From f7053b6ccb65a36fdfed6ad92b808464839f0eb6 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Wed, 12 Sep 2018 11:17:02 +0800 Subject: [PATCH] tuntap: simplify error handling in tun_build_skb() There's no need to duplicate page get logic in each action. So this patch tries to get page and calculate the offset before processing XDP actions (except for XDP_DROP), and undo them when meet errors (we don't care the performance on errors). This will be used for factoring out XDP logic. Signed-off-by: Jason Wang Signed-off-by: David S. Miller --- drivers/net/tun.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 372caf7d67d9..257cf7342d54 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1701,17 +1701,13 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, xdp_do_flush_map(); if (err) goto err_redirect; - rcu_read_unlock(); - local_bh_enable(); - return NULL; + goto out; case XDP_TX: get_page(alloc_frag->page); alloc_frag->offset += buflen; if (tun_xdp_tx(tun->dev, &xdp) < 0) goto err_redirect; - rcu_read_unlock(); - local_bh_enable(); - return NULL; + goto out; case XDP_PASS: delta = orig_data - xdp.data; len = xdp.data_end - xdp.data; @@ -1742,7 +1738,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, err_redirect: put_page(alloc_frag->page); -err_xdp: +out: rcu_read_unlock(); local_bh_enable(); this_cpu_inc(tun->pcpu_stats->rx_dropped); -- 2.11.0