[dm-devel] [RFC PATCH V2 06/13] block: add new field into 'struct bvec_iter'

[Mike Snitzer]

On Thu, Mar 18 2021 at 12:48pm -0400,
Ming Lei <ming.lei at redhat.com> wrote:

> There is a hole at the end of 'struct bvec_iter', so put a new field
> here and we can save cookie returned from submit_bio() here for
> supporting bio based polling.
> 
> This way can avoid to extend bio unnecessarily.
> 
> Signed-off-by: Ming Lei <ming.lei at redhat.com>
> ---
>  include/linux/bvec.h | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/include/linux/bvec.h b/include/linux/bvec.h
> index ff832e698efb..61c0f55f7165 100644
> --- a/include/linux/bvec.h
> +++ b/include/linux/bvec.h
> @@ -43,6 +43,15 @@ struct bvec_iter {
>  
>  	unsigned int            bi_bvec_done;	/* number of bytes completed in
>  						   current bvec */
> +
> +	/*
> +	 * There is a hole at the end of bvec_iter, define one filed to

s/filed/field/

> +	 * hold something which isn't relate with 'bvec_iter', so that we can

s/relate/related/
or
s/isn't relate with/doesn't relate to/

> +	 * avoid to extend bio. So far this new field is used for bio based

s/to extend/extending/

> +	 * pooling, we will store returning value of underlying queue's

s/pooling/polling/

> +	 * submit_bio() here.
> +	 */
> +	unsigned int		bi_private_data;
>  };
>  
>  struct bvec_iter_all {
> -- 
> 2.29.2
>