diff --git a/init/reboot.cpp b/init/reboot.cpp
index 242750a..03ed55a 100644
--- a/init/reboot.cpp
+++ b/init/reboot.cpp
@@ -20,6 +20,7 @@
 #include <fcntl.h>
 #include <linux/fs.h>
 #include <mntent.h>
+#include <semaphore.h>
 #include <sys/capability.h>
 #include <sys/cdefs.h>
 #include <sys/ioctl.h>
@@ -89,12 +90,13 @@
           mnt_opts_(entry.mnt_opts) {}
 
     bool Umount(bool force) {
+        LOG(INFO) << "Unmounting " << mnt_fsname_ << ":" << mnt_dir_ << " opts " << mnt_opts_;
         int r = umount2(mnt_dir_.c_str(), force ? MNT_FORCE : 0);
         if (r == 0) {
-            LOG(INFO) << "umounted " << mnt_fsname_ << ":" << mnt_dir_ << " opts " << mnt_opts_;
+            LOG(INFO) << "Umounted " << mnt_fsname_ << ":" << mnt_dir_ << " opts " << mnt_opts_;
             return true;
         } else {
-            PLOG(WARNING) << "cannot umount " << mnt_fsname_ << ":" << mnt_dir_ << " opts "
+            PLOG(WARNING) << "Cannot umount " << mnt_fsname_ << ":" << mnt_dir_ << " opts "
                           << mnt_opts_;
             return false;
         }
@@ -328,39 +330,9 @@
     return stat;
 }
 
-void DoReboot(unsigned int cmd, const std::string& reason, const std::string& rebootTarget,
-              bool runFsck) {
+void RebootThread(unsigned int cmd, std::chrono::milliseconds shutdown_timeout, bool runFsck,
+                  sem_t* reboot_semaphore) {
     Timer t;
-    LOG(INFO) << "Reboot start, reason: " << reason << ", rebootTarget: " << rebootTarget;
-
-    // Ensure last reboot reason is reduced to canonical
-    // alias reported in bootloader or system boot reason.
-    size_t skip = 0;
-    std::vector<std::string> reasons = Split(reason, ",");
-    if (reasons.size() >= 2 && reasons[0] == "reboot" &&
-        (reasons[1] == "recovery" || reasons[1] == "bootloader" || reasons[1] == "cold" ||
-         reasons[1] == "hard" || reasons[1] == "warm")) {
-        skip = strlen("reboot,");
-    }
-    property_set(LAST_REBOOT_REASON_PROPERTY, reason.c_str() + skip);
-    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.
@@ -384,7 +356,7 @@
     }
 
     // remaining operations (specifically fsck) may take a substantial duration
-    if (cmd == ANDROID_RB_POWEROFF || is_thermal_shutdown) {
+    if (cmd == ANDROID_RB_POWEROFF || cmd == ANDROID_RB_THERMOFF) {
         TurnOffBacklight();
     }
 
@@ -461,8 +433,77 @@
     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);
+    if (cmd != ANDROID_RB_THERMOFF) std::this_thread::sleep_for(100ms);
     LogShutdownTime(stat, &t);
+
+    if (reboot_semaphore != nullptr) {
+        sem_post(reboot_semaphore);
+    }
+}
+
+void RunRebootThread(unsigned int cmd, std::chrono::milliseconds shutdown_timeout) {
+    sem_t reboot_semaphore;
+    timespec shutdown_timeout_timespec;
+
+    if (sem_init(&reboot_semaphore, false, 0) == -1 ||
+        clock_gettime(CLOCK_REALTIME, &shutdown_timeout_timespec) == -1) {
+        // These should never fail, but if they do, skip the graceful reboot and reboot immediately.
+        return;
+    }
+
+    std::thread reboot_thread(&RebootThread, cmd, shutdown_timeout, false, &reboot_semaphore);
+    reboot_thread.detach();
+
+    // One extra second than the timeout passed to the thread as there is a final Umount pass
+    // after the timeout is reached.
+    shutdown_timeout_timespec.tv_sec += 1 + shutdown_timeout.count() / 1000;
+
+    int sem_return = 0;
+    while ((sem_return = sem_timedwait(&reboot_semaphore, &shutdown_timeout_timespec)) == -1 &&
+           errno == EINTR) {
+    }
+
+    if (sem_return == -1) {
+        LOG(ERROR) << "Reboot thread timed out";
+    }
+}
+
+void DoReboot(unsigned int cmd, const std::string& reason, const std::string& rebootTarget,
+              bool runFsck) {
+    LOG(INFO) << "Reboot start, reason: " << reason << ", rebootTarget: " << rebootTarget;
+
+    // Ensure last reboot reason is reduced to canonical
+    // alias reported in bootloader or system boot reason.
+    size_t skip = 0;
+    std::vector<std::string> reasons = Split(reason, ",");
+    if (reasons.size() >= 2 && reasons[0] == "reboot" &&
+        (reasons[1] == "recovery" || reasons[1] == "bootloader" || reasons[1] == "cold" ||
+         reasons[1] == "hard" || reasons[1] == "warm")) {
+        skip = strlen("reboot,");
+    }
+    property_set(LAST_REBOOT_REASON_PROPERTY, reason.c_str() + skip);
+    sync();
+
+    auto shutdown_timeout = 0ms;
+    if (!SHUTDOWN_ZERO_TIMEOUT) {
+        if (cmd == ANDROID_RB_THERMOFF) {
+            constexpr auto kThermalShutdownTimeout = 1s;
+            shutdown_timeout = kThermalShutdownTimeout;
+        } else {
+            constexpr unsigned int kShutdownTimeoutDefault = 6;
+            auto shutdown_timeout_property = android::base::GetUintProperty(
+                "ro.build.shutdown_timeout", kShutdownTimeoutDefault);
+            shutdown_timeout = std::chrono::seconds(shutdown_timeout_property);
+        }
+    }
+    LOG(INFO) << "Shutdown timeout: " << shutdown_timeout.count() << " ms";
+
+    if (runFsck) {
+        RebootThread(cmd, shutdown_timeout, true, nullptr);
+    } else {
+        RunRebootThread(cmd, shutdown_timeout);
+    }
+
     // Reboot regardless of umount status. If umount fails, fsck after reboot will fix it.
     RebootSystem(cmd, rebootTarget);
     abort();