On Fri, Jan 20, 2023 at 05:55:50PM +0000, David Howells wrote: > (3) Any other sort of iterator. > > No refs or pins are obtained on the page, the assumption is made that > the caller will manage page retention. ITER_ALLOW_P2PDMA is not > permitted. The ITER_ALLOW_P2PDMA check here is fundamentally wrong and will break things like io_uring to fixed buffers on NVMe. ITER_ALLOW_P2PDMA should strictly increase the group of acceptable iters, it does must not restrict anything.
