Re: [PATCH v2 08/11] rust/block: Add driver module

[Zhao Liu]

> +impl BdrvChild {
> +    /// Creates a new child reference from a `BlockdevRef`.
> +    pub unsafe fn new(
> +        parent: *mut bindings::BlockDriverState,
> +        bref: *mut bindings::BlockdevRef,
> +        errp: *mut *mut bindings::Error,
> +    ) -> Option<Self> {
> +        unsafe {
> +            let child_bs = bindings::bdrv_open_blockdev_ref_file(bref, 
> parent, errp);
> +            if child_bs.is_null() {
> +                return None;
> +            }
> +
> +            bindings::bdrv_graph_wrlock();
> +            let child = bindings::bdrv_attach_child(
> +                parent,
> +                child_bs,
> +                c"file".as_ptr(),

c literal starts from v1.77, and there's a workaround provided by
c_str.rs:

c_str!("file").as_ptr()

> +                &bindings::child_of_bds as *const _,
> +                bindings::BDRV_CHILD_IMAGE,
> +                errp,
> +            );
> +            bindings::bdrv_graph_wrunlock();
> +
> +            if child.is_null() {
> +                None
> +            } else {
> +                Some(BdrvChild { child })
> +            }
> +        }
> +    }
> +