Hi all, this series cleans up various places where bcache is way too intimate with bio internals. This is intended as a baseline for the multi-page biovec work, which requires some nasty workarounds for the existing code. Note that I do not have a bcache test setup, so this will require some careful actual testing with whatever test cases are used for bcache. Also the new bio_reused helper should be useful at least for MD raid, but that work is left for later.
