[PATCH v3 08/30] block: Introduce zone write plugging

[Christoph Hellwig]

> +	spin_lock_irqsave(&zwplug->lock, flags);
> +	while (zwplug->wp_offset < zone_capacity &&
> +	       (bio = bio_list_peek(&zwplug->bio_list))) {

Nit: I find this mix of a comparism and a combined assignment / NULL
check just a bit too dense.  I'd move one them out of the loop condition
and to use a separate break to make things a little easier to digest.

Otherwise this looks good modulo the freelist discissoon in the
next patch.