Re: [RFD w/info-PATCH] device arguments from lookup, partion code inuserspace

[Andrew Clausen <clausen@gnu.org>]

Ben LaHaise wrote:
> The work-in-progress patch for-demonstration-purposes-only below consists
> of 3 major components, and is meant to start discussion about the future
> direction of device naming and its interaction block layer.  The main
> motivations here are the wasting of minor numbers for partitions, and the
> duplication of code between user and kernel space in areas such as
> partition detection, uuid location, lvm setup, mount by label, journal
> replay, and so on...

(1) these issues are independent.  The partition parsing could
be done in user space, today, by blkpg, if I read the code correctly
;-)  (there's an ioctl for [un]registering partitions)  Never
tried it though ;-)

(2) what about bootstrapping?  how do you find the root device?
Do you do "root=/dev/hda/offset=63,limit=1235823"?  Bit nasty.

(3) how does this work for LVM and RAID?

(4) <propaganda>libparted already has a fair bit of partition
scanning code, etc.  Should be trivial to hack it up... That said,
it should be split up into .so modules... 200k is a bit heavy just
for mounting partitions (most of the bulk is file system stuff).
</propaganda>

(5) what happens to /etc/fstab?  User-space ([u]mount?) translates
/dev/hda1 into /dev/hda/offset=63,limit=1235823, and back?

Andrew Clausen