Re: [PATCH v3] mm: Change return type to vm_fault_t

[Joe Perches]

On Sat, 2018-05-12 at 11:47 +0530, Souptick Joarder wrote:
> Use new return type vm_fault_t for fault handler
> in struct vm_operations_struct. For now, this is
> just documenting that the function returns a
> VM_FAULT value rather than an errno.  Once all
> instances are converted, vm_fault_t will become
> a distinct type.

trivia:

> diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
[]
> @@ -627,7 +627,7 @@ struct vm_special_mapping {
>  	 * If non-NULL, then this is called to resolve page faults
>  	 * on the special mapping.  If used, .pages is not checked.
>  	 */
> -	int (*fault)(const struct vm_special_mapping *sm,
> +	vm_fault_t (*fault)(const struct vm_special_mapping *sm,
>  		     struct vm_area_struct *vma,
>  		     struct vm_fault *vmf);


It'd be nicer to realign the 2nd and 3rd arguments
on the subsequent lines.

	vm_fault_t (*fault)(const struct vm_special_mapping *sm,
			    struct vm_area_struct *vma,
			    struct vm_fault *vmf);