Re: [PATCH v3 6/7] block: unpin all pages of a bvec in bio_iov_iter_align_down()

[Christoph Hellwig]

> +
> +	/*
> +	 * __bio_release_pages() only unpins the pages still covered by
> +	 * bv_len, so drop the pins for the pages trimmed off here.
> +	 */
> +	npages = bvec_nr_pages(bv);
>  	bv->bv_len -= nbytes;
> +	npages -= bvec_nr_pages(bv);

Wouldn't it make more sense to calculate npages once after the
decrement here, or am I missing something?