[PATCH net-next] ipv6: Simplify rt6_qualify_for_ecmp

[PATCH net-next] ipv6: Simplify rt6_qualify_for_ecmp

[David Ahern]

From: David Ahern <dsahern@gmail.com>

After commit c7a1ce397ada ("ipv6: Change addrconf_f6i_alloc to use
ip6_route_info_create"), the gateway is no longer filled in for fib6_nh
structs in a prefix route. Accordingly, the RTF_ADDRCONF flag check can
be dropped from the 'rt6_qualify_for_ecmp'.

Further, RTF_DYNAMIC is only set in rt6_info instances, so it can be
removed from the check as well.

This reduces rt6_qualify_for_ecmp and the mlxsw version to just checking
if the nexthop has a gateway which is the real indication of whether
entries can be coalesced into a multipath route.

Signed-off-by: David Ahern <dsahern@gmail.com>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 2 +-
 include/net/ip6_route.h                               | 3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
index 64498c9f55ab..779f5a7c85f2 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -4928,7 +4928,7 @@ static void mlxsw_sp_rt6_destroy(struct mlxsw_sp_rt6 *mlxsw_sp_rt6)
 static bool mlxsw_sp_fib6_rt_can_mp(const struct fib6_info *rt)
 {
 	/* RTF_CACHE routes are ignored */
-	return !(rt->fib6_flags & RTF_ADDRCONF) && rt->fib6_nh.fib_nh_gw_family;
+	return rt->fib6_nh.fib_nh_gw_family;
 }
 
 static struct fib6_info *
diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index 46bbd8ff9cc6..518d97fbe074 100644
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -68,8 +68,7 @@ static inline bool rt6_need_strict(const struct in6_addr *daddr)
 
 static inline bool rt6_qualify_for_ecmp(const struct fib6_info *f6i)
 {
-	return !(f6i->fib6_flags & (RTF_ADDRCONF|RTF_DYNAMIC)) &&
-		f6i->fib6_nh.fib_nh_gw_family;
+	return f6i->fib6_nh.fib_nh_gw_family;
 }
 
 void ip6_route_input(struct sk_buff *skb);
-- 
2.11.0

Re: [PATCH net-next] ipv6: Simplify rt6_qualify_for_ecmp

[Ido Schimmel]

On Sun, Apr 21, 2019 at 08:49:01AM -0700, David Ahern wrote:
> From: David Ahern <dsahern@gmail.com>
> 
> After commit c7a1ce397ada ("ipv6: Change addrconf_f6i_alloc to use
> ip6_route_info_create"), the gateway is no longer filled in for fib6_nh
> structs in a prefix route. Accordingly, the RTF_ADDRCONF flag check can
> be dropped from the 'rt6_qualify_for_ecmp'.
> 
> Further, RTF_DYNAMIC is only set in rt6_info instances, so it can be
> removed from the check as well.
> 
> This reduces rt6_qualify_for_ecmp and the mlxsw version to just checking
> if the nexthop has a gateway which is the real indication of whether
> entries can be coalesced into a multipath route.
> 
> Signed-off-by: David Ahern <dsahern@gmail.com>

Reviewed-by: Ido Schimmel <idosch@mellanox.com>

Re: [PATCH net-next] ipv6: Simplify rt6_qualify_for_ecmp

[David Miller]

From: David Ahern <dsahern@kernel.org>
Date: Sun, 21 Apr 2019 08:49:01 -0700

> From: David Ahern <dsahern@gmail.com>
> 
> After commit c7a1ce397ada ("ipv6: Change addrconf_f6i_alloc to use
> ip6_route_info_create"), the gateway is no longer filled in for fib6_nh
> structs in a prefix route. Accordingly, the RTF_ADDRCONF flag check can
> be dropped from the 'rt6_qualify_for_ecmp'.
> 
> Further, RTF_DYNAMIC is only set in rt6_info instances, so it can be
> removed from the check as well.
> 
> This reduces rt6_qualify_for_ecmp and the mlxsw version to just checking
> if the nexthop has a gateway which is the real indication of whether
> entries can be coalesced into a multipath route.
> 
> Signed-off-by: David Ahern <dsahern@gmail.com>

Applied, thanks David.