Subject: Re: linux-next: build failure after merge of the akpm-current tree

From: Andrew Morton <[email-masked]>
Date: Wed, 14 May 2014 14:55:20 -0700

On Wed, 14 May 2014 17:47:49 +1000 Stephen Rothwell <[email-masked]> wrote:

> Hi Andrew,
> 
> After merging the akpm-current tree, today's linux-next build (x86_64
> allmodconfig) failed like this:
> 
> mm/memcontrol.c: In function 'mem_cgroup_write':
> mm/memcontrol.c:5088:45: error: 'buffer' undeclared (first use in this function)
>    ret = res_counter_memparse_write_strategy(buffer, &val);
>                                              ^
> mm/memcontrol.c: At top level:
> /scratch/sfr/next/mm/memcontrol.c:6029:3: error: unknown field 'write_string' specified in initializer
>    .write_string = mem_cgroup_write,
>    ^
> 
> Caused by commit a4bf584ed8c2 ("memcg: allow setting low_limit")
> interacting with commit 451af504df0c ("cgroup: replace
> cftype->write_string() with cftype->write()") from the cgroup tree.
> (I love API changes and unnecessary variable renaming :-()
> 
> ...
>
> @@ -6026,7 +6026,7 @@ static struct cftype mem_cgroup_files[] = {
>  	{
>  		.name = "low_limit_in_bytes",
>  		.private = MEMFILE_PRIVATE(_MEM, RES_LOW_LIMIT),
> -		.write_string = mem_cgroup_write,
> +		.write = mem_cgroup_write,
>  		.read_u64 = mem_cgroup_read_u64,
>  	},

Renaming buffer to buf was rather unneeded.

I have 24 patches here against mm/memcontrol.c.  Go gently, please.