#5724 reclaimed the synthetic inline-rollback dir after a committed rename with delete_data_dir(recursive: true), which has no notion of object metadata: for unversioned objects the synthetic UUID is a fixed, publicly-known constant, so object/<rollback-dir> can simultaneously be a legitimate child key's directory, and recursively deleting it reopens the authorization bypass #5703 closed (PutObject on K destroying K/<uuid> without DeleteObject permission).
Replace the recursive pass with a file-precise one: after quorum commit, delete exactly object/<rollback>/xl.meta.bkp with a non-recursive delete on every disk whose rollback dir is not also the cleanup dir. The parent-rmdir walk removes the dir only when the backup was its sole content, so the BucketNotEmpty leak fix is preserved (#5724's regression test passes unchanged) while a child key at the same path keeps its metadata. The undo path's restore_metadata_backup now also reclaims the emptied synthetic dir, mirroring restore_delete_rollback.
Zhengchao An
8c9e884cf2