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Add Android/data mounting along with obb mounting in vold

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We should mount Android/data also, not only Android/obb.

Test: After flag is enabled, AdoptableHostTest still pass.
Bug: 148049767
Change-Id: I26dc3756aa5843b85565495e9c2698130113f49a
This commit is contained in:
Ricky Wai 2020-02-20 16:10:01 +00:00
parent 07e64a4cea
commit d88e090098
3 changed files with 59 additions and 22 deletions
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75
VolumeManager.cpp
View file

@ -738,7 +738,7 @@ int VolumeManager::remountUid(uid_t uid, int32_t mountMode) {
forkAndRemountChild, &mountMode) ? 0 : -1;
}
// Bind mount obb dir for an app if necessary.
// Bind mount obb & data dir for an app if necessary.
// How it works:
// 1). Check if a pid is an app uid and not the FuseDaemon, if not then return.
// 2). Get the mounts for that pid.
@ -746,18 +746,18 @@ int VolumeManager::remountUid(uid_t uid, int32_t mountMode) {
// 4). Get all packages and uid mounted for jit profile. These packages are all packages with
// same uid or whitelisted apps.
// 5a). If there's no package, it means it's not a process running app data isolation, so
// just bind mount Android/obb dir.
// just bind mount Android/obb & Android/data dir.
// 5b). Otherwise, for each package, create obb dir if it's not created and bind mount it.
// TODO: Should we get some reliable data from system server instead of scanning /proc ?
static bool bindMountAppObbDir(uid_t uid, pid_t pid, int nsFd, const char* name, void* params) {
static bool bindMountAppDataObbDir(uid_t uid, pid_t pid, int nsFd, const char* name, void* params) {
if (uid < AID_APP_START || uid > AID_APP_END) {
return true;
}
if (android::vold::IsFuseDaemon(pid)) {
return true;
}
async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Start mounting obb for uid:%d, pid:%d", uid,
pid);
async_safe_format_log(ANDROID_LOG_ERROR, "vold",
"Start mounting obb and data for uid:%d, pid:%d", uid, pid);
userid_t userId = multiuser_get_user_id(uid);
if (setns(nsFd, CLONE_NEWNS) != 0) {
@ -782,6 +782,7 @@ static bool bindMountAppObbDir(uid_t uid, pid_t pid, int nsFd, const char* name,
}
// Check if obb directory is mounted, and get all packages of mounted app data directory.
// We only need to check obb directory and assume if obb is mounted, data is mounted also.
bool obb_mounted = false;
std::vector<std::string> pkg_name_list;
mntent* mentry;
@ -799,47 +800,70 @@ static bool bindMountAppObbDir(uid_t uid, pid_t pid, int nsFd, const char* name,
return true;
}
// Ensure obb parent directory exists
std::string obbSource;
std::string obbSource, dataSource;
if (IsFilesystemSupported("sdcardfs")) {
obbSource = StringPrintf("/mnt/runtime/default/emulated/%d/Android/obb", userId);
dataSource = StringPrintf("/mnt/runtime/default/emulated/%d/Android/data", userId);
} else {
obbSource = StringPrintf("/mnt/pass_through/%d/emulated/%d/Android/obb", userId, userId);
dataSource = StringPrintf("/mnt/pass_through/%d/emulated/%d/Android/data", userId, userId);
}
std::string obbTarget(StringPrintf("/storage/emulated/%d/Android/obb", userId));
std::string dataTarget(StringPrintf("/storage/emulated/%d/Android/data", userId));
// TODO: Review if these checks are still necessary
auto status = EnsureDirExists(obbSource, 0771, AID_MEDIA_RW, AID_MEDIA_RW);
if (status != OK) {
async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Failed to create dir %s %s",
obbSource.c_str(), strerror(-status));
return false;
}
status = EnsureDirExists(dataSource, 0771, AID_MEDIA_RW, AID_MEDIA_RW);
if (status != OK) {
async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Failed to create dir %s %s",
dataSource.c_str(), strerror(-status));
return false;
}
// It means app data isolation is not applied to this, so we can just bind the whole obb
// directory instead.
if (pkg_name_list.empty()) {
async_safe_format_log(ANDROID_LOG_INFO, "vold",
"Bind mounting whole obb directory for pid %d", pid);
status = BindMount(obbSource, obbTarget);
if (status != OK) {
"Bind mounting whole obb and data directory for pid %d", pid);
auto status1 = BindMount(obbSource, obbTarget);
// Still bind mount data even obb fails, just slower to access obb dir
auto status2 = BindMount(dataSource, dataTarget);
if (status1 != OK) {
async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Failed to mount %s %s %s",
obbSource.c_str(), obbTarget.c_str(), strerror(-status));
return false;
}
if (status2 != OK) {
