pkt_sched: Move gso_skb into Qdisc.

We liberate any dangling gso_skb during qdisc destruction.

It really only matters for the root qdisc.  But when qdiscs
can be shared by multiple netdev_queue objects, we can't
have the gso_skb in the netdev_queue any more.

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 10 insertions, 11 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 787fbfc5aebb..0883fcf2d16a 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -449,7 +449,6 @@ struct netdev_queue {
         struct net_device       *dev;
         struct Qdisc            *qdisc;
         unsigned long           state;
-        struct sk_buff          *gso_skb;
         spinlock_t              _xmit_lock;
         int                     xmit_lock_owner;
         struct Qdisc            *qdisc_sleeping;
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index b47f556c66f8..b96c3d9e10a8 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -36,6 +36,7 @@ struct Qdisc
         u32                     handle;
         u32                     parent;
         atomic_t                refcnt;
+        struct sk_buff          *gso_skb;
         struct sk_buff_head     q;
         struct netdev_queue     *dev_queue;
         struct list_head        list;
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 2f575b9017d1..2bd75befa066 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -77,7 +77,7 @@ static inline int dev_requeue_skb(struct sk_buff *skb,
                                   struct Qdisc *q)
 {
         if (unlikely(skb->next))
-                dev_queue->gso_skb = skb;
+                q->gso_skb = skb;
         else
                 q->ops->requeue(skb, q);
 
@@ -85,13 +85,12 @@ static inline int dev_requeue_skb(struct sk_buff *skb,
         return 0;
 }
 
-static inline struct sk_buff *dequeue_skb(struct netdev_queue *dev_queue,
-                                          struct Qdisc *q)
+static inline struct sk_buff *dequeue_skb(struct Qdisc *q)
 {
         struct sk_buff *skb;
 
-        if ((skb = dev_queue->gso_skb))
-                dev_queue->gso_skb = NULL;
+        if ((skb = q->gso_skb))
+                q->gso_skb = NULL;
         else
                 skb = q->dequeue(q);
 
@@ -155,10 +154,9 @@ static inline int qdisc_restart(struct netdev_queue *txq)
         struct sk_buff *skb;
 
         /* Dequeue packet */
-        if (unlikely((skb = dequeue_skb(txq, q)) == NULL))
+        if (unlikely((skb = dequeue_skb(q)) == NULL))
                 return 0;
 
-
         /* And release queue */
         spin_unlock(&txq->lock);
 
@@ -643,8 +641,8 @@ static void dev_deactivate_queue(struct net_device *dev,
                                  void *_qdisc_default)
 {
         struct Qdisc *qdisc_default = _qdisc_default;
+        struct sk_buff *skb = NULL;
         struct Qdisc *qdisc;
-        struct sk_buff *skb;
 
         spin_lock_bh(&dev_queue->lock);
 
@@ -652,9 +650,10 @@ static void dev_deactivate_queue(struct net_device *dev,
         if (qdisc) {
                 dev_queue->qdisc = qdisc_default;
                 qdisc_reset(qdisc);
+
+                skb = qdisc->gso_skb;
+                qdisc->gso_skb = NULL;
         }
-        skb = dev_queue->gso_skb;
-        dev_queue->gso_skb = NULL;
 
         spin_unlock_bh(&dev_queue->lock);