diff --git a/net/sched/sch_prio.c b/net/sched/sch_prio.c index 071718bccdab..a356450b747b 100644 --- a/net/sched/sch_prio.c +++ b/net/sched/sch_prio.c @@ -172,8 +172,9 @@ prio_destroy(struct Qdisc *sch) static int prio_tune(struct Qdisc *sch, struct nlattr *opt) { struct prio_sched_data *q = qdisc_priv(sch); + struct Qdisc *queues[TCQ_PRIO_BANDS]; + int oldbands = q->bands, i; struct tc_prio_qopt *qopt; - int i; if (nla_len(opt) < sizeof(*qopt)) return -EINVAL; @@ -187,54 +188,42 @@ static int prio_tune(struct Qdisc *sch, struct nlattr *opt) return -EINVAL; } + /* Before commit, make sure we can allocate all new qdiscs */ + for (i = oldbands; i < qopt->bands; i++) { + queues[i] = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, + TC_H_MAKE(sch->handle, i + 1)); + if (!queues[i]) { + while (i > oldbands) + qdisc_destroy(queues[--i]); + return -ENOMEM; + } + } + sch_tree_lock(sch); q->bands = qopt->bands; memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1); - for (i = q->bands; i < TCQ_PRIO_BANDS; i++) { + for (i = q->bands; i < oldbands; i++) { struct Qdisc *child = q->queues[i]; - q->queues[i] = &noop_qdisc; - if (child != &noop_qdisc) { - qdisc_tree_reduce_backlog(child, child->q.qlen, child->qstats.backlog); - qdisc_destroy(child); - } + + qdisc_tree_reduce_backlog(child, child->q.qlen, + child->qstats.backlog); + qdisc_destroy(child); } + + for (i = oldbands; i < q->bands; i++) + q->queues[i] = queues[i]; + sch_tree_unlock(sch); - - for (i = 0; i < q->bands; i++) { - 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; } static int prio_init(struct Qdisc *sch, struct nlattr *opt) { - struct prio_sched_data *q = qdisc_priv(sch); - int 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; + return prio_tune(sch, opt); } static int prio_dump(struct Qdisc *sch, struct sk_buff *skb)