Interface for removing persistent bitmap from its storage.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
---
 block/dirty-bitmap.c         | 18 ++++++++++++++++++
 include/block/block_int.h    |  3 +++
 include/block/dirty-bitmap.h |  3 +++
 3 files changed, 24 insertions(+)

diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index 2ae64fc9e8..6b43ad04fc 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -334,12 +334,30 @@ void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap)
 /**
  * Release all named dirty bitmaps attached to a BDS (for use in bdrv_close()).
  * There must not be any frozen bitmaps attached.
+ * This function does not remove persistent bitmaps from the storage.
  */
 void bdrv_release_named_dirty_bitmaps(BlockDriverState *bs)
 {
     bdrv_do_release_matching_dirty_bitmap(bs, NULL, true);
 }
 
+/**
+ * Remove persistent dirty bitmap from the storage if it exists.
+ * Absence of bitmap is not an error, because we have the following scenario:
+ * BdrvDirtyBitmap can have .persistent = true but not yet saved and have no
+ * stored version. For such bitmap bdrv_remove_persistent_dirty_bitmap() should
+ * not fail.
+ * This function doesn't release corresponding BdrvDirtyBitmap.
+ */
+void bdrv_remove_persistent_dirty_bitmap(BlockDriverState *bs,
+                                         const char *name,
+                                         Error **errp)
+{
+    if (bs->drv && bs->drv->bdrv_remove_persistent_dirty_bitmap) {
+        bs->drv->bdrv_remove_persistent_dirty_bitmap(bs, name, errp);
+    }
+}
+
 void bdrv_disable_dirty_bitmap(BdrvDirtyBitmap *bitmap)
 {
     assert(!bdrv_dirty_bitmap_frozen(bitmap));
diff --git a/include/block/block_int.h b/include/block/block_int.h
index adda0894c7..953107f095 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -390,6 +390,9 @@ struct BlockDriver {
                                             const char *name,
                                             uint32_t granularity,
                                             Error **errp);
+    void (*bdrv_remove_persistent_dirty_bitmap)(BlockDriverState *bs,
+                                                const char *name,
+                                                Error **errp);
 
     QLIST_ENTRY(BlockDriver) list;
 };
diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index 00b298330c..5fac2d8411 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -25,6 +25,9 @@ BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs,
 void bdrv_dirty_bitmap_make_anon(BdrvDirtyBitmap *bitmap);
 void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap);
 void bdrv_release_named_dirty_bitmaps(BlockDriverState *bs);
+void bdrv_remove_persistent_dirty_bitmap(BlockDriverState *bs,
+                                         const char *name,
+                                         Error **errp);
 void bdrv_disable_dirty_bitmap(BdrvDirtyBitmap *bitmap);
 void bdrv_enable_dirty_bitmap(BdrvDirtyBitmap *bitmap);
 BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs);
-- 
2.11.1