* [PATCH net-next] bonding: fix send_peer_notif leekage on rtnl lock congestion
@ 2013-08-05 19:47 Veaceslav Falico
2013-08-05 23:12 ` David Miller
0 siblings, 1 reply; 3+ messages in thread
From: Veaceslav Falico @ 2013-08-05 19:47 UTC (permalink / raw)
To: netdev; +Cc: Veaceslav Falico, Jay Vosburgh, Andy Gospodarek
In bond_mii_monitor()/bond_activebackup_arp_mon(), we verify if we have any
notifications to be sent before trying to get the rtnl_trylock(), and if
we have - we set should_notify_peers and withdraw a notification. However,
if we fail the get the rtnl_trylock(), we don't send out any notification
and don't put the notification back to bond->send_peer_notif.
Fix it by putting back the notification to send_peer_notif in case of
rtnl_trylock() failure.
CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
---
drivers/net/bonding/bond_main.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 5697043..fd92738 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -2383,7 +2383,10 @@ void bond_mii_monitor(struct work_struct *work)
if (!rtnl_trylock()) {
read_lock(&bond->lock);
delay = 1;
- should_notify_peers = false;
+ if (should_notify_peers) {
+ bond->send_peer_notif++;
+ should_notify_peers = false;
+ }
goto re_arm;
}
@@ -2999,7 +3002,10 @@ void bond_activebackup_arp_mon(struct work_struct *work)
if (!rtnl_trylock()) {
read_lock(&bond->lock);
delta_in_ticks = 1;
- should_notify_peers = false;
+ if (should_notify_peers) {
+ bond->send_peer_notif++;
+ should_notify_peers = false;
+ }
goto re_arm;
}
--
1.8.1.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH net-next] bonding: fix send_peer_notif leekage on rtnl lock congestion
2013-08-05 19:47 [PATCH net-next] bonding: fix send_peer_notif leekage on rtnl lock congestion Veaceslav Falico
@ 2013-08-05 23:12 ` David Miller
2013-08-06 12:17 ` Veaceslav Falico
0 siblings, 1 reply; 3+ messages in thread
From: David Miller @ 2013-08-05 23:12 UTC (permalink / raw)
To: vfalico; +Cc: netdev, fubar, andy
From: Veaceslav Falico <vfalico@redhat.com>
Date: Mon, 5 Aug 2013 21:47:33 +0200
> @@ -2999,7 +3002,10 @@ void bond_activebackup_arp_mon(struct work_struct *work)
> if (!rtnl_trylock()) {
> read_lock(&bond->lock);
> delta_in_ticks = 1;
> - should_notify_peers = false;
> + if (should_notify_peers) {
> + bond->send_peer_notif++;
I doubt this increment to a shared datastructure is safe with
the locks you hold here.
You don't hold RTNL and you only have bond->lock as a reader.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH net-next] bonding: fix send_peer_notif leekage on rtnl lock congestion
2013-08-05 23:12 ` David Miller
@ 2013-08-06 12:17 ` Veaceslav Falico
0 siblings, 0 replies; 3+ messages in thread
From: Veaceslav Falico @ 2013-08-06 12:17 UTC (permalink / raw)
To: David Miller; +Cc: netdev, fubar, andy
On Mon, Aug 05, 2013 at 04:12:12PM -0700, David Miller wrote:
>From: Veaceslav Falico <vfalico@redhat.com>
>Date: Mon, 5 Aug 2013 21:47:33 +0200
>
>> @@ -2999,7 +3002,10 @@ void bond_activebackup_arp_mon(struct work_struct *work)
>> if (!rtnl_trylock()) {
>> read_lock(&bond->lock);
>> delta_in_ticks = 1;
>> - should_notify_peers = false;
>> + if (should_notify_peers) {
>> + bond->send_peer_notif++;
>
>I doubt this increment to a shared datastructure is safe with
>the locks you hold here.
>
>You don't hold RTNL and you only have bond->lock as a reader.
You're right, we can race here. This whole locking juggling should be
changed.
Self-NAK for this, I'll rework it.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2013-08-06 12:17 UTC | newest]
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2013-08-05 19:47 [PATCH net-next] bonding: fix send_peer_notif leekage on rtnl lock congestion Veaceslav Falico
2013-08-05 23:12 ` David Miller
2013-08-06 12:17 ` Veaceslav Falico
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