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

[Keith Busch]

On Mon, Nov 27, 2023 at 04:56:49PM +0100, Christoph Hellwig wrote:
> On Mon, Nov 27, 2023 at 08:44:52AM -0700, Keith Busch wrote:
> > > I'd probably spell out metadata_size, or probably even better
> > > metadata_bytes to match the unit postfixes elsewhere in the block code.
> > 
> > Should this even be an nvme specific attribute? I thought we should have
> > blk-integrity.c report its 'tuple_size' attribute instead. That should
> > work as long as we're not dealing with extended metadata at least, but
> > that's kind of a special format that doesn't have block layer support.
> 
> Reporting the tuple size is a good idea.  But is that enough for
> the existing nvme-cli use case?

nvme-cli currently queries with admin passthrough identify command, so
adding a new attribute won't break that. I assume Daniel would have it
fallback to that same command for backward compatibilty if a desired
sysfs attribute doesn't exist.