[PATCH] nvme: freeze IO accesses around format

[Christoph Hellwig]

On Fri, Oct 27, 2017 at 10:35:58AM -0600, Jens Axboe wrote:
> Prevents this by freezing IO access to the device around a format.
> Without this, the following set of commands can easily make your device
> disappear:
> 
> parted -s /dev/nvme3n1 mklabel gpt
> parted -s /dev/nvme3n1 mkpart primary 0G 100G
> parted -s /dev/nvme3n1 rm 1
> nvme format /dev/nvme3

Can you wire this test case up for blktests?