init/reboot.cpp - platform/system/core - Gitiles

 /*
  * Copyright (C) 2017 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 "reboot.h"

 #include <dirent.h>
 #include <fcntl.h>
 #include <linux/fs.h>
 #include <mntent.h>
 #include <sys/capability.h>
 #include <sys/cdefs.h>
 #include <sys/ioctl.h>
 #include <sys/mount.h>
 #include <sys/reboot.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
 #include <sys/types.h>
 #include <sys/wait.h>

 #include <memory>
 #include <set>
 #include <thread>
 #include <vector>

 #include <android-base/chrono_utils.h>
 #include <android-base/file.h>
 #include <android-base/logging.h>
 #include <android-base/macros.h>
 #include <android-base/properties.h>
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>
 #include <android-base/unique_fd.h>
 #include <bootloader_message/bootloader_message.h>
 #include <cutils/android_reboot.h>
 #include <fs_mgr.h>
 #include <logwrap/logwrap.h>
 #include <private/android_filesystem_config.h>
 #include <selinux/selinux.h>

 #include "capabilities.h"
 #include "init.h"
 #include "property_service.h"
 #include "service.h"
 #include "sigchld_handler.h"

 using android::base::StringPrintf;
 using android::base::Timer;

 namespace android {
 namespace init {

 // represents umount status during reboot / shutdown.
 enum UmountStat {
     /* umount succeeded. */
     UMOUNT_STAT_SUCCESS = 0,
     /* umount was not run. */
     UMOUNT_STAT_SKIPPED = 1,
     /* umount failed with timeout. */
     UMOUNT_STAT_TIMEOUT = 2,
     /* could not run due to error */
     UMOUNT_STAT_ERROR = 3,
     /* not used by init but reserved for other part to use this to represent the
        the state where umount status before reboot is not found / available. */
     UMOUNT_STAT_NOT_AVAILABLE = 4,
 };

 // Utility for struct mntent
 class MountEntry {
   public:
     explicit MountEntry(const mntent& entry)
         : mnt_fsname_(entry.mnt_fsname),
           mnt_dir_(entry.mnt_dir),
           mnt_type_(entry.mnt_type),
           mnt_opts_(entry.mnt_opts) {}

     bool Umount() {
         int r = umount2(mnt_dir_.c_str(), 0);
         if (r == 0) {
             LOG(INFO) << "umounted " << mnt_fsname_ << ":" << mnt_dir_ << " opts " << mnt_opts_;
             return true;
         } else {
             PLOG(WARNING) << "cannot umount " << mnt_fsname_ << ":" << mnt_dir_ << " opts "
                           << mnt_opts_;
             return false;
         }
     }

     void DoFsck() {
         int st;
         if (IsF2Fs()) {
             const char* f2fs_argv[] = {
                 "/system/bin/fsck.f2fs", "-f", mnt_fsname_.c_str(),
             };
             android_fork_execvp_ext(arraysize(f2fs_argv), (char**)f2fs_argv, &st, true, LOG_KLOG,
                                     true, nullptr, nullptr, 0);
         } else if (IsExt4()) {
             const char* ext4_argv[] = {
                 "/system/bin/e2fsck", "-f", "-y", mnt_fsname_.c_str(),
             };
             android_fork_execvp_ext(arraysize(ext4_argv), (char**)ext4_argv, &st, true, LOG_KLOG,
                                     true, nullptr, nullptr, 0);
         }
     }

     static bool IsBlockDevice(const struct mntent& mntent) {
         return android::base::StartsWith(mntent.mnt_fsname, "/dev/block");
     }

     static bool IsEmulatedDevice(const struct mntent& mntent) {
         return android::base::StartsWith(mntent.mnt_fsname, "/data/");
     }

   private:
     bool IsF2Fs() const { return mnt_type_ == "f2fs"; }

     bool IsExt4() const { return mnt_type_ == "ext4"; }

     std::string mnt_fsname_;
     std::string mnt_dir_;
     std::string mnt_type_;
     std::string mnt_opts_;
 };

 // Turn off backlight while we are performing power down cleanup activities.
 static void TurnOffBacklight() {
     static constexpr char OFF[] = "0";

     android::base::WriteStringToFile(OFF, "/sys/class/leds/lcd-backlight/brightness");

     static const char backlightDir[] = "/sys/class/backlight";
     std::unique_ptr<DIR, int (*)(DIR*)> dir(opendir(backlightDir), closedir);
     if (!dir) {
         return;
     }

     struct dirent* dp;
     while ((dp = readdir(dir.get())) != nullptr) {
         if (((dp->d_type != DT_DIR) && (dp->d_type != DT_LNK)) || (dp->d_name[0] == '.')) {
             continue;
         }

         std::string fileName = StringPrintf("%s/%s/brightness", backlightDir, dp->d_name);
         android::base::WriteStringToFile(OFF, fileName);
     }
 }

 static void ShutdownVold() {
     const char* vdc_argv[] = {"/system/bin/vdc", "volume", "shutdown"};
     int status;
     android_fork_execvp_ext(arraysize(vdc_argv), (char**)vdc_argv, &status, true, LOG_KLOG, true,
                             nullptr, nullptr, 0);
 }

 static void LogShutdownTime(UmountStat stat, Timer* t) {
     LOG(WARNING) << "powerctl_shutdown_time_ms:" << std::to_string(t->duration().count()) << ":"
                  << stat;
 }

 bool IsRebootCapable() {
     if (!CAP_IS_SUPPORTED(CAP_SYS_BOOT)) {
         PLOG(WARNING) << "CAP_SYS_BOOT is not supported";
         return true;
     }

