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.