ZAC / Shingled Magnetic Recording Device Work For The Linux 4.7 Kernel

Another one of the interesting pull requests this week for the Linux 4.7 merge window is the addition of ZAC (Zone ATA Command) support for Singled Magnetic Recording (SMR) devices.

Tejun Heo reported in, "This pull request contains Zone ATA Command support for Shingled Magnetic Recording devices. In addition to sending the new commands down to the device, as ZAC commands depend on getting a lot of responses from the device, piping up responses is beefed up too."

As part of this thousand lines of new code is also NCQ autosense ACS-4, sense data reporting, and related work for handling device-managed and host-managed ZAC devices. For those unfamiliar with Shingled Magnetic Recording, there is always Wikipedia. Details on Zone ATA Command and Zone Block Command, etc, can be found via this WD presentation.