On Thu, Jun 28 2018 at 11:21am -0400, Bart Van Assche <bart.vanassche@xxxxxxx> wrote: > On 06/27/18 17:30, Ming Lei wrote: > >One core idea of immutable bvec is to use bio->bi_iter and the original > >bvec table to iterate over anywhere in the bio. That is why .bi_io_vec > >needs to copy, but not see any reason why .bi_vcnt needs to do. > > > >Do you have use cases on .bi_vcnt for cloned bio? > > So far this is only a theoretical concern. There are many functions > in the block layer that use .bi_vcnt, and it is a lot of work to > figure out all the callers of all these functions. No point wasting time with that. I don't understand why Ming cares. Your change is obviously correct. The state should get transfered over to reflect reality. This patch doesn't harm anything, it just prevents some clone-specific failure in the future. Acked-by: Mike Snitzer <snitzer@xxxxxxxxxx>
