Re: [PATCH 4/8] rust: debugfs: Allow subdir creation in builder interface

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Tue, Apr 29, 2025 at 11:15:58PM +0000, Matthew Maurer wrote:
> Allows creating subdirectories in the builder intended to be cleaned up
> by `debugfs_remove` at the same time as the root.
> 
> Signed-off-by: Matthew Maurer <mmaurer@google.com>
> ---
>  rust/kernel/debugfs.rs | 26 ++++++++++++++++++++++++++
>  1 file changed, 26 insertions(+)
> 
> diff --git a/rust/kernel/debugfs.rs b/rust/kernel/debugfs.rs
> index f6240fd056f8598d5ef06bdaf61c5c33eab5b734..6c7cf7e97741b98d2c0654d01fca3de0d8047e97 100644
> --- a/rust/kernel/debugfs.rs
> +++ b/rust/kernel/debugfs.rs
> @@ -347,6 +347,32 @@ pub fn display_file<T: Display + Sized>(&self, name: &CStr, data: &'a T) -> Resu
>          core::mem::forget(unsafe { self.inner.display_file_raw(name, data)? });
>          Ok(())
>      }
> +
> +    /// Creates a nested directory that may live as long as its parent

Ick, why make it complex?

> +    ///
> +    /// # Example
> +    ///
> +    /// ```
> +    /// # use kernel::c_str;
> +    /// # use kernel::debugfs::{Dir, Values};
> +    /// let dir = Dir::new(c_str!("foo"), None)?;

Again, no checking please :)

> +    /// let foo = KBox::pin_init(Values::attach(0, dir), GFP_KERNEL)?;
> +    /// foo.as_ref().build(|_value, builder| {
> +    ///   builder.dir(c_str!("bar"))?;
> +    ///   Ok::<(), Error>(())
> +    /// })?;
> +    /// // foo/bar will still exist at this point in DebugFS
> +    /// # Ok::<(), Error>(())

Again, no errors :)

thanks,

greg k-h