bonding: Incorrect TX queue offset

When packets come in from a device with >= 16 receive queues
headed out a bonding interface, syslog gets filled with this:

    kernel: bond0 selects TX queue 16, but real number of TX queues is 16

because queue_mapping is offset by 1.  Adjust return value
to account for the offset.

This is a revision of my earlier patch (which did not use the
skb_rx_queue_* helpers - thanks to Ben for the suggestion).
Andy submitted a similar patch which emits a pr_warning on
invalid queue selection, but I believe the log spew is
not useful.  We can revisit that question in the future,
but in the interim I believe fixing the core problem is
worthwhile.

Signed-off-by: Phil Oester <kernel@linuxace.com>
Signed-off-by: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 3ad4f50..a93d941 100644 (file)
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -4341,11 +4341,18 @@ static u16 bond_select_queue(struct net_device *dev, struct sk_buff *skb)
 {
        /*
         * This helper function exists to help dev_pick_tx get the correct
-        * destination queue.  Using a helper function skips the a call to
+        * destination queue.  Using a helper function skips a call to
         * skb_tx_hash and will put the skbs in the queue we expect on their
         * way down to the bonding driver.
         */
-       return skb->queue_mapping;
+       u16 txq = skb_rx_queue_recorded(skb) ? skb_get_rx_queue(skb) : 0;
+
+       if (unlikely(txq >= dev->real_num_tx_queues)) {
+               do
+                       txq -= dev->real_num_tx_queues;
+               while (txq >= dev->real_num_tx_queues);
+       }
+       return txq;
 }
 
 static netdev_tx_t bond_start_xmit(struct sk_buff *skb, struct net_device *dev)