[RFC v1] nvme: add cse, ds, ms, nsze and nuse to sysfs

[Keith Busch]

On Mon, Nov 27, 2023 at 11:32:08AM +0100, Daniel Wagner wrote:
> libnvme is using the sysfs for enumarating the nvme resources. Though
> there are few missing attritbutes in the sysfs. For these libnvme issues
> commands during discovering.
> 
> As the kernel already knows all these attributes and we would like to
> avoid libnvme to issue commands all the time, expose these missing
> attributes.

The id namespace 'nuse' field can be quite volatile: it can change on
any write or discard command, so caching it may quickly get out of sync
with the actual value.