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 "status_or.h" 21 22 #include <android-base/unique_fd.h> 23 24 #include <functional> 25 #include <string> 26 27 namespace android { 28 namespace apex { 29 namespace loop { 30 31 using android::base::unique_fd; 32 33 struct LoopbackDeviceUniqueFd { 34 unique_fd device_fd; 35 std::string name; 36 LoopbackDeviceUniqueFdLoopbackDeviceUniqueFd37 LoopbackDeviceUniqueFd() {} LoopbackDeviceUniqueFdLoopbackDeviceUniqueFd38 LoopbackDeviceUniqueFd(unique_fd&& fd, const std::string& name) 39 : device_fd(std::move(fd)), name(name) {} 40 LoopbackDeviceUniqueFdLoopbackDeviceUniqueFd41 LoopbackDeviceUniqueFd(LoopbackDeviceUniqueFd&& fd) noexcept 42 : device_fd(std::move(fd.device_fd)), name(fd.name) {} 43 LoopbackDeviceUniqueFd& operator=(LoopbackDeviceUniqueFd&& other) noexcept { 44 MaybeCloseBad(); 45 device_fd = std::move(other.device_fd); 46 name = std::move(other.name); 47 return *this; 48 } 49 ~LoopbackDeviceUniqueFdLoopbackDeviceUniqueFd50 ~LoopbackDeviceUniqueFd() { MaybeCloseBad(); } 51 52 void MaybeCloseBad(); 53 CloseGoodLoopbackDeviceUniqueFd54 void CloseGood() { device_fd.reset(-1); } 55 getLoopbackDeviceUniqueFd56 int get() { return device_fd.get(); } 57 }; 58 59 Status configureReadAhead(const std::string& device_path); 60 61 Status preAllocateLoopDevices(size_t num); 62 63 StatusOr<LoopbackDeviceUniqueFd> createLoopDevice(const std::string& target, 64 const int32_t imageOffset, 65 const size_t imageSize); 66 67 using DestroyLoopFn = 68 std::function<void(const std::string&, const std::string&)>; 69 void DestroyLoopDevice(const std::string& path, const DestroyLoopFn& extra); 70 71 } // namespace loop 72 } // namespace apex 73 } // namespace android 74 75 #endif // ANDROID_APEXD_APEXD_LOOP_H_ 76