iotests: add simple incremental backup case

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1429314609-29776-20-git-send-email-jsnow@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

tests/qemu-iotests/124

@@ -29,6 +29,51 @@ def io_write_patterns(img, patterns):
         iotests.qemu_io('-c', 'write -P%s %s %s' % pattern, img)
 
 
+def try_remove(img):
+    try:
+        os.remove(img)
+    except OSError:
+        pass
+
+
+class Bitmap:
+    def __init__(self, name, drive):
+        self.name = name
+        self.drive = drive
+        self.num = 0
+        self.backups = list()
+
+    def base_target(self):
+        return (self.drive['backup'], None)
+
+    def new_target(self, num=None):
+        if num is None:
+            num = self.num
+        self.num = num + 1
+        base = os.path.join(iotests.test_dir,
+                            "%s.%s." % (self.drive['id'], self.name))
+        suff = "%i.%s" % (num, self.drive['fmt'])
+        target = base + "inc" + suff
+        reference = base + "ref" + suff
+        self.backups.append((target, reference))
+        return (target, reference)
+
+    def last_target(self):
+        if self.backups:
+            return self.backups[-1]
+        return self.base_target()
+
+    def del_target(self):
+        for image in self.backups.pop():
+            try_remove(image)
+        self.num -= 1
+
+    def cleanup(self):
+        for backup in self.backups:
+            for image in backup:
+                try_remove(image)
+
+
 class TestIncrementalBackup(iotests.QMPTestCase):
     def setUp(self):
         self.bitmaps = list()
@@ -73,6 +118,128 @@ class TestIncrementalBackup(iotests.QMPTestCase):
             iotests.qemu_img('create', '-f', fmt, img, size)
         self.files.append(img)
 
+
+    def do_qmp_backup(self, error='Input/output error', **kwargs):
+        res = self.vm.qmp('drive-backup', **kwargs)
+        self.assert_qmp(res, 'return', {})
+
+        event = self.vm.event_wait(name="BLOCK_JOB_COMPLETED",
+                                   match={'data': {'device': kwargs['device']}})
+        self.assertIsNotNone(event)
+
+        try:
+            failure = self.dictpath(event, 'data/error')
+        except AssertionError:
+            # Backup succeeded.
+            self.assert_qmp(event, 'data/offset', event['data']['len'])
+            return True
+        else:
+            # Backup failed.
+            self.assert_qmp(event, 'data/error', error)
+            return False
+
+
+    def create_anchor_backup(self, drive=None):
+        if drive is None:
+            drive = self.drives[-1]
+        res = self.do_qmp_backup(device=drive['id'], sync='full',
+                                 format=drive['fmt'], target=drive['backup'])
+        self.assertTrue(res)
+        self.files.append(drive['backup'])
+        return drive['backup']
+
+
+    def make_reference_backup(self, bitmap=None):
+        if bitmap is None:
+            bitmap = self.bitmaps[-1]
+        _, reference = bitmap.last_target()
+        res = self.do_qmp_backup(device=bitmap.drive['id'], sync='full',
+                                 format=bitmap.drive['fmt'], target=reference)
+        self.assertTrue(res)
+
+
+    def add_bitmap(self, name, drive):
+        bitmap = Bitmap(name, drive)
+        self.bitmaps.append(bitmap)
+        result = self.vm.qmp('block-dirty-bitmap-add', node=drive['id'],
+                             name=bitmap.name)
+        self.assert_qmp(result, 'return', {})
+        return bitmap
+
+
+    def prepare_backup(self, bitmap=None, parent=None):
+        if bitmap is None:
+            bitmap = self.bitmaps[-1]
+        if parent is None:
+            parent, _ = bitmap.last_target()
+
+        target, _ = bitmap.new_target()
+        self.img_create(target, bitmap.drive['fmt'], parent=parent)
+        return target
+
+
+    def create_incremental(self, bitmap=None, parent=None,
+                           parentFormat=None, validate=True):
+        if bitmap is None:
+            bitmap = self.bitmaps[-1]
+        if parent is None:
+            parent, _ = bitmap.last_target()
+
+        target = self.prepare_backup(bitmap, parent)
+        res = self.do_qmp_backup(device=bitmap.drive['id'],
+                                 sync='dirty-bitmap', bitmap=bitmap.name,
+                                 format=bitmap.drive['fmt'], target=target,
+                                 mode='existing')
+        if not res:
+            bitmap.del_target();
+            self.assertFalse(validate)
+        else:
+            self.make_reference_backup(bitmap)
+        return res
+
+
+    def check_backups(self):
+        for bitmap in self.bitmaps:
+            for incremental, reference in bitmap.backups:
+                self.assertTrue(iotests.compare_images(incremental, reference))
+            last = bitmap.last_target()[0]
+            self.assertTrue(iotests.compare_images(last, bitmap.drive['file']))
+
+
+    def hmp_io_writes(self, drive, patterns):
+        for pattern in patterns:
+            self.vm.hmp_qemu_io(drive, 'write -P%s %s %s' % pattern)
+        self.vm.hmp_qemu_io(drive, 'flush')
+
+
+    def test_incremental_simple(self):
+        '''
+        Test: Create and verify three incremental backups.
+
+        Create a bitmap and a full backup before VM execution begins,
+        then create a series of three incremental backups "during execution,"
+        i.e.; after IO requests begin modifying the drive.
+        '''
+        self.create_anchor_backup()
+        self.add_bitmap('bitmap0', self.drives[0])
+
+        # Sanity: Create a "hollow" incremental backup
+        self.create_incremental()
+        # Three writes: One complete overwrite, one new segment,
+        # and one partial overlap.
+        self.hmp_io_writes(self.drives[0]['id'], (('0xab', 0, 512),
+                                                  ('0xfe', '16M', '256k'),
+                                                  ('0x64', '32736k', '64k')))
+        self.create_incremental()
+        # Three more writes, one of each kind, like above
+        self.hmp_io_writes(self.drives[0]['id'], (('0x9a', 0, 512),
+                                                  ('0x55', '8M', '352k'),
+                                                  ('0x78', '15872k', '1M')))
+        self.create_incremental()
+        self.vm.shutdown()
+        self.check_backups()
+
+
     def test_sync_dirty_bitmap_missing(self):
         self.assert_no_active_block_jobs()
         self.files.append(self.err_img)
@@ -93,11 +260,10 @@ class TestIncrementalBackup(iotests.QMPTestCase):
 
     def tearDown(self):
         self.vm.shutdown()
+        for bitmap in self.bitmaps:
+            bitmap.cleanup()
         for filename in self.files:
-            try:
+            try_remove(filename)
-                os.remove(filename)
-            except OSError:
-                pass
 
 
 if __name__ == '__main__':

tests/qemu-iotests/124.out

@@ -1,5 +1,5 @@
-..
+...
 ----------------------------------------------------------------------
-Ran 2 tests
+Ran 3 tests
 
 OK