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| author | David S. Miller <davem@davemloft.net> | 2008-08-02 20:02:43 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-08-02 20:02:43 -0700 |
| commit | 5fb662297b8a4bdadd60371c34b760efca948ebc (patch) | |
| tree | ef1def70cfa440ab3d367f6f67d466227ffdf0ef | |
| parent | 82f97b8d3cb3982ec97e081598c671fab2c321b0 (diff) | |
| download | linux-5fb662297b8a4bdadd60371c34b760efca948ebc.tar.gz linux-5fb662297b8a4bdadd60371c34b760efca948ebc.tar.bz2 linux-5fb662297b8a4bdadd60371c34b760efca948ebc.zip | |
pkt_sched: Use qdisc_lock() on already sampled root qdisc.
Based upon a bug report by Jeff Kirsher.
Don't use qdisc_root_lock() in these cases as the root
qdisc could have been changed, and we'd thus lock the
wrong object.
Tested by Emil S Tantilov who confirms that this seems
to fix the problem.
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/core/dev.c | 4 | ||||
| -rw-r--r-- | net/sched/sch_generic.c | 12 |
2 files changed, 8 insertions, 8 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 69320a56a084..da7acacf02b5 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1796,7 +1796,7 @@ gso: skb->tc_verd = SET_TC_AT(skb->tc_verd,AT_EGRESS); #endif if (q->enqueue) { - spinlock_t *root_lock = qdisc_root_lock(q); + spinlock_t *root_lock = qdisc_lock(q); spin_lock(root_lock); @@ -1995,7 +1995,7 @@ static void net_tx_action(struct softirq_action *h) smp_mb__before_clear_bit(); clear_bit(__QDISC_STATE_SCHED, &q->state); - root_lock = qdisc_root_lock(q); + root_lock = qdisc_lock(q); if (spin_trylock(root_lock)) { qdisc_run(q); spin_unlock(root_lock); diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 9c9cd4d94890..7cf83b37459d 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -29,7 +29,7 @@ /* Main transmission queue. */ /* Modifications to data participating in scheduling must be protected with - * qdisc_root_lock(qdisc) spinlock. + * qdisc_lock(qdisc) spinlock. * * The idea is the following: * - enqueue, dequeue are serialized via qdisc root lock @@ -126,7 +126,7 @@ static inline int qdisc_restart(struct Qdisc *q) if (unlikely((skb = dequeue_skb(q)) == NULL)) return 0; - root_lock = qdisc_root_lock(q); + root_lock = qdisc_lock(q); /* And release qdisc */ spin_unlock(root_lock); @@ -507,7 +507,7 @@ errout: } EXPORT_SYMBOL(qdisc_create_dflt); -/* Under qdisc_root_lock(qdisc) and BH! */ +/* Under qdisc_lock(qdisc) and BH! */ void qdisc_reset(struct Qdisc *qdisc) { @@ -543,7 +543,7 @@ static void __qdisc_destroy(struct rcu_head *head) kfree((char *) qdisc - qdisc->padded); } -/* Under qdisc_root_lock(qdisc) and BH! */ +/* Under qdisc_lock(qdisc) and BH! */ void qdisc_destroy(struct Qdisc *qdisc) { @@ -659,7 +659,7 @@ static bool some_qdisc_is_running(struct net_device *dev, int lock) dev_queue = netdev_get_tx_queue(dev, i); q = dev_queue->qdisc; - root_lock = qdisc_root_lock(q); + root_lock = qdisc_lock(q); if (lock) spin_lock_bh(root_lock); @@ -735,7 +735,7 @@ static void shutdown_scheduler_queue(struct net_device *dev, struct Qdisc *qdisc_default = _qdisc_default; if (qdisc) { - spinlock_t *root_lock = qdisc_root_lock(qdisc); + spinlock_t *root_lock = qdisc_lock(qdisc); dev_queue->qdisc = qdisc_default; dev_queue->qdisc_sleeping = qdisc_default; |