content: /*
   * Copyright (C) 2009 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.
   */
  
  package com.android.server;
  
  import android.content.BroadcastReceiver;
  import android.content.Context;
  import android.content.Intent;
  import android.content.pm.IPackageManager;
  import android.os.Build;
  import android.os.DropBoxManager;
  import android.os.Environment;
  import android.os.FileObserver;
  import android.os.FileUtils;
  import android.os.RecoverySystem;
  import android.os.RemoteException;
  import android.os.ServiceManager;
  import android.os.SystemProperties;
  import android.os.storage.StorageManager;
  import android.provider.Downloads;
  import android.text.TextUtils;
  import android.util.AtomicFile;
  import android.util.EventLog;
  import android.util.Slog;
  import android.util.StatsLog;
  import android.util.Xml;
  
  import com.android.internal.annotations.VisibleForTesting;
  import com.android.internal.logging.MetricsLogger;
  import com.android.internal.util.FastXmlSerializer;
  import com.android.internal.util.XmlUtils;
  import com.android.server.DropboxLogTags;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.FileNotFoundException;
  import java.nio.charset.StandardCharsets;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import org.xmlpull.v1.XmlPullParser;
  import org.xmlpull.v1.XmlPullParserException;
  import org.xmlpull.v1.XmlSerializer;
  
  /**
   * Performs a number of miscellaneous, non-system-critical actions
   * after the system has finished booting.
   */
  public class BootReceiver extends BroadcastReceiver {
      private static final String TAG = "BootReceiver";
  
      // Maximum size of a logged event (files get truncated if they're longer).
      // Give userdebug builds a larger max to capture extra debug, esp. for last_kmsg.
      private static final int LOG_SIZE =
          SystemProperties.getInt("ro.debuggable", 0) == 1 ? 98304 : 65536;
  
      private static final File TOMBSTONE_DIR = new File("/data/tombstones");
      private static final String TAG_TOMBSTONE = "SYSTEM_TOMBSTONE";
  
      // The pre-froyo package and class of the system updater, which
      // ran in the system process.  We need to remove its packages here
      // in order to clean up after a pre-froyo-to-froyo update.
      private static final String OLD_UPDATER_PACKAGE =
          "com.google.android.systemupdater";
      private static final String OLD_UPDATER_CLASS =
          "com.google.android.systemupdater.SystemUpdateReceiver";
  
      // Keep a reference to the observer so the finalizer doesn't disable it.
      private static FileObserver sTombstoneObserver = null;
  
      private static final String LOG_FILES_FILE = "log-files.xml";
      private static final AtomicFile sFile = new AtomicFile(new File(
              Environment.getDataSystemDirectory(), LOG_FILES_FILE), "log-files");
      private static final String LAST_HEADER_FILE = "last-header.txt";
      private static final File lastHeaderFile = new File(
              Environment.getDataSystemDirectory(), LAST_HEADER_FILE);
  
      // example: fs_stat,/dev/block/platform/soc/by-name/userdata,0x5
      private static final String FS_STAT_PATTERN = "fs_stat,[^,]*/([^/,]+),(0x[0-9a-fA-F]+)";
      private static final int FS_STAT_FS_FIXED = 0x400; // should match with fs_mgr.cpp:FsStatFlags
      private static final String FSCK_PASS_PATTERN = "Pass ([1-9]E?):";
      private static final String FSCK_TREE_OPTIMIZATION_PATTERN =
              "Inode [0-9]+ extent tree.*could be shorter";
      private static final String FSCK_FS_MODIFIED = "FILE SYSTEM WAS MODIFIED";
      // ro.boottime.init.mount_all. + postfix for mount_all duration
      private static final String[] MOUNT_DURATION_PROPS_POSTFIX =
              new String[] { "early", "default", "late" };
      // for reboot, fs shutdown time is recorded in last_kmsg.
      private static final String[] LAST_KMSG_FILES =
              new String[] { "/sys/fs/pstore/console-ramoops", "/proc/last_kmsg" };
      // first: fs shutdown time in ms, second: umount status defined in init/reboot.h
      private static final String LAST_SHUTDOWN_TIME_PATTERN =
              "powerctl_shutdown_time_ms:([0-9]+):([0-9]+)";
      private static final int UMOUNT_STATUS_NOT_AVAILABLE = 4; // should match with init/reboot.h
  
