Ceph » rgw

RGWInitSyncStatusCoroutine locks the mdlog.sync-status object, queries log positions from the remote, writes shard marker objects, then writes the mdlog.sync-status object. The cls lock operation will actually create mdlog.sync-status, so there's a window where RGWReadSyncStatusCoroutine can read an empty buffer instead of getting ENOENT (before RGWInitSyncStatusCoroutine starts) or valid data (after RGWInitSyncStatusCoroutine completes). When RGWReadSyncStatusCoroutine sees a successful read with an empty buffer, RGWSimpleRadosReadCR tries to decode that into rgw_meta_sync_info and fails with EIO.