From: "Linus Lüssing" <linus.luessing@web.de>
To: b.a.t.m.a.n@lists.open-mesh.org
Subject: [B.A.T.M.A.N.] [PATCH 4/5] batman-adv: Fix a potential bcast/ogm qeueue purging race condition (2)
Date: Mon, 18 Mar 2013 06:09:56 +0100 [thread overview]
Message-ID: <1363583397-4800-4-git-send-email-linus.luessing@web.de> (raw)
In-Reply-To: <1363583397-4800-1-git-send-email-linus.luessing@web.de>
- Avoid rearmed bcast packet being missed by cancel_delayed_work_sync().
When a scheduled broadcast packet sending work executes and removes
itself from the broadcast queue, it becomes invisible for the purging
methods until it re-arms.
This means a to be re-armed broadcast work might slip through a
cancel_delayed_work_sync() between the removal from and readdition to
the broadcast queue.
To avoid this we perform the removal and readdition in one atomic step.
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
---
send.c | 19 ++++++++++++-------
1 file changed, 12 insertions(+), 7 deletions(-)
diff --git a/send.c b/send.c
index 1ddfae7..34c54e9 100644
--- a/send.c
+++ b/send.c
@@ -217,12 +217,9 @@ _batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
struct batadv_forw_packet *forw_packet,
unsigned long send_time)
{
- /* add new packet to packet list and start its timer */
- spin_lock_bh(&bat_priv->forw_bcast_list_lock);
hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
queue_delayed_work(batadv_event_workqueue, &forw_packet->delayed_work,
send_time);
- spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
}
/* add a broadcast packet to the queue and setup timers. broadcast packets
@@ -272,7 +269,10 @@ int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
INIT_DELAYED_WORK(&forw_packet->delayed_work,
batadv_send_outstanding_bcast_packet);
+ spin_lock_bh(&bat_priv->forw_bcast_list_lock);
_batadv_add_bcast_packet_to_list(bat_priv, forw_packet, delay);
+ spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
+
return NETDEV_TX_OK;
packet_free:
@@ -296,10 +296,6 @@ static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
soft_iface = forw_packet->if_incoming->soft_iface;
bat_priv = netdev_priv(soft_iface);
- spin_lock_bh(&bat_priv->forw_bcast_list_lock);
- hlist_del(&forw_packet->list);
- spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
-
if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
goto out;
@@ -327,12 +323,21 @@ static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
/* if we still have some more bcasts to send */
if (forw_packet->num_packets < BATADV_NUM_BCASTS_MAX) {
+ spin_lock_bh(&bat_priv->forw_bcast_list_lock);
+ hlist_del(&forw_packet->list);
+
_batadv_add_bcast_packet_to_list(bat_priv, forw_packet,
msecs_to_jiffies(5));
+ spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
+
return;
}
out:
+ spin_lock_bh(&bat_priv->forw_bcast_list_lock);
+ hlist_del(&forw_packet->list);
+ spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
+
batadv_forw_packet_free(forw_packet);
}
--
1.7.10.4
next prev parent reply other threads:[~2013-03-18 5:09 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-27 9:58 [B.A.T.M.A.N.] [PATCH 1/2] batman-adv: Fix broadcast+ogm queue purging race condition Linus Lüssing
2013-02-27 9:58 ` [B.A.T.M.A.N.] [PATCH 2/2] batman-adv: Fix another, potential broadcast+ogm " Linus Lüssing
2013-03-03 5:06 ` [B.A.T.M.A.N.] [PATCH 1/2] batman-adv: Fix broadcast+ogm queue " Marek Lindner
2013-03-07 6:27 ` Marek Lindner
2013-03-18 5:09 ` [B.A.T.M.A.N.] [PATCH 1/5] batman-adv: Fix broadcast queue limit on a removed interface Linus Lüssing
2013-03-18 5:09 ` [B.A.T.M.A.N.] [PATCH 2/5] batman-adv: Remove unnecessary INIT_HLIST_NODE() calls Linus Lüssing
2013-03-18 5:09 ` [B.A.T.M.A.N.] [PATCH 3/5] batman-adv: Fix a potential bcast/ogm queue purging race condition (1) Linus Lüssing
2016-03-10 17:00 ` Sven Eckelmann
2016-04-09 16:23 ` Sven Eckelmann
2016-07-21 22:27 ` Sven Eckelmann
2016-07-22 11:46 ` Linus Lüssing
2013-03-18 5:09 ` Linus Lüssing [this message]
2013-03-18 5:09 ` [B.A.T.M.A.N.] [PATCH 5/5] batman-adv: Fix a potential bcast/ogm queue purging race condition (3) Linus Lüssing
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