     ScopedCaps caps(cap_get_proc());
     if (!caps) {
         PLOG(WARNING) << "cap_get_proc() failed";
         return true;
     }

     cap_flag_value_t value = CAP_SET;
     if (cap_get_flag(caps.get(), CAP_SYS_BOOT, CAP_EFFECTIVE, &value) != 0) {
         PLOG(WARNING) << "cap_get_flag(CAP_SYS_BOOT, EFFECTIVE) failed";
         return true;
     }
     return value == CAP_SET;
 }

 void __attribute__((noreturn)) RebootSystem(unsigned int cmd, const std::string& rebootTarget) {
     LOG(INFO) << "Reboot ending, jumping to kernel";

     if (!IsRebootCapable()) {
         // On systems where init does not have the capability of rebooting the
         // device, just exit cleanly.
         exit(0);
     }

     switch (cmd) {
         case ANDROID_RB_POWEROFF:
             reboot(RB_POWER_OFF);
             break;

         case ANDROID_RB_RESTART2:
             syscall(__NR_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2,
                     LINUX_REBOOT_CMD_RESTART2, rebootTarget.c_str());
             break;

         case ANDROID_RB_THERMOFF:
             reboot(RB_POWER_OFF);
             break;
     }
     // In normal case, reboot should not return.
     PLOG(ERROR) << "reboot call returned";
     abort();
 }

 /* Find all read+write block devices and emulated devices in /proc/mounts
  * and add them to correpsponding list.
  */
 static bool FindPartitionsToUmount(std::vector<MountEntry>* blockDevPartitions,
                                    std::vector<MountEntry>* emulatedPartitions, bool dump) {
     std::unique_ptr<std::FILE, int (*)(std::FILE*)> fp(setmntent("/proc/mounts", "r"), endmntent);
     if (fp == nullptr) {
         PLOG(ERROR) << "Failed to open /proc/mounts";
         return false;
     }
     mntent* mentry;
     while ((mentry = getmntent(fp.get())) != nullptr) {
         if (dump) {
             LOG(INFO) << "mount entry " << mentry->mnt_fsname << ":" << mentry->mnt_dir << " opts "
                       << mentry->mnt_opts << " type " << mentry->mnt_type;
         } else if (MountEntry::IsBlockDevice(*mentry) && hasmntopt(mentry, "rw")) {
             std::string mount_dir(mentry->mnt_dir);
             // These are R/O partitions changed to R/W after adb remount.
             // Do not umount them as shutdown critical services may rely on them.
             if (mount_dir != "/" && mount_dir != "/system" && mount_dir != "/vendor" &&
                 mount_dir != "/oem") {
                 blockDevPartitions->emplace(blockDevPartitions->begin(), *mentry);
             }
         } else if (MountEntry::IsEmulatedDevice(*mentry)) {
             emulatedPartitions->emplace(emulatedPartitions->begin(), *mentry);
         }
     }
     return true;
 }

 static void DumpUmountDebuggingInfo(bool dump_all) {
     int status;
     if (!security_getenforce()) {
         LOG(INFO) << "Run lsof";
         const char* lsof_argv[] = {"/system/bin/lsof"};
         android_fork_execvp_ext(arraysize(lsof_argv), (char**)lsof_argv, &status, true, LOG_KLOG,
                                 true, nullptr, nullptr, 0);
     }
     FindPartitionsToUmount(nullptr, nullptr, true);
     if (dump_all) {
         // dump current tasks, this log can be lengthy, so only dump with dump_all
         android::base::WriteStringToFile("t", "/proc/sysrq-trigger");
     }
 }

 static UmountStat UmountPartitions(std::chrono::milliseconds timeout) {
     Timer t;
     /* data partition needs all pending writes to be completed and all emulated partitions
      * umounted.If the current waiting is not good enough, give
      * up and leave it to e2fsck after reboot to fix it.
      */
     while (true) {
         std::vector<MountEntry> block_devices;
         std::vector<MountEntry> emulated_devices;
         if (!FindPartitionsToUmount(&block_devices, &emulated_devices, false)) {
             return UMOUNT_STAT_ERROR;
         }
         if (block_devices.size() == 0) {
             return UMOUNT_STAT_SUCCESS;
         }
         bool unmount_done = true;
         if (emulated_devices.size() > 0) {
             unmount_done = std::all_of(emulated_devices.begin(), emulated_devices.end(),
                                        [](auto& entry) { return entry.Umount(); });
             if (unmount_done) {
                 sync();
             }
         }
         unmount_done = std::all_of(block_devices.begin(), block_devices.end(),
                                    [](auto& entry) { return entry.Umount(); }) &&
                        unmount_done;
         if (unmount_done) {
             return UMOUNT_STAT_SUCCESS;
         }
         if ((timeout < t.duration())) {  // try umount at least once
             return UMOUNT_STAT_TIMEOUT;
         }
         std::this_thread::sleep_for(100ms);
     }
 }

 static void KillAllProcesses() { android::base::WriteStringToFile("i", "/proc/sysrq-trigger"); }

