qcow2: fix image corruption after committing qcow2 image into base

After committing the qcow2 image contents into the base image, qemu-img
will call bdrv_make_empty to drop the payload in the layered image.

When this is done for qcow2 images, it blows away the LUKS encryption
header, making the resulting image unusable. There are two codepaths
for emptying a qcow2 image, and the second (slower) codepath leaves
the LUKS header intact, so force use of that codepath.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 104 insertions, 0 deletions

diff --git a/tests/qemu-iotests/198 b/tests/qemu-iotests/198
new file mode 100755
index 0000000000..34ef666381
--- /dev/null
+++ b/tests/qemu-iotests/198
@@ -0,0 +1,104 @@
+#!/bin/bash
+#
+# Test commit of encrypted qcow2 files
+#
+# Copyright (C) 2017 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=berrange@redhat.com
+
+seq=`basename $0`
+echo "QA output created by $seq"
+
+here=`pwd`
+status=1	# failure is the default!
+
+_cleanup()
+{
+	_cleanup_test_img
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+
+_supported_fmt qcow2
+_supported_proto generic
+_supported_os Linux
+
+
+size=16M
+TEST_IMG_BASE=$TEST_IMG.base
+SECRET0="secret,id=sec0,data=astrochicken"
+SECRET1="secret,id=sec1,data=furby"
+
+TEST_IMG_SAVE=$TEST_IMG
+TEST_IMG=$TEST_IMG_BASE
+echo "== create base =="
+_make_test_img --object $SECRET0 -o "encrypt.format=luks,encrypt.key-secret=sec0,encrypt.iter-time=10" $size
+TEST_IMG=$TEST_IMG_SAVE
+
+IMGSPECBASE="driver=$IMGFMT,file.filename=$TEST_IMG_BASE,encrypt.key-secret=sec0"
+IMGSPECLAYER="driver=$IMGFMT,file.filename=$TEST_IMG,encrypt.key-secret=sec1"
+IMGSPEC="$IMGSPECLAYER,backing.driver=$IMGFMT,backing.file.filename=$TEST_IMG_BASE,backing.encrypt.key-secret=sec0"
+QEMU_IO_OPTIONS=$QEMU_IO_OPTIONS_NO_FMT
+
+echo
+echo "== writing whole image base =="
+$QEMU_IO --object $SECRET0 -c "write -P 0xa 0 $size" --image-opts $IMGSPECBASE | _filter_qemu_io | _filter_testdir
+
+echo "== create overlay =="
+_make_test_img --object $SECRET1 -o "encrypt.format=luks,encrypt.key-secret=sec1,encrypt.iter-time=10" -u -b "$TEST_IMG_BASE" $size
+
+echo
+echo "== writing whole image layer =="
+$QEMU_IO --object $SECRET0 --object $SECRET1 -c "write -P 0x9 0 $size" --image-opts $IMGSPEC | _filter_qemu_io | _filter_testdir
+
+echo
+echo "== verify pattern base =="
+$QEMU_IO --object $SECRET0 -c "read -P 0xa 0 $size" --image-opts $IMGSPECBASE | _filter_qemu_io | _filter_testdir
+
+echo
+echo "== verify pattern layer =="
+$QEMU_IO --object $SECRET0 --object $SECRET1 -c "read -P 0x9 0 $size" --image-opts $IMGSPEC | _filter_qemu_io | _filter_testdir
+
+echo
+echo "== committing layer into base =="
+$QEMU_IMG commit --object $SECRET0 --object $SECRET1 --image-opts $IMGSPEC | _filter_testdir
+
+echo
+echo "== verify pattern base =="
+$QEMU_IO --object $SECRET0 -c "read -P 0x9 0 $size" --image-opts $IMGSPECBASE | _filter_qemu_io | _filter_testdir
+
+echo
+echo "== verify pattern layer =="
+$QEMU_IO --object $SECRET0 --object $SECRET1 -c "read -P 0x9 0 $size" --image-opts $IMGSPEC | _filter_qemu_io | _filter_testdir
+
+echo
+echo "== checking image base =="
+$QEMU_IMG info --image-opts $IMGSPECBASE | _filter_img_info | _filter_testdir | sed -e "/^disk size:/ D"
+
+echo
+echo "== checking image layer =="
+$QEMU_IMG info --image-opts $IMGSPECLAYER | _filter_img_info | _filter_testdir | sed -e "/^disk size:/ D"
+
+
+# success, all done
+echo "*** done"
+rm -f $seq.full
+status=0