[PATCHv3 06/10] blk-integrity: simplify counting segments

[Keith Busch]

On Wed, Sep 11, 2024 at 10:17:20AM +0200, Christoph Hellwig wrote:
> On Tue, Sep 10, 2024 at 10:06:03AM -0600, Keith Busch wrote:
> > Exactly. bio_integrity_add_page will use the queue's limits to decide if
> > it can combine pages into one vector, so appending pages through that
> > interface will always result in the most compact bip vector.
> > 
> > This patch doesn't combine merged bio's but that's unlikely to have
> > mergable segments.
> 
> Oh, bio_integrity_add_page uses bvec_try_merge_hw_page.  That means it
> doesn't really work well for our stacking model, as any stacking driver
> can and will change these.  Maybe we need to take a step back and fully
> apply the immutable biovec and split at final submission model to
> metadata?

Would you be okay if I resubmit this patchset with just the minimum to
fix the existing merging? I agree stacking and splitting integrity is
currently broken, but I think the merging fixes from this series need to
happen regardless of the how the block stack might change when integrity
data is set in bios.