IdleMaint.cpp - SHIFTPHONES/android_system_vold - Gitiles

 /*
  * 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 "IdleMaint.h"
 #include "FileDeviceUtils.h"
 #include "Utils.h"
 #include "VolumeManager.h"
 #include "model/PrivateVolume.h"

 #include <thread>

 #include <android-base/chrono_utils.h>
 #include <android-base/file.h>
 #include <android-base/logging.h>
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>
 #include <android/hardware/health/storage/1.0/IStorage.h>
 #include <fs_mgr.h>
 #include <hardware_legacy/power.h>
 #include <private/android_filesystem_config.h>

 #include <dirent.h>
 #include <fcntl.h>
 #include <sys/mount.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/wait.h>

 using android::base::Basename;
 using android::base::ReadFileToString;
 using android::base::Realpath;
 using android::base::StringPrintf;
 using android::base::Timer;
 using android::base::WriteStringToFile;
 using android::hardware::Return;
 using android::hardware::Void;
 using android::hardware::health::storage::V1_0::IStorage;
 using android::hardware::health::storage::V1_0::IGarbageCollectCallback;
 using android::hardware::health::storage::V1_0::Result;

 namespace android {
 namespace vold {

 enum class PathTypes {
     kMountPoint = 1,
     kBlkDevice,
 };

 enum class IdleMaintStats {
     kStopped = 1,
     kRunning,
     kAbort,
 };

 static const char* kWakeLock = "IdleMaint";
 static const int DIRTY_SEGMENTS_THRESHOLD = 100;
 /*
  * Timing policy:
  *  1. F2FS_GC = 7 mins
  *  2. Trim = 1 min
  *  3. Dev GC = 2 mins
  */
 static const int GC_TIMEOUT_SEC = 420;
 static const int DEVGC_TIMEOUT_SEC = 120;

 static IdleMaintStats idle_maint_stat(IdleMaintStats::kStopped);
 static std::condition_variable cv_abort, cv_stop;
 static std::mutex cv_m;

 static void addFromVolumeManager(std::list<std::string>* paths, PathTypes path_type) {
     VolumeManager* vm = VolumeManager::Instance();
     std::list<std::string> privateIds;
     vm->listVolumes(VolumeBase::Type::kPrivate, privateIds);
     for (const auto& id : privateIds) {
         PrivateVolume* vol = static_cast<PrivateVolume*>(vm->findVolume(id).get());
         if (vol != nullptr && vol->getState() == VolumeBase::State::kMounted) {
             if (path_type == PathTypes::kMountPoint) {
                 paths->push_back(vol->getPath());
             } else if (path_type == PathTypes::kBlkDevice) {
                 std::string gc_path;
                 const std::string& fs_type = vol->getFsType();
                 if (fs_type == "f2fs" && (Realpath(vol->getRawDmDevPath(), &gc_path) ||
                                           Realpath(vol->getRawDevPath(), &gc_path))) {
                     paths->push_back(std::string("/sys/fs/") + fs_type + "/" + Basename(gc_path));
                 }
             }
         }
     }
 }

 static void addFromFstab(std::list<std::string>* paths, PathTypes path_type) {
     std::unique_ptr<fstab, decltype(&fs_mgr_free_fstab)> fstab(fs_mgr_read_fstab_default(),
                                                                fs_mgr_free_fstab);
     struct fstab_rec* prev_rec = NULL;

     for (int i = 0; i < fstab->num_entries; i++) {
         auto fs_type = std::string(fstab->recs[i].fs_type);
         /* Skip raw partitions */
         if (fs_type == "emmc" || fs_type == "mtd") {
             continue;
         }
         /* Skip read-only filesystems */
         if (fstab->recs[i].flags & MS_RDONLY) {
             continue;
         }
         if (fs_mgr_is_voldmanaged(&fstab->recs[i])) {
             continue; /* Should we trim fat32 filesystems? */
         }
         if (fs_mgr_is_notrim(&fstab->recs[i])) {
             continue;
         }

