From bb8dde3258d2f8453baabcd730ea84a30420af7c Mon Sep 17 00:00:00 2001
From: Ashwin Naren <arihant2math@gmail.com>
Date: Mon, 4 May 2026 12:33:45 -0700
Subject: [PATCH] address review

---
 libkernel/src/error.rs               | 4 ++++
 libkernel/src/error/syscall_error.rs | 4 ++++
 src/drivers/fs/cgroup/mod.rs         | 8 ++++----
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/libkernel/src/error.rs b/libkernel/src/error.rs
index 1f959f4..1df0249 100644
--- a/libkernel/src/error.rs
+++ b/libkernel/src/error.rs
@@ -121,6 +121,10 @@ pub enum FsError {
     #[error("The directory is not empty.")]
     DirectoryNotEmpty,
 
+    /// The device or resource is busy.
+    #[error("The device or resource is busy.")]
+    Busy,
+
     /// Invalid input parameters.
     #[error("Invalid input parameters.")]
     InvalidInput,
diff --git a/libkernel/src/error/syscall_error.rs b/libkernel/src/error/syscall_error.rs
index da68933..c4de29a 100644
--- a/libkernel/src/error/syscall_error.rs
+++ b/libkernel/src/error/syscall_error.rs
@@ -44,6 +44,7 @@ pub const ERANGE: isize = -34;
 pub const EWOULDBLOCK: isize = -EAGAIN;
 pub const ENAMETOOLONG: isize = -36;
 pub const ENOSYS: isize = -38;
+pub const ENOTEMPTY: isize = -39;
 pub const ELOOP: isize = -40;
 pub const EAFNOSUPPORT: isize = -97;
 pub const EOPNOTSUPP: isize = -95;
@@ -63,7 +64,10 @@ pub fn kern_err_to_syscall(err: KernelError) -> isize {
         KernelError::Fs(FsError::IsADirectory) => EISDIR,
         KernelError::Fs(FsError::NotADirectory) => ENOTDIR,
         KernelError::Fs(FsError::AlreadyExists) => EEXIST,
+        KernelError::Fs(FsError::DirectoryNotEmpty) => ENOTEMPTY,
+        KernelError::Fs(FsError::Busy) => EBUSY,
         KernelError::Fs(FsError::InvalidInput) => EINVAL, // TODO: Is this right?
+        KernelError::InUse => EBUSY,
         KernelError::Fs(FsError::PermissionDenied) => EACCES,
         KernelError::Fs(FsError::TooManyFiles) => EMFILE,
         KernelError::Fs(FsError::NoDevice) => ENODEV,
diff --git a/src/drivers/fs/cgroup/mod.rs b/src/drivers/fs/cgroup/mod.rs
index 86a4afe..a02059e 100644
--- a/src/drivers/fs/cgroup/mod.rs
+++ b/src/drivers/fs/cgroup/mod.rs
@@ -316,11 +316,11 @@ impl Inode for CgroupDirInode {
         let child = children.get(name).cloned().ok_or(FsError::NotFound)?;
 
         if !child.children.lock_save_irq().is_empty() {
-            return Err(FsError::DirectoryNotEmpty.into());
+            return Err(FsError::Busy.into());
         }
 
         if cgroupfs().has_live_processes_direct(&child) {
-            return Err(FsError::DirectoryNotEmpty.into());
+            return Err(FsError::Busy.into());
         }
 
         children.remove(name);
@@ -612,7 +612,7 @@ impl CgroupFs {
     fn new() -> Arc<Self> {
         Arc::new(Self {
             root: CgroupDirInode::new_root(),
-            next_inode_id: AtomicU64::new(2),
+            next_inode_id: AtomicU64::new(2 << 8),
             memberships: SpinLock::new(BTreeMap::new()),
         })
     }
@@ -620,7 +620,7 @@ impl CgroupFs {
     fn alloc_inode_id(&self) -> InodeId {
         InodeId::from_fsid_and_inodeid(
             CGROUPFS_ID,
-            self.next_inode_id.fetch_add(1, Ordering::SeqCst),
+            self.next_inode_id.fetch_add(1 << 8, Ordering::Relaxed),
         )
     }