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

On Sun, Feb 26, 2017 at 2:23 AM, Christoph Hellwig [off-list ref] wrote:

On Fri, Feb 24, 2017 at 11:42:39PM +0800, Ming Lei wrote:

quoted

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.

Thinking about MD's case further, and looks bio_add_page() won't
fail at all in case that queue's limit isn't applied in bio_add_page()
in future.

So I will change MD's handling in this case and avoid to introduce
bio_remove_last_page() in V2.

Thanks,
Ming Lei