migration/postcopy: discard_length must not be 0

[mirror_qemu.git] / blockdev.c

diff --git a/blockdev.c b/blockdev.c
index 5d6a13dea93fc720358f380d3473d813ba5e879c..4d141e9a1fba68a40a5ad69f43ef270d279d025f 100644 (file)
--- a/blockdev.c
+++ b/blockdev.c
@@ -1774,7 +1774,7 @@ static void drive_backup_prepare(BlkActionState *common, Error **errp)
     assert(common->action->type == TRANSACTION_ACTION_KIND_DRIVE_BACKUP);
     backup = common->action->u.drive_backup.data;
 
-    bs = qmp_get_root_bs(backup->device, errp);
+    bs = bdrv_lookup_bs(backup->device, backup->device, errp);
     if (!bs) {
         return;
     }