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

[Christoph Hellwig]

Ok, I think I understand the problem now - the problem is when
break_up_discard_bio does not actually call pool->process_prepared
_discard directly, but instead defers it to a worker thread.  At that
point we might have already completed all the chained bios and
the original one by the time we run another instance of
process_discard_cell_passdown.

So I guess we'll have to live with this for now.  I really don't
like it very much, and the comments could use a massive improvement,
but instead of duplicating the code let's just export the helper:

Acked-by: Christoph Hellwig <hch at lst.de>