 /* Try umounting all emulated file systems R/W block device cfile systems.
  * This will just try umount and give it up if it fails.
  * For fs like ext4, this is ok as file system will be marked as unclean shutdown
  * and necessary check can be done at the next reboot.
  * For safer shutdown, caller needs to make sure that
  * all processes / emulated partition for the target fs are all cleaned-up.
  *
  * return true when umount was successful. false when timed out.
  */
 static UmountStat TryUmountAndFsck(bool runFsck, std::chrono::milliseconds timeout) {
     Timer t;
     std::vector<MountEntry> block_devices;
     std::vector<MountEntry> emulated_devices;

     TurnOffBacklight();  // this part can take time. save power.

     if (runFsck && !FindPartitionsToUmount(&block_devices, &emulated_devices, false)) {
         return UMOUNT_STAT_ERROR;
     }

     UmountStat stat = UmountPartitions(timeout - t.duration());
     if (stat != UMOUNT_STAT_SUCCESS) {
         LOG(INFO) << "umount timeout, last resort, kill all and try";
         if (DUMP_ON_UMOUNT_FAILURE) DumpUmountDebuggingInfo(true);
         KillAllProcesses();
         // even if it succeeds, still it is timeout and do not run fsck with all processes killed
         UmountStat st = UmountPartitions(0ms);
         if ((st != UMOUNT_STAT_SUCCESS) && DUMP_ON_UMOUNT_FAILURE) DumpUmountDebuggingInfo(false);
     }

     if (stat == UMOUNT_STAT_SUCCESS && runFsck) {
         // fsck part is excluded from timeout check. It only runs for user initiated shutdown
         // and should not affect reboot time.
         for (auto& entry : block_devices) {
             entry.DoFsck();
         }
     }
     return stat;
 }

 void DoReboot(unsigned int cmd, const std::string& reason, const std::string& rebootTarget,
               bool runFsck) {
     Timer t;
     LOG(INFO) << "Reboot start, reason: " << reason << ", rebootTarget: " << rebootTarget;

     property_set(LAST_REBOOT_REASON_PROPERTY, reason.c_str());
     sync();

     bool is_thermal_shutdown = cmd == ANDROID_RB_THERMOFF;

     auto shutdown_timeout = 0ms;
     if (!SHUTDOWN_ZERO_TIMEOUT) {
         if (is_thermal_shutdown) {
             constexpr unsigned int thermal_shutdown_timeout = 1;
             shutdown_timeout = std::chrono::seconds(thermal_shutdown_timeout);
         } else {
             constexpr unsigned int shutdown_timeout_default = 6;
             auto shutdown_timeout_property = android::base::GetUintProperty(
                 "ro.build.shutdown_timeout", shutdown_timeout_default);
             shutdown_timeout = std::chrono::seconds(shutdown_timeout_property);
         }
     }
     LOG(INFO) << "Shutdown timeout: " << shutdown_timeout.count() << " ms";

     // keep debugging tools until non critical ones are all gone.
     const std::set<std::string> kill_after_apps{"tombstoned", "logd", "adbd"};
     // watchdogd is a vendor specific component but should be alive to complete shutdown safely.
     const std::set<std::string> to_starts{"watchdogd"};
     for (const auto& s : ServiceList::GetInstance()) {
         if (kill_after_apps.count(s->name())) {
             s->SetShutdownCritical();
         } else if (to_starts.count(s->name())) {
             if (auto result = s->Start(); !result) {
                 LOG(ERROR) << "Could not start shutdown 'to_start' service '" << s->name()
                            << "': " << result.error();
             }
             s->SetShutdownCritical();
         } else if (s->IsShutdownCritical()) {
             // Start shutdown critical service if not started.
             if (auto result = s->Start(); !result) {
                 LOG(ERROR) << "Could not start shutdown critical service '" << s->name()
                            << "': " << result.error();
             }
         }
     }

     Service* bootAnim = ServiceList::GetInstance().FindService("bootanim");
     Service* surfaceFlinger = ServiceList::GetInstance().FindService("surfaceflinger");
     if (bootAnim != nullptr && surfaceFlinger != nullptr && surfaceFlinger->IsRunning()) {
         // will not check animation class separately
         for (const auto& service : ServiceList::GetInstance()) {
             if (service->classnames().count("animation")) service->SetShutdownCritical();
         }
     }

     // optional shutdown step
     // 1. terminate all services except shutdown critical ones. wait for delay to finish
     if (shutdown_timeout > 0ms) {
         LOG(INFO) << "terminating init services";

