commit e4a6ed853416232b25bd51da61864b5e3096fd12
author Tom Cherry <tomcherry@google.com> Mon Mar 30 14:54:49 2020 -0700
committer Tom Cherry <tomcherry@google.com> Tue Mar 31 10:54:58 2020 -0700
tree 2171a51c2c5bd8ae7ba6c232fcee53f40cb1ff62
parent db22f23dd325fe11103d7c8a4304bde179b8b5c7

fastbootd: sync() after flashing partitions or updating super

There is a chance that devices are failing to reboot in the lab due to
sync() taking explicitly long during reboot.  Let's add the sync()'s
here to ensure they get accounted for in the flashing process.

A side benefit is it's likely safer to sync immediately after
flashing than to hope init does it during reboot.

Bug: 150863651
Test: flash local devices successfully
Change-Id: I4c4b0114f3cde8af4b8b2cb283ec21f869ef9f6f

fastboot/device/flashing.cpp

diff --git a/fastboot/device/flashing.cpp b/fastboot/device/flashing.cpp
index 7e7e507..fd6ff8e 100644
--- a/fastboot/device/flashing.cpp
+++ b/fastboot/device/flashing.cpp
@@ -135,7 +135,9 @@
         return -EOVERFLOW;
     }
     WipeOverlayfsForPartition(device, partition_name);
-    return FlashBlockDevice(handle.fd(), data);
+    int result = FlashBlockDevice(handle.fd(), data);
+    sync();
+    return result;
 }
 
 bool UpdateSuper(FastbootDevice* device, const std::string& super_name, bool wipe) {
@@ -165,6 +167,7 @@
             return device->WriteFail("Unable to flash new partition table");
         }
         fs_mgr_overlayfs_teardown();
+        sync();
         return device->WriteOkay("Successfully flashed partition table");
     }
 
@@ -204,5 +207,6 @@
         return device->WriteFail("Unable to write new partition table");
     }
     fs_mgr_overlayfs_teardown();
+    sync();
     return device->WriteOkay("Successfully updated partition table");
 }