block: add bdrv_co_drain_end callback
BlockDriverState has a bdrv_co_drain() callback but no equivalent for
the end of the drain. The throttle driver (block/throttle.c) needs a way
to mark the end of the drain in order to toggle io_limits_disabled
correctly, thus bdrv_co_drain_end is needed.
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 7e8a206..dd62f4d 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -354,10 +354,17 @@
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 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_end)(BlockDriverState *bs);
void (*bdrv_add_child)(BlockDriverState *parent, BlockDriverState *child,
Error **errp);
