Pull new zonefs file system from Damien Le Moal:
 "Zonefs is a very simple file system exposing each zone of a zoned
  block device as a file.

  Unlike a regular file system with native zoned block device support
  (e.g. f2fs or the on-going btrfs effort), zonefs does not hide the
  sequential write constraint of zoned block devices to the user. As a
  result, zonefs is not a POSIX compliant file system. Its goal is to
  simplify the implementation of zoned block devices support in
  applications by replacing raw block device file accesses with a richer
  file based API, avoiding relying on direct block device file ioctls
  which may be more obscure to developers.

  One example of this approach is the implementation of LSM
  (log-structured merge) tree structures (such as used in RocksDB and
  LevelDB) on zoned block devices by allowing SSTables to be stored in a
  zone file similarly to a regular file system rath...