         /* Skip the multi-type partitions, which are required to be following each other.
          * See fs_mgr.c's mount_with_alternatives().
          */
         if (prev_rec && !strcmp(prev_rec->mount_point, fstab->recs[i].mount_point)) {
             continue;
         }

         if (path_type == PathTypes::kMountPoint) {
             paths->push_back(fstab->recs[i].mount_point);
         } else if (path_type == PathTypes::kBlkDevice) {
             std::string gc_path;
             if (std::string(fstab->recs[i].fs_type) == "f2fs" &&
                 Realpath(
                     android::vold::BlockDeviceForPath(std::string(fstab->recs[i].mount_point) + "/"),
                     &gc_path)) {
                 paths->push_back(std::string("/sys/fs/") + fstab->recs[i].fs_type + "/" +
                                  Basename(gc_path));
             }
         }

         prev_rec = &fstab->recs[i];
     }
 }

 void Trim(const android::sp<android::os::IVoldTaskListener>& listener) {
     acquire_wake_lock(PARTIAL_WAKE_LOCK, kWakeLock);

     // Collect both fstab and vold volumes
     std::list<std::string> paths;
     addFromFstab(&paths, PathTypes::kMountPoint);
     addFromVolumeManager(&paths, PathTypes::kMountPoint);

     for (const auto& path : paths) {
         LOG(DEBUG) << "Starting trim of " << path;

         android::os::PersistableBundle extras;
         extras.putString(String16("path"), String16(path.c_str()));

         int fd = open(path.c_str(), O_RDONLY | O_DIRECTORY | O_CLOEXEC | O_NOFOLLOW);
         if (fd < 0) {
             PLOG(WARNING) << "Failed to open " << path;
             if (listener) {
                 listener->onStatus(-1, extras);
             }
             continue;
         }

         struct fstrim_range range;
         memset(&range, 0, sizeof(range));
         range.len = ULLONG_MAX;

         nsecs_t start = systemTime(SYSTEM_TIME_BOOTTIME);
         if (ioctl(fd, FITRIM, &range)) {
             PLOG(WARNING) << "Trim failed on " << path;
             if (listener) {
                 listener->onStatus(-1, extras);
             }
         } else {
             nsecs_t time = systemTime(SYSTEM_TIME_BOOTTIME) - start;
             LOG(INFO) << "Trimmed " << range.len << " bytes on " << path << " in "
                       << nanoseconds_to_milliseconds(time) << "ms";
             extras.putLong(String16("bytes"), range.len);
             extras.putLong(String16("time"), time);
             if (listener) {
                 listener->onStatus(0, extras);
             }
         }
         close(fd);
     }

     if (listener) {
         android::os::PersistableBundle extras;
         listener->onFinished(0, extras);
     }

     release_wake_lock(kWakeLock);
 }

 static bool waitForGc(const std::list<std::string>& paths) {
     std::unique_lock<std::mutex> lk(cv_m, std::defer_lock);
     bool stop = false, aborted = false;
     Timer timer;

     while (!stop && !aborted) {
         stop = true;
         for (const auto& path : paths) {
             std::string dirty_segments;
             if (!ReadFileToString(path + "/dirty_segments", &dirty_segments)) {
                 PLOG(WARNING) << "Reading dirty_segments failed in " << path;
                 continue;
             }
             if (std::stoi(dirty_segments) > DIRTY_SEGMENTS_THRESHOLD) {
                 stop = false;
                 break;
             }
         }

         if (stop) break;

         if (timer.duration() >= std::chrono::seconds(GC_TIMEOUT_SEC)) {
             LOG(WARNING) << "GC timeout";
             break;
         }

         lk.lock();
         aborted =
             cv_abort.wait_for(lk, 10s, [] { return idle_maint_stat == IdleMaintStats::kAbort; });
         lk.unlock();
     }

     return aborted;
 }

 static int startGc(const std::list<std::string>& paths) {
     for (const auto& path : paths) {
         LOG(DEBUG) << "Start GC on " << path;
         if (!WriteStringToFile("1", path + "/discard_granularity")) {
             PLOG(WARNING) << "Set discard gralunarity failed on" << path;
         }
         if (!WriteStringToFile("1", path + "/gc_urgent")) {
             PLOG(WARNING) << "Start GC failed on " << path;
         }
     }
     return android::OK;
 }

