WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

Re: [Xen-devel] [PATCH] Safely finish closing protocol when guest fails

To: Keir Fraser <keir@xxxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] Safely finish closing protocol when guest fails in blkfront
From: Glauber de Oliveira Costa <gcosta@xxxxxxxxxx>
Date: Tue, 5 Dec 2006 08:22:02 -0200
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Tue, 05 Dec 2006 02:22:05 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <C19AD29F.5577%keir@xxxxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <20061204214017.GA12102@xxxxxxxxxx> <C19AD29F.5577%keir@xxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mutt/1.5.11
On Tue, Dec 05, 2006 at 07:39:11AM +0000, Keir Fraser wrote:
> On 4/12/06 9:40 pm, "Glauber de Oliveira Costa" <gcosta@xxxxxxxxxx> wrote:
> 
> > If a guest finds any error and aborts the connection of a block device,
> > it's online state set at device create phase will stop it from being
> > properly cleaned up.
> > 
> > Follows a fix for it.
> 
> Assignment and unassignment of physical resources is really a tools issue.
> Tools should really be integrated with device-hotplug success/failure anyway
> -- for example, it is likely the initiator would like confirmation of
> success/failure in most cases.
> 
Agree. But what if after properly initiation, frontend finds an error
and starts Closing protocol? What will happen is that the test

        if (xenbus_dev_is_online(dev))

will cause the device to not be unregistered. At this point, it do not
see frontend changes. (putting backend in closing leads to frontend
closing,closed, but backend never see frontend closing, never going to
closed).

Given that, what tools can do ? At the current point, this is what leads
me to believe that arbitrary frontend-failure cases should be handled in the 
frontend.


-- 
Glauber de Oliveira Costa
Red Hat Inc.
"Free as in Freedom"

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel

<Prev in Thread] Current Thread [Next in Thread>