diff --git a/adb/apex/Android.bp b/adb/apex/Android.bp
index 75c4ed9..a6b1e78 100644
--- a/adb/apex/Android.bp
+++ b/adb/apex/Android.bp
@@ -21,7 +21,7 @@
 }
 
 // adbd apex with INT_MAX version code, to allow for upgrade/rollback testing.
-apex {
+apex_test {
     name: "test_com.android.adbd",
     defaults: ["com.android.adbd-defaults"],
     manifest: "test_apex_manifest.json",
diff --git a/adb/client/adb_install.cpp b/adb/client/adb_install.cpp
index 73dcde1..2bcd0a6 100644
--- a/adb/client/adb_install.cpp
+++ b/adb/client/adb_install.cpp
@@ -227,16 +227,20 @@
         return 1;
     }
 
-    copy_to_file(local_fd.get(), remote_fd.get());
+    if (!copy_to_file(local_fd.get(), remote_fd.get())) {
+        fprintf(stderr, "adb: failed to install: copy_to_file: %s: %s", file, strerror(errno));
+        return 1;
+    }
 
     char buf[BUFSIZ];
     read_status_line(remote_fd.get(), buf, sizeof(buf));
-    if (!strncmp("Success", buf, 7)) {
-        fputs(buf, stdout);
-        return 0;
+    if (strncmp("Success", buf, 7) != 0) {
+        fprintf(stderr, "adb: failed to install %s: %s", file, buf);
+        return 1;
     }
-    fprintf(stderr, "adb: failed to install %s: %s", file, buf);
-    return 1;
+
+    fputs(buf, stdout);
+    return 0;
 }
 
 static int install_app_legacy(int argc, const char** argv, bool use_fastdeploy) {
@@ -455,7 +459,12 @@
             goto finalize_session;
         }
 
-        copy_to_file(local_fd.get(), remote_fd.get());
+        if (!copy_to_file(local_fd.get(), remote_fd.get())) {
+            fprintf(stderr, "adb: failed to write \"%s\": %s\n", file, strerror(errno));
+            success = false;
+            goto finalize_session;
+        }
+
         read_status_line(remote_fd.get(), buf, sizeof(buf));
 
         if (strncmp("Success", buf, 7)) {
@@ -634,7 +643,11 @@
                 goto finalize_multi_package_session;
             }
 
-            copy_to_file(local_fd.get(), remote_fd.get());
+            if (!copy_to_file(local_fd.get(), remote_fd.get())) {
+                fprintf(stderr, "adb: failed to write %s: %s\n", split.c_str(), strerror(errno));
+                goto finalize_multi_package_session;
+            }
+
             read_status_line(remote_fd.get(), buf, sizeof(buf));
 
             if (strncmp("Success", buf, 7)) {
diff --git a/adb/client/commandline.cpp b/adb/client/commandline.cpp
index a6d7e31..c302965 100644
--- a/adb/client/commandline.cpp
+++ b/adb/client/commandline.cpp
@@ -352,7 +352,8 @@
 #endif
 }
 
-void copy_to_file(int inFd, int outFd) {
+bool copy_to_file(int inFd, int outFd) {
+    bool result = true;
     std::vector<char> buf(64 * 1024);
     int len;
     long total = 0;
@@ -375,6 +376,7 @@
         }
         if (len < 0) {
             D("copy_to_file(): read failed: %s", strerror(errno));
+            result = false;
             break;
         }
         if (outFd == STDOUT_FILENO) {
@@ -388,7 +390,8 @@
 
     stdinout_raw_epilogue(inFd, outFd, old_stdin_mode, old_stdout_mode);
 
-    D("copy_to_file() finished after %lu bytes", total);
+    D("copy_to_file() finished with %s after %lu bytes", result ? "success" : "failure", total);
+    return result;
 }
 
 static void send_window_size_change(int fd, std::unique_ptr<ShellProtocol>& shell) {
diff --git a/adb/client/commandline.h b/adb/client/commandline.h
index ab77b29..b9dee56 100644
--- a/adb/client/commandline.h
+++ b/adb/client/commandline.h
@@ -100,7 +100,7 @@
 
 int adb_commandline(int argc, const char** argv);
 
-void copy_to_file(int inFd, int outFd);
+bool copy_to_file(int inFd, int outFd);
 
 // Connects to the device "shell" service with |command| and prints the
 // resulting output.
diff --git a/base/expected_test.cpp b/base/expected_test.cpp
index a74bc1d..47e396a 100644
--- a/base/expected_test.cpp
+++ b/base/expected_test.cpp
@@ -408,11 +408,11 @@
 
 TEST(Expected, testTest) {
   exp_int e = 10;
-  EXPECT_TRUE(e);
+  EXPECT_TRUE(e.ok());
   EXPECT_TRUE(e.has_value());
 
   exp_int e2 = unexpected(10);
-  EXPECT_FALSE(e2);
+  EXPECT_FALSE(e2.ok());
   EXPECT_FALSE(e2.has_value());
 }
 
@@ -499,24 +499,6 @@
   EXPECT_TRUE(e4 != e3);
 }
 
-TEST(Expected, testCompareWithSameValue) {
-  exp_int e = 10;
-  int value = 10;
-  EXPECT_TRUE(e == value);
-  EXPECT_TRUE(value == e);
-  EXPECT_FALSE(e != value);
-  EXPECT_FALSE(value != e);
-}
-
-TEST(Expected, testCompareWithDifferentValue) {
-  exp_int e = 10;
-  int value = 20;
-  EXPECT_FALSE(e == value);
-  EXPECT_FALSE(value == e);
-  EXPECT_TRUE(e != value);
-  EXPECT_TRUE(value != e);
-}
-
 TEST(Expected, testCompareWithSameError) {
   exp_int e = unexpected(10);
   exp_int::unexpected_type error = 10;
@@ -589,12 +571,12 @@
     }
   };
 
-  EXPECT_FALSE(divide(10, 0));
+  EXPECT_FALSE(divide(10, 0).ok());
   EXPECT_EQ("divide by zero", divide(10, 0).error().message);
   EXPECT_EQ(-1, divide(10, 0).error().cause);
 
-  EXPECT_TRUE(divide(10, 3));
-  EXPECT_EQ(QR(3, 1), divide(10, 3));
+  EXPECT_TRUE(divide(10, 3).ok());
+  EXPECT_EQ(QR(3, 1), *divide(10, 3));
 }
 
 TEST(Expected, testPair) {
@@ -607,7 +589,7 @@
   };
 
   auto r = test(true);
-  EXPECT_TRUE(r);
+  EXPECT_TRUE(r.ok());
   EXPECT_EQ("yes", r->first);
 }
 
@@ -621,9 +603,9 @@
   };
 
   auto r = test(true);
-  EXPECT_TRUE(r);
+  EXPECT_TRUE(r.ok());
   r = test(false);
-  EXPECT_FALSE(r);
+  EXPECT_FALSE(r.ok());
   EXPECT_EQ(10, r.error());
 }
 
@@ -772,7 +754,7 @@
 
   ConstructorTracker::Reset();
   auto result1 = test("");
-  ASSERT_TRUE(result1);
+  ASSERT_TRUE(result1.ok());
   EXPECT_EQ("literal string", result1->string);
   EXPECT_EQ(1U, ConstructorTracker::constructor_called);
   EXPECT_EQ(0U, ConstructorTracker::copy_constructor_called);
@@ -782,7 +764,7 @@
 
   ConstructorTracker::Reset();
   auto result2 = test("test2");
-  ASSERT_TRUE(result2);
+  ASSERT_TRUE(result2.ok());
   EXPECT_EQ("test2test22", result2->string);
   EXPECT_EQ(1U, ConstructorTracker::constructor_called);
   EXPECT_EQ(0U, ConstructorTracker::copy_constructor_called);
@@ -792,7 +774,7 @@
 
   ConstructorTracker::Reset();
   auto result3 = test("test3");
-  ASSERT_TRUE(result3);
+  ASSERT_TRUE(result3.ok());
   EXPECT_EQ("test3 test3", result3->string);
   EXPECT_EQ(1U, ConstructorTracker::constructor_called);
   EXPECT_EQ(0U, ConstructorTracker::copy_constructor_called);
@@ -804,22 +786,22 @@
 TEST(Expected, testNested) {
   expected<exp_string, std::string> e = "hello";
 
+  EXPECT_TRUE(e.ok());
   EXPECT_TRUE(e.has_value());
   EXPECT_TRUE(e.value().has_value());
-  EXPECT_TRUE(e);
-  EXPECT_TRUE(*e);
+  EXPECT_TRUE(e->ok());
   EXPECT_EQ("hello", e.value().value());
 
   expected<exp_string, std::string> e2 = unexpected("world");
   EXPECT_FALSE(e2.has_value());
-  EXPECT_FALSE(e2);
+  EXPECT_FALSE(e2.ok());
   EXPECT_EQ("world", e2.error());
 
   expected<exp_string, std::string> e3 = exp_string(unexpected("world"));
   EXPECT_TRUE(e3.has_value());
   EXPECT_FALSE(e3.value().has_value());
-  EXPECT_TRUE(e3);
-  EXPECT_FALSE(*e3);
+  EXPECT_TRUE(e3.ok());
+  EXPECT_FALSE(e3->ok());
   EXPECT_EQ("world", e3.value().error());
 }
 
diff --git a/base/include/android-base/expected.h b/base/include/android-base/expected.h
index b3f5adb..9603bb1 100644
--- a/base/include/android-base/expected.h
+++ b/base/include/android-base/expected.h
@@ -331,6 +331,7 @@
 
   constexpr explicit operator bool() const noexcept { return has_value(); }
   constexpr bool has_value() const noexcept { return var_.index() == 0; }
+  constexpr bool ok() const noexcept { return has_value(); }
 
   constexpr const T& value() const& { return std::get<T>(var_); }
   constexpr T& value() & { return std::get<T>(var_); }
@@ -366,16 +367,6 @@
   template<class T1, class E1, class T2, class E2>
   friend constexpr bool operator!=(const expected<T1, E1>& x, const expected<T2, E2>& y);
 
-  // comparison with T
-  template<class T1, class E1, class T2>
-  friend constexpr bool operator==(const expected<T1, E1>&, const T2&);
-  template<class T1, class E1, class T2>
-  friend constexpr bool operator==(const T2&, const expected<T1, E1>&);
-  template<class T1, class E1, class T2>
-  friend constexpr bool operator!=(const expected<T1, E1>&, const T2&);
-  template<class T1, class E1, class T2>
-  friend constexpr bool operator!=(const T2&, const expected<T1, E1>&);
-
   // Comparison with unexpected<E>
   template<class T1, class E1, class E2>
   friend constexpr bool operator==(const expected<T1, E1>&, const unexpected<E2>&);
@@ -410,24 +401,6 @@
   return !(x == y);
 }
 
-// comparison with T
-template<class T1, class E1, class T2>
-constexpr bool operator==(const expected<T1, E1>& x, const T2& y) {
-  return x.has_value() && (*x == y);
-}
-template<class T1, class E1, class T2>
-constexpr bool operator==(const T2& x, const expected<T1, E1>& y) {
-  return y.has_value() && (x == *y);
-}
-template<class T1, class E1, class T2>
-constexpr bool operator!=(const expected<T1, E1>& x, const T2& y) {
-  return !x.has_value() || (*x != y);
-}
-template<class T1, class E1, class T2>
-constexpr bool operator!=(const T2& x, const expected<T1, E1>& y) {
-  return !y.has_value() || (x != *y);
-}
-
 // Comparison with unexpected<E>
 template<class T1, class E1, class E2>
 constexpr bool operator==(const expected<T1, E1>& x, const unexpected<E2>& y) {
@@ -585,6 +558,7 @@
   // observers
   constexpr explicit operator bool() const noexcept { return has_value(); }
   constexpr bool has_value() const noexcept { return var_.index() == 0; }
+  constexpr bool ok() const noexcept { return has_value(); }
 
   constexpr void value() const& { if (!has_value()) std::get<0>(var_); }
 
diff --git a/base/include/android-base/result.h b/base/include/android-base/result.h
index b6d26e7..4a59552 100644
--- a/base/include/android-base/result.h
+++ b/base/include/android-base/result.h
@@ -156,11 +156,11 @@
   Error& operator=(const Error&) = delete;
   Error& operator=(Error&&) = delete;
 
-  template <typename... Args>
-  friend Error Errorf(const char* fmt, const Args&... args);
+  template <typename T, typename... Args>
+  friend Error ErrorfImpl(const T&& fmt, const Args&... args);
 
-  template <typename... Args>
-  friend Error ErrnoErrorf(const char* fmt, const Args&... args);
+  template <typename T, typename... Args>
+  friend Error ErrnoErrorfImpl(const T&& fmt, const Args&... args);
 
  private:
   Error(bool append_errno, int errno_to_append, const std::string& message)
@@ -191,18 +191,49 @@
   return ErrorCode(code, args...);
 }
 
-template <typename... Args>
-inline Error Errorf(const char* fmt, const Args&... args) {
+// TODO(tomcherry): Remove this once we've removed all `using android::base::Errorf` and `using
+// android::base::ErrnoErrorf` lines.
+enum Errorf {};
+enum ErrnoErrorf {};
+
+template <typename T, typename... Args>
+inline Error ErrorfImpl(const T&& fmt, const Args&... args) {
   return Error(false, ErrorCode(0, args...), fmt::format(fmt, args...));
 }
 
-template <typename... Args>
-inline Error ErrnoErrorf(const char* fmt, const Args&... args) {
+template <typename T, typename... Args>
+inline Error ErrnoErrorfImpl(const T&& fmt, const Args&... args) {
   return Error(true, errno, fmt::format(fmt, args...));
 }
 
+#define Errorf(fmt, ...) android::base::ErrorfImpl(FMT_STRING(fmt), ##__VA_ARGS__)
+#define ErrnoErrorf(fmt, ...) android::base::ErrnoErrorfImpl(FMT_STRING(fmt), ##__VA_ARGS__)
+
 template <typename T>
 using Result = android::base::expected<T, ResultError>;
 
+// Macros for testing the results of functions that return android::base::Result.
+// These also work with base::android::expected.
+
+#define CHECK_RESULT_OK(stmt)       \
+  do {                              \
+    const auto& tmp = (stmt);       \
+    CHECK(tmp.ok()) << tmp.error(); \
+  } while (0)
+
+#define ASSERT_RESULT_OK(stmt)            \
+  do {                                    \
+    const auto& tmp = (stmt);             \
+    ASSERT_TRUE(tmp.ok()) << tmp.error(); \
+  } while (0)
+
+#define EXPECT_RESULT_OK(stmt)            \
+  do {                                    \
+    auto tmp = (stmt);                    \
+    EXPECT_TRUE(tmp.ok()) << tmp.error(); \
+  } while (0)
+
+// TODO: Maybe add RETURN_IF_ERROR() and ASSIGN_OR_RETURN()
+
 }  // namespace base
 }  // namespace android
diff --git a/base/result_test.cpp b/base/result_test.cpp
index 2ee4057..c0ac0fd 100644
--- a/base/result_test.cpp
+++ b/base/result_test.cpp
@@ -30,7 +30,7 @@
 
 TEST(result, result_accessors) {
   Result<std::string> result = "success";
-  ASSERT_TRUE(result);
+  ASSERT_RESULT_OK(result);
   ASSERT_TRUE(result.has_value());
 
   EXPECT_EQ("success", *result);
@@ -40,7 +40,7 @@
 }
 
 TEST(result, result_accessors_rvalue) {
-  ASSERT_TRUE(Result<std::string>("success"));
+  ASSERT_TRUE(Result<std::string>("success").ok());
   ASSERT_TRUE(Result<std::string>("success").has_value());
 
   EXPECT_EQ("success", *Result<std::string>("success"));
@@ -51,12 +51,12 @@
 
 TEST(result, result_void) {
   Result<void> ok = {};
-  EXPECT_TRUE(ok);
+  EXPECT_RESULT_OK(ok);
   ok.value();  // should not crash
   ASSERT_DEATH(ok.error(), "");
 
   Result<void> fail = Error() << "failure" << 1;
-  EXPECT_FALSE(fail);
+  EXPECT_FALSE(fail.ok());
   EXPECT_EQ("failure1", fail.error().message());
   EXPECT_EQ(0, fail.error().code());
   EXPECT_TRUE(ok != fail);
@@ -66,8 +66,8 @@
     if (ok) return {};
     else return Error() << "failure" << 1;
   };
-  EXPECT_TRUE(test(true));
-  EXPECT_FALSE(test(false));
+  EXPECT_TRUE(test(true).ok());
+  EXPECT_FALSE(test(false).ok());
   test(true).value();  // should not crash
   ASSERT_DEATH(test(true).error(), "");
   ASSERT_DEATH(test(false).value(), "");
@@ -76,7 +76,7 @@
 
 TEST(result, result_error) {
   Result<void> result = Error() << "failure" << 1;
-  ASSERT_FALSE(result);
+  ASSERT_FALSE(result.ok());
   ASSERT_FALSE(result.has_value());
 
   EXPECT_EQ(0, result.error().code());
@@ -85,7 +85,7 @@
 
 TEST(result, result_error_empty) {
   Result<void> result = Error();
-  ASSERT_FALSE(result);
+  ASSERT_FALSE(result.ok());
   ASSERT_FALSE(result.has_value());
 
   EXPECT_EQ(0, result.error().code());
@@ -100,7 +100,7 @@
   // create is.
 
   auto MakeRvalueErrorResult = []() -> Result<void> { return Error() << "failure" << 1; };
-  ASSERT_FALSE(MakeRvalueErrorResult());
+  ASSERT_FALSE(MakeRvalueErrorResult().ok());
   ASSERT_FALSE(MakeRvalueErrorResult().has_value());
 
   EXPECT_EQ(0, MakeRvalueErrorResult().error().code());
@@ -112,7 +112,7 @@
   errno = test_errno;
   Result<void> result = ErrnoError() << "failure" << 1;
 
-  ASSERT_FALSE(result);
+  ASSERT_FALSE(result.ok());
   ASSERT_FALSE(result.has_value());
 
   EXPECT_EQ(test_errno, result.error().code());
@@ -124,7 +124,7 @@
   errno = test_errno;
   Result<void> result = ErrnoError();
 
-  ASSERT_FALSE(result);
+  ASSERT_FALSE(result.ok());
   ASSERT_FALSE(result.has_value());
 
   EXPECT_EQ(test_errno, result.error().code());
@@ -135,12 +135,12 @@
   auto error_text = "test error"s;
   Result<void> result = Error() << error_text;
 
-  ASSERT_FALSE(result);
+  ASSERT_FALSE(result.ok());
   ASSERT_FALSE(result.has_value());
 
   Result<std::string> result2 = result.error();
 
-  ASSERT_FALSE(result2);
+  ASSERT_FALSE(result2.ok());
   ASSERT_FALSE(result2.has_value());
 
   EXPECT_EQ(0, result2.error().code());
@@ -151,12 +151,12 @@
   auto error_text = "test error"s;
   Result<void> result = Error() << error_text;
 
-  ASSERT_FALSE(result);
+  ASSERT_FALSE(result.ok());
   ASSERT_FALSE(result.has_value());
 
   Result<std::string> result2 = Error() << result.error();
 
-  ASSERT_FALSE(result2);
+  ASSERT_FALSE(result2.ok());
   ASSERT_FALSE(result2.has_value());
 
   EXPECT_EQ(0, result2.error().code());
@@ -171,12 +171,12 @@
 
   errno = 0;
 
-  ASSERT_FALSE(result);
+  ASSERT_FALSE(result.ok());
   ASSERT_FALSE(result.has_value());
 
   Result<std::string> result2 = Error() << result.error();
 
-  ASSERT_FALSE(result2);
+  ASSERT_FALSE(result2.ok());
   ASSERT_FALSE(result2.has_value());
 
   EXPECT_EQ(test_errno, result2.error().code());
@@ -186,7 +186,7 @@
 TEST(result, constructor_forwarding) {
   auto result = Result<std::string>(std::in_place, 5, 'a');
 
-  ASSERT_TRUE(result);
+  ASSERT_RESULT_OK(result);
   ASSERT_TRUE(result.has_value());
 
