From 2d8f7e2c8a63131828e8d4e2d98835399f27319e Mon Sep 17 00:00:00 2001
From: Scott Wood <scottwood@freescale.com>
Date: Wed, 10 Sep 2014 21:23:18 -0500
Subject: [PATCH] udp: Fix inverted NAPI_GRO_CB(skb)->flush test
Commit 2abb7cdc0d ("udp: Add support for doing checksum unnecessary
conversion") caused napi_gro_cb structs with the "flush" field zero to
take the "udp_gro_receive" path rather than the "set flush to 1" path
that they would previously take. As a result I saw booting from an NFS
root hang shortly after starting userspace, with "server not
responding" messages.
This change to the handling of "flush == 0" packets appears to be
incidental to the goal of adding new code in the case where
skb_gro_checksum_validate_zero_check() returns zero. Based on that and
the fact that it breaks things, I'm assuming that it is unintentional.
Fixes: 2abb7cdc0d ("udp: Add support for doing checksum unnecessary conversion")
Cc: Tom Herbert <therbert@google.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/ipv4/udp_offload.c | 2 +-
net/ipv6/udp_offload.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index 52d5f46abf863..adab393b2fe5f 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -294,7 +294,7 @@ static struct sk_buff **udp4_gro_receive(struct sk_buff **head,
goto flush;
/* Don't bother verifying checksum if we're going to flush anyway. */
- if (!NAPI_GRO_CB(skb)->flush)
+ if (NAPI_GRO_CB(skb)->flush)
goto skip;
if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check,
diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c
index a1ad34b1c4ecd..de85f809bf298 100644
--- a/net/ipv6/udp_offload.c
+++ b/net/ipv6/udp_offload.c
@@ -138,7 +138,7 @@ static struct sk_buff **udp6_gro_receive(struct sk_buff **head,
goto flush;
/* Don't bother verifying checksum if we're going to flush anyway. */
- if (!NAPI_GRO_CB(skb)->flush)
+ if (NAPI_GRO_CB(skb)->flush)
goto skip;
if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check,
--
2.30.2