From: Paolo Abeni <pabeni@redhat.com>
Date: Wed, 10 Apr 2019 14:32:37 +0200
Subject: net: caif: avoid using qdisc_qlen()
Patch-mainline: v5.2-rc1
Git-commit: b0a231a26d56265521abbb6db1748accd6bb036a
References: bsc#1183405
Such helper does not cope correctly with NOLOCK qdiscs.
In the following patches we will move back qlen to per CPU
values for such qdiscs, so qdisc_qlen_sum() is not an option,
too.
Instead, use qlen only for lock qdiscs, and always set
flow off for NOLOCK qdiscs with a not empty tx queue.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Michal Kubecek <mkubecek@suse.cz>
---
net/caif/caif_dev.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
--- a/net/caif/caif_dev.c
+++ b/net/caif/caif_dev.c
@@ -184,15 +184,19 @@ static int transmit(struct cflayer *layer, struct cfpkt *pkt)
goto noxoff;
if (likely(!netif_queue_stopped(caifd->netdev))) {
+ struct Qdisc *sch;
+
/* If we run with a TX queue, check if the queue is too long*/
txq = netdev_get_tx_queue(skb->dev, 0);
- qlen = qdisc_qlen(rcu_dereference_bh(txq->qdisc));
-
- if (likely(qlen == 0))
+ sch = rcu_dereference_bh(txq->qdisc);
+ if (likely(qdisc_is_empty(sch)))
goto noxoff;
+ /* can check for explicit qdisc len value only !NOLOCK,
+ * always set flow off otherwise
+ */
high = (caifd->netdev->tx_queue_len * q_high) / 100;
- if (likely(qlen < high))
+ if (!(sch->flags & TCQ_F_NOLOCK) && likely(sch->q.qlen < high))
goto noxoff;
}