vold & storaged

storaged

源码目录：android/system/core/storaged

java 层

• StorageManager
• StorageManagerService
  • $Lifecycle#onStart()
    • mStorageManagerService = new StorageManagerService(getContext());
    • publishBinderService(“mount”, mStorageManagerService); # 真正的服务名 mount
    • mStorageManagerService.start();
  • #start() -> #connect()
    • IBinder binder = ServiceManager.getService(“storaged”);
    • mStoraged = IStoraged.Stub.asInterface(binder);

native 层

• android/system/core/storaged/storaged.rc 文件

  1 2 3 4 5 6 7 8

  service storaged /system/bin/storaged class main capabilities DAC_READ_SEARCH priority 10 file /d/mmc0/mmc0:0001/ext_csd r writepid /dev/cpuset/system-background/tasks user root group package_info

• 入口：android/system/core/storaged/main.c
• 重要文件

  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

  $ tree storaged/ storaged/ ├── binder │   └── android │   └── os # java 层的 aidl 接口 │   ├── IStoraged.aidl │   └── storaged │   ├── IStoragedPrivate.aidl │   └── UidInfo.aidl ├── include │   ├── storaged.h # 定义了 storaged 在 native 层的服务名 static char const* getServiceName() { return "storaged"; } # 使用 dumpsys storaged 会报错 -> Can't find service: storaged │   ├── storaged_service.h ├── main.cpp # 主函数文件 ├── storaged.cpp ├── storaged.rc ├── storaged_service.cpp

vold

源码目录： android/system/vold/

java 层

• StorageManager
• StorageManagerService
  • $Lifecycle#onStart()
    • mStorageManagerService = new StorageManagerService(getContext());
    • publishBinderService(“mount”, mStorageManagerService); # 真正的服务名 mount
    • mStorageManagerService.start();
  • #start() -> #connect()
    • IBinder binder = ServiceManager.getService(“vold”);
    • mVold = IVold.Stub.asInterface(binder);

native层

• android/system/vold/vold.rc

  1 2 3 4 5 6 7 8

  service vold /system/bin/vold \ --blkid_context=u:r:blkid:s0 --blkid_untrusted_context=u:r:blkid_untrusted:s0 \ --fsck_context=u:r:fsck:s0 --fsck_untrusted_context=u:r:fsck_untrusted:s0 class core ioprio be 2 writepid /dev/cpuset/foreground/tasks shutdown critical group reserved_disk

• 入口: android/system/vold/main.cpp
• 重要文件

  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39

  ├── binder │   └── android │   └── os # java 层 aidl 接口 │   ├── IVold.aidl │   ├── IVoldListener.aidl │   └── IVoldTaskListener.aidl ├── fs │   ├── Exfat.cpp │   ├── Exfat.h │   ├── Ext4.cpp │   ├── Ext4.h │   ├── F2fs.cpp │   ├── F2fs.h │   ├── Ntfs.cpp │   ├── Ntfs.h │   ├── Vfat.cpp │   └── Vfat.h ├── main.cpp # 主函数文件 ├── model │   ├── Disk.cpp │   ├── Disk.h │   ├── EmulatedVolume.cpp │   ├── EmulatedVolume.h │   ├── ObbVolume.cpp │   ├── ObbVolume.h │   ├── PrivateVolume.cpp │   ├── PrivateVolume.h │   ├── PublicVolume.cpp │   ├── PublicVolume.h │   ├── VolumeBase.cpp │   └── VolumeBase.h ├── Process.cpp ├── Process.h ├── vdc.rc ├── VoldNativeService.cpp # native 层服务具体实现 ├── VoldNativeService.h # 定义 native 层服务的头文件 static char const* getServiceName() { return "vold"; } ├── vold.rc ├── VolumeManager.cpp ├── VolumeManager.h

其他

• 系统服务是通过 SystemServiceManager 通过反射创建实例对象的
  • 对象创建之后先注册（mServices.add(service)）后调用 onStart() 方法启动服务
• /system/etc/init/*.rc 文件定义了哪些服务是需要开机启动的
• MountService
• java 层的 Parcel 和 native 层 parcel 的区别与联系
• 系统权限定义
  • system/core/libcutils/include/private/android_filesystem_config.h