[$] A decision on composefs

At the end of our February article aboutthe debate around the composefs read-only,integrity-protected filesystem, it was predicted that the topic would come up at the2023 Linux Storage, Filesystem,Memory-Management and BPF Summit. That happened on the second day ofthe summit whenAlexander Larsson led a session on composefs. While the mailing-listdiscussion was somewhat contentious, the session was less so, since overlayfs canbe made to fit the needs of the composefs use cases. It turnsout that an entirely newfilesystem is not really needed.