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Commit 4cccb737 authored by Petr Machata's avatar Petr Machata Committed by David S. Miller
Browse files

mlxsw: spectrum: Drop refcounting of IPIP entries 



Formerly, IPIP entries were created lazily by next hops that referenced
an offloadable IP-in-IP netdevice. However now that they are created
eagerly as a reaction to events on such netdevices, the reference
counting is useless. Hence drop it.

The routes whose next hops reference an offloaded IP-in-IP netdevice
actually linger around a bit after their device is unregistered.
However, mlxsw_sp_ipip_entry_destroy() also destroys the backing
loopback, and mlxsw_sp_rif_destroy() transitively (via
mlxsw_sp_nexthop_rif_gone_sync()) calls mlxsw_sp_nexthop_ipip_fini(),
which unlinks the IPIP entry from a next hop. Thus no dangling pointers
are left behind for the brief window after netdevice is gone, but routes
not yet.

Signed-off-by: default avatarPetr Machata <petrm@mellanox.com>
Reviewed-by: default avatarIdo Schimmel <idosch@mellanox.com>
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f63ce4e5

drivers/net/ethernet/mellanox/mlxsw/spectrum_ipip.h

+0 −1
Original line number Diff line number Diff line
@@ -47,7 +47,6 @@ struct mlxsw_sp_ipip_entry { 
	enum mlxsw_sp_ipip_type ipipt;

	struct net_device *ol_dev; /* Overlay. */

	struct mlxsw_sp_rif_ipip_lb *ol_lb;

	unsigned int ref_count; /* Number of next hops using the tunnel. */

	struct mlxsw_sp_fib_entry *decap_fib_entry;

	struct list_head ipip_list_node;

};

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c

+20 −29
Original line number Diff line number Diff line
@@ -1002,9 +1002,8 @@ mlxsw_sp_ipip_entry_alloc(struct mlxsw_sp *mlxsw_sp, 
}



static void

mlxsw_sp_ipip_entry_destroy(struct mlxsw_sp_ipip_entry *ipip_entry)

mlxsw_sp_ipip_entry_dealloc(struct mlxsw_sp_ipip_entry *ipip_entry)

{

	WARN_ON(ipip_entry->ref_count > 0);

	mlxsw_sp_rif_destroy(&ipip_entry->ol_lb->common);

	kfree(ipip_entry);

}
@@ -1200,7 +1199,7 @@ mlxsw_sp_ipip_entry_find_decap(struct mlxsw_sp *mlxsw_sp, 
}



static struct mlxsw_sp_ipip_entry *

mlxsw_sp_ipip_entry_get(struct mlxsw_sp *mlxsw_sp,

mlxsw_sp_ipip_entry_create(struct mlxsw_sp *mlxsw_sp,

			   enum mlxsw_sp_ipip_type ipipt,

			   struct net_device *ol_dev)

{
@@ -1210,15 +1209,12 @@ mlxsw_sp_ipip_entry_get(struct mlxsw_sp *mlxsw_sp, 
	enum mlxsw_sp_l3proto ul_proto;

	union mlxsw_sp_l3addr saddr;



	/* The configuration where several tunnels have the same local address

	 * in the same underlay table needs special treatment in the HW. That is

	 * currently not implemented in the driver.

	 */

	list_for_each_entry(ipip_entry, &mlxsw_sp->router->ipip_list,

			    ipip_list_node) {

		if (ipip_entry->ol_dev == ol_dev)

			goto inc_ref_count;



		/* The configuration where several tunnels have the same local

		 * address in the same underlay table needs special treatment in

		 * the HW. That is currently not implemented in the driver.

		 */

		ul_proto = router->ipip_ops_arr[ipip_entry->ipipt]->ul_proto;

		saddr = mlxsw_sp_ipip_netdev_saddr(ul_proto, ol_dev);

		if (mlxsw_sp_ipip_entry_saddr_matches(mlxsw_sp, ul_proto, saddr,
@@ -1233,19 +1229,15 @@ mlxsw_sp_ipip_entry_get(struct mlxsw_sp *mlxsw_sp, 
	list_add_tail(&ipip_entry->ipip_list_node,

		      &mlxsw_sp->router->ipip_list);



inc_ref_count:

	++ipip_entry->ref_count;

	return ipip_entry;

}



static void

mlxsw_sp_ipip_entry_put(struct mlxsw_sp *mlxsw_sp,

mlxsw_sp_ipip_entry_destroy(struct mlxsw_sp *mlxsw_sp,

			    struct mlxsw_sp_ipip_entry *ipip_entry)

