| Message ID | 20220711211112.18951-2-leobras@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Zero copy improvements (QIOChannel + multifd) | expand |
On Mon, Jul 11, 2022 at 06:11:11PM -0300, Leonardo Bras wrote: > If flush is called when no buffer was sent with MSG_ZEROCOPY, it currently > returns 1. This return code should be used only when Linux fails to use > MSG_ZEROCOPY on a lot of sendmsg(). > > Fix this by returning early from flush if no sendmsg(...,MSG_ZEROCOPY) > was attempted. > > Fixes: 2bc58ffc2926 ("QIOChannelSocket: Implement io_writev zero copy flag & io_flush for CONFIG_LINUX") > Signed-off-by: Leonardo Bras <leobras@redhat.com> > Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> > Acked-by: Daniel P. Berrangé <berrange@redhat.com> > Reviewed-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com>
diff --git a/io/channel-socket.c b/io/channel-socket.c index 4466bb1cd4..74a936cc1f 100644 --- a/io/channel-socket.c +++ b/io/channel-socket.c @@ -716,12 +716,18 @@ static int qio_channel_socket_flush(QIOChannel *ioc, struct cmsghdr *cm; char control[CMSG_SPACE(sizeof(*serr))]; int received; - int ret = 1; + int ret; + + if (sioc->zero_copy_queued == sioc->zero_copy_sent) { + return 0; + } msg.msg_control = control; msg.msg_controllen = sizeof(control); memset(control, 0, sizeof(control)); + ret = 1; + while (sioc->zero_copy_sent < sioc->zero_copy_queued) { received = recvmsg(sioc->fd, &msg, MSG_ERRQUEUE); if (received < 0) {
If flush is called when no buffer was sent with MSG_ZEROCOPY, it currently returns 1. This return code should be used only when Linux fails to use MSG_ZEROCOPY on a lot of sendmsg(). Fix this by returning early from flush if no sendmsg(...,MSG_ZEROCOPY) was attempted. Fixes: 2bc58ffc2926 ("QIOChannelSocket: Implement io_writev zero copy flag & io_flush for CONFIG_LINUX") Signed-off-by: Leonardo Bras <leobras@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Acked-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> --- io/channel-socket.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)