1 files changed, 10 insertions, 3 deletions

diff --git a/include/block/block_int.h b/include/block/block_int.h
index 7e8a206239..885c08e989 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -354,10 +354,17 @@ struct BlockDriver {
     int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo);
 
     /**
-     * Drain and stop any internal sources of requests in the driver, and
-     * remain so until next I/O callback (e.g. bdrv_co_writev) is called.
+     * bdrv_co_drain_begin is called if implemented in the beginning of a
+     * drain operation to drain and stop any internal sources of requests in
+     * the driver.
+     * bdrv_co_drain_end is called if implemented at the end of the drain.
+     *
+     * They should be used by the driver to e.g. manage scheduled I/O
+     * requests, or toggle an internal state. After the end of the drain new
+     * requests will continue normally.
      */
-    void coroutine_fn (*bdrv_co_drain)(BlockDriverState *bs);
+    void coroutine_fn (*bdrv_co_drain_begin)(BlockDriverState *bs);
+    void coroutine_fn (*bdrv_co_drain_end)(BlockDriverState *bs);
 
     void (*bdrv_add_child)(BlockDriverState *parent, BlockDriverState *child,
                            Error **errp);