[PATCH] nvme: mask CSE effects for security receive

[Jens Axboe]

On 1/20/23 10:17 AM, Keith Busch wrote:
> From: Keith Busch <kbusch at kernel.org>
> 
> The nvme driver will freeze the IO queues in response to an admin
> command with CSE bits set. These bits notify the host that the command
> that's about to be executed needs to be done exclusively, hence the
> freeze.
> 
> The Security Receive command is often reported by multiple vendors with
> CSE bits set. The reason for this is that the result depends on the
> previous Security Send. This has nothing to do with IO queues, though,
> so the driver is taking an overly cautious response to seeing this
> passthrough command, while unable to fufill the intended admin queue
> action.
> 
> Rather than freeze IO during this harmless command, mask off the
> effects. This freezing is observed to cause IO latency spikes when host
> software periodically validates the security state of the drives.

Reviewed-by: Jens Axboe <axboe at kernel.dk>

-- 
Jens Axboe