kernel/patches/linux-3.1-bridge-master-device-stuck-in-no-carrier-state-forever-when-in-user-stp-mode.patch

   1 From b03b6dd58cef7d15b7c46a6729b83dd535ef08ab Mon Sep 17 00:00:00 2001
   2 From: Vitalii Demianets <vitas@nppfactor.kiev.ua>
   3 Date: Fri, 25 Nov 2011 00:16:37 +0000
   4 Subject: [PATCH] bridge: master device stuck in no-carrier state forever when
   5  in user-stp mode
   6
   7 When in user-stp mode, bridge master do not follow state of its slaves, so
   8 after the following sequence of events it can stuck forever in no-carrier
   9 state:
  10 1) turn stp off
  11 2) put all slaves down - master device will follow their state and also go in
  12 no-carrier state
  13 3) turn stp on with bridge-stp script returning 0 (go to the user-stp mode)
  14 Now bridge master won't follow slaves' state and will never reach running
  15 state.
  16
  17 This patch solves the problem by making user-stp and kernel-stp behavior
  18 similar regarding master following slaves' states.
  19
  20 Signed-off-by: Vitalii Demianets <vitas@nppfactor.kiev.ua>
  21 Acked-by: Stephen Hemminger <shemminger@vyatta.com>
  22 Signed-off-by: David S. Miller <davem@davemloft.net>
  23 ---
  24  net/bridge/br_netlink.c |    6 ++++++
  25  net/bridge/br_stp.c     |   29 ++++++++++++++---------------
  26  2 files changed, 20 insertions(+), 15 deletions(-)
  27
  28 diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
  29 index e5f9ece3..a1daf82 100644
  30 --- a/net/bridge/br_netlink.c
  31 +++ b/net/bridge/br_netlink.c
  32 @@ -18,6 +18,7 @@
  33  #include <net/sock.h>
  34
  35  #include "br_private.h"
  36 +#include "br_private_stp.h"
  37
  38  static inline size_t br_nlmsg_size(void)
  39  {
  40 @@ -188,6 +189,11 @@ static int br_rtm_setlink(struct sk_buff *skb,  struct nlmsghdr *nlh, void *arg)
  41
  42         p->state = new_state;
  43         br_log_state(p);
  44 +
  45 +       spin_lock_bh(&p->br->lock);
  46 +       br_port_state_selection(p->br);
  47 +       spin_unlock_bh(&p->br->lock);
  48 +
  49         br_ifinfo_notify(RTM_NEWLINK, p);
  50
  51         return 0;
  52 diff --git a/net/bridge/br_stp.c b/net/bridge/br_stp.c
  53 index ad0a3f7..dd147d7 100644
  54 --- a/net/bridge/br_stp.c
  55 +++ b/net/bridge/br_stp.c
  56 @@ -399,25 +399,24 @@ void br_port_state_selection(struct net_bridge *br)
  57         struct net_bridge_port *p;
  58         unsigned int liveports = 0;
  59
  60 -       /* Don't change port states if userspace is handling STP */
  61 -       if (br->stp_enabled == BR_USER_STP)
  62 -               return;
  63 -
  64         list_for_each_entry(p, &br->port_list, list) {
  65                 if (p->state == BR_STATE_DISABLED)
  66                         continue;
  67
  68 -               if (p->port_no == br->root_port) {
  69 -                       p->config_pending = 0;
  70 -                       p->topology_change_ack = 0;
  71 -                       br_make_forwarding(p);
  72 -               } else if (br_is_designated_port(p)) {
  73 -                       del_timer(&p->message_age_timer);
  74 -                       br_make_forwarding(p);
  75 -               } else {
  76 -                       p->config_pending = 0;
  77 -                       p->topology_change_ack = 0;
  78 -                       br_make_blocking(p);
  79 +               /* Don't change port states if userspace is handling STP */
  80 +               if (br->stp_enabled != BR_USER_STP) {
  81 +                       if (p->port_no == br->root_port) {
  82 +                               p->config_pending = 0;
  83 +                               p->topology_change_ack = 0;
  84 +                               br_make_forwarding(p);
  85 +                       } else if (br_is_designated_port(p)) {
  86 +                               del_timer(&p->message_age_timer);
  87 +                               br_make_forwarding(p);
  88 +                       } else {
  89 +                               p->config_pending = 0;
  90 +                               p->topology_change_ack = 0;
  91 +                               br_make_blocking(p);
  92 +                       }
  93                 }
  94
  95                 if (p->state == BR_STATE_FORWARDING)
  96 --
  97 1.7.6.2
  98