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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Ido Schimmel <idosch@mellanox.com>,
        Alexander Petrovskiy <alexpe@mellanox.com>,
        Jiri Pirko <jiri@mellanox.com>,
        "David S. Miller" <davem@davemloft.net>
Subject: [PATCH 4.15 073/122] mlxsw: spectrum_router: Do not unconditionally clear route offload indication
Date:   Wed,  7 Mar 2018 11:38:05 -0800
Message-Id: <20180307191739.900424076@linuxfoundation.org>
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4.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ido Schimmel <idosch@mellanox.com>


[ Upstream commit d1c95af366961101819f07e3c64d44f3be7f0367 ]

When mlxsw replaces (or deletes) a route it removes the offload
indication from the replaced route. This is problematic for IPv4 routes,
as the offload indication is stored in the fib_info which is usually
shared between multiple routes.

Instead of unconditionally clearing the offload indication, only clear
it if no other route is using the fib_info.

Fixes: 3984d1a89fe7 ("mlxsw: spectrum_router: Provide offload indication using nexthop flags")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reported-by: Alexander Petrovskiy <alexpe@mellanox.com>
Tested-by: Alexander Petrovskiy <alexpe@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -3765,6 +3765,9 @@ mlxsw_sp_fib4_entry_offload_unset(struct
 	struct mlxsw_sp_nexthop_group *nh_grp = fib_entry->nh_group;
 	int i;
 
+	if (!list_is_singular(&nh_grp->fib_list))
+		return;
+
 	for (i = 0; i < nh_grp->count; i++) {
 		struct mlxsw_sp_nexthop *nh = &nh_grp->nexthops[i];