From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Fri, 22 Aug 2008 20:15:26 +1000

On Fri, Aug 22, 2008 at 09:27:30AM +0000, Jarek Poplawski wrote:

quoted

pkt_sched: Fix qdisc list locking

Since some qdiscs call qdisc_tree_decrease_qlen() (so qdisc_lookup())
without rtnl_lock(), adding and deleting from a qdisc list needs
additional locking. This patch adds global spinlock qdisc_list_lock
and wrapper functions for modifying the list. It is considered as a
temporary solution until hfsc_dequeue(), netem_dequeue() and
tbf_dequeue() (or qdisc_tree_decrease_qlen()) are redone.

With feedback from Herbert Xu and David S. Miller.

Signed-off-by: Jarek Poplawski <redacted>

Acked-by: Herbert Xu <herbert@gondor.apana.org.au>

I'll add you ACK, thanks Herbert.

Good catch! I'm not sure whether this would actually break but
it certainly makes me feel a lot better :)

Thankfully list_del() on an empty list works or we'd have tons of
reports :)