Re: [PATCH v1 02/14] block: introduce bio_remove_last_page()

[Christoph Hellwig]

On Fri, Feb 24, 2017 at 11:42:39PM +0800, Ming Lei wrote:
> MD need this helper to remove the last added page, so introduce
> it.

If MD really has a valid use case for this it should open code the
operation.  The semantics look deeply fishy to me.