Re: [dm-devel] [PATCH 05/13] block: Only clone bio vecs that are in use

[Tejun Heo <tj kernel org>]

On Thu, May 17, 2012 at 10:59:52PM -0400, koverstreet google com wrote:
> diff --git a/fs/bio.c b/fs/bio.c
> index e2c0970..de0733e 100644
> --- a/fs/bio.c
> +++ b/fs/bio.c
> @@ -435,8 +435,9 @@ EXPORT_SYMBOL(bio_phys_segments);
>   */
>  void __bio_clone(struct bio *bio, struct bio *bio_src)
>  {
> -	memcpy(bio->bi_io_vec, bio_src->bi_io_vec,
> -		bio_src->bi_max_vecs * sizeof(struct bio_vec));
> +	memcpy(bio->bi_io_vec,
> +	       bio_iovec(bio_src),

Unnecessary line break.

> +	       bio_segments(bio_src) * sizeof(struct bio_vec));
>  
>  	/*
>  	 * most users will be overriding ->bi_bdev with a new target,
> @@ -445,10 +446,10 @@ void __bio_clone(struct bio *bio, struct bio *bio_src)
>  	bio->bi_sector = bio_src->bi_sector;
>  	bio->bi_bdev = bio_src->bi_bdev;
>  	bio->bi_flags |= 1 << BIO_CLONED;
> +	bio->bi_flags &= ~(1 << BIO_SEG_VALID);

Can probably be conditionalized on bi_idx?

Thanks.

-- 
tejun