[CRIU] [PATCH 13/12] page-xfer: Don't send zero pages if none found

[Mike Rapoport]

On Thu, Jun 29, 2017 at 01:33:44PM +0300, Pavel Emelyanov wrote:
> When page-server gets a request from lazy-daemon for a pagemap,
> the former cannot read no pages from the image.

Hm? Can you please rephrase a bit? "cannot read no pages" really finished
me :-P
 
> Mike says: "The pagemap should be completely in sync between src
> and dst and dst should never request pages that are not present.
> Maybe we should return -1 here? At least we'll have a chance that
> dump will unroll everything..."
> 
> Why not?!
> 
> Signed-off-by: Pavel Emelyanov <xemul at virtuozzo.com>
> ---
>  criu/page-xfer.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/criu/page-xfer.c b/criu/page-xfer.c
> index 24fc565..d949c06 100644
> --- a/criu/page-xfer.c
> +++ b/criu/page-xfer.c
> @@ -678,10 +678,8 @@ static int page_server_get_pages(int sk, struct page_server_iov *pi)
>  	 */
> 
>  	if (pi->nr_pages == 0) {
> -		/* no iovs found means we've hit a zero page */
>  		pr_debug("no iovs found, zero pages\n");
> -		pi->cmd = encode_ps_cmd(PS_IOV_ADD_F, 0);
> -		return send_psi(sk, pi);
> +		return -1;
>  	}
> 
>  	pi->cmd = encode_ps_cmd(PS_IOV_ADD_F, PE_PRESENT);
> -- 
> 2.1.4
> 
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