NVMe ZNS Support Coming To Linux 5.9

Landing in the block subsystem's "-next" tree today is ZNS support for NVMe drives.

NVMe ZNS is for the Zoned Namespaces support that is part of the NVMe 2.0 specification debuting in H2'2020. ZNS is similar to existing SMR (Shingled Magnetic Recording) and ZBC (Zoned Block Commands) with allowing applications/software to control the placement of data on the NVMe SSD within zones rather than relying upon the SSD device exclusively for data placement. NVMe ZNS aims to improve solid-state drive lifetime with reducing write amplification, reducing latency, improving throughput, and potential TCO benefits.

Starting with Linux 5.9, the kernel has the NVMe ZNS support in place for supporting these management roles on the host laid out by the forthcoming NVMe 2.0 specification. More details on the Linux NVMe ZNS support via ZonedStorage.io.

This pull request merged today to the Linux block Git tree has the bulk of the NVMe changes for the 5.9 kernel, including the ZNS support.