[Qemu-block] [PATCH v8 03/14] block/dirty-bitmap: add bdrv_dirty_bitmap_release_successor

[Vladimir Sementsov-Ogievskiy]

To just release successor and unfreeze bitmap without any additional
work.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
Signed-off-by: Denis V. Lunev <d...@openvz.org>
---
 include/block/dirty-bitmap.h |  2 ++
 block/dirty-bitmap.c         | 14 ++++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index 93d4336505..a9e2a92e4f 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -20,6 +20,8 @@ BdrvDirtyBitmap *bdrv_dirty_bitmap_abdicate(BlockDriverState 
*bs,
 BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BlockDriverState *bs,
                                            BdrvDirtyBitmap *bitmap,
                                            Error **errp);
+void bdrv_dirty_bitmap_release_successor(BlockDriverState *bs,
+                                         BdrvDirtyBitmap *bitmap);
 void bdrv_dirty_bitmap_enable_successor(BdrvDirtyBitmap *bitmap);
 BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs,
                                         const char *name);
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index 981f99d362..7578863aa1 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -431,6 +431,20 @@ void bdrv_enable_dirty_bitmap(BdrvDirtyBitmap *bitmap)
     bitmap->disabled = false;
 }
 
+/* Called with BQL taken. */
+void bdrv_dirty_bitmap_release_successor(BlockDriverState *bs,
+                                         BdrvDirtyBitmap *parent)
+{
+    qemu_mutex_lock(parent->mutex);
+
+    if (parent->successor) {
+        bdrv_release_dirty_bitmap_locked(bs, parent->successor);
+        parent->successor = NULL;
+    }
+
+    qemu_mutex_unlock(parent->mutex);
+}
+
 BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs)
 {
     BdrvDirtyBitmap *bm;
-- 
2.11.1