[PATCH 01/10] block: introduce BLK_FEAT_WRITE_ZEROES_UNMAP to queue limits features

[Christoph Hellwig]

On Fri, Jun 13, 2025 at 11:15:41AM +0800, Zhang Yi wrote:
> Yeah, this solution looks good to me. However, we currently have only
> two selections (none and unmap). What if we keep it as is and simply
> hide this interface if BLK_FEAT_WRITE_ZEROES_UNMAP is not set, making
> it visible only when the device supports this feature? Something like
> below:

I really hate having all kinds of different interfaces for configurations.
Maybe we should redo this similar to the other hardware/software interfaces
and have a hw_ limit that is exposed by the driver and re-only in
sysfs, and then the user configurable one without _hw.  Setting it to
zero disables the feature.