   EXPECT_EQ("aaaaa", *result);
@@ -254,7 +254,7 @@
   // are called.
 
   auto result1 = ReturnConstructorTracker("");
-  ASSERT_TRUE(result1);
+  ASSERT_RESULT_OK(result1);
   EXPECT_EQ("literal string", result1->string);
   EXPECT_EQ(1U, ConstructorTracker::constructor_called);
   EXPECT_EQ(0U, ConstructorTracker::copy_constructor_called);
@@ -263,7 +263,7 @@
   EXPECT_EQ(0U, ConstructorTracker::move_assignment_called);
 
   auto result2 = ReturnConstructorTracker("test2");
-  ASSERT_TRUE(result2);
+  ASSERT_RESULT_OK(result2);
   EXPECT_EQ("test2test22", result2->string);
   EXPECT_EQ(2U, ConstructorTracker::constructor_called);
   EXPECT_EQ(0U, ConstructorTracker::copy_constructor_called);
@@ -272,7 +272,7 @@
   EXPECT_EQ(0U, ConstructorTracker::move_assignment_called);
 
   auto result3 = ReturnConstructorTracker("test3");
-  ASSERT_TRUE(result3);
+  ASSERT_RESULT_OK(result3);
   EXPECT_EQ("test3 test3", result3->string);
   EXPECT_EQ(3U, ConstructorTracker::constructor_called);
   EXPECT_EQ(0U, ConstructorTracker::copy_constructor_called);
@@ -287,11 +287,11 @@
 TEST(result, result_result_with_success) {
   auto return_result_result_with_success = []() -> Result<Result<void>> { return Result<void>(); };
   auto result = return_result_result_with_success();
-  ASSERT_TRUE(result);
-  ASSERT_TRUE(*result);
+  ASSERT_RESULT_OK(result);
+  ASSERT_RESULT_OK(*result);
 
   auto inner_result = result.value();
-  ASSERT_TRUE(inner_result);
+  ASSERT_RESULT_OK(inner_result);
 }
 
 TEST(result, result_result_with_failure) {
@@ -299,8 +299,8 @@
     return Result<void>(ResultError("failure string", 6));
   };
   auto result = return_result_result_with_error();
-  ASSERT_TRUE(result);
-  ASSERT_FALSE(*result);
+  ASSERT_RESULT_OK(result);
+  ASSERT_FALSE(result->ok());
   EXPECT_EQ("failure string", (*result).error().message());
   EXPECT_EQ(6, (*result).error().code());
 }
@@ -320,7 +320,7 @@
   };
 
   auto result = return_test_struct();
-  ASSERT_TRUE(result);
+  ASSERT_RESULT_OK(result);
   EXPECT_EQ(36, result->value_);
 }
 
@@ -344,13 +344,13 @@
   errno = 1;
   int old_errno = errno;
   Result<int> result = Error() << "Failed" << SetErrnoToTwo<char>;
-  ASSERT_FALSE(result);
+  ASSERT_FALSE(result.ok());
   EXPECT_EQ(old_errno, errno);
 
   errno = 1;
   old_errno = errno;
   Result<int> result2 = ErrnoError() << "Failed" << SetErrnoToTwo<char>;
-  ASSERT_FALSE(result2);
+  ASSERT_FALSE(result2.ok());
   EXPECT_EQ(old_errno, errno);
   EXPECT_EQ(old_errno, result2.error().code());
 }
@@ -362,7 +362,7 @@
   result = Errorf("{} {}!", std::string("hello"), std::string("world"));
   EXPECT_EQ("hello world!", result.error().message());
 
-  result = Errorf("{h} {w}!", fmt::arg("w", "world"), fmt::arg("h", "hello"));
+  result = Errorf("{1} {0}!", "world", "hello");
   EXPECT_EQ("hello world!", result.error().message());
 
   result = Errorf("hello world!");
diff --git a/bootstat/bootstat.cpp b/bootstat/bootstat.cpp
index 6b8a09a..9ffe5dd 100644
--- a/bootstat/bootstat.cpp
+++ b/bootstat/bootstat.cpp
@@ -32,6 +32,8 @@
 #include <memory>
 #include <regex>
 #include <string>
+#include <string_view>
+#include <unordered_map>
 #include <utility>
 #include <vector>
 
@@ -50,16 +52,133 @@
 
 namespace {
 
+struct AtomInfo {
+  int32_t atom;
+  int32_t event;
+};
+
+// Maps BootEvent used inside bootstat into statsd atom defined in
+// frameworks/base/cmds/statsd/src/atoms.proto.
+const std::unordered_map<std::string_view, AtomInfo> kBootEventToAtomInfo = {
+    // ELAPSED_TIME
+    {"ro.boottime.init",
+     {android::util::BOOT_TIME_EVENT_ELAPSED_TIME_REPORTED,
+      android::util::BOOT_TIME_EVENT_ELAPSED_TIME__EVENT__ANDROID_INIT_STAGE_1}},
+    {"boot_complete",
+     {android::util::BOOT_TIME_EVENT_ELAPSED_TIME_REPORTED,
+      android::util::BOOT_TIME_EVENT_ELAPSED_TIME__EVENT__BOOT_COMPLETE}},
+    {"boot_decryption_complete",
+     {android::util::BOOT_TIME_EVENT_ELAPSED_TIME_REPORTED,
+      android::util::BOOT_TIME_EVENT_ELAPSED_TIME__EVENT__BOOT_COMPLETE_ENCRYPTION}},
+    {"boot_complete_no_encryption",
+     {android::util::BOOT_TIME_EVENT_ELAPSED_TIME_REPORTED,
+      android::util::BOOT_TIME_EVENT_ELAPSED_TIME__EVENT__BOOT_COMPLETE_NO_ENCRYPTION}},
+    {"boot_complete_post_decrypt",
+     {android::util::BOOT_TIME_EVENT_ELAPSED_TIME_REPORTED,
+      android::util::BOOT_TIME_EVENT_ELAPSED_TIME__EVENT__BOOT_COMPLETE_POST_DECRYPT}},
+    {"factory_reset_boot_complete",
+     {android::util::BOOT_TIME_EVENT_ELAPSED_TIME_REPORTED,
+      android::util::BOOT_TIME_EVENT_ELAPSED_TIME__EVENT__FACTORY_RESET_BOOT_COMPLETE}},
+    {"factory_reset_boot_complete_no_encryption",
+     {android::util::BOOT_TIME_EVENT_ELAPSED_TIME_REPORTED,
+      android::util::
+          BOOT_TIME_EVENT_ELAPSED_TIME__EVENT__FACTORY_RESET_BOOT_COMPLETE_NO_ENCRYPTION}},
+    {"factory_reset_boot_complete_post_decrypt",
+     {android::util::BOOT_TIME_EVENT_ELAPSED_TIME_REPORTED,
+      android::util::
+          BOOT_TIME_EVENT_ELAPSED_TIME__EVENT__FACTORY_RESET_BOOT_COMPLETE_POST_DECRYPT}},
+    {"ota_boot_complete",
+     {android::util::BOOT_TIME_EVENT_ELAPSED_TIME_REPORTED,
+      android::util::BOOT_TIME_EVENT_ELAPSED_TIME__EVENT__OTA_BOOT_COMPLETE}},
+    {"ota_boot_complete_no_encryption",
+     {android::util::BOOT_TIME_EVENT_ELAPSED_TIME_REPORTED,
+      android::util::BOOT_TIME_EVENT_ELAPSED_TIME__EVENT__OTA_BOOT_COMPLETE_NO_ENCRYPTION}},
+    {"ota_boot_complete_post_decrypt",
+     {android::util::BOOT_TIME_EVENT_ELAPSED_TIME_REPORTED,
+      android::util::BOOT_TIME_EVENT_ELAPSED_TIME__EVENT__OTA_BOOT_COMPLETE_POST_DECRYPT}},
+    {"post_decrypt_time_elapsed",
+     {android::util::BOOT_TIME_EVENT_ELAPSED_TIME_REPORTED,
+      android::util::BOOT_TIME_EVENT_ELAPSED_TIME__EVENT__POST_DECRYPT}},
+    // DURATION
+    {"absolute_boot_time",
+     {android::util::BOOT_TIME_EVENT_DURATION_REPORTED,
+      android::util::BOOT_TIME_EVENT_DURATION__EVENT__ABSOLUTE_BOOT_TIME}},
+    {"boottime.bootloader.1BLE",
+     {android::util::BOOT_TIME_EVENT_DURATION_REPORTED,
+      android::util::BOOT_TIME_EVENT_DURATION__EVENT__BOOTLOADER_FIRST_STAGE_EXEC}},
+    {"boottime.bootloader.1BLL",
+     {android::util::BOOT_TIME_EVENT_DURATION_REPORTED,
+      android::util::BOOT_TIME_EVENT_DURATION__EVENT__BOOTLOADER_FIRST_STAGE_LOAD}},
+    {"boottime.bootloader.KL",
+     {android::util::BOOT_TIME_EVENT_DURATION_REPORTED,
+      android::util::BOOT_TIME_EVENT_DURATION__EVENT__BOOTLOADER_KERNEL_LOAD}},
+    {"boottime.bootloader.2BLE",
+     {android::util::BOOT_TIME_EVENT_DURATION_REPORTED,
+      android::util::BOOT_TIME_EVENT_DURATION__EVENT__BOOTLOADER_SECOND_STAGE_EXEC}},
+    {"boottime.bootloader.2BLL",
+     {android::util::BOOT_TIME_EVENT_DURATION_REPORTED,
+      android::util::BOOT_TIME_EVENT_DURATION__EVENT__BOOTLOADER_SECOND_STAGE_LOAD}},
+    {"boottime.bootloader.SW",
+     {android::util::BOOT_TIME_EVENT_DURATION_REPORTED,
+      android::util::BOOT_TIME_EVENT_DURATION__EVENT__BOOTLOADER_UI_WAIT}},
+    {"boottime.bootloader.total",
+     {android::util::BOOT_TIME_EVENT_DURATION_REPORTED,
+      android::util::BOOT_TIME_EVENT_DURATION__EVENT__BOOTLOADER_TOTAL}},
+    {"boottime.init.cold_boot_wait",
+     {android::util::BOOT_TIME_EVENT_DURATION_REPORTED,
+      android::util::BOOT_TIME_EVENT_DURATION__EVENT__COLDBOOT_WAIT}},
+    {"time_since_factory_reset",
+     {android::util::BOOT_TIME_EVENT_DURATION_REPORTED,
+      android::util::BOOT_TIME_EVENT_DURATION__EVENT__FACTORY_RESET_TIME_SINCE_RESET}},
+    {"ro.boottime.init.first_stage",
+     {android::util::BOOT_TIME_EVENT_DURATION_REPORTED,
+      android::util::BOOT_TIME_EVENT_DURATION__EVENT__ANDROID_INIT_STAGE_1}},
+    {"ro.boottime.init.selinux",
+     {android::util::BOOT_TIME_EVENT_DURATION_REPORTED,
+      android::util::BOOT_TIME_EVENT_DURATION__EVENT__SELINUX_INIT}},
+    // UTC_TIME
+    {"factory_reset",
+     {android::util::BOOT_TIME_EVENT_UTC_TIME_REPORTED,
+      android::util::BOOT_TIME_EVENT_UTC_TIME__EVENT__FACTORY_RESET_RESET_TIME}},
+    {"factory_reset_current_time",
+     {android::util::BOOT_TIME_EVENT_UTC_TIME_REPORTED,
+      android::util::BOOT_TIME_EVENT_UTC_TIME__EVENT__FACTORY_RESET_CURRENT_TIME}},
+    {"factory_reset_record_value",
+     {android::util::BOOT_TIME_EVENT_UTC_TIME_REPORTED,
+      android::util::BOOT_TIME_EVENT_UTC_TIME__EVENT__FACTORY_RESET_RECORD_VALUE}},
+    // ERROR_CODE
+    {"factory_reset_current_time_failure",
+     {android::util::BOOT_TIME_EVENT_ERROR_CODE_REPORTED,
+      android::util::BOOT_TIME_EVENT_ERROR_CODE__EVENT__FACTORY_RESET_CURRENT_TIME_FAILURE}},
+};
+
 // Scans the boot event record store for record files and logs each boot event
 // via EventLog.
 void LogBootEvents() {
   BootEventRecordStore boot_event_store;
-
   auto events = boot_event_store.GetAllBootEvents();
-  // TODO(b/148575354): Replace with statsd.
-  // for (auto i = events.cbegin(); i != events.cend(); ++i) {
-  //   android::metricslogger::LogHistogram(i->first, i->second);
-  // }
+  std::vector<std::string_view> notSupportedEvents;
+  for (const auto& event : events) {
+    const auto& name = event.first;
+    const auto& info = kBootEventToAtomInfo.find(name);
+    if (info != kBootEventToAtomInfo.end()) {
+      if (info->second.atom == android::util::BOOT_TIME_EVENT_ERROR_CODE_REPORTED) {
+        android::util::stats_write(static_cast<int32_t>(info->second.atom),
+                                   static_cast<int32_t>(info->second.event),
+                                   static_cast<int32_t>(event.second));
+      } else {
+        android::util::stats_write(static_cast<int32_t>(info->second.atom),
+                                   static_cast<int32_t>(info->second.event),
+                                   static_cast<int64_t>(event.second));
+      }
+    } else {
+      notSupportedEvents.push_back(name);
+    }
+  }
+  if (!notSupportedEvents.empty()) {
+    LOG(WARNING) << "LogBootEvents, atomInfo not defined for events:"
+                 << android::base::Join(notSupportedEvents, ',');
+  }
 }
 
 // Records the named boot |event| to the record store. If |value| is non-empty
@@ -1250,10 +1369,13 @@
   time_t current_time_utc = time(nullptr);
 
   if (current_time_utc < 0) {
-    // TODO(b/148575354): Replace with statsd.
     // UMA does not display negative values in buckets, so convert to positive.
-    // android::metricslogger::LogHistogram("factory_reset_current_time_failure",
-    //                                      std::abs(current_time_utc));
+    // Logging via BootEventRecordStore.
+    android::util::stats_write(
+        static_cast<int32_t>(android::util::BOOT_TIME_EVENT_ERROR_CODE_REPORTED),
+        static_cast<int32_t>(
+            android::util::BOOT_TIME_EVENT_ERROR_CODE__EVENT__FACTORY_RESET_CURRENT_TIME_FAILURE),
+        static_cast<int32_t>(std::abs(current_time_utc)));
 
     // Logging via BootEventRecordStore to see if using android::metricslogger::LogHistogram
     // is losing records somehow.
@@ -1261,8 +1383,11 @@
                                            std::abs(current_time_utc));
     return;
   } else {
-    // TODO(b/148575354): Replace with statsd.
-    // android::metricslogger::LogHistogram("factory_reset_current_time", current_time_utc);
+    android::util::stats_write(
+        static_cast<int32_t>(android::util::BOOT_TIME_EVENT_UTC_TIME_REPORTED),
+        static_cast<int32_t>(
+            android::util::BOOT_TIME_EVENT_UTC_TIME__EVENT__FACTORY_RESET_CURRENT_TIME),
+        static_cast<int64_t>(current_time_utc));
 
     // Logging via BootEventRecordStore to see if using android::metricslogger::LogHistogram
     // is losing records somehow.
@@ -1282,8 +1407,11 @@
   // Calculate and record the difference in time between now and the
   // factory_reset time.
   time_t factory_reset_utc = record.second;
-  // TODO(b/148575354): Replace with statsd.
-  // android::metricslogger::LogHistogram("factory_reset_record_value", factory_reset_utc);
+  android::util::stats_write(
+      static_cast<int32_t>(android::util::BOOT_TIME_EVENT_UTC_TIME_REPORTED),
+      static_cast<int32_t>(
+          android::util::BOOT_TIME_EVENT_UTC_TIME__EVENT__FACTORY_RESET_RECORD_VALUE),
+      static_cast<int64_t>(factory_reset_utc));
 
   // Logging via BootEventRecordStore to see if using android::metricslogger::LogHistogram
   // is losing records somehow.
diff --git a/fastboot/constants.h b/fastboot/constants.h
index aefd448..ba43ca5 100644
--- a/fastboot/constants.h
+++ b/fastboot/constants.h
@@ -42,7 +42,7 @@
 #define RESPONSE_INFO "INFO"
 
 #define FB_COMMAND_SZ 64
-#define FB_RESPONSE_SZ 64
+#define FB_RESPONSE_SZ 256
 
 #define FB_VAR_VERSION "version"
 #define FB_VAR_VERSION_BOOTLOADER "version-bootloader"
diff --git a/fastboot/fuzzy_fastboot/main.cpp b/fastboot/fuzzy_fastboot/main.cpp
index b9784fe..d9167e7 100644
--- a/fastboot/fuzzy_fastboot/main.cpp
+++ b/fastboot/fuzzy_fastboot/main.cpp
@@ -227,13 +227,6 @@
 
 TEST_F(LogicalPartitionCompliance, FastbootRebootTest) {
     ASSERT_TRUE(UserSpaceFastboot());
-    GTEST_LOG_(INFO) << "Rebooting to bootloader mode";
-    // Test 'fastboot reboot bootloader' from fastbootd
-    fb->RebootTo("bootloader");
-
-    // Test fastboot reboot fastboot from bootloader
-    ReconnectFastbootDevice();
-    ASSERT_FALSE(UserSpaceFastboot());
     GTEST_LOG_(INFO) << "Rebooting back to fastbootd mode";
     fb->RebootTo("fastboot");
 
@@ -268,23 +261,6 @@
     GTEST_LOG_(INFO) << "Flashing a logical partition..";
     EXPECT_EQ(fb->FlashPartition(test_partition_name, buf), SUCCESS)
             << "flash logical -partition failed";
-    GTEST_LOG_(INFO) << "Rebooting to bootloader mode";
-    // Reboot to bootloader mode and attempt to flash the logical partitions
-    fb->RebootTo("bootloader");
-
-    ReconnectFastbootDevice();
-    ASSERT_FALSE(UserSpaceFastboot());
-    GTEST_LOG_(INFO) << "Attempt to flash a logical partition..";
-    EXPECT_EQ(fb->FlashPartition(test_partition_name, buf), DEVICE_FAIL)
-            << "flash logical partition must fail in bootloader";
-    GTEST_LOG_(INFO) << "Rebooting back to fastbootd mode";
-    fb->RebootTo("fastboot");
-
-    ReconnectFastbootDevice();
-    ASSERT_TRUE(UserSpaceFastboot());
-    GTEST_LOG_(INFO) << "Testing 'fastboot delete-logical-partition' command";
-    EXPECT_EQ(fb->DeletePartition(test_partition_name), SUCCESS)
-            << "delete logical-partition failed";
 }
 
 // Conformance tests
diff --git a/fs_mgr/TEST_MAPPING b/fs_mgr/TEST_MAPPING
index a947b4e..705d4e3 100644
--- a/fs_mgr/TEST_MAPPING
+++ b/fs_mgr/TEST_MAPPING
@@ -2,6 +2,18 @@
   "presubmit": [
     {
       "name": "libdm_test"
+    },
+    {
+      "name": "liblp_test"
+    },
+    {
+      "name": "fiemap_image_test_presubmit"
+    },
+    {
+      "name": "fiemap_writer_test"
+    },
+    {
+      "name": "vts_libsnapshot_test_presubmit"
     }
   ]
 }
diff --git a/fs_mgr/libfiemap/Android.bp b/fs_mgr/libfiemap/Android.bp
index 1bf457f..2fd463c 100644
--- a/fs_mgr/libfiemap/Android.bp
+++ b/fs_mgr/libfiemap/Android.bp
@@ -104,4 +104,34 @@
     srcs: [
         "image_test.cpp",
     ],
+    test_suites: ["device-tests"],
+    auto_gen_config: true,
+    require_root: true,
+}
+
+/* BUG(148874852) temporary test */
+cc_test {
+    name: "fiemap_image_test_presubmit",
+    cppflags: [
+        "-DSKIP_TEST_IN_PRESUBMIT",
+    ],
+    static_libs: [
+        "libdm",
+        "libext4_utils",
+        "libfs_mgr",
+        "liblp",
+    ],
+    shared_libs: [
+        "libbase",
+        "libcrypto",
+        "libcrypto_utils",
+        "libcutils",
+        "liblog",
+    ],
+    srcs: [
+        "image_test.cpp",
+    ],
+    test_suites: ["device-tests"],
+    auto_gen_config: true,
+    require_root: true,
 }
diff --git a/fs_mgr/libfiemap/fiemap_writer.cpp b/fs_mgr/libfiemap/fiemap_writer.cpp
index b911234..4dd4bcc 100644
--- a/fs_mgr/libfiemap/fiemap_writer.cpp
+++ b/fs_mgr/libfiemap/fiemap_writer.cpp
@@ -526,11 +526,7 @@
 }
 
 static bool IsLastExtent(const fiemap_extent* extent) {
-    if (!(extent->fe_flags & FIEMAP_EXTENT_LAST)) {
-        LOG(ERROR) << "Extents are being received out-of-order";
-        return false;
-    }
-    return true;
+    return !!(extent->fe_flags & FIEMAP_EXTENT_LAST);
 }
 
 static bool FiemapToExtents(struct fiemap* fiemap, std::vector<struct fiemap_extent>* extents,
@@ -552,7 +548,10 @@
         fiemap_extent* next = &fiemap->fm_extents[i];
 
