[$] epoll_pwait2(), close_range(), and encoded I/O

The various system calls and other APIs that the kernel provides for accessto files and filesystems has grown increasingly comprehensive over theyears. That does not mean, though, that there is no need or room forimprovement. Several relatively small additions to the kernel'sfilesystem-related API are under consideration in the developmentcommunity; read on for a survey of some of this work.