Re: [PATCH 1/3] nvme: do not check for ns on rw path

From: Christoph Hellwig <hch@lst.de>
To: Keith Busch <keith.busch@intel.com>
Cc: "Christoph Hellwig" <hch@lst.de>,
	"Javier González" <jg@lightnvm.io>,
	sagi@grimberg.me, linux-nvme@lists.infradead.org,
	linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
	"Javier González" <javier@cnexlabs.com>
Subject: Re: [PATCH 1/3] nvme: do not check for ns on rw path
Date: Mon, 6 Nov 2017 10:13:24 +0100	[thread overview]
Message-ID: <20171106091323.GA30382@lst.de> (raw)
In-Reply-To: <20171104153844.GA12777@localhost.localdomain>

On Sat, Nov 04, 2017 at 09:38:45AM -0600, Keith Busch wrote:
> That's not quite right. For non-PI metadata formats, we use the
> 'nop_profile', which gets the metadata buffer allocated so we can safely
> use a metadata formatted namespace. There's no in-kernel user of the
> allocated payload, but we still need the metadata buffer in order to
> use the namespace at all.

You're right.  But that means we will indeed always have a matching
integrity payload here and the check should not be needed.

Are you fine with turning it into something like:

	if (WARN_ON_ONCE(ns->ms && !blk_integrity_rq(req)))
		return BLK_STS_IOERR;

?