How to force GEOM to recalculate the free space after the disk is resized?

[Dexuan Cui]

> From: Andrey V. Elsukov [mailto:bu7cher at yandex.ru]
> Sent: Saturday, July 9, 2016 16:22
> To: Dexuan Cui <decui at microsoft.com>; freebsd-geom at freebsd.org
> Subject: Re: How to force GEOM to recalculate the free space after the disk is
> resized?
> 
> On 09.07.16 05:32, Dexuan Cui wrote:
> >> What FreeBSD version do you use?
> >> What messages do you see in the console/dmesg after resizing of disk?
> >>
> >> WBR, Andrey V. Elsukov
> >
> > I'm using 11-CURRENT, but I also tried 10.3 and got the same result.
> 
> GEOM should be notified by disk driver, but I don't see that it did.
> I think you need to try `camcontrol reprobe` command
> 
> WBR, Andrey V. Elsukov

Hi Andrey,
Thank you for the suggestion!

With "camcontrol reprobe", GEOM can detect the new disk capacity and the
new "free" space! :-)

However, there is a strange issue:  after I resize "da1" from Hyper-V, 
if there is a disk read before "camcontrol reprobe da1", gpart couldn't
detect the new free space, though it can detect the new disk capacity.

I reported a bug for this:
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=211028

The workaround is to open da1 for writing.

This is weird: how can "read" prevent "camcontrol reprobe da1" from
working? It looks there is still a bug somewhere?

Thanks,
-- Dexuan