Commit 0fcece25 authored by Stefan Hajnoczi's avatar Stefan Hajnoczi Committed by Paolo Bonzini
Browse files

nbd: use TCP_CORK in nbd_co_send_request() 



Use TCP_CORK to defer packet transmission until both the header and the
payload have been written.

Suggested-by: default avatarNick Thomas <nick@bytemark.co.uk>
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 6760c47a

block/nbd.c

+16 −6
Original line number Diff line number Diff line
@@ -334,14 +334,24 @@ static int nbd_co_send_request(BDRVNBDState *s, struct nbd_request *request, 
    s->send_coroutine = qemu_coroutine_self();

    qemu_aio_set_fd_handler(s->sock, nbd_reply_ready, nbd_restart_write,

                            nbd_have_request, s);

    if (qiov) {

        if (!s->is_unix) {

            socket_set_cork(s->sock, 1);

        }

        rc = nbd_send_request(s->sock, request);

    if (rc >= 0 && qiov) {

        if (rc >= 0) {

            ret = qemu_co_sendv(s->sock, qiov->iov, qiov->niov,

                                offset, request->len);

            if (ret != request->len) {

                rc = -EIO;

            }

        }

        if (!s->is_unix) {

            socket_set_cork(s->sock, 0);

        }

    } else {

        rc = nbd_send_request(s->sock, request);

    }

    qemu_aio_set_fd_handler(s->sock, nbd_reply_ready, NULL,

                            nbd_have_request, s);

    s->send_coroutine = NULL;