block: add qemu-iotest for resize base during live commit

If 'base' is smaller than the overlay image being committed into it,
then the base image will be grown in commit_run via bdrv_truncate().

This tests to make sure that this works, and the bdrv_truncate() is
not blocked when it shouldn't be.
Signed-off-by: NJeff Cody <jcody@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

tests/qemu-iotests/095

+#!/bin/bash
+#
+# Test for commit of larger active layer
+#
+# This tests live snapshots of images on a running QEMU instance, using
+# QMP commands.  Both single disk snapshots, and transactional group
+# snapshots are performed.
+#
+# Copyright (C) 2014 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=jcody@redhat.com
+
+seq=`basename $0`
+echo "QA output created by $seq"
+
+here=`pwd`
+status=1	# failure is the default!
+
+_cleanup()
+{
+    _cleanup_qemu
+    rm  -f "${TEST_IMG}.base" "${TEST_IMG}.snp1"
+	_cleanup_test_img
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+. ./common.qemu
+
+_supported_fmt qcow2
+_supported_proto file
+_supported_os Linux
+
+size_smaller=5M
+size_larger=100M
+
+_make_test_img $size_smaller
+mv "${TEST_IMG}" "${TEST_IMG}.base"
+
+_make_test_img -b "${TEST_IMG}.base" $size_larger
+mv "${TEST_IMG}" "${TEST_IMG}.snp1"
+
+_make_test_img -b "${TEST_IMG}.snp1" $size_larger
+
+echo
+echo "=== Base image info before commit and resize ==="
+$QEMU_IMG info "${TEST_IMG}.base" | _filter_testdir
+
+echo
+echo === Running QEMU Live Commit Test ===
+echo
+
+qemu_comm_method="qmp"
+_launch_qemu -drive file="${TEST_IMG}",if=virtio,id=test
+h=$QEMU_HANDLE
+
+_send_qemu_cmd $h "{ 'execute': 'qmp_capabilities' }" "return"
+
+_send_qemu_cmd $h "{ 'execute': 'block-commit',
+                                 'arguments': { 'device': 'test',
+                                 'top': '"${TEST_IMG}.snp1"' } }" "BLOCK_JOB_COMPLETED"
+
+echo
+echo "=== Base image info after commit and resize ==="
+$QEMU_IMG info "${TEST_IMG}.base" | _filter_testdir
+
+# success, all done
+echo "*** done"
+rm -f $seq.full
+status=0

tests/qemu-iotests/095.out

+QA output created by 095
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=5242880 
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=104857600 backing_file='TEST_DIR/t.IMGFMT.base' 
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=104857600 backing_file='TEST_DIR/t.IMGFMT.snp1' 
+
+=== Base image info before commit and resize ===
+image: TEST_DIR/t.qcow2.base
+file format: qcow2
+virtual size: 5.0M (5242880 bytes)
+disk size: 196K
+cluster_size: 65536
+Format specific information:
+    compat: 1.1
+    lazy refcounts: false
+
+=== Running QEMU Live Commit Test ===
+
+{"return": {}}
+{"return": {}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_COMPLETED", "data": {"device": "test", "len": 104857600, "offset": 104857600, "speed": 0, "type": "commit"}}
+
+=== Base image info after commit and resize ===
+image: TEST_DIR/t.qcow2.base
+file format: qcow2
+virtual size: 100M (104857600 bytes)
+disk size: 196K
+cluster_size: 65536
+Format specific information:
+    compat: 1.1
+    lazy refcounts: false
+*** done

tests/qemu-iotests/group

@@ -99,3 +99,4 @@
 090 rw auto quick
 091 rw auto
 092 rw auto quick
+095 rw auto