tests/qemu-iotests/112

#!/bin/bash
#
# Test cases for different refcount_bits values
#
# Copyright (C) 2015 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"

here="$PWD"
tmp=/tmp/$$
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

# This tests qcow2-specific low-level functionality
_supported_fmt qcow2
_supported_proto file
_supported_os Linux
# This test will set refcount_bits on its own which would conflict with the
# manual setting; compat will be overridden as well
_unsupported_imgopts refcount_bits 'compat=0.10'

function print_refcount_bits()
{
    $QEMU_IMG info "$TEST_IMG" | sed -n '/refcount bits:/ s/^ *//p'
}

echo
echo '=== refcount_bits limits ==='
echo

# Must be positive (non-zero)
IMGOPTS="$IMGOPTS,refcount_bits=0" _make_test_img 64M
# Must be positive (non-negative)
IMGOPTS="$IMGOPTS,refcount_bits=-1" _make_test_img 64M
# May not exceed 64
IMGOPTS="$IMGOPTS,refcount_bits=128" _make_test_img 64M
# Must be a power of two
IMGOPTS="$IMGOPTS,refcount_bits=42" _make_test_img 64M

# 1 is the minimum
IMGOPTS="$IMGOPTS,refcount_bits=1" _make_test_img 64M
print_refcount_bits

# 64 is the maximum
IMGOPTS="$IMGOPTS,refcount_bits=64" _make_test_img 64M
print_refcount_bits

# 16 is the default
_make_test_img 64M
print_refcount_bits

echo
echo '=== refcount_bits and compat=0.10 ==='
echo

# Should work
IMGOPTS="$IMGOPTS,compat=0.10,refcount_bits=16" _make_test_img 64M
print_refcount_bits

# Should not work
IMGOPTS="$IMGOPTS,compat=0.10,refcount_bits=1" _make_test_img 64M
IMGOPTS="$IMGOPTS,compat=0.10,refcount_bits=64" _make_test_img 64M


echo
echo '=== Snapshot limit on refcount_bits=1 ==='
echo

IMGOPTS="$IMGOPTS,refcount_bits=1" _make_test_img 64M
print_refcount_bits

$QEMU_IO -c 'write 0 512' "$TEST_IMG" | _filter_qemu_io

# Should fail for now; in the future, this might be supported by automatically
# copying all clusters with overflowing refcount
$QEMU_IMG snapshot -c foo "$TEST_IMG"

# The new L1 table could/should be leaked
_check_test_img

echo
echo '=== Snapshot limit on refcount_bits=2 ==='
echo

IMGOPTS="$IMGOPTS,refcount_bits=2" _make_test_img 64M
print_refcount_bits

$QEMU_IO -c 'write 0 512' "$TEST_IMG" | _filter_qemu_io

# Should succeed
$QEMU_IMG snapshot -c foo "$TEST_IMG"
$QEMU_IMG snapshot -c bar "$TEST_IMG"
# Should fail (4th reference)
$QEMU_IMG snapshot -c baz "$TEST_IMG"

# The new L1 table could/should be leaked
_check_test_img

echo
echo '=== Compressed clusters with refcount_bits=1 ==='
echo

IMGOPTS="$IMGOPTS,refcount_bits=1" _make_test_img 64M
print_refcount_bits

# Both should fit into a single host cluster; instead of failing to increase the
# refcount of that cluster, qemu should just allocate a new cluster and make
# this operation succeed
$QEMU_IO -c 'write -P 0 -c  0  64k' \
         -c 'write -P 1 -c 64k 64k' \
         "$TEST_IMG" | _filter_qemu_io

_check_test_img

echo
echo '=== MSb set in 64 bit refcount ==='
echo

IMGOPTS="$IMGOPTS,refcount_bits=64" _make_test_img 64M
print_refcount_bits

$QEMU_IO -c 'write 0 512' "$TEST_IMG" | _filter_qemu_io

# Set the MSb in the refblock entry of the data cluster
poke_file "$TEST_IMG" $((0x20028)) "\x80\x00\x00\x00\x00\x00\x00\x00"

# Clear OFLAG_COPIED in the L2 entry of the data cluster
poke_file "$TEST_IMG" $((0x40000)) "\x00\x00\x00\x00\x00\x05\x00\x00"

# Try to write to that cluster (should work, even though the MSb is set)
$QEMU_IO -c 'write 0 512' "$TEST_IMG" | _filter_qemu_io

echo
echo '=== Snapshot on maximum 64 bit refcount value ==='
echo

IMGOPTS="$IMGOPTS,refcount_bits=64" _make_test_img 64M
print_refcount_bits

$QEMU_IO -c 'write 0 512' "$TEST_IMG" | _filter_qemu_io

# Set the refblock entry to the maximum value possible
poke_file "$TEST_IMG" $((0x20028)) "\xff\xff\xff\xff\xff\xff\xff\xff"

# Clear OFLAG_COPIED in the L2 entry of the data cluster
poke_file "$TEST_IMG" $((0x40000)) "\x00\x00\x00\x00\x00\x05\x00\x00"

# Try a snapshot (should correctly identify the overflow; may work in the future
# by falling back to COW)
$QEMU_IMG snapshot -c foo "$TEST_IMG"

# The new L1 table could/should be leaked; and obviously the data cluster is
# leaked (refcount=UINT64_MAX reference=1)
_check_test_img


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