[PATCH] nvme: implement the DEAC bit for the Write Zeroes command

[Christoph Hellwig]

On Mon, Oct 31, 2022 at 09:07:47AM -0600, Keith Busch wrote:
> Minor nit on the patch: I think seeing the dlfeat value as an enum would
> help.

The issue here is that the bit doesn't have a name in the NVMe spec,
so making up one would be a bit odd.  But Mike is set out to eventually
name all the bits, and if that happens I'd be glad to add a name.

That's also an argument against the check if the lower flfeat bits
that Martin suggested, which shouldn't be needed but is otherwise
harmless: due to the lack of naming in dlfeat it would be really hard
to read..