AU: do not copy filesystem during full updates
The filesystem copying stage is redundant during full updates, where the
partition is being entirely overwritten regardless of its previous
content. It is also a very wasteful step, causing intensive I/O and
kernel buffer pressure, and known to (sometimes) cause jank and
otherwise have detrimental effects on our user experience.
This CL eliminates filesystem copying for full updates:
1) The decision is based on whether the Omaha response indicates that
this is a full update.
2) To be safe, we also ensure that the payload manifest does not contain
old partition hashes, which is indicative of a delta update.
Note that it is generally desirable to base the decision solely on #2
above (and ignore #1 altogether). However, this will require more
extensive re-engineering of the update flow, as filesystem copying
currently happens prior to the manifest being downloaded.
BUG=chromium:189855
TEST=Full and delta updates run correctly on x86-alex
Change-Id: Ic0dc6e32913cfb96019606624ec6b87c2e5b3ebb
Reviewed-on: https://gerrit.chromium.org/gerrit/43665
Commit-Queue: Gilad Arnold <garnold@chromium.org>
Reviewed-by: Gilad Arnold <garnold@chromium.org>
Tested-by: Gilad Arnold <garnold@chromium.org>
diff --git a/delta_performer.h b/delta_performer.h
index 1f8f5cb..33e39d7 100644
--- a/delta_performer.h
+++ b/delta_performer.h
@@ -193,6 +193,10 @@
bool CanPerformInstallOperation(
const DeltaArchiveManifest_InstallOperation& operation);
+ // Checks the integrity of the payload manifest. Returns true upon success,
+ // false otherwise.
+ ErrorCode ValidateManifest();
+
// Validates that the hash of the blobs corresponding to the given |operation|
// matches what's specified in the manifest in the payload.
// Returns kErrorCodeSuccess on match or a suitable error code otherwise.