         // Make sure extents are returned in order
-        if (next != last_extent && IsLastExtent(next)) return false;
+        if (next != last_extent && IsLastExtent(next)) {
+            LOG(ERROR) << "Extents are being received out-of-order";
+            return false;
+        }
 
         // Check if extent's flags are valid
         if (!IsValidExtent(next, file_path)) return false;
@@ -592,8 +591,7 @@
         return false;
     }
 
-    uint64_t fiemap_size =
-            sizeof(struct fiemap_extent) + num_extents * sizeof(struct fiemap_extent);
+    uint64_t fiemap_size = sizeof(struct fiemap) + num_extents * sizeof(struct fiemap_extent);
     auto buffer = std::unique_ptr<void, decltype(&free)>(calloc(1, fiemap_size), free);
     if (buffer == nullptr) {
         LOG(ERROR) << "Failed to allocate memory for fiemap";
diff --git a/fs_mgr/libfiemap/image_test.cpp b/fs_mgr/libfiemap/image_test.cpp
index 80c340f..5388b44 100644
--- a/fs_mgr/libfiemap/image_test.cpp
+++ b/fs_mgr/libfiemap/image_test.cpp
@@ -212,6 +212,9 @@
 }
 
 TEST_F(ImageTest, IndirectMount) {
+#ifdef SKIP_TEST_IN_PRESUBMIT
+    GTEST_SKIP() << "WIP failure b/148874852";
+#endif
     // Create a simple wrapper around the base device that we'll mount from
     // instead. This will simulate the code paths for dm-crypt/default-key/bow
     // and force us to use device-mapper rather than loop devices.
diff --git a/fs_mgr/libfs_avb/fs_avb.cpp b/fs_mgr/libfs_avb/fs_avb.cpp
index 8770a6b..ed623bc 100644
--- a/fs_mgr/libfs_avb/fs_avb.cpp
+++ b/fs_mgr/libfs_avb/fs_avb.cpp
@@ -266,8 +266,10 @@
     return avb_handle;
 }
 
-AvbUniquePtr AvbHandle::LoadAndVerifyVbmeta(const FstabEntry& fstab_entry) {
-    if (fstab_entry.avb_keys.empty()) {
+AvbUniquePtr AvbHandle::LoadAndVerifyVbmeta(const FstabEntry& fstab_entry,
+                                            const std::vector<std::string>& preload_avb_key_blobs) {
+    // At least one of the following should be provided for public key matching.
+    if (preload_avb_key_blobs.empty() && fstab_entry.avb_keys.empty()) {
         LERROR << "avb_keys=/path/to/key(s) is missing for " << fstab_entry.mount_point;
         return nullptr;
     }
@@ -309,18 +311,36 @@
             return nullptr;
     }
 
-    // fstab_entry.avb_keys might be either a directory containing multiple keys,
-    // or a string indicating multiple keys separated by ':'.
-    std::vector<std::string> allowed_avb_keys;
-    auto list_avb_keys_in_dir = ListFiles(fstab_entry.avb_keys);
-    if (list_avb_keys_in_dir) {
-        std::sort(list_avb_keys_in_dir->begin(), list_avb_keys_in_dir->end());
-        allowed_avb_keys = *list_avb_keys_in_dir;
-    } else {
-        allowed_avb_keys = Split(fstab_entry.avb_keys, ":");
+    bool public_key_match = false;
+    // Performs key matching for preload_avb_key_blobs first, if it is present.
+    if (!public_key_data.empty() && !preload_avb_key_blobs.empty()) {
+        if (std::find(preload_avb_key_blobs.begin(), preload_avb_key_blobs.end(),
+                      public_key_data) != preload_avb_key_blobs.end()) {
+            public_key_match = true;
+        }
+    }
+    // Performs key matching for fstab_entry.avb_keys if necessary.
+    // Note that it is intentional to match both preload_avb_key_blobs and fstab_entry.avb_keys.
+    // Some keys might only be availble before init chroots into /system, e.g., /avb/key1
+    // in the first-stage ramdisk, while other keys might only be available after the chroot,
+    // e.g., /system/etc/avb/key2.
+    if (!public_key_data.empty() && !public_key_match) {
+        // fstab_entry.avb_keys might be either a directory containing multiple keys,
+        // or a string indicating multiple keys separated by ':'.
+        std::vector<std::string> allowed_avb_keys;
+        auto list_avb_keys_in_dir = ListFiles(fstab_entry.avb_keys);
+        if (list_avb_keys_in_dir.ok()) {
+            std::sort(list_avb_keys_in_dir->begin(), list_avb_keys_in_dir->end());
+            allowed_avb_keys = *list_avb_keys_in_dir;
+        } else {
+            allowed_avb_keys = Split(fstab_entry.avb_keys, ":");
+        }
+        if (ValidatePublicKeyBlob(public_key_data, allowed_avb_keys)) {
+            public_key_match = true;
+        }
     }
 
-    if (!ValidatePublicKeyBlob(public_key_data, allowed_avb_keys)) {
+    if (!public_key_match) {
         avb_handle->status_ = AvbHandleStatus::kVerificationError;
         LWARNING << "Found unknown public key used to sign " << fstab_entry.mount_point;
         if (!allow_verification_error) {
diff --git a/fs_mgr/libfs_avb/include/fs_avb/fs_avb.h b/fs_mgr/libfs_avb/include/fs_avb/fs_avb.h
index 521f2d5..4702e68 100644
--- a/fs_mgr/libfs_avb/include/fs_avb/fs_avb.h
+++ b/fs_mgr/libfs_avb/include/fs_avb/fs_avb.h
@@ -85,8 +85,15 @@
     // TODO(bowgotsai): remove Open() and switch to LoadAndVerifyVbmeta().
     static AvbUniquePtr Open();                 // loads inline vbmeta, via libavb.
     static AvbUniquePtr LoadAndVerifyVbmeta();  // loads inline vbmeta.
-    static AvbUniquePtr LoadAndVerifyVbmeta(
-            const FstabEntry& fstab_entry);     // loads offline vbmeta.
+
+    // The caller can specify optional preload_avb_key_blobs for public key matching.
+    // This is mostly for init to preload AVB keys before chroot into /system.
+    // Both preload_avb_key_blobs and fstab_entry.avb_keys (file paths) will be used
+    // for public key matching.
+    static AvbUniquePtr LoadAndVerifyVbmeta(  // loads offline vbmeta.
+            const FstabEntry& fstab_entry,
+            const std::vector<std::string>& preload_avb_key_blobs = {});
+
     static AvbUniquePtr LoadAndVerifyVbmeta(    // loads offline vbmeta.
             const std::string& partition_name, const std::string& ab_suffix,
             const std::string& ab_other_suffix, const std::string& expected_public_key,
diff --git a/fs_mgr/libfs_avb/tests/util_test.cpp b/fs_mgr/libfs_avb/tests/util_test.cpp
index e64282b..5c388aa 100644
--- a/fs_mgr/libfs_avb/tests/util_test.cpp
+++ b/fs_mgr/libfs_avb/tests/util_test.cpp
@@ -232,8 +232,7 @@
 
     // List files for comparison.
     auto result = ListFiles(test_dir.value());
-    ASSERT_TRUE(result);
-    ASSERT_TRUE(result.has_value());
+    ASSERT_RESULT_OK(result);
     auto files = result.value();
     EXPECT_EQ(3UL, files.size());
     // Sort them offline for comparison.
@@ -266,8 +265,7 @@
 
     // List files for comparison.
     auto result = ListFiles(test_dir.value());
-    ASSERT_TRUE(result);
-    ASSERT_TRUE(result.has_value());
+    ASSERT_RESULT_OK(result);
     auto files = result.value();
     EXPECT_EQ(2UL, files.size());  // Should not include the symlink file.
     // Sort them offline for comparison.
@@ -287,7 +285,7 @@
     base::FilePath no_such_dir = tmp_dir.Append("not_such_dir");
 
     auto fail = ListFiles(no_such_dir.value());
-    ASSERT_FALSE(fail);
+    ASSERT_FALSE(fail.ok());
     EXPECT_EQ(ENOENT, fail.error().code());
     EXPECT_TRUE(android::base::StartsWith(fail.error().message(), "Failed to opendir: "));
 }
@@ -303,8 +301,7 @@
 
     // List files without sorting.
     auto result = ListFiles(test_dir.value());
-    ASSERT_TRUE(result);
-    ASSERT_TRUE(result.has_value());
+    ASSERT_RESULT_OK(result);
     auto files = result.value();
     EXPECT_EQ(0UL, files.size());
 
diff --git a/fs_mgr/libsnapshot/Android.bp b/fs_mgr/libsnapshot/Android.bp
index c58101a..adfee1d 100644
--- a/fs_mgr/libsnapshot/Android.bp
+++ b/fs_mgr/libsnapshot/Android.bp
@@ -160,8 +160,8 @@
     ],
 }
 
-cc_test {
-    name: "libsnapshot_test",
+cc_defaults {
+    name: "libsnapshot_test_defaults",
     defaults: ["libsnapshot_defaults"],
     srcs: [
         "partition_cow_creator_test.cpp",
@@ -173,10 +173,7 @@
         "android.hardware.boot@1.1",
         "libbinder",
         "libcrypto",
-        "libfs_mgr",
-        "libgsi",
         "libhidlbase",
-        "liblp",
         "libprotobuf-cpp-lite",
         "libsparse",
         "libutils",
@@ -186,16 +183,38 @@
         "libutilscallstack",
     ],
     static_libs: [
+        "libfs_mgr",
+        "libgsi",
         "libgmock",
+        "liblp",
         "libsnapshot",
         "libsnapshot_test_helpers",
     ],
     header_libs: [
         "libstorage_literals_headers",
     ],
+    test_suites: [
+        "vts-core",
+        "device-tests"
+    ],
+    test_min_api_level: 29,
+    auto_gen_config: true,
     require_root: true,
 }
 
+cc_test {
+    name: "vts_libsnapshot_test",
+    defaults: ["libsnapshot_test_defaults"],
+}
+
+cc_test {
+    name: "vts_libsnapshot_test_presubmit",
+    defaults: ["libsnapshot_test_defaults"],
+    cppflags: [
+        "-DSKIP_TEST_IN_PRESUBMIT",
+    ],
+}
+
 cc_binary {
     name: "snapshotctl",
     srcs: [
@@ -211,7 +230,6 @@
         "android.hardware.boot@1.1",
         "libbase",
         "libbinder",
-        "libbinderthreadstate",
         "libext2_uuid",
         "libext4_utils",
         "libfs_mgr_binder",
diff --git a/fs_mgr/libsnapshot/device_info.cpp b/fs_mgr/libsnapshot/device_info.cpp
index bacb41c..0e90100 100644
--- a/fs_mgr/libsnapshot/device_info.cpp
+++ b/fs_mgr/libsnapshot/device_info.cpp
@@ -22,6 +22,7 @@
 namespace snapshot {
 
 #ifdef LIBSNAPSHOT_USE_HAL
+using android::hardware::boot::V1_0::BoolResult;
 using android::hardware::boot::V1_0::CommandResult;
 #endif
 
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
index e786bc9..ed92dd7 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
@@ -174,6 +174,7 @@
     // See InitiateMerge() and ProcessUpdateState() for details.
     // Returns:
     //   - None if no merge to initiate
+    //   - Unverified if called on the source slot
     //   - MergeCompleted if merge is completed
     //   - other states indicating an error has occurred
     UpdateState InitiateMergeAndWait();
@@ -273,6 +274,7 @@
     FRIEND_TEST(SnapshotTest, UpdateBootControlHal);
     FRIEND_TEST(SnapshotUpdateTest, DataWipeAfterRollback);
     FRIEND_TEST(SnapshotUpdateTest, DataWipeRollbackInRecovery);
+    FRIEND_TEST(SnapshotUpdateTest, FullUpdateFlow);
     FRIEND_TEST(SnapshotUpdateTest, MergeCannotRemoveCow);
     FRIEND_TEST(SnapshotUpdateTest, MergeInRecovery);
     FRIEND_TEST(SnapshotUpdateTest, SnapshotStatusFileWithoutCow);
@@ -374,7 +376,7 @@
     bool HandleCancelledUpdate(LockedFile* lock);
 
     // Helper for HandleCancelledUpdate. Assumes booting from new slot.
-    bool HandleCancelledUpdateOnNewSlot(LockedFile* lock);
+    bool AreAllSnapshotsCancelled(LockedFile* lock);
 
     // Remove artifacts created by the update process, such as snapshots, and
     // set the update state to None.
@@ -439,7 +441,7 @@
     std::string GetSnapshotStatusFilePath(const std::string& name);
 
     std::string GetSnapshotBootIndicatorPath();
-    void RemoveSnapshotBootIndicator();
+    std::string GetRollbackIndicatorPath();
 
     // Return the name of the device holding the "snapshot" or "snapshot-merge"
     // target. This may not be the final device presented via MapSnapshot(), if
@@ -503,6 +505,8 @@
     friend std::ostream& operator<<(std::ostream& os, SnapshotManager::Slot slot);
     Slot GetCurrentSlot();
 
+    std::string ReadUpdateSourceSlotSuffix();
+
     std::string gsid_dir_;
     std::string metadata_dir_;
     std::unique_ptr<IDeviceInfo> device_;
diff --git a/fs_mgr/libsnapshot/snapshot.cpp b/fs_mgr/libsnapshot/snapshot.cpp
index 63a9302..a937b43 100644
--- a/fs_mgr/libsnapshot/snapshot.cpp
+++ b/fs_mgr/libsnapshot/snapshot.cpp
@@ -188,11 +188,19 @@
     return true;
 }
 
-SnapshotManager::Slot SnapshotManager::GetCurrentSlot() {
+std::string SnapshotManager::ReadUpdateSourceSlotSuffix() {
     auto boot_file = GetSnapshotBootIndicatorPath();
     std::string contents;
     if (!android::base::ReadFileToString(boot_file, &contents)) {
         PLOG(WARNING) << "Cannot read " << boot_file;
+        return {};
+    }
+    return contents;
+}
+
+SnapshotManager::Slot SnapshotManager::GetCurrentSlot() {
+    auto contents = ReadUpdateSourceSlotSuffix();
+    if (contents.empty()) {
         return Slot::Unknown;
     }
     if (device_->GetSlotSuffix() == contents) {
@@ -201,6 +209,15 @@
     return Slot::Target;
 }
 
+static bool RemoveFileIfExists(const std::string& path) {
+    std::string message;
+    if (!android::base::RemoveFileIfExists(path, &message)) {
+        LOG(ERROR) << "Remove failed: " << path << ": " << message;
+        return false;
+    }
+    return true;
+}
+
 bool SnapshotManager::RemoveAllUpdateState(LockedFile* lock) {
     LOG(INFO) << "Removing all update state.";
 
@@ -223,7 +240,13 @@
         return false;
     }
 
-    RemoveSnapshotBootIndicator();
+    // It's okay if these fail - first-stage init performs a deeper check after
+    // reading the indicator file, so it's not a problem if it still exists
+    // after the update completes.
+    std::vector<std::string> files = {GetSnapshotBootIndicatorPath(), GetRollbackIndicatorPath()};
+    for (const auto& file : files) {
+        RemoveFileIfExists(file);
+    }
 
     // If this fails, we'll keep trying to remove the update state (as the
     // device reboots or starts a new update) until it finally succeeds.
@@ -250,6 +273,13 @@
         return false;
     }
 
+    // This file is written on boot to detect whether a rollback occurred. It
+    // MUST NOT exist before rebooting, otherwise, we're at risk of deleting
+    // snapshots too early.
+    if (!RemoveFileIfExists(GetRollbackIndicatorPath())) {
+        return false;
+    }
+
     // This file acts as both a quick indicator for init (it can use access(2)
     // to decide how to do first-stage mounts), and it stores the old slot, so
     // we can tell whether or not we performed a rollback.
@@ -966,14 +996,8 @@
     return metadata_dir_ + "/" + android::base::Basename(kBootIndicatorPath);
 }
 
-void SnapshotManager::RemoveSnapshotBootIndicator() {
-    // It's okay if this fails - first-stage init performs a deeper check after
-    // reading the indicator file, so it's not a problem if it still exists
-    // after the update completes.
-    auto boot_file = GetSnapshotBootIndicatorPath();
-    if (unlink(boot_file.c_str()) == -1 && errno != ENOENT) {
-        PLOG(ERROR) << "unlink " << boot_file;
-    }
+std::string SnapshotManager::GetRollbackIndicatorPath() {
+    return metadata_dir_ + "/rollback-indicator";
 }
 
 void SnapshotManager::AcknowledgeMergeSuccess(LockedFile* lock) {
@@ -1144,25 +1168,18 @@
     if (slot == Slot::Unknown) {
         return false;
     }
-    if (slot == Slot::Target) {
-        // We're booted into the target slot, which means we just rebooted
-        // after applying the update.
-        if (!HandleCancelledUpdateOnNewSlot(lock)) {
-            return false;
-        }
+
+    // If all snapshots were reflashed, then cancel the entire update.
+    if (AreAllSnapshotsCancelled(lock)) {
+        RemoveAllUpdateState(lock);
+        return true;
     }
 
-    // The only way we can get here is if:
-    //  (1) The device rolled back to the previous slot.
-    //  (2) This function was called prematurely before rebooting the device.
-    //  (3) fastboot set_active was used.
-    //  (4) The device updates to the new slot but re-flashed *all* partitions
-    //      in the new slot.
-    //
-    // In any case, delete the snapshots. It may be worth using the boot_control
-    // HAL to differentiate case (2).
-    RemoveAllUpdateState(lock);
-    return true;
+    // This unverified update might be rolled back, or it might not (b/147347110
+    // comment #77). Take no action, as update_engine is responsible for deciding
+    // whether to cancel.
+    LOG(ERROR) << "Update state is being processed before reboot, taking no action.";
+    return false;
 }
 
 std::unique_ptr<LpMetadata> SnapshotManager::ReadCurrentMetadata() {
@@ -1187,7 +1204,7 @@
     return MetadataPartitionState::Flashed;
 }
 
-bool SnapshotManager::HandleCancelledUpdateOnNewSlot(LockedFile* lock) {
+bool SnapshotManager::AreAllSnapshotsCancelled(LockedFile* lock) {
     std::vector<std::string> snapshots;
     if (!ListSnapshots(lock, &snapshots)) {
         LOG(WARNING) << "Failed to list snapshots to determine whether device has been flashed "
@@ -1196,35 +1213,45 @@
         return true;
     }
 
