Add support for clobbered blocks
In ext4 filesystems, some blocks might be changed even being mounted
R/O, such as the superblock (block 0). We need to exclude such blocks
from integrity verification. Plus such blocks should always be
written to the target by copying instead of patching.
Bug: http://b/20939131
Change-Id: I991169ec307dfb231b2fe8908a0668595ecb2060
diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index 227dcb8..b44f959 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -1141,6 +1141,9 @@
self.partition = partition
self.check_first_block = check_first_block
+ # Due to http://b/20939131, check_first_block is disabled temporarily.
+ assert not self.check_first_block
+
if version is None:
version = 1
if OPTIONS.info_dict:
@@ -1174,18 +1177,18 @@
if not self.src:
script.Print("Image %s will be patched unconditionally." % (partition,))
else:
+ ranges = self.src.care_map.subtract(self.src.clobbered_blocks)
+ ranges_str = ranges.to_string_raw()
if self.version >= 3:
script.AppendExtra(('if (range_sha1("%s", "%s") == "%s" || '
'block_image_verify("%s", '
'package_extract_file("%s.transfer.list"), '
'"%s.new.dat", "%s.patch.dat")) then') % (
- self.device, self.src.care_map.to_string_raw(),
- self.src.TotalSha1(),
+ self.device, ranges_str, self.src.TotalSha1(),
self.device, partition, partition, partition))
else:
script.AppendExtra('if range_sha1("%s", "%s") == "%s" then' % (
- self.device, self.src.care_map.to_string_raw(),
- self.src.TotalSha1()))
+ self.device, ranges_str, self.src.TotalSha1()))
script.Print('Verified %s image...' % (partition,))
script.AppendExtra('else')
@@ -1233,6 +1236,9 @@
return ctx.hexdigest()
+ # TODO(tbao): Due to http://b/20939131, block 0 may be changed without
+ # remounting R/W. Will change the checking to a finer-grained way to
+ # mask off those bits.
def _CheckFirstBlock(self, script):
r = rangelib.RangeSet((0, 1))
srchash = self._HashBlocks(self.src, r)