[review request] zfsboot/zfsloader: support accessing filesystems within a pool

[Andrey V. Elsukov]

On 27.04.2012 13:14, Andriy Gapon wrote:
>> I also have some WIP related to moving partition table handling into MD

Oh, i did mean MI part.

>> part. You can look here: http://people.freebsd.org/~ae/sys_boot.diff
> 
> I like this patch.  OTOH, I couldn't help by wonder if it is possible to
> somehow directly re-use the results of dv_init probing by other drivers (or
> subset of the drivers, like only 'disk').  E.g. if instead of re-examining the
> partition tables, we could ask a driver for a list of devices that it discovered.
> But how to do that is not something that I can answer.

What you think about this concept:
We can implement some MI API to query disks count and each disk parameters (mediasize,
sectorsize). This MI code will use some IOCTL that will act with MD "disk"'s devsw->ioctl.

devicename.c functions can be changed to use MI DISK API together with PART API,
or maybe even moved to the MI code.

In the result we will have some MI API to get access to the disks and partitions,
that we can use anywhere, e.g. in the ZFS code.

-- 
WBR, Andrey V. Elsukov