async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Failed to mount %s %s %s",
dataSource.c_str(), dataTarget.c_str(), strerror(-status));
return false;
}
return true;
}
// Bind mount each app's obb directory
for (const auto& pkg_name : pkg_name_list) {
std::string appObbSource;
std::string appObbSource, appDataSource;
if (IsFilesystemSupported("sdcardfs")) {
appObbSource = StringPrintf("/mnt/runtime/default/emulated/%d/Android/obb/%s",
userId, pkg_name.c_str());
appDataSource = StringPrintf("/mnt/runtime/default/emulated/%d/Android/data/%s",
userId, pkg_name.c_str());
} else {
appObbSource = StringPrintf("/mnt/pass_through/%d/emulated/%d/Android/obb/%s",
userId, userId, pkg_name.c_str());
appDataSource = StringPrintf("/mnt/pass_through/%d/emulated/%d/Android/data/%s",
userId, userId, pkg_name.c_str());
}
std::string appObbTarget(StringPrintf("/storage/emulated/%d/Android/obb/%s",
userId, pkg_name.c_str()));
std::string appDataTarget(StringPrintf("/storage/emulated/%d/Android/data/%s",
userId, pkg_name.c_str()));
status = EnsureDirExists(appObbSource, 0770, uid, AID_MEDIA_RW);
if (status != OK) {
@ -847,24 +871,37 @@ static bool bindMountAppObbDir(uid_t uid, pid_t pid, int nsFd, const char* name,
appObbSource.c_str());
continue;
}
async_safe_format_log(ANDROID_LOG_INFO, "vold",
"Bind mounting app obb directory(%s) for pid %d", pkg_name.c_str(),
pid);
status = BindMount(appObbSource, appObbTarget);
status = EnsureDirExists(appDataSource, 0770, uid, AID_MEDIA_RW);
if (status != OK) {
async_safe_format_log(ANDROID_LOG_INFO, "vold", "Failed to ensure dir %s exists",
appDataSource.c_str());
continue;
}
async_safe_format_log(ANDROID_LOG_INFO, "vold",
"Bind mounting app obb and data directory(%s) for pid %d",
pkg_name.c_str(), pid);
auto status1 = BindMount(appObbSource, appObbTarget);
// Still bind mount data even obb fails, just slower to access obb dir
auto status2 = BindMount(appDataSource, appDataTarget);
if (status1 != OK) {
async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Failed to mount %s %s %s",
obbSource.c_str(), obbTarget.c_str(), strerror(-status));
continue;
}
if (status2 != OK) {
async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Failed to mount %s %s %s",
appDataSource.c_str(), appDataTarget.c_str(), strerror(-status));
continue;
}
}
return true;
}
int VolumeManager::remountAppObb(userid_t userId) {
int VolumeManager::remountAppStorageDirs(userid_t userId) {
if (!GetBoolProperty(android::vold::kPropFuse, false)) {
return 0;
}
LOG(INFO) << "Start remounting app obb";
LOG(INFO) << "Start remounting app obb and data";
pid_t child;
if (!(child = fork())) {
// Child process
@ -872,12 +909,12 @@ int VolumeManager::remountAppObb(userid_t userId) {
PLOG(FATAL) << "Cannot create daemon";
}
// TODO(149548518): Refactor the code so minimize the work after fork to prevent deadlock.
if (scanProcProcesses(0, userId, bindMountAppObbDir, nullptr)) {
if (scanProcProcesses(0, userId, bindMountAppDataObbDir, nullptr)) {
// As some forked zygote processes may not setuid and recognized as an app yet, sleep
// 3s and try again to catch 'em all.
usleep(3 * 1000 * 1000); // 3s
async_safe_format_log(ANDROID_LOG_ERROR, "vold", "Retry remounting app obb");
scanProcProcesses(0, userId, bindMountAppObbDir, nullptr);
scanProcProcesses(0, userId, bindMountAppDataObbDir, nullptr);
_exit(0);
} else {
_exit(1);

2
VolumeManager.h
View file

@ -118,7 +118,7 @@ class VolumeManager {
int setPrimary(const std::shared_ptr<android::vold::VolumeBase>& vol);
int remountUid(uid_t uid, int32_t remountMode);
int remountAppObb(userid_t userId);
int remountAppStorageDirs(userid_t userId);
bool addFuseMountedUser(userid_t userId);
bool removeFuseMountedUser(userid_t userId);

4
model/EmulatedVolume.cpp
View file

@ -127,7 +127,7 @@ status_t EmulatedVolume::mountFuseBindMounts() {
}
if (mAppDataIsolationEnabled) {
// Starting from now, fuse is running, and zygote will bind app obb data directory
// Starting from now, fuse is running, and zygote will bind app obb & data directory
if (!VolumeManager::Instance()->addFuseMountedUser(userId)) {
return UNKNOWN_ERROR;
}
@ -135,7 +135,7 @@ status_t EmulatedVolume::mountFuseBindMounts() {
// As all new processes created by zygote will bind app obb data directory, we just need
// to have a snapshot of all existing processes and see if any existing process needs to
// remount obb data directory.
VolumeManager::Instance()->remountAppObb(userId);
VolumeManager::Instance()->remountAppStorageDirs(userId);
}
return OK;