+    auto source_slot_suffix = ReadUpdateSourceSlotSuffix();
+    if (source_slot_suffix.empty()) {
+        return false;
+    }
+    uint32_t source_slot = SlotNumberForSlotSuffix(source_slot_suffix);
+    uint32_t target_slot = (source_slot == 0) ? 1 : 0;
+
     // Attempt to detect re-flashing on each partition.
     // - If all partitions are re-flashed, we can proceed to cancel the whole update.
     // - If only some of the partitions are re-flashed, snapshots for re-flashed partitions are
     //   deleted. Caller is responsible for merging the rest of the snapshots.
     // - If none of the partitions are re-flashed, caller is responsible for merging the snapshots.
-    auto metadata = ReadCurrentMetadata();
-    if (!metadata) return false;
-    bool all_snapshot_cancelled = true;
+    //
+    // Note that we use target slot metadata, since if an OTA has been applied
+    // to the target slot, we can detect the UPDATED flag. Any kind of flash
+    // operation against dynamic partitions ensures that all copies of the
+    // metadata are in sync, so flashing all partitions on the source slot will
+    // remove the UPDATED flag on the target slot as well.
+    const auto& opener = device_->GetPartitionOpener();
+    auto super_device = device_->GetSuperDevice(target_slot);
+    auto metadata = android::fs_mgr::ReadMetadata(opener, super_device, target_slot);
+    if (!metadata) {
+        return false;
+    }
+
+    bool all_snapshots_cancelled = true;
     for (const auto& snapshot_name : snapshots) {
         if (GetMetadataPartitionState(*metadata, snapshot_name) ==
             MetadataPartitionState::Updated) {
-            LOG(WARNING) << "Cannot cancel update because snapshot" << snapshot_name
-                         << " is in use.";
-            all_snapshot_cancelled = false;
+            all_snapshots_cancelled = false;
             continue;
         }
         // Delete snapshots for partitions that are re-flashed after the update.
-        LOG(INFO) << "Detected re-flashing of partition " << snapshot_name << ".";
-        if (!DeleteSnapshot(lock, snapshot_name)) {
-            // This is an error, but it is okay to leave the snapshot in the short term.
-            // However, if all_snapshot_cancelled == false after exiting the loop, caller may
-            // initiate merge for this unused snapshot, which is likely to fail.
-            LOG(WARNING) << "Failed to delete snapshot for re-flashed partition " << snapshot_name;
-        }
+        LOG(WARNING) << "Detected re-flashing of partition " << snapshot_name << ".";
     }
-    if (!all_snapshot_cancelled) return false;
-
-    LOG(INFO) << "All partitions are re-flashed after update, removing all update states.";
-    return true;
+    if (all_snapshots_cancelled) {
+        LOG(WARNING) << "All partitions are re-flashed after update, removing all update states.";
+    }
+    return all_snapshots_cancelled;
 }
 
 bool SnapshotManager::RemoveAllSnapshots(LockedFile* lock) {
@@ -1344,7 +1371,16 @@
     // the reason be clearer? Because the indicator file still exists, and
     // if this was FATAL, reverting to the old slot would be broken.
     auto slot = GetCurrentSlot();
+
     if (slot != Slot::Target) {
+        if (slot == Slot::Source && !device_->IsRecovery()) {
+            // Device is rebooting into the original slot, so mark this as a
+            // rollback.
+            auto path = GetRollbackIndicatorPath();
+            if (!android::base::WriteStringToFile("1", path)) {
+                PLOG(ERROR) << "Unable to write rollback indicator: " << path;
+            }
+        }
         LOG(INFO) << "Not booting from new slot. Will not mount snapshots.";
         return false;
     }
@@ -2370,6 +2406,10 @@
         return state;
     }
     if (state == UpdateState::Unverified) {
+        if (GetCurrentSlot() != Slot::Target) {
+            LOG(INFO) << "Cannot merge until device reboots.";
+            return state;
+        }
         if (!InitiateMerge()) {
             LOG(ERROR) << "Failed to initiate merge.";
             return state;
diff --git a/fs_mgr/libsnapshot/snapshot_test.cpp b/fs_mgr/libsnapshot/snapshot_test.cpp
index c5ad44c..d87274d 100644
--- a/fs_mgr/libsnapshot/snapshot_test.cpp
+++ b/fs_mgr/libsnapshot/snapshot_test.cpp
@@ -447,6 +447,9 @@
     auto sm = SnapshotManager::NewForFirstStageMount(info);
     ASSERT_NE(sm, nullptr);
     ASSERT_FALSE(sm->NeedSnapshotsInFirstStageMount());
+
+    auto indicator = sm->GetRollbackIndicatorPath();
+    ASSERT_EQ(access(indicator.c_str(), R_OK), 0);
 }
 
 TEST_F(SnapshotTest, Merge) {
@@ -503,6 +506,9 @@
 }
 
 TEST_F(SnapshotTest, FirstStageMountAndMerge) {
+#ifdef SKIP_TEST_IN_PRESUBMIT
+    GTEST_SKIP() << "WIP failure b/148889015";
+#endif
     ASSERT_TRUE(AcquireLock());
 
     static const uint64_t kDeviceSize = 1024 * 1024;
@@ -559,6 +565,9 @@
 }
 
 TEST_F(SnapshotTest, FlashSuperDuringMerge) {
+#ifdef SKIP_TEST_IN_PRESUBMIT
+    GTEST_SKIP() << "WIP failure b/148889015";
+#endif
     ASSERT_TRUE(AcquireLock());
 
     static const uint64_t kDeviceSize = 1024 * 1024;
@@ -970,6 +979,9 @@
 // Also test UnmapUpdateSnapshot unmaps everything.
 // Also test first stage mount and merge after this.
 TEST_F(SnapshotUpdateTest, FullUpdateFlow) {
+#ifdef SKIP_TEST_IN_PRESUBMIT
+    GTEST_SKIP() << "WIP failure b/148889015";
+#endif
     // OTA client blindly unmaps all partitions that are possibly mapped.
     for (const auto& name : {"sys_b", "vnd_b", "prd_b"}) {
         ASSERT_TRUE(sm->UnmapUpdateSnapshot(name));
@@ -1015,6 +1027,9 @@
     ASSERT_TRUE(init->NeedSnapshotsInFirstStageMount());
     ASSERT_TRUE(init->CreateLogicalAndSnapshotPartitions("super", snapshot_timeout_));
 
+    auto indicator = sm->GetRollbackIndicatorPath();
+    ASSERT_NE(access(indicator.c_str(), R_OK), 0);
+
     // Check that the target partitions have the same content.
     for (const auto& name : {"sys_b", "vnd_b", "prd_b"}) {
         ASSERT_TRUE(IsPartitionUnchanged(name));
@@ -1114,6 +1129,9 @@
 
 // Test that the old partitions are not modified.
 TEST_F(SnapshotUpdateTest, TestRollback) {
+#ifdef SKIP_TEST_IN_PRESUBMIT
+    GTEST_SKIP() << "WIP failure b/148889015";
+#endif
     // Execute the update.
     ASSERT_TRUE(sm->BeginUpdate());
     ASSERT_TRUE(sm->UnmapUpdateSnapshot("sys_b"));
@@ -1291,6 +1309,9 @@
 }
 
 TEST_F(SnapshotUpdateTest, MergeCannotRemoveCow) {
+#ifdef SKIP_TEST_IN_PRESUBMIT
+    GTEST_SKIP() << "WIP failure b/148889015";
+#endif
     // Make source partitions as big as possible to force COW image to be created.
     SetSize(sys_, 5_MiB);
     SetSize(vnd_, 5_MiB);
@@ -1565,6 +1586,9 @@
 }
 
 TEST_F(SnapshotUpdateTest, WaitForMerge) {
+#ifdef SKIP_TEST_IN_PRESUBMIT
+    GTEST_SKIP() << "WIP failure b/148889015";
+#endif
     AddOperationForPartitions();
 
     // Execute the update.
@@ -1681,9 +1705,11 @@
     ASSERT_NE(nullptr, flashed_builder->FindPartition("prd" + flashed_slot_suffix));
     flashed_builder->RemovePartition("prd" + flashed_slot_suffix);
 
+    // Note that fastbootd always updates the partition table of both slots.
     auto flashed_metadata = flashed_builder->Export();
     ASSERT_NE(nullptr, flashed_metadata);
-    ASSERT_TRUE(UpdatePartitionTable(*opener_, "super", *flashed_metadata, flashed_slot));
+    ASSERT_TRUE(UpdatePartitionTable(*opener_, "super", *flashed_metadata, 0));
+    ASSERT_TRUE(UpdatePartitionTable(*opener_, "super", *flashed_metadata, 1));
 
     std::string path;
     for (const auto& name : {"sys", "vnd"}) {
@@ -1782,6 +1808,10 @@
     std::vector<uint64_t> ret;
     for (uint64_t size = 1_MiB; size <= 512_MiB; size *= 2) {
         ret.push_back(size);
+#ifdef SKIP_TEST_IN_PRESUBMIT
+        // BUG(148889015);
+        break;
+#endif
     }
     return ret;
 }
diff --git a/fs_mgr/libsnapshot/snapshotctl.cpp b/fs_mgr/libsnapshot/snapshotctl.cpp
index 9f23c45..d724be3 100644
--- a/fs_mgr/libsnapshot/snapshotctl.cpp
+++ b/fs_mgr/libsnapshot/snapshotctl.cpp
@@ -112,7 +112,9 @@
 
     auto state = SnapshotManager::New()->InitiateMergeAndWait();
 
-    if (state == UpdateState::None) {
+    // We could wind up in the Unverified state if the device rolled back or
+    // hasn't fully rebooted. Ignore this.
+    if (state == UpdateState::None || state == UpdateState::Unverified) {
         return true;
     }
     if (state == UpdateState::MergeCompleted) {
diff --git a/fs_mgr/libvbmeta/builder.cpp b/fs_mgr/libvbmeta/builder.cpp
index a901a4f..e6576ce 100644
--- a/fs_mgr/libvbmeta/builder.cpp
+++ b/fs_mgr/libvbmeta/builder.cpp
@@ -40,18 +40,18 @@
 Result<void> SuperVBMetaBuilder::Build() {
     for (const auto& [vbmeta_name, file_path] : images_path_) {
         Result<std::string> content = ReadVBMetaImageFromFile(file_path);
-        if (!content) {
+        if (!content.ok()) {
             return content.error();
         }
 
         Result<uint8_t> vbmeta_index = AddVBMetaImage(vbmeta_name);
-        if (!vbmeta_index) {
+        if (!vbmeta_index.ok()) {
             return vbmeta_index.error();
         }
 
         Result<void> rv_export_vbmeta_image =
                 ExportVBMetaImageToFile(vbmeta_index.value(), content.value());
-        if (!rv_export_vbmeta_image) {
+        if (!rv_export_vbmeta_image.ok()) {
             return rv_export_vbmeta_image;
         }
     }
@@ -65,7 +65,7 @@
     }
 
     Result<uint64_t> file_size = GetFileSize(source_fd);
-    if (!file_size) {
+    if (!file_size.ok()) {
         return file_size.error();
     }
 
@@ -98,7 +98,7 @@
         slot_number = desc->vbmeta_index;
     } else {
         Result<uint8_t> new_slot = GetEmptySlot();
-        if (!new_slot) {
+        if (!new_slot.ok()) {
             return new_slot;
         }
         slot_number = new_slot.value();
@@ -162,7 +162,7 @@
 
     android::base::Result<void> rv_write_primary_vbmeta_table =
             WritePrimaryVBMetaTable(super_vbmeta_fd_, serialized_table);
-    if (!rv_write_primary_vbmeta_table) {
+    if (!rv_write_primary_vbmeta_table.ok()) {
         return rv_write_primary_vbmeta_table;
     }
 
@@ -175,7 +175,7 @@
                                                          const std::string& vbmeta_image) {
     Result<void> rv_write_vbmeta_image =
             WriteVBMetaImage(super_vbmeta_fd_, vbmeta_index, vbmeta_image);
-    if (!rv_write_vbmeta_image) {
+    if (!rv_write_vbmeta_image.ok()) {
         return rv_write_vbmeta_image;
     }
 
@@ -196,13 +196,13 @@
     SuperVBMetaBuilder builder(super_vbmeta_fd, images_path);
 
     Result<void> rv_build = builder.Build();
-    if (!rv_build) {
+    if (!rv_build.ok()) {
         LERROR << rv_build.error();
         return false;
     }
 
     Result<void> rv_export = builder.ExportVBMetaTableToFile();
-    if (!rv_export) {
+    if (!rv_export.ok()) {
         LERROR << rv_export.error();
         return false;
     }
@@ -211,4 +211,4 @@
 }
 
 }  // namespace fs_mgr
-}  // namespace android
\ No newline at end of file
+}  // namespace android
diff --git a/fs_mgr/libvbmeta/builder_test.cpp b/fs_mgr/libvbmeta/builder_test.cpp
index 9a015fd..487bece 100644
--- a/fs_mgr/libvbmeta/builder_test.cpp
+++ b/fs_mgr/libvbmeta/builder_test.cpp
@@ -26,24 +26,20 @@
     std::unique_ptr<SuperVBMetaBuilder> builder = std::make_unique<SuperVBMetaBuilder>();
     ASSERT_NE(builder, nullptr);
 
-    Result<uint8_t> vbmeta_index = builder->AddVBMetaImage("vbmeta" /* vbmeta_name */
-    );
-    EXPECT_TRUE(vbmeta_index);
+    Result<uint8_t> vbmeta_index = builder->AddVBMetaImage("vbmeta" /* vbmeta_name */);
+    EXPECT_RESULT_OK(vbmeta_index);
 
-    Result<uint8_t> vbmeta_system_slot = builder->AddVBMetaImage("vbmeta_system" /* vbmeta_name */
-    );
-    EXPECT_TRUE(vbmeta_system_slot);
+    Result<uint8_t> vbmeta_system_slot = builder->AddVBMetaImage("vbmeta_system" /* vbmeta_name */);
+    EXPECT_RESULT_OK(vbmeta_system_slot);
 
-    Result<uint8_t> vbmeta_vendor_slot = builder->AddVBMetaImage("vbmeta_vendor" /* vbmeta_name */
-    );
-    EXPECT_TRUE(vbmeta_vendor_slot);
+    Result<uint8_t> vbmeta_vendor_slot = builder->AddVBMetaImage("vbmeta_vendor" /* vbmeta_name */);
+    EXPECT_RESULT_OK(vbmeta_vendor_slot);
 
-    builder->DeleteVBMetaImage("vbmeta_system" /* vbmeta_name */
-    );
+    builder->DeleteVBMetaImage("vbmeta_system" /* vbmeta_name */);
 
-    Result<uint8_t> vbmeta_product_slot = builder->AddVBMetaImage("vbmeta_product" /* vbmeta_name */
-    );
-    EXPECT_TRUE(vbmeta_product_slot);
+    Result<uint8_t> vbmeta_product_slot =
+            builder->AddVBMetaImage("vbmeta_product" /* vbmeta_name */);
+    EXPECT_RESULT_OK(vbmeta_product_slot);
 
     std::unique_ptr<VBMetaTable> table = builder->ExportVBMetaTable();
     ASSERT_NE(table, nullptr);
@@ -77,4 +73,4 @@
     for (int i = 0; i < sizeof(table->descriptors[2].reserved); i++)
         EXPECT_EQ(table->descriptors[2].reserved[i], 0);
     EXPECT_EQ(table->descriptors[2].vbmeta_name, "vbmeta_product");
-}
\ No newline at end of file
+}
diff --git a/fs_mgr/libvbmeta/reader.cpp b/fs_mgr/libvbmeta/reader.cpp
index 212d186..7b5ed93 100644
--- a/fs_mgr/libvbmeta/reader.cpp
+++ b/fs_mgr/libvbmeta/reader.cpp
@@ -64,7 +64,7 @@
     }
 
     Result<void> rv_header = LoadAndVerifySuperVBMetaHeader(header_buffer.get(), &table->header);
-    if (!rv_header) {
+    if (!rv_header.ok()) {
         return rv_header;
     }
 
@@ -104,7 +104,7 @@
 Result<void> ValidateVBMetaImage(int super_vbmeta_fd, int vbmeta_index,
                                  const std::string& vbmeta_image) {
     Result<std::string> content = ReadVBMetaImage(super_vbmeta_fd, vbmeta_index);
-    if (!content) {
+    if (!content.ok()) {
         return content.error();
     }
 
diff --git a/fs_mgr/libvbmeta/super_vbmeta_test.cpp b/fs_mgr/libvbmeta/super_vbmeta_test.cpp
index 6b4fc5d..daed0d1 100644
--- a/fs_mgr/libvbmeta/super_vbmeta_test.cpp
+++ b/fs_mgr/libvbmeta/super_vbmeta_test.cpp
@@ -77,7 +77,7 @@
     android::base::unique_fd fd(open(file.c_str(), O_RDONLY | O_CLOEXEC));
     EXPECT_GT(fd, 0);
     Result<uint64_t> file_size = GetFileSize(fd);
-    EXPECT_TRUE(file_size);
+    EXPECT_RESULT_OK(file_size);
     std::unique_ptr<uint8_t[]> buffer = std::make_unique<uint8_t[]>(VBMETA_IMAGE_MAX_SIZE);
     EXPECT_TRUE(android::base::ReadFully(fd, buffer.get(), file_size.value()));
     return std::string(reinterpret_cast<char*>(buffer.get()), VBMETA_IMAGE_MAX_SIZE);
@@ -138,15 +138,15 @@
 
     // Check the size of vbmeta table
     Result<uint64_t> super_vbmeta_size = GetFileSize(fd);
-    EXPECT_TRUE(super_vbmeta_size);
+    EXPECT_RESULT_OK(super_vbmeta_size);
     EXPECT_EQ(super_vbmeta_size.value(),
               SUPER_VBMETA_TABLE_MAX_SIZE * 2 + VBMETA_IMAGE_MAX_SIZE * 3);
 
     // Check Primary vbmeta table is equal to Backup one
     VBMetaTable table;
-    EXPECT_TRUE(android::fs_mgr::ReadPrimaryVBMetaTable(fd, &table));
+    EXPECT_RESULT_OK(android::fs_mgr::ReadPrimaryVBMetaTable(fd, &table));
     VBMetaTable table_backup;
-    EXPECT_TRUE(android::fs_mgr::ReadBackupVBMetaTable(fd, &table_backup));
+    EXPECT_RESULT_OK(android::fs_mgr::ReadBackupVBMetaTable(fd, &table_backup));
     EXPECT_EQ(android::fs_mgr::SerializeVBMetaTable(table),
               android::fs_mgr::SerializeVBMetaTable(table_backup));
 
@@ -167,25 +167,25 @@
     EXPECT_EQ(table.descriptors[0].vbmeta_name_length, 14);
     EXPECT_EQ(table.descriptors[0].vbmeta_name, "vbmeta_product");
     Result<std::string> vbmeta_product_content = ReadVBMetaImage(fd, 0);
-    EXPECT_TRUE(vbmeta_product_content);
+    EXPECT_RESULT_OK(vbmeta_product_content);
     EXPECT_EQ(ReadVBMetaImageFromFile(vbmeta_product_path), vbmeta_product_content.value());
 
     EXPECT_EQ(table.descriptors[1].vbmeta_index, 1);
     EXPECT_EQ(table.descriptors[1].vbmeta_name_length, 13);
     EXPECT_EQ(table.descriptors[1].vbmeta_name, "vbmeta_system");
     Result<std::string> vbmeta_system_content = ReadVBMetaImage(fd, 1);
-    EXPECT_TRUE(vbmeta_system_content);
+    EXPECT_RESULT_OK(vbmeta_system_content);
     EXPECT_EQ(ReadVBMetaImageFromFile(vbmeta_system_path), vbmeta_system_content.value());
 
     EXPECT_EQ(table.descriptors[2].vbmeta_index, 2);
     EXPECT_EQ(table.descriptors[2].vbmeta_name_length, 13);
     EXPECT_EQ(table.descriptors[2].vbmeta_name, "vbmeta_vendor");
     Result<std::string> vbmeta_vendor_content = ReadVBMetaImage(fd, 2);
-    EXPECT_TRUE(vbmeta_vendor_content);
+    EXPECT_RESULT_OK(vbmeta_vendor_content);
     EXPECT_EQ(ReadVBMetaImageFromFile(vbmeta_vendor_path), vbmeta_vendor_content.value());
 }
 
 int main(int argc, char** argv) {
     ::testing::InitGoogleTest(&argc, argv);
     return RUN_ALL_TESTS();
-}
\ No newline at end of file
+}
diff --git a/init/Android.bp b/init/Android.bp
index 42d0b33..f28934e 100644
--- a/init/Android.bp
+++ b/init/Android.bp
@@ -14,6 +14,61 @@
 // limitations under the License.
 //
 
