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Subject: Re: [PATCH] xen-blkback: Switch to closed state after releasing the
 backing device
To:     Valentin Vidic <Valentin.Vidic@CARNet.hr>
Cc:     =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= <roger.pau@citrix.com>,
        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
        Jens Axboe <axboe@kernel.dk>, xen-devel@lists.xenproject.org,
        linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        stable@vger.kernel.org
References: <20180829065214.23546-1-Valentin.Vidic@CARNet.hr>
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From:   Juergen Gross <jgross@suse.com>
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Message-ID: <7afb803f-a2d2-73c8-f2d3-8b866dc89e87@suse.com>
Date:   Wed, 29 Aug 2018 11:29:30 +0200
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On 29/08/18 11:23, Valentin Vidic wrote:
> On Wed, Aug 29, 2018 at 10:43:48AM +0200, Juergen Gross wrote:
>> I think this should be an action triggered by the frontend, not by dom0
>> (xen tools will always set "online" to 0 when removing a device, AFAIK).
>>
>> I'm not sure this is relevant, but I realized this behavior is changed
>> by your patch.
> 
> Can't find any place in xen-blkfront.c (or the rest of the kernel) where
> the "online" value gets set, so it seems xen tools in dom0 is the only
> thing that modifies this Xenbus node?
> 

I think so, yes.

It will be set to "1" at device creation and to "0" when removing the
device, both times by Xen tools.


Juergen