tree 031ce7a911fc5bff995421a5615d9ab25416a479
parent e2627c8c2241bce45e368e150654d076b58a4595
author David S. Miller <davem@davemloft.net> 1216197760 -0700
committer David S. Miller <davem@davemloft.net> 1216347679 -0700

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 <davem@davemloft.net>