Re: [patch 3/3] mm: fault handler to replace nopage and populate

Christoph Hellwig
2006-10-10T12:10:20Z

On Sat, Oct 07, 2006 at 03:06:32PM +0200, Nick Piggin wrote:
> +/*
> + * fault_data is filled in the the pagefault handler and passed to the
> + * vma's ->fault function. That function is responsible for filling in
> + * 'type', which is the type of fault if a page is returned, or the type
> + * of error if NULL is returned.
> + */
> +struct fault_data {
> + struct vm_area_struct *vma;
> + unsigned long address;
> + pgoff_t pgoff;
> + unsigned int flags;
> +
> + int type;
> +};
>
> /*
> * These are the virtual MM functions - opening of an area, closing and
> @@ -203,6 +221,7 @@ extern pgprot_t protection_map[16];
> struct vm_operations_struct {
> void (*open)(struct vm_area_struct * area);
> void (*close)(struct vm_area_struct * area);
> + struct page * (*fault)(struct fault_data * data);

Please pass the vma as an explicit first argument so that all vm_operations
operate on a vma. It's also much cleaner to have the separate between the
the object operated on (the vma) and all the fault details (struct fault_data).