Pull block fixes from Jens Axboe:
 "Round 2 of this.  I cut back to the bare necessities, the patch is
  still larger than it usually would be at this time, due to the number
  of NVMe fixes in there.  This pull request contains:

   - The 4 core fixes from Ming, that fix both problems with exceeding
     the virtual boundary limit in case of merging, and the gap checking
     for cloned bio's.

   - NVMe fixes from Keith and Christoph:

        - Regression on larger user commands, causing problems with
          reading log pages (for instance). This touches both NVMe,
          and the block core since that is now generally utilized also
          for these types of commands.

        - Hot removal fixes.

        - User exploitable issue with passthrough IO commands, if !length
          is given, causing us to fault on writing to the zero
          page.

        - Fix for a hang under error conditions

   - And finally, the current series regression for umount with cgroup
     writeback, where the final flush would happen async and hence open
     up window after umount where the device wasn't consistent.  fsck
     right after umount would show this.  From Tejun"

* 'for-linus2' of git://git.kernel.dk/linux-block:
  block: support large requests in blk_rq_map_user_iov
  block: fix blk_rq_get_max_sectors for driver private requests
  nvme: fix max_segments integer truncation
  nvme: set queue limits for the admin queue
  writeback: flush inode cgroup wb switches instead of pinning super_block
  NVMe: Fix 0-length integrity payload
  NVMe: Don't allow unsupported flags
  NVMe: Move error handling to failed reset handler
  NVMe: Simplify device reset failure
  NVMe: Fix namespace removal deadlock
  NVMe: Use IDA for namespace disk naming
  NVMe: Don't unmap controller registers on reset
  block: merge: get the 1st and last bvec via helpers
  block: get the 1st and last bvec via helpers
  block: check virt boundary in bio_will_gap()
  block: bio: introduce helpers to get the 1st and last bvec