From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jakub Kicinski Subject: [PATCH net-next 2/3] xsk: refactor xdp_umem_assign_dev() Date: Mon, 30 Jul 2018 20:43:52 -0700 Message-ID: <20180731034353.3774-3-jakub.kicinski@netronome.com> References: <20180731034353.3774-1-jakub.kicinski@netronome.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: netdev@vger.kernel.org, oss-drivers@netronome.com, bjorn.topel@intel.com, Jakub Kicinski To: davem@davemloft.net, alexei.starovoitov@gmail.com, daniel@iogearbox.net Return-path: Received: from mail-qt0-f194.google.com ([209.85.216.194]:39098 "EHLO mail-qt0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726332AbeGaFWc (ORCPT ); Tue, 31 Jul 2018 01:22:32 -0400 Received: by mail-qt0-f194.google.com with SMTP id q12-v6so14505684qtp.6 for ; Mon, 30 Jul 2018 20:44:23 -0700 (PDT) In-Reply-To: <20180731034353.3774-1-jakub.kicinski@netronome.com> Sender: netdev-owner@vger.kernel.org List-ID: Return early and only take the ref on dev once there is no possibility of failing. Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Acked-by: Björn Töpel --- net/xdp/xdp_umem.c | 49 ++++++++++++++++++++-------------------------- 1 file changed, 21 insertions(+), 28 deletions(-) diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c index f47abb46c587..c199d66b5f3f 100644 --- a/net/xdp/xdp_umem.c +++ b/net/xdp/xdp_umem.c @@ -56,41 +56,34 @@ int xdp_umem_assign_dev(struct xdp_umem *umem, struct net_device *dev, if (force_copy) return 0; - dev_hold(dev); + if (!dev->netdev_ops->ndo_bpf || !dev->netdev_ops->ndo_xsk_async_xmit) + return force_zc ? -ENOTSUPP : 0; /* fail or fallback */ - if (dev->netdev_ops->ndo_bpf && dev->netdev_ops->ndo_xsk_async_xmit) { - bpf.command = XDP_QUERY_XSK_UMEM; + bpf.command = XDP_QUERY_XSK_UMEM; - rtnl_lock(); - err = dev->netdev_ops->ndo_bpf(dev, &bpf); - rtnl_unlock(); + rtnl_lock(); + err = dev->netdev_ops->ndo_bpf(dev, &bpf); + rtnl_unlock(); - if (err) { - dev_put(dev); - return force_zc ? -ENOTSUPP : 0; - } + if (err) + return force_zc ? -ENOTSUPP : 0; - bpf.command = XDP_SETUP_XSK_UMEM; - bpf.xsk.umem = umem; - bpf.xsk.queue_id = queue_id; + bpf.command = XDP_SETUP_XSK_UMEM; + bpf.xsk.umem = umem; + bpf.xsk.queue_id = queue_id; - rtnl_lock(); - err = dev->netdev_ops->ndo_bpf(dev, &bpf); - rtnl_unlock(); + rtnl_lock(); + err = dev->netdev_ops->ndo_bpf(dev, &bpf); + rtnl_unlock(); - if (err) { - dev_put(dev); - return force_zc ? err : 0; /* fail or fallback */ - } - - umem->dev = dev; - umem->queue_id = queue_id; - umem->zc = true; - return 0; - } + if (err) + return force_zc ? err : 0; /* fail or fallback */ - dev_put(dev); - return force_zc ? -ENOTSUPP : 0; /* fail or fallback */ + dev_hold(dev); + umem->dev = dev; + umem->queue_id = queue_id; + umem->zc = true; + return 0; } static void xdp_umem_clear_dev(struct xdp_umem *umem) -- 2.17.1