Merge remote-tracking branch 'remotes/cody/tags/block-pull-request' into staging
# gpg: Signature made Wed 01 Feb 2017 05:32:23 GMT
# gpg: using RSA key 0xBDBE7B27C0DE3057
# gpg: Good signature from "Jeffrey Cody <jcody@redhat.com>"
# gpg: aka "Jeffrey Cody <jeff@codyprime.org>"
# gpg: aka "Jeffrey Cody <codyprime@gmail.com>"
# Primary key fingerprint: 9957 4B4D 3474 90E7 9D98 D624 BDBE 7B27 C0DE 3057
* remotes/cody/tags/block-pull-request:
sheepdog: reorganize check for overlapping requests
sheepdog: simplify inflight_aio_head management
sheepdog: do not use BlockAIOCB
sheepdog: reorganize coroutine flow
sheepdog: remove unused cancellation support
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>