WIP: Add tar utility

kernel/libk/src/vfs/node/mod.rs

@@ -503,6 +503,18 @@ impl Node {
     }
 }
 
+impl DirectoryData {
+    fn contains(&self, node: &NodeRef, name: &Filename) -> bool {
+        {
+            let cache = self.children.lock();
+            if cache.iter().any(|(n, _)| n == name) {
+                return true;
+            }
+        }
+        self.imp.contains(node, name)
+    }
+}
+
 impl HardlinkData {
     fn target(&self, link: &NodeRef) -> Result<NodeRef, Error> {
         let target = self.imp.target(link)?;

kernel/libk/src/vfs/node/ops.rs

@@ -110,6 +110,9 @@ impl Node {
     /// Creates an entry within a directory with given [CreateInfo].
     pub fn create(self: &NodeRef, info: CreateInfo, check: AccessToken) -> Result<NodeRef, Error> {
         let directory = self.as_directory()?;
+        if directory.contains(self, info.name) {
+            return Err(Error::AlreadyExists);
+        }
         let node = directory.imp.create_node(self, &info)?;
 
         self.create_node(node.clone(), info.name, check.clone())?;

kernel/libk/src/vfs/node/traits.rs

@@ -149,6 +149,13 @@ pub trait DirectoryImpl: CommonImpl {
         Err(Error::NotImplemented)
     }
 
+    fn contains(&self, node: &NodeRef, name: &Filename) -> bool {
+        match self.lookup(node, name) {
+            Ok(_) => true,
+            Err(_) => false,
+        }
+    }
+
     /// Returns the "length" of the directory in entries
     fn len(&self, node: &NodeRef) -> Result<usize, Error> {
         let _ = node;

kernel/libk/src/vfs/node/tree.rs

@@ -32,12 +32,9 @@ impl Node {
         let directory = self.as_directory()?;
         let mut children = directory.children.lock();
 
-        // TODO check if an entry already exists with such name
-
-        // if children.contains_key(&name) {
-        //     log::warn!("Directory cache already contains an entry: {:?}", name);
-        //     return Err(Error::AlreadyExists);
-        // }
+        if children.iter().any(|(n, _)| name == *n) {
+            return Err(Error::AlreadyExists);
+        }
 
         assert!(child.parent.replace(Some(self.clone())).is_none());
         children.push((name, child));