From a9312ae89324438b0edc554eb36c3ec6bf927d04 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Sun, 17 Aug 2008 21:51:03 -0700 Subject: 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 + 1 file changed, 1 insertion(+) (limited to 'include/net/sch_generic.h') 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 { -- cgit v1.2.2 From 1e0d5a5747772182d1bb2525d8153da640fdfb58 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Sun, 17 Aug 2008 22:31:26 -0700 Subject: pkt_sched: No longer destroy qdiscs from RCU. We can now kill them synchronously with all of the previous dev_deactivate() cures. This makes netdev destruction and shutdown saner as the qdiscs hold references to the device. Signed-off-by: David S. Miller --- include/net/sch_generic.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/net/sch_generic.h') diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index 757ab087adbf..84d25f2e6188 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -61,7 +61,6 @@ struct Qdisc struct gnet_stats_basic bstats; struct gnet_stats_queue qstats; struct gnet_stats_rate_est rate_est; - struct rcu_head q_rcu; int (*reshape_fail)(struct sk_buff *skb, struct Qdisc *q); -- cgit v1.2.2 From 2540e0511ea17e25831be543cdf9381e6209950d Mon Sep 17 00:00:00 2001 From: Jarek Poplawski Date: Thu, 21 Aug 2008 05:11:14 -0700 Subject: pkt_sched: Fix qdisc_watchdog() vs. dev_deactivate() race dev_deactivate() can skip rescheduling of a qdisc by qdisc_watchdog() or other timer calling netif_schedule() after dev_queue_deactivate(). We prevent this checking aliveness before scheduling the timer. Since during deactivation the root qdisc is available only as qdisc_sleeping additional accessor qdisc_root_sleeping() is created. With feedback from Herbert Xu Signed-off-by: Jarek Poplawski Signed-off-by: David S. Miller --- include/net/sch_generic.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/net/sch_generic.h') diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index 84d25f2e6188..b1d2cfea89c5 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -193,6 +193,11 @@ static inline struct Qdisc *qdisc_root(struct Qdisc *qdisc) return qdisc->dev_queue->qdisc; } +static inline struct Qdisc *qdisc_root_sleeping(struct Qdisc *qdisc) +{ + return qdisc->dev_queue->qdisc_sleeping; +} + /* The qdisc root lock is a mechanism by which to top level * of a qdisc tree can be locked from any qdisc node in the * forest. This allows changing the configuration of some -- cgit v1.2.2 From f6f9b93f1624206c802ac9162c9302edaf59bfd9 Mon Sep 17 00:00:00 2001 From: Jarek Poplawski Date: Wed, 27 Aug 2008 02:25:17 -0700 Subject: pkt_sched: Fix gen_estimator locks While passing a qdisc root lock to gen_new_estimator() and gen_replace_estimator() dev could be deactivated or even before grafting proper root qdisc as qdisc_sleeping (e.g. qdisc_create), so using qdisc_root_lock() is not enough. This patch adds qdisc_root_sleeping_lock() for this, plus additional checks, where necessary. Signed-off-by: Jarek Poplawski Signed-off-by: David S. Miller --- include/net/sch_generic.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/net/sch_generic.h') diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index b1d2cfea89c5..ef8a7e2e12e7 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -217,6 +217,14 @@ static inline spinlock_t *qdisc_root_lock(struct Qdisc *qdisc) return qdisc_lock(root); } +static inline spinlock_t *qdisc_root_sleeping_lock(struct Qdisc *qdisc) +{ + struct Qdisc *root = qdisc_root_sleeping(qdisc); + + ASSERT_RTNL(); + return qdisc_lock(root); +} + static inline struct net_device *qdisc_dev(struct Qdisc *qdisc) { return qdisc->dev_queue->dev; -- cgit v1.2.2 From fe439dd09d3e4da6a44d35df7371b9c6a2661b99 Mon Sep 17 00:00:00 2001 From: Jarek Poplawski Date: Wed, 27 Aug 2008 02:27:10 -0700 Subject: pkt_sched: Fix sch_tree_lock() Use new qdisc_root_sleeping_lock() instead of qdisc_root_lock() as sch_tree_lock() because this lock could be used while dev is deactivated, but we never need to use this with noop_qdisc as a root. Signed-off-by: Jarek Poplawski Signed-off-by: David S. Miller --- include/net/sch_generic.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/net/sch_generic.h') diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index ef8a7e2e12e7..e5569625d2a5 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -232,12 +232,12 @@ static inline struct net_device *qdisc_dev(struct Qdisc *qdisc) static inline void sch_tree_lock(struct Qdisc *q) { - spin_lock_bh(qdisc_root_lock(q)); + spin_lock_bh(qdisc_root_sleeping_lock(q)); } static inline void sch_tree_unlock(struct Qdisc *q) { - spin_unlock_bh(qdisc_root_lock(q)); + spin_unlock_bh(qdisc_root_sleeping_lock(q)); } #define tcf_tree_lock(tp) sch_tree_lock((tp)->q) -- cgit v1.2.2