Re: [Xen-devel] Re: blktap race against xenstore startup

To:	"Stephen C. Tweedie" <sct@xxxxxxxxxx>, Anthony Liguori <aliguori@xxxxxxxxxx>
Subject:	Re: [Xen-devel] Re: blktap race against xenstore startup
From:	Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Date:	Fri, 29 Sep 2006 07:54:45 +0100
Cc:	Andrew Warfield <andrew.warfield@xxxxxxxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>, Steven Rostedt <rostedt@xxxxxxxxxxx>, Julian Chesterfield <jac90@xxxxxxxxx>
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On 29/9/06 12:23 am, "Stephen C. Tweedie" <sct@xxxxxxxxxx> wrote:

> It (the blktapctrl userland daemon) gets execve'd by xend:
> 
>     elif sys.argv[1] == 'start':
>         start_xenstored()
>         start_consoled()
>         start_blktapctrl()
>         return daemon.start()
> 
> The problem is not that xenstored is dead: it's alive and running, it
> just hasn't had the /local/domain tree filled in, so it returns ENOENT.
> xenstored *is* ready, but that's not enough.

Set a watch on /local/domain and wait for the directory to appear? Not a
beautiful approach, but better than spinning a few times? :-)

 -- Keir



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