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-rw-r--r--include/linux/rtnetlink.h5
-rw-r--r--include/net/pkt_sched.h1
-rw-r--r--include/net/sch_generic.h2
-rw-r--r--net/sched/sch_api.c18
-rw-r--r--net/sched/sch_generic.c25
5 files changed, 50 insertions, 1 deletions
diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index 9cdd76348d9a..bb9cb84114c1 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -85,6 +85,11 @@ static inline struct netdev_queue *dev_ingress_queue(struct net_device *dev)
return rtnl_dereference(dev->ingress_queue);
}
+static inline struct netdev_queue *dev_ingress_queue_rcu(struct net_device *dev)
+{
+ return rcu_dereference(dev->ingress_queue);
+}
+
struct netdev_queue *dev_ingress_queue_create(struct net_device *dev);
#ifdef CONFIG_NET_INGRESS
diff --git a/include/net/pkt_sched.h b/include/net/pkt_sched.h
index 7dc769e5452b..a16fbe9a2a67 100644
--- a/include/net/pkt_sched.h
+++ b/include/net/pkt_sched.h
@@ -102,6 +102,7 @@ int qdisc_set_default(const char *id);
void qdisc_hash_add(struct Qdisc *q, bool invisible);
void qdisc_hash_del(struct Qdisc *q);
struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle);
+struct Qdisc *qdisc_lookup_rcu(struct net_device *dev, u32 handle);
struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
struct nlattr *tab,
struct netlink_ext_ack *extack);
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index fadb1a4d4ee8..091b40c198ff 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -105,6 +105,7 @@ struct Qdisc {
spinlock_t busylock ____cacheline_aligned_in_smp;
spinlock_t seqlock;
+ struct rcu_head rcu;
};
static inline void qdisc_refcount_inc(struct Qdisc *qdisc)
@@ -555,6 +556,7 @@ struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
struct Qdisc *qdisc);
void qdisc_reset(struct Qdisc *qdisc);
void qdisc_put(struct Qdisc *qdisc);
+void qdisc_put_unlocked(struct Qdisc *qdisc);
void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, unsigned int n,
unsigned int len);
struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 2096138c4bf6..22e9799e5b69 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -314,6 +314,24 @@ out:
return q;
}
+struct Qdisc *qdisc_lookup_rcu(struct net_device *dev, u32 handle)
+{
+ struct netdev_queue *nq;
+ struct Qdisc *q;
+
+ if (!handle)
+ return NULL;
+ q = qdisc_match_from_root(dev->qdisc, handle);
+ if (q)
+ goto out;
+
+ nq = dev_ingress_queue_rcu(dev);
+ if (nq)
+ q = qdisc_match_from_root(nq->qdisc_sleeping, handle);
+out:
+ return q;
+}
+
static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
{
unsigned long cl;
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 3e7696f3e053..531fac1d2875 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -941,6 +941,13 @@ void qdisc_free(struct Qdisc *qdisc)
kfree((char *) qdisc - qdisc->padded);
}
+void qdisc_free_cb(struct rcu_head *head)
+{
+ struct Qdisc *q = container_of(head, struct Qdisc, rcu);
+
+ qdisc_free(q);
+}
+
static void qdisc_destroy(struct Qdisc *qdisc)
{
const struct Qdisc_ops *ops = qdisc->ops;
@@ -970,7 +977,7 @@ static void qdisc_destroy(struct Qdisc *qdisc)
kfree_skb_list(skb);
}
- qdisc_free(qdisc);
+ call_rcu(&qdisc->rcu, qdisc_free_cb);
}
void qdisc_put(struct Qdisc *qdisc)
@@ -983,6 +990,22 @@ void qdisc_put(struct Qdisc *qdisc)
}
EXPORT_SYMBOL(qdisc_put);
+/* Version of qdisc_put() that is called with rtnl mutex unlocked.
+ * Intended to be used as optimization, this function only takes rtnl lock if
+ * qdisc reference counter reached zero.
+ */
+
+void qdisc_put_unlocked(struct Qdisc *qdisc)
+{
+ if (qdisc->flags & TCQ_F_BUILTIN ||
+ !refcount_dec_and_rtnl_lock(&qdisc->refcnt))
+ return;
+
+ qdisc_destroy(qdisc);
+ rtnl_unlock();
+}
+EXPORT_SYMBOL(qdisc_put_unlocked);
+
/* Attach toplevel qdisc to device queue. */
struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
struct Qdisc *qdisc)