 static int stopGc(const std::list<std::string>& paths) {
     for (const auto& path : paths) {
         LOG(DEBUG) << "Stop GC on " << path;
         if (!WriteStringToFile("0", path + "/gc_urgent")) {
             PLOG(WARNING) << "Stop GC failed on " << path;
         }
         if (!WriteStringToFile("16", path + "/discard_granularity")) {
             PLOG(WARNING) << "Set discard gralunarity failed on" << path;
         }
     }
     return android::OK;
 }

 static void runDevGcFstab(void) {
     std::unique_ptr<fstab, decltype(&fs_mgr_free_fstab)> fstab(fs_mgr_read_fstab_default(),
                                                                fs_mgr_free_fstab);
     struct fstab_rec* rec = NULL;

     for (int i = 0; i < fstab->num_entries; i++) {
         if (fs_mgr_has_sysfs_path(&fstab->recs[i])) {
             rec = &fstab->recs[i];
             break;
         }
     }
     if (!rec) {
         return;
     }

     std::string path;
     path.append(rec->sysfs_path);
     path = path + "/manual_gc";
     Timer timer;

     LOG(DEBUG) << "Start Dev GC on " << path;
     while (1) {
         std::string require;
         if (!ReadFileToString(path, &require)) {
             PLOG(WARNING) << "Reading manual_gc failed in " << path;
             break;
         }
         require = android::base::Trim(require);
         if (require == "" || require == "off" || require == "disabled") {
             LOG(DEBUG) << "No more to do Dev GC";
             break;
         }

         LOG(DEBUG) << "Trigger Dev GC on " << path;
         if (!WriteStringToFile("1", path)) {
             PLOG(WARNING) << "Start Dev GC failed on " << path;
             break;
         }

         if (timer.duration() >= std::chrono::seconds(DEVGC_TIMEOUT_SEC)) {
             LOG(WARNING) << "Dev GC timeout";
             break;
         }
         sleep(2);
     }
     LOG(DEBUG) << "Stop Dev GC on " << path;
     if (!WriteStringToFile("0", path)) {
         PLOG(WARNING) << "Stop Dev GC failed on " << path;
     }
     return;
 }

 class GcCallback : public IGarbageCollectCallback {
   public:
     Return<void> onFinish(Result result) override {
         std::unique_lock<std::mutex> lock(mMutex);
         mFinished = true;
         mResult = result;
         lock.unlock();
         mCv.notify_all();
         return Void();
     }
     void wait(uint64_t seconds) {
         std::unique_lock<std::mutex> lock(mMutex);
         mCv.wait_for(lock, std::chrono::seconds(seconds), [this] { return mFinished; });

         if (!mFinished) {
             LOG(WARNING) << "Dev GC on HAL timeout";
         } else if (mResult != Result::SUCCESS) {
             LOG(WARNING) << "Dev GC on HAL failed with " << toString(mResult);
         } else {
             LOG(INFO) << "Dev GC on HAL successful";
         }
     }

   private:
     std::mutex mMutex;
     std::condition_variable mCv;
     bool mFinished{false};
     Result mResult{Result::UNKNOWN_ERROR};
 };

 static void runDevGcOnHal(sp<IStorage> service) {
     LOG(DEBUG) << "Start Dev GC on HAL";
     sp<GcCallback> cb = new GcCallback();
     auto ret = service->garbageCollect(DEVGC_TIMEOUT_SEC, cb);
     if (!ret.isOk()) {
         LOG(WARNING) << "Cannot start Dev GC on HAL: " << ret.description();
         return;
     }
     cb->wait(DEVGC_TIMEOUT_SEC);
 }

 static void runDevGc(void) {
     auto service = IStorage::getService();
     if (service != nullptr) {
         runDevGcOnHal(service);
     } else {
         // fallback to legacy code path
         runDevGcFstab();
     }
 }

 int RunIdleMaint(const android::sp<android::os::IVoldTaskListener>& listener) {
     std::unique_lock<std::mutex> lk(cv_m);
     if (idle_maint_stat != IdleMaintStats::kStopped) {
         LOG(DEBUG) << "idle maintenance is already running";
         if (listener) {
             android::os::PersistableBundle extras;
             listener->onFinished(0, extras);
         }
         return android::OK;
     }
     idle_maint_stat = IdleMaintStats::kRunning;
     lk.unlock();

