very difficult to identify if its odour of like the onion than please check alliaceae family, otherwise it is in Liliaceae. Unless microscopic studies are not done it is very difficult to identify.
Looks like Allium neapolitanum - not quite onion, but close enough. Stopped being Liliaceae long ago though - call it Alliaceae or Amaryllidaceae s.l. But I can't write off Ornithogalum completely, and that would be Asparagaceae s.l.