Merge remote-tracking branches 'spi/topic/spidev', 'spi/topic/sunxi', 'spi/topic...

[linux.git] / net / sched / sch_prio.c

diff --git a/net/sched/sch_prio.c b/net/sched/sch_prio.c
index 4b0a82191bc4011c9574a029fe8c30133c5f6f50..a356450b747ba57552d6c1e1e35255935580f02a 100644 (file)
--- 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;
@@ -187,62 +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);
-               }
-       }
-       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);
-                       }
-               }
+               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);
        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)