Setup Android/, Android/data and Android/obb dirs correctly.
Normally sdcardfs takes care of setting up these directories on-demand,
for example when an app requests its private data directory to be
created. On devices without sdcardfs however, we ourselves need to make
sure to setup the UID/GID of these directories correctly.
Introduce a new PrepareAndroidDirs() function which sets the dirs up
correctly. On devices without sdcardfs, that means:
Path UID GID mode
/Android media_rw media_rw 771
/Android/data media_rw ext_data_rw 771
/Android/obb media_rw ext_obb_rw 771
Bug: 146419093
Test: wipe Android/, reboot, with and without sdcardfs, verify
contents
Change-Id: I3a879089422c7fc449b6a3e6f1c4b386b86687a4
diff --git a/VolumeManager.cpp b/VolumeManager.cpp
index 3de89ab..e6d593a 100644
--- a/VolumeManager.cpp
+++ b/VolumeManager.cpp
@@ -81,7 +81,9 @@
using android::vold::CreateDir;
using android::vold::DeleteDirContents;
using android::vold::DeleteDirContentsAndDir;
-using android::vold::PrepareDirsFromRoot;
+using android::vold::IsFilesystemSupported;
+using android::vold::PrepareAndroidDirs;
+using android::vold::PrepareAppDirsFromRoot;
using android::vold::PrivateVolume;
using android::vold::Symlink;
using android::vold::Unlink;
@@ -822,6 +824,29 @@
return 0;
}
+static gid_t getAppDirGid(const std::string& appDir) {
+ // Create app-specific dirs with the correct UID/GID
+ gid_t gid = AID_MEDIA_RW;
+ if (!IsFilesystemSupported("sdcardfs")) {
+ if (appDir == android::vold::kAppDataDir) {
+ gid = AID_EXT_DATA_RW;
+ } else if (appDir == android::vold::kAppObbDir) {
+ gid = AID_EXT_OBB_RW;
+ } else if (appDir == android::vold::kAppMediaDir) {
+ gid = AID_MEDIA_RW;
+ } else {
+ gid = AID_MEDIA_RW;
+ }
+ }
+
+ return gid;
+}
+
+static bool isValidAppDirRoot(const std::string& appDirRoot) {
+ return appDirRoot == android::vold::kAppDataDir || appDirRoot == android::vold::kAppMediaDir ||
+ appDirRoot == android::vold::kAppObbDir;
+}
+
int VolumeManager::setupAppDir(const std::string& path, const std::string& appDirRoot,
int32_t appUid) {
// Only offer to create directories for paths managed by vold
@@ -868,14 +893,25 @@
const std::string lowerAppDirRoot =
volume->getInternalPath() + appDirRoot.substr(volume->getPath().length());
- // First create the root which holds app dirs, if needed.
- int ret = PrepareDirsFromRoot(lowerAppDirRoot, volume->getInternalPath(), 0771, AID_MEDIA_RW,
- AID_MEDIA_RW);
+ // Do some sanity checking on the app dir (relative from root)
+ const std::string volumeRoot = volume->getRootPath(); // eg /data/media/0
+
+ // eg, if lowerAppDirRoot = /data/media/0/Android/data, this is /Android/data
+ const std::string relativeAppRoot = lowerAppDirRoot.substr(volumeRoot.length());
+ if (!isValidAppDirRoot(relativeAppRoot)) {
+ LOG(ERROR) << path << " is not a valid application directory.";
+ return -EINVAL;
+ }
+
+ // Make sure the Android/ directories exist and are setup correctly
+ int ret = PrepareAndroidDirs(volumeRoot);
if (ret != 0) {
+ LOG(ERROR) << "Failed to prepare Android/ directories.";
return ret;
}
- // Then, create app-specific dirs with the correct UID/GID
- return PrepareDirsFromRoot(lowerPath, lowerAppDirRoot, 0770, appUid, AID_MEDIA_RW);
+
+ gid_t gid = getAppDirGid(relativeAppRoot);
+ return PrepareAppDirsFromRoot(lowerPath, lowerAppDirRoot, 0770, appUid, gid);
}
int VolumeManager::createObb(const std::string& sourcePath, const std::string& sourceKey,