      // Location of file with metrics recorded during shutdown
      private static final String SHUTDOWN_METRICS_FILE = "/data/system/shutdown-metrics.txt";
  
      private static final String SHUTDOWN_TRON_METRICS_PREFIX = "shutdown_";
      private static final String METRIC_SYSTEM_SERVER = "shutdown_system_server";
      private static final String METRIC_SHUTDOWN_TIME_START = "begin_shutdown";
  
      @Override
      public void onReceive(final Context context, Intent intent) {
          // Log boot events in the background to avoid blocking the main thread with I/O
          new Thread() {
              @Override
              public void run() {
                  try {
                      logBootEvents(context);
                  } catch (Exception e) {
                      Slog.e(TAG, "Can't log boot events", e);
                  }
                  try {
                      boolean onlyCore = false;
                      try {
                          onlyCore = IPackageManager.Stub.asInterface(ServiceManager.getService(
                                  "package")).isOnlyCoreApps();
                      } catch (RemoteException e) {
                      }
                      if (!onlyCore) {
                          removeOldUpdatePackages(context);
                      }
                  } catch (Exception e) {
                      Slog.e(TAG, "Can't remove old update packages", e);
                  }
  
              }
          }.start();
      }
  
      private void removeOldUpdatePackages(Context context) {
          Downloads.removeAllDownloadsByPackage(context, OLD_UPDATER_PACKAGE, OLD_UPDATER_CLASS);
      }
  
      private String getPreviousBootHeaders() {
          try {
              return FileUtils.readTextFile(lastHeaderFile, 0, null);
          } catch (IOException e) {
              return null;
          }
      }
  
      private String getCurrentBootHeaders() throws IOException {
          return new StringBuilder(512)
              .append("Build: ").append(Build.FINGERPRINT).append("\n")
              .append("Hardware: ").append(Build.BOARD).append("\n")
              .append("Revision: ")
              .append(SystemProperties.get("ro.revision", "")).append("\n")
              .append("Bootloader: ").append(Build.BOOTLOADER).append("\n")
              .append("Radio: ").append(Build.getRadioVersion()).append("\n")
              .append("Kernel: ")
              .append(FileUtils.readTextFile(new File("/proc/version"), 1024, "...\n"))
              .append("\n").toString();
      }
  
  
      private String getBootHeadersToLogAndUpdate() throws IOException {
          final String oldHeaders = getPreviousBootHeaders();
          final String newHeaders = getCurrentBootHeaders();
  
          try {
              FileUtils.stringToFile(lastHeaderFile, newHeaders);
          } catch (IOException e) {
              Slog.e(TAG, "Error writing " + lastHeaderFile, e);
          }
  
          if (oldHeaders == null) {
              // If we failed to read the old headers, use the current headers
              // but note this in the headers so we know
              return "isPrevious: false\n" + newHeaders;
          }
  
          return "isPrevious: true\n" + oldHeaders;
      }
  
      private void logBootEvents(Context ctx) throws IOException {
          final DropBoxManager db = (DropBoxManager) ctx.getSystemService(Context.DROPBOX_SERVICE);
          final String headers = getBootHeadersToLogAndUpdate();
          final String bootReason = SystemProperties.get("ro.boot.bootreason", null);
  
          String recovery = RecoverySystem.handleAftermath(ctx);
          if (recovery != null && db != null) {
              db.addText("SYSTEM_RECOVERY_LOG", headers + recovery);
          }
  
          String lastKmsgFooter = "";
          if (bootReason != null) {
              lastKmsgFooter = new StringBuilder(512)
                  .append("\n")
                  .append("Boot info:\n")
                  .append("Last boot reason: ").append(bootReason).append("\n")
                  .toString();
          }
  
          HashMap<String, Long> timestamps = readTimestamps();
  
          if (SystemProperties.getLong("ro.runtime.firstboot", 0) == 0) {
              if (StorageManager.inCryptKeeperBounce()) {
                  // Encrypted, first boot to get PIN/pattern/password so data is tmpfs
                  // Don't set ro.runtime.firstboot so that we will do this again
                  // when data is properly mounted
              } else {
                  String now = Long.toString(System.currentTimeMillis());
                  SystemProperties.set("ro.runtime.firstboot", now);
              }
              if (db != null) db.addText("SYSTEM_BOOT", headers);
  
