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

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

# gpg: Signature made Tue 19 Apr 2016 17:28:01 BST using RSA key ID C0DE3057
# gpg: Good signature from "Jeffrey Cody <jcody@redhat.com>"
# gpg:                 aka "Jeffrey Cody <jeff@codyprime.org>"
# gpg:                 aka "Jeffrey Cody <codyprime@gmail.com>"

* remotes/cody/tags/block-pull-request:
  block/gluster: prevent data loss after i/o error
  block/gluster: code movement of qemu_gluster_close()
  block/gluster: return correct error value

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