[sheepdog] async flush in the object cache

[Christoph Hellwig]

On Fri, May 18, 2012 at 10:00:22AM +0800, Liu Yuan wrote:
> This is supposed to be an interim solution for the inefficiency of
> current recovery against heavy IO. Currently, without it, we can't run
> massive nodes at all, even a single node event will put the cluster into
> useless. I'd like to remove it until we have settle down all the
> inefficiency problem in recovery code.

What issues are still outstanding?  I'd really be a lot happier if this
violation of block device semantics didn't make it into a release.