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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: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
hifive-unleashed-5.1
Petr Machata 2017-10-16 16:26:39 +02:00 committed by David S. Miller
parent f63ce4e54a
commit 4cccb737d2
2 changed files with 20 additions and 30 deletions
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1
drivers/net/ethernet/mellanox/mlxsw/spectrum_ipip.h
View File

@ -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;
};

49
drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
View File

@ -1002,9 +1002,8 @@ err_ol_ipip_lb_create:
}
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);
}
@ -1200,9 +1199,9 @@ 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,
enum mlxsw_sp_ipip_type ipipt,
struct net_device *ol_dev)
mlxsw_sp_ipip_entry_create(struct mlxsw_sp *mlxsw_sp,
enum mlxsw_sp_ipip_type ipipt,
struct net_device *ol_dev)
{
u32 ul_tb_id = mlxsw_sp_ipip_dev_ul_tb_id(ol_dev);
struct mlxsw_sp_router *router = mlxsw_sp->router;
@ -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,
struct mlxsw_sp_ipip_entry *ipip_entry)
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);
}
list_del(&ipip_entry->ipip_list_node);
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);