qemu.tests: new test to check image backingfile after stream done

new test to verify image file no backingfile after stream done;

changes from v1:
    update test steps in doc string;
Signed-off-by: NXu Tian <xutian@redhat.com>

qemu/tests/block_stream_check_backingfile.py

+import logging
+from autotest.client.shared import error
+from qemu.tests import blk_stream
+
+class BlockStreamCheckBackingfile(blk_stream.BlockStream):
+
+
+    def __init__(self, test, params, env, tag):
+        super(BlockStreamCheckBackingfile, self).__init__(test,
+                params, env, tag)
+
+    @error.context_aware
+    def check_backingfile(self):
+        """
+        check no backingfile found after stream job done via qemu-img info;
+        """
+        fail = False
+        error.context("Check image file backing-file", logging.info)
+        backingfile = self.get_backingfile("qemu-img")
+        if backingfile:
+            img_file = self.get_image_file()
+            logging.debug("Got backing-file: %s" % backingfile +
+                          "by 'qemu-img info %s'" % img_file)
+            fail |= bool(backingfile)
+        backingfile = self.get_backingfile("monitor")
+        if backingfile:
+            logging.debug("Got backing-file: %s" % backingfile +
+                          "by 'info/query block' " +
+                          "in %s monitor" % self.vm.monitor.protocol)
+            fail |= bool(backingfile)
+        if fail:
+            msg = ("Unexpected backing file found, there should be "
+                   "no backing file")
+            raise error.TestFail(msg)
+
+    @error.context_aware
+    def check_imagefile(self):
+        """
+        verify current image file is expected image file
+        """
+        params = self.parser_test_args()
+        exp_img_file = params["expected_image_file"]
+        error.context("Check image file is '%s'" % exp_img_file, logging.info)
+        img_file = self.get_image_file()
+        if exp_img_file != img_file:
+            msg = "Excepted image file: %s," % exp_img_file
+            msg += "Actual image file: %s" % img_file
+            raise error.TestFail(msg)
+
+
+def run_block_stream_check_backingfile(test, params, env):
+    """
+    block_stream.check_backingfile test:
+    1). boot up vm and create snapshots;
+    2). start block steam job, then wait block job done;
+    3). check backing-file in monitor and qemu-img command;
+    4). verify image file is excepted image file;
+    5). vierfy guest is alive;
+
+    @param test: QEMU test object
+    @param params: Dictionary with the test parameters
+    @param env: Dictionary with test environment.
+    """
+    tag = params.get("source_images", "image1")
+    backingfile_test = BlockStreamCheckBackingfile(test, params, env, tag)
+    try:
+        backingfile_test.create_snapshots()
+        backingfile_test.start()
+        backingfile_test.action_after_finished()
+    finally:
+        backingfile_test.clean()

qemu/tests/cfg/block_stream.cfg

@@ -48,6 +48,11 @@
             # set limited_speed to 10MB/s eq 10485760B/s
             limited_speed = 10485760
             snapshot_check_cmd = "lsof -p %s|awk '{print $9}'|grep ^/"
+        - check_backingfile:
+            type = block_stream_check_backingfile
+            snapshot_chain = "/tmp/sn1"
+            expected_image_file = "/tmp/sn1"
+            after_finished = "check_backingfile check_imagefile verify_alive"
         - with_stress:
             type = block_stream_stress
             wait_timeout = 3600