io_uring/zctx: separate notification user_data

People previously asked for the notification CQE to have a different
user_data value from the main request completion. It's useful to
separate buffer and request handling logic and avoid separately
refcounting the request.

Let the user pass the notification user_data in sqe->addr3. If zero,
it'll inherit sqe->user_data as before. It doesn't change the rules for
when the user can expect a notification CQE, and it should still check
the IORING_CQE_F_MORE flag.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/io_uring/net.c b/io_uring/net.c
index 3e68593e816483806fc056b0a156fd2e6d84c237..3f9d08b78c21fee3b844947c27a9749c8d0f84a0 100644 (file)
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -1333,11 +1333,12 @@ int io_send_zc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
        struct io_ring_ctx *ctx = req->ctx;
        struct io_async_msghdr *iomsg;
        struct io_kiocb *notif;
+       u64 user_data;
        int ret;
 
        zc->done_io = 0;
 
-       if (unlikely(READ_ONCE(sqe->__pad2[0]) || READ_ONCE(sqe->addr3)))
+       if (unlikely(READ_ONCE(sqe->__pad2[0])))
                return -EINVAL;
        /* we don't support IOSQE_CQE_SKIP_SUCCESS just yet */
        if (req->flags & REQ_F_CQE_SKIP)
@@ -1346,7 +1347,11 @@ int io_send_zc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
        notif = zc->notif = io_alloc_notif(ctx);
        if (!notif)
                return -ENOMEM;
-       notif->cqe.user_data = req->cqe.user_data;
+       user_data = READ_ONCE(sqe->addr3);
+       if (!user_data)
+               user_data = req->cqe.user_data;
+
+       notif->cqe.user_data = user_data;
        notif->cqe.res = 0;
        notif->cqe.flags = IORING_CQE_F_NOTIF;
        req->flags |= REQ_F_NEED_CLEANUP | REQ_F_POLL_NO_LAZY;