Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into staging

# gpg: Signature made Fri 13 Oct 2017 14:49:22 BST
# gpg:                using RSA key 0x9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha/tags/block-pull-request:
  block/throttle.c: add bdrv_co_drain_begin/end callbacks
  block: rename bdrv_co_drain to bdrv_co_drain_begin
  block: add bdrv_co_drain_end callback

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 10 insertions, 3 deletions

diff --git a/include/block/block_int.h b/include/block/block_int.h
index 7e8a206..885c08e 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);