From 53049978df1d9ae55bf397c9879e6b33218352db Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Wed, 16 Jul 2008 03:00:19 -0700 Subject: [PATCH] pkt_sched: Make qdisc grafting locking more specific. Lock the root of the qdisc being operated upon. All explicit references to qdisc_tree_lock() are now gone. The only remaining uses are via the sch_tree_{lock,unlock}() and tcf_tree_{lock,unlock}() macros. Signed-off-by: David S. Miller --- net/sched/sch_api.c | 41 +++++++++++++++++++++++++++++------------ 1 file changed, 29 insertions(+), 12 deletions(-) diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index 6958fe7c9a77..74924893ef7f 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -441,15 +441,29 @@ static struct Qdisc * dev_graft_qdisc(struct net_device *dev, struct Qdisc *qdisc) { struct netdev_queue *dev_queue; + spinlock_t *root_lock; struct Qdisc *oqdisc; + int ingress; if (dev->flags & IFF_UP) dev_deactivate(dev); - qdisc_lock_tree(dev); - if (qdisc && qdisc->flags&TCQ_F_INGRESS) { + ingress = 0; + if (qdisc && qdisc->flags&TCQ_F_INGRESS) + ingress = 1; + + if (ingress) { dev_queue = &dev->rx_queue; oqdisc = dev_queue->qdisc; + } else { + dev_queue = netdev_get_tx_queue(dev, 0); + 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 */ @@ -460,9 +474,6 @@ dev_graft_qdisc(struct net_device *dev, struct Qdisc *qdisc) } } else { - dev_queue = netdev_get_tx_queue(dev, 0); - oqdisc = dev_queue->qdisc_sleeping; - /* Prune old scheduler */ if (oqdisc && atomic_read(&oqdisc->refcnt) <= 1) qdisc_reset(oqdisc); @@ -474,7 +485,7 @@ dev_graft_qdisc(struct net_device *dev, struct Qdisc *qdisc) dev_queue->qdisc = &noop_qdisc; } - qdisc_unlock_tree(dev); + spin_unlock_bh(root_lock); if (dev->flags & IFF_UP) dev_activate(dev); @@ -765,10 +776,12 @@ static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg) if ((err = qdisc_graft(dev, p, clid, NULL, &q)) != 0) return err; if (q) { + spinlock_t *root_lock = qdisc_root_lock(q); + qdisc_notify(skb, n, clid, q, NULL); - qdisc_lock_tree(dev); + spin_unlock_bh(root_lock); qdisc_destroy(q); - qdisc_unlock_tree(dev); + spin_unlock_bh(root_lock); } } else { qdisc_notify(skb, n, clid, NULL, q); @@ -911,20 +924,24 @@ create_n_graft: graft: if (1) { struct Qdisc *old_q = NULL; + spinlock_t *root_lock; + err = qdisc_graft(dev, p, clid, q, &old_q); if (err) { if (q) { - qdisc_lock_tree(dev); + root_lock = qdisc_root_lock(q); + spin_lock_bh(root_lock); qdisc_destroy(q); - qdisc_unlock_tree(dev); + spin_unlock_bh(root_lock); } return err; } qdisc_notify(skb, n, clid, old_q, q); if (old_q) { - qdisc_lock_tree(dev); + root_lock = qdisc_root_lock(old_q); + spin_lock_bh(root_lock); qdisc_destroy(old_q); - qdisc_unlock_tree(dev); + spin_unlock_bh(root_lock); } } return 0; -- 2.20.1