iotests/257: add EmulatedBitmap class (32afa5a1) · Commits · SUMMER2020 / students / proj-2021291

tests/qemu-iotests/257

+75 −49

Original line number	Diff line number	Diff line
		@@ -85,6 +85,59 @@ GROUPS = [
		Pattern('0xdd', 0x3fc0000)]), # New; leaving a gap to the right
		]


		class EmulatedBitmap:
		def __init__(self, granularity=GRANULARITY):
		self._bits = set()
		self.granularity = granularity

		def dirty_bits(self, bits):
		self._bits \|= set(bits)

		def dirty_group(self, n):
		self.dirty_bits(GROUPS[n].bits(self.granularity))

		def clear(self):
		self._bits = set()

		def clear_bits(self, bits):
		self._bits -= set(bits)

		def clear_bit(self, bit):
		self.clear_bits({bit})

		def clear_group(self, n):
		self.clear_bits(GROUPS[n].bits(self.granularity))

		@property
		def first_bit(self):
		return sorted(self.bits)[0]

		@property
		def bits(self):
		return self._bits

		@property
		def count(self):
		return len(self.bits)

		def compare(self, qmp_bitmap):
		"""
		Print a nice human-readable message checking that a bitmap as reported
		by the QMP interface has as many bits set as we expect it to.
		"""

		name = qmp_bitmap.get('name', '(anonymous)')
		log("= Checking Bitmap {:s} =".format(name))

		want = self.count
		have = qmp_bitmap['count'] // qmp_bitmap['granularity']

		log("expecting {:d} dirty sectors; have {:d}. {:s}".format(
		want, have, "OK!" if want == have else "ERROR!"))
		log('')


		class Drive:
		"""Represents, vaguely, a drive attached to a VM.
		Includes format, graph, and device information."""
		@@ -195,27 +248,6 @@ def perform_writes(drive, n):
		log('')
		return bitmaps

		def calculate_bits(groups=None):
		"""Calculate how many bits we expect to see dirtied."""
		if groups:
		bits = set.union(*(GROUPS[group].bits(GRANULARITY) for group in groups))
		return len(bits)
		return 0

		def bitmap_comparison(bitmap, groups=None, want=0):
		"""
		Print a nice human-readable message checking that this bitmap has as
		many bits set as we expect it to.
		"""
		log("= Checking Bitmap {:s} =".format(bitmap.get('name', '(anonymous)')))

		if groups:
		want = calculate_bits(groups)
		have = bitmap['count'] // bitmap['granularity']

		log("expecting {:d} dirty sectors; have {:d}. {:s}".format(
		want, have, "OK!" if want == have else "ERROR!"))
		log('')

		def compare_images(image, reference, baseimg=None, expected_match=True):
		"""
		@@ -321,12 +353,13 @@ def test_bitmap_sync(bsync_mode, failure=None):
		vm.qmp_log("block-dirty-bitmap-add", node=drive0.name,
		name="bitmap0", granularity=GRANULARITY)
		log('')
		ebitmap = EmulatedBitmap()

		# 1 - Writes and Reference Backup
		bitmaps = perform_writes(drive0, 1)
		dirty_groups = {1}
		ebitmap.dirty_group(1)
		bitmap = get_bitmap(bitmaps, drive0.device, 'bitmap0')
		bitmap_comparison(bitmap, groups=dirty_groups)
		ebitmap.compare(bitmap)
		reference_backup(drive0, 1, fbackup1)

		# 1 - Bitmap Backup (Optional induced failure)
		@@ -342,54 +375,47 @@ def test_bitmap_sync(bsync_mode, failure=None):
		log('')
		bitmaps = perform_writes(drive0, 2)
		# Named bitmap (static, should be unchanged)
		bitmap_comparison(get_bitmap(bitmaps, drive0.device, 'bitmap0'),
		groups=dirty_groups)
		ebitmap.compare(get_bitmap(bitmaps, drive0.device, 'bitmap0'))
		# Anonymous bitmap (dynamic, shows new writes)
		bitmap_comparison(get_bitmap(bitmaps, drive0.device, '',
		recording=True), groups={2})
		dirty_groups.add(2)
		anonymous = EmulatedBitmap()
		anonymous.dirty_group(2)
		anonymous.compare(get_bitmap(bitmaps, drive0.device, '',
		recording=True))

		# Simulate the order in which this will happen:
		# group 1 gets cleared first, then group two gets written.
		if ((bsync_mode == 'on-success' and not failure) or
		(bsync_mode == 'always')):
		ebitmap.clear_group(1)
		ebitmap.dirty_group(2)

		vm.run_job(job, auto_dismiss=True, auto_finalize=False,
		pre_finalize=_callback,
		cancel=(failure == 'simulated'))
		bitmaps = query_bitmaps(vm)
		bitmap = get_bitmap(bitmaps, drive0.device, 'bitmap0')
		log(bitmaps, indent=2)
		log('')

		if ((bsync_mode == 'on-success' and not failure) or
		(bsync_mode == 'always' and failure != 'intermediate')):
		dirty_groups.remove(1)

		if bsync_mode == 'always' and failure == 'intermediate':
		# We manage to copy one sector (one bit) before the error.
		bitmap_comparison(bitmap,
		want=calculate_bits(groups=dirty_groups) - 1)
		else:
		bitmap_comparison(bitmap, groups=dirty_groups)
		ebitmap.clear_bit(ebitmap.first_bit)
		ebitmap.compare(get_bitmap(bitmaps, drive0.device, 'bitmap0'))

		# 2 - Writes and Reference Backup
		bitmaps = perform_writes(drive0, 3)
		dirty_groups.add(3)
		bitmap = get_bitmap(bitmaps, drive0.device, 'bitmap0')
		if bsync_mode == 'always' and failure == 'intermediate':
		# We're one bit short, still.
		bitmap_comparison(bitmap,
		want=calculate_bits(groups=dirty_groups) - 1)
		else:
		bitmap_comparison(bitmap, groups=dirty_groups)
		ebitmap.dirty_group(3)
		ebitmap.compare(get_bitmap(bitmaps, drive0.device, 'bitmap0'))
		reference_backup(drive0, 2, fbackup2)

		# 2 - Bitmap Backup (In failure modes, this is a recovery.)
		job = bitmap_backup(drive0, 2, bsync2, "bitmap0", bsync_mode)
		vm.run_job(job, auto_dismiss=True, auto_finalize=False)
		bitmaps = query_bitmaps(vm)
		bitmap = get_bitmap(bitmaps, drive0.device, 'bitmap0')
		log(bitmaps, indent=2)
		log('')
		bitmap_comparison(bitmap, groups={}
		if bsync_mode != 'never'
		else dirty_groups)
		if bsync_mode != 'never':
		ebitmap.clear()
		ebitmap.compare(get_bitmap(bitmaps, drive0.device, 'bitmap0'))

		log('--- Cleanup ---\n')
		vm.qmp_log("block-dirty-bitmap-remove",