target/linux/generic/patches-2.6.39/622-sched_sfq_fix_enqueue.patch

   1 From: Eric Dumazet <eric.dumazet@gmail.com>
   2 Date: Fri, 29 Jul 2011 19:22:42 +0000 (+0000)
   3 Subject: sch_sfq: fix sfq_enqueue()
   4 X-Git-Tag: v3.1-rc1~24^2~29
   5 X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux-2.6.git;a=commitdiff_plain;h=e1738bd9cecc5c867b0e2996470c1ff20f66ba79
   6
   7 sch_sfq: fix sfq_enqueue()
   8
   9 commit 8efa88540635 (sch_sfq: avoid giving spurious NET_XMIT_CN signals)
  10 forgot to call qdisc_tree_decrease_qlen() to signal upper levels that a
  11 packet (from another flow) was dropped, leading to various problems.
  12
  13 With help from Michal Soltys and Michal Pokrywka, who did a bisection.
  14
  15 Bugzilla ref: https://bugzilla.kernel.org/show_bug.cgi?id=39372
  16 Debian ref: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=631945
  17
  18 Reported-by: Lucas Bocchi <lucas.bocchi@gmail.com>
  19 Reported-and-bisected-by: Michal Pokrywka <wolfmoon@o2.pl>
  20 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
  21 CC: Michal Soltys <soltys@ziu.info>
  22 Acked-by: Patrick McHardy <kaber@trash.net>
  23 Signed-off-by: David S. Miller <davem@davemloft.net>
  24 ---
  25
  26 --- a/net/sched/sch_sfq.c
  27 +++ b/net/sched/sch_sfq.c
  28 @@ -410,7 +410,12 @@ sfq_enqueue(struct sk_buff *skb, struct
  29         /* Return Congestion Notification only if we dropped a packet
  30          * from this flow.
  31          */
  32 -       return (qlen != slot->qlen) ? NET_XMIT_CN : NET_XMIT_SUCCESS;
  33 +       if (qlen != slot->qlen)
  34 +               return NET_XMIT_CN;
  35 +
  36 +       /* As we dropped a packet, better let upper stack know this */
  37 +       qdisc_tree_decrease_qlen(sch, 1);
  38 +       return NET_XMIT_SUCCESS;
  39  }
  40
  41  static struct sk_buff *