qemu/tests/qemu-iotests/290

#!/usr/bin/env bash
# group: rw auto quick
#
# Test how 'qemu-io -c discard' behaves on v2 and v3 qcow2 images
#
# Copyright (C) 2020 Igalia, S.L.
# Author: Alberto Garcia <berto@igalia.com>
#
# 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=berto@igalia.com

seq=`basename $0`
echo "QA output created by $seq"

status=1    # failure is the default!

_cleanup()
{
    _cleanup_test_img
}
trap "_cleanup; exit \$status" 0 1 2 3 15

# get standard environment, filters and checks
. ./common.rc
. ./common.filter

_supported_fmt qcow2
_supported_proto file fuse
_supported_os Linux
_unsupported_imgopts 'compat=0.10' refcount_bits data_file

echo
echo "### Test 'qemu-io -c discard' on a QCOW2 image without a backing file"
echo
for qcow2_compat in 0.10 1.1; do
    echo "# Create an image with compat=$qcow2_compat without a backing file"
    _make_test_img -o "compat=$qcow2_compat" 128k

    echo "# Fill all clusters with data and then discard them"
    $QEMU_IO -c 'write -P 0x01 0 128k' "$TEST_IMG" | _filter_qemu_io
    $QEMU_IO -c 'discard 0 128k' "$TEST_IMG" | _filter_qemu_io

    echo "# Read the data from the discarded clusters"
    $QEMU_IO -c 'read -P 0x00 0 128k' "$TEST_IMG" | _filter_qemu_io

    echo "# Output of qemu-img map"
    $QEMU_IMG map "$TEST_IMG" | _filter_testdir
done

echo
echo "### Test 'qemu-io -c discard' on a QCOW2 image with a backing file"
echo

echo "# Create a backing image and fill it with data"
BACKING_IMG="$TEST_IMG.base"
TEST_IMG="$BACKING_IMG" _make_test_img 128k
$QEMU_IO -c 'write -P 0xff 0 128k' "$BACKING_IMG" | _filter_qemu_io

for qcow2_compat in 0.10 1.1; do
    echo "# Create an image with compat=$qcow2_compat and a backing file"
    _make_test_img -o "compat=$qcow2_compat" -b "$BACKING_IMG" -F $IMGFMT

    echo "# Fill all clusters with data and then discard them"
    $QEMU_IO -c 'write -P 0x01 0 128k' "$TEST_IMG" | _filter_qemu_io
    $QEMU_IO -c 'discard 0 128k' "$TEST_IMG" | _filter_qemu_io

    echo "# Read the data from the discarded clusters"
    if [ "$qcow2_compat" = "1.1" ]; then
        # In qcow2 v3 clusters are zeroed (with QCOW_OFLAG_ZERO)
        $QEMU_IO -c 'read -P 0x00 0 128k' "$TEST_IMG" | _filter_qemu_io
    else
        # In qcow2 v2 if there's a backing image we cannot zero the clusters
        # without exposing the backing file data so discard does nothing
        $QEMU_IO -c 'read -P 0x01 0 128k' "$TEST_IMG" | _filter_qemu_io
    fi

    echo "# Output of qemu-img map"
    $QEMU_IMG map "$TEST_IMG" | _filter_testdir
done

# success, all done
echo "*** done"
rm -f $seq.full
status=0