[Drbd-dev] [PATCH v5 01/11] block: make generic_make_request handle arbitrarily sized bios

[Christoph Hellwig]

I'm for solution 3:

 - keep blk_bio_{discard,write_same}_split, but ensure we never built
   a > 4GB bio in blkdev_issue_{discard,write_same}.

Note that this isn't special casing, we can't build > 4GB bios for
data either, it's just implemented as a side effect right now instead
of checked explicitly.