diff options
| author | Jens Axboe <axboe@kernel.dk> | 2024-09-24 05:57:31 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2024-10-29 13:43:26 -0600 |
| commit | a377132154ab8404dafcc52e8bc0c73050a954c2 (patch) | |
| tree | 7007cd6f5c29e31dcea173774bf53c7d4e07fc14 /include/uapi/linux | |
| parent | 95d6c9229a04cc12d39034cd6be6446a55a85d6d (diff) | |
io_uring/msg_ring: add support for sending a sync message
Normally MSG_RING requires both a source and a destination ring. But
some users don't always have a ring avilable to send a message from, yet
they still need to notify a target ring.
Add support for using io_uring_register(2) without having a source ring,
using a file descriptor of -1 for that. Internally those are called
blind registration opcodes. Implement IORING_REGISTER_SEND_MSG_RING as a
blind opcode, which simply takes an sqe that the application can put on
the stack and use the normal liburing helpers to initialize it. Then the
app can call:
io_uring_register(-1, IORING_REGISTER_SEND_MSG_RING, &sqe, 1);
and get the same behavior in terms of the target, where a CQE is posted
with the details given in the sqe.
For now this takes a single sqe pointer argument, and hence arg must
be set to that, and nr_args must be 1. Could easily be extended to take
an array of sqes, but for now let's keep it simple.
Link: https://lore.kernel.org/r/20240924115932.116167-3-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include/uapi/linux')
| -rw-r--r-- | include/uapi/linux/io_uring.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 1fe79e750470..86cb385fe0b5 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -612,6 +612,9 @@ enum io_uring_register_op { /* clone registered buffers from source ring to current ring */ IORING_REGISTER_CLONE_BUFFERS = 30, + /* send MSG_RING without having a ring */ + IORING_REGISTER_SEND_MSG_RING = 31, + /* this goes last */ IORING_REGISTER_LAST, |