commit 2af145ef20f9047fb9abbe7d40046ab9ab1f3249
author Jaegeuk Kim <jaegeuk@google.com> Mon Aug 12 11:39:55 2019 -0700
committer android-build-merger <android-build-merger@google.com> Mon Aug 12 11:39:55 2019 -0700
tree 24dc2843d4e13ab8cbf39bb73478cc004a9c323a
parent 0be952d36299537ee0a1f6db5c7bdef708ded811
parent 6c5e453f9ee8363e970c7b5e2be503879089c3c3

secdiscard: should call fsync to avoid reordering IOs
am: 6c5e453f9e

Change-Id: I90de814c136171d4ff2ce913b801171e7f27c70e

secdiscard.cpp

diff --git a/secdiscard.cpp b/secdiscard.cpp
index 0ff05d6..4659eed 100644
--- a/secdiscard.cpp
+++ b/secdiscard.cpp
@@ -147,6 +147,10 @@
             if (!overwrite_with_zeros(fs_fd.get(), range[0], range[1])) return false;
         }
     }
+    // Should wait for overwrites completion. Otherwise after unlink(),
+    // filesystem can allocate these blocks and IO can be reordered, resulting
+    // in making zero blocks to filesystem blocks.
+    fsync(fs_fd.get());
     return true;
 }