[RFC PATCH] nvmet: Make blksize_shift configurable

[Christoph Hellwig]

On Fri, Apr 18, 2025 at 11:56:30AM +0200, Richard Weinberger wrote:
> TBH, I'm not sure whether it makes actually sense for the bdev case to make
> blksize_shift configurable.

> It's also worth discussing whether we should limit blksize_shift to a specific
> range. Right now, any shift is accepted, and it is up to the user to
> use a sane value.

It should have a hard lower bound of 512 bytes (9) and for direct I/O and
the bdev backend the reported dio alignment.

The upper bound is capped by the nvme_lbaf field being a 8-bit value on
the wire, no real need to require anything lower than that probably.