Re: [PATCH 5/5] brd: Add getgeo to block ops for fdisk

From: Karel Zak
Date: Fri Nov 07 2014 - 05:00:19 EST


On Wed, Nov 05, 2014 at 04:10:50PM +0200, Boaz Harrosh wrote:
> From: Boaz Harrosh <boaz@xxxxxxxxxxxxx>
>
> Now when fdisk is run on brd it will ask some cryptic
> questions about CHS. This is because the getgeo block operation
> is not implemented.

Again, what fdisk (util-linux) version?

> I have done a quick audit of the fdisk code. The CHS calculation
> is very convoluted but at the end it comes out with a number.
> Which is taken into consideration in first-sector to allow. With
> all 1(s) this numbers is very small and other numbers come into
> account. Also note that if the device is big like 1G (not sure what
> is the threshold) fdisk will offer 1M (2048) as possible first-
> sector, and it does not matter what numbers we give here.

oh.. sounds like archeology, CHS calculation does not mater in the
current code, it follows I/O limits (including crazy alignment
offset).

Karel


--
Karel Zak <kzak@xxxxxxxxxx>
http://karelzak.blogspot.com
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/