diff options
| author | Eric Dumazet <edumazet@google.com> | 2013-02-07 14:00:34 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-02-08 01:49:49 -0500 |
| commit | 87c084a980325d877dc7e388b8f2f26d5d3b4d01 (patch) | |
| tree | badbd875581132a7634c6203fcf68f0785449abe | |
| parent | 586c31f3bf04c290dc0a0de7fc91d20aa9a5ee53 (diff) | |
l2tp: dont play with skb->truesize
Andrew Savchenko reported a DNS failure and we diagnosed that
some UDP sockets were unable to send more packets because their
sk_wmem_alloc was corrupted after a while (tx_queue column in
following trace)
$ cat /proc/net/udp
sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode ref pointer drops
...
459: 00000000:0270 00000000:0000 07 00000000:00000000 00:00000000 00000000 0 0 4507 2 ffff88003d612380 0
466: 00000000:0277 00000000:0000 07 00000000:00000000 00:00000000 00000000 0 0 4802 2 ffff88003d613180 0
470: 076A070A:007B 00000000:0000 07 FFFF4600:00000000 00:00000000 00000000 123 0 5552 2 ffff880039974380 0
470: 010213AC:007B 00000000:0000 07 00000000:00000000 00:00000000 00000000 0 0 4986 2 ffff88003dbd3180 0
470: 010013AC:007B 00000000:0000 07 00000000:00000000 00:00000000 00000000 0 0 4985 2 ffff88003dbd2e00 0
470: 00FCA8C0:007B 00000000:0000 07 FFFFFB00:00000000 00:00000000 00000000 0 0 4984 2 ffff88003dbd2a80 0
...
Playing with skb->truesize is tricky, especially when
skb is attached to a socket, as we can fool memory charging.
Just remove this code, its not worth trying to be ultra
precise in xmit path.
Reported-by: Andrew Savchenko <bircoph@gmail.com>
Tested-by: Andrew Savchenko <bircoph@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/l2tp/l2tp_core.c | 6 | ||||
| -rw-r--r-- | net/l2tp/l2tp_ppp.c | 6 |
2 files changed, 0 insertions, 12 deletions
diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index 06389d5ff12..2ac884d0e89 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -1168,8 +1168,6 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len struct udphdr *uh; struct inet_sock *inet; __wsum csum; - int old_headroom; - int new_headroom; int headroom; int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; int udp_len; @@ -1181,16 +1179,12 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len */ headroom = NET_SKB_PAD + sizeof(struct iphdr) + uhlen + hdr_len; - old_headroom = skb_headroom(skb); if (skb_cow_head(skb, headroom)) { kfree_skb(skb); return NET_XMIT_DROP; } - new_headroom = skb_headroom(skb); skb_orphan(skb); - skb->truesize += new_headroom - old_headroom; - /* Setup L2TP header */ session->build_header(session, __skb_push(skb, hdr_len)); diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c index 286366ef893..716605c241f 100644 --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -388,8 +388,6 @@ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb) struct l2tp_session *session; struct l2tp_tunnel *tunnel; struct pppol2tp_session *ps; - int old_headroom; - int new_headroom; int uhlen, headroom; if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) @@ -408,7 +406,6 @@ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb) if (tunnel == NULL) goto abort_put_sess; - old_headroom = skb_headroom(skb); uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; headroom = NET_SKB_PAD + sizeof(struct iphdr) + /* IP header */ @@ -418,9 +415,6 @@ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb) if (skb_cow_head(skb, headroom)) goto abort_put_sess_tun; - new_headroom = skb_headroom(skb); - skb->truesize += new_headroom - old_headroom; - /* Setup PPP header */ __skb_push(skb, sizeof(ppph)); skb->data[0] = ppph[0]; |