On Fri, Apr 21, 2017 at 04:36:20AM -0700, Christoph Hellwig wrote:

Btw, I really don't understand why this code even looks at bios over
just requeueing the request.  Can someone explain that bit to me?

This was done because Linux could migrate from a host supporting indirect
descriptors to a host not supporting them, and so the maximum number of
segments per request could change, and the requests already on the queue might
need to be split.

Roger.