Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1327573

Re: [PATCH v2] nbd: Issue a uevent when disconnecting

Show all headers | View raw

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 :-)

-- 
It is easy to love a country that is famous for chocolate and beer

  -- Barack Obama, speaking in Brussels, Belgium, 2014-03-26

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH v2] nbd: Issue a uevent when disconnecting Wouter Verhelst <w@uter.be> - 2016-02-02 16:30 +0100
  Re: [PATCH v2] nbd: Issue a uevent when disconnecting Markus Pargmann <mpa@pengutronix.de> - 2016-02-05 10:10 +0100
    Re: [PATCH v2] nbd: Issue a uevent when disconnecting Wouter Verhelst <w@uter.be> - 2016-02-05 10:50 +0100
  [PATCH] nbd: Create size change events for userspace Markus Pargmann <mpa@pengutronix.de> - 2016-02-05 10:10 +0100

csiph-web