Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-2017-02-12' into staging

Block patches

# gpg: Signature made Sun 12 Feb 2017 01:26:20 GMT
# 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-2017-02-12: (21 commits)
  qemu-img: Avoid setting ret to unused value in img_convert()
  qemu-img: Use qemu_strtoul() rather than raw strtoul()
  qemu-io: don't allow I/O operations larger than BDRV_REQUEST_MAX_BYTES
  qcow2: Optimize the refcount-block overlap check
  qemu-io: Add failure regression tests
  qemu-iotests: Add _unsupported_fmt helper
  qemu-io: Return non-zero exit code on failure
  block/nfs: fix naming of runtime opts
  block/nfs: fix NULL pointer dereference in URI parsing
  block: bdrv_invalidate_cache: invalidate children first
  block/qapi: reduce the execution time of qmp_query_blockstats
  block/qapi: reduce the coupling between the bdrv_query_stats and bdrv_query_bds_stats
  qemu-iotest: test to lookup protocol-based image with relative backing
  qemu-iotests: Don't create fifos / pidfiles with protocol paths
  block: check full backing filename when searching protocol filenames
  block/vmdk: Fix the endian problem of buf_len and lba
  iotests: record separate timings per format,protocol pair
  iotests: Fix reference output for 059
  qapi: Tweak error message of bdrv_query_image_info
  qemu-img: Improve commit invalid base message
  ...

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