[dpdk-dev] [PATCH] net/mlx4: fix drop flow resources not freed

[Moti Haimovsky]

This patch fixes the drop-flow resources not being freed when the device
is closed.
Issue can be observed when running testpmd and adding the following rule
more than once:
"flow create 0 ingress pattern eth / end actions drop / end"
then either exiting testpmd using the "quit" command or by running the
command: "port stop all"

Fixes: d3a7e09234e4 ("net/mlx4: allocate drop flow resources on demand")
Cc: sta...@dpdk.org

Signed-off-by: Moti Haimovsky <mo...@mellanox.com>
---
 drivers/net/mlx4/mlx4_flow.c | 33 +++++++++++++++++++++++++++++----
 1 file changed, 29 insertions(+), 4 deletions(-)

diff --git a/drivers/net/mlx4/mlx4_flow.c b/drivers/net/mlx4/mlx4_flow.c
index fb84060..9e6d8dc 100644
--- a/drivers/net/mlx4/mlx4_flow.c
+++ b/drivers/net/mlx4/mlx4_flow.c
@@ -895,6 +895,30 @@ struct mlx4_drop {
 }
 
 /**
+ * Return the number of active drop flow rules currently present
+ * in the list of flows.
+ * Active flow is defined as a flow associated with an ibv_flow.
+ *
+ * @param priv
+ *   Pointer to private structure.
+ *
+ * @return
+ *   Number of active drop-flows.
+ */
+static int
+drop_refcnt(struct priv *priv)
+{
+       struct rte_flow *flow;
+       int count = 0;
+
+       LIST_FOREACH(flow, &priv->flows, next) {
+               if (flow->drop && flow->ibv_flow)
+                       count++;
+       }
+       return count;
+}
+
+/**
  * Get a drop flow rule resources instance.
  *
  * @param priv
@@ -910,9 +934,8 @@ struct mlx4_drop {
        struct mlx4_drop *drop = priv->drop;
 
        if (drop) {
-               assert(drop->refcnt);
+               assert(drop_refcnt(priv));
                assert(drop->priv == priv);
-               ++drop->refcnt;
                return drop;
        }
        drop = rte_malloc(__func__, sizeof(*drop), 0);
@@ -955,8 +978,10 @@ struct mlx4_drop {
 static void
 mlx4_drop_put(struct mlx4_drop *drop)
 {
-       assert(drop->refcnt);
-       if (--drop->refcnt)
+       int refcnt = drop_refcnt(drop->priv);
+
+       assert(refcnt >= 0);
+       if (refcnt)
                return;
        drop->priv->drop = NULL;
        claim_zero(ibv_destroy_qp(drop->qp));
-- 
1.8.3.1