Syncing: what is 'gsdata'?

Some of the albums that have recently been added to AO have a strange file location: Music…gsdata…saved. These albums are not even in the only file location that I have specified for syncing. Some of them have synced in as single files (i.e. without tracks) even though the source file location has album with named tracks. I imagine too that they are duplicates, but anyone know what’s going on?
Update: Just figured out it’s a Goodsync file (hidden). I use Goodsync for incremental backups. I have deleted the hidden folder, but it may show up again…