On Wed, Jun 13, 2018 at 07:56:54AM -0700, Christoph Hellwig wrote: > On Sat, Jun 09, 2018 at 08:29:59PM +0800, Ming Lei wrote: > > There is one use case(DM) which requires to clone bio chunk by > > chunk, so introduce this API. > > I don't think DM is the special case here. The special case is the > bounce code that only wants single page bios. Between that, and the > fact that we only have two callers and one of them is inside the > block layer I would suggest to fold in the following patch to make > bio_clone_bioset clone in multi-page bvecs and make the bounce code > use the low-level interface directly: Bounce limits the max pages as 256 will do bio splitting, so won't need this change. Thanks, Ming