[PATCH v3 2/4] net/axgbe: fix Rx queue leak on descriptor init failure

[Stephen Hemminger <stephen@networkplumber.org>]

When wrapper_rx_desc_init() fails to allocate an mbuf for queue i,
only queue i is released. Queues 0 through i-1 have already been
fully populated with mbufs assigned to sw_ring entries and
programmed into hardware descriptors, but are never cleaned up.
This leaks all mbufs from the previously initialized queues.

Fix by allocating all needed buffers ahead of time with
rte_pktmbuf_alloc_bulk().

Fixes: 7c4158a5b592 ("net/axgbe: add DMA programming and start/stop")
Cc: stable@dpdk.org

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 drivers/net/axgbe/axgbe_dev.c | 43 +++++++++++++++++++----------------
 1 file changed, 24 insertions(+), 19 deletions(-)

diff --git a/drivers/net/axgbe/axgbe_dev.c b/drivers/net/axgbe/axgbe_dev.c
index 482d3d8062..10ddecf968 100644
--- a/drivers/net/axgbe/axgbe_dev.c
+++ b/drivers/net/axgbe/axgbe_dev.c
@@ -1011,13 +1011,29 @@ static void wrapper_tx_desc_init(struct axgbe_port *pdata)
 
 static int wrapper_rx_desc_init(struct axgbe_port *pdata)
 {
-	struct axgbe_rx_queue *rxq;
-	struct rte_mbuf *mbuf;
 	volatile union axgbe_rx_desc *desc;
-	unsigned int i, j;
+	unsigned int i, j, k;
 
+	/* Allocate all receive buffers up front. */
 	for (i = 0; i < pdata->eth_dev->data->nb_rx_queues; i++) {
-		rxq = pdata->eth_dev->data->rx_queues[i];
+		struct axgbe_rx_queue *rxq = pdata->eth_dev->data->rx_queues[i];
+
+		if (rte_pktmbuf_alloc_bulk(rxq->mb_pool, rxq->sw_ring, rxq->nb_desc) != 0) {
+			PMD_DRV_LOG_LINE(ERR, "RX mbuf alloc failed queue_id = %u, nb_desc = %u",
+					 i, rxq->nb_desc);
+			for (k = 0; k < i; k++) {
+				rxq = pdata->eth_dev->data->rx_queues[k];
+
+				rte_pktmbuf_free_bulk(rxq->sw_ring, rxq->nb_desc);
+				memset(rxq->sw_ring, 0, rxq->nb_desc * sizeof(*rxq->sw_ring));
+			}
+			return -ENOMEM;
+		}
+	}
+
+	/* Buffers are available; publish them to the hardware */
+	for (i = 0; i < pdata->eth_dev->data->nb_rx_queues; i++) {
+		struct axgbe_rx_queue *rxq = pdata->eth_dev->data->rx_queues[i];
 
 		/* Initialize software ring entries */
 		rxq->mbuf_alloc = 0;
@@ -1026,22 +1042,11 @@ static int wrapper_rx_desc_init(struct axgbe_port *pdata)
 		desc = AXGBE_GET_DESC_PT(rxq, 0);
 
 		for (j = 0; j < rxq->nb_desc; j++) {
-			mbuf = rte_mbuf_raw_alloc(rxq->mb_pool);
-			if (mbuf == NULL) {
-				PMD_DRV_LOG_LINE(ERR, "RX mbuf alloc failed queue_id = %u, idx = %d",
-					    (unsigned int)rxq->queue_id, j);
-				axgbe_dev_rx_queue_release(pdata->eth_dev, i);
-				return -ENOMEM;
-			}
-			rxq->sw_ring[j] = mbuf;
-			/* Mbuf populate */
-			mbuf->next = NULL;
-			mbuf->data_off = RTE_PKTMBUF_HEADROOM;
-			mbuf->nb_segs = 1;
+			struct rte_mbuf *mbuf = rxq->sw_ring[j];
+
+			/* mbuf is in reset state (nb_segs = 1, headroom, etc)  */
 			mbuf->port = rxq->port_id;
-			desc->read.baddr =
-				rte_cpu_to_le_64(
-					rte_mbuf_data_iova_default(mbuf));
+			desc->read.baddr = rte_cpu_to_le_64(rte_mbuf_data_iova_default(mbuf));
 			rte_wmb();
 			AXGMAC_SET_BITS_LE(desc->read.desc3,
 						RX_NORMAL_DESC3, OWN, 1);
-- 
2.53.0