[$] A discussion on folios

A few weeks ago, Matthew Wilcox might have guessed that his sessionat the 2021 LinuxPlumbers Conference would be focused rather differently. But, as we reported earlier in September, his folio patch set ran into some, perhapsunexpected, opposition and, ultimately, did not land in the mainline for5.15. Instead of discussing how to use folios as partof the FileSystems microconference, he led a discussion that was, at least in part, on thepath forward for them.