Try locking after mounting metadata

In rescue mode, if /metadata is mounted but /metadata/ota does
not exist, immediately unmount /metadata and fallback to the code
path when /metadata is not mounted; that is, old partitions are
overwritten.

Test: in recovery, select wipe then immediately sideload
Bug: 160457903
Change-Id: I412d62b7005c81a7126106edc471622e6a7ef813
This commit is contained in:
Yifan Hong 2020-07-07 13:23:07 -07:00 committed by Alessio Balsini
parent 4e864e1216
commit 44033e75cc
1 changed files with 13 additions and 1 deletions

View File

@ -2516,7 +2516,19 @@ std::unique_ptr<AutoDevice> SnapshotManager::EnsureMetadataMounted() {
LOG(INFO) << "EnsureMetadataMounted does nothing in Android mode.";
return std::unique_ptr<AutoUnmountDevice>(new AutoUnmountDevice());
}
return AutoUnmountDevice::New(device_->GetMetadataDir());
auto ret = AutoUnmountDevice::New(device_->GetMetadataDir());
if (ret == nullptr) return nullptr;
// In rescue mode, it is possible to erase and format metadata, but /metadata/ota is not
// created to execute snapshot updates. Hence, subsequent calls is likely to fail because
// Lock*() fails. By failing early and returning nullptr here, update_engine_sideload can
// treat this case as if /metadata is not mounted.
if (!LockShared()) {
LOG(WARNING) << "/metadata is mounted, but errors occur when acquiring a shared lock. "
"Subsequent calls to SnapshotManager will fail. Unmounting /metadata now.";
return nullptr;
}
return ret;
}
bool SnapshotManager::HandleImminentDataWipe(const std::function<void()>& callback) {