     LOG(DEBUG) << "idle maintenance started";

     acquire_wake_lock(PARTIAL_WAKE_LOCK, kWakeLock);

     std::list<std::string> paths;
     addFromFstab(&paths, PathTypes::kBlkDevice);
     addFromVolumeManager(&paths, PathTypes::kBlkDevice);

     startGc(paths);

     bool gc_aborted = waitForGc(paths);

     stopGc(paths);

     lk.lock();
     idle_maint_stat = IdleMaintStats::kStopped;
     lk.unlock();

     cv_stop.notify_one();

     if (!gc_aborted) {
         Trim(nullptr);
         runDevGc();
     }

     if (listener) {
         android::os::PersistableBundle extras;
         listener->onFinished(0, extras);
     }

     LOG(DEBUG) << "idle maintenance completed";

     release_wake_lock(kWakeLock);

     return android::OK;
 }

 int AbortIdleMaint(const android::sp<android::os::IVoldTaskListener>& listener) {
     acquire_wake_lock(PARTIAL_WAKE_LOCK, kWakeLock);

     std::unique_lock<std::mutex> lk(cv_m);
     if (idle_maint_stat != IdleMaintStats::kStopped) {
         idle_maint_stat = IdleMaintStats::kAbort;
         lk.unlock();
         cv_abort.notify_one();
         lk.lock();
         LOG(DEBUG) << "aborting idle maintenance";
         cv_stop.wait(lk, [] { return idle_maint_stat == IdleMaintStats::kStopped; });
     }
     lk.unlock();

     if (listener) {
         android::os::PersistableBundle extras;
         listener->onFinished(0, extras);
     }

     release_wake_lock(kWakeLock);

     LOG(DEBUG) << "idle maintenance stopped";

     return android::OK;
 }

 }  // namespace vold
 }  // namespace android
	/*
	* 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 "IdleMaint.h"
	#include "FileDeviceUtils.h"
	#include "Utils.h"
	#include "VolumeManager.h"
	#include "model/PrivateVolume.h"

	#include <thread>

	#include <android-base/chrono_utils.h>
	#include <android-base/file.h>
	#include <android-base/logging.h>
	#include <android-base/stringprintf.h>
	#include <android-base/strings.h>
	#include <android/hardware/health/storage/1.0/IStorage.h>
	#include <fs_mgr.h>
	#include <hardware_legacy/power.h>
	#include <private/android_filesystem_config.h>

	#include <dirent.h>
	#include <fcntl.h>
	#include <sys/mount.h>
	#include <sys/stat.h>
	#include <sys/types.h>
	#include <sys/wait.h>

	using android::base::Basename;
	using android::base::ReadFileToString;
	using android::base::Realpath;
	using android::base::StringPrintf;
	using android::base::Timer;
	using android::base::WriteStringToFile;
	using android::hardware::Return;
	using android::hardware::Void;
	using android::hardware::health::storage::V1_0::IStorage;
	using android::hardware::health::storage::V1_0::IGarbageCollectCallback;
	using android::hardware::health::storage::V1_0::Result;

	namespace android {
	namespace vold {

	enum class PathTypes {
	kMountPoint = 1,
	kBlkDevice,
	};

	enum class IdleMaintStats {
	kStopped = 1,
	kRunning,
	kAbort,
	};

	static const char* kWakeLock = "IdleMaint";
	static const int DIRTY_SEGMENTS_THRESHOLD = 100;
	/*
	* Timing policy:
	* 1. F2FS_GC = 7 mins
	* 2. Trim = 1 min
	* 3. Dev GC = 2 mins
	*/
	static const int GC_TIMEOUT_SEC = 420;
	static const int DEVGC_TIMEOUT_SEC = 120;

	static IdleMaintStats idle_maint_stat(IdleMaintStats::kStopped);
	static std::condition_variable cv_abort, cv_stop;
	static std::mutex cv_m;

