From 722374c6ccd4aed968cd80104d569bd8dec9da4f Mon Sep 17 00:00:00 2001 From: Ivan Khoronzhuk Date: Tue, 19 Nov 2019 02:23:12 +0200 Subject: [PATCH] taprio: don't reject same mqprio settings [ Upstream commit b5a0faa3572ac70bd374bd66190ac3ad4fddab20 ] The taprio qdisc allows to set mqprio setting but only once. In case if mqprio settings are provided next time the error is returned as it's not allowed to change traffic class mapping in-flignt and that is normal. But if configuration is absolutely the same - no need to return error. It allows to provide same command couple times, changing only base time for instance, or changing only scheds maps, but leaving mqprio setting w/o modification. It more corresponds the message: "Changing the traffic mapping of a running schedule is not supported", so reject mqprio if it's really changed. Also corrected TC_BITMASK + 1 for consistency, as proposed. Fixes: a3d43c0d56f1 ("taprio: Add support adding an admin schedule") Reviewed-by: Vladimir Oltean Tested-by: Vladimir Oltean Acked-by: Vinicius Costa Gomes Signed-off-by: Ivan Khoronzhuk Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/sched/sch_taprio.c | 28 ++++++++++++++++++++++++++-- 1 file changed, 26 insertions(+), 2 deletions(-) diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index 76bebe5161948..92c0766d7f4f3 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -842,7 +842,7 @@ static int taprio_parse_mqprio_opt(struct net_device *dev, } /* Verify priority mapping uses valid tcs */ - for (i = 0; i < TC_BITMASK + 1; i++) { + for (i = 0; i <= TC_BITMASK; i++) { if (qopt->prio_tc_map[i] >= qopt->num_tc) { NL_SET_ERR_MSG(extack, "Invalid traffic class in priority to traffic class mapping"); return -EINVAL; @@ -1014,6 +1014,26 @@ static void setup_txtime(struct taprio_sched *q, } } +static int taprio_mqprio_cmp(const struct net_device *dev, + const struct tc_mqprio_qopt *mqprio) +{ + int i; + + if (!mqprio || mqprio->num_tc != dev->num_tc) + return -1; + + for (i = 0; i < mqprio->num_tc; i++) + if (dev->tc_to_txq[i].count != mqprio->count[i] || + dev->tc_to_txq[i].offset != mqprio->offset[i]) + return -1; + + for (i = 0; i <= TC_BITMASK; i++) + if (dev->prio_tc_map[i] != mqprio->prio_tc_map[i]) + return -1; + + return 0; +} + static int taprio_change(struct Qdisc *sch, struct nlattr *opt, struct netlink_ext_ack *extack) { @@ -1065,6 +1085,10 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt, admin = rcu_dereference(q->admin_sched); rcu_read_unlock(); + /* no changes - no new mqprio settings */ + if (!taprio_mqprio_cmp(dev, mqprio)) + mqprio = NULL; + if (mqprio && (oper || admin)) { NL_SET_ERR_MSG(extack, "Changing the traffic mapping of a running schedule is not supported"); err = -ENOTSUPP; @@ -1132,7 +1156,7 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt, mqprio->offset[i]); /* Always use supplied priority mappings */ - for (i = 0; i < TC_BITMASK + 1; i++) + for (i = 0; i <= TC_BITMASK; i++) netdev_set_prio_tc_map(dev, i, mqprio->prio_tc_map[i]); } -- 2.47.2