vfs: improve _find() path handling

kernel/libk/src/vfs/ioctx.rs

@@ -540,49 +540,44 @@ impl IoContext {
         Ok((buffer, node.flatten_hardlink()?))
     }
 
-    fn _find(&self, mut at: NodeRef, path: &Path, follow_links: bool) -> Result<NodeRef, Error> {
-        log::debug!("_find({path:?})");
-        let mut element;
-        let mut rest = path;
+    fn _find(&self, mut at: NodeRef, mut path: &Path, follow_link: bool) -> Result<NodeRef, Error> {
+        while !path.is_empty() {
+            let (name, tail) = path.split_left();
 
-        loop {
-            (element, rest) = rest.split_left();
+            let name = match name {
+                Path::SELF_NAME => {
+                    path = tail;
+                    continue;
+                }
+                Path::PARENT_NAME => {
+                    at = at.parent();
+                    if at.mountpoint_target().is_some() {
+                        // Just exited root -> mountpoint, go up to mountpoint's parent
+                        at = at.parent();
+                    }
+                    path = tail;
+                    continue;
+                }
+                name => name,
+            };
 
             if !at.is_directory() {
+                log::info!("at is not a dir");
                 return Err(Error::NotADirectory);
             }
 
-            match element {
-                Path::PARENT_NAME => {
-                    at = at.parent();
-                }
-                Path::SELF_NAME => {}
-                _ => break,
-            }
+            let access = self.check_access(&at, AccessMode::EXEC)?;
+            let filename = Filename::new(name)?;
+            let child = at.lookup_or_load(filename, access)?.flatten_hardlink()?;
+            let follow_links = follow_link || !tail.is_empty();
+
+            let child = self._resolve(child, follow_links)?;
+
+            at = child;
+            path = tail;
         }
 
-        let is_end = element.is_empty() && rest.is_empty();
-
-        at = self._resolve(at, follow_links || !is_end)?;
-
-        if !at.is_directory() {
-            return Err(Error::NotADirectory);
-        }
-
-        if element.is_empty() && rest.is_empty() {
-            return Ok(at);
-        }
-
-        let access = self.check_access(&at, AccessMode::EXEC)?;
-        let filename = Filename::new(element)?;
-        let node = at.lookup_or_load(filename, access)?.flatten_hardlink()?;
-        let node = self._resolve(node, follow_links)?;
-
-        if rest.is_empty() {
-            Ok(node.flatten_hardlink()?)
-        } else {
-            self._find(node, rest, follow_links)
-        }
+        at.flatten_hardlink()
     }
 }