Re: [PATCH 1/7] block: Clean up merge logic

[Vivek Goyal <vgoyal@redhat.com>]

On Thu, Mar 01, 2012 at 10:22:45PM -0500, Martin K. Petersen wrote:

[..]
> -static inline int bio_has_data(struct bio *bio)
> +static inline bool bio_has_data(struct bio *bio)
>  {
> -	return bio && bio->bi_io_vec != NULL;
> +	if (bio && bio->bi_io_vec)
> +		return true;
> +
> +	return false;
> +}
> +
> +static inline bool bio_is_rw(struct bio *bio)
> +{
> +	if (!bio_has_data(bio))
> +		return false;
> +
> +	return true;
> +}
> +

Hi Martin,

So in this patch bio_is_rw() == bio_is_data(). Do they diverge in later
patches?

> +static inline bool bio_mergeable(struct bio *bio)
> +{
> +	if (bio->bi_rw & REQ_NOMERGE_FLAGS)
> +		return false;
> +
> +	return true;
>  }

Some of the flags in REQ_NOMERGE_FLAGS are rq only and should not be used on
bio. For example REQ_NOMERGE and REQ_STARTED.

Will it be better to define BIO_NOMERGE_FLAGS separately?

Thanks
Vivek