block/dirty-bitmap: add bdrv_remove_persistent_dirty_bitmap

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>
Message-id: 20170628120530.31251-28-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>

3 files changed, 24 insertions, 0 deletions

diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index 5fcf917..b2ca78b 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -395,6 +395,7 @@ 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.
  * Called with BQL taken.
  */
 void bdrv_release_named_dirty_bitmaps(BlockDriverState *bs)
@@ -402,6 +403,23 @@ 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);
+    }
+}
+
 /* Called with BQL taken.  */
 void bdrv_disable_dirty_bitmap(BdrvDirtyBitmap *bitmap)
 {
diff --git a/include/block/block_int.h b/include/block/block_int.h
index c9e29bf..58d4ffd 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -391,6 +391,9 @@ 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 8e98aef..93d97f0 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);