On Sat, Jun 14, 2025 at 12:48:26PM +0800, Zhang Yi wrote:

quoted

quoted

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.

Yeah, that fits the /sys/block/foo/queue model better.

OK, well. Please let me confirm, are you both suggesting adding
max_hw_write_zeores_unmap_sectors and max_write_zeroes_unmap_sectors to
the queue_limits instead of adding BLK_FEAT_WRITE_ZEROES_UNMAP to the
queue_limits->features. Something like the following.

Yes.

Besides, we should also rename max_write_zeroes_sectors to
max_hw_write_zeroes_sectors since it is a hardware limitation reported
by the driver.  If the device supports unmap write zeroes,
max_hw_write_zeores_unmap_sectors should be equal to
max_hw_write_zeroes_sectors, otherwise it should be 0.

We've only done the hw names when we allow and overwrite or cap based
on other values.  So far we've not done any of that to
max_write_zeroes_sectors.