> From: Stephen Hemminger
> Sent: Tuesday, February 28, 2017 01:02
>
> The patch looks good. I don't understand the exact semantics here and
> therefore have a couple of naïve questions
>
> Is it possible device could be opened multiple times? Is reference counting
> done above?
The file can only be opened once.
When we open it for the first time, in hvt_op_open() we run
hvt->mode = HVUTIL_TRANSPORT_CHARDEV, and when we try to open it later,
the open() gets -EBUSY.
When the first fd is closed, in hvt_op_release() we run
hvt->mode = HVUTIL_TRANSPORT_INIT, so we can re-open it successfully later.
> If device was never opened do you even have to do all the cleanup steps at
> all?
Yes, e.g. we do need the 3 cancel_*work_sync calls in hv_kvp_deinit():
the driver schedules the 3 works even if there is no daemon at all, e.g.
hv_kvp_onchannelcallback ->
schedule_delayed_work(&kvp_host_handshake_work, ...).
Thanks,
-- Dexuan
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