[RFC bpf-next 2/6] xsk: refactor xdp_umem_assign_dev()
From: Jakub Kicinski <hidden>
Date: 2018-07-26 23:01:18
Subsystem:
networking [general], the rest, xdp sockets (af_xdp) · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Magnus Karlsson, Maciej Fijalkowski
Return early and only take the ref on dev once there is no possibility of failing. Signed-off-by: Jakub Kicinski <redacted> Reviewed-by: Quentin Monnet <redacted> --- 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