+init_common_sources = [
+    "action.cpp",
+    "action_manager.cpp",
+    "action_parser.cpp",
+    "capabilities.cpp",
+    "epoll.cpp",
+    "import_parser.cpp",
+    "interface_utils.cpp",
+    "keychords.cpp",
+    "parser.cpp",
+    "property_type.cpp",
+    "rlimit_parser.cpp",
+    "service.cpp",
+    "service_list.cpp",
+    "service_parser.cpp",
+    "service_utils.cpp",
+    "subcontext.cpp",
+    "subcontext.proto",
+    "tokenizer.cpp",
+    "util.cpp",
+]
+init_device_sources = [
+    "bootchart.cpp",
+    "builtins.cpp",
+    "devices.cpp",
+    "firmware_handler.cpp",
+    "first_stage_init.cpp",
+    "first_stage_mount.cpp",
+    "fscrypt_init_extensions.cpp",
+    "init.cpp",
+    "lmkd_service.cpp",
+    "modalias_handler.cpp",
+    "mount_handler.cpp",
+    "mount_namespace.cpp",
+    "persistent_properties.cpp",
+    "persistent_properties.proto",
+    "property_service.cpp",
+    "property_service.proto",
+    "reboot.cpp",
+    "reboot_utils.cpp",
+    "security.cpp",
+    "selabel.cpp",
+    "selinux.cpp",
+    "sigchld_handler.cpp",
+    "switch_root.cpp",
+    "uevent_listener.cpp",
+    "ueventd.cpp",
+    "ueventd_parser.cpp",
+]
+init_host_sources = [
+    "check_builtins.cpp",
+    "host_import_parser.cpp",
+    "host_init_verifier.cpp",
+]
+
 cc_defaults {
     name: "init_defaults",
     cpp_std: "experimental",
@@ -103,53 +158,7 @@
         "init_defaults",
         "selinux_policy_version",
     ],
-    srcs: [
-        "action.cpp",
-        "action_manager.cpp",
-        "action_parser.cpp",
-        "bootchart.cpp",
-        "builtins.cpp",
-        "capabilities.cpp",
-        "devices.cpp",
-        "epoll.cpp",
-        "firmware_handler.cpp",
-        "first_stage_init.cpp",
-        "first_stage_mount.cpp",
-        "fscrypt_init_extensions.cpp",
-        "import_parser.cpp",
-        "init.cpp",
-        "interface_utils.cpp",
-        "keychords.cpp",
-        "lmkd_service.cpp",
-        "modalias_handler.cpp",
-        "mount_handler.cpp",
-        "mount_namespace.cpp",
-        "parser.cpp",
-        "persistent_properties.cpp",
-        "persistent_properties.proto",
-        "property_service.cpp",
-        "property_service.proto",
-        "property_type.cpp",
-        "reboot.cpp",
-        "reboot_utils.cpp",
-        "security.cpp",
-        "selabel.cpp",
-        "selinux.cpp",
-        "service.cpp",
-        "service_list.cpp",
-        "service_parser.cpp",
-        "service_utils.cpp",
-        "sigchld_handler.cpp",
-        "subcontext.cpp",
-        "subcontext.proto",
-        "switch_root.cpp",
-        "rlimit_parser.cpp",
-        "tokenizer.cpp",
-        "uevent_listener.cpp",
-        "ueventd.cpp",
-        "ueventd_parser.cpp",
-        "util.cpp",
-    ],
+    srcs: init_common_sources + init_device_sources,
     whole_static_libs: [
         "libcap",
         "com.android.sysprop.apex",
@@ -297,30 +306,7 @@
         "libprocessgroup",
         "libprotobuf-cpp-lite",
     ],
-    srcs: [
-        "action.cpp",
-        "action_manager.cpp",
-        "action_parser.cpp",
-        "capabilities.cpp",
-        "check_builtins.cpp",
-        "epoll.cpp",
-        "keychords.cpp",
-        "import_parser.cpp",
-        "interface_utils.cpp",
-        "host_import_parser.cpp",
-        "host_init_verifier.cpp",
-        "parser.cpp",
-        "property_type.cpp",
-        "rlimit_parser.cpp",
-        "tokenizer.cpp",
-        "service.cpp",
-        "service_list.cpp",
-        "service_parser.cpp",
-        "service_utils.cpp",
-        "subcontext.cpp",
-        "subcontext.proto",
-        "util.cpp",
-    ],
+    srcs: init_common_sources + init_host_sources,
     proto: {
         type: "lite",
     },
diff --git a/init/action.cpp b/init/action.cpp
index f05fa7c..1e998ae 100644
--- a/init/action.cpp
+++ b/init/action.cpp
@@ -36,7 +36,7 @@
     builtin_arguments.args[0] = args[0];
     for (std::size_t i = 1; i < args.size(); ++i) {
         auto expanded_arg = ExpandProps(args[i]);
-        if (!expanded_arg) {
+        if (!expanded_arg.ok()) {
             return expanded_arg.error();
         }
         builtin_arguments.args[i] = std::move(*expanded_arg);
@@ -59,7 +59,7 @@
         }
 
         auto expanded_args = subcontext->ExpandArgs(args_);
-        if (!expanded_args) {
+        if (!expanded_args.ok()) {
             return expanded_args.error();
         }
         return RunBuiltinFunction(func_, *expanded_args, subcontext->context());
@@ -75,7 +75,7 @@
     builtin_arguments.args[0] = args_[0];
     for (size_t i = 1; i < args_.size(); ++i) {
         auto expanded_arg = ExpandProps(args_[i]);
-        if (!expanded_arg) {
+        if (!expanded_arg.ok()) {
             if (expanded_arg.error().message().find("doesn't exist while expanding") !=
                 std::string::npos) {
                 // If we failed because we won't have a property, use an empty string, which is
@@ -114,7 +114,7 @@
     }
 
     auto map_result = function_map_->Find(args);
-    if (!map_result) {
+    if (!map_result.ok()) {
         return Error() << map_result.error();
     }
 
@@ -134,7 +134,7 @@
 size_t Action::CheckAllCommands() const {
     size_t failures = 0;
     for (const auto& command : commands_) {
-        if (auto result = command.CheckCommand(); !result) {
+        if (auto result = command.CheckCommand(); !result.ok()) {
             LOG(ERROR) << "Command '" << command.BuildCommandString() << "' (" << filename_ << ":"
                        << command.line() << ") failed: " << result.error();
             ++failures;
@@ -169,7 +169,7 @@
 
         LOG(INFO) << "Command '" << cmd_str << "' action=" << trigger_name << " (" << filename_
                   << ":" << command.line() << ") took " << duration.count() << "ms and "
-                  << (result ? "succeeded" : "failed: " + result.error().message());
+                  << (result.ok() ? "succeeded" : "failed: " + result.error().message());
     }
 }
 
diff --git a/init/action_parser.cpp b/init/action_parser.cpp
index a8e1e09..f316871 100644
--- a/init/action_parser.cpp
+++ b/init/action_parser.cpp
@@ -110,14 +110,14 @@
 
         if (!args[i].compare(0, prop_str.length(), prop_str)) {
             if (auto result = ParsePropertyTrigger(args[i], subcontext, property_triggers);
-                !result) {
+                !result.ok()) {
                 return result;
             }
         } else {
             if (!event_trigger->empty()) {
                 return Error() << "multiple event triggers are not allowed";
             }
-            if (auto result = ValidateEventTrigger(args[i]); !result) {
+            if (auto result = ValidateEventTrigger(args[i]); !result.ok()) {
                 return result;
             }
 
@@ -145,8 +145,9 @@
     std::string event_trigger;
     std::map<std::string, std::string> property_triggers;
 
-    if (auto result = ParseTriggers(triggers, action_subcontext, &event_trigger, &property_triggers);
-        !result) {
+    if (auto result =
+                ParseTriggers(triggers, action_subcontext, &event_trigger, &property_triggers);
+        !result.ok()) {
         return Error() << "ParseTriggers() failed: " << result.error();
     }
 
diff --git a/init/builtins.cpp b/init/builtins.cpp
index 742e089..60c3d40 100644
--- a/init/builtins.cpp
+++ b/init/builtins.cpp
@@ -164,7 +164,7 @@
     // They must  be started individually.
     for (const auto& service : ServiceList::GetInstance()) {
         if (service->classnames().count(args[1])) {
-            if (auto result = service->StartIfNotDisabled(); !result) {
+            if (auto result = service->StartIfNotDisabled(); !result.ok()) {
                 LOG(ERROR) << "Could not start service '" << service->name()
                            << "' as part of class '" << args[1] << "': " << result.error();
             }
@@ -186,7 +186,7 @@
     }
     for (const auto& service : ServiceList::GetInstance()) {
         if (service->classnames().count(args[1])) {
-            if (auto result = service->StartIfPostData(); !result) {
+            if (auto result = service->StartIfPostData(); !result.ok()) {
                 LOG(ERROR) << "Could not start service '" << service->name()
                            << "' as part of class '" << args[1] << "': " << result.error();
             }
@@ -227,7 +227,7 @@
 }
 
 static Result<void> do_domainname(const BuiltinArguments& args) {
-    if (auto result = WriteFile("/proc/sys/kernel/domainname", args[1]); !result) {
+    if (auto result = WriteFile("/proc/sys/kernel/domainname", args[1]); !result.ok()) {
         return Error() << "Unable to write to /proc/sys/kernel/domainname: " << result.error();
     }
     return {};
@@ -237,7 +237,7 @@
     Service* svc = ServiceList::GetInstance().FindService(args[1]);
     if (!svc) return Error() << "Could not find service";
 
-    if (auto result = svc->Enable(); !result) {
+    if (auto result = svc->Enable(); !result.ok()) {
         return Error() << "Could not enable service: " << result.error();
     }
 
@@ -246,10 +246,10 @@
 
 static Result<void> do_exec(const BuiltinArguments& args) {
     auto service = Service::MakeTemporaryOneshotService(args.args);
-    if (!service) {
+    if (!service.ok()) {
         return Error() << "Could not create exec service: " << service.error();
     }
-    if (auto result = (*service)->ExecStart(); !result) {
+    if (auto result = (*service)->ExecStart(); !result.ok()) {
         return Error() << "Could not start exec service: " << result.error();
     }
 
@@ -259,10 +259,10 @@
 
 static Result<void> do_exec_background(const BuiltinArguments& args) {
     auto service = Service::MakeTemporaryOneshotService(args.args);
-    if (!service) {
+    if (!service.ok()) {
         return Error() << "Could not create exec background service: " << service.error();
     }
-    if (auto result = (*service)->Start(); !result) {
+    if (auto result = (*service)->Start(); !result.ok()) {
         return Error() << "Could not start exec background service: " << result.error();
     }
 
@@ -276,7 +276,7 @@
         return Error() << "Service not found";
     }
 
-    if (auto result = service->ExecStart(); !result) {
+    if (auto result = service->ExecStart(); !result.ok()) {
         return Error() << "Could not start exec service: " << result.error();
     }
 
@@ -291,7 +291,7 @@
 }
 
 static Result<void> do_hostname(const BuiltinArguments& args) {
-    if (auto result = WriteFile("/proc/sys/kernel/hostname", args[1]); !result) {
+    if (auto result = WriteFile("/proc/sys/kernel/hostname", args[1]); !result.ok()) {
         return Error() << "Unable to write to /proc/sys/kernel/hostname: " << result.error();
     }
     return {};
@@ -349,7 +349,7 @@
 static Result<void> do_interface_start(const BuiltinArguments& args) {
     Service* svc = ServiceList::GetInstance().FindInterface(args[1]);
     if (!svc) return Error() << "interface " << args[1] << " not found";
-    if (auto result = svc->Start(); !result) {
+    if (auto result = svc->Start(); !result.ok()) {
         return Error() << "Could not start interface: " << result.error();
     }
     return {};
@@ -413,7 +413,7 @@
 // mkdir <path> [mode] [owner] [group] [<option> ...]
 static Result<void> do_mkdir(const BuiltinArguments& args) {
     auto options = ParseMkdir(args.args);
-    if (!options) return options.error();
+    if (!options.ok()) return options.error();
     return make_dir_with_options(*options);
 }
 
@@ -681,7 +681,7 @@
          * and return processed return code*/
         initial_mount_fstab_return_code = mount_fstab_return_code;
         auto queue_fs_result = queue_fs_event(mount_fstab_return_code, false);
-        if (!queue_fs_result) {
+        if (!queue_fs_result.ok()) {
             return Error() << "queue_fs_event() failed: " << queue_fs_result.error();
         }
     }
@@ -731,7 +731,7 @@
 
 static Result<void> do_setrlimit(const BuiltinArguments& args) {
     auto rlimit = ParseRlimit(args.args);
-    if (!rlimit) return rlimit.error();
+    if (!rlimit.ok()) return rlimit.error();
 
     if (setrlimit(rlimit->first, &rlimit->second) == -1) {
         return ErrnoError() << "setrlimit failed";
@@ -742,7 +742,7 @@
 static Result<void> do_start(const BuiltinArguments& args) {
     Service* svc = ServiceList::GetInstance().FindService(args[1]);
     if (!svc) return Error() << "service " << args[1] << " not found";
-    if (auto result = svc->Start(); !result) {
+    if (auto result = svc->Start(); !result.ok()) {
         return ErrorIgnoreEnoent() << "Could not start service: " << result.error();
     }
     return {};
@@ -846,7 +846,7 @@
 }
 
 static Result<void> do_write(const BuiltinArguments& args) {
-    if (auto result = WriteFile(args[1], args[2]); !result) {
+    if (auto result = WriteFile(args[1], args[2]); !result.ok()) {
         return ErrorIgnoreEnoent()
                << "Unable to write to file '" << args[1] << "': " << result.error();
     }
@@ -904,7 +904,7 @@
         }
         android::base::Timer t;
         if (S_ISREG(sb.st_mode)) {
-            if (auto result = readahead_file(args[1], readfully); !result) {
+            if (auto result = readahead_file(args[1], readfully); !result.ok()) {
                 LOG(WARNING) << "Unable to readahead '" << args[1] << "': " << result.error();
                 _exit(EXIT_FAILURE);
             }
@@ -921,7 +921,7 @@
                  ftsent = fts_read(fts.get())) {
                 if (ftsent->fts_info & FTS_F) {
                     const std::string filename = ftsent->fts_accpath;
-                    if (auto result = readahead_file(filename, readfully); !result) {
+                    if (auto result = readahead_file(filename, readfully); !result.ok()) {
                         LOG(WARNING)
                             << "Unable to readahead '" << filename << "': " << result.error();
                     }
@@ -938,10 +938,10 @@
 
 static Result<void> do_copy(const BuiltinArguments& args) {
     auto file_contents = ReadFile(args[1]);
-    if (!file_contents) {
+    if (!file_contents.ok()) {
         return Error() << "Could not read input file '" << args[1] << "': " << file_contents.error();
     }
-    if (auto result = WriteFile(args[2], *file_contents); !result) {
+    if (auto result = WriteFile(args[2], *file_contents); !result.ok()) {
         return Error() << "Could not write to output file '" << args[2] << "': " << result.error();
     }
 
@@ -950,7 +950,7 @@
 
 static Result<void> do_chown(const BuiltinArguments& args) {
     auto uid = DecodeUid(args[1]);
-    if (!uid) {
+    if (!uid.ok()) {
         return Error() << "Unable to decode UID for '" << args[1] << "': " << uid.error();
     }
 
@@ -960,7 +960,7 @@
 
     if (args.size() == 4) {
         gid = DecodeUid(args[2]);
-        if (!gid) {
+        if (!gid.ok()) {
             return Error() << "Unable to decode GID for '" << args[2] << "': " << gid.error();
         }
     }
@@ -995,7 +995,7 @@
 
 static Result<void> do_restorecon(const BuiltinArguments& args) {
     auto restorecon_info = ParseRestorecon(args.args);
-    if (!restorecon_info) {
+    if (!restorecon_info.ok()) {
         return restorecon_info.error();
     }
 
@@ -1103,7 +1103,7 @@
 static Result<void> ExecWithFunctionOnFailure(const std::vector<std::string>& args,
                                               std::function<void(const std::string&)> function) {
     auto service = Service::MakeTemporaryOneshotService(args);
-    if (!service) {
+    if (!service.ok()) {
         function("MakeTemporaryOneshotService failed: " + service.error().message());
     }
     (*service)->AddReapCallback([function](const siginfo_t& siginfo) {
@@ -1111,7 +1111,7 @@
             function(StringPrintf("Exec service failed, status %d", siginfo.si_status));
         }
     });
-    if (auto result = (*service)->ExecStart(); !result) {
+    if (auto result = (*service)->ExecStart(); !result.ok()) {
         function("ExecStart failed: " + result.error().message());
     }
     ServiceList::GetInstance().AddService(std::move(*service));
@@ -1133,7 +1133,7 @@
                 LOG(ERROR) << message << ": Rebooting into recovery, reason: " << reboot_reason;
                 if (auto result = reboot_into_recovery(
                             {"--prompt_and_wipe_data", "--reason="s + reboot_reason});
-                    !result) {
+                    !result.ok()) {
                     LOG(FATAL) << "Could not reboot into recovery: " << result.error();
                 }
             } else {
@@ -1162,7 +1162,7 @@
     if (auto rc = fs_mgr_remount_userdata_into_checkpointing(&fstab); rc < 0) {
         trigger_shutdown("reboot,mount_userdata_failed");
     }
-    if (auto result = queue_fs_event(initial_mount_fstab_return_code, true); !result) {
+    if (auto result = queue_fs_event(initial_mount_fstab_return_code, true); !result.ok()) {
         return Error() << "queue_fs_event() failed: " << result.error();
     }
     return {};
@@ -1285,16 +1285,16 @@
 
 static Result<void> do_perform_apex_config(const BuiltinArguments& args) {
     auto create_dirs = create_apex_data_dirs();
-    if (!create_dirs) {
+    if (!create_dirs.ok()) {
         return create_dirs.error();
     }
     auto parse_configs = parse_apex_configs();
-    if (!parse_configs) {
+    if (!parse_configs.ok()) {
         return parse_configs.error();
     }
 
     auto update_linker_config = do_update_linker_config(args);
-    if (!update_linker_config) {
+    if (!update_linker_config.ok()) {
         return update_linker_config.error();
     }
 
diff --git a/init/check_builtins.cpp b/init/check_builtins.cpp
index bef6966..d62ecb0 100644
--- a/init/check_builtins.cpp
+++ b/init/check_builtins.cpp
@@ -52,7 +52,7 @@
 Result<void> check_chown(const BuiltinArguments& args) {
     if (!args[1].empty()) {
         auto uid = DecodeUid(args[1]);
-        if (!uid) {
+        if (!uid.ok()) {
             return Error() << "Unable to decode UID for '" << args[1] << "': " << uid.error();
         }
     }
@@ -60,7 +60,7 @@
     // GID is optional and pushes the index of path out by one if specified.
     if (args.size() == 4 && !args[2].empty()) {
         auto gid = DecodeUid(args[2]);
-        if (!gid) {
+        if (!gid.ok()) {
             return Error() << "Unable to decode GID for '" << args[2] << "': " << gid.error();
         }
     }
@@ -72,7 +72,7 @@
     ReturnIfAnyArgsEmpty();
 
     auto result = Service::MakeTemporaryOneshotService(args.args);
-    if (!result) {
+    if (!result.ok()) {
         return result.error();
     }
 
@@ -93,7 +93,7 @@
 }
 
 Result<void> check_interface_restart(const BuiltinArguments& args) {
-    if (auto result = IsKnownInterface(args[1]); !result) {
+    if (auto result = IsKnownInterface(args[1]); !result.ok()) {
         return result.error();
     }
     return {};
@@ -124,7 +124,7 @@
 