              // Negative sizes mean to take the *tail* of the file (see FileUtils.readTextFile())
              addFileWithFootersToDropBox(db, timestamps, headers, lastKmsgFooter,
                      "/proc/last_kmsg", -LOG_SIZE, "SYSTEM_LAST_KMSG");
              addFileWithFootersToDropBox(db, timestamps, headers, lastKmsgFooter,
                      "/sys/fs/pstore/console-ramoops", -LOG_SIZE, "SYSTEM_LAST_KMSG");
              addFileWithFootersToDropBox(db, timestamps, headers, lastKmsgFooter,
                      "/sys/fs/pstore/console-ramoops-0", -LOG_SIZE, "SYSTEM_LAST_KMSG");
              addFileToDropBox(db, timestamps, headers, "/cache/recovery/log", -LOG_SIZE,
                      "SYSTEM_RECOVERY_LOG");
              addFileToDropBox(db, timestamps, headers, "/cache/recovery/last_kmsg",
                      -LOG_SIZE, "SYSTEM_RECOVERY_KMSG");
              addAuditErrorsToDropBox(db, timestamps, headers, -LOG_SIZE, "SYSTEM_AUDIT");
          } else {
              if (db != null) db.addText("SYSTEM_RESTART", headers);
          }
          // log always available fs_stat last so that logcat collecting tools can wait until
          // fs_stat to get all file system metrics.
          logFsShutdownTime();
          logFsMountTime();
          addFsckErrorsToDropBoxAndLogFsStat(db, timestamps, headers, -LOG_SIZE, "SYSTEM_FSCK");
          logSystemServerShutdownTimeMetrics();
  
          // Scan existing tombstones (in case any new ones appeared)
          File[] tombstoneFiles = TOMBSTONE_DIR.listFiles();
          for (int i = 0; tombstoneFiles != null && i < tombstoneFiles.length; i++) {
              if (tombstoneFiles[i].isFile()) {
                  addFileToDropBox(db, timestamps, headers, tombstoneFiles[i].getPath(),
                          LOG_SIZE, "SYSTEM_TOMBSTONE");
              }
          }
  
          writeTimestamps(timestamps);
  
          // Start watching for new tombstone files; will record them as they occur.
          // This gets registered with the singleton file observer thread.
          sTombstoneObserver = new FileObserver(TOMBSTONE_DIR.getPath(), FileObserver.CREATE) {
              @Override
              public void onEvent(int event, String path) {
                  HashMap<String, Long> timestamps = readTimestamps();
                  try {
                      File file = new File(TOMBSTONE_DIR, path);
                      if (file.isFile() && file.getName().startsWith("tombstone_")) {
                          addFileToDropBox(db, timestamps, headers, file.getPath(), LOG_SIZE,
                                  TAG_TOMBSTONE);
                      }
                  } catch (IOException e) {
                      Slog.e(TAG, "Can't log tombstone", e);
                  }
                  writeTimestamps(timestamps);
              }
          };
  
          sTombstoneObserver.startWatching();
      }
  
      private static void addFileToDropBox(
              DropBoxManager db, HashMap<String, Long> timestamps,
              String headers, String filename, int maxSize, String tag) throws IOException {
          addFileWithFootersToDropBox(db, timestamps, headers, "", filename, maxSize, tag);
      }
  
      private static void addFileWithFootersToDropBox(
              DropBoxManager db, HashMap<String, Long> timestamps,
              String headers, String footers, String filename, int maxSize,
              String tag) throws IOException {
          if (db == null || !db.isTagEnabled(tag)) return;  // Logging disabled
  
          File file = new File(filename);
          long fileTime = file.lastModified();
          if (fileTime <= 0) return;  // File does not exist
  
          if (timestamps.containsKey(filename) && timestamps.get(filename) == fileTime) {
              return;  // Already logged this particular file
          }
  
          timestamps.put(filename, fileTime);
  
