On Mon, 21 Jun 2010 23:25:21 +0200
Piergiorgio Sartor [off-list ref] wrote:

Any other suggestions or ideas?

You cannot use the BLKRRPART ioctl while any partition of the device is open.
However you can use BLKPG_ADD_PARTITION to add a new partition providing it
doesn't overlap any existing partition.
Unfortunately parted doesn't use this ioctl, nor am I aware of anything which
does. (Google suggests something called DeviceKit does, but I know nothing
about that).
You could write a program which reads the the partition table and tries to
add each partition individually.  Some might fail but others might succeed.
... or maybe you don't need to- 'partx' in util-linux-ng seems to do what you
want.

NeilBrown