xen/blkfront: allow xenbus state transition to Closing->Closed when not Connected

This situation can occur when attempting to attach a block device whose
backend is an empty physical CD-ROM driver. The backend in this case
will go directly from the Initialising state to Closing->Closed.
Previously this would result in a NULL pointer deref on info->gd
(xenbus_dev_fatal does not return as a1a15ac5 seems to expect)

Cc: stable@kernel.org
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Ian Campbell 2009-05-19 08:25:48 +02:00 committed by Jens Axboe
parent 22ef37eed6
commit 28afea5b2f

View file

@ -977,8 +977,10 @@ static void backend_changed(struct xenbus_device *dev,
break;
case XenbusStateClosing:
if (info->gd == NULL)
xenbus_dev_fatal(dev, -ENODEV, "gd is NULL");
if (info->gd == NULL) {
xenbus_frontend_closed(dev);
break;
}
bd = bdget_disk(info->gd, 0);
if (bd == NULL)
xenbus_dev_fatal(dev, -ENODEV, "bdget failed");