         // Ask all services to terminate except shutdown critical ones.
         for (const auto& s : ServiceList::GetInstance().services_in_shutdown_order()) {
             if (!s->IsShutdownCritical()) s->Terminate();
         }

         int service_count = 0;
         // Only wait up to half of timeout here
         auto termination_wait_timeout = shutdown_timeout / 2;
         while (t.duration() < termination_wait_timeout) {
             ReapAnyOutstandingChildren();

             service_count = 0;
             for (const auto& s : ServiceList::GetInstance()) {
                 // Count the number of services running except shutdown critical.
                 // Exclude the console as it will ignore the SIGTERM signal
                 // and not exit.
                 // Note: SVC_CONSOLE actually means "requires console" but
                 // it is only used by the shell.
                 if (!s->IsShutdownCritical() && s->pid() != 0 && (s->flags() & SVC_CONSOLE) == 0) {
                     service_count++;
                 }
             }

             if (service_count == 0) {
                 // All terminable services terminated. We can exit early.
                 break;
             }

             // Wait a bit before recounting the number or running services.
             std::this_thread::sleep_for(50ms);
         }
         LOG(INFO) << "Terminating running services took " << t
                   << " with remaining services:" << service_count;
     }

     // minimum safety steps before restarting
     // 2. kill all services except ones that are necessary for the shutdown sequence.
     for (const auto& s : ServiceList::GetInstance().services_in_shutdown_order()) {
         if (!s->IsShutdownCritical()) s->Stop();
     }
     ReapAnyOutstandingChildren();

     // 3. send volume shutdown to vold
     Service* voldService = ServiceList::GetInstance().FindService("vold");
     if (voldService != nullptr && voldService->IsRunning()) {
         ShutdownVold();
         voldService->Stop();
     } else {
         LOG(INFO) << "vold not running, skipping vold shutdown";
     }
     // logcat stopped here
     for (const auto& s : ServiceList::GetInstance().services_in_shutdown_order()) {
         if (kill_after_apps.count(s->name())) s->Stop();
     }
     // 4. sync, try umount, and optionally run fsck for user shutdown
     sync();
     UmountStat stat = TryUmountAndFsck(runFsck, shutdown_timeout - t.duration());
     // Follow what linux shutdown is doing: one more sync with little bit delay
     sync();
     if (!is_thermal_shutdown) std::this_thread::sleep_for(100ms);
     LogShutdownTime(stat, &t);
     // Reboot regardless of umount status. If umount fails, fsck after reboot will fix it.
     RebootSystem(cmd, rebootTarget);
     abort();
 }

 bool HandlePowerctlMessage(const std::string& command) {
     unsigned int cmd = 0;
     std::vector<std::string> cmd_params = android::base::Split(command, ",");
     std::string reboot_target = "";
     bool run_fsck = false;
     bool command_invalid = false;

     if (cmd_params.size() > 3) {
         command_invalid = true;
     } else if (cmd_params[0] == "shutdown") {
         cmd = ANDROID_RB_POWEROFF;
         if (cmd_params.size() == 2) {
             if (cmd_params[1] == "userrequested") {
                 // The shutdown reason is PowerManager.SHUTDOWN_USER_REQUESTED.
                 // Run fsck once the file system is remounted in read-only mode.
                 run_fsck = true;
             } else if (cmd_params[1] == "thermal") {
                 // run_fsck is false to avoid delay
                 cmd = ANDROID_RB_THERMOFF;
             }
         }
     } else if (cmd_params[0] == "reboot") {
         cmd = ANDROID_RB_RESTART2;
         if (cmd_params.size() >= 2) {
             reboot_target = cmd_params[1];
             // When rebooting to the bootloader notify the bootloader writing
             // also the BCB.
             if (reboot_target == "bootloader") {
                 std::string err;
                 if (!write_reboot_bootloader(&err)) {
                     LOG(ERROR) << "reboot-bootloader: Error writing "
                                   "bootloader_message: "
                                << err;
                 }
             }
             // If there is an additional parameter, pass it along
             if ((cmd_params.size() == 3) && cmd_params[2].size()) {
                 reboot_target += "," + cmd_params[2];
             }
         }
     } else {
         command_invalid = true;
     }
     if (command_invalid) {
         LOG(ERROR) << "powerctl: unrecognized command '" << command << "'";
         return false;
     }

     LOG(INFO) << "Clear action queue and start shutdown trigger";
     ActionManager::GetInstance().ClearQueue();
     // Queue shutdown trigger first
     ActionManager::GetInstance().QueueEventTrigger("shutdown");
     // Queue built-in shutdown_done
     auto shutdown_handler = [cmd, command, reboot_target,
                              run_fsck](const std::vector<std::string>&) {
         DoReboot(cmd, command, reboot_target, run_fsck);
         return Success();
     };
     ActionManager::GetInstance().QueueBuiltinAction(shutdown_handler, "shutdown_done");

     // Skip wait for prop if it is in progress
     ResetWaitForProp();

     // Clear EXEC flag if there is one pending
     for (const auto& s : ServiceList::GetInstance()) {
         s->UnSetExec();
     }

     return true;
 }

 }  // namespace init
 }  // namespace android
	/*
	* Copyright (C) 2017 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 "reboot.h"

