Re: [PATCH V6 1/3] vhost_net: correct error handling invhost_net_set_backend()

From: Michael S. Tsirkin
Date: Thu Jan 24 2013 - 05:34:14 EST


On Wed, Jan 16, 2013 at 11:44:36PM +0800, Jason Wang wrote:
> Currently, when vhost_init_used() fails the sock refcnt and ubufs were
> leaked. Correct this by calling vhost_init_used() before assign ubufs and
> restore the oldsock when it fails.
>
> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>

Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>

> ---
> drivers/vhost/net.c | 16 +++++++++++-----
> 1 files changed, 11 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
> index ebd08b2..d10ad6f 100644
> --- a/drivers/vhost/net.c
> +++ b/drivers/vhost/net.c
> @@ -827,15 +827,16 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
> r = PTR_ERR(ubufs);
> goto err_ubufs;
> }
> - oldubufs = vq->ubufs;
> - vq->ubufs = ubufs;
> +
> vhost_net_disable_vq(n, vq);
> rcu_assign_pointer(vq->private_data, sock);
> - vhost_net_enable_vq(n, vq);
> -
> r = vhost_init_used(vq);
> if (r)
> - goto err_vq;
> + goto err_used;
> + vhost_net_enable_vq(n, vq);
> +
> + oldubufs = vq->ubufs;
> + vq->ubufs = ubufs;
>
> n->tx_packets = 0;
> n->tx_zcopy_err = 0;
> @@ -859,6 +860,11 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
> mutex_unlock(&n->dev.mutex);
> return 0;
>
> +err_used:
> + rcu_assign_pointer(vq->private_data, oldsock);
> + vhost_net_enable_vq(n, vq);
> + if (ubufs)
> + vhost_ubuf_put_and_wait(ubufs);
> err_ubufs:
> fput(sock->file);
> err_vq:
> --
> 1.7.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/