Bad use of highmem with buffer_migrate_page?

[Cong Wang]

On Thu, 05 Jul 2012 at 10:45 GMT, Rabin Vincent <rabin at rab.in> wrote:
> 8<----
> From 8a94126eb3aa2824866405fb78bb0b8316f8fd00 Mon Sep 17 00:00:00 2001
> From: Rabin Vincent <rabin at rab.in>
> Date: Thu, 5 Jul 2012 15:52:23 +0530
> Subject: [PATCH] mm: cma: don't replace lowmem pages with highmem
>
> The filesystem layer expects pages in the block device's mapping to not
> be in highmem (the mapping's gfp mask is set in bdget()), but CMA can
> currently replace lowmem pages with highmem pages, leading to crashes in
> filesystem code such as the one below:
>
...
> Fix this by replacing only highmem pages with highmem.
>

Looks good to me too,

    Reviewed-by: WANG Cong <xiyou.wangcong at gmail.com>