Re: [bug report] nvme4: inconsistent AWUPF, controller not added (0/7).

[Ming Lei <ming.lei@redhat.com>]

On Fri, Jul 04, 2025 at 01:47:50AM +0800, Yi Zhang wrote:
> On Thu, Jul 3, 2025 at 4:04 PM Christoph Hellwig <hch@lst.de> wrote:
> >
> > On Wed, Jul 02, 2025 at 09:33:32AM -0700, alan.adamson@oracle.com wrote:
> > > Looks like the device isn't reporting AWUPF after the format/reset.
> >
> > The other option would be that the format changed the value.
> >
> > The mess NVMe creasted with the totally un-thought out atomics is
> > beyond belive :(
> >
> > I wonder if we should just back out the whole thing and wait for the
> > working group to come up with something that can actually safely work.
> >
> 
> Yeah, the format operation will change the awupf value.
> Here is the reset operation pass[1] and fail[2] log
> [1]
> + nvme format -l0 -f /dev/nvme3n1
> Success formatting namespace:1
> + nvme id-ctrl /dev/nvme3
> + grep awupf
> awupf     : 7
> + grep nawupf
> + nvme id-ns /dev/nvme3n1
> nawupf  : 7
> + nvme format -l1 -f /dev/nvme3n1
> Success formatting namespace:1
> + nvme id-ctrl /dev/nvme3
> + grep awupf
> awupf     : 0
> + nvme id-ns /dev/nvme3n1
> + grep nawupf
> nawupf  : 0
> + nvme reset /dev/nvme3
> + nvme id-ctrl /dev/nvme3
> + grep awupf
> awupf     : 0
> 
> [2]
> + nvme format -l0 -f /dev/nvme5n1
> Success formatting namespace:1
> + nvme id-ctrl /dev/nvme5
> + grep awupf
> awupf     : 7
> + nvme id-ns /dev/nvme5n1
> + grep nawupf
> nawupf  : 7
> + nvme format -l1 -f /dev/nvme5n1
> Success formatting namespace:1
> + nvme id-ctrl /dev/nvme5
> + grep awupf
> awupf     : 0

Per NVMe spec, AWUPF unit is 'logical blocks', and logical block size is changed
by 'nvme format', so AWUPF value retuned from `Identify command` can be changed
because the controller implements fixed-length atomic write size(512*8, 4096 * 1)?


Thanks,
Ming