	#include <dirent.h>
	#include <fcntl.h>
	#include <linux/fs.h>
	#include <mntent.h>
	#include <sys/capability.h>
	#include <sys/cdefs.h>
	#include <sys/ioctl.h>
	#include <sys/mount.h>
	#include <sys/reboot.h>
	#include <sys/stat.h>
	#include <sys/syscall.h>
	#include <sys/types.h>
	#include <sys/wait.h>

	#include <memory>
	#include <set>
	#include <thread>
	#include <vector>

	#include <android-base/chrono_utils.h>
	#include <android-base/file.h>
	#include <android-base/logging.h>
	#include <android-base/macros.h>
	#include <android-base/properties.h>
	#include <android-base/stringprintf.h>
	#include <android-base/strings.h>
	#include <android-base/unique_fd.h>
	#include <bootloader_message/bootloader_message.h>
	#include <cutils/android_reboot.h>
	#include <fs_mgr.h>
	#include <logwrap/logwrap.h>
	#include <private/android_filesystem_config.h>
	#include <selinux/selinux.h>

	#include "capabilities.h"
	#include "init.h"
	#include "property_service.h"
	#include "service.h"
	#include "sigchld_handler.h"

	using android::base::StringPrintf;
	using android::base::Timer;

	namespace android {
	namespace init {

	// represents umount status during reboot / shutdown.
	enum UmountStat {
	/* umount succeeded. */
	UMOUNT_STAT_SUCCESS = 0,
	/* umount was not run. */
	UMOUNT_STAT_SKIPPED = 1,
	/* umount failed with timeout. */
	UMOUNT_STAT_TIMEOUT = 2,
	/* could not run due to error */
	UMOUNT_STAT_ERROR = 3,
	/* not used by init but reserved for other part to use this to represent the
	the state where umount status before reboot is not found / available. */
	UMOUNT_STAT_NOT_AVAILABLE = 4,
	};

	// Utility for struct mntent
	class MountEntry {
	public:
	explicit MountEntry(const mntent& entry)
	: mnt_fsname_(entry.mnt_fsname),
	mnt_dir_(entry.mnt_dir),
	mnt_type_(entry.mnt_type),
	mnt_opts_(entry.mnt_opts) {}

	bool Umount() {
	int r = umount2(mnt_dir_.c_str(), 0);
	if (r == 0) {
	LOG(INFO) << "umounted " << mnt_fsname_ << ":" << mnt_dir_ << " opts " << mnt_opts_;
	return true;
	} else {
	PLOG(WARNING) << "cannot umount " << mnt_fsname_ << ":" << mnt_dir_ << " opts "
	<< mnt_opts_;
	return false;
	}
	}

	void DoFsck() {
	int st;
	if (IsF2Fs()) {
	const char* f2fs_argv[] = {
	"/system/bin/fsck.f2fs", "-f", mnt_fsname_.c_str(),
	};
	android_fork_execvp_ext(arraysize(f2fs_argv), (char**)f2fs_argv, &st, true, LOG_KLOG,
	true, nullptr, nullptr, 0);
	} else if (IsExt4()) {
	const char* ext4_argv[] = {
	"/system/bin/e2fsck", "-f", "-y", mnt_fsname_.c_str(),
	};
	android_fork_execvp_ext(arraysize(ext4_argv), (char**)ext4_argv, &st, true, LOG_KLOG,
	true, nullptr, nullptr, 0);
	}
	}

	static bool IsBlockDevice(const struct mntent& mntent) {
	return android::base::StartsWith(mntent.mnt_fsname, "/dev/block");
	}

	static bool IsEmulatedDevice(const struct mntent& mntent) {
	return android::base::StartsWith(mntent.mnt_fsname, "/data/");
	}

	private:
	bool IsF2Fs() const { return mnt_type_ == "f2fs"; }

	bool IsExt4() const { return mnt_type_ == "ext4"; }

	std::string mnt_fsname_;
	std::string mnt_dir_;
	std::string mnt_type_;
	std::string mnt_opts_;
	};

	// Turn off backlight while we are performing power down cleanup activities.
	static void TurnOffBacklight() {
	static constexpr char OFF[] = "0";

	android::base::WriteStringToFile(OFF, "/sys/class/leds/lcd-backlight/brightness");

	static const char backlightDir[] = "/sys/class/backlight";
	std::unique_ptr<DIR, int ()(DIR)> dir(opendir(backlightDir), closedir);
	if (!dir) {
	return;
	}

	struct dirent* dp;
	while ((dp = readdir(dir.get())) != nullptr) {
	if (((dp->d_type != DT_DIR) && (dp->d_type != DT_LNK)) \|\| (dp->d_name[0] == '.')) {
	continue;
	}

	std::string fileName = StringPrintf("%s/%s/brightness", backlightDir, dp->d_name);
	android::base::WriteStringToFile(OFF, fileName);
	}
	}

	static void ShutdownVold() {
	const char* vdc_argv[] = {"/system/bin/vdc", "volume", "shutdown"};
	int status;
	android_fork_execvp_ext(arraysize(vdc_argv), (char**)vdc_argv, &status, true, LOG_KLOG, true,
	nullptr, nullptr, 0);
	}

	static void LogShutdownTime(UmountStat stat, Timer* t) {
	LOG(WARNING) << "powerctl_shutdown_time_ms:" << std::to_string(t->duration().count()) << ":"
	<< stat;
	}

	bool IsRebootCapable() {
	if (!CAP_IS_SUPPORTED(CAP_SYS_BOOT)) {
	PLOG(WARNING) << "CAP_SYS_BOOT is not supported";
	return true;
	}

