[PATCH net] net_sched: prio: properly report out of memory errors
From: Eric Dumazet <hidden>
Date: 2016-06-12 23:21:50
Subsystem:
networking [general], tc subsystem, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Jamal Hadi Salim, Jiri Pirko, Linus Torvalds
From: Eric Dumazet <edumazet@google.com> At Qdisc creation or change time, prio_tune() creates missing pfifo qdiscs but does not return an error code if one qdisc could not be allocated. Leaving a qdisc in non operational state without telling user anything about this problem is not good. Also, testing if we replace something different than noop_qdisc a second time makes no sense so I removed useless code. Signed-off-by: Eric Dumazet <edumazet@google.com> --- net/sched/sch_prio.c | 32 ++++++++++++-------------------- 1 file changed, 12 insertions(+), 20 deletions(-)
diff --git a/net/sched/sch_prio.c b/net/sched/sch_prio.c
index 4b0a82191bc4..071718bccdab 100644
--- a/net/sched/sch_prio.c
+++ b/net/sched/sch_prio.c@@ -202,26 +202,18 @@ static int prio_tune(struct Qdisc *sch, struct nlattr *opt) sch_tree_unlock(sch); for (i = 0; i < q->bands; i++) { - if (q->queues[i] == &noop_qdisc) { - struct Qdisc *child, *old; - - child = qdisc_create_dflt(sch->dev_queue, - &pfifo_qdisc_ops, - TC_H_MAKE(sch->handle, i + 1)); - if (child) { - sch_tree_lock(sch); - old = q->queues[i]; - q->queues[i] = child; - - if (old != &noop_qdisc) { - qdisc_tree_reduce_backlog(old, - old->q.qlen, - old->qstats.backlog); - qdisc_destroy(old); - } - sch_tree_unlock(sch); - } - } + struct Qdisc *child; + + if (q->queues[i] != &noop_qdisc) + continue; + + child = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, + TC_H_MAKE(sch->handle, i + 1)); + if (!child) + return -ENOMEM; + sch_tree_lock(sch); + q->queues[i] = child; + sch_tree_unlock(sch); } return 0; }