net/tap: fix check for mbuf number of segment

[ upstream commit cc6cf04 ]

Now the rxq->pool is mbuf concatenation, but its nb_segs is 1. When
conducting some sanity checks on the mbuf with debug enabled, it fails.

Fixes: 0781f57 ("net/tap: support segmented mbufs")

Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>

drivers/net/tap/rte_eth_tap.c

@@ -340,6 +340,23 @@ tap_rx_offload_get_queue_capa(void)
 	       DEV_RX_OFFLOAD_TCP_CKSUM;
 }
 
+static void
+tap_rxq_pool_free(struct rte_mbuf *pool)
+{
+	struct rte_mbuf *mbuf = pool;
+	uint16_t nb_segs = 1;
+
+	if (mbuf == NULL)
+		return;
+
+	while (mbuf->next) {
+		mbuf = mbuf->next;
+		nb_segs++;
+	}
+	pool->nb_segs = nb_segs;
+	rte_pktmbuf_free(pool);
+}
+
 /* Callback to handle the rx burst of packets to the correct interface and
  * file descriptor(s) in a multi-queue setup.
  */
@@ -390,7 +407,7 @@ pmd_rx_burst(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 					goto end;
 
 				seg->next = NULL;
-				rte_pktmbuf_free(mbuf);
+				tap_rxq_pool_free(mbuf);
 
 				goto end;
 			}
@@ -1022,7 +1039,7 @@ tap_dev_close(struct rte_eth_dev *dev)
 			rxq = &internals->rxq[i];
 			close(process_private->rxq_fds[i]);
 			process_private->rxq_fds[i] = -1;
-			rte_pktmbuf_free(rxq->pool);
+			tap_rxq_pool_free(rxq->pool);
 			rte_free(rxq->iovecs);
 			rxq->pool = NULL;
 			rxq->iovecs = NULL;
@@ -1061,7 +1078,7 @@ tap_rx_queue_release(void *queue)
 	if (process_private->rxq_fds[rxq->queue_id] > 0) {
 		close(process_private->rxq_fds[rxq->queue_id]);
 		process_private->rxq_fds[rxq->queue_id] = -1;
-		rte_pktmbuf_free(rxq->pool);
+		tap_rxq_pool_free(rxq->pool);
 		rte_free(rxq->iovecs);
 		rxq->pool = NULL;
 		rxq->iovecs = NULL;
@@ -1405,7 +1422,7 @@ tap_rx_queue_setup(struct rte_eth_dev *dev,
 	return 0;
 
 error:
-	rte_pktmbuf_free(rxq->pool);
+	tap_rxq_pool_free(rxq->pool);
 	rxq->pool = NULL;
 	rte_free(rxq->iovecs);
 	rxq->iovecs = NULL;