[libvirt] [PATCH] Add source check before attaching device

[Jiri Denemark]

On Thu, Apr 16, 2015 at 16:51:52 +0800, zhang bo wrote:
> Source device/file is not unique now, we should check it when attach device.

The check is vary fragile and unreliable. It would be very hard (perhaps
even impossible) to really detect that the two disks/filesystems point
to the same source, which means libvirt would not really prevent anyone
from attaching a single source twice. Moreover, the code as written
would incorrectly refuse to attach disks that do not point to the same
source (network disks, e.g.).

But anyway, I don't think libvirt should be doing this in general, so
NACK to this idea.

Moreover, you should be able to achieve the same goal (and even more) by
using a locking driver.

Jirka