[PATCH AUTOSEL for 4.15 028/124] net_sch: red: Fix the new offload indication

Sasha Levin
2018-03-19T22:36:54Z

From: Nogah Frankel <nogahf@mellanox.com>

[ 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@mellanox.com>
Reviewed-by: Yuval Mintz <yuvalm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
net/sched/sch_red.c | 26 ++++++++++++++------------
1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c
index f0747eb87dc4..cca57e93a810 100644
--- a/net/sched/sch_red.c
+++ b/net/sched/sch_red.c
@@ -157,7 +157,6 @@ static int red_offload(struct Qdisc *sch, bool enable)
.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, bool enable)
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 Qdisc *sch, struct tc_red_qopt *opt)
.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)
--
2.14.1