From: Markus Pargmann <mpa@pengutronix.de>
To: Wouter Verhelst <w@uter.be>
Cc: nbd-general <nbd-general@lists.sourceforge.net>,
lkml <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] nbd: Issue a uevent when disconnecting
Date: Fri, 12 Feb 2016 15:49:32 +0100 [thread overview]
Message-ID: <2089906.hSTA6UrdgZ@adelgunde> (raw)
In-Reply-To: <20160205094241.GC6366@grep.be>
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Hi Wouter,
On Friday, February 05, 2016 10:42:41 AM Wouter Verhelst wrote:
> Hi Markus,
>
> On Fri, Feb 05, 2016 at 10:03:41AM +0100, Markus Pargmann wrote:
> > Hi Wouter,
> >
> > On Tuesday, February 02, 2016 04:27:00 PM Wouter Verhelst wrote:
> > > There already is a uevent by default when closing a device upon connect
> > > of the device. However, the same isn't true on disconnect.
> > >
> > > This makes it hard for userspace to keep track of whether a device is
> > > connected, since we are notified when the connection is created, but not
> > > when it is removed again.
> > >
> > > Explicitly issue a "change" uevent to remedy.
> > >
> > > [v2: incorporate feedback from udev maintainer and make sure that we
> > > issue a uevent upon connect as well as disconnect, rather than connect
> > > only]
> >
> > The systemd people had the same feedback.
>
> Well, the systemd people and the udev people are the same people these
> days :-)
>
> > Basically the device is not marked as ready until a uevent is received. My
> > idea was to use the size property consistently. If the device is connected
> > the size is correctly changed and a uevent is created. On disconnect the size
> > is set to 0 with another uevent.
> >
> > Does this work for you as well? I will send the patch as reply.
>
> Sure. What matters most is that the uevent is done; how it's done, less
> so.
>
> I should add that this was meant to go with systemd #2422. I wasn't
> aware of #358, or I would've talked to you more :-)
Ah I see, thanks.
I wrote some tests yesterday to ensure that I don't break other things
with the new size calculations. I will send the pull request with this
patch for 4.6.
Best Regards,
Markus
--
Pengutronix e.K. | |
Industrial Linux Solutions | http://www.pengutronix.de/ |
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next prev parent reply other threads:[~2016-02-12 14:49 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-23 16:23 [PATCH] Issue a uevent when disconnecting Wouter Verhelst
2016-02-02 15:27 ` [PATCH v2] nbd: " Wouter Verhelst
2016-02-05 9:03 ` Markus Pargmann
2016-02-05 9:42 ` Wouter Verhelst
2016-02-12 14:49 ` Markus Pargmann [this message]
2016-02-05 9:04 ` [PATCH] nbd: Create size change events for userspace Markus Pargmann
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