[PATCH 4.15 026/168] net_sch: red: Fix the new offload indication

[Greg Kroah-Hartman]

4.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Nogah Frankel <nogahf@xxxxxxxxxxxx>


[ Upstream commit 8234af2db3614d78b49e77ef46ea8cfab6586568 ]

Update the offload flag, TCQ_F_OFFLOADED, in each dump call (and ignore
the offloading function return value in relation to this flag).
This is done because a qdisc is being initialized, and therefore offloaded
before being grafted. Since the ability of the driver to offload the qdisc
depends on its location, a qdisc can be offloaded and un-offloaded by graft
calls, that doesn't effect the qdisc itself.

Fixes: 428a68af3a7c ("net: sched: Move to new offload indication in RED"
Signed-off-by: Nogah Frankel <nogahf@xxxxxxxxxxxx>
Reviewed-by: Yuval Mintz <yuvalm@xxxxxxxxxxxx>
Acked-by: Jiri Pirko <jiri@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 net/sched/sch_red.c |   26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

--- a/net/sched/sch_red.c
+++ b/net/sched/sch_red.c
@@ -157,7 +157,6 @@ static int red_offload(struct Qdisc *sch
 		.handle = sch->handle,
 		.parent = sch->parent,
 	};
-	int err;
 
 	if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
 		return -EOPNOTSUPP;
@@ -172,14 +171,7 @@ static int red_offload(struct Qdisc *sch
 		opt.command = TC_RED_DESTROY;
 	}
 
-	err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_RED, &opt);
-
-	if (!err && enable)
-		sch->flags |= TCQ_F_OFFLOADED;
-	else
-		sch->flags &= ~TCQ_F_OFFLOADED;
-
-	return err;
+	return dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_RED, &opt);
 }
 
 static void red_destroy(struct Qdisc *sch)
@@ -294,12 +286,22 @@ static int red_dump_offload_stats(struct
 			.stats.qstats = &sch->qstats,
 		},
 	};
+	int err;
+
+	sch->flags &= ~TCQ_F_OFFLOADED;
 
-	if (!(sch->flags & TCQ_F_OFFLOADED))
+	if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
+		return 0;
+
+	err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_RED,
+					    &hw_stats);
+	if (err == -EOPNOTSUPP)
 		return 0;
 
-	return dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_RED,
-					     &hw_stats);
+	if (!err)
+		sch->flags |= TCQ_F_OFFLOADED;
+
+	return err;
 }
 
 static int red_dump(struct Qdisc *sch, struct sk_buff *skb)