iotests: add LUKS payload overhead to 178 qemu-img measure test

The previous patch includes the LUKS payload overhead into the qemu-img
measure calculation for qcow2.  Update qemu-iotests 178 to exercise this
new code path.

Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190218104525.23674-3-stefanha@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>

tests/qemu-iotests/178

@@ -142,6 +142,14 @@ for ofmt in human json; do
             # The backing file doesn't need to exist :)
             $QEMU_IMG measure --output=$ofmt -o backing_file=x \
                               -f "$fmt" -O "$IMGFMT" "$TEST_IMG"
+
+            echo
+            echo "== $fmt input image and LUKS encryption =="
+            echo
+            $QEMU_IMG measure --output=$ofmt \
+                              --object secret,id=sec0,data=base \
+                              -o encrypt.format=luks,encrypt.key-secret=sec0,encrypt.iter-time=10 \
+                              -f "$fmt" -O "$IMGFMT" "$TEST_IMG"
         fi
 
         echo

tests/qemu-iotests/178.out.qcow2

@@ -68,6 +68,11 @@ converted image file size in bytes: 458752
 required size: 1074135040
 fully allocated size: 1074135040
 
+== qcow2 input image and LUKS encryption ==
+
+required size: 2686976
+fully allocated size: 1076232192
+
 == qcow2 input image and preallocation (human) ==
 
 required size: 1074135040
@@ -114,6 +119,11 @@ converted image file size in bytes: 524288
 required size: 1074135040
 fully allocated size: 1074135040
 
+== raw input image and LUKS encryption ==
+
+required size: 2686976
+fully allocated size: 1076232192
+
 == raw input image and preallocation (human) ==
 
 required size: 1074135040
@@ -205,6 +215,13 @@ converted image file size in bytes: 458752
     "fully-allocated": 1074135040
 }
 
+== qcow2 input image and LUKS encryption ==
+
+{
+    "required": 2686976,
+    "fully-allocated": 1076232192
+}
+
 == qcow2 input image and preallocation (json) ==
 
 {
@@ -263,6 +280,13 @@ converted image file size in bytes: 524288
     "fully-allocated": 1074135040
 }
 
+== raw input image and LUKS encryption ==
+
+{
+    "required": 2686976,
+    "fully-allocated": 1076232192
+}
+
 == raw input image and preallocation (json) ==
 
 {