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authorEric Dumazet <edumazet@google.com>2013-02-07 14:00:34 (GMT)
committerDavid S. Miller <davem@davemloft.net>2013-02-08 06:49:49 (GMT)
commit87c084a980325d877dc7e388b8f2f26d5d3b4d01 (patch)
treebadbd875581132a7634c6203fcf68f0785449abe /net
parent586c31f3bf04c290dc0a0de7fc91d20aa9a5ee53 (diff)
downloadlinux-87c084a980325d877dc7e388b8f2f26d5d3b4d01.tar.xz
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>
Diffstat (limited to 'net')
-rw-r--r--net/l2tp/l2tp_core.c6
-rw-r--r--net/l2tp/l2tp_ppp.c6
2 files changed, 0 insertions, 12 deletions
diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index 06389d5..2ac884d 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 286366e..716605c 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];