Re: [PATCH v7 1/1] nvmet: support reservation feature

[Keith Busch <kbusch@kernel.org>]

On Wed, Feb 28, 2024 at 10:21:57AM +0800, Guixin Liu wrote:
> 
> 在 2024/2/28 08:40, Sagi Grimberg 写道:
> > Hey Guixin,
> > 
> > On 01/02/2024 4:32, Guixin Liu wrote:
> > > This patch implements the reservation feature, includes:
> > > 1. reservation register(register, unregister and replace).
> > > 2. reservation acquire(acquire, preempt, preempt and abort).
> > 
> > 
> > Overall patchset looks in decent shape to me now.
> > 
> > I do have one more question though.
> My thanks for your patient review.
> > 
> > You say that this patchset implements preempt and abort, however I don't
> > see how this is actually implemented or even how can it be implemented
> > at all at this point.
> 
> Yes, the nvme target does not do any useful workto abort command, the
> comment of nvmet_execute_abort() says that
> 
> "we are not required to do any useful work, and we couldn't really do a
> useful abort",
> 
> so I don't know what to do about preempt and abort, and the NVMe spec says
> that the abort is best effor.
> 
> My statement here may be a little inaccurate.

I think you may be mixing up the NVMe "Abort" command with a different
command, "Reservation Acquire", where RACQA is set to value 010b,
"Preempt and Abort".