1 /* 2 * Copyright (C) 2008 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_VOLD_VOLUME_BASE_H 18 #define ANDROID_VOLD_VOLUME_BASE_H 19 20 #include "Utils.h" 21 22 #include <cutils/multiuser.h> 23 #include <utils/Errors.h> 24 25 #include <sys/types.h> 26 #include <list> 27 #include <string> 28 29 namespace android { 30 namespace vold { 31 32 /* 33 * Representation of a mounted volume ready for presentation. 34 * 35 * Various subclasses handle the different mounting prerequisites, such as 36 * encryption details, etc. Volumes can also be "stacked" above other 37 * volumes to help communicate dependencies. For example, an ASEC volume 38 * can be stacked on a vfat volume. 39 * 40 * Mounted volumes can be asked to manage bind mounts to present themselves 41 * to specific users on the device. 42 * 43 * When an unmount is requested, the volume recursively unmounts any stacked 44 * volumes and removes any bind mounts before finally unmounting itself. 45 */ 46 class VolumeBase { 47 public: 48 virtual ~VolumeBase(); 49 50 enum class Type { 51 kPublic = 0, 52 kPrivate, 53 kEmulated, 54 kAsec, 55 kObb, 56 }; 57 58 enum MountFlags { 59 /* Flag that volume is primary external storage */ 60 kPrimary = 1 << 0, 61 /* Flag that volume is visible to normal apps */ 62 kVisible = 1 << 1, 63 }; 64 65 enum class State { 66 kUnmounted = 0, 67 kChecking, 68 kMounted, 69 kMountedReadOnly, 70 kFormatting, 71 kEjecting, 72 kUnmountable, 73 kRemoved, 74 kBadRemoval, 75 }; 76 getId()77 const std::string& getId() { return mId; } getDiskId()78 const std::string& getDiskId() { return mDiskId; } getPartGuid()79 const std::string& getPartGuid() { return mPartGuid; } getType()80 Type getType() { return mType; } getMountFlags()81 int getMountFlags() { return mMountFlags; } getMountUserId()82 userid_t getMountUserId() { return mMountUserId; } getState()83 State getState() { return mState; } getPath()84 const std::string& getPath() { return mPath; } getInternalPath()85 const std::string& getInternalPath() { return mInternalPath; } 86 87 status_t setDiskId(const std::string& diskId); 88 status_t setPartGuid(const std::string& partGuid); 89 status_t setMountFlags(int mountFlags); 90 status_t setMountUserId(userid_t mountUserId); 91 status_t setSilent(bool silent); 92 93 void addVolume(const std::shared_ptr<VolumeBase>& volume); 94 void removeVolume(const std::shared_ptr<VolumeBase>& volume); 95 96 std::shared_ptr<VolumeBase> findVolume(const std::string& id); 97 98 status_t create(); 99 status_t destroy(); 100 status_t mount(); 101 status_t unmount(); 102 status_t format(const std::string& fsType); 103 104 protected: 105 explicit VolumeBase(Type type); 106 107 virtual status_t doCreate(); 108 virtual status_t doDestroy(); 109 virtual status_t doMount() = 0; 110 virtual status_t doUnmount() = 0; 111 virtual status_t doFormat(const std::string& fsType); 112 113 status_t setId(const std::string& id); 114 status_t setPath(const std::string& path); 115 status_t setInternalPath(const std::string& internalPath); 116 117 void notifyEvent(int msg); 118 void notifyEvent(int msg, const std::string& value); 119 120 private: 121 /* ID that uniquely references volume while alive */ 122 std::string mId; 123 /* ID that uniquely references parent disk while alive */ 124 std::string mDiskId; 125 /* Partition GUID of this volume */ 126 std::string mPartGuid; 127 /* Volume type */ 128 Type mType; 129 /* Flags used when mounting this volume */ 130 int mMountFlags; 131 /* User that owns this volume, otherwise -1 */ 132 userid_t mMountUserId; 133 /* Flag indicating object is created */ 134 bool mCreated; 135 /* Current state of volume */ 136 State mState; 137 /* Path to mounted volume */ 138 std::string mPath; 139 /* Path to internal backing storage */ 140 std::string mInternalPath; 141 /* Flag indicating that volume should emit no events */ 142 bool mSilent; 143 144 /* Volumes stacked on top of this volume */ 145 std::list<std::shared_ptr<VolumeBase>> mVolumes; 146 147 void setState(State state); 148 149 DISALLOW_COPY_AND_ASSIGN(VolumeBase); 150 }; 151 152 } // namespace vold 153 } // namespace android 154 155 #endif 156