commit 45eee7fe521901f4a2e271d34212267bc3974f84
author Zhou Xuezan <zhou.xuezan@zte.com.cn> Tue Jan 17 11:32:40 2023 +0800
committer Jia Jia <jia.jia@zte.com.cn> Wed Feb 01 08:17:38 2023 +0000
tree 9b26a79aa6257d046121b7d2669e6ec14228671d
parent 06a150b9f5bfe8543115f0f1f6f45e512aef9e24

OTA: make lp_metadata write more atomic

Powerloss of OS failure occurs when super is merging,
then the device can't bring up again for no lp_metadata sync,
so make lp_metadata sync in time.

Change-Id: I1ea31662b838e35022a566b614796f2d5e05df4b
Signed-off-by: Jia Jia <jia.jia@zte.com.cn>

fs_mgr/libfiemap/metadata.cpp

diff --git a/fs_mgr/libfiemap/metadata.cpp b/fs_mgr/libfiemap/metadata.cpp
index b0dfb5c..22b8afb 100644
--- a/fs_mgr/libfiemap/metadata.cpp
+++ b/fs_mgr/libfiemap/metadata.cpp
@@ -30,6 +30,7 @@
 namespace fiemap {
 
 using namespace android::fs_mgr;
+using android::base::unique_fd;
 
 static constexpr uint32_t kMaxMetadataSize = 256 * 1024;
 
@@ -109,10 +110,18 @@
     if (exported->partitions.empty() && android::base::RemoveFileIfExists(metadata_file)) {
         return true;
     }
-    if (!WriteToImageFile(metadata_file, *exported.get())) {
+
+    unique_fd fd(open(metadata_file.c_str(), O_CREAT | O_RDWR | O_TRUNC | O_CLOEXEC | O_BINARY | O_SYNC, 0644));
+    if (fd < 0) {
+        LOG(ERROR) << "open failed: " << metadata_file;
+        return false;
+    }
+
+    if (!WriteToImageFile(fd, *exported.get())) {
         LOG(ERROR) << "Unable to save new metadata";
         return false;
     }
+
     return true;
 }