On Tue, Aug 27, 2019 at 2:54 PM Ilya Dryomov <idryomov@xxxxxxxxx> wrote:
>
> The parent image is read only up to the overlap point, the rest of
> the buffer should be zeroed. This snuck in because as it turns out
> the overlap test case has not been triggering this code path for
> a while now.
>
> Fixes: a9b67e69949d ("rbd: replace obj_req->tried_parent with obj_req->read_state")
> Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx>
> ---
> drivers/block/rbd.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
> index 58d9f17363d7..13f42f5b06cc 100644
> --- a/drivers/block/rbd.c
> +++ b/drivers/block/rbd.c
> @@ -3038,6 +3038,17 @@ static bool rbd_obj_advance_read(struct rbd_obj_request *obj_req, int *result)
> }
> return true;
> case RBD_OBJ_READ_PARENT:
> + /*
> + * The parent image is read only up to the overlap -- zero-fill
> + * from the overlap to the end of the request.
> + */
> + if (!*result) {
> + u32 obj_overlap = rbd_obj_img_extents_bytes(obj_req);
> +
> + if (obj_overlap < obj_req->ex.oe_len)
> + rbd_obj_zero_range(obj_req, obj_overlap,
> + obj_req->ex.oe_len - obj_overlap);
> + }
> return true;
> default:
> BUG();
> --
> 2.19.2
>
Reviewed-by: Jason Dillaman <dillaman@xxxxxxxxxx>
--
Jason
