From 7698b4fcabcd790efc4f226bada1e7b5870653af Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Wed, 16 Jul 2008 01:42:40 -0700 Subject: [PATCH] pkt_sched: Add and use qdisc_root() and qdisc_root_lock(). When code wants to lock the qdisc tree state, the logic operation it's doing is locking the top-level qdisc that sits of the root of the netdev_queue. Add qdisc_root_lock() to represent this and convert the easiest cases. In order for this to work out in all cases, we have to hook up the noop_qdisc to a dummy netdev_queue. Signed-off-by: David S. Miller --- include/net/sch_generic.h | 12 ++++++++++++ net/sched/sch_api.c | 8 ++++---- net/sched/sch_cbq.c | 9 +++++---- net/sched/sch_generic.c | 21 ++++++++++++++++----- net/sched/sch_hfsc.c | 4 ++-- net/sched/sch_htb.c | 18 ++++++++++-------- net/sched/sch_netem.c | 9 ++++++--- 7 files changed, 55 insertions(+), 26 deletions(-) diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index bc2a09da21..92417825d3 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -161,6 +161,18 @@ struct tcf_proto struct tcf_proto_ops *ops; }; +static inline struct Qdisc *qdisc_root(struct Qdisc *qdisc) +{ + return qdisc->dev_queue->qdisc; +} + +static inline spinlock_t *qdisc_root_lock(struct Qdisc *qdisc) +{ + struct Qdisc *root = qdisc_root(qdisc); + + return &root->dev_queue->lock; +} + static inline struct net_device *qdisc_dev(struct Qdisc *qdisc) { return qdisc->dev_queue->dev; diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index 830ccc544a..19c244a008 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -633,7 +633,7 @@ qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue, if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) { if (tca[TCA_RATE]) { err = gen_new_estimator(&sch->bstats, &sch->rate_est, - &sch->dev_queue->lock, + qdisc_root_lock(sch), tca[TCA_RATE]); if (err) { /* @@ -675,7 +675,7 @@ static int qdisc_change(struct Qdisc *sch, struct nlattr **tca) } if (tca[TCA_RATE]) gen_replace_estimator(&sch->bstats, &sch->rate_est, - &sch->dev_queue->lock, tca[TCA_RATE]); + qdisc_root_lock(sch), tca[TCA_RATE]); return 0; } @@ -967,7 +967,7 @@ static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid, q->qstats.qlen = q->q.qlen; if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, - TCA_XSTATS, &q->dev_queue->lock, &d) < 0) + TCA_XSTATS, qdisc_root_lock(q), &d) < 0) goto nla_put_failure; if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0) @@ -1216,7 +1216,7 @@ static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q, goto nla_put_failure; if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, - TCA_XSTATS, &q->dev_queue->lock, &d) < 0) + TCA_XSTATS, qdisc_root_lock(q), &d) < 0) goto nla_put_failure; if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0) diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c index 4efc836cbf..37ae653db6 100644 --- a/net/sched/sch_cbq.c +++ b/net/sched/sch_cbq.c @@ -1744,12 +1744,13 @@ static void cbq_put(struct Qdisc *sch, unsigned long arg) if (--cl->refcnt == 0) { #ifdef CONFIG_NET_CLS_ACT + spinlock_t *root_lock = qdisc_root_lock(sch); struct cbq_sched_data *q = qdisc_priv(sch); - spin_lock_bh(&sch->dev_queue->lock); + spin_lock_bh(root_lock); if (q->rx_class == cl) q->rx_class = NULL; - spin_unlock_bh(&sch->dev_queue->lock); + spin_unlock_bh(root_lock); #endif cbq_destroy_class(sch, cl); @@ -1828,7 +1829,7 @@ cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **t if (tca[TCA_RATE]) gen_replace_estimator(&cl->bstats, &cl->rate_est, - &sch->dev_queue->lock, + qdisc_root_lock(sch), tca[TCA_RATE]); return 0; } @@ -1919,7 +1920,7 @@ cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **t if (tca[TCA_RATE]) gen_new_estimator(&cl->bstats, &cl->rate_est, - &sch->dev_queue->lock, tca[TCA_RATE]); + qdisc_root_lock(sch), tca[TCA_RATE]); *arg = (unsigned long)cl; return 0; diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index ac208c2b2d..739a8711ab 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -151,14 +151,17 @@ static inline int qdisc_restart(struct netdev_queue *txq, { int ret = NETDEV_TX_BUSY; struct net_device *dev; + spinlock_t *root_lock; struct sk_buff *skb; /* Dequeue packet */ if (unlikely((skb = dequeue_skb(q)) == NULL)) return 0; - /* And release queue */ - spin_unlock(&txq->lock); + root_lock = qdisc_root_lock(q); + + /* And release qdisc */ + spin_unlock(root_lock); dev = txq->dev; @@ -167,7 +170,7 @@ static inline int qdisc_restart(struct netdev_queue *txq, ret = dev_hard_start_xmit(skb, dev, txq); HARD_TX_UNLOCK(dev, txq); - spin_lock(&txq->lock); + spin_lock(root_lock); switch (ret) { case NETDEV_TX_OK: @@ -345,12 +348,18 @@ struct Qdisc_ops noop_qdisc_ops __read_mostly = { .owner = THIS_MODULE, }; +static struct netdev_queue noop_netdev_queue = { + .lock = __SPIN_LOCK_UNLOCKED(noop_netdev_queue.lock), + .qdisc = &noop_qdisc, +}; + struct Qdisc noop_qdisc = { .enqueue = noop_enqueue, .dequeue = noop_dequeue, .flags = TCQ_F_BUILTIN, .ops = &noop_qdisc_ops, .list = LIST_HEAD_INIT(noop_qdisc.list), + .dev_queue = &noop_netdev_queue, }; EXPORT_SYMBOL(noop_qdisc); @@ -666,19 +675,21 @@ static bool some_qdisc_is_running(struct net_device *dev, int lock) for (i = 0; i < dev->num_tx_queues; i++) { struct netdev_queue *dev_queue; + spinlock_t *root_lock; struct Qdisc *q; int val; dev_queue = netdev_get_tx_queue(dev, i); q = dev_queue->qdisc; + root_lock = qdisc_root_lock(q); if (lock) - spin_lock_bh(&dev_queue->lock); + spin_lock_bh(root_lock); val = test_bit(__QDISC_STATE_RUNNING, &q->state); if (lock) - spin_unlock_bh(&dev_queue->lock); + spin_unlock_bh(root_lock); if (val) return true; diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c index 997d520ca5..5090708ba3 100644 --- a/net/sched/sch_hfsc.c +++ b/net/sched/sch_hfsc.c @@ -1045,7 +1045,7 @@ hfsc_change_class(struct Qdisc *sch, u32 classid, u32 parentid, if (tca[TCA_RATE]) gen_replace_estimator(&cl->bstats, &cl->rate_est, - &sch->dev_queue->lock, + qdisc_root_lock(sch), tca[TCA_RATE]); return 0; } @@ -1104,7 +1104,7 @@ hfsc_change_class(struct Qdisc *sch, u32 classid, u32 parentid, if (tca[TCA_RATE]) gen_new_estimator(&cl->bstats, &cl->rate_est, - &sch->dev_queue->lock, tca[TCA_RATE]); + qdisc_root_lock(sch), tca[TCA_RATE]); *arg = (unsigned long)cl; return 0; } diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c index c8ca54cc26..ee48457eaa 100644 --- a/net/sched/sch_htb.c +++ b/net/sched/sch_htb.c @@ -1039,11 +1039,12 @@ static int htb_init(struct Qdisc *sch, struct nlattr *opt) static int htb_dump(struct Qdisc *sch, struct sk_buff *skb) { + spinlock_t *root_lock = qdisc_root_lock(sch); struct htb_sched *q = qdisc_priv(sch); struct nlattr *nest; struct tc_htb_glob gopt; - spin_lock_bh(&sch->dev_queue->lock); + spin_lock_bh(root_lock); gopt.direct_pkts = q->direct_pkts; gopt.version = HTB_VER; @@ -1057,11 +1058,11 @@ static int htb_dump(struct Qdisc *sch, struct sk_buff *skb) NLA_PUT(skb, TCA_HTB_INIT, sizeof(gopt), &gopt); nla_nest_end(skb, nest); - spin_unlock_bh(&sch->dev_queue->lock); + spin_unlock_bh(root_lock); return skb->len; nla_put_failure: - spin_unlock_bh(&sch->dev_queue->lock); + spin_unlock_bh(root_lock); nla_nest_cancel(skb, nest); return -1; } @@ -1070,10 +1071,11 @@ static int htb_dump_class(struct Qdisc *sch, unsigned long arg, struct sk_buff *skb, struct tcmsg *tcm) { struct htb_class *cl = (struct htb_class *)arg; + spinlock_t *root_lock = qdisc_root_lock(sch); struct nlattr *nest; struct tc_htb_opt opt; - spin_lock_bh(&sch->dev_queue->lock); + spin_lock_bh(root_lock); tcm->tcm_parent = cl->parent ? cl->parent->common.classid : TC_H_ROOT; tcm->tcm_handle = cl->common.classid; if (!cl->level && cl->un.leaf.q) @@ -1095,11 +1097,11 @@ static int htb_dump_class(struct Qdisc *sch, unsigned long arg, NLA_PUT(skb, TCA_HTB_PARMS, sizeof(opt), &opt); nla_nest_end(skb, nest); - spin_unlock_bh(&sch->dev_queue->lock); + spin_unlock_bh(root_lock); return skb->len; nla_put_failure: - spin_unlock_bh(&sch->dev_queue->lock); + spin_unlock_bh(root_lock); nla_nest_cancel(skb, nest); return -1; } @@ -1365,7 +1367,7 @@ static int htb_change_class(struct Qdisc *sch, u32 classid, goto failure; gen_new_estimator(&cl->bstats, &cl->rate_est, - &sch->dev_queue->lock, + qdisc_root_lock(sch), tca[TCA_RATE] ? : &est.nla); cl->refcnt = 1; cl->children = 0; @@ -1420,7 +1422,7 @@ static int htb_change_class(struct Qdisc *sch, u32 classid, } else { if (tca[TCA_RATE]) gen_replace_estimator(&cl->bstats, &cl->rate_est, - &sch->dev_queue->lock, + qdisc_root_lock(sch), tca[TCA_RATE]); sch_tree_lock(sch); } diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c index bc585f2089..c5ea40c9eb 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -180,7 +180,7 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch) * skb will be queued. */ if (count > 1 && (skb2 = skb_clone(skb, GFP_ATOMIC)) != NULL) { - struct Qdisc *rootq = sch->dev_queue->qdisc; + struct Qdisc *rootq = qdisc_root(sch); u32 dupsave = q->duplicate; /* prevent duplicating a dup... */ q->duplicate = 0; @@ -319,6 +319,7 @@ static int get_dist_table(struct Qdisc *sch, const struct nlattr *attr) struct netem_sched_data *q = qdisc_priv(sch); unsigned long n = nla_len(attr)/sizeof(__s16); const __s16 *data = nla_data(attr); + spinlock_t *root_lock; struct disttable *d; int i; @@ -333,9 +334,11 @@ static int get_dist_table(struct Qdisc *sch, const struct nlattr *attr) for (i = 0; i < n; i++) d->table[i] = data[i]; - spin_lock_bh(&sch->dev_queue->lock); + root_lock = qdisc_root_lock(sch); + + spin_lock_bh(root_lock); d = xchg(&q->delay_dist, d); - spin_unlock_bh(&sch->dev_queue->lock); + spin_unlock_bh(root_lock); kfree(d); return 0; -- 2.39.5