Re: [PATCH v2 2/3] xen/privcmd: Mark pages as dirty

[Jürgen Groß <jgross@xxxxxxxx>]

On 06.07.20 20:16, Souptick Joarder wrote:
> pages need to be marked as dirty before unpinned it in
> unlock_pages() which was oversight. This is fixed now.
>
> Signed-off-by: Souptick Joarder <jrdr.linux@xxxxxxxxx>
> Suggested-by: John Hubbard <jhubbard@xxxxxxxxxx>
> Cc: John Hubbard <jhubbard@xxxxxxxxxx>
> Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
> Cc: Paul Durrant <xadimgnik@xxxxxxxxx>
> ---
>   drivers/xen/privcmd.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
> index 33677ea..f6c1543 100644
> --- a/drivers/xen/privcmd.c
> +++ b/drivers/xen/privcmd.c
> @@ -612,8 +612,11 @@ static void unlock_pages(struct page *pages[], unsigned 
> int nr_pages)
>   {
>         unsigned int i;
>   
> -	for (i = 0; i < nr_pages; i++)
> +       for (i = 0; i < nr_pages; i++) {
> +               if (!PageDirty(pages[i]))
> +                       set_page_dirty_lock(pages[i]);
With put_page() directly following I think you should be able to use
set_page_dirty() instead, as there is obviously a reference to the page
existing.

>                 put_page(pages[i]);
> +       }
>   }
>   
>   static long privcmd_ioctl_dm_op(struct file *file, void __user *udata)
Juergen