  
          String fileContents = FileUtils.readTextFile(file, maxSize, "[[TRUNCATED]]\n");
          String text = headers + fileContents + footers;
          // Create an additional report for system server native crashes, with a special tag.
          if (tag.equals(TAG_TOMBSTONE) && fileContents.contains(">>> system_server <<<")) {
              addTextToDropBox(db, "system_server_native_crash", text, filename, maxSize);
          }
          if (tag.equals(TAG_TOMBSTONE)) {
              StatsLog.write(StatsLog.TOMB_STONE_OCCURRED);
          }
          addTextToDropBox(db, tag, text, filename, maxSize);
      }
  
      private static void addTextToDropBox(DropBoxManager db, String tag, String text,
              String filename, int maxSize) {
          Slog.i(TAG, "Copying " + filename + " to DropBox (" + tag + ")");
          db.addText(tag, text);
          EventLog.writeEvent(DropboxLogTags.DROPBOX_FILE_COPY, filename, maxSize, tag);
      }
  
      private static void addAuditErrorsToDropBox(DropBoxManager db,
              HashMap<String, Long> timestamps, String headers, int maxSize, String tag)
              throws IOException {
          if (db == null || !db.isTagEnabled(tag)) return;  // Logging disabled
          Slog.i(TAG, "Copying audit failures to DropBox");
  
          File file = new File("/proc/last_kmsg");
          long fileTime = file.lastModified();
          if (fileTime <= 0) {
              file = new File("/sys/fs/pstore/console-ramoops");
              fileTime = file.lastModified();
              if (fileTime <= 0) {
                  file = new File("/sys/fs/pstore/console-ramoops-0");
                  fileTime = file.lastModified();
              }
          }
  
          if (fileTime <= 0) return;  // File does not exist
  
          if (timestamps.containsKey(tag) && timestamps.get(tag) == fileTime) {
              return;  // Already logged this particular file
          }
  
          timestamps.put(tag, fileTime);
  
          String log = FileUtils.readTextFile(file, maxSize, "[[TRUNCATED]]\n");
          StringBuilder sb = new StringBuilder();
          for (String line : log.split("\n")) {
              if (line.contains("audit")) {
                  sb.append(line + "\n");
              }
          }
          Slog.i(TAG, "Copied " + sb.toString().length() + " worth of audits to DropBox");
          db.addText(tag, headers + sb.toString());
      }
  
      private static void addFsckErrorsToDropBoxAndLogFsStat(DropBoxManager db,
              HashMap<String, Long> timestamps, String headers, int maxSize, String tag)
              throws IOException {
          boolean uploadEnabled = true;
          if (db == null || !db.isTagEnabled(tag)) {
              uploadEnabled = false;
          }
          boolean uploadNeeded = false;
          Slog.i(TAG, "Checking for fsck errors");
  
          File file = new File("/dev/fscklogs/log");
          long fileTime = file.lastModified();
          if (fileTime <= 0) return;  // File does not exist
  
          String log = FileUtils.readTextFile(file, maxSize, "[[TRUNCATED]]\n");
          Pattern pattern = Pattern.compile(FS_STAT_PATTERN);
          String lines[] = log.split("\n");
          int lineNumber = 0;
          int lastFsStatLineNumber = 0;
          for (String line : lines) { // should check all lines
              if (line.contains(FSCK_FS_MODIFIED)) {
                  uploadNeeded = true;
              } else if (line.contains("fs_stat")){
                  Matcher matcher = pattern.matcher(line);
                  if (matcher.find()) {
                      handleFsckFsStat(matcher, lines, lastFsStatLineNumber, lineNumber);
                      lastFsStatLineNumber = lineNumber;
                  } else {
                      Slog.w(TAG, "cannot parse fs_stat:" + line);
                  }
              }
              lineNumber++;
          }
  
          if (uploadEnabled && uploadNeeded ) {
              addFileToDropBox(db, timestamps, headers, "/dev/fscklogs/log", maxSize, tag);
          }
  
          // Remove the file so we don't re-upload if the runtime restarts.
          file.delete();
      }
  
      private static void logFsMountTime() {
          for (String propPostfix : MOUNT_DURATION_PROPS_POSTFIX) {
              int duration = SystemProperties.getInt("ro.boottime.init.mount_all." + propPostfix, 0);
              if (duration != 0) {
                  MetricsLogger.histogram(null, "boot_mount_all_duration_" + propPostfix, duration);
              }
          }
      }
  
