Migrate module mounting to Rust

native/src/base/cstr.rs

@@ -68,7 +68,7 @@ pub mod buf {
 
 // Trait definitions
 
-pub trait Utf8CStrBuf: Write + AsRef<Utf8CStr> + Deref<Target = Utf8CStr> {
+pub trait Utf8CStrBuf: Display + Write + AsRef<Utf8CStr> + Deref<Target = Utf8CStr> {
     // The length of the string without the terminating null character.
     // assert_true(len <= capacity - 1)
     fn len(&self) -> usize;

native/src/base/files.rs

@@ -182,6 +182,10 @@ impl FileAttr {
     pub fn is_socket(&self) -> bool {
         self.is(libc::S_IFSOCK)
     }
+
+    pub fn is_whiteout(&self) -> bool {
+        self.is_char_device() && self.st.st_rdev == 0
+    }
 }
 
 const XATTR_NAME_SELINUX: &CStr = c"security.selinux";

native/src/base/mount.rs

@@ -3,13 +3,14 @@ use libc::c_ulong;
 use std::ptr;
 
 impl Utf8CStr {
-    pub fn bind_mount_to<'a>(&'a self, path: &'a Utf8CStr) -> OsResult<'a, ()> {
+    pub fn bind_mount_to<'a>(&'a self, path: &'a Utf8CStr, rec: bool) -> OsResult<'a, ()> {
+        let flag = if rec { libc::MS_REC } else { 0 };
         unsafe {
             libc::mount(
                 self.as_ptr(),
                 path.as_ptr(),
                 ptr::null(),
-                libc::MS_BIND,
+                libc::MS_BIND | flag,
                 ptr::null(),
             )
             .check_os_err("bind_mount", Some(self), Some(path))