Re: CVS commit: src/sys/opencrypto

[Paul Goyette <paul%whooppee.com@localhost>]

Taylor R Campbell wrote:

> It seems to me that the crux of the problem is that devsw_detach
> doesn't fail if the device is still in use, because we do keep no
> books about which devsws are still in use, so there's nothing to stop
> you from unloading a device's module before you've given a its close
> routine a chance to clean up.
>
> Would it suffice to add an open count to struct bdevsw and struct
> cdevsw, to be maintained by {bdev,cdev}_{open,close}?

I think this would be sufficient.

> A lesser problem is that the steps to finalize a device driver module
> are complicated (attach/detach the devsw, the cfdriver, the cfattach,
> the cfdata) and different drivers do them in a different order and may
> or may not back out the same way (e.g., dtv(4) ignores devsw_detach
> failure), so we ought to formalize what the right way to do this is
> once we have a way that can work.

That would definitely be appreciated.

It would seem that config_{init,fini}_component() are intended to handle 
much/most of this, but these routines are not documented and not used 
universally. (see sys/kern/subr_autoconf.c)

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