iotests: Test backup job with two guest writes

Perform two guest writes to not yet backed up areas of an image, where
the former touches an inner area of the latter.

Before HEAD^, copy offloading broke this in two ways:
(1) The target image differs from the reference image (what the source
    was when the backup started).
(2) But you will not see that in the failing output, because the job
    offset is reported as being greater than the job length.  This is
    because one cluster is copied twice, and thus accounted for twice,
    but of course the job length does not increase.

Signed-off-by: Max Reitz <[email protected]>
Message-id: 20190801173900[email protected]
Reviewed-by: Vladimir Sementsov-Ogievskiy <[email protected]>
Tested-by: Vladimir Sementsov-Ogievskiy <[email protected]>
Signed-off-by: Max Reitz <[email protected]>

diff --git a/tests/qemu-iotests/056 b/tests/qemu-iotests/056
index f40fc11a09df8d39b576e3539a29c77e32f007bf..e761e465aef2ae35df6144c209b10c9708be05c7 100755 (executable)
--- a/tests/qemu-iotests/056
+++ b/tests/qemu-iotests/056
@@ -133,6 +133,7 @@ class BackupTest(iotests.QMPTestCase):
         self.vm = iotests.VM()
         self.test_img = img_create('test')
         self.dest_img = img_create('dest')
+        self.ref_img = img_create('ref')
         self.vm.add_drive(self.test_img)
         self.vm.launch()
 
@@ -140,6 +141,7 @@ class BackupTest(iotests.QMPTestCase):
         self.vm.shutdown()
         try_remove(self.test_img)
         try_remove(self.dest_img)
+        try_remove(self.ref_img)
 
     def hmp_io_writes(self, drive, patterns):
         for pattern in patterns:
@@ -177,6 +179,43 @@ class BackupTest(iotests.QMPTestCase):
             self.assert_qmp(event, 'data/error', qerror)
             return False
 
+    def test_overlapping_writes(self):
+        # Write something to back up
+        self.hmp_io_writes('drive0', [('42', '0M', '2M')])
+
+        # Create a reference backup
+        self.qmp_backup_and_wait(device='drive0', format=iotests.imgfmt,
+                                 sync='full', target=self.ref_img,
+                                 auto_dismiss=False)
+        res = self.vm.qmp('block-job-dismiss', id='drive0')
+        self.assert_qmp(res, 'return', {})
+
+        # Now to the test backup: We simulate the following guest
+        # writes:
+        # (1) [1M + 64k, 1M + 128k): Afterwards, everything in that
+        #     area should be in the target image, and we must not copy
+        #     it again (because the source image has changed now)
+        #     (64k is the job's cluster size)
+        # (2) [1M, 2M): The backup job must not get overeager.  It
+        #     must copy [1M, 1M + 64k) and [1M + 128k, 2M) separately,
+        #     but not the area in between.
+
+        self.qmp_backup(device='drive0', format=iotests.imgfmt, sync='full',
+                        target=self.dest_img, speed=1, auto_dismiss=False)
+
+        self.hmp_io_writes('drive0', [('23', '%ik' % (1024 + 64), '64k'),
+                                      ('66', '1M', '1M')])
+
+        # Let the job complete
+        res = self.vm.qmp('block-job-set-speed', device='drive0', speed=0)
+        self.assert_qmp(res, 'return', {})
+        self.qmp_backup_wait('drive0')
+        res = self.vm.qmp('block-job-dismiss', id='drive0')
+        self.assert_qmp(res, 'return', {})
+
+        self.assertTrue(iotests.compare_images(self.ref_img, self.dest_img),
+                        'target image does not match reference image')
+
     def test_dismiss_false(self):
         res = self.vm.qmp('query-block-jobs')
         self.assert_qmp(res, 'return', [])

diff --git a/tests/qemu-iotests/056.out b/tests/qemu-iotests/056.out
index dae404e27863c06aad317476b6160ec79284b337..36376bed875a4185824775ca94f7acfd2b66616e 100644 (file)
--- a/tests/qemu-iotests/056.out
+++ b/tests/qemu-iotests/056.out
@@ -1,5 +1,5 @@
-.........
+..........
 ----------------------------------------------------------------------
-Ran 9 tests
+Ran 10 tests
 
 OK