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authorDavid S. Miller <davem@davemloft.net>2008-07-16 03:00:19 -0700
committerDavid S. Miller <davem@davemloft.net>2008-07-17 19:21:27 -0700
commit53049978df1d9ae55bf397c9879e6b33218352db (patch)
tree18369747279ef1c0b807fe19e80d5d6c96d099bb /net/sched
parentead81cc5fc6d996db6afb20f211241612610a07a (diff)
downloadop-kernel-dev-53049978df1d9ae55bf397c9879e6b33218352db.zip
op-kernel-dev-53049978df1d9ae55bf397c9879e6b33218352db.tar.gz
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 <davem@davemloft.net>
Diffstat (limited to 'net/sched')
-rw-r--r--net/sched/sch_api.c41
1 files changed, 29 insertions, 12 deletions
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 6958fe7..7492489 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;
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