5.4-stable review patch. If anyone has any objections, please let me know.
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From: Cong Wang xiyou.wangcong@gmail.com
commit 342debc12183b51773b3345ba267e9263bdfaaef upstream.
After making all ->qlen_notify() callbacks idempotent, now it is safe to remove the check of qlen!=0 from both fq_codel_dequeue() and codel_qdisc_dequeue().
Reported-by: Gerrard Tai gerrard.tai@starlabs.sg Fixes: 4b549a2ef4be ("fq_codel: Fair Queue Codel AQM") Fixes: 76e3cc126bb2 ("codel: Controlled Delay AQM") Signed-off-by: Cong Wang xiyou.wangcong@gmail.com Reviewed-by: Simon Horman horms@kernel.org Link: https://patch.msgid.link/20250403211636.166257-1-xiyou.wangcong@gmail.com Acked-by: Jamal Hadi Salim jhs@mojatatu.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Siddh Raman Pant siddh.raman.pant@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/sched/sch_codel.c | 5 +---- net/sched/sch_fq_codel.c | 6 ++---- 2 files changed, 3 insertions(+), 8 deletions(-)
--- a/net/sched/sch_codel.c +++ b/net/sched/sch_codel.c @@ -95,10 +95,7 @@ static struct sk_buff *codel_qdisc_deque &q->stats, qdisc_pkt_len, codel_get_enqueue_time, drop_func, dequeue_func);
- /* We cant call qdisc_tree_reduce_backlog() if our qlen is 0, - * or HTB crashes. Defer it for next round. - */ - if (q->stats.drop_count && sch->q.qlen) { + if (q->stats.drop_count) { qdisc_tree_reduce_backlog(sch, q->stats.drop_count, q->stats.drop_len); q->stats.drop_count = 0; q->stats.drop_len = 0; --- a/net/sched/sch_fq_codel.c +++ b/net/sched/sch_fq_codel.c @@ -315,10 +315,8 @@ begin: } qdisc_bstats_update(sch, skb); flow->deficit -= qdisc_pkt_len(skb); - /* We cant call qdisc_tree_reduce_backlog() if our qlen is 0, - * or HTB crashes. Defer it for next round. - */ - if (q->cstats.drop_count && sch->q.qlen) { + + if (q->cstats.drop_count) { qdisc_tree_reduce_backlog(sch, q->cstats.drop_count, q->cstats.drop_len); q->cstats.drop_count = 0;