Only verify the source partition which target hash mismatch.

There's no need to go back to the first partition when target partition
hash failed, those partitions already passed target hash verification.
We should directly go ahead and verify the source partition corresponding
to the current partition which target hash doesn't match, and that should
be the only source partition we verify.

Test: ./update_engine_unittests
Bug: None

Change-Id: I6754d329d62fbed214e2b01568b290a60ad746ac

1 files changed, 8 insertions, 15 deletions

diff --git a/payload_consumer/filesystem_verifier_action.cc b/payload_consumer/filesystem_verifier_action.cc
index 4b476dbd..5156f966 100644
--- a/payload_consumer/filesystem_verifier_action.cc
+++ b/payload_consumer/filesystem_verifier_action.cc
@@ -91,18 +91,7 @@ void FilesystemVerifierAction::Cleanup(ErrorCode code) {
 
 void FilesystemVerifierAction::StartPartitionHashing() {
   if (partition_index_ == install_plan_.partitions.size()) {
-    switch (verifier_step_) {
-      case VerifierStep::kVerifySourceHash:
-        // The action will skip kVerifySourceHash step if target partition hash
-        // matches, if we are in this step, it means target hash does not match,
-        // and now that the source hash matches, we should set the error code to
-        // reflect the error in target partition.
-        Cleanup(ErrorCode::kNewRootfsVerificationError);
-        break;
-      case VerifierStep::kVerifyTargetHash:
-        Cleanup(ErrorCode::kSuccess);
-        break;
-    }
+    Cleanup(ErrorCode::kSuccess);
     return;
   }
   InstallPlan::Partition& partition =
@@ -224,7 +213,6 @@ void FilesystemVerifierAction::FinishPartitionHashing() {
         // switch to kVerifySourceHash step to check if it's because the source
         // partition does not match either.
         verifier_step_ = VerifierStep::kVerifySourceHash;
-        partition_index_ = 0;
       } else {
         partition_index_++;
       }
@@ -256,8 +244,13 @@ void FilesystemVerifierAction::FinishPartitionHashing() {
                   << "run: .../src/scripts/sha256_partitions.sh .../file.bin";
         return Cleanup(ErrorCode::kDownloadStateInitializationError);
       }
-      partition_index_++;
-      break;
+      // The action will skip kVerifySourceHash step if target partition hash
+      // matches, if we are in this step, it means target hash does not match,
+      // and now that the source partition hash matches, we should set the error
+      // code to reflect the error in target partition.
+      // We only need to verify the source partition which the target hash does
+      // not match, the rest of the partitions don't matter.
+      return Cleanup(ErrorCode::kNewRootfsVerificationError);
   }
   // Start hashing the next partition, if any.
   hasher_.reset();