[CRIU] [PATCH v5 5/8] criu: pagemap: add entries for zero pages

[Pavel Emelyanov]

> @@ -165,9 +168,12 @@ static int generate_iovs(struct vma_area *vma, struct page_pipe *pp, u64 *map, u
>  		if (has_parent && page_in_parent(at[pfn])) {
>  			ret = page_pipe_add_hole(pp, vaddr);
>  			pages[0]++;
> +		} else if (page_is_zero(at[pfn])) {
> +			ret = page_pipe_add_zero(pp, vaddr);
> +			pages[1]++;

This means, that zero holes that are in parent will be written as ... has_parent :\
Hm... Is this correct? Presumably yes, but ...

>  		} else {
>  			ret = page_pipe_add_page(pp, vaddr, ppb_flags);
> -			pages[1]++;
> +			pages[2]++;
>  		}
>  
>  		if (ret) {

> @@ -342,6 +355,15 @@ static int dump_hole(struct page_xfer *xfer, struct page_pipe_iovs *iov,
>  	return 0;
>  }
>  
> +static int dump_holes(struct page_xfer *xfer, struct page_pipe *pp,
> +		      void *limit, unsigned long off)
> +{
> +	if (dump_hole(xfer, &pp->holes, limit, off, PS_IOV_HOLE))
> +		return -1;
> +
> +	return dump_hole(xfer, &pp->zeros, limit, off, PS_IOV_ZERO);

This generates unsorted pagemap.img. Restore part currently assumes that it's sorted.

> +}
> +
>  int page_xfer_dump_pages(struct page_xfer *xfer, struct page_pipe *pp,
>  		unsigned long off)
>  {