Heinz Graalfs <[email protected]> writes:
> If virtqueue_get_buf() returned with a NULL pointer avoid a possibly
> endless loop by checking for a broken virtqueue.
>
> Signed-off-by: Heinz Graalfs <[email protected]>
> ---
> drivers/scsi/virtio_scsi.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
> index 74b88ef..45bcdb5 100644
> --- a/drivers/scsi/virtio_scsi.c
> +++ b/drivers/scsi/virtio_scsi.c
> @@ -224,7 +224,8 @@ static void virtscsi_vq_done(struct virtio_scsi *vscsi,
> virtqueue_disable_cb(vq);
> while ((buf = virtqueue_get_buf(vq, &len)) != NULL)
> fn(vscsi, buf);
> - } while (!virtqueue_enable_cb(vq));
> + } while (unlikely(!virtqueue_is_broken(vq)) &&
> + !virtqueue_enable_cb(vq));
> spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags);
unlikely(!virtqueue_is_broken(vq))?
I didn't apply this one.
I'd prefer:
spin_lock_irqsave(&virtscsi_vq->vq_lock, flags);
do {
virtqueue_disable_cb(vq);
while ((buf = virtqueue_get_buf(vq, &len)) != NULL)
fn(vscsi, buf);
if (unlikely(virtqueue_is_broken(vq)))
break;
} while (!virtqueue_enable_cb(vq));
spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags);
Thanks,
Rusty.
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