Merge remote-tracking branch 'public/tags/block-pull-request' into staging

# gpg: Signature made Tue 08 Nov 2016 06:12:29 PM GMT
# gpg:                using RSA key 0x9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* public/tags/block-pull-request:
  aio-posix: simplify aio_epoll_update
  aio-posix: avoid NULL pointer dereference in aio_epoll_update
  block: Don't mark node clean after failed flush

Message-id: 1478628762-31050-1-git-send-email-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>