On Thu, 23 Oct 2014 19:25:01 +0300
"Michael S. Tsirkin" <mst@xxxxxxxxxx> wrote:
> Gracefully handle failure to write device status.
> We really should handle other errors as well, but this one is needed for
> virtio 1.0 compliance.
>
> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
> ---
> drivers/s390/kvm/virtio_ccw.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c
> index a994078..26e737c 100644
> --- a/drivers/s390/kvm/virtio_ccw.c
> +++ b/drivers/s390/kvm/virtio_ccw.c
> @@ -862,7 +862,9 @@ static u8 virtio_ccw_get_status(struct virtio_device *vdev)
> static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
> {
> struct virtio_ccw_device *vcdev = to_vc_device(vdev);
> + u8 old_status = vcdev->status;
*vcdev->status
> struct ccw1 *ccw;
> + int ret;
>
> ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
> if (!ccw)
> @@ -874,7 +876,10 @@ static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
> ccw->flags = 0;
> ccw->count = sizeof(status);
> ccw->cda = (__u32)(unsigned long)vcdev->status;
> - ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
> + ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
> + /* Write failed? We assume status is unchanged. */
> + if (ret)
> + *vcdev->status = old_status;
If we fail the write, ccw->cda should be unchanged; but this doesn't
hurt.
> kfree(ccw);
> }
>
--
To unsubscribe from this list: send the line "unsubscribe linux-s390" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
