On Mon, Nov 07, 2022 at 09:56:06AM -0800, Keith Busch wrote: > 1. io_uring will always prefer using the _iter versions of read/write > callbacks if file_operations implement both, where as the generic > syscalls will use .read/.write (if implemented) for non-vectored IO. There are very few file operations that have both, and for those the difference matters, e.g. the strange vectors semantics for the sound code. I would strongly suggest to mirror what the normal read/write path does here. > 2. io_uring will use the ITER_UBUF representation for single vector > readv/writev, but the generic syscalls currently uses ITER_IOVEC for > these. Same here. It might be woth to use ITER_UBUF for single vector readv/writev, but this should be the same for all interfaces. I'd suggest to drop this for now and do a separate series with careful review from Al for this.