net: sched: store net pointer in block and introduce qdisc_net helper

Store net pointer in the block structure. Along the way, introduce
qdisc_net helper which allows to easily obtain net pointer for
qdisc instance.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/pkt_sched.h

@@ -4,7 +4,9 @@
 #include <linux/jiffies.h>
 #include <linux/ktime.h>
 #include <linux/if_vlan.h>
+#include <linux/netdevice.h>
 #include <net/sch_generic.h>
+#include <net/net_namespace.h>
 #include <uapi/linux/pkt_sched.h>
 
 #define DEFAULT_TX_QUEUE_LEN	1000
@@ -146,4 +148,9 @@ static inline bool is_classid_clsact_egress(u32 classid)
 	       TC_H_MIN(classid) == TC_H_MIN(TC_H_MIN_EGRESS);
 }
 
+static inline struct net *qdisc_net(struct Qdisc *q)
+{
+	return dev_net(q->dev_queue->dev);
+}
+
 #endif

include/net/sch_generic.h

@@ -270,6 +270,7 @@ struct tcf_chain {
 
 struct tcf_block {
 	struct list_head chain_list;
+	struct net *net;
 	struct Qdisc *q;
 };
 

net/sched/cls_api.c

@@ -257,6 +257,7 @@ int tcf_block_get(struct tcf_block **p_block,
 		goto err_chain_create;
 	}
 	tcf_chain_filter_chain_ptr_set(chain, p_filter_chain);
+	block->net = qdisc_net(q);
 	block->q = q;
 	*p_block = block;
 	return 0;