 Result<void> check_mkdir(const BuiltinArguments& args) {
     auto options = ParseMkdir(args.args);
-    if (!options) {
+    if (!options.ok()) {
         return options.error();
     }
     return {};
@@ -134,7 +134,7 @@
     ReturnIfAnyArgsEmpty();
 
     auto restorecon_info = ParseRestorecon(args.args);
-    if (!restorecon_info) {
+    if (!restorecon_info.ok()) {
         return restorecon_info.error();
     }
 
@@ -157,7 +157,7 @@
     }
 
     if (!value.empty()) {
-        if (auto result = IsLegalPropertyValue(name, value); !result) {
+        if (auto result = IsLegalPropertyValue(name, value); !result.ok()) {
             return result.error();
         }
     }
@@ -189,7 +189,7 @@
     ReturnIfAnyArgsEmpty();
 
     auto rlimit = ParseRlimit(args.args);
-    if (!rlimit) return rlimit.error();
+    if (!rlimit.ok()) return rlimit.error();
     return {};
 }
 
diff --git a/init/firmware_handler.cpp b/init/firmware_handler.cpp
index 1dce2d5..dff7b69 100644
--- a/init/firmware_handler.cpp
+++ b/init/firmware_handler.cpp
@@ -165,7 +165,7 @@
 
             auto result =
                     RunExternalHandler(external_handler.handler_path, external_handler.uid, uevent);
-            if (!result) {
+            if (!result.ok()) {
                 LOG(ERROR) << "Using default firmware; External firmware handler failed: "
                            << result.error();
                 return uevent.firmware;
diff --git a/init/first_stage_mount.cpp b/init/first_stage_mount.cpp
index d8c4843..21663e6 100644
--- a/init/first_stage_mount.cpp
+++ b/init/first_stage_mount.cpp
@@ -21,6 +21,7 @@
 #include <unistd.h>
 
 #include <chrono>
+#include <map>
 #include <memory>
 #include <set>
 #include <string>
@@ -29,6 +30,7 @@
 #include <android-base/chrono_utils.h>
 #include <android-base/file.h>
 #include <android-base/logging.h>
+#include <android-base/stringprintf.h>
 #include <android-base/strings.h>
 #include <fs_avb/fs_avb.h>
 #include <fs_mgr.h>
@@ -45,7 +47,9 @@
 #include "uevent_listener.h"
 #include "util.h"
 
+using android::base::ReadFileToString;
 using android::base::Split;
+using android::base::StringPrintf;
 using android::base::Timer;
 using android::fiemap::IImageManager;
 using android::fs_mgr::AvbHandle;
@@ -95,6 +99,7 @@
     void GetDmLinearMetadataDevice(std::set<std::string>* devices);
     bool InitDmLinearBackingDevices(const android::fs_mgr::LpMetadata& metadata);
     void UseDsuIfPresent();
+    void PreloadAvbKeys();
 
     ListenerAction UeventCallback(const Uevent& uevent, std::set<std::string>* required_devices);
 
@@ -110,6 +115,9 @@
     std::string super_partition_name_;
     std::unique_ptr<DeviceHandler> device_handler_;
     UeventListener uevent_listener_;
+    // Reads all AVB keys before chroot into /system, as they might be used
+    // later when mounting other partitions, e.g., /vendor and /product.
+    std::map<std::string, std::vector<std::string>> preload_avb_key_blobs_;
 };
 
 class FirstStageMountVBootV1 : public FirstStageMount {
@@ -508,11 +516,57 @@
     return mounted;
 }
 
+void FirstStageMount::PreloadAvbKeys() {
+    for (const auto& entry : fstab_) {
+        // No need to cache the key content if it's empty, or is already cached.
+        if (entry.avb_keys.empty() || preload_avb_key_blobs_.count(entry.avb_keys)) {
+            continue;
+        }
+
+        // Determines all key paths first.
+        std::vector<std::string> key_paths;
+        if (is_dir(entry.avb_keys.c_str())) {  // fstab_keys might be a dir, e.g., /avb.
+            const char* avb_key_dir = entry.avb_keys.c_str();
+            std::unique_ptr<DIR, int (*)(DIR*)> dir(opendir(avb_key_dir), closedir);
+            if (!dir) {
+                LOG(ERROR) << "Failed to opendir: " << dir;
+                continue;
+            }
+            // Gets all key pathes under the dir.
+            struct dirent* de;
+            while ((de = readdir(dir.get()))) {
+                if (de->d_type != DT_REG) continue;
+                std::string full_path = StringPrintf("%s/%s", avb_key_dir, de->d_name);
+                key_paths.emplace_back(std::move(full_path));
+            }
+            std::sort(key_paths.begin(), key_paths.end());
+        } else {
+            // avb_keys are key paths separated by ":", if it's not a dir.
+            key_paths = Split(entry.avb_keys, ":");
+        }
+
+        // Reads the key content then cache it.
+        std::vector<std::string> key_blobs;
+        for (const auto& path : key_paths) {
+            std::string key_value;
+            if (!ReadFileToString(path, &key_value)) {
+                continue;
+            }
+            key_blobs.emplace_back(std::move(key_value));
+        }
+
+        // Maps entry.avb_keys to actual key blobs.
+        preload_avb_key_blobs_[entry.avb_keys] = std::move(key_blobs);
+    }
+}
+
 // If system is in the fstab then we're not a system-as-root device, and in
 // this case, we mount system first then pivot to it.  From that point on,
 // we are effectively identical to a system-as-root device.
 bool FirstStageMount::TrySwitchSystemAsRoot() {
     UseDsuIfPresent();
+    // Preloading all AVB keys from the ramdisk before switching root to /system.
+    PreloadAvbKeys();
 
     auto system_partition = std::find_if(fstab_.begin(), fstab_.end(), [](const auto& entry) {
         return entry.mount_point == "/system";
@@ -776,7 +830,8 @@
                        << fstab_entry->mount_point;
             return true;  // Returns true to mount the partition directly.
         } else {
-            auto avb_standalone_handle = AvbHandle::LoadAndVerifyVbmeta(*fstab_entry);
+            auto avb_standalone_handle = AvbHandle::LoadAndVerifyVbmeta(
+                    *fstab_entry, preload_avb_key_blobs_[fstab_entry->avb_keys]);
             if (!avb_standalone_handle) {
                 LOG(ERROR) << "Failed to load offline vbmeta for " << fstab_entry->mount_point;
                 // Fallbacks to built-in hashtree if fs_mgr_flags.avb is set.
diff --git a/init/host_init_verifier.cpp b/init/host_init_verifier.cpp
index 22de846..0bd4df4 100644
--- a/init/host_init_verifier.cpp
+++ b/init/host_init_verifier.cpp
@@ -248,7 +248,7 @@
     }
 
     auto interface_inheritance_hierarchy_map = ReadInterfaceInheritanceHierarchy();
-    if (!interface_inheritance_hierarchy_map) {
+    if (!interface_inheritance_hierarchy_map.ok()) {
         LOG(ERROR) << interface_inheritance_hierarchy_map.error();
         return EXIT_FAILURE;
     }
diff --git a/init/import_parser.cpp b/init/import_parser.cpp
index 1a43508..e4b25ca 100644
--- a/init/import_parser.cpp
+++ b/init/import_parser.cpp
@@ -30,7 +30,7 @@
     }
 
     auto conf_file = ExpandProps(args[1]);
-    if (!conf_file) {
+    if (!conf_file.ok()) {
         return Error() << "Could not expand import: " << conf_file.error();
     }
 
diff --git a/init/init.cpp b/init/init.cpp
index 10701da..5bf1b36 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -237,7 +237,7 @@
 
         auto restart_time = s->time_started() + s->restart_period();
         if (boot_clock::now() > restart_time) {
-            if (auto result = s->Start(); !result) {
+            if (auto result = s->Start(); !result.ok()) {
                 LOG(ERROR) << "Could not restart process '" << s->name() << "': " << result.error();
             }
         } else {
@@ -333,7 +333,7 @@
         return false;
     }
 
-    if (auto result = function.action(svc); !result) {
+    if (auto result = function.action(svc); !result.ok()) {
         LOG(ERROR) << "Control message: Could not ctl." << msg << " for '" << name
                    << "' from pid: " << pid << " (" << process_cmdline << "): " << result.error();
         return false;
@@ -478,7 +478,7 @@
         PLOG(FATAL) << "failed to create signalfd";
     }
 
-    if (auto result = epoll->RegisterHandler(signal_fd, HandleSignalFd); !result) {
+    if (auto result = epoll->RegisterHandler(signal_fd, HandleSignalFd); !result.ok()) {
         LOG(FATAL) << result.error();
     }
 }
@@ -499,7 +499,7 @@
             found = true;
             LOG(INFO) << "Starting service '" << svc->name() << "' from keychord "
                       << android::base::Join(keycodes, ' ');
-            if (auto result = svc->Start(); !result) {
+            if (auto result = svc->Start(); !result.ok()) {
                 LOG(ERROR) << "Could not start service '" << svc->name() << "' from keychord "
                            << android::base::Join(keycodes, ' ') << ": " << result.error();
             }
@@ -558,7 +558,7 @@
 void SendLoadPersistentPropertiesMessage() {
     auto init_message = InitMessage{};
     init_message.set_load_persistent_properties(true);
-    if (auto result = SendMessage(property_fd, init_message); !result) {
+    if (auto result = SendMessage(property_fd, init_message); !result.ok()) {
         LOG(ERROR) << "Failed to send load persistent properties message: " << result.error();
     }
 }
@@ -566,7 +566,7 @@
 void SendStopSendingMessagesMessage() {
     auto init_message = InitMessage{};
     init_message.set_stop_sending_messages(true);
-    if (auto result = SendMessage(property_fd, init_message); !result) {
+    if (auto result = SendMessage(property_fd, init_message); !result.ok()) {
         LOG(ERROR) << "Failed to send 'stop sending messages' message: " << result.error();
     }
 }
@@ -574,14 +574,14 @@
 void SendStartSendingMessagesMessage() {
     auto init_message = InitMessage{};
     init_message.set_start_sending_messages(true);
-    if (auto result = SendMessage(property_fd, init_message); !result) {
+    if (auto result = SendMessage(property_fd, init_message); !result.ok()) {
         LOG(ERROR) << "Failed to send 'start sending messages' message: " << result.error();
     }
 }
 
 static void HandlePropertyFd() {
     auto message = ReadMessage(property_fd);
-    if (!message) {
+    if (!message.ok()) {
         LOG(ERROR) << "Could not read message from property service: " << message.error();
         return;
     }
@@ -636,7 +636,7 @@
     // Set init and its forked children's oom_adj.
     if (auto result =
                 WriteFile("/proc/1/oom_score_adj", StringPrintf("%d", DEFAULT_OOM_SCORE_ADJUST));
-        !result) {
+        !result.ok()) {
         LOG(ERROR) << "Unable to write " << DEFAULT_OOM_SCORE_ADJUST
                    << " to /proc/1/oom_score_adj: " << result.error();
     }
@@ -679,14 +679,14 @@
     SelinuxRestoreContext();
 
     Epoll epoll;
-    if (auto result = epoll.Open(); !result) {
+    if (auto result = epoll.Open(); !result.ok()) {
         PLOG(FATAL) << result.error();
     }
 
     InstallSignalFdHandler(&epoll);
 
     StartPropertyService(&property_fd);
-    if (auto result = epoll.RegisterHandler(property_fd, HandlePropertyFd); !result) {
+    if (auto result = epoll.RegisterHandler(property_fd, HandlePropertyFd); !result.ok()) {
         LOG(FATAL) << "Could not register epoll handler for property fd: " << result.error();
     }
 
@@ -797,7 +797,7 @@
         }
 
         auto pending_functions = epoll.Wait(epoll_timeout);
-        if (!pending_functions) {
+        if (!pending_functions.ok()) {
             LOG(ERROR) << pending_functions.error();
         } else if (!pending_functions->empty()) {
             // We always reap children before responding to the other pending functions. This is to
diff --git a/init/init_test.cpp b/init/init_test.cpp
index 9f63e4f..caf3e03 100644
--- a/init/init_test.cpp
+++ b/init/init_test.cpp
@@ -204,9 +204,9 @@
                                "execute 3";
     // clang-format on
     // WriteFile() ensures the right mode is set
-    ASSERT_TRUE(WriteFile(std::string(dir.path) + "/a.rc", dir_a_script));
+    ASSERT_RESULT_OK(WriteFile(std::string(dir.path) + "/a.rc", dir_a_script));
 
-    ASSERT_TRUE(WriteFile(std::string(dir.path) + "/b.rc", "on boot\nexecute 5"));
+    ASSERT_RESULT_OK(WriteFile(std::string(dir.path) + "/b.rc", "on boot\nexecute 5"));
 
     // clang-format off
     std::string start_script = "import " + std::string(first_import.path) + "\n"
diff --git a/init/keychords.cpp b/init/keychords.cpp
index 5f2682b..adec383 100644
--- a/init/keychords.cpp
+++ b/init/keychords.cpp
@@ -187,7 +187,7 @@
         LambdaCheck();
     }
     if (auto result = epoll_->RegisterHandler(fd, [this, fd]() { this->LambdaHandler(fd); });
-        !result) {
+        !result.ok()) {
         LOG(WARNING) << "Could not register keychord epoll handler: " << result.error();
         return false;
     }
@@ -272,7 +272,7 @@
     if (inotify_fd_ >= 0) {
         if (auto result =
                     epoll_->RegisterHandler(inotify_fd_, [this]() { this->InotifyHandler(); });
-            !result) {
+            !result.ok()) {
             LOG(WARNING) << "Could not register keychord epoll handler: " << result.error();
         }
     }
diff --git a/init/keychords_test.cpp b/init/keychords_test.cpp
index 6e9b337..8a333a2 100644
--- a/init/keychords_test.cpp
+++ b/init/keychords_test.cpp
@@ -204,7 +204,7 @@
 
 TestFrame::TestFrame(const std::vector<const std::vector<int>>& chords, EventHandler* ev)
     : ev_(ev) {
-    if (!epoll_.Open()) return;
+    if (!epoll_.Open().ok()) return;
     for (const auto& keycodes : chords) keychords_.Register(keycodes);
     keychords_.Start(&epoll_, [this](const std::vector<int>& keycodes) {
         this->keycodes_.emplace_back(keycodes);
@@ -213,7 +213,7 @@
 
 void TestFrame::RelaxForMs(std::chrono::milliseconds wait) {
     auto pending_functions = epoll_.Wait(wait);
-    ASSERT_TRUE(pending_functions) << pending_functions.error();
+    ASSERT_RESULT_OK(pending_functions);
     for (const auto& function : *pending_functions) {
         (*function)();
     }
diff --git a/init/mount_handler.cpp b/init/mount_handler.cpp
index 0e4e024..01abba8 100644
--- a/init/mount_handler.cpp
+++ b/init/mount_handler.cpp
@@ -116,7 +116,7 @@
     if (!fp_) PLOG(FATAL) << "Could not open /proc/mounts";
     auto result = epoll->RegisterHandler(
             fileno(fp_.get()), [this]() { this->MountHandlerFunction(); }, EPOLLERR | EPOLLPRI);
-    if (!result) LOG(FATAL) << result.error();
+    if (!result.ok()) LOG(FATAL) << result.error();
 }
 
 MountHandler::~MountHandler() {
diff --git a/init/mount_namespace.cpp b/init/mount_namespace.cpp
index 1a474fb..0749fe3 100644
--- a/init/mount_namespace.cpp
+++ b/init/mount_namespace.cpp
@@ -141,12 +141,12 @@
         if (entry->d_type == DT_DIR) {
             const std::string apex_path = from_dir + "/" + entry->d_name;
             const auto apex_name = GetApexName(apex_path);
-            if (!apex_name) {
+            if (!apex_name.ok()) {
                 LOG(ERROR) << apex_path << " is not an APEX directory: " << apex_name.error();
                 continue;
             }
             const std::string mount_path = to_dir + "/" + (*apex_name);
-            if (auto result = MountDir(apex_path, mount_path); !result) {
+            if (auto result = MountDir(apex_path, mount_path); !result.ok()) {
                 return result;
             }
         }
@@ -168,7 +168,7 @@
     };
 
     for (const auto& dir : kBuiltinDirsForApexes) {
-        if (auto result = ActivateFlattenedApexesFrom(dir, kApexTop); !result) {
+        if (auto result = ActivateFlattenedApexesFrom(dir, kApexTop); !result.ok()) {
             LOG(ERROR) << result.error();
             return false;
         }
@@ -295,7 +295,7 @@
             return false;
         }
 
-        if (auto result = MountLinkerConfigForDefaultNamespace(); !result) {
+        if (auto result = MountLinkerConfigForDefaultNamespace(); !result.ok()) {
             LOG(ERROR) << result.error();
             return false;
         }
diff --git a/init/parser.cpp b/init/parser.cpp
index 6ab61cb..507ee4a 100644
--- a/init/parser.cpp
+++ b/init/parser.cpp
@@ -61,7 +61,7 @@
         bad_section_found = false;
         if (section_parser == nullptr) return;
 
-        if (auto result = section_parser->EndSection(); !result) {
+        if (auto result = section_parser->EndSection(); !result.ok()) {
             parse_error_count_++;
             LOG(ERROR) << filename << ": " << section_start_line << ": " << result.error();
         }
@@ -92,7 +92,7 @@
                 if (line_callback != line_callbacks_.end()) {
                     end_section();
 
-                    if (auto result = line_callback->second(std::move(args)); !result) {
+                    if (auto result = line_callback->second(std::move(args)); !result.ok()) {
                         parse_error_count_++;
                         LOG(ERROR) << filename << ": " << state.line << ": " << result.error();
                     }
@@ -101,8 +101,8 @@
                     section_parser = section_parsers_[args[0]].get();
                     section_start_line = state.line;
                     if (auto result =
-                            section_parser->ParseSection(std::move(args), filename, state.line);
-                        !result) {
+                                section_parser->ParseSection(std::move(args), filename, state.line);
+                        !result.ok()) {
                         parse_error_count_++;
                         LOG(ERROR) << filename << ": " << state.line << ": " << result.error();
                         section_parser = nullptr;
@@ -110,7 +110,7 @@
                     }
                 } else if (section_parser) {
                     if (auto result = section_parser->ParseLineSection(std::move(args), state.line);
-                        !result) {
+                        !result.ok()) {
                         parse_error_count_++;
                         LOG(ERROR) << filename << ": " << state.line << ": " << result.error();
                     }
@@ -143,7 +143,7 @@
     LOG(INFO) << "Parsing file " << path << "...";
     android::base::Timer t;
     auto config_contents = ReadFile(path);
-    if (!config_contents) {
+    if (!config_contents.ok()) {
         LOG(INFO) << "Unable to read config file '" << path << "': " << config_contents.error();
         return false;
     }
diff --git a/init/persistent_properties.cpp b/init/persistent_properties.cpp
index 1758cfa..716f62e 100644
--- a/init/persistent_properties.cpp
+++ b/init/persistent_properties.cpp
@@ -149,7 +149,7 @@
         unlink(temp_filename.c_str());
     }
     auto file_contents = ReadFile(persistent_property_filename);
-    if (!file_contents) {
+    if (!file_contents.ok()) {
         return Error() << "Unable to read persistent property file: " << file_contents.error();
     }
     return *file_contents;
@@ -159,7 +159,7 @@
 
 Result<PersistentProperties> LoadPersistentPropertyFile() {
     auto file_contents = ReadPersistentPropertyFile();
-    if (!file_contents) return file_contents.error();
+    if (!file_contents.ok()) return file_contents.error();
 
     PersistentProperties persistent_properties;
     if (persistent_properties.ParseFromString(*file_contents)) return persistent_properties;
@@ -212,7 +212,7 @@
 void WritePersistentProperty(const std::string& name, const std::string& value) {
     auto persistent_properties = LoadPersistentPropertyFile();
 
-    if (!persistent_properties) {
+    if (!persistent_properties.ok()) {
         LOG(ERROR) << "Recovering persistent properties from memory: "
                    << persistent_properties.error();
         persistent_properties = LoadPersistentPropertiesFromMemory();
@@ -227,7 +227,7 @@
         AddPersistentProperty(name, value, &persistent_properties.value());
     }
 
