[PATCH net] IB/IPoIB: ndo_set_rx_mode_async conversion

[PATCH net] IB/IPoIB: ndo_set_rx_mode_async conversion

[Dragos Tatulea]

The commit in the fixes tag added a warning for devices
that are netdev ops locked that they should be converted
to .ndo_set_rx_mode_async. IPoIB for mlx5 is such a
driver which was missed during the conversion because the
flow is more complex:
- mlx5 part of IPoIB device was converted to ops-lock in commit [1].
- ipoib_intf_init() then overrides netdev_ops with
  ipoib_netdev_ops_{pf,vf}, which still wired ndo_set_rx_mode to the
  legacy sync path -- tripping the new warning on every probe.

So now we have the following splat:
  netdevice: ib0 (uninitialized): ops-locked drivers should use ndo_set_rx_mode_async
  WARNING: net/core/dev.c:11366 at register_netdevice+0x83c/0x21d0
  ...
  register_netdev+0x1f/0x40
  ipoib_add_one+0x35c/0x880 [ib_ipoib]

This patch implements .ndo_set_rx_mode_async but it simply schedules the
multicast restart task like before. This is done to maintain the
assumption that this task and others [2] must run on the same order
workqueue to avoid racing with themselves. The race between
ipoib_mcast_join_task() and ipoib_mcast_restart_task() would be the most
obvious example.

[1] 8f7b00307bf1, "net/mlx5e: Convert mlx5 netdevs to instance locking")
[2] ipoib_mcast_join_task, ipoib_mcast_restart_task,
    ipoib_mcast_carrier_on_task, ipoib_reap_ah, ipoib_reap_neigh

Fixes: 3cbd22938877 ("net: warn ops-locked drivers still using ndo_set_rx_mode")
Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
Reviewed-by: Cosmin Ratiu <cratiu@nvidia.com>
---
 drivers/infiniband/ulp/ipoib/ipoib_main.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index 402671567736..3e1e1e861739 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -1297,7 +1297,9 @@ static int ipoib_hard_header(struct sk_buff *skb,
 	return IPOIB_HARD_LEN;
 }
 
-static void ipoib_set_mcast_list(struct net_device *dev)
+static void ipoib_set_rx_mode_async(struct net_device *dev,
+				    struct netdev_hw_addr_list *uc,
+				    struct netdev_hw_addr_list *mc)
 {
 	struct ipoib_dev_priv *priv = ipoib_priv(dev);
 
@@ -2160,7 +2162,7 @@ static const struct net_device_ops ipoib_netdev_ops_pf = {
 	.ndo_fix_features	 = ipoib_fix_features,
 	.ndo_start_xmit		 = ipoib_start_xmit,
 	.ndo_tx_timeout		 = ipoib_timeout,
-	.ndo_set_rx_mode	 = ipoib_set_mcast_list,
+	.ndo_set_rx_mode_async	 = ipoib_set_rx_mode_async,
 	.ndo_get_iflink		 = ipoib_get_iflink,
 	.ndo_set_vf_link_state	 = ipoib_set_vf_link_state,
 	.ndo_get_vf_config	 = ipoib_get_vf_config,
@@ -2183,7 +2185,7 @@ static const struct net_device_ops ipoib_netdev_ops_vf = {
 	.ndo_fix_features	 = ipoib_fix_features,
 	.ndo_start_xmit	 	 = ipoib_start_xmit,
 	.ndo_tx_timeout		 = ipoib_timeout,
-	.ndo_set_rx_mode	 = ipoib_set_mcast_list,
+	.ndo_set_rx_mode_async	 = ipoib_set_rx_mode_async,
 	.ndo_get_iflink		 = ipoib_get_iflink,
 	.ndo_get_stats64	 = ipoib_get_stats,
 	.ndo_eth_ioctl		 = ipoib_ioctl,
-- 
2.54.0