pkt_sched: Fix gen_estimator locks

While passing a qdisc root lock to gen_new_estimator() and
gen_replace_estimator() dev could be deactivated or even before
grafting proper root qdisc as qdisc_sleeping (e.g. qdisc_create), so
using qdisc_root_lock() is not enough. This patch adds
qdisc_root_sleeping_lock() for this, plus additional checks, where
necessary.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index b1d2cfea89c5..ef8a7e2e12e7 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -217,6 +217,14 @@ static inline spinlock_t *qdisc_root_lock(struct Qdisc *qdisc)
         return qdisc_lock(root);
 }
 
+static inline spinlock_t *qdisc_root_sleeping_lock(struct Qdisc *qdisc)
+{
+        struct Qdisc *root = qdisc_root_sleeping(qdisc);
+
+        ASSERT_RTNL();
+        return qdisc_lock(root);
+}
+
 static inline struct net_device *qdisc_dev(struct Qdisc *qdisc)
 {
         return qdisc->dev_queue->dev;