qemu/tests/qemu-iotests/161

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block: Update BlockDriverState.inherits_from on bdrv_set_backing_hd() When a BlockDriverState's child is opened (be it a backing file, the protocol layer, or any other) inherits_from is set to point to the parent node. Children opened separately and then attached to a parent don't have this pointer set. bdrv_reopen_queue_child() uses this to determine whether a node's children must also be reopened inheriting the options from the parent or not. If inherits_from points to the parent then the child is reopened and its options can be changed, like in this example: $ qemu-img create -f qcow2 hd0.qcow2 1M $ qemu-img create -f qcow2 hd1.qcow2 1M $ $QEMU -drive if=none,node-name=hd0,file=hd0.qcow2,\ backing.driver=qcow2,backing.file.filename=hd1.qcow2 (qemu) qemu-io hd0 "reopen -o backing.l2-cache-size=2M" If the child does not inherit from the parent then it does not get reopened and its options cannot be changed: $ $QEMU -drive if=none,node-name=hd1,file=hd1.qcow2 -drive if=none,node-name=hd0,file=hd0.qcow2,backing=hd1 (qemu) qemu-io hd0 "reopen -o backing.l2-cache-size=2M" Cannot change the option 'backing.l2-cache-size' If a disk image has a chain of backing files then all of them are also connected through their inherits_from pointers (i.e. it's possible to walk the chain in reverse order from base to top). However this is broken if the intermediate nodes are removed using e.g. block-stream because the inherits_from pointer from the base node becomes NULL: $ qemu-img create -f qcow2 hd0.qcow2 1M $ qemu-img create -f qcow2 -b hd0.qcow2 hd1.qcow2 $ qemu-img create -f qcow2 -b hd1.qcow2 hd2.qcow2 $ $QEMU -drive if=none,file=hd2.qcow2 (qemu) qemu-io none0 "reopen -o backing.l2-cache-size=2M" (qemu) block_stream none0 0 hd0.qcow2 (qemu) qemu-io none0 "reopen -o backing.l2-cache-size=2M" Cannot change the option 'backing.l2-cache-size' This patch updates the inherits_from pointer if the intermediate nodes of a backing chain are removed using bdrv_set_backing_hd(), and adds a test case for this scenario. Signed-off-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-10-31 19:16:37 +03:00
#!/bin/bash
#
# Test reopening a backing image after block-stream
#
# Copyright (C) 2018 Igalia, S.L.
#
# 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 $seq"
here=`pwd`
status=1 # failure is the default!
_cleanup()
{
_cleanup_test_img
rm -f "$TEST_IMG.base"
rm -f "$TEST_IMG.int"
}
trap "_cleanup; exit \$status" 0 1 2 3 15
# get standard environment, filters and checks
. ./common.rc
. ./common.filter
. ./common.qemu
# Any format implementing BlockDriver.bdrv_change_backing_file
_supported_fmt qcow2 qed
_supported_proto file
_supported_os Linux
IMG_SIZE=1M
# Create the images
TEST_IMG="$TEST_IMG.base" _make_test_img $IMG_SIZE | _filter_imgfmt
TEST_IMG="$TEST_IMG.int" _make_test_img -b "$TEST_IMG.base" | _filter_imgfmt
_make_test_img -b "$TEST_IMG.int" | _filter_imgfmt
# First test: reopen $TEST.IMG changing the detect-zeroes option on
# its backing file ($TEST_IMG.int).
echo
echo "*** Change an option on the backing file"
echo
_launch_qemu -drive if=none,file="${TEST_IMG}"
_send_qemu_cmd $QEMU_HANDLE \
"{ 'execute': 'qmp_capabilities' }" \
'return'
_send_qemu_cmd $QEMU_HANDLE \
"{ 'execute': 'human-monitor-command',
'arguments': { 'command-line':
'qemu-io none0 \"reopen -o backing.detect-zeroes=on\"' } }" \
"return"
_cleanup_qemu
# Second test: stream $TEST_IMG.base into $TEST_IMG.int and then
# reopen $TEST.IMG changing the detect-zeroes option on its new
# backing file ($TEST_IMG.base).
echo
echo "*** Stream and then change an option on the backing file"
echo
_launch_qemu -drive if=none,file="${TEST_IMG}"
_send_qemu_cmd $QEMU_HANDLE \
"{ 'execute': 'qmp_capabilities' }" \
'return'
_send_qemu_cmd $QEMU_HANDLE \
"{ 'execute': 'block-stream', \
'arguments': { 'device': 'none0',
'base': '${TEST_IMG}.base' } }" \
'return'
# Wait for block-stream to finish
sleep 0.5
_send_qemu_cmd $QEMU_HANDLE \
"{ 'execute': 'human-monitor-command',
'arguments': { 'command-line':
'qemu-io none0 \"reopen -o backing.detect-zeroes=on\"' } }" \
"return"
_cleanup_qemu
# success, all done
echo "*** done"
rm -f $seq.full
status=0