• Pavel Begunkov's avatar
    io_uring/net: simplify zerocopy send user API · b48c312b
    Pavel Begunkov authored
    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: default avatarPavel Begunkov <asml.silence@gmail.com>
    Link: https://lore.kernel.org/r/95287640ab98fc9417370afb16e310677c63e6ce.1662027856.git.asml.silence@gmail.comSigned-off-by: default avatarJens Axboe <axboe@kernel.dk>
    b48c312b
net.c 31.5 KB