Re: [PATCH v2 03/11] mm: Return the address from page_mapped_in_vma()

[Jane Chu <jane.chu@oracle.com>]

On 4/8/2024 12:42 PM, Matthew Wilcox (Oracle) wrote:

> The only user of this function calls page_address_in_vma() immediately
> after page_mapped_in_vma() calculates it and uses it to return true/false.
> Return the address instead, allowing memory-failure to skip the call
> to page_address_in_vma().
>
> Acked-by: Miaohe Lin <linmiaohe@huawei.com>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
>   mm/page_vma_mapped.c | 14 ++++++++------
>   1 file changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c
> index 53b8868ede61..48bfc17934cd 100644
> --- a/mm/page_vma_mapped.c
> +++ b/mm/page_vma_mapped.c
> @@ -319,9 +319,10 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw)
>    * @page: the page to test
>    * @vma: the VMA to test
>    *
> - * Returns 1 if the page is mapped into the page tables of the VMA, 0
> - * if the page is not mapped into the page tables of this VMA.  Only
> - * valid for normal file or anonymous VMAs.
> + * Return: The address the page is mapped at if the page is in the range
> + * covered by the VMA and present in the page table.  If the page is
> + * outside the VMA or not present, returns -EFAULT.
> + * Only valid for normal file or anonymous VMAs.
>    */
>   int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma)
>   {
> @@ -336,9 +337,10 @@ int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma)
>   
>   	pvmw.address = vma_address(vma, pgoff, 1);
>   	if (pvmw.address == -EFAULT)
> -		return 0;
> +	       goto out;
>   	if (!page_vma_mapped_walk(&pvmw))
> -		return 0;
> +		return -EFAULT;
>   	page_vma_mapped_walk_done(&pvmw);
> -	return 1;
> +out:
> +	return pvmw.address;
>   }

Looks good.

Reviewed-by: Jane Chu <jane.chu@oracle.com>

-jane