[dm-devel] can we reduce bio_set_dev overhead due to bio_associate_blkg?

[Christoph Hellwig]

On Fri, Apr 08, 2022 at 11:42:51AM -0400, Mike Snitzer wrote:
> I think we can achieve the goal of efficient cloning/remapping for
> both usecases simply by splitting out the bio_set_dev() and leaving it
> to the caller to pick which interface to use (e.g. clone vs
> clone_and_remap).

You can just pass a NULL bdev to bio_alloc_clone/bio_init_clone.
I've been hoping to get rid of that, but if we have a clear use case
it will have to stay.