On Wed, May 23, 2018 at 03:27:35PM +0200, Hannes Reinecke wrote:

Is there a way of _testing_ this patch?

Use the error injection framework Johannes wrote?  Use blktests
(but make sure you have a fixed version of test 011).

It looks pretty dodgy, just replacing BLK_EH_HANDLED with 
BLK_EH_NOT_HANDLED.
And, as nothing else has changed, would imply that we can do it on 
older/stable versions, too.
Which means that the original code was buggy to start with.
Hence a test here would be really beneficial.

NVMe always completed the requests itself, so not too much changed.