iotests: Add creation test to 153
This patch adds a test case to 153 which tries to overwrite an image
(using qemu-img create) while it is in use. Without the original user
explicitly sharing the necessary permissions (writing and truncation),
this should not be allowed.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20180509215336.31304-4-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
diff --git a/tests/qemu-iotests/153 b/tests/qemu-iotests/153
index ec508c7..673813c 100755
--- a/tests/qemu-iotests/153
+++ b/tests/qemu-iotests/153
@@ -137,6 +137,24 @@
_run_cmd $QEMU_IMG dd $L if="${TEST_IMG}" of="${TEST_IMG}.convert" bs=512 count=1
_run_cmd $QEMU_IMG bench $L -c 1 "${TEST_IMG}"
_run_cmd $QEMU_IMG bench $L -w -c 1 "${TEST_IMG}"
+
+ # qemu-img create does not support -U
+ if [ -z "$L" ]; then
+ _run_cmd $QEMU_IMG create -f $IMGFMT "${TEST_IMG}" \
+ -b ${TEST_IMG}.base
+ # Read the file format. It used to be the case that
+ # file-posix simply truncated the file, but the qcow2
+ # driver then failed to format it because it was unable
+ # to acquire the necessary WRITE permission. However, the
+ # truncation was already wrong, and the whole process
+ # resulted in the file being completely empty and thus its
+ # format would be detected to be raw.
+ # So we read it here to see that creation either completed
+ # successfully (thus the format is qcow2) or it aborted
+ # before the file was changed at all (thus the format stays
+ # qcow2).
+ _img_info -U | grep 'file format'
+ fi
done
_send_qemu_cmd $h "{ 'execute': 'quit', }" ""
echo
