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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, Maor Gottlieb <maorg@nvidia.com>,
        Mark Bloch <mbloch@nvidia.com>,
        Saeed Mahameed <saeedm@nvidia.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.9 139/255] net/mlx5: Fix deletion of duplicate rules
Date:   Tue, 17 Nov 2020 14:04:39 +0100
Message-Id: <20201117122145.711151547@linuxfoundation.org>
In-Reply-To: <20201117122138.925150709@linuxfoundation.org>
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From: Maor Gottlieb <maorg@nvidia.com>

[ Upstream commit 465e7baab6d93b399344f5868f84c177ab5cd16f ]

When a rule is duplicated, the refcount of the rule is increased so only
the second deletion of the rule should cause destruction of the FTE.
Currently, the FTE will be destroyed in the first deletion of rule since
the modify_mask will be 0.
Fix it and call to destroy FTE only if all the rules (FTE's children)
have been removed.

Fixes: 718ce4d601db ("net/mlx5: Consolidate update FTE for all removal changes")
Signed-off-by: Maor Gottlieb <maorg@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/mellanox/mlx5/core/fs_core.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
index 75fa44eee434d..d4755d61dd740 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
@@ -1994,10 +1994,11 @@ void mlx5_del_flow_rules(struct mlx5_flow_handle *handle)
 	down_write_ref_node(&fte->node, false);
 	for (i = handle->num_rules - 1; i >= 0; i--)
 		tree_remove_node(&handle->rule[i]->node, true);
-	if (fte->modify_mask && fte->dests_size) {
-		modify_fte(fte);
+	if (fte->dests_size) {
+		if (fte->modify_mask)
+			modify_fte(fte);
 		up_write_ref_node(&fte->node, false);
-	} else {
+	} else if (list_empty(&fte->node.children)) {
 		del_hw_fte(&fte->node);
 		/* Avoid double call to del_hw_fte */
 		fte->node.del_hw_func = NULL;
-- 
2.27.0