1 /* 2 * Copyright (C) 2018 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef ANDROID_APEXD_APEXD_LOOP_H_ 18 #define ANDROID_APEXD_APEXD_LOOP_H_ 19 20 #include <android-base/result.h> 21 #include <android-base/unique_fd.h> 22 23 #include <functional> 24 #include <string> 25 26 namespace android { 27 namespace apex { 28 namespace loop { 29 30 using android::base::unique_fd; 31 32 struct LoopbackDeviceUniqueFd { 33 unique_fd device_fd; 34 std::string name; 35 LoopbackDeviceUniqueFdLoopbackDeviceUniqueFd36 LoopbackDeviceUniqueFd() {} LoopbackDeviceUniqueFdLoopbackDeviceUniqueFd37 LoopbackDeviceUniqueFd(unique_fd&& fd, const std::string& name) 38 : device_fd(std::move(fd)), name(name) {} 39 LoopbackDeviceUniqueFdLoopbackDeviceUniqueFd40 LoopbackDeviceUniqueFd(LoopbackDeviceUniqueFd&& fd) noexcept 41 : device_fd(std::move(fd.device_fd)), name(std::move(fd.name)) {} 42 LoopbackDeviceUniqueFd& operator=(LoopbackDeviceUniqueFd&& other) noexcept { 43 MaybeCloseBad(); 44 device_fd = std::move(other.device_fd); 45 name = std::move(other.name); 46 return *this; 47 } 48 ~LoopbackDeviceUniqueFdLoopbackDeviceUniqueFd49 ~LoopbackDeviceUniqueFd() { MaybeCloseBad(); } 50 51 void MaybeCloseBad(); 52 CloseGoodLoopbackDeviceUniqueFd53 void CloseGood() { device_fd.reset(-1); } 54 GetLoopbackDeviceUniqueFd55 int Get() { return device_fd.get(); } 56 }; 57 58 android::base::Result<void> ConfigureReadAhead(const std::string& device_path); 59 60 android::base::Result<void> PreAllocateLoopDevices(size_t num); 61 62 android::base::Result<LoopbackDeviceUniqueFd> CreateLoopDevice( 63 const std::string& target, const int32_t image_offset, 64 const size_t image_size); 65 66 using DestroyLoopFn = 67 std::function<void(const std::string&, const std::string&)>; 68 void DestroyLoopDevice(const std::string& path, const DestroyLoopFn& extra); 69 70 } // namespace loop 71 } // namespace apex 72 } // namespace android 73 74 #endif // ANDROID_APEXD_APEXD_LOOP_H_ 75