[PATCH 0/3] io_uring/uring_cmd: allow non-iopoll cmds with IORING_SETUP_IOPOLL

[Caleb Sander Mateos]

Currently, creating an io_uring with IORING_SETUP_IOPOLL requires all
requests issued to it to support iopoll. This prevents, for example,
using ublk zero-copy together with IORING_SETUP_IOPOLL, as ublk
zero-copy buffer registrations are performed using a uring_cmd. There's
no technical reason why these non-iopoll uring_cmds can't be supported.
They will either complete synchronously or via an external mechanism
that calls io_uring_cmd_done(), so they don't need to be polled.

Allow uring_cmd requests to be issued to IORING_SETUP_IOPOLL io_urings
even if their files don't implement ->uring_cmd_iopoll().

The first commit fixes a few bugs where IORING_OP_URING_CMD128 isn't
treated as IORING_OP_URING_CMD with iopoll and provided buffers.

The last commit removes an unnecessary IO_URING_F_IOPOLL check in
nvme_dev_uring_cmd() as NVMe admin passthru commands can be issued to
IORING_SETUP_IOPOLL io_urings now.

Caleb Sander Mateos (3):
  io_uring: add IORING_OP_URING_CMD128 to opcode checks
  io_uring/uring_cmd: allow non-iopoll cmds with IORING_SETUP_IOPOLL
  nvme: remove nvme_dev_uring_cmd() IO_URING_F_IOPOLL check

 drivers/nvme/host/ioctl.c |  4 ----
 io_uring/io_uring.c       |  4 +++-
 io_uring/io_uring.h       |  6 ++++++
 io_uring/kbuf.c           |  2 +-
 io_uring/rw.c             |  4 ++--
 io_uring/uring_cmd.c      | 11 +++++------
 6 files changed, 17 insertions(+), 14 deletions(-)

-- 
2.45.2