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| author | Eric Dumazet <eric.dumazet@gmail.com> | 2012-01-02 15:47:50 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-01-03 22:02:19 +0400 |
| commit | d32ae76f2b776347051cf821ebe690602e38dfc7 (patch) | |
| tree | 3f17a0c00e2ac7cc982c47e442661517ae010d5c | |
| parent | d47a0ac7b66883987275598d6039f902f4410ca9 (diff) | |
| download | linux-d32ae76f2b776347051cf821ebe690602e38dfc7.tar.xz | |
sch_qfq: accurate wsum handling
We can underestimate q->wsum in case of "tc class replace ... qfq"
and/or qdisc_create_dflt() error.
wsum is not really used in fast path, only at qfq qdisc/class setup,
to catch user error.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/sched/sch_qfq.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c index 103343408593..2c5ff6148589 100644 --- a/net/sched/sch_qfq.c +++ b/net/sched/sch_qfq.c @@ -211,6 +211,7 @@ static int qfq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr *tb[TCA_QFQ_MAX + 1]; u32 weight, lmax, inv_w; int i, err; + int delta_w; if (tca[TCA_OPTIONS] == NULL) { pr_notice("qfq: no options\n"); @@ -232,9 +233,10 @@ static int qfq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, inv_w = ONE_FP / weight; weight = ONE_FP / inv_w; - if (q->wsum + weight > QFQ_MAX_WSUM) { + delta_w = weight - (cl ? ONE_FP / cl->inv_w : 0); + if (q->wsum + delta_w > QFQ_MAX_WSUM) { pr_notice("qfq: total weight out of range (%u + %u)\n", - weight, q->wsum); + delta_w, q->wsum); return -EINVAL; } @@ -256,13 +258,12 @@ static int qfq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, return err; } - sch_tree_lock(sch); - if (tb[TCA_QFQ_WEIGHT]) { - q->wsum = weight - ONE_FP / cl->inv_w; + if (inv_w != cl->inv_w) { + sch_tree_lock(sch); + q->wsum += delta_w; cl->inv_w = inv_w; + sch_tree_unlock(sch); } - sch_tree_unlock(sch); - return 0; } @@ -277,7 +278,6 @@ static int qfq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, i = qfq_calc_index(cl->inv_w, cl->lmax); cl->grp = &q->groups[i]; - q->wsum += weight; cl->qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, classid); @@ -294,6 +294,7 @@ static int qfq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, return err; } } + q->wsum += weight; sch_tree_lock(sch); qdisc_class_hash_insert(&q->clhash, &cl->common); |