From 98766add2d55194be9f7d88628a058ceab3b06e6 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Mon, 7 Aug 2023 22:33:16 +0300 Subject: [PATCH] net/sched: taprio: try again to report q->qdiscs[] to qdisc_leaf() This is another stab at commit 1461d212ab27 ("net/sched: taprio: make qdisc_leaf() see the per-netdev-queue pfifo child qdiscs"), later reverted in commit af7b29b1deaa ("Revert "net/sched: taprio: make qdisc_leaf() see the per-netdev-queue pfifo child qdiscs""). I believe that the problems that caused the revert were fixed, and thus, this change is identical to the original patch. Its purpose is to properly reject attaching a software taprio child qdisc to a software taprio parent. Because unoffloaded taprio currently reports itself (the root Qdisc) as the return value from qdisc_leaf(), then the process of attaching another taprio as child to a Qdisc class of the root will just result in a Qdisc_ops :: change() call for the root. Whereas that's not we want. We want Qdisc_ops :: init() to be called for the taprio child, in order to give the taprio child a chance to check whether its sch->parent is TC_H_ROOT or not (and reject this configuration). Signed-off-by: Vladimir Oltean Link: https://lore.kernel.org/r/20230807193324.4128292-4-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski --- net/sched/sch_taprio.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index 7c1fc3dc3e55f..831e6f3fda2a0 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -2453,12 +2453,14 @@ start_error: static struct Qdisc *taprio_leaf(struct Qdisc *sch, unsigned long cl) { - struct netdev_queue *dev_queue = taprio_queue_get(sch, cl); + struct taprio_sched *q = qdisc_priv(sch); + struct net_device *dev = qdisc_dev(sch); + unsigned int ntx = cl - 1; - if (!dev_queue) + if (ntx >= dev->num_tx_queues) return NULL; - return rtnl_dereference(dev_queue->qdisc_sleeping); + return q->qdiscs[ntx]; } static unsigned long taprio_find(struct Qdisc *sch, u32 classid) -- 2.30.2