USB2+umass: root mount fails

[Andrew Thompson]

On Sun, Mar 01, 2009 at 12:16:20PM -0700, M. Warner Losh wrote:
> In message: <20090301190057.GD90301 at citylink.fud.org.nz>
>             Andrew Thompson <thompsa at freebsd.org> writes:
> : On Mon, Feb 16, 2009 at 01:53:36PM -0800, Marcel Moolenaar wrote:
> : > It appears that the root mount isn't serialized with USB discovery
> : > in the same way it was under USB1.
> : 
> : It seems that this is not completly resolved with the root mount hold in
> : r188907 as geom may not have tasted the partition tables when
> : vfs_rootmount is woken. USB still needs to finish its bus probe earlier
> : on the boot process.
> 
> This sounds like a more fundamental ordering problem.  It sounds like
> we need two gates here.  (1) All the underlying devices are there and
> (2) All tasting is done.

So should another root hold token be grabbed in disk_create() and
released on taste?

Andrew