[$] Filesystems for zoned block devices

Damien Le Moal and Naohiro Aota led a combined storage and filesystemsession at the 2019 Linux Storage, Filesystem, and Memory-Management Summit(LSFMM) on filesystem work that has been done for zoned block devices.These devices have multiple zones with different characteristics; usuallythere are zones that can only be written in sequential order as well asconventional zones that can be written in random order. The genesis of zonedblock devices is shingledmagnetic recording (SMR) devices, which were created to increase thecapacity of hard disks, but at the cost of some flexibility.