Date: Wed, 6 Sep 2017 15:57:10 +0100
From: Roger Pau =?iso-8859-1?Q?Monn=E9?= <roger.pau@citrix.com>
To: Juergen Gross <jgross@suse.com>
CC: Vincent Legout <vincent.legout@gandi.net>,
        Jan Beulich <JBeulich@suse.com>, <xen-devel@lists.xenproject.org>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        <linux-kernel@vger.kernel.org>
Subject: Re: [Xen-devel] [PATCH] xen-blkfront: emit KOBJ_OFFLINE uevent when
 detaching device
Message-ID: <20170906145710.7o6wmnfxq32z2bgw@dhcp-3-128.uk.xensource.com>
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On Wed, Sep 06, 2017 at 12:18:03PM +0200, Juergen Gross wrote:
> On 05/09/17 09:28, Vincent Legout wrote:
> > Hello,
> > 
> > Sorry for such a long delay. I'm still interested in having this patch
> > merged.
> > 
> > I've tried to make the patch more generic and move it to xenbus as
> > discussed during the Xen summit, but I'm not sure how or if it's
> > possible. Would doing something in xenbus_otherend_changed() make sense?
> > But do we have enough information there? I'd be happy to get any advice,
> > I've re-attached the original patch.
> 
> Maybe you could add a callback to struct xenbus_driver which is called
> by xenbus_otherend_changed() if available and which will return the
> missing information (e.g. the kobj).

Hello,

I'm still unsure we should call KOBJ_OFFLINE, mostly because I don't
see any other block devices doing so. AFAICT it seems to be used only
by cpu and memory hotplug. Maybe xenbus should use the device_offline
function instead on each device it wants to remove?

>From my limited Linux bus handling understanding, this seems to be
more in line with what ACPI does for example.

Thanks, Roger.