[dm-devel] [PATCH 2/5] block: make bio_inc_remaining() interface accessible again

[Joe Thornber]

On Fri, May 06, 2016 at 12:19:16PM -0400, Mike Snitzer wrote:
> As you know not all code is simple.  I've looked at this for quite a bit
> this week and unfortunately I don't see a way forward (yet) that doesn't
> require the use of bio_inc_remaining() to take extra bi_remaining
> references.

Well there is a way around it;  we just maintain our own reference
counter and use that to determine when to complete the original bio.

It just seems a shame when there's a ref count in the bio already.
But if Jens and Christophe are adamant that bio_chain is going to be
the one and only way to access that ref count then I'll allocate
another object to hold the ref count.

- Joe