rbd: don't put snap_context twice in rbd_queue_workfn()

commit 70b16db86f564977df074072143284aec2cb1162 upstream.

Commit 4e752f0ab0e8 ("rbd: access snapshot context and mapping size
safely") moved ceph_get_snap_context() out of rbd_img_request_create()
and into rbd_queue_workfn(), adding a ceph_put_snap_context() to the
error path in rbd_queue_workfn().  However, rbd_img_request_create()
consumes a ref on snapc, so calling ceph_put_snap_context() after
a successful rbd_img_request_create() leads to an extra put.  Fix it.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Josh Durgin <jdurgin@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 1ec6441fe2a5a4ce98067123333f10fe42fcaa40..09138ceba046b8bc7985571246e6310d229008e3 100644 (file)
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -3417,6 +3417,7 @@ static void rbd_queue_workfn(struct work_struct *work)
                goto err_rq;
        }
        img_request->rq = rq;
+       snapc = NULL; /* img_request consumes a ref */
 
        if (op_type == OBJ_OP_DISCARD)
                result = rbd_img_request_fill(img_request, OBJ_REQUEST_NODATA,