1 files changed, 102 insertions, 0 deletions
diff --git a/tests/qemu-iotests/028 b/tests/qemu-iotests/028
new file mode 100755
index 0000000000..07c5bb6975
--- /dev/null
+++ b/tests/qemu-iotests/028
@@ -0,0 +1,102 @@
+#!/bin/bash
+#
+# Test that backing files can be smaller than the image
+#
+# Copyright (C) 2010 IBM, Corp.
+#
+# Based on 017:
+# Copyright (C) 2009 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=stefanha@linux.vnet.ibm.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
+. ./common.pattern
+
+# Any format supporting backing files except vmdk and qcow which do not support
+# smaller backing files.
+_supported_fmt qcow2 qed
+_supported_proto generic
+_supported_os Linux
+
+# Choose a size that is not necessarily a cluster size multiple for image
+# formats that use clusters.  This will ensure that the base image doesn't end
+# precisely on a cluster boundary (the easy case).
+image_size=$(( 4 * 1024 * 1024 * 1024 + 3 * 512 ))
+
+# The base image is smaller than the image file
+base_size=$(( image_size - 1024 * 1024 * 1024 ))
+
+offset=$(( base_size - 32 * 1024 ))
+
+_make_test_img $base_size
+
+echo "Filling base image"
+echo
+
+# Fill end of base image with a pattern, skipping every other sector
+io writev $offset 512 1024 32
+
+_check_test_img
+
+echo "Creating test image with backing file"
+echo
+
+mv $TEST_IMG $TEST_IMG.base
+_make_test_img -b $TEST_IMG.base $image_size
+
+echo "Filling test image"
+echo
+
+# Write every other sector around where the base image ends
+io writev $(( offset + 512 )) 512 1024 64
+
+_check_test_img
+
+echo "Reading"
+echo
+
+# Base image sectors
+io readv $(( offset )) 512 1024 32
+
+# Image sectors
+io readv $(( offset + 512 )) 512 1024 64
+
+# Zero sectors beyond end of base image
+io_zero readv $(( offset + 32 * 1024 )) 512 1024 32
+
+_check_test_img
+
+# success, all done
+echo "*** done"
+rm -f $seq.full
+status=0