{

	if (--ipip_entry->ref_count == 0) {

	list_del(&ipip_entry->ipip_list_node);

		mlxsw_sp_ipip_entry_destroy(ipip_entry);

	}

	mlxsw_sp_ipip_entry_dealloc(ipip_entry);

}



static bool
@@ -1338,7 +1330,8 @@ static int mlxsw_sp_netdevice_ipip_reg_event(struct mlxsw_sp *mlxsw_sp, 
						     MLXSW_SP_L3_PROTO_IPV4) ||

	    router->ipip_ops_arr[ipipt]->can_offload(mlxsw_sp, ol_dev,

						     MLXSW_SP_L3_PROTO_IPV6)) {

		ipip_entry = mlxsw_sp_ipip_entry_get(mlxsw_sp, ipipt, ol_dev);

		ipip_entry = mlxsw_sp_ipip_entry_create(mlxsw_sp, ipipt,

							ol_dev);

		if (IS_ERR(ipip_entry))

			return PTR_ERR(ipip_entry);

	}
@@ -1353,7 +1346,7 @@ static void mlxsw_sp_netdevice_ipip_unreg_event(struct mlxsw_sp *mlxsw_sp, 


	ipip_entry = mlxsw_sp_ipip_entry_find_by_ol_dev(mlxsw_sp, ol_dev);

	if (ipip_entry)

		mlxsw_sp_ipip_entry_put(mlxsw_sp, ipip_entry);

		mlxsw_sp_ipip_entry_destroy(mlxsw_sp, ipip_entry);

}



static int mlxsw_sp_netdevice_ipip_up_event(struct mlxsw_sp *mlxsw_sp,
@@ -2939,16 +2932,15 @@ static void mlxsw_sp_nexthop_neigh_fini(struct mlxsw_sp *mlxsw_sp, 
}



static int mlxsw_sp_nexthop_ipip_init(struct mlxsw_sp *mlxsw_sp,

				      enum mlxsw_sp_ipip_type ipipt,

				      struct mlxsw_sp_nexthop *nh,

				      struct net_device *ol_dev)

{

	if (!nh->nh_grp->gateway || nh->ipip_entry)

		return 0;



	nh->ipip_entry = mlxsw_sp_ipip_entry_get(mlxsw_sp, ipipt, ol_dev);

	if (IS_ERR(nh->ipip_entry))

		return PTR_ERR(nh->ipip_entry);

	nh->ipip_entry = mlxsw_sp_ipip_entry_find_by_ol_dev(mlxsw_sp, ol_dev);

	if (!nh->ipip_entry)

		return -ENOENT;



	__mlxsw_sp_nexthop_neigh_update(nh, false);

	return 0;
@@ -2963,7 +2955,6 @@ static void mlxsw_sp_nexthop_ipip_fini(struct mlxsw_sp *mlxsw_sp, 
		return;



	__mlxsw_sp_nexthop_neigh_update(nh, true);

	mlxsw_sp_ipip_entry_put(mlxsw_sp, ipip_entry);

	nh->ipip_entry = NULL;

}
@@ -3007,7 +2998,7 @@ static int mlxsw_sp_nexthop4_type_init(struct mlxsw_sp *mlxsw_sp, 
	    router->ipip_ops_arr[ipipt]->can_offload(mlxsw_sp, dev,

						     MLXSW_SP_L3_PROTO_IPV4)) {

		nh->type = MLXSW_SP_NEXTHOP_TYPE_IPIP;

		err = mlxsw_sp_nexthop_ipip_init(mlxsw_sp, ipipt, nh, dev);

		err = mlxsw_sp_nexthop_ipip_init(mlxsw_sp, nh, dev);

		if (err)

			return err;

		mlxsw_sp_nexthop_rif_init(nh, &nh->ipip_entry->ol_lb->common);
@@ -4269,7 +4260,7 @@ static int mlxsw_sp_nexthop6_type_init(struct mlxsw_sp *mlxsw_sp, 
	    router->ipip_ops_arr[ipipt]->can_offload(mlxsw_sp, dev,

						     MLXSW_SP_L3_PROTO_IPV6)) {

		nh->type = MLXSW_SP_NEXTHOP_TYPE_IPIP;

		err = mlxsw_sp_nexthop_ipip_init(mlxsw_sp, ipipt, nh, dev);

		err = mlxsw_sp_nexthop_ipip_init(mlxsw_sp, nh, dev);

		if (err)

			return err;

		mlxsw_sp_nexthop_rif_init(nh, &nh->ipip_entry->ol_lb->common);