re: Adding an ioctl to check for disklabel existence

[matthew green <mrg%eterna.com.au@localhost>]

> Yes, we will - but can't we make that something detectable?   If the
> kernel invents a lael, it says "fictitious" in the label field.

i had a similar idea, and i like your "converted" idea too.

i was looking at struct disklabel itself, and while i realised
we could probably abuse d_subtype to mark this?  it seems to
be entirely unused in our code base.

however, disklabel fails at >2TiB for 512 byte sector, so i'm
now thinking that fixing this doesn't really solve the problem
for the future properly -- disklabel doesn't return a true
label here anyway... so it seems that we should be retiring
DIOCGDINFO usage as much as possible, rather than figuring out
how to enhance it..


.mrg.