f35687df6e
When we run MapPartitionWithSnapshot, intermediate devices aren't cleaned up if the call fails. Hence, record these intermediate devices we have created along the way using the new AutoDevices class. Upon failure, the AutoDevices object will be destroyed, and all the intermediate devices will be deleted from device mapper or image manager. Upon success, AutoDevices::Release() makes sure the intermediate devices aren't deleted. Test: libsnapshot_test Change-Id: Iff4c1297528288a27765c0224b67254b68c89776
85 lines
2.6 KiB
C++
85 lines
2.6 KiB
C++
// Copyright (C) 2019 The Android Open Source Project
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#pragma once
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#include <string>
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#include <android-base/macros.h>
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#include <libdm/dm.h>
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#include <libfiemap/image_manager.h>
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namespace android {
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namespace snapshot {
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struct AutoDevice {
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virtual ~AutoDevice(){};
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void Release();
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protected:
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AutoDevice(const std::string& name) : name_(name) {}
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std::string name_;
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private:
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DISALLOW_COPY_AND_ASSIGN(AutoDevice);
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AutoDevice(AutoDevice&& other) = delete;
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};
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// A list of devices we created along the way.
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// - Whenever a device is created that is subject to GC'ed at the end of
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// this function, add it to this list.
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// - If any error has occurred, the list is destroyed, and all these devices
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// are cleaned up.
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// - Upon success, Release() should be called so that the created devices
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// are kept.
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struct AutoDeviceList {
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~AutoDeviceList();
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template <typename T, typename... Args>
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void EmplaceBack(Args&&... args) {
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devices_.emplace_back(std::make_unique<T>(std::forward<Args>(args)...));
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}
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void Release();
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private:
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std::vector<std::unique_ptr<AutoDevice>> devices_;
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};
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// Automatically unmap a device upon deletion.
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struct AutoUnmapDevice : AutoDevice {
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// On destruct, delete |name| from device mapper.
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AutoUnmapDevice(android::dm::DeviceMapper* dm, const std::string& name)
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: AutoDevice(name), dm_(dm) {}
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AutoUnmapDevice(AutoUnmapDevice&& other) = default;
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~AutoUnmapDevice();
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private:
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DISALLOW_COPY_AND_ASSIGN(AutoUnmapDevice);
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android::dm::DeviceMapper* dm_ = nullptr;
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};
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// Automatically unmap an image upon deletion.
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struct AutoUnmapImage : AutoDevice {
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// On destruct, delete |name| from image manager.
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AutoUnmapImage(android::fiemap::IImageManager* images, const std::string& name)
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: AutoDevice(name), images_(images) {}
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AutoUnmapImage(AutoUnmapImage&& other) = default;
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~AutoUnmapImage();
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private:
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DISALLOW_COPY_AND_ASSIGN(AutoUnmapImage);
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android::fiemap::IImageManager* images_ = nullptr;
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};
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} // namespace snapshot
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} // namespace android
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