Re: [PATCH 3/5] xen-pcifront: handle backend CLOSED without CLOSING

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Fri, Nov 30, 2012 at 02:42:14PM -0700, Bjorn Helgaas wrote:
> On Fri, Nov 30, 2012 at 11:41 AM, Bjorn Helgaas <bhelgaas@google.com> wrote:
> > On Fri, Oct 19, 2012 at 6:59 AM, Konrad Rzeszutek Wilk
> > <konrad.wilk@oracle.com> wrote:
> >> On Thu, Oct 18, 2012 at 11:03:36AM +0100, David Vrabel wrote:
> >>> From: David Vrabel <david.vrabel@citrix.com>
> >>>
> >>> Backend drivers shouldn't transistion to CLOSED unless the frontend is
> >>> CLOSED.  If a backend does transition to CLOSED too soon then the
> >>> frontend may not see the CLOSING state and will not properly shutdown.
> >>>
> >>> So, treat an unexpected backend CLOSED state the same as CLOSING.
> >>>
> >>> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
> >>> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> >>> ---
> >>> Cc: linux-pci@vger.kernel.org
> >>> Cc: Bjorn Helgaas <bhelgaas@google.com>
> >>
> >> Bjorn, do you want me to prep a git pull with this patch
> >> or can I have your Ack to put it my tree and have it part of my
> >> git pull to Linus?
> >
> > Sorry, I missed this.  I can put it in my -next branch for the v3.8
> > merge window.  Would that work for you?
> 
> I put this in my -next branch, so we'll at least have a chance of
> making a linux-next cycle before v3.7 pops.

Great. Thx!
> 
> >>> ---
> >>>  drivers/pci/xen-pcifront.c |    5 ++++-
> >>>  1 files changed, 4 insertions(+), 1 deletions(-)
> >>>
> >>> diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c
> >>> index 0aab85a..a0c7312 100644
> >>> --- a/drivers/pci/xen-pcifront.c
> >>> +++ b/drivers/pci/xen-pcifront.c
> >>> @@ -1068,13 +1068,16 @@ static void __init_refok pcifront_backend_changed(struct xenbus_device *xdev,
> >>>       case XenbusStateInitialising:
> >>>       case XenbusStateInitWait:
> >>>       case XenbusStateInitialised:
> >>> -     case XenbusStateClosed:
> >>>               break;
> >>>
> >>>       case XenbusStateConnected:
> >>>               pcifront_try_connect(pdev);
> >>>               break;
> >>>
> >>> +     case XenbusStateClosed:
> >>> +             if (xdev->state == XenbusStateClosed)
> >>> +                     break;
> >>> +             /* Missed the backend's CLOSING state -- fallthrough */
> >>>       case XenbusStateClosing:
> >>>               dev_warn(&xdev->dev, "backend going away!\n");
> >>>               pcifront_try_disconnect(pdev);
> >>> --
> >>> 1.7.2.5