[PATCH 4.1 33/45] rbd: dont put snap_context twice in rbd_queue_workfn()

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ilya Dryomov <idryomov@gmail.com>

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>

---
 drivers/block/rbd.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -3417,6 +3417,7 @@ static void rbd_queue_workfn(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,