Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-2017-07-11' into staging

Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-2017-07-11' into staging

Block layer patches

# gpg: Signature made Tue 11 Jul 2017 17:05:56 BST
# gpg:                using RSA key 0xF407DB0061D5CF40
# gpg: Good signature from "Max Reitz <mreitz@redhat.com>"
# Primary key fingerprint: 91BE B60A 30DB 3E88 57D1  1829 F407 DB00 61D5 CF40

* remotes/maxreitz/tags/pull-block-2017-07-11: (85 commits)
  iotests: Add preallocated growth test for qcow2
  iotests: Add preallocated resize test for raw
  block/qcow2: falloc/full preallocating growth
  block/qcow2: Rename "fail_block" to just "fail"
  block/qcow2: Add qcow2_refcount_area()
  block/qcow2: Metadata preallocation for truncate
  block/qcow2: Lock s->lock in preallocate()
  block/qcow2: Generalize preallocate()
  block/file-posix: Preallocation for truncate
  block/file-posix: Generalize raw_regular_truncate
  block/file-posix: Extract raw_regular_truncate()
  block/file-posix: Small fixes in raw_create()
  qemu-img: Expose PreallocMode for resizing
  block: Add PreallocMode to blk_truncate()
  block: Add PreallocMode to bdrv_truncate()
  block: Add PreallocMode to BD.bdrv_truncate()
  iotests: add test 178 for qemu-img measure
  qemu-iotests: support per-format golden output files
  qemu-img: add measure subcommand
  qcow2: add bdrv_measure() support
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>