	static void addFromVolumeManager(std::list<std::string>* paths, PathTypes path_type) {
	VolumeManager* vm = VolumeManager::Instance();
	std::list<std::string> privateIds;
	vm->listVolumes(VolumeBase::Type::kPrivate, privateIds);
	for (const auto& id : privateIds) {
	PrivateVolume* vol = static_cast<PrivateVolume*>(vm->findVolume(id).get());
	if (vol != nullptr && vol->getState() == VolumeBase::State::kMounted) {
	if (path_type == PathTypes::kMountPoint) {
	paths->push_back(vol->getPath());
	} else if (path_type == PathTypes::kBlkDevice) {
	std::string gc_path;
	const std::string& fs_type = vol->getFsType();
	if (fs_type == "f2fs" && (Realpath(vol->getRawDmDevPath(), &gc_path) \|\|
	Realpath(vol->getRawDevPath(), &gc_path))) {
	paths->push_back(std::string("/sys/fs/") + fs_type + "/" + Basename(gc_path));
	}
	}
	}
	}
	}

	static void addFromFstab(std::list<std::string>* paths, PathTypes path_type) {
	std::unique_ptr<fstab, decltype(&fs_mgr_free_fstab)> fstab(fs_mgr_read_fstab_default(),
	fs_mgr_free_fstab);
	struct fstab_rec* prev_rec = NULL;

	for (int i = 0; i < fstab->num_entries; i++) {
	auto fs_type = std::string(fstab->recs[i].fs_type);
	/* Skip raw partitions */
	if (fs_type == "emmc" \|\| fs_type == "mtd") {
	continue;
	}
	/* Skip read-only filesystems */
	if (fstab->recs[i].flags & MS_RDONLY) {
	continue;
	}
	if (fs_mgr_is_voldmanaged(&fstab->recs[i])) {
	continue; /* Should we trim fat32 filesystems? */
	}
	if (fs_mgr_is_notrim(&fstab->recs[i])) {
	continue;
	}

	/* Skip the multi-type partitions, which are required to be following each other.
	* See fs_mgr.c's mount_with_alternatives().
	*/
	if (prev_rec && !strcmp(prev_rec->mount_point, fstab->recs[i].mount_point)) {
	continue;
	}

	if (path_type == PathTypes::kMountPoint) {
	paths->push_back(fstab->recs[i].mount_point);
	} else if (path_type == PathTypes::kBlkDevice) {
	std::string gc_path;
	if (std::string(fstab->recs[i].fs_type) == "f2fs" &&
	Realpath(
	android::vold::BlockDeviceForPath(std::string(fstab->recs[i].mount_point) + "/"),
	&gc_path)) {
	paths->push_back(std::string("/sys/fs/") + fstab->recs[i].fs_type + "/" +
	Basename(gc_path));
	}
	}

	prev_rec = &fstab->recs[i];
	}
	}

	void Trim(const android::sp<android::os::IVoldTaskListener>& listener) {
	acquire_wake_lock(PARTIAL_WAKE_LOCK, kWakeLock);

	// Collect both fstab and vold volumes
	std::list<std::string> paths;
	addFromFstab(&paths, PathTypes::kMountPoint);
	addFromVolumeManager(&paths, PathTypes::kMountPoint);

	for (const auto& path : paths) {
	LOG(DEBUG) << "Starting trim of " << path;

	android::os::PersistableBundle extras;
	extras.putString(String16("path"), String16(path.c_str()));

	int fd = open(path.c_str(), O_RDONLY \| O_DIRECTORY \| O_CLOEXEC \| O_NOFOLLOW);
	if (fd < 0) {
	PLOG(WARNING) << "Failed to open " << path;
	if (listener) {
	listener->onStatus(-1, extras);
	}
	continue;
	}

	struct fstrim_range range;
	memset(&range, 0, sizeof(range));
	range.len = ULLONG_MAX;

