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Date:   Wed, 28 Nov 2018 08:49:28 -0700
From:   Keith Busch <keith.busch@intel.com>
To:     Christoph Hellwig <hch@lst.de>
Cc:     Ming Lei <ming.lei@redhat.com>, Jens Axboe <axboe@kernel.dk>,
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Subject: Re: [PATCHv4 0/3] scsi timeout handling updates
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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.