mac80211: fix skb buffering issue

Since I removed the master netdev, we've been
keeping internal queues only, and even before
that we never told the networking stack above
the virtual interfaces about congestion. This
means that packets are queued in mac80211 and
the upper layers never know, possibly leading
to memory exhaustion and other problems.

This patch makes all interfaces multiqueue and
uses ndo_select_queue to put the packets into
queues per AC. Additionally, when the driver
stops a queue, we now stop all corresponding
queues for the virtual interfaces as well.

The injection case will use VO by default for
non-data frames, and BE for data frames, but
downgrade any data frames according to ACM. It
needs to be fleshed out in the future to allow
chosing the queue/AC in radiotap.

Reported-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: stable@kernel.org [2.6.32]
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index dc76267e436e..3848140313f5 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -269,6 +269,7 @@ static void __ieee80211_wake_queue(struct ieee80211_hw *hw, int queue,
                                    enum queue_stop_reason reason)
 {
         struct ieee80211_local *local = hw_to_local(hw);
+        struct ieee80211_sub_if_data *sdata;
 
         if (WARN_ON(queue >= hw->queues))
                 return;
@@ -281,6 +282,11 @@ static void __ieee80211_wake_queue(struct ieee80211_hw *hw, int queue,
 
         if (!skb_queue_empty(&local->pending[queue]))
                 tasklet_schedule(&local->tx_pending_tasklet);
+
+        rcu_read_lock();
+        list_for_each_entry_rcu(sdata, &local->interfaces, list)
+                netif_tx_wake_queue(netdev_get_tx_queue(sdata->dev, queue));
+        rcu_read_unlock();
 }
 
 void ieee80211_wake_queue_by_reason(struct ieee80211_hw *hw, int queue,
@@ -305,11 +311,17 @@ static void __ieee80211_stop_queue(struct ieee80211_hw *hw, int queue,
                                    enum queue_stop_reason reason)
 {
         struct ieee80211_local *local = hw_to_local(hw);
+        struct ieee80211_sub_if_data *sdata;
 
         if (WARN_ON(queue >= hw->queues))
                 return;
 
         __set_bit(reason, &local->queue_stop_reasons[queue]);
+
+        rcu_read_lock();
+        list_for_each_entry_rcu(sdata, &local->interfaces, list)
+                netif_tx_stop_queue(netdev_get_tx_queue(sdata->dev, queue));
+        rcu_read_unlock();
 }
 
 void ieee80211_stop_queue_by_reason(struct ieee80211_hw *hw, int queue,