      // TODO b/64815357 Move to bootstat.cpp and log AbsoluteRebootTime
      private static void logSystemServerShutdownTimeMetrics() {
          File metricsFile = new File(SHUTDOWN_METRICS_FILE);
          String metricsStr = null;
          if (metricsFile.exists()) {
              try {
                  metricsStr = FileUtils.readTextFile(metricsFile, 0, null);
              } catch (IOException e) {
                  Slog.e(TAG, "Problem reading " + metricsFile, e);
              }
          }
          if (!TextUtils.isEmpty(metricsStr)) {
              String reboot = null;
              String reason = null;
              String start_time = null;
              String duration = null;
              String[] array = metricsStr.split(",");
              for (String keyValueStr : array) {
                  String[] keyValue = keyValueStr.split(":");
                  if (keyValue.length != 2) {
                      Slog.e(TAG, "Wrong format of shutdown metrics - " + metricsStr);
                      continue;
                  }
                  // Ignore keys that are not indended for tron
                  if (keyValue[0].startsWith(SHUTDOWN_TRON_METRICS_PREFIX)) {
                      logTronShutdownMetric(keyValue[0], keyValue[1]);
                      if (keyValue[0].equals(METRIC_SYSTEM_SERVER)) {
                          duration = keyValue[1];
                      }
                  }
                  if (keyValue[0].equals("reboot")) {
                      reboot = keyValue[1];
                  } else if (keyValue[0].equals("reason")) {
                      reason = keyValue[1];
                  } else if (keyValue[0].equals(METRIC_SHUTDOWN_TIME_START)) {
                      start_time = keyValue[1];
                  }
              }
              logStatsdShutdownAtom(reboot, reason, start_time, duration);
          }
          metricsFile.delete();
      }
  
      private static void logTronShutdownMetric(String metricName, String valueStr) {
          int value;
          try {
              value = Integer.parseInt(valueStr);
          } catch (NumberFormatException e) {
              Slog.e(TAG, "Cannot parse metric " + metricName + " int value - " + valueStr);
              return;
          }
          if (value >= 0) {
              MetricsLogger.histogram(null, metricName, value);
          }
      }
  
      private static void logStatsdShutdownAtom(
              String rebootStr, String reasonStr, String startStr, String durationStr) {
          boolean reboot = false;
          String reason = "<EMPTY>";
          long start = 0;
          long duration = 0;
  
          if (rebootStr != null) {
              if (rebootStr.equals("y")) {
                  reboot = true;
              } else if (!rebootStr.equals("n")) {
                  Slog.e(TAG, "Unexpected value for reboot : " + rebootStr);
              }
          } else {
              Slog.e(TAG, "No value received for reboot");
          }
  
          if (reasonStr != null) {
              reason = reasonStr;
          } else {
              Slog.e(TAG, "No value received for shutdown reason");
          }
  
          if (startStr != null) {
              try {
                  start = Long.parseLong(startStr);
              } catch (NumberFormatException e) {
                  Slog.e(TAG, "Cannot parse shutdown start time: " + startStr);
              }
          } else {
              Slog.e(TAG, "No value received for shutdown start time");
          }
  
          if (durationStr != null) {
              try {
                  duration = Long.parseLong(durationStr);
              } catch (NumberFormatException e) {
                  Slog.e(TAG, "Cannot parse shutdown duration: " + startStr);
              }
          } else {
              Slog.e(TAG, "No value received for shutdown duration");
          }
  
          StatsLog.write(StatsLog.SHUTDOWN_SEQUENCE_REPORTED, reboot, reason, start, duration);
      }
  
      private static void logFsShutdownTime() {
          File f = null;
          for (String fileName : LAST_KMSG_FILES) {
              File file = new File(fileName);
              if (!file.exists()) continue;
              f = file;
              break;
          }
          if (f == null) { // no last_kmsg
              return;
          }
  
          final int maxReadSize = 16*1024;
          // last_kmsg can be very big, so only parse the last part
          String lines;
          try {
              lines = FileUtils.readTextFile(f, -maxReadSize, null);
          } catch (IOException e) {
              Slog.w(TAG, "cannot read last msg", e);
              return;
          }
          Pattern pattern = Pattern.compile(LAST_SHUTDOWN_TIME_PATTERN, Pattern.MULTILINE);
          Matcher matcher = pattern.matcher(lines);
          if (matcher.find()) {
              MetricsLogger.histogram(null, "boot_fs_shutdown_duration",
                      Integer.parseInt(matcher.group(1)));
              MetricsLogger.histogram(null, "boot_fs_shutdown_umount_stat",
                      Integer.parseInt(matcher.group(2)));
              Slog.i(TAG, "boot_fs_shutdown," + matcher.group(1) + "," + matcher.group(2));
          } else { // not found
              // This can happen when a device has too much kernel log after file system unmount
              // ,exceeding maxReadSize. And having that much kernel logging can affect overall
              // performance as well. So it is better to fix the kernel to reduce the amount of log.
              MetricsLogger.histogram(null, "boot_fs_shutdown_umount_stat",
                      UMOUNT_STATUS_NOT_AVAILABLE);
              Slog.w(TAG, "boot_fs_shutdown, string not found");
          }
      }
  
