[PATCH net] net_sched: prio: rollback allocations if prio_init() fails

[Eric Dumazet]

From: Eric Dumazet <eduma...@google.com>

Now prio_init() can return -ENOMEM, it also has to make sure
any allocated qdisc are freed, since the caller (qdisc_create()) wont
call ->destroy() handler for us.

Fixes: cbdf45116478 ("net_sched: prio: properly report out of memory errors")
Signed-off-by: Eric Dumazet <eduma...@google.com>
Reported-by: Cong Wang <xiyou.wangc...@gmail.com>
---
 net/sched/sch_prio.c |   14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/net/sched/sch_prio.c b/net/sched/sch_prio.c
index 071718bccdab..9b703f2c921b 100644
--- a/net/sched/sch_prio.c
+++ b/net/sched/sch_prio.c
@@ -221,20 +221,18 @@ static int prio_tune(struct Qdisc *sch, struct nlattr 
*opt)
 static int prio_init(struct Qdisc *sch, struct nlattr *opt)
 {
        struct prio_sched_data *q = qdisc_priv(sch);
-       int i;
+       int err, i;
 
        for (i = 0; i < TCQ_PRIO_BANDS; i++)
                q->queues[i] = &noop_qdisc;
 
-       if (opt == NULL) {
+       if (!opt)
                return -EINVAL;
-       } else {
-               int err;
 
-               if ((err = prio_tune(sch, opt)) != 0)
-                       return err;
-       }
-       return 0;
+       err = prio_tune(sch, opt);
+       if (err)
+               prio_destroy(sch);
+       return err;
 }
 
 static int prio_dump(struct Qdisc *sch, struct sk_buff *skb)