1 // 2 // Copyright (C) 2021 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 UPDATE_ENGINE_PAYLOAD_GENERATOR_EROFS_FILESYSTEM_H_ 18 #define UPDATE_ENGINE_PAYLOAD_GENERATOR_EROFS_FILESYSTEM_H_ 19 20 #include "update_engine/payload_generator/filesystem_interface.h" 21 #include "update_engine/payload_generator/delta_diff_generator.h" 22 23 struct erofs_sb_info; 24 25 namespace chromeos_update_engine { 26 27 class ErofsFilesystem final : public FilesystemInterface { 28 public: 29 // Creates an ErofsFilesystem from a erofs formatted filesystem stored in a 30 // file. The file doesn't need to be loop-back mounted. Since erofs-utils 31 // library functions are not concurrency safe(can't be used in multi-threaded 32 // context, can't even work with multiple EROFS images concurrently on 1 33 // thread), this function takes a global mutex. 34 static std::unique_ptr<ErofsFilesystem> CreateFromFile( 35 const std::string& filename, 36 const CompressionAlgorithm& algo = 37 PartitionConfig::GetDefaultCompressionParam()); 38 virtual ~ErofsFilesystem() = default; 39 40 // FilesystemInterface overrides. GetBlockSize()41 size_t GetBlockSize() const override { return kBlockSize; } GetBlockCount()42 size_t GetBlockCount() const override { return fs_size_ / kBlockSize; } 43 44 // GetFiles will return one FilesystemInterface::File for every file and every 45 // directory in the filesystem. Hard-linked files will appear in the list 46 // several times with the same list of blocks. 47 // On addition to actual files, it also returns these pseudo-files: 48 // <free-space>: With all the unallocated data-blocks. 49 // <inode-blocks>: Will all the data-blocks for second and third level inodes 50 // of all the files. 51 // <group-descriptors>: With the block group descriptor and their reserved 52 // space. 53 // <metadata>: With the rest of ext2 metadata blocks, such as superblocks 54 // and bitmap tables. 55 static bool GetFiles(struct erofs_sb_info* sbi, 56 const std::string& filename, 57 std::vector<File>* files, 58 const CompressionAlgorithm& algo); 59 60 bool GetFiles(std::vector<File>* files) const override; 61 62 private: ErofsFilesystem(std::string filename,size_t fs_size,std::vector<File> files)63 ErofsFilesystem(std::string filename, size_t fs_size, std::vector<File> files) 64 : filename_(filename), fs_size_(fs_size), files_(std::move(files)) {} 65 66 // The file where the filesystem is stored. 67 const std::string filename_; 68 const size_t fs_size_; 69 const std::vector<File> files_; 70 }; // namespace chromeos_update_engine 71 72 } // namespace chromeos_update_engine 73 74 #endif