i in $(zfs get -Ht snapshot userrefs | grep -v $'\t'0 | cut -d $'\t' -f 1 | cut -f1 -d @ | uniq -d) ; do
  for j in $(zfs list -H -t snapshot "$i" | awk '{ print $1 }') ; do
    for k in $(zfs holds -H "$j") ; do
      echo sudo zfs release syncoid_pbs "$k" | grep "@"
    done
  done
done