net_sch: red: Fix the new offload indication

BugLink: http://bugs.launchpad.net/bugs/1763366
[ 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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c
index f0747eb87dc4784e67e0b5872dcf37effaaa4060..cca57e93a8109ad9ef9ef96a6faa568d55d9d88b 100644 (file)
--- 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)