Pull aio updates from Jens Axboe:
"Flushing out pre-patches for the buffered/polled aio series. Some
fixes in here, but also optimizations"
* tag 'for-4.21/aio-
20181221' of git://git.kernel.dk/linux-block:
aio: abstract out io_event filler helper
aio: split out iocb copy from io_submit_one()
aio: use iocb_put() instead of open coding it
aio: only use blk plugs for > 2 depth submissions
aio: don't zero entire aio_kiocb aio_get_req()
aio: separate out ring reservation from req allocation
aio: use assigned completion handler