aya: Make MapData::pin pub

Signed-off-by: Dave Tucker <[email protected]>

aya/src/maps/mod.rs

@@ -469,7 +469,8 @@ impl MapData {
             }
             Err(_) => {
                 let mut map = Self::create(obj, name, btf_fd)?;
-                map.pin(name, path).map_err(|error| MapError::PinError {
+                let path = path.join(name);
+                map.pin(&path).map_err(|error| MapError::PinError {
                     name: Some(name.into()),
                     error,
                 })?;
@@ -542,13 +543,35 @@ impl MapData {
         })
     }
 
-    pub(crate) fn pin<P: AsRef<Path>>(&mut self, name: &str, path: P) -> Result<(), PinError> {
+    /// Allows the map to be pinned to the provided path.
+    ///
+    /// Any directories in the the path provided should have been created by the caller.
+    /// The path must be on a BPF filesystem.
+    ///
+    /// # Errors
+    ///
+    /// Returns a [`SyscallError`] if the underlying syscall fails. This may also happen
+    /// if the path already exists, in which case the inner [`std::io::Error`] kind
+    /// will be [`std::io::ErrorKind::AlreadyExists`].
+    ///
+    /// # Example
+    ///
+    /// ```no_run
+    /// # let mut bpf = aya::Bpf::load(&[])?;
+    /// # use aya::maps::MapData;
+    ///
+    /// let mut map = MapData::from_pin("/sys/fs/bpf/my_map")?;
+    /// map.pin("/sys/fs/bpf/my_map2")?;
+    ///
+    /// # Ok::<(), Box<dyn std::error::Error>>(())
+    /// ```
+    pub fn pin<P: AsRef<Path>>(&mut self, path: P) -> Result<(), PinError> {
         use std::os::unix::ffi::OsStrExt as _;
+        let path = path.as_ref();
         let Self { fd, obj: _ } = self;
-        let path = path.as_ref().join(name);
         let path_string = CString::new(path.as_os_str().as_bytes()).map_err(|error| {
             PinError::InvalidPinPath {
-                path: path.clone(),
+                path: path.to_path_buf(),
                 error,
             }
         })?;