From b24983257121ea0ab05c0f6892ac002e14006f3f Mon Sep 17 00:00:00 2001
From: LoveSy <shana@zju.edu.cn>
Date: Sat, 11 Feb 2023 16:20:24 +0800
Subject: [PATCH] Use statfs to check rootfs

This helps support adb remount
---
 native/src/init/twostage.cpp | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/native/src/init/twostage.cpp b/native/src/init/twostage.cpp
index e7fd1ee31..ca4529aa7 100644
--- a/native/src/init/twostage.cpp
+++ b/native/src/init/twostage.cpp
@@ -3,6 +3,7 @@
 #include <magisk.hpp>
 #include <base.hpp>
 #include <socket.hpp>
+#include <sys/vfs.h>
 
 #include "init.hpp"
 
@@ -39,11 +40,7 @@ bool SecondStageInit::prepare() {
     argv[0] = (char *) INIT_PATH;
 
     // Some weird devices like meizu, uses 2SI but still have legacy rootfs
-    // Check if root and system are on different filesystems
-    struct stat root{}, system{};
-    xstat("/", &root);
-    xstat("/system", &system);
-    if (root.st_dev != system.st_dev) {
+    if (struct statfs sfs{}; statfs("/", &sfs) == 0 && sfs.f_type == RAMFS_MAGIC) {
         // We are still on rootfs, so make sure we will execute the init of the 2nd stage
         unlink("/init");
         xsymlink(INIT_PATH, "/init");