	nsecs_t start = systemTime(SYSTEM_TIME_BOOTTIME);
	if (ioctl(fd, FITRIM, &range)) {
	PLOG(WARNING) << "Trim failed on " << path;
	if (listener) {
	listener->onStatus(-1, extras);
	}
	} else {
	nsecs_t time = systemTime(SYSTEM_TIME_BOOTTIME) - start;
	LOG(INFO) << "Trimmed " << range.len << " bytes on " << path << " in "
	<< nanoseconds_to_milliseconds(time) << "ms";
	extras.putLong(String16("bytes"), range.len);
	extras.putLong(String16("time"), time);
	if (listener) {
	listener->onStatus(0, extras);
	}
	}
	close(fd);
	}

	if (listener) {
	android::os::PersistableBundle extras;
	listener->onFinished(0, extras);
	}

	release_wake_lock(kWakeLock);
	}

	static bool waitForGc(const std::list<std::string>& paths) {
	std::unique_lock<std::mutex> lk(cv_m, std::defer_lock);
	bool stop = false, aborted = false;
	Timer timer;

	while (!stop && !aborted) {
	stop = true;
	for (const auto& path : paths) {
	std::string dirty_segments;
	if (!ReadFileToString(path + "/dirty_segments", &dirty_segments)) {
	PLOG(WARNING) << "Reading dirty_segments failed in " << path;
	continue;
	}
	if (std::stoi(dirty_segments) > DIRTY_SEGMENTS_THRESHOLD) {
	stop = false;
	break;
	}
	}

	if (stop) break;

	if (timer.duration() >= std::chrono::seconds(GC_TIMEOUT_SEC)) {
	LOG(WARNING) << "GC timeout";
	break;
	}

	lk.lock();
	aborted =
	cv_abort.wait_for(lk, 10s, [] { return idle_maint_stat == IdleMaintStats::kAbort; });
	lk.unlock();
	}

	return aborted;
	}

	static int startGc(const std::list<std::string>& paths) {
	for (const auto& path : paths) {
	LOG(DEBUG) << "Start GC on " << path;
	if (!WriteStringToFile("1", path + "/discard_granularity")) {
	PLOG(WARNING) << "Set discard gralunarity failed on" << path;
	}
	if (!WriteStringToFile("1", path + "/gc_urgent")) {
	PLOG(WARNING) << "Start GC failed on " << path;
	}
	}
	return android::OK;
	}

	static int stopGc(const std::list<std::string>& paths) {
	for (const auto& path : paths) {
	LOG(DEBUG) << "Stop GC on " << path;
	if (!WriteStringToFile("0", path + "/gc_urgent")) {
	PLOG(WARNING) << "Stop GC failed on " << path;
	}
	if (!WriteStringToFile("16", path + "/discard_granularity")) {
	PLOG(WARNING) << "Set discard gralunarity failed on" << path;
	}
	}
	return android::OK;
	}

	static void runDevGcFstab(void) {
	std::unique_ptr<fstab, decltype(&fs_mgr_free_fstab)> fstab(fs_mgr_read_fstab_default(),
	fs_mgr_free_fstab);
	struct fstab_rec* rec = NULL;

	for (int i = 0; i < fstab->num_entries; i++) {
	if (fs_mgr_has_sysfs_path(&fstab->recs[i])) {
	rec = &fstab->recs[i];
	break;
	}
	}
	if (!rec) {
	return;
	}

	std::string path;
	path.append(rec->sysfs_path);
	path = path + "/manual_gc";
	Timer timer;

	LOG(DEBUG) << "Start Dev GC on " << path;
	while (1) {
	std::string require;
	if (!ReadFileToString(path, &require)) {
	PLOG(WARNING) << "Reading manual_gc failed in " << path;
	break;
	}
	require = android::base::Trim(require);
	if (require == "" \|\| require == "off" \|\| require == "disabled") {
	LOG(DEBUG) << "No more to do Dev GC";
	break;
	}

