diff options
Diffstat (limited to 'payload_consumer/cow_writer_file_descriptor.cc')
| -rw-r--r-- | payload_consumer/cow_writer_file_descriptor.cc | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/payload_consumer/cow_writer_file_descriptor.cc b/payload_consumer/cow_writer_file_descriptor.cc index d8c7afb8..2de6664a 100644 --- a/payload_consumer/cow_writer_file_descriptor.cc +++ b/payload_consumer/cow_writer_file_descriptor.cc @@ -28,7 +28,10 @@ namespace chromeos_update_engine { CowWriterFileDescriptor::CowWriterFileDescriptor( std::unique_ptr<android::snapshot::ISnapshotWriter> cow_writer) : cow_writer_(std::move(cow_writer)), - cow_reader_(cow_writer_->OpenReader()) {} + cow_reader_(cow_writer_->OpenReader()) { + CHECK_NE(cow_writer_, nullptr); + CHECK_NE(cow_reader_, nullptr); +} bool CowWriterFileDescriptor::Open(const char* path, int flags, mode_t mode) { LOG(ERROR) << "CowWriterFileDescriptor doesn't support Open()"; @@ -113,7 +116,17 @@ bool CowWriterFileDescriptor::Flush() { bool CowWriterFileDescriptor::Close() { if (cow_writer_) { - TEST_AND_RETURN_FALSE(cow_writer_->Finalize()); + // b/186196758 + // When calling + // InitializeAppend(kEndOfInstall), the SnapshotWriter only reads up to the + // given label. But OpenReader() completely disregards the resume label and + // reads all ops. Therefore, update_engine sees the verity data. However, + // when calling SnapshotWriter::Finalize(), data after resume label are + // discarded, therefore verity data is gone. To prevent phantom reads, don't + // call Finalize() unless we actually write something. + if (dirty_) { + TEST_AND_RETURN_FALSE(cow_writer_->Finalize()); + } cow_writer_ = nullptr; } if (cow_reader_) { |