From eb42cebb2cf24c48f60c32856a4bba93d42659c8 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Tue, 12 Jul 2022 21:52:38 +0100 Subject: io_uring: add zc notification infrastructure Add internal part of send zerocopy notifications. There are two main structures, the first one is struct io_notif, which carries inside struct ubuf_info and maps 1:1 to it. io_uring will be binding a number of zerocopy send requests to it and ask to complete (aka flush) it. When flushed and all attached requests and skbs complete, it'll generate one and only one CQE. There are intended to be passed into the network layer as struct msghdr::msg_ubuf. The second concept is notification slots. The userspace will be able to register an array of slots and subsequently addressing them by the index in the array. Slots are independent of each other. Each slot can have only one notifier at a time (called active notifier) but many notifiers during the lifetime. When active, a notifier not going to post any completion but the userspace can attach requests to it by specifying the corresponding slot while issueing send zc requests. Eventually, the userspace will want to "flush" the notifier losing any way to attach new requests to it, however it can use the next atomatically added notifier of this slot or of any other slot. When the network layer is done with all enqueued skbs attached to a notifier and doesn't need the specified in them user data, the flushed notifier will post a CQE. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/3ecf54c31a85762bf679b0a432c9f43ecf7e61cc.1657643355.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- io_uring/io_uring.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'io_uring/io_uring.h') diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h index b1c0c0a400d8..66bfd880d07f 100644 --- a/io_uring/io_uring.h +++ b/io_uring/io_uring.h @@ -33,6 +33,8 @@ void io_req_complete_post(struct io_kiocb *req); void __io_req_complete_post(struct io_kiocb *req); bool io_post_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags, bool allow_overflow); +bool io_fill_cqe_aux(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags, + bool allow_overflow); void __io_commit_cqring_flush(struct io_ring_ctx *ctx); struct page **io_pin_pages(unsigned long ubuf, unsigned long len, int *npages); -- cgit v1.2.3-58-ga151