	LOG(DEBUG) << "Trigger Dev GC on " << path;
	if (!WriteStringToFile("1", path)) {
	PLOG(WARNING) << "Start Dev GC failed on " << path;
	break;
	}

	if (timer.duration() >= std::chrono::seconds(DEVGC_TIMEOUT_SEC)) {
	LOG(WARNING) << "Dev GC timeout";
	break;
	}
	sleep(2);
	}
	LOG(DEBUG) << "Stop Dev GC on " << path;
	if (!WriteStringToFile("0", path)) {
	PLOG(WARNING) << "Stop Dev GC failed on " << path;
	}
	return;
	}

	class GcCallback : public IGarbageCollectCallback {
	public:
	Return<void> onFinish(Result result) override {
	std::unique_lock<std::mutex> lock(mMutex);
	mFinished = true;
	mResult = result;
	lock.unlock();
	mCv.notify_all();
	return Void();
	}
	void wait(uint64_t seconds) {
	std::unique_lock<std::mutex> lock(mMutex);
	mCv.wait_for(lock, std::chrono::seconds(seconds), [this] { return mFinished; });

	if (!mFinished) {
	LOG(WARNING) << "Dev GC on HAL timeout";
	} else if (mResult != Result::SUCCESS) {
	LOG(WARNING) << "Dev GC on HAL failed with " << toString(mResult);
	} else {
	LOG(INFO) << "Dev GC on HAL successful";
	}
	}

	private:
	std::mutex mMutex;
	std::condition_variable mCv;
	bool mFinished{false};
	Result mResult{Result::UNKNOWN_ERROR};
	};

	static void runDevGcOnHal(sp<IStorage> service) {
	LOG(DEBUG) << "Start Dev GC on HAL";
	sp<GcCallback> cb = new GcCallback();
	auto ret = service->garbageCollect(DEVGC_TIMEOUT_SEC, cb);
	if (!ret.isOk()) {
	LOG(WARNING) << "Cannot start Dev GC on HAL: " << ret.description();
	return;
	}
	cb->wait(DEVGC_TIMEOUT_SEC);
	}

	static void runDevGc(void) {
	auto service = IStorage::getService();
	if (service != nullptr) {
	runDevGcOnHal(service);
	} else {
	// fallback to legacy code path
	runDevGcFstab();
	}
	}

	int RunIdleMaint(const android::sp<android::os::IVoldTaskListener>& listener) {
	std::unique_lock<std::mutex> lk(cv_m);
	if (idle_maint_stat != IdleMaintStats::kStopped) {
	LOG(DEBUG) << "idle maintenance is already running";
	if (listener) {
	android::os::PersistableBundle extras;
	listener->onFinished(0, extras);
	}
	return android::OK;
	}
	idle_maint_stat = IdleMaintStats::kRunning;
	lk.unlock();

	LOG(DEBUG) << "idle maintenance started";

	acquire_wake_lock(PARTIAL_WAKE_LOCK, kWakeLock);

	std::list<std::string> paths;
	addFromFstab(&paths, PathTypes::kBlkDevice);
	addFromVolumeManager(&paths, PathTypes::kBlkDevice);

	startGc(paths);

	bool gc_aborted = waitForGc(paths);

	stopGc(paths);

	lk.lock();
	idle_maint_stat = IdleMaintStats::kStopped;
	lk.unlock();

	cv_stop.notify_one();

	if (!gc_aborted) {
	Trim(nullptr);
	runDevGc();
	}

	if (listener) {
	android::os::PersistableBundle extras;
	listener->onFinished(0, extras);
	}

	LOG(DEBUG) << "idle maintenance completed";

	release_wake_lock(kWakeLock);

	return android::OK;
	}

	int AbortIdleMaint(const android::sp<android::os::IVoldTaskListener>& listener) {
	acquire_wake_lock(PARTIAL_WAKE_LOCK, kWakeLock);

	std::unique_lock<std::mutex> lk(cv_m);
	if (idle_maint_stat != IdleMaintStats::kStopped) {
	idle_maint_stat = IdleMaintStats::kAbort;
	lk.unlock();
	cv_abort.notify_one();
	lk.lock();
	LOG(DEBUG) << "aborting idle maintenance";
	cv_stop.wait(lk, [] { return idle_maint_stat == IdleMaintStats::kStopped; });
	}
	lk.unlock();

	if (listener) {
	android::os::PersistableBundle extras;
	listener->onFinished(0, extras);
	}

	release_wake_lock(kWakeLock);

	LOG(DEBUG) << "idle maintenance stopped";

	return android::OK;
	}

	} // namespace vold
	} // namespace android