virtio_ring: allow to store zero as the ctx

Allow zero to be store as a ctx, with this we could store e.g zero
value which could be meaningful for the case of storing headroom
through ctx.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 5e1b548828e60745ba87581d2b9bcb6380b092f8..9aaa177e8209731cbe63aef3c7f1479ab2497851 100644 (file)
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -391,7 +391,7 @@ static inline int virtqueue_add(struct virtqueue *_vq,
        vq->desc_state[head].data = data;
        if (indirect)
                vq->desc_state[head].indir_desc = desc;
-       if (ctx)
+       else
                vq->desc_state[head].indir_desc = ctx;
 
        /* Put entry in available array (but don't update avail->idx until they