-    if (auto result = WritePersistentPropertyFile(*persistent_properties); !result) {
+    if (auto result = WritePersistentPropertyFile(*persistent_properties); !result.ok()) {
         LOG(ERROR) << "Could not store persistent property: " << result.error();
     }
 }
@@ -235,16 +235,16 @@
 PersistentProperties LoadPersistentProperties() {
     auto persistent_properties = LoadPersistentPropertyFile();
 
-    if (!persistent_properties) {
+    if (!persistent_properties.ok()) {
         LOG(ERROR) << "Could not load single persistent property file, trying legacy directory: "
                    << persistent_properties.error();
         persistent_properties = LoadLegacyPersistentProperties();
-        if (!persistent_properties) {
+        if (!persistent_properties.ok()) {
             LOG(ERROR) << "Unable to load legacy persistent properties: "
                        << persistent_properties.error();
             return {};
         }
-        if (auto result = WritePersistentPropertyFile(*persistent_properties); result) {
+        if (auto result = WritePersistentPropertyFile(*persistent_properties); result.ok()) {
             RemoveLegacyPersistentPropertyFiles();
         } else {
             LOG(ERROR) << "Unable to write single persistent property file: " << result.error();
diff --git a/init/persistent_properties_test.cpp b/init/persistent_properties_test.cpp
index 13796a6..60cecde 100644
--- a/init/persistent_properties_test.cpp
+++ b/init/persistent_properties_test.cpp
@@ -83,7 +83,8 @@
         {"persist.\x00\x01\x02\xFF\xFE\xFD\x7F\x8F\x9F", "non-ascii-name"},
     };
 
-    ASSERT_TRUE(WritePersistentPropertyFile(VectorToPersistentProperties(persistent_properties)));
+    ASSERT_RESULT_OK(
+            WritePersistentPropertyFile(VectorToPersistentProperties(persistent_properties)));
 
     auto read_back_properties = LoadPersistentProperties();
     CheckPropertiesEqual(persistent_properties, read_back_properties);
@@ -97,7 +98,8 @@
     std::vector<std::pair<std::string, std::string>> persistent_properties = {
         {"persist.sys.timezone", "America/Los_Angeles"},
     };
-    ASSERT_TRUE(WritePersistentPropertyFile(VectorToPersistentProperties(persistent_properties)));
+    ASSERT_RESULT_OK(
+            WritePersistentPropertyFile(VectorToPersistentProperties(persistent_properties)));
 
     WritePersistentProperty("persist.sys.locale", "pt-BR");
 
@@ -119,7 +121,8 @@
         {"persist.sys.locale", "en-US"},
         {"persist.sys.timezone", "America/Los_Angeles"},
     };
-    ASSERT_TRUE(WritePersistentPropertyFile(VectorToPersistentProperties(persistent_properties)));
+    ASSERT_RESULT_OK(
+            WritePersistentPropertyFile(VectorToPersistentProperties(persistent_properties)));
 
     WritePersistentProperty("persist.sys.locale", "pt-BR");
 
@@ -137,7 +140,7 @@
     ASSERT_TRUE(tf.fd != -1);
     persistent_property_filename = tf.path;
 
-    ASSERT_TRUE(WriteFile(tf.path, "ab"));
+    ASSERT_RESULT_OK(WriteFile(tf.path, "ab"));
 
     WritePersistentProperty("persist.sys.locale", "pt-BR");
 
diff --git a/init/property_service.cpp b/init/property_service.cpp
index 5b35ad2..84644e8 100644
--- a/init/property_service.cpp
+++ b/init/property_service.cpp
@@ -153,7 +153,7 @@
     changed_message->set_name(name);
     changed_message->set_value(value);
 
-    if (auto result = SendMessage(init_socket, property_msg); !result) {
+    if (auto result = SendMessage(init_socket, property_msg); !result.ok()) {
         LOG(ERROR) << "Failed to send property changed message: " << result.error();
     }
 }
@@ -166,7 +166,7 @@
         return PROP_ERROR_INVALID_NAME;
     }
 
-    if (auto result = IsLegalPropertyValue(name, value); !result) {
+    if (auto result = IsLegalPropertyValue(name, value); !result.ok()) {
         *error = result.error().message();
         return PROP_ERROR_INVALID_VALUE;
     }
@@ -392,7 +392,7 @@
         control_message->set_fd(fd);
     }
 
-    if (auto result = SendMessage(init_socket, property_msg); !result) {
+    if (auto result = SendMessage(init_socket, property_msg); !result.ok()) {
         // We've already released the fd above, so if we fail to send the message to init, we need
         // to manually free it here.
         if (fd != -1) {
@@ -670,7 +670,7 @@
             std::string raw_filename(fn);
             auto expanded_filename = ExpandProps(raw_filename);
 
-            if (!expanded_filename) {
+            if (!expanded_filename.ok()) {
                 LOG(ERROR) << "Could not expand filename ': " << expanded_filename.error();
                 continue;
             }
@@ -726,7 +726,7 @@
                                       std::map<std::string, std::string>* properties) {
     Timer t;
     auto file_contents = ReadFile(filename);
-    if (!file_contents) {
+    if (!file_contents.ok()) {
         PLOG(WARNING) << "Couldn't load property file '" << filename
                       << "': " << file_contents.error();
         return false;
@@ -1084,7 +1084,7 @@
 
 static void HandleInitSocket() {
     auto message = ReadMessage(init_socket);
-    if (!message) {
+    if (!message.ok()) {
         LOG(ERROR) << "Could not read message from init_dedicated_recv_socket: " << message.error();
         return;
     }
@@ -1123,21 +1123,22 @@
 
 static void PropertyServiceThread() {
     Epoll epoll;
-    if (auto result = epoll.Open(); !result) {
+    if (auto result = epoll.Open(); !result.ok()) {
         LOG(FATAL) << result.error();
     }
 
-    if (auto result = epoll.RegisterHandler(property_set_fd, handle_property_set_fd); !result) {
+    if (auto result = epoll.RegisterHandler(property_set_fd, handle_property_set_fd);
+        !result.ok()) {
         LOG(FATAL) << result.error();
     }
 
-    if (auto result = epoll.RegisterHandler(init_socket, HandleInitSocket); !result) {
+    if (auto result = epoll.RegisterHandler(init_socket, HandleInitSocket); !result.ok()) {
         LOG(FATAL) << result.error();
     }
 
     while (true) {
         auto pending_functions = epoll.Wait(std::nullopt);
-        if (!pending_functions) {
+        if (!pending_functions.ok()) {
             LOG(ERROR) << pending_functions.error();
         } else {
             for (const auto& function : *pending_functions) {
@@ -1159,7 +1160,8 @@
     accept_messages = true;
 
     if (auto result = CreateSocket(PROP_SERVICE_NAME, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
-                                   false, 0666, 0, 0, {})) {
+                                   false, 0666, 0, 0, {});
+        result.ok()) {
         property_set_fd = *result;
     } else {
         LOG(FATAL) << "start_property_service socket creation failed: " << result.error();
diff --git a/init/reboot.cpp b/init/reboot.cpp
index 8b239fe..2f32a88 100644
--- a/init/reboot.cpp
+++ b/init/reboot.cpp
@@ -180,7 +180,7 @@
         LOG(WARNING) << "cannot find blank_screen in TurnOffBacklight";
         return;
     }
-    if (auto result = service->Start(); !result) {
+    if (auto result = service->Start(); !result.ok()) {
         LOG(WARNING) << "Could not start blank_screen service: " << result.error();
     }
 }
@@ -591,14 +591,14 @@
             // keep debugging tools until non critical ones are all gone.
             s->SetShutdownCritical();
         } else if (to_starts.count(s->name())) {
-            if (auto result = s->Start(); !result) {
+            if (auto result = s->Start(); !result.ok()) {
                 LOG(ERROR) << "Could not start shutdown 'to_start' service '" << s->name()
                            << "': " << result.error();
             }
             s->SetShutdownCritical();
         } else if (s->IsShutdownCritical()) {
             // Start shutdown critical service if not started.
-            if (auto result = s->Start(); !result) {
+            if (auto result = s->Start(); !result.ok()) {
                 LOG(ERROR) << "Could not start shutdown critical service '" << s->name()
                            << "': " << result.error();
             }
@@ -776,10 +776,10 @@
         // TODO(b/135984674): store information about offending services for debugging.
         return Error() << r << " post-data services are still running";
     }
-    if (auto result = KillZramBackingDevice(); !result) {
+    if (auto result = KillZramBackingDevice(); !result.ok()) {
         return result;
     }
-    if (auto result = CallVdc("volume", "reset"); !result) {
+    if (auto result = CallVdc("volume", "reset"); !result.ok()) {
         return result;
     }
     if (int r = StopServicesAndLogViolations(GetDebuggingServices(true /* only_post_data */), 5s,
@@ -794,7 +794,7 @@
         sync();
         LOG(INFO) << "sync() took " << sync_timer;
     }
-    if (auto result = UnmountAllApexes(); !result) {
+    if (auto result = UnmountAllApexes(); !result.ok()) {
         return result;
     }
     if (!SwitchToBootstrapMountNamespaceIfNeeded()) {
diff --git a/init/result.h b/init/result.h
index b70dd1b..8c1f91e 100644
--- a/init/result.h
+++ b/init/result.h
@@ -22,8 +22,6 @@
 #include <android-base/result.h>
 
 using android::base::ErrnoError;
-using android::base::ErrnoErrorf;
 using android::base::Error;
-using android::base::Errorf;
 using android::base::Result;
 using android::base::ResultError;
diff --git a/init/rlimit_parser_test.cpp b/init/rlimit_parser_test.cpp
index 6a16d3b..3c3f848 100644
--- a/init/rlimit_parser_test.cpp
+++ b/init/rlimit_parser_test.cpp
@@ -29,7 +29,7 @@
     ASSERT_EQ(4U, input.size());
     auto result = ParseRlimit(input);
 
-    ASSERT_TRUE(result) << "input: " << input[1];
+    ASSERT_TRUE(result.ok()) << "input: " << input[1];
     const auto& [resource, rlimit] = *result;
     const auto& [expected_resource, expected_rlimit] = expected_result;
     EXPECT_EQ(expected_resource, resource);
@@ -42,7 +42,7 @@
     ASSERT_EQ(4U, input.size());
     auto result = ParseRlimit(input);
 
-    ASSERT_FALSE(result) << "input: " << input[1];
+    ASSERT_FALSE(result.ok()) << "input: " << input[1];
     EXPECT_EQ(expected_result, result.error().message());
     EXPECT_EQ(0, result.error().code());
 }
diff --git a/init/selinux.cpp b/init/selinux.cpp
index 852d6ca..41007c1 100644
--- a/init/selinux.cpp
+++ b/init/selinux.cpp
@@ -477,7 +477,7 @@
         }
     }
 
-    if (auto result = WriteFile("/sys/fs/selinux/checkreqprot", "0"); !result) {
+    if (auto result = WriteFile("/sys/fs/selinux/checkreqprot", "0"); !result.ok()) {
         LOG(FATAL) << "Unable to write to /sys/fs/selinux/checkreqprot: " << result.error();
     }
 }
diff --git a/init/service.cpp b/init/service.cpp
index 0e27ff1..665a1b0 100644
--- a/init/service.cpp
+++ b/init/service.cpp
@@ -106,7 +106,7 @@
     c_strings.push_back(const_cast<char*>(args[0].data()));
     for (std::size_t i = 1; i < args.size(); ++i) {
         auto expanded_arg = ExpandProps(args[i]);
-        if (!expanded_arg) {
+        if (!expanded_arg.ok()) {
             LOG(FATAL) << args[0] << ": cannot expand arguments': " << expanded_arg.error();
         }
         expanded_args[i] = *expanded_arg;
@@ -232,7 +232,7 @@
         }
     }
 
-    if (auto result = SetProcessAttributes(proc_attr_); !result) {
+    if (auto result = SetProcessAttributes(proc_attr_); !result.ok()) {
         LOG(FATAL) << "cannot set attribute for " << name_ << ": " << result.error();
     }
 
@@ -374,7 +374,7 @@
 
     flags_ |= SVC_ONESHOT;
 
-    if (auto result = Start(); !result) {
+    if (auto result = Start(); !result.ok()) {
         return result;
     }
 
@@ -449,7 +449,7 @@
         scon = seclabel_;
     } else {
         auto result = ComputeContextFromExecutable(args_[0]);
-        if (!result) {
+        if (!result.ok()) {
             return result.error();
         }
         scon = *result;
@@ -469,7 +469,7 @@
 
     std::vector<Descriptor> descriptors;
     for (const auto& socket : sockets_) {
-        if (auto result = socket.Create(scon)) {
+        if (auto result = socket.Create(scon); result.ok()) {
             descriptors.emplace_back(std::move(*result));
         } else {
             LOG(INFO) << "Could not create socket '" << socket.name << "': " << result.error();
@@ -477,7 +477,7 @@
     }
 
     for (const auto& file : files_) {
-        if (auto result = file.Create()) {
+        if (auto result = file.Create(); result.ok()) {
             descriptors.emplace_back(std::move(*result));
         } else {
             LOG(INFO) << "Could not open file '" << file.name << "': " << result.error();
@@ -494,7 +494,7 @@
     if (pid == 0) {
         umask(077);
 
-        if (auto result = EnterNamespaces(namespaces_, name_, pre_apexd_); !result) {
+        if (auto result = EnterNamespaces(namespaces_, name_, pre_apexd_); !result.ok()) {
             LOG(FATAL) << "Service '" << name_
                        << "' failed to set up namespaces: " << result.error();
         }
@@ -507,7 +507,7 @@
             descriptor.Publish();
         }
 
-        if (auto result = WritePidToFiles(&writepid_files_); !result) {
+        if (auto result = WritePidToFiles(&writepid_files_); !result.ok()) {
             LOG(ERROR) << "failed to write pid to files: " << result.error();
         }
 
@@ -669,7 +669,7 @@
         StopOrReset(SVC_RESTART);
     } else if (!(flags_ & SVC_RESTARTING)) {
         /* Just start the service since it's not running. */
-        if (auto result = Start(); !result) {
+        if (auto result = Start(); !result.ok()) {
             LOG(ERROR) << "Could not restart '" << name_ << "': " << result.error();
         }
     } /* else: Service is restarting anyways. */
@@ -742,7 +742,7 @@
     Result<uid_t> uid = 0;
     if (command_arg > 3) {
         uid = DecodeUid(args[2]);
-        if (!uid) {
+        if (!uid.ok()) {
             return Error() << "Unable to decode UID for '" << args[2] << "': " << uid.error();
         }
     }
@@ -750,13 +750,13 @@
     std::vector<gid_t> supp_gids;
     if (command_arg > 4) {
         gid = DecodeUid(args[3]);
-        if (!gid) {
+        if (!gid.ok()) {
             return Error() << "Unable to decode GID for '" << args[3] << "': " << gid.error();
         }
         std::size_t nr_supp_gids = command_arg - 1 /* -- */ - 4 /* exec SECLABEL UID GID */;
         for (size_t i = 0; i < nr_supp_gids; ++i) {
             auto supp_gid = DecodeUid(args[4 + i]);
-            if (!supp_gid) {
+            if (!supp_gid.ok()) {
                 return Error() << "Unable to decode GID for '" << args[4 + i]
                                << "': " << supp_gid.error();
             }
diff --git a/init/service_list.cpp b/init/service_list.cpp
index c51a9cf..3047821 100644
--- a/init/service_list.cpp
+++ b/init/service_list.cpp
@@ -86,7 +86,7 @@
             LOG(ERROR) << "delayed service '" << name << "' could not be found.";
             continue;
         }
-        if (auto result = service->Start(); !result) {
+        if (auto result = service->Start(); !result.ok()) {
             LOG(ERROR) << result.error().message();
         }
     }
diff --git a/init/service_parser.cpp b/init/service_parser.cpp
index 1d431e3..4b04ba0 100644
--- a/init/service_parser.cpp
+++ b/init/service_parser.cpp
@@ -119,14 +119,14 @@
 
 Result<void> ServiceParser::ParseGroup(std::vector<std::string>&& args) {
     auto gid = DecodeUid(args[1]);
-    if (!gid) {
+    if (!gid.ok()) {
         return Error() << "Unable to decode GID for '" << args[1] << "': " << gid.error();
     }
     service_->proc_attr_.gid = *gid;
 
     for (std::size_t n = 2; n < args.size(); n++) {
         gid = DecodeUid(args[n]);
-        if (!gid) {
+        if (!gid.ok()) {
             return Error() << "Unable to decode GID for '" << args[n] << "': " << gid.error();
         }
         service_->proc_attr_.supp_gids.emplace_back(*gid);
@@ -202,13 +202,13 @@
     auto it = args.begin() + 1;
     if (args.size() == 2 && StartsWith(args[1], "$")) {
         auto expanded = ExpandProps(args[1]);
-        if (!expanded) {
+        if (!expanded.ok()) {
             return expanded.error();
         }
 
         // If the property is not set, it defaults to none, in which case there are no keycodes
         // for this service.
-        if (expanded == "none") {
+        if (*expanded == "none") {
             return {};
         }
 
@@ -240,7 +240,7 @@
 Result<void> ServiceParser::ParseOnrestart(std::vector<std::string>&& args) {
     args.erase(args.begin());
     int line = service_->onrestart_.NumCommands() + 1;
-    if (auto result = service_->onrestart_.AddCommand(std::move(args), line); !result) {
+    if (auto result = service_->onrestart_.AddCommand(std::move(args), line); !result.ok()) {
         return Error() << "cannot add Onrestart command: " << result.error();
     }
     return {};
@@ -310,7 +310,7 @@
 
 Result<void> ServiceParser::ParseProcessRlimit(std::vector<std::string>&& args) {
     auto rlimit = ParseRlimit(args);
-    if (!rlimit) return rlimit.error();
+    if (!rlimit.ok()) return rlimit.error();
 
     service_->proc_attr_.rlimits.emplace_back(*rlimit);
     return {};
@@ -407,7 +407,7 @@
 
     if (args.size() > 4) {
         auto uid = DecodeUid(args[4]);
-        if (!uid) {
+        if (!uid.ok()) {
             return Error() << "Unable to find UID for '" << args[4] << "': " << uid.error();
         }
         socket.uid = *uid;
@@ -415,7 +415,7 @@
 
     if (args.size() > 5) {
         auto gid = DecodeUid(args[5]);
-        if (!gid) {
+        if (!gid.ok()) {
             return Error() << "Unable to find GID for '" << args[5] << "': " << gid.error();
         }
         socket.gid = *gid;
@@ -453,7 +453,7 @@
     file.type = args[2];
 
     auto file_name = ExpandProps(args[1]);
-    if (!file_name) {
+    if (!file_name.ok()) {
         return Error() << "Could not expand file path ': " << file_name.error();
     }
     file.name = *file_name;
@@ -475,7 +475,7 @@
 
 Result<void> ServiceParser::ParseUser(std::vector<std::string>&& args) {
     auto uid = DecodeUid(args[1]);
-    if (!uid) {
+    if (!uid.ok()) {
         return Error() << "Unable to find UID for '" << args[1] << "': " << uid.error();
     }
     service_->proc_attr_.uid = *uid;
@@ -580,7 +580,7 @@
 
     auto parser = GetParserMap().Find(args);
 
-    if (!parser) return parser.error();
+    if (!parser.ok()) return parser.error();
 
     return std::invoke(*parser, this, std::move(args));
 }
@@ -593,7 +593,7 @@
     if (interface_inheritance_hierarchy_) {
         if (const auto& check_hierarchy_result = CheckInterfaceInheritanceHierarchy(
                     service_->interfaces(), *interface_inheritance_hierarchy_);
-            !check_hierarchy_result) {
+            !check_hierarchy_result.ok()) {
             return Error() << check_hierarchy_result.error();
         }
     }
diff --git a/init/service_test.cpp b/init/service_test.cpp
index c158b0a..22ee844 100644
--- a/init/service_test.cpp
+++ b/init/service_test.cpp
@@ -76,15 +76,15 @@
 TEST(service, make_temporary_oneshot_service_invalid_syntax) {
     std::vector<std::string> args;
     // Nothing.
-    ASSERT_FALSE(Service::MakeTemporaryOneshotService(args));
+    ASSERT_FALSE(Service::MakeTemporaryOneshotService(args).ok());
 
