[patch net 0/3] mlxsw: Router fixes

[patch net 0/3] mlxsw: Router fixes

[Jiri Pirko]

From: Jiri Pirko <jiri@mellanox.com>

Ido says:

First two patches ensure we remove from the device's table neighbours
that are considered to be dead by the neighbour core.

The last patch removes nexthop groups from the device when they are no
longer valid.

Ido Schimmel (3):
  neigh: Send netevent after marking neigh as dead
  mlxsw: spectrum_router: Don't reflect dead neighs
  mlxsw: spectrum_router: Correctly remove nexthop groups

 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 13 +++++++++----
 net/core/neighbour.c                                  |  1 +
 2 files changed, 10 insertions(+), 4 deletions(-)

-- 
2.7.4

[patch net 1/3] neigh: Send netevent after marking neigh as dead

[Jiri Pirko]

From: Ido Schimmel <idosch@mellanox.com>

neigh_cleanup_and_release() is always called after marking a neighbour
as dead, but it only notifies user space and not in-kernel listeners of
the netevent notification chain.

This can cause multiple problems. In my specific use case, it causes the
listener (a switch driver capable of L3 offloads) to believe a neighbour
entry is still valid, and is thus erroneously kept in the device's
table.

Fix that by sending a netevent after marking the neighbour as dead.

Fixes: a6bf9e933daf ("mlxsw: spectrum_router: Offload neighbours based on NUD state change")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
---
 net/core/neighbour.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 782dd86..7bb12e0 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -100,6 +100,7 @@ static void neigh_cleanup_and_release(struct neighbour *neigh)
 		neigh->parms->neigh_cleanup(neigh);
 
 	__neigh_notify(neigh, RTM_DELNEIGH, 0);
+	call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, neigh);
 	neigh_release(neigh);
 }
 
-- 
2.7.4

[patch net 2/3] mlxsw: spectrum_router: Don't reflect dead neighs

[Jiri Pirko]

From: Ido Schimmel <idosch@mellanox.com>

When a neighbour is considered to be dead, we should remove it from the
device's table regardless of its NUD state.

Without this patch, after setting a port to be administratively down we
get the following errors when we periodically try to update the kernel
about neighbours activity:

[  461.947268] mlxsw_spectrum 0000:03:00.0 sw1p3: Failed to find
matching neighbour for IP=192.168.100.2

Fixes: a6bf9e933daf ("mlxsw: spectrum_router: Offload neighbours based on NUD state change")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
index 53126bf..a0f9742 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -942,7 +942,7 @@ static void mlxsw_sp_router_neigh_update_hw(struct work_struct *work)
 	char rauht_pl[MLXSW_REG_RAUHT_LEN];
 	struct net_device *dev;
 	bool entry_connected;
-	u8 nud_state;
+	u8 nud_state, dead;
 	bool updating;
 	bool removing;
 	bool adding;
@@ -953,10 +953,11 @@ static void mlxsw_sp_router_neigh_update_hw(struct work_struct *work)
 	dip = ntohl(*((__be32 *) n->primary_key));
 	memcpy(neigh_entry->ha, n->ha, sizeof(neigh_entry->ha));
 	nud_state = n->nud_state;
+	dead = n->dead;
 	dev = n->dev;
 	read_unlock_bh(&n->lock);
 
-	entry_connected = nud_state & NUD_VALID;
+	entry_connected = nud_state & NUD_VALID && !dead;
 	adding = (!neigh_entry->offloaded) && entry_connected;
 	updating = neigh_entry->offloaded && entry_connected;
 	removing = neigh_entry->offloaded && !entry_connected;
@@ -1351,7 +1352,7 @@ static int mlxsw_sp_nexthop_init(struct mlxsw_sp *mlxsw_sp,
 	struct mlxsw_sp_neigh_entry *neigh_entry;
 	struct net_device *dev = fib_nh->nh_dev;
 	struct neighbour *n;
-	u8 nud_state;
+	u8 nud_state, dead;
 
 	/* Take a reference of neigh here ensuring that neigh would
 	 * not be detructed before the nexthop entry is finished.
@@ -1383,8 +1384,9 @@ static int mlxsw_sp_nexthop_init(struct mlxsw_sp *mlxsw_sp,
 	list_add_tail(&nh->neigh_list_node, &neigh_entry->nexthop_list);
 	read_lock_bh(&n->lock);
 	nud_state = n->nud_state;
+	dead = n->dead;
 	read_unlock_bh(&n->lock);
-	__mlxsw_sp_nexthop_neigh_update(nh, !(nud_state & NUD_VALID));
+	__mlxsw_sp_nexthop_neigh_update(nh, !(nud_state & NUD_VALID && !dead));
 
 	return 0;
 }
-- 
2.7.4

[patch net 3/3] mlxsw: spectrum_router: Correctly remove nexthop groups

[Jiri Pirko]

From: Ido Schimmel <idosch@mellanox.com>

At the end of the nexthop initialization process we determine whether
the nexthop should be offloaded or not based on the NUD state of the
neighbour representing it. After all the nexthops were initialized we
refresh the nexthop group and potentially offload it to the device, in
case some of the nexthops were resolved.

Make the destruction of a nexthop group symmetric with its creation by
marking all nexthops as invalid and then refresh the nexthop group to
make sure it was removed from the device's tables.

Fixes: b2157149b0b0 ("mlxsw: spectrum_router: Add the nexthop neigh activity update")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
index a0f9742..01d0efa 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -1396,6 +1396,7 @@ static void mlxsw_sp_nexthop_fini(struct mlxsw_sp *mlxsw_sp,
 {
 	struct mlxsw_sp_neigh_entry *neigh_entry = nh->neigh_entry;
 
+	__mlxsw_sp_nexthop_neigh_update(nh, true);
 	list_del(&nh->neigh_list_node);
 
 	/* If that is the last nexthop connected to that neigh, remove from
@@ -1454,6 +1455,8 @@ mlxsw_sp_nexthop_group_destroy(struct mlxsw_sp *mlxsw_sp,
 		nh = &nh_grp->nexthops[i];
 		mlxsw_sp_nexthop_fini(mlxsw_sp, nh);
 	}
+	mlxsw_sp_nexthop_group_refresh(mlxsw_sp, nh_grp);
+	WARN_ON_ONCE(nh_grp->adj_index_valid);
 	kfree(nh_grp);
 }
 
-- 
2.7.4

Re: [patch net 0/3] mlxsw: Router fixes

[David Miller]

From: Jiri Pirko <jiri@resnulli.us>
Date: Fri, 23 Dec 2016 09:32:47 +0100

> From: Jiri Pirko <jiri@mellanox.com>
> 
> Ido says:
> 
> First two patches ensure we remove from the device's table neighbours
> that are considered to be dead by the neighbour core.
> 
> The last patch removes nexthop groups from the device when they are no
> longer valid.

Series applied, thank you.