text: #!/usr/bin/env bash
  #
  # Test that qemu-img info --backing-chain detects infinite loops
  #
  # Copyright (C) 2012 Red Hat, Inc.
  #
  # This program is free software; you can redistribute it and/or modify
  # it under the terms of the GNU General Public License as published by
  # the Free Software Foundation; either version 2 of the License, or
  # (at your option) any later version.
  #
  # This program is distributed in the hope that it will be useful,
  # but WITHOUT ANY WARRANTY; without even the implied warranty of
  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  # GNU General Public License for more details.
  #
  # You should have received a copy of the GNU General Public License
  # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  #
  
  # creator
  owner=stefanha@redhat.com
  
  seq=`basename $0`
  echo "QA output created by $seq"
  
  status=1	# failure is the default!
  
  _cleanup()
  {
      _cleanup_test_img
      for img in "$TEST_IMG".[123].base; do
          _rm_test_img "$img"
      done
  }
  trap "_cleanup; exit \$status" 0 1 2 3 15
  
  # get standard environment, filters and checks
  . ./common.rc
  . ./common.filter
  
  # Any format supporting backing files
  _supported_fmt qcow2 qed
  _supported_proto file
  
  
  size=128M
  _make_test_img $size
  $QEMU_IMG rebase -u -b "$TEST_IMG" "$TEST_IMG"
  
  echo
  echo "== backing file references self =="
  _img_info --backing-chain
  
  _make_test_img $size
  mv "$TEST_IMG" "$TEST_IMG.base"
  _make_test_img -b "$TEST_IMG.base" $size
  $QEMU_IMG rebase -u -b "$TEST_IMG" "$TEST_IMG.base"
  
  echo
  echo "== parent references self =="
  _img_info --backing-chain
  
  _make_test_img $size
  mv "$TEST_IMG" "$TEST_IMG.1.base"
  _make_test_img -b "$TEST_IMG.1.base" $size
  mv "$TEST_IMG" "$TEST_IMG.2.base"
  _make_test_img -b "$TEST_IMG.2.base" $size
  mv "$TEST_IMG" "$TEST_IMG.3.base"
  _make_test_img -b "$TEST_IMG.3.base" $size
  $QEMU_IMG rebase -u -b "$TEST_IMG.2.base" "$TEST_IMG.1.base"
  
  echo
  echo "== ancestor references another ancestor =="
  _img_info --backing-chain
  
  _make_test_img $size
  mv "$TEST_IMG" "$TEST_IMG.1.base"
  _make_test_img -b "$TEST_IMG.1.base" $size
  mv "$TEST_IMG" "$TEST_IMG.2.base"
  _make_test_img -b "$TEST_IMG.2.base" $size
  
  echo
  echo "== finite chain of length 3 (human) =="
  _img_info --backing-chain
  
  echo
  echo "== finite chain of length 3 (json) =="
  _img_info --backing-chain --output=json
  
  # success, all done
  echo "*** done"
  rm -f $seq.full
  status=0
  