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authorDavid S. Miller <davem@davemloft.net>2008-07-30 02:37:46 -0700
committerDavid S. Miller <davem@davemloft.net>2008-07-30 02:44:25 -0700
commit8d50b53d66a8a6ae41bafbdcabe401467803f33a (patch)
tree7a23efd740161b5b32d3fd473cf024e1a8931ce1 /net/sched/sch_api.c
parent38c080ffa9c1b840390832b42ce8621464ab9f97 (diff)
pkt_sched: Fix OOPS on ingress qdisc add.
Bug report from Steven Jan Springl: Issuing the following command causes a kernel oops: tc qdisc add dev eth0 handle ffff: ingress The problem mostly stems from all of the special case handling of ingress qdiscs. So, to fix this, do the grafting operation the same way we do for TX qdiscs. Which means that dev_activate() and dev_deactivate() now do the "qdisc_sleeping <--> qdisc" transitions on dev->rx_queue too. Future simplifications are possible now, mainly because it is impossible for dev_queue->{qdisc,qdisc_sleeping} to be NULL. There are NULL checks all over to handle the ingress qdisc special case that used to exist before this commit. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched/sch_api.c')
-rw-r--r--net/sched/sch_api.c57
1 files changed, 16 insertions, 41 deletions
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index b0601642e227..4840aff47256 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -572,44 +572,21 @@ static u32 qdisc_alloc_handle(struct net_device *dev)
static struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
struct Qdisc *qdisc)
{
+ struct Qdisc *oqdisc = dev_queue->qdisc_sleeping;
spinlock_t *root_lock;
- struct Qdisc *oqdisc;
- int ingress;
-
- ingress = 0;
- if (qdisc && qdisc->flags&TCQ_F_INGRESS)
- ingress = 1;
-
- if (ingress) {
- oqdisc = dev_queue->qdisc;
- } else {
- oqdisc = dev_queue->qdisc_sleeping;
- }
root_lock = qdisc_root_lock(oqdisc);
spin_lock_bh(root_lock);
- if (ingress) {
- /* Prune old scheduler */
- if (oqdisc && atomic_read(&oqdisc->refcnt) <= 1) {
- /* delete */
- qdisc_reset(oqdisc);
- dev_queue->qdisc = NULL;
- } else { /* new */
- dev_queue->qdisc = qdisc;
- }
+ /* Prune old scheduler */
+ if (oqdisc && atomic_read(&oqdisc->refcnt) <= 1)
+ qdisc_reset(oqdisc);
- } else {
- /* Prune old scheduler */
- if (oqdisc && atomic_read(&oqdisc->refcnt) <= 1)
- qdisc_reset(oqdisc);
-
- /* ... and graft new one */
- if (qdisc == NULL)
- qdisc = &noop_qdisc;
- dev_queue->qdisc_sleeping = qdisc;
- dev_queue->qdisc = &noop_qdisc;
- }
+ /* ... and graft new one */
+ if (qdisc == NULL)
+ qdisc = &noop_qdisc;
+ dev_queue->qdisc_sleeping = qdisc;
+ dev_queue->qdisc = &noop_qdisc;
spin_unlock_bh(root_lock);
@@ -678,7 +655,8 @@ static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
ingress = 0;
num_q = dev->num_tx_queues;
- if (q && q->flags & TCQ_F_INGRESS) {
+ if ((q && q->flags & TCQ_F_INGRESS) ||
+ (new && new->flags & TCQ_F_INGRESS)) {
num_q = 1;
ingress = 1;
}
@@ -692,13 +670,10 @@ static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
if (!ingress)
dev_queue = netdev_get_tx_queue(dev, i);
- if (ingress) {
- old = dev_graft_qdisc(dev_queue, q);
- } else {
- old = dev_graft_qdisc(dev_queue, new);
- if (new && i > 0)
- atomic_inc(&new->refcnt);
- }
+ old = dev_graft_qdisc(dev_queue, new);
+ if (new && i > 0)
+ atomic_inc(&new->refcnt);
+
notify_and_destroy(skb, n, classid, old, new);
}
@@ -817,7 +792,7 @@ qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue,
goto err_out3;
}
}
- if (parent)
+ if (parent && !(sch->flags & TCQ_F_INGRESS))
list_add_tail(&sch->list, &dev_queue->qdisc->list);
return sch;