Re: [PATCH 4/5] cgroup, buffer_head: implement submit_bh_blkcg_css()

[Jan Kara <jack@suse.cz>]

On Tue 10-10-17 08:54:40, Tejun Heo wrote:
> Implement submit_bh_blkcg_css() which will be used to override cgroup
> membership on specific buffer_heads.
> 
> v2: Reimplemented using create_bh_bio() as suggested by Jan.
> 
> Signed-off-by: Tejun Heo <tj@kernel.org>
> Cc: Jan Kara <jack@suse.cz>
> Cc: Jens Axboe <axboe@kernel.dk>

Looks good. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  fs/buffer.c                 | 12 ++++++++++++
>  include/linux/buffer_head.h |  3 +++
>  2 files changed, 15 insertions(+)
> 
> diff --git a/fs/buffer.c b/fs/buffer.c
> index b4b2169..ed0e473 100644
> --- a/fs/buffer.c
> +++ b/fs/buffer.c
> @@ -3147,6 +3147,18 @@ static int submit_bh_wbc(int op, int op_flags, struct buffer_head *bh,
>  	return 0;
>  }
>  
> +int submit_bh_blkcg_css(int op, int op_flags, struct buffer_head *bh,
> +			struct cgroup_subsys_state *blkcg_css)
> +{
> +	struct bio *bio;
> +
> +	bio = create_bh_bio(op, op_flags, bh, 0);
> +	bio_associate_blkcg(bio, blkcg_css);
> +	submit_bio(bio);
> +	return 0;
> +}
> +EXPORT_SYMBOL(submit_bh_blkcg_css);
> +
>  int submit_bh(int op, int op_flags, struct buffer_head *bh)
>  {
>  	struct bio *bio;
> diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
> index c8dae55..dca5b3b 100644
> --- a/include/linux/buffer_head.h
> +++ b/include/linux/buffer_head.h
> @@ -13,6 +13,7 @@
>  #include <linux/pagemap.h>
>  #include <linux/wait.h>
>  #include <linux/atomic.h>
> +#include <linux/cgroup.h>
>  
>  #ifdef CONFIG_BLOCK
>  
> @@ -197,6 +198,8 @@ void ll_rw_block(int, int, int, struct buffer_head * bh[]);
>  int sync_dirty_buffer(struct buffer_head *bh);
>  int __sync_dirty_buffer(struct buffer_head *bh, int op_flags);
>  void write_dirty_buffer(struct buffer_head *bh, int op_flags);
> +int submit_bh_blkcg_css(int op, int op_flags, struct buffer_head *bh,
> +			struct cgroup_subsys_state *blkcg_css);
>  int submit_bh(int, int, struct buffer_head *);
>  void write_boundary_block(struct block_device *bdev,
>  			sector_t bblock, unsigned blocksize);
> -- 
> 2.9.5
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR