From: Ivan Khoronzhuk ivan.khoronzhuk@linaro.org
[ 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 olteanv@gmail.com Tested-by: Vladimir Oltean olteanv@gmail.com Acked-by: Vinicius Costa Gomes vinicius.gomes@intel.com Signed-off-by: Ivan Khoronzhuk ivan.khoronzhuk@linaro.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/sched/sch_taprio.c | 28 ++++++++++++++++++++++++++-- 1 file changed, 26 insertions(+), 2 deletions(-)
--- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -842,7 +842,7 @@ static int taprio_parse_mqprio_opt(struc }
/* 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_s } }
+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 *s 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 *s 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]); }