ext2_filesystem.h revision fca4775f0b1ad4e7c013bf626b42d06f6b74738e 
1//
2// Copyright (C) 2015 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_EXT2_FILESYSTEM_H_
18#define UPDATE_ENGINE_PAYLOAD_GENERATOR_EXT2_FILESYSTEM_H_
19
20#include "update_engine/payload_generator/filesystem_interface.h"
21
22#include <memory>
23#include <string>
24#include <vector>
25
26#if defined(__clang__)
27// TODO: Remove these pragmas when b/35721782 is fixed.
28#pragma clang diagnostic push
29#pragma clang diagnostic ignored "-Wmacro-redefined"
30#endif
31#include <ext2fs/ext2fs.h>
32#if defined(__clang__)
33#pragma clang diagnostic pop
34#endif
35
36namespace chromeos_update_engine {
37
38class Ext2Filesystem : public FilesystemInterface {
39 public:
40  // Creates an Ext2Filesystem from a ext2 formatted filesystem stored in a
41  // file. The file doesn't need to be loop-back mounted.
42  static std::unique_ptr<Ext2Filesystem> CreateFromFile(
43      const std::string& filename);
44  virtual ~Ext2Filesystem();
45
46  // FilesystemInterface overrides.
47  size_t GetBlockSize() const override;
48  size_t GetBlockCount() const override;
49
50  // GetFiles will return one FilesystemInterface::File for every file and every
51  // directory in the filesystem. Hard-linked files will appear in the list
52  // several times with the same list of blocks.
53  // On addition to actual files, it also returns these pseudo-files:
54  //  <free-space>: With all the unallocated data-blocks.
55  //  <inode-blocks>: Will all the data-blocks for second and third level inodes
56  //    of all the files.
57  //  <group-descriptors>: With the block group descriptor and their reserved
58  //    space.
59  //  <metadata>: With the rest of ext2 metadata blocks, such as superblocks
60  //    and bitmap tables.
61  bool GetFiles(std::vector<File>* files) const override;
62
63  bool LoadSettings(brillo::KeyValueStore* store) const override;
64
65 private:
66  Ext2Filesystem() = default;
67
68  // The ext2 main data structure holding the filesystem.
69  ext2_filsys filsys_ = nullptr;
70
71  // The file where the filesystem is stored.
72  std::string filename_;
73
74  DISALLOW_COPY_AND_ASSIGN(Ext2Filesystem);
75};
76
77}  // namespace chromeos_update_engine
78
79#endif  // UPDATE_ENGINE_PAYLOAD_GENERATOR_EXT2_FILESYSTEM_H_
80