From 98296fcf2a400bd8bea504514b4b39502997e18f Mon Sep 17 00:00:00 2001
From: Victor Hsieh <victorhsieh@google.com>
Date: Mon, 24 Feb 2020 16:02:32 -0800
Subject: [PATCH] Mark fs-verity support for ext4 userdata if first_api_level
 >= R

fs-verity is required for new devices launched with R. This change
remove a manual setup for vendors going forward. The original fs mgr
flag still allows old devices to opt in, which can only to be done
manually because of kernel dependency.

Test: build
Bug: 150034150
Change-Id: I152b63d7889153d41f29677f72074afb1881b65d
---
 fs_mgr/fs_mgr_fstab.cpp | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/fs_mgr/fs_mgr_fstab.cpp b/fs_mgr/fs_mgr_fstab.cpp
index 65f710a33..4ebe0855c 100644
--- a/fs_mgr/fs_mgr_fstab.cpp
+++ b/fs_mgr/fs_mgr_fstab.cpp
@@ -30,6 +30,7 @@
 
 #include <android-base/file.h>
 #include <android-base/parseint.h>
+#include <android-base/properties.h>
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>
 #include <libgsi/libgsi.h>
@@ -659,6 +660,21 @@ void TransformFstabForDsu(Fstab* fstab, const std::vector<std::string>& dsu_part
     }
 }
 
+void EnableMandatoryFlags(Fstab* fstab) {
+    // Devices launched in R and after should enable fs_verity on userdata. The flag causes tune2fs
+    // to enable the feature. A better alternative would be to enable on mkfs at the beginning.
+    if (android::base::GetIntProperty("ro.product.first_api_level", 0) >= 30) {
+        std::vector<FstabEntry*> data_entries = GetEntriesForMountPoint(fstab, "/data");
+        for (auto&& entry : data_entries) {
+            // Besides ext4, f2fs is also supported. But the image is already created with verity
+            // turned on when it was first introduced.
+            if (entry->fs_type == "ext4") {
+                entry->fs_mgr_flags.fs_verity = true;
+            }
+        }
+    }
+}
+
 bool ReadFstabFromFile(const std::string& path, Fstab* fstab) {
     auto fstab_file = std::unique_ptr<FILE, decltype(&fclose)>{fopen(path.c_str(), "re"), fclose};
     if (!fstab_file) {
@@ -679,6 +695,7 @@ bool ReadFstabFromFile(const std::string& path, Fstab* fstab) {
     }
 
     SkipMountingPartitions(fstab);
+    EnableMandatoryFlags(fstab);
 
     return true;
 }