From mboxrd@z Thu Jan  1 00:00:00 1970
From: hch@lst.de (Christoph Hellwig)
Date: Fri, 21 Aug 2015 08:59:54 +0200
Subject: Persistent Reservation API V2
In-Reply-To: <alpine.LNX.2.00.1508202317270.15930@localhost.lm.intel.com>
References: <1439360604-16192-1-git-send-email-hch@lst.de>
 <alpine.LNX.2.00.1508202317270.15930@localhost.lm.intel.com>
Message-ID: <20150821065954.GA14559@lst.de>

On Thu, Aug 20, 2015@11:56:36PM +0000, Keith Busch wrote:

> NVMe can also specify
> if whether or not a reservation should persist through power-loss.

SCSI does as well, it's the APTPL flag.  However reservations not persistent
through a power loss are basically useless, so I decided to force them on
in the API.  From the documentation:

"All implementations are expected to ensure the reservations survive
 a power loss"

So I would prefer not to add it, or if we really have to as a negative flag
to specifically opt out of the APTPL behavior.

> with it. For example, NVMe can ignore existing keys when acquiring a
> reservation in addition to registering a new key.

This sounds like a sensible addition to me, and I wouldn't be surprised
if future SPC versions will add this flag.