kill req->errors V4

[Jens Axboe]

On Thu, Apr 20 2017, Christoph Hellwig wrote:
> Currently the request structure has an errors field that is used in
> various different ways.  The oldest drivers use it as an error count,
> blk-mq and the generic timeout code assume that it holds a Linux
> errno for block completions, and various drivers use it for internal
> status values, often overwriting them with Linux errnos later,
> that is unless they are processing passthrough requests in which
> case they'll leave their errors in it.
> 
> This series kills the ->errors field and replaced it with new fields
> in the drivers (or an odd hack in a union in struct request for
> two bitrotting old drivers).

Applied for 4.12, thanks.

-- 
Jens Axboe