Re: [PATCH 04/18] libmpathutil: add implementation of generic shared pointer

On Tue, May 05, 2026 at 05:43:18PM +0200, Martin Wilck wrote:
> Add a set of simple functions to handle refcounted pointers.
> 
> Signed-off-by: Martin Wilck <[email protected]>
> ---
> diff --git a/libmpathutil/util.c b/libmpathutil/util.c
> index 23a9797..3c623ec 100644
> --- a/libmpathutil/util.c
> +++ b/libmpathutil/util.c
[...]
> +void get_shared_ptr(void *ptr)
> +{
> +	struct shared_ptr *sp = container_of(ptr, struct shared_ptr, ptr);
> +
> +	if (uatomic_add_return(&sp->refcnt, 1) < 0)

This is fine, but what about using an unsigned refcnt, and checking if
this returns 1? It would catch the cases where wrap-around happened,
but it would also catch if something incremented a freed pointer. Just
a thought. But like I said, this is fine as is, so

Reviewed-by: Benjamin Marzinski <[email protected]>

> +		condlog(0, "%s: refcount overflow", __func__);
> +}