commit 3b06f80f60b26a5b825aa276bc4616298c0c2ea9
author Jacob Abrams <satur9nine@gmail.com> Wed Apr 20 13:39:50 2016 -0700
committer Jacob Abrams <satur9nine@gmail.com> Wed Aug 31 21:23:54 2016 +0000
tree e35f87effc80b3077753d5dbecd7243b4ee2f23c
parent 451f205ba2744effd53fd3555cdc4080c14d7d9b

Reduce chance of zero-length keystore files

The open/write/close/rename pattern can result in
zero-length files on some file systems if crash or power
loss occurs. Prefer open/write/fsync/close/rename.

BUG: https://code.google.com/p/android/issues/detail?id=207607
Change-Id: I2742c3ab967d5cf254b22cffb5164881315623d5

keystore/keystore_utils.cpp

diff --git a/keystore/keystore_utils.cpp b/keystore/keystore_utils.cpp
index b653dd8..4617afd 100644
--- a/keystore/keystore_utils.cpp
+++ b/keystore/keystore_utils.cpp
@@ -51,6 +51,10 @@
         data += n;
         remaining -= n;
     }
+    if (TEMP_FAILURE_RETRY(fsync(fd)) == -1) {
+        ALOGW("fsync failed: %s", strerror(errno));
+        return -1;
+    }
     return size;
 }