Re: [dm-devel] [PATCH v3 02/26] block: Convert integrity to bvec_alloc_bs()

[Vivek Goyal <vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

On Mon, Sep 24, 2012 at 03:34:42PM -0700, Kent Overstreet wrote:

[..]
>  /**
>   * bio_integrity_alloc - Allocate integrity payload and attach it to bio
>   * @bio:	bio to attach integrity metadata to
> @@ -84,37 +47,39 @@ struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
>  						  unsigned int nr_vecs)
>  {
>  	struct bio_integrity_payload *bip;
> -	unsigned int idx = vecs_to_idx(nr_vecs);
>  	struct bio_set *bs = bio->bi_pool;
> +	unsigned long idx = BIO_POOL_NONE;
> +	unsigned inline_vecs;
> +
> +	if (!bs) {
> +		bip = kmalloc(sizeof(struct bio_integrity_payload) +
> +			      sizeof(struct bio_vec) * nr_vecs, gfp_mask);
> +		inline_vecs = nr_vecs;
> +	} else {
> +		bip = mempool_alloc(bs->bio_integrity_pool, gfp_mask);
> +		inline_vecs = BIP_INLINE_VECS;
> +	}
>  
> -	if (!bs)
> -		bs = fs_bio_set;

Ok, this is change of behavior. Previously we will fall back to fs_bio_set
and now you do kmalloc. This change looks to be independent of bip_vec
pointer. Can you please break it out in a separate patch and also explain
that how does this change help.

Thanks
Vivek