This will be needed to check some restrictions before making bitmap
persistent in qmp-block-dirty-bitmap-add (this functionality will be
added by future patch)

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
---
 block.c                   | 22 ++++++++++++++++++++++
 include/block/block.h     |  2 ++
 include/block/block_int.h |  4 ++++
 3 files changed, 28 insertions(+)

diff --git a/block.c b/block.c
index 970e4ca..d5f8af8 100644
--- a/block.c
+++ b/block.c
@@ -4139,3 +4139,25 @@ void bdrv_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **errp)
 
     drv->bdrv_store_persistent_dirty_bitmaps(bs, errp);
 }
+
+bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
+                                     uint32_t granularity, Error **errp)
+{
+    BlockDriver *drv = bs->drv;
+
+    if (!drv) {
+        error_setg_errno(errp, ENOMEDIUM,
+                         "Can't store persistent bitmaps to %s",
+                         bdrv_get_device_or_node_name(bs));
+        return false;
+    }
+
+    if (!drv->bdrv_can_store_new_dirty_bitmap) {
+        error_setg_errno(errp, ENOTSUP,
+                         "Can't store persistent bitmaps to %s",
+                         bdrv_get_device_or_node_name(bs));
+        return false;
+    }
+
+    return drv->bdrv_can_store_new_dirty_bitmap(bs, name, granularity, errp);
+}
diff --git a/include/block/block.h b/include/block/block.h
index 0a20d68..ebf99b3 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -553,5 +553,7 @@ void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp);
 
 void bdrv_load_autoloading_dirty_bitmaps(BlockDriverState *bs, Error **errp);
 void bdrv_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **errp);
+bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
+                                     uint32_t granularity, Error **errp);
 
 #endif
diff --git a/include/block/block_int.h b/include/block/block_int.h
index c3505da..db68067 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -324,6 +324,10 @@ struct BlockDriver {
                                                 Error **errp);
     void (*bdrv_store_persistent_dirty_bitmaps)(BlockDriverState *bs,
                                                 Error **errp);
+    bool (*bdrv_can_store_new_dirty_bitmap)(BlockDriverState *bs,
+                                            const char *name,
+                                            uint32_t granularity,
+                                            Error **errp);
 
     QLIST_ENTRY(BlockDriver) list;
 };
-- 
1.8.3.1