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

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

Block layer patches:

- qcow2: Decompression worker threads
- dmg: lzfse compression support
- file-posix: Simplify delegation to worker thread
- Don't pass flags to bdrv_reopen_queue()
- iotests: make 235 work on s390 (and others)

# gpg: Signature made Fri 14 Dec 2018 10:55:09 GMT
# gpg:                using RSA key 7F09B272C88F2FD6
# 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: (42 commits)
  block/mirror: add missing coroutine_fn annotations
  iotests: make 235 work on s390 (and others)
  block: Assert that flags are up-to-date in bdrv_reopen_prepare()
  block: Remove assertions from update_flags_from_options()
  block: Stop passing flags to bdrv_reopen_queue_child()
  block: Remove flags parameter from bdrv_reopen_queue()
  block: Clean up reopen_backing_file() in block/replication.c
  qemu-io: Put flag changes in the options QDict in reopen_f()
  block: Drop bdrv_reopen()
  block: Use bdrv_reopen_set_read_only() in the mirror driver
  block: Use bdrv_reopen_set_read_only() in external_snapshot_commit()
  block: Use bdrv_reopen_set_read_only() in qmp_change_backing_file()
  block: Use bdrv_reopen_set_read_only() in stream_start/complete()
  block: Use bdrv_reopen_set_read_only() in bdrv_commit()
  block: Use bdrv_reopen_set_read_only() in commit_start/complete()
  block: Use bdrv_reopen_set_read_only() in bdrv_backing_update_filename()
  block: Add bdrv_reopen_set_read_only()
  file-posix: Avoid aio_worker() for QEMU_AIO_IOCTL
  file-posix: Switch to .bdrv_co_ioctl
  file-posix: Remove paio_submit_co()
  ...

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