RB_NOSYNC -> no device_shutdown ?

Andriy Gapon avg at FreeBSD.org
Tue Jan 10 10:23:50 UTC 2012

on 20/12/2011 16:11 John Baldwin said the following:
> On Saturday, December 17, 2011 6:07:51 pm Andriy Gapon wrote:
>> and wonder why RB_NOSYNC is overloaded to mean that no
>> MOD_SHUTDOWN/device_shutdown cleanup should be done?
> Presumably most device_shutdown handlers were used for syncing storage when 
> the module stuff was first added.  I'm not sure how you would fix this now 
> since you can't easily pass the 'arg2' flags down to each handler so that the 
> appropriate ones could skip their shutdown actions.

I see what you are saying.
Couple of thoughts:
- maybe MOD_EVENT interface could/should be extended to pass another argument
along with the event type
- maybe various sync-ing stuff should be done in shutdown_post_sync event
handlers, or even via a new dedicated event

Hmm, it looks like the latter might actually already be the case.

And another tangentially related idea:  maybe we should inhibit device/module
shutdown for the RB_HALT case given that it is a quite special case where the
system actually stays up and at least the keyboard is expected to be still

Andriy Gapon

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