From mboxrd@z Thu Jan  1 00:00:00 1970
From: hch@lst.de (Christoph Hellwig)
Date: Mon, 28 Jan 2019 08:39:24 +0100
Subject: [PATCH] nvme: Block ns inventory changes during admin
In-Reply-To: <20190125194819.11476-1-keith.busch@intel.com>
References: <20190125194819.11476-1-keith.busch@intel.com>
Message-ID: <20190128073924.GB3287@lst.de>

On Fri, Jan 25, 2019@12:48:19PM -0700, Keith Busch wrote:
> The driver quiesces IO when the admin command effects say it may alter
> namespaces.
> 
> A device that supports nvme namespace management may trigger a namespace
> scan automatically. If this changes the namespace inventory by adding
> more namespace, the driver's unquiesce sequence at the end of sending
> the admin command may try to unfreeze a queue that isn't frozen,
> breaking the freeze depth for future use.
> 
> Fix that by preventing scan work from altering the namespace list while
> we are pairing freeze and unfreeze operations.

Do you have a reference for the bug report?