1 files changed, 6 insertions, 0 deletions
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 17b26b2a9f..a48731d539 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -67,6 +67,12 @@ typedef struct BdrvTrackedRequest {
 struct BlockDriver {
     const char *format_name;
     int instance_size;
+
+    /* if not defined external snapshots are allowed
+     * future block filters will query their children to build the response
+     */
+    ExtSnapshotPerm (*bdrv_check_ext_snapshot)(BlockDriverState *bs);
+
     int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
     int (*bdrv_probe_device)(const char *filename);