Pull block driver updates from Jens Axboe:
 "On top of the 4.3 core block IO changes, here are the driver related
  changes for 4.3.  Basically just NVMe and nbd this time around:

   - NVMe:
      - PRACT PI improvement from Alok Pandey.
      - Cleanups and improvements on submission queue doorbell and
        writing, using CMB if available.  From Jon Derrick.
      - From Keith, support for setting queue maximum segments, and
        reset support.
      - Also from Jon, fixup of u64 division issue on 32-bit archs and
        wiring up of the reset support through and ioctl.
      - Two small cleanups from Matias and Sunad

  - Various code cleanups and fixes from Markus Pargmann"

* 'for-4.3/drivers' of git://git.kernel.dk/linux-block:
  NVMe: Using PRACT bit to generate and verify PI by controller
  NVMe:Remove unreachable code in nvme_abort_req
  NVMe: Add nvme subsystem reset IOCTL
  NVMe: Add nvme subsystem reset support
  NVMe: removed unused nn var from nvme_dev_add
  NVMe: Set queue max segments
  nbd: flags is a u32 variable
  nbd: Rename functions for clearness of recv/send path
  nbd: Change 'disconnect' to be boolean
  nbd: Add debugfs entries
  nbd: Remove variable 'pid'
  nbd: Move clear queue debug message
  nbd: Remove 'harderror' and propagate error properly
  nbd: restructure sock_shutdown
  nbd: sock_shutdown, remove conditional lock
  nbd: Fix timeout detection
  nvme: Fixes u64 division which breaks i386 builds
  NVMe: Use CMB for the IO SQes if available
  NVMe: Unify SQ entry writing and doorbell ringing