From: Christoph Hellwig > Sent: 27 August 2020 16:00 > > Don't allow calling ->read or ->write with set_fs as a preparation for > killing off set_fs. All the instances that we use kernel_read/write on > are using the iter ops already. > > If a file has both the regular ->read/->write methods and the iter > variants those could have different semantics for messed up enough > drivers. Also fails the kernel access to them in that case. Is there a real justification for that? For system calls supplying both methods makes sense to avoid the extra code paths for a simple read/write. Any one stupid enough to make them behave differently gets what they deserve. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)