      /**
       * Fix fs_stat from e2fsck.
       * For now, only handle the case of quota warning caused by tree optimization. Clear fs fix
       * flag (=0x400) caused by that.
       *
       * @param partition partition name
       * @param statOrg original stat reported from e2fsck log
       * @param lines e2fsck logs broken down into lines
       * @param startLineNumber start line to parse
       * @param endLineNumber end line. exclusive.
       * @return updated fs_stat. For tree optimization, will clear bit 0x400.
       */
      @VisibleForTesting
      public static int fixFsckFsStat(String partition, int statOrg, String[] lines,
              int startLineNumber, int endLineNumber) {
          int stat = statOrg;
          if ((stat & FS_STAT_FS_FIXED) != 0) {
              // fs was fixed. should check if quota warning was caused by tree optimization.
              // This is not a real fix but optimization, so should not be counted as a fs fix.
              Pattern passPattern = Pattern.compile(FSCK_PASS_PATTERN);
              Pattern treeOptPattern = Pattern.compile(FSCK_TREE_OPTIMIZATION_PATTERN);
              String currentPass = "";
              boolean foundTreeOptimization = false;
              boolean foundQuotaFix = false;
              boolean foundTimestampAdjustment = false;
              boolean foundOtherFix = false;
              String otherFixLine = null;
              for (int i = startLineNumber; i < endLineNumber; i++) {
                  String line = lines[i];
                  if (line.contains(FSCK_FS_MODIFIED)) { // no need to parse above this
                      break;
                  } else if (line.startsWith("Pass ")) {
                      Matcher matcher = passPattern.matcher(line);
                      if (matcher.find()) {
                          currentPass = matcher.group(1);
                      }
                  } else if (line.startsWith("Inode ")) {
                      Matcher matcher = treeOptPattern.matcher(line);
                      if (matcher.find() && currentPass.equals("1")) {
                          foundTreeOptimization = true;
                          Slog.i(TAG, "fs_stat, partition:" + partition + " found tree optimization:"
                                  + line);
                      } else {
                          foundOtherFix = true;
                          otherFixLine = line;
                          break;
                      }
                  } else if (line.startsWith("[QUOTA WARNING]") && currentPass.equals("5")) {
                      Slog.i(TAG, "fs_stat, partition:" + partition + " found quota warning:"
                              + line);
                      foundQuotaFix = true;
                      if (!foundTreeOptimization) { // only quota warning, this is real fix.
                          otherFixLine = line;
                          break;
                      }
                  } else if (line.startsWith("Update quota info") && currentPass.equals("5")) {
                      // follows "[QUOTA WARNING]", ignore
                  } else if (line.startsWith("Timestamp(s) on inode") &&
                          line.contains("beyond 2310-04-04 are likely pre-1970") &&
                          currentPass.equals("1")) {
                      Slog.i(TAG, "fs_stat, partition:" + partition + " found timestamp adjustment:"
                              + line);
                      // followed by next line, "Fix? yes"
                      if (lines[i + 1].contains("Fix? yes")) {
                          i++;
                      }
                      foundTimestampAdjustment = true;
                  } else {
                      line = line.trim();
                      // ignore empty msg or any msg before Pass 1
                      if (!line.isEmpty() && !currentPass.isEmpty()) {
                          foundOtherFix = true;
                          otherFixLine = line;
                          break;
                      }
                  }
              }
              if (foundOtherFix) {
                  if (otherFixLine != null) {
                      Slog.i(TAG, "fs_stat, partition:" + partition + " fix:" + otherFixLine);
                  }
              } else if (foundQuotaFix && !foundTreeOptimization) {
                  Slog.i(TAG, "fs_stat, got quota fix without tree optimization, partition:" +
                          partition);
              } else if ((foundTreeOptimization && foundQuotaFix) || foundTimestampAdjustment) {
                  // not a real fix, so clear it.
                  Slog.i(TAG, "fs_stat, partition:" + partition + " fix ignored");
                  stat &= ~FS_STAT_FS_FIXED;
              }
          }
          return stat;
      }
  