	ScopedCaps caps(cap_get_proc());
	if (!caps) {
	PLOG(WARNING) << "cap_get_proc() failed";
	return true;
	}

	cap_flag_value_t value = CAP_SET;
	if (cap_get_flag(caps.get(), CAP_SYS_BOOT, CAP_EFFECTIVE, &value) != 0) {
	PLOG(WARNING) << "cap_get_flag(CAP_SYS_BOOT, EFFECTIVE) failed";
	return true;
	}
	return value == CAP_SET;
	}

	void __attribute__((noreturn)) RebootSystem(unsigned int cmd, const std::string& rebootTarget) {
	LOG(INFO) << "Reboot ending, jumping to kernel";

	if (!IsRebootCapable()) {
	// On systems where init does not have the capability of rebooting the
	// device, just exit cleanly.
	exit(0);
	}

	switch (cmd) {
	case ANDROID_RB_POWEROFF:
	reboot(RB_POWER_OFF);
	break;

	case ANDROID_RB_RESTART2:
	syscall(__NR_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2,
	LINUX_REBOOT_CMD_RESTART2, rebootTarget.c_str());
	break;

	case ANDROID_RB_THERMOFF:
	reboot(RB_POWER_OFF);
	break;
	}
	// In normal case, reboot should not return.
	PLOG(ERROR) << "reboot call returned";
	abort();
	}

	/* Find all read+write block devices and emulated devices in /proc/mounts
	* and add them to correpsponding list.
	*/
	static bool FindPartitionsToUmount(std::vector<MountEntry>* blockDevPartitions,
	std::vector<MountEntry>* emulatedPartitions, bool dump) {
	std::unique_ptr<std::FILE, int ()(std::FILE)> fp(setmntent("/proc/mounts", "r"), endmntent);
	if (fp == nullptr) {
	PLOG(ERROR) << "Failed to open /proc/mounts";
	return false;
	}
	mntent* mentry;
	while ((mentry = getmntent(fp.get())) != nullptr) {
	if (dump) {
	LOG(INFO) << "mount entry " << mentry->mnt_fsname << ":" << mentry->mnt_dir << " opts "
	<< mentry->mnt_opts << " type " << mentry->mnt_type;
	} else if (MountEntry::IsBlockDevice(*mentry) && hasmntopt(mentry, "rw")) {
	std::string mount_dir(mentry->mnt_dir);
	// These are R/O partitions changed to R/W after adb remount.
	// Do not umount them as shutdown critical services may rely on them.
	if (mount_dir != "/" && mount_dir != "/system" && mount_dir != "/vendor" &&
	mount_dir != "/oem") {
	blockDevPartitions->emplace(blockDevPartitions->begin(), *mentry);
	}
	} else if (MountEntry::IsEmulatedDevice(*mentry)) {
	emulatedPartitions->emplace(emulatedPartitions->begin(), *mentry);
	}
	}
	return true;
	}

	static void DumpUmountDebuggingInfo(bool dump_all) {
	int status;
	if (!security_getenforce()) {
	LOG(INFO) << "Run lsof";
	const char* lsof_argv[] = {"/system/bin/lsof"};
	android_fork_execvp_ext(arraysize(lsof_argv), (char**)lsof_argv, &status, true, LOG_KLOG,
	true, nullptr, nullptr, 0);
	}
	FindPartitionsToUmount(nullptr, nullptr, true);
	if (dump_all) {
	// dump current tasks, this log can be lengthy, so only dump with dump_all
	android::base::WriteStringToFile("t", "/proc/sysrq-trigger");
	}
	}

	static UmountStat UmountPartitions(std::chrono::milliseconds timeout) {
	Timer t;
	/* data partition needs all pending writes to be completed and all emulated partitions
	* umounted.If the current waiting is not good enough, give
	* up and leave it to e2fsck after reboot to fix it.
	*/
	while (true) {
	std::vector<MountEntry> block_devices;
	std::vector<MountEntry> emulated_devices;
	if (!FindPartitionsToUmount(&block_devices, &emulated_devices, false)) {
	return UMOUNT_STAT_ERROR;
	}
	if (block_devices.size() == 0) {
	return UMOUNT_STAT_SUCCESS;
	}
	bool unmount_done = true;
	if (emulated_devices.size() > 0) {
	unmount_done = std::all_of(emulated_devices.begin(), emulated_devices.end(),
	[](auto& entry) { return entry.Umount(); });
	if (unmount_done) {
	sync();
	}
	}
	unmount_done = std::all_of(block_devices.begin(), block_devices.end(),
	[](auto& entry) { return entry.Umount(); }) &&
	unmount_done;
	if (unmount_done) {
	return UMOUNT_STAT_SUCCESS;
	}
	if ((timeout < t.duration())) { // try umount at least once
	return UMOUNT_STAT_TIMEOUT;
	}
	std::this_thread::sleep_for(100ms);
	}
	}

	static void KillAllProcesses() { android::base::WriteStringToFile("i", "/proc/sysrq-trigger"); }

