Merge "libsnapshot: Use words for xor ops" into main (dcb13446) · Commits · e / os / android_system_core

fs_mgr/libsnapshot/snapuserd/user-space-merge/read_worker.cpp

+8 −3

Original line number	Diff line number	Diff line
		@@ -104,6 +104,8 @@ bool ReadWorker::ProcessCopyOp(const CowOperation* cow_op, void* buffer) {
		}

		bool ReadWorker::ProcessXorOp(const CowOperation* cow_op, void* buffer) {
		using WordType = std::conditional_t<sizeof(void*) == sizeof(uint64_t), uint64_t, uint32_t>;

		if (!ReadFromSourceDevice(cow_op, buffer)) {
		return false;
		}
		@@ -120,9 +122,12 @@ bool ReadWorker::ProcessXorOp(const CowOperation* cow_op, void* buffer) {
		return false;
		}

		auto xor_out = reinterpret_cast<uint8_t*>(buffer);
		for (size_t i = 0; i < BLOCK_SZ; i++) {
		xor_out[i] ^= xor_buffer_[i];
		auto xor_in = reinterpret_cast<const WordType*>(xor_buffer_.data());
		auto xor_out = reinterpret_cast<WordType*>(buffer);
		auto num_words = BLOCK_SZ / sizeof(WordType);

		for (auto i = 0; i < num_words; i++) {
		xor_out[i] ^= xor_in[i];
		}
		return true;
		}

+7 −5

Original line number	Diff line number	Diff line
		@@ -458,6 +458,7 @@ bool ReadAhead::ReapIoCompletions(int pending_ios_to_complete) {
		void ReadAhead::ProcessXorData(size_t& block_xor_index, size_t& xor_index,
		std::vector<const CowOperation>& xor_op_vec, void buffer,
		loff_t& buffer_offset) {
		using WordType = std::conditional_t<sizeof(void*) == sizeof(uint64_t), uint64_t, uint32_t>;
		loff_t xor_buf_offset = 0;

		while (block_xor_index < blocks_.size()) {
		@@ -470,13 +471,14 @@ void ReadAhead::ProcessXorData(size_t& block_xor_index, size_t& xor_index,
		// Check if this block is an XOR op
		if (xor_op->new_block == new_block) {
		// Pointer to the data read from base device
		uint8_t* buffer = reinterpret_cast<uint8_t*>(bufptr);
		auto buffer_words = reinterpret_cast<WordType*>(bufptr);
		// Get the xor'ed data read from COW device
		uint8_t* xor_data = reinterpret_cast<uint8_t>((char)bufsink_.GetPayloadBufPtr() +
		xor_buf_offset);
		auto xor_data_words = reinterpret_cast<WordType*>(
		(char*)bufsink_.GetPayloadBufPtr() + xor_buf_offset);
		auto num_words = BLOCK_SZ / sizeof(WordType);

		for (size_t byte_offset = 0; byte_offset < BLOCK_SZ; byte_offset++) {
		buffer[byte_offset] ^= xor_data[byte_offset];
		for (auto i = 0; i < num_words; i++) {
		buffer_words[i] ^= xor_data_words[i];
		}

		// Move to next XOR op