[PATCHv3 net-next 10/14] net: sch: api: add extack support in qdisc_alloc

[Alexander Aring]

This patch adds extack support for the function qdisc_alloc which is
a common used function in the tc subsystem. Callers which are interested
in the receiving error can assign extack to get a more detailed
information why qdisc_alloc failed.

Cc: David Ahern <dsah...@gmail.com>
Signed-off-by: Alexander Aring <ar...@mojatatu.com>
---
 include/net/sch_generic.h | 3 ++-
 net/sched/sch_api.c       | 2 +-
 net/sched/sch_generic.c   | 6 ++++--
 3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 2ea04863ea34..1dbfbec00050 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -470,7 +470,8 @@ void qdisc_destroy(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,
-                         const struct Qdisc_ops *ops);
+                         const struct Qdisc_ops *ops,
+                         struct netlink_ext_ack *extack);
 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
                                const struct Qdisc_ops *ops, u32 parentid);
 void __qdisc_calculate_pkt_len(struct sk_buff *skb,
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index a58459569f35..fd3960ff0fe4 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -1050,7 +1050,7 @@ static struct Qdisc *qdisc_create(struct net_device *dev,
                goto err_out;
        }
 
-       sch = qdisc_alloc(dev_queue, ops);
+       sch = qdisc_alloc(dev_queue, ops, extack);
        if (IS_ERR(sch)) {
                err = PTR_ERR(sch);
                goto err_out2;
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 5cdafe88b902..01457b27d36e 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -749,7 +749,8 @@ static struct lock_class_key qdisc_tx_busylock;
 static struct lock_class_key qdisc_running_key;
 
 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
-                         const struct Qdisc_ops *ops)
+                         const struct Qdisc_ops *ops,
+                         struct netlink_ext_ack *extack)
 {
        void *p;
        struct Qdisc *sch;
@@ -758,6 +759,7 @@ struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
        struct net_device *dev;
 
        if (!dev_queue) {
+               NL_SET_ERR_MSG(extack, "No device queue given");
                err = -EINVAL;
                goto errout;
        }
@@ -829,7 +831,7 @@ struct Qdisc *qdisc_create_dflt(struct netdev_queue 
*dev_queue,
        if (!try_module_get(ops->owner))
                return NULL;
 
-       sch = qdisc_alloc(dev_queue, ops);
+       sch = qdisc_alloc(dev_queue, ops, NULL);
        if (IS_ERR(sch)) {
                module_put(ops->owner);
                return NULL;
-- 
2.11.0