qemu/tests/qemu-iotests/252

#!/usr/bin/env bash
#
# Tests for rebasing COW images that require zero cluster support
#
# Copyright (C) 2019 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=mreitz@redhat.com

seq=$(basename $0)
echo "QA output created by $seq"

status=1	# failure is the default!

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

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

# Currently only qcow2 and qed support rebasing, and only qcow2 v3 has
# zero cluster support
_supported_fmt qcow2
_unsupported_imgopts 'compat=0.10'
_supported_proto file
_supported_os Linux

CLUSTER_SIZE=65536

echo
echo "=== Test rebase without input base ==="
echo

# Cluster allocations to be tested:
#
# Backing (new) 11 -- 11 -- 11 --
# COW image     22 22 11 11 -- --
#
# Expected result:
#
# COW image     22 22 11 11 00 --
#
# (Cluster 2 might be "--" after the rebase, too, but rebase just
#  compares the new backing file to the old one and disregards the
#  overlay.  Therefore, it will never discard overlay clusters.)

_make_test_img $((6 * CLUSTER_SIZE))
TEST_IMG="$TEST_IMG.base_new" _make_test_img $((6 * CLUSTER_SIZE))

echo

$QEMU_IO "$TEST_IMG" \
    -c "write -P 0x22 $((0 * CLUSTER_SIZE)) $((2 * CLUSTER_SIZE))" \
    -c "write -P 0x11 $((2 * CLUSTER_SIZE)) $((2 * CLUSTER_SIZE))" \
    | _filter_qemu_io

$QEMU_IO "$TEST_IMG.base_new" \
    -c "write -P 0x11 $((0 * CLUSTER_SIZE)) $CLUSTER_SIZE" \
    -c "write -P 0x11 $((2 * CLUSTER_SIZE)) $CLUSTER_SIZE" \
    -c "write -P 0x11 $((4 * CLUSTER_SIZE)) $CLUSTER_SIZE" \
    | _filter_qemu_io

echo

# This should be a no-op
$QEMU_IMG rebase -b "" "$TEST_IMG"

# Verify the data is correct
$QEMU_IO "$TEST_IMG" \
    -c "read -P 0x22 $((0 * CLUSTER_SIZE)) $((2 * CLUSTER_SIZE))" \
    -c "read -P 0x11 $((2 * CLUSTER_SIZE)) $((2 * CLUSTER_SIZE))" \
    -c "read -P 0x00 $((4 * CLUSTER_SIZE)) $((2 * CLUSTER_SIZE))" \
    | _filter_qemu_io

echo

# Verify the allocation status (first four cluster should be allocated
# in TEST_IMG, clusters 4 and 5 should be unallocated (marked as zero
# clusters here because there is no backing file))
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map

echo

$QEMU_IMG rebase -b "$TEST_IMG.base_new" -F $IMGFMT "$TEST_IMG"

# Verify the data is correct
$QEMU_IO "$TEST_IMG" \
    -c "read -P 0x22 $((0 * CLUSTER_SIZE)) $((2 * CLUSTER_SIZE))" \
    -c "read -P 0x11 $((2 * CLUSTER_SIZE)) $((2 * CLUSTER_SIZE))" \
    -c "read -P 0x00 $((4 * CLUSTER_SIZE)) $((2 * CLUSTER_SIZE))" \
    | _filter_qemu_io

echo

# Verify the allocation status (first four cluster should be allocated
# in TEST_IMG, cluster 4 should be zero, and cluster 5 should be
# unallocated (signified by '"depth": 1'))
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map


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