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authorEric Dumazet <edumazet@google.com>2014-10-30 10:32:34 -0700
committerDavid S. Miller <davem@davemloft.net>2014-10-30 19:58:30 -0400
commit39bb5e62867de82b269b07df900165029b928359 (patch)
treef0cbefb0eee4eda2697c4e2fd6e0ad3ee7331f43
parent14051f0452a2c26a3f4791e6ad6a435e8f1945ff (diff)
downloadlinux-39bb5e62867de82b269b07df900165029b928359.tar.bz2
net: skb_fclone_busy() needs to detect orphaned skb
Some drivers are unable to perform TX completions in a bound time. They instead call skb_orphan() Problem is skb_fclone_busy() has to detect this case, otherwise we block TCP retransmits and can freeze unlucky tcp sessions on mostly idle hosts. Signed-off-by: Eric Dumazet <edumazet@google.com> Fixes: 1f3279ae0c13 ("tcp: avoid retransmits of TCP packets hanging in host queues") Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/linux/skbuff.h8
-rw-r--r--net/ipv4/tcp_output.c2
-rw-r--r--net/xfrm/xfrm_policy.c2
3 files changed, 8 insertions, 4 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 5884f95ff0e9..6c8b6f604e76 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -799,15 +799,19 @@ struct sk_buff_fclones {
* @skb: buffer
*
* Returns true is skb is a fast clone, and its clone is not freed.
+ * Some drivers call skb_orphan() in their ndo_start_xmit(),
+ * so we also check that this didnt happen.
*/
-static inline bool skb_fclone_busy(const struct sk_buff *skb)
+static inline bool skb_fclone_busy(const struct sock *sk,
+ const struct sk_buff *skb)
{
const struct sk_buff_fclones *fclones;
fclones = container_of(skb, struct sk_buff_fclones, skb1);
return skb->fclone == SKB_FCLONE_ORIG &&
- fclones->skb2.fclone == SKB_FCLONE_CLONE;
+ fclones->skb2.fclone == SKB_FCLONE_CLONE &&
+ fclones->skb2.sk == sk;
}
static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 3af21296d967..a3d453b94747 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2126,7 +2126,7 @@ bool tcp_schedule_loss_probe(struct sock *sk)
static bool skb_still_in_host_queue(const struct sock *sk,
const struct sk_buff *skb)
{
- if (unlikely(skb_fclone_busy(skb))) {
+ if (unlikely(skb_fclone_busy(sk, skb))) {
NET_INC_STATS_BH(sock_net(sk),
LINUX_MIB_TCPSPURIOUS_RTX_HOSTQUEUES);
return true;
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 4c4e457e7888..88bf289abdc9 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1962,7 +1962,7 @@ static int xdst_queue_output(struct sock *sk, struct sk_buff *skb)
struct xfrm_policy *pol = xdst->pols[0];
struct xfrm_policy_queue *pq = &pol->polq;
- if (unlikely(skb_fclone_busy(skb))) {
+ if (unlikely(skb_fclone_busy(sk, skb))) {
kfree_skb(skb);
return 0;
}