      private static void handleFsckFsStat(Matcher match, String[] lines, int startLineNumber,
              int endLineNumber) {
          String partition = match.group(1);
          int stat;
          try {
              stat = Integer.decode(match.group(2));
          } catch (NumberFormatException e) {
              Slog.w(TAG, "cannot parse fs_stat: partition:" + partition + " stat:" + match.group(2));
              return;
          }
          stat = fixFsckFsStat(partition, stat, lines, startLineNumber, endLineNumber);
          MetricsLogger.histogram(null, "boot_fs_stat_" + partition, stat);
          Slog.i(TAG, "fs_stat, partition:" + partition + " stat:0x" + Integer.toHexString(stat));
      }
  
      private static HashMap<String, Long> readTimestamps() {
          synchronized (sFile) {
              HashMap<String, Long> timestamps = new HashMap<String, Long>();
              boolean success = false;
              try (final FileInputStream stream = sFile.openRead()) {
                  XmlPullParser parser = Xml.newPullParser();
                  parser.setInput(stream, StandardCharsets.UTF_8.name());
  
                  int type;
                  while ((type = parser.next()) != XmlPullParser.START_TAG
                          && type != XmlPullParser.END_DOCUMENT) {
                      ;
                  }
  
                  if (type != XmlPullParser.START_TAG) {
                      throw new IllegalStateException("no start tag found");
                  }
  
                  int outerDepth = parser.getDepth();  // Skip the outer <log-files> tag.
                  while ((type = parser.next()) != XmlPullParser.END_DOCUMENT
                          && (type != XmlPullParser.END_TAG || parser.getDepth() > outerDepth)) {
                      if (type == XmlPullParser.END_TAG || type == XmlPullParser.TEXT) {
                          continue;
                      }
  
                      String tagName = parser.getName();
                      if (tagName.equals("log")) {
                          final String filename = parser.getAttributeValue(null, "filename");
                          final long timestamp = Long.valueOf(parser.getAttributeValue(
                                      null, "timestamp"));
                          timestamps.put(filename, timestamp);
                      } else {
                          Slog.w(TAG, "Unknown tag: " + parser.getName());
                          XmlUtils.skipCurrentTag(parser);
                      }
                  }
                  success = true;
              } catch (FileNotFoundException e) {
                  Slog.i(TAG, "No existing last log timestamp file " + sFile.getBaseFile() +
                          "; starting empty");
              } catch (IOException e) {
                  Slog.w(TAG, "Failed parsing " + e);
              } catch (IllegalStateException e) {
                  Slog.w(TAG, "Failed parsing " + e);
              } catch (NullPointerException e) {
                  Slog.w(TAG, "Failed parsing " + e);
              } catch (XmlPullParserException e) {
                  Slog.w(TAG, "Failed parsing " + e);
              } finally {
                  if (!success) {
                      timestamps.clear();
                  }
              }
              return timestamps;
          }
      }
  
      private void writeTimestamps(HashMap<String, Long> timestamps) {
          synchronized (sFile) {
              final FileOutputStream stream;
              try {
                  stream = sFile.startWrite();
              } catch (IOException e) {
                  Slog.w(TAG, "Failed to write timestamp file: " + e);
                  return;
              }
  
              try {
                  XmlSerializer out = new FastXmlSerializer();
                  out.setOutput(stream, StandardCharsets.UTF_8.name());
                  out.startDocument(null, true);
                  out.startTag(null, "log-files");
  
                  Iterator<String> itor = timestamps.keySet().iterator();
                  while (itor.hasNext()) {
                      String filename = itor.next();
                      out.startTag(null, "log");
                      out.attribute(null, "filename", filename);
                      out.attribute(null, "timestamp", timestamps.get(filename).toString());
                      out.endTag(null, "log");
                  }
  
                  out.endTag(null, "log-files");
                  out.endDocument();
  
                  sFile.finishWrite(stream);
              } catch (IOException e) {
                  Slog.w(TAG, "Failed to write timestamp file, using the backup: " + e);
                  sFile.failWrite(stream);
              }
          }
      }
  }
  