sgl (or uio) in struct buf / bio

[Joel Jacobson]

a few years ago (2008), i asked about the prospect of getting an sgl passed through struct buf / bio, and was referred to the jhb_bio branch.  i never did figure out how to view it, though, and it fell off my radar for a while.

did anything ever come of it, and if so/not, are there any plans for switching to something like using a uio instead of a pointer/length pair?

- j