On 11/28/18 9:26 AM, Keith Busch wrote: > On Wed, Nov 28, 2018 at 08:58:00AM -0700, Jens Axboe wrote: >> On 11/28/18 8:49 AM, Keith Busch wrote: >>> On Wed, Nov 28, 2018 at 11:08:48AM +0100, Christoph Hellwig wrote: >>>> On Wed, Nov 28, 2018 at 06:07:01PM +0800, Ming Lei wrote: >>>>>> Is this the nvme target on top of null_blk? >>>>> >>>>> Yes. >>>> >>>> And it goes away if you revert just the last patch? >>> >>> It looks like a problem existed before that last patch. Reverting it >>> helps only if the request happened to have not been reallocated. If it >>> had been reallocated, the NULL_IRQ_TIMER would have completed the wrong >>> request out-of-order. If this were a real device, that'd probably result >>> in data corruption. >> >> null_blk just needs updating for this. > > Isn't this the nvme target's problem? It shouldn't complete requests > dispatched to its backing device, so I'm thinking something like the > following is what should happen. Untested at the moment, but will try > it out shortly. I looked at null_blk after the fact, and my recollection of how that timeout stuff worked was wrong. I think you are right. -- Jens Axboe