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/*
* Copyright (C) 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "MoveStorage.h"
#include "Utils.h"
#include "VolumeManager.h"
#include <android-base/logging.h>
#include <android-base/properties.h>
#include <android-base/stringprintf.h>
#include <private/android_filesystem_config.h>
#include <wakelock/wakelock.h>
#include <thread>
#include <dirent.h>
#include <sys/wait.h>
#define CONSTRAIN(amount, low, high) \
((amount) < (low) ? (low) : ((amount) > (high) ? (high) : (amount)))
static const char* kPropBlockingExec = "persist.sys.blocking_exec";
using android::base::StringPrintf;
namespace android {
namespace vold {
// TODO: keep in sync with PackageManager
static const int kMoveSucceeded = -100;
static const int kMoveFailedInternalError = -6;
static const char* kCpPath = "/system/bin/cp";
static const char* kRmPath = "/system/bin/rm";
static const char* kWakeLock = "MoveTask";
static void notifyProgress(int progress,
const android::sp<android::os::IVoldTaskListener>& listener) {
if (listener) {
android::os::PersistableBundle extras;
listener->onStatus(progress, extras);
}
}
static bool pushBackContents(const std::string& path, std::vector<std::string>& cmd,
int searchLevels) {
if (searchLevels == 0) {
cmd.emplace_back(path);
return true;
}
auto dirp = std::unique_ptr<DIR, int (*)(DIR*)>(opendir(path.c_str()), closedir);
if (!dirp) {
PLOG(ERROR) << "Unable to open directory: " << path;
return false;
}
bool found = false;
struct dirent* ent;
while ((ent = readdir(dirp.get())) != NULL) {
if (IsDotOrDotDot(*ent)) continue;
auto subdir = path + "/" + ent->d_name;
found |= pushBackContents(subdir, cmd, searchLevels - 1);
}
return found;
}
static status_t execRm(const std::string& path, int startProgress, int stepProgress,
const android::sp<android::os::IVoldTaskListener>& listener) {
notifyProgress(startProgress, listener);
uint64_t expectedBytes = GetTreeBytes(path);
uint64_t startFreeBytes = GetFreeBytes(path);
std::vector<std::string> cmd;
cmd.push_back(kRmPath);
cmd.push_back("-f"); /* force: remove without confirmation, no error if it doesn't exist */
cmd.push_back("-R"); /* recursive: remove directory contents */
if (!pushBackContents(path, cmd, 2)) {
LOG(WARNING) << "No contents in " << path;
return OK;
}
if (android::base::GetBoolProperty(kPropBlockingExec, false)) {
return ForkExecvp(cmd);
}
pid_t pid = ForkExecvpAsync(cmd);
if (pid == -1) return -1;
int status;
while (true) {
if (waitpid(pid, &status, WNOHANG) == pid) {
if (WIFEXITED(status)) {
LOG(DEBUG) << "Finished rm with status " << WEXITSTATUS(status);
return (WEXITSTATUS(status) == 0) ? OK : -1;
} else {
break;
}
}
sleep(1);
uint64_t deltaFreeBytes = GetFreeBytes(path) - startFreeBytes;
notifyProgress(
startProgress +
CONSTRAIN((int)((deltaFreeBytes * stepProgress) / expectedBytes), 0, stepProgress),
listener);
}
return -1;
}
static status_t execCp(const std::string& fromPath, const std::string& toPath, int startProgress,
int stepProgress,
const android::sp<android::os::IVoldTaskListener>& listener) {
notifyProgress(startProgress, listener);
uint64_t expectedBytes = GetTreeBytes(fromPath);
uint64_t startFreeBytes = GetFreeBytes(toPath);
if (expectedBytes > startFreeBytes) {
LOG(ERROR) << "Data size " << expectedBytes << " is too large to fit in free space "
<< startFreeBytes;
return -1;
}
std::vector<std::string> cmd;
cmd.push_back(kCpPath);
cmd.push_back("-p"); /* preserve timestamps, ownership, and permissions */
cmd.push_back("-R"); /* recurse into subdirectories (DEST must be a directory) */
cmd.push_back("-P"); /* Do not follow symlinks [default] */
cmd.push_back("-d"); /* don't dereference symlinks */
if (!pushBackContents(fromPath, cmd, 1)) {
LOG(WARNING) << "No contents in " << fromPath;
return OK;
}
cmd.push_back(toPath.c_str());
if (android::base::GetBoolProperty(kPropBlockingExec, false)) {
return ForkExecvp(cmd);
}
pid_t pid = ForkExecvpAsync(cmd);
if (pid == -1) return -1;
int status;
while (true) {
if (waitpid(pid, &status, WNOHANG) == pid) {
if (WIFEXITED(status)) {
LOG(DEBUG) << "Finished cp with status " << WEXITSTATUS(status);
return (WEXITSTATUS(status) == 0) ? OK : -1;
} else {
break;
}
}
sleep(1);
uint64_t deltaFreeBytes = startFreeBytes - GetFreeBytes(toPath);
notifyProgress(
startProgress +
CONSTRAIN((int)((deltaFreeBytes * stepProgress) / expectedBytes), 0, stepProgress),
listener);
}
return -1;
}
static void bringOffline(const std::shared_ptr<VolumeBase>& vol) {
vol->destroy();
vol->setSilent(true);
vol->create();
vol->setMountFlags(0);
vol->mount();
}
static void bringOnline(const std::shared_ptr<VolumeBase>& vol) {
vol->destroy();
vol->setSilent(false);
vol->create();
}
static status_t moveStorageInternal(const std::shared_ptr<VolumeBase>& from,
const std::shared_ptr<VolumeBase>& to,
const android::sp<android::os::IVoldTaskListener>& listener) {
std::string fromPath;
std::string toPath;
// TODO: add support for public volumes
if (from->getType() != VolumeBase::Type::kEmulated) goto fail;
if (to->getType() != VolumeBase::Type::kEmulated) goto fail;
// Step 1: tear down volumes and mount silently without making
// visible to userspace apps
{
std::lock_guard<std::mutex> lock(VolumeManager::Instance()->getLock());
bringOffline(from);
bringOffline(to);
}
fromPath = from->getInternalPath();
toPath = to->getInternalPath();
// Step 2: clean up any stale data
if (execRm(toPath, 10, 10, listener) != OK) {
goto fail;
}
// Step 3: perform actual copy
if (execCp(fromPath, toPath, 20, 60, listener) != OK) {
goto copy_fail;
}
// NOTE: MountService watches for this magic value to know
// that move was successful
notifyProgress(82, listener);
{
std::lock_guard<std::mutex> lock(VolumeManager::Instance()->getLock());
bringOnline(from);
bringOnline(to);
}
// Step 4: clean up old data
if (execRm(fromPath, 85, 15, listener) != OK) {
goto fail;
}
notifyProgress(kMoveSucceeded, listener);
return OK;
copy_fail:
// if we failed to copy the data we should not leave it laying around
// in target location. Do not check return value, we can not do any
// useful anyway.
execRm(toPath, 80, 1, listener);
fail:
// clang-format off
{
std::lock_guard<std::mutex> lock(VolumeManager::Instance()->getLock());
bringOnline(from);
bringOnline(to);
}
// clang-format on
notifyProgress(kMoveFailedInternalError, listener);
return -1;
}
void MoveStorage(const std::shared_ptr<VolumeBase>& from, const std::shared_ptr<VolumeBase>& to,
const android::sp<android::os::IVoldTaskListener>& listener) {
auto wl = android::wakelock::WakeLock::tryGet(kWakeLock);
if (!wl.has_value()) {
return;
}
android::os::PersistableBundle extras;
status_t res = moveStorageInternal(from, to, listener);
if (listener) {
listener->onFinished(res, extras);
}
}
} // namespace vold
} // namespace android