Migrate magiskinit selinux.cpp to Rust

native/src/base/mount.rs

@@ -1,4 +1,4 @@
-use crate::{FsPath, LibcReturn};
+use crate::{FsPath, LibcReturn, Utf8CStr};
 use libc::c_ulong;
 use std::ptr;
 
@@ -29,6 +29,19 @@ impl FsPath {
         }
     }
 
+    pub fn remount_with_data(&self, data: &Utf8CStr) -> std::io::Result<()> {
+        unsafe {
+            libc::mount(
+                ptr::null(),
+                self.as_ptr(),
+                ptr::null(),
+                libc::MS_REMOUNT,
+                data.as_ptr().cast(),
+            )
+            .as_os_err()
+        }
+    }
+
     pub fn move_mount_to(&self, path: &FsPath) -> std::io::Result<()> {
         unsafe {
             libc::mount(