From: Eric Dumazet <eduma...@google.com>
Revert to the tcp_skb_cb size check that tcp_init() had before commit
b4772ef879a8 ("net: use common macro for assering skb->cb[] available
size in protocol families"). As related commit 744d5a3e9fe2 ("net:
move skb->dropcount to skb->cb[]") explains, the
sock_skb_cb_check_size() mechanism was added to ensure that there is
space for dropcount, "for protocol families using it". But TCP is not
a protocol using dropcount, so tcp_init() doesn't need to provision
space for dropcount in the skb->cb[], and thus we can revert to the
older form of the tcp_skb_cb size check. Doing so allows TCP to use 4
more bytes of the skb->cb[] space.
Fixes: b4772ef879a8 ("net: use common macro for assering skb->cb[] available
size in protocol families")
Signed-off-by: Eric Dumazet <eduma...@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soh...@google.com>
Signed-off-by: Neal Cardwell <ncardw...@google.com>
Signed-off-by: Yuchung Cheng <ych...@google.com>
---
net/ipv4/tcp.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 5b0b49c..53798e1 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3244,11 +3244,12 @@ static void __init tcp_init_mem(void)
void __init tcp_init(void)
{
- unsigned long limit;
int max_rshare, max_wshare, cnt;
+ unsigned long limit;
+ struct sk_buff *skb;
unsigned int i;
- sock_skb_cb_check_size(sizeof(struct tcp_skb_cb));
+ BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb));
percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL);
percpu_counter_init(&tcp_orphan_count, 0, GFP_KERNEL);
--
2.8.0.rc3.226.g39d4020
