LightNVM Getting Open-Channel 2.0 Support For Linux 4.17

LightNVM patches are called for pulling into the Linux kernel's block layer that would land for the Linux 4.17 kernel and provide Open-Channel 2.0 support.

The Open-Channel SSD 2.0 specification was ratified in January by the LightNVM group. As a reminder, LightNVM / Open-Channel is a specification for extending the NVMe specification whereby the solid-state drive exposes its internal parallelism and lets the host operating system determine data placement and I/O scheduling rather than the SSD itself. Open-Channel SSDs aim for better I/O isolation, predictable latency, and better drive management.

The Open-Channel SSD 2.0 specification has various improvements over the now-deprecated 1.2 release. Those wanting to learn more about the innards of this NVMe extension can do so via the OCSSD 2.0 specification.

The patches pending implement the 2.0 changes to the LightNVM Linux kernel code and end up adding around an extra thousand lines of code to the kernel.