Re: Bugs on Linux 2.6.18-rc2 sg code?

[Matthew Wilcox <matthew@wil.cx>]

On Sat, Aug 19, 2006 at 12:11:34AM -0400, Douglas Gilbert wrote:
> > Your point about the change to sg_vma_nopage() between
> > lk 2.6.15 and lk 2.6.16 also seems to be correct.
> > The most indented part of that function has been
> > changed from incrementing the change count on the
> > reported page (as indicated by 'offset') in a
> > compound page allocation to ignoring the 'offset'
> > and incrementing the page count on the first page
> > in a compound page allocation.
>  		if (offset < len) {
> -			page = sg->page;
> +			page = virt_to_page(page_address(sg->page) + offset);
>  			get_page(page);	/* increment page count */

But page_address can return NULL on highmem machines.  Or are you
guaranteed that these are lowmem pages?