Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches for 2.10.0-rc2

# gpg: Signature made Tue 08 Aug 2017 14:56:15 BST
# gpg:                using RSA key 0x7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream:
  block/nfs: fix mutex assertion in nfs_file_close()
  qemu-iotests: Test reopen between read-only and read-write
  qemu-io: Allow reopen read-write
  block: Set BDRV_O_ALLOW_RDWR during rw reopen
  block: Allow reopen rw without BDRV_O_ALLOW_RDWR
  block: Fix order in bdrv_replace_child()
  parallels: drop check that bdrv_truncate() is working
  parallels: respect error code of bdrv_getlength() in allocate_clusters()
  block: respect error code from bdrv_getlength in handle_aiocb_write_zeroes
  vmdk: Fix error handling/reporting of vmdk_check
  block/null: Remove 'filename' option
  block: drop bdrv_set_key from BlockDriver
  block/vhdx: check error return of bdrv_truncate()
  block/vhdx: check error return of bdrv_flush()
  block/vhdx: check for offset overflow to bdrv_truncate()
  block/vhdx: check error return of bdrv_getlength()
  quorum: Set sectors-count to 0 when reporting a flush error
  qemu-iotests/109: Fix lock race condition

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