libsnapshot: Implement OnlineKernelSnapshotWriter::OpenReader. (39f25089) · Commits · e / os / android_system_core

fs_mgr/libsnapshot/Android.bp

+1 −0

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		@@ -74,6 +74,7 @@ filegroup {
		"android/snapshot/snapshot.proto",
		"device_info.cpp",
		"snapshot.cpp",
		"snapshot_reader.cpp",
		"snapshot_stats.cpp",
		"snapshot_stub.cpp",
		"snapshot_metadata_updater.cpp",

fs_mgr/libsnapshot/snapshot.cpp

+1 −0

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		@@ -44,6 +44,7 @@
		#include "device_info.h"
		#include "partition_cow_creator.h"
		#include "snapshot_metadata_updater.h"
		#include "snapshot_reader.h"
		#include "utility.h"

		namespace android {

fs_mgr/libsnapshot/snapshot_reader.cpp

0 → 100644

+77 −0

Original line number	Diff line number	Diff line
		//
		// Copyright (C) 2020 The Android Open Source Project
		//
		// Licensed under the Apache License, Version 2.0 (the "License");
		// you may not use this file except in compliance with the License.
		// You may obtain a copy of the License at
		//
		// http://www.apache.org/licenses/LICENSE-2.0
		//
		// Unless required by applicable law or agreed to in writing, software
		// distributed under the License is distributed on an "AS IS" BASIS,
		// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		// See the License for the specific language governing permissions and
		// limitations under the License.
		//

		#include <ext4_utils/ext4_utils.h>

		#include "snapshot_reader.h"

		namespace android {
		namespace snapshot {

		// Not supported.
		bool ReadOnlyFileDescriptor::Open(const char*, int, mode_t) {
		errno = EINVAL;
		return false;
		}

		bool ReadOnlyFileDescriptor::Open(const char*, int) {
		errno = EINVAL;
		return false;
		}

		ssize_t ReadOnlyFileDescriptor::Write(const void*, size_t) {
		errno = EINVAL;
		return false;
		}

		bool ReadOnlyFileDescriptor::BlkIoctl(int, uint64_t, uint64_t, int*) {
		errno = EINVAL;
		return false;
		}

		ReadFdFileDescriptor::ReadFdFileDescriptor(android::base::unique_fd&& fd) : fd_(std::move(fd)) {}

		ssize_t ReadFdFileDescriptor::Read(void* buf, size_t count) {
		return read(fd_.get(), buf, count);
		}

		off64_t ReadFdFileDescriptor::Seek(off64_t offset, int whence) {
		return lseek(fd_.get(), offset, whence);
		}

		uint64_t ReadFdFileDescriptor::BlockDevSize() {
		return get_block_device_size(fd_.get());
		}

		bool ReadFdFileDescriptor::Close() {
		fd_ = {};
		return true;
		}

		bool ReadFdFileDescriptor::IsSettingErrno() {
		return true;
		}

		bool ReadFdFileDescriptor::IsOpen() {
		return fd_ >= 0;
		}

		bool ReadFdFileDescriptor::Flush() {
		return true;
		}

		} // namespace snapshot
		} // namespace android

fs_mgr/libsnapshot/snapshot_reader.h

0 → 100644

+50 −0

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		//
		// Copyright (C) 2020 The Android Open Source Project
		//
		// Licensed under the Apache License, Version 2.0 (the "License");
		// you may not use this file except in compliance with the License.
		// You may obtain a copy of the License at
		//
		// http://www.apache.org/licenses/LICENSE-2.0
		//
		// Unless required by applicable law or agreed to in writing, software
		// distributed under the License is distributed on an "AS IS" BASIS,
		// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		// See the License for the specific language governing permissions and
		// limitations under the License.
		//

		#pragma once

		#include <android-base/file.h>
		#include <payload_consumer/file_descriptor.h>

		namespace android {
		namespace snapshot {

		class ReadOnlyFileDescriptor : public chromeos_update_engine::FileDescriptor {
		public:
		bool Open(const char* path, int flags, mode_t mode) override;
		bool Open(const char* path, int flags) override;
		ssize_t Write(const void* buf, size_t count) override;
		bool BlkIoctl(int request, uint64_t start, uint64_t length, int* result) override;
		};

		class ReadFdFileDescriptor : public ReadOnlyFileDescriptor {
		public:
		explicit ReadFdFileDescriptor(android::base::unique_fd&& fd);

		ssize_t Read(void* buf, size_t count) override;
		off64_t Seek(off64_t offset, int whence) override;
		uint64_t BlockDevSize() override;
		bool Close() override;
		bool IsSettingErrno() override;
		bool IsOpen() override;
		bool Flush() override;

		private:
		android::base::unique_fd fd_;
		};

		} // namespace snapshot
		} // namespace android

fs_mgr/libsnapshot/snapshot_writer.cpp

+8 −2

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		@@ -19,10 +19,12 @@
		#include <android-base/file.h>
		#include <android-base/logging.h>
		#include <payload_consumer/file_descriptor.h>
		#include "snapshot_reader.h"

		namespace android {
		namespace snapshot {

		using android::base::unique_fd;
		using chromeos_update_engine::FileDescriptor;

		ISnapshotWriter::ISnapshotWriter(const CowOptions& options) : ICowWriter(options) {}
		@@ -83,9 +85,13 @@ bool OnlineKernelSnapshotWriter::EmitCopy(uint64_t new_block, uint64_t old_block
		}

		std::unique_ptr<FileDescriptor> OnlineKernelSnapshotWriter::OpenReader() {
		LOG(ERROR) << "OnlineKernelSnapshotWriter::OpenReader not yet implemented";
		unique_fd fd(dup(snapshot_fd_.get()));
		if (fd < 0) {
		PLOG(ERROR) << "dup2 failed in OpenReader";
		return nullptr;
		}
		return std::make_unique<ReadFdFileDescriptor>(std::move(fd));
		}

		} // namespace snapshot
		} // namespace android