Current error handling of virtqueue_kick() was wrong in two places:
- The skb were freed immediately when virtqueue_kick() fail during
xmit. This may lead double free since the skb was not detached from
the virtqueue.
- try_fill_recv() returns false when virtqueue_kick() fail. This will
lead unnecessary rescheduling of refill work.
Actually, it's safe to just ignore the kick failure in those two
places. So this patch fixes this by partially revert commit
67975901183799af8e93ec60e322f9e2a1940b9b.
Fixes 67975901183799af8e93ec60e322f9e2a1940b9b
(virtio_net: verify if virtqueue_kick() succeeded).
Cc: Heinz Graalfs <graa...@linux.vnet.ibm.com>
Cc: Rusty Russell <ru...@rustcorp.com.au>
Cc: Michael S. Tsirkin <m...@redhat.com>
Signed-off-by: Jason Wang <jasow...@redhat.com>
---
drivers/net/virtio_net.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 5632a99..841b608 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -671,8 +671,7 @@ static bool try_fill_recv(struct receive_queue *rq, gfp_t
gfp)
if (err)
break;
} while (rq->vq->num_free);
- if (unlikely(!virtqueue_kick(rq->vq)))
- return false;
+ virtqueue_kick(rq->vq);
return !oom;
}
@@ -877,7 +876,7 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct
net_device *dev)
err = xmit_skb(sq, skb);
/* This should not happen! */
- if (unlikely(err) || unlikely(!virtqueue_kick(sq->vq))) {
+ if (unlikely(err)) {
dev->stats.tx_fifo_errors++;
if (net_ratelimit())
dev_warn(&dev->dev,
@@ -886,6 +885,7 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct
net_device *dev)
kfree_skb(skb);
return NETDEV_TX_OK;
}
+ virtqueue_kick(sq->vq);
/* Don't wait up for transmitted skbs to be freed. */
skb_orphan(skb);
--
1.7.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