	/* Try umounting all emulated file systems R/W block device cfile systems.
	* This will just try umount and give it up if it fails.
	* For fs like ext4, this is ok as file system will be marked as unclean shutdown
	* and necessary check can be done at the next reboot.
	* For safer shutdown, caller needs to make sure that
	* all processes / emulated partition for the target fs are all cleaned-up.
	*
	* return true when umount was successful. false when timed out.
	*/
	static UmountStat TryUmountAndFsck(bool runFsck, std::chrono::milliseconds timeout) {
	Timer t;
	std::vector<MountEntry> block_devices;
	std::vector<MountEntry> emulated_devices;

	TurnOffBacklight(); // this part can take time. save power.

	if (runFsck && !FindPartitionsToUmount(&block_devices, &emulated_devices, false)) {
	return UMOUNT_STAT_ERROR;
	}

	UmountStat stat = UmountPartitions(timeout - t.duration());
	if (stat != UMOUNT_STAT_SUCCESS) {
	LOG(INFO) << "umount timeout, last resort, kill all and try";
	if (DUMP_ON_UMOUNT_FAILURE) DumpUmountDebuggingInfo(true);
	KillAllProcesses();
	// even if it succeeds, still it is timeout and do not run fsck with all processes killed
	UmountStat st = UmountPartitions(0ms);
	if ((st != UMOUNT_STAT_SUCCESS) && DUMP_ON_UMOUNT_FAILURE) DumpUmountDebuggingInfo(false);
	}

	if (stat == UMOUNT_STAT_SUCCESS && runFsck) {
	// fsck part is excluded from timeout check. It only runs for user initiated shutdown
	// and should not affect reboot time.
	for (auto& entry : block_devices) {
	entry.DoFsck();
	}
	}
	return stat;
	}

	void DoReboot(unsigned int cmd, const std::string& reason, const std::string& rebootTarget,
	bool runFsck) {
	Timer t;
	LOG(INFO) << "Reboot start, reason: " << reason << ", rebootTarget: " << rebootTarget;

	property_set(LAST_REBOOT_REASON_PROPERTY, reason.c_str());
	sync();

	bool is_thermal_shutdown = cmd == ANDROID_RB_THERMOFF;

	auto shutdown_timeout = 0ms;
	if (!SHUTDOWN_ZERO_TIMEOUT) {
	if (is_thermal_shutdown) {
	constexpr unsigned int thermal_shutdown_timeout = 1;
	shutdown_timeout = std::chrono::seconds(thermal_shutdown_timeout);
	} else {
	constexpr unsigned int shutdown_timeout_default = 6;
	auto shutdown_timeout_property = android::base::GetUintProperty(
	"ro.build.shutdown_timeout", shutdown_timeout_default);
	shutdown_timeout = std::chrono::seconds(shutdown_timeout_property);
	}
	}
	LOG(INFO) << "Shutdown timeout: " << shutdown_timeout.count() << " ms";

	// keep debugging tools until non critical ones are all gone.
	const std::set<std::string> kill_after_apps{"tombstoned", "logd", "adbd"};
	// watchdogd is a vendor specific component but should be alive to complete shutdown safely.
	const std::set<std::string> to_starts{"watchdogd"};
	for (const auto& s : ServiceList::GetInstance()) {
	if (kill_after_apps.count(s->name())) {
	s->SetShutdownCritical();
	} else if (to_starts.count(s->name())) {
	if (auto result = s->Start(); !result) {
	LOG(ERROR) << "Could not start shutdown 'to_start' service '" << s->name()
	<< "': " << result.error();
	}
	s->SetShutdownCritical();
	} else if (s->IsShutdownCritical()) {
	// Start shutdown critical service if not started.
	if (auto result = s->Start(); !result) {
	LOG(ERROR) << "Could not start shutdown critical service '" << s->name()
	<< "': " << result.error();
	}
	}
	}

	Service* bootAnim = ServiceList::GetInstance().FindService("bootanim");
	Service* surfaceFlinger = ServiceList::GetInstance().FindService("surfaceflinger");
	if (bootAnim != nullptr && surfaceFlinger != nullptr && surfaceFlinger->IsRunning()) {
	// will not check animation class separately
	for (const auto& service : ServiceList::GetInstance()) {
	if (service->classnames().count("animation")) service->SetShutdownCritical();
	}
	}

	// optional shutdown step
	// 1. terminate all services except shutdown critical ones. wait for delay to finish
	if (shutdown_timeout > 0ms) {
	LOG(INFO) << "terminating init services";

