linux-toradex.git/include/uapi/linux/io_uring.h, branch v6.0-rc6

io_uring/net: simplify zerocopy send user API

2022-09-01T15:13:33+00:00

Following user feedback, this patch simplifies zerocopy send API. One of
the main complaints is that the current API is difficult with the
userspace managing notification slots, and then send retries with error
handling make it even worse.

Instead of keeping notification slots change it to the per-request
notifications model, which posts both completion and notification CQEs
for each request when any data has been sent, and only one CQE if it
fails. All notification CQEs will have IORING_CQE_F_NOTIF set and
IORING_CQE_F_MORE in completion CQEs indicates whether to wait a
notification or not.

IOSQE_CQE_SKIP_SUCCESS is disallowed with zerocopy sends for now.

This is less flexible, but greatly simplifies the user API and also the
kernel implementation. We reuse notif helpers in this patch, but in the
future there won't be need for keeping two requests.

Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/95287640ab98fc9417370afb16e310677c63e6ce.1662027856.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe

io_uring/notif: remove notif registration

2022-09-01T15:13:33+00:00

We're going to remove the userspace exposed zerocopy notification API,
remove notification registration.

Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/6ff00b97be99869c386958a990593c9c31cf105b.1662027856.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe

Revert "io_uring: rename IORING_OP_FILES_UPDATE"

2022-09-01T15:13:33+00:00

This reverts commit 4379d5f15b3fd4224c37841029178aa8082a242e.

We removed notification flushing, also cleanup uapi preparation changes
to not pollute it.

Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/89edc3905350f91e1b6e26d9dbf42ee44fd451a2.1662027856.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe

Revert "io_uring: add zc notification flush requests"

2022-09-01T15:13:33+00:00

This reverts commit 492dddb4f6e3a5839c27d41ff1fecdbe6c3ab851.

Soon we won't have the very notion of notification flushing, so remove
notification flushing requests.

Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/8850334ca56e65b413cb34fd158db81d7b2865a3.1662027856.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe

io_uring: uapi: Add `extern "C"` in io_uring.h for liburing

2022-08-23T13:22:33+00:00

Make it easy for liburing to integrate uapi header with the kernel.
Previously, when this header changes, the liburing side can't directly
copy this header file due to some small differences. Sync them.

Link: https://lore.kernel.org/io-uring/f1feef16-6ea2-0653-238f-4aaee35060b6@kernel.dk
Cc: Bart Van Assche 
Cc: Dylan Yudaken 
Cc: Facebook Kernel Team 
Signed-off-by: Ammar Faizi 
Signed-off-by: Jens Axboe

io_uring: add zc notification flush requests

2022-07-25T00:41:07+00:00

Overlay notification control onto IORING_OP_RSRC_UPDATE (former
IORING_OP_FILES_UPDATE). It allows to flush a range of zc notifications
from slots with indexes [sqe->off, sqe->off+sqe->len). If sqe->arg is
not zero, it also copies sqe->arg as a new tag for all flushed
notifications.

Note, it doesn't flush a notification of a slot if there was no requests
attached to it (since last flush or registration).

Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/df13e2363400682a73dd9e71c3b990b8d1ff0333.1657643355.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe

io_uring: rename IORING_OP_FILES_UPDATE

2022-07-25T00:41:07+00:00

IORING_OP_FILES_UPDATE will be a more generic opcode serving different
resource types, rename it into IORING_OP_RSRC_UPDATE and add subtype
handling.

Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/0a907133907d9af3415a8a7aa1802c6aa97c03c6.1657643355.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe

io_uring: flush notifiers after sendzc

2022-07-25T00:41:07+00:00

Allow to flush notifiers as a part of sendzc request by setting
IORING_SENDZC_FLUSH flag. When the sendzc request succeedes it will
flush the used [active] notifier.

Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/e0b4d9a6797e2fd6092824fe42953db7a519bbc8.1657643355.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe

io_uring: sendzc with fixed buffers

2022-07-25T00:41:07+00:00

Allow zerocopy sends to use fixed buffers. There is an optimisation for
this case, the network layer don't need to reference the pages, see
SKBFL_MANAGED_FRAG_REFS, so io_uring have to ensure validity of fixed
buffers until the notifier is released.

Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/e1d8bd1b5934e541d90c1824eb4020ae3f5f43f3.1657643355.git.asml.silence@gmail.com
[axboe: fold in 32-bit pointer cast warning fix]
Signed-off-by: Jens Axboe

io_uring: allow to pass addr into sendzc

2022-07-25T00:41:07+00:00

Allow to specify an address to zerocopy sends making it more like
sendto(2).

Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/70417a8f7c5b51ab454690bae08adc0c187f89e8.1657643355.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe