From a9312ae89324438b0edc554eb36c3ec6bf927d04 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Sun, 17 Aug 2008 21:51:03 -0700 Subject: [PATCH] pkt_sched: Add 'deactivated' state. This new state lets dev_deactivate() mark a qdisc as having been deactivated. dev_queue_xmit() and ing_filter() check for this bit and do not try to process the qdisc if the bit is set. dev_deactivate() polls the qdisc after setting the bit, waiting for both __QDISC_STATE_RUNNING and __QDISC_STATE_SCHED to clear. This isn't perfect yet, but subsequent changesets will make it so. This part is just one piece of the puzzle. Signed-off-by: David S. Miller --- include/net/sch_generic.h | 1 + net/core/dev.c | 9 ++++++++- net/sched/sch_generic.c | 6 ++++++ 3 files changed, 15 insertions(+), 1 deletion(-) diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index a7abfda3e447..757ab087adbf 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -27,6 +27,7 @@ enum qdisc_state_t { __QDISC_STATE_RUNNING, __QDISC_STATE_SCHED, + __QDISC_STATE_DEACTIVATED, }; struct qdisc_size_table { diff --git a/net/core/dev.c b/net/core/dev.c index 600bb23c4c2e..d9e31f63aded 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1800,6 +1800,12 @@ gso: spin_lock(root_lock); + if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) { + spin_unlock(root_lock); + rc = NET_XMIT_DROP; + goto out_kfree_skb; + } + rc = qdisc_enqueue_root(skb, q); qdisc_run(q); @@ -2084,7 +2090,8 @@ static int ing_filter(struct sk_buff *skb) q = rxq->qdisc; if (q != &noop_qdisc) { spin_lock(qdisc_lock(q)); - result = qdisc_enqueue_root(skb, q); + if (likely(!test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) + result = qdisc_enqueue_root(skb, q); spin_unlock(qdisc_lock(q)); } diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 468574682caa..ff1c4557e5f8 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -597,6 +597,9 @@ static void transition_one_qdisc(struct net_device *dev, struct Qdisc *new_qdisc = dev_queue->qdisc_sleeping; int *need_watchdog_p = _need_watchdog; + if (!(new_qdisc->flags & TCQ_F_BUILTIN)) + clear_bit(__QDISC_STATE_DEACTIVATED, &new_qdisc->state); + rcu_assign_pointer(dev_queue->qdisc, new_qdisc); if (need_watchdog_p && new_qdisc != &noqueue_qdisc) *need_watchdog_p = 1; @@ -640,6 +643,9 @@ static void dev_deactivate_queue(struct net_device *dev, if (qdisc) { spin_lock_bh(qdisc_lock(qdisc)); + if (!(qdisc->flags & TCQ_F_BUILTIN)) + set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state); + dev_queue->qdisc = qdisc_default; qdisc_reset(qdisc);