iotests: Convert to preallocated encrypted qcow2

Add a test case for converting an empty image (which only returns zeroes
when read) to a preallocated encrypted qcow2 image.
qcow2_has_zero_init() should return 0 then, thus forcing qemu-img
convert to create zero clusters.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Acked-by: NStefano Garzarella <sgarzare@redhat.com>
Tested-by: NStefano Garzarella <sgarzare@redhat.com>
Message-id: 20190724171239.8764-10-mreitz@redhat.com
Reviewed-by: NMaxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: NMax Reitz <mreitz@redhat.com>

tests/qemu-iotests/188

@@ -48,7 +48,7 @@ SECRETALT="secret,id=sec0,data=platypus"
 
 _make_test_img --object $SECRET -o "encrypt.format=luks,encrypt.key-secret=sec0,encrypt.iter-time=10" $size
 
-IMGSPEC="driver=$IMGFMT,file.filename=$TEST_IMG,encrypt.key-secret=sec0"
+IMGSPEC="driver=$IMGFMT,encrypt.key-secret=sec0,file.filename=$TEST_IMG"
 
 QEMU_IO_OPTIONS=$QEMU_IO_OPTIONS_NO_FMT
 
@@ -68,6 +68,24 @@ echo
 echo "== verify open failure with wrong password =="
 $QEMU_IO --object $SECRETALT -c "read -P 0xa 0 $size" --image-opts $IMGSPEC | _filter_qemu_io | _filter_testdir
 
+_cleanup_test_img
+
+echo
+echo "== verify that has_zero_init returns false when preallocating =="
+
+# Empty source file
+if [ -n "$TEST_IMG_FILE" ]; then
+    TEST_IMG_FILE="${TEST_IMG_FILE}.orig" _make_test_img $size
+else
+    TEST_IMG="${TEST_IMG}.orig" _make_test_img $size
+fi
+
+$QEMU_IMG convert -O "$IMGFMT" --object $SECRET \
+    -o "encrypt.format=luks,encrypt.key-secret=sec0,encrypt.iter-time=10,preallocation=metadata" \
+    "${TEST_IMG}.orig" "$TEST_IMG"
+
+$QEMU_IMG compare --object $SECRET --image-opts "${IMGSPEC}.orig" "$IMGSPEC"
+
 
 # success, all done
 echo "*** done"

tests/qemu-iotests/188.out

@@ -15,4 +15,8 @@ read 16777216/16777216 bytes at offset 0
 
 == verify open failure with wrong password ==
 qemu-io: can't open: Invalid password, cannot unlock any keyslot
+
+== verify that has_zero_init returns false when preallocating ==
+Formatting 'TEST_DIR/t.IMGFMT.orig', fmt=IMGFMT size=16777216
+Images are identical.
 *** done