libsnapshot: Pause snapshot merge during shutdown (d48e75a1) · Commits · e / os / android_system_core

fs_mgr/libsnapshot/include/libsnapshot/snapshot.h

+10 −3

Original line number	Diff line number	Diff line
		@@ -418,9 +418,16 @@ class SnapshotManager final : public ISnapshotManager {
		// first-stage to decide whether to launch snapuserd.
		bool IsSnapuserdRequired();

		// This is primarily used to device reboot. If OTA update is in progress,
		// init will avoid killing processes
		bool IsUserspaceSnapshotUpdateInProgress();
		// This is primarily invoked during device reboot after an OTA update.
		//
		// a: Check if the partitions are mounted off snapshots.
		//
		// b: Store all dynamic partitions which are mounted off snapshots. This
		// is used to unmount the partition.
		bool IsUserspaceSnapshotUpdateInProgress(std::vector<std::string>& dynamic_partitions);

		// Pause the snapshot merge.
		bool PauseSnapshotMerge();

		enum class SnapshotDriver {
		DM_SNAPSHOT,

fs_mgr/libsnapshot/snapshot.cpp

+18 −4

Original line number	Diff line number	Diff line
		@@ -4687,7 +4687,17 @@ std::string SnapshotManager::ReadSourceBuildFingerprint() {
		return status.source_build_fingerprint();
		}

		bool SnapshotManager::IsUserspaceSnapshotUpdateInProgress() {
		bool SnapshotManager::PauseSnapshotMerge() {
		auto snapuserd_client = SnapuserdClient::TryConnect(kSnapuserdSocket, 5s);
		if (snapuserd_client) {
		// Pause the snapshot-merge
		return snapuserd_client->PauseMerge();
		}
		return false;
		}

		bool SnapshotManager::IsUserspaceSnapshotUpdateInProgress(
		std::vector<std::string>& dynamic_partitions) {
		// We cannot grab /metadata/ota lock here as this
		// is in reboot path. See b/308900853
		//
		@@ -4701,18 +4711,22 @@ bool SnapshotManager::IsUserspaceSnapshotUpdateInProgress() {
		LOG(ERROR) << "No dm-enabled block device is found.";
		return false;
		}

		bool is_ota_in_progress = false;
		for (auto& partition : dm_block_devices) {
		std::string partition_name = partition.first + current_suffix;
		DeviceMapper::TargetInfo snap_target;
		if (!GetSingleTarget(partition_name, TableQuery::Status, &snap_target)) {
		return false;
		continue;
		}
		auto type = DeviceMapper::GetTargetType(snap_target.spec);
		// Partition is mounted off snapshots
		if (type == "user") {
		return true;
		dynamic_partitions.emplace_back("/" + partition.first);
		is_ota_in_progress = true;
		}
		}
		return false;
		return is_ota_in_progress;
		}

		bool SnapshotManager::BootFromSnapshotsWithoutSlotSwitch() {

fs_mgr/libsnapshot/snapshot_test.cpp

+4 −2

Original line number	Diff line number	Diff line
		@@ -3112,8 +3112,10 @@ int main(int argc, char** argv) {
		// thereby interfering with the update and snapshot-merge progress.
		// Hence, wait until the update is complete.
		auto sm = android::snapshot::SnapshotManager::New();
		while (sm->IsUserspaceSnapshotUpdateInProgress()) {
		LOG(INFO) << "Snapshot update is in progress. Waiting...";
		std::vector<std::string> snapshot_partitions;
		while (sm->IsUserspaceSnapshotUpdateInProgress(snapshot_partitions)) {
		LOG(INFO) << "Waiting for: " << snapshot_partitions.size()
		<< " partitions to finish snapshot-merge";
		std::this_thread::sleep_for(std::chrono::milliseconds(1000));
		}

init/reboot.cpp

+22 −2

Original line number	Diff line number	Diff line
		@@ -394,6 +394,21 @@ void RebootMonitorThread(unsigned int cmd, const std::string& reboot_target,
		}
		}

		static void UmountDynamicPartitions(const std::vector<std::string>& dynamic_partitions) {
		for (auto device : dynamic_partitions) {
		// Cannot unmount /system
		if (device == "/system") {
		continue;
		}
		int r = umount2(device.c_str(), MNT_FORCE);
		if (r == 0) {
		LOG(INFO) << "Umounted success: " << device;
		} else {
		PLOG(WARNING) << "Cannot umount: " << device;
		}
		}
		}

		/* Try umounting all emulated file systems R/W block device cfile systems.
		* This will just try umount and give it up if it fails.
		* For fs like ext4, this is ok as file system will be marked as unclean shutdown
		@@ -408,14 +423,18 @@ static UmountStat TryUmountAndFsck(unsigned int cmd, bool run_fsck,
		Timer t;
		std::vector<MountEntry> block_devices;
		std::vector<MountEntry> emulated_devices;
		std::vector<std::string> dynamic_partitions;

		if (run_fsck && !FindPartitionsToUmount(&block_devices, &emulated_devices, false)) {
		return UMOUNT_STAT_ERROR;
		}
		auto sm = snapshot::SnapshotManager::New();
		bool ota_update_in_progress = false;
		if (sm->IsUserspaceSnapshotUpdateInProgress()) {
		LOG(INFO) << "OTA update in progress";
		if (sm->IsUserspaceSnapshotUpdateInProgress(dynamic_partitions)) {
		LOG(INFO) << "OTA update in progress. Pause snapshot merge";
		if (!sm->PauseSnapshotMerge()) {
		LOG(ERROR) << "Snapshot-merge pause failed";
		}
		ota_update_in_progress = true;
		}
		UmountStat stat = UmountPartitions(timeout - t.duration());
		@@ -435,6 +454,7 @@ static UmountStat TryUmountAndFsck(unsigned int cmd, bool run_fsck,
		// still not doing fsck when all processes are killed.
		//
		if (ota_update_in_progress) {
		UmountDynamicPartitions(dynamic_partitions);
		return stat;
		}
		KillAllProcesses();