Merge "Add write_cow functionality" into main (2851af05) · Commits · e / os / android_system_core

fs_mgr/libsnapshot/tools/Android.bp

+1 −0

Original line number	Diff line number	Diff line
		@@ -34,6 +34,7 @@ cc_binary {

		static_libs: [
		"libsnapshot_cow",
		"libgflags",
		],

		shared_libs: [

fs_mgr/libsnapshot/tools/write_cow.cpp

+55 −4

Original line number	Diff line number	Diff line
		@@ -18,10 +18,18 @@
		#include <libsnapshot/cow_compress.h>
		#include <libsnapshot/cow_format.h>
		#include <libsnapshot/cow_writer.h>
		#include <filesystem>

		#include <gflags/gflags.h>
		#include <iostream>

		#include "android-base/unique_fd.h"

		DEFINE_bool(silent, false, "Run silently");
		DEFINE_int32(writer_version, 2, "which version of COW writer to be used");
		DEFINE_bool(write_legacy, false,
		"Writes a legacy cow_v2 in current directory, this cow was used to test backwards "
		"compatibility between version 2 and version 3");
		DEFINE_bool(write_header, false, "Test reading/writing just the header");
		using namespace android::snapshot;

		// This writes a simple cow v2 file in the current directory. This file will serve as testdata for
		@@ -29,7 +37,7 @@ using namespace android::snapshot;
		//
		// WARNING: We should not be overriding this test file, as it will serve as historic marker for what
		// a device with old writer_v2 will write as a cow.
		void write_cow_v2() {
		static void write_legacy_cow_v2() {
		CowOptions options;
		options.cluster_ops = 5;
		options.num_merge_ops = 1;
		@@ -58,6 +66,49 @@ void write_cow_v2() {
		writer->Finalize();
		}

		int main() {
		write_cow_v2();
		static bool WriteCow(const std::string& path) {
		android::base::unique_fd fd(open(path.c_str(), O_RDONLY));
		fd.reset(open(path.c_str(), O_RDWR \| O_CREAT \| O_TRUNC, 0664));
		if (fd < 0) {
		PLOG(ERROR) << "could not open " << path << " for writing";
		return false;
		}
		CowOptions options;
		std::string data = "This is some data, believe it";
		data.resize(options.block_size, '\0');

		std::unique_ptr<ICowWriter> writer =
		CreateCowWriter(FLAGS_writer_version, options, std::move(fd));
		if (!writer) {
		return false;
		}

		writer->AddCopy(0, 5);
		writer->AddRawBlocks(2, data.data(), data.size());
		writer->AddLabel(1);
		writer->AddXorBlocks(50, data.data(), data.size(), 24, 10);
		writer->AddZeroBlocks(5, 10);
		writer->AddLabel(2);
		writer->Finalize();

		if (!FLAGS_silent) {
		std::cout << "Writing COW with writer v" << FLAGS_writer_version << "\n";
		}

		return true;
		}

		int main(int argc, char** argv) {
		gflags::ParseCommandLineFlags(&argc, &argv, true);
		if (FLAGS_write_legacy) {
		write_legacy_cow_v2();
		return 0;
		}
		if (argc < 2) {
		gflags::ShowUsageWithFlags(argv[0]);
		return 1;
		}
		if (!WriteCow(argv[1])) {
		return 1;
		}
		}