* [PATCH] udp: Fix inverted NAPI_GRO_CB(skb)->flush test
@ 2014-09-11 2:23 Scott Wood
2014-09-11 5:13 ` Eric Dumazet
2014-09-12 21:55 ` David Miller
0 siblings, 2 replies; 3+ messages in thread
From: Scott Wood @ 2014-09-11 2:23 UTC (permalink / raw)
To: netdev, davem, Tom Herbert; +Cc: Scott Wood
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>
---
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 84e0e05..b8c845a 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 89cb9a9..2907fb8 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,
--
1.9.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] udp: Fix inverted NAPI_GRO_CB(skb)->flush test
2014-09-11 2:23 [PATCH] udp: Fix inverted NAPI_GRO_CB(skb)->flush test Scott Wood
@ 2014-09-11 5:13 ` Eric Dumazet
2014-09-12 21:55 ` David Miller
1 sibling, 0 replies; 3+ messages in thread
From: Eric Dumazet @ 2014-09-11 5:13 UTC (permalink / raw)
To: Scott Wood; +Cc: netdev, davem, Tom Herbert
On Wed, 2014-09-10 at 21:23 -0500, Scott Wood wrote:
> 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>
> ---
> net/ipv4/udp_offload.c | 2 +-
> net/ipv6/udp_offload.c | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
Good catch, thanks !
Acked-by: Eric Dumazet <edumazet@google.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] udp: Fix inverted NAPI_GRO_CB(skb)->flush test
2014-09-11 2:23 [PATCH] udp: Fix inverted NAPI_GRO_CB(skb)->flush test Scott Wood
2014-09-11 5:13 ` Eric Dumazet
@ 2014-09-12 21:55 ` David Miller
1 sibling, 0 replies; 3+ messages in thread
From: David Miller @ 2014-09-12 21:55 UTC (permalink / raw)
To: scottwood; +Cc: netdev, therbert
From: Scott Wood <scottwood@freescale.com>
Date: Wed, 10 Sep 2014 21:23:18 -0500
> 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>
Applied, thank you.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2014-09-12 21:55 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2014-09-11 2:23 [PATCH] udp: Fix inverted NAPI_GRO_CB(skb)->flush test Scott Wood
2014-09-11 5:13 ` Eric Dumazet
2014-09-12 21:55 ` David Miller
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