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-rw-r--r--drivers/net/virtio_net.c10
-rw-r--r--drivers/virtio/virtio_ring.c1
-rw-r--r--include/linux/virtio.h5
3 files changed, 10 insertions, 6 deletions
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index e575df8..b58472c 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -203,8 +203,11 @@ again:
if (received < budget) {
netif_rx_complete(vi->dev, napi);
if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq))
- && netif_rx_reschedule(vi->dev, napi))
+ && napi_schedule_prep(napi)) {
+ vi->rvq->vq_ops->disable_cb(vi->rvq);
+ __netif_rx_schedule(vi->dev, napi);
goto again;
+ }
}
return received;
@@ -278,10 +281,11 @@ again:
pr_debug("%s: virtio not prepared to send\n", dev->name);
netif_stop_queue(dev);
- /* Activate callback for using skbs: if this fails it
+ /* Activate callback for using skbs: if this returns false it
* means some were used in the meantime. */
if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
- printk("Unlikely: restart svq failed\n");
+ printk("Unlikely: restart svq race\n");
+ vi->svq->vq_ops->disable_cb(vi->svq);
netif_start_queue(dev);
goto again;
}
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 3a28c13..aa71402 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -232,7 +232,6 @@ static bool vring_enable_cb(struct virtqueue *_vq)
vq->vring.avail->flags &= ~VRING_AVAIL_F_NO_INTERRUPT;
mb();
if (unlikely(more_used(vq))) {
- vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
END_USE(vq);
return false;
}
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 260d1fc..12c18ac 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -43,8 +43,9 @@ struct virtqueue
* vq: the struct virtqueue we're talking about.
* @enable_cb: restart callbacks after disable_cb.
* vq: the struct virtqueue we're talking about.
- * This returns "false" (and doesn't re-enable) if there are pending
- * buffers in the queue, to avoid a race.
+ * This re-enables callbacks; it returns "false" if there are pending
+ * buffers in the queue, to detect a possible race between the driver
+ * checking for more work, and enabling callbacks.
*
* Locking rules are straightforward: the driver is responsible for
* locking. No two operations may be invoked simultaneously.
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