     // No arguments to 'exec'.
     args.push_back("exec");
-    ASSERT_FALSE(Service::MakeTemporaryOneshotService(args));
+    ASSERT_FALSE(Service::MakeTemporaryOneshotService(args).ok());
 
     // No command in "exec --".
     args.push_back("--");
-    ASSERT_FALSE(Service::MakeTemporaryOneshotService(args));
+    ASSERT_FALSE(Service::MakeTemporaryOneshotService(args).ok());
 }
 
 TEST(service, make_temporary_oneshot_service_too_many_supplementary_gids) {
@@ -98,7 +98,7 @@
     }
     args.push_back("--");
     args.push_back("/system/bin/id");
-    ASSERT_FALSE(Service::MakeTemporaryOneshotService(args));
+    ASSERT_FALSE(Service::MakeTemporaryOneshotService(args).ok());
 }
 
 static void Test_make_temporary_oneshot_service(bool dash_dash, bool seclabel, bool uid, bool gid,
@@ -124,7 +124,7 @@
     args.push_back("/system/bin/toybox");
     args.push_back("id");
     auto service_ret = Service::MakeTemporaryOneshotService(args);
-    ASSERT_TRUE(service_ret);
+    ASSERT_RESULT_OK(service_ret);
     auto svc = std::move(*service_ret);
 
     if (seclabel) {
@@ -134,14 +134,14 @@
     }
     if (uid) {
         auto decoded_uid = DecodeUid("log");
-        ASSERT_TRUE(decoded_uid);
+        ASSERT_RESULT_OK(decoded_uid);
         ASSERT_EQ(*decoded_uid, svc->uid());
     } else {
         ASSERT_EQ(0U, svc->uid());
     }
     if (gid) {
         auto decoded_uid = DecodeUid("shell");
-        ASSERT_TRUE(decoded_uid);
+        ASSERT_RESULT_OK(decoded_uid);
         ASSERT_EQ(*decoded_uid, svc->gid());
     } else {
         ASSERT_EQ(0U, svc->gid());
@@ -150,11 +150,11 @@
         ASSERT_EQ(2U, svc->supp_gids().size());
 
         auto decoded_uid = DecodeUid("system");
-        ASSERT_TRUE(decoded_uid);
+        ASSERT_RESULT_OK(decoded_uid);
         ASSERT_EQ(*decoded_uid, svc->supp_gids()[0]);
 
         decoded_uid = DecodeUid("adb");
-        ASSERT_TRUE(decoded_uid);
+        ASSERT_RESULT_OK(decoded_uid);
         ASSERT_EQ(*decoded_uid, svc->supp_gids()[1]);
     } else {
         ASSERT_EQ(0U, svc->supp_gids().size());
diff --git a/init/service_utils.cpp b/init/service_utils.cpp
index 93cffd8..484c2c8 100644
--- a/init/service_utils.cpp
+++ b/init/service_utils.cpp
@@ -167,7 +167,7 @@
 Result<Descriptor> SocketDescriptor::Create(const std::string& global_context) const {
     const auto& socket_context = context.empty() ? global_context : context;
     auto result = CreateSocket(name, type | SOCK_CLOEXEC, passcred, perm, uid, gid, socket_context);
-    if (!result) {
+    if (!result.ok()) {
         return result.error();
     }
 
@@ -196,7 +196,7 @@
 
 Result<void> EnterNamespaces(const NamespaceInfo& info, const std::string& name, bool pre_apexd) {
     for (const auto& [nstype, path] : info.namespaces_to_enter) {
-        if (auto result = EnterNamespace(nstype, path.c_str()); !result) {
+        if (auto result = EnterNamespace(nstype, path.c_str()); !result.ok()) {
             return result;
         }
     }
@@ -214,14 +214,14 @@
         bool remount_sys =
                 std::any_of(info.namespaces_to_enter.begin(), info.namespaces_to_enter.end(),
                             [](const auto& entry) { return entry.first == CLONE_NEWNET; });
-        if (auto result = SetUpMountNamespace(remount_proc, remount_sys); !result) {
+        if (auto result = SetUpMountNamespace(remount_proc, remount_sys); !result.ok()) {
             return result;
         }
     }
 
     if (info.flags & CLONE_NEWPID) {
         // This will fork again to run an init process inside the PID namespace.
-        if (auto result = SetUpPidNamespace(name.c_str()); !result) {
+        if (auto result = SetUpPidNamespace(name.c_str()); !result.ok()) {
             return result;
         }
     }
@@ -249,9 +249,8 @@
 
     for (const auto& rlimit : attr.rlimits) {
         if (setrlimit(rlimit.first, &rlimit.second) == -1) {
-            return ErrnoError() << StringPrintf(
-                           "setrlimit(%d, {rlim_cur=%ld, rlim_max=%ld}) failed", rlimit.first,
-                           rlimit.second.rlim_cur, rlimit.second.rlim_max);
+            return ErrnoErrorf("setrlimit({}, {{rlim_cur={}, rlim_max={}}}) failed", rlimit.first,
+                               rlimit.second.rlim_cur, rlimit.second.rlim_max);
         }
     }
 
diff --git a/init/subcontext.cpp b/init/subcontext.cpp
index f3f759d..3260159 100644
--- a/init/subcontext.cpp
+++ b/init/subcontext.cpp
@@ -80,13 +80,13 @@
 
     auto map_result = function_map_->Find(args);
     Result<void> result;
-    if (!map_result) {
+    if (!map_result.ok()) {
         result = Error() << "Cannot find command: " << map_result.error();
     } else {
         result = RunBuiltinFunction(map_result->function, args, context_);
     }
 
-    if (result) {
+    if (result.ok()) {
         reply->set_success(true);
     } else {
         auto* failure = reply->mutable_failure();
@@ -99,7 +99,7 @@
                                    SubcontextReply* reply) const {
     for (const auto& arg : expand_args_command.args()) {
         auto expanded_arg = ExpandProps(arg);
-        if (!expanded_arg) {
+        if (!expanded_arg.ok()) {
             auto* failure = reply->mutable_failure();
             failure->set_error_string(expanded_arg.error().message());
             failure->set_error_errno(0);
@@ -125,7 +125,7 @@
         }
 
         auto init_message = ReadMessage(init_fd_);
-        if (!init_message) {
+        if (!init_message.ok()) {
             if (init_message.error().code() == 0) {
                 // If the init file descriptor was closed, let's exit quietly. If
                 // this was accidental, init will restart us. If init died, this
@@ -160,7 +160,7 @@
             shutdown_command.clear();
         }
 
-        if (auto result = SendMessage(init_fd_, reply); !result) {
+        if (auto result = SendMessage(init_fd_, reply); !result.ok()) {
             LOG(FATAL) << "Failed to send message to init: " << result.error();
         }
     }
@@ -246,13 +246,13 @@
 }
 
 Result<SubcontextReply> Subcontext::TransmitMessage(const SubcontextCommand& subcontext_command) {
-    if (auto result = SendMessage(socket_, subcontext_command); !result) {
+    if (auto result = SendMessage(socket_, subcontext_command); !result.ok()) {
         Restart();
         return ErrnoError() << "Failed to send message to subcontext";
     }
 
     auto subcontext_message = ReadMessage(socket_);
-    if (!subcontext_message) {
+    if (!subcontext_message.ok()) {
         Restart();
         return Error() << "Failed to receive result from subcontext: " << subcontext_message.error();
     }
@@ -277,7 +277,7 @@
         RepeatedPtrFieldBackInserter(subcontext_command.mutable_execute_command()->mutable_args()));
 
     auto subcontext_reply = TransmitMessage(subcontext_command);
-    if (!subcontext_reply) {
+    if (!subcontext_reply.ok()) {
         return subcontext_reply.error();
     }
 
@@ -301,7 +301,7 @@
                   subcontext_command.mutable_expand_args_command()->mutable_args()));
 
     auto subcontext_reply = TransmitMessage(subcontext_command);
-    if (!subcontext_reply) {
+    if (!subcontext_reply.ok()) {
         return subcontext_reply.error();
     }
 
diff --git a/init/subcontext_test.cpp b/init/subcontext_test.cpp
index 2e5a256..ee765a7 100644
--- a/init/subcontext_test.cpp
+++ b/init/subcontext_test.cpp
@@ -55,7 +55,7 @@
 TEST(subcontext, CheckDifferentPid) {
     RunTest([](auto& subcontext) {
         auto result = subcontext.Execute(std::vector<std::string>{"return_pids_as_error"});
-        ASSERT_FALSE(result);
+        ASSERT_FALSE(result.ok());
 
         auto pids = Split(result.error().message(), " ");
         ASSERT_EQ(2U, pids.size());
@@ -81,7 +81,7 @@
             "success",
         };
         auto result = subcontext.Execute(args);
-        ASSERT_TRUE(result) << result.error();
+        ASSERT_RESULT_OK(result);
 
         EXPECT_TRUE(WaitForProperty("init.test.subcontext", "success", 10s));
     });
@@ -104,11 +104,11 @@
                 word,
             };
             auto result = subcontext.Execute(args);
-            ASSERT_TRUE(result) << result.error();
+            ASSERT_RESULT_OK(result);
         }
 
         auto result = subcontext.Execute(std::vector<std::string>{"return_words_as_error"});
-        ASSERT_FALSE(result);
+        ASSERT_FALSE(result.ok());
         EXPECT_EQ(Join(expected_words, " "), result.error().message());
         EXPECT_EQ(first_pid, subcontext.pid());
     });
@@ -119,10 +119,10 @@
         auto first_pid = subcontext.pid();
 
         auto result = subcontext.Execute(std::vector<std::string>{"cause_log_fatal"});
-        ASSERT_FALSE(result);
+        ASSERT_FALSE(result.ok());
 
         auto result2 = subcontext.Execute(std::vector<std::string>{"generate_sane_error"});
-        ASSERT_FALSE(result2);
+        ASSERT_FALSE(result2.ok());
         EXPECT_EQ("Sane error!", result2.error().message());
         EXPECT_NE(subcontext.pid(), first_pid);
     });
@@ -131,7 +131,7 @@
 TEST(subcontext, ContextString) {
     RunTest([](auto& subcontext) {
         auto result = subcontext.Execute(std::vector<std::string>{"return_context_as_error"});
-        ASSERT_FALSE(result);
+        ASSERT_FALSE(result.ok());
         ASSERT_EQ(kTestContext, result.error().message());
     });
 }
@@ -143,7 +143,7 @@
     RunTest([](auto& subcontext) {
         auto result = subcontext.Execute(
                 std::vector<std::string>{"trigger_shutdown", kTestShutdownCommand});
-        ASSERT_TRUE(result);
+        ASSERT_RESULT_OK(result);
     });
     EXPECT_EQ(kTestShutdownCommand, trigger_shutdown_command);
 }
@@ -156,7 +156,7 @@
             "$$third",
         };
         auto result = subcontext.ExpandArgs(args);
-        ASSERT_TRUE(result) << result.error();
+        ASSERT_RESULT_OK(result);
         ASSERT_EQ(3U, result->size());
         EXPECT_EQ(args[0], result->at(0));
         EXPECT_EQ(GetProperty("ro.hardware", ""), result->at(1));
@@ -171,7 +171,7 @@
             "${",
         };
         auto result = subcontext.ExpandArgs(args);
-        ASSERT_FALSE(result);
+        ASSERT_FALSE(result.ok());
         EXPECT_EQ("unexpected end of string in '" + args[1] + "', looking for }",
                   result.error().message());
     });
diff --git a/init/ueventd_parser.cpp b/init/ueventd_parser.cpp
index a74b247..09dce44 100644
--- a/init/ueventd_parser.cpp
+++ b/init/ueventd_parser.cpp
@@ -209,7 +209,7 @@
 
     auto parser = parser_map.Find(args);
 
-    if (!parser) return Error() << parser.error();
+    if (!parser.ok()) return Error() << parser.error();
 
     return std::invoke(*parser, this, std::move(args));
 }
diff --git a/init/util.cpp b/init/util.cpp
index 0ca0da5..503c705 100644
--- a/init/util.cpp
+++ b/init/util.cpp
@@ -497,14 +497,14 @@
                 break;
             case 3:
                 uid = DecodeUid(args[3]);
-                if (!uid) {
+                if (!uid.ok()) {
                     return Error()
                            << "Unable to decode UID for '" << args[3] << "': " << uid.error();
                 }
                 break;
             case 4:
                 gid = DecodeUid(args[4]);
-                if (!gid) {
+                if (!gid.ok()) {
                     return Error()
                            << "Unable to decode GID for '" << args[4] << "': " << gid.error();
                 }
diff --git a/init/util_test.cpp b/init/util_test.cpp
index a8fcc87..96a5b55 100644
--- a/init/util_test.cpp
+++ b/init/util_test.cpp
@@ -33,7 +33,7 @@
     errno = 0;
     auto file_contents = ReadFile("/proc/does-not-exist");
     EXPECT_EQ(ENOENT, errno);
-    ASSERT_FALSE(file_contents);
+    ASSERT_FALSE(file_contents.ok());
     EXPECT_EQ("open() failed: No such file or directory", file_contents.error().message());
 }
 
@@ -41,10 +41,10 @@
     std::string s("hello");
     TemporaryFile tf;
     ASSERT_TRUE(tf.fd != -1);
-    EXPECT_TRUE(WriteFile(tf.path, s)) << strerror(errno);
+    EXPECT_RESULT_OK(WriteFile(tf.path, s));
     EXPECT_NE(-1, fchmodat(AT_FDCWD, tf.path, 0620, AT_SYMLINK_NOFOLLOW)) << strerror(errno);
     auto file_contents = ReadFile(tf.path);
-    ASSERT_FALSE(file_contents) << strerror(errno);
+    ASSERT_FALSE(file_contents.ok()) << strerror(errno);
     EXPECT_EQ("Skipping insecure file", file_contents.error().message());
 }
 
@@ -52,10 +52,10 @@
     std::string s("hello");
     TemporaryFile tf;
     ASSERT_TRUE(tf.fd != -1);
-    EXPECT_TRUE(WriteFile(tf.path, s)) << strerror(errno);
+    EXPECT_RESULT_OK(WriteFile(tf.path, s));
     EXPECT_NE(-1, fchmodat(AT_FDCWD, tf.path, 0602, AT_SYMLINK_NOFOLLOW)) << strerror(errno);
     auto file_contents = ReadFile(tf.path);
-    ASSERT_FALSE(file_contents) << strerror(errno);
+    ASSERT_FALSE(file_contents.ok());
     EXPECT_EQ("Skipping insecure file", file_contents.error().message());
 }
 
@@ -64,14 +64,14 @@
     // lrw------- 1 root root 23 2008-12-31 19:00 default.prop -> system/etc/prop.default
     auto file_contents = ReadFile("/default.prop");
     EXPECT_EQ(ELOOP, errno);
-    ASSERT_FALSE(file_contents);
+    ASSERT_FALSE(file_contents.ok());
     EXPECT_EQ("open() failed: Too many symbolic links encountered",
               file_contents.error().message());
 }
 
 TEST(util, ReadFileSuccess) {
     auto file_contents = ReadFile("/proc/version");
-    ASSERT_TRUE(file_contents);
+    ASSERT_TRUE(file_contents.ok());
     EXPECT_GT(file_contents->length(), 6U);
     EXPECT_EQ('\n', file_contents->at(file_contents->length() - 1));
     (*file_contents)[5] = 0;
@@ -87,10 +87,10 @@
 
     TemporaryFile tf;
     ASSERT_TRUE(tf.fd != -1);
-    EXPECT_TRUE(WriteFile(tf.path, contents)) << strerror(errno);
+    EXPECT_RESULT_OK(WriteFile(tf.path, contents));
 
     auto read_back_contents = ReadFile(tf.path);
-    ASSERT_TRUE(read_back_contents) << strerror(errno);
+    ASSERT_RESULT_OK(read_back_contents);
     EXPECT_EQ(contents, *read_back_contents);
     EXPECT_EQ(10u, read_back_contents->size());
 }
@@ -99,14 +99,15 @@
     std::string s("hello");
     TemporaryDir test_dir;
     std::string path = android::base::StringPrintf("%s/does-not-exist", test_dir.path);
-    EXPECT_TRUE(WriteFile(path, s));
+    EXPECT_RESULT_OK(WriteFile(path, s));
     auto file_contents = ReadFile(path);
-    ASSERT_TRUE(file_contents);
+    ASSERT_RESULT_OK(file_contents);
     EXPECT_EQ(s, *file_contents);
     struct stat sb;
     int fd = open(path.c_str(), O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
     EXPECT_NE(-1, fd);
     EXPECT_EQ(0, fstat(fd, &sb));
+    EXPECT_EQ(0, close(fd));
     EXPECT_EQ((const unsigned int)(S_IRUSR | S_IWUSR), sb.st_mode & 0777);
     EXPECT_EQ(0, unlink(path.c_str()));
 }
@@ -114,27 +115,27 @@
 TEST(util, WriteFileExist) {
     TemporaryFile tf;
     ASSERT_TRUE(tf.fd != -1);
-    EXPECT_TRUE(WriteFile(tf.path, "1hello1")) << strerror(errno);
+    EXPECT_RESULT_OK(WriteFile(tf.path, "1hello1"));
     auto file_contents = ReadFile(tf.path);
-    ASSERT_TRUE(file_contents);
+    ASSERT_RESULT_OK(file_contents);
     EXPECT_EQ("1hello1", *file_contents);
-    EXPECT_TRUE(WriteFile(tf.path, "2ll2"));
+    EXPECT_RESULT_OK(WriteFile(tf.path, "2ll2"));
     file_contents = ReadFile(tf.path);
-    ASSERT_TRUE(file_contents);
+    ASSERT_RESULT_OK(file_contents);
     EXPECT_EQ("2ll2", *file_contents);
 }
 
 TEST(util, DecodeUid) {
     auto decoded_uid = DecodeUid("root");
-    EXPECT_TRUE(decoded_uid);
+    EXPECT_TRUE(decoded_uid.ok());
     EXPECT_EQ(0U, *decoded_uid);
 
     decoded_uid = DecodeUid("toot");
-    EXPECT_FALSE(decoded_uid);
+    EXPECT_FALSE(decoded_uid.ok());
     EXPECT_EQ("getpwnam failed: No such file or directory", decoded_uid.error().message());
 
     decoded_uid = DecodeUid("123");
-    EXPECT_TRUE(decoded_uid);
+    EXPECT_RESULT_OK(decoded_uid);
     EXPECT_EQ(123U, *decoded_uid);
 }
 
diff --git a/liblog/logger_read.cpp b/liblog/logger_read.cpp
index a0c526b..4937042 100644
--- a/liblog/logger_read.cpp
+++ b/liblog/logger_read.cpp
@@ -109,8 +109,8 @@
     return ret;
   }
 
-  if (ret > (int)sizeof(*log_msg)) {
-    ret = sizeof(*log_msg);
+  if (ret > LOGGER_ENTRY_MAX_LEN) {
+    ret = LOGGER_ENTRY_MAX_LEN;
   }
 
   if (ret < static_cast<int>(sizeof(log_msg->entry))) {
@@ -118,7 +118,7 @@
   }
 
   if (log_msg->entry.hdr_size < sizeof(log_msg->entry) ||
-      log_msg->entry.hdr_size >= sizeof(struct log_msg) - sizeof(log_msg->entry)) {
+      log_msg->entry.hdr_size >= LOGGER_ENTRY_MAX_LEN - sizeof(log_msg->entry)) {
     return -EINVAL;
   }
 
@@ -126,6 +126,8 @@
     return -EINVAL;
   }
 
+  log_msg->buf[log_msg->entry.len + log_msg->entry.hdr_size] = '\0';
+
   return ret;
 }
 
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 5fbad75..51c6a3b 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -1033,6 +1033,7 @@
 on userspace-reboot-requested
   # TODO(b/135984674): reset all necessary properties here.
   setprop sys.boot_completed ""
+  setprop dev.bootcomplete ""
   setprop sys.init.updatable_crashing ""
   setprop sys.init.updatable_crashing_process_name ""
   setprop apexd.status ""