	// Ask all services to terminate except shutdown critical ones.
	for (const auto& s : ServiceList::GetInstance().services_in_shutdown_order()) {
	if (!s->IsShutdownCritical()) s->Terminate();
	}

	int service_count = 0;
	// Only wait up to half of timeout here
	auto termination_wait_timeout = shutdown_timeout / 2;
	while (t.duration() < termination_wait_timeout) {
	ReapAnyOutstandingChildren();

	service_count = 0;
	for (const auto& s : ServiceList::GetInstance()) {
	// Count the number of services running except shutdown critical.
	// Exclude the console as it will ignore the SIGTERM signal
	// and not exit.
	// Note: SVC_CONSOLE actually means "requires console" but
	// it is only used by the shell.
	if (!s->IsShutdownCritical() && s->pid() != 0 && (s->flags() & SVC_CONSOLE) == 0) {
	service_count++;
	}
	}

	if (service_count == 0) {
	// All terminable services terminated. We can exit early.
	break;
	}

	// Wait a bit before recounting the number or running services.
	std::this_thread::sleep_for(50ms);
	}
	LOG(INFO) << "Terminating running services took " << t
	<< " with remaining services:" << service_count;
	}

	// minimum safety steps before restarting
	// 2. kill all services except ones that are necessary for the shutdown sequence.
	for (const auto& s : ServiceList::GetInstance().services_in_shutdown_order()) {
	if (!s->IsShutdownCritical()) s->Stop();
	}
	ReapAnyOutstandingChildren();

	// 3. send volume shutdown to vold
	Service* voldService = ServiceList::GetInstance().FindService("vold");
	if (voldService != nullptr && voldService->IsRunning()) {
	ShutdownVold();
	voldService->Stop();
	} else {
	LOG(INFO) << "vold not running, skipping vold shutdown";
	}
	// logcat stopped here
	for (const auto& s : ServiceList::GetInstance().services_in_shutdown_order()) {
	if (kill_after_apps.count(s->name())) s->Stop();
	}
	// 4. sync, try umount, and optionally run fsck for user shutdown
	sync();
	UmountStat stat = TryUmountAndFsck(runFsck, shutdown_timeout - t.duration());
	// Follow what linux shutdown is doing: one more sync with little bit delay
	sync();
	if (!is_thermal_shutdown) std::this_thread::sleep_for(100ms);
	LogShutdownTime(stat, &t);
	// Reboot regardless of umount status. If umount fails, fsck after reboot will fix it.
	RebootSystem(cmd, rebootTarget);
	abort();
	}

	bool HandlePowerctlMessage(const std::string& command) {
	unsigned int cmd = 0;
	std::vector<std::string> cmd_params = android::base::Split(command, ",");
	std::string reboot_target = "";
	bool run_fsck = false;
	bool command_invalid = false;

	if (cmd_params.size() > 3) {
	command_invalid = true;
	} else if (cmd_params[0] == "shutdown") {
	cmd = ANDROID_RB_POWEROFF;
	if (cmd_params.size() == 2) {
	if (cmd_params[1] == "userrequested") {
	// The shutdown reason is PowerManager.SHUTDOWN_USER_REQUESTED.
	// Run fsck once the file system is remounted in read-only mode.
	run_fsck = true;
	} else if (cmd_params[1] == "thermal") {
	// run_fsck is false to avoid delay
	cmd = ANDROID_RB_THERMOFF;
	}
	}
	} else if (cmd_params[0] == "reboot") {
	cmd = ANDROID_RB_RESTART2;
	if (cmd_params.size() >= 2) {
	reboot_target = cmd_params[1];
	// When rebooting to the bootloader notify the bootloader writing
	// also the BCB.
	if (reboot_target == "bootloader") {
	std::string err;
	if (!write_reboot_bootloader(&err)) {
	LOG(ERROR) << "reboot-bootloader: Error writing "
	"bootloader_message: "
	<< err;
	}
	}
	// If there is an additional parameter, pass it along
	if ((cmd_params.size() == 3) && cmd_params[2].size()) {
	reboot_target += "," + cmd_params[2];
	}
	}
	} else {
	command_invalid = true;
	}
	if (command_invalid) {
	LOG(ERROR) << "powerctl: unrecognized command '" << command << "'";
	return false;
	}

	LOG(INFO) << "Clear action queue and start shutdown trigger";
	ActionManager::GetInstance().ClearQueue();
	// Queue shutdown trigger first
	ActionManager::GetInstance().QueueEventTrigger("shutdown");
	// Queue built-in shutdown_done
	auto shutdown_handler = [cmd, command, reboot_target,
	run_fsck](const std::vector<std::string>&) {
	DoReboot(cmd, command, reboot_target, run_fsck);
	return Success();
	};
	ActionManager::GetInstance().QueueBuiltinAction(shutdown_handler, "shutdown_done");

	// Skip wait for prop if it is in progress
	ResetWaitForProp();

	// Clear EXEC flag if there is one pending
	for (const auto& s : ServiceList::GetInstance()) {
	s->UnSetExec();
	}

	return true;
	}

	} // namespace init
	} // namespace android