[2/2] net/netvsc: detach external buffer on failure

Message ID 1592961106-82820-2-git-send-email-longli@linuxonhyperv.com (mailing list archive)
State Accepted, archived
Delegated to: Ferruh Yigit
Headers
Series [1/2] net/netvsc: fix underflow error when external mbuf are used in the receive path |

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/Intel-compilation success Compilation OK
ci/travis-robot success Travis build: passed

Commit Message

Long Li June 24, 2020, 1:11 a.m. UTC
  From: Long Li <longli@microsoft.com>

When external buffer is used, driver should detach it if it doesn't make it
successfully to the queue.

Signed-off-by: Long Li <longli@microsoft.com>
---
 drivers/net/netvsc/hn_rxtx.c | 6 ++++++
 1 file changed, 6 insertions(+)
  

Comments

Stephen Hemminger July 2, 2020, 12:05 a.m. UTC | #1
On Tue, 23 Jun 2020 18:11:46 -0700
longli@linuxonhyperv.com wrote:

> From: Long Li <longli@microsoft.com>
> 
> When external buffer is used, driver should detach it if it doesn't make it
> successfully to the queue.
> 
> Signed-off-by: Long Li <longli@microsoft.com>

Good catch

Acked-by: Stephen Hemminger <stephen@networkplumber.org>
  

Patch

diff --git a/drivers/net/netvsc/hn_rxtx.c b/drivers/net/netvsc/hn_rxtx.c
index aece38e2d..52f5c0191 100644
--- a/drivers/net/netvsc/hn_rxtx.c
+++ b/drivers/net/netvsc/hn_rxtx.c
@@ -550,6 +550,7 @@  static void hn_rxpkt(struct hn_rx_queue *rxq, struct hn_rx_bufinfo *rxb,
 {
 	struct hn_data *hv = rxq->hv;
 	struct rte_mbuf *m;
+	bool use_extbuf = false;
 
 	m = rte_pktmbuf_alloc(rxq->mb_pool);
 	if (unlikely(!m)) {
@@ -587,6 +588,7 @@  static void hn_rxpkt(struct hn_rx_queue *rxq, struct hn_rx_bufinfo *rxb,
 		rte_pktmbuf_attach_extbuf(m, data, iova,
 					  dlen + headroom, shinfo);
 		m->data_off = headroom;
+		use_extbuf = true;
 	} else {
 		/* Mbuf's in pool must be large enough to hold small packets */
 		if (unlikely(rte_pktmbuf_tailroom(m) < dlen)) {
@@ -614,6 +616,8 @@  static void hn_rxpkt(struct hn_rx_queue *rxq, struct hn_rx_bufinfo *rxb,
 		if (!hv->vlan_strip && rte_vlan_insert(&m)) {
 			PMD_DRV_LOG(DEBUG, "vlan insert failed");
 			++rxq->stats.errors;
+			if (use_extbuf)
+				rte_pktmbuf_detach_extbuf(m);
 			rte_pktmbuf_free(m);
 			return;
 		}
@@ -648,6 +652,8 @@  static void hn_rxpkt(struct hn_rx_queue *rxq, struct hn_rx_bufinfo *rxb,
 	if (unlikely(rte_ring_sp_enqueue(rxq->rx_ring, m) != 0)) {
 		++rxq->stats.ring_full;
 		PMD_RX_LOG(DEBUG, "rx ring full");
+		if (use_extbuf)
+			rte_pktmbuf_detach_extbuf(m);
 		rte_pktmbuf_free(m);
 	}
 }