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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 "PrivateVolume.h"
#include "EmulatedVolume.h"
#include "Utils.h"
#include "VolumeEncryption.h"
#include "VolumeManager.h"
#include "fs/Ext4.h"
#include "fs/F2fs.h"
#include <android-base/logging.h>
#include <android-base/stringprintf.h>
#include <cutils/fs.h>
#include <libdm/dm.h>
#include <private/android_filesystem_config.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/mount.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/sysmacros.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <thread>
using android::base::StringPrintf;
using android::vold::IsVirtioBlkDevice;
namespace android {
namespace vold {
static const unsigned int kMajorBlockLoop = 7;
static const unsigned int kMajorBlockMmc = 179;
PrivateVolume::PrivateVolume(dev_t device, const KeyBuffer& keyRaw)
: VolumeBase(Type::kPrivate), mRawDevice(device), mKeyRaw(keyRaw) {
setId(StringPrintf("private:%u,%u", major(device), minor(device)));
mRawDevPath = StringPrintf("/dev/block/vold/%s", getId().c_str());
}
PrivateVolume::~PrivateVolume() {}
status_t PrivateVolume::readMetadata() {
status_t res = ReadMetadata(mDmDevPath, &mFsType, &mFsUuid, &mFsLabel);
auto listener = getListener();
if (listener) listener->onVolumeMetadataChanged(getId(), mFsType, mFsUuid, mFsLabel);
return res;
}
status_t PrivateVolume::doCreate() {
if (CreateDeviceNode(mRawDevPath, mRawDevice)) {
return -EIO;
}
// Recover from stale vold by tearing down any old mappings
auto& dm = dm::DeviceMapper::Instance();
// TODO(b/149396179) there appears to be a race somewhere in the system where trying
// to delete the device fails with EBUSY; for now, work around this by retrying.
bool ret;
int tries = 10;
while (tries-- > 0) {
ret = dm.DeleteDeviceIfExists(getId());
if (ret || errno != EBUSY) {
break;
}
PLOG(ERROR) << "Cannot remove dm device " << getId();
std::this_thread::sleep_for(std::chrono::milliseconds(100));
}
if (!ret) {
return -EIO;
}
// TODO: figure out better SELinux labels for private volumes
if (!setup_ext_volume(getId(), mRawDevPath, mKeyRaw, &mDmDevPath)) {
LOG(ERROR) << getId() << " failed to setup metadata encryption";
return -EIO;
}
return OK;
}
status_t PrivateVolume::doDestroy() {
auto& dm = dm::DeviceMapper::Instance();
// TODO(b/149396179) there appears to be a race somewhere in the system where trying
// to delete the device fails with EBUSY; for now, work around this by retrying.
bool ret;
int tries = 10;
while (tries-- > 0) {
ret = dm.DeleteDevice(getId());
if (ret || errno != EBUSY) {
break;
}
PLOG(ERROR) << "Cannot remove dm device " << getId();
std::this_thread::sleep_for(std::chrono::milliseconds(100));
}
if (!ret) {
return -EIO;
}
return DestroyDeviceNode(mRawDevPath);
}
status_t PrivateVolume::doMount() {
if (readMetadata()) {
LOG(ERROR) << getId() << " failed to read metadata";
return -EIO;
}
mPath = StringPrintf("/mnt/expand/%s", mFsUuid.c_str());
setPath(mPath);
if (PrepareDir(mPath, 0700, AID_ROOT, AID_ROOT)) {
PLOG(ERROR) << getId() << " failed to create mount point " << mPath;
return -EIO;
}
if (mFsType == "ext4") {
int res = ext4::Check(mDmDevPath, mPath);
if (res == 0 || res == 1) {
LOG(DEBUG) << getId() << " passed filesystem check";
} else {
PLOG(ERROR) << getId() << " failed filesystem check";
return -EIO;
}
if (ext4::Mount(mDmDevPath, mPath, false, false, true)) {
PLOG(ERROR) << getId() << " failed to mount";
return -EIO;
}
} else if (mFsType == "f2fs") {
int res = f2fs::Check(mDmDevPath);
if (res == 0) {
LOG(DEBUG) << getId() << " passed filesystem check";
} else {
PLOG(ERROR) << getId() << " failed filesystem check";
return -EIO;
}
if (f2fs::Mount(mDmDevPath, mPath)) {
PLOG(ERROR) << getId() << " failed to mount";
return -EIO;
}
} else {
LOG(ERROR) << getId() << " unsupported filesystem " << mFsType;
return -EIO;
}
RestoreconRecursive(mPath);
int attrs = 0;
if (!IsSdcardfsUsed()) attrs = FS_CASEFOLD_FL;
// Verify that common directories are ready to roll
if (PrepareDir(mPath + "/app", 0771, AID_SYSTEM, AID_SYSTEM) ||
PrepareDir(mPath + "/user", 0711, AID_SYSTEM, AID_SYSTEM) ||
PrepareDir(mPath + "/user_de", 0711, AID_SYSTEM, AID_SYSTEM) ||
PrepareDir(mPath + "/media", 0770, AID_MEDIA_RW, AID_MEDIA_RW, attrs) ||
PrepareDir(mPath + "/media/0", 0770, AID_MEDIA_RW, AID_MEDIA_RW) ||
PrepareDir(mPath + "/local", 0751, AID_ROOT, AID_ROOT) ||
PrepareDir(mPath + "/local/tmp", 0771, AID_SHELL, AID_SHELL)) {
PLOG(ERROR) << getId() << " failed to prepare";
return -EIO;
}
return OK;
}
void PrivateVolume::doPostMount() {
auto vol_manager = VolumeManager::Instance();
std::string mediaPath(mPath + "/media");
// Create a new emulated volume stacked above us for all added users, they will automatically
// be destroyed during unmount
for (userid_t user : vol_manager->getStartedUsers()) {
auto vol = std::shared_ptr<VolumeBase>(
new EmulatedVolume(mediaPath, mRawDevice, mFsUuid, user));
vol->setMountUserId(user);
addVolume(vol);
vol->create();
}
}
status_t PrivateVolume::doUnmount() {
ForceUnmount(mPath);
if (TEMP_FAILURE_RETRY(rmdir(mPath.c_str()))) {
PLOG(ERROR) << getId() << " failed to rmdir mount point " << mPath;
}
return OK;
}
status_t PrivateVolume::doFormat(const std::string& fsType) {
std::string resolvedFsType = fsType;
if (fsType == "auto") {
// For now, assume that all MMC devices are flash-based SD cards, and
// give everyone else ext4 because sysfs rotational isn't reliable.
// Additionally, prefer f2fs for loop-based devices
if ((major(mRawDevice) == kMajorBlockMmc ||
major(mRawDevice) == kMajorBlockLoop ||
IsVirtioBlkDevice(major(mRawDevice))) && f2fs::IsSupported()) {
resolvedFsType = "f2fs";
} else {
resolvedFsType = "ext4";
}
LOG(DEBUG) << "Resolved auto to " << resolvedFsType;
}
if (resolvedFsType == "ext4") {
// TODO: change reported mountpoint once we have better selinux support
if (ext4::Format(mDmDevPath, 0, "/data")) {
PLOG(ERROR) << getId() << " failed to format";
return -EIO;
}
} else if (resolvedFsType == "f2fs") {
if (f2fs::Format(mDmDevPath)) {
PLOG(ERROR) << getId() << " failed to format";
return -EIO;
}
} else {
LOG(ERROR) << getId() << " unsupported filesystem " << fsType;
return -EINVAL;
}
return OK;
}
} // namespace vold
} // namespace android