From 8c00e42f20edbfb6108b9544c1bc80476a6a427a Mon Sep 17 00:00:00 2001
From: Wei Wang <wvw@google.com>
Date: Wed, 16 Aug 2017 14:01:46 -0700
Subject: [PATCH] Skip unnecessary sleep during shutdown

Skip sleep if timeout is zero
Skip sleep if first pass umount succeed

Bug: 64768138
Test: reboot
Change-Id: I5ef731611320ade51974b414f7e47520ce36b287
---
 init/reboot.cpp | 30 +++++++++++++++---------------
 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/init/reboot.cpp b/init/reboot.cpp
index 24ccdfc6a..4d580f2ad 100644
--- a/init/reboot.cpp
+++ b/init/reboot.cpp
@@ -267,8 +267,6 @@ static void DumpUmountDebuggingInfo(bool dump_all) {
 
 static UmountStat UmountPartitions(std::chrono::milliseconds timeout) {
     Timer t;
-    UmountStat stat = UMOUNT_STAT_TIMEOUT;
-    int retry = 0;
     /* 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.
@@ -280,25 +278,27 @@ static UmountStat UmountPartitions(std::chrono::milliseconds timeout) {
             return UMOUNT_STAT_ERROR;
         }
         if (block_devices.size() == 0) {
-            stat = UMOUNT_STAT_SUCCESS;
-            break;
+            return UMOUNT_STAT_SUCCESS;
         }
-        if ((timeout < t.duration()) && retry > 0) {  // try umount at least once
-            stat = UMOUNT_STAT_TIMEOUT;
-            break;
+        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();
+            }
         }
-        if (emulated_devices.size() > 0 &&
-            std::all_of(emulated_devices.begin(), emulated_devices.end(),
-                        [](auto& entry) { return entry.Umount(); })) {
-            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;
         }
-        for (auto& entry : block_devices) {
-            entry.Umount();
+        if ((timeout < t.duration())) {  // try umount at least once
+            return UMOUNT_STAT_TIMEOUT;
         }
-        retry++;
         std::this_thread::sleep_for(100ms);
     }
-    return stat;
 }
 
 static void KillAllProcesses() { android::base::WriteStringToFile("i", "/proc/sysrq-trigger"); }