Re: [PATCH] pagemap: Add alert to mapping_set_release_always() for mapping with no release_folio

[Matthew Wilcox]

On Thu, Dec 11, 2025 at 01:31:04AM +0530, Deepakkumar Karn wrote:
>  static inline void mapping_set_release_always(struct address_space *mapping)
>  {
> +	/* Alert while setting the flag with no release_folio callback */

The comment is superfluous.

> +	VM_WARN_ONCE(!mapping->a_ops->release_folio,
> +		     "Setting AS_RELEASE_ALWAYS with no release_folio");

But you haven't said why we need to do this.  Surely the NULL pointer
splat is enough to tell you that you did something stupid?

>  	set_bit(AS_RELEASE_ALWAYS, &mapping->flags);
>  }
>  
> -- 
> 2.52.0
> 
>