From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jakub Kicinski Subject: [RFC bpf-next 2/6] xsk: refactor xdp_umem_assign_dev() Date: Thu, 26 Jul 2018 14:41:44 -0700 Message-ID: <20180726214148.2087-3-jakub.kicinski@netronome.com> References: <20180726214148.2087-1-jakub.kicinski@netronome.com> Cc: oss-drivers@netronome.com, netdev@vger.kernel.org, Jakub Kicinski To: alexei.starovoitov@gmail.com, daniel@iogearbox.net, brouer@redhat.com, =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , Magnus Karlsson Return-path: Received: from mail-qt0-f194.google.com ([209.85.216.194]:37567 "EHLO mail-qt0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730581AbeGZXBS (ORCPT ); Thu, 26 Jul 2018 19:01:18 -0400 Received: by mail-qt0-f194.google.com with SMTP id n6-v6so3151785qtl.4 for ; Thu, 26 Jul 2018 14:42:35 -0700 (PDT) In